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

Web over Wireless Group 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

4/2/2002Web over Wireless Group Research Focus  Cellular networks  Ad Hoc wireless networks  Sensor networks  Applications

4/2/2002Web over Wireless Group Cellular Networks  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

4/2/2002Web over Wireless Group Heterogeneous Wireless Networks  Wireless LANs Upto 50 Mbps Unlicensed spectrum Cheap and easy to set up  Hot spot coverage with wireless LANs  Mobility between networks  Applications Wide Area Cellular Coverage Hot Spot Coverage

4/2/2002Web over Wireless Group Ad Hoc Wireless Networks  Wireless token ring  DSDV routing  Geographical routing  WTP  Sensor Networks

4/2/2002Web over Wireless Group 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

4/2/2002Web over Wireless Group DSDV - Wireless Routers  Cheaper/better performance cellular networks  Ad Hoc wireless networks Internet Wireless Router

4/2/2002Web over Wireless Group Geographical Routing Algorithm Geographical network  All nodes know their positions  Packet for a destination postion  Use geographical information in routing i.e, route to neighbor nearest to the destination

4/2/2002Web over Wireless Group 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

4/2/2002Web over Wireless Group Network Architecture Physical Layer Data Link MAC Network Layer Transport Layer Token ring, bluetooth , Seedex Geographic routing, DSDV, QOS, TBRF, STARA TCP/UDP/WTP Mobility Management OFDM

4/2/2002Web over Wireless Group Mobility and Internetworking Among Networks Internet Geographic Routing Sensor Networks Token Ring DSDV

4/2/2002Web over Wireless Group Technology  Wireless Token Ring  DSDV routing  Geographical routing and WTP  Mobile IP  Fast Handoff  MEWLANA  Sensor Networks

Web over Wireless Group WIRELESS TOKEN RING PROTOCOL

4/2/2002Web over Wireless Group  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. Introduction

4/2/2002Web over Wireless Group 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. A B C D E F 1. SET_SUC C 2. SET_PRED A Invite Contend Token

4/2/2002Web over Wireless Group 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 AB C D E F 2. SET_PRED A 1. Retransmit TOKEN Token Recovery Multiple token is deleted using unique priority of token based on generation sequence number and token ring address pair

4/2/2002Web over Wireless Group WTRP Deliverables

4/2/2002Web over Wireless Group WTRP USER-SPACE

4/2/2002Web over Wireless Group WTRS-WTR Simulator

4/2/2002Web over Wireless Group Performance Analysis

4/2/2002Web over Wireless Group Performance Analysis

Web over Wireless Group DSDV Routing

4/2/2002Web over Wireless Group 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

4/2/2002Web over Wireless Group System Architecture

4/2/2002Web over Wireless Group 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 1.response to a specific query 2.regular updates 3.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

4/2/2002Web over Wireless Group 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 time so 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.

4/2/2002Web over Wireless Group 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 Geographical Routing

4/2/2002Web over Wireless Group 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.

4/2/2002Web over Wireless Group 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

4/2/2002Web over Wireless Group 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 Geographical Routing Protocol

4/2/2002Web over Wireless Group l 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. l 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 Route Discovery Protocol

4/2/2002Web over Wireless Group Packet Format Eth. HeaderGeog. HeaderData (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 WTP Hdr

4/2/2002Web over Wireless Group Geographic Header Src Loc + MACDst Loc + MACChecksum  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) p.lenseqopts

4/2/2002Web over Wireless Group 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. UTM Coordinates

4/2/2002Web over Wireless Group Demo Scenario MAC Filter Transport Layer WTP A { , , 100 } B { , , 100 } C { , , 100 } DstGw CC BB DstGw AA BB CC DstGw AA BB DstGw AA BB CB

Web over Wireless Group WOW Mobile IP

4/2/2002Web over Wireless Group Overview  IP Mobility Support, C. Perkins, RFC 2002  Protocols Tunneling (HA – FA) Registration (MA - FA - HA) Agent Advertisement (FA)

4/2/2002Web over Wireless Group Mobile IP Correspondent Host Home Agent Foreign Agent # & Foreign Agent # & subnet subnet subnet Mobile Agent Router

4/2/2002Web over Wireless Group 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

4/2/2002Web over Wireless Group 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)

4/2/2002Web over Wireless Group 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

4/2/2002Web over Wireless Group Demo Setup Correspondent Host Home Agent Foreign Agent # & Foreign Agent # & subnet subnet subnet Mobile Agent Router CH: Netmeeting (video + audio) Mobile: OpenH323 Client

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. DFA FA2FA1 FA3FA5 Gatew ay FA6 FA4 FA7 FAST HANDOFF with position based routing

FAST HANDOFF

MEWLANA M obile E nriched W ireless L ocal A rea N etwork A rchitecture

SENSOR NETWORKS