Technology always comes into being. When everyone is talking about how 3G is developing and whether WIFI is likely to replace 3G and other topics, a new wireless broadband access, WiMax technology, has emerged. WiMAX is an emerging technology that can provide "last mile" broadband connectivity in a wider geographic area than Wi-Fi, thereby supporting corporate customers to enjoy T1 services and residential users have access equivalent to cable / DSL ability. With its 1 to 6 mile coverage in any location (depending on various factors), WiMAX will provide better mobility for high-speed data applications. In addition, with this coverage and high throughput, WiMAX can also provide backhaul for telecommunications infrastructure, enterprise parks, and Wi-Fi hotspots. What is WiMax technology The so-called WiMAX (Worldwide Interoperability for Microwave Access) is a standard-based technology that can replace the existing wired and DSL connection methods to provide last-mile wireless broadband access. WiMAX will provide fixed, mobile, and portable wireless broadband connections, and will eventually be able to provide mobile wireless broadband connections without requiring direct line-of-sight base stations. To this end, the Global Interoperability Certification Industry Alliance for Microwave Access, including equipment manufacturers, device suppliers, and operators, has been established. The main task is to eliminate the obstacles to the application of the IEEE802.16 standard and expand the scope of application of the standard by performing product compatibility and interoperability certification. Advantages of WiMax technology WiMax has fundamentally changed the original application direction and added services in mobile communications. By adding mobile features, on the one hand, WiMax can be used as a technical means for service providers and telecommunications providers to access the last mile as originally envisioned, and at the same time, it can also become the mainstream technology for operators to build voice and data backbone networks. According to Wimax's commercial plan, it is expected that 802.16 will be integrated into notebook computers by 2006, enabling mobile broadband wireless data services within the metropolitan area network. Within the scope of the metropolitan area network, users do not need to purchase a new terminal, only using a laptop with integrated 802.16 function, they can move at a speed of more than 60km / hour, and enjoy a broadband composed of more than ten times the rate of 3G without interruption. Wonderful content service. And WiMax can also be used as a backup of WiFi, allowing users to quickly and easily access and roam WiFi hotspots, and laptops, PDAs, and mobile phones can also access the Internet by freely switching between WiFi and WiMAX to achieve a seamless wireless connection. WiMax has also greatly increased the network capacity by lifting the wireless access system to the wireless access network and sharing the load among multiple central stations. At the same time, WiMax has the capability of non-trial transmission through OFDM technology, so it can obtain the best transmission performance in different environments. WiMax also uses smart antenna technology to improve coverage. In addition, WiMax also has the advantages of low cost and easy implementation, so it is beneficial to get wider support and participation, thereby forming a new industrial chain, and emerging operators, equipment manufacturers, and users will all benefit. In terms of base station construction, WiMax is different from the wireless technology used in the past. Mobile signal stations need to build high base stations in order to work better and reduce the impact of obstacles. WiMax can greatly reduce the cost of mobile operators. Problems with WiMax technology As an emerging broadband wireless access technology, WiMAX compared with traditional last-mile access methods, such as DSL, FTTP, HFC, Wi-Fi, non-standard broadband wireless systems, CDMA1X, and CDMA 2000, WCDMA, HSPDA Although other access methods have unique advantages and market space, if you want to use WiMAX to achieve the last mile of access, you still need to solve the following problems: 1. How to solve the cost problem? WiMAX products use its standardization, and the cost of non-standard broadband wireless products has dropped significantly, but the terminal (fixed) price of WiMAX products is still expected to be roughly 400-500 US dollars, which is higher than DSL (terminal price is 50-60 US dollars ), Ethernet switches (each port is about 10 US dollars) are much higher, especially in China, where wireline is very developed, for the use of WiMAX products to intervene in the broadband data market, the cost pressure is relatively high. These conditions are relatively low in Europe and the United States due to their relatively high tariffs and relatively low pressure. With the further development of WiMAX technology, the further promotion of core chip manufacturers (such as Intel and Fujitsu), the high integration and optimization of technical solutions, and the cost may be greatly reduced, then WiMAX products will be in the competition. For a favorable position. The current situation is as pointed out by Lindsay Schroth, an analyst at Yankee Group, a market research organization. The average deployment cost of MMDS (MulTIpointMulTIchannelDistribuTIonSystem) multi-point multi-channel distributed system providers, including WiMax antenna installation, that provides wireless broadband access services is about $ 3,000 per user Around this, this high deployment cost not only makes it difficult for service providers to obtain sufficient return on investment, but also allows most users to retreat. Although Wavesat and Intel are optimistic about the future commercial prospects of WiMax, but in a short time, due to the difficulty of widespread application, the cost of WiMax will be the biggest bottleneck restricting its development. 2. How to solve technical standards and frequency problems In terms of technical standards, WiMAX has not yet completed the great cause of unification, and it is unclear how ITU determines its standards. At the same time, for wireless systems, the most critical issue is frequency. The amount of frequency resources and the way of allocation will directly determine the capacity and scale of the wireless system. The capacity and scale of the system will directly determine the operator's investment and operating direction. The licensed frequencies currently planned for broadband wireless internationally are mainly 2.5G (US) and 3.5G (globally except the US), unlicensed frequencies are 5.8G, and potential frequencies include 3.3G. According to the current frequency allocation methods of various countries, the frequency points obtained by each operator are far away from the large-scale cellular networking requirements. Generally, about 6 to 8 frequency points are required to achieve large-scale Networking, and the current allocation method is at most about 4 frequency points. Therefore, if WiMAX products are to become the last one-kilometer access method in the mainstream, they also need to seek a breakthrough in the way of frequency resource allocation. In China, the working frequency band of 802.16a is 2-11GHz. The frequency band to be assigned has been allocated in the new radio frequency allocation regulations promulgated two years ago, leaving no blank frequency band for Wimax. At the same time, the maturity of 3G technology and large-scale commercial use will also greatly affect the investment and construction of WiMax by operators. Therefore, Wang Zhanqiang, director of Huawei's WiMAX product department, believes that WiMAX's frequency spectrum is the most prioritized problem. At present, the WiMAX Forum tends to unify the two frequency bands of 2.5G or 3.5G, but now all parties are independent and develop products on multiple frequency bands. Moreover, some frequency band applications require government approval, and in some countries, license fees are required. At this point, Intel said it is communicating with the Chinese government and operators, but the government's attitude is still unclear. 3. How to integrate with the existing network As a new access method, WiMAX products also need to solve an important problem is how to integrate with the existing network. At present, WiMAX products are still mainly a means of access and transmission. 802.16-2004 is only a matter of specifying the air interface. There is no unified consideration in the standards of business, user authentication, and charging. In this case, how to use the existing core network to complete the integration of user authentication management and billing platform is a key issue for WiMAX products as a new last-mile solution. 4. How to solve the indoor coverage problem As a wireless system, outdoor coverage cannot be achieved. Otherwise, extremely high installation costs will be incurred. These costs include direct materials and installation cost costs, as well as other costs, such as rental costs for properties and installation locations. These costs may be Will account for 20% to 50% of equipment costs. In areas such as North America, where land and houses are privately owned, often outdoor terminals cannot be installed. In addition, the outdoor installation method also greatly limits the range of potential users and limits the development of operator customers. To achieve indoor coverage, sufficient link margin is required. Specific to WiMAX products, technologies such as AAS, STC, and subcarriers can be quickly integrated into WiMAX products. The future of WiMax The future development of WiMax depends largely on its relationship with 3G, WIFI and other technologies. 1. See the future development of WiMax from the relationship between WiMax and 3G 3G is an ITU specification that supports high-speed wireless communications. This worldwide wireless connection is compatible with GSM, TDMA and CDMA. The next generation of 3G cellular services can provide a remote wireless access range for voice and data. Operators around the world are currently deploying 3G network infrastructure for towns, suburbs, and rural areas with heavy traffic. The next generation of 3G cellular services can create a wide range of data access across multiple geographies, thereby providing the most ideal mobile computing capabilities for voice communications and Internet connections. WiMax has been attracting more attention since its introduction, especially with the promotion of industry giants such as Intel and the WiMAX organization. The industry has launched a heated discussion on WiMax, especially the relationship between WiMax and 3G. There are many different views: Yes 'S point of view is that WiMax will replace 3G, while others believe that WiMax cannot replace 3G, but is a complementary technology to 3G. Therefore, it can be seen that only when the relationship between WiMax and 3G is established can the future development of WiMax be clarified For 802.16e (WiMax) technology and 3G technology, first of all, due to the difference in positioning, there is a big difference between the two. From the perspective of standardization, 802.16e only defines the physical layer and MAC layer of the air interface. The protocol and core network part adopted above the MAC layer are not included in the scope of 802.16e. The air interface standardization of 802.16e is expected to be completed in the near future. As a complete network, 3G technology has completed standardization of air interface specifications, core network series specifications, and service specifications, involving wireless transmission, mobility management, business applications, and user number management. From the perspective of coverage, in order to obtain higher data access bandwidth (30Mbit / s), 802.16e must sacrifice coverage and mobility. Therefore, 802.16e will mainly solve hotspot coverage in a long time, and the network can provide some For mobility, the main application will focus on data access in nomadic or low-speed mobile states. 3G is a ubiquitous network with continuous coverage, and users can achieve uninterrupted communication. From the perspective of wireless spectrum resources, 3G has a unified global spectrum resource, and 802.16e is trying to find frequency resources between 2 and 6GHZ. The frequencies currently available in various countries are inconsistent. Therefore, it is difficult for 802.16e to finally obtain sufficient global uniform frequency. In terms of service capabilities, 802.16e mainly provides broadband data services with certain mobile characteristics, and the users are mainly notebook terminals and 802.16e terminal holders. 802.16e accesses the IP core network and can also provide VoIP services. From the beginning, 3G was designed for voice services and data services. For voice services, the core network is still implemented by circuit switching, and QoS is guaranteed. 802.16e sacrifices mobility in exchange for the improvement of data transmission capabilities, and its data bandwidth is superior to 3G systems. However, the data capacity of 3G is also constantly improving. 3G enhanced types such as HSDPA can already achieve an access rate of 10 Mbit / s. According to ITU's definition, the ultimate goal of 3G enhanced can reach 30Mbit / s. Although the transmission rate of WiMAX can reach 10 times or more of 3G, and its coverage can be matched with or even further away from 3G when using low-order modulation, but this is not a 3G standard. It uses wireless wide area network WWAN as the basic mode, and uses public voice and multimedia data. For the basic market positioning of personal mobile terminals roaming around the world, WiMAX is essentially an important support method for 3G and 3G evolution as a wireless metropolitan area network and multi-point base station interconnection. The potential market size of the two There are also huge differences, making it impossible to say that WiMAX will become the terminator of 3G. From the analysis of the above perspectives, it can be seen that although 802.16e is superior to 3G in data capabilities, from the perspective of standardization, global unified spectrum, and technical characteristics, 802.16e still has a long way to go before it is truly commercial. And, in a long time, it mainly solves hot spot coverage and solves some mobility. The emergence of 802.16e will not affect the development of China's 3G industry, and it should continue to develop as a supplement to 3G in the future. 2. Look at the future of WiMax from the relationship between WiMax and Wi-Fi Wi-Fi is an abbreviation of Wireless Fidelity. Wi-Fi technology includes the IEEE802.11a, b, and g specifications that have been approved and the 802.11n specifications that are pending approval. It is the first high-speed wireless technology that has been widely deployed and is particularly noticeable in global hotspots-including homes and offices and more and more coffee houses, hotels and airports, and Wi-Fi hotspots are almost immediately popular all over the world And because of its ability to improve work efficiency, it is sought after by people who travel abroad. However, the range it can support is very limited: users can only achieve high-speed connections by staying within 300 feet of the wireless access point device (AP). Wi-Fi has set off a strong boom in the market in recent years. It is predicted that by 2007 there will be 530,000 hotspots in the US, 700,000 in Europe, and more than 1 million hotspots in Asia. Wi-Fi has the reputation of "wireless version of Ethernet". Since the current Ethernet standard (IEEE802.3 standard) has almost become synonymous with local area networks, at least 80% of the local area networks in the world use Ethernet technology. And WLAN is also a standard formulated by IEEE, so it can almost be regarded as an extension of the Ethernet standard in the wireless field. This makes WLAN has the characteristics of seamless and smooth installation. Moreover, the installation and setting of WLAN is quite simple-when you need to establish a network connection in a certain area, you only need to set up the corresponding access point within a certain range, and the traditional procedures such as planning, wiring, and testing can be ignored. And the operation when the user needs to add, remove and relocate is also very simple. If deploying a LAN in an Internet cafe, it will take a lot of time in HUB, cable layout, etc., and after the introduction of Wi-Fi at home, the entire access process is less than 10 minutes. At the same time, the overall cost of WLAN is very low. It is reported that through the implementation of wireless LAN solutions, enterprises with an average user size of 400 points can save up to 4.9 million US dollars in networking costs. Due to the convenient access, low cost and no need to apply for a license, WLAN is in the field of public access services Become a star. In terms of bandwidth, the bandwidth of 802.11b can reach 11Mbit / s, while 802.11a and 802.11g can reach 54Mbit / s. Such a high bandwidth almost catches up with the connection of cables, greatly surpassing the same type of wireless network technology. In addition to the network, the application of WLAN will be expanded to a wider range, in addition to being integrated in devices such as notebook computers, PDAs, mobile phones, etc., it will also be integrated into products such as printers, DVD players, game consoles, MP3, etc. The function will be further enhanced. In summary, Wi-Fi has many advantages, but it cannot be ignored that its hidden safety hazard is a fatal flaw. Wi-Fi uses radio frequency (RF) technology to send and receive data over the air. Because wireless networks use radio waves to transmit data signals, they are very vulnerable to attacks from outside. Radio waves can penetrate walls and partitions, and hackers can easily steal data within the coverage of radio waves and even enter unprotected companies. Internal LAN. However, although the rise of Wi-Fi is rapid, WiMAX has considerable advantages in comparison. WiMAX will not replace Wi-Fi in the future, and both parties will complement each other in wireless access. The most obvious difference between WiMAX and Wi-Fi is the huge difference in coverage. Wi-Fi can only reach a maximum coverage of 300 feet, and can only be used in a wireless LAN environment, while WiMAX802.16e can usually reach 1 to 3 Miles, so it is mainly used in the mobile wireless metropolitan area network environment. Future commercial prospects of WiMax technology In the second half of 2004, three companies, including Motorola, Western Multiway and Alvarion, launched corresponding WiMax fixed access products, and the productization process of WiMax has exceeded expectations. In October 2004, Alvarion announced the launch of its quasi-WiMAX platform BreezeMAX to the Chinese local market. This platform product is based on the IEEE802.16 / ETSIHiperMAN standard and the WiMAX Forum agreement, condensing Alvarion in Broadband Wireless Access (BWA), Over ten years of commercial deployment experience in cross frequency division multiplexing (OFDM) systems and networks. BreezeMAX operates in the 3.5GHz frequency band and can provide high-bandwidth access services. The scope of application includes various broadband access areas such as residents, enterprises, multi-tenancy and multi-resident units (MTU / MDU), hotspot network relay stations, and home networks. It provides market-leading integrated services of high-quality IP voice and high-speed data transmission. Relying on leading technology, BreezeMAX Si products are the most advanced WiMAX customer terminal equipment today, with the following characteristics: Aluminum Electrolytic Capacitors/ Ceramic Capacitors Aluminum Electrolytic Capacitors/ Ceramic Capacitors Aluminum Electrolytic Capacitors,Electrolytic capacitor,Ceramic Capacitor YANGZHOU POSITIONING TECH CO., LTD. , https://www.pst-thyristor.com
The quasi-WiMAX technology six-beam switching antenna design equipped with Intel PRO / Wireless 5116 broadband access chip provides 360-degree coverage. The iFAS (Intelligent Fast Antenna Selection) algorithm is used to ensure that the best antenna can be quickly found to improve anti-interference and reduce signal attenuation. OFDM and OFDMA wireless technology are used to enhance indoor penetration and NLOS non-line-of-sight operation capabilities The configuration and authentication architecture can provide fast connection at any point within the BreezeMAX network coverage. The SIM card or friendly interface installation program is used to quickly install the device. End users can install the BreezeMAX Si client terminal themselves and get a broadband connection immediately.