一种密集BLE网络的随机退避机制  

Random Back-Off Scheme in Dense Bluetooth Low Energy Networks

作　　者：叶晓雷 黄开枝[1] 江涛[1] 陈亚军[1] YE Xiaolei;HUANG Kaizhi;JIANG Tao;CHEN Yajun(National Digital Switching System Engineering and Technological R&D Center,Zhengzhou 450002,China)

机构地区：[1]国家数字交换系统工程技术研究中心

出　　处：《信息工程大学学报》2019年第2期141-146,共6页Journal of Information Engineering University

基　　金：国家重点研发计划资助项目(2017YFB0801903)

摘　　要：作为极具应用前景的物联网备选方案之一,低功耗蓝牙(BLE)技术受到广泛关注。但是在BLE设备密集的场景中,设备发现过程会遇到大量冲突,导致网络性能显著下降。标准BLE协议中,扫描设备在发生冲突后的一段时间内丢弃接收到的所有广播包,放弃对信道的争用以降低冲突概率,但导致部分时间段所有扫描设备都选择放弃而造成信道的空闲和浪费。提出一种密集BLE网络的随机退避机制,将广播设备发送广播数据包后等待响应的时间分为数个时隙,扫描设备随机退避不同长度的时隙后发送响应数据包,从而避免碰撞,完成与广播设备的信息交换。数值仿真表明,该机制可有效减少密集BLE网络设备发现过程中的冲突,当设备数量低于30时,可将冲突概率降低30%~50%。Bluetooth low energy(BLE)has received much attention as one of the prominent solutions for short-range communication.Devices discovery may experience a lot of collisions in a crowded environment,which results in a significant decrease in network performance.In the standard BLE protocol,all broadcast packets received by the scanning device are discarded within a period of time after the occurrence of conflict,and the right to use the channel is abandoned to reduce the probability of conflict.However,this leads to the abandonment of all scanning devices in some period of time,resulting in idle and wasted channels.In this paper,we propose a random backoff scheme in dense BLE networks,which divides the response time waiting for the broadcast packet sent by the broadcasting device into several time slots,and then the response packet is sent after the scanning device randomly withstands the gap of different lengths,so as to avoid collision and complete the information exchange with the broadcasting device.Numerical simulation shows that this mechanism can effectively reduce conflicts in the process of BLE network device discovery.When the number of devices is less than 30,the probability of conflicts can be reduced by 30-50%.

关 键 词：低功耗蓝牙 信道冲突 随机退避 

分 类 号：TN510.5[电子电信]