Call admission control (CAC) is one of the basic mechanisms which are used in the wireless networks for ensuring high quality of service (QoS) offered to the users. A bandwidth adaptation technique has been proposed for the Adaptive Joint CAC (AJCAC) algorithm, solution of congestion, where it degrades the basic bandwidth units of some ongoing users to make space for new incoming ones. Similarly a restoration process takes place when the network is underutilized and underperformed, where the algorithm restores the maximum bandwidth service to the degraded users. As the degradation in the bandwidth increases, the adaption required in the network also goes up and vise-versa. The drawback with this algorithm is that it is applicable only with homogeneous terminals. The presence of heterogeneous network leads to the necessity of multi-mode terminals i.e. single mode, dual mode, triple mode, quad mode etc. To overcome this issue of unfair allocation of radio resources (RRM), a terminal modality based joint call admission control (TJCAC) algorithm has been proposed and the resultant effect on call blocking and call dropping probabilities in the networks has been evaluated. © International Science Press.