Patent ID: 7299041
Filing Date: 2007-11-20
Classification: H04W

Abstract:
1. A method of selecting a communication system, comprising: receiving a first quality indicator for a current channel by a mobile communication device from a current communication system; remaining in communication with the current system; receiving a second quality indicator for the current channel after a predetermined time period in response to the first quality indicator being below a predetermined threshold value; adding the current channel to a grey zone channel list in a mobile communication device in response to the second quality indicator being below the predetermined threshold value to avoid a grey zone condition, wherein the grey zone condition includes the mobile communication device being able to receive a page on a forward link from the current communication system to the mobile communication device, but a page response or a system access attempt on a reverse link failing because of insufficient transmit power in the mobile communication device caused by a power control measure of the current communication system which permits interference from other mobile communication devices operating on the current communication system; scanning any channels in a channel scan list in response to the second quality indicator being below the predetermined threshold value; skipping any channels on the grey zone channel list during scanning to avoid the grey zone condition; and acquiring a new channel from the channel scan list in response to the new channel having an associated quality indicator greater than or equal to the predetermined threshold value.