Patent ID: 9572123
Date: 2017-02-14
CPC Classifications: H04L,H04W

Claim:
1. A system comprising a mobile terminal configured to: receive a first time advance value associated with a first base station; detect a secondary synchronization signal transmitted by a second base station, and, in response to determining that a voltage of the secondary synchronization signal is within a preset window, deriving a cell identity of the second base station from a system-information block transmitted by the second base station; communicate to the first base station an availability message indicating that the second base station is capable of receiving transmissions from the mobile terminal, the availability message including the cell identity of the second base station determined from the system-information block; receive a first signal transmitted by the first base station, the first signal including a first time reference; receive a second signal transmitted by the second base station, the second signal including a second time reference, the second time reference transmitted by the second base station and the first time reference transmitted by the first base station at a same transmission time; receive the first time reference of the first signal at a first reception time; receive the second time reference of the second signal at a second reception time; determine a first propagation delay difference between the first signal and the second signal based on the first reception time of the first time reference of the first signal and the second reception time of the second time reference of the second signal; and determine a second time advance value related to the second base station by correlating the first time advance value related to the first base station with the first propagation delay difference, the second time advance value including a measure of time in a special subframe of a communication protocol structure during which the mobile terminal is configured to advance an uplink transmission sent to the second base station.