Is a transition from GSM to 3G technology, it is mainly in GSM system adopted a new modulation method, namely the most advanced much time buttress operation and 8PSK modulation technology. Because 8PSK can will existing GSM network USES GMSK signal of modulation technology from 2 to 8 expanded space, thus make each symbol information contained herein is the original 4 times.
Basic introduction
What is the EDGE network:
I call EDGE for GPRS to the third generation mobile communication transitional technical scheme, the main reason is that this technology can make full use of the existing GSM resources. Because it besides using existing GSM frequency outside, also used the most existing GSM equipment, but only need to network software and hardware do some small change, can help operators to provide mobile users such as Internet browsing, video conference call and high-speed email transmission wireless multimedia services, namely in the third generation mobile network commercialization in advance in order to provide users before personal multimedia communication business.
Due to the EDGE is a cross between the existing second-generation mobile network and the third generation mobile network the transition between the technology, therefore also have called it "second-generation half" technology. EDGE can coexist with later WCDMA formats, and this is its possesses elastic advantage.
EDGE technology orientation
GSM and TDMA / 136 now be universal second generation cellular mobile communication standards. Currently has more than 100 countries 100 million people using GSM, there are nearly 100 countries about 95 million users using TDMA / 136 system family (including ELA - 553 and IS - 54) service. As between existing second generation mobile communication system and the third generation mobile communication system of transition between data communication technology, EDGE (EnhancedDatarate for GSM technology can greatly improve the similarities existing GSM network data service rate. But to give full play to the rate of EDGE, operators must to advantage of existing GSM system structure and all equipment modification.
EDGE technology is different from the GSM advantage lies in: (1). 8 PSK air interface mode (2). Enhanced AMR encoding (3). MCS1 ~ 9 nine kinds of channel coding way (4). Link adaptive (5). Increasing redundancy transmission (6). RLC window size automatically adjusted
Four, emergence background
Voice communications is the second generation mobile system's main service, in recent years, mobile communications equipment are greatly enhance the support ability of data communication, some standard mobile communications equipment current can provide KBPS data rate of 9.6 service. But this low data communication rate obviously can't satisfy mobile equipment multimedia data communication demand, therefore, manufacturers in succession in developing new and faster mobile data communication technology, one of the most typical is GPRS (general packet radio service), HSCSD (high rate of circuit switching data) and EDGE.
These three technology can solve different degree higher data rate demand. More than HSCSD introduced the concept of time, HSCSD and GPRS technologies are oriented to the connection technology, user only truly in sending and receiving data is only necessary to maintain a network connection, thus greatly improve the wireless resources utilization. In addition, many new core network components products will make the future mobile communications product can directly access Internet/Intranet.
HSCSD and GPRS through multiple time buttress operation achieved high bit rates. But because of these technologies are based on gauss minimum frequency shift keying (GMSK) modulation technology, so every time buttress can get the rate of increase is limited. Therefore, many more efficient modulation scheme are introduced, such as in the TDMA / 136 +, much time buttress operation and new modulation scheme based on 8PSK (30kHz carrier bandwidth) combination will make a data improve the rate of about four times.
The third generation wireless communication IMT - 2000 advantage lies mainly in can use broadband service, greatly improve the current in GSM and TDMA / 136 providing standardized service. The third generation mobile communication system will provide 384kbps the wide-area data communications services and 2Mbps about the local data communication services. New for CDMA access (W - CDMA) of 2GHz band has already got the ETSI, radio industry and radio association (ARIB) support. W - CDMA will include IMT - 2000 equipment needed all functions. However, to higher data rate development is not limited to the new 2GHz frequency band, EDGE technology can also make use of 800, 900, 1800, 1900MHz frequency band network to provide the third generation mobile communication network part function.
On this basis, Ericsson company in 1997 first put forward to ETSI EDGE concepts. That same year, ETSI approved feasibility study, this EDGE to EDGE development after paving the road. Although still USES the GSM EDGE carrier bandwidth and time buttress structure, but it can also used for other cellular communication systems. EDGE can be seen as a provide high bit rates, and thus promote cellular mobile systems to the third generation function evolution and effective general wireless interface technology. On this basis, the unified wireless communication BBS (UWCC) evaluation for TDMA / 136 of EDGE technology, and in January 1998 approved the technology.
In the existing GSM network in introducing EDGE technology will inevitably to existing network structure and mobile communications equipment bring influence. To make EDGE are easily accessible by network operators to accept and promotion, EDGE must will of its existing network structure is minimized, and the influence of EDGE system should allow operators again use existing base station equipment. In addition, use EDGE, operators should not need to modify their wireless network planning, and the introduction of EDGE also cannot affect the quality of the mobile communication.
EDGE main influencing network wireless access part transceiver base station (BTS), GSM base of controller (BSC) and the base station (TDMA BS), but based on circuit switching and packet switching access application and interface and no adverse effects. By moving the exchange center (MSC) and service support node (GPRS SGSN) can keep using existing network interface. In fact, EDGE improve some existing GSM application performance and efficiency for future broadband services to provide the possibility.
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