8/11/2019 IS-54 dan IS-136

1/29

L O G O

IS-54 and IS-136 Hasbi Nur P.W / 23212019

MATA KULIAH SISTEM KOMUNIKASI NIRKAWAT (ET-5188)

Dosen : Dr. Ir Suhartono Tjondronegoro

8/11/2019 IS-54 dan IS-136

2/29

L O G O

Contents

Introduction of NA-TDMA

1

Frequency Allocations & Bandwidth2

Modulation & Coding3

Capacity4

Propagation Model5

How NA-TDMA works6

8/11/2019 IS-54 dan IS-136

3/29

L O G O

Introduction

NA-TDMA (North America TDMA) ADC (American Digital Celluler)D-AMPS (Digital AMPS)NADC (North American Digital Celluler)USDC (United States Digital Celluler)IS-54 / IS-136

Terminology

8/11/2019 IS-54 dan IS-136

4/29

L O G O

IntroductionIS-54 Network Architecture

VLR : Visitor Location Registration

HLR : Home Location Regstration BS : Base Station AUC : Authentication Center EIR : Equipment Identity Register BSC : Base Station Controller BTS : Base Transceiver Station

8/11/2019 IS-54 dan IS-136

5/29

L O G O

IntroductionIS-136 Network Architecture

8/11/2019 IS-54 dan IS-136

6/29

L O G O

Frequency Allocation & Bandwidth

ReverseChannel

FrequencyChannel

Frequency Allocation

ForwardChannel

Mobile-to-BS BS-to-Mobile

869 894 MHz824 849 MHz Spacing

45 MHz

8/11/2019 IS-54 dan IS-136

7/29

L O G O

1 Digital Channel : 30 kHzContains 25 frame/sEach frame is 40-ms long and has 6 time

slotsOne frame contains 1944 bits (972 symbols)Each slot contains 324 bits (162 symbols)

Frequency Allocation & BandwidthTDMA Channel

8/11/2019 IS-54 dan IS-136

8/29

L O G O

Frequency Allocation & BandwidthTDMA Slot

skb framems frametimeslotstimeslot bits

/6.48/40

/6/324

8/11/2019 IS-54 dan IS-136

9/29

L O G O

Frequency Allocation & BandwidthFrame Structure

Slow AssociatedControl Channel (SACCH)

Digital VerificationColor Code (DVCC)

Reserved for FutureUse (RSVD)

Frame offsetForward frame=reverse frame+(1 time slot+44 symbols)

=reverse frame+206 symbols

8/11/2019 IS-54 dan IS-136

10/29

8/11/2019 IS-54 dan IS-136

11/29

L O G O

Modulation and Coding/4 DQPSK Transimitter

8/11/2019 IS-54 dan IS-136

12/29

L O G O

Modulation and CodingCarrier phase shift corresponding to various input bit pairs

when

8/11/2019 IS-54 dan IS-136

13/29

L O G O

VSELP ( Vector-sum Excited Linier Predictive )

speech coder bit rate : 7950 bpsspeech is broken into frameseach frame is 20-ms (160 symbols)

subframes 40 samples (5 ms)

Modulation and CodingSpeech Coding (full rate)

uses a codebook to vector-quantize the excitation(residual) signalsuch that the computation required for the codebook searchprocess at the sender can be significantly reduced

8/11/2019 IS-54 dan IS-136

14/29

L O G O

Modulation and CodingVSELP Speech Decoder

8/11/2019 IS-54 dan IS-136

15/29

L O G O

Modulation and CodingChannel Coding

159 bits within speech coder frame divided into 2 class77 class-1 bits82 class-2 bits

Rate after channel coding : 13 kbps

8/11/2019 IS-54 dan IS-136

16/29

L O G O

Modulation and CodingBER Performance

BER Performance of /4 DQPSK in slow flat -fading channel corrupted by CCI and AWGNfc= 850 MHz, fs=24 ksps raised-cosine roll-off factor = 0,2, C/I = (1) 20 dB, (2) 30 dB, (3)40 dB (4) 50 dB, (5) infinity

8/11/2019 IS-54 dan IS-136

17/29

L O G O

Modulation and CodingBER Performance

BER Performance vs Eb/No for /4 DQPSK in Rayleigh flat -fading channel forvarious mobile speeds, fc= 850 MHz, fs=24 ksps raised-cosine roll-off factor =0,2, C/I = 100 dB, Generated by BERSIM

8/11/2019 IS-54 dan IS-136

18/29

L O G O

Capacity

Full Rate Speech Coder of 7,95 Kbps/user

Channel Mode (1) Full Rate, (2) Half Rate

Half Rate Speech coder of3,975 Kbps/user

8/11/2019 IS-54 dan IS-136

19/29

L O G O

Carrier Channel Bandwidth

Number of User per channel :

Total number of available channel

Total number of user per channel

Frequency Reuse Factor : 4 or 7- user/cell = 2500/4 = 625 user/cell- user/cell = 2500/7 = 357 user/cell

CapacityCapacity Calculation

8/11/2019 IS-54 dan IS-136

20/29

L O G O

CapacityCapacity Comparison of AMPS with Digital TDMA Based Cellular Systm

Parameter AMPS GSM USDC PDC

Bandwidth (MHz) 25 25 25 25

Voice channel 833 1000 2500 3000

Frequency Reuse (Cluster size) 7 4 atau 3 7 atau 4 7 atau 4

Channel/site 119 250 atau 333 357 atau 625 429 atau 750

Traffic (Erlang/km 2) 11,9 27,7 atau 40 41 atau 74,8 50 atau 90,8

Capacity Gain 1,0 2,3 atau 3,4 3,5 atau 6,3 4,2 atau 7,6

In practice TDMA systems improve capacity by factor of three to six timeas compare to analog cellular radio system.

8/11/2019 IS-54 dan IS-136

21/29

L O G O

CapacityComparison of Spectral Efficiency between NA-TDMA with other systm

Spectral Efficiency IS-54 > GSM

The bandwidth efficiency (or spectrum efficiency) is defined as theinformation bit rate, Rb, per unit bandwidth occupied, and is measuredin bits/sec/Hz (bps/Hz)

8/11/2019 IS-54 dan IS-136

22/29

L O G O

Power TransmitPower Classification in IS-54

8/11/2019 IS-54 dan IS-136

23/29

L O G O

Power TransmitPower Classification in IS-136

8/11/2019 IS-54 dan IS-136

24/29

L O G O

Propagation Model

Typical Urban

a(hm) : correction factor for mobile antenna heightFor large cities :

For Small and Medium Cities :

Typical Sub-Urban

Rural

Okumura-Hata Model

This Model is Valid for :

L O G O

8/11/2019 IS-54 dan IS-136

25/29

L O G O

Propagation Model

This Model is a combination of empirical and deterministicmodels for estimating the path loss in an urban area over thefrequency range of 800 MHz to 2000 MHz

Free Space Loss is given :

Cost 231 Model

L O G O

8/11/2019 IS-54 dan IS-136

26/29

L O G O

Propagation ModelComparison of Okumura-Hata and Cost 231 Model

In PCS System : 1, 2, 3, 4 and 5 km distance, hb =30 m, hm =2 m,and carrier frequency fc =900 MHz

L O G O

8/11/2019 IS-54 dan IS-136

27/29

L O G O

IS-136

The main difference between IS-54 and IS-136 is,that IS-136 uses TDMA also on the control channel, DCCH ( Digital Control Channel )

Basic Feature :Operates in 800/1900 MHz band Channel bandwidth 30 kHz TDMA frame 40 ms in 6 time slots The control Channel : IS-136 has both digital(DCCH) and analog (ACC) control channels.

L O G O

8/11/2019 IS-54 dan IS-136

28/29

L O G O

How NA-TDMA worksIS-136 Call Processing

1. Scanning and Lockingfinding the most suitable control channel, obtaining inf. aboutthe system. Find DCCH or ACC

2. Campingcamping state : when MS is idle on a DCCH and waiting for pagesfrom the system. Doing many task : re-evaluate the DCCH environment.- MS must monitor its assigned paging slot to look for message from

BS- MS must check to determine whether any inf. has changed on the BCCH

3. System AccessIVDC message is sent to the phone to provide the phone with selectedvoice channel to be used to start the conversation

4. ConversationThe phone is in the conversation mode when it is turned to a voice or DTCand is providing a voice path for a call- MS continually measures neighboring radio channel

5. MAHO ( M o b i l e A s s i s t e d H an d -o f fdigital-to-digital, digital-to-analog, analog-to-analog, dan digital-to-analog

6. Call Completiona release message is either received from the system or sent from MS

8/11/2019 IS-54 dan IS-136

29/29

L O G O