Abstract: Multicasting is one of the best solutions for sending data to a particular group of users. It became so prominent because it reduces the bandwidth of data that is intended to transfer than compared to unicast transmission. In multicast transmission data rate in WLAN is limited by the user with lowest receiving data rate in multicast group, which was named as constant base rate problem. We propose a delivery method that utilizes both multicasting and unicasting to solve the constant base rate problem with multirate technique. Multicasting is used between IPV4 server to Access Point (AP) and unicasting is used between AP and mobile nodes. AP converts the multicast packets to unicast packets in order to provide end-to-end multicast transmission. By combing both multicasting and unicasting we are able to solve the problem of constant base rate problem. But if more number of users under an AP wants to receive many streams of multicast type then the congestion is occurred in the wireless network under AP. In the proposed method, the AP switches to multirate mode to solve the congestion problem because the bandwidth utilized by the multirate technique at AP is very less when compared to the existing method.
Keywords: Multicast, Unicast, Constant base rate and Quality of Experience.