A transmit assignment algorithm for uplink flow control in WCDMA networks
Elias Chafic Haddad, Paul G. Mermelstein, Charles L. Despins · 1999
We consider a distributed flow control algorithm which operates as part of the bandwidth management module of each cell in a multi-cellular wideband CDMA network. The algorithm controls the flow of packets time-slot by time-slot depending on the availability of radio resources as measured or predicted. A terminal's distance from the base station significantly influences the resources needed to transmit a packet, therefore terminals are grouped into spatial regions within which their resource requirements can be assumed equal. We formulate the position-based transmit assignment problem and propose a sub-optimal heuristic solution. Improvement in throughput and its trade-off with fairness among users in different regions is discussed. Results for average delay and throughput for a bursty packet arrival model are presented for two sets of radio resource conditions, an in-cell constrained system state and an out-of-cell constrained system state. The algorithm achieves high throughput and adapts easily to any desirable trade-off between throughput and fairness goals.