Ntt Docomo, Inc.

Youngjune Lee Gwon

Atsushi Takeshita

Daichi Funato

Ravi Kumar Jain

Toshiro Kawahara

Guangrui Fu

A method for location estimation employs filtering in both the radio signal domain and the space domain separately. The method filters raw values of the run-time radio signal measurements to reject distorted inputs. A region of confidence (RoC) is formed according to certain algorithms. Only location estimates falling within the RoC are considered for further processing. The location estimate candidates filtered by the RoC are put in a number of time-indexed bins. Each of the bins contains location estimate candidates obtained at similar times. A shortest route connecting a candidate from each bin is calculated to further improve the accuracy of the location estimation.

Method and apparatus for location estimation using region of confidence filtering

In an RF environment serviced by 802.11, Bluetooth(&#x2122;), or other network transmitters, or combinations, location-estimation methods and systems can advantageously use redundancy to refine an estimated location of an RF receiver. In one embodiment, a method for finding a receiver's location includes receiving signals from fixed transmitters, calculating preliminary location estimates, and combining the estimates using predetermined reference information on the RF environment. The reference information preferably includes minimum mean-squared error optimizing coefficients.

Selective fusion location estimation (SELFLOC) for wireless access technologies

A method and system for providing an adaptive IP handoff triggering system for a wireless communication system that consists of either the same or heterogeneous wireless access technologies. A mobile node is notified of at least one pre-trigger timing parameter by a current access network. At least one variable handoff threshold is constructed with the mobile node based on the at least one pre-trigger timing parameter. An IP handoff is then initiated to a candidate access network when pilot beacon signal strength of the mobile node reaches the variable handoff threshold.

Adaptive IP handoff triggering and iterative tuning of IP handoff trigger timing

A method and system for providing a handoff trigger in a wireless communication system. A mobile handoff prediction is generated with a mobile node. At least one handoff prediction is generated with at least one access network within radio range of the mobile node. The mobile handoff prediction and the at least one network handoff prediction are transmitted to a network control server. A handoff is initiated if the mobile handoff prediction and a respective one of the at least one handoff predictions match.

Aggregation point prediction matching for coherent layer three signaling and fast IP mobility triggering

The present invention provides a tunnel-based IP handoff process that can minimize the handoff latency associated with the standard Mobile IP registration. In the present invention, when neighboring nodes are detected, these detected nodes are identified as candidate nodes. Detection of just the existence of neighboring nodes should be possible even in situations where these neighboring nodes use different access technologies. For instance, pilot beacon signals may be taken as indication of the existence of candidate nodes although it may be impossible to compare them quantitatively if the beacon signals emanate from different access technologies. As soon as candidate nodes are identified, tunnels are established between the source node and the candidate nodes. The tunnels are used to forward data to the mobile node after a communication link between the mobile node and the source node goes down. As soon as the mobile node enters one of the neighboring networks and identifies a target node, the tunnels are torn down except the tunnel for the target node.

Growing community of inventors

Mountain View, CA, United States of America

Youngjune Lee Gwon