The call admission scheme (CAS) optimizes the use of allocated channels against multi dimensional offered traffic maintaining the required quality of service (QoS). In this paper, a call admission control scheme is proposed for mobile cellular network as an extension of the dynamic partition scheme. The proposed scheme for call admission is based upon the channel borrowing mechanism for voice/data integrated service including thinning scheme of borrowed channel in a one-dimensional Markov model. The model is applicable for underlay overlay mobile cellular network. The proposed scheme has greatly reduced the forced termination (handover failure) of voice calls at the expense of other traffic parameters (blocking of new originated voice call and data call) and the model is also able to make explicit comparison with the different existing call admission schemes like guard channel (GC), dynamic partition (DP) and dual threshold bandwidth reservation (DTBR).