Overview Application of WLAN standard in Wireless LAN

This topic describes the application of WLAN standard in Wireless LAN, the network parameter settings in WLAN standard, the LAN port parameter settings, and the SSID settings, I hope you will have a clear understanding after reading the following articles.

1. WLAN standard for wireless LAN

WLAN standards can be achieved through wireless Hub, wireless Access station (Access Point, AP, also translated as Network Bridge), Wireless Bridge, wireless Modem and wireless network card on the basis of common LAN. In the industry, WLAN standards coexist. Too many IEEE 802.11 standards can easily cause confusion and standards should be reduced.

In addition to fully defining the three main specifications for WLAN systems: 802.11a, 802.11b, and 802.11g), IEEE is currently working on developing enhanced standards to reduce the defects of existing protocols. This is not to develop a new wireless LAN system, but to expand the original standards, and ultimately form a category-at most three types of standards are retained.

802.11a expands the 802.11 standard physical layer, which requires that the layer use a 5G Hz band. The standard uses OFDM Orthogonal Frequency Division) modulation technology, and the transmission rate range is 6 Mbps ~ 54 Mbps. There are two non-overlapping transmission channels. This speed can meet both indoor applications and outdoor applications.

802.11b requires the 2.4GH z band and the modulation method uses the compensation code keying (CKK). There are three non-overlapping transmission channels. The transmission rate can be automatically reduced from 11 Mbps to 5.5 Mbps, or adjusted to 2 Mbps and 1 Mbps based on the direct sequence spread spectrum technology to ensure the normal operation and Stability of the device.

802.11g is the third standard for transmission officially finalized in June 12 this year. There are three non-overlapping transmission channels. Although it also runs at 2.4 GHz, because the standard uses the same modulation method as 802.11a, the network achieves a high transmission rate of 54Mbps, the price of products based on this standard is only slightly higher than that of 802.11b.

802.11e will solve the QoS characteristics of the 802.11 Network. Unlike Ethernet, it uses the MAC layer, instead of time-division multiplexing (TDMA) technology, and adds additional error correction functions for important communications. The standards have not yet been finalized, because there are still disputes over the service level. In addition, how to implement a specific service level is still a problem.

802.11f mainly solves the shortcomings of 802. 11 in the interconnection between networks. How can users maintain network connections when roaming between two wireless channels in different CIDR blocks or two access points in different types of wireless networks, it is vital that a wireless LAN has the flexibility of a cellular phone.

802.11h strives to outshine 802.11a in terms of transmission power and wireless channel selection. It, together with 802.11e, will become a widely accepted standard in Europe. 802.11i is mainly used to overcome the security limitations of 802.11. Unlike WEP, the working group in charge of this standard has not yet selected the authentication protocol: some Members want to adopt a new system called "office-based telegraph cipher book OCB)", but it belongs to three different patents. It is a new type of complete standard based on AES encryption algorithm. Others tend to use a common password.

802.11j is in the future, and I EEE has not yet formally set up a Special Task Group for discussion. It is in the drafting stage and will adopt the frequencies shared by 802.11a and HiperLAN2. 802.11n, the next new wireless specification, the data transmission rate of this new specification has not yet been determined, but it will be at least Mbps. Due to mobile and high-speed data transmission, WLAN is widely used in practice.

Building a network connection between buildings replaces leased lines, which is simple and inexpensive. Catering and retail catering services can use wireless lan wlan standard products, directly from the dining table can be input and transmitted to the Guests ordering content to the kitchen, counters. During the sales promotion, retailers can use the WLAN standard product to set up a temporary cashier counter.

WLAN standard medical care

Use a portable computer with a WLAN standard network product to obtain real-time information, medical staff can avoid delay in treatment of injury, unnecessary homework on paper, delay in circulation of documents, and misdiagnosis, so as to improve the quality of care for injury.

WLAN standard enterprise

When employees in an enterprise use wireless LAN products, no matter whether they are in any corner of the office, there are wireless LAN products, you can send emails, share files, and browse through the Internet at will.

Standard Storage Management for WLAN

General warehouse personnel can input the latest data into the computer warehouse system through wireless network applications.

WLAN standard container hub

Generally, when the container hub is used to transfer the container, the real-time information is sent back to the office to facilitate related operations.

WLAN standard monitoring system

Generally, it is located in a distant location and needs to be monitored. Due to wiring difficulties, remote images can be sent back to the master station through a wireless network.

WLAN standard display venue

For example, the general electronic exhibition and computer exhibition, due to the high network demand, and wiring will make the venue appear messy, so if you can use a wireless network, it is a good choice.

2. Broadband Wireless Access System (MMDS/LMDS)

The Broadband Wireless Access System is a fixed wireless access system that provides high-speed, bidirectional data, voice, or video services through point-to-point transmission, it can be used as a powerful means for applications such as ddnleased line, RST relay or E1 transmission, high-speed Internet access, lan and man interconnection. The broadband wireless access system can be divided into MMDSMulti-channel Multi-point Distribution Service and LMDSLocal Multi-pointDistribution Service based on different frequency bands.

The overall architecture of the Broadband Wireless Access System. The Broadband Wireless Access system consists of a base station and a remote station. A base station can communicate with Multiple Remote stations in its own wireless coverage. The Base Station aggregates the data of the remote station and then connects to the backbone data network through the light loop or microwave SDH loop.

3. Wireless Optical Access System FSO

FSO is a wireless transmission technology that uses infrared laser to carry high-speed signals based on optical transmission. It uses laser as the carrier and air as the media, point-to-point or point-to-point connections are implemented. Because their devices use light emitting diodes or laser diodes as the light source, they are also referred to as "virtual optical fiber.

The FSO technology uses a low-power infrared laser beam as a carrier to transmit data between receivers located on the roof or outside the window. The infrared band is smaller than the microwave band, making it more flexible and convenient. The FSO system operates at a frequency of over GHz. Its applications are not controlled worldwide and free to use. FSO technology has the same bandwidth transfer capability as optical fiber, using similar optical transmitters and receivers.

It can even achieve wavelength division multiplexing (WDM) technology in free space. It has incomparable advantages such as low rain attenuation, no need to apply for frequency bands, and easy upgrade of equipment, moreover, its open interfaces support instruments from multiple vendors. Currently, products on the market support a maximum transmission rate of Gbps, with a maximum transmission distance of 4 kilometers. However, FSO technology theoretically has no upper bandwidth limit, and Gbps devices are being developed.

FSO technology can transmit data, voice, images, and other content. It features high bandwidth, Fast deployment, reasonable cost, small size, and convenient activation, it has the advantages of rapid activation, convenient demolition, and other advantages in emergency communications such as large-scale conference communication, emergency service activation, and route backup. In addition, FSO devices can more easily obtain "roof right" than microwave devices that require antennas, and can also be installed in the household through a window. This is sometimes critical for operators in large and medium-sized Chinese cities.