Content Layer3 Message Analysis
AMR CS Call Call Phases UE
BTS
DRNC
1. Cell search, BCCH decoding & RACH access 2. RRC Connection Setup 3. UE <-> CS-CN signalling 4. RAB Set-up 5. UE <-> CS-CN signalling 6. Service Established 7. Branch addition/deletion & active set update 8. Service Released
SRNC
CN
RRC Connection Set-up Signalling Flow UE
WBTS
RNC
RRC: RRC CONNECTION REQUEST (RACH) Admission Control NBAP: RADIO LINK SETUP REQUEST NBAP: RADIO LINK SETUP RESPONSE ALCAP: ERQ ALCAP: ECF FP Downlink Sync FP Uplink Sync RRC: RRC CONNECTION SETUP (FACH) L1 Sync NBAP: SYNCH INDICATION RRC: CONNECTION SETUP COMPLETE (DCH)
UE< –> CS_CN signalling
•Location Update • Authentication •Security Mode Setup •Paging •Call Setup
MSC / VLR
U E
RNC WBTS
MGW
PS Call Phase UE
BTS
DRNC
SRNC
1. Cell search, BCCH decoding & RACH access 2. RRC Connection Setup 3. GPRS Attach 4. RAB Set-up 5. UE <-> PS-CN signalling (PDP context activation Accept) 6. Radio Bearer Reconfiguration 7. PS Data Session Established 8. State Transitions 9. Branch addition/deletion & active set update 10. PS Data Session Released
CN
GPRS Attach •
UE performs cell search and RRC Connection Establishment in the same way as for an AMR call
•
The UE registers with the PS-CN through the GPRS Attach procedure UE
Node B
RNC
SGSN
RRC Connection Initial Direct Transfer: GPRS Attach Request (DCH)
SCCP: Connection Request Initial UE message : GPRS Attach Request SCCP: Connection Confirm
Downlink Direct Transfer: Authentication and Ciphering Request (DCH) Direct Transfer: Authentication and Ciphering Request Uplink Direct Transfer: Authenication and Ciphering Response (DCH)
Direct Transfer: Authentication and Ciphering Response
Security Mode Command (DCH)
Security Mode Command
Secuirty Mode Complete (DCH) Common ID Downlink Direct Transfer: Common ID (DCH) Uplink Direct Transfer: Identity Response (DCH) Downlink Direct Transfer: Location Attach Accept (DCH) Uplink Direct Transfer: Attach Complete (DCH)
Direct Transfer: Identity Request Direct Transfer: Identity Response Direct Transfer: Attach Accept Direct Transfer: Attach Complete
PDP Context
UE
Node B
SGSN
RNC GPRS Attach
Uplink Direct Transfer : Activate PDP context request (DCH)
Direct Transfer : Activate PDP context request RANAP: RAB Assignment Request RRC: Radio Bearer Setup
Radio Bearer Setup Complete RAB Assignment Response Measurement Control Measurement Control Downlink Direct Transfer : Activate PDP Context Accept (DCH) Call Established
Direct Transfer: Activate PDP Context Accept
Radio Bearer Setup/Complete & RAB Assignment Response •
Once the RANAP: RAB Assignment Request message has been received from PS CN and RNC has resources to setup the 0/0 kbps RB the RNC sends a RRC: Radio Bearer Setup message to the UE
•
The UE acknowledges the RRC: Radio Bearer Setup message with a RRC: Radio Bearer Setup Complete message
•
Once the radio bearer establishment has been acknowledged, the RNC indicates to the PS core that the RAB has been established using the RANAP: RAB Assignment Response message
UE
Node B
SGSN
RNC GPRS Attach
Uplink Direct Transfer : Activate PDP context request (DCH)
Direct Transfer : Activate PDP context request RANAP: RAB Assignment Request RRC: Radio Bearer Setup
Radio Bearer Setup Complete RAB Assignment Response
Radio Bearer Reconfiguration UE
Node B
SGSN
RNC GPRS Attach
Uplink Direct Transfer : Activate PDP context request (DCH)
Direct Transfer : Activate PDP context request RANAP: RAB Assignment Request RRC: Radio Bearer Setup
Radio Bearer Setup Complete RAB Assignment Response Measurement Control Measurement Control Downlink Direct Transfer : Activate PDP Context Accept (DCH)
Direct Transfer: Activate PDP Context Accept
Call Established Measurement Report : e4a NBAP: Radio Link Reconfigure Prepare
Admission Control Radio Link Reconfigure Ready AAL2SIG:ERQ AAL2SIG:ECF FP: Downlink Sync FP: Uplink Sync Radio Link Reconfiguration Commit RRC: Radio Bearer Reconfiguration (DCH) RRC: Radio Bearer Reconfiguration Complete (DCH) Measurement Control
HSPA Setup •
HSUPA cannot be established without HSDPA, HSDPA UL return channe l is HSUPA instead of R99 • High level procedure is the same as that for an NRT DCH • RNC starts by allocation a 0/0kbps connection • Selection between DCH and E-DCH is then completed when RNC receives the uplink or downlink capacity request
UE
Node B
RNC
SGSN
RRC Establishment GPRS Attach PDP Context Activation
0/0 kbps DCH allocated
Measurement Report : e4a Uplink capacity request
•
RNC completes channel type selection procedure
HSUPA connection can be established • RRC Idle mode directly from CELL_PCH (Cell Update with reason Uplink Capacity Request)
RRC Services • Broadcast services • Paging and Notification services • Dedicated Control services • Encapsulation of NAS signaling (CC, SM, MM, GMM, SMS)
RRC States
RRC Procedure
System Information • Within UTRAN system information is broadcasted with the help of the RRC messages •System Information, •Paging Type I, and •System Information Change Indication. • Most system information parameters are determined by the RNC. The Node B is informed about the parameters via the NBAP message BCCH Information. Some system parameters can be made available by the Node B, such as interference values, which change fast. • Given the system information, the UE is capable to decide, whether or how to access the PLMN via the existing cell. • System information is organised in System Information Blocks (SIBs). •System information is grouped into SIB 1 to SIB 18. •Each SIB is responsible to carry a specific content. For instance, SIB 12 holds measurement control information and parameters. •Depending on the UE‘s RRC state, is reads specific SIBs, and uses the transmitted parameters. • There is a huge amount of SIBs, which have to be read by the UE. This requires a lot of battery power. Therefore, a Master Information Block (MIB) was introduced, which gives references and scheduling information about the SIBs. The MIB is transmitted in every 8 th radio frame on the P-CCPCH (on position SFN mod 8 = 0, and with a TTI of 20 ms). For most of the SIBs used within the system, the MIB may carry a value tag. The only exceptions are SIB 15.2, SIB 15.3 and SIB 16. If a value tag is unchanged, the corresponding system information has not been modified. Thus, there is no need for the UE to read the SIB. SIB 7 has no value tag. It changes with each occurrence. Scheduling information is used to inform the UE, where and when a specific system information is transmitted.
System Information UTRAN
System Information ( )
NBAP: BCCH Information
RNC
UE Node B
TS 25.433: NBAP 8.2.16 System Information Update
MIB value tag M MIB: Master Information Block SIB: System Information Block SFN: System Frame Number
SIB 1 value tag 1
position on P-CCPCH: SFN mod 8* = 0 TTI: 20 ms value tag M: range 1..8
SB value tag N
SIB 2 value tag 2
SIB 3 value tag 3
SIB 18 value tag 18
System Information Blocks • For each SIB, following characteristics were specified: • Area scope: Where is the value tag valid: within one cell or within a PLMN/ equivalent PLMN? •UE RRC state: When the SIB is valid? •UE RRC state: When the SIB is read? •Scheduling information: At which position is the SIB transmitted and what is its repetition period? •Modification of system information: Is it indicated by a value tag, or is it timer based? • The UE receives all SIBs via the BCCH. There is only one exception: SIB 10. If a UE is capable to receive simultaneously on one S-CCPCH and on one DPCH, then it receives SIB 10 on a FACH. • Master Information Block (MIB): •The MIB informs the UE about the supported PLMN types and the PLMN identity. •The UE finds in the MIB also references to up to maxSIB (=32) SIBs, including their scheduling information and type. •A MIB is valid in one cell. If a UE changes the cell, is must read the new cell‘s MIB. •The MIB is read in the RRC modes/states RRC idle, CELL_FACH, CELL_PCH and URA PCH. •Its parameter are valid in the same states. • A change of the MIB information is indicated by a value tag. • In this course documentation, we only describe the System Information Blocks (SIBs), which are used in NSN‘s RAN, and SIB 4 and SIB16.
System Information Blocks • System Information Block 1 (SIB 1) •This SIB is used to inform the UE about NAS system information. •The NAS system information characterises the NAS domains. •SIB 1 also delivers UE timers and counters, which have to be used by the UE in the RRC idle and RRC connected mode. •For instance, a UE in the RRC connected mode uses the timer T305 for periodic cell and URA updates. •SIB 1 is valid in one PLMN. • The MIB is read in the RRC modes/states RRC idle, CELL_FACH, CELL_PCH and URA PCH. Its parameter are valid in the same states, and the the RRC sub-state CELL_DCH. •If the UE selects a new cell, and the SIB 1 value tag has the same number as in the preceding cell, the same content is transmitted in this SIB. There is then no necessity for the UE to read this SIB after cell re-selection. • System Information Block 2 (SIB 2) •This SIB contains an URA identity list. •SIB 2 is read and valid in the RRC sub-state URA_PCH. A change of the SIB 2 information is indicated by a value tag. • System Information Block 3 (SIB 3) •This SIB contains relevant parameters for cell selection and re-selection. •It also holds the cell identity and cell restriction data, such as „cell barred“ IEs. •SIB 3 must be read and is valid in the RRC idle mode. It is read and valid in the RRC connected mode substates CELL_FACH, CELL_PCH and URA_PCH, if SIB 4 is not broadcasted. • A change of the SIB 3 information is indicated by a value tag.
System Information Blocks • System Information Block 4 (SIB 4) •This SIB holds mostly the same data fields as SIB 3 *, but it is read and valid only, when the UE is in the RRC connected mode. I.e, this optional SIB is read and valid in the CELL_FACH, CELL_PACH and URA_PCH substate. • A change of the SIB 4 information is indicated by a value tag. • System Information Block 5 (SIB 5) •The parameters for the configuration of physical channels are broadcasted in this SIB. •The parameters cover the PICH power offset, the AICH power offset, P-CCPCH, S-CCPCH and PRACH system information lists. •SIB 5 must be read and is valid in the RRC idle mode. •It is read and valid in the RRC connected mode sub-states CELL_FACH, CELL_PCH and URA_PCH, if SIB 6 is not available. • A change of the SIB 5 information is indicated by a value tag. • System Information Block 7 (SIB 7) •This SIB holds fast changing parameters . Therefore no value tag is used for it. •The UE has to read its parameters periodically. •For that, an expiration timer ( Expiration Time Factor ) is broadcasted with this message. •SIB 7 expires at max(32, 8 * Expiration Time Factor). •Expiration Time Factor can have the values 2times, 4 times, 8 times ... 256 times . Its default value is 1. •The fast changing parameters transmitted with SIB 7 include the UL interference and dynamic persistence level. •It is read and valid in all states except for the CELL_DCH sub-state .
System Information scope/ modification
SIB
broadcasted information
read
valid
MIB
• PLMN types & identities # • SIB Scheduling information • SIB references
RRC idle mode, CELL_FACH, CELL_PCH, URA_PCH
RRC idle mode, CELL_FACH, CELL_PCH, URA_PCH
cell/ value tag
SIB 1
• NAS information • UE timers & counters
RRC idle mode, CELL_FACH, CELL_PCH, URA_PCH
RRC idle mode, CELL_DCH, CELL_FACH, CELL_PCH, URA_PCH
PLMN/ value tag
URA_PCH
URA_PCH
cell/ value tag
e.g. T305: Periodic Cell/URA Update T301, 302, 304, 307-317
SIB 2
SIB 3*
• URA identity list
• Cell selection and re-selection parameters° e.g. CPICH Ec/N0 or CPICH RSCP; Sintrasearch, Sintersearch, Ssearch,RAT, Qqualmin, Qrxlevmin,..
SIB 4*
SIB 5*
• Cell selection & reselection parameters for UEs in the connected mode • Parameters for common physical channel configuration
RRC idle mode, RRC idle mode, (CELL_FACH, CELL_PCH, (CELL_FACH, CELL_PCH, URA_PCH) URA_PCH)
cell/ value tag
CELL_FACH, CELL_PCH, URA_PCH
CELL_FACH, CELL_PCH, URA_PCH
cell/ value tag
RRC idle mode, (CELL_FACH, CELL_PCH, URA_PCH)
RRC idle mode, (CELL_FACH, CELL_PCH, URA_PCH)
cell/ value tag
# GSM-MAP/ANSI41; MCC+MNC;
° + Cell Access Restrictions
System Information Blocks • System Information Block 11 (SIB 11) •This SIB holds measurement control information. •The UE gets here the relevant date for traffic measurement, intra-frequency measurements, etc. •SIB 11 must be read and is valid in the RRC idle mode. It is read and valid in the RRC connected mode substates CELL_FACH, CELL_PCH and URA_PCH, if SIB 12 is not broadcasted. •It is also valid in the RRC sub-state CELL_DCH, as long as the UE did not get a Measurement Control message from UTRAN and SIB 12 is not broadcasted. • A change of the SIB 11 information is indicated by a value tag. • System Information Block 12 (SIB 12) •SIB 12 transmits measurement control information for UEs in the RRC connected mode. •If not transmitted, the UEs take the parameters broadcasted with SIB 11. •If available, SIB 12 is read and valid in the RRC connected mode sub-states CELL_FACH, CELL_PCH and URA_PCH. •It is also valid in the RRC sub-state CELL_DCH, as long as the UE did not get a Measurement Control message from UTRAN. A change of the SIB 12 information is indicated by a value tag. • System Information Block 16 (SIB 16) •RB, TrCH, and PhyCH parameters are broadcasted, which are stored by the UE both in the RRC idle and RRC connected mode. •The parameters are used during a handover to UTRAN. Consequently, these parameters stay valid, when the UE is connected to GSM and GPRS. •This SIB is valid in all RRC states, and read in all RRC states except for the CELL_DCH. The UE reads and stores the parameters. A change of the SIB 16 information is indicated by a value tag.
System Information Blocks SIB
broadcasted information
read
valid
SIB 7
Fast changing parameters: • UL interference level • Dynamic persistence level
RRC idle mode, CELL_FACH, CELL_PCH, URA_PCH
RRC idle mode, CELL_FACH, CELL_PCH, URA_PCH
SIB 11
Measurement control information*
scope/ modification
cell/ max(32, 8 * Expir-‘ ation Time Factor)
RRC idle mode, RRC idle mode, (CELL_FACH, CELL_PCH, (CELL_DCH, CELL_FACH, URA_PCH) CELL_PCH, URA_PCH)
cell/ value tag
SIB 12
• Measurement control information* for UEs in the RRC connected mode
CELL_FACH, CELL_PCH, URA_PCH
CELL_DCH, CELL_FACH, CELL_PCH, URA_PCH
cell/ value tag
SIB 16
• RB, TrCH, and PhyCH parameters for a GSM/GPRS-UMTS HO
RRC idle mode, CELL_FACH, CELL_PCH, URA_PCH
RRC idle mode, CELL_FACH, CELL_PCH, URA_PCH)
cell/ value tag
* e.g. FMCx & HOPx par .; Use of HCS; Ec/N0 orRSCP; Intra-, Inter-Frequency, Inter-RAT meas. info; Traffic volume meas. Info (e.g. RLC buffer payload)
Examples of other SIB’s: SIB 13: ANSI-41 system information SIB 14: Only for 3.84 Mcps TDD SIB 15: useful for UE-based or UE-assisted positioning methods SIB 17: only for TDD SIB 18: contains PLMN identities of neighbouring cells to be considered in idle mode as well as in connected mode. (adopted from TS 25.331 RRC)
