RFID BASED DESIGN FOR VEHICLE LOCATION SYSTEM A Thesis Submitted to the College of Engineering of Al-Nahrain University in Partial Fulfillment of the Requirements for the Degree of Master of Science in Computer Engineering
by HASSAN ABDULSALAM HAMID
(B.Sc., 2006)
Thoul Hijjah
1432
November
2011
Abstracts
Due to the rapid growth in the number of vehicles on the street, traffic problems are bound to exist. Hence, implementation of Intelligent Transportation Systems (ITS) to obtain traffic information from roads by Automatic Vehicle Identification (AVI) is becoming an urgent necessity. The Radio Frequency Identification (RFID) Technology can be used for AVI to collect the traffic information in real-time from roads by getting the vehicles ID from RFID readers. This thesis tackles the problem of designing Vehicle Location System (VLS), the proposed system consists of a passive RFID tags on vehicles, RFID reader, reader's antenna, wireless communication with a Central Computer System (CCS) and commanding software (RFID middleware and database structure), also VLS applications, SMS server and website. The designed system controls, manages and monitors the performance of RFID readers. It also filters and stores the information in a suitable form to be easily used in the application system and website. The system implemented by using Rifidi Platform as simulator for RFID system and VLS is programmed by Visual Basic 2010. The VLS is composed of installing of two RFID readers in traffic intersections; each reader has four antennas, for monitoring all entries and exits of the intersection. The VLS used the gathered data from traffic intersections RFID readers in many applications including the following: location of vehicles in intersections at any time, path and orientation of vehicle in intersections, numbers and vehicles ID passed in each intersection at any time, estimate the traffic congestion situation in roads and intersections through SMS server and websites, drawing path of vehicles within VLS region on map, monitoring illegal and stolen vehicles real-time and tracking certain vehicle color. I
List of Contents Contents
Abstract List of Contents List of Abbreviations List of Tables List of Figures
Page
I II IV VI VII
Chapter One: Introduction 1.1 Overview 1.2 Literature Survey 1.3 Aim of the Work 1.4 Thesis Outline
1 2 6 7
Chapter Two: RFID Technology and Applications 2.1 Introduction 2.2 RFID System Components 2.3 RFID Tags 2.3.1 Tag Types 2.3.2 Tag operation 2.3.3 Electronic Product Code (EPC) Tag
8 8 9 11 12 12
2.3.4 Tag Memory 2.4 RFID Reader 2.4.1 Energize the Tag 2.4.2 Frequency ranges 2.4.3 Communicate with the Host Computer 2.5 RFID Antenna 2.6 RFID Middleware 2.7 Automatic Vehicles Identification (AVI) based on RFID 2.7.1 RFID Hardware’s Properties Requirements 2.7.2 Applications of System
14 15 17 18 19 19 22 25 25 26
Chapter Three: The Proposed Vehicle Location System 3.1 Introduction 3.2 System Architecture 3.3 System Structure
29 29 32
II
3.3.1 The VLS Middleware 3.3.2 Database 3.3.2.1 Traffic Intersections Table 3.3.2.2 Vehicles Table 3.3.2.3 Data Online Table 3.3.2.4 Vehicle Location Table 3.3.2.5 Black List Vehicles Table 3.3.2.6 Authorized Users Table 3.4 Rifidi Platform 3.5 Roads and Traffic Intersections Simulation (RTIS) 3.5.1. The RTIS Architecture 3.5.2. The RTIS Scenario 3.6 RFID Readers Connection Protocols 3.7 The Methods of VLS Applications 3.7.1 Tracking Method for Vehicle Movement 3.7.2 Estimation of Traffic Congestion 3.8 VLS Client Access
33 37 37 38 38 39 39 39 39 41 41 42 45 46 46 49 51
Chapter Four: Implementation of Vehicle Location System 4.1 Introduction 4.2 Vehicle Location System 4.3 The Main Program of VLS 4.3.1 The VLS Security 4.3.2 The VLS Tables 4.3.3 Setting Database and Authorization 4.3.4 The Connection with RFID Readers 4.3.5 The Traffic Congestion Appraisal 4.3.6 The Vehicles Locations Discovery 4.3.7 The Vehicle Path Map 4.3.8 The Intersection Monitoring and Tracking Vehicle Color 4.4 Traffic Congestion Status Website in VLS 4.5 Street Traffic Congestion Appraisal / SMS Server 4.6 General Discussion
74 76 78
Chapter Five: Conclusions and Suggestions for Future Work 5.1 Conclusions 5.2 Suggestions for Future Work
80 81
References
83
III
54 54 56 56 57 63 66 68 71 71 72
List of Abbreviations
AT
Attention
AT commands
Set of commands used to control the modem
AVI
Automatic Vehicles Identification
AIDC API
Automatic Identification Data Collection Application Programming Interface
ASP.Net
Active Server Pages.Net
CCS
Center Computer System
DHCP
Dynamic Host Configuration Protocol
DSRC
Dedicated-Short Range Communications
EAS EIRP
Electronic Article Surveillance Effective Isotropic Radiated Power
EPC ETC
Electronic Product Code Electronic Toll Collection
GIS
Geographic Information System
GPRS
General Packet Radio Service
GPS
Global Positioning System
GSM GUI
Global System for Mobile Communications Graphical User Interface
IFF IIS
Identity: Friend or Foe Internet Information Server
IOT
Internet of Things
ISO ITMS
International Standards Organization Intelligent Traffic Management System
ITS PDU
Intelligent Transport System Protocol Description Unit
RFID RO
Radio Frequency Identification Read-Only
RTIS RW
Roads and Traffic Intersections Simulation Read-Write
SIM
Subscriber Identity Module
SMS
Short Message Service
IV
SNMP SQL
Simple Network Management Protocol Structured Query Language
STCA TCP
Street Traffic Congestion Appraisal Transmission Control Protocol
TCP/IP TICS
Transmission Control Protocol/Internet Protocol Traffic Information Collection System
TMS
Traffic Management System
UHF V2I
Ultra High Frequency Vehicle-to-Infrastructure
V2V VLS
Vehicle-to-Vehicle Vehicle Location System
VRT Wi-Fi
Virtual Route Tracking Wireless Fidelity
WORM
Write Once-Read Many
V
List of Tables Table
2-1 2-2 2-3
Title
EPC RFID classes EPC RFID chip generations RFID frequency bands
VI
Page
13 14 18
List of Figures Figure
(2-1) (2-2) (2-3) (2-4) (2-5) (2-6) (2-7) (3-1) (3-2) (3-3) (3-4) (3-5) (3-6) (3-7) (3-8) (3-9) (3-10) (3-11) (3-12) (4-1) (4-2) (4-3) (4-4) (4-5) (4-6) (4-7) (4-8) (4-9) (4-10) (4-11) (4-12) (4-13) (4-14)
Title
Components of an RFID system Typical design of passive tag Passive UHF RFID tag block diagram EPC tag content Typical electrical connections for RFID reader Typical passive RFID tags with different antennas Estimation of velocity Architecture of traffic intersection in VLS Simulation of traffic intersection The communication method for VLS system The flowchart of the middleware performance The vehicles and roads network in RTIS The gathered data The significance of the gathered data The connection between client and server on specific port Principle of VRT algorithms The flowchart for drawing the VRT on the map The flowchart for traffic congestion estimation GSM modem communications The layout of the VLS environment The implemented VLS Main form of VLS The security form Traffic intersection table Vehicles table Data online table Vehicle location table Black list vehicles table The vehicle which in black list is detected Deleting vehicle ID from black list table Tables update form Update of traffic intersections table Update of vehicles table
VII
Page
9 9 10 14 16 20 28 30 31 32 36 43 44 44 45 46 48 51 52 55 55 56 56 57 58 59 59 60 60 61 61 62 63
(4-15) (4-16) (4-17) (4-18) (4-19) (4-20) (4-21) (4-22) (4-23) (4-24) (4-25) (4-26) (4-27) (4-28) (4-29) (4-30) (4-31) (4-32)
Setting database and authorization A message of cleaning tables successfully Restore database Password change form The connection form with RFID readers The connection shutdown irregularly RFID readers table The connection stream The traffic intersections congestion appraisal The street traffic congestion appraisal The vehicles locations discovery The vehicle path map The Intersection Monitoring Tracking vehicle color The website of intersection congestion estimation The website of street congestion estimation Street Traffic Congestion Appraisal / SMS Server Sony Ericsson GSM Modem Configurations
VIII
63 64 65 65 66 67 67 68 69 70 71 72 73 73 75 75 76 77
Chapter One Introduction 1.1 Overview The modernization of transport has become one of the essential signs for the urban modernization level, the increase in the number of cars leads to serious problems concerning transport system. With the development of the technology
of
computer,
communication,
electron,
information
and
intelligence has become important factors in achieving convenient and efficient transport system. According to these circumstances, the Intelligent Transport System (ITS) came into existence [1]. Collection of transportation information systems based on conventional detection techniques such as loop detectors,
video
image
processing,
and
Dedicated
Short
Range
Communication Communication (DSRC) leads to high installation and maintenance costs, the high costs prevented the proliferation of these detection techniques [2]. Radio Frequency Identification (RFID) technology is one of the most rapidly growing segments of today's Automatic Identification Data Collection (AIDC) industry [3]. Using "RFID tags" on objects or assets, and "RFID readers" to gather the tag information, RFID represents an improvement over bar codes in terms of non-optical proximity communication, information density, and two-way communication ability. It can automatically identify target and obtain relevant data without contacting with the target. It has many advantages such as high precision, easy adapting ability and quickly operation and so on. Moreover, it is able to work under harsh environment and reads from long distance [4].
1
Automatic Vehicles Identification (AVI) system based on RFID is design for all legally registered vehicles; these vehicles must hold RFID tags. When these vehicles travel along a road or intersection which is installed AVI system (RFID reader), the information of vehicle tag is read and sent immediately to Center Computer System (CCS) for achieving the purpose of real-time monitoring and management for vehicle movement conditions. The CCS receives the information and position of the vehicle from traffic intersection and then analyzes and filters to store it in database [5].
1.2 Literature Survey In an endeavor to enhance efficiency and safety in transport systems, research is being done in RFID applications in smart E-parking, toll collection, virtual route tracking, digital traffic light control and with some other RFID applications. Several designs of such systems are given in the following literature:
S. Tenqchen et al. in 2006 [6] proposed a website to exhibit the traffic
information for every 5 minutes at certain places of street measured by three RFID readers for 125 tags installed on two different urban-bus companies and transmit that information via GPRS modem from testing point to control center. Each data can be used to indicate the exact point of traffic condition in a big city. Three different readers installed in certain places; those readers are used to collect traffic information by recording the tag’s information of incoming urban-buses. urban -buses. The result shows that the application of RFID tag and reader is an alternative way to extract the traffic information instead of traditional loop detector.
J. D. Tseng et al. in 2007 [7] proposed a vehicle management system
based on UHF band RFID technology. The system is applied for
2
vehicle entering/leaving at road gates. The system consists of tag-oncar, reader antenna, reader controller, and the monitoring and commanding software. The entering time, leaving time, and tag number of each vehicle are all recorded and saved for further processing. The experimental results demonstrated the proposed system is reliable on this application. The system could not only reduce the cost of guard and payload in the maximum by the decrement of manpower, but also promote the security and efficiency of the parking lot.
M. Kim et al. in 2008 [8] developed an active RFID - based national
Traffic
Information
Collection
System
(TICS)
in
ubiquitous
environments. RFID readers have been installed at 130 spots and operate as 65 pairs at road side to obtain speed and location of vehicles. Active RFID tags are attached to 2,000 vehicles including normal cars, taxies and buses. The tag information is sent to middleware in the central center through the communication network, processed and saved in database, and utilized by various traffic related applications. Experiments were performed for four months. As time goes, the number of recognized tag identifiers decreases quite fast due to battery failures, detached tags, and other reasons.
K. A. S. Al-Khateeb et al. in 2008 [9] developed an intelligent RFID traffic
control, to solve the traffic congestion problem. RFID technology with appropriate algorithm and data base were applied to provide an efficient time management scheme. The simulation result has shown that, the dynamic sequence algorithm has the ability to intelligently adjust itself even with the presence of some extreme cases. The real time operation of the system emulated the judgment of a traffic policeman on duty, by considering the number of vehicles in each column and the routing proprieties. The great challenge would be to
3
design a system that is capable of understanding and identifying traffic movement for a whole city. Understanding the routine traffic pattern can provide accurate information to the traffic planner or urban designer to develop a traffic jam free city.
Y. Zhang in 2009 [10] proposed a framework in which moving vehicles
with attached passive RFID tags can be located with RFID readers installed at the roadside near the road intersections thus to improve the ITS traffic real-time road status. A challenging issue in his approach is to avoid multiple RFID reader collision problems to ensure the integrity of traffic sampling data. The location information of road intersection is preloaded in RFID reader. By tracing individual vehicles ’ information the system can evaluate the road status throughout the city. Implementations have been conducted to evaluate the feasibility of the proposed framework.
H. He and Y. Zhang in 2009 [11] introduced a new method based on RFID
technology to get the vehicle running state parameters. Vehicle traveling data recorder (which is also called automobile block box) can accurately record the state parameters of the automotive traveling process, which can offer a real, effective and scientific legal basis for the analysis of traffic accidents. The system adds RFID module on the base of the traditional vehicle traveling data recorder, which achieves non-stopping to get the vehicle’s running parameters on some section of highway. The tag module of this system adopts Mifare1 S50 card, the reader module uses MCM200 produced by PHILIPS Company; and the system takes Linux as the operating system. The results show that the system has a small volume, complete function, high reliability and high performance ratio.
4
H. Tao et al. in 2010 [12] proposed management system optimized design
to solve traffic intersection problems in the management of traditional vehicles. The system includes the hardware architecture and system software. At the four directions of the intersection (e.g. east, south, west, north), in each direction to set two RFID readers, they can simultaneously scan in the reverse direction from the two vehicles, and can record relevant information for each vehicle, including the vehicle electronic tag encoding and the driver electronic label encoding.
Z. Feng et al. in 2010 [13] designed the vehicle path recognition based on
RFID and an Electronic Toll Collection (ETC) system of expressway. The ETC system will toll collection without parking, also census traffic flow and audit road maintenance fees. It uses 920MHz passive RFID tag as carrier to identify actual vehicle path. High-speed long-distance UHF reader is installed in all sections of the monitoring points and highway entrances and exits, so as to automatically read the electronic tag information carried by the vehicles pass through the marking station, so that the system can record the driving path.
Iswanjono et al. in 2011 [14] proposed an algorithm for predicting the
speed of traffic light violators. The traffic light system is equipped RFID reader as the main tool for identifying the vehicle's RFID tags. The simulation by Scilab simulator gives evidence of violation and prediction of vehicle flow. The violation can detect if the vehicle's IDs have moved from one RFID reader to the others. A randomization generates vehicle IDs, vehicle numbers and vehicle branch destination that can show the function of RFID reader to detect tags. From the simulation conducted, the algorithm is able to predict the speed of traffic light violators ranging from 5 km/h up to 80 km/h in real-time.
5
M. Yu et al. in 2011 [15] implemented active RFID tag based system for
automatically identifying running vehicles on roads and collecting their data. The design principles and the architecture of the system includes active electronic tags and reading equipment (readers and antennas), the monitoring base station deployment, the two-layered network construction, and the monitoring software. The system used electronic tag and reading base station is based on SCM C8051F920; it is a lowpower high-speed general with a 24.5MHz oscillator, and a programmable flash memory. The effectiveness and efficiency of the system is analyzed. The system will have wide applications in traffic IOT (Internet of Things) to support traffic monitoring, traffic flow statistics, traffic scheduling, and special vehicle tracking.
1.3 Aim of the Work The aim of this work is to show how technologies of identification by RFID can be used to build VLS by collecting the traffic information in urban cities. This work is designed to monitor the traffic intersections in real-time via RFID system. This will be applied in all intersections for each vehicle. This is achieved by installing RFID readers in the traffic intersections and attaching RFID tags in vehicles. Then, the VLS will use the acquired information in several applications of ITS as the following:
Discovery the vehicles locations.
Displaying the route of the vehicle on the city map.
Monitoring the intersections.
Tracking vehicles color.
Tracking the illegal and robbed vehicles in real-time.
Estimating the status of congestion in roads and traffic intersections.
6
1.4 Thesis Outline This thesis is organized in five chapters. The contents of the following chapters are briefly reviewed as follows:
Chapter Two: This chapter explains RIFD technology and RFID
system components like readers, tags and host system. Then specify the discussion on using RFID technology in transport systems.
Chapter Three: This chapter discusses the proposed VLS, VLS
structure, the database of VLS, RFID simulation and the methods of VLS applications.
Chapter Four: This chapter discusses the implementation of VLS,
SMS server and websites.
Chapter Five: This chapter includes conclusions and suggestions for
possible future work.
7
Chapter Two RFID Technology and Applications 2.1 Introduction RFID technology is currently being used in numerous applications throughout the world [3]. RFID is not a new technology, for example, the principles of RFID has been employed by the British in World War II to identify their aircraft using the IFF system (Identity: Friend or Foe) [16], and it is still being used today for the same purposes. RFID uses tags to transmit data upon RFID reader queries. RFID tag responds to a reader query with its fixed unique serial number (tag ID). This fixed tag ID enables tracking of tags and the bearers. In addition to the unique serial number, some tags carry information about the objects they are attached to [17]. RFID is used for a wide variety of applications ranging from the familiar building access control proximity cards to supply chain tracking, toll collection, vehicle parking access control, retail stock management, tracking library books, theft prevention, etc.
2.2 RFID System Components RFID is a generic term for technologies that use radio waves to automatically identify people or objects. There are several methods of identification, the most common of which is to associate the RFID tag unique identifier with an object or person. RFID system (as shown in Fig. 2-1 ) will typically comprise the following [4]:
RFID tag.
8
RFID reader with an antenna and transceiver.
A host system or connection to an enterprise system.
Figure 2-1 Components of RFID system [18]
2.3 RFID Tags The tag, also known as the transponder (derived from the terms transmitter and responder), holds the data that is transmitted to the reader when the tag is interrogated by the reader. The most common tags today consist
of
an
Integrated
Circuit
(IC)
with
memory,
microprocessor chip [19], see Fig. 2-2.
Figure 2-2 Typical design of passive tag [3]
9
essentially
a
The implementation of a passive UHF RFID tag is shown in Fig. 2-3, a block diagram of RFID tag using backscatter modulation. The tag consists of tag antenna and tag chip. The tag chip contains a RF-analog front end (voltage rectifier, clock generator, modulator and demodulator), a digital control block, and a non-volatile memory [17].
Figure 2-3 Passive UHF RFID tag block diagram [17]
Other tags are chipless and have no onboard IC. Chipless tags are most effective in applications where simpler range of functions is required; although they can help achieve more accuracy and better detection range, at potentially lower cost than their IC-based counterparts [19]. When a tag is interrogated, the data from its memory is retrieved and transmitted. A tag can perform basic tasks (read/write from/to memory) or manipulate the data in its memory in other ways [19]. RFID tags can interfere with each other. When multiple tags are present in a reader‟s field, the reader may be unable to decipher the signals from the tags. For many applications, such as raising the gate in a parking lot, this is not a problem. The systems are optimized so that only one tag is within range at a time. However, for other applications, reading multiple tags at once is essential, for these applications, the tags need to support an anti-collision protocol to allow each tag reads without interference from the others [20]. An effective anti-collision algorithm can reduce the operating time and increase
10
the read rate. Two algorithms, slotted ALOHA and binary search, are always used in the RFID protocol. The slotted ALOHA algorithm needs a synchronous signal and a longer time to process when more tags are in collision. Also the discrimination ratio is not as high as that with the binary search algorithm. However, the binary search algorithm has strict requirements for its computing slot and bad security [21].
2.3.1 Tag Types RFID tags fall into two broad categories: those with a power supply (a battery) and those without. RFID tag that actively transmitted to a reader is known as „„active tags‟‟. Unpowered passive tags are known as „„passive tags‟‟. Active tags are typically also read/write tags while passive tags are generally read only. Active tags are larger and more expensive than passive tags. The use of a battery places a limit on the life of the tag, although with current battery technology this may be as much as 10 years [4]. Passive tags have an unlimited life, are lighter, smaller and cheaper. The trade-off is limited data storage capability, a shorter read range and they require a higher-power reader. Performance is reduced in electromagnetically „„noisy‟‟ environments. There are also semi- passive tags where the battery runs the chip‟s circuitry but the tag communicates by drawing power from the reader. Tags are available in a wide variety of shapes, sizes and protective housings. The smallest tags commercially available measure 0.4 x 0.4 mm and are thinner than a sheet of paper [4].
11
2.3.2 Tag operation In LF or HF systems, tag-to-reader communication is achieved via inductive coupling (load modulation). Load modulation is achieved by modulating the impedance of the tag as seen by the reader. In UHF or above systems, tag-toreader communication is achieved via propagation coupling (backscatter). Backscatter is achieved by modulating the radar cross section of the tag antenna [3]. In load modulation process, when a tag is placed within the alternating magnetic field created by the reader, it draws energy from the magnetic field. This additional power consumption can be measured remotely as a voltage perturbation at the internal impedance of the reader antenna. The periodic switching on/off of a load resistance at the tag therefore affects voltage changes at the reader‟s antenna and thus has the effect of an amplitude modulation of the antenna voltage by the remote tag. If the switching on and off of the load resista nce is controlled by the tag‟s stored data stream, then this data is transferred from the tag to the reader. In load modulation the carrier signal is modulated by switching impedance from a matched condition to an unmatched condition to alter the reflection coefficient [3]. In backscatter modulation process, a reader sends a signal (energy) to a tag, and the tag responds by reflecting a part of this energy back to the reader. A charge device such as a capacitor contained in the tag makes this reflection possible. The capacitor gets charged as it stores the energy received from the reader. As the tag responds back, it uses this energy to send the signal back to the reader. The capacitor discharges in the process [19].
2.3.3 Electronic Product Code (EPC) Tag The specifications for UHF passive tags and RFID readers developed first by the Auto-ID Center and then by EPCglobal, a standards body that was formed
12
from the article-numbering barcode associations around the world, to promote the use of RFID in commerce [21]. At the heart of the EPC suite of standards is the EPCglobal EPC Gen2 protocol (as well as its counterpart ISO 180006c) that specifies the air interface protocol for communication between readers and tags [3]. The EPC Gen2 protocol is a very powerful one with a number of features almost unimaginable in a lower-cost tag even a few years ago [21]. EPCglobal has defined a series of RFID tag “classes” and “generations” of RFID tags, see Tables 2-1 and 2-2.
Table 2-1 EPC RFID classes [20]
13
Table 2-2 EPC RFID chip generations [20]
The EPC tag data standard specifies the format for encoding and reading data from 96-bit RFID tags, as shown in Fig. 2-4.
Figure 2-4 EPC tag content [4]
2.3.4 Tag Memory A tag's memory attribute can be read-only (RO), write once-read many (WORM), or read-write (RW), see Table 2-1. Memory write capability
14
generally increases the cost of a tag, along with its capability to perform higher-level functions. At the same time, read-only tags eliminate the risk of accidental or malicious over-writing of tag data [19]. Tag memory configurations can vary greatly based on cost and physical requirements. In case of Electronic Article Surveillance (EAS), tags have essentially 1 bit of memory and are relatively inexpensive when compared to tags with more memory. These tags have no unique identifiers and are used only to signal their presence when they are in the field of a reader. Beyond the 1-bit tags, typical memory footprints can range from 16 bits to several hundred Kbits for certain active tags. The amount of memory present on a tag is then defined by application requirements and/or any relevant standards or regulations. For example, due to the expected global acceptance of the EPCglobal standards, the memory size for the newer generation of passive tags will be 2 Kbits or more [19].
2.4 RFID Reader Reader, as a scanning device, detects the tags that attached to or embedded in the selected items. It varies in size, weight and may be stationary or mobile. Reader communicates with the tag through the reader antenna, as shown in Fig. 2-5, which broadcasting radio waves and receiving the tags response signals within its reading area. After the signals from tags are detected, reader decodes them and passes the information to middleware [18]. The reader for a read/write tag is often called an interrogator. Unlike the reader for a read-only tag, the interrogator uses command pulses to communicate with a tag for reading and writing data [3].
15
Figure 2-5 Typical electrical connections for RFID reader
RFID reader sends a pulse of radio energy to the tag and listens for the tag‟s response. The tag detects this energy and sends back a response that contains the tag‟s serial number and possibly other information as well. Historically, RFID readers were designed to read only a particular kind of tag, but so-called multimode readers that can read many different kinds of tags are becoming increasingly popular. Like the tags themselves, RFID readers come in many sizes. The largest readers might consist of a desktop personal computer with a special card and multiple antennas connected to the card through shielded cable. Such a reader would typically have a network connection as well so that it could
16
report tags that it reads to other computers. The smallest readers are the size of a postage stamp and are designed to be embedded in mobile telephones [20].
2.4.1 Energize the Tag In the case of passive and semi-active tags, the reader provides the energy required to activate or energize the tag in the reader's electromagnetic field. The reach of this field is generally determined by the size of the antenna and the power of the reader. The size of the antenna is generally defined by application requirements. However, the power of the reader (through the antenna), which defines the intensity and reach the electromagnetic field produced, is generally limited by regulations. Each country has its own set of standards and regulations relating to the amount of power generated at various frequencies. For this reason, incompatibilities do exist between RFID systems in various countries [19]. EPCglobal and ISO created standards to solve this problem. EPCglobal initiated the creation of a standard to facilitate full-scale interoperability between multivendor RFID systems and to propel RFID technology into a broad array of markets. EPCglobal established and supports the EPC as the worldwide standard for immediate, automatic, and accurate identification of any item in the supply chain. EPCglobal is sponsored by many of the world's leading corporations and it has published a set of RFID protocol standards (see sec. 2.3.3). Also, ISO is a network of the national standards institutes of 148 countries, making it more global and governmental than EPCglobal. ISO bridges the needs of the public and private sectors, focusing on creating standards and building universal consensus for the acceptance of those standards [19].
17
2.4.2 Frequency Ranges One of the more important aspects of a tag and reader connection (coupling) is the frequency at which it operates. Frequency allocations are generally managed through legislation and regulation by individual governments. Internationally, there are differences in frequencies allocated for RFID applications although standardization through ISO and similar organizations is assisting in compatibility [4]. In general, the frequency defines the data transfer rate (speed) between the tag and the reader. Lower frequency performs slower transfer rate. However, speed is not the only consideration in designing RFID solution. Environmental conditions can play a significant role in determining the optimal operating frequency for a particular application. Higher frequency usually means smaller antenna, smaller tag size, and greater range and typically, more regulatory of use restrictions and often, higher cost [19]. Table 2-3 summarizes the most popular frequency bands, and characteristics. Table 2-3 RFID frequency bands [16]
18
2.4.3 Communication with the Host Computer The reader is also responsible for the flow of data between the tags and the host computer. Typically the reader communicates with a host computer through a Serial or Ethernet connection. A reader may also be equipped to communicate with the host computer through a wireless connection, particularly if the reader is a portable or handheld device [19].
2.5 RFID Antenna The reader antenna establishes a connection between the reader electronics and the electromagnetic wave in the space. In the HF range, the reader antenna is a coil (like the tag antenna), designed to produce as strong a coupling as possible with the tag antenna. In the UHF range, reader antennas (like tag antennas) come in a variety of designs. Highly directional, high-gain antennas are used for large read distances [3]. Antenna design and placement plays a significant factor in determining the coverage zone, range and accuracy of communication [19]. Physical interdependencies mean that the antenna gain is linked to the antenna size. The higher the gain (or the smaller the solid angle into which the antenna emits), the larger the mechanical design of the antenna will be. All other things being equal, a high-gain antenna will transmit and receive weaker signals farther than a low-gain antenna. Omnidirectional antennas, such as dipole antennas, will have lower gain than directional antennas because they distribute their power over a wider area. Parabolic antennas usually have the highest gain of any type of antenna [3]. The tag antenna is usually mounted on the same surface as the IC and packaged as a single unit. Fig. 2-6 shows several common passive tag and antenna configurations. Although the tag IC can be tiny (the size of a grain of
19
rice or smaller), the size and shape of the antenna typically determines the limits of the dimensions of the entire tag packaging [19].
Figure 2-6 Typical passive RFID tags with different antennas [19]
Let the power transmitted by the reader be
and the gain of the
reader antenna be Greader . The power density at distance R where the tag is placed can be expressed as
The power received by the tag is calculated by
Where
Then
20
The power density of the return wave from the tag at the position of the reader is
Thus the power received by the reader is
That is
Where Greader stands for the gain of the reader antenna, Areader the equivalent aperture of the reader antenna, Gtag the gain of the tag antenna, and Atag the equivalent aperture of the tag antenna. Where Effective Isotropic Radiated Power (EIRP) is the power transmitted by the reader, the equivalent transmitted power as
Then
Denote by
the threshold power of the sensitivity. Then the maximum
reading range is expressed as
21
Now we analyze the RFID system by using the radar principle. Suppose that the backscattering section of the tag, including the antenna and the chip, is tag
σ
, then the backscattering power of the tag is
The power density of the backscattering wave at the position of the reader is
So we have
By adjusting the tag chip impedance according to the stored data in tag,
tag
σ
will be changed, and then the return wave coming from the tag and received by the reader will be changed such that the amplitude modulation and demodulation can be realized. In this manner, the tag information can be read, and the object detected by the tag can be identified [22].
2.6 RFID Middleware A middleware, as the name suggests, is a piece of software that lies between a lower layer processing device or software and an upper layer server or software, usually at the application level. Therefore, data from RFID readers are sent to a middleware platform that acts as a bridge between RFID readers and host application software [23] [24]. Typically, RFID middleware platform performs aggregation of data across different readers, filtering of unwanted or noisy RFID data, forwarding of relevant data to subscriber servers or application-level systems, and persistent storage for context aware and other added value services. However,
22
RFID middleware is often given the task of managing, monitoring and configuring the different readers and interrogators. The middleware performs monitoring task on RFID readers to check operational status of the readers. This is a very important function, especially when readers are located in distributed manner, and manual monitoring is impractical [23] [24]. According to the main functionalities hosted by RFID middleware platform can be classified as follows [23]:
1- Configuration Service Set
Network
interface
configuration.
Discovers
and
sets
reader
networking parameters and identity, e.g. the IP address.
Firmware management. Distribute and manage firmware version on
readers
Antenna, tag population and memory selection. Specify reader
antennas and tag population to be inventoried. In case of tag memory access, specifies memory fields to be accessed.
Base service set scheduling. Sets how different services, such as tag
inventory, access, and deactivation, are triggered and stopped.
RF transmitter configuration . Sets transmit channel, hop sequence,
and transmit power for readers.
Air interface protocol configuration. Configures timing, coding and
modulation parameter of a specific air interface protocol on the readers.
2- Data Processing Service Set
Filtering. Removes unwanted tag identifiers from the set of tag
identifiers captured, e.g. based on the product type or manufacturer encoded in the identifier.
23
Aggregation. Computes aggregates in the time domain (entry/exit
events) and the space domain (across reader antennas and readers) and generates the corresponding “super” events.
Identifier translation. Translates between different representation of
the identifier, e.g. from raw tag object identifier in hexadecimal format to EPC.
Persistent storage. Stores RFID data captured for future application
requests.
Reliable messaging. Allow RFID data to be delivered reliably in the
presence of software component, system and network failures.
Location/Movement estimation. Detects false positive reads of far-
away tags that are outside the “typical” read range and estimate the direction of movement.
Application Logic execution. Interprets the RFID data captured in an
application context and generate the corresponding application events, e.g. detect whether a shipment is complete.
3- Monitoring Service Set
Network connection monitoring. Check that the reader can
communicate captured RFID data over the network
RF environment monitoring. Check RF noise and interference levels
to safeguard reliable identification operation
Reader Monitoring. Check that the reader is up, running and
executing as configured for example via monitoring the number of successful/failed read and write operations. Now, not all these functionalities are mandatory to be hosted by the middleware. This depends on the reader architecture employed. Two types of architectures can be followed: one in which many of the above functionalities
24
are hosted by the reader itself, which will be called decentralized reader architecture, and the one in which all the functionalities, except the basic ones used in the reader, will be hosted by the middleware platform or a controller appliance [23].
2.7 Automatic Vehicles Identification (AVI) based on RFID AVI system based on RFID is a design that covers every vehicle legally registered which carries RFID tag. When these vehicles travel along a road in which AVI system is installed, all kinds of vehicles information of car tag is read and transmitted in real-time to data processing controlling unit realizing the purpose of real-time monitor and management for vehicle operating conditions [5]. The main components of the AVI system based on RFID include: (i) hardware, i.e. passive RFID tags and readers for generation of traffic information; (ii) RFID middleware and database structure, and application software consisting of real-time process; and (iii) network architecture to deploy AVI system nationwide [8].
2.7.1 RFID Hardware’s Properties Requirements Using RFID in AVI systems that requires specific properties for RFID reader‟s devices to realizes the system requirements. The following characteristics should be available in RFID reader for using it in AVI system: 1. Multi-tags recognition rate 2. High tag recognition speeds 3. Operating in UHF or higher frequency 4. Read only (not need writing in tags) 5. Large coverage distance, for 9 meters or higher
25
6. The antenna is separated from reader‟s device (not incorporated with reader) 7. Support multi-static antenna system (transmit and receive) 8. Support for multiple antenna‟s ports, four or more 9. Support for Ethernet connection, TCP/IP
2.7.2 Applications of System The ITS based on RFID technology is a comprehensive managing system, which
integrates
information
technology,
communication
technology,
automatic control technology and information processing technology, combines traffic planning, traffic engineering and traffic management as a whole to enhance traffic capability. The communication between road and vehicles is one of the key technologies [1]. The application of RFID technology in ITS is widely utilized at the present time and in the future. The following list of applications of AVI system based on RFID: 1. Electronic Toll Collection (ETC) System
ETC system adopted in highways can solve many problems brought by traditional way of charging, such as time-consuming and inconvenience of supervision. The system can read the ID number from the vehicles affixed with RFID tags, and transmits the information to the manage center through network under the control of the RF controller, with the exact passing time and the driveway number. The ETC system will charge automatically according to the passing time and give green light to the cars with the effective tags, and hold up the cars without card or the null card [1] [25] [26].
26
2. Gate Automatic Identification System
RFID technology could also be utilized in some military places, parking places, communities and confidential departments by adopting GAI system. When the vehicles affixed with RFID tags approach the driveway, the system can get the ID of RFID tags, and transmits the vehicles‟ information to the manage center. Then, the manage center decides whether or not give green light the vehicles, by means of sending control order to the executive machine. Under the surveillance of GAI system, it can identify all the passing cars and give green lights to the cars which have been registered (affixed with effective RFID tags), solving the problems often existed in the traditional way of household guards, which often causes big loss, inconvenience, and feelings of insecurity, etc. [1]. 3. Automatic Equipment Identification System
AEI systems are mainly used in the identification of the containers, such as application to the sea, road and rail containers transport or logistics management with the advantages of both safety and convenience. RFID tags would be affixed to these containers, with the information of containers‟ number, quantity, and the shipping sites and its destination. Once the containers are shipped to the port of destination, AEI system would read the information via the automatic identification, and then exchange information with these tags [1]. 4. Vehicles Speed Estimation
The speed of vehicle is estimated to check if vehicle exceeded the limited speed of street or not. The speed of vehicle is estimated based on measured detection time difference and distance between two readers. To estimate the velocity of the vehicle, two RFID readers must be installed [24].
27
Figure 2-7 Estimation of velocity [24]
As shown in Fig. 2-7, (d 1) is the distance between reader A and the vehicle, (d 2) is the distance between the readers and (d 3) is the distance between reader B and the vehicle. Then, the velocity of the vehicle calculates as
Where t1 and t2 denote the communication moment between readers and tags. Other applications of AVI system fall in many fields [5,27-30] such as smart E-parking, intelligent security management system, customs electronic license plate AVI system, public transport e-ticketing, missing and stolen vehicle tracking system, virtual route tracking, TICS, traffic violation monitoring, variable speed limits, enhancement of driver‟s situation awareness, collision avoidance systems, Intelligent Traffic Management System (ITMS), digital traffic light control, the data dissemination between vehicle-to-infrastructure (V2I) or vehicle-to-vehicle (V2V), etc.
28
Chapter Three The Proposed Vehicle Location System 3.1 Introduction This chapter discusses the design of VLS which consists of CCS, SMS server and websites. The CCS contains the middleware, database management and the system applications. The RFID readers of VLS are simulated to evaluate the system works and test its ability to collect and manage the traffic information from several RFID readers in real-time. The middleware is programmed to connect the VLS with readers from one side and with database on the other, and to arrange the information that is received from readers in appropriate format to be used in the application system and website. Wireless communication system is used to communicate the CCS with readers.
3.2 System Architecture The first step in the VLS is to attach RFID tag to all vehicles that can be identified by RFID readers. It is suggested that the data is stored in tag only be tag ID and without any other details of vehicle, so to keep the persons' privacy of the vehicles ’ owners. In this form no privacy’s information is available, and if any snooper tries to install illegal reader to snoop, he cannot enter to the private information of vehicle owner, he will save the normal information like he records the information by sight to vehicle license plate. The VLS is composed of installing of two RFID readers in each traffic intersections, as shown in Fig. 3-1. The four branches of the traffic
29
intersection are North, East, South and West were represented as Road 1, Road 2, Road 3 and Road 4 respectively. In each branch set two RFID antennas, they can simultaneously scan in the opposite directions from the two vehicles, and these antennas can record relevant information for each vehicle.
Figure 3-1 Architecture of traffic intersection in VLS
In each branch, two antennas are installed in the mid island of the road near the traffic intersection, and separated by a convenient distance. In this architecture of arranging the direction of antennas, each antenna's RF radiation areas do not overlap each other. The RFID antennas are numbered as 0, 1, 2 and 3. The even antennas are installed on the ways-in of intersections while the odd antennas are installed on the ways-out of intersections. Hence, for reader 1 install antenna (0) is on way-in of road 1, antenna (2) is on way-in of road 2, antenna (1) is
30
on way-out of road 1 and antenna (3) is on way-out of road 2, so for reader 2 in roads 3 and 4, see the simulation of traffic intersection in VLS in Fig. 3-2.
Figure 3-2 Simulation of traffic intersection
In CCS, according to the order of receiving the same tag ID from two different antennas, the direction of vehicle movement will be known from its entry and to its exit. In this architecture of the system, the VLS will monitor the path direction for all vehicles in the traffic intersections in real-time. In the proposed VLS, RFID readers communicate with CCS via wireless network, RFID reader is connected with wireless station by STP cable, while the wireless access point is connected with CCS directly by UTP cable. The stations communicate with access point as shown in Fig. 3-3.
31
Figure 3-3 The communication method for VLS system
3.3 System Structure The VLS components are divided into two parts: software and hardware. The software part is implemented while the hardware part is simulated. The software part is programmed by using (Microsoft Visual Basic 2010 program) that works in (Microsoft .NET Framework 4.0) environment and the large database system is designed by (Microsoft SQL Server 2008 R2 Management Studio). The hardware part of VLS consists of RFID readers and tags, wireless network, CCS, GSM modem, database's storage memory and cables. In VLS, the RFID readers are simulated by the use of Rifidi Platform (see sec. 3.4) and Roads and Traffic Intersections Simulation (RTIS) (see sec. 3.5). In brief, the following components are used for building VLS system:
32
Two computer devices (one as RFID reader(s) via Rifidi and/or RTIS simulators and another for CCS)
Wi-Fi system
Microsoft Visual Basic 2010 with .NET Framework 4.0 and Microsoft ASP .NET Web Site Designer.
Microsoft SQL Server 2008 R2 Management Studio
Sony Ericsson GSM Modem
3.3.1 The VLS Middleware The middleware is the software program (see sec. 2.6) used to establish the connections with several RFID readers synchronous and communicate with them. On the other side, it connects with SQL Server Management Studio to communicates with database. To connect VLS to RFID reader the middleware must have the following: 1- Traffic Intersection ID 2- RFID reader IP and Port 3- RFID reader Username and Password To get this information, the system should communicate with the database and request this information from Traffic Intersections Table (see sec. 3.3.2). After getting the traffic intersection ID, IP, Port, Username and Password, the system will achieve connection with that reader. After the connection is accomplished, the system sends (Get TagList) request. The reader will reply by the list of tags that is gathered from antennas. Each tag's information is sent as a form of one packet, see a flowchart in Fig. 3-4. The packet information is filtered as tag ID, antenna number, date and time. This information will be stored in Data Online Table. Then check antenna number whether even or odd (see sec. 3.2). If the antenna number is even, the packet data are stored in temporary table, and if
33
the antenna number is odd, the system requests to search in temporary table on that tag ID. When fetch the even packet with odd packet, the system infer the vehicle ID from tag ID that is passed through, traffic intersection ID, from-road, to-road, date, in-time and out-time. The inferred information will be stored in the Vehicle Location Table. The next step is to check whether this vehicle ID is in Black List Table or not. If this is detected, the system displays warning message that the vehicle passed through the traffic intersection ID, from-road, to-road, date, and time. Then, the following step checks the connection with that reader if still connected or not. If not, the system will display (The reader -ID- is disconnected or turn off) message.
34
Start Load from database: Reader’s IP, Port, Username and Password Connecting with reader via socket
Connection established?
No
Display: Can’t connect to reader
Yes
Display: Login Successfully 1 Send: Get TagList
Receive: Tag List
No tags?
Yes
No
Analyzing data into:Vehicle IDs, Date, Time and Antenna No. Storing data in data online table 2
3 35
2
Is antenna no. even?
Yes
Storing in temporary table
No
Looking for vehicle ID in temporary table No
Display: Miss Data
ID found? Yes
Store in vehicle location table: Vehicle ID, Intersection ID, from-road, to-road, date and time (in-out) Looking for vehicle ID in black list table Yes
ID found?
Display: Warning
No
Connection Status: OK?
Yes
1
No
Display: Reader is disconnected or turned off 3 End Figure 3-4 The flowchart of the middleware performance
36
3.3.2 Database All RFID systems require smart database for storing all data received from readers in real-time. Microsoft SQL Server 2008 R2 Management Studio was selected to build the VLS's database, as it is robust compatible with Microsoft Visual Basic 2010 and Visual Basic support special Application Programming Interface (API) command to communicate with it. Also SQL has fast response and effective with robust request such as in one instruction that can query many tables. Besides, SQL Server can have enough large database size for VLS. It supports databases ’ size over a terabyte [31]. SQL Server is necessary to build several tables for VLS system, each one for specific purpose. These tables are: traffic intersections table, vehicles table, data online table, vehicle location table, black list table and authorized users table.
3.3.2.1 Traffic Intersections Table This table is constructed to define each intersection by a unique ID and each intersection must have eight records (if the intersection has four roads) to define all ways and antennas ’ number that are installed in them. The traffic intersections table has all the information about intersections. It has the intersection ID, intersection number (from 0 to 7 if the intersection has four roads), the region of the traffic intersection within the city as (Baghdad/Al-Mansur), the IPs and Ports of the readers that are installed in that intersection, the number of antenna on the road, the road is going to any intersection ID (if possible) and the distance between them, and the Username and Password of readers. Besides, through the traffic intersections table, the system can define the number of roads meeting in intersection, whether the intersection has three, four, five or more roads. Also, if the road is one or two ways, that
37
depends on the number of records and the distribution of antennas in ways. For example, five roads meeting in the intersection, VLS must have three RFID readers and ten antennas, one of these readers have two antennas only and they are numerated (from 0 to 9).
3.3.2.2 Vehicles Table This table is used to register all vehicles’ information and properties. The vehicles table contains the vehicle ID, the vehicle's owner, vehicle's type, vehicle's description, vehicle's color, vehicle's model, the engine number of vehicle and the tag ID that is attached in the vehicle. The vehicle ID is a unique ID for each vehicle and consists of the city that this vehicle is registered in, the number of this vehicle and the type of number. The number type is P as Private (the plate’s color is white), L as Load (the plate’s color is yellow), T as Taxi (the plate’s color is red) or Gov as Government (the plate’s color is blue) and it takes the first character from the name of any ministry. The
vehicle
ID
form
is
(city/number/type),
for
example:
(Baghdad/1234/P) the city is Baghdad, the number of the vehicle is 1234 and the number type is Private that has white color. Other example: (Gov/4321/H), H as Ministry of Higher Education and Scientific Research.
3.3.2.3 Data Online Table This table is constructed to keep all the useful data received from readers. It keeps all the information of tag recognition arrived online to CCS as tag ID, the reader IP and Port that sent this tag, antenna number, the date and time of detection.
38
3.3.2.4 Vehicle Location Table A vehicle location table is an important table because it keeps all the inferred information by middleware. It keeps information of vehicle path in all intersections for each vehicle. The vehicle location table records the vehicle ID that passed through specific intersection ID, from-road number, to-road number, the date and the entry time and the exit time from intersection.
3.3.2.5 Black List Vehicles Table The black list table is used to enable the administrator to monitor set of vehicles ID. Also, it will enable the administrator to add and delete vehicle’s ID. The black list table has set of vehicles ID with their tags ID and the date of the addition these vehicles in black list table.
3.3.2.6 Authorized Users Table This table is constructed to secure and protect the information of VLS from anyone unlicensed that may be penetrating VLS system and destroying a system and database. The authorized users table consists of set of pairs as administrators name and passwords.
3.4 Rifidi Platform Rifidi is the premier open source simulator for RFID. It enables to develop RFID system entirely with software components and remove the dependency on hardware and infrastructure that RFID typically demands. Furthermore, Rifidi is implemented in Java and it is possible to download the source code and modify it.
39
Rifidi makes it possible to 'Virtualize' the RFID infrastructure with software that defines RFID Readers, RFID Tags, and RFID Events that behave like their real-life counterparts [32]. This Rifidi development project was born when a team of industrial engineers tried to implement a client for 10’s a readers and they were stuck by the complexity of this task. After discussing with many software development companies and RFID experts they realized that RFID simulation tool would be appreciable for testing applications. Since that, in March 2006, this team of developers and RFID consultants started to work on this RFID simulation project [32]. Rifidi is a complete RFID application platform; it allows the virtual creation of RFID-based scenario while being sure that the software created for this purpose will run as it is also in the real world. Indeed, Rifidi is a program that simulates the reader/client interface of RFID reader. This means that a client communicates with the Rifidi reader in the same way that it would communicate with a real reader. For example, with the Alien reader, a client would send messages to retrieve tag reads. The virtual Alien reader in Rifidi Emulator responds to messages in the same way a real Alien reader does [33]. Rifidi team provided several software programs; each one has its properties and design for specific case. The programs are Rifidi Edge server and client, Rifidi Designer, Prototyper, Rifidi Emulator and Rifidi Tag Streamer. In VLS tests, two Alien ALR-9800 readers are considered that have four antennas, as intersection readers and also several RFID tags are created. The RFID tags are represented as vehicles. The operations with Rifidi can be divided into two parts: connection and send/receive data. In the first part, the connection is started between the middleware and virtual readers. In fact, CCS will manage these readers and
40
will set the connections. In the second part, the virtual readers reply (Get TagList) request by sending the tags list to CCS at each second. In VLS, the both Rifidi Emulator and Rifidi Tag Streamer are used for testing the system. Rifidi Emulator is used to test the middleware connection protocols in communication performance with Alien ALR-9800 Reader and to test sending the request (Get TagList) at each second and receive the reply (the tags) from the reader. Also, Rifidi Tag Streamer is used to test the robust of VLS middleware in filtering the data that are received from readers at real-time and stored it in data online table.
3.5 Roads and Traffic Intersections Simulation (RTIS) Before introducing VLS in a real-life, the ability, functionality, efficiency, and further effects have to be tested carefully. To evaluate the improvements that can be achieved, the simulations have to be done.
3.5.1 The RTIS Architecture A realistic simulation of roads and traffic intersections scenarios is needed. Various parameters are needed to simulate the traffic, the application, and the environment. Traffic includes the physical movements of vehicles on an arbitrary road network. Application simulation means the simulation of applications that are to be integrated in real world vehicles. For this purpose, inner vehicle interfaces have to be emulated to allow the application to interact with RFID readers, as attached RFID tag on vehicles. The last part is the environment simulation which includes the roads network with traffic intersections. Also, TCP/IP server is built to simulate connection method in RTIS as
41
Alien ALR-9800 Enterprise RFID reader. The VLS connection with RTIS is like the connection with real Alien readers.
3.5.2 The RTIS Scenario To evaluate the effectiveness of the VLS and to identify potential problems, a simulation scenario is selected as uncomplex as possible. For this reason, a special region is assumed. This region has nine in-out ways and five traffic intersections. One intersection is composed of three roads intersected and the others are composed of four roads intersected. This region is chosen because it provides a good road structure for VLS tests. The assumed region is called Al-Mansur in VLS simulation. The intersection ID is given to each intersection as sequence 146, 147, …,150. Ten RFID readers are simulated, two readers to each intersection. Each
reader
has
IP
and
Port
as
sequence
10.20.30.22:20000,
10.20.30.23:20000,...., 10.20.30.31:20000, as shown in Fig. 3-5. Seven vehicles are simulated and each vehicle is given specific vehicle ID, tag ID and color. These vehicles move on the road network in random path. Several routes are designed for each vehicle on road network. The vehicle selects specific route which will pass through it by using random function (that is supported in Visual Basic program). The random function gives a random value, by depending on this value RTIS will decide the route that the vehicle will pass.
42
Figure 3-5 The vehicles and roads network in RTIS
Specific car can be activated in the test to simplify tracking its information in VLS by selecting the car check box, or activate all cars to test the ability of VLS system. Also the speed of vehicles moving can be controlled in RTIS. The RTIS simulates RFID reader scanning and receiving tag ID from vehicles. The virtual reader accumulates these data until it receives (Get TagList) instruction from VLS. Then, it will send the gathered data to VLS in CCS by TCP/IP server. To illuminate the data sent to VLS, RTIS displays all data that are gathered in the readers and will send them online to VLS in table. This table displays the vehicle's tag ID that is captured by a reader, reader's IP and Port, the number of antenna, the date, and the time of capturing tag ID, as shown in Fig. 3-6.
43
Figure 3-6 The gathered data
Also, RTIS displays the meaning of these data that will be concluded in the middleware of VLS as vehicle ID, intersection ID, from-road and to-road in another table, as shown in Fig. 3-7.
Figure 3-7 The significance of the gathered data
The RTIS is designed for creating a scenario that is as real as possible. All the unnecessary or unpredictable factors that can influence the results such as side roads traffic or complex traffic light systems are avoided in order to provide significant results.
44
3.6 RFID Readers Connection Protocols Alien ALR-9800 Enterprise RFID Reader supports Serial port (RS-232, DB-9 F) and TCP (LAN, RJ-45) connections. Serial connection is not useful in VLS because the readers are distributed on large area. A TCP connection provides DHCP, TCP/IP and SNMP network protocols. When a CCS needs to connect to RFID reader in wide area network such as the Internet, it uses a software component called a socket. The socket opens the network connection for the middleware, allowing data to be sent and read over the network. It is important to note that these sockets are software, not hardware. The socket interface is originally developed in UNIX to provide an interface to the TCP/IP protocol suite. Internet socket, network socket or socket is used for inter-process communication. A socket is one end of a twoway communication link between two programs running on the network. A socket address is the combination of an IP address and a port number [34]. Sockets are used to represent the connectivity between client and server. Fig. 3-8 shows the connection between client and server on specific port.
Figure 3-8 The connection between client and server on specific port [35]
Normally, a server runs on a specific host (RFID reader in VLS) and has socket which is bound to a specific port number. The server waits from
45
client side for listening to the socket and makes a connection request. On the client end (the middleware in VLS) the client knows the IP address of the server and the port number of the server listening. Making a connection request the client program tries to negotiate with the server program on the IP address and port number. When connection is established between server and client, client used that socket to communicate with server (read/write) [35].
3.7 The Methods of VLS Applications VLS has several applications; these applications infer the useful information from VLS data in database. The VLS applications display the results in tables, figures or as reports. The following, the methods those used in VLS applications.
3.7.1 Tracking Method for Vehicle Movement The theoretical basis of virtual route tracking (VRT) algorithm is that the interrogation range of RFID system is very short as compared to the distance between readers. So, the position of the corresponding reader is used to stand for the current position of tag (vehicle).
Figure 3-9 Principle of VRT algorithms [36]
In Fig. 3-9, the black points stand for RFID readers and the matrix is RFID reader network (assume each reader or point represent one traffic
46
intersection). As the figure depicts, when a tag moves from reader (1, 1) to reader (2, 2), the straight line between them is regarded as the track of the tag by us. The virtual line (VRT) in figure is defined as the track of the tag. So, the track in the figure is: Track = Virtual Route: (1,1) →(2,2) → (2,3) → (1,4) → (2,5) → (3,5) → (4,4) → (4,3) → (3,2) → (4,1) It is noted that, when a reader interrogates one tag, the next reader interrogating it along the track must be adjacent to the previous reader. It is obvious in Fig. 3-10 that the tag at (2, 3) cannot jump to (2, 5) directly without activating reader (1, 4), (2, 4) or (3, 4). Therefore, VRT algorithm must choose adjacent readers along the track [36]. The hierarchical structure of vehicle location over RFID reader network is constructed and dynamically maintained while the vehicle is moving along. Exploiting the inherent spatiotemporal locality of vehicle movements, this hierarchy enables the system to conservatively update the vehicle location information of moving vehicle only in adjacent traffic intersections [37]. Of course, real-world RFID reader network is impossible to place readers so regular (exactly like a matrix) and previous figure here only depicts fundamental of this algorithm theoretically. In VLS, the VRT is used and the route is displayed in table or drawing the path on region map. The vehicle path map application will be explained; the system calls the vehicle ID, region of search, date and period of time from GUI. The system will be connected with database for request that vehicle passed through any traffic intersections IDs and also from where it is coming and to where it is going. Then, the intersections ID organized as First, Second…. etc. depending on sequence of time appeared in database. After the system got all the information about that vehicle at that period of time, the system would call graphics functions to draw the VRT of a vehicle on a map
47
of this region. First draw from-road then draw to-road in each intersection, see Fig 3-10. To recognize the direction of VRT, i.e. the beginning and the ending of path, the system will draw the last intersection with blue color.
Figure 3-10 The flowchart for drawing the VRT on the map
48
3.7.2 Estimation of Traffic Congestion Reporting road traffic congestion can be a confusion task since there are different algorithms measuring congestion. Typical users need a conciseness and easiness to understand traffic report. The normal traffic situation can be roughly categorized into two states, open and congestion [38]. But it is observed that such a classification is not enough to describe the traffic situation. Thus, in VLS three traffic patterns are used to facilitate quickness and easiness to understand report [39]. Namely Red (Traffic Jam), Yellow (Slow Moving), and Green (Free Flow) are defined as the following: 1. Traffic Jam: there are large numbers of vehicles and almost all of the vehicles run very slowly and it will be represented as red color. 2. Slow Moving: there are many vehicles and most of the vehicles run at half speed and it will be represented as yellow color. 3. Free Flow: there are few vehicles and the vehicles run at normal speed in the region of interest and it will be represented as green color. To determine a congestion level, three steps are applied to estimate the congestion status: 1) Compute the average time spent, 2) Compute the average speed of vehicles and 3) Determining the final congestion level that is compatible to the current system and ready to be reported to the public. Next, each procedure will be explained in detail. 1. Compute the Average Time Spent
To compute the average time that is required to pass the road, the first step the system gets the time from GUI. Then, the system goes back five minutes past. Therewith it requests vehicles ’ IDs that went out from road within these five minutes. The next step, the system calls the entry time to road for those vehicles. Then, it subtracts the exit time
49
from entry time for each vehicle, see Fig. 3-11. The last step is computing the time average via sum the spent time of all the vehicles and divides it on the number of vehicles. 2. Compute the Average Speed of Vehicles
The system will compute the average speed of vehicles after it gets the distance of the road from traffic intersections table [24]. The system computes the average speed of vehicles via dividing the distance on average time spent. 3. Determining the Congestion Level
After the system obtained the average speed of vehicles in road, the next step, congestion levels are classified using speed into three levels: red, yellow and green. The VLS uses two classifications thresholds,
γ
and δ for adjusting
parameters of the algorithm, as follows [39]:
Green level, if average speed is larger than or equal
Yellow level, if average speed is less than
Red level, if average speed is less than δ.
γ
γ.
and larger than δ.
At the end, the user obtains from the system the average required time to pass the road and the average speed of vehicles in the last five minutes as well as estimating the traffic congestion level.
50
Figure 3-11 The flowchart for traffic congestion estimation
3.8 VLS Client Access The VLS collects and stores the data in a database; these are private data and can only be entered by an administrator. But some information in VLS applications the user can access them by internet or cellular telecommunications (GSM Mobile). The internet pages can be uploaded by web servers such as Apache server, IIS server (Internet Information Server) or any other web server.
51
Cellular telecommunications through GSM network must be supported by modem device. Wireless modems are the modem devices that generate, transmit or decode data from a cellular network for establishing communication between the cellular network and the computer. Wireless modems like other modem devices use serial communication to interface with the computer (any microprocessor or microcontroller system) [40]. A GSM modem is a wireless modem that connects a computer to a GSM network. Like a GSM mobile phone, a GSM modem requires a SIM card in order to operate. Fig. 3-12 shows the established communication between the cellular network and the computer via GSM modem.
Figure 3-12 GSM modem communications [40]
An external GSM modem is connected to a computer by a serial cable. It is possible to make and receive phone calls and send text messages SMS (Short Message Service). AT commands must be used for establishing communication between the GSM modem and the computer [40]. AT is the abbreviation for Attention, AT commands are the set of commands that are specified for controlling a GSM phone or modem and managing the SMS feature of GSM. The AT commands are sent by the computer to the modem. The modem sends back an Information Response, which is followed by a Result Code. The result code tells about the successful execution of that command. If an error occurs in the
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execution of a command, an error result code is returned by the modem and the execution of the command line is terminated [41] . The mode of modem can be either text mode (available on some modems) or Protocol Description Unit (PDU) mode. In text mode, headers and body of the messages are given as separate parameters. PDU mode is execution command sends message from a terminal equipment to the network. The PDU shall be hexadecimal format and given in one line; phone converts this coding into the actual octets of PDU [41]. In VLS, the Sony Ericsson Mobile Phone Modem AAD-3880020-BV is used, that has the Sony Ericsson built-in modem software. The VLS modem is programmed by AT commands with PDU format mode. It is used to send/receive SMS message with the user (the driver).
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Chapter Four Implementation of Vehicle Location System 4.1 Introduction The VLS programs are implemented by applying the proposed methods and algorithms that were explained in the previous chapter. These are achieved using Visual Basic, ASP.Net Web Site and SQL Server Management Studio. This chapter will discuss all parts of these programs and how they can be used, as well as the chapter will discuss system applications, SMS server and websites.
4.2 Vehicle Location System VLS is composed of three parts which are main program, SMS server and websites. The main program comprises the middleware, database management and applications. The middleware controls the connection and communication all RFID readers and database with CCS, as shown in Fig. 41. The database management organizes the data and allows user to add, update and modify records in tables. All VLS applications depend on the data received from RFID readers.
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Figure 4-1 The layout of the VLS environment
The implemented VLS, which includes main program of VLS, RTIS and Wi-Fi system, as shown in Fig. 4-2.
Figure 4-2 The implemented VLS
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4.3 The Main Program of VLS The main program is the CCS program; it is used to control RFID readers, and manage the database and VLS applications. Fig. 4-3 shows the main form of the VLS which has buttons to link all parts of the system. Each button will be explained in the following subsections.
Figure 4-3 Main form of VLS
4.3.1 The VLS Security After running the VLS program, the user name and password form appears as shown in Fig. 4-4. This form is necessary to avoid accessing the VLS by an unauthorized person. The administrator must know the user name and the password. The default for both user name and password of VLS is (admin). If anyone tries to use invalid user name and password, an error message will appear. To let this program to be more flexible and more secure, the VLS has the ability to change the password (see sec. 4.3.3).
Figure 4-4 The security form
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4.3.2 The VLS Tables VLS system contains six tables in database (see sec. 4.4.2). Specific GUI forms are designed to display the content of VLS tables. The first table is the traffic intersections table, which defines all the intersections and RFID readers which are installed in these intersections, as shown in Fig. 4-5. The columns of usernames and passwords of RFID readers are not displayed in this form because they will be displayed in RFID readers table (see sec. 4.3.4). To enter the traffic intersections table form Intersections button in main form of VLS must be pressed on. Also, to return back the Back button should be pressed on.
Figure 4-5 Traffic intersections table
The vehicles table is an important table in the system because VLS depends on it to recognize whether the received tag ID from reader belongs to a vehicle or other object. This table contains all the information of vehicle and its owner, as well as the ID of tag that is attached in vehicle. This table must contain the information about all the vehicles in different cities. GUI of
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vehicles table as shown in Fig. 4-6 . To open this form, Vehicles button in the main form of VLS should be pressed.
Figure 4-6 Vehicles table
The data online table keeps all tags IDs received from readers. This table is used when there is loss in some information or tag ID is not detected, e.g. if the vehicle is detected on entering the intersection and VLS could not detect it on leaving the intersection for unknown reason. This vehicle ID is not saved in the vehicle location table (see sec. 4.4.1), data online table will be used to prove a vehicle passed through that intersection at that date and time. Via clicking on Data Online button in the VLS form, the GUI of data online table will show, as shown in Fig. 4-7.
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Figure 4-7 Data online table
In VLS project, all the gathered data must be analyzed and filtered. At the end all concluded information will be saved in vehicle location table. All the paths of vehicles are stored in this table and the date and time of in and out. To access the GUI of the vehicle location table, Vehicle Location button should be clicked on, as shown in Fig. 4-8.
Figure 4-8 Vehicle location table
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The form in Fig. 4-9 shows the black list vehicles table and two buttons for adding and deleting vehicle ID.
Figure 4-9 Black list vehicles table
The black list vehicles table is used to monitor in real time the illegal and the stolen vehicles by adding vehicle ID to the table. Fig. 4-10 shows the vehicle that is detected in real time.
Figure 4-10 The vehicle which in black list is detected
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To delete any vehicle ID from black list table, Delete Vehicle button must be clicked on. Then, text box will appear to write the ID of vehicle that needs elimination from black list, as shown in Fig. 4-11.
Figure 4-11 Deleting vehicle ID from black list table
By clicking on Tables Update button in the main VLS form, the form in Fig. 4-12 will appear. This form gives the ability to the user to add, update and modify traffic intersections and vehicles tables.
Figure 4-12 Tables update form
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To update traffic intersections table, Intersections button should be selected. Through this form the user can add, delete and modify records of intersections table via using Navigator Tool, as shown in Fig. 4-13. Return button is used to return to tables update form.
Add New Records
Delete Record
Save All Updates
Figure 4-13 Update of traffic intersections table
By selecting Vehicles button, the update form of vehicles table will be opened, as shown in Fig. 4-14.
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Figure 4-14 Update of vehicles table
4.3.3 Setting Database and Authorization Via clicking on Setting button in the main form of VLS, the form in Fig. 4-15 will appear. This is an important form because it can store the database as archive and clean the tables that are automatically and continuously update (i.e. Data Online and Vehicle Location Tables).
Figure 4-15 Setting database and authorization
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By clicking on Backup Database button, the "Save File" dialog box will appear to specify the place to store backup database file. After backup database file is stored, a message (Backup database is created successfully) will be displayed. By clicking on Backup and Cleaning button, the VLS will create backup database and clean data online and vehicle location tables. After completing the backup and cleaning tables, the message in Fig. 4-16 will be shown.
Figure 4-16 A message of cleaning tables successfully
By clicking Restore Database button, the monition message (The restoring operation will delete the current data in database) will be shown, as shown in Fig. 4-17. Then, by clicking on yes button, the "Open File" dialog box will be appeared to specify place of backup file of database. The restoration operation may need few minutes to be completed.
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Figure 4-17 Restore database
To allow the program to be more flexible and more secure, VLS gives the ability for the administrator to change the password by clicking on Change Password button, then Fig. 4-18 will be shown. The old and new password must be entered in the form. After pressing the Save Change button, a message (Changing Password Successfully) will appear.
Figure 4-18 Password change form
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4.3.4 The Connection with RFID Readers This is a presentation form of the middleware. By this form RFID readers can be connected or disconnected. Also, the performance of readers can be managed and monitored in real-time. As well as monitoring the numbers of tags that are received and compared with the number of the tags that are filtered and stored in data online table. To enter this form, Connect To Readers button in main form of VLS should be clicked on, as shown in Fig. 4-19.
Figure 4-19 The connection form with RFID readers
To connect with reader, the administrator must enter IP, Port, User Name and Password of reader and select its check box (as shown in Fig. 419). Then, by clicking on Connect button, the system will initialize the connection and display if the connection is successful or failed. The disconnection of any reader is achieved by selecting its check box and click on Disconnect button. If this reader is already disconnected a monition message will be displayed.
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When VLS project is running, if any reader's connection is shut irregularly, the VLS will display a warning message as shown in Fig. 4-20.
Figure 4-20 The connection shutdown irregularly
The RFID Readers button will open a new form to display the information of traffic intersections' readers. These are subset of information that is stored in traffic intersections table, as shown in Fig. 4-21.
Figure 4-21 RFID readers table
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The Conn. Show button in Fig. 4-20 will display a new form to show the connection stream, as shown in Fig. 4-22
Figure 4-22 The connection stream
Also, the Display the Display button will show statistics for the numbers of tags that are received and the numbers of the tags that are filtered and stored in data online table.
4.3.5 The Traffic Congestion Appraisal The VLS system supports some applications for the data that are gathered and analyzed. Most of these applications depend on vehicle location table. The traffic congestion appraisal is one of them. This application can estimate the congestion in two conditions: along the street or within the intersection. Via click on Intersection Status button in the main form of VLS, the GUI of intersection congestion appraisal will be shown, as shown in Fig. 4-
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23. Appraisal of traffic intersections congestion is used to estimate the required time to cross the intersection. It calculates the average of the required time to cross the distance between the antenna of entry and the antenna of exit. This application uses only the first step of Estimation of Traffic Congestion method (see sec. 4.8.2). The traffic intersection ID should be entered in its specific field. The congestion can be appraised for the time being (default) or at previous date and time by selecting its button then specifying the date and time. The suggested system uses α and β criteria to estimate the status of congestion in intersection. The system enables α and β to be changed by the user, via click on Setting button that activate its texts boxes. α and β are the time range that are required (in seconds) to cross the intersection. By clicking on Congestion Status button, the system will compute and display results as the number of vehicles passed through the intersection in the last five minutes, average of the required time to pass this intersection (in seconds) and the intersection congestion status as Free Flow, Slow Moving or Traffic Jam.
Figure 4-23 The traffic intersections congestion appraisal
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Via click on Street Status button in main form of VLS, the form in Fig. 4-24 will be appeared. The street congestion appraisal is very important application of VLS. By this application the street congestion status can be estimated in real-time. The user must specify the street and the direction of traffic. This is done by giving the ID of the intersections i.e. from-intersection tointersection. The time must be specified at the present time (default) or on the previous date and time by selecting its button then specifying the date and time. In this application, the system uses γ and δ criteria to decide status of traffic congestion in street, γ and δ are the range of vehicles’ speed criteria (in km/Hr) that pass through street. VLS system enables the user to change γ and δ, via click on Setting button that activate its texts boxes.
Figure 4-24 The street traffic congestion appraisal
This application uses all steps in the method of Estimation of Traffic Congestion. By clicking on Congestion Status button, the system will display the required time average to pass that street, the speed average of vehicles that passed through the street and the street traffic congestion status.
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4.3.6 The Vehicles Locations Discovery VLS system provides vehicles locations discovery application. This application is used to detect the intersections where the vehicle passes through them, also the time and the position of entry and exit within intersections. The user ought to enter vehicle ID and specify the date and the period of time. Then by clicking on Locating Vehicle button, the VLS will search for that ID in this period and display the result in table, as shown in Fig. 4-25.
Figure 4-25 The vehicles locations discovery
4.3.7 The Vehicle Path Map Vehicle path map is an application provided by VLS, it is used to draw the route of vehicles on map of the region. This service uses The Tracking Method for Vehicle Movement (see sec. 4.8.1). First, the user selects the region of his search. VLS will immediately load the map of this region. Second, the user enters vehicle ID and specifies the date and the period of time for tracking. By clicking on Path button, the system will draw the route of vehicle on map in red color, and the last
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intersection the vehicle passed in will be drawn in blue color. This is done for recognizing the beginning and the ending of the route, as shown in Fig. 4-26. The thin violet rectangular is drawn to identify the search region on map. Clean button must be clicked to draw route for another vehicle.
Figure 4-26 The vehicle path map
4.3.8 The Intersection Monitoring and Tracking Vehicle Color Through intersection monitoring application certain intersection can be monitored in terms of the number of vehicles that are passed, their IDs and where they have come from, where to go, the time of entry and exit from the intersection. The user enters the ID of the intersection, limits the time and date. Then, by pressing the Monitoring Intersection button, the system will then show the number of vehicles that have passed during that time period, as well as the ID of vehicles, where they have come from and where to go and the time of entry and exit, as shown in Fig. 4-27.
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Figure 4-27 The Intersection Monitoring
Tracking certain vehicle color is another service that is provided by the VLS. It enables the user to track certain color of vehicle, VLS will search all vehicles that are passed through the intersection during that time period. Then, VLS will filter them for that color and display the result in table, as shown in Fig. 4-28.
Figure 4-28 Tracking vehicle color
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4.4 Traffic Congestion Status Website in VLS The VLS system collects useful data from intersections about vehicles movement. This data are only allowed for administrator use. Two websites are designed to allow any user to benefit from traffic congestion estimation applications, as shown in Fig. 4-1. Via these websites, the user can avoid entering in traffic congestion through checking congestion status in intersection or street. Intersection congestion status estimation website estimates the requirement time to cross the intersection. This website uses only the first step of Estimation of Traffic Congestion method. The client (user) should enter the traffic intersection ID. The website loads the present date and time, also α and β criteria automatically. The website enables the user to change α and β criteria and specify previous date and time. By pressing on Intersection Congestion Status button the website computes and displays the results online. The street congestion status website is designed for any user (driver) to check the congestion status of street before going into it. The user ought to define the street by from-intersection ID to-intersection ID. The website loads the present date and time, also γ and δ criteria automatically or can be defined manually. This website uses all steps in the method of Estimation of Traffic Congestion. By clicking on Street Congestion Status button, the system will display the average of the required time to pass that street, the speed average of vehicles that passed through the street and the street traffic congestion status. Fig. 4-29 and Fig. 4-30 show both internet pages.
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Figure 4-29 The website of intersection congestion estimation
Figure 4-30 The website of street congestion estimation
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4.5 Street Traffic Congestion Appraisal / SMS Server In the VLS project, Street Traffic Congestion Appraisal / SMS Server (STCA/SMS) is designed for the user to facilitate knowledge of the congestion of street without access to internet. This is done by sending SMS message to STCA/SMS server. The STCA/SMS server is composed of two parts: STCA and GSM modem (as shown in Fig. 4-1). STCA receives the request from GSM modem and calculates the congestion status at the present time by the use of Estimation of Traffic Congestion method, as shown in Fig. 4-31. Then, it sends the reply to GSM modem.
Figure 4-31 Street Traffic Congestion Appraisal / SMS Server
The GSM modem receives SMS message from GSM network and sends it to STCA and vice versa, as shown in Fig. 4-32.
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Figure 4-32 Sony Ericsson GSM Modem Configurations
To configure the VLS modem, the administrator must select the serial port and specify its baud rate. Then, he clicks on Connect button. The modem must be set, by clicking on Configuration button, which is configuring the modem automatically. Then, by clicking on Start button the system will listen to see if a new message arrived. Now the modem can receive and send SMS messages. The STCA/SMS button is used to go to STCA/SMS server form. The user (driver) must send message in a specific form to use this service. The message ought to start by (STCA) symbol capital or small, that are followed by a space, then the user must specify the street by entering the ID of intersection followed by a space and the ID of the opposite intersection. For example, the text of message is (STCA 150 149). The message is sent to
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the service number; the modem receives a message and sends it to STCA/SMS server. The server will send the reply to the modem to send it to the user.
4.6 General Discussion The performance of VLS is tested by Rifidi Platform and RTIS. Rifidi Emulator simulated two Alien RFID readers and four antennas to each reader and more than 100 tags; these are representing as one traffic intersection. The VLS connected and negotiated with readers by sent the Username and Password to each reader. Then, it sent the request and received the list of tags, the system filtered and analyzed these data and stored them as expected with excellence performance. Also, Rifidi Tag Streamer simulated two RFID readers but have unlimited number of tags. To test the ability and the efficiency of system, the readers are regulated to detect 8 tags at each second. After VLS connected with readers, it sent first request (Get TagList), the response of readers is a huge numbers of tags (more than 400) those are gathered in readers through previous time. The VLS cannot receive all those packets, it received only last 93 packets, and ignored the other. Then, VLS filtered and analyzed these 93 tags and stored them. The second, third… etc. requests are processed as expected with excellence performance. To handle this fault, the size of buffer in TCP client is increased up to 51200 Bytes. Thereon, the VLS can receive and analyze 518 tags successfully. Also, VLS used RTIS to test the performance of its applications. The speed of vehicle in RTIS is controlled by timer interval of system, through
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testing multi points and records the speed of vehicles, mathematical equation was derived by using (Curve Fitting) method for determining the speed of vehicles. Where S= speed, T= timer interval, the equation is S=200-0.88T. The vehicles locations discovery, the intersection monitoring, the tracking vehicle color, and tracking stolen and illegal vehicle applications are checked, the results were as expected with very good performance. The vehicle path map application is tested and the result is disarranged some times, displaying multi path for same vehicle on map, to solve this disarranging must decrease the time period of search to limit the time of each path. The traffic intersections congestion appraisal and the streets traffic congestion appraisal applications are tested, the results have some errors. The sources of these errors in the project can be summarized as follows: 1. The distance approximation, through approximating the distance between the intersections. 2. The scaling errors, through scaling the distance and the speed on the RTIS as real-life, by each centimeter equivalent to 100 meters. 3. The mathematics operations, through subtracting the entering time from leaving time.
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Chapter Five Conclusions and Suggestions for Future Work 5.1 Conclusions The rapid spreading of ITS enables the researchers to find new methods or algorithms to use RFID technology in transport systems. The structure of the VLS based on RFID is designed depending upon that every vehicle is attached with RFID tags. When these vehicles travel along a road, all information of vehicle's tag is read and transmitted real-time to CCS unit, to realize the purpose of real-time monitor of vehicles movement. Therefore, after finishing the project the following conclusions can be noted:
During the design of the VLS, Rifidi Platform is used to simulate the connection RFID reader with the system and to testing the receiving, analysis and storage the data. The ability, functionality, efficiency, and further effects were tested by RTIS carefully, before introducing the system in a real-life. By the use RTIS, the system successfully synchronously connected with ten RFID readers, those readers are distributed on five intersections.
VLS analyzed the received data from the distributed RFID readers in traffic intersections. Then, VLS concluded the vehicles locations and stored it in table. Vehicles locations table contained all the useful information about travels of the vehicles in road network.
The location information of road intersection is preloaded by RFID readers. By tracing individual vehicles' information, VLS evaluated the road status throughout the city. VLS appraised the streets and traffic
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intersections congestion by depending on the average speed of vehicles in that location.
The information of vehicle location table is used to estimate the routes of vehicles via use VRT algorithms. The estimated route was displayed by VLS in a table as traffic intersections respectively or drawn the route on road network map of the city.
The VLS monitored the intersections if a stolen or an illegal vehicle passed through them via checking blacklist in real-time. Also, it tracked vehicles that have a specific color in a traffic intersection during a certain period of time.
5.2 Suggestions for Future Work The ITS is predicted to be one of the major growth areas for RFID. These are some suggestion for future work:
Implementation of the VLS in real-life, Alien ALR 9800 RFID readers must be installed in all the traffic intersection of the city and the RFID antennas must be installed at the ingress and egress points of intersections. As well as RFID tag must be attached in all vehicles.
The VLS system can be enhanced by developing new middleware that control the system. The new middleware must have faster analysis and filter the data with less error than the current middleware. Also, VLS can be programmed to connect with unlimited numbers of RFID readers, rather than limited numbers.
The VLS provide very important information about traffic in roads network of city. The developer can use this information in developing of ITS applications, such as dynamic traffic light control, traffic
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violation monitoring, variable speed limits, trip planning with optimal route selection, etc.
The developer can use GIS system rather than the vehicle path map application to draw the VRT of vehicle on road network map of the city.
Traffic congestion status estimation can be improved using other methods with more accuracy in estimation of the traffic congestion.
Fixed WiMAX technique can be used for traffic information collection system which is based on RFID rather than Wi-Fi technique.
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صةالخ حؼ وخٌح ا ) RFID( تٕابث انٕت انإ ت انخؼحٌا ٍ ٔ AVI( ن ل ػهٕت انسصإ قان ي تٕ ةٕص يبث انٕغ يؼهند ) ت ا انؼ ٍ َ تم انت انا بثح از حؼخ انخٔ ) RFID Reader( ئبان ي بثبو انا ٍ مبي ٕٓظ ث انا ق انخان بثان ااػ ؼتة انب انش .)ITS( ٔ ٔ AVI تا قان ت ػيبث ييؼه ل ػهنهسص ITS اوخأ ا نك ن،ت انز ٕ ٕ ٕ ٍ َ .انؼبنى غٔا بق ػه َ ْ ٔ ٌٕخ ،)VLS( بثغ انٕاي ف ػهبو انخؼ ىنت حصزت ئطاِ لٔبحخ شةٓٔا بثان ختي ) Passive RFID tags( ؼبنت بثَب بثب ذ يخ بو ان ان ٍ ٔ َ ٔ بو احصبلٔ )بثَبان اػٕ ٕن ا( تي اي تشت يزبٔ بثإْٔ ئبان ٔ َ ٔ غٕي SMS مبيت ان بثغ انٕاي ف ػهبو انخؼ بثح ت انضبب .ه ٔ ٔ ٔ ٌش ر ب RFID ئ انـب اءا ا ىصبو انانٌا . جَخَا بلخؼب م حى انؼ.جَخَغ إٔي بوبث انح وخح ت نت يْ يبثٕؼهان َ ٔ ك الٕد بيَ اوخب VLS بو يدت RFID بون سب Rifidiصتي ٔ ؼتّأ ئ نب م ُ ،تبطؼبث انانخ RFID ٍب ح ي بوانٌٕخ .202 ٍ .بطغ انخبئ مام ي ُ تا ن،بثإْ َ ٔ ٍي انؼ تبطؼبث اناء انخ ت ٍيخيبث انٕؼه انVLS بو وخا ٔ حسٔ ، تي اثخ ت ضبطؼبث انانخ بثغ انٕاي ب حسٓ ب بثانخ ٍ ،بطؼبثانخ ثي بث انخبو انأ اازصبء اػٔ ،بطؼبثانخ بثانِ احدبٔ بي SMS ةصم انبيت ان اوخل ا ي بطؼبثانخٔ عاان زبوزبنت ا حٔ ٕ ٍ ٍ ٔ َ بث ان ت ػهٕت انائ ،تان بث ػهان بى ي ،جخَغ إٔي ا ٔ .تانٔ اًَبَٕب تزان
شكر و تقدير ًٌاه ذظ ٌه س
ٌا وت ر ٍُ
ّ س ي خ سد أى أّأ
و هشْ
ًّ مو ح
زْكا
ثِجْ
ذظل اا
هي ه َق
و
ّ تس ا
.
ظتٌِا
ّ ت كو س
عنء ا اجوّ
بْظا
س م أكو ظتٌُ
ط قعنزئّ
لاْ ون اِو ّ كل هي اس س ماقّ .
ٌِ ز هْكا ّ ا دّدا زضواّ ثِجْ
زو
ىوظ ْ هيه ٍق
سج
زْك اّ ويأ
ها
وعا
نك
زضو اّ
و ف زدز ظ وعا ةظ
.
ّ س
ًٌاهّ ساه ا خ ه
س ماقّ
ساد اوّ جّ شّ يصصي ااْا ت ك ندّ
ْ هيه ٍ ق
ا
و ئ
اّ زاظتسة ا ت ةا
.
