The development of wireless communication technology has become increasingly important in the communications industry.How to allocate limited channel resources reasonably and reliably to each competing user is a probl...The development of wireless communication technology has become increasingly important in the communications industry.How to allocate limited channel resources reasonably and reliably to each competing user is a problem that the access protocol of the MAC(Multiple Access Control)layer needs to solve.As an important way of random access,NP-CSMA(Non Persistent Carrier Sense Multiple Access)has a higher network throughput rate when the arrival rate is higher.This paper analyzes and improves the implemented NP-CSMA model,and obtains a three-slot NP-CSMA model.The mathematical tool MATLAB is used to analyze the network throughput,delay and energy efficiency of the model,and compare several random multiple access protocols adheres to the network throughput,they are NP-CSMA,Three-slot NP-CSMA,1-persistent CSMA,P-persistent CSMA,and concludes that the three-slot NP-CSMA is significantly letter than several other multiple access protocols.Finally,using Quartus to design the three-slot NP-CSMA circuit,the statistical value of the circuit system is compared with the theoretical value of the model,and the error is less than 0.01,which proves that the system is reasonable in design and can be applied to wireless communication networks.展开更多
LoRaWAN是低功耗广域网(LPWAN)中的一种无线通信标准,为物联网的发展提供了支撑。然而,受限于扩频因子(SF)间不完全正交性的特点和LoRaWAN不具备先听后发(LBT)机制的事实,基于ALOHA的传输调度方式会引发严重的信道冲突,极大降低了LoRa(L...LoRaWAN是低功耗广域网(LPWAN)中的一种无线通信标准,为物联网的发展提供了支撑。然而,受限于扩频因子(SF)间不完全正交性的特点和LoRaWAN不具备先听后发(LBT)机制的事实,基于ALOHA的传输调度方式会引发严重的信道冲突,极大降低了LoRa(Long Range Radio)网络的扩展性。为提高LoRa网络的扩展性,提出用非坚持型载波监听多路访问(NP-CSMA)机制替代LoRaWAN中ALOHA的介质访问控制机制,通过LBT协调LoRa网络中SF相同的各个节点接入信道的时间。不同SF之间的传输则采用多种SF信号并行传输,以减少共信道中同SF干扰和避免SF间干扰。为了分析NP-CSMA对LoRa网络扩展性的影响,通过理论分析和NS3仿真对LoRaWAN与NP-CSMA构建的LoRa网络进行比较。实验结果表明,在相同的条件下,与LoRaWAN相比,NP-CSMA在网络通信负载率为1的情况下,它的理论数据包交付率(PDR)性能比LoRaWAN高58.09%。在信道利用率方面,与LoRaWAN相比,NP-CSMA的饱和信道利用率提高了214.9%,容纳的节点数量也增加了60.0%。另外,NP-CSMA的平均时延在网络通信负载率小于1.7时也低于确认型LoRaWAN,而且在扩频因子为7和10时,它用于维持信道活动检测(CAD)模式所造成的额外能耗也比LoRaWAN用于接收来自网关确认消息所需的额外能耗低1.0~1.3 mJ和2.5~5.1 mJ;充分反映了NP-CSMA可以有效提高LoRa网络的可扩展性。展开更多
基金This work was supported by the National Natural Science Foundation of China(61461053,61461054,61072079,61463049)The Financial Support of Yunnan University(No.XT412004).
文摘The development of wireless communication technology has become increasingly important in the communications industry.How to allocate limited channel resources reasonably and reliably to each competing user is a problem that the access protocol of the MAC(Multiple Access Control)layer needs to solve.As an important way of random access,NP-CSMA(Non Persistent Carrier Sense Multiple Access)has a higher network throughput rate when the arrival rate is higher.This paper analyzes and improves the implemented NP-CSMA model,and obtains a three-slot NP-CSMA model.The mathematical tool MATLAB is used to analyze the network throughput,delay and energy efficiency of the model,and compare several random multiple access protocols adheres to the network throughput,they are NP-CSMA,Three-slot NP-CSMA,1-persistent CSMA,P-persistent CSMA,and concludes that the three-slot NP-CSMA is significantly letter than several other multiple access protocols.Finally,using Quartus to design the three-slot NP-CSMA circuit,the statistical value of the circuit system is compared with the theoretical value of the model,and the error is less than 0.01,which proves that the system is reasonable in design and can be applied to wireless communication networks.
文摘LoRaWAN是低功耗广域网(LPWAN)中的一种无线通信标准,为物联网的发展提供了支撑。然而,受限于扩频因子(SF)间不完全正交性的特点和LoRaWAN不具备先听后发(LBT)机制的事实,基于ALOHA的传输调度方式会引发严重的信道冲突,极大降低了LoRa(Long Range Radio)网络的扩展性。为提高LoRa网络的扩展性,提出用非坚持型载波监听多路访问(NP-CSMA)机制替代LoRaWAN中ALOHA的介质访问控制机制,通过LBT协调LoRa网络中SF相同的各个节点接入信道的时间。不同SF之间的传输则采用多种SF信号并行传输,以减少共信道中同SF干扰和避免SF间干扰。为了分析NP-CSMA对LoRa网络扩展性的影响,通过理论分析和NS3仿真对LoRaWAN与NP-CSMA构建的LoRa网络进行比较。实验结果表明,在相同的条件下,与LoRaWAN相比,NP-CSMA在网络通信负载率为1的情况下,它的理论数据包交付率(PDR)性能比LoRaWAN高58.09%。在信道利用率方面,与LoRaWAN相比,NP-CSMA的饱和信道利用率提高了214.9%,容纳的节点数量也增加了60.0%。另外,NP-CSMA的平均时延在网络通信负载率小于1.7时也低于确认型LoRaWAN,而且在扩频因子为7和10时,它用于维持信道活动检测(CAD)模式所造成的额外能耗也比LoRaWAN用于接收来自网关确认消息所需的额外能耗低1.0~1.3 mJ和2.5~5.1 mJ;充分反映了NP-CSMA可以有效提高LoRa网络的可扩展性。
