Oblivious parallel probabilistic channel utilization without control channels

The research interest in sensor nets is still growing because they simplify data acquisition in many applications. If hardware resources are very sparse, routing algorithms cannot use data gathering. However, if a large number of channels can be used, then parallel transmission can compensate this drawback. If the senders and receivers are not known in advance, then a control channel poses a bottleneck for communication. We present an oblivious MAC protocol, called the funnel protocol, where the channels are nearly optimally utilized in parallel. In this, senders and receivers choose for a polylogarithmic number of rounds (several sending attempts) a decreasing number of channels which are selected equiprobably. Then, we show that a previously presented approach using only one round and therefore one type of probability distribution is optimal up to some constant factor, and considerably worse than the funnel protocol. The protocol works with few resources if a sufficient number of channels is available. The funnel protocol is simple, elegant, and does not need to know the number of senders and receivers, thus being oblivious. On the bottom line we prove that small messages can be efficiently transmitted by the MAC layer in parallel without a control channel if more than one channel for communication can be used