Patent ID: 6611507
Filing Date: 2003-08-26
Classification: H04W

Abstract:
A method for controlling mobile unit communication handoffs between a frequency division duplex (FDD) communication system and a time division duplex (TDD) communication system, the method comprising:transmitting between the mobile unit and a current one of the FDD and TDD communication systems while moving towards a targeted one of the FDD and TDD communication systems, the current communication system being different from the targeted communication system; generating a pilot search signal corresponding to a transmission range of the targeted communication system; monitoring pilot search signals at designated frequencies using one of time division processing and frequency division processing; initiating the communication handoff from the current communication system to the targeted communication system when the mobile unit recognizes a predetermined threshold level of the pilot search signal; synchronizing concurrent communications between the mobile unit and both the current and targeted communications systems; and terminating transmission between the mobile unit and the current communication system and maintaining communication between the mobile unit and the targeted communication system when synchronization is complete.