1 Nortel Confidential Information

EDGE RF Seminar 1

Wireless Network EngineeringWireless Network EngineeringNortel Networks

2 Nortel Confidential Information

EDGE RF Seminar Part – IBackground & Basics

3 Nortel Confidential Information

EDGE IntroductionEDGE stands for Enhanced Data rates for Gsm Evolution and is basically an extension of the GSM/GPRS Access network.

The administration, maintenance and supervision of EDGE is based on the currently deployed BSS and it utilizes the GSM / GPRS protocols and architecture.

The GPRS Coding Schemes (CS) are enhanced with new EDGE Modulation and Coding Schemes (MCS). MCS2 and MCS3 are two coding schemes based on GMSK whereas MCS 5, 6, 7, 8 and 9 are based on 8-PSK.

This new modulation increases the peak radio throughput of a carrier by a factor 3 compared to GPRS.

4 Nortel Confidential Information

8

2014.4

12

GPRSGPRSCS-1

CS-3CS-2

CS-4

Header + Protection

User Payload

User PayloadHeader + Protection

8.8

54.444.8

29.622.4

17.614.8

11.2

EDGEEDGE

MCS-959.2MCS-8MCS-9

MCS-7MCS-6MCS-5

MCS-4MCS-3MCS-2MCS-1

GMSKmodulation

GMSKmodulation

8PSKmodulation

8

2014.4

12

GPRSGPRSCS-1

CS-3CS-2

CS-4

Header + Protection

User Payload

8

2014.4

12

GPRSGPRSCS-1

CS-3CS-2

CS-4

Header + Protection

User Payload

User PayloadHeader + Protection

8.8

54.444.8

29.622.4

17.614.8

11.2

EDGEEDGE

MCS-959.2MCS-8MCS-9

MCS-7MCS-6MCS-5

MCS-4MCS-3MCS-2MCS-1

User PayloadHeader + Protection

8.8

54.444.8

29.622.4

17.614.8

11.2

EDGEEDGE

MCS-959.2MCS-8MCS-9

MCS-7MCS-6MCS-5

MCS-4MCS-3MCS-2MCS-1

GMSKmodulation

GMSKmodulation

8PSKmodulation

What is EDGE ?

EDGE is an extension of GPRS. The 4 GPRS Coding Schemes are extended with 9 new EDGE Modulation and Coding Schemes

GPRS

1214.4

20

8CS-1

CS-3CS-2

CS-4

Maximum Throughput per TS is increased from 20 kbps to 59.2 kbps.

5 Nortel Confidential Information

> EDGE = Enhanced Data Rates for GSM (or Global) Evolution

> Enhancement results from introduction of new modulation (8-PSK) + channel coding schemes• ECSD (Enhanced Circuit Switched Data): circuit switched

channels/ services• EGPRS (Enhanced GPRS): packet switched channels/ services

> Wireless packet data access to Internet• Same as GPRS only faster and more robust

> New modulation triples the nominal bit rates

> Update of the GSM Standard towards 3rd generation networks/mobiles

> Supports asymmetric traffic on the radio link

> Strict separation between radio and network subsystem• Difference between EDGE and GPRS is only on air interface• EDGE and GPRS mobiles can be supported simultaneously in a

network> Resides on ‘existing’ GSM BSS equipment

• EDGE is the ‘in-band’ 3G solution for GSM operators

EDGE Summary

6 Nortel Confidential Information

EDGE RF Seminar Part – IIE-GPRS architecture

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EDGE / GPRS Architecture (Nortel)

8 Nortel Confidential Information

Packet Architecture Overview

GPRS is an extension of the GSM network, built on top of

the existing infrastructure and consisting of 33 major new components.

PSTNExisting GSM NSS

PCUSNBSCSGSN

ServingNode

GPRS Network

Internet GGSN

GatewayNode

1 2 3

9 Nortel Confidential Information

Manages packet radio resources. Processes the radio packets for the uplink and downlink transmission so as to minimize the load on the BSC.Performs buffer management for the arrival packets before they get processed in the PCUSN, also supports retransmissions between the MS and the BSS

MSC

A

VLR

BSC

Gb

SGSN

Gn Gi

GGSN

Agprs

PCUSNBTS

A bis PDN

IntranetCES

The Packetizer: PCUSN

GSM Counterpart: BSC

10 Nortel Confidential Information

Performs IP-based packet routingProvides mobility management (including location tracking of the MS inside the Service Area) and session management. Performs authentication procedures and security functionsPerforms network access control and compression

The Packet Router: SGSN

MSC

A

VLR

BSC

Gb

SGSN

Gn Gi

GGSN

Agprs

PCUSNBTS

A bis PDN

IntranetCES

GSM Counterpart: MSC

11 Nortel Confidential Information

Provides a point of interconnection between the (E)GPRS network and external data network. Forwards the data packets to and from the PLMN and PDN Collects charging information that is used for customer billingProtocol stack has GTP layer which creates a ‘tunnel’ for the secure transmission of packetsRequests location information from the HLR for mobile terminated data packets

The Data Network Gateway: GGSN

GSM Counterpart: Gateway-MSCMSC

A

VLR

BSC

Gb

SGSN

Gn Gi

GGSN

Agprs

PCUSNBTS

A bis PDN

IntranetCES

12 Nortel Confidential Information

TCUBSC

BTS

MSC

Core Network

HLR/AUC

PSTN

Access Network

SCP

A

GPRS

SGSN

GGSN

IntranetInternet

PCUSN

Backbone

GbEDGE Radio

SW Upgrade v15

EDGE Implementation Requirements

BSC 3000

Terminals No change on Core Network

S8000/S12000 with eDRX/ePAe-cell

13 Nortel Confidential Information

EDGE RF Seminar Part – IIIE-GPRS Radio interface physical layer

14 Nortel Confidential Information

EDGE/GPRS Protocol Stack

TMSI/TLLI

L1

L2

IP

UDP

BSSGP

LLC Relay

RF RF

MAC

RLC RLC

MAC

LLC

SNDCP

IP

Application

TFI

L1

L2

IP

UDP

BSSGP

LLC

SNDCP

L1

L2

IP

UDP

GTP

L1

L2

IP

UDP

GTPTID

SAPI

NSAPI

TLLI

L1

L2

IP

L1

L2

IP

Application

Um Gbip Gn GiBSSMS SGSN GGSN End HostTMSI/TLLI

Packet Layer

Application Layer

IP Relay

EDGE is here

15 Nortel Confidential Information

E-GPRS Protocol Stack - BSS

EDGE is here

16 Nortel Confidential Information

GSM RF Layer

> The GSM RF layer manages the physical link between MS and BSS. • This layer corresponds physically to the CCU inside the BTS.

> The layer is divided into 2 sub layers:• The Physical RF layer is similar to GSM and is responsible for

modulation/demodulation.• The Physical Link Layer provides information transfer over a

physical channel on the radio interface.• Forward Error Correction

• Interleaving of 1 radio block over 4 bursts.

• Synchronization procedures (Timing advance).

• Radio channel measurements

• Power control procedures.

17 Nortel Confidential Information

(E)GPRS Physical Layer

Codeword (456 bits) Bit reordering 0 1 2 3 4 5 6 757 57 57 57 57 57 57 57

0 4

1 5

2 6

3 7

Training sequence

57 bits 57 bits

Burst (114 informationbits)

Block rectangular interleaving

Interleaving

GSMModulator

Source

ChannelEncoder Interleaver Burst

Formatter

Propagation channel

FiltersSynchronizationViterbi Equalizer

GSM Demodulator

De-interleaverDe-partition/reordChannel Decoder

Output bits

Burst De-Formatter

Reord &Partition

Burst Formatting

• In (E)GPRS, the physical layer is similar to GSM with some exceptions:— Channel coding scheme / Modulation is different

– CS-x / MCS-x vs. TCH/F, TCH/H, TCH/9.6, TCH/14.4 etc.– Modulation for some EDGE coding schemes is 8-PSK vs GMSK

— Interleaving scheme is different– Block rectangular instead of block diagonal or 19-burst interleaving

18 Nortel Confidential Information

PH User Data

BH Info Field BCS BH Info Field BCS BH Info Field BCS

Primary Block … Following Blocks ...

FH Information Field FCS

Normal

Burst

Normal

Burst

Normal

Burst

Normal

Burst

Packet (NL PDU)

Frame

(LLC

PDU)

Blocks

FH = Frame Header

FCS = Frame Check Sequence

Network layer

SNDCP layer

LLC layer

RLC/MAC layer

Physical layer

BH = Block Header

BCS = Block Check Sequence

data compr ./ decompr .

segmentation/assembly (not shown)encryption/decryption

channel coding (FEC)

interleaving

burst formatting

(E)GPRS Physical Layer: Block Transmission

19 Nortel Confidential Information

8

2014.4

12

GPRSGPRSCS-1

CS-3CS-2

CS-4Header + Protection User Payload

Header + Protection User Payload

8.8

54.444.8

29.622.4

17.614.8

11.2

EDGEEDGE

MCS-959.2MCS-8MCS-9

MCS-7MCS-6MCS-5

MCS-4MCS-3MCS-2MCS-1

GMSK

8-PSK

> GMSK Modulation• 1 bit per symbol• Robust but not spectrally efficient

• 8-PSK Modulation– 3 bits per symbol– Less robust but spectrally efficient

Maximum Throughput per TS is increased from 20 kbps to 59.2 kbps.

EDGE Improves GPRS Thruput with 8-PSK and New Modulation & Coding

(E)GPRS Physical Layer: EDGE coding schemes

20 Nortel Confidential Information

(E)GPRS Physical Layer:EDGE Coding Schemes

Family Coding Scheme

EGPRS RLC data unit

size - octets

Number of Basic data unit

Number of Radio

Block

Number of RLC

data Block

Required jokers

Data rate in kb/s

C MCS-1 22 1 1 1 or 1/2* 0 8.8 B MCS-2 28 1 1 1 or 1/2* 0 11.2 A MCS-3 37 1 1 1 or 1/2* 1 14.8 C MCS-4 44 2 1 1 1 17.6 B MCS-5 56 2 1 1 1 22.4 A MCS-6 74 2 1 1 2 29.6 B MCS-7 2x56 = 112 4 1 2 3 44.8 A MCS-8 2x68 = 136 4 1 2 4 54.4 A MCS-9 2x74 = 148 4 1 2 4 59.2

* When MCS6, MCS5 and MCS4 is respectively re-segmented in MCS3, MCS2 and MCS1

21 Nortel Confidential Information

> Each coding scheme belong to a family which is based on the the same unit of payload size in order to allow retransmission of RLC block with more robust coding.

Edge gives the possibility to retransmit a block in a different MCS belonging to the same family, according to the success or failure of previous transmission

Family Name

Modulation Coding Schemes

User Payload (octets)

A MCS-3, MCS-6, MCS-9 37, 2x37, 4x37

A with padding

MCS-3, MCS-6, MCS-8 34+padding, 2x(34+padding), 4*34

B MCS2, MCS-5, MCS-7 28, 2x28, 4x28

C MCS-1 and MCS-4 22 and 2x22

37 octets 37 octets 37 octets37 octets

MCS-3

MCS-6

Family AMCS-9

28 octets 28 octets 28 octets28 octets

MCS-2

MCS-5

MCS-7Family B

22 octets22 octets

MCS-1

MCS-4Family C

Improving Retransmissions with Lower MCS

(E)GPRS Physical Layer:EDGE MCS families

22 Nortel Confidential Information

P2P1puncturing

1836 bits

USF RLC/MACHdr.

Data = 74 octets = 592 bits BCS

36 bits

Rate 1/3 convolutional coding

96 bits

612 bits

1256 bits96 bits36 bitsSB = 4

1392 bits

32 bits

TBFBI EHCS

3 bits

1256 bits

(E)GPRS Coding Scheme Example: MCS-6 (EDGE)

23 Nortel Confidential Information

P2 P3P1 P2

puncturingpuncturing

1836 bits

USF RLC/M ACHdr.

36 bits

Rate 1/3 convolutional coding

135 bits

612 bits

612 bits128 bits36 bitsSB = 4

1392 bits

45 bits

Data = 592 bits B CS TB

612 bits

612 bits 612 bits

1836 bits

Rate 1/3 convolutional coding

EFB ID ata = 592 bits B CS TBEFBI

612 bits 612 bits 612 bits

P3 P1

3 bits

HCS

puncturing

IR is achieved by retransmission of different Puncturing scheme: P1, P2, P3

(E)GPRS Coding Scheme Example: MCS-8 (EDGE)

24 Nortel Confidential Information

8.8

11.2

14.8

17.6

22.4

29.6

44.8

54.4

59.2

0.0 23.2 46.4 69.6

Raw Bit Rate per TS (kbps)

MCS1

MCS2

MCS3

MCS4

MCS5

MCS6

MCS7

MCS8

MCS9

LLC raw bit rate RLC/MAC Header (including USF, …) Data overhead, coding & protection

8-PSK

GMSK

Fam

ily A

: M

CS

-3, M

CS

-6, M

CS

-8, M

CS

-9

Fam

ily B

: M

CS-

2, M

CS-

5, M

CS-

7

EDGE MCS Throughputs per TS

Note that Nortel did not implement MCS-1 & MCS-4 (both from family C), since there is no real gain.

MCS-2,MCS-3,MCS-5,MCS-6,MCS-7,MCS-8,MCS-9 from families A & B are implemented.

For GPRS, only CS-1 & CS-2 are implemented.

25 Nortel Confidential Information

> GSM/GPRS uses GMSK modulation (Gaussian Modulated Shift Keying) and 4 Coding Schemes are defined in GPRS : CS1 to CS4.

> EDGE introduces a new modulation : 8PSK (8 Phase Shift Keying).• 8PSK defines 8 states of the radio signal instead of 2 for GMSK.• 3 bits can be coded with 8PSK instead of 1 for GMSK.• 8PSK provides 3X the raw TS bit rate compared to GMSK.

8.8

11.2

14.8

17.6

22.4

29.6

44.8

54.4

59.2

0.0 23.2 46.4 69.6

Raw Bit Rate per TS (kbps)

MCS1

MCS2

MCS3

MCS4

MCS5

MCS6

MCS7

MCS8

MCS9

Layer 1 RF Radio Time Slot Occupancy

User Payload

RLC/MAC Hdr(including USF …)

Data overhead,coding &protection

8PSK

GMSK

5 MCS are using 8PSK :MCS5 to MCS9

4 MCS are using GMSK :MCS1 to MCS4

Ideal throughput at 0% error

EDGE MCS Throughputs per TS

26 Nortel Confidential Information

New modulation: 8-PSK

EDGE GSM Modulation 8-PSK, 3bit/sym GMSK, 1 bit/sym Symbol rate 270.833 ksps 270.833 ksps Payload/burst 346 bits 114 bits Gross rate/time slot 69.2 kbps 22.8 kbps

(0,0,1)

(1,0,1)

(d(3k),d(3k+1),d(3k+2))=(0,0,0) (0,1,0)

(0,1,1)

(1,1,1)

(1,1,0)(1,0,0)

• 8-PSK (Phase Shift Keying) has been selected as the new modulation used in EDGE

DL: 8-PSK (3п/8 shift) UL: 8-PSK (3п/8 shift)• Non-constant envelope (unlike

GMSK) ⇒ high requirements for linearity of the power amplifier

• Peak to Average Ratio (PAR) = 3.2 dB• Peak to Minimum Ratio (PMR) = 17 dB• PAR and high symbol dynamic requires

excellent linearity in the modulator (DRX) and PA to limit distorsions

• Due to amplifier non-linearities, a 2-4 dB power decrease (back-off) is typically needed

• 3 bits per symbol• Symbol rate and burst length identical

to those of GMSK

27 Nortel Confidential Information

differentialencoding

-1, +1

Gaussianprefiltering

for frequencypulses

frequencymodulator

local oscillator

rotation byk3pi/8

LinearizedGaussian

Filterfor Diracpulses

Gray mappingto 8PSK

constellation

3 bits persymbol

I & Q

(0,0,1)

(1,0,1)

(d3i, d3i+1, d3i+2)=(0,0,0)

(0,1,0)(0,1,1)

(1,1,1)

(1,1,0)(1,0,0)

I

Q

Gray mapping: 3 bits per symboland only one bit changes between adjacent symbols

GMSK Modulator 8-PSK modulator

> The following block diagrams presents the key differences between GMSK and 8-PSK modulations.

> EDGE uses a 3п/8-shifted 8-PSK modulation

Gray coding bit Ik symbol 111 (7) 0 011 (3) 1 010 (2) 2 000 (0) 3 001 (1) 4 101 (5) 5 100 (4) 6 110 (6) 7

Gray coding symbolBER minimization

New modulation: 8-PSK

28 Nortel Confidential Information

• Same structure as for GSM• term 'bit' is replaced by 'symbol’• Same training sequence correlation

• 8-PSK symbol 0 and 4 replace GMSK bit 0 and 1• PAR = 1.5 dB ; PMR = 4.3 dB

• Mobile blind detection GMSK/8-PSK thanks to rotation within Training Sequence• Training sequence (TS) has lower envelope variations• It has seamless switchover between timeslots

Training Sequence 26 symbol

[same correlation as GMSK ]

Payload 58 symbol 8-PSK

174 bits

Payload 58 symbol 8-PSK

174 bits3 Sy. 3 Sy. GP

Burst topology

1 symbol equals 1 bit in GMSK vs 3 bits in 8PSK

29 Nortel Confidential Information

EDGE RF Seminar Part – IVE-GPRS Radio interface logical channels

30 Nortel Confidential Information

(E)GPRS Logical Channels

• PDTCH (UL or DL) for data traffic

• PACCH (UL or DL) for control signaling

• PTCCH (UL andDL) for TA update

GSM / (E) GPRSGSM / (E) GPRS

CommonGSM / (E) GPRS

BCCH &CCCH

(SI, RACH, Paging)

PDCH

> Existing GSM CCCH and BCCH (with additional system info messages) are used for EGPRS as well• PDCH will carry PDTCH, PACCH and

PTCCH (uplink / downlink)

31 Nortel Confidential Information

(E)GPRS Logical Channels> Current (E)GPRS solution

• GSM Broadcast Control CHannel will be used• GSM Common Control CHannels will be used • Packet Traffic CHannels will be used.

• PDTCH: Packet Data Traffic Channel• PACCH: Packet Associated Control Channel• PTCCH: Packet Timing Advance Control Channel

BSS

DLDLPCH

AGCH

PDTCHPACCHPTCCH

ULUL

PDTCHPACCHPTCCH RACH

BCCHBCCH

32 Nortel Confidential Information

(E)GPRS logical channels

> All necessary parameters for (E)GPRS access will be broadcast on the BCCH using SI 13.(sys info 13 ) • SI 13 is broadcast by the network on the BCCH• The message provides the MS with GPRS cell specific access

related information.

> SI 13 message contains information for the (E)GPRS MS:• Routing area code (RAC)• network control parameters (NC0,NC1,NC2) • GPRS power control parameters• Etc.

33 Nortel Confidential Information

(E)GPRS Logical Channels

> The PDTCH is used to carry traffic in the UL or DL• Up to 8 PDTCH may be allocated to 1 subscriber on the same TDMA

and up to 8 MS can share the same PDCH. (7 on the UL due to one of the USF flags being reserved).

• The MAC layer is responsible for the management and contention resolution of the PDCH by static* or dynamic allocation.

> The PACCH is associated with the assigned PDTCH and is used to carry control messages.• The PACCH and PDTCH positions (PDCH number) are provided to the

MS in the immediate assignment or resource assignment stage.

> The PTCCH is used for Timing Advance procedure.

34 Nortel Confidential Information

(E)GPRS Logical Channels> In (E)GPRS, the data traffic channels are

not paired (UL/DL)• PDTCH/UL and PDTCH/DL are assigned

independently depending on the direction of data being transferred

• Not all MS are required to be capable of full duplex operation anyway

• The PACCH/DL and PACCH/UL are used during a packet transfer to carry ‘ack’ messages in the other direction and also for assignment/ re-assignment

• PACCH is dynamically multiplexed on the same TS/PDCH as PDTCH but has no fixed position and may be used whenever necessary

• The PTCCH is the only bi-directional logical channel• Each MS uses access bursts on the PTCCH/UL during packet

transfer and the BTS calculates the TA and updates the MS • Multiple MS on the same TS are updated by the same

PTCCH/DL control block with different TAI (timing advance identifier) for each mobile

35 Nortel Confidential Information

(E)GPRS Logical Channels> PDCH Multiframe structure

• PDTCH, PACCH & PTCCH (for GPRS Phase1)• 52 burst Multiframe• Radio blocks transmitted over 4 bursts belonging to 4

consecutive TDMA frames. (PDTCH, PACCH)• Idle frames used for PTCCH

• GSM control channel TS will follow the GSM 51-frame multiframe structure• GSM traffic channels TS will follow the GSM 26-frame multiframe structure• (E)GPRS channels TS will follow the GPRS 52-frame multiframe structure

Idle Frames

Radio Blocks Radio Blocks

UL

Idle Frames

Radio Blocks Radio Blocks

DLTDMA FN 0 1 2 3 4 5 6 7 8 9 10 1112 13 14 1516 1718 1920 2122 23 24 25 26 27 28 29 30 31 32 33 34 3536 3738 39 40 4142 43 44 4546 4748 49 50 51

Block B0 B1 B2 X B3 B4 B5 X B6 B7 B8 X B9 B10 B11 X

TDMA FN 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51

Block B0 B1 B2 X B3 B4 B5 X B6 B7 B8 X B9 B10 B11 X

This example shows repetition of bursts over time on the same time slot

36 Nortel Confidential Information

Packet Data Unit: PDU

37 Nortel Confidential Information

EDGE RF Seminar Part – VE-GPRS Procedures & concepts

38 Nortel Confidential Information

(E)GPRS Procedures

> Network acquisition• The MS monitors the SYS INFO messages on

the BCCH of a cell• The MS then determines whether there is GPRS available

on this cell. • The MS can then use the CCCH to attach to the

GPRS network and get ready to transmit or receive

> Call setup• A (E)GPRS call is initiated in a similar way as compared to

GSM except that instead of SDCCH and TCH/SACCH assignment, the MS is assigned PACCH / PDTCH UL or DL

• The TSs are assigned based on MS capability and availability of resources

39 Nortel Confidential Information

(E)GPRS protocol stack

FrameRelay

GTP

Application

IP / X.25

SNDCP

LLC

RLC

MAC

GSM RF

SNDCP

LLC

BSSGP

L1bis

RLC

MAC

GSM RF

BSSGP

L1bis

LLC Relay

L2

L1

IP

L2

L1

IP

GTP

IP / X.25

Um

Gn Gi

MS BSSSGSN GGSN

UDP /TCP

UDP /TCP

Gb

RelayFrame

TFI

TLLI

SAPI

NSAPI

Packet Layer

Application LayerApplicationApplication

TID

Physical Layer

RLC/MAC layer

40 Nortel Confidential Information

RLC/MAC & LLC Layer> RLC/MAC is the logical link between the MS and BSS.

• Interface between MS and PCU

> RLC layer functions• segmentation and re-assembly of LLC frames into RLC data blocks.• Backward error correction (ack mode) and radio block retransmission

of unsuccessfully delivered RLC/MAC blocks.

> MAC layer functions• Multiplexing of uplink and downlink traffic• Allocation modes: static and dynamic• channel access control (allocation of TBF)

> LLC is the logical link between the MS and the SGSN.• Helps in re-initiating a connection after an unwanted TBF release

41 Nortel Confidential Information

(E)GPRS Key Concepts

> MM States• Mobility management states (idle, standby, ready)

> RR States• Radio resource states (packet idle, packet transfer)

> TBF/TFI (b/w MS and the BSS)• Temporary block flow / temporary flow identifier.

A TBF corresponds to a set of radio TS (belonging to the same TDMA) allocated to a user

> PDP context (b/w MS and GGSN)• Packet data protocol context indicating a high layer service

connection between the MS and an access point

42 Nortel Confidential Information

Mobility Management and PDP Context

Ready

Idle

Standby

GPRS Attach

GPRSDetach

STANDBYTimerExpiry

READY Timer Expiry orForce to STANDBY

PDUTransmission

Ready

Idle

Standby

GPRS Attach

GPRSDetach orCancelLocation

STANDBYTimerExpiry

orCancel

Location READY Timer Expiry orForce to STANDBY or

Abnormal RLC Condition

MS

Mobility Management State Model

SGSN

Activate PDP Context

BSS SGSN GGSN

The GGSN is then able to route PDP packets for the MS to its SGSN

The GGSN is then able to route PDP packets for the MS to its SGSN

PDP Context Activation Procedure

Activate PDP Context

Security FunctionsCreate PDP Context Request

Create PDP Context Response

Inactive

Active

Inactive

Active

Activate PDPcontext

DeactivatePDPContext

Inactive

Active

DeactivatePDPContext

SGSNMSGGSN

PDP Context State Model

Activate PDPcontext

Activate PDPcontext

BSS SGSN HLR

GPRS Attach Procedure

GPRS Attach AcceptUpdate LocationInsert Sub Data

Insert Sub Data AckUpdate Location Ack

Packet Data Channel RequestPacket Uplink Assignment

GPRS Attach Request

43 Nortel Confidential Information

(E)GPRS Mobility Management

IDLE

STANDBY

READY Cell UpdatesNo Paging

RA UpdatesPaging

READYtimer expiry

GPRS Attach

PDU transmission

GPRS Detach

STANDBY timer expiry

The GMM takes place between the MS and the SGSN. The mobility management activities related to a GPRS subscriber are characterized by one of three different GMM states: IDLE, READY and STANDBY.

44 Nortel Confidential Information

(E)GPRS Mobility ManagementIn GPRS IDLE state, the subscriber is not attached to the GMM. Thus, the MS and SGSN MM contexts hold no valid location or routing information for the subscriber. Data transmissions to and from the MS as well as the paging of the subscriber are not possible.

In GPRS STANDBY state, the subscriber is attached to the GMM. PS-paging and CS-paging via the SGSN may be received, but data transmission and reception are not possible. At this point, if the subscriber wants to request an e-mail message or a web page, a PDP context must be activated before.

In the READY state, the MS location is known on a cell level. The MS performs GMM procedures to provide the network with the actual selected cell, i.e. when reselecting a new GPRS cell the MS shall carry out a Cell update procedure. The MS may send and receive PDP PDU and paging is not performed. The MS may also initiate PDP context activation or deactivation.

45 Nortel Confidential Information

(E)GPRS Session Management

IN A C T IV E

A c tiv a te P D P

c o n te x t

A C T IV E

D e a c tiv a te P D P c o n te x t o r

G M M s ta te c h a n g e to ID L E

A GPRS subscription contains one or more PDP addresses. Each PDP address is described by an individual PDP context in the MS, SGSN and GGSN.

Every PDP context exists independently in one of two states: INACTIVE or ACTIVE.

The PDP state indicates whether the PDP address is activated for data transfer or not. All PDP contexts of a subscriber are associated with the same MM context.

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(E)GPRS Session ManagementThe INACTIVE state characterizes the data service for a certain PDP address of the subscriber as not activated. This means that the PDP context contains no routing or mapping information to process PDP PDU related to that PDP address. So, no data can be transferred. The MS moves from INACTIVE to ACTIVE state by initiating the PDP context activation.

In ACTIVE State, the PDP context for the PDP address in use is activated in MS, SGSN and GGSN. The PDP context contains mapping and routing information for transferring PDP PDU for that particular PDP address between MS and GGSN. The PDP state ACTIVE is permitted only whenthe GMM state of the subscriber is STANDBY or READY. An ACTIVE PDP context for an MS is moved to INACTIVE state when the deactivation procedure is initiated. All active PDP contexts for an MS are moved to INACTIVE when the GMM state changes to IDLE.

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Packet Assignment

> MS initiates a packet transfer by sending a Packet channel request on the (P)RACH.• 1 phase (GPRS only) or 2 phase access (GPRS / E-GPRS)

> Short access or 1 phase access* • The MS includes all the information needed for channel

establishment on the (P)RACH.

> Two phase access • This can be initiated by MS or network.• MS receives a single block on (P)AGCH and responds with

the Packet resource request message on PACCH. This contains information on the requested resources for UL transfer, I.e. MS capability, file size etc.

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Packet Assignment example

> MS - PCU packet transfer procedures

MSMSPCUPCU

Packet channel requestPacket channel request

Packet immediate assignment

One block allocation

Packet resource request (TLLI)MS capability (2 +1), MS capability (2 +1), RLC octet count, RLC mode

Packet uplink assignment

ARFCN, TBF start time, TFI, TAI, CS

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RR Activation/UL TBF Establishment

• Random Access on RACH (TA calculated by BSS)

• Immediate Assignment on AGCH

• Packet Resource Request by MS on PACCH

• Packet UL Assignment by BSS on PACCH

• UL PDTCH

MM Ready / RR Packet Transfer

MM Ready / RR Packet Transfer

MM Standby / RR Packet IdleMM Standby / RR Packet Idle

TBFRelease

MM Ready / RR Packet Transfer

MM Ready / RR Packet Transfer

MM Ready / RR Packet Transfer

MM Ready / RR Packet Transfer

• Packet UL Assignment on PACCH

• Packet Control Ackfrom MS on PACCH

• UL PDTCH

TBFRelease

DL TBF Already assignedMS known in a cellMS known in a RA

MM Ready / RR Packet Idle

MM Ready / RR Packet Idle

MM Ready / RR Packet Transfer

MM Ready / RR Packet Transfer

• Random Access on RACH (TA calculated by BSS)

• Immediate Assignment on AGCH

• Packet Resource Request by MS on PACCH

• Packet UL Assignment by BSS on PACCH

• UL PDTCH

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RR Activation/UL TBF Establishment

Packet Downlink ACK/NACK

Downlink Data

Packet Uplink Assignment(S/P=1)

Packet Control Acknowledgement

Downlink Data

Downlink Data

Uplink Data

Establishment of an Uplink TBF/ Acces Establishment of an Uplink TBF During Downlink Transfer

RACH (CCCH) Channel Required Channel Required

IMM. Assign. (AGCH)

IMM. Assign. Command

IMM. Assign. Command

PacketUplink

Assignment

FIRST PDTCH

Packet Resource Request

MS PCUBTS BSCMS PCU

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RR Activation/DL TBF Establishment

• Paging on PCH• Random Access on

RACH (TA calculated by BSS)

• Immediate Assignment on AGCH

• Packet DL Assignment on PACCH

• Packet Control Ackfrom MS on PACCH

• DL PDTCH

MM Ready / RR Packet Transfer

MM Ready / RR Packet Transfer

MM Standby / RR Packet IdleMM Standby / RR Packet Idle

MM Ready / RR Packet Idle

MM Ready / RR Packet Idle

MM Ready / RR Packet Transfer

MM Ready / RR Packet Transfer

• Immediate Assignment on AGCH

• Packet DL Assignment on PACCH

• Packet Control Ack from MS on PACCH (Access bursts on PACCH for TA calculation)

• Packet Timing Advance on PTCCH

• DL PDTCH

MM Ready / RR Packet Transfer

MM Ready / RR Packet Transfer

MM Ready / RR Packet Transfer

MM Ready / RR Packet Transfer

• Packet DL Assignment on PACCH

• Packet Control Ackfrom MS on PACCH

• DL PDTCH

UL TBF Already assignedMS known in a cellMS known in a RA

TBFRelease

TBFRelease

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RR Activation/DL TBF Establishment

Establishment of a DownLink TBF Establishment of a Downlink TBF during

Uplink transfer

MS PCUBTS BSC

UplinkBitmap i

UplinkBitmap

i+1

MS PCU

BSSGP-DL-Unit-Data

IMM. Assign. Command

IMM. Assignment

PacketDownlink

Assignment

Packet Control Acknowledgement (Over 4 bursts )

Packet Timing Advance

First PDTCH

PDTCHPacket Uplink Assignment (Bitmap i+1)

PDTCHPDTCH

Packet Control AcknowledgementPDTCH

Packet Downlink AssignmentPDTCH

Packet Control AcknowledgementPDTCHPDTCH

PDTCH

PDTCH

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EDGE RF Seminar

Part – VIE-GPRS usage

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> Same radio TS can be used simultaneously for GPRS and EDGE> Bandwidth is dynamically shared between :

• Voice traffic• GPRS/EDGE traffic

> Allows a smooth migration from GPRS MS towards EDGE MS.Increases capacity at no costEnables EDGE also in low capacity sites

BCCH Voice Voice VoiceVoiceGPRSEDGE

GSM TDMA Radio (BCCH in this instance)VoiceGPRSEDGE

VoiceGPRSEDGE

GPRSEDGE

Voice Voice VoiceVoiceGPRSEDGE

GSM TDMA Radio (non-BCCH in this instance)VoiceGPRSEDGE

VoiceGPRSEDGE

GPRSEDGE

Voice

EDGE TS multiplexing

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EDGE Benefits over GPRSHow the Operator can implement it

BCCH Voice Voice Voice Voice Voice EDGE EDGE EDGE: 60Kbps data (118Kbps peak), 5 voice channels

BCCH Voice Voice GPRS GPRS GPRS GPRSVoiceGPRS: 40Kbps data (48 kbps peak), 3 voice channels

BCCH Voice Voice GPRS GPRS GPRS GPRSVoice

GPRS GPRS GPRS GPRSGPRS GPRS GPRS GPRSGPRS 2 radios: 120Kbps data (144Kbps peak), 3 voice channels

BCCH Voice Voice Voice EDGE EDGEEDGE EDGEEDGE 1 radio: 120Kbps data (237Kbps peak), 3 voice channels

EDGE as a Capacity Solution

EDGE as a Data Quality SolutionOr

Or a mix of both

Increased data and voice capacity

Increased data and voice capacity

Equal capacity with half the equipment!

EDGE Improves Radio Efficiency- Reduces Equipment RequirementsEDGE Improves Radio Efficiency- Reduces Equipment Requirements

On a given DRX, number of voice and data users increases.

Improves spectral efficiency :

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Data applications

Find out where you are

1. Email via mobile Phone or PDA (MMS)2. Email + Attachment via Laptop3. Internet/Intranet Access browsing4. Internet Intranet Access File Transfer5. Net Meeting6. Travel Information services7. Navigation Services8. Text Based Information (push/pull)9. Reference services (yellow pages, directory…)10. Interactive games11. Banking applications12. Electronic Ticketing13. Interactive shopping14. Image/Video Streaming (MPEG4)15. Audio Based Services (MP3)

> High data rate availability encourages the customers to use these services

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EDGE RF Seminar Part – VIIAbbreviations

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EDGE ABBREVIATIONS

A ETSI generic name for BSS-NSS i/f

Abis ETSI generic name for BTS-BSC i/f

Agprs NORTEL specific name for BSC-PCU i/f

ARQ Automatic repeat request

APN Access point name

BCCH Broadcast control channel

BH Busy hour

BLER Block error rate

BSC Base station controller

BSN Block sequence number

BSN’ Absolute block sequence number

BSS Base station subsystem

BTS Base transceiver station

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BSSGP BSS GPRS protocol

BVC BSSGP virtual connection

CCCH Common control channel

CS Coding scheme

CS-paging Circuit Switched-paging

CV Countdown value

DL Downlink

FAI Final acknowledgement indicator

FBI Final block indicator

FN Frame number

Gb ETSI generic name for PCU-SGSN i/f

GGSN Gateway GPRS support node

Gi ETSI generic name for GGSN-PDN i/f

EDGE ABBREVIATIONS

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GMM GPRS mobility management

Gn ETSI generic name for SGSN-GGSN i/f

GPRS General packet radio service

GSL GPRS signaling link

GTP GPRS tunneling protocol

HO Handover

IE Information element

I/F Interface

IP Internet protocol

IAS Immediate assignment

IAREJ Immediate assignment reject

IOT Inter-operability tests

LA Location area

EDGE ABBREVIATIONS

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LAC Location area code

LAI Location area identity

LAPD Link access protocol on D channel

LLC Logical link control

MAC Medium access control

MCS Modulation and Coding Scheme

MO Mobile originated

MS Mobile station

MT Mobile terminated

NMS Network management system

N-PDU Network layer-packet data unit

NS Network service

NSAPI Network service access point identifier

EDGE ABBREVIATIONS

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NSS Network and switching subsystem

NTS Number of TS assigned to the UL TBF

O&M Operation and maintenance

OAM Operation administration maintenance

OML OAM link

PACCH Packet associated control channel

PAREJ Packet access reject

PBCCH Packet broadcast control channel

PCA Packet control acknowledgement

PCCCH Packet common control channel

PCM Pulse coded modulation

PCU Packet control unit

PDAN Packet DL Ack/Nack

EDGE ABBREVIATIONS

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PDAS Packet DL assignment

PDCH Packet data channel

PDCB Packet dummy control block

PDN Packet data network

PDP Packet data protocol

PDTCH Packet data traffic channel

PDU Packet Data Unit

PLMN Public land mobile network

PPCTA Packet power control timing advance

PPR Packet polling request

PRR Packet resource request

PTCCH Packet TA control channel

PTR Packet TS Reconfigure

EDGE ABBREVIATIONS

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PSI Packet system information

PS-paging Packet Switched-paging

PUAN Packet UL Ack/Nack

PUAS Packet UL Assignment

QoS Quality of service

RA Routing area

RAC Routing area code

RAI Routing area identifier

RACH Random access channel

RBB Receive block bitmap

RLC Radio link control

RRBP Related reserved block period

RRM Radio Resource Management

EDGE ABBREVIATIONS

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RSL Radio signaling link

SAPI Service access point identifier

SFH Slow frequency hopping

SI Stall indicator

SI n SysInfo n

SGSN Serving GPRS support node

SM Session management

SNDCP Sub-network dependent convergence protocol

SSN Starting sequence number

TA Timing advance

TAI Timing advance index

TBC Number of RLC data blocks to be transmitted in the TBF

TBF Temporary block flow

EDGE ABBREVIATIONS

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TCP Transmission control protocol

TDMA Time division multiple access

TFI Temporary flow identity

TID Tunnel identity

TLLI Temporary logical link identifier

TRX BTS transceiver entity

TS Timeslot

UL Uplink

USF UL state flag

EDGE ABBREVIATIONS

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Access Time Slot : TS assigned by the PCU to the BTS and containing access blocks. Those blocks may be allocated by the BTS for Packet Resources Request transmission (“CCCH at BTS” feature).

Block period: is the sequence of 4 TS on 4 successive TDMA used to convey 1 radio block. (20ms)

CV: indicates in which state the countdown procedure is.

EDGE Radio data block: represents a block of the TRAU frame that is sent or received every 20ms and that uses MCS1 to MCS9. An EDGE data block using MCS7, MCS8 or MCS9 is composed of 2 RLC data blocks. All other MCS are composed of only 1 RLC data block, except MCS2 and 3 if the block has been re-segmented (1/2 RLC block in that case).

Joker DS0 : On Abis, 64 kbps timeslot used as joker for an Edge TDMA.

The total number of DS0 used for an Edge TDMA consists in 2 main DS0 plus joker(s) DS0.

Multi-slot Class: indicates the UL and DL capabilities of the MS.

EDGE DEFINITIONS

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PDP context: information set stored at MS, SGSN and GGSN, enabling data exchange with a PDP network.

ON period: one ON period corresponds to the transfer of information (web page, e-mail…) at the GPRS application layer (above IP/X25).

OFF period: one OFF period corresponds to the time between two ON periods.

Packet idle mode: in this mode, one MS is not allocated any radio resource on a PDCH. Then, it listens to the BCCH and the CCCH.

Packet transfer mode: in this mode, one MS is prepared to transfer LLC PDU and then is allocated radio resource on one or more PDCH to carry out this transfer.

PBCCH: used to broadcast the PSI. The presence of PBCCH logical channel in the cell is indicated in the SI 13 on BCCH (providing GPRS specific information). If PBCCH is not present in the serving cell (V15.0 case), the MS shall receive the SI n messages broadcast on BCCH. Most of these SI are for GSM, only SI 13 and minor extensions in SI 3, SI 4, SI 7 and SI 8 are needed for GPRS. Then, all the common control channels are the GSM CCCH logical channels and the only GPRS logical channels used on PDCH are PDTCH for data traffic and the associated control channels PACCH and PTCCH.

EDGE DEFINITIONS

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PDCH: is a physical channel dedicated to packet data traffic.

Pipe: set of resources allocated to one TBF at one time characterized by:

All parameters allocated to the TBF (USF, TFI…).

A set of UL and/or DL TS.

When a TBF is opened, a pipe is opened. In order to optimize the throughput, a TBF can be associated to a set of subsequent pipes. One pipe in a TBF is closed, and replaced by another one, when:

The PCU allocator modifies the UL and/or DL TS allocation.

A switch from half-duplex to full-duplex transfer is done.

QoS parameters change.

The TBF is released.

Reaction time: the GSM specifications (see [5.08]) gives 3 blocks delay (60 ms) to the MS, in order to listen allocated TS, after reception of the allocation order.

EDGE DEFINITIONS

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RLC Data Block: Block uniquely identified by its Block Sequence Number (BSN), as defined in 04.60

RLC-MODE: indicates the acknowledged (0) or non-acknowledged (1) RLC mode of operation.

SI: indicates whether the MS RLC transmit window is stalled (1) or not (0).

TBF: the radio resource allocations are called TBF in GPRS. One TBF is allocated to a GPRS MS during radio transfer duration. It corresponds to a set of radio blocks on packet switched TS (PDCH) belonging to the same TDMA.

•From the PCU allocator point of view, a TBF has been established as soon as one block is allocated to on the Um i/f.

•From a user point of view, it can be considered that a TBF has been established when user data is transferred on the Um i/f.

TFI: identifies the TBF.

Timeslot DS0 : On Abis, 64 kbps timeslot

Timeslot Agprs : On Agprs, 16 kbps timeslot

EDGE DEFINITIONS

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