Optimal Energy and Delay Tradeoffs for Multi-User Wireless Downlinks

— We consider the fundamental delay tradeoffs for minimizing energy expenditure in a multi-user wireless downlink with randomly varying channels. First, we extend the BerryGallager bound to a multi-user context, demonstrating that any algorithm that yields average power within O(1/V ) of the minimum power required for network stability must also have an average queueing delay greater than or equal to Ω( √ V ). We then develop a class of algorithms, parameterized by V , that come within a logarithmic factor of achieving this fundamental tradeoff. The algorithms overcome an exponential state space explosion, and can be implemented in real time without apriori knowledge of traffic rates or channel statistics. Further, we discover a “super-fast” scheduling mode that beats the BerryGallager bound in the exceptional case when power functions are piecewise linear.

• Type: Conference
• Year: 2006
• Where: INFOCOM
• Authors: Michael J. Neely
• Keywords: Average Queueing Delay, Communications, Fundamental Delay Tradeoffs, INFOCOM 2006, Multi-user Wireless Downlink