In Shadow-Fading model, it is difficult to achieve higher Packet Delivery Ratio (PDR) due to the effects of large scale fading. The main goal of this paper is to improve the PDR in Shadow-Fading environment. To achiev...In Shadow-Fading model, it is difficult to achieve higher Packet Delivery Ratio (PDR) due to the effects of large scale fading. The main goal of this paper is to improve the PDR in Shadow-Fading environment. To achieve this objective a protocol has been proposed that discovers backup routes for active sessions. These backup routes salvage the packets of active session in case of active route failure. It is found by research that proactively maintaining backup routes for ac-tive sessions can noticeably improve the PDR in Shadow-Fading environment. This protocol has been implemented with a mechanism of having backup routes and simulations have been conducted by using both node disjoint paths and link disjoint paths. Comparisons have been made between new protocol as well as AODV protocol. Simulation has been carried out using Network Simulator 2 (NS2) and the results show that the proposed QoSAR protocol exhibits higher PDR than AODV protocol in Shadow-fading environment.展开更多
As one of the most promising communication technologies for vehicular networks, LTE-V has the advantages of wide coverage and a high transmission rate. 3 GPP released the technical specification of LTE-V in March 2017...As one of the most promising communication technologies for vehicular networks, LTE-V has the advantages of wide coverage and a high transmission rate. 3 GPP released the technical specification of LTE-V in March 2017, launching a spate of related research and industrialization. In this paper, we propose a communication model based on Markov process to evaluate the reliability of LTE-V. We derived the Packet Delivery Rate(PDR) of LTE-V based on the model. Moreover, we use Poisson process to model the distribution of vehicles on a highway,then combine the communication model with the vehicles’ distribution to derive the PDR under this scenario. To verify the correctness of the proposed model, we established a simulation program on the MATLAB platform. By comparing the simulation results and the mathematical results, we found that simulation results are a very good fit for the model.展开更多
AODV协议通过选择跳数最少的路径传输数据,却未考虑路径稳定性,当路径存活时间短时就会引发路径修复或路由重新发起,耗费大量网络资源。为提高网络性能,对该协议进行改进,提出了AODV-S-M(multi-path protocol of AODV based on stabili...AODV协议通过选择跳数最少的路径传输数据,却未考虑路径稳定性,当路径存活时间短时就会引发路径修复或路由重新发起,耗费大量网络资源。为提高网络性能,对该协议进行改进,提出了AODV-S-M(multi-path protocol of AODV based on stability)协议。其采用定位技术预测路径生存期,选择跳数少、稳定性高的路径发送数据;并引入多路由来保证传输可靠性。最后,使用网络模拟器将两个协议进行模拟比较,验证了AODV-S-M协议可有效提高路据包投递率、减少路由开销。展开更多
文摘In Shadow-Fading model, it is difficult to achieve higher Packet Delivery Ratio (PDR) due to the effects of large scale fading. The main goal of this paper is to improve the PDR in Shadow-Fading environment. To achieve this objective a protocol has been proposed that discovers backup routes for active sessions. These backup routes salvage the packets of active session in case of active route failure. It is found by research that proactively maintaining backup routes for ac-tive sessions can noticeably improve the PDR in Shadow-Fading environment. This protocol has been implemented with a mechanism of having backup routes and simulations have been conducted by using both node disjoint paths and link disjoint paths. Comparisons have been made between new protocol as well as AODV protocol. Simulation has been carried out using Network Simulator 2 (NS2) and the results show that the proposed QoSAR protocol exhibits higher PDR than AODV protocol in Shadow-fading environment.
基金supported in part by the National Key Research and Development Program of China (No. 2018YFB1600600)the National Natural Science Foundation of China (No. 61673233)
文摘As one of the most promising communication technologies for vehicular networks, LTE-V has the advantages of wide coverage and a high transmission rate. 3 GPP released the technical specification of LTE-V in March 2017, launching a spate of related research and industrialization. In this paper, we propose a communication model based on Markov process to evaluate the reliability of LTE-V. We derived the Packet Delivery Rate(PDR) of LTE-V based on the model. Moreover, we use Poisson process to model the distribution of vehicles on a highway,then combine the communication model with the vehicles’ distribution to derive the PDR under this scenario. To verify the correctness of the proposed model, we established a simulation program on the MATLAB platform. By comparing the simulation results and the mathematical results, we found that simulation results are a very good fit for the model.
文摘AODV协议通过选择跳数最少的路径传输数据,却未考虑路径稳定性,当路径存活时间短时就会引发路径修复或路由重新发起,耗费大量网络资源。为提高网络性能,对该协议进行改进,提出了AODV-S-M(multi-path protocol of AODV based on stability)协议。其采用定位技术预测路径生存期,选择跳数少、稳定性高的路径发送数据;并引入多路由来保证传输可靠性。最后,使用网络模拟器将两个协议进行模拟比较,验证了AODV-S-M协议可有效提高路据包投递率、减少路由开销。
