POWER POINT PRESENTATION NAME : MAHESHWARAN D DEPT : CSE-A 3 ND YEAR SUB CODE : CS8601 SUBJECT : MOBILE COMPUTING SUBMITTED DATE : 17 \02 \2021 REG NO : 810418104059 REFERENCE : www. mc. edu . in
Mobile Ad-Hoc Networking
What is a MANET ? MANET – (Mobile Ad-Hoc NETwork) a system of mobile nodes (laptops, sensors, etc.) interfacing without the assistance of centralized infrastructure (access points, bridges, etc.) Mobile Ad-Hoc Networking
The Problem Unstable paths Processing power Battery life Time delays High cost of memory
Factors Affecting MANETs Scalability Power vs. Latency Incompatible Standards Data Rates User Education Security Coverage
Solutions Table Driven DSDV CGSR WRP Source-initiated On-Demand Driven AODV DSR LMR TORA ABR SSR
The Family Tree
Destination-Sequenced Distance-Vector Routing (DSDV) Every node maintains a routing table. “Full” vs. “incremental” update Settling time – the weighted average time that routes to a destination will fluctuate before the route with the best metric is received.
Clusterhead Gateway Switch Routing (CGSR) A central “clusterhead” node is chosen. The clusterhead is chosen by the “Least Cluster Change” algorithm Traffic is routed to the current clusterhead who forwards the traffic through a gateway node to the next clusterhead in line until the clusterhead of the destination node is located. Each node must maintain a cluster member table
CGSR (cont.)
Wireless Routing Protocol (WRP) 4 tables: Distance, routing, link-cost, and message retransmission list Neighboring nodes broadcast update messages Uses hello messages to establish connectivity Checks all incoming update information
Comparing Table Driven Routing Protocols
Ad-hoc On-demand Distance Vector Routing (AODV) Route Request Packets (RREQ) The source node broadcasts an RREQ to all neighboring nodes. Nodes record the source of the first RREQ received to establish a reverse path.
AODV (cont.) Route Reply Packets (RREP) The destination or node with a route to the destination unicasts a RREP back to the source to establish a route.
Dynamic Source Routing (DSR) Each node maintains a route cache. If a source node has no route in its cache, it broadcasts a route request. A route reply is generated when either the destination or a node with a route to the destination is found. Supports symmetric links
DSR (cont.) Maintenance is accomplished by route error packets and acknowledgements. If a node fails to send an acknowledgement, any route that contains that node is truncated.
Temporally-Ordered Routing Algorithm (TORA) Used in highly dynamic networks Provides multiple routes for source/destination pair Uses direct acyclic graphs to measure “height” Assumes all nodes have synchronized clocks Classifies links as upstream and downstream
TORA (cont.)
Associativity-Based Routing (ABR) Uses degree of association stability as a metric Strives to build “longer-lived” routes
Signal Stability Routing (SSR) Selects routes based on signal strength and location stability Periodic beacons update signal strength tables Only requests that are received over strong channels are forwarded unless the PREF field in the header is set to allow weak channels
What is VANET ? Vehicular Ad–Hoc Network, or VANET a form of Mobile ad-hoc network provide communication - among nearby vehicles - between vehicles - nearby fixed equipment
How vehicular communications work - road-side infrastructure units (RSUs), named network nodes , are equipped with on-board processing and wireless communication modules
How vehicular communications work (Continue) - vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) communication will be possible
What can VANET provide The VANET can provide Safety Efficiency Traffic and road conditions Road signal alarm Local information
Related work Research have been worked Outline challenges for VANET - availablility , mobility Describe particular attacks -DoS, alteration attacks Suggest solution towards attacks
Security Requirements Message Authentication and Integrity Message Non-Repudiation Entity Authentication Access Control Authorization Message Confidentiality Privacy and Anonymity Availability Liability Identification
Security Requirements Message Authentication and Integrity - Message must be protected from any alteration Message Non-Repudiation - The sender of a message cannot deny having sent a message Entity Authentication - The receiver is ensured that the sender generated a message - The receiver has evidence of the liveness of the sender
System Model Vehicular communications system - Users - Network nodes - Authorities
System Model Users - user is the owner or the driver or a passenger of the vehicle Network Nodes - processes running on computing platforms capable of wireless communication - Mounted on vehicles and road-side units (RSUs)
Communication Model Frequent Broadcast Communication Most of the vehicular network traffic is Broadcasted at the network or application layers Message are transmitted either periodically or triggered by network events Transmission period is low Time-sensitive Communication Message delivery can be constrained by deadlines - different messages have different delay requirements