Abstract: A communications node of a multi-node communications network is disclosed. In embodiments, the communications node includes a communications interface and controller. The controller transitions the clustering status of the communications node to a clusterhead node status. The clusterhead node identifies a cluster of neighboring nodes with which it is in communication by transmitting hello messages identifying the clusterhead node and its status but omitting a one-hop neighbor list. The clusterhead node refines link discovery to the nodes of the multi-node communications network by flooding the network (e.g., via its cluster of neighboring nodes) with routing status messages, which network nodes not part of the dominating set of clusterhead nodes are restricted from sending.

Abstract: A communications node of a multi-node communications network is disclosed. In embodiments, the communications node includes a communications interface and controller. The controller transitions the clustering status of the communications node to a clusterhead node status. The clusterhead node identifies a cluster of neighboring nodes with which it is in communication by transmitting hello messages identifying the clusterhead node and its status but omitting a one-hop neighbor list. The clusterhead node refines link discovery to the nodes of the multi-node communications network by flooding the network (e.g., via its cluster of neighboring nodes) with routing status messages, which network nodes not part of the dominating set of clusterhead nodes are restricted from sending.

Abstract: A system and method for reducing the duration of destructive interference received at a location from two transmitting antennas where either a time varying phase shift or time varying delay or both are introduced into the signal paths of one or both of the two antennas.

Abstract: A processor determines, from signals received from other communication devices, one selected transmission mode for the communication channel conditions. The processor projects multiple channel characterization parameters in a mathematical model to each of the candidate transmission modes using a model of nominal communication channel conditions to predict whether each of the candidate transmission modes will achieve the desired communication under the nominal communication channel conditions. This results in the generation of a first subset of transmission modes. The processor also projects the multiple channel characterization parameters to each of the candidate transmission modes using a model of degraded communication channel conditions to predict whether each of the candidate transmission modes will achieve the desired communication under the degraded communication channel conditions.

Abstract: A wideband phase and frequency modulator using a direct digital synthesis alias frequency band is described. The modulator is spurious free by the utilization of a fixed frequency at the output of the direct digital synthesizer wherein only certain submultiples of the clock frequency are used. Known frequency ratios relative to the clock frequency of the direct digital synthesizer (DDS) cause the DDS to function as a simple divider resulting in extremely low spurious levels when additional conditions are met. An additional frequency synthesizer may be utilized to achieve a tuning range since the DDS output is preferably held at a fixed frequency. At least one additional mixing operation is utilized for upconversion to a microwave frequency. Since fixed frequency ratios are used, implementation simpler than a full DDS may also be constructed consisting of digital modulators, multiplexers, digital to analog convertors, and filters.