Research status of wireless mesh network technology

In June 2004, 5438+ 10, the IEEE 802. 1 1 working group formally established the grid research group, and in March of the same year, the Mesh task group was established, which marked that WMN technology officially embarked on the road of extensive standardization. In addition, other standards, such as 802. 15.3a, 802. 15.4 and dedicated short-range communication (DSRC), have also begun to explore how to improve their existing technology through grid embedded devices. IEEE802. 16 has incorporated grid technology into its MAC layer protocol standard [3]. 1. Research on application basic theory and technology In recent 10 years, many researches including mobile ad hoc networks and WMN have made many achievements, mainly in the following aspects: ① Research on routing protocols. The core of the protocol is to adapt to the characteristics of decentralized control and time-varying network; ② Research on Media Access Control (MAC) protocol. It mainly solves the problems of hiding terminals and improving access ability, such as MACA protocol, dual-channel scheme of separating control channel and data channel, and MAC protocol based on directional antenna [4, 5, 6]; ③ In terms of network connectivity, the main background is wireless sensor networks, and the core of discussion is node density and distribution [7 ~11]; ④ There are some research achievements in multicast/multicast protocol, TCP protocol, network resource allocation such as address and bandwidth, power (energy saving) control, security issues, distributed algorithms, QoS and so on, but the number of each part is relatively small [6]; ⑤ Some new achievements have been made in the simulation and experimental research of some protocols and systems of WMN [12, 13]. Recently, some scholars are studying the key technology of Bluetooth scattering network in short-range Ad Hoc network construction [4,5]. 2. Patented technology At present, patents related to WMN are mainly held by some American companies and research institutions. For example, in June 2002, MeshNetworks Company obtained the patent "System and method for providing wireless service message storage and forwarding for end-to-end and end-to-end infrastructure communication networks" [14]. This patent proposes a system and method for wireless communication between mobile nodes and wireless infrastructure components that are not within each other's transmission range. The basic idea is to use the ability of intermediate mobile nodes to store and forward information. In April 2004, the company obtained the patent "System and method for mapping IP address to MAC address and automatic configuration and discovery of existing gateways in wireless end-to-end Ad Hoc network routing" [15]. The main idea of this patent is to use a hash function to convert an IP address into a 6-byte MAC address and attach it to a routing broadcast for active transmission to other nodes. In addition, in June 2003, Motorola obtained the patent of "Method and equipment for improving service efficiency in Ad Hoc grid network", which relates to the communication system and equipment for improving service efficiency in WMN [16]. Caly Company obtained the patent of "Packet Data Communication Protocol in Grid Wireless Network" in March 2002, which mainly relates to the communication method of packet data between nodes in grid wireless network [17]. 3. Application system integration In recent years, due to the demand of wireless data communication and the rapid development of semiconductor, computer and other related electronic technologies, short-range wireless communication technology has also experienced a rapid development stage, and has made remarkable achievements in WLAN technology, Bluetooth technology, mobile ad hoc network technology and ultra-wideband (UWB) technology. It is generally believed that the future 4G system network is the integration of various network topologies [26], including the future cellular mobile communication network, satellite network, public switched telephone network, WLAN, mobile ad hoc network and so on. These networks are all integrated into the Internet backbone or the Internet through WMN, which can be regarded as the "wireless version of the Internet". It can be seen that WMN will be a major technological innovation in the future wireless communication field.