Reducing Routing Overhead in MANET

1. Overhead Problem in Topology based routing protocols

Dynamic nature of MANET causes frequent link failure, which in turn requires the new route to be discovered. Frequent route discovery increases the overhead in the network. Scalability of the MANET can be improved if the routing overhead is reduced.

Solution

A neighbor coverage-based probabilistic rebroadcast (NCPR) protocol exploits the neighbor coverage knowledge effectively. To reduce the number of rebroadcasts of the RREQ packet, rebroadcast probability is used that combines the additional coverage ratio and the connectivity factor.

Solution in NS2

 
  • Routing overhead before and applying NCPR can be calculated from the trace file and the results can be compared using x-graph.

  • Impact of routing overhead reduction lies in improving the packet delivery ratio and reducing end-to-end delay.

Related Project Titles:

 
  • Xin Ming Zhang, En Bo Wang, Jing Jing Xia, and Dan Keun Sung “A Neighbor Coverage-Based Probabilistic Rebroadcast for Reducing Routing Overhead in Mobile Ad Hoc Networks” IEEE TRANSACTIONS ON MOBILE COMPUTING, VOL. 12, NO. 3, MARCH 2013.

2. Overhead Problem in location based routing protocols

The location based routing process uses the immediate next hop information to forward the data. Immediate next hop is the one among the neighbors. Beacon update assists in neighbor identification. Periodic beacon update causes the high overhead in the network.

Solution

Adaptive Position Update (APU) process reduces the beacon overhead on the basis of node mobility pattern and packet forwarding pattern. Mobility Prediction (MP) rule and On Demand Learning (ODL) rule apply in APU strategy. Solution in NS2.

Solution in NS2

 
  • Data Transmission is established between the source and destination. From the trace obtained from the data transmission from source to destination, performance metrics such as energy consumption, overhead, and packet delivery ratio are obtained using the AWK script. The AWK script processes the trace file and produces the result. Using the results obtained from the AWK script graph is plotted for performance metrics using the X-graph tool available in NS-2.

  • Performance of APU is evaluated using extensive NS-2 simulations for varying node speeds and traffic load. Results indicate that the APU strategy generates fewer beacons overhead as other beaconing schemes, but achieve better packet delivery ratios, less overhead and energy consumption.

Related Project Titles:

 
  • Quanjun Chen, Salil S. Kanhere, and Mahbub Hassan “Adaptive Position Update for Geographic Routing in Mobile Ad Hoc Networks” IEEE TRANSACTIONS ON MOBILE COMPUTING, VOL. 12, NO. 3, MARCH 2013.