Routing and Broadcasting in Hybrid Ad Hoc and Sensor Networks

Hybrid ad hoc networks consist of two kinds of nodes, regular nodes and nodes with additional capabilities. For example, multi-hop cellular and wireless Internet networks consist of static or mobile nodes and access points to a fixed infrastructure. Each node may access fixed infrastructure either directly or via other nodes in multi-hop fashion. Another example is heterogeneous sensor networks, which consists of regular tiny sensors, and special nodes capable of communicating between themselves and to monitoring station using their own backbone network. In this paper, we propose some protocols for broadcasting and routing in hybrid ad hoc networks. Hybrid blind flooding uses backbone of access nodes to spread the message, otherwise blind flooding is applied. Component neighbor elimination based flooding applies neighbor elimination based broadcasting separately within each component, consisting of all nodes with the same closest access point. In adaptive flooding, each node additionally estimates whether each of its neighbor from a different component already received the packet via its own access point in the neighbor elimination process. Multipoint relaying, and dominating set based broadcasting are generalized from existing ad hoc network protocols, utilizing the capabilities of access points. These broadcasting protocols can be applied for route discovery in proactive or reactive routing protocols for hybrid ad hoc networks. In particular, broadcasting from multiple sinks in sensor networks can be used to set up routes from each sensor to its closest sink. Hybrid routing protocol for hybrid ad hoc networks applies proactive routing to maintain the link to the closest access point, and reactive routing to find route between two ad hoc nodes. Access points cooperate to reduce the hop count of later route discovery.