Task Assignment Strategies for Pools of Baseband Computation Units in 4G Cellular Networks

A popular architecture for cellular mobile networks is to place Remote Radio Heads (RRHs) on the cell towers and connect those via fibers with a centralized pool of baseband Units (BBUs). Among other things, the centralization of baseband computation faciliates multiplexing gains and can thereby save compute resources. To realize these gains, an efficient and loadbalancing assignment of compute jobs to computation units is required. In contrast to approaches in literature, our architecture virtualizes the processing for each UE separately. It thereby provides a higher granularity and allows to newly decide the assignment of a compute job to a processing unit whenever a UE starts transmitting data. In this publication, we present multiple heuristics to decide this assignment. We compare the efficiency of the assigment and the perceived service quality realized by the heuristics with an ideal assigment and the classical static assignment. Our evaluation shows that by using a good assignment heuristic, about 50% of the hardware resources can be saved.