Optimal Transmission Scheduling in Symmetric Communication Models With Intermittent Connectivity

• Published in: IEEE transactions on information theory Vol. 53; no. 3; pp. 998 - 1008
• Main Authors: Ganti, A., Modiano, E., Tsitsiklis, J.N.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.03.2007; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Applied sciences; Buffer storage; Channels; Communication channels; Communication networks; Communication system control; Constraining; Couplings; Downlink; Exact sciences and technology; Information theory; Information, signal and communications theory; Internet; Laboratories; Longest-queue-first; minimum-delay scheduling; Optimization; Packet transmission; Policies; Queues; Queuing; Radiocommunications; Satellites; Scheduling; Servers; stochastic coupling; Stochastic processes; Systems, networks and services of telecommunications; Telecommunications; Telecommunications and information theory; Teletraffic; transmission scheduling; Transmitters; Transmitters. Receivers; wireless channel; Performance evaluation; minimum-delay scheduling; Wireless telecommunication; Transmitter; Teletraffic; Scheduling; Queue length; Queueing system; Traffic management; Fluid model; Telecommunication channels; Traffic control; Delay time; wireless channel; Optimal planning; Longest-queue-first; stochastic coupling; transmission scheduling
• ISSN: 0018-9448; 1557-9654
• DOI: 10.1109/TIT.2006.890695

We consider a slotted system with N queues, and independent and identically distributed (i.i.d.) Bernoulli arrivals at each queue during each slot. Each queue is associated with a channel that changes between "on" and "off" states according to i.i.d. Bernoulli processes. We assume that the system has K identical transmitters ("servers"). Each server, during each slot, can transmit up to C packets from each queue associated with an "on" channel. We show that a policy that assigns the servers to the longest queues whose channel is "on" minimizes the total queue size, as well as a broad class of other performance criteria. We provide several extensions, as well as some qualitative results for the limiting case where N is very large. Finally, we consider a "fluid" model under which fractional packets can be served, and subject to a constraint that at most C packets can be served in total from all of the N queues. We show that when K=N, there is an optimal policy which serves the queues so that the resulting vector of queue lengths is "Most Balanced" (MB)