Exploiting Mobility in Proportional Fair Cellular Scheduling: Measurements and Algorithms

• Published in: IEEE/ACM transactions on networking Vol. 24; no. 1; pp. 355 - 367
• Main Authors: Margolies, Robert, Sridharan, Ashwin, Aggarwal, Vaneet, Jana, Rittwik, Shankaranarayanan, N. K., Vaishampayan, Vinay A., Zussman, Gil
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.02.2016; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Algorithms; Cellular networks; channel state prediction; Delays; measurements; Mobile communication; mobility; Packet switched networks; Prediction algorithms; proportional fairness; Scheduling; slow-fading; Throughput; Traffic flow
• ISSN: 1063-6692; 1558-2566
• DOI: 10.1109/TNET.2014.2362928

Proportional Fair (PF) scheduling algorithms are the de facto standard in cellular networks. They exploit the users' channel state diversity (induced by fast-fading) and are optimal for stationary channel state distributions and an infinite time-horizon. However, mobile users experience a nonstationary channel, due to slow-fading (on the order of seconds), and are associated with base stations for short periods. Hence, we develop the Predictive Finite-horizon PF Scheduling ((PF) 2 S) Framework that exploits mobility. We present extensive channel measurement results from a 3G network and characterize mobility-induced channel state trends. We show that a user's channel state is highly reproducible and leverage that to develop a data rate prediction mechanism. We then present a few channel allocation estimation algorithms that exploit the prediction mechanism. Our trace-based simulations consider instances of the (PF) 2 S Framework composed of combinations of prediction and channel allocation estimation algorithms. They indicate that the framework can increase the throughput by 15%-55% compared to traditional PF schedulers, while improving fairness.