Constant-Rate Server Output in WEBRC

With the initial design of WEBRC, as described in the -00 and -01 IETF RMT building block drafts [1, 2], the server output rate varies in time with period TSD (recommended to be 10 seconds). The variation is quite significant; when the recommended multiplicative decrease value P = 0.75 is used, it causes the average output rate to be at least 13.1% less than the peak rate. This document describes how increasing the number of wave channels by one and changing the shape of the initial portion of the wave makes it possible to have constant-rate server output. (A possibility that had been discussed but is not described in this document would not increase the number of wave channels and would make the variation at most 13.1%.) For the sake of brevity, this document is not self-contained. Those unfamiliar with WEBRC should see [2, 3] for terminology.