Distinguishing between voice traffic and data links
US8776221B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 3, 2012 |
| Grant date | Jul 8, 2014 |
| Priority date | — |
| Expiry date | Jun 8, 2032 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L1/0091
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
Techniques are provided for receiving a transmitted first packet that was formatted using a known scrambling algorithm with an unknown scrambling seed. An encoded packet payload is extracted from the first packet header. The encoded packet payload header is decoded to obtain a first scrambled packet payload header. For each potential value of the unknown seed, the first scrambled packet payload header is descrambled to produce a first set of descrambled packet payload headers and for each potential value of initial register values associated with a cyclic redundancy check, the cyclic redundancy check is executed comprising polynomial division on each of the descrambled packet payload headers such that when the polynomial division results in a zero remainder, a potential unscrambled payload header for the first packet is obtained. Information about the first packet is obtained from the potential unscrambled payload header.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.