1. Overview of Current Communications
Systems

2. Growth of cellular telephone
subscribers throughout the world
1000
Worldwide subscribers (millions)
100
10
1
0.1
1985 1990 1995 2000

3. Second generation (2G)
cellular methods
400
Subscribers Using Technology (millions)
300
200
100
0
1st Generation GSM IS-136 & IS-95
Analog PDC CDMA

4. 2G systems
 Most of today’s cellular methods
use second generation or
2G technologies
 While first generation systems relied on
FDMA/FDD and only FM, second
generation standards use digital
modulation and TDMA/FDD or CDMA/FDD

5. Most popular systems
 GSM (Global System Mobile)
 IS-136 (NADC)
(North American Digital Cellular)
 PDC (Pacific Digital Cellular)
 IS-95 CDMA

6. Key Specifications of leading
2G technologies
cdmaOne, IS-95, GSM, DCS-1900, NADC, IS-54/IS-
ANSI J-STD-008 ANSI J-STD-007 136, ANSI J-
STD-011, PDC
Uplink Frequencies 824-849 MHz 890-915 MHz 800 MHz, 1500 MHz
(US Cellular) (Europe) (Japan)
1850-1910 MHz (US 1850-1910 MHz (US 1850-1910 MHz (US
PCS) PCS) PCS)
Downlink Frequencies 869-894 MHz 935-960 MHz 869-894 MHz,
(US Cellular) (Europe) (US Cellular)
1930-1990 MHz (US 1930-1990 MHz (US 1930-1990 MHz (US
PCS) PCS) PCS)
800 MHz, 1500 MHz
(Japan)

7. . . . Key specifications of
leading 2G technologies
cdmaOne, IS-95, GSM, DCS-1900, NADC, IS-54/IS-
ANSI J-STD-008 ANSI J-STD-007 136, ANSI J-
STD-011, PDC
Duplexing FDD FDD FDD
Multiple Access CDMA TDMA TDMA
Technology
Modulation BPSK with GMSK with π /4 DQPSK
Quadrature BT = 0.3
Spreading
Carrier Separation 1.25 MHz 200 kHz 30 kHz (IS-136)
(25 kHz for PDC)

8. . . . Key specifications of
leading 2G technologies
cdmaOne, IS-95, GSM, DCS-1900, NADC, IS-54/IS-
ANSI J-STD-008 ANSI J-STD-007 136, ANSI J-
STD-011, PDC
Channel Data Rate 1.2288 Mchips/see 270.833 kbps 48.6 kbps (IS-136)
(42kbps for PDC)
Voice Channels per 64 8 8
Carrier
Speech coding Code Excited Linear Residual Pulse Vector Sun Excited
Prediction (CELP) Excited Long Tern Linear Predictive
@ 13kbps, Prediction (RPE- Coder (VSELP) @
Enhanced Variable LTP) @ 13 kbps 7.95 kbps
Rate Codec (EVRC)
@ 8 kbps

9. 2.5G Mobile radio networks
 Evolution from 2G  2.5G required to
support increased data rates for
modern Internet applications.
 2.5G are new data-centric standard that can be
overlaid on existing 2G technologies
 2.5G supports new web browsing format
language called WAP (Wireless applications
Protocol)

10. 2.5G Mobile radio networks
 WAP enables standard web pages to
be viewed in a compressed format 
suitable for small portable hand-held
wireless devices.
 First developed in Japan by
NTT-DoCoMo  I-mode for PDC network -
supports games, color graphics and interactive
web pages using 9.6 kbps
 25 million Japanese subscribers in 2001

11. 2.5G TDMA standards
 HSCSD (High Speed Circuit Switched
Data) for 2.5G GSM
 Allows a single mobile user to use more
than one specific time slot as in GSM TDMA
 Increases application rate from 9,600 bps (2G GSM)
to 14,400 bps (2.5G GSM)
 Ideal for streaming internet access or real-time
interactive web sessions.
 Can be implemented by a software change at existing
GSM base stations.

12. . . . 2.5G TDMA standards GPRS
(General Packet Radio Service)
 GPRS for 2.5G GSM and IS-136
 Packet based data network suited
for non-real time internet usage
 E-mail retrieving, faxes and where
download  upload
 GPRS can support more users that HSCSD,
but in a bursty manner.

13. . . . 2.5G TDMA standards EDGE
(Enhanced Data Ration for GSM
[or Global]) for 2.5G GSM and IS-136
 More advanced upgrade to GSM standard
 Regains additional hardware/software at
existing base stations
 New digital modulation format (8-
PSK/octal PSK)
 Raw data rate of 547.2 kbps possible with
8 GSM slots of a GSM channel are allowed
for each user.

14. 2.5G CDMA standards
 IS-95B for 2.5G CDMA
 Medium data rate (MDR) service with
throughput of 115.2 kbps per user
(8 x 14.4 kbps)
 Advanced handoff procedures allows mobiles
to search different radio channels
independently

15. Third generation
3G wireless methods
 Unparalleled wireless access
 Multi Mbps Internet access using
VoIP (Voice Over Internet Protocol),
voice activated calls
 Ability to receive live music, interactive
web sessions, voice and data access with
multiple features at the same time, at all
times

16. . . . Third generation
3G wireless methods
 ITU (International
Telecommunications Union)
proposed
 A global frequency band in 2000 MHz range
• Single wireless communications standard for all countries
in the world IMT-2000.
• World community remains split between GSM/IS-136/PDC
and CDMA
• www.gsmworld.com
• www.edg.org

17. 2G - 3G evolution
IS-136
IS-95 GSM
& PDC
GPRS
IS-95B
HSCSD HSCSD
cdma2000-1xRTT
W-CDMA
Cdma2000-1xEV, DV, DO EDGE
3GPP2
TD-SCDMA
cdma2000-3xRTT 3GPP

18. 3G CDMA standards
 3G W-CDMA (UMTS - Universal Mobile
Telecommunications System)
 Packet based wireless service which enables
computers, entertainment devices, telephones to
connect to internet anytime, anywhere.
 Packet data rates up to 2.048 Mbps per
stationary user
 Broadcasting, VHE (Virtual Home Entertainment) m-
commerce (mobile commerce), games, interactive
video, virtual private technology - all possible from
small portable wireless device

19. . . . 3G CDMA standards
 3G cdma2000 or cmda2000 IX
 New high data rate internet access
with backward compatibility to IS-95 and
IS-95B systems - 1.25 MHz bandwidth
 Instantaneous data rate of 307 kbps
in packet mode
 Both FDD (mobile radio) and
TDD (in-building cordless) applications

20. 3G TDMA standards
 3G TD-SCDMA (Time Division
Synchronous Code Division
Multiple Access)
 Developed by CATT (Chinese Academy of
Telecommunications Technology) and Siemens.
 Adopted by ITU as one of 3G options in 1999
 Existing GSM - 3G evolution through additions of
high data rate equipment in each GSM station -
1.6 MHz bandwidth
 Utilizes smart antennas, spatial filtering and joint
detection technologies

21. Broadband wireless
services
 Wireless Local Loop (WLL)
 Demand for broadband internet and
computer access from businesses and homes
 Fixed wireless equipment have advantages such as
fixed path between T-R
 Microwave or millimeter radio frequencies used
>28GHz - wave length is very small - small high gain
antennas.
 Especially useful in developing nations with less
telecommunications setup.

22. Emerging applications and markets for
broadband services
Fiber
Large business in
high-density urban areas
Backbone
Network Wireless
Central Mid-market business
Mid-market
outside the urban core
outside the urban core
Office
Central Office Copper/xDSL
OC-3 Small business
Small business
DAX Cable
Residences
ISP

23. Broadband wireless spectrum world-
wide

24. . . . Broadband
wireless services
 Wireless Local Area Networks (WLANS)
 UNII (Unlicensed National Information
Infrastructure) hand allocated by FCC for
low power spread spectrum
 5.150 - 5.35 Ghz, 5.725 - 5.825 GHz (1997)
 902-928 Mhz, 2400-2483.5Mhz, 5.725-5.825 MHz
(1980s end)
 IEEE 802.11 (1997) standard and (IEEE 802.11b)
approved to provide guidelines for WLAN
manufacturers

25. IEEE 802.11 Wireless LAN
IEEE 802.11
2.4 GHZ 850 TO 950 NM
FHSS DSSS Diffuse IR
2 Mbps 1 Mbps 1 Mbps 2 Mbps IEEE 802.11b
4GFSK 2GFSK DBPSK DQPSK Extension
5.5 Mbps
5.5 Mbps 11 Mbps
DQPSK--CCK DQPSK--CCK
DQPSK--CCK
BPSK--PBCC
BPSK--PBCC BPSK--PBCC

26. IEEE 802.11b Wireless LAN

27. High Performance Radio Local
Area Network (HIPERLAN)
 Europe standard to provide
similar capability to IEEE 802.11
 5.2 GHz and 17.1Ghz frequency lands
 Up to 20 Mbps data rate at 50m range and
vehicle speeds of 35km/hr
 Advanced standards include Europe’s
ETSI-BRAN (Broadband Radio Access
Network) and HIPERLAN/2.

28. Personal Area Networks
 Ability to replace cables between devices with
wireless short range connection
 Bluetooth operates in 2.4GHz ISM band (2900-
2483.5MHz) with 1 MHz channel bandwidth
 Uses FH-SS TDD scheme with 1600 hps
 1Mbps symbol rate using GSFSk modulation
 IEEE 802.15 sttandards committee is our
international forum for developing Bluetooth and
other PANS

29. PAN Bluetooth standard