What is the Wireless Mesh Network?
The Wireless Mesh Network is a new wireless network. It is a technology that dynamically establishes new links and connects with other nodes. It has the advantages of self-organizing network, self-repairing, multi-hop cascading, and node self-management, which can greatly reduce the cost and complexity of network deployment.
Currently, Wireless Mesh Network mainly uses the following technologies:
According to the networking frequency band, Mesh is divided into multi-frequency multi-channel networking and single-frequency networking. Single-frequency network transmission and reception uses a single frequency, and the bandwidth capacity is reduced by half. In multi-frequency multi-channel networking, the device uses multiple orthogonal frequencies for different links, which can increase system throughput.
In terms of radio frequency technology, in order to improve transmission rate and performance, technologies such as OFDM, MIMO, and smart antenna have been widely used in recent years.
In terms of resource scheduling, it is usually divided into CSMA/CA mode and TDMA mode. CSMA/CA adopts the resource competition mode, but when the number of nodes and hops is high and the network load is high, the effective resource utilization rate is low. The TDMA mode is a scheduling mechanism based on time allocation. When the network load is heavy, the efficiency is high.
In terms of network routing algorithms, unlike RIP and OSPF routing protocols used in fixed routes, common Mesh wireless routing algorithms include DSDV, DSR, AODV, and so on.
What are the advantages of the Wireless Mesh Network?
Equipment deployment is fast / easy to install
Easy to install, you can access the network without too much complicated configuration and wiring.
Non-line-of-sight transmission (NLOS)
For a data transmission point, the data is first accepted by the device or user with direct line of sight for the transmission point, and the receiving device and the user are an AP, which can continue to forward the data to reach the device without direct line of sight. Equipment and users. In this way, the Wireless Mesh Network's ability to non-line-of-sight transmission greatly expands the application and coverage of wireless broadband. It has broad application prospects in outdoor and public places.
Data in the Wireless Mesh Network can be forwarded and sent through different nodes. When one or some nodes fail or interfere, data can be forwarded through other working nodes. Data transmission throughout the network is not affected.
The physical characteristics of wireless communication determine the shorter the distance of communication transmission, the easier it is to obtain high bandwidth and less interference. Therefore, selecting multiple short hop transmission data can obtain higher bandwidth in the network, and one node can not only transmit and receive information at the same time, but also act as a router to forward information to other nodes. As the number of nodes increases and the number of propagation paths increases, the total bandwidth increases greatly.
What are the disadvantages of the Wireless Mesh Network?
Security is tested.
Compared with the single-hop mechanism of the WLAN, the multi-hop mechanism of the Wireless Mesh Network determines that the user's communication needs to pass through multiple nodes. Security risks are becoming more pronounced as the number of nodes increases. The security risks of the Internet are well known, although in wired networks, end-to-end security technologies such as virtual private networks (VPNs) can be used to address the security issues of the Wireless Mesh Network. However, with the exponential growth of Internet and IoT business data, the Wireless Mesh Network security issue will be a topic that cannot be ignored.
In a mesh network, data is forwarded through the intermediate node, and each hop brings at least some delay. As the range of the Wireless Mesh Network expands, the larger total delay will be added. The current main solution to this problem is to optimize the corresponding network protocol. With the advent of multi-wireless Mesh node technology, this problem will be finally solved.