Modern Wireless Communication Systems This document discusses the evolution of wireless communication systems from 1G to 4G. It provides details on each generation including the technologies used, key standards, capabilities and comparisons. 1G systems were analog and offered basic voice calls. 2G introduced digital networks and supported limited data. 2.5G enhanced 2G for higher speeds. 3G enabled multimedia and high-speed data using standards like W-CDMA, CDMA2000 and TD-SCDMA. 4G provides speeds up to 20 Mbps for improved multimedia services on mobile networks. The document also discusses short-range wireless technologies like Bluetooth and wireless LANs that operate without licensed spectrum.

1. Modern Wireless Communication
Systems
zaahir salam

2. Overview
 Wireless communication networks was concept of 1960s and 1970s and
become much more popular in 1990’s.
 Radio Spectrum licenses for personal communication service(PCS) in the 1800-
2000 MHz frequency bands.
 The rapid growth in cellular telephone subscribers has demonstrated
conclusively that wireless communications are:
Robust
Viable voice and data transport mechanism.
 Next generations are being designed to facilitate high speed data
communications traffic in addition to voice calls.
 New standards and technology are being implemented to replace fiber optic or
copper lines.

3. No.ofworldwidesubscribers(millions)

4.  Used as a replacement for wires within the homes, buildings, and office
settings through the development of wireless local area networks
(WLANs).
 Bluetooth modem standard promises to replace troublesome appliance
communication cords with invisible wireless connections within a personal
workspace.
 The WLAN’s and Bluetooth use low power levels and generally do not
require a license for spectrum use.
 They are used as data networks within buildings without a license.
Networks that don't require a licensed spectrum for there use

5. First Generation Wireless Systems (1G)
 First-generation wireless technology is based on analog signals.
 Mostly relied on FDMA/FDD and analog FM.
 Are very limited in capacity and did not extend across geographic areas
 Systems using 1G :
AMPS, TACS, and NMT
 Working of 1G
 In this, mobile device sends the waves to a base station where they are
processed to determine the signal’s next destination Once the destination is
determined, the signal is reconstructed as accurately as possible

6.  The analog signal received by the end user may closely resemble the
original transmission but rarely duplicate it.
 Noticeable differences in quality and form occur due to:
 recreation errors.
 Signal destruction .
 translation and interference problems .

7. 2 Generation wireless systems
 Developed in Europe and the US to provide better voice quality, higher capacity
as well as lower power consumption.
 2G services are frequently referred as Personal Communications Service or PCS
in the US.
 Offer support for simple non-voice services like SMS (simple messaging
service).
 Difficult roaming between countries using different systems.
 Cannot meet subscriber demands for new, faster non-voice services on the
move.
 Its standards use digital modulation formats and TDMA/FDD and CDMA/FDD
multiple access techniques.

8. 2 G Continued………
 The Standards include 3 TDMA standards and 1 CDMA:
• A) Global System Mobile(GSM)
It supports 8 time slotted users for each 200kHz radio channel
• B) Interim Standard 136(IS-126)
It supports 3 time slotted users for each 30KHz radio channel.
• C) Pacific Digital Cellular
It is similar to IS-136 with more than 50 million users
• D) CDMA one
It supports upto 64 users that are orthogonology coded and
transmitted on each 1.25MHz channel.
 Modern cellular systems are also being installed to provide fixed
telephone service to residences and businesses in developing nations- this
is particularly cost effective for providing plain old telephone
service(POTS)
 2G technologies offer a three times increase in spectrum efficiency .

9. 0
50
100
150
200
250
300
350
400
Worldwide subscriber base as a function of cellular technology in late 2001
No.ofSubscribersusing(inmill)
1st GA GSM IS-136 &PDC IS-95 CDMA

10. Cdma2000-1xEV,DV,DO
Cdma2000-
3xRTT
IS-9 IS-136
& PDC
GPRS
HSCSD
IS-95B
EDGE
Cdma200-1xRTT
3GPP2
HSCSD
HSCSD
HSCSD 3GPP
2G
3G
2.5G
Various upgrade paths for 2G technologies
GSM

11. What is 2.5G Wireless?
 It was an effort to retrofit the 2G standards for compatibility with increased
throughput data rates that are required to support modern internet
applications.
 This standard allows existing 2G equipment to be modified and
supplemented with new base station add-ons and subscriber unit software
updates to support:
High data rate transmission .
E-mail traffic
Mobile commerce
Location based mobile services.
 This technology also support new web browsing format language , called
wireless Applications Protocol (WAP).
 WAP allows standard web pages to be viewed in a compressed format
specifically designed for small, portable hand held devices.

12. • HSCSD (High speed circuit switched data ) for 2.5G GSM
• It simply requires the service provider to implement a software change at
existing GSM base station.
• is a circuit switched technique that allows a single mobile subscriber to use
consecutive user time slots in the GSM standard .
• HSCSD relaxes the error control coding algorithms
• increases the available application data rate to 14,440bps as compared to
9,600bps in GSM specification.
• by using up to 4 consecutive time slots it is able to provide a raw
transmission rate of up to 57.6kbps to individual users.
• GPRS (General Packet Radio Service) for 2.5G GSM and IS-136
• It is a packet based data network which is well suited for:
» Non-real time internet usage
• It supports multi-user network sharing individual radio channels and time
slots.
• In this all 8time slots of a GSM radio channel are dedicated to GPRS by
which an individual user is able to achieve as much as 171.2kbps.

13. • EDGE(Enhanced data rates for GSM)
• It is a more advanced upgrade to GSM standard.
• It requires addition of new hardware and software at existing base
stations.
• It introduces a new digital modulation format, 8-PSK(octal phase shift
keying) which is used in addition to GSM’s standard GMSK
modulation.
• IS-95B for 2.5G CDMA
» CDMA has a single upgrade path for eventual 3G operation.
» It supports medium data rate (MDR) service by allowing a dedicated user to
command up to 8 different users walsh codes simultaneously and in parallel
for an instantaneous throughput of 115.2 kbps per user.

14. CDMA Evolution
•Voice Data
up to 14.4
Kbps
•Voice Data
up to 115
Kbps
•2x increases in
voice capacity
upto 307 kbps*
packet data on a
single (1.25 MHz)
carrier
•First 3G system
for any
technology
worldwide
•Optimized, very
high-speed data
(Phase 1)
•Up to 2.4Mbps*
packet data on a
single (1.25 MHz)
carrier.
•Integrated voice
and data (Phase 2);
up to 3.09 Mbps

15. 3G Wireless Systems
 They are new generation of systems that offer high bandwidth and support
digital voice along with multimedia and global roaming.
 Globally, different systems are being used, so, to migrate to globally acceptable
systems, numerous standardization activities were carried out and three
systems emerged: W-CDMA, CDMA2000, and TD-SCDMA
 W-CDMA (Wideband Code-Division Multiple Access)
 Standard derived from Code-Division Multiple Access (CDMA), is
officially known as IMT-2000 direct spread. W-CDMA is a 3G mobile
wireless technology that promises much higher data speeds to mobile
and portable wireless devices than commonly offered in today's
market.
 It can support mobile/portable voice, images, data, and video
communications at up to 2 Mbps (local area access) or 384 Kbps (wide
area access). The input signals are digitized and transmitted in coded,
spread-spectrum mode over a broad range of frequencies. A 5
MHz-wide carrier is used, compared with 200 kHz-wide carrier for
narrowband CDMA.

16.  TD-SCDMA (time division synchronous code division multiple access)
 Supporting data transmission at speeds up to 2 Mbps, TD-SCDMA
combines support for both circuit-switched data, such as speech or
video, and also packet-switched data from the Internet. The standard
combines time division multiple access (TDMA) with an adaptive,
synchronous-mode code division multiple access (CDMA) component.
 cdma2000
 The name cdma2000 actually denotes a family of standards that
represent the successive, evolutionary stages of the underlying
technology. These are, in order of evolution:
CDMA2000 1xRTT
CDMA2000 1xEV-DO: Release 0, Revision A, Revision B
CDMA2000 1xEV-DO Revision C or Ultra Mobile Broadband (UMB)
CDMA2000 1xEVDV
 In the above nomenclature, EVDO is short for Evolution - Data Optimized
and EVDV, for Evolution - Data and Voice.

17. 3G System Capabilities
 Capabilities to support circuit and packet data at high bit rates:
•144 kilobits/second or higher in mobility (vehicular) traffic
•384 kilobits/second for pedestrian traffic
•2 Megabits/second or higher for indoor traffic
Common Billing/User Profiles
Sharing of usage/rate information between service providers
Standardized call detail recording
Standardized user profiles
 Capability to determine geographic position of mobiles and report it to
both the network and the mobile terminal
 Interoperability and roaming

18. 3G System Capabilities ….
 Capability to determine geographic position of mobiles and report it to
both the network and the mobile terminal
 Support of Multimedia Services/Capabilities
 Fixed and variable rate bit traffic
 Bandwidth on demand
 Asymmetric data rates in the forward and reverse links
 Multimedia mail store and forward
 Broadband access up to 2 Megabits/second

19. Communication services
•Video telephony
•Video conference
•Personal location (GPS)
Education
•Virtual schools
•On-line science lab
•On-line library
•On-line language labs
•Training
Applications Using 3G
Business services
• Mobile office
•Narrowcast business TV
•Virtual workgroups
•Expertise on tap
Entertainment
•Audio on demand
•Games
•Video clips
•Virtual sightseeing

20. 1G 2G 3G
System Analogue Digital Digital
Major Systems AMPS,NMT,TACS GSM,CDMA,TDMA
WCDMA,CDMA2000,
TD-SCDMA
Application Voice
Voice + little Circuit
switch-data
Voice + Packet-
switch-data
Local Subscriber Less than 500k About 5.9 Million
More than 5Million
(estimated)
Speed
Depends on
Analogue Signal
9.6kbps to 14.4kbps
144kbps for mobile to
2Mbps for stationary
Properties
Unstable,
incomplete coverage
and poor sound
quality
More secure data
services available,
broader coverage,
more stable, allow
more users, better
sound quality
Multimedia data,
positioning capability,
connection to
internet, always
connected
Comparison of Generations

22. Key Parameters of 3G and 4G Systems
3G 4G
Frequency
Band
1.8 - 2.5 GHz 2 - 8 GHz
Bandwidth 5 - 20 MHz 5 - 20 MHz
Data Rate
Up to 2 Mbps (384
Kbps deployed)
Up to 20 Mbps
Access
W - CDMA / CDMA
2000 / TD -SCDMA
MC - CDMA or OFDMA
(TDMA)
Switching Circuit / Packet Packet
Mobile top
speeds
200 Km/h 200 Km/h

23. Technologies that use Non licensed Spectrum
• Bluetooth is a new short-range wireless technology designed to enable
wireless communication between diverse devices.
• A local area network (LAN) is a group of computers and associated devices
that share a common communications line or wireless link. Typically,
connected devices share the resources of a single processor or server within
a small geographic area (for example, within an office building)

24. REFERENCES
• Modern wireless communication by rappaport
• Internet
• 3G wireless ppt. by keith doughlas