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Wireless networks: from cellular to ad hoc

Wireless networks: from cellular to ad hoc. The three wireless “waves”. Wave #1: cellular telephony Still, biggest profit maker Wave #2 : wireless Internet access Most Internet access on US campuses is wireless

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Wireless networks: from cellular to ad hoc

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  1. Wireless networks: from cellular to ad hoc

  2. The three wireless “waves” • Wave #1: cellular telephony • Still, biggest profit maker • Wave #2 : wireless Internet access • Most Internet access on US campuses is wireless • Hot spots are rapidly proliferating in the US; Europe and Asia to follow soon • 2.5 G and 3G trying to keep up; competitive edge? • Wave #3: ad hoc wireless nets (now) • Set up in an area with NO infrastructure; to respond to a specific, time limited need

  3. Wireless Internet Options - Cellular • 2.5 G • 1xRTT: CDMA based; 144Kbps • GPRS: Time Division based (GSM); < 100Kbps • Packet oriented; “always on”; per packet (instead of per call) charge • 3G • UMTS: Wide Band CDMA from 384 Kbps to 2Mbps • Integrates packet service with connection oriented service (voice, video, etc)

  4. Wireless Internet Option: 802.11 • Replacement for wired Ethernet • Unlicensed spectrum (ISM) • Several options and rates • 802.11 b: 11, 5.5, 2, 1 Mbps; @ 2.4 GHz • 802.11 a up to 54 Mbps in 5.7 GHz band • 802.11 n, up to 100Mps with MIMO and OFDM technologies • Range • Indoor 20 - 25 meters • Outdoor: 50 – 100 meters • Transmit power up to 100 mW

  5. Wireless Internet options: Bluetooth • 1998: Bluetooth SIG : Ericsson, IBM, Intel, Nokia, Toshiba • A cable replacement technology • Max rate 700Kbps @2.4 Ghz • Range 10+ meters • Single chip radio + baseband • at low power (1mw) & low price point ($5) • Convergence of 802.15 and Bluetooth in a single PAN standard

  6. New developments are blurring the distinction • 802.11b for PDAs • Bluetooth for LAN access Emerging Landscape Bluetooth 802.11 • Both 802.11 and Bluetooth will be used for access • Complementary benefits Cordless headset LAN AP

  7. Which Internet access to choose? • Most portables have multiple radio interfaces • 802.11, Bluetooth and 1xRTT supported on PDAs • Dynamically select best access: • Lowest connection charge • Best reception • Best power budget (must save battery power) • Suitable Qos • Challenges: • Seamless handoff (network, session) • Rate content adaptation if data rates are different

  8. Gateway Download Discovery “Vertical” Handoff between 802.11 and 1XRTTUCLA Project, 2003 Italy Internet US ? BR JP Music download application Session synch points

  9. The 3rd Wave: Infrastructure vs Ad Hoc Infrastructure Network (cellular or Hot spot) Ad Hoc, Multihop wireless Network

  10. General Ad Hoc Network Characteristics • Instantly deployable, re-configurable (No fixed infrastructure) • Created to satisfy a “temporary” need • Node portability (eg sensors), mobility • Limited battery power • Multi-hopping ( to save power, overcome obstacles, enhance spatial spectrum reuse, etc.)

  11. Ad Hoc Network Applications Military • Automated battlefield Civilian • Disaster Recovery (flood, fire, earthquakes etc) • Law enforcement (crowd control) • Homeland defense • Search and rescue in remote areas • Environment monitoring (sensors) • Space/planet exploration

  12. Ad Hoc Network Applications (cont) Commercial • Sport events, festivals, conventions • Ad hoc collaborative computing (Bluetooth) • Sensors on cars (car navigation safety); sensors on cows • Networked video games at amusement parks, etc Opportunistic ad hoc extensions (of Wireless Internet) • Indoor W-LAN extended coverage • Indoor network appliances (Bluetooth, Home RF) • Hot spots (Mesh Networks) • Campus, shopping mall, etc • Urban grid

  13. The Battlefield • DoD was first to understand the value of ad hoc networks for the automated battlefield • In 1971 (two years after ARPANET), DARPA starts the Packet Radio project • ONR (Office of Naval Research) sponsors MINUTEMAN - a 5 year program at UCLA (2000–2005) • Goal: develop an “unmanned” , airborne ad hoc architecture

  14. SURVEILLANCE MISSION AIR-TO-AIR MISSION STRIKE MISSION RESUPPLY MISSION FRIENDLY GROUND CONTROL (MOBILE) SATELLITE COMMS SURVEILLANCE MISSION UAV-UAV NETWORK COMM/TASKING COMM/TASKING Unmanned UAV-UGV NETWORK Control Platform COMM/TASKING Manned Control Platform Minuteman: Algorithms and Protocols for Network of Autonomous Agents

  15. The MINUTEMAN “Internet in the Sky”

  16. Transferring Battlefield technology to civilian applications Disaster recovery: • Flood, mud slide, eruption, chemical or nuclear plant disaster • Several rescue teams involved, with different functions • Autonomous vehicle swarms (ground/airborne) are deployed (with sensors/actuators) • Manned and unmanned teams cooperate in rescue • “Ad Hoc networking” will be central to make the operation work

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