Well, it’s system that dynamicly controls two parameters of “Leaky bucket” algorithm: “Bucket size” and “Bucket leak rate”. This algorithm allows to smooth transmission rate in downlink direction. It basicly consists of transit buffer with size=”Bucket size” and transmission rate from that buffer to MS limited by value of “Bucket leak rate”. When buffer is full all inbound from ip-backbone ip-packets placed in queue on time that calculated by “Bucket leak rate”.
Strange… I always thought that this mechanism works by default.