多接口多信道无线Mesh网络路由与部分重叠信道分配研究
发布时间：2019-06-29 06:55
【摘要】：无线Mesh网络WMNs(Wireless Mesh Networks)能扩展现有无线网络的覆盖范围,是构建宽带无线接入网络的关键组网类型,近年来受到了学术界和业界的广泛关注。WMNs的网络容量随并行传输间干扰的增加而迅速下降。有效的路由与信道分配策略是提升网络容量的有效方案,它们能显著提升WMNs的整体性能。有效的信道分配方案能保证有通信需求的邻近节点运行在相同信道上;有效的路由选择策略从多条可行路径中选择出满足端到端服务质量要求的最优路径。信道分配决定了节点在通信过程中可能受到的干扰,也决定了源节点与目的节点之间的可行路径集合。路由度量是路由计算与选择的基础,其设计的优劣直接决定了源节点与目的节点间通信路径的好坏,进而影响网络整体性能。WMNs中节点间通信方式分为单播和多播两种,路由与信道分配策略的设计要充分考虑单播与多播通信的特点,才能充分发挥WMNs的优势。目前针对WMNs路由与信道分配的研究,虽然取得了一定进展,但是仍存在诸多问题。其中主要的问题有:为邻近的传输节点分配正交信道,由此引入的同信道干扰会阻止节点的并行传输并引发网络吞吐量下降;采用实测方法估计部分重叠信道POCs(Partially Overlapped Channels)干扰范围,获得的测量结果可移植性差;信道分配只考虑骨干链路,忽略接入链路,得到的信道分配结果无法应用于端到端的数据流传输;路由度量设计考虑单一网络业务类型、忽略网关节点的选择、分开描述各类干扰导致引入可调参数;多播路由与信道分配研究大多面向单个多播会话,只为一个会话优化网络资源使用,忽略网络整体负载均衡。本文针对现有研究中存在的主要问题,提出使用频谱上有交叠的信道即POCs来提升网络性能的路由与信道分配方案。从单播路由度量设计与POCs信道分配、多播路由与POCs信道分配方面入手解决数据流的路由与信道选择问题,提出了综合考虑POCs WMNs特点的路由与信道分配策略,为单播和多播数据流选择合理的传输路径并为路径上的链路分配合理的信道,实现高吞吐量数据传输。本文的主要创新工作可以总结为以下五方面:(1)使用理论推导方法获取对应不同信道间隔的POCs干扰范围,解决实测方法估计干扰范围的准确性和可移植性问题。使用双径地面传播模型模拟开放空间环境中信号的路径损耗,用归一化的发送和接收端功率谱密度的卷积量化POCs干扰范围的缩减,得出理想发送信号频率模板下的POCs干扰范围和使用不同滚降因子的升余弦滚降滤波器的POCs干扰范围。由推导结果可以看到POCs干扰范围随信道间隔的增大而减小,这是POCs能够得到应用的基础。(2)提出端到端POCs信道分配方案,实现有效的端到端数据流传输。使用综合考虑链路位置、链路负载和干扰邻居数的Rank值确定链路的信道分配次序,赋予拥塞可能性高的链路更高的信道分配优先权。考虑骨干链路与接入链路使用同频段信道和异频段信道进行通信的两种情况,根据节点度或链路负载进行邻居—接口绑定,确定相邻节点间通信使用的接口;以最小化网络干扰为目标进行接口—信道绑定,确定相邻节点间通信使用的信道。当网络中正交信道数量不足时,可以充分利用POCs增加骨干并行传输数;当网络中有足够的正交信道能消除骨干链路之间的干扰时,尽量避免使用POCs。(3)设计多网关POCs干扰统一描述路由度量,解决POCs WMNs中数据流的路由选择问题。该路由度量使用等效带宽准确捕捉POCs WMNs中的物理干扰、逻辑流内干扰和逻辑流间干扰对数据传输的影响,简化路由度量表达式;根据不同业务类型,使用不同的路由度量表达式计算并选择路由,指导数据包通过最优网关和去向最优网关的最优路径进行传输;考虑网关对路由选择的影响,避免网关附近形成容量瓶颈制约网络的整体服务能力。(4)提出多播加权冲突图模型建模面向混合业务的POCs干扰。多播加权冲突图模型将起始于同一节点的一组链路视为一次传输,充分考虑多播的无线广播优势;使用链路权重衡量链路间的干扰程度,充分考虑POCs干扰特性。(5)提出面向混合业务的联合多播路由与POCs信道分配的二进制规划构建和启发式求解方案,从业务管理角度均衡网络负载、优化整体网络资源使用。将节点负载均衡和信道负载均衡引入联合问题的规划构建中,避免了某些链路高度拥塞而其他链路利用率低下的情况。由规划构建得出的最优解可以作为评价其他集中式或分布式方案性能的基准。启发式方案通过比较各尚未被覆盖的多播接收端到源节点的所有可行路径的代价,从中不断寻找代价最小的路径构建多播树并为路径上的链路分配信道,直到将所有多播接收端与源节点连接起来。启发式方案能在多项式时间内找到逼近最优网络性能的路由与POCs信道分配结果,可以应用于实际。本文通过对WMNs路由与POCs信道分配问题的深入研究,提出利用POCs提升网络性能的单播、多播路由与信道分配方案,克服了现有研究的局限性,实现了高效的端到端通信。研究成果有助于提升网络整体性能,推动POCs在WMNs中的应用。
[Abstract]:Wireless Mesh Networks (WMNs) can expand the coverage of the existing wireless network, and it is the key networking type to construct the broadband wireless access network. In recent years, the wireless Mesh Networks has received extensive attention from the academic community and the industry. The network capacity of the WMNs decreases rapidly with the increase of the interference between the parallel transmission. The effective routing and channel allocation strategy is an effective solution to improve the network capacity, which can significantly improve the overall performance of the WMNs. The effective channel allocation scheme can ensure that the neighboring nodes with communication requirements run on the same channel; the effective route selection strategy selects an optimal path satisfying the end-to-end service quality requirement from a plurality of feasible paths. The channel assignment determines the possible interference of the node in the communication process and also determines a set of feasible paths between the source node and the destination node. The routing metric is the basis of the route calculation and selection, and the design of the routing metric directly determines the communication path between the source node and the destination node, thereby affecting the overall performance of the network. The inter-node communication method in WMNs is divided into two types: unicast and multicast. The design of the routing and channel allocation strategy should take full account of the characteristics of unicast and multicast communication, so as to give full play to the advantages of WMNs. At present, the research on the route and channel assignment of WMNs, although some progress has been made, there are still many problems. The main problem is that the orthogonal channel is allocated to the adjacent transmission nodes, the co-channel interference introduced by the method can prevent the parallel transmission of the nodes and cause the network throughput to drop, and the interference range of the partially overlapped channels POCs is estimated by the measured method. the obtained measurement result is poor in portability; only the backbone link is considered in the channel allocation, the access link is ignored, the obtained channel allocation result cannot be applied to the end-to-end data flow transmission, the routing metric design takes into account the single network service type, and the selection of the gateway node is ignored, Separate description of various interference results in the introduction of tunable parameters; most of the multicast routing and channel allocation studies face a single multicast session, only one session optimizes network resource usage, and ignores the overall network load balance. In this paper, aiming at the main problems existing in the existing research, a routing and channel allocation scheme is proposed to improve the network performance using the overlapping channels, i.e., POCs. From the aspects of unicast route metric design and POCs channel allocation, multicast routing and POCs channel allocation, the problem of routing and channel selection of data flow is solved, and the strategy of routing and channel allocation considering the characteristics of POCs WMNs is proposed. A reasonable transmission path is selected for the unicast and multicast data streams and a reasonable channel is allocated for the links on the path, and high-throughput data transmission is realized. The main innovative work of this paper can be summarized in the following five aspects: (1) the theoretical derivation method is used to obtain the interference range of the POCs corresponding to different channel intervals, and the accuracy and the portability of the interference range are estimated by the measured method. the path loss of a signal in an open space environment is simulated by using a double-diameter ground propagation model, and the reduction of the interference range of the POCs is quantified by the convolution of the normalized transmission and receiving end power spectral density, It is concluded that the POCs interference range under the ideal transmission signal frequency template and the POCs interference range of the raised cosine roll-down filter using different roll-off factors are obtained. The result of the derivation can see that the interference range of the POCs decreases with the increase of the channel spacing, which is the basis for the application of the POCs. (2) An end-to-end POCs channel allocation scheme is proposed, and the effective end-to-end data stream transmission is realized. The channel allocation order of the link is determined using the Rank value combining the link position, the link load, and the interference neighbor number, and the channel allocation priority that is higher than the link with which the congestion probability is high is given. considering the two cases of communication between the backbone link and the access link using the same frequency band channel and the different frequency band channel, the neighbor base interface binding is carried out according to the node degree or the link load, the interface used by the communication among the adjacent nodes is determined, A channel used for inter-node communication is determined. When the number of orthogonal channels in the network is not enough, the POCs can be fully utilized to increase the number of parallel transmission of the backbone; when there is enough orthogonal channel in the network to eliminate the interference between the backbone links, the use of the POCs is avoided as much as possible. And (3) designing the multi-gateway POCs interference to uniformly describe the route metric and solving the routing problem of the data flow in the POCs WMNs. the route metric uses the equivalent bandwidth to accurately capture the physical interference in the POCs WMNs, the interference between the logic flow and the logical inter-flow interference on the data transmission, simplifies the routing metric expression, calculates and selects the route using different route metric expressions according to different service types, The guide data packet is transmitted through the optimal gateway and the optimal path to the optimal gateway; the influence of the gateway on the route selection is taken into account, and the capacity bottleneck of the gateway near the gateway is avoided to restrict the overall service capability of the network. And (4) a multicast weighted collision graph model is proposed to model the POCs interference for the mixed service. The multicast weighted collision graph model considers a group of links starting from the same node as one transmission, and fully considers the radio broadcast advantages of the multicast; the interference degree between the links is measured by using the link weight, and the interference characteristics of the POCs are fully taken into account. And (5) putting forward a binary plan construction and a heuristic solution scheme for the combined multicast routing and the POCs channel allocation for the mixed service, and balancing the network load from the service management angle and optimizing the use of the whole network resource. The node load balancing and the channel load balancing are introduced into the planning construction of the joint problem, and the situation that some link is highly congested and other link utilization rate is low is avoided. The optimal solution derived from the planning can be used as a benchmark for evaluating the performance of other centralized or distributed schemes. The heuristic scheme constructs the multicast tree and assigns a channel to the link on the path by comparing the cost of all possible paths to the source node that have not yet been covered, until all the multicast receiving ends are connected to the source node. The heuristic scheme can find the route to the optimal network performance and the POCs channel assignment result in the polynomial time, and can be applied to the practical application. In this paper, through the deep study of the distribution of the WMNs route and the POCs channel, a unicast, multicast routing and channel allocation scheme using the POCs to improve the network performance is proposed, and the limitation of the existing research is overcome, and the high-efficiency end-to-end communication is realized. The research results help to improve the overall performance of the network and promote the application of the POCs in the WMNs.
【学位授予单位】：吉林大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：TN929.5
，
本文编号：2507633
[Abstract]:Wireless Mesh Networks (WMNs) can expand the coverage of the existing wireless network, and it is the key networking type to construct the broadband wireless access network. In recent years, the wireless Mesh Networks has received extensive attention from the academic community and the industry. The network capacity of the WMNs decreases rapidly with the increase of the interference between the parallel transmission. The effective routing and channel allocation strategy is an effective solution to improve the network capacity, which can significantly improve the overall performance of the WMNs. The effective channel allocation scheme can ensure that the neighboring nodes with communication requirements run on the same channel; the effective route selection strategy selects an optimal path satisfying the end-to-end service quality requirement from a plurality of feasible paths. The channel assignment determines the possible interference of the node in the communication process and also determines a set of feasible paths between the source node and the destination node. The routing metric is the basis of the route calculation and selection, and the design of the routing metric directly determines the communication path between the source node and the destination node, thereby affecting the overall performance of the network. The inter-node communication method in WMNs is divided into two types: unicast and multicast. The design of the routing and channel allocation strategy should take full account of the characteristics of unicast and multicast communication, so as to give full play to the advantages of WMNs. At present, the research on the route and channel assignment of WMNs, although some progress has been made, there are still many problems. The main problem is that the orthogonal channel is allocated to the adjacent transmission nodes, the co-channel interference introduced by the method can prevent the parallel transmission of the nodes and cause the network throughput to drop, and the interference range of the partially overlapped channels POCs is estimated by the measured method. the obtained measurement result is poor in portability; only the backbone link is considered in the channel allocation, the access link is ignored, the obtained channel allocation result cannot be applied to the end-to-end data flow transmission, the routing metric design takes into account the single network service type, and the selection of the gateway node is ignored, Separate description of various interference results in the introduction of tunable parameters; most of the multicast routing and channel allocation studies face a single multicast session, only one session optimizes network resource usage, and ignores the overall network load balance. In this paper, aiming at the main problems existing in the existing research, a routing and channel allocation scheme is proposed to improve the network performance using the overlapping channels, i.e., POCs. From the aspects of unicast route metric design and POCs channel allocation, multicast routing and POCs channel allocation, the problem of routing and channel selection of data flow is solved, and the strategy of routing and channel allocation considering the characteristics of POCs WMNs is proposed. A reasonable transmission path is selected for the unicast and multicast data streams and a reasonable channel is allocated for the links on the path, and high-throughput data transmission is realized. The main innovative work of this paper can be summarized in the following five aspects: (1) the theoretical derivation method is used to obtain the interference range of the POCs corresponding to different channel intervals, and the accuracy and the portability of the interference range are estimated by the measured method. the path loss of a signal in an open space environment is simulated by using a double-diameter ground propagation model, and the reduction of the interference range of the POCs is quantified by the convolution of the normalized transmission and receiving end power spectral density, It is concluded that the POCs interference range under the ideal transmission signal frequency template and the POCs interference range of the raised cosine roll-down filter using different roll-off factors are obtained. The result of the derivation can see that the interference range of the POCs decreases with the increase of the channel spacing, which is the basis for the application of the POCs. (2) An end-to-end POCs channel allocation scheme is proposed, and the effective end-to-end data stream transmission is realized. The channel allocation order of the link is determined using the Rank value combining the link position, the link load, and the interference neighbor number, and the channel allocation priority that is higher than the link with which the congestion probability is high is given. considering the two cases of communication between the backbone link and the access link using the same frequency band channel and the different frequency band channel, the neighbor base interface binding is carried out according to the node degree or the link load, the interface used by the communication among the adjacent nodes is determined, A channel used for inter-node communication is determined. When the number of orthogonal channels in the network is not enough, the POCs can be fully utilized to increase the number of parallel transmission of the backbone; when there is enough orthogonal channel in the network to eliminate the interference between the backbone links, the use of the POCs is avoided as much as possible. And (3) designing the multi-gateway POCs interference to uniformly describe the route metric and solving the routing problem of the data flow in the POCs WMNs. the route metric uses the equivalent bandwidth to accurately capture the physical interference in the POCs WMNs, the interference between the logic flow and the logical inter-flow interference on the data transmission, simplifies the routing metric expression, calculates and selects the route using different route metric expressions according to different service types, The guide data packet is transmitted through the optimal gateway and the optimal path to the optimal gateway; the influence of the gateway on the route selection is taken into account, and the capacity bottleneck of the gateway near the gateway is avoided to restrict the overall service capability of the network. And (4) a multicast weighted collision graph model is proposed to model the POCs interference for the mixed service. The multicast weighted collision graph model considers a group of links starting from the same node as one transmission, and fully considers the radio broadcast advantages of the multicast; the interference degree between the links is measured by using the link weight, and the interference characteristics of the POCs are fully taken into account. And (5) putting forward a binary plan construction and a heuristic solution scheme for the combined multicast routing and the POCs channel allocation for the mixed service, and balancing the network load from the service management angle and optimizing the use of the whole network resource. The node load balancing and the channel load balancing are introduced into the planning construction of the joint problem, and the situation that some link is highly congested and other link utilization rate is low is avoided. The optimal solution derived from the planning can be used as a benchmark for evaluating the performance of other centralized or distributed schemes. The heuristic scheme constructs the multicast tree and assigns a channel to the link on the path by comparing the cost of all possible paths to the source node that have not yet been covered, until all the multicast receiving ends are connected to the source node. The heuristic scheme can find the route to the optimal network performance and the POCs channel assignment result in the polynomial time, and can be applied to the practical application. In this paper, through the deep study of the distribution of the WMNs route and the POCs channel, a unicast, multicast routing and channel allocation scheme using the POCs to improve the network performance is proposed, and the limitation of the existing research is overcome, and the high-efficiency end-to-end communication is realized. The research results help to improve the overall performance of the network and promote the application of the POCs in the WMNs.
【学位授予单位】：吉林大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：TN929.5
，
本文编号：2507633
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