1、厦门大学软件学院毕业设计（论文）开题报告 学生姓名 班级 学号 指导教师姓 名 职称 教授 教授 所在单位 中国厦门大学 韩国 首尔国立大学 毕业设计（论文）题 目 一种无线网状网中的多接口多路径路由协议 1、 毕业设计（论文）的目标： In recent years, the wireless mesh network (WMN) becomes a hot topic. WMNs are special case of mobile ad hoc networks where nodes have relative fixed position and communicate to the
2、 Internet through one or more gateways. The potential of wireless mesh network make broadband wireless Internet access possible and practical. There are many differences between wireless and wired networks, thus not all of the existing network notions could be used in wireless mesh networks. Routing
3、 is one of the key research areas in Wireless Mesh Network. Nowadays, million papers on this area have established routing protocols in wireless mesh networks to improve end-to-end throughput. Before we start, we have to know the fact that there are two main problems in WMN communications. First is
4、the CS-channel competition. In case of a mesh node is transmitting data with others, no wireless communications in the transmitting channel will be admitted in its carry sensing area. Thus it limits the performance of the network. The second problem is Hidden Terminal. Protocol Hidden Terminal cause
5、s collisions (always be solved by RTS/CTS System) and Physical Hidden Terminal (can not be solved by RTS/CTS System) causes interferences. People implements multi-channel in order to avoid those problems Another concept I have to introduce is Multipath. Multipath is a way of improving throughput. Us
6、ing multipath, one flow is divided into several flows, and be transmitted to destination concurrently, in order to achieve times of throughput than single flow. From the related works which have been done, we knew that there are four scenarios in routing protocols and their ideal packet scheduling a
7、s below: A. Single-Channel, Single-Path (SCSP) Scenario B. Multi-Channel, Single-Path (MCSP) Scenario C. Single-Channel, Multi-Path (SCMP) Scenario D. Multi-Channel, Multi-Path (MCMP) Scenario Fig.1. Ideal packet scheduling in (a) SCSP, (b)MCSP,(c)SCMP, and (d)MCMP scenarios Due to the ideal packet
8、scheduling of them, we could know that Multi-path & Multi-channel routing has the best throughput among the scenarios. One successful Multi-path & Multi-channel routing available is JMM protocol. However, JMM is static predispose, while our approach try to establish a novel dynamic scheme called Mul
9、ti-path & Multi-channel Ad hoc On-Demand Distance Vector (MMAODV) Routing Protocol based on the result above. The proposed protocol maintains two or more paths to increase the throughput of the nodes and select optimal channel from available ones to provide interferences between paths. To validate o
10、ur scheme, a simulation based on QualNet4.0 will be run. As QualNet4.0 has provided AODV routing simulation, and it is an open source application, we will modify the codes to test our approach. Final result will be released to show both the benefit and drawback of MMAODV routing protocol. 2、 实现方法： 2
11、.1 Assumptions: In our research, we assume some conditions. First is that each mesh node could know the channel using status of its neighbors. This assumption could be easily implemented in real experience base on the Paper of RSS-based Carrier Sensing and Interference Estimation in 802.11 Wireless
12、Networks from multimedia and mobile communications lab, Seoul National University. Second, the mesh networks in our research are bi-directional link networks. 2.2 Algorithm: Our scheme mainly bases on the Ad hoc On-Demand Distance Vector Routing (AODV), a reactive routing protocol which uses a broad
13、cast route discovery mechanism and relies on dynamically establishing route table entries at intermediate nodes. 2.2.1 Predefinition We predefine two tables which are stored and maintained by each node. The first one is Channel Status Table, which stores the channel using status of the node itself a
14、nd its neighbors. The second one is a modified AODV route table, which stores the rout vectors to set up the reverse path vectors. Channel using status will be added in our new routing table. 2.2.2 Path Discovery The Path Discovery process is initiated whenever a source node needs to communicate wit
15、h another node for which it has no routing information in its routing table. The source node used flood mechanism such as AODV routing protocol. The different from AODV protocol is that the message it broadcast is Multi-path & Multi-channel Route Request (MMRREQ), which include more information on t
16、he channel status. Each neighbor either satisfies the MMRREQ by sending a multi-path & multi-channel route reply (MMRREP) back to the source, or then rebroadcasts the MMRREQ to its own neighbors after increasing the hop counter. To choose an optimal channel for rebroadcasting is one of the key issue
17、s in the proposed scheme. As each node is maintaining its channel Status Table, it could clearly know the channel status of itself and its neighbor nodes. A special elect algorithm will be established to decide the rebroadcasting channel. 2.2.3 Reverse Path Setup To set up a reverse path, a node rec
18、ords the address of the neighbor from which it received the first copy of the MMRREQ. These reverse path route entries are maintained for at least enough time for the MMRREQ to traverse the network and produce a reply to the sender. The abandon mechanism in MMAODV is a bit different from the one in
19、AODV. When an intermediate node receives a MMRREQ if it has already received a MMRREQ with the same broadcast id, source address, and also the channel, or the MMRREQ is from one of it next hop node, it recognize the MMRREQ as a redundant one and does not rebroadcast but drop it. 2.2.4 Forward Path S
20、etup Eventually, a MMRREQ will arrive at a node (possibly the destination itself) that possesses a current route to the destination. Once the destination node received the MMRREQ, it replies the MMRREP. Then the MMRREP tracing the vectors in each node to reach the source node. This is the way of set
21、ting up the forward path from all nodes back to the source. Addition to AODV routing protocol, reverse path setup duration is accompanying the channel status table maintenance. Once MMRREP reach a node, the node have to broadcast a channel announce message (CAM) which contain the channels it used fo
22、r receive and forward the MMRREP to its neighbor nodes. All of the neighbor nodes use the CAM to fresh its Channel Status Table. 2.2.5 Multi-path Maintenance After the path initialization, in ideal situation, we can get more than three paths in the mesh network. A special calculation will be done to
23、 select two or three of the paths for data transmission simultaneously. Dynamic maintenances based on the mesh network quality are still in consideration. 2.2.6 Data Transmission Data is divided into several concurrent flows, and be transmitted to the destination simultaneously. By this kind of mult
24、ipath and multi-channel routing scheme, which also avoids much of intra-flow and inter-flow channel competition and interference, we can achieve times of high performance than normal single path scheme. 2.3 Simulation The simulation will be performed in QUALNET 4.0. We will modify the module of AODV
25、 routing adding our required lists and abilities, and then simulate our proposal in order to validate and evaluate our algorithm. 2.4 Future work In future we will set up a new plan of real implementation on wireless mesh network test bed in the Multimedia And Mobile Communications Lab of Seoul Nati
26、onal University. 3、 时间进度安排： 2008 年 2 月 13 日 - 4 月 1 日 Read related papers and documents and study related protocol 2008 年 4 月 2 日 -4 月 23 日 Analyze and develop beta version of MMAODV protocol 2008 年 4 月 24 日 -5 月 8日 MMAODV Java demo implementation and Algorithm improvement 2008 年 5 月 9 日 -5 月 21日 Si
27、mulation and Evaluation 2008 年 5 月 22 日 - 6 月 6 日 Paper work 指导教师审核意见： 校内指导教师签名： 年 月 日 毕业论文任务书 （以下由学生填写） 题 目： MMAODV Routing Protocol in WMNs 目标要求： In this project, we summarize the existing works on routing protocols of Wireless Mesh Network, compare four types of scenarios of them, and then set up
28、 a novel dynamic scheme called Multi-Interface and Multi-Path Ad hoc On-Demand Distance Vector (MMAODV) Routing Protocol based on the effort above. The proposed protocol dynamically establishes and maintains two or more paths for data transmission to increase the throughput of the flow in a distribu
29、ted manner. Dynamical channel assignment is incorporated to avoid channel competition and interference intra and/or inter paths. To evaluate the system performance in terms of throughput in our proposed protocol, we also perform a simulation study on NS2 in our work. MMAODV was compared to AODV and
30、other WMN routing protocols in different scenarios. 支持条件： NS 2.0, J2SE, Qualnet4.0, Microsoft Visio 2003, Microsoft Windows Vista 校外指导教师（签名） 职称 Professor 单位 Seoul National University 校内指导教师（签名） 职称 学生（签名） 分阶段进度安排 阶段 起讫时间 计划完成内容 1 2008 年 2 月 13 日 - 4 月 1 日 Reading related papers and documents Study re
31、lated protocol 2 2008 年 4 月 2 日 -4 月 23 日 Analyzing and develop beta version of MMAODV protocol 3 2008 年 4 月 24 日 -5 月 8 日 MMAODV Java demo implementation Algorithm improvement 4 2008 年 5 月 9 日 -5 月 21 日 Simulation Evaluation 5 2008 年 5 月 22 日 - 6 月 6 日 Paper work 注：一般可分为资料文献搜索、拟定方案（提纲）、试验或初稿、定稿等阶段
32、教师分阶段指导记录 第一阶段： Read related papers in the field of 1. Basic knowledge of wireless mesh network 2. Routing protocols of wireless mesh networking techniques. 3. Papers related with multi-channel, multi-interface, multi-path. 教师分阶段指导记录 第二阶段： Algorithm develop: Analyze the pros & cons of different rout
33、ing protocols in wireless mesh networks, as well as ad hoc network systems. Develop our MMAODV based on multi-interface and multi-path. Draw flow charts of the algorithm. 第三阶段： Implement MMAODV algorithm in JAVA demo. Find mistakes and also fix those unexpected problems and Improve our algorithm. 第四
34、阶段： Simulation by NS2 based on the Java demo. Analyze and compare MMAODV with others. And draw performance figures, and write brief paper. 第 五 阶段： Write paper 论文评语 拟评成绩 校外指导教师（签名） 职称 Professor 单位 Seoul National University 校内指导教师（签名） 职称 年 月 日 论文评阅 评阅成绩 评阅教师（签名） 职称 年 月 日 答辩记录 演示成绩 答辩成绩 答辩小组组长（签名） 职务（称） 年 月 日 总评 成绩 学院负责人（签盖） 年 月 日
