Forward error correction for data dissemination in MANET

Interconnecting consumer electronic devices in an ad-hoc manner is considered one of the solutions to provide next generation services like “Ambient Intelligence” or the “Internet of Things”. Since the transmission range of a single device is limited, multi-hop techniques are often employed to provide a larger network coverage. In such a mobile ad-hoc network (MANET) broadcast data is often disseminated via a simple flooding algorithm. Due to the high mobility and changing link conditions data packets get lost on their way to the receiver. To achieve acceptable user experience for these applications, forward error correction (FEC) schemes can be used. In this work we evaluate some of these schemes for multi-level coded audio data, using a simulator. An overview of the recovery results and the additional costs for the data overhead is presented for each FEC scheme. Furthermore based on the simulation results we implemented an application-layer based Parity FEC in a testbed which is used to broadcast real-time voice data in a MANET. Measurements for the real world performance of single- and multi-hop testcases are presented. Additionally a simple adaptive scheme was developed to provide a good balance between loss rate and overhead.