High precision access point to access point synchronization in an indoor position location system
US9363776B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 30, 2013 |
| Grant date | Jun 7, 2016 |
| Priority date | — |
| Expiry date | Feb 17, 2034 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04W56/0035
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
Methods, systems, and devices are described that provide for high precision synchronization between pairs of APs within a tracking area of a position location network. These tools and techniques may provide for incrementally synchronizing timers and oscillators located at respective APs. An AP may transmit a course frequency and timing acquisition signal that a second AP utilizes to estimate a frequency offset and/or time offset. The AP may transmit a subsequent fine frequency and timing acquisition signal which may be used to accurately adjust the estimated frequency offset and/or time offset of the second AP. The second AP may thus incrementally synchronize its oscillator(s) and/or timer(s). These techniques may be utilized over a multi-hop wireless network. The methods, systems, and devices may be applicable to single- and multi-floor location tracking systems.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.