Introduction to WiMax wireless communication technology WiMax is a wireless communication technology that provides high-speed Internet-facing connections. WiMax's wireless signal transmission distance can be up to 50 kilometers, and its network coverage area is 10 times that of 3G base stations. WiMax (World Interoperability for Microwave Access) is a broadband wireless access Metropolitan Area Network (BWAMAN) technology based on the IEEE 802.16 standard. WiMax is also often referred to as IEEE Wireless MAN (Metropolitan Area Network), and its basic goal is to provide a broadband wireless access method that can effectively interoperate in a multi-vendor environment with one-to-many points in a metropolitan area network. Many WiMax supporters established the WiMax Forum organization as early as 2001, and related research was carried out earlier. The WiMax Forum aims to promote IEEE 802.16 wireless broadband network technology. The organization currently has 105 members, including industry giants such as Alcatel, AT & T, BT, FUJITSU, Nokia and Intel. The development and promotion of WiMax technology is a long-anticipated plan, and the rise of WiMax reflects the trend of industrial development. The members of the WiMax alliance include operators, chip manufacturers, equipment manufacturers, etc., with a complete industrial chain. According to statistics, 1/4 of the members in the WiMax alliance are currently telecom operators. As an emerging technology, it can attract the attention of many large operators, which itself shows great market appeal. Operators joining the WiMax alliance will also help solve WiMax's future interoperability issues. The reason why WiMax can get such extensive attention is inseparable from its inherent technical advantages. It is precisely because of the broad market demand that WiMax's advantages may trigger that various manufacturers have a strong interest in it. Technical advantages of WiMax The technical advantages of WiMax can be summarized as follows: ◆ Long transmission distance The wireless signal transmission distance of WiMax can be up to 50 kilometers, which is unmatched by wireless local area networks. Its network coverage area is 10 times that of 3G (3rd GeneraTIon, third-generation mobile communication) base stations. City coverage, which greatly expands the scope of wireless network applications. ◆ High access speed The maximum access speed that WiMax can provide is 70M, which is 30 times the broadband speed that 3G can provide. For wireless networks, this is indeed an amazing progress. WiMax uses the same OFDM (Orthogonal Frequency Division MulTIplexing) modulation method as the wireless LAN (Local Area Network) standards 802.11a and 11g, and the bandwidth of each channel is 20MHz. This is almost the same as 11a and 11g. However, because radio waves can be stably transmitted and received through outdoor fixed antennas, the number of bits that radio waves can carry is higher than 11a and 11g. Therefore, a maximum transmission speed of 74.81M can be achieved. ◆ No “last mile†bottleneck restriction As a wireless metropolitan area network technology, it can connect Wi-Fi hotspots to the Internet, and can also be used as a wireless extension of wired access methods such as DSL (Digital Subscriber Line) to achieve broadband access for the last mile . WiMax can provide services for users in a 50-km linear area. Users can establish broadband connections with base stations without cables. ◆ Provide a wide range of multimedia communication services Because WiMax has better scalability and security than Wi-Fi, it can achieve carrier-grade multimedia communication services. High bandwidth can greatly reduce the shortcomings of the IP network, thereby greatly improving the QoS (quality of service) of VoIP. From a technical perspective, WiMax is more suitable for the "last mile" wireless access part of the metropolitan area network construction, especially for emerging operators. WiMax development status Complementing the heated discussion of the WiMax concept, commercial application research is also in full swing with the strong support of various IT vendors. Intel is the core leader in this movement. As the world's largest chip supplier, the support of its products for various agreements has always been one of the important factors for whether a certain technology can finally achieve market success. For example, with the support of Intel and other chip makers, Wi-Fi has already earned $ 3.3 billion in revenue worldwide in 2003. It is said that Intel will launch chip products containing the WiMax standard in the second half of the year. Not only Intel but also more chip manufacturers are joining the WiMax chip R & D team. In early June 2004, Intel reached an agreement with the municipal governments of Dalian and Chengdu to deploy the latest WiMax broadband wireless technology in these two cities. According to the memorandum of understanding signed between Intel and these two cities, Chengdu and Dalian will set up the network facilities required to access WiMax, and enterprises and families will be able to use wireless methods for broadband connection. Through investment in new technologies and IT facilities, Dalian and Chengdu will be far ahead in the application of new wireless broadband technologies. In the context of global economic integration, the creative use of wireless broadband technology will increase the competitiveness of cities. This is also a milestone in the development of WiMax. In May 2004, Nokia did not renew its membership after its WiMax forum membership expired, which made the industry full of doubts. A month later, it announced that it would rejoin the WiMax Forum organization, which became the focus of the industry at that time. In any case, Nokia's return to the WiMax forum is good news for the promotion of WiMax technology, which will give investors more confidence in this technology. With the support of industry giants such as Nokia and Intel, WiMax has a brighter future. The difference between WiMax, Wi-Fi and 3G Wi-Fi access Wi-Fi is a wireless LAN (Wireless LAN, WLAN) access technology, and its signal transmission radius is only a few hundred meters away. The purpose of Wi-Fi is to enable various portable devices (mobile phones, notebook computers, PDAs, etc.) to access the local area network within a small range through self-arranged access devices, thereby achieving connection with the Internet. The Wi-Fi network uses the common channel used by devices such as cordless phones. As long as there is a "hot spot" and a high-speed Internet connection, a Wi-Fi network can be set up within a few hundred meters around it. With the increase of "hot spots", the area covered by the Wi-Fi network is continuously expanding like a spider web. The transmission speed of Wi-Fi can reach 11M per second, which belongs to the category of broadband and can meet the needs of personal and social information. The structure of the Wi-Fi network is very simple. After manufacturers set up "hot spots" in densely populated areas such as airports, stations, coffee shops, and libraries, users only need to bring Wi-Fi-enabled devices into the area. Accept its signal and access the Internet at high speed. WiMax access WiMax is a wireless metropolitan area network (MAN) access technology. Its signal transmission radius can reach 50 kilometers, which can basically cover the suburbs. Because of this long-distance transmission feature, WiMax can not only solve the problem of wireless access, but also serve as a wireless extension of wired network access (Cable, DSL) to easily achieve network connectivity in remote areas. Enterprises or government agencies can set up WiMax base stations in cities, and all mobile devices within the coverage of the base stations can access the Internet through the base stations. Since WiMax can only provide data services, the provision of voice services needs to be achieved with the help of VoIP technology. Like the 3G network, WiMax network construction requires large base stations. But because it only needs to achieve metro coverage, the network construction cost is relatively low compared to 3G networks. 3G technology 3G is a wide area network (Wide Area Network, WAN) technology. The 3G network is a global mobile integrated service digital network, which integrates the functions of various mobile communication systems such as cellular, cordless, trunking, mobile data, and satellite. It is compatible with fixed telecommunications network services and can provide both voice and data services. The goal of 3G is to achieve seamless coverage in all areas (urban and wild), so that users can use the various services provided by the system anywhere. 3G provides both voice and data services. Under current conditions, the service quality of voice services based on circuit switching is much higher than that of VoIP. The relationship between the three Compared with 3G technology, WiMax has shown huge advantages in many aspects. Although the speed of the 3G network has been greatly improved compared with the current technology, the speed of the 3G network is 30 times slower than that of WiMax. In the network coverage area, the coverage of a 3G base station is only one-tenth of WiMax. In the past few years, wireless operators have invested hundreds of billions of dollars in order to obtain 3G operation licenses, and they are currently spending tens of billions of dollars to operate 3G networks. The current WiMax spectrum does not require additional costs, and the number of base stations required for networks based on WiMax technology will be greatly reduced compared to 3G. For fixed-line telephone operators, they can first establish a low-cost network based on WiMax technology, and connect the wireless network to the Internet through their fixed-line telephone network, which can gradually regain some market share from mobile operators. The core function of the 3G network is to provide mobile phone services and can also be used to transmit data; WiMax's standard is high-speed data transmission, and voice quality is not a critical requirement. Therefore, the respective tasks and objectives of these two technologies are different. The focus of WiMax is to achieve broadband wireless, while 3G is more inclined to achieve wireless broadband. In short, under the joint promotion of so many large manufacturers, we seem to have good reason to believe that WiMax will become a revolutionary application technology in the future. But when we have such confidence, we also need to retain a more objective understanding of the relationship between WiMax and other wireless network technologies. Is WiMAX the terminator of 3G? Some analysts believe that WiMAX will be the terminator of 3G. But will this really be the case? First of all, WiMAX and Wi-Fi and 3G do have many overlapping or even surpassing functions, and have a competitive relationship with Wi-Fi and 3G, but they are more of a complementary relationship. This is because Wi-Fi, WiMAX, and 3G respectively target wireless local area network WLAN, metropolitan area network MAN, and wide area network WAN, and have different market positioning. In particular, 3G has made substantial progress. Operators and equipment manufacturers have made a lot of investment. It is impossible to expect that operators who have invested heavily in 3G will give up 3G technology. The telecommunications regulator will not let existing investments go to waste. Therefore, in the future, WiMAX and other wireless network technologies are likely to coexist in the market, just like the coexistence of GSM and CDMA standards for mobile communications today. Secondly, although WiMAX is very popular now, it still needs to be improved, such as standard unification, interconnection, and cost reduction. Therefore, it is premature to assert that WiMAX can replace the 3G technology already operating in many countries while WiMAX is still in its perfection and promotion period. Again, one of WiMAX's current strengths: free spectrum will not be a free lunch in the future. When WiMAX is put into large-scale application, regulatory agencies will require operators to pay the same high rental fees for free spectrum now. These costs will eventually be reflected in the cost of their services, which will weaken the appeal of WiMAX. Finally, because WiMAX uses free spectrum, compared to 3G networks, WiMAX signals are more likely to be interfered by other signals. In addition, because the frequency range (2G ～ 11GHz) used by WiMAX is much higher than that of GSM (Global System for Mobile CommunicaTIon) and 3G, the signal penetration capability will be even worse. In complex urban terrain, the realization Seamless coverage is bound to make the entire network extremely complex. Some analysis pointed out that WiMAX will not replace 3G, but create a junction between wireless LAN and WAN. WiMAX and 3G dual-mode phones will appear on the market in 2006 or 2007. Mobile operators have global coverage that WiMAX cannot match. Telecom operators should develop wireless strategies that include local area networks, wide area networks, and metropolitan area networks.
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