IEEE 802.11n Method and apparatus for multicast over IEEE 802.11n LANs

摘要

The present invention relates to a multicast method in an IEEE 802.11 wireless LAN and a device thereof. The multicast device includes: an access point (AP) device (10); and a user terminal (20) for communicating with the AP device (10) through the wireless LAN (WL). The multicast method includes: a monitoring step (S1); a modulation and coding scheme (MCS) sorting step (S2); a transmission timing determination step (S3); a primary random phase signal transmission step (S4); and a secondary random phase signal transmission step (S5). Unlike existing techniques, the multicast method can be designed with taking the aggregated MAC protocol data unit (A-MPDU) sufficiently. More specifically, the multicast method utilizes the orthogonal frequency-division multiplexing (OFDM) in order to transmit multiple pieces of feedback information to the APs from multiple multicast clients without any collision at the same time. The multicast method enables wireless multicasting with 100% reliability with a significantly small control overhead operation and adaptively adjusts the transmission MCS in accordance with the channel state of the multicast clients in order to significantly increase the spectrum efficiency. The method is realized through an experiment based on the universal software radio peripheral and GNU USRP/GNU radio being a software-defined radio (SDR) platform. The method can have excellent performance compared to the conventional and latest wireless multicast techniques through performance evaluations through ns-2 as a network simulator.