A wireless transceiver will generally include at least one reference clock. This clock will be set at a nominal frequency for operation of the transceiver. However, irregularities in the formation of clock crystals, changes in temperature, and other factors can introduce slight variations in frequency. When two wireless devices are communicating it may be necessary for two devices to synchronize their clocks to each other. This can be made more difficult by the fact that although the two devices might have the same nominal frequency, their actual frequencies may have slight variations. Such variations can cause their clocks to drift over time, upsetting their synchronization.
One way that this problem has been addressed is through the use of an agile clock, which can make slight variations to the frequency of the reference clock and provide this new agile clock signal in place of the reference clock signal. If one device in a pair of communicating wireless devices (generally a receiver) employs an agile clock, it can modify its effective reference clock to match that of the device it's communicating with.
However, the process of synchronizing clock frequencies takes time, and this is time that the devices are not performing their primary function. It would therefore be desirable provide a way to minimize the time required to perform the synchronization process. 
USPTO Backgrounds
USPTO Backgrounds