基于LBT-SA的LoRaWAN信道接入方法研究  

Research on Channel Access Method of LoRaWAN Based on LBT-SA

作　　者：禹忠 顾仁彬 范九伦 YU Zhong;GU Renbin;FAN Jiulun(School of Communications and Information Engineering,Xi’an University of Posts&Telecommunications,Xi’an 710061,China)

机构地区：[1]西安邮电大学通信与信息工程学院,西安710061

出　　处：《计算机工程与应用》2020年第24期95-101,共7页Computer Engineering and Applications

基　　金：陕西省重点研发计划(No.2018ZDCXL-GY-04-01)。

摘　　要：标准LoRaWAN协议中定义的纯ALOHA信道接入方法在网络负载较大时会造成大量碰撞,使LoRa网络的可扩展性和可靠性受到极大挑战。为此提出了一种将先听后说与模拟退火相结合(Listen Before Talk combined with Simulated Annealing,LBT-SA)的LoRa信道接入方法。该方法通过在设备发送之前先监听信道,降低信道被同时接入的概率,并以成功传输所需退避时间为初始值,搜索更小的退避时间。仿真结果表明,LBT-SA和基于二元指数退避算法的先听后说(Listen Before Talk,LBT)方法在包成功传输率方面保持了高度的一致,并且LBT-SA在周期传输过程中逐渐减少了不必要的退避时间,从而减少了时延。在多达10 000个终端接入单个网关的场景中,该算法的平均退避时间至少降低了16.38%。The pure ALOHA channel access method defined in the standard LoRaWAN protocol can cause a lot of collisions and transmissions failed when in a heavy load,it challenges the scalability and reliability of the LoRa network greatly.A new channel access method,LBT-SA(Listen Before Talk combined with Simulated Annealing),is proposed.This method reduces the probability that multiple devices access the channel by detecting the channel before sending,and searches for a smaller backoff time by taking the backoff time required for successful transmission as the initial value.Simulation results show that LBT-SA can not only maintain the packet delivery rate provided by LBT with binary exponential backoff algorithm,but also minimize the unnecessary backoff in the transmission,thus reducing the delay.In a scenario where up to 10,000 end-devices access a single gateway,the average backoff time of the algorithm is reduced by at least 16.38%.

关 键 词：LoRaWAN 信道接入方法 先听后说 模拟退火算法 竞争窗口 

分 类 号：TN911[电子电信—通信与信息系统]