Overview of IEEE 802 standard
Most IEEE 802 standards were formulated by the Committee in the 1980s, when people were only interested in personal computer networks. With the continuous progress of network technology, many new standards have been expanded and formulated. Therefore, the IEEE 802 family has become larger and larger, with more and more members.
● Definition of IEEE 801.1interconnection between networks
802. 1 is the basic standard about LAN/MAN bridging, LAN architecture, LAN management and protocol layer above MAC layer and LLC layer. Now, most of these standards are related to switch technology, including: 802. 1q(VLAN standard), 802.3ad (VLAN standard with dynamic GVRP label), 802. 1v(VLAN classification), 802. 1d (spanning tree protocol), etc.
● IEEE802.2 logical link control
This protocol well standardizes the interface of logical link control (LLC), high-level protocol and MAC sublayer, thus ensuring the accuracy and efficiency of network information transmission. Since logical theory control has become a part of the whole 802 standard, this working group is currently in a "dormant" state, and there are no ongoing projects.
●IEEE 802.3 CSMA/ optical disk network
IEEE802.3 defines the embryonic Ethernet of 10Mbps, 100Mbps, 1Gbps, and even 10Gbps. It also defines that the fifth kind of shielded twisted pair and optical cable are effective cable types. The working group has determined how many suppliers can cooperate with each other, regardless of their respective speeds and cable types. In addition, this method defines the access technical specification of CSMA/CD (Carrier Sense Multiple Access with Collision Detection). IEEE802.3 has produced many extended standards, such as IEEE802.3u for fast Ethernet, IEEE802.3z for gigabit Ethernet and IEEE802.3ab for 10G Ethernet. At present, all kinds of Ethernet based on IEEE802.3 standard are widely used in LAN.
● IEEE802.4 token ring bus
This standard defines the access method of token passing bus and the physical layer specification (token bus). The working group has been dormant recently, and there are no ongoing projects.
● IEEE802.5 Token Ring Network
IEEE802.5 standard defines token ring access method and token ring. The standard token ring runs at 4Mbps or 16Mbps. Because this rate can't meet the increasing data transmission requirements, the working group is currently planning 100Mbps token ring (802.5t) and Gigabit token ring (802.5v). Examples of other 802.5 specifications are 802.5c (double-ring package) and 802.5j (optical fiber station accessories). Token rings are rarely used in China.
● IEEE802.6 metropolitan area network (WAN)
This standard defines the access mode and physical layer specification (DQDB) of MAN. At present, the 802.6 working group is dormant and has not carried out any research and development work, because MAN is created and managed by Internet working standards.
● IEEE802.7 Broadband Technical Advisory Group
This standard is a practical technology recommended by IEEE for broadband LAN. 1989 working group recommended the practice of broadband LAN, and 1997 recommended it again. The working group is currently dormant and has no ongoing projects. The maintenance of 802.7 is now the responsibility of the 802.438+04 team.
● IEEE802.8 Optical Fiber Technical Advisory Group
This standard defines some standards used in optical fiber technology. Much of the time recommended by the working group for optical fiber technology is encapsulated in other standards in the physical layer.
● IEEE802.9 integrated data voice network
This standard defines the interface between Media Access Control Sublayer (MAC) and Integrated Services (is) on the physical layer (PHY). At the same time, this standard is also called Synchronous Service Local Area Network (ISLAN). Synchronization service refers to the process that data must be transmitted within a certain time limit. Streaming media and sound unit are examples of synchronous transmission communication in the system.
● IEEE802. 10 Network Security Technical Advisory Group
This standard defines interoperable LAN security standards. The working group put forward some data security standards in the form of 802. 10a (security architecture) and 802. 10c (key management). The working group is currently dormant and has no ongoing projects.
● IEEE802. 1 1 wireless network.
This standard defines the media access control sublayer and physical layer specification (WLAN) of WLAN. The working group is developing wireless standards for data transmission in 2.4GHz and 5. 1GHz wireless spectrum. The IEEE802. 1 1 standard mainly includes three standards, namely, IEEE 802.1a, IEEE 802.1b and IEEE 802.1/kloc.
● IEEE802. 12 needs first (100VG-AnyLAN)
The IEEE802. 12 rules define the methods that need priority access. The working group provided two physical layers and relay specifications for the development of 100Mbps demand-first MAC. Although their use has been patented and accepted as ISO standard, their widespread acceptance is far less than Ethernet. 802. 12 is currently in the stage of being separated.
● IEEE802. 14 interactive TV.
This standard defines interactive TV network (including cable modem) and corresponding technical parameters. The working group formulates specifications for the physical and media access control layers of cable TV and cable modems. Make sure that after their work is completed, the working group has no ongoing projects.
● IEEE802. 15 short-range wireless network
This standard specifies the short-range wireless network (WPAN), including all technical parameters of Bluetooth technology. Personal Area Network (PENs) should create wireless interconnection between portable and mobile computing devices, such as PC, peripheral devices, cellular phones, personal digital assistants (PDA), pagers and consumer electronic products, which can be used by the network to communicate and interoperate with each other without interference from other wireless communications.
● IEEE802. 16 broadband wireless access
This standard is mainly used for broadband wireless access. 802. The goal of the16 working group is to formulate the standard of fixed broadband wireless access system, mainly to solve the last mile local loop problem. 802. 16 is similar to 802. 1 1a in that 802. 16 uses unauthorized frequencies on the U-NII spectrum without the permission of the authorities. 802. The difference between16 and 802. 1 1a is that in order to provide a standard to support the detour of real wireless networks, the quality of service of voice, video and data was put forward from the beginning.
Ii. IEEE 802. 1 1 standard
802. 1 1 is a wireless LAN standard originally formulated by IEEE, which is mainly used for wireless access of computers in the environment where wiring is difficult or impossible, and the service is mainly used for data access because the highest transmission rate can only reach 2Mbps. In view of the fact that 802. 1 1 can't meet people's needs in speed and transmission distance, IEEE Group has successively introduced three new standards: 802. 1 1a and 802.5438.
802. 1 1b works in the 2.4GHz band, and the physical layer supports two new rates, 5.5 Mbps and1/Mbps. 802. The transmission rate of11b will change due to environmental interference or transmission distance, switching between 1 1 Mbps, 5.5 Mbps, 2 Mbps and 1 Mbps, and 802.//Mbps at 2 Mbps and 1 Mbps. 802. 1 1b uses direct sequence (DSSS) as the protocol. Provide data encryption using WEP with up to 128 bits. It should be noted that 802. 1 1b is not compatible with the 802.1a standard operating at the frequency of 5GHz. Because of its low price, 802. 1 1b products have been widely put into the market and run in many practical workplaces.
802. 1 1a works in 5GHz band, with a physical layer rate of 54 Mb/s and a transport layer of 25Mbps. 802. 1 1a adopts the unique spread spectrum technology of orthogonal frequency division multiplexing (OFDM); Can provide 25Mbps wireless ATM interface and 10Mbps Ethernet wireless frame structure interface, as well as TDD/TDMA air interface; Support voice, data and image services; A sector can access multiple users, and each user can take multiple user terminals. 802. 1 1a uses the vertical frequency division multiplexing transmission (OFDM) list to increase the transmission range, and the data encryption can reach 152bit WEP.
1 15 years1October 15, IEEE preliminarily approved a new technology 802.11g. 802. 1 1g also works in the 2.4GHz band, which makes the wireless network transmission rate reach 54Mbps, five times faster than the current 802. 1 1b, and fully compatible with 802.438+01b. Because the designs of 802. 1 1g and 802. 1 1a are the same. Therefore, equipment suppliers can manufacture wireless PC cards that support these three standards at the same time.
802. 1 1b+ is an informal standard called enhanced 802. 1 1b. 802. 1 1b+ is fully compatible with 802. 1 1b, and only adopts the data modulation technology of block binary convolutional coding (PBCC), so it can achieve a communication rate of up to 22Mbps, which is completely suitable for the transmission of multimedia files such as digital images, videos and mp3s.
Three. IEEE802. 15 standard
Bluetooth (IEEE 802. 15) is the latest standard. For 802. 1 1, it appears not for competition, but for supplement. Bluetooth is more mobile than 802. 1 1. For example, 802. 1 1 is limited to local area networks. Bluetooth can connect devices not only to local area networks, but also to wide area networks and even support global roaming. Of course, the application of Bluetooth with low power consumption, short distance and low bandwidth is not a real LAN technology strictly speaking. But it has low cost and small size, and can be used in more devices, mainly for point-to-point short-distance wireless transmission technology.
Schedule: Comparison between IEEE802. 1 1 and IEEE802. 15.
802. 1 1 802. 1 1b 802. 1b+802. 1 1a 802. 1 1g 802. 15. 1
Frequency 2.4ghz 2.4ghz 2.4ghz 5 GHz 2.4ghz 2.4ghz 2.4ghz.
Bandwidth 2/1Mbps11/5.5/2/1mbp22/1/5.5/2/1mbps721mbps72.
Distance 100 m 100 ~ 300 m 100 ~ 300 m 5 ~ 10 km 5 ~ 10 km 3 m
Business data data image data image voice data image voice data image data.