Priority-Based Multiplexing of IP-Streams onto Shared Cellular Links.pdf

Priority-Based Multiplexing of IP-Streams onto Shared Cellular Links G. Liebl, T. Stockhammer, and P. Strasser Institute for Communications Engineering (LNT) Munich University of Technology (TUM) Arcisstra?e 21, D-80290 Munich, Germanyfguenther.liebl,thomas.stockhammerg@ei.tum.de, peter.strasser@gmx.de Abstract We will present a new resource allocation strat- egy that allows efficient mapping of variable-rate IP- streams onto shared cellular links, while minimizing the overall bandwidth consumption and still meet- ing the individual quality-of-service constraints. It is based on the general principle of Class-Based Queu- ing, with several modifications to adapt it to the specific characteristics of wireless links. Compared to other simpler solutions that do not support any prioritiza- tion of data streams, it yields significant performance improvements in terms of guaranteed bandwidth per user/service and fairness among competing streams, as will be shown for a GSM-GPRS system. 1. Introduction While current cellular networks primarily offer sim- ple speech service, but only very low-rate data connec- tions or simple “short message service” (SMS), next generation systems will have to be far more power- ful: The desire for fast and efficient wireless access to the numerous multimedia contents on the Internet is already evident in today’s society. Hence, new ap- plications and services, like multimedia streaming or location-based information retrieval, have been pro- posed for future wireless terminals, which altogether require higher data rates and a guaranteed quality-of- service in terms of connectivity and response-time. For this reason, several new cellular systems have been developed over the recent years to meet this in- creased demand. Among them are GSM-GPRS, which is just an evolution of the widespread GSM stan- dard, but also completely new system proposals based on WCDMA technology, like UMTS in Europe and CDMA-2000 in the US. A common design criteria for a