Patent ID: 8351861
Filing Date: 2013-01-08
Classification: H04W

Abstract:
1. A method of spectrum access for wireless communications by a secondary unlicensed unit in a cognitive radio network (CRN) environment comprising one or more secondary unlicensed units and one or more primary licensed units, wherein the one or more secondary units are mobile units, the method comprising: receiving information indicative of a location and movement of the one or more secondary unlicensed units and a channel usage pattern and spatial distribution of the one or more primary licensed units; providing a guard distance to shield the one or more primary licensed units from interference induced by the one or more secondary unlicensed units, the guard distance specifying a radius of the one or more primary licensed units within which the one or more secondary unlicensed units will not have spectrum access, wherein the guard distance is optimized based on an average speed of the secondary unlicensed unit; calculating channel availability to the one or more secondary unlicensed units according to a two-state Markov model including the guard distance as a constraint and based on the information indicative of the location and movement of the one or more secondary unlicensed units and the channel usage pattern and spatial distribution of the one or more primary licensed units; and accessing the spectrum in the CRN environment from the one or more secondary unlicensed units based on the calculated channel availability.