Spread routing with FEC for real-time multimedia in wireless networks

Efficiency of Forward Error Correction (FEC) in packet switched networks strongly depends on the buffer size. Use of FEC in off-line streaming, offering large buffers, gives spectacular results; but real-time streaming puts hard restrictions on the buffer size leaving FEC helpless for combating long link failures on a single path route. Apart the buffering ax, there exists however another orthogonal method, the multipath routing, which can make FEC effective also for the real-time streaming. Previous works already demonstrated the advantage of the path diversity but limited themselves to restricted topologies, often double-path examples. Although the pure fact of diversity is an important step, we, however, explore also the wide space of possible multi-path routing topologies. For measuring the friendliness of a particular multi-path routing suggestion, we introduce Adaptive Redundancy Overall Need (ARON), which is proportional to the total encoding effort needed for combating the failure of each link in the multi-path route. A novelty brought by ARON is that a routing topology of any complexity can be rated by a single scalar value. Finally, we introduce capillary routing iterative algorithm leading us to a large range of multi-path spread routing patterns, starting from a simple (max-flow multi-path) suggestion toward more elaborated and spreader solutions (by individually equilibrating the sub-flows of previous solutions). Capillary routing layers are built on numerous network samples obtained from a random walk wireless Mobile Ad-Hoc Network (MANET) and we rate them with ARON showing that the FEC friendliness improves substantially as the routing grows more spreader.