WMCNR

The wireless multihop communication has been one of key research issues in recent years both in academia and wireless industry. It encompasses ad hoc radio networks, sensor networks, wireless mesh networks and mobile multihop relay related to the industrial and standardization efforts such as IEEE 802.11s, 802.15.4, 802.16j, etc. Further the multihop communications can be combined with cooperative communications and network coding, which attracted more researchers in this field.

The idea behind such multihop communications is to utilize the availability of other nodes or to borrow their transmission capability. This in many cases exceeds the delay caused by the multihop relay, the gain from which is capacity enhancement as well as coverage extension of plain radio networks.

On the other hand, there is also an unsolved problem, which may not be necessarily related to the technical issues; one question is directed to the motivation of a relay node that allows packet relay for the other transmitting nodes, by consuming its own energy. There is also a security issue for such multihop communications, noting that my own data transmission is received/captured by someone else in the air. Multiple hops also increase latency and jitter that can be problematic if close to real-time communication is needed. In that sense, there is still controversy over successful commercialization of wireless multihop communications.

Now we turn our attention to the robotics area. In these days, many researchers are noticing group behaviors found in small insects or animals such as ants, birds, and fishes, trying to realize such behaviors into the control and coordination of a team of robots with their local interaction. The multiple (usually small) robots communicate each other, sharing the same mission, naturally through wireless communications. In this respect, wireless multihop communication is an excellent candidate for inter-robot information exchange.