tailieunhanh - Wireless LANs: 802.11 and Mobile IP

The Distribution system interconnects multiple BSSs. standard logically separates the wireless medium from the distribution system – it does not preclude, nor demand, that the multiple media be same or different. An Access Point (AP) is a STA that provides access to the DS by providing DS services in addition to acting as a STA. | Wireless LANs: and Mobile IP Sridhar Iyer Leena Chandran-Wadia K R School of Information Technology IIT Bombay {sri, leena}@ Outline Overview of wireless networks Single-hop wireless: Cellular, Wireless LANs (WLANs) multiple wireless hops – Mobile ad hoc networks (MANETS) Challenges of wireless communications IEEE spread spectrum and physical layer specification MAC functional specification: DCF mode role in WLANs – infrastructure networks role in MANETs MAC functional specification: PCF mode Mobile IPv4 Mobile IPv6 IIT Bombay References IEEE Computer Society 1999, Wireless LAN MAC and PHY layer specification J. Schiller, “Mobile Communications”, Addison Wesley, 1999. – several figures Short tutorials on and spread spectrum by , , Mobile IPv4 – RFC 3344 (main) IPv6 and Mobile IPv6 many RFCs, Internet drafts IIT Bombay Overview of wireless networks IIT Bombay Wireless networks Access computing/communication services, on the move Cellular Networks traditional base station infrastructure systems Wireless LANs infrastructure as well as ad-hoc networks possible very flexible within the reception area low bandwidth compared to wired networks (1-10 Mbit/s) Multihop Ad hoc Networks useful when infrastructure not available, impractical, or expensive military applications, rescue, home networking IIT Bombay Cellular Wireless Single hop wireless connectivity to the wired world Space divided into cells, and hosts assigned to a cell A base station is responsible for communicating with hosts/nodes in its cell Mobile hosts can change cells while communicating Hand-off occurs when a mobile host starts communicating via a new base station IIT Bombay Evolution of cellular networks First-generation: Analog cellular systems (450-900 MHz) Frequency shift keying; FDMA for . | Wireless LANs: and Mobile IP Sridhar Iyer Leena Chandran-Wadia K R School of Information Technology IIT Bombay {sri, leena}@ Outline Overview of wireless networks Single-hop wireless: Cellular, Wireless LANs (WLANs) multiple wireless hops – Mobile ad hoc networks (MANETS) Challenges of wireless communications IEEE spread spectrum and physical layer specification MAC functional specification: DCF mode role in WLANs – infrastructure networks role in MANETs MAC functional specification: PCF mode Mobile IPv4 Mobile IPv6 IIT Bombay References IEEE Computer Society 1999, Wireless LAN MAC and PHY layer specification J. Schiller, “Mobile Communications”, Addison Wesley, 1999. – several figures Short tutorials on and spread spectrum by , , Mobile IPv4 – RFC 3344 (main) IPv6 and Mobile IPv6 many RFCs, Internet drafts .