Improvement of handover traffic performance in two-tier cellular mobile networks

With the increase of teletraffic demands in mobile cellular system, hierarchical cellular systems (HCS) have been adopted extensively for more efficient channel utilization and better GoS (grade of service). In a hierarchical cellular network, cells of different sizes in multilayered structure provide multiple routes for calls that may be dropped or rejected to seize traffic channels when a part of the network is congested. Hence, it can provide higher traffic capacity by maintaining alternate routing through over-flow and, in consequence, may reduce the call-dropping probability. An analytical model will be deduced for an overlaid macrocell over microcells to investigate the handover failure and the new call blocking probabilities in heavy traffic mall.