基于BTMA的LoRa网络隐藏终端MAC协议研究  

Study on MAC Protocol of LoRa Network Hidden Terminal Based on BTMA

作　　者：汪浩 蔡宇航 陈国杰 王璐 WANG Hao;CAI Yuhang;CHEN Guojie;WANG Lu(School of Computer Science,Wuhan University,Wuhan 430072,China;College of Computer Science and Software Engineering,Shenzhen University,Shenzhen,Guangdong 518060,China)

机构地区：[1]武汉大学计算机学院,武汉430072 [2]深圳大学计算机与软件学院,广东深圳518060

出　　处：《计算机科学》2025年第3期318-325,共8页Computer Science

摘　　要：低功耗广域网(Low Power Wide Area Network,LPWAN)技术的出现,能够在保证更远距离的通信传输的同时,最大限度地降低功耗,节约传输成本。LoRa(Long Range)技术作为其中的佼佼者,凭借其远距离、低功耗、大容量、强抗干扰、高接收灵敏度的特点,备受工业界和学术界的青睐。针对目前工业中主流使用的基于ALOHA的LoRaWAN协议无法很好地解决海量终端设备接入LoRa网络后所带来的严重数据包冲突以及LoRa CAD(Channel Activity Detection)功能带来的隐藏终端问题,提出了一种基于BTMA(Busy Tone Multiple Access)的LoRa网络MAC协议——BT-MAC协议。该协议利用了LoRa高接收灵敏度的特性,网关利用“忙音”信标来通知各个节点网关的工作情况,减少了无效包的发送。同时,节点端通过记录有“忙音”信息和本地信息的逻辑信道矩阵,结合最优信道选择算法,选出最优逻辑信道进行发送,降低了端节点上行数据包之间的冲突,有效缓解了LoRa网络中的隐藏终端问题以及阻塞问题。此外,搭建了LoRa网络MAC协议测试平台,并测试了BT-MAC的有效性,完成了室内和室外环境大规模的并发实验和能耗检测实验。实验结果表明,BT-MAC协议的吞吐量是LMAC-2协议的1.6倍,是ALOHA协议的5.1倍;同时其包接收率达到LMAC-2协议的1.53倍,ALOHA协议的17.2倍;其包接收平均能耗约为LMAC-2协议的64.1%,为ALOHA协议的14.2%。The emergence of low power wide area network(LPWAN)technology allows for longer-distance communication while minimizing power consumption and reducing transmission costs.LoRa(long range)technology,as a standout in this field,is highlyfavored in both industrial and academic circles due to its long-range capabilities,low power consumption,high capacity,strong anti-interference,and high reception sensitivity.However,the widely used ALOHA-based LoRaWAN protocol in the industry struggles to effectively address severe data packet collisions resulting from the massive access of terminal devices to the LoRa network,as well as the hidden terminal problem caused by the LoRa CAD(channel activity detection)feature.This paper proposes a BTMA(busy tone multiple access)-based MAC protocol for LoRa networks,known as the BT-MAC protocol.This protocol leverages LoRa’s high reception sensitivity,with the gateway using“busy tone”beacons to inform each node of the gateway’s operational status,thereby reducing the transmission of invalid packets.Simultaneously,nodes maintain a logical channel matrix with“busy tone”information and local information.By employing an optimal channel selection algorithm,nodes select the best logical channel for transmission,reducing collisions among uplink data packets from end nodes.This effectively mitigates the hidden terminal problem and congestion in LoRa networks.A LoRa network MAC protocol testing platform is built to test the effectiveness of BT-MAC.Extensive concurrent experiments and energy consumption tests are conducted in both indoor and outdoor environments.The experimental results show that the throughput of the BT-MAC protocol is 1.6 times that of the LMAC-2 protocol and 5.1 times that of the ALOHA protocol.Additionally,its packet reception rate is 1.53 times that of the LMAC-2 protocol and 17.2 times that of the ALOHA protocol..The average energy consumption per packet is approximately 64.1% of that of the LMAC-2 protocol and 14.2% of that of the ALOHA protocol.

关 键 词：LoRa MAC协议 BTMA 隐藏终端 CAD 

分 类 号：TN092[电子电信—物理电子学]