基于IGMP的IEEE 802.11无线组播速率自适应机制

针对组播速率不能满足传输需求的问题,提出了基于因特网组管理协议(IGMP)与改进自动速率回退(ARF)算法的无线组播速率自适应机制.该机制利用组播中必须发送的IGMP报文来获取接收信噪比,进而决定组播速率.基于IGMP报文的周期间隙调整,加入了改进后的ARF算法进行速率调整.该机制规避了大量反馈帧产生碰撞的问题,可以使组播路由器获得传输结果的有效反馈,从而更准确地进行速率调整.结果表明,所提机制能够较好地调整无线组播速率,提升无线组播的吞吐量.

Rate adaptive mechanism for wireless multicast based on IGMP in IEEE 802.11

Aiming at the problem that the multicast rate can not meet the transmission demand, a rate adaptive mechanism for wireless multicast based on both internet group management protocol(IGMP)and improved auto rate fallback(ARF)algorithm was proposed. In the proposed mechanism, the IGMP packets which must be sent were used to get the received signal to noise ratio(SNR), and then the multicast rate was determined. Based on the adjustment cycle interval of IGMP packets, an improved ARF algorithm was added to adjust the multicast rate. The proposed mechanism avoided the collision problem occured among a lot of feedback frames, so that the multicast access point(AP)could get the effective feedback of transmission results to perform the more accurate rate adjustment. The results indicate that the proposed mechanism can better adjust the wireless multicast rate and promote the throughput of wireless multicast.