Method and apparatus for reflective mixer testing of a cable modem
US6662135B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 9, 1998 |
| Grant date | Dec 9, 2003 |
| Priority date | — |
| Expiry date | Dec 9, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L43/50
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A method and apparatus for performing an operability test on a communications system device such as a cable modem is provided. The testing method comprises the steps of providing a set of output test data to the communications system device being tested, and generating an output signal with the device in a manner that is responsive to the output test data. In the case of a cable modem, the output signal is generated by the modem's modulator. The output signal is then provided as an input to a reflective mixer which generates a reflected signal in response to the output signal and directs it back into the communications system device being tested. The communications device can then use the reflected signal to generate a set of input test data that can be compared to the output test data to check the accuracy of the device's operation. In the case of a cable modem, the reflected signal is demodulated by a demodulator at one or more frequencies, and this demodulated data can then be compared to the output test data. In one case, the testing method is controlled by a computer device running a program of instructions to carry out the aforementioned steps. The computer device can send co…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.