handout

HANDOUT

BSC

RNC

MSCVLR

GMSC

CS

TRANSPORT NETWORK

ISDN

PSTN

PLMN

Gateway MSCMobile Services

Switching Center

Visitor LocationRegister

Base StationController

Base TransceiverStation

Home LocationRegister

AuthenticationCentre

EquipmentIdentityRegister

Service ControlPoint

SGSN GGSN

Intermediate exchanges

B-Node Radio NetworkController

Serving

GPRSSupportNode

IP BACKBONE

NETWORK

Routers

Internet

Corporate

Intranet

Streaming

Services

Telemetry

Optional (specified). In practice

not implemented – no mobile terminated data services

•call routing and switching•charging (CDR)•database (subs. profiles)

•security•mobility management

•call routing and switching

•charging (CDR)•interface to external networksINCOMING CALLS

•packet routing and switching

•charging (CDR)•database (subs. profiles)•security•mobility management

•session management•CIPHERING•compression (IP, payload) - /// features

•packet routing and switching•charging (CDR)

•session management•interface to external networksOUTGOING PACKETTRANSFERS

Gr GfGe

Gd

software hardware (PLD implemented)

HLR AUC EIR

SDP

GPRS

for prepaidSMSsymmetry line

Gb

Abis

IuIub

UTRANUMTS Terrestial

Radio Access Network

GERAN

GSM/EDGERadio Access Network

•WPP: Wireless Packe Platform, AXE cabinet

compliant•J20: platform invented by JUNIPER (now ///)•CPP: Connectivity Packet Platform•TSP: Telephony Server Platform (in future

replacement of AXE)

•RPP: Regional Processor with PCI bus

WPP/J20CPP

CPP

RBS AXE AXE

AXE

AXEPCURPP

Packet

ControlUnit

SCPAXE/TSP

UNIX

IN

Service Data Point

Intelligent

Network

UNIXAXE AXE/UNIX

GatewayGPRS

SupportNode

~MSC

~GMSC

WPP

System Architecture

Connection Sequence

0

Sender Receiver

SYN,seq=x

SYN/ACK,seq=y,ack=x+1

Internet

ACK, seq=x+1,ack=y+1

(SYN,seq=x)

(SYN,seq=y,ack=x+1)

(ACK, seq=x+1,ack=y+1)DATA,seq=x+1,ack=y+1

(DATA,seq=x+1,ack=y+1)

1

2

3

4

Legend:

CLOSED

LISTEN

SYN-SENT

ESTABLISHED

(received and sent)

SYN-RECEIVED

4

0

1 3

2

4

Note: ACK does not use sequence space

Closing Sequence

FIN,seq=x,ack=y

ACK,seq=y, ack=x+1

ACK, seq=x+1,ack=y+1

(ACK, seq=y,ack=x+1)

(ACK, seq=x+1,ack=y+1)

FIN/ACK,seq=y ack=x+1

(FIN/ACK, seq=y,ack=x+1)

Inform Application ->

(CLOSE ->)

(<- CLOSE)

(FIN,seq=x,ack=y)

Wait=2*MSL

ESTABLISHED

FIN-WAIT-1

FIN-WAIT-2

CLOSE-WAIT

LAST-ACK

TIME-WAIT CLOSED

InternetSender Receiver

4 4

5

7

6

9

10

00

010

9

74

5

6

Legend:

MSL - Maximum Segment Life

Round Trip Time - RTT

Transmission of 64 Kbytes (TCP)

Dat

a

Ack

nowle

dgemen

t

At t=0 After 500 µµµµs After 15 ms After 30 ms

a b c d

Slow Start Algorithm

Advertised Window

1 2 3 4 5 6 7 8 9 10

Initial widow size = 1

TransmissionAcknowledgement

3rd Duplicatr ACK, Packet lostWindow is too bigStart Congestion Avoidance

Window size is increased exponentially contraryto Congestion Avoidance Algorithm, where

window is increased linearly.

Network

Service

GTP

Application

IP / X.25

SNDCP

LLC

RLC

MAC

GSM RF

SNDCP

LLC

BSSGP

L1bis

RLC

MAC

GSM RF

BSSGP

L1bis

L2

L1

IP

L2

L1

IP

GTP

IP / X.25

Um Gb Gn GiMS BSS SGSN GGSN

Network

Service

UDP /

TCP

UDP /

TCP

IP / X.25IP / X.25

IP Packet

GTP

Relay

SNDCP

SNDCP SEGMENT

LLC LLCLLC FRAME

Transmission protocol architecture

RLC RLC

Relay

RLC/MACBLOCK

Selection of default coding scheme for the whole BSC/PCU

RAEPC:

PROP=CHCODING–1; Choosing appropriate channel coding 1 – CS1 , 2 – CS2 (UL,DL)

Selection of dedicated coding scheme for the particular cell

RLGSC: CELL=KISTA, Cell nameNA

CS1

CHCSDL= CS2, CS downlink for the particular cell. If NA is CS3 selected, the exchange property CHCODING

CS4 is used

LA = ON/OFF; Activation of Link Adaptation feature. CS specified by CHCSDL will be taken as initial value.

Control Parameters

EGPRS Coding Schemeskbps

10

20

30

40

50

60

0

MC

S1

MC

S2

MC

S3

MC

S4

MC

S5

MC

S6

MC

S7

MC

S8

MC

S9

CS

1

CS

2

CS

3

CS

4

GMSK modulation 8PSK modulation

8.0

12.0

14.4

20.0

8.4

11.214.8

16.8

22.4

29.6

44.8

54.4

59.2

GPRS EGPRS

1/The same bit 3,7 µs

0/Different bit

0,0,0

0,0,1

0,1,0

0,1,1

1,1,1

1,0,1 1,1,0

Q

I

1,0,0

amplitude (const.)

phase

1

2

3011 110 000

1 2 3

amplitude (var.)

Problem amplitude = 0

Solution – axis rotate

Q

I

SS

time

SS

time

GMSKGaussian

Minimum

Shift

Keyiing

8-PSK8 - Phase

Shift

Keyiing

Class C amplifier required.

Simple and cheapClass A amplifier required.

Expensive and complicated

GMSK vs 8PSK

#1 sequential number

#2

#3

coding user data

#2

In GPRS retransmission is allowed only

with the same coding scheme.

#???

Transmission window 64 frames

(stall if exceeded)

#2 retransmission, more coding required

#1 ACK, #3 ACK, #2 NOT ACK

CS 4

CS 2

#1

NOT ACK

#1

In EDGE retransmission is allowed with

different coding scheme and modulation.

#2

MCS 9

MCS3

(GMSK)

#2

MCS 6

NOT ACK

NOT ACK

#1.1

#1.2

#2.1

#2.2

Transmission window 1024 frames

RETRANSMISSIONS

Example of coding procedure for MCS9

MCS-9

1224 data bits

612 612

1836 1836

convolutional

coding 1/3

612P1 P1P2 P3 P2 P3

puncturing 2/3

interleaving 20 ms – 4 bursts

MCS-9 and MCS-5 - comparison

P1 P2 P3

1 1 1 1 2 3

1, P1

1, P2

1, P3

P1

P1

P1

P2

P2 P3

PCU

after 2 re-transmissions the code rate is 1/3

1

2

3

PCU

code rate is 1/3

MCS-9 MCS-5

Selection of Default Modulation and Coding Scheme (MCS) DL/UL

RAEPC: Changing exchange properties

PROP=LQCDEFAULTMCSDL–5; Default MCS downlink. Values 1-9

~ MCS1 - MCS9 (valid if LQCACT≠1 or 3, no EGPRS LQC DL)

PROP=LQCDEFAULTMCSUL–5; Default MCS uplink. Values 1-9

~ MCS1- MCS9 (valid if LQCACT≠2 or 3, no EGPRS LQC UL

Activation/Deactivation of EGPRS Link Quality Control (ELQC)

RAEPC: 0 ELQC deactivatedPROP=LQCACT– 1; ELQC activated for DL TBFs only

2 ELQC activated for UL TBFs only3 ELQC activated for DL and UL TBFs

Control Parameters

Activation/Deactivation of Incremental Redundancy on UL

RAEPC: 0 IR UL not activatedPROP=EGPRSIRUL– 1; IR UL activated

Limiting the highest MCS than can be selected by the system in LQC procedures (UL/DL)

RAEPC: PROP=LQCHIGHMCS–9; Values 1-9 ~ MCS1- MCS9

Link Adaptation and Incremental Redundancy (LA/IR/BLER) activation

RAEPC: 0 LA modePROP=LQCMODEDL/UL 1; LA/IR mode

2 LA/IR BLER mode

Control Parameters

B

Dedicated (Fixed)Packed Data Channels

On DemandPacket Data Channels

GSMBasic Physical Channels permanently reserved for GPRS

temporarily used by GPRS(dynamic allocation)

0 1 2 3 4 5 6 7

GPRS Channels

COMBINED RA/LA UPDATE

Logical Channels

GSM GPRS

BCH:

FCCH

SCHBCCH PBCCH

CCCH:

PCH PPCH

RACH PRACHAGCH PAGCH

DCCH:

SDCCH

FACCH PACCHSACCH

PTCCH

TCH PDTCH

Option

MPDCH parameter

MPDCH - first of dedicated PDCHs, carry DATA + SIGNALLING

(80-90%) (10-20%)

RLGSC: Changing of GPRS cell parameters

CELL=KISTA, Cell name

FPDCH/SPDCH=3, Number of Fixed/Semi-dedicated

PDCHs (max 16)

MPDCH=YES/NO; Allocation of MPDCH in the cell

Control Parameters

NETWORK OPERATION MODES

BSC

MSC

SGSN

Gs

ACTIVE DATA

TRANSFER

CS PAGING MULTIPLEXED

WITH USER DATA

PCH

MS LISTENS

ONLY TO PCHCS PAGING

PS PAGING

-COMBINED RA&LA UPDATE

-COMBINED GPRS/IMSI ATTACH

-PAGING COORDINATION

NOM I no MPDCH

BSC

MSC

SGSN

Gs

ACTIVE DATA

TRANSFER

CS PAGING MULTIPLEXED

WITH USER DATA

PPCH

MS LISTENS

ONLY TO PPCH

NOM I, MPDCH exists

PCH

PCH FOR NON GPRS MSs

BSC

MSC

SGSNPCH

MS LISTENS

ONLY TO PCH

-NO PAGING COORDINATION WITH DATA TRANSFER

NOM II (no MPDCH)

NO Gs

BSC

MSC

SGSN

PPCH

MS LISTENS TO PCH

AND PPCH

-NO PAGING COORDINATION WITH DATA TRANSFER

NOM III (MPDCH exists)

NO Gs

PCH

parameter GPRSNWMODE=0

GPRSNWMODE=1

GPRSNWMODE=2

GPRSNWMODE=3

DUAL TRANSFER MODEMS Classes

A

B

C

DTM (simplified A)

0 1 2 3 4 5 6 7

GSM and GPRS channel allocation must be coordinated.

(GPRS channel administration is responsible for this).

PAGING

BSC is responsible for paging coordination.

BSC

MSC

SGSN

NO Gs

DATA TRANSFER

CS PAGING

PS PAGING

FACCH

RA/LA UPDATE

BSC is responsible for paging coordination.

MS must support DTM. However, paging coordination

works for all MSs (session must be suspended)

BSC

MSC

SGSN

LA UPDATESDCCH

RA UPDATE

TUNNELED

Setting Network Operation Mode

RAEPC: Changing exchange properties

(many different properties are changed with this command)

PROP=GPRSNWMODE–1; Choosing appropriate NOM

Control Parameters

Activation of Dual Transfer Mode in the cell

RLDUI: Initiation of DTM

CELL=KISTA, Cell name

0 1 2 3 4 5 6 7

Primary PDCH Set (PSET) limit

PRIMPLIM

B

Primary PSET

PRIMLIM = 4PRIMPLIM = 1

MPDCH = 1

M

RLGSC command

Changing PBCH configuration

RLPDC: GPRS Packet Control Channel Data, Change

MAXSBLK = 1-4, Maximum number of PBCCH radio blocks to be used within a multiframe.

MAXSMSG = 1-16, Preferred maximum number of Packet System Information messages per PBCCH radio block.

TRAFBLK = 0-10; Number of traffic radio blocks on MPDCH TS

Control Parameters

(12 - MAXSBLK - TRAFBLK ) >= 1 At least 1 block required for paging

TBF is unidirectional (independent control of UL and DL radio resources)• 1MS → 1 UL (↑) TBF• 1MS → 1 DL (↓) TBF• 1MS → 1 UL (↑) TBF + 1 DL (↓) TBF

DL

UL

More than 1 MS per single PDCH

More than 1 PDCH per single MS (but only one TBF)

DL TransferTFI (Temporary Flow Identity) – TBF ID (VALUES 0-31)

DL

TFI=3

TS=3&4

TFI=1

TS=4&5

TFI=7

TS=6&7

TFI=1

OK (my TFI, process)DISCARD (not my TFI)

MSs listen to all PDCHs allocated to them. Moreover they read

all radio blocks. However, only radio blocks allocated to them

(proper TFI) are processed.

Without QoS resources are divided evenly among all MSs.

(MSs and will use TS4 alternately.

0 1 2 3 4 5 6 7

0 1 2 3 4 5 6 7

0 1 2 3 4 5 6 7

UL TransferUSF (Uplink State/Status Flag) – (VALUES 0-7)• transmitted downlink• designates the MS that is allowed to transmit in UL direction on the particular TS

DL

UL

0 1 2 3 4 5 6 7

0 1 2 3 4 5 6 7

31USF

54TS

41USF

65TS

32USF

76TS

5USF

7TS

USF=1

1

2

USF=1

content addressed for

USF=4 USF=5

[Hint] Parameter TBF Granularity enables transmission of more UL Radio Blocks upon reception of proper TFI (TBF Granularity =4 → 4 Radio Blocks may be transmitted)

PCU CAPACITYMaximum number of RPP: 64 book, now 128.

• Maximum number of Cells: 512.

• Maximum number of PDCHs: 4096.

RPP Limitations

• Maximum number of PDCHs: 150 software limitation (6 DSP*25 PDCHs)• Maximum number of PDCHs: 64 hardware limitation for CS3&4, EDGE (64 Devices)

DSP#1

DSP#2

DSP#3

DSP#4

DSP#5

DSP#6

DSP#7

DSP#8

Can work only towards Gb

0 1 2

32 33 34

29 30 31

61 62 63

GS

RTGPHDV-0&&-31

RTGPHDV-32&&-63

1 RTGPHDV = 4 Logical PDCHs for CS1&2

1 RTGPHDV = 1 Logical PDCHs for CS3&4 and EDGE

0 1 2 3 4 5 6 7

Packet Data Channels (PDCHs)RADIO

LPDCH~PDCH

64 kb/s

0 1 2 3 4 5 6 7

BSC/TRC

Um A-bis

0 1 2 3 4 3031

…

GPRS

CS 1&2

speech

0 1 2 3 4

…

CS 1-4

EDGE

5 3031

Abis Capacity

Definition of required number of PDCH

RLBDC: Changing configuration of BPDCHCELL=KISTA, Cell name

CHGR=0-15, Channel Group number

NUMREQBPC=8-128, Number of required BPCs, if not given all TSs are GPRS capable

NUMREQCS3CS4BPC=0-128 Number of required GPRS CS-3 or CS-4 BPCs

NUMREQEGPRSBPC=0-128, Number of required EGPRS BPCs

TN7BCCH=GPRS/EGPRS; This parameter indicates if Timeslot Number (TN) 7 on the BCCH frequency can be configured with Traffic Channels (TCHs) supporting EGPRS or GPRS only.

Control Parameters


RXMOI: Definition of Managed Object

ABISALLOC = FIXED, Abis configurationFLEXIBLE

RLGSC: General Packet Radio Service, Change

FLEXHIGHGPRS = 0, How to access Abis resources for MSs

1 not capable of EGPRS using E-PDCHs.

Control Parameters


RLGSC: CELL=KISTA,

0 All on-demand PDCHs are possible to preempt 1 On-demand PDCHs not used for Dual Transfer Mode(DTM)

are possible to preempt 2 On-demand PDCHs not used for Streaming are possible to...

3 On-demand PDCHs not used for DTM nor for Streaming are…

PDCHPREEMPT= 4 ; On-demand PDCHs that are not essential are…

5 On-demand PDCHs that are not essential nor DTM PDCHs …6 On-demand PDCHs that are not essential nor Streaming

PDCHs are possible to preempt7 On-demand PDCHs that are not essential nor DTM nor

Streaming … 8 Idle on-demand PDCHs are possible to preempt

Control Parameters

Background

?

Interactive

(Round Trip Time) RTT ↓

(Traffic Handling Priority) THP = 1 (high priority), 2, 3 (low priority)

Streaming

asymmetrical

(only DL is important)

GBR ↑ ~ (MAY VARY)

AV_BR

DEL ↓ ~

AV_DEL

Conversational

symmetrical

(Guaranteed Bitrate) GBR ↑ (HIGH & STEADY)

(Delay) DEL ↓ (LOW & STEADY)20 sBUFFER

Similiar to CS

MBR(max bitrate)

Not implemented in GERAN

V (OPTION)

V (OPTION) (BASIC)

VoIPoGPRS STREAMING

WWW, WAP, CHAT

E-MAIL, FTP

Quality of Service

QoS IMPLEMENTATION

STREAMING

GBR

BPDCH BR or GPDCH BR or EPDCH BRCS 1&2 CS 1-4 CS 1-4,

MCS 1-9

= # TS

BR WE CAN EXPECT FROM 1 TS

AV 50%

0 1 2 3 4 5 6 7

TSs FOR STREAMING

ONLY 1 STREAMING TBF PER PDCH

STREAMING

STREAMING

INTERACTIVE

# OF SAMPLES

BR8K

50%

2 TSs for 16 K

6K

95%

3 TSs/16 K

PRIORITY:

1. Signalling

2. Streaming media

3. Streaming Ericsson Instant Talk

4. Interactive

5. Background

INTERACTIVE

STREAMING INTER. THP 1 INTER. THP 2 INTER. THP 3 BACKGROUND

TS

SELECED BY LOT

Definition of Power Control Parameters

RLGSC: Definition of GAMMA

CELL=KISTA,

GAMMA = 0 – 62 [dB] only even

RAEPC: Definition of ALPHA

CELL=KISTA,

PROP = ALPHA – 0-10 2~0.2

Control Parameters

BSC SGSN

2

1

CELL CHANGE DOWNLINK

Cell change

Uplink resources

are allocated for

acknowledgement

New

packetsNot confirmed

Packets

9

Buffers for old cell

BCCH

4

3

5RACH

6

AGCH

7

LLC –TLLI ~ P-TMSI

7

LLC frame + Cell ID

(BVCI, not CGI)

FLUSH 8

Move data

to new buffers

10

[Hint] If MS moves to new BSC, data is deleted from the old buffers and higher layers protocols (TCP) performsretransmissions. Up to R11 subscriber is charged for this data. In R12 CDRs are modified and „minus”quantity may occur.

Definition of Cell Reselection Parameters

RLSBC: Definition of GAMMA

CELL=KISTA,

CRO = 0,1,2, … ,63 (corresponding to 0,2,4, … ,126 [dB])

PT = 0,1,2, … ,30 (corresponding to 20,40,60, … ,620 s)31 (temporary offset is ignored and the sign of

cell reselect offset is changed)TO = 0,1,, … ,6,7 (corresponding to 0,10, … ,60, infinite [dB])

Control Parameters

BSC SGSN

2

1

CELL CHANGE DOWNLINK

Cell change

Uplink resources

are allocated for

acknowledgement

New


Packets

9

Buffers for old cell

BCCH

4

3

5RACH

6

AGCH

7


7

LLC frame + Cell ID

(BVCI, not CGI)

FLUSH 8

Move data

to new buffers

10

[Hint] If MS moves to new BSC, data is deleted from the old buffers and higher layers protocols (TCP) performsretransmissions. Up to R11 subscriber is charged for this data. In R12 CDRs are modified and „minus”quantity may occur.

BSC SGSN

2

NETWORK ASSISTED CELL CHANGE

Uplink resources

are allocated for

acknowledgement

New


Packets

6RACH

7

AGCH

8


[Hint] In R.11 working only for INTRA BSC CELL CHANGEIn R.12 working also for INTER BSC CELL CHANGEIn R.06 working also for INTER SYSTEM CELL CHANGE

Cell change

notification

message

1

Network increases

throughput taking

resources from other

MSs to finish LLC

frame

3Cell Change Notification

(Don’t send any info)

Empty buffers

4

System info about the

new cell concluded with

<CELL CHANGE ORDER>

„you can go”

5

8

9

[Hint] Network controlled CC. System behaves similarly to CS HO. In R.06 available only for GSM-UMTS CC.Implemented by Alcatel.

Activation of Network Control Mode 2 in a cell

RLNMI: Activation of NCM2 in a cell

CELL=KISTA;

Changing of reporting period for NMC 2

RLNMC: Modification of NCM2 in a cell

CELL=KISTA;

0 - 0.48 seconds

1 - 0.96 seconds

2 - 1.92 seconds

CELL=KISTA; 3 - 3.84 seconds

4 - 7.68 seconds

5 - 15.36 seconds

6 - 30.72 seconds

7 - 61.44 seconds

Control Parameters

RAEPC command

GPRS Extended Dynamic Allocation activation (more UL TCHs)

PROP=GPRSEDAACT 0 not active1 active

GPRS Neutral UL/DL State Handling activation

PROP=GPRSNEUTRALACT 0 not active1 active

Dynamic Uplink (UL) and DL Resource Handling activation

PROP=DYNULDLACT 0 not active1 active

Control Parameters

requires

requires

Counter examples (per Cell)

� User sending data in Background Class

� Capable of EDGE

� Downloading the data

� Total LLC data volume of GMM/SM signaling transferred

� 100 kbit with 20 kbit/s + 200 kbit with 30 kbit/s

DLBGEGTHR = 100*20+200*30 = 2000 + 6000 = 8000 kbit2/s

DLBGEGDATA = 100 + 200 = 300 kbit

error in the previous slide

kbit/s 26,7kbit 300

/skbit 8000 Throughput WeightedIP

2

==

KPI: IP buffer discardsCounters (per Cell)

� IP Discards due to no available PDCH:s or no TFI

LDISTFI

� IP Discards due to Radio Contact Lost (T3195=5 sec.)

LDISRR

� IP Discards due to Other Reasons

LDISOTH

� IP Discards due to RAU (Routing Area Update)

FLUDISC

Counters (per Cell)

� ACCEGEXTIPLAT IP Latency measured for EGPRS capable and Extended UL MSs. Units: ms

EGEXTIPLAT – accumulator

� ACCEGNOEXTIPLAT IP Latency measured for EGPRS capable and not Extended UL capable MSs. Units: ms

EGNOEXTIPLAT – accumulator

� ACCGEXTIPLAT IP Latency measured for GPRS capable and Extended UL MSs. Units: ms

GEXTIPLAT – accumulator

� ACCGNOEXTIPLAT IP Latency measured for GPRS capable and not Extended UL capable MSs. Units: ms

GNOEXTIPLAT – accumulator

Counters (per Cell)

� INT8BRGPRSTBF Volume of RLC data successfully received by the MS in TBFs with a radio link bit rate in the 8 kbps (X < 9 ) interval for CS-1/2/3/4, RLC acknowledged mode TBFs.

INT10BRGPRSTBF (9 < X < 11)




INT18BRGPRSTBF (X > 17 )

Counters (per Cell)

� INT10BREGPRSTBF Volume of RLC data successfully received by the MS in TBFs with a radio link bit rate in the 10 kbps interval (X < 12.5) for EGPRS, RLC acknowledged mode TBFs.

INT15BREGPRSTBF (17,5 < X < 22,5)








INT55BREGPRSTBF (X > 52,5)

PCU Limitations

• Maximum number of RPP: 64 book, now 128.

• Maximum number of Cells: 512.• Maximum number of PDCHs: 4096.

RPP Limitations

• Maximum number of PDCHs: 150 software limitation (6 DSP*25 PDCHs)• Maximum number of PDCHs: 64 hardware limitation for CS3&4, EDGE (64 Devices)

DSP#1

DSP#2

DSP#3

DSP#4

DSP#5

DSP#6

DSP#7

DSP#8

Can work only towards Gb

0 1 2

32 33 34

29 30 31

61 62 63

GS

RTGPHDV-0&&-31

RTGPHDV-32&&-63

1 RTGPHDV = 4 Logical PDCHs for CS1&2

1 RTGPHDV = 1 Logical PDCHs for CS3&4 and EDGE

0 1 2 3 4 5 6 7

Packet Data Channels (PDCHs)RADIO

LPDCH~PDCH

64 kb/s

handout

Documents

higher layers

extended ul

packet data

active active

uplink resources

required number

proper tfi

control parametersdefinition