Congestion awareness in tactical wireless networks: Discerning congestion-induced losses from wireless link effects

Efficient congestion detection represents an unsolved challenge for tactical networks. This paper presents an edge-based packet probing technique to detect congestion that incurs modest control overhead. The approach presented, herein, is “Differential Performance Packet Probing” (DP3) and leverages the differential treatment of packets at the queues of routers and radios. By measuring loss rates across different types of probe packets, DP3 can detect congestion events and, furthermore, distinguish packet losses due to path congestion events from losses due to link outage events. Extensive results are reported for lab experiments of the DP3 concept in an emulated wireless network environment and in a wired Cisco environment. Detailed statistical analysis of the tradeoff between reliability and agility of the DP3 congestion indicator is also described.