Exploiting cognitive radios in tactical point to multipoint communications

Spanning several frequencies, cognitive radios support dynamic management of the rate vs. range requirements of new generation tactical radio networks. We exploit this agility to offer point to multipoint transport implementing group communication for data services in the network. The key feature of our proposed transport protocol (PMT) resides in its ability to convey common traffic to multiple users, while at the same time carrying information to each user as quickly as possible. This is achieved by performing high level clustering of receivers in homogeneous groups, each group being served at a suitable throughput. We present an implementation of the PMT protocol in software over a GNU radio based hardware and demonstrate the performance enhancements this brings in the case of two groups of receivers, with nodes operating dynamically on different frequencies. It is therefore fully suited for novel data centric services mandated by the next generation tactical networks.