PROJECT 12-WIRELESS MESH NETWORK Wireless Communication -Project Report 3 Project 12-Wireless Mesh Network Jiesi LI,Student ID:5080309713 Abstract-Wireless mesh networks(WMN)has become a key Wireless mesh networks technology is flexible and has technology for next generation wireless networking.Wireless low budget which is now growing in the market due to its mesh networks are undergoing rapid progress and inspiring numerous applications because of their advantages over networks advantages or benefits both in developed and developing coun- like DSL.However,many technical issues still exist in this field. tries.According to a report by MuniWireless.com in March 2007,81 U.S.cities have already installed citywide or region- Index Terms-WMN. wide municipal wireless networks and 164 more are actively building such networks.The report also says that 38 U.S.cities I.INTRODUCTION already have municipal wireless networks for the exclusive IRELESS mesh networks is an emerging technology use of public safety and city employees.In this project,I will and may bring the dream of a seamlessly connected discuss what wireless mesh network is.how it functions.its world into reality.Mesh networks can easily and effectively advantages,the network architecture,applications,problems connect a significantly large area e.g.a city.In a wireless mesh the new technology is facing and possible ways of solving network,the network connection is spread out among dozens them while using a better protocal. or even hundreds of wireless mesh nodes that"talk"to each other to share the network connection across a large area.Mesh II.NETWORK ARCHITECTURE nodes are small radio transmitters that function in the same way as a wireless router.They use Wi-Fi standards known as Mesh itself is a type of architecture.Originally.Ethernet 802.11a,b and g in order to communicate with users and with was a shared bus topology in which every node tapped each other.They are programmed to tell them how to interact into a common cable that carried all transmissions from all with each other.Only a fraction of nodes have direct access nodes.In bus networks,any node on the network hears all to the internet.That wired node shares the internet connection transmissions from every other node in the network.Most wirelessly with the nearest cluster of nodes,which then shares local area networks (LANs)today use a star topology in which it with the nearest cluster of nodes and so on.In this case,the every network node is connected to a switch (switches can be nodes don?need to be wired to anything but a power supply. interconnected to form larger networks). WMNs are has two types of nodes:mesh routers and mesh Mesh networks are different full physical layer connectivity clients.Other than the routing capability for gateway/bridge is not required.As long as a node is connected to at least one functions as in a conventional wireless router,a mesh router other node in a mesh network,it will have full connectivity to contains additional routing functions to support mesh network-the entire network because each mesh node forwards packets ing.Through multi-hop communications,the same coverage to other nodes in the network as required.Mesh protocols can be achieved by a mesh router with much lower trans- automatically determine the best route through the network mission power.To further improve the flexibility of mesh and can dynamically reconfigure the network if a link becomes networking,a mesh router is usually equipped with multiple unusable. wireless interfaces built on either the same or different wireless There are many different types of mesh networks.Mesh access technologies Mesh routers have minimal mobility and networks can be wired or Wireless.For wireless networks there form the mesh backbone for mesh clients.Thus,although mesh are ad-hoc mobile mesh networks and permanent infrastructure clients can also work as a router for mesh networking,the mesh networks.There are single radio mesh networks.dual- hardware platform and software for them can be much simpler radio mesh networks and multi-radio mesh networks.All of than those for mesh routers To date,several companies have these approaches have their strengths and weaknesses.They already realized the potential of this technology and offer can be targeted at different applications and used to address wireless mesh networking products. different stages in the evolution and growth of the network. Wireless mesh networks are preferable to existing cable Wireless mesh networks has of two types of nodes:mesh based networks or wireless LANs,due to the following clients and mesh routers.Compared with a conventional potential advantages:(a)it is more cost effective,as service wireless router,a wireless mesh router can achieve the same providers do not have to install a wired connection to each coverage with much lower transmission power through multi- subscriber:(b)it is more reliable,as each node has redundant hop communications.Optionally,the medium access control paths to reach the Internet;(c)the throughput got by a user can (MAC)protocol in a mesh router is enhanced with better be increased through routing via multiple,bandwidth-abundant scalability in a multi-hop mesh environment. paths and (d)the wireless network can readily extend their Even though there are the above differences,mesh and coverage by installing additional ad-hoc hops. conventional wireless routers are more often built on a similarPROJECT 12 – WIRELESS MESH NETWORK 1 Wireless Communication - Project Report 3 Project 12 – Wireless Mesh Network Jiesi LI, Student ID: 5080309713 Abstract—Wireless mesh networks(WMN) has become a key technology for next generation wireless networking. Wireless mesh networks are undergoing rapid progress and inspiring numerous applications because of their advantages over networks like DSL .However, many technical issues still exist in this field. Index Terms—WMN. I. INTRODUCTION WIRELESS mesh networks is an emerging technology and may bring the dream of a seamlessly connected world into reality. Mesh networks can easily and effectively connect a significantly large area e.g. a city. In a wireless mesh network, the network connection is spread out among dozens or even hundreds of wireless mesh nodes that ”talk” to each other to share the network connection across a large area. Mesh nodes are small radio transmitters that function in the same way as a wireless router. They use Wi-Fi standards known as 802.11a, b and g in order to communicate with users and with each other. They are programmed to tell them how to interact with each other. Only a fraction of nodes have direct access to the internet. That wired node shares the internet connection wirelessly with the nearest cluster of nodes, which then shares it with the nearest cluster of nodes and so on. In this case, the nodes don? need to be wired to anything but a power supply. WMNs are has two types of nodes: mesh routers and mesh clients. Other than the routing capability for gateway/bridge functions as in a conventional wireless router, a mesh router contains additional routing functions to support mesh network￾ing. Through multi-hop communications, the same coverage can be achieved by a mesh router with much lower trans￾mission power. To further improve the flexibility of mesh networking, a mesh router is usually equipped with multiple wireless interfaces built on either the same or different wireless access technologies Mesh routers have minimal mobility and form the mesh backbone for mesh clients. Thus, although mesh clients can also work as a router for mesh networking, the hardware platform and software for them can be much simpler than those for mesh routers .To date, several companies have already realized the potential of this technology and offer wireless mesh networking products. Wireless mesh networks are preferable to existing cable based networks or wireless LANs , due to the following potential advantages: (a) it is more cost effective, as service providers do not have to install a wired connection to each subscriber; (b) it is more reliable, as each node has redundant paths to reach the Internet; (c) the throughput got by a user can be increased through routing via multiple, bandwidth-abundant paths and (d) the wireless network can readily extend their coverage by installing additional ad-hoc hops. Wireless mesh networks technology is flexible and has low budget which is now growing in the market due to its advantages or benefits both in developed and developing coun￾tries. According to a report by MuniWireless.com in March 2007, 81 U.S. cities have already installed citywide or region￾wide municipal wireless networks and 164 more are actively building such networks. The report also says that 38 U.S. cities already have municipal wireless networks for the exclusive use of public safety and city employees.In this project, I will discuss what wireless mesh network is, how it functions, its advantages, the network architecture, applications, problems the new technology is facing and possible ways of solving them while using a better protocal. II. NETWORK ARCHITECTURE Mesh itself is a type of architecture. Originally, Ethernet was a shared bus topology in which every node tapped into a common cable that carried all transmissions from all nodes. In bus networks, any node on the network hears all transmissions from every other node in the network. Most local area networks (LANs) today use a star topology in which every network node is connected to a switch (switches can be interconnected to form larger networks). Mesh networks are different full physical layer connectivity is not required. As long as a node is connected to at least one other node in a mesh network, it will have full connectivity to the entire network because each mesh node forwards packets to other nodes in the network as required. Mesh protocols automatically determine the best route through the network and can dynamically reconfigure the network if a link becomes unusable. There are many different types of mesh networks. Mesh networks can be wired or Wireless. For wireless networks there are ad-hoc mobile mesh networks and permanent infrastructure mesh networks. There are single radio mesh networks, dual￾radio mesh networks and multi-radio mesh networks. All of these approaches have their strengths and weaknesses. They can be targeted at different applications and used to address different stages in the evolution and growth of the network. Wireless mesh networks has of two types of nodes: mesh clients and mesh routers. Compared with a conventional wireless router, a wireless mesh router can achieve the same coverage with much lower transmission power through multi￾hop communications. Optionally, the medium access control (MAC) protocol in a mesh router is enhanced with better scalability in a multi-hop mesh environment. Even though there are the above differences, mesh and conventional wireless routers are more often built on a similar