Copyright ©1998 Alex Hills 1 The “Vision” of Wireless Access: Anyone Anything Anytime Anywhere Graphic: IEEE Spectrum
Copyright ©1998 Alex Hills 2 Wireless Andrew Mobile computers (laptops -> handhelds) Full peers Full functionality Full connectivity IEEE Personal Communications February 1996
Copyright ©1998 Alex Hills 3 Wireless Technologies Cordless Cellular Personal Communications Services (PCS) Paging Wireless PBX (WPBX) Wireless LAN (WLAN) Packet radio Low earth orbiting satellites (LEOS)
Copyright ©1998 Alex Hills 4 Wireless Technologies From Smaller to Larger Areas RoomBldgCampusCityWAN VOICE CordlessWPBXPCS/CellularLEOS DATA WLANWLANPacket Radio LEOS
Copyright ©1998 Alex Hills 5 Metro Area Wireless Data Options Packet radio ARDIS RAM Metricom Cellular Analog CDPD PCS GSM
Copyright ©1998 Alex Hills 6 Wireless LAN IEEE or LAN Access Point
Copyright ©1998 Alex Hills 7 Wireless LAN Characteristics Unlicensed frequencies 900 Mhz 2.4 GHz 5.7 GHz Infrared Modulation Frequency shift keying Spread spectrum - Frequency hopping (FHSS) - Direct sequence (DSSS)
Copyright ©1998 Alex Hills 8 Wireless LAN Characteristics Speed 60 kbps - 10 Mbps Range feet Interface Ethernet Token Ring
Copyright ©1998 Alex Hills 9 IEEE “Standard” Adopted June 1997 Allows speeds up to 2 Mbps (10 Mbps soon) Includes multiple PHY layers Infrared 2.4 GHz Direct sequence (DSSS) 2.4 GHz Frequency hopping (FHSS) University of New Hampshire doing interoperability testing DSSS FHSS IEEE product deliveries began in 1998
Copyright ©1998 Alex Hills 10 Wireless LAN Products Aironet Breezecom Digital Roamabout Lucent - WaveLAN Proxim RangeLAN2 Symbol Technologies - Spectrum 24
Copyright ©1998 Alex Hills 11 WaveLAN Market Share Proxim 15% Aironet 17% Symbol 9% Breezecom 4% Other 12% Digital 2% Lucent Technologies 41% Source: BRG Dec ‘97
Copyright ©1998 Alex Hills 12 Lucent WaveLAN II Frequency: 2.4 GHz Modulation: DSSS Speed: 2 -> 10 Mbps Coverage: 50, ,000 sq ft Interface: Ethernet (IEEE or Token Ring (IEEE 802.5)
Copyright ©1998 Alex Hills 13 Lucent WaveLAN II WavePoint Access Point ($995) Bridging function Mounts on wall Ethernet interface Token ring interface Optional WaveLAN Network Adapter ($295) PCMCIA Type II
Copyright ©1998 Alex Hills 14 Wireless Andrew I Research network Covers seven buildings 101 access points More than 100 users Lucent WaveLAN I equipment MHz Full operation Spring 1997
Copyright ©1998 Alex Hills 15 Wireless Andrew II Production network Will cover all academic and administrative buildings -- no residence halls About 400 access points Available to all 10,000 students, faculty, staff Lucent WaveLAN II equipment GHz - IEEE Full operation late 1999
Copyright ©1998 Alex Hills 16 Wireless Andrew II Technical Issues Coverage oriented access point layout Complete coverage with minimal overlap Changing environment Interference sources Capacity oriented access point layout Enough capacity for expected usage Consideration of high- and low-density areas Use of threshold setting and frequency reuse
Copyright ©1998 Alex Hills 17 Issues for research Likely, customers will need to use one or more wireless networks Several now, more future Shakeout unlikely Inherent tradeoffs in speed, distance, and coverage - Wireless LANs - CDPD - RAM and ARDIS - Analog Cellular - LEOS
Copyright ©1998 Alex Hills 18 Most of the Layers of OSI Model Layer 2: Roaming (wireless LAN) Layer 3,4: “Mobile IP” addressing and routing Layer 6: Adaptive compression Layer 7: Mobile-aware applications and Distributed file systems
Copyright ©1998 Alex Hills 19 Research Projects Transparent Networking Support for Mobile Hosts: David Johnson Wearable Computers: Dan Siewiorek Image and Video Compression for Wireless Links: Jose Moura Handheld Andrew: Tracy Futhey
Copyright ©1998 Alex Hills 20 Wearable Computers Marines (Ft Pendleton): Technical inspections
Copyright ©1998 Alex Hills 21 AEG at Pittsburgh International Maintenance inspection and repair