Hrl Laboratories, LLC

Mrl Laboratories, LLC

Srikanth V Krishnamurthy

Son K Dao

George Dionyssios Kondylis

Tamer ElBatt

Dennis Connors

Dorgham Sisalem

Prasun Sinha

Mohin Ahmed

Ozgur Ercetin

The present invention relates to power management within the context of wireless ad-hoc networks. More specifically to the effects of using different transmit powers on the average power consumption and end-to-end network throughput in a wireless ad-hoc environment. This power management approach reduces the system power consumption and thereby prolongs the battery life of mobile nodes. Furthermore, the invention improves the end-to-end network throughput as compared to other ad-hoc networks in which all mobile nodes use the same transmit power. The improvement is due to the achievement of a tradeoff between minimizing interference ranges, reduction in the average number of hops to reach a destination, reducing the probability of having isolated clusters, and reducing the average number of transmissions including retransmissions due to collisions. The present invention provides a network with enhanced end-to-end throughput performance, and lower transmit power.

Power management for throughput enhancement in wireless ad-hoc networks

The present invention provides a method and apparatus for extending a zone routing protocol. The invention is configured to provide a robust scalable framework for routing data in wireless ad-hoc networks when unidirectional linksare present. When the reverse path from a destination node (the tail) of a unidirectional linkto the originating node (the head) of the link is beyond a designated length, the invention is configured to revert to an on-demand search mechanism. The on-demand search mechanism recursively attempts to build a path to the destinationby recognizing nodes that have a route to the destination.

Scalable unidirectional routing with zone routing protocol extensions for mobile AD-HOC networks

A data flow system, where a sourcetransmits a reservation packet to an ingress element. The ingress elementpolices incoming message traffic and collects data flow information. Quality of service differentiation is realized by marking data packets of different data flows. The ingress elementregisters the reservation packet and forwards the request to a core router. The core routerevaluates the service level required, and available resources. Based on this evaluation the core routerwill reject, accept, or modify the received message, indicate the price for the requested level of service, and forward the reservation packet. The process is repeated until the reservation packet reaches the destination, which sends a feedback message to the sourceindicating the result of the reservation packet. After establishing a reservation, sourcetransmits periodic control messages and collects information regarding resource availability, and the flow path.

System for pricing-based quality of service (PQoS) control in networks

A wireless hybrid network consisting at least one satellite and a plurality mobile ad hoc nodes . The nodes are assumed to be clustered into mobile groups within the footprint of the satellite , and the objective is to enable reliable communications between the various nodes . At least one relatively powerful gateway , also mobile, is deployed for each cluster of nodes to facilitate communication with a LEO or GEO satellite . The environment is characterized by the presence of terrestrial barriers or other severe channel impairments. One of the goals of the invention is to provide a mechanism by which a mobile gateway can change its position or define its trajectory based on the position and loading of the nodes in an ad hoc network, so as to optimize certain pre-defined performance criterion, such as power, overhead, throughput.

Method and apparatus for determining position and trajectory of gateways to optimize performance in hybrid non-terrestrial-terrestrial multi-hop mobile networks

The present invention relates to power management within the context of wireless ad-hoc networks. More specifically to the effects of using different transmit powers on the average power consumption and end-to-end network throughput in a wireless ad-hoc environment. This power management approach reduces the system power consumption and thereby prolongs the battery life of mobile nodes. Furthermore, the invention improves the end-to-end network throughput as compared to other ad-hoc networks in which all mobile nodes use the same transmit power. The improvement is due to the achievement of a tradeoff between minimizing interference ranges, reduction in the average number of hops to reach a destination, reducing the probability of having isolated clusters, and reducing the average number of transmissions including retransmissions due to collisions. The present invention provides a network with better end-to-end throughput performance, and lower transmit power.

A real-time multicast scheduler method and apparatus is presented, to facilitate multicasting of real-time constant bit rate data in wireless ad-hoc networks. Constant bit rate traffic cannot tolerate delay jitter. However, a small amount of packet losses may be tolerable. In order to ensure the provisioning of a desired level of quality of service, bandwidth is reserved on the multicast structure. A goal of the real-time multicast scheduler is to avoid packet collisions and to facilitate color re-use, where &ldquo;color&rdquo; is defined as a channel selected as a combination of time-division multiple access, frequency-division multiple access, and code-division multiple access schemes. The real-time multicast scheduler provides a self-healing network which corrects for disconnections caused by node movement and nodes moving out of range of each other, while accounting for colors already assigned for data transmission in order to prevent packet collisions.

Method and apparatus for multicasting real time traffic in wireless ad-hoc networks

A real-time multicast scheduler method and apparatus is presented, to facilitate multicasting of real-time variable bit rate data in wireless ad-hoc networks. Variable bit rate traffic cannot tolerate delay jitter. However, a small amount of packet losses may be tolerable. In order to ensure the provisioning of a desired level of quality of service, bandwidth is reserved on the multicast structure. A goal of the real-time multicast scheduler is to avoid packet collisions and to facilitate color re-use, where &ldquo;color&rdquo; is defined as a channel selected as a combination of time-division multiple access, frequency-division multiple access, and code-division multiple access schemes. The real-time multicast scheduler provides a self-healing network which corrects for disconnections caused by node movement and nodes moving out of range of each other, while accounting for colors already assigned for data transmission in order to prevent packet collisions.

Method and apparatus for multicasting real-time variable bit-rate traffic in wireless Ad-Hoc networks

A predictive routing scheme for broad band Low Earth Orbit (LEO) satellite constellations is presented. The predictive routing scheme may be used to provide Quality of Service (QoS) guarantees for both Constant Bit-Rate (CBR) and Variable Bit-Rate (VBR) traffic types. The predictive routing scheme takes advantage of the predictable qualities of a LEO constellation, such as constant satellite footprint, constant satellite velocity, and predictable satellite trajectory. By using this information, combined with satellite-fixed cells which are divided into a set of equal-sized slots, along with user information such as the location of each particular user as well as the geographic concentrations of user traffic, each satellite may cooperate with surrounding satellites which have recently passed through the area into which they are entering, in order to receive predictive information regarding their future load. The information for each of the individual satellites may be used in order to determine a set of possible routes for new calls based on the predictive information regarding the future load distribution on the network. The predictive routing scheme utilizes a cost function in order to determine an optimal set of routes that maximizes the amount of unused bandwidth of the network, while still providing the required QoS guarantees.

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Calabasas, CA, United States of America

Srikanth V Krishnamurthy