<span lang="EN-US">Femtocells can significantly boost up wireless cellular network capacity by reducing communication distances to user equipment and also by reusing resources already utilized in the macrocell network on which they overlay. However, the deployment of femtocells within a macrocell coverage area, causes severe interference between the femtocell and the macrocell, which may have an impact on the overall performance of the femtocells. Avoiding such interference is very important for the effective co-existence </span><span lang="EN-US">of femtocells and macrocell. This paper proposes an algorithm to mitigate cross-tier interference between </span><span lang="EN-US">a femtocell and a macrocell using adaptive power control. The proposed approach is modeled and simulated using MATLAB. The impact on the performance of the </span><span lang="EN-US">femtocell using the proposed algorithm </span><span lang="EN-US">is analysed. Results show that the proposed adaptive power control algorithm has tremendously reduced the negative effects on the system throughput, delay and outage probability for voice and data traffics.</span>
