Patent ID: 7917140
Filing Date: 2011-03-29
Classification: H04W,Y02D

Abstract:
1. A method of locating cells in a telecommunication system, comprising: defining a set of carrier frequencies to be searched; providing a wide cell search mode and a narrow cell search mode for use in a selection step; selecting as a cell search mode either the wide cell search mode or the narrow cell search mode, wherein selecting the cell search mode is based on a level of frequency generation accuracy of a local frequency generator in a mobile terminal; for each carrier frequency in the set of carrier frequencies to be searched, using a most-recently selected cell search mode when searching for a cell transmitting on the carrier frequency, wherein: the method is performed without prior knowledge of base station availability, and wherein the method further comprises: initially selecting one of the wide cell search mode and the narrow cell search mode for use whenever searching for a cell transmitting on one of the carrier frequencies to be searched, wherein the initial selection is based on one or more parameters that are indicative of a present level of frequency generation accuracy; locating a cell as a result of performing a cell search on one of the carrier frequencies to be searched; using a signal received from the located cell to improve the level of frequency generation accuracy; and in response to improving the level of frequency generation accuracy, ensuring that the narrow cell search mode is selected for use when performing a next search for a cell transmitting on another one of the carrier frequencies to be searched.