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Evolution of Wireless Communication By Chandra Thapa

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

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Evolution of Wireless Communication By Chandra Thapa

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  1. Evolution of Wireless Communication By 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 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.

  4. Evolution of Wireless Sys. (2.5G) • 2G telephony is highly successful • Enhancement to 2Gon data service • GSM: HSCSD and GPRS • IS-95: IS-95b • IS-136: D-AMPS+ and CDPD • The improved data rate is still too lowto 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. Internet PSTN ISDN All IP based Mobile InternetApplication Servers Broadband Accesses Network Domain Mobile Internet Application Platforms Mobility, Connection& Control Servers Broadband Gateway Service Domain OWLAN IP Multi Radio IP/ATM/MPLS Backbone Mobility Gateway Intelligent Edge Media Gateway

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

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

  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. Subscriptions (millions) 1800 Mobile User Mobile Fixed Mobile Internet Fixed Internet 1600 1400 1200 1000 Mobile Internet User 800 600 400 200 0 1995 2000 2005 2010 Drivers of 3G Beyond 3G evolution : 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

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

  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

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