Performance Improvement Using Self-Link-Breakage Announcement in Wireless Ad-hoc Networks

Functions of wireless routing protocols are classified two: finding a route and maintaining the route. The route maintenance function also has two functions: detecting a link-breakage and recovering the broken route. This paper proposes a method to actively detect link breakages unlike conventional methods such as using a hello messages in the routing layer, using transmission failure notification from MAC layer, and using channel condition changes in the physical layer. This paper considers scenarios that nodes can anticipates the link breakages such as the link breakage caused by nodes´ physical damages or power off or power save mode. For the cases, this paper proposes that a node causing a link breakage actively sends a built-in message to its neighbors, allowing them to instantly detect the upcoming link-breakage. Therefore, it quickly starts link recovery processes from the neighbor nodes. This paper proposes brief system architecture of a node as well as a protocol for performing the method. Delay reduction in detecting link breakage by using the proposed method is compared with MAC layer-based detecting method.