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Explore the complexities of routing in ad-hoc networks without infrastructure, where nodes act as routers. Learn about distance vector routing, conventional solutions, new approaches, and types of ad-hoc routing protocols like DSDV and source-initiated on-demand routing. Discover strategies for efficient data transmission and network reliability.
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Challenges of Routing in Ad-hoc Networks Chandra D Yarlagadda
Ad-hoc Networks • No infrastructure • Wireless • Node acts as router • Used in meetings, emergency situations • No home agent or foreign agent
Distance vector routing Distance in hops Periodic broadcasts Router sends to next hop Fast convergence but bandwidth wasted RIP Conventional Routing Solutions • Link State • State of link • Topology of entire network • Periodic updates • Shortest path based on metric • More accurate but much more bandwidth wasted • OSPF
Problems of Using Conventional Routing protocols • Uplink and Downlink • Link Redundancy • Routing updates • Nature of routers
New Approach • Route Discovery • Simple Method is ARP • Flooding • Transmissions are broadcast • Id’s for duplicate packets • Caching of routes for future use
New Approach • Route Maintenance • Use of Caching prevents nodes to know change of state • Deals with accuracy of the route • Hop by Hop acknowledgement • Bit in the packet to request acknowledgement
Types of Ad-Hoc routing protocols • Table Driven • Source Initiated
Table Driven • Maintain up-to-date information from one node to all other nodes • Information stored in tables • Updates are used to maintain the tables • Differ from conventional routing protocols on the basis of tables maintained and updates sent
Destination-Sequenced Distance-Vector Routing (DSDV) • Every node contains a table containing all other nodes and the hops required • Sequence numbers to maintain new routes • Periodic updates are required • Network traffic is decreased by Full Dump & Incremental packets • Loop Free network • Settling Time
Wireless Routing Protocol • Distance Table • Routing Table • Link-Cost Table • Message Re-transmission List Table
Source-Initiated On-Demand Routing • Source starts a discovery process • Path found only when required • Multiple paths are found • Paths maintained till node is active or is accessible