an overview of the web over wireless group n.
Skip this Video
Loading SlideShow in 5 Seconds..
An Overview of the Web over Wireless Group PowerPoint Presentation
Download Presentation
An Overview of the Web over Wireless Group

Loading in 2 Seconds...

play fullscreen
1 / 48
Download Presentation

An Overview of the Web over Wireless Group - PowerPoint PPT Presentation

Download Presentation

An Overview of the Web over Wireless Group

- - - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

  1. An Overview of the Web over Wireless Group Web over Wireless Group UC, Berkeley Web over Wireless Group

  2. Group Prof. Pravin Varaiya Researchers: Dr. Anuj Puri Baris Dundar Graduate Students: Mustafa Ergen Sinem Coleri Duke Lee Xuanming Dong Rahul Jain Mohit Agarwal Amit Mahajan Under Graduate Students: Jeff Ko Yan Li Web over Wireless Group

  3. Research Focus • Cellular networks • Ad Hoc wireless networks • Sensor networks • Applications Web over Wireless Group

  4. Current Cellular newtorks Geographical area divided into cells Base station (BS) in each cell Primary traffic is voice What will future wireless networks look like? Primary traffic is data Cellular + Wireless LANs Cellular Networks Web over Wireless Group

  5. 802.11 Wireless LANs Upto 50 Mbps Unlicensed spectrum Cheap and easy to set up Hot spot coverage with wireless LANs Mobility between networks Applications 802.11 Hot Spot Coverage Wide Area Cellular Coverage Heterogeneous Wireless Networks Web over Wireless Group

  6. Wireless token ring DSDV routing Geographical routing WTP Sensor Networks Ad Hoc Wireless Networks Web over Wireless Group

  7. Wireless Token Ring Protocol • Multiple rings • Station with token transmits • Deterministic bounds on access time • “Adjacent” rings transmit on different channels • Basic operations of “join” and “leave” to allow mobility Web over Wireless Group

  8. DSDV - Wireless Routers • Cheaper/better performance cellular networks • Ad Hoc wireless networks Internet Wireless Router Web over Wireless Group

  9. Geographical Routing Algorithm • All nodes know their positions • Packet for a destination postion • Use geographical information in routing • i.e, route to neighbor nearest to the destination Geographical network Web over Wireless Group

  10. Transport Layer (WTP) • UDP: Connectionless but unreliable • TCP: Connection oriented and reliable • WTP: Connectionless and reliable • Used by WAP (Wireless application protocol) as a “transaction protocol” for cell phones • Optimized for wireless links for short messages • Doesn’t use congestion control • Small WTP headers • Message based protocol Web over Wireless Group

  11. Network Architecture TCP/UDP/WTP Transport Layer Mobility Management Geographic routing, DSDV, QOS, TBRF, STARA Network Layer Data Link Token ring, bluetooth 802.11, Seedex MAC Physical Layer OFDM Web over Wireless Group

  12. Mobility and Internetworking Among Networks Internet 802.11 Token Ring DSDV Geographic Routing Sensor Networks Web over Wireless Group

  13. Technology • Wireless Token Ring • DSDV routing • Geographical routing and WTP • Mobile IP • Fast Handoff • MEWLANA • Sensor Networks Web over Wireless Group

  14. WIRELESS TOKEN RING PROTOCOL Web over Wireless Group

  15. Introduction • The Wireless Token Ring Protocol (WTRP) is a medium access control protocol for wireless networks in mission critical systems. • It supports quality of service in terms of bounded latency and reserved bandwidth. • The token passing defines the transmission order, and each token is forced to give up the token after a specified amount of time. • Each ring has unique ring id based on unique MAC address of one of the stations of the ring. (The station is called the owner of the ring). • When owner leaves the ring, another station elects itself to be the owner of the ring. Web over Wireless Group

  16. Invite Contend Token Token 1. SET_SUC C 2. SET_PRED A A C B F D E Descriptions (Operations) Joining: Stations periodically invite other nodes to join the ring by broadcasting the available resources left in the medium Leaving: When B wants to leave, it requests A to connect to its successor, C. If A does not have connection with C, then it connects to the next node in terms of the transmission order of the ring. Web over Wireless Group

  17. C A B 6 2 6 2 F D 2 2 E 1. Retransmit TOKEN 6 6 6 2 2. SET_PRED A 2 6 6 6 6 Descriptions (Management) Ring Recovery Able to recover quickly by keeping information about topology of the ring, recovers from multiple simultaneous faults by taking increasingly drastic actions Token Recovery Multiple token is deleted using unique priority of token based on generation sequence number and token ring address pair. Web over Wireless Group

  18. WTRP Deliverables Web over Wireless Group

  19. WTRP USER-SPACE Web over Wireless Group

  20. WTRS-WTR Simulator Web over Wireless Group

  21. Performance Analysis Web over Wireless Group

  22. Performance Analysis Web over Wireless Group

  23. DSDV Routing Web over Wireless Group

  24. DSDV Routing Protocol • Based on Bellman-Ford algorithm • Use sequence number to avoid loop-forming and make convergence fast • The sequence number must be originated by the destination node • There is a trade off between the stability and the convergence speed of the routing table Web over Wireless Group

  25. System Architecture Web over Wireless Group

  26. Events of DSDV Protocol 1.Timers • Periodical updates (30-second) • Random offset timer (at most 30-second) • Timeout (30-second) • garbage-collection (120-second) 2.Input processing • Request • Response • response to a specific query • regular updates • triggered updates triggered by a metric change 3.Output Processing • by input processing when a request is received • by the periodical routing update • by triggered updates caused by changed route metric Web over Wireless Group

  27. Timers in DSDV • Periodical updates (T) • send the full routing table to the neighbors. • Random offset timer (<T) • suppress the triggered updates and avoid unnecessary collisions on broadcast networks. • Timeout (3*T) • the routing entry is no longer valid if the TTL is zero. However, it will be retained in the table for a short timeso that neighbors can be notified. • garbage-collection (3*T) • the route is deleted from the table and no longer included in all updates with a metric of infinity. Web over Wireless Group

  28. How does the DSDV Daemon work DSDV_Daemon() { Detect network interfaces and copy required information; Read configure file and initialize all variables and routing table; Create a UDP socket for DSDV routing messages; Send hello message to all neighbors; Install signal handlers for different kinds of timers; Loop for events (select()) Different timers: Input processing: Output processing: Other system events: Loop end } Web over Wireless Group

  29. Geographical Routing Web over Wireless Group

  30. Overview • “Geographical Routing using partial information for Wireless Ad Hoc Networks”, R. Jain, A. Puri and R. Sengupta • A routing protocol for wireless ad hoc networks using information about geographical location of nodes. Web over Wireless Group

  31. Architecture • Multi-threaded • Location Advertisement Protocol • Geographic Routing Protocol • Route Discovery Protocol • Routing Table Update Daemon • Assumes the presence of a GPS system at each node in the network Web over Wireless Group

  32. Geographical Routing Protocol When a node receives data packet : Check_final_destination if (final_destination is a neighbor) forward the packet else check the routing table, find the closest neighbor to this destination and then forward the packet to that neighbor Web over Wireless Group

  33. Route Discovery Protocol • If a node can not send a packet to a destination because of a physical barrier it will use a DFS type of algorithm in order to find an alternate route to the destination. • When the route discovery packet reaches the final destination, the destination node will send the packet back to the sender and this way the sender will discover the route to that specific destination Web over Wireless Group

  34. Packet Format Eth. Header Geog. Header WTP Hdr Data (if any) • Route advertisement and route discovery packets don’t need the data field (i.e. length field in the geographic header is equal to the length of the geographic header) • Length field for Data packets is equal to the length of geographic header + length of data Web over Wireless Group

  35. Geographic Header Src Loc + MAC Dst Loc + MAC Checksum p.len seq opts • Location: UTM Location of the node • MAC: MAC Addr of the node • Checksum: checksum over the header • Packet Len: length of the packet • Seq: Sequence number • Opts: options (TBD) Web over Wireless Group

  36. UTM Coordinates • The Universal Transverse Mercator projection and • grid system was adopted by the U.S. Army in 1947 • for designating rectangular coordinates on large • scale military maps. UTM is currently used by the • United States and NATO armed forces. • Why UTM? • Supported by all GPS receivers • Simpler to use than latitude and longitude. Web over Wireless Group

  37. Demo Scenario C { 500000, 4000500, 100 } B{ 500500, 4000250, 100 } A{ 500000, 4000000, 100 } • MAC Filter • Transport Layer • WTP Web over Wireless Group

  38. WOW Mobile IP Web over Wireless Group

  39. Overview • IP Mobility Support, C. Perkins, RFC 2002 • Protocols • Tunneling (HA – FA) • Registration (MA - FA - HA) • Agent Advertisement (FA) Web over Wireless Group

  40. Mobile Agent Mobile Agent Mobile IP subnet Foreign Agent #1 & Home Agent Correspondent Host Router subnet subnet Foreign Agent #2 & Web over Wireless Group

  41. Registration • Mobile needs to make the home agent aware of its present location i.e, the care of address • Using UDP • Registration request (mobile -> home) • Registration reply (home -> mobile) contains duration of validity (~100 seconds) • What if UDP packet is dropped!! • Request sent again after reasonable time Web over Wireless Group

  42. Tunneling • Encapsulation is done for redirection • Home agent tunnels the packet to the care of address • Destination foreign agent de-tunnels the packet and transmits it to the mobile • Packets from mobile to correspondent host go directly (with source IP as original (fixed) IP of the mobile node) Web over Wireless Group

  43. MA Software • Listens the Agent Advertisement broadcasts sent by the FAs • Registers with FAs automatically depending on • S/N over the link , signal qualities, BER • The bandwidth available on the link • The encryption provided on the network • The cost Web over Wireless Group

  44. Mobile Agent Mobile Agent Demo Setup CH: Netmeeting (video + audio) Mobile: OpenH323 Client subnet Foreign Agent #1 & Home Agent Correspondent Host Router subnet subnet Foreign Agent #2 & Web over Wireless Group

  45. Gateway DFA FA1 FA2 FA7 FA4 FA3 FA5 FA6 FAST HANDOFFwith position based routing Intra-Domain Handoff • DFA • Takes packet from HA or CH. • Decapsulates and checks its visitor list. • Sends the packet to the related branches according to Location FA table. • FA • If it is an adjacent FA, buffer the packets. • Else send the packet to the related branches according to Location FA table.


  47. MEWLANA Mobile Enriched Wireless Local Area Network Architecture