Apparatus and method for transmitting a ranging packet compatible with legacy 802.11 systems
US10660085B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 27, 2018 |
| Grant date | May 19, 2020 |
| Priority date | — |
| Expiry date | Jul 8, 2038 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04W84/12
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
Communicating wireless devices collaborate and utilize waveforms to enable secure channel estimation. To protect against a repetitive replay attack, some embodiments include Single Carrier Physical Layer (SC-PHY) waveforms and/or interpolated OFDM waveforms that do not include a repeatable or predictable structure. The waveforms are transmitted in ranging packet structures that are compatible with legacy 802.11 technologies that do not utilize secure channel estimation. The ranging packets are received in combination with the information previously exchanged to enable the receiving wireless system to securely determine a channel estimate (e.g., determine a channel estimate without an interloper transmission that is not an authentic first arrival path in a multi-path channel between the wireless systems). Thus, one or both of the wireless systems can estimate the distance between them (or range). Devices utilizing legacy 802.11 technologies may receive the ranging packet structures and determine durations for deferring access to the channel.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.