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Wireless Ethernet (IEEE 802.11b). Team-9 Zennon Fernandes Kiran Kumar Ka Kit. Wireless LAN?. Definition A data transmission system designed to provide location-independent network access between computing devices by using radio waves rather than cable infrastructure
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Wireless Ethernet(IEEE 802.11b) Team-9 Zennon Fernandes Kiran Kumar Ka Kit
Wireless LAN? • Definition • A data transmission system designed to provide location-independent network access between computing devices by using radio waves rather than cable infrastructure • IEEE 802.11 (1997) – Wireless LANs • IEEE 802.11b or 802.11 “High Rate” (1999) • Wireless Ethernet, 11 Mbps • WECA • Wi-Fi certification
The Competitive Advantage • Mobility • Flexibility and scalability • Cost savings
Applications • Dynamic environments • Old buildings, cost-effective network infrastructure solution • Temporary networks on exhibitions and seminars • Backup for mission-critical applications running on wired networks • Enterprise networks • Small / Home-office networks • Education – Schools and Universities
Application Examples • Immediate bedside access to patient information for doctors and hospital staff. • Real-time access for on-site consultants and auditors. • Improved database access for roving supervisors such as production line mangers, warehouse auditors etc. • Real-time access to study group meetings and research links for students. • Location-independent access for network administrators, for easier on-site troubleshooting and support.
802.11b Technology • Architecture • Infrastructure mode • Ad Hoc mode • 802.11b Physical Layer • DSSS • CKK • QPSK • 802.11b MAC Layer • CSMA/ CA
Infrastructure Mode 3Com Technical Paper, IEEE 802.11b Wireless LANs
Ad Hoc mode 3Com Technical Paper, IEEE 802.11b Wireless LANs
CSMA/ CA Protocols: RTS – Request to Send CTS – Clear to Send CSMA/ CA, Timing sequences.
Roaming and Hand-off 3Com Technical Paper, IEEE 802.11b Wireless LANs
Security • Wired Equivalent Privacy Security • Access Control • Encryption • ESSID (WLAN Service Area ID) • 40-bit shared-key RC4 algorithm (RSA)
Range & Throughput • 802.11b data rate • 5 Mbps • 11 Mbps • Indoor range (typical) – 45 to 90 meters • Outdoor range – *Kilometers depends on external antenna • Throughput decreases with distance
Attractiveness of WLANs • Wireless wherever you want to be • You don’t have to pull wires through your walls • Standards make cool things happen
Dark Side of WLANs • You are the broadband wireless Internet DHCP server for your entire neighborhood • Being mobile does not mean wireless • Serious networking technology is still wired
Making the Business Case The economic benefits can add up to as much as $16,000 per user - measured in worker productivity, organizational efficiency, revenue gain and cost savings - over wired alternatives.