Method and apparatus for detecting forward and reverse link imbalance in digital cellular communication system

An apparatus (402, 404) is provided for detecting link imbalances in a digital cellular communications system including a plurality of wireless units (400) and base stations. The apparatus (402, 404) determines if a link failure in a first radio link between a wireless unit (400) and a base station during call initialisation, whether the link failure is a reverse or forward link failure, whether the link failure is due to a link imbalance in the first radio link, and if so instructs the wireless unit (400) to switch to a second radio link. If the link failure is due to a weak reverse link, the apparatus (402, 404) determines the maximum number of access probes. If the wireless unit (400) has transmitted the maximum number of probes, then communication is initiated on a secondary communication system, or an idle state is entered and communication reinitiated with a primary digital cellular communication system.