Method and apparatus for using the unused bits of a data packet to transmit additional information
US5944843A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 21, 1997 |
| Grant date | Aug 31, 1999 |
| Priority date | — |
| Expiry date | Aug 21, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L2001/0095
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A method and apparatus in accordance with the present invention uses the unused bits of a data packet to transmit additional information by piggy-backing "secondary" code words into a data packet containing a "primary" code word. A secondary code word may be piggy-backed into a data packet containing a primary code word when the primary code word and any secondary code words already stored in the data packet leave sufficient unused space in the data packet to store an additional secondary code word, and the route traveled by the data packet as the packet is routed to the network node addressed by the primary code passes through (or ends at) the network node addressed by the secondary code word, or passes through (or ends at) a network node that can relay the secondary code word to the network node addressed by the secondary code word. In a first embodiment, an ECC is generated for the primary code word using a predefined bit pattern (such as all 0's) for any unused bit positions in the data packet. The same predefined bit pattern is used for the unused bit positions when the integrity of the primary code word is verified at the destination. If it is desired to protect the secondary…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.