Efficient dynamic load balancing algorithms using iCAR systems: a generalized framework

Coping with congestion or hot spots is one of the common problems currently faced by wireless service providers. To handle this hot spot or congestion problem in a cellular network, several dynamic load balancing schemes based on channel borrowing have previously been proposed. A recent approach to dynamic load balancing is the integrated cellular and ad hoc relay (iCAR) system (see Wu, H. et al., 2001; De, S. et al., 2002; Qiao, C. et al., 2000). iCAR employs ad hoc relay stations (ARS) in the cellular network to balance traffic loads efficiently and to share channels between cells via primary and secondary relaying. We provide a general framework for dynamic load balancing in iCAR systems, where the number of hot cells, the location of these hot cells and the traffic distribution in the system is arbitrary. Results show that the call blocking probabilities of the hot cells can be decreased substantially. Moreover, a threshold traffic, which is a function of the average traffic intensity in the overall system, is specified to determine the hot cells in the system, and the effect of the threshold value on the computational complexity of the dynamic load balancing algorithm is examined and quantified.