基于zigbee的如光温室有害气体检测报警系统设计外文翻译.doc

外文翻译题 目:Using Limited Flooding in On-Demand Distance Vector Junior for Reduction Power Consumption in ZigBee Networks 姓 名: 史顺宗 学 院: 工学院 专 业: 电子信息科学与技术 班 级: 信息92 学 号: 32309203 指导教师: 汪小旵 职称: 教授 2013年 3月 20日 南京农业大学教务处制Zigbee网络中采取有限洪泛源驱动路由协议减少功耗Arman Zare, Hasan Taheri, and Meisam Nesary Moghaddam电气工程学院，Amirkabir科技大学，德黑兰，伊朗arman .zare , htaheri,nesariaut.ac.ir摘要：ZigBee网络采用源驱动路由（AODV）的简化版本，被称为AODV简化协议（AODVjr）。和AODV相比有三个主要的区别：它没有目的节点的序列号并且在一个节点崩溃时可以消除发送错误分组信息。第三个不同的是，防止为检测有源节点而周期性地发送HELLO消息并且使用由目的节点传送的连接信息。两者的其他功能都是相同的。其中之一是为寻找最短路径而在网络中发送的广播路由请求（RREQ）。它导致网络中大量功率消耗。其结果是，由电池供电的ZigBee节点会过早衰竭。因此，本文提出了一种ZigBee网络中采取有限洪泛的AODVjr（flaodvjr）协议。这种方法使用的是限制RREQ分组广播树路由算法的信息。仿真结果表明这种方法有其先进性。关键词：ZigBee，有限洪泛，简化源驱动路由协议，功率消耗1 介绍ZigBee网络是提供低数据速率，低功耗，低成本和可靠通信的无线网络技术。由于这些特点被用在多种用处。这是对许多不需要高数据并有外接电源网络的一个最佳选择，比如自动化监测中的应用1。ZigBee的物理（PHY）层和介质访问控制（MAC）层是基于IEEE 802.15.4 2，是由ZigBee联盟3开发。该技术工作在868MHz、915MHz和2.4GHz无证频率范围，数据速率20-250kbps还具有10米2的覆盖范围。节点可分为全功能设备（FFD）和精简功能设备（RFD）两种类型。一个FFD节点可以作为协调器、路由器和终端设备。事实上，如果它作为一个协调器，它可以形成一个网络，并指定加入节点的地址。此外，它可以作为终端节点发送路由数据包，即发送它的信息到父节点。另一种类型的节点，RFD，只可以作为网络中的终端设备。从拓扑角度来看，ZigBee有三种拓扑结构，包括在图1中所示的星形，树形和网状。在星型拓扑结构中，有一个协调器和其他几个节点连接到它。树结构是基于父、子节点关系构成的。有一个协调器为根的树和其他子加入的节点。如果一个子节点是路由器，它能在某些情况下接受一些子节点。最后一种拓扑结构是网状的，这种拓扑结构有一个协调器、一些路由器和终端设备。如果他们的覆盖范围相同，FFD节点可以与其他节点通信。因此，源节点和目标节点之间可能存在一些路径3。为了找到最短路径，ZigBee采用基于AODV的路由算法4。通过使用广播路由请求（RREQ），它可以找到合适的路线。目的节点可能会收到RREQ路径的包数。然后，它通过最短路径发送路由回复（RREP）。图1 ZigBee技术的拓扑结构：（a）星形 （b）网状 （C） 树形此外，该算法为检测活动节点定期发送Hello报文，此功能会消耗功率，这对ZigBee技术而言是不适合的。他们之间的主要区别是在AODVjr中不再发送Hello消息和前体的列表，只是目的节点发送连接消息。它是为了了解一条路线的情况。如果源节点接收到这个包，它可以通过这条路线发送数据包。这种差异减少了发送数据包的数量和功率消耗，但AODVjr类似在广播RREQ分组中的AODV，它消耗了很高的功率。因此，本文提出的寻找一种合适的方法，以减少发送的路由信息包是非常重要的。它使用在AODVjr中的树状路由信息。 本文的组织如下：第2节介绍了ZigBee路由协议，第3条是有关建议的路由方法的概述，第4节给出了所讨论的问题的模拟及结果，最后一节总结本文。2 ZigBee路由协议概述ZigBee技术有两个主要的路由协议：其一是树状路由，另一个则是AODV 2.1树状路由 树路由算法是基于被称为“CSKIP”的解决方案。它分配一个地址到每个加入网络中的节点。它的操作是基于三个参数的基础上，包括路由器父节点下最大子节点数Lm，网络的最大深度和父节点的最大数目Cm。地址由CSKIP（D）和分配给他们父节点数计算出。公式如下：该式中，d是网络中路由节点的深度。如果CSKIP（d）为0，路由器节点可以不接受其他节点作为它的子节点。如果其CSKIP（D）大于等于1，一个路由器节点可以分配地址到其子节点。连接到一个节点的第一个节点的地址是一个超过它的父节点的地址并且下一个子节点将有一个与以前的路由器子节点相比具有CSKIP（d）差异的地址。如果父节点的地址AP，第n个路由器的子节点ARP的地址是：并且它的第m个终端设备的地址将是：分配地址到所有节点后，树路由算法使用它和父子节点之间关系发送数据包。当一个节点接收到一个数据包时，它必须基于目标地址将它发送到父子节点。如果目的地址是其子之间的地址，它会发送数据包给其子节点，否则将发送给它的父节点。2.2 AODVjr该算法会像之前说的那样采用广播数据包路由寻找源和目的地之间的路径。当目标节点接收到RREQ，它会像图2所示那样中发送RREP去寻找它们之间的一个合适的节点到源节点。为明确这个路径是活跃的，目的节点定期传送连接消息至源节点。图 2 AODVjr中的路由发现3 使用有限洪泛的AODVjr 在网络中广播RREQ分组消耗要很高的功率，这在一般使用电池作为电源的ZigBee技术中，降低了网络的生命周期。为减小发送的网络中路由数据包的数目，提出一种方法，该方法6被施加到AODVjr中。在该方法中，树路由的信息用于限制RREQ的分组洪泛。此数据包将被跳数不为0的节点发送。当每个节点发送完，其跳数递减一个单位。因此，我们可以用它来限制广播RREQ包。这种方法被命名为有限洪泛的AODVjr（FLAODVjr）。每个节点都有一个基于CSKIP解决方案的唯一地址。当一个节点要发送信息到目的节点，它会基于树路由信息制定跳数。树路由中，当节点A想要发送数据包到节点B，该数据包发送到节点A和B的第一个共同的源然后，它发送数据包到节点B，因此，它们之间的跳数Ht的是与从源到A的跳数的总和相等，并且源和B Ht之间，可以计算出通过寻找甲乙与所述第一共同的源的深度的差异。4仿真及结果进行仿真，要使用OPNET7模拟器。在这种情况下，区域范围为100m100m并且工作频率是2.4GHz与250Kbps的。节点的数目增加至200并且Rm，Cm和Lm的所有量是相同的，即7。此外，实现了当目的地节点是随机的， AODVjr 的耗能是超过FLAODVjr的，这是实验的预期目标。上述参数的减少会导致功耗降低。 图3演示了这两种方法的通信耗能。在这种情况下，FLAODVjr发送通信开销小于AODVjr。这种差异会随着网络中的节点的数目增加而上升。节点的数量太高会导致网络深度的上升。源和目的节点之间的跳数也会随之增加。因此，发送路由数据包或通信消耗将攀升。图3 AODVjr 和 FLAODVjr耗能比较图5结论本文提出一种降低ZigBee技术功耗的方案。它限制了在AODV路由算法中使用树路由算法使用的广播路由数据包。跳数根据树算法对应的参数设置。做这方面的工作，减少源和目的节点之间发送数据包的数量。由此，因发送数据包而节省的功率有助于增加网络的生命周期。此外，仿真的结果验证了上述论证方案。参考文献1. Lin, S.: ZigBee Based Wireless Sensor Networks and Its Applications in Industrial. In: IEEE International Conference on Automation and Logistics, pp. 19791983. IEEE Xplore, Jinan (2007)2. IEEE Standard 802.15.: Standard for Information Technology-telecommunications and information exchange Systems between systems - Local and metropolitan area networks(2006), /3. Li, J., Zhu, X., Tang, N., Sui, J.: Study on ZigBee Network Architecture and Routing Algorithm. In: International Conference on Signal Processing Systems, pp. 389393. IEEE Xplore, Dalian (2010)4. Perkins, C.E., Royer, E.M.: Ad Hoc On-Demand Distance Vector Routing. In: Second IEEE Workshop Mobile Computing Systems and Applications, pp. 90100. IEEE Xplore, New Orleans (1999)5. Chakeres, I.D., Klein-Berndt, L.: AODVjr, AODV Simplified. ACM Mobile Computing and Communications Review, 100101 (2002)6. Lin, Z., Meng, Q.H., Liang, H.: A Route Discovery Method Based on Limited Flooding in ZigBee Network. In: IEEE International Conference on Automation and Logistics, Qingdao, pp. 30393044 (2008)7. OPNET Network Simulator Software, Using Limited Flooding in On-Demand Distance Vector Junior for Reduction Power Consumption in ZigBee NetworksArman Zare, Hasan Taheri, and Meisam Nesary MoghaddamElectrical Engineering Faculty, Amirkabir University of Technology, Tehran, Iranarman .zare , htaheri,nesariaut.ac.irAbstract. ZigBee network uses the simplified version of on-demand distance vector (AODV) routing which is named AODV junior (AODVjr). There are three main differences between it and AODV. It does not have sequence number of destination and eliminates the sending error packet when a node crashes. The third difference is preventing form sending Hello messages periodically for detecting the active nodes and use connect message that it sends by destination node. The other features are the same in both of them. One of them is the broadcasting of Route Request (RREQ) in the network for finding the shortest path. It causes that high energy is consumed in the network. As a result, ZigBee nodes that are supplied by batteries will die early. Therefore, an AODVjr based on Limited Flooding (FLAODVjr) in the network is suggested in this paper. This approach uses the information of tree routing algorithm for limiting the broadcasting of RREQ packets. The results of simulations prove the improvement of using this method.Keywords: ZigBee, Limited Flooding, AODVjr, Power Consumption.1 Introduction ZigBee network is a wireless network technology which provides low data rate, low power consumption, low cost and reliable communications. It is used in a variety ofapplications due to these features. It is one of the best choices for many networks that they do not need to high data and have restrictions in the accessing in power supplies such as automation and monitoring applications 1.The Physical (PHY) and Medium Access Control (MAC) layers of ZigBee are based on IEEE 802.15.4 2. It is developed by ZigBee Alliance 3. This technology operates in unlicensed frequency range of 868MHz, 915MHz and 2.4GHz with data rate 20-250kbps and also has a coverage range of 10-100m 2.The nodes are divided into two types that include Full Function Device (FFD) and Reduced Function Device (RFD). A FFD node can act as a coordinator, router and end-device. In fact, it can form a network and specify address to joint nodes, if it acts as a coordinator. Also, it enables to route the packets and plays the role of end-device, namely, send its information to parent node. Another type of node, RFD, can just be end-device in the network. From topological point of view, ZigBee has three topologies including star, tree and mesh that they are shown in figure 1. In the star topology, there are a coordinator and several other nodes which are connected to it by a hop. Tree is constituted based on parents-child relationships. There are a coordinator as a root of tree and other nodes that join as child to it. If a children node is a router, itcan accept some child under certain circumstances. The last topology is mesh. This topology has a coordinator and some routers and end-devices. The FFD nodes can communicate with others, if they are in the coverage range of together. Thereby, there are maybe some paths between source and destination 3.For finding shortest path, ZigBee uses routing algorithm based on AODV 4. It can find the appropriate route by the use of broadcasting Route Request (RREQ). The destination node may receive RREQ packet from several paths.Then, it sends Route Reply (RREP) through shortest pathFig. 1. Topologies of ZigBee Technology: (a). Star, (b). Mesh and (C). Tree.Also, this algorithm sends Hello message periodically for detecting active nodes. This feature consumes energy that is not suitable for ZigBee technology. Therefore, the use of AODVjr 5 is suggested in 3.The main difference between them is that sending Hello message and precursor list are eliminated in AODVjr and just destination node transmits connect message. It is for understanding the situation of a route. If source node receives this packet, it can send their packet from that route. This difference reduces the number of sent packets and power consumption but AODVjr is similar to AODV in broadcasting RREQ packet that it consumes a high level of energy. Thus, finding a suitable method for reduction in sending routing packets is very important that is suggested in this paper. It use information of tree routing in AODVjr.The paper is organized as follows: section 2 introduces the overview of ZigBee routing protocol, section 3 is about the suggested routing method, section 4 presents the simulations of the discussed issues and the results of them; and the last section concludes this paper.2 Overview of ZigBee Routing ProtocolsZigBee technology has two main routing protocols. One of them is tree routing and another is AODV that AODVjr is introduced in this paper rather than it due to the above discussed reason. These approaches are explained as follow.2.1 Tree RoutingTree routing algorithm is based on addressing scheme that is named “Cskip”. It assigns an address to each joint node to the network. It operates based on three parameters including the maximum number of router children of a parent Rm, the maximum depth of network Lm and the maximum number of children of a parent Cm. The Addresses are calculated by Cskip(d) and assigned to nodes by their parents. It is calculated from below formula: In this formula , d is the depth of a router node in the network. If Cskip(d) is 0, the router node cannot accept other nodes as child of it. A router node can distribute addresses to its child, if its Cskip(d) is greater and equal than 1. The address of the first node that joins to a node is one more than its parent node and the next router children node will have an address that has Cskip(d) difference with previous router children node. If the address of parent node is supposed Ap, the address of its nth router child Arp will be:and the address of its mth end-devices will be : After the assigning address to all the nodes tree routing algorithm uses it and parent children relationships between nodes for sending packets. When a node receives a packet, it must send it based on destination address to its child or parent. If the address of destination is between the address of its child, it will send that packet to it else it will send it to its parent. 2.2 AODVjrThis algorithm uses broadcasting routing packets for finding a path between source and destination as it was said before. When destination node receives RREQ, it sends RREP to source node for creating a suitable node between them that is shown in figure 2. For understanding that the path is active, destination transmits connect message to source periodically .Fig. 2. Route Discovery in AODVjr3 Using Limited Flooding in AODVjrBroadcasting the RREQ packet in the network consumes a high level of power and in the ZigBee technology which uses batteries as a power supply generally; it reduces the lifetime of the network.For decreasing the number of sent routing packets in the network, a method that has suggested in 6 is applied to AODVjr. In this method, the information of tree routing is used for limiting the flooding of RREQ packet. This packet will be sent by nodes, if the amount of hop count is not 0. When each node transmits it, their amounts of hop count decrement one unit. Therefore, we can use it for limitation of broadcasting RREQ packet. This method is named Flooding Limitation AODVjr (FLAODVjr).Each node has a unique address based on Cskip addressing scheme. When a node wants to send its information to a destination, it set the amount of hop count based on information of tree routing. In the tree routing, when node A wants to send packet to node B, the packet send to the first common ancestor of node A and B. Then, it sends the packet to node B. Hence, the number of hops between them Ht is equal with the sum of the number of hops from A until the first ancestor and between that ancestor and B. Ht can be calculated by finding the difference of depth A and B with the first common ancestor.For finding the depth of nodes, if the address of sender is 0, it is coordinator with depth 0. If it is greater than 0, will start searching in the depth 0. If the parent of node is in that depth, its depth will be 1 else, will continue searching in next depth until Lm. when a node can find the depth of its parent dp, its depth is dp+1. For finding the depth of first common ancestor, it starts searching from d=0 until Lm-1 (because, nodes in the last depth is leaves of tree and cannot be parents of other nodes). At first, searching starts in the child of depth 0, namely, in the router child of the coordinator. It supposes the address of the first common ancestor is 1. If the address of A and B are in the range of 1 and 1+Cskip(0), it will start searching in the router child of it and this trend will use for them. If they do not have common ancestor in the child of the first found ancestor, the depth of it is the depth of the first common ancestor. In the same depth, searching happens in router child and is started with one of them that it has smallest address.After calculating the Ht and setting the hop count equal to it, destination node receives RREQ packet. Sometimes the optimal hop count is not Ht. Because, in tree routing, it is possible that source and destination are in the coverage range of together or destination can receive packets, if it is in the coverage range of a router node that is not its parent but it can ensure that packets receive to their destinations. It can reduce the number of sent RREQ packet. As a consequence, the amount of consumed energy decreases.4 Simulations and ResultsFor simulation, OPNET 7 simulator is used. In this case, area is considered100m100m and operational frequency is 2.4GHz with 250Kbps. Also, the number of nodes increases up to 200 and the all amounts of Rm, Cm and Lm are the same, namely, 7. Also, achieving to comparison of the amounts of sent overhead is the goal of experiments in the AODVjr and FLAODVjr methods when the destination node is random. Reduction in mentioned parameter causes reduction in power consumption.Figure 3 demonstrates the amount of communication overhead of both approaches. In this case, FLAODVjr sends communication overhead less than another. This difference rises with increasing the number of node in the network. The high number of nodes causes the rising in the depth of the network. It increases the number of hops between source and destination. Thereby, sent routing packets or communication overhead will climb .Fig. 3. Comparison of Overhead in AODVjr and FLAODVjr5 ConclusionIn this paper, a method is suggested for reducing in power co