Determining parameters to minimize jitter generation in the SRTS method

The synchronous residual time stamp (SRTS) method has been recommended by the ITU-T as one approach to the transfer of timing information for continuous bit rate (CBR) services being carried by the asynchronous transfer mode (ATM) adaptation layer 1 (AAL1) of the broadband integrated services digital network (B-ISDN). We give an overview of the SRTS method including a description of service clock recovery at the destination. On the basis of analytical expressions derived, we show that even in an ideal SRTS system, where all clocks are jitter-free, the SRTS method inherently generates jitter. We also show that this jitter is equivalent to the so-called waiting time jitter that is found in conventional timing justification techniques. In other systems where waiting time jitter is generated, parameters are chosen in order to minimize the amount of waiting time jitter produced and in which part of the spectrum it is located. We show that for the SRTS method, the choice of parameters to minimize waiting time jitter is quite restricted. For higher service clock frequencies and clocks with large tolerances, it may be impossible to choose parameters to influence the characteristics of the waiting time jitter produced