Integrating Local Neighborhood Congestion and Path Stability into QoS Routing for Tactical Networks

Routing protocols for wireless Mobile Ad Hoc Networks (MANETs) have been explored extensively in recent years. However, most of the work thus far has focused on finding a feasible route from a source to a destination in a timely and efficient manner without considering the impact on the transport performance of existing application traffic or the newly added flows. As a result, parts of the network become saturated with no means of adaptively compensating for or routing traffic around the overloaded areas, thereby lowering network efficiency. While this limitation may be acceptable for best-effort or delay-tolerant data transfers, real-time applications often require a certain level of Quality-of-Service (QoS) from the network. A comprehensive QoS-enabled MANET solution benefits from a QoS-aware routing scheme that considers the application's transport requirements and the data transport conditions of available paths. We propose a distributed multi-path QoS-aware routing scheme that leverages common MANET characteristics (e.g., neighborhood congestion and path stability) to meet the transport service requirements of real-time applications. The QoS routing scheme implements a method of superimposing distributed neighborhood congestion, neighborhood density, link stability and delay information over multiple discovered paths when calculating the next hop decision. In addition, the solution increases overall network capacity by using otherwise idle network resources. In this paper, we discuss multi-path discovery, the associated QoS metric calculations, and the QoS-aware path selection process.