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IIT Colloquium: NRC Ottawa, Canada A Vision for Evolving Local Wideband Wireless Networks Kaveh Pahlavan, Professor of Electrical and Computer Engineering and Director, CWINS/WLRL WPI, Worcester, MA http://www.cwins.wpi.edu. Outline. Applications and the market
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IIT Colloquium: NRC Ottawa, Canada A Vision for Evolving Local Wideband Wireless Networks Kaveh Pahlavan, Professor of Electrical and Computer Engineering and Director, CWINS/WLRL WPI, Worcester, MA http://www.cwins.wpi.edu
Outline • Applications and the market • Existing technologies and limitations • Evolving standards • Overview of Global activities • Some research projects
Classification of Existing Wireless Networks Voice Driven Networks • Low power, high quality, local services (PCS, wireless PBX, telepoint)-Result of success in cordless telephone industry • High power, low quality, wide area (Digital Cellular) -Result of demand for higher capacity for mobile radio Data Driven Networks • High speed local (Wireless LAN) - A new approach for local area networking • Low speed wide area (mobile data) - Result of success in paging industry
Wireless LANs • Minimum data rate: 1Mbps (IEEE 802) • Designed for local indoor - less than 100m • Should interoperate with wired LANs • Does not need large investment on infrastructure and does not collect service charges. • Transmission technology: spread spectrum, standard radio, IR • Examples: Roamabout, WAVELan, Photolink, FreePort • Standards: IEEE 802.11, HIPERLAN
History of Wireless LANs • Diffused Infrared - 1979 (IBM Rueschlikon Labs - Switzerland) • Spread Spectrum using SAW Devices - 1980 (HP Labs - California) • Wireless modems - early 1980's (Data Radio) • ISM bands for commercial spread spectrum applications - 1985 • IEEE 802.11 for Wireless LAN standards - 1990 • Announcement of wireless LAN products - 1990 • Formation of WINForum - 1992 • ETSI and HIPERLAN in Europe - 1992 • Release of 2.4, 5.2 and 17.1-17.3GHz bands in EC - 1993 • PCS licensed and unlicensed bands for PCS - 1993 • 1996: .........
Three Views of WWLA • Existing WLAN Applications • Vision for Military Applications • Vision of the Service Providers
Service Scenarios • Workplace - the main market of today, TCP/IP applications, legacy LAN backbone • Home - universal access point: Internet connection, cordless telephone, flexible speakers, etc. backbone unknown (ATM preferred). • Nomadic public access - backbone unknown, easier traffic policing and charging with WATM.
Wireless LAN Market 1200 1000 800 K-Unit 600 400 200 0 1992 1993 1994 1995 1996
Local Wideband Wireless Activities • Evolving Standard Technologies • IEEE 802.11 • RES-10 HIPERLAN • Wireless ATM Forum • International Activities • In the US • WINForum, U-NII • In the EC • MEDIAN, WAND, SAMBA and AWACS • In Japan • MMAC (High-Speed WirelessAccess and Ultra High-Speed Radio LAN)
IEEE 802.11 and ISM bands • Media Access Protocol (MAC) for both peer-to-peer and centralized topologies • Uses 2.4 MHz ISM bands • Supports DSSS (BPSK and QPSK), FHSS (GFSK), and DFIR (OOK) • Data rates are 1 and 2 Mbps for DSSS and FHSS, 1Mbpsfor DFIR • For DSSS the band is divided in two groups: Group I centralized at: 2412, 2442, and 2472 MHz Group II centralized at: 2427, and 2457 MHz • For FHSS three patterns of 22 hops out of 79 available I MHz bands with GFSK. Minimum hop rate is 2,5 hops/second • Provide interoperatability among all stations
IAPP(Supported byLucent, Aironet, Digital Ocean) • The IAPP specification defines how access points from different vendors communicate with each other to support mobile stations roaming across cells and how they communicate across the backbone network to hand over mobile stations. • The IAPP specification builds on the baseline capabilities of the IEEE 802.11 standard. • The IAPP specification tackles higher-level OSI layers such as logical link control that facilitates inter-access point communications. • The IAPP specification supports interoperability between products. • Should be applicable to large infra-structures
ETSI Res-10: HIPERLAN • MAC for both peer-to-peer and centralized networks • Uses 5.25-5.3 GHz and 17.1-17.3 GHz • Uses GMSK modulation with DFE • Data rates are 10-20 Mbps • The maximum range is 50m • Supports asynchronous data as well as isochronous voice
Japanese Wideband Wireless Activities MMAC: Multemedia Mobile Access Communications
Unlicensed PCS Activity (Spectrum Etiquette) • Three basic Principles: • Listen before talk (or transmit) LBT Protocol • Low transmitter power • Restricted duration of transmissions
Issues in a Mobile Network • Type of roaming • Intra-Net (802.11) • Inter-Net (GPRS) • Inter-Tech (between GPRS and 802.11) • Type of mobility • Continual during a move • Access at different locations • Type of connection • With a unique address (mobile IP) • With any address (cash IP) • Type of initiation for roaming • From the terminal • From th network
Evolving Roaming Related Technologies • Intra-Net Roaming • LANE in WATM • 802.11 • Hiperlan • Inter-Tech Roaming • MASE • Artour • Inter-Net Roaming • Mobile-IP
Layers for Implementation { MASE Application Presentation Winsock Session Mobile IP Transportation TCP ARTour Network IP 802.11, HIPERLAN,LANE MAC Physical
Mobile IP LC Mobile Host M Local cache Sender M R20 S Mobile Host Foreign Agent inform if possible Home Agent Router R1 R2 R3 R4
“IP in IP” Encapsulation IP Version number, and other header fields Tunnel Source IP address (home agent) CARE-OF Address (foreign agent) IP Version number, and other header fields Original source IP address Home IP address of mobile host TCP and rest of packet
Why Client-Server is Important • Most of the current legacy applications are client-server • Facilitates implementation of mobility • Facilitates interoperability • Facilitates scaleability • Can support multiple platforms • Local optimization of the server to enhance reliability and availability and results in reducing costs
Important Client-Server Applications • Web search, • FTP, • Data base access, • Telnet, • Email
References • K. Pahlavan , A. Zahedi, and P. Krishnamurty, “ Wideband Local Access: Wireless LAN and Wireless ATM”, invited paper, Speical Issue on WATM, IEEE Comm. Soc. Mag., Nov. 1997. • K. Pahlavan and A. Levesque, Wireless Information Networks, New York: John Wiley and Sons, 1995. • K. Pahlavan, A. Falsafi, G. Yang, “Transmission Techniques for Wireless LANs”, IEEE JSAC, Speical Issue on Wireless Local Communications, May 1996. • K. Pahlavan and A. Levesque, “Wireless Data Communication”, Invited Paper, IEEE Proceedings, Sep. 1994. • K. Pahlavan, “Wireless Intra-Office Networks”, Invited paper, ACM Trans. on Office Inf. Sys., July 1988. (also published as the opening paper in “Advances in Local and Metropolitan Area Networks”, edited by William Stalling, IEEE Press, 1994) • K. Pahlavan, “Wireless Office Information Networks”, IEEE Comm. Soc. Mag, Sep. 1985. • K. Pahlavan, T. H. Probert, and M. E. Chase, “Trends in Local Wireless Networks”, Invited Paper, IEEE Comm. Soc. Mag., March 1995.