The multicast system for seamless live multimedia in WLAN

摘要

This paper proposes the multicast system for seamless live multimedia in a wireless network. The multicast technique for live multimedia and a part of handover mechanism are performed on the buffered multicasting/switching agent (BMSA) in a wireless local area network (WLAN). The rest of the handover mechanism is performed on access points (APs). This paper uses a new Internet Protocol (IP) header that is composed of three AP numbers (AP_#s) and 1-bit overwrite bit (OB) to perform seamless service. The three AP_#s support a smooth handover for solving the cutoff service when mobile nodes (MNs) move among other APs in WLAN. The overhead for a new IP header (2 bytes long) is negligible in comparison with multimedia service, and the overhead for the multicast group address (MGA) packet that is used in the transmission of MGA is only 11 bits. The MGA packet is composed of two AP_#s, an overwriting group address (OGA) bit, and MGA. We confirmed that the proposed multicast system can decrease the number of channels required, the delay of service, and the possibility of packet duplication because multicast is not provided on the multimedia server but on the BMSA in WLAN.