Prioritization Procedures for Resource Management in Cellular Networks

Abstract: In order to be competitive, it is crucial for cellular operators to use their resources, such as spectrum and equipment, as effectively as possible. A more efficient usage of the available resources enables the operators to reduce the necessary deployment cost and/or to improve the offered Quality of Service in their networks. The concept of resource management includes among other things admission control procedures and channel assignment methods. To satisfy the subscriber requirements in a cellular network, a higher priority needs to be assigned to certain connection (call) types. For instance, most subscribers find it much more annoying to have an ongoing connection dropped than a new call attempt blocked. This means that it is a good idea for the operators to assign a higher priority to already ongoing connections than to new call attempts. Further, a higher priority can be assigned to calls carrying certain services as well as to users with more expensive subscriptions. There exist several different methods that can be applied for the prioritization procedure. These include bandwidth reservation, bandwidth borrowing, handover queuing, handover parameter adjustments and dynamic bandwidth allocation. In this thesis, several advanced prioritization procedures intended for cellular networks are introduced. These methods enhance the network performance through reduced call blocking and/or handover dropping probabilities. The introduced methods include a bandwidth reservation scheme that estimates the handover arrival rate to each cell using advanced subscriber movement predictions. A combination of history-based measurements and positioning is used as input to the movement prediction feature. Another introduced prioritization procedure combines bandwidth borrowing with bandwidth reservation. Here, the rate adaptiveness of the ongoing connections in a cell is together with the estimated handover arrival rate applied to determine the amount of bandwidth to reserve. Further, a bandwidth reservation procedure that considers the soft property of CDMA networks is also introduced. Moreover, layer assignment schemes suitable for hierarchical cellular structures, and load balancing procedures are presented.