Disaster scenario optimised link state routing protocol for disaster recovery and rescue operations

The success of disaster recovery and rescue operations depends largely on effective communication. Unfortunately, the communication infrastructures are among the first victims of most natural disasters such as tsunami, floods, fire, and earthquakes as well as artificial disasters (human-made) caused by terrorist attacks and war. In this emergency condition, water, food, shelter, medical helps, and protections are required; the effort and strength needed to save lives and provide disaster victims with these basic needs must be quickly organised via an effective and reliable disaster communication network. Mobile ad-hoc networks (MANETs) enable rescuers, disaster victims and rescue volunteer workers to communicate when disasters cripple/impair communication infrastructures as the technology require to set up the network is already available in their smart phones. However, provision of a temporary OLSR protocol driven MANET for survivors to communicate often affects their device battery energy, since message routing and network flooding are prominent requirements of OLSR protocol. This unpleasant situation makes it difficult to use mobile devices for extended periods. As a result, this Thesis examines MANET’s popular Optimized Link State Routing (OLSR) protocol and identifies current energy and overhead challenges facing the protocol and modifies the protocol to create a new energy and overhead friendly OLSR protocol called Disaster Scenario Optimized Link State Routing (DS-OLSR) protocol to allow communication needs during disaster recovery and rescue operations. DS-OLSR introduces the concept of Time Slices (TSs) which confines OLSR messages (Hello, TC, HNA), and of course ALERT message (a new message type created specifically for DS-OLSR) into their respective TSs. The act of compartmenting messages into TSs greatly reduces message synchronization problems, which in turn minimises associated control overheads and energy requirement of the process. DS-OLSR equally modifies OLSR packet header through the addition of a new field, namely Originator ID (device’s phone number) and introduces message prioritisation in DS-OLSR based on devices’ Battery life called DS-OLSRMP. The introduction of Originator ID leads to the elimination of Multiple Interface Declaration (MID) messages of OLSR and message prioritisation technique extends the lifetime of low battery devices. The proposed routing protocols (DS-OLSR and DS-OLSRMP) were initially implemented in NS-3 and compared with both OLSRv1 and OLSRv2. The simulation results showed that both DS-OLSR and DS-OLSRMP performed better than both versions of OLSR as it achieves considerable energy saving, improved packet delivery, reduced routing overhead in both sparse and dense network simulation scenarios. Analytical results were obtained through mathematical models and were compared with the simulation results which proved that the new routing techniques achieve considerable energy savings along with reduction in routing overheads, thereby extending lifespan of low battery devices, and improving message delivery, leading to a better mental state of such victims during disaster recovery and rescue operations