Wireless Scheduling Approaches and Practical Implementation Issues

In the recent years, well-known scheduling algorithms like Weighted Fair Queueing, Round Robin and their extended and improved variations have been developed in relation to fixed wired networks. Based on the great differences between the wired and the wireless channel, wireless scheduling algorithms have been developed to reach the aims of fairness, guaranteed throughput and delay in terms of QoS as well as a minimized loss of PDUs over a wireless channel. The general ideas of several algorithms are presented and discussed with respect to their complexity and their implementability. Related to the practical implementation of these algorithms, additional assumptions and extensions have to be taken into account, for example the retrieval of the buffer states of remote queues located at the mobile stations or the influence of non-transparent transmissions concerning the required Quality of Service (QoS). Another point is the simultaneous support of different transmission techniques like ATM or IP with the same scheduling algorithms which is also discussed. The most important issues and ideas will be adressed in brief to give a complete overview over the main concerns which must be considered with regard to the practical implementation of effective and fair scheduling algorithms in the wireless domain.