Addressing Scalability in Mobile Ad hoc Networks

Mobile Ad hoc Networks (MANETs) are wireless networks comprised of nodes which exhibit varying mobility and availability. Such networks are highly volatile, with network membership changing unpredictably over time. As Wifi-enabled mobile devices such as smartphones have become more ubiquitous and powerful, new applications which utilize ad hoc networking have emerged such as mobile multiplayer games and data sharing applications. Such applications currently work within single-hop distances, however, in the future multi-hop connections may be required in order to enable communication at increased distances. In such a scenario, routing protocols which can operate at high device densities and cope with large networks will be needed. The provision of routing information can, however, have a detrimental effect on application throughput and network scalability due to medium access limitations and radio interference. Attempting to provide relevant routing information without negatively impacting MANET usability represents a significant challenge. Existing approaches to routing in MANETs attempt to reduce these effects through the use of intelligent forwarding algorithms, flood propagation restrictions, dependence on geographical information or combinations of these approaches. These approaches are based upon wired network routing protocols which attempt to route packets to nodes with specific and unique identities or addresses. In a MANET, however, the identities of nodes may not be known in advance. Thus address or identity-based routing makes little sense in a MANET context. Additionally, the overheads generated by existing protocols when distributing routing information for every node or flooding queries throughout the network can have a significant negative impact on application throughput and network scalability. In recent years, new communication approaches have emerged, such as protocols designed to dynamically discover services and resources in the network. These protocols attempt to provide information regarding available services to interested clients. This function is necessary as uncertainties regarding network membership and node capability caused by mobility and limited battery capacity make the use static associations between services and specific node