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(E)GPRS Signaling
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EGPRS Explain
(E)GPRS Signaling
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Module objectives
After completing this learning element, the participant will be able to:
Theory:
• Explain the (E)GPRS main Mobility Management and Session Management procedures
• Understand the concept behind Routing Area design
• Explain Paging coordination
• Explain the concept of a Temporary Block Flow TBF
• Describe the different identities used on different interfaces
• List different categories of MSs
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(E)GPRS Procedures - Content
GPRS Mobility Management (GMM) and GMM State Management
• GMM States
• GPRS attach
• GPRS detach
• Routing Area updates
Session Management
• PDP context activation/modification/deactivation
Temporary Block Flow
• Radio Resource states
• TBF establishment
• RLC/MAC Header
Categories of MSs
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GPRS Mobility Management - Mobile States
The GPRS Mobility Management (GMM) is a protocol which manages Security (ciphering, P-TMSI allocation) and GMM States.
State Transition are based on Signaling procedures and timers configured in the SGSN:
GPRS Attach:
• The MS makes itself known to the network
• The authentication is checked and the location in HLR is updated
• Subscriber Information is downloaded from the HLR to the SGSN
• State transition Idle to Ready
• Normal procedure may take 5 seconds
Session Management (SM):
• before any PDP context activation the MS has to be GPRS attached.
• If the MS is detached any existing active PDP context is automatically deactivated
Timers controlling state transitions
• READY Timer (set in SGSN, default 44s)• MOBILE REACHABLE Timer (default about 2 hours – recommendation: bigger than 2x the
Periodic Routing Area update timer)
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Attach Procedure
The GPRS Attach procedure establishes a GMM context between MS and SGSN. There are
two types of attach possible:
• a normal GPRS Attach, performed by the MS to attach the IMSI for GPRS services only
• a combined GPRS Attach, performed by the MS to attach the IMSI for GPRS and non-GPRS
services (in case of Gs being implemented)
The Gs interface enables two functions:
• Paging Coordination (needed for DTM operation and additionally any MS will not loose CS
pagings, while in packet transfer)
• Combined Mobility Management (combined attach/Location updates)
The presence of the Gs is indicated to the MS in System Information as Network Operation
Mode (NOM) parameter (sometimes called Network Mode of Operation, NMO)
• NMO 1: Gs is present
• NMO 2: Gs is not present
Gb
Gs is option
MSC/VLR
BSS
A
SGSN
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Paging coordination
Paging Coordination can be provided in
• NMO 1 with Gs:
CS pagings for a IMSI and GPRS
attached MS would run through Gs-Gb
• NMO 2 without Gs by BSC:
Any CS paging would come through A.
BSC has to check if there is ongoing TBF
for each incoming CS paging
Gb
Gs
MSC/VLR
BSC
A
SGSN
Gb
No Gs
MSC/VLR
BSC
A
SGSN
NMO 1
NMO 2
The “Paging coordination in BSC” feature
- requires PCU2 functionality
- generates a lot of signaling between the PCUs and the BCSUs, an overload mechanism is implemented
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Paging coordination
NMO 2 without Gs handled by BSC:
CS Paging Coordination in NMO II means that MS in Packet Transfer Mode can be paged
for CS connection with Packet Paging Request messages sent on PACCH
• CS paging is received via A interface (no Gs between MSC and SGSN)
• CS Paging makes MS to abort PS session before CS connection setup
• If support for DTM (from MS and network) is given, the session can be continued duringcall
Gb
no Gs
MSC/VLR
A
SGSN
NMO 2
BSCIf MS transfers packets, paging
is sent on PACCH and PCH
If MS transfers packets, paging
is sent on PACCH and PCH
If MS does not transfer packets,
paging is sent on PCH as usual
If MS does not transfer packets,
paging is sent on PCH as usual
PACCH
PCHCS paging
“Paging coordination in BSC” feature is active:
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Attach procedure in brief:
MS initiates by sending Attach Request (here no Gs so normal GPRS attach only)
- If network accepts Attach Request it sends Attach Accept with P-TMSI and RAI
- If network does not accept Attach request it sends Attach Reject
- MS responds for Attach Accept message with Attach Complete (only if P-TMSI changes)
(E)GPRS Attach Process – GPRS Attach
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(E)GPRS Attach Process
Attach Request
( old [LAI,P-TMSI] ) Identification Request
( RAI, P-TMSI )
Identification Response
( cause, IMSI, authentication data )
Update GPRS Location
( IMSI, SGSN-no., SGSN-IP-address )
Authentication
Insert Subscriber Data
( IMSI, PS subscription information )
Cancel Location( IMSI, type=update )
Cancel Location Ack
( )
Insert Subscriber Data Ack
Update GPRS Location Ack
( HLR number )Attach Accept
( new P-TMSI, new RAI )
Attach Complete
( )
MS New SGSN Old SGSN HLR
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Suspend/Resume procedure
A GPRS MS when attached will be temporarily suspended from GPRS services, when in
dedicated mode (at least as long no support for simultaneous CS and PS traffic is given byMS or network (Dual Transfer Mode-DTM)).
MS gives SUSPEND indication on SDCCH to BSC. BSC forwardens it to PCU and PCU to
SGSN.
The MS‘s identity TLLI and its current location RA is delivered with this message. The SGSN
confirms the reception of this message by either returning SUSPEND-ACK or SUSPEND
NACK. A SUSPEND request is not acknowledge, if for instance the MS is unknown.
A packet switched service can be resumed, if the BSS sends the PDU RESUME to the
SGSN (during call release). The TLLI, the routing area of the MS and the Suspend
Reference Number are included in this PDU. Under normal conditions, the SGSN returns a
SUSPEND-ACK PDU, otherwise a SUSPEND-NACK is returned to the BSS.
If the suspension is not successful, the MS would initiate a Routing Area Update in order to
resume GPRS services.Suspension will happen whenever the MS enters dedicated mode (not when DTM is
supported) while GPRS attached.
- for SMS
- for Location Update
- for call
- for …
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Suspend/Resume procedure
SUSPEND
( TLLI, Routing Area )
SUSPEND-ACK
( TLLI, Routing Area,
Suspend Reference Number )
RESUME
RESUME-ACK
( TLLI, Routing Area )
( TLLI, Routing Area,
Suspend Reference Number )
Call Control for a cs service
RR Suspend
condition for GPRS
suspension disappears
RR Channel Release
MS enters de-
dicated mode
MS leaves de-
dicated mode
Routing Area Update Request if resume was not successful
( resume )
MS BSS
SGSN
MSS/VLR
RR radio resource
TLLI temporary logical link identifier
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Detach Process
GPRS Detach procedure is used for the following two purposes:
• a normal GPRS Detach
• a combined GPRS Detach (GPRS/IMSI detach, MS originated in case of Gs)
MS is detached either explicitly (by message for example when MS is powered off) or implicitly
(upon timer expiry for example when battery runs empty):
• Explicit detach: The network or the MS explicitly requests detach.
• Implicit detach: The network detaches the MS, without notifying the MS, a configuration-
dependent time after the mobile reachable timer expired (settings in SGSN).
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(E)GPRS Detach Process
MS initiated detach (here combined detach with Gs interface)
NW initiated detach (here with Gs, MS remains IMSI attached)
HLRMS BSS GGSNSGSN MSC/VLR
3. Delete PDP Context Request
1. Cancel Location
4. GPRS Detach Indication
2. Detach Request
6. Cancel Location Ack
3. Delete PDP Context Response
5. Detach Accept
3. IMSI Detach Indication
2. Delete PDP Context Response
1. Detach Request
2. Delete PDP Context Request
5. Detach Accept
MS BSS GGSNSGSN MSC/VLR
4. GPRS Detach Indication
GMM signalling
GMM signalling
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Routing Area
Routing Area (RA):
• One RA is a subset of one and only one Location Area (LA)• Without “Multipoint Gb Interface” feature one RA is served by only one SGSN, but one SGSN
can serve several RAs
• With “Multipoint Gb Interface” feature one RA can be served by several SGSNs, anyway oneMS will allways be attached in only one SGSN
• For simplicity, one LA can contain one RA
• Too big LA/RA increases the paging traffic, while too small LA/RA increases the signaling forLA/RA Update
• Routing Area Identity (RAI) = Location Area Identity (LAI) + Routing Area Code (RAC)
Location Area (LA)
Routing Area (RA) SGSN
MSC/VLR
GS Interface
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Combined Mobility Management
LA 1
LA 2
RA 11
RA 13
RA 12
RA 22
RA 21
MS classA or B
I haveto
indicatea new
LA andRA
SGSN
MSC/VLR
Gs
C o m
b i n e d
l o c a t i o n u p d a t e
LA updateinternally
SAVINGS:
• Combined
GPRS/IMSI attach
and detach
• Combined RA/LA
update
• Circuit switched
services paging
via GPRS network
• Non-GPRS alerts
• Identification
procedure
• MM information
procedure
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Routing Area
The Routing Area Update procedure can be:- a normal Routing Area Update
- a combined Routing Area Update (in case of Gs)
- a periodic Routing Area Update
The Routing Area Update is only initiated by the MS once the MS is GPRS attached.
Routing Area Update AcceptRouting Area Update Accept (PDCCH)
Location update request (SDCCH)
Routing Area Update complete (PDCH)
Location Update Accept (SDCCH)
Channel Release (SDCCH)
Routing Area Update Request
Routing Area Update Request (PDTCH)
Read System information message (BCCH)
MS BSS SGSN
MSC
Location area Update and Routing Area update at LA/RA border (no Gs):
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MS BTS BSC New SGSN
Routing Area Update
Request (PDTCH)
Routing Area Update
RequestRouting Area Update
Request
Routing Area Update
Complete (PDTCH)
Routing Area Update
Complete
Routing Area Update
Complete
Routing Area Update AcceptRouting Area Update
Accept (PDTCH)
Routing Area Update
Accept
RA Update
New SGSN sends ‘context req’ to old SGSN
Old SGSN sends response and starts tunneling data to new SGSN (if there is any data)
New SGSN sends ‘Update PDP context request’ to GGSN for any active PDP context
New SGSN informs HLR about SGSN change by sending ‘Update location’
HLR provides Subscriber data to SGSN
HLR sends ‘Cancel location’ to old SGSN.
With Gs interface the SGSN would initiate the Location Area update towards the MSS (when the
Location Area change took place)
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The PDP (Packet Data Protocol) Context is mainly designed for two purposes for the
terminal.
- Firstly PDP Context is designed to allocate a Packet Data Protocol (PDP) address,
either IP version 4 or IP version 6 type of address, to the mobile terminal.
- Secondly it is used to make a logical connection with QoS (Quality of Service) profiles,
the set of QoS attributes negotiated for and utilized by one PDP context, through the
GPRS network (from MS to GGSN)
Session Management - Establishing a PDPContext
P D P C o n t e x t R e
q u e s t
155.1 31
. 3 3.55
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Session Management - Establishing a PDPContext
MS SGSN GGSN
1. Activate PDP Context Request
2. Security Functions (optional)
3a. Create PDP Context Request
3b. Request PDP Context Activation4. Activate PDP Context Accept
SM signallingGTP signalling
GTP GPRS Tunnel Protocol
PDP Context Activation
This procedure is initiated by the MS (mobile terminated PDP activation currently notimplemented). The PDP context contains QoS and routing information enabling datatransfer between MS and GGSN. PDP Context - Activation and - Deactivation takesabout 2 seconds (can be longer).
Like GMM procedures the messages for SM procedures are exchanged on GPRSresources.
GMM signalling
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Session Management – PDP contextDeactivation and Modification
MS SGSN GGSN
1. Deactivate PDP Context Request
2. Security Functions (optional)
3a. Delete PDP Context Request
3b. Delete PDP Context Response4. Deactivate PDP Context Accept
SM signallingGTP signalling
The Deactivation of a PDP context can be initiated by MS (as seen below) ornetwork (in case of inactivity for example). PDPs can only be active as long as the MSis attached. Any kind of detach (with detach procedure or timer expiry in SGSN) willdeactivate any active PDP context for a certain UE.
Additionally it is possible to modify QoS parameters related with one active PDPcontext with PDP context modification procedure. This procedure will be initiated bythe SGSN, for example when a MS changes from 3G or LTE (where better QoSsupport is given) to the (E)GPRS network
GMM signalling
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HLR QoS Profile
Reliability
ClassGTP Mode
LLC Frame
Mode
LLC Data
Protection
RLC Block
Mode
1 Acknowledged Acknowledged Protected Acknowledged
4 Unacknowledged Unacknowledged Protected Unacknowledged
5 Unacknowledged Unacknowledged Unprotected Unacknowledged
For real-time traffic, the QoS profile also requires appropriate settings for delay and throughput.
2 Unacknowledged Acknowledged Protected Acknowledged
3 Unacknowledged Unacknowledged Protected Acknowledged
Traffic Type
Non real-time traffic, error-sensitive
application that cannot cope with data
loss.
Real-time traffic, error-sensitive
application that can cope with data loss.
Real-time traffic, error non-sensitive
application that can cope with data loss.
Non real-time traffic, error-sensitive
application that can cope with infrequent
data loss.
Non real-time traffic, error-sensitive
application that can cope with data loss,
GMM/SM, and SMS.
usage of Rel 97/98 Reliability Classes QoS parameter 3GPP TS 03.60 (Rel 98)
Precedence Class Delay Class
Peak throughput Class
Mean throughput Class
A GPRS Subscriber profile describes a service in terms of QoS parameters. The GPRS subscription is
stored in the HLR and delivered towards the current SGSN. When a Service is activated the network isrequested to provide a bearer with the described characteristics. Correspondingly the network will use Ack
or Nack mode on the different interfaces for example.
Reliability Class
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HLR QoS Parameters
HLR parameters define if LLC or RLC
protocol work in Ack or NACK mode.
GPRS introduced Rel 97/98 attributes.
With UMTS introduction a new set of
attributes has been defined in Rel 99,
which is common for UMTS and GPRS.
In practice only reliability classes 2 and 3
work today properly from the end user
satisfaction perspective and can thus be
commercially used.
There are some terminals in the market
that can not support the usage of
reliability class 2.
5'yes'
Reliability
class
1, 2, 3, 4'no'Delivery of
erroneous SDUs
54*10- 3
Reliability
class
1, 2, 3, 410- 5Residual bit error
ratio
4, 510- 3
310- 4
Reliability
class
1, 210- 6SDU error ratio
NameValueValueName
Derived from R97/98
Attribute
Resulting R99 Attribute
SDU error ratio:
<= 5*10- 4 : RLC ack
> 5*10- 4 : RLC unack
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TBF Concept3GPP 43.064
Class A
(DTM)
Class B
Packet
Transfer
Idle/
Packet
Idle
Packetaccess
Dedicated
Mode
RRrelease
TBF(s)
released
DTM assignment
DTM Release
RRestablishment
Dual
Transfer
Mode
The Temporary Block Flow (TBF) is active when the MS is in Packet Transfer mode
or in DTM (dual transfer mode) State.
The TBF is identified by a Temporary Flow Identifier (TFI) which identifies
unidirectional transmission resources on one or several PDCHs. They comprise a
number of RLC/MAC blocks, which are used to carry one or several upper layer PDUs
or RLC signalling. The TFI is allocated only for the duration of the transmission, i.e. it is
temporary.
Radio Resource (RR) States are defined between the MS and PCU
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RR (Radio Resource states) and GMM states
StandbyReady
Once the MS is in GMM standby (and of course GMM idle) the MS can not be in
packet transfer mode.
3GPP 43.064
Correspondence between RR operating modes and MM states (non-DTM capable MS) .
RR BSS Packet transfermode
Measurementreport reception
No state No state
RR MSPacket transfer
modePacket idle mode
Packet idle
modeGMM (NSS
and MS)
Standby
RR BSSDual
transfer
mode
Dedicated
mode
Packet
transfe
r mode
Measurement
report
reception
No
stateDedicate
d mode
No state
RR MSCS idle and packet idle
CS idle
and packet
idle
GMM
(NSS and
MS)
Ready
Correspondence between RR operating modes and MM states (DTM capable MS) .
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Temporary Block Flow
DL TBF
• Network starts and releases DL TBFs by simply sending an assignment (eg when MS listens to its paging)
• FBI (Final Block Indicator) indicates the last block in a DL TBF
• The SGSN has to know the cell of the MS and has to provide this information to PCU, so that the DL TBF
can be established (the MS has to be in GMM ready state)
Once a UL TBF is running a DL TBFs can be established as concurrent TBF on the PACCH (as RLC
signalling on PACCH).
UL TBF
• MS requests for (E)GPRS resources on the RACH
• Then the MS gets an UL TBF assignment indicating the USF per allocated PDCH, USF granularity,
RTSLs and the frequency
• When TBF is finished the MS indicates this by starting the countdown procedure (The MS indicates the
number of remaining RLC blocks in its buffer)
Once a DL TBF is running an UL TBFs can be established as concurrent TBF on the PACCH (as RLC
signalling on PACCH)
BSC/PCUBSC/PCU
Uplink TBF (+ PACCH for downlink TBF)
Downlink TBF (+ PACCH for uplink TBF)
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Establishing a DL TBF and Sending Data
Packet Control Ack (for TA)
Packet Polling
Packet Downlink Assignment
Data / Signalling
Ack / Nack
BTSBTS
PACCH
PACCH
PACCH
Immediate Assignment for DL TBF
AGCH
PDTCH
PACCH
PACCH
Data
PDTCH
MSMS
TA Timing Advance
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Multiple Mobiles and Downlink Transmission
TFI 2
TFI 5
TFI 3
TFI = 2
Several MS may have ongoing DL TBF on the same RTSL. The TFI included in the
downlink RLC Block header indicates which mobile is the receiver of the data (or
signalling).
There is one RLC/MAC block every 20 ms.
Scheduling of signalling or data for different MS is performed by the PCU.
DL Radio Block
BTSBTS
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Establishing an UL TBF and Sending Data
Channel Request
Immediate Assignment for UL TBF
UL Data or Signaling
Signaling + Ack/Nack
Final UL Data
Final Ack/Nack
Packet control Ack
RACH
AGCH
PDTCH / PACCH
PACCH
PDTCH
PACCH
PACCH BTSBTS
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• Maximum of 7 Mobiles can be queued in the uplink per RTSL (there are 3 bits and one
value is reserved for the MSs that have DL TBF to transmit the PACCH)
• Mobile transmission is controlled by USF (Uplink State Flag) sent in DL RLC/MAC blocks.
The MS is going to send in the next UL block (or next 4 UL Blocks) when it finds its USF
value in DL
• In standard implementation one MS has to monitor the DL Blocks for each assigned RTSL
• With EDA (Extended Dynamic Allocation) the MS will monitor only one DL RTSL and if it
finds its USF it can transmit on all assigned UL RTSL in parallel
Multiple Mobiles and Uplink Transmission
USF = 1USF = 2
USF = 3
USF = 3(in MAC header)
BTSBTS
DL Radio Block
This MS is allowed
to transmit the
next UL block
(or 4 UL Blocks)
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USF granularity
There are 2 ways to allocate UL resources to one MS in (E)GPRS:
USF granularity 1 implemented with PCU1 and USF granularity 4 with PCU2:
USFUSF……
USFUSFRadio Block 4
USFUSFRadio Block 3
USFUSFRadio Block 2
USFUSFRadio Block 1
76543210
USFUSF……
Radio Block 4
Radio Block 3
Radio Block 2
USFUSFRadio Block 1
76543210
U S F g r anu l ar i t y
1
U S F g r anu l ar i t y
1
U S F
g r anu l ar i t y 4
U S F
g r anu l ar i t y 4
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Extended UL TBF mode EUTM release
Data block with CV = 0
EUTM delay timer starts
Schedule USF turn for MS
UL dummy control block
Schedule USF turn for MS
UL dummy control block
EUTM delay timer expiresPACKET UL ACK/NACK (FAI=1,
Polling=YES)
PACKET UL ACK/NACK (FAI=0,
Polling=NO)
PACKET CONTROL ACKUL TBF terminated
Data block with CV = 1
U L
T B F
e x t e n d e d
s t a t e
Short description:• Countdown procedure is ongoing.
EUTM supporting mobile is allowed torecalculate Countdown Value CVduring procedure, if it gets more data tosend. PCU notices this by monitoringBlock Sequence Number (BSN) andCountdown value (CV) sent by MS.
• After receiving CV=0 block PCU startsUL extended state. It sends PacketUplink Ack/Nack message to MS withno Final Ack Indicator (FAI) on, butacknowledging all received blocks.
• During UL extended state PCUschedules USFs for MS accordingadjustable scheduling rate parameter.If MS has no new data to send it sendsUL dummy control blocks on its
sending turn.
• When UL extended state ends,according adjustable release delayparameter, PCU sends Packet Uplink Ack/Nack message to MS with Final Ack Indicator (FAI) on.
UL TBF Schedule Rate Ext
Schedule USF turn for MS
UL dummy control block
MS BSS
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Radio Link Control (RLC)/ Medium Access Control(MAC) Header
Switching between PACCH and Data is managed with the Payload Type field in the
RLC/MAC header. The RLC/MAC header is different for UL and DL and for EGPRS.
The presented Headers are for GPRS. In case of EDGE there are several header types
defined, but the fields are almost the same (with one exception: in GPRS there is no
indication about the used CS (CS 1 to 4) but in EGPRS there is an indication of the used
MCS (MCS 1 to 9) and PS (Puncturing Scheme 1 to 3).
Complete description can be found in 3GPP 43.064.
Abbreviations of the fields in the RLC/MAC header:
E Extension
FBI Final block indicator (last block or not)
R Retry bit (if several access burst have been sent or not)
PFI Packet Flow Identifier Indicator (if PFI field is present or not in the header)
PR Power Reduction (DL only and not implemented)
PT Payload Type (signalling or data)TI TLLI Indicator (TLLI present or not)
RRBP Relative Reserved Block Period (when to sent the UL PACCH)
SI Stalled indication (if UL RLC numbers are sufficient)
S/P Supplementary/Polling
LLC
SNDCP
IP
TCP/UDP
APP
RLC
MAC
GSM RF
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E
Downlink RLC Data Block with MAC Header
USF - Uplink State Flag FBI - Final Block Indicator
TFI - Temporary Flow Indicator BSN - Block Sequence Number
BSN
8 7 6 5 3 2 14 Bit-NoUSFS/PPayload Type RRBP
TFI FBIPR
Length Indicator EM
Length Indicator EM
RLC data
MAC
header octet 1
octet 2
octet 3
octet M+1
octet M
octet N-1
optional
octets
RLC
header
RLC
data
unit
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Uplink RLC Data Block with MAC Header
MACheader
RLC
header
BSN
.
.
.
8 7 6 5 3 2 14 Bit-No
Payload Type Countdown Value
TFI TI
Length Indicator
E
EM
Length Indicator EM
RLC data
Spare bitsSpare bits
octet 1
octet 2
octet 3
octet M+5
octet M
octet N-1octet N(if present)
Optional
octets
RLC
dataunit
TLLI
SI R
octet M+1
octet M+4
PIspare
PFI E
BSN - Block Sequence Number= RLC block number TFI - Temporary Flow IndicatorCountdown value - used to calculate number of remaining RLC blocksTLLI Temporary Logical Link Identifier (identity of MS)
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(E)GPRS Identities
Air A-bis A-ter A
GbGs
TFI
TLLI (Temporary Logical Link Identifier)
IMSI or P-TMSI
-Temporary Flow Identifier (TFI) is allocated by PCU as long of TBF is running
-The MS has independent TFI for UL and DL TBFs in case of UL and DL TBFs are active.
-Temporary Logical Link Identifier (TLLI) in UL is chosen by MS (based on P-TMSI or
random TLLI in case of MS has no P-TMSI, then MS has to do the attach procedure)
-TLLI is carried in the RLC protocol to PCU in UL TBF and forwarded to the SGSN in
BSSGP protocol. There are 2 ways to transfer the TLLI,
-It can be part of the RLC header in case of one phase access type
-It can be transferred as part of RLC control message (Packet Resource Request)
for other access types (on PACCH)
-TLLI is carried in BSSGP protocol by SGSN to PCU in DL TBF and PCU can check if
there is already UL TBF running or an assignment has to be sent
MS BTS BSC
SGSN
TC
PCU
MSC
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BSC
BTS
• Class C Packet only(Can not be attached in CS and PS core)
• Class B Packet and Speech (not at same time)(can be attached in CS and PS core, but can only make call or sent data)
• Class A Packet and Speech at the same time(support for Dual Transfer Mode [DTM] is given)
(E)GPRS Mobile Terminal Classes
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(E)GPRS Multislot Classes
Type 1
Multislot Classes 1-12- Max 4 DL or 4 UL TSL (not at same time)
- Up to 5 TSL shared between UL and DL
- Minimum 1 TSL for frequency change
- 2-4 TSL freq. change
Multislot Classes 19-29
- Max 8 downlink or 8 uplink
(not at same time)
- 0-3 TSL for frequency change
High Multislot Classes 30-45 (3GPP Rel-5)
- Max: 5 DL or 5 UL (6 UL+DL) or
- Max: 6 DL or 6 UL (7 UL+DL)
Type 2Multislot Classes 13-18
- simultaneous receive & transmit
- max 8 DL and 8 UL
(Not available yet, difficult RF design)
DL
UL
1 TSL for Frequency Change
DL
UL
1 TSL for Measurement
DL
UL
DL
UL
1
1 2 3 4 5 6 70
1 2 3 4 5 6 70
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DA/EDA Allocation
• Dynamic Allocation: Multislot MS needs to monitor UplinkState Flag (USF) on each timeslot allocated in Uplinkdirection. Max UL allocation is 2 RTSL.
• Extended Dynamic Allocation: Multislot MS monitorsUplink State Flag (USF) until it receives it on one timeslotand transfers data on UL assigned resources (numberdepends on MS class)
USF gives permission to send inthe corresponding uplink slotduring the next block period
USF gives permission to send inthe corresponding uplink slotduring the next block period
USF gives permission to send inthe corresponding and all highernumbered allocated uplink slots
during the next block period.
USF gives permission to send inthe corresponding and all highernumbered allocated uplink slots
during the next block period.
0 1 2 3 4 5 6 7
0 1 2 3 4 5 6 7
T
USFUSF
T
0 1 2 3 4 5 6 7
0 1 2 3 4 5 6 7
T
USF
TT T
0
50
100
150
200
250
300
350
GPRS GPRS CS3/4 EDGE
k b i t / s S11.5
S12
Peak uplink throughput
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Dual Transfer ModeSupported MS Multislot Classes
DTM Multislot Classes• Class 5: Voice & 1 + 1
• Class 9: Voice & 2 + 1
• Class 11: Voice & 2 + 1 or 1 + 2
(2 in UL only with with EDA)
Downlink radio slots: 0 1 2 3 4 5 6 7
Uplink radio slots: 0 1 2 3 4 5 6 7
DTM Class 5,9,11 PS CS
2+2=4 PS CS
DTM Class 5,9,11 CS PS
2+2=4 CS PS
DTM Class 9,11 PS PS CS
3+2=5 PS CS
DTM Class 9,11 PS CS PS
3+2=5 CS PS
DTM Class 11 PS CS
2+3=5 EDA PS CS PS
DTM MS Class 31,32 PS PS PS CS
HMC PS CS
DTM MS Class 31,32 PS PS CS PS
HMC CS PS
DTM MS Class 32 PS PS CS
HMC, EDA PS CS PS
Will be supported
as class 5,9, or 11
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(E)GPRS Multislot Classes - Dual carrier
A key part of the evolution of EDGE is the utilization of more than one radio frequency
carrier. This overcomes the inherent limitation of the narrow channel bandwidth of GSM.Using two carriers enables the reception of twice as many radio blocks simultaneously or,
alternatively, the original number of radio blocks can be divided between the two carriers
enabling a bigger flexibility, resulting in trunking gain.
Downlink dual carrier (DLDC) is only for DL and EGPRS, not GPRS!
- requires optional support of MS (3GPP Rel 7)
- existing Multislot classes are used (MS indicates additionally support for DLDC)
- requires re-dimensioning of EGPRS resources
- doubles downlink peak throughput up to 1184 kbps (but not for all Multi-slot classes)
- One of the carriers can be the BCCH carrier and the other on a TCH/TRX with frequency
hopping
- since S15 DLDC allows for individual link adaptation on the different carriers
- EDA is not supported with DLDC
- Asymmetric allocations are possible.
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(E)GPRS Multislot Classes - Dual carrier
Example: Multislot class 12, Dual carrier, with DL (8 TSL) plus UL (1 TSL) TBFs
Neighbour cell
measurements (Rx)
UL bursts, Tx
DL bursts, Rx 2
DL bursts, Rx 11 2 3 4 5 6 70
1 2 3 4 5 6 70
IDLE
IDLE
1 2 3 4 5 6 70 1 2 3 4 5 6 70
1 2 3 4 5 6 70 1 2 3 4 5 6 70