The current free-drifting sonobuoy systems provide information that is uplinked on a very high frequency to distribute collected data needed by the aircrew to detect, localize, track and attack hostile submarines. The addition of a capability for multiple-sensor node and platform networking is essential in the future utilization of sonobuoys in a network-centric battlespace. True multi-node, routed networking among sonobuoys, with improved telemetry permitting higher bandwidth data to be transmitted from platform to platform and from deployed sensors to platform and shore stations, unmanned autonomous vehicles, surface vessels, submarines, aircraft, and shore-based installations is highly desirable. A local area network is envisioned using standard or modified commercial off-the-shelf protocols with the capability of point-to-point, peer-to-peer, and multicast connectivity among multiple sensor nodes and platforms. An important point is that any intra-platform communication protocol should not be selected with simple point-to-point applications in mind so that obstacles for future multiple-node networking can be avoided. Furthermore, sensor networks should be self-organizing to permit an easy deployment and to be fault tolerant. Traffic should be evenly distributed over all the nodes, such that all nodes die approximately at the same time within given power constraints. As a result, NAL Research proposes the use of Iridium modem, the Iridium network, and the iSAT communication software modules to meet these requirements.
Keywords: Iridium, Satellite, Low-Earth Orbit, L-Band, Point-to-Point, Peer-to-Peer, Multicast
