Wireless LAN protocol and Basic Language analysis

Although the wireless network is roughly similar to the cable network in structure and principle, the wireless internet and the wired Internet still differ greatly in the terminal equipment and network performance. It is obvious that wireless data network has the disadvantages of limited bandwidth, high latency, poor connection stability and difficulty in predicting usability, but it has the advantages of strong mobility, which will not affect the development of wireless network in the slightest. What this article will bring to you is the concept of the bottom of the wireless network, understanding these basic concepts, for the more in-depth use of wireless networks is of great significance.





first, wireless network basic protocol article





mentions that the wireless protocol also has to mention IEEE





Knowledge gas Station 1: "IEEE"





This is the January 1, 1963 by the AIEE (American Institute of Electrical Engineers) and IRE (American Society of Radio Engineers) merged, is the largest professional society in the United States. IEEE is a non-profit science and technology society, with more than 360,000 members in nearly 175 countries worldwide. The organization is a major authority in space, computers, telecommunications, biomedicine, electricity and consumer electronics. Its standard formulation includes: Electrical and electronic equipment, test methods, original devices, symbols, definitions and test methods.





OK, with the above basis, and then back to understand the standard protocol of wireless network, content mainly includes ieee802.11b, 802.11a, 802.11g and so on. Usually we can see in the wireless network product description Also, its support protocol standard, supports the different protocol standard to have the difference in the function and the rate.





1, ieee802.11b protocol





IEEE802.11B is a 11mb/s wireless standard that provides full network services for laptops or desktop users. The wireless network operating frequency band of the Protocol is 2.4GHZ, the maximum transmission rate can reach 11Mbps, can realize the automatic switching between 1Mbps, 2Mbps, 5.5Mbps and 11Mbps, theoretically the maximum transmission distance in the room can reach 100 meters, outdoor can reach 300 meters. Currently also known as 802.11b Wi-Fi. Analysis: This kind of standard implementation time is earlier, currently on the market still many wireless products only support to this Agreement standard scope. This type of product is characterized by "inexpensive", although the speed of support can only reach 11Mbps, but its affordable price for the initial wireless network users to reduce the threshold. Such products are already part of the transition "product".





2, ieee802.11a protocol





the agreement is a follow-up standard for 802.11B wireless networking standards that have been widely used in offices, homes, guesthouses, airports and many other occasions. Its working frequency band is 5GHz, the maximum transmission rate can reach 54Mbps, the transport layer can reach 25Mbps. can provide 25Mbps wireless ATM interface and 10Mbps Ethernet wireless frame structure interface, transmission distance between 10 meters ~100 meters; OFDM (orthogonal Frequency Division multiplexing) modulation technology is adopted, which can support the transmission of voice, data and image. Note, however, that this Protocol is incompatible with the 802.11B protocol.





Analysis: 802.11A protocol by virtue of its fast transmission, the use of 5GHz operating frequency and so on, so that its interference is less; Wireless products with such protocols can also be widely used in WLAN. But because the price is more expensive, and incompatible, so the current market is not very popular.





3, ieee802.11g protocol





IEEE802.11G can be seen as the ieee802.11b of the high-speed version, like 802.11B, ieee802.11g also work in the 2.4GHz band, but in order to achieve 54mbit/s transmission speed, IEEE802.11G uses different OFDM (orthogonal Frequency Division multiplexing) modulation mode with IEEE802.11B, it supports the 54Mbps transmission rate. IEEE802.11G can be compatible with ieee802.11b, but it is also incompatible with 802.11a. Analysis: Along with people to the wireless LAN data transmission request, the Support 802.11G protocol standard Wireless product has already become the market mainstream, moreover its enhancement version 802.11g+ product has already risen to the 108M wireless age.





Knowledge gas station 2: "Wi-Fi"





is a generic certification of wireless network products based on the IEEE 802.11 series standard, implemented by WEGA (the organization Weca of WLAN standardization, also known as the "Wi-Fi Alliance"). It is not correct to refer to all wireless LANs as "Wi-Fi", which should be called a Wireless LAN (WLAN).





Knowledge gas Station 3: "Working Band"





This is a range of wireless network operating frequencies. The simple understanding is: the usual use of mobile phones must also work in a certain frequency range (the frequency of mobile phones typically used between 800 to 2000GHZ).


II, wireless Network security protocol Chapter





this mainly refers to the WEP protocol, which is all called Wired equivalent Protocol (wire equivalent protocol). It is a security protocol to guarantee the security of 802.11B protocol data transmission.





the protocol can encrypt the transmitted data so as to guarantee the security of data transmission in wireless LAN. Currently, the General wireless network products on the market support 64/128 or even 256-bit WEP encryption. This protocol is embodied in the wireless network to enable WEP on the wireless router and each wireless client, and enter the key, which ensures a secure connection.





Analysis: WEP provides data confidentiality services by encrypting the data sent between wireless nodes. In addition, in practice, one of the pitfalls of this protocol is that there is no definition and distribution method for WEP keys. The WEP key must be distributed using a secure channel other than the 802.11 protocol, and it must use the keyboard manually configured text strings for wireless APs and wireless clients. Obviously, this key distribution system does not extend well to enterprise organizations, and is less secure.





Knowledge gas station 4: "SSID value"





This is an identity authentication method used by wireless networks. Simply put, the SSID is the name of a local area network, and only computers set to values with the same SSID name can communicate with each other.





Three, the agreement enhances the article





here mainly introduces some common user unusual standard of agreement.





1, 802.11E





QoS protocol based on WLAN, through which VoIP can be 802.11a,b,g. That is to say, 802.11e is the protocol that realizes voice call function through wireless data network. The protocol will be a powerful weapon for the wireless data network to compete with the traditional mobile communication network.





2, 802.11i





802.11i is a new wireless data network security protocol, which has been widely exploited in the WEP protocol, and will become a security risk for wireless data networks. 802.11i proposes a new TKIP protocol to solve this security problem.





3, Wireless Application Protocol (WAP)





Wireless Application Protocol WAP is currently a hot spot in the mobile communications industry, it is a rising in the wireless network protocol standards, the major communications companies are sparing no effort to promote it. WAP was first developed and deployed jointly by Motorola, Nokia, Ericsson and American software company Phone.com.





PostScript:





Any network must comply with certain protocol standards, as we live in society to comply with laws and regulations. Understand the basic characteristics of these agreements, for the future of product selection, wireless network construction and other practical applications, can play a multiplier effect.