1. Evolution of Wireless CommunicationBy
Chandra Thapa

2. Evolution of Wireless Systems
Guglielmo Marconi invented the wireless telegraph in 1896
Communication by encoding alphanumeric characters in analog signal
Sent telegraphic signals across the Atlantic Ocean
First public mobile (car-based) telephone system (MTS) introduced in 1946
Analog frequency modulation
High power BS tower to cover 50 miles radius
Inefficient (120K spectrum for a voice connection)

3. Evolution of Wireless Sys. (Contd)
Improved mobile telephone system (IMTS) developed in 1960
Full duplex services and direct-dialing
23 FM channels with BW reduced to KHz
Cellular concept
Exploits the attenuation of radio signal with distance to achieve frequency reuse.
originally proposed by D. H. Ring in 1947
Bell Labs began work on cellular telephone system in the late 1960s.

4. Evolution of Wireless Sys. (2.5G)
2G telephony is highly successful
Enhancement to 2G on data service
GSM: HSCSD and GPRS
IS-95: IS-95b
IS-136: D-AMPS+ and CDPD
The improved data rate is still too low to support multimedia traffic
ITU initiated 3G standardization effort in 1992, and the outcome is IMT-2000.

5. Evolution of Wireless Sys. (1G)
Handoff was not solved until the development of microprocessor, efficient remote-controlled RF synthesizer, and switching center.
1G Cellular System
Designed in 1970s, deployed in early 1980s
Analog, 42 control channels, 790 voice channels
Handoff performed at BS based on received power
AMPS in US; TACS in part of Europe; NTT in Japan; C450 in West German, and NMT in some countries.
Became highly popular; AMPS still popular in US!

6. Evolution of Wireless Sys. (2G)
2G Systems
Digital cellular telephony
Modest data support, incompatible
GSM: a common TDMA technology for Europe; claim about 3/4 of subscribers worldwide.
IS-54 and IS-136: TDMA technology in US; compatible with AMPS;
IS-95: CDMA; standardized in 1993; South Korea and Hong Kong deployed it in 1995; US in 1996.

7. Evolution of Wireless Sys. (3G)
IMT-2000 comprises several 3G standards:
EDGE, data rate up to 473Kbps, backward compatible with GSM/IS-136
cdma2000 (Qualcomm), data rate up to 2Mbps, backward compatible with IS-95
WCDMA (Europe), introduces a new 5MHz channel structure; data rate up to 2Mbps;
TD-SCDMA (China), CDMA in TDD fashion

8. Evolution of Wireless Sys. (4G)
Problems of 3G systems
Immature 3G license auction increases the financial burden
Difficult to extend to higher data rates
No unified standard (political factors dominate)
4G systems
Research initiated, but still not well-defined
Data-oriented, seamless integrated with wireline
Indoor data rate up to 100 Mbps, outdoor data rate up to 20Mbps.

9. Evolution of Mobile Radio Communications

10. Trends in Wireless Comm.
Personal Communications (Goal of mobile communications)
All IP based (IPv6) (Packet switched)
Flexible platform of complementary access systems( Combination of different wireless access systems, Hot spot services will be introduced by high-speed wireless access (>100mbps))
Higher system capacity (Users/Service, 5-10 times higher than 3G)
Higher Transmission Data rate
Higher frequency efficiency
More advanced multimedia applications
Improved QoS
Realize high levels of security and authentication
Global coverage
Global roaming

11. All IP Based

12. All IP based Intelligent Edge Network Domain Service Domain Internet
Mobile Internet Application Servers
Broadband Accesses
Network Domain
Mobile Internet
Application Platforms
Mobility, Connection & Control Servers
Broadband Gateway
Service Domain
OWLAN
Internet
IP Multi
Radio
IP/ATM/MPLS Backbone
Mobility Gateway
PSTN
ISDN
Intelligent Edge
Media Gateway

13. Combination of different wireless access systems
IEEE WLAN
PAN Bluetooth
PDMA
WPAN WLAN WWAN

14. Network of 3G beyond Media access system IP based core network
Services and
applications
IP based core network
Media access system
IMT-2000
UMTS
WLAN
type
cellular
GSM
short range
connectivity
Wireline
xDSL
other
entities
DAB
DVB
return channel:
e.g. GSM
download channel
New radio
interface

15. Transmission Data Rate
Highest data rate(3G)
at least 144 Kb/s in a vehicular environment,
384 Kb/s in a pedestrian environment,
2048 Kb/s in an indoor office environment.
Highest data rate (4G)
2Mbps in a vehicular environment, 20Mbps in a pedestrian environment
Wide Area, high velocity：100Mbps
Indoor, lower velocity：1Gbps
Evolution of transmission data rate

16. Drivers of 3G Beyond 3G evolution : Drawback Difficult
to extend to higher data rate with CDMA only technology;
to provide various services with different QoS
to have enough frequency resource to accommodate more subscribers
Drawback
Low system capacity
Low spectrum efficiency
Mobile
Internet
User
200
400
600
800
1000
1200
1400
1600
1800
1995
2000
2005
2010
Subscriptions (millions)
Fixed
Mobile Internet
Fixed Internet

17. Revolution from IP infrastructure
Drivers of 3G Beyond IP
Revolution from IP infrastructure
and Beyond 3G
Evolution from 2G systems 2G
Revolution from subscriber service expectations

18. Multimedia Services Internet access Shopping/banking(e-commerce)
Video conferencing
Video on demand
Telemedicine
Distance learning

19. Challenges Unreliable Channels Scarce Spectrum and Resource Management
Stringent Power Budget
Security
Location and Routing
Interfacing with Wired Networks
Health Concern
Diversified Standards and Political Struggle