Bae Systems Information and Electronic Systems Integration Inc.

Kevin M McNeill

Matthew J Sherman

Keith Faulk Conner

Phong C Khuu

Timothy McNevin

Tim McNevin

Michael J Weber

Naresh Chand

Brian D Loop

Ralph E Martinez

David Claypool

John C Deal

Todd Haynes

Walter G Whimpenny

Thai N Nguyen

Scott A Burgan

Qui M Le

Alim Needham

The present invention relates to a system and method for providing channel access synchronization in a time division multiple access (TDMA) multi-hop network employing a plurality of time slots defined within a frame structure which repeats. The system and method includes nodes which have local clock variables. The local clock variables generate an expected arrival time of signals from other nodes in the network. Each node then determines whether the local clock variable needs adjusting after receiving a transmission and comparing the expected arrival time with the actual arrival time. Thus, time synchronization across the network is distributed and updated locally at each node. Networks may be merged by casting out nodes in one network and joining those cast out nodes with the other network. Newly joined nodes are thereafter time synchronized into their new network by comparing actual and expected arrival times and updating their clock accordingly.

System and method to provide channel access synchronization without time-stamp exchange in time division multiple access (TDMA) multi-hop networks

Nodes in a wireless network participate in either point-to-multipoint (PMP) or MANET/mesh communications with other nodes on one or more shared channels of the network. A first or base station node transmits a downlink signal having a time frame structure of determined duration to a number of second or subscriber nodes. Portions of the frame structure establish (i) first time periods during which messages are transmitted from the first node to the second nodes, and (ii) second time periods during which messages are transmitted from the second nodes to the first node, using the PMP protocol on one or more shared channels or subchannels of the network. Other portions of the time frame structure establish third time periods during which nodes communicate with one another using the MANET/mesh protocol on the shared channels or subchannels, while avoiding interference with messages transmitted under the PMP protocol.

Supporting mobile ad-hoc network (MANET) and point to multi-point (PMP) communications among nodes in a wireless network

Real and simulated (virtual) networks are interfaced with one another for carrying out hardware-in-the-loop (HITL) testing and evaluations. A simulated network is modeled at a workstation by running a network simulation or discrete event modeling tool on the workstation. A virtual gateway node is defined in the simulated network, and the gateway node is linked with a network adapter on the workstation. An external real network operating with Internet protocol (IP) is also linked with the adapter. The adapter and the gateway node are configured to (i) translate simulated data packets sent from nodes of the simulated network and designated for the real network, into IP data packets for routing or processing by the real network, and (ii) translate IP data packets sent from nodes of the real network and designated for the simulated network, into simulated data packets for muting or processing by the simulated network.

Interfacing real and virtual networks in hardware-in-the-loop (HITL) simulations

A fiber optic link for platforms with data sources including, e.g., sensors, cameras, radars and antennas. An array of optical transmitter/receiver pairs is coupled to an integrating network of the platform. Data modules are each coupled to certain ones of the data sources and include a receiver for detecting control data, and a modulator for modulating a light signal according to signals from the module's data sources. At least one optical fiber is coupled between a given transmitter/receiver pair of the array, and a corresponding data module. A laser source associated with each transmitter supplies a light signal with the control data to a corresponding data module downstream over an optical fiber. The light signal is modulated by the signals from the module's data sources, and the modulated light signal is returned to an array receiver upstream over an optical fiber.

Bi-directional optical link between multiple data sources and a processing node in an avionics platform

A process and system for enhancing connectivity among nodes of a wireless communications network by adapting to changes in the network topology. Nodes of the network are configured to operate according to either (i) an ad hoc protocol wherein a given node assumes a role of a mesh node capable of connecting with other like-configured nodes, or (ii) a point-to-multipoint protocol wherein the given node assumes a role of either a base station, or a subscriber station being served by another node which is assuming the role of a base station. A determination is made as to whether each node should operate according to the ad hoc protocol or the point-to-multipoint protocol, in order to maintain an optimum state of connectivity among all nodes of the network. The determined operating protocol is then implemented for each node.

Enhancement of node connectivity in a wireless communications network with changing topology via adaptive role changing

Member nodes of a wireless point-to-multipoint (PMP) network may participate in mobile ad hoc (MANET) or mesh communications with other nodes on the same channels used by the network for PMP communications. A PMP network base station node transmits a downlink signal defining a downlink map for scheduling first time periods for transmitting messages to subscriber station nodes, and an uplink map for scheduling second time periods allowing a subscriber station node to transmit messages to the base station node in a scheduled second time period. A MANET/mesh zone is allocated in either or both the downlink and the uplink maps, each zone operating to reserve one or more time slots and channels in which the base station and other nodes may communicate using a MANET/mesh protocol, thus avoiding interference with communications that are being conducted between the base and the subscriber station nodes under the PMP protocol.

Supporting mobile Ad-Hoc network (MANET) and point to multi-point (PMP) communications among nodes in a wireless network

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Alexandria, VA, United States of America

Kevin M McNeill