Wireless Mesh Network

Wireless mesh network routers and mesh, the mesh of clients, including routers constitute the backbone network, mesh and and cable Internet network connections, responsible for clients provide multiple hops mesh of wireless Internet connection. Wireless Mesh network (wireless Mesh network), also known as "multiple hops (multi - hop)" network, it is a completely different with traditional wireless network new wireless network technology.

introduction

In traditional wireless local-area network (WLAN), each client are connected through a wireless link with the AP to access to the network, if a user to communicate words, must first visit to a fixed access point (AP), the network structure is called one hop network. And in wireless Mesh network, to any wireless device node can be same as AP and routers, network in each node can send and receive signal, each node can and one or more equivalence nodes direct communication.

The biggest advantage of this structure is: if recent AP due to excessive flow caused congestion, then the data can be automatically re-engage routing to a communications flow smaller neighboring nodes transmission. By analogy, packets can also according to the network, continue to route to the recent next with nodes are transmission, until you reach the final destination. Such access method is more jump access.

People actually known as the Internet is a typical example of Mesh network. For example, when we send an E-mail, E-mail and not to go directly to the recipient mailbox, but from a server forwarding through a router to another server, finally after many routing forwarding to reach the user's mailbox. In forwarding process, the router will generally choose the most efficient transmission path, so that E-mail can get user's mailbox.

Compared with the traditional switched network, wireless Mesh network removed node of cabling needs between distributed network, but still have provided redundant mechanism and routing function again. In the wireless Mesh network, if want to add new equipment, simply connected to the power source, it can automatic self configuration, and determine the best multiple hops transmission path. Add or mobile device, the network can be found, and automatically adjust topology changes, in order to get the most communications routing of effective transmission path.

The Mesh network five advantages

Compared with the traditional wireless Mesh network, wireless local-area network (WLAN) has several incomparable advantage:

1. Rapid deployment and easy to install.

Install Mesh nodes is very simple, will be taken out from the box equipment, connected to the power source line. Because greatly simplifies installation, users can easily add new node to expand the wireless network coverage and network capacity. In the wireless Mesh network, not every Mesh nodes need cable connections, this is it the biggest difference with cable AP. The design of Mesh goal was to make cable equipment and cable AP quantity is reduced to the minimum, thus greatly reduces the total cost of ownership and installation time, only it bring cost savings is very considerable. Wireless Mesh network configuration and other network management function and traditional WLAN, the same user experience can easily wireless local-area network (WLAN Mesh network used to.

2. Non line-of-sight transmission (NLOS).

Using wireless Mesh technology can be implemented easily, so in outdoor NLOS configuration and public places have broad application prospect. And the users is directly over the launch pad to receive radio signals, then received signals transmitted to the direct sights users. This way, signal automatically choose the best path constantly from a user to jump to another user, and eventually to no direct stadia target user. So, the user actually has direct stadia for not directly over the adjacent provides users with a wireless broadband access functions. Wireless Mesh networks to non line-of-sight transmission characteristics greatly expanded wireless broadband application fields and coverage.

3. Robustness.

The network robustness usually method is to use many routers to transmit data. If a router fault by other routers, information by alternate paths. E-mail is such an example, E-mail messages are divided into several packet, then by multiple routers through the Internet to send, then assembled into the information reach users' inbox. Mesh networks are more robust than one hop network, because it does not rely on a single node performance. In one hop network, if a node breaks down, the whole networks are then paralyzed. And in Mesh network structure, since each node has one or a few transmits data path. If recent node malfunction or interference, packets will automatically routing to the alternate path to continue for transmission, the whole network of operation will not be affected.

4. Structure flexible.

In one hop network, the equipment must be Shared AP. If several equipment should also access to the network, may generate communication congestion and leads to the operation of the system speed reduced. And in multiple hops network, the equipment can through different node also connected to the network, so won't cause the system performance reduced.

Mesh network also provides greater redundancy mechanism and communication load balance function. In the wireless Mesh networks, each device have multiple transmission path is available, network can according to each node communications load conditions dynamically allocate communications routing, thus it can effectively avoid the node communications congestion. And at present one hop network and cannot dynamically handling communication jamming and access points overload problems.

5. High bandwidth.

The physical characteristics of wireless communication determines the shorter the transmission distance are easier to obtain high bandwidth, because with the increase of wireless transmission distance, all sorts of interference and other cause data loss factor will increase. So choose the more short jump to transmit data will get higher network bandwidth is an effective method of Mesh network, which is the advantage.

In the Mesh network, a node can not only send and receive information, also can act as a router to forward information to the nearby nodes, as more nodes connected and the increase in the number of possible paths, total bandwidth also increase greatly.

In addition, because each short jump the transmission distance is short, transmitting data needed power lesser also. Since many jump network usually use lower power will data transmission to neighboring nodes. The nodes of the wireless signal interference between also small, network channel quality and channel utilization efficiency greatly improved, so as to achieve higher network capacity. For instance in high-density city network environment, Mesh network can reduce the use of wireless network adjacent users, greatly improving the mutual interference of the utilization efficiency of channel.