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Faruk Hadziomerovic: Wireless Communications and Services, SSST Fall 2009 1 Wireless Communications • GSM • GPRS • UMTS • CDMA 2000 • WiFi References: http://www.privateline.com/PCS/GSM05.html http://www.trillium.com/products/trillium/wireless.html GPRS Cisco White Paper UMTS Forum White Paper 2005
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Page 1: Faruk Hadziomerovic: Wireless Communications and Services, SSST Fall 2009 1 Wireless Communications GSM GPRS UMTS CDMA 2000 WiFi References: .

Faruk Hadziomerovic: Wireless Communications and Services, SSST Fall 2009 1

Wireless Communications

• GSM

• GPRS

• UMTS

• CDMA 2000

• WiFi

References: http://www.privateline.com/PCS/GSM05.htmlhttp://www.trillium.com/products/trillium/wireless.htmlGPRS Cisco White PaperUMTS Forum White Paper 2005

Page 2: Faruk Hadziomerovic: Wireless Communications and Services, SSST Fall 2009 1 Wireless Communications GSM GPRS UMTS CDMA 2000 WiFi References: .

Faruk Hadziomerovic: Wireless Communications and Services, SSST Fall 2009 2

Wireless Migration Path

TACS

NMT(900)

GSM(900)

AMPS

SMR

1G

GSM(1800)

GSM(1900)

IS-136(1900)

IS-95(1900)

GPRS WCDMA

GPRS

EDGE

IS-136(800)

IS-95(800)

iDEN(800)

2G

CDMA20001X

CDMA20003X

2.5G 3G

192 kbps

384 kbps

200 kbps

2 Mbps

2 Mbps

TACS – Total Access Communication SystemNMT – Nordic Mobile TelephoneSMR – Specialized Mobile radioiDEN – Integrated Dispatch Enhanced Network (Motorola)EDGE – Enhanced Data Rates for Global Evolution

Page 3: Faruk Hadziomerovic: Wireless Communications and Services, SSST Fall 2009 1 Wireless Communications GSM GPRS UMTS CDMA 2000 WiFi References: .

Faruk Hadziomerovic: Wireless Communications and Services, SSST Fall 2009 3

2G spectrum allocationD-AMPS/TDMA

IS-54/136 (800)

GSM

(850)

GSM-EU

(900)

EGSM-EU

(900)

GSM-EU (1800)

Year 1983/1991 1983 1991 1992 1992

Base Tx MHz 869-894 869-894 935-960 925-934.8 1805-1880

Base Rx MHz 824-849 824-849 890-915 870-889.8 1710-1785

Spectr. allocat. 25 MHz 25 MHz 25 MHz 9.8 MHz 150 MHz

Radio Channel 30 kHz 200 kHz 200 kHz 200 kHz 200 kHz

No of carriers 832 125 125 49 375

channel/carrier 3 (6) 8 8 8 8

Modulation 4DPSK1 0.3GMSK2 0.3GMSK 0.3GMSK 0.3GMSK

CODEC A/VCELP3 RELP4/

ACELP

RELP/

ACELP

RELP/

ACELP

RELP/

ACELP

1DMSK – Differential Phase Shift Keying, 2GMSK – Gaussian Maximum Shift Keying, 3CELP – Code Excited Linear Prediction, A – Algebraic, V – Vector (8 kbps), 4RELP – Residual ELP (13 kbps). Tanenbaum page 687: G723.1 – 5.3 to 6.4 kbps.

Page 4: Faruk Hadziomerovic: Wireless Communications and Services, SSST Fall 2009 1 Wireless Communications GSM GPRS UMTS CDMA 2000 WiFi References: .

Faruk Hadziomerovic: Wireless Communications and Services, SSST Fall 2009 4

3G spectrum allocation

GSM-US(1900)1

CDMAIS-951

CDMA2000

1X

WCDMA

IS-661

Year 2003 1993 2000 2003

Base Tx MHz 1930-1990 869-894 1930-1990 2110-2170

Base Rx MHz 1850-1910 824-849 1850-1910 1920-1980

Spectr. allocat. 60 MHz 50 MHz 120 MHz 120 MHz

Radio Channel 200 kHz 1.25 MHz 1.25 MHz 5 MHz

No of carriers 300 20 48 15*12 = 180

channel/carrier 8 64 64 64

Modulation 0.3GMSK QPSK2 QPSK

CODEC RELP/

ACELP

CELP3 CELP

12G2QPSK – Quadrature Phase Shift Keying.3CELP – Code Excited Linear Prediction,

Page 5: Faruk Hadziomerovic: Wireless Communications and Services, SSST Fall 2009 1 Wireless Communications GSM GPRS UMTS CDMA 2000 WiFi References: .

Faruk Hadziomerovic: Wireless Communications and Services, SSST Fall 2009 5

Spectrum Frequency Chart

Page 6: Faruk Hadziomerovic: Wireless Communications and Services, SSST Fall 2009 1 Wireless Communications GSM GPRS UMTS CDMA 2000 WiFi References: .

Faruk Hadziomerovic: Wireless Communications and Services, SSST Fall 2009 6

GSM Spectrum

ARFCN – Absolute Radio Frequency Channel Number.Offset between downlink and uplink

Page 7: Faruk Hadziomerovic: Wireless Communications and Services, SSST Fall 2009 1 Wireless Communications GSM GPRS UMTS CDMA 2000 WiFi References: .

Faruk Hadziomerovic: Wireless Communications and Services, SSST Fall 2009 7

Offset

Page 8: Faruk Hadziomerovic: Wireless Communications and Services, SSST Fall 2009 1 Wireless Communications GSM GPRS UMTS CDMA 2000 WiFi References: .

Faruk Hadziomerovic: Wireless Communications and Services, SSST Fall 2009 8

Coverage – Frequency Reuse

Carrier/Interference = 17 dBFor N (reuse pattern) = 7, d/r = 4.6MSC – Mobile Service/Switching Center

G

F

ED

C

B

A

D

r

d

MSC1

MSC2

Page 9: Faruk Hadziomerovic: Wireless Communications and Services, SSST Fall 2009 1 Wireless Communications GSM GPRS UMTS CDMA 2000 WiFi References: .

Faruk Hadziomerovic: Wireless Communications and Services, SSST Fall 2009 9

GSM (2G) Standard Reference Model

AuC - Authentication CenterBSC - Base Stations ControllerBTS – Base Transceiver Station (50–100 BTS)EIR – Equipment Identity RegisterGMSC - Gateway Mobile Service CenterHLR – Home Location Register (one per ntwk)VLR – Visitor Location Register

MT – Mobile Terminal ME - Mobile Equipment (IMEI – International Mobile Equipment Identity) + SIM (Subscriber Identity Card containing IMSI – International Mobile Subscriber Identity)SMSC - Short Message Service CenterPSTN - Public Switching Telephone NetworkTRAU – Transcoding and Rate Adaptation Unit

BSC

BTS

BTS

AbisMSC/VLRA GMSCE

VLR

B

D

SS7 signalingSS7 signaling + trunks

PSTN

C

HLR

AuCSMSC

Um

MT

TRAUoptionalAter

EIRF

Page 10: Faruk Hadziomerovic: Wireless Communications and Services, SSST Fall 2009 1 Wireless Communications GSM GPRS UMTS CDMA 2000 WiFi References: .

Faruk Hadziomerovic: Wireless Communications and Services, SSST Fall 2009 10

Location update

A B

distance

Registration (passive), Handover (active)

Page 11: Faruk Hadziomerovic: Wireless Communications and Services, SSST Fall 2009 1 Wireless Communications GSM GPRS UMTS CDMA 2000 WiFi References: .

Faruk Hadziomerovic: Wireless Communications and Services, SSST Fall 2009 11

MS*

EIR

GMSC

Um

BTS1

BSC1

MSC1

A

E

C

PSTN

VLR1

Abis

F

HLRAuC

SMSC

MSC2 VLR2

G

D

BTS2

BSC2

A

Abis

Um

B B

Public Land Mobile Network (PLMN)

*Mobile Station = MT + ME

Page 12: Faruk Hadziomerovic: Wireless Communications and Services, SSST Fall 2009 1 Wireless Communications GSM GPRS UMTS CDMA 2000 WiFi References: .

Faruk Hadziomerovic: Wireless Communications and Services, SSST Fall 2009 12

GSM Location Update (Registration)MS

PreviousMSC1/VLRGMSC/HLR/AuCNew

MSC2/VLRBSS2*

Channel Request

Channel Assigned

Loc Update Request

Authentication Info

Loc. info UpdateSend Auth. Info

Authentication Challenge

Authentication ResponseUpdate Location

Cancel Location

Cancel Location AckInsert Subscr. Data

Location Update Accept

Clear Channel

Subscr. Data Ack

Update Location Ack

Channel ReleasedClear Complete

*BSS = BTS + BSC

Page 13: Faruk Hadziomerovic: Wireless Communications and Services, SSST Fall 2009 1 Wireless Communications GSM GPRS UMTS CDMA 2000 WiFi References: .

Faruk Hadziomerovic: Wireless Communications and Services, SSST Fall 2009 13

GSM Standard Reference Model (2)

SignalingGSM signaling + voice

MT

EIR

GMSC

Um

BTS BSC

MSC

A

EC

D

PSTN

VLR

Abis

TE

R

F

HLRAuC

SMSC

BTS: radio station that talks to mobiles.BSC: allocate channels and other resources.HLR: IMSI, last location area, class of service.VLR: IMSI, class of service.AuC: secret key (the same as in SIM card).EIR: IMEI if reported stolen marked invalid.SMSC: Short Message Service data base.

Radio Resource Management: BSC radio/fixedchannels/slots Allocation during call setup, and handoffs.Mobility management: HLR/VLR – registration, inter MSC handoffs, authenticationConnection Management: MSC + supplementary services and Short Message Service.

All Interfaces are SS7 protocol based

Page 14: Faruk Hadziomerovic: Wireless Communications and Services, SSST Fall 2009 1 Wireless Communications GSM GPRS UMTS CDMA 2000 WiFi References: .

Faruk Hadziomerovic: Wireless Communications and Services, SSST Fall 2009 14

GPRS: GSM Packet Radio Service (2.5G)

BSC – splits voice and data traffic)GGSN - Gateway GPRS Support Node SGSN - Serving GPRS Support Node (protocol converter and router)Signaling

Signaling + data

GSM signaling + voice

PDN TEMT SGSN

EIR

GMSC

Um

Gn

Gb

Gs

Gr

Gi

Gc

Gd

Gp

Gf

other PLMN

SGSN

BTS BSC

MSC

A

EC

D

PSTN

VLR

Abis

TE

R

F

HLRAuC

SGSN

Gn

GGSN

SMSC

PDN - Packet Data Network (Internet)PLMN - Public Land Mobile NetworkPSTN – Public Switching Telephone Network

Page 15: Faruk Hadziomerovic: Wireless Communications and Services, SSST Fall 2009 1 Wireless Communications GSM GPRS UMTS CDMA 2000 WiFi References: .

Faruk Hadziomerovic: Wireless Communications and Services, SSST Fall 2009 15

UMTS (3G)

RNCUE NodeB

PDN TEMT SGSN GGSN

EIR

GMSC

Um

Gn

Gb

GsGr

Gi

Gc

Gd

Gp

Gf

IuPS

other PLMN

SGSNUE - User Equipment Node B - Logical node for radio T/R. (equivalent to BTS).RNC - Radio Network Controller (equivalent to BSC).

BTS BSC

Signaling

Signaling + data

MSC

A

EC

D

GSM signaling + voice

PSTN

VLR

Uu Iubis

Abis

TE

R

IuCS

F

SMSC

HLRAuC

(BTS)

Page 16: Faruk Hadziomerovic: Wireless Communications and Services, SSST Fall 2009 1 Wireless Communications GSM GPRS UMTS CDMA 2000 WiFi References: .

Faruk Hadziomerovic: Wireless Communications and Services, SSST Fall 2009 16

GSM Air Interface Um

T T T T T T T T T T T T A T T T T T T T T T T T T -

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

One multiframe = 26 frames = 120 msec

0* 1 2 3 4 5 6 7

1 frame = 8 slots = 4.62 ms

3tailbits

T - Traffic Channel (TCH)A - Slow Associated Control Channel (SACCH)

57 message/data bits

57 message/data bits

26 trainingSequence bits

8.25 gua-rd bits

1

Stealing bitsFor FACCH

1156.25 bits/0.577 msec = 270.797 kbps140 useful bits.

3tailbits

*If only one carrier per cell this slot is shared by: BCCH, CCCH, and SDCCH.If more then one carrier this slot is shared by BCCH and CCCH and next slot Carries SDCCH.

TCH for uplink and downlink are separated by 3 burst periods so that MS does not have to transmit and receive simultaneously.

Page 17: Faruk Hadziomerovic: Wireless Communications and Services, SSST Fall 2009 1 Wireless Communications GSM GPRS UMTS CDMA 2000 WiFi References: .

Faruk Hadziomerovic: Wireless Communications and Services, SSST Fall 2009 17

GPRS CCHs

RACHRandom Access Ch.

PRACHPacket Random Access Ch.

Uplink

CCCHCommon Control Ch.

PCHPaging Ch.

AGCHAccess Grant Ch.

NCHNotification Ch.

Downlink

PCCCHCommon Control Ch.

PPCHPaging Ch.

PAGCHAccess Grant Ch.

PNCHNotification Ch.

voice

packet

BCCH Broadcast Control Channel

PBCCH Packet Broadcast Control Channel

BCCH – general info regarding BTS and network and of the CCCH configuration.CCCH – Common Control Channel

Random Access use Slotted Aloha

Page 18: Faruk Hadziomerovic: Wireless Communications and Services, SSST Fall 2009 1 Wireless Communications GSM GPRS UMTS CDMA 2000 WiFi References: .

Faruk Hadziomerovic: Wireless Communications and Services, SSST Fall 2009 18

GPRS TCH and Associated CCHs

FACCH/F(H)Fast Associated Control Ch.

E-FACCH/FEnhanced Fast Associated Control Ch.

SACCH/F(H)Slow Associated Control Ch.

TCHTraffic Ch.

stand-alone 4(8) slots

Voice Traffic Channel F(H) Full(Half) Rate

SDCCH/4(8)Stand-alone Dedicated Control Ch.

SACCH/MSlow Associated Control Ch. for Multislot configur.

SACCH/C4(C8)Slow SDCCH/4(8) Associated Control Ch.

SACCH/CTSSlow Associated Control Ch. for CTS

PACCH Packet Associated Control Ch.PTCCH Packet timing Advance Control Ch.

Packet Traffic Channel

SDCCH – used prior to call for SMS or signaling.SACCH – used when MS in on call to signal power strength in preparation for handoff and SMS.FACCH – used when MS on call for non-voice info like supplementary services and control

Page 19: Faruk Hadziomerovic: Wireless Communications and Services, SSST Fall 2009 1 Wireless Communications GSM GPRS UMTS CDMA 2000 WiFi References: .

Faruk Hadziomerovic: Wireless Communications and Services, SSST Fall 2009 19

Burst Structure

3tailbits

57 message/data bits

57 message/data bits

26 trainingsequence bits

8.25 guard bits1

Stealing bits for FACCH

1 3tailbits

Training bits are for equalization. Radio waves bounce of everything. Which one to use is determined by training sequence bits. It keeps MS in phase with BTS.

Normal Burst

3tailbits 142 “0” bits (empty frame) 8.25 guard bits3tail

bits

FCB Frequency Control Burst

3tailbits

8.25 guard bits3tailbits

SCB Synchronous Control Burst38 message ortraining bits

1 138 message ortraining bits

64 extended trainingsequence bits

8 tail bits 8.25 guard bits

Access Control Burst

44 synchronization bits 60 guard bits36 encryption bits

Voice coders (Vocoders) full-rate 13 kbps, half-rate 7 kbps.

Page 20: Faruk Hadziomerovic: Wireless Communications and Services, SSST Fall 2009 1 Wireless Communications GSM GPRS UMTS CDMA 2000 WiFi References: .

Faruk Hadziomerovic: Wireless Communications and Services, SSST Fall 2009 20

GPRS Interfaces

Application

IP/X.25

SNDCP

LLC

RLC

MAC

GSM RF

RLC BSSGP

MAC Ntwk

GSM RF L1bis

Um Gb

relay

SNDCP GTP

LLCTCP/

UDP

BSSGP IP

Ntwk L2

L1bis L1

relay

Gn

IP/X.25

GTP

TCP/

UDP

IP

L2

L1

Gi

SNDCP – Sub-Network Dependent Convergence Protocol.Maps networks layer protocol like IP/X.25 into underlying LLCBSSGP – Base Station GPRS Protocol. Processes routing and QoS for BSS.LLC – Link Layer Control (LAPD).GTP – GPRS Tunnel Protocol

MS BSSSGSN

GGSN

Page 21: Faruk Hadziomerovic: Wireless Communications and Services, SSST Fall 2009 1 Wireless Communications GSM GPRS UMTS CDMA 2000 WiFi References: .

Faruk Hadziomerovic: Wireless Communications and Services, SSST Fall 2009 21

GPRS Location Update - Attach

MSPrevious

SGSN/VLRHLR/AuCNew

SGSN/VLRBSS

Packet Channel Req.

Channel Assigned

Attach Request

Authentication Info

Send Auth. Info

Authentication Challenge

Authentication ResponseUpdate GPRS Loc Cancel Location

Cancel Location RRInsert Subscr. Data

Attach Accept

Ack

Subscr. Data RR

Update GPRS Loc RR

Attach Complete

Attach Request

Packet Channel Req.

Channel Assigned

Packet Channel Req.

Channel Assigned

Attach Complete

Page 22: Faruk Hadziomerovic: Wireless Communications and Services, SSST Fall 2009 1 Wireless Communications GSM GPRS UMTS CDMA 2000 WiFi References: .

Faruk Hadziomerovic: Wireless Communications and Services, SSST Fall 2009 22

PDP Context (IP address allocation)

MS InternetGGSNSGSNBSS

Activate PDP Context

Autentication Request

PDP Context Req.

SNDCP PDU

GTP PDUTCP/IP PDU

Autentication Response

PDP Context Resp.PDP Context Accept

TCP/IP PDUGTP PDU

SNDCP PDU

Page 23: Faruk Hadziomerovic: Wireless Communications and Services, SSST Fall 2009 1 Wireless Communications GSM GPRS UMTS CDMA 2000 WiFi References: .

Faruk Hadziomerovic: Wireless Communications and Services, SSST Fall 2009 23

CDMA concept

1 1 1 1

-1 -1 -1 -1

1 1 1 1

-1 -1 -1 -1

d1o=1

d11=-1Data bits

Chips

Senders

1 1 1 1 1 1

-1 -1

d2o=1d2

1=1

1 1 1 1 1 1

-1 -1

Data bits

Chips

Zi,1

m = di1cm

1

Zi,2

m = di2cm

2

2 2 2 2 2 2

-2 -2

1 1 1 1

-1 -1 -1 -1

1 1 1 1

Channel Zi,*m

d1o=1

d11=-1

d1i = (m Zi,

*mc1

m)/M -1 -1 -1 -1

1 1 1 1 1 1

-1 -1

1 1 1 1 1 1

-1 -1

d2i = (m Zi,

*mc2

m)/M

d2o=1d2

1=1

Chip rate Spreading factor = chip_rate/data_rate.dB = 10 log( spreading rate/data rate )has the same effect as dB (signal/noise).

Page 24: Faruk Hadziomerovic: Wireless Communications and Services, SSST Fall 2009 1 Wireless Communications GSM GPRS UMTS CDMA 2000 WiFi References: .

Faruk Hadziomerovic: Wireless Communications and Services, SSST Fall 2009 24

UMTS W-CDMA (Wideband CDMA)

5 10 15 etc. MHzCDMA channels 5 MHz each

15 TDD slots/frame

etc.

2,000 mks

1,333 mks

667 mks

EUUplink: 1920 - 1980 MHzDownlink: 2110 - 2170 MHz12 Channels * 15 slots = 180 channelsEach channel can be used as up-link and down-link.This enables asymmetric slot allocation.

Page 25: Faruk Hadziomerovic: Wireless Communications and Services, SSST Fall 2009 1 Wireless Communications GSM GPRS UMTS CDMA 2000 WiFi References: .

Faruk Hadziomerovic: Wireless Communications and Services, SSST Fall 2009 25

W-CDMA Frame Format

0 1 2 3 4 5 6 7 8 9 10 11 12 60 61 62 63 64 65 66 67 68 69 70 71

One superframe = 72 frames = 720 msec

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14

1 frame = 15 slots = 10 ms

1 slot = 2560 chips = 0.667 ms Data or Control: Uplink or Downlink

Page 26: Faruk Hadziomerovic: Wireless Communications and Services, SSST Fall 2009 1 Wireless Communications GSM GPRS UMTS CDMA 2000 WiFi References: .

Faruk Hadziomerovic: Wireless Communications and Services, SSST Fall 2009 26

WCDMA Concept

data sequence (bits/sec)

spreading sequence (chips/sec)

transmit sequence

SF (Spreading Factor) = chip_rate/bit_rate = 2^k.

Chip Rate = 3.84 Mbps

For transmit sequences to be orthogonal it must be:

==> SF (chosen) = 3.84 Mbps/bit_rate.

1

SF=1

1 1

1 1 1 1

1 1-1-1

1-1

1-11-1

1-1-11

SF=2 SF=4

Orthogonal functions with spreading factors

For speech of 12.2 kbps the spreadingfactor = 314.75 or gain = 25 dB. Max spreading factor = 256 with gain 24 dB.Maximum data rate = 960 kbps (gross) = 460 (net) which gives spreading factor = 4 andthe gain of 6 dB.How do we achieve 2 Mbps (net). Using 5 time slots.

Page 27: Faruk Hadziomerovic: Wireless Communications and Services, SSST Fall 2009 1 Wireless Communications GSM GPRS UMTS CDMA 2000 WiFi References: .

Faruk Hadziomerovic: Wireless Communications and Services, SSST Fall 2009 27

Evolution of UMTS Core Network3GPP 1999 (from slide 9)

UMTS Terrestrial Radio Access Network

ME

USIM

UE

Node B

RNC

Iub

Iub

Iur

UTRAN

RNC

Node B

PCMMSC/VLR

Iu-cs

SGSNIu-ps

Gn(GTP/IP)

Core Network

GMSC

HSSAuC

PCM

GGSN

PSTN

Internet

Gi(IP)

HSS – Home Subscriber Server (previous HLR)

signaling

CS (voice)

PS (data)GcGr

CD

GdGs

SMSC

Signaling+ SMS

Page 28: Faruk Hadziomerovic: Wireless Communications and Services, SSST Fall 2009 1 Wireless Communications GSM GPRS UMTS CDMA 2000 WiFi References: .

Faruk Hadziomerovic: Wireless Communications and Services, SSST Fall 2009 28

RTP/IP

3GPP Release 4 March 2004

H248/IP

MGW

Iu-cs(control) IP

MSC/VLRServer

SGSNIu-ps

Iu-cs(bearer)

Gn(GTP/IP)

Core Network

H248/IP

MGW

GMSCServer

HSSAuC

PCM

GGSN

SS7GW

PSTN

Internet

Gi(IP)

HSS – Home Subscriber Server (previous HLR)

Node B

RNC

Iub

Iub

Iur

UTRAN

RNC

Node B

signaling

CS (voice)

PS (data)

Page 29: Faruk Hadziomerovic: Wireless Communications and Services, SSST Fall 2009 1 Wireless Communications GSM GPRS UMTS CDMA 2000 WiFi References: .

Faruk Hadziomerovic: Wireless Communications and Services, SSST Fall 2009 29

3GPP Release 5 June 2004

Node B

Node B

RNC

Iub

Iub

Gr

CxIur

SGSN

Iu-IM

UTRAN Core Network

RNC

CSCF

Gn

HSSAuC

Gi

GGSN PSTN

InternetGi

IM – IP Media domainMGC – Media Gateway ControllerCSCF – Call State Control Function

background

all

Streamline/interactive

MGW

MGCMg

Mc

conversationalSIP proxy

Page 30: Faruk Hadziomerovic: Wireless Communications and Services, SSST Fall 2009 1 Wireless Communications GSM GPRS UMTS CDMA 2000 WiFi References: .

Faruk Hadziomerovic: Wireless Communications and Services, SSST Fall 2009 30

WiFi (Wireless LAN) architecture*

RouterServer

AccessPoint - AP

AccessPoint - AP

WirelessLAN – BSS**

LAN

WirelessLAN

AP polls base stations

about 30 m

*Tanenbaum Chapter 4.4.** Basic Service Set

PCF (Point Cordination Function) or infrastructure mode

Page 31: Faruk Hadziomerovic: Wireless Communications and Services, SSST Fall 2009 1 Wireless Communications GSM GPRS UMTS CDMA 2000 WiFi References: .

Faruk Hadziomerovic: Wireless Communications and Services, SSST Fall 2009 31

WiFi (Wireless LAN) architecture

AB CD

Rangeof A

Rangeof B

1. Hidden station problem: A is transmitting to B. If D senses the channel it will not hear anything and falsely conclude that it may start transmitting to B.

2. Exposed station problem (inverse): A is transmitting to D. B wants to transmit to C however it hears channel busy.

DCF (Distributed Cordination Function) or point-to-point mode

Page 32: Faruk Hadziomerovic: Wireless Communications and Services, SSST Fall 2009 1 Wireless Communications GSM GPRS UMTS CDMA 2000 WiFi References: .

Faruk Hadziomerovic: Wireless Communications and Services, SSST Fall 2009 32

Frequency range and IEEE 802.11

ISM (Industrial, Scientific, Medical) band:– 902 – 928 MHz– 2.4 – 2.4835 GHz– 5.735 – 5.860 GHz

Upper layers

Logical Link Control

DCF PCF

Infrared FHSS DSSS

MAC

physical

DCF – Distributed Coordination FunctionPCF – Point Coordination FunctionFHSS – Frequency Hopping Spread SpectrumDSSS – Direct Sequence Spread Spectrum

Page 33: Faruk Hadziomerovic: Wireless Communications and Services, SSST Fall 2009 1 Wireless Communications GSM GPRS UMTS CDMA 2000 WiFi References: .

Faruk Hadziomerovic: Wireless Communications and Services, SSST Fall 2009 33

DCF MACAW (Multiple Access with Collision Avoidence for Wireless)

Since probability of correct frame is low, MAC layer splits the frame into fragments and creates acknowledgment.

*Network Allocation Vector

Station ARTS Fragm1

Station BCTS

Station C(hidden from B)

NAV*

Ack

Station D(hidden from A)

NAV

Fragm2

Ack

Page 34: Faruk Hadziomerovic: Wireless Communications and Services, SSST Fall 2009 1 Wireless Communications GSM GPRS UMTS CDMA 2000 WiFi References: .

Faruk Hadziomerovic: Wireless Communications and Services, SSST Fall 2009 34

Combo: DCF and PCF

SIFS (Shortest InterFrame Spacing) allows parties already in a dialog to go first letting: sender to send next fragment without repeated RTS, receiver to send ack, receiver to respond to RTS by CTS, etc.

PIFS (PCF InterFrame Spacing) allows Base Station to grab a channel. Base Station (if nothing to send) broadcasts beacon frame every 1 to 10 msec to inform about clock synchronization, polling sequence etc.

DIFS (DCF InterFrame Spacing) any station may attempt to get a channel to start a new frame.

EIFS (Extended InterFrame Spacing) allows receiving station to report a bad frame.

Station BAck

SIFS

PIFS

DIFS

EIFS

Page 35: Faruk Hadziomerovic: Wireless Communications and Services, SSST Fall 2009 1 Wireless Communications GSM GPRS UMTS CDMA 2000 WiFi References: .

Faruk Hadziomerovic: Wireless Communications and Services, SSST Fall 2009 35

802.11 Data Frame, Fig. 4-30

Frame

control

Dur-

ation

Addr1

Addr2 Addr3 Seq Addr4 Data (0-2312) CHK

2 2 6 6 6 2 6 0 – 2312 4 Bytes

OWMorePwrRetryMFFrom

DS

To

DS

Sub-

type

TypeVer-

sion

2 2 4 1 1 1 1 1 1 1 1 bits

Version - protocol version.Type - data, control, or management frame.Subtype - RTS, CTS or Ack.To/From DS - frame is coming from another distribution system (another Ethernet cell).MF - more fragments will follow.Retry - retransmission of a frame sent earlier.Pwr - used by the Base Station to off/on power of the receiver.More - sender has more frames.W - frame body has been encrypted into WEP (Wireless Equivalent Privacy).O - sequence of frames with this bit must be processed strictly in order.

Duration - duration in the channel of this frame and its ack.Addr1 and 2 - source and destination address.Addr3 and 4 - source and destination address within another (inter)cell.Seq - 12 bits are for frame number and 4 for fragment.Data - payload up to 2312 bytes.

Page 36: Faruk Hadziomerovic: Wireless Communications and Services, SSST Fall 2009 1 Wireless Communications GSM GPRS UMTS CDMA 2000 WiFi References: .

Faruk Hadziomerovic: Wireless Communications and Services, SSST Fall 2009 36

• DNS – Domain Name System• Electronic mail

– MIME – Multipurpose Internet Mail Extensions

• World Wide Web

HTML – HyperText Markup Language

XML – eXtesible Markup Language

XHTML – eXtended HyperText Markup Language

Dynamic Web Documents

Internet Applications and Services

Page 37: Faruk Hadziomerovic: Wireless Communications and Services, SSST Fall 2009 1 Wireless Communications GSM GPRS UMTS CDMA 2000 WiFi References: .

Faruk Hadziomerovic: Wireless Communications and Services, SSST Fall 2009 37

Wireless Application and Services

• SMS - Short Message Service– Infrastructure– Protocol layers– Structure of Message Segment– Network Functions for Message Delivery– SMS and Email Delivery

• EMS - Enhanced Messaging Service – Basic EMS– Animation– MIDI – Musical Instruments Digital Interface– Color Animation

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• WAP – Wireless Application Protocol– WAP Protocol Stack– WAP Languages and Design Tool– WAP Traffic Modelling and Performance issues– Wireless Web

Wireless Multimedia Application and Services

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MMS - Multimedia Messaging Service

• MMS Architecture– MMS Environment– MMS Client– MMS Center– Interfaces– WAP realization of MMS– Message sending, retrieval, forwarding,

reports.

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• Transaction Flow– Person-to-Person– Content-to-Person– Message delivery, cancellation, replacement– Delivery Report and Error Handling

MMS - Multimedia Messaging Service

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IMPS - Instant Messaging and Presence Service

• Infrastructure

• Protocols

• Security

• Evolution

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Push-to-Talk

• Architecture

• Standardization

• Service Access

• Performance

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LBS - Location based Services

• LBS server

• Positioning System

• Supplementary Systems

• LBS Clients

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3GPP – Third Generation Partnership Project

History: ETSI (European Telecommunications Standard Institute) SMG (Special Mobile Group) + CEPT (Conference Europeanne des Postes et Telecommunications carried GSM standards for 18 years -> 2000 -> 3GPP.1998 Joint project between 6 standardization bodies from:Europe (ETSI), North America (T1), Korea (TTA – Telecommunication Technology Association), Japan (TTC - Telecommunication Technology Committee and ARIB – Association of Radio Industries and Business), China (CWCS – China Wireless Telecommunications Standard)

Structure:3GPP = PCG (Project Coordination Group) => TSG (Technical Specification Groups) to

create and maintain 3GPP specifications.Objective:

– UMTS technical specification– maintain existing GSM specifications – developing further GSM extensions (like GPRS)

Involved in development of messaging standards:– General service requirements– Architecture– Formats and codecs– Low level technical realizations

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3GPP – Documents

TR – Technical Reports:• Feasibility studies that may become standards.

TS – Technical Specifications:• Define GSM/UMTS standards published

independently by constituents.• Specs are usually frozen for 1 to 1.5 years

between releases (only essential corrections allowed).

• Three stages: – Service description from user’s perspective– Logical analysis -> functional architecture and

information flow– Implementation = technical realizations

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3GPP – Organizational Structure

Project

Coordination Group

(PCG)

TSG CNCore Network

TSG GERANGSM EDGERadio Access

Network

TSG RANRadio Access

Network

TSG SAServices &

System Aspects

TSG TTerminals

CN (Core Network):-WG1 Call Control, Session Management, Mobility Management (Iu)-WG2 CAMEL (Customized Applications for Mobile Network Enhanced Logic)-WG3 Interworking with external networks-WG4 MAP/GTB/BCH/SS-WG5 Open Service Architecture (OSA)

GERAN (GSM EDGE Radio Access network):-WG1 Radio Access-WG2 Protocol aspects-WG3 Base Station Testing and OA&M-WG4 Terminal Testing Radio Aspects-WG5 Terminal Testing Protocol Aspects

RAN (Radio Access Network):-WG1 Radio Layer 1 Spec-WG2 Radio Layer 2 Spec-WG3 Iub, Iur, Iu specs and UTRAN O7M requirement

SA (Service Architecture):-WG1 Services-WG2 Architecture-WG3 Security-WG4 Codec-WG5 Telecom Management

T (Terminals):-WG1 Mobile Terminal Conformance Testing-WG2 MT Services and Capabilities-WG3 Universal Subscriber identity Module

TSG - Technical Specification Groups

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3GPP Milestones

Timeline 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 MMS EMS

Service availability

SMS UMTS GPRS

Network availability

GSM

3GPP R96

3GPP R97

3GPP R98

3GPP Rel.99

3GPP Rel.4

3GPP Rel.5 3GPP

Rel.6 Standardiza-tion milestone

WAP 1.0

WAP 1.2.1

WAP 2.0

OMA MMS 1.1

OMA MMS 1.2

OMA MMS 1.3

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3GPP – Documents

Document number

aa.bbb or aa.bb

3GPP TS 23.040 V5.1.0

Document type:

TS: Techn. Spec

TR: Techn Report

Document version:

x: major version or release

y: technical version

z: editorial version

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3GPP2 Third Generation Partnership Project 2

Joint project between ITU (International Telecommunication Union) and IMT-200 (International Mobile Telecommunications.

Objective:– produce specification for services deployed in North

American and Asian markets for CDMA networks– Adopting 3GPP and OMA interfaces for CDMA.

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GSMA – GSM Association

Global trade organization that represents the interest of several hundreds of GSM mobile operators.

Objective: promoting, protecting, enhancing the interests of GSM operators. It publishes technical recommendations widely endorsed by GSM community.

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IETF – Internet Engineering Task Force

Documents start by RFC (Request For Comments), i.e. RFC 822Stable RFC may fall into Standard Track documents:

* technical specifications (description of protocol, service, procedure, convention, or format.* applicability statements.

1. Proposed standard is registered by IESG (Internet Engeneering Steering Group) and given to public for review.

2. Proposed standard is moved to draft standard if it has at least two implementations.

3. If proposed standard reaches maturity for many implementations it becomes Internet Standard and gets the name:

RFC 822 Standard for the format of ARPA Internet text messages.D. Crocker. Aug-13-1982/Status: STANDARD/STD0011.

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W3C – WWW Consortium created 1994

Development widely accepted protocols and formats for WWW.TS from W3C are known as recommendations.W3C collaborates closely with IETF. Example of documents are:HTML, URI, HTTP, XML, XHTML, SVG, SMIL.W3C are organized into following five domains:• Architecture domain: WWW architecture.• Documents format domain: definition of formats and languages.• Interaction domain: user interactions with WWW.•Technology and Society domain: social and legal issues.•Web Accessibility Initiative: promoting usability for disabled people.

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W3C documents release procedures

Proposed recommendation

Candidaterecommendation

Last callWorking draft

Working draft

Increasing levelof maturity

www.w3c.org

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WAP ForumWAP forum -> 2002 -> Open Mobile Alliance (OMA)

Documents:

• Specification: proposal, draft, etc.

• Change Request: unofficial proposal to change spec. initiated by individuals (forum members).

• Specification Change Documents (SCD): proposed modification of specification released only by specification working group.

• Specification Implementation Note (SIN): an approved modification of previously published spec.

WAP-205-MMSArchOverview-20010425-a

Specification stateA: approvedP: proposedT: prototypeO: obsoleteD: draft

Specification version (date)25/04/2001

Specification registered name

Documentidentifier

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OMA – Open Mobile AllianceEstablished 2002 by about 200 companies to develop interoperable

application enablers, which are bearer agnostic, and independent of

any operating system.

Working groups:• Requirements (REQ); identify cases for services and interoperability

requirements.• Architecture (ARCH): design of overall OMA architecture.• Messaging group (MWG): building application enablers for

messaging services. Sub-working group MMSG is responsible for design of OMA MMS standard

• Mobile Web Services (MWS): responsible for OMA Web Services.


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