Downlink channel locking method and device as well as on-line method and device of cable modem

Abstract

The embodiment of the invention provides downlink channel locking method and device as well as on-line method and device of a cable modem, in order to shorten the downlink channel locking time and the on-line time of the cable modem. The method comprises the following steps: determining whether signals corresponding to current frequency to be scanned are effective or not; if the signals to current frequency to be scanned are effective, then determining a downlink channel according to the current frequency to be scanned; and carrying out on-line operation on the cable modem in the determined downlink channel. Compared with the on-line method of the cable modem provided by the prior art, the method provided by the embodiment of the invention has the advantages that time wasted on many useless frequency points and broadcast television signal frequency points is reduced, and scanning of a great amount of useless channels is avoided during frequency locking, so that the whole on-line process of the cable modem is obviously shortened.

Description

technical field [0001] The invention relates to the communication field, in particular to a downlink channel locking method and device, and a cable modem online method and device. Background technique [0002] With the continuous development of coaxial cable network technology, radio and television operators are gradually carrying out more and more extended services in addition to transmitting radio and television programs in the coaxial cable network. Modem, CM) provides users with two-way digital TV services and Internet access services. [0003] CM is an access device used in coaxial cable network for data transmission, and provides a way for user terminals (such as computers, interactive digital TV set-top boxes, etc.) to access the Internet through coaxial cables. CM can be made into an independent product, and can also be integrated in a digital TV set-top box. Compared with ordinary modems, CM does not need to dial up to get online, does not occupy telephone lines, ...

AI Technical Summary

Problems solved by technology

If the establishment of communication fails, continue to scan the next channel with a certain frequency deviation (for example, 250KHz) until the establishment of communication with the front-end CMTS server is successful, or the communication with the front-end CMTS server cannot be established

[0005] The CM online method provided by the above-mentioned prior art is to divide the entire frequency spectrum into a large number of channels with very small frequency differences to scan one by one, and to perform a complete frequency locking operation process on each channel. A lot of time wasted on point

When the frequency difference between the available downlink channel of the CM and the first scanned channel is large, it will take a long time to lock the frequency, which will cause the CM to go online slowly.

Taking the spectrum range of 112MHz~858Mhz as an example, using the method provided by the above-mentioned prior art, it takes an average of more than 300 milliseconds to complete the scanning process of a channel. If all the spectrum of 112MHz~858Mhz is scanned, the longest time-consuming may reach about More than 30 minutes, seriously affecting the online speed of CM

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