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EMERGING TECHNOLOGIES IN WIRELESS. Jack H. Winters. Chief Scientist, Motia jwinters@motia.com. Outline. Technologies Service Limitations Multiplatform Systems Conclusions. SUMMARY. New wireless technologies: Physical Layer: WiFi (IEEE802.11a/b/g, n) WiMax UWB Bluetooth

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    1. EMERGING TECHNOLOGIES IN WIRELESS Jack H. Winters Chief Scientist, Motia jwinters@motia.com

    2. Outline • Technologies • Service Limitations • Multiplatform Systems • Conclusions

    3. SUMMARY • New wireless technologies: • Physical Layer: • WiFi (IEEE802.11a/b/g, n) • WiMax • UWB • Bluetooth • EvDO • RFID • Zigbee • Applications: VoIP • Interconnection: Mesh networks, WLAN-WWAN convergence

    4. $/Cell $/Sub UWB 3.1-10.6 GHz $ 500,000 $ 1000 $ 100 $ 500 $ 100 $ 10 802.11a/g 2.4, 5.5GHz Unlicensed 802.11b 2.4GHz Unlicensed 2G/3G Wireless 0.9, 2GHz Wireless System Enhancements Peak Data Rate High performance/price 100 Mbps WiMAX 10 Mbps Enhanced 1 Mbps BlueTooth 2.4GHz 100 kbps High ubiquity and mobility Range 10 feet 100 feet 1 mile 10 miles 60 mph Mobile Speed 2 mph 10 mph 30 mph

    5. Service Limitations of Wireless • Quality of service for each user is not consistent: • Too far away from the access point/base station/etc. • Behind a wall • In a “dead” spot • Working off a battery, as with a laptop • Suffering from low bandwidth due to range/interference • VoIP applications cannot tolerate fading or brief outages

    6. Solutions • Change among platforms to maximize performance • Further enhance performance of each system through: • Smart Antennas • Being implemented today (e.g., MIMO) • Ad Hoc Networks • Interconnections of multiple clients • Combination of Smart Antennas with Ad Hoc Networks (can give greater gains than the sum of the two)

    7. Multiplatform Devices • Multimode devices adapt to maximize performance, minimize cost and/or power: • Laptops with WiFi, WiMax, and Cellular (GSM, EDGE, WCDMA, EvDO) • Handsets with WiFi and Cellular: • VoIP • Single spatial stream 802.11n under discussion

    8. Smart Antennas A smart antenna is a multi-element antenna where the signals received at each antenna element are intelligently combined to improve the performance of the wireless system. The reverse is performed on transmit. Smart antennas can: • Increase signal range • Suppress interfering signals • Combat signal fading • Increase the capacity of wireless systems

    9. SIGNAL SIGNAL BEAM SELECT SIGNAL OUTPUT BEAMFORMER SIGNAL OUTPUT INTERFERENCE BEAMFORMER WEIGHTS INTERFERENCE Switched Multibeam Adaptive Antenna Array Smart Antennas • Simple beam tracking • limited interference suppression • limited diversity gain • Antenna gain of M • Suppression of M-1 interferers • M-fold multipath diversity gain (with multipath) • With M Tx antennas (MIMO), M-fold data rate increase in same channel with same total transmit power (with multipath)

    10. Multiple-Input Multiple-Output (MIMO) Radio • With M transmit and M receive antennas, can provide M independent channels, to increase data rate M-fold with no increase in total transmit power (with sufficient multipath) – only an increase in DSP • Indoors – up to 150-fold increase in theory • Outdoors – 8-12-fold increase typical • Measurements (e.g., AT&T) show 4x data rate & capacity increase in all mobile & indoor/outdoor environments (4 TX and 4 RX antennas) • 216 Mbps 802.11a (4X 54 Mbps) • 1.5 Mbps EDGE • 19 Mbps WCDMA

    11. Gains for with Smart Antennas • WiFi/WiMax (4 antennas) • 13 dB (one side), 18 dB (both sides) – > 2-4 times range, throughput • Cellular (4 antennas): • >6 dB gain on receive – 2X range, throughput

    12. Multiplatform Smart Antenna Systems • WiFi, WiMax, Cellular: • Use one array (4 antennas) for all platforms • Digital interface from array (RFIC) to BB/MAC’s • Cable from laptop display back or handset case • Standard in development: • JC-61 (initially for 802.11n) – single merged proposal at next meeting in July

    13. JEDEC Standard JC-61Block Diagram Baseband I/Q RX_CLK 802.11n, WiMax, Cellular RFIC 802.11n , WiMax, Cellular Baseband/MAC Processor Host Interface RX_DATA JESD96 Interface: A/D, D/A, Control Logic TX_DATA TX_CLK Control Signals

    14. Mobile Ad Hoc/Mesh Networks • Network of wireless hosts which may be mobile • No pre-existing infrastructure • Multiple hops for routing • Neighbors and routing changes with time (mobility, environment)

    15. Impact of Smart Antennas in Ad Hoc Networks • Since smart antennas are a physical layer technique, existing approaches for MAC/routing in ad hoc networks will work with smart antennas, but these MAC/routing techniques need to be modified to achieve the full benefit • Need to use hooks: • Hooks for frequency assignment techniques to include reusing a frequency (up to M-1 times). • Hooks for the inclusion of multiple radio capability to include multiple radios in the same channel. • This can be done in such a way to actually reduce the complexity of the MAC/routing algorithms.

    16. Conclusions • Wide variety of wireless technologies, each with different capabilities • Multiplatform devices will allow for adaptation among platforms to maximize performance • Smart antennas and ad hoc network techniques with these various platforms will further enhance and overcome most of current wireless limitations • Adaptation of platforms, signal processing, and interconnection techniques may look confusing, but if done correctly will lead to high performance, ubiquitous wireless systems, without requiring user sophistication