Wideband code division multiple access (WCDMA) is selected as the air interface scheme for 3G wireless networks. This scheme offers a high data rate that makes the wireless networks a suitable environment for real-time packet data services. 3G networks can be used to deliver multimedia traffic with guaranteed quality of service, but faces the scalability challenge in terms of the number of connections that can be setup in the cellular network. The more connections take place in WCDMA based network, the more interference is created, which yields more QoS degradation. To handle this issue, several algorithms that are collectively alleviate the QoS degradation have been developed and implemented. In this paper, we provide a system link simulator that models the WCDMA cellular network with the necessary radio resource management algorithms. The downlink direction has been simulated as it is usually the limiting link in setting up multimedia sessions, and interactive web sessions. The simulation environment provides, through the implementation of new wrap-around technique, a fair source of intra-cell and inter-cell interference, and avoids session disconnections due to the limited simulation area. Then, we suggest an admission control algorithm for admitting immediate and advance radio resource reservation requests. The admission control algorithm decision is based on the amount of interference that the new request will add to the network. The algorithm relies on the radio resource reservation states that stores all admitted immediate and advance sessions.