Comparison of WiFi, WiMAX, WBMA and 3G (Figure)
Http://www.chinatelecom.com.cn September 08, 2004 China Telecom Co., Ltd. Beijing Research Institute Sun Zhenqiang
Abstract: This paper analyzes WiFi, WiMAX, WBMA, and 3G standard systems and related technical indicators, in detail, in detail, explore their respective applications and complementary development prospects. Key words: WiFi, WiMAX, WBMA, 3G 1. Introduction The third generation mobile communication system (3G) is proposed by ITU-R, because its main operating frequency band is around 2000MHz, and has the highest speed of 2000kbps, general The IMT-2000.3G system is capable of meeting high-rate transfer to support multimedia services, which can reach 2Mbps indoors, within indoor walking environments up to 384kbps, outdoor fast moving environment up to 144kbps. Three of the world's mainstream 3G systems are WCDMA, CDMA2000, TD-SCDMA. At present, most operators who have got 3G licenses in the world have chosen WCDMA formats, and their standardization is mainly responsible for 3GPP. In the past few years, due to the criteria, the terminal shortage, the market outlook is unknown, the development of 3G in many countries is not as optimistic. In contrast, the development of various wireless access technologies is a red fire. Especially 802.15 (wireless Domain Net, WPAN), 802.11 (Wireless LAN, WLAN), 802.16A / D (Wireless Fixed Access, FWA), 802.16A / D (Wireless Fixed Access, FWA), 802.16A / D (Wireless Fixed Access, FWA) Waiting for standards. WPAN mainly includes Bluetooth technology and ultra-wideband (UWB) technology, and WLANs using 802.11 standards and FWAs employing 802.16a / d standards are also known as WiFi and WiMAX. Since WiFi, WiMAX, WBMA, and 3G can have a telecommunications application, this paper will compare these three technical standards and 3G standards, explore their respective applications and complementary development prospects. 2. WiFi and 3G WLAN standards mainly include 802.11b, 802.11a and 802.11g, and the like. Among them, 802.11b uses a 2.4 GHz frequency band, which can support the shared access rate of 11Mbps; 802.11A uses 5GHz frequency band, with a rate of up to 54Mbps, using OFDM (orthogonal frequency division multiplexing) technology, but the access distance of accessibility By 30-50 meters; 802.11g is actually a mixed standard, which can adapt to 802.11b standards, in accordance with 802.11A standards, 5 times faster than 802.11b, and 802.11b. In addition, the main progress of IEEE in WLAN also includes 802.11i (security aspects), 802.11e (contents of QoS), 802.11f (switching protocols between access points), 802.11n (up to 320 Mbps). At present, WLAN promotion and certification work is mainly completed by the Industry Standards Organization WiFi (WiDelity, Wireless Fidel) Alliance, so WLAN technology is often referred to as WiFi. Table 1 lists the main differences between 3G and WiFi. Obviously, the 3G network can utilize the characteristics of WiFi high-speed data transmission to make up for the shortcomings of their own data transmission rate, but WiFi can not only use 3G network perfect authentication and billing mechanism, but also combined with 3G network wide-covered features. Access switching function. This will achieve the convergence of WiFi and 3G, which makes 3G operations to add flowers to further expand business.
At present, both ETSI and 3GPP have made some integration of 3G and WiFi. We believe that mainly include: 1) The new technology of terminals does not immediately go out of the rooted technology, especially when the economy is sluggish, currently fold The program is large, in the WLAN field, there is a dual-mode or multimode chip that is compatible with 802.11A / b / g, in the field of mobile communication, there is a dual-mode or multimode mobile phone that is compatible with GSM / CDMA / 3G, people The study of WLAN / 3G dual mode chip or terminal is also under progress. 2) The fusion of the network can be combined by two ways and WCDMA mobile networks: loose and compact mode. • Compact mode WLAN network is connected to the GPRS core network with the same way as the WCDMA base station (IUPS interface). This approach takes full advantage of the mechanisms of the GPRS core network existing movement, security and service quality, and can provide strong mobility between two networks. But there is two shortcomings in compact mode. First, in order to connect directly to the WCDMA core network, you need to re-modify and customize the existing WLAN products. Secondly, the WLAN has a very different mobile model and service traffic characteristics compared to the WCDMA mobile network and WLAN in this program. Therefore, this combination is in engineering, Perhaps to redesign WCDMA's backbone transfer network. • Loose mode WLAN is combined with the mobile network (GI interface) in the WCDMA network (GI interface), without passing the GPRS core network, only authentication, billing letter from GGSN or dedicated equipment into the GPRS core network, thereby avoiding two different The data traffic brought by the access technology to the mixing of the GPRS core network node. This combination ensures that the two wireless networks are completely separated, both completely independent, and there is no change in WLAN IEEE 802.11 standard. At the same time, loose coupling can use mobile IP support network mobility, but this will result in higher delays. Sharing AAA architecture in a loose scheme, allowing WCDMA operators to use consistent user authentication mechanisms in a mixed network environment, or make telecom operators better build their own unique business models to make full use of the original Billing system and customer relationship. WLAN can utilize the security mechanism of WCDMA's USIM card to ensure that the WLAN user's authentication is read out, and the information of the USIM card is read. The WLAN network is transmitted to the AS, and the authentication is performed in HLR, then allow customers to use WLAN and will WLAN The billing information is transferred to the billing system, and the fee is calculated on the USIM account to generate a unified customer bill containing WCDMA and WLAN usage. 3. WIMAX and 3G as wireless expansion technology for cable and XDSL, 802.16a specification was passed by IEEE January 29, 2003. This is a new broadband FWA technology designed to solve the problem of "the last km" issue of broadband access. In order to ensure the compatibility and interoperability of FWA, WiMAX (Global Microwave Access Interoperability Alliance) was established in April 2003, mainly engaged in promotion and certification 802.16a equipment, and there are currently more than 70 communications equipment companies have joined. On July 10, 2003, Intel officially announced the development of WiMAX standard chips and will be launched in the second quarter of 2004. Table 2 lists 3G and WiMAX technology comparison, the author believes that WiMAX is different from the 3G application market, and its application range is similar to LMDS, but there is much lower cost, and it can be used in the telecom operator in the future. Widely used, for example: 1) For new communities, cover the network access of the entire community, directly provide voice and data, video images, etc.
