WCDMA/HSPA enables hundreds of millions of people to access mobile broadband (MBB) through their smartphones every day as part of their daily lives. Today, new, low-priced WCDMA/HSPA smartphones are entering the market, and they will enable MBB for new hundreds-of-million-sized markets.
Since the seminal paper by Knopp and Humblet that showed that the system throughput of a singlecel l system is maximized if only one terminal transmits at a time, there has been a large interest in opportunistic communications and its relation to various fairness measures. On the other hand, in multicel l systems there is a need to allocate transmission power such that some overall utility function is maximized typically under fairness constraints. Furthermore, in multicell systems the degree of resource allocation freedom includes the serving cell selection that allows for load balancing and thereby the efficient use of radio resources. In this paper we formulate the joint serving cell selection (link selection) and power allocation problem as an optimization task whose purpose is to maximize either the minimum user throughput or the multicell sum throughput. The max-min problem and a simplified max throughput problem are both NP-hard and we therefore propose heuristic solution approaches.We present numerical results that give new and valuable insights into the trade off between fair and sum throughput optimal joint resource allocation strategies.
In this paper we demonstrate an effective way to classify repeated handovers (ping-pongs) in mobile broadband networks. The paper also presents a method that can significantly reduce unwanted ping-pongs in the network. The method combines a sub cell movement detection method and ping-pong detection to decide when it is most effective to apply handover threshold tuning (pinning) without increasing the risk of late or failed handovers. The algorithm was evaluated based on live network measurements.