Whether it is a home or business user, there are many options for finding a wireless local area network (WLAN) solution. Many products support Wi-Fi technology standards such as 802.11a, 802.11b, 802.11g, and 802.11n. In addition, there are Bluetooth and other non-Wi-Fi technologies, all of which have their own specific network standards.
This article will introduce you to the comparison of Wi-Fi and related technologies to help readers choose the wireless network application that suits them.
802.11 standard
In 1997, the American Institute of Electrical and Electronics Engineers (IEEE) formulated the first wireless LAN standard 802.11, which is mainly used to solve the wireless access between users and user terminals in office LANs and campus networks. The business is mainly limited to data access, and the highest rate is only Can reach 2Mbps. Because it cannot meet people's needs in terms of speed and transmission distance, 802.11 wireless products are no longer produced.
802.11n
This standard is the latest standard introduced by IEEE. By adopting smart antenna technology, 802.11n can provide the transmission rate of WLAN from 54Mbps, 108Mbps provided by the current 802.11a and 802.11g to 300Mbps or even 600Mbps. Thanks to the MIMO OFDM technology that combines MIMO (Multiple Input Multiple Output) and OFDM (Orthogonal Frequency Division Multiplexing) technology, the wireless transmission quality is improved and the transmission rate is greatly improved.
In addition, 802.11n uses a software radio technology, which is a fully programmable hardware platform, so that base stations and terminals of different systems can achieve interoperability and compatibility through different software of this platform, which makes WLAN compatibility Greatly improved. This means that WLAN will not only achieve 802.11n backward and forward compatibility, but also realize the combination of WLAN and wireless wide area networks, such as 3G.
802.11n advantage-has the fastest network rate and the widest signal coverage; signal interference has less effect.
Disadvantages of 802.11n-the standard has not been formally determined; the cost is higher; using multiple signals, it is easy to interfere with the attached 802.11b / g network.
802.11g
Between 2002 and 2003, WLAN products began to have a new standard 802.11g. 802.11g combines the advantages of both 802.11a and 802.11b and can be said to be a hybrid standard. It can adapt to the traditional 802.11b standard and provide a data transmission rate of 11 Mbit / s per second at a frequency of 2.4 GHz. It also conforms to the 802.11a standard and provides a data transmission rate of 56 Mbit / s at a frequency of 5 GHz.
Advantages of 802.11g-higher network rate; good signal quality, not easily blocked.
Disadvantages of 802.11g-cost is higher than 802.11b; electrical equipment may affect signals in the 2.4GHz band.
802.11b
In July 1999, IEEE expanded the 802.11 application standard and created the 802.11b standard. Compared to traditional Ethernet, the standard can support data transfer rates up to 11 Mbps. 802.11b inherits the 802.11 wireless signal frequency standard and uses 2.4GHz direct sequence spread spectrum. Manufacturers are more willing to adopt this frequency standard, because it can reduce product costs. On the other hand, due to the use of unspecified 2.4GHz spread spectrum, wireless LAN signals are also easily interfered by signals from microwave ovens, cordless phones, or other electrical equipment. Of course, solving this problem is also very simple. When installing 802.11b devices, pay attention to keeping a certain distance from other devices.
802.11b advantages-low cost; good signal radiation, not easily blocked.
Disadvantages of 802.11b-lower bandwidth rates; signals are susceptible to interference.
802.11a
While 802.11b is still under development, IEEE has created another wireless local area network standard, 802.11a. Because 802.11b is more popular than 802.11a, some people think that 802.11a was created after 802.11b. In fact, 802.11a and 802.11b were created almost at the same time. Due to the high cost of 802.11a, it is mainly used in the commercial field, while 802.11b is mainly used in the home market.
The highest data transmission rate provided by 802.11a is 54Mbps, and it operates in the 5GHz frequency band. This higher frequency means that the 802.11a signal is more susceptible to walls or other obstacles.
In addition, because 802.11a and 802.11b use different frequency standards, the two are incompatible with each other. For this reason, some manufacturers provide 802.11a / b network modules in their computers to cope with the needs of wireless networking in different environments.
802.11a advantage-has a higher network rate; the signal is not easily interfered.
Disadvantages of 802.11a-higher cost; signals are easily blocked by obstacles.
Bluetooth and others
In addition to the four common Wi-Fi standards mentioned above, there are other wireless network technologies.
Other IEEE 802.11 working group standards such as 802.11h and 802.11j also exist as an extension of Wi-Fi technology.
Bluetooth is an alternative wireless network technology that complements the 802.11 family. Bluetooth can achieve network transmission (1 ~ 3Mbps rate) on low-power network devices within a short distance (about 10 meters), such as handheld computers and Bluetooth mobile phones. The low manufacturing cost of Bluetooth makes Bluetooth quickly form an industrial scale. Today, you can see PDAs and smartphones that use Bluetooth technology anytime, anywhere. But Bluetooth is rarely used on WLAN networks, because of the adverse factors in consideration of Bluetooth application range and transmission rate.
WiMax (aka 802.16) is an emerging broadband wireless access technology that can provide high-speed Internet-facing connections with data transmission distances up to 50km. WiMAX is also a technical system of the future public wireless broadband data network proposed by the Internet camp, which represents the broadband and intelligent features of future wireless communication systems, such as flattening the protocol structure and network structure, supporting high-speed data transmission and seamless roaming, and supporting Various types of services and guarantee their QoS at the MAC layer and physical layer.
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