Location based handoff for mobile devices
US7840227B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 30, 2005 |
| Grant date | Nov 23, 2010 |
| Priority date | — |
| Expiry date | Oct 2, 2026 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04W88/08
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
Mobile devices (121, 122, . . . , 12n) are handed off in overlapping cells (181, 182, . . . , 18n) by tracking a velocity (speed and direction) of movement of any number of the mobile devices (121, 122, . . . , 12n). Access points (141, 142, . . . , 14n) are each located in an associated operational cell (181, 182, . . . , 18n) and each operates at a dedicated frequency. The initial signal strengths are measured in advance at predefined locations within a defined space (16) to define signal strengths as location map (42). A nearby initial access point (typically the nearest) and at least two nearby (typically next nearest) access points are assigned for one of the mobile devices (121, 122, . . . , 12n), and the frequencies of each access point identified. A tracking processor (50) periodically scans the frequencies of the nearby access points to determine the location velocity of the mobile device and predict when a handoff will be appropriate. E.g., the actual signal strength measurements between the mobile device and the nearby access points are collected and analyzed to determine a proper time for a handoff of one or more of the nearby access points.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.