| 摘要 |
Adaptive clock recovery enables the clock of a CBR service to be recovered, this service being emulated from an ATM transmitter, is provided at an ATM receiver. The fill level of a first buffer receiving a stream of cells is used to provide coarse control of the rate of output of a stream of cells from the first buffer. The fill level of a further, fine, buffer receiving said stream of cells from the first buffer is monitored for determining a clock frequency, corresponding to the service clock frequency, for outputting cells from the fine buffer. The first buffer fill level control provides low pass cell jitter filtering by selectively supplying a first or a second clock frequency for outputting cells from the first buffer. The fine filter fill level control employs a phase locked loop responsive to the current fill level to set a clock frequency for reading out said fine buffer at the service clock frequency. <IMAGE> |
