A novel cluster-based routing protocol and cluster reformation criteria for mobile ad hoc networks

In many traditional hierarchical routing protocols proposed for mobile ad hoc networks, each cluster designates a single cluster-head (CH) node to relay inter-cluster traffic. These cluster-head nodes become traffic “hot-spots” and restricting cluster to access through cluster-head nodes can lead to sub-optimal route. To solve these problems, we proposed a novel cluster-based distributed gateways routing protocol, namely DGR. In our proposed scheme, we rely on border mobile terminals (BMTs) as gateways for inter-cluster routing instead of relying on CHs. CHs are not necessarily involved in each route search and data transmission process. In addition, we also proposed a cluster reformation criterion to avoid unnecessary cluster reformation. It is proved that the proposed scheme can reduce the route search time, alleviate the burden of CHs and achieve optimal routes. Moreover, it can make clusters much more stable for nodes mobility under the proposed cluster reformation criteria.