Mobile EDGE network technology literacy

Modern man in a lot of people are using mobile Internet access, for convenience. The mobile Internet is divided into three types of GPRS network, is the EDGE network, another is the emergence of this year is only 3 g network. Former present technical backwardness, who have not used. The latter, because just rising. Network stability not enough and the price relatively inconsistent with mass consumption levels. While the EDGE is now one of the most widely used 2.5G network, both speed and price comparison is currently the highest price. What is the EDGE network? today we're coming up on the EDGE of universal knowledge!

First, the introduction of EDGE technology EDGE is English for Enhanced Data Rate for GSM Evolution, which is an abbreviation of enhanced data rates for GSM evolution of technology. EDGE is a transition to 3 g GSM technology, mainly in the GSM system uses a new modulation method, which is the most advanced multi slot operations and 8PSK modulation.　　Due to existing 8PSK GSM networks use of GMSK modulation signal space from 2 to 8, so that each symbol contain information of the original four times. The reason that a GPRS EDGE to third generation mobile communications in the transitional technical programmes, mainly because of this technology to be able to take full advantage of the existing GSM resources. Because it uses the existing GSM frequencies, while leveraging the majority of the existing GSM devices only need to network software and hardware to do some small changes, you can enable operators to provide mobile users, such as Internet browsing, video teleconferencing and high-speed e-mail transmission wireless multimedia services, i.e. in the third generation mobile network business in advance of providing users with personal multimedia communication service. Because the EDGE is a cross between existing second generation mobile networks and third-generation mobile networks between technology, than the "second generation-" technology GPRS better, so some people call it "2.75 generation" technology. EDGE will be capable and WCDMA standards coexistence after, this is what it has the advantage of flexibility. EDGE technology mainly affect existing GSM networks with wireless access, that is, base station transceiver (BTS) and GSM base station controller in (BSC), which is based on circuit-switched and packet-switched applications and interfaces and there is no significant impact. As a result, network operators can make the best use of existing wireless network device, you only need a small amount of capital you can deploy the EDGE, and the adoption of mobile switching Center (MSC) and service GPRS support node (SGSN) you can keep using your existing network interface. In fact, EDGE improves the existing GSM application performance and efficiency as well as the future of broadband service providers. -EDGE technology to effectively increase the efficiency of the GPRS channel coding and high-speed mobile data standards, it's the highest 384kbit/s up to a certain extent, saving a network investment, can fully meet the future wireless bandwidth requirements for multimedia applications. From a long-term point of view, it would gradually replace the GPRS as third generation mobile communications system for the closest one.

Second, the positioning of EDGE technology GSM and TDMA/136 is now a global generic second-generation cellular communication standard. There are currently more than 100 countries by 1 million people use GSM, nearly 100 countries of about 9500 million users use TDMA/136 system family (including ELA-553 and IS-54) service. As between existing second generation mobile communication systems and third-generation mobile communication system to a transitional data communication technology, the EDGE (EnhancedDatarate for GSM Evolution) technologies to greatly enhance the existing GSM network data service rate.　　But if you want to fully exploit the advantages of speed EDGE, operators must be on the existing structure of GSM system and all devices to be modified. EDGE technology is different from the advantage of GSM: (1). 8 PSK air interface mode (2). the enhanced by AMR encoding (3) .MCS1 ~ 9 nine channel encoding (4). the link adaptation (5). the increment redundant transmission (6) .RLC window size automatically adjusts the

III. background voice communication is the second generation mobile system for major services, in recent years, mobile communication devices is dramatically enhanced support for data communication, some standard mobile device currently provides data rate up to 9.6kbps.　　But such a low rate of data communication is obviously unable to meet mobile devices multimedia data communications needs, therefore, manufacturers are developing new, rate faster mobile data communication technology, one of the most typical is GPRS (General Packet Radio Service), HSCSD (high-speed circuit switched data) and EDGE. These three technologies are to varying degrees, more demand for high data rate. HSCSD introduced the concept of multiple time slots, HSCSD and GPRS technology is a non-connected technology, users can only send and receive data in real time before they need to remain on the network, thus greatly improving the wireless resource utilization.　　In addition, many new core network components product will make the future of mobile communication products can directly access the Internet/Intranet. HSCSD and GPRS through multiple time slots operations achieved a higher bit rate. But because these technologies are based on the Gaussian minimum shift keying (GMSK) modulation techniques, so each time slot can get rate are limited.　　For this reason, many more efficient modulation schemes have been introduced, for example in TDMA/136 +, multiple time slots operations and new 8PSK modulation schemes (based on carrier bandwidth 30kHz) combination will enable the data rate of approximately 4 times. The third generation of wireless communication IMT-2000

The main advantage is the ability to use the broadband service, significantly improve the current GSM and TDMA/136 of standardized services on offer. Third generation mobile communications system provides wide-area data communication 384kbps services and about 2Mbps data communication service of the local area. New for code division multiple access (W-CDMA) 2GHz band has been the ETSI, the radio industry and Broadcasting Association (ARIB) support. W-CDMA will include IMT-2000 device all the features you need.　　However, the higher data rate development is not limited to new 2GHz band, EDGE technology also enables the use of 800, 900, 1800, 1900mhz network providing third generation mobile communication networks, as part of its function. On this basis, the Ericsson company in 1997 as first presented to the ETSI EDGE concept. The same year, ETSI has ratified a feasibility study on the EDGE, the EDGE of the development in the future. Although the EDGE GSM carrier was still use bandwidth and time slot structure, but it can also be used for other cellular communication system. EDGE can be considered a high bit rate, and thus promote cellular mobile systems to third generation function evolution, effective universal wireless interface technology.　　On this basis, the Unified Wireless Communications Forum (UWCC) assessed for TDMA/136 of EDGE technology, and in January 1998, the technology was approved. Within the existing GSM network to introduce EDGE technology bound to an existing network and mobile communication devices. To make the EDGE are network operators to accept and promote the EDGE must be an existing network structure to minimize the impact, and EDGE system should allow operators to once again take advantage of the existing base station equipment.　　In addition, the use of EDGE, operators should not need to modify their wireless network planning, and the introduction of EDGE cannot affect the quality of mobile communication. The main impact network EDGE wireless access part of the base station transceiver (BTS), GSM base station controller in (BSC) and TDMA in the base station (BS), but is based on circuit-switched and packet-switched access of applications and interfaces do not have adverse effects. Through the mobile switching Center (MSC) and service GPRS support node (SGSN) you can keep using your existing network interface. In fact, EDGE improves some of the existing GSM application performance and efficiency for future broadband service providers.

IV. technical characteristics of the EDGE of the EDGE is a further enhanced mobile data transfer rate and from GSM to 3G transition in important technology. Its access business and network building has the following characteristics:

1. in the access business performance (1) bandwidth is markedly improved, single point access rate 2Mbit/s peak, single-slot channel rate can reach 48kbit/s, enabling mobile data transfer rate in peak can achieve 384kbit/s, this is a mobile multimedia service provides the basis for implementation. (2) a more precise location of the network layer to provide the service.

2. network-building features (1) the EDGE is a modulation and coding technique, it changes the rate at which the air interface. (2)　　EDGE of the air channel distribution, and the TDMA frame structure, characteristics and GSM air interface. (3)　　EDGE does not change the GSM or GPRS network structure nor the introduction of a new network element, simply upgrade to the BTS. (4) core network using 3-layer model: business application layer, communications control layer and communication connection layer, the interface between tiers should be standardized.　　Using hierarchical structure makes the call control and communication connection relatively independent, it can give full play to the advantages of packet switching networks, the business volume and bandwidth allocation closer, especially adapted to the VoIP business. (5) introduces media gateway (MGW). MGW with STP capabilities, you can implement IP network signaling network of formation (VPN support).　　In addition, MGW is GSM circuit-switched services and PSTN interfaces and radio access network (RAN) and 3G core network interfaces. (6) EDGE rate is high, the existing GSM network mainly uses Gaussian minimum shift keying (GMSK) modulation, EDGE used octal phase shift keying (8PSK)-modulation, in a mobile environment can achieve stable 384kbit/s, in the static environment can even reach the 2Mbit/s, basically to satisfy the needs of a variety of wireless applications. (7) EDGE while supporting packet switching and circuit-switched data transmission mode. It supports packet data services can realize up to each timeslot 11.2kbit/s-69.2kbit/s rates. EDGE can use 28.8kbit/s rate support for circuit-switched services, it support symmetric and asymmetric two data transmission, Internet access for mobile devices is very important. For example, in the EDGE system, users can use the downlink than uplink higher rate.

3. Overview of the wireless interface EDGE wireless interface's main role is to make the current cellular communication system can get higher data communication rates. The existing GSM network mainly uses GMSK modulation techniques, to increase the total rate of the wireless interface, introduces an EDGE to provide high data rates, modulation schemes, namely octal phase shift keying (8PSK) modulation. As a result of 8PSK will signal space GMSK from 2 to 8, each symbol can include information that is the original 4 times.　　Symbol rate keep 8PSK in 271kbps, each time slot can be 69.2kbps total rate, and still be able to complete GSM spectrum mask. EDGE basic guideline specification is learn as much as they can leverage existing GSM-data service types, greatly enhance its data communication rate. It defines several channel coding scheme to ensure that the various channels

Robust, use the link adaptation technology for encoding and modulation scheme between the dynamic conversion. By once again using GPRS packet data service structure, you can implement each timeslot 11.2-69.2kbps wireless communication rate.　　EDGE by using a high speed each time slot 28.8kbps wireless interface rate to support circuit-switched services.　　The EDGE program, support all the services of multiple-slot communication resulting rate is the single slot communication of 8 times, used for packet data services peak wireless communication rate can be as high as 554kbps.　　(1) on the wireless interface device of EDGE on the GSM network modifications of existing wireless interface will have a direct impact on the base station and mobile terminal design, people must use the new terminal and base station transceiver can send and receive information using EDGE modulation. (2) the effect on the linear modulation of new modulation schemes for linear power amplifier new requirements. And GMSK, 8PSK and does not have a fixed package.　　In fact, EDGE facing the biggest challenge is to create a cost effective, complete GSM Transmitter frequency shielding. In order to maximize use of the existing GSM network, EDGE transceivers must be packed in a standard transceiver design of base station tanks and EDGE transceivers must emission spectrum and heat dispersion can be accepted.　　In General, high-performance EDGE transceiver in emission reduction 8PSK may need its average transmit power, compared with the average power GMSK reduce (SPD) between the 2-5dB.　　How to design a low-power transceiver that micro base station, indoor or Pico base stations (picobase) and mobile terminals will bring further challenges, such as the EDGE system will no longer be used for optimization of nonlinear modulation transmitter structure. In the connect mobile terminals where you can take two modulation. The first is to be transmitted for uplink GMSK, 8PSK for downlink. This rate of uplink will limit the scope of the GPRS, and EDGE of high-rate will be made available to downlink. Because the vast majority of services on downlink rate requirements are higher than uplink, such programmes can use one of the most economical way to meet the needs of the mobile terminal.　　The second way is in the uplink and downlink are taken in a summary way for transmission. 8PSK　　Existing GSM standard defines a variety of mobile terminals, for example from a low complexity of single-slot device to have a bit of 8-slot device. (3) on the total rate of the total rate, the higher the interface technology becomes more sophisticated, high-speed EDGE interface is not available through the best Equalizer structures to deal with, and can only consider the ideal design of the equalizer.　　According to the simulation results for 8PSK best Equalizer design will be only better than standard GSM Equalizer slightly more complicated. Enhanced bit-rate (compared with standard GPRS) also reduces the time distribution and mobile terminal velocity of robustness. However in the vast majority of cases, the EDGE service will be relatively static users, this means that mobile terminal's high-speed mobile and excessive time distribution is not possible. In addition, when the movement speed and time distribution beyond the EDGE of competence, or require the use of GMSK modulation.