Patent ID: 7885229
Filing Date: 2011-02-08
Classification: H04W

Abstract:
1. A method comprising: determining by an apparatus a frequency channel of a spectrum; receiving by the apparatus information on which channels are in use and which channels are backup; locally storing by the apparatus an association of the channels in use with one of at least two categories and an association of the backup channels with another of the at least two categories; determining by the apparatus, from the locally stored association of the channels, a selected category for the determined frequency channel, the selected category comprising one of in use and backup and neither in use nor backup; determining by the apparatus from the selected category a time at which to sense the determined frequency channel, wherein the determined time is sooner for a case where the selected category is in use, and the determined time is later for a case where the selected category is backup, and the determined time is later than the backup category for a case where the selected category is neither in use nor backup; and sensing by the apparatus the determined frequency channel at the determined time.