Evolution of Wireless Communication By Chandra Thapa

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)

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 25-30 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.

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.

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!

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.

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

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.

Evolution of Mobile Radio Communications

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

All IP Based

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

Combination of different wireless access systems IEEE.802.11 WLAN PAN Bluetooth PDMA WPAN WLAN WWAN

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

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

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

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

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

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