Abstract: A wireless communication system and method for a network having a tree topology. An initial path from a base station to an end relay node is selected. The path selection includes an active communication path and a redundant communication path. The path selection is based on at least one policy factor. The at least one policy factor is monitored and the path is updated based on a change to the monitored at least one policy factor.

Abstract: A wireless network includes a base station and a relay station for extending wireless coverage of the base station. Downlink data is sent by the base station and relayed through the relay station to a mobile station, where the downlink data is associated with a preamble that is sent directly from the base station to the mobile station. A transmit power of the relay station is adjusted for transmitting the downlink data from the relay station to the mobile station to reduce a difference between a first power level of the preamble received at the mobile station and a second power level of the downlink data received at the mobile station. The uplink transmit power of the mobile station for the data sent to the relay station is adjusted to compensate for the difference in path loss from mobile station to base station and mobile station to relay station and to compensate for the difference in noise_plus_interference level at relay station compared to that of the base station.

Abstract: Systems and methods are provided for delivering both PMP communications, for example standard cellular communications via a base station, and also delivering P2P communications, for example, communications between two mobile stations, using the same spectral resources for both types of communication.

Abstract: One or more relay stations may be employed along a wireless communication access path between an ingress station and an egress station. A logical communication tunnel is established between the ingress and egress stations through any number of intermediate relay stations to handle session flows of PDUs. As PDUs arrive, the ingress station may determine and add scheduling information to the PDUs before they are delivered to the downstream intermediate relay stations or egress stations. The scheduling information is used by the downstream stations to schedule the PDUs for further delivery. The scheduling information may also be used by the egress station to schedule the PDUs for delivery. The scheduling information added to the PDU by the ingress station bears on a QoS class associated with the PDU, a deadline for the egress station to deliver the PDU, or a combination thereof.

Abstract: Systems and methods are provided for delivering both PMP communications, for example standard cellular communications via a base station, and also delivering P2P communications, for example, communications between two mobile stations, using the same spectral resources for both types of communication.

Abstract: The invention provides a high flow power cable for a welding system designed for effective cooling of the power cable while maintaining maneuverability of the cable. Provided is a power cable having two segments, the first segment being larger in diameter than the second segment. The first segment is generally coupled to the power source and the second segment is coupled to the welding torch. The first segment includes a thicker wire, which has less resistance and dissipates less heat while the second segment includes a thinner wire, allowing for easier handling. Additionally, cooling fluid is conducted through the first segment and the second segment, further cooling the cable.

Abstract: A method selects a path for forwarding a data packet in a wireless communication system. A system capacity versus delay impact curve is calculated for a direct path to mobile station. The direct path has a capacity cost based on communication quality of a direct link between a base station and the mobile station. This curve is shifted by a predetermined time corresponding to an additional delay over a relay path to produce a projected capacity curve for the relay path having a second capacity cost determined according to a combined measure of signal quality of multiple links in the relay path. The second capacity cost is multiplied by a capacity cost ratio to produce a relay capacity curve. The direct path or the relay path is selected based on a comparison of the system capacity versus delay impact curve and the relay capacity curve according to a QoS requirement.

Abstract: Systems and methods for improved liquid cooling of a tungsten inert gas (TIG) welding torch are provided. The improved welding torch may feature conduits for conveying coolant from a cooling system to a collar, which holds a tungsten electrode of the welding torch, and back. A coolant return conduit may be disposed in a coolant supply conduit to improve thermal insulation of an outer surface of the welding torch. Some embodiments may feature a helical channel formed in the collar for conveying coolant around the electrode multiple times before returning the coolant through the return conduit.

Abstract: Embodiments of a tungsten inert gas (TIG) welding torch with an improved air cooled handle are provided. The welding torch may include a body, a cable assembly, and a torch head, with a handle placed over the body and the cable assembly. The handle may feature a curved end designed to fit near the torch head without contacting the torch head, providing a closer gripping point to allow greater control of the torch. In addition, the handle may be spaced from the body and the cable assembly to form an air space within the handle through which air may flow to cool the handle.

Abstract: A method selects a path for forwarding a data packet in a wireless communication system. A system capacity versus delay impact curve is calculated for a direct path to mobile station. The direct path has a capacity cost based on communication quality of a direct link between a base station and the mobile station. This curve is shifted by a predetermined time corresponding to an additional delay over a relay path to produce a projected capacity curve for the relay path having a second capacity cost determined according to a combined measure of signal quality of multiple links in the relay path. The second capacity cost is multiplied by a capacity cost ratio to produce a relay capacity curve. The direct path or the relay path is selected based on a comparison of the system capacity versus delay impact curve and the relay capacity curve according to a QoS requirement.

Abstract: Methods and systems for providing efficient communications between two mobile stations served by the same base station or relay station are provided. A base station maintains information identifying which mobile stations it is serving. When a connection is set up between two mobile stations, if they are both being served by the same base station, the base station forwards traffic directly between the two mobile stations without forwarding it on to higher level network entities.

Abstract: Methods and systems for providing efficient communications between two mobile stations served by the same base station or relay station are provided. A base station maintains information identifying which mobile stations it is serving. When a connection is set up between two mobile stations, if they are both being served by the same base station, the base station forwards traffic directly between the two mobile stations without forwarding it on to higher level network entities.

Abstract: Systems and methods are provided for delivering both PMP communications, for example standard cellular communications via a base station, and also delivering P2P communications, for example, communications between two mobile stations, using the same spectral resources for both types of communication.

Abstract: One or more relay stations may be employed along a wireless communication access path between an ingress station and an egress station. A logical communication tunnel is established between the ingress and egress stations through any number of intermediate relay stations to handle session flows of PDUs. As PDUs arrive, the ingress station may determine and add scheduling information to the PDUs before they are delivered to the downstream intermediate relay stations or egress stations. The scheduling information is used by the downstream stations to schedule the PDUs for further delivery. The scheduling information may also be used by the egress station to schedule the PDUs for delivery. The scheduling information added to the PDU by the ingress station bears on a QoS class associated with the PDU, a deadline for the egress station to deliver the PDU, or a combination thereof.

Abstract: In a method of operating a relay station in a multihop wireless relay network, the relay station in communication with a superordinate station and a subordinate station: a downlink transmission from the superordinate station is received at a first carrier frequency; an uplink transmission from the subordinate station is received at a second carrier frequency; a downlink transmission to the subordinate station is transmitted at the first carrier frequency; and an uplink transmission to the superordinate station is transmitted at the second carrier frequency.

Abstract: A relay station is provided for use in a wireless communication system. The wireless communication system includes a plurality of base stations communicatively coupled to a backhaul network and at least one mobile station. The relay station is shared by at least a first base station and a second base station. The relay station includes a transceiver, a controller and relay circuitry. The transceiver transmits signals to and receives signals both base stations and a mobile station. Signals transmitted to the base stations include a single preamble, MAP and FCH. The controller is electrically connected to the transceiver and is operable to measure a signal quality of the mobile station while connected to the first base station. The relay circuitry is electrically connected to the controller and is operable to conduct a phased handoff from the first base station to the second base station based on the signal quality.

Abstract: Systems and methods are provided for delivering both PMP communications, for example standard cellular communications via a base station, and also delivering P2P communications, for example, communications between two mobile stations, using the same spectral resources for both types of communication.

Abstract: A mobile relay system for supporting communications between a fixed station and mobile terminals comprising a plurality of mobile relay stations that are associated with each other and provided on a moving platform, wherein each of the plurality of mobile relay stations is capable of facilitating communications with mobile terminals within communication range and at least one of the plurality of mobile relay stations is further capable of facilitating communications with a fixed station within communication range of the at least one of the plurality of mobile relay stations.

Abstract: Security in wireless communication networks that employ relay stations to facilitate communications between base stations and mobile stations is enhanced. In one embodiment, resource information provided to one or more relay stations from a base station or another relay station is encrypted prior to being delivered to the one or more relay stations. Only authorized relay stations are allocated an appropriate key necessary to decrypt the resource information. As such, only appropriate relay stations are able to access and use the resource information to effect communications directly or indirectly between the base stations and the mobile stations. In certain embodiments, the resource information is delivered between the various base and relay stations using either unicast or multicast delivery techniques.

Abstract: A wireless communication system and method for wireless communication in a multi-hop network. A first preamble is transmitted using a first repetition cycle. Monitoring for a second preamble is done in a second repetition cycle. The first repetition cycle is different than the second repetition cycle.