| Patent application number | Description | Published |
|---|
| 20080231511 | Beacon-Assisted Precision Location of Untethered Client in Packet Networks - A novel beacon-based position location technique for efficient location discovery of untethered clients in packet networks is disclosed. The position location technique utilizes the time-difference-of-arrival (“TDOA”) of a first signal transmitted by a beacon of known location and a second signal transmitted by an untethered client. The TDOA of these two signals is measured locally by at least three non-collinear signal receivers. For each of the receivers, the TDOA is used to calculate a perceived distance to the client. A circle is then calculated for each receiver, centered on the receiver and having a radius equal to the perceived distance. At least two lines defined by points of intersection of the calculated circles are then calculated. The point of intersection of the lines represents the location of the client. To facilitate operation, the signal receivers may be arranged on vertices which define a convex polygon as viewed from above. The location system requires no time (time-of-day) synchronization of the signal receivers, and only the coarse frequency synchronization, on the order of, tens of parts-per-million (ppm). The technique even works for the case where the signal receivers are run asynchronously, provided the frequency accuracies of the signal receivers are on the order of about 50ppm or better. The technique introduces no communication overhead for the beacon, client and signal receivers. Further, the computation overhead at the signal receivers is relatively low because the location detection algorithm involves only simple algebraic operations over scalar values. | 09-25-2008 |
| 20080254797 | SEAMLESS AND VERTICAL CALL HANDOFF SOLUTION ARCHITECTURE - A system, method and apparatus for facilitating handoff of communications with a user device between a first communication network having a first domain technology, and a second communication network having a second domain technology different from the first domain technology, the system, method and apparatus includes an anchor point that establishes a first service flow with the first communication network, and a second service flow with the second communication network based upon a triggering event respectively, with the user device, and a handoff device that receives at least one handoff parameter for determining a handoff operation of the user device from the first communication network to the second communication network. | 10-16-2008 |
| 20090161537 | NETWORK DATA ROUTING PROTECTION CYCLES FOR AUTOMATIC PROTECTION SWITCHING - A computer network processes data packets in the event of a network link failure. The network includes a plurality of routers that deliver data packets to the network via a plurality of links. At least one router includes a protection cycle manager. The protection cycle manager has a protection cycle packet identifier and a protection cycle packet processor. The protection cycle packet identifier identifies, as protection cycle packets, data packets having a specific protection cycle format. The protection cycle packet processor processes protection cycle packets to determine whether the packet destination corresponds to the routing node, and if the packet destination corresponds to the routing node, the protection cycle packet is treated by the routing node as a data packet received from the packet source via the failed link. Otherwise, if the packet destination does not correspond to the routing node, the protection cycle packet is sent to a protection cycle node for the routing node. | 06-25-2009 |
| 20100008351 | METHOD AND SYSTEM FOR ROUTE SYNCHRONIZATION USING TIME SYNCHRONIZATION - A system, method and apparatus synchronize protocol events in a distributed communication network. The network includes a plurality of nodes. Each node in the network includes a time source which maintains a clock signal synchronized with each other node time source in the network. An announcement of a protocol event is sent to at least one node. The announcement includes a predetermined time for implementing the protocol event. The protocol event is acted upon at the predetermined time. | 01-14-2010 |
