Mobile communications: what is EDGE. What is EDGE in the phone and how does it work What does edge mean

Historically, the life of a modern person is becoming more information-rich every year. It is not always possible to extract interesting news, a description of technological innovations, or just a recipe for a new dish from “old” products in the daily bustle of the information flow.

Today we're going to talk about EDGE (pronounced edge). What is EDGE Network? In fact, this combination of letters GPRS / EDGE refers to mobile communications... More precisely, we are talking about a technology for transmitting data over long distances without the use of wires. In addition to voice communication, operators provide the ability to transfer data using mobile phones.

*** Brief information: all familiar mobile phones can transmit / receive data (information in digital form) in addition to voice - photos, music, video, text. In addition, the ability to transfer data allows you to use the version of programs for communication (SKYPE, ICQ), using a browser to view the pages of Internet resources.

The subscriber pays not for the time spent on the network, but for the amount of downloaded / transmitted information (traffic). The use of packet data does not interfere with voice communication - the line is not busy, you can talk and transmit / receive data in parallel.

Initially, data was transferred to operators using GPRS technology (transmission speed up to 171.2 kbps, real - within 30 kbps). These speeds are clearly not enough for comfortable work with data. In 2004, several US cellular operators began to use for data transmission new standard EDGE. What is EDGE? The standard in which it was three times higher than when using GPRS. This has significantly increased the attractiveness of their offerings in comparison with competitors.

EDGE gradually moved overseas and spread among European mobile operators. The question of what is EDGE is still relevant today. There is a simple explanation for this. Today, the EDGE network is successfully operating where much higher data transfer rates (3G networks) have not yet reached. Thus, EDGE is the “today” of our mobile communications.

Why is data transfer important? After all, mobile communication is intended for voice communication. At first glance, this is certainly true. But in business there is such a thing as "average income per subscriber." Subscribers already use voice communication. If, in addition to voice communication, we add mobile traffic with good speed and at a "pleasant price" to the package of services provided, this will significantly increase the amount of money that subscribers will spend on communication every month.

Due to the massive demand, which was successfully formed by the players of the telecommunications market, services based on GPRS / EDGE began to bring significant income and significantly increased the amount of money that the average subscriber spends on cellular communications. If we are still considering what EDGE is, then the potential of the mobile Internet has not yet been fully revealed, we have something to strive for.

An overview of the services provided by mobile operators today reveals a noticeable increase in the consumption of mobile traffic. Given the availability of relatively inexpensive unlimited internet and not very developed 3G coverage, it can be predicted that the EDGE standard will not be released very soon. Numerous "smart" gadgets and the trend of "mobility" among the population from 5 to 35 years old provide a steadily growing demand for mobile traffic.

In the West, work with fourth-generation networks is already in full swing, and the third generation has not yet taken root in our country. Normal stable operation and 3G coverage is still available only in megacities, and even then not in all. However, this is not a reason to lament about unfulfilled dreams and hopelessly lost prospects. The question of what is EDGE, we have safely considered. And everything else is still "very likely" - globalization and the search for new sales markets make us very attractive to the specialists. Specialists firmly believe that we will not be bypassed by the benefits of scientific and technological progress. It's just that it will happen a little later than the rest.

EDGE technology is the next step in the development of GSM networks. The purpose of the introduction of the new technology is to increase the speed of data transmission and more efficient use of the radio frequency spectrum. With the advent of EDGE in phase 2+ GSM networks, the existing GPRS and HSCSD parameters are significantly improved due to changes in signal transmission at the physical layer (modulation and coding) and new radio exchange algorithms for data transmission. The GPRS and HSCS D technologies themselves do not change and can work in parallel with EDG E. Along with the EDGE abbreviation, you can also find the term EGPRS (Enhanced GPRS - "improved" GPRS), denoting the use of the GPRS service with the new EDGE physical layer. Further, we will consider EDGE only in relation to GPRS, since HSCSD technology has not become widespread in Russia.

The theoretical limit for the radio data rate with EGPRS is 473.6 kbaud, while with GPRS it is only 160 kbaud. High speed values are achieved thanks to the new modulation method and the use of a modified radio signal transmission method that is resistant to errors. In addition, the changes affected the algorithms for adapting to the quality of the channel.

Based on the above, we can conclude that EDGE is an addition to GPRS and cannot exist separately. From a consumer point of view, GPRS enhances the capabilities of the GSM network, while EDGE improves the technical parameters of GPRS.

With regard to the GSM network infrastructure, EGPR S requires modifications to the base stations. At the same time, the already existing core of the GSM infrastructure is used, and the introduction of EDGE means only the installation of additional equipment (Fig. 1).

Rice. 1.

EDGE parameters

The table lists the main specifications GPRS and EDGE technologies.

Table 1.

As you can see from the table, EDGE can transmit three times more data than GPRS in the same time period. The difference between the speed in the radio channel (Radi o data rate) and the actual data rate of the user (User data rate) is explained by the fact that during transmission over the radio channel, an overhead data in the form of a packet header is added to the user data block. This often leads to confusion when determining the GPRS and EGPRS throughput, since there are different speed indicators in the publications. In connection with EDGE technology, the figure 384 kbps is more common: the International Telecommunications Union (ITU) defines given speed in accordance with the requirements of the IMT-2000 (International Mobile Telecommunications) standard, which assumes the use of eight 48 kbps time slots each.

New type of modulation

When transmitting data in GPRS mode, Gaussian keying is used with a minimum frequency shift GMSK - Gaussian Minimum Shift Keying (Fig. 2), which is a type of phase modulation. When a bit "0" or "1" is transmitted, the signal phase is incremented positively or negatively. Each transmitted symbol contains one bit of information, that is, each phase shift represents one bit. To achieve a higher data transfer rate in one time slot (in one time slot), it is necessary to change the modulation method.

Rice. 2.

EDGE was designed to use the same frequency grid, channel widths, channel coding techniques, and existing mechanisms and functions used by GPRS and HSCSD. For EDG E, eight-position 8PSK (8-Phase Shift Keying) phase modulation was chosen, which satisfies all these conditions. When it comes to interference between adjacent channels, 8PSK has the same quality parameters as GMSK. This allows you to integrate EDGE channels into your existing frequency plan and assign new EDGE channels in the same order as regular GSM channels.

8PSK is a linear modulation technique in which 3 bits of information correspond to one transmitted symbol. The symbol rate (or the number of symbols transmitted per unit of time) remains the same as in GMSK, but each symbol carries 3 information instead of 1 bit. Consequently, the data transfer rate is increased by 3 times. The phase distance between symbols in 8PSK is less than in GMSK, which increases the risk of a symbol recognition error by the receiver. With a good signal-to-noise ratio, this is not a problem. For successful operation in conditions of a poor radio channel, error correction codes should be used. Only with a very weak radio signal does GMSK modulation take precedence over 8PSK. In order to be able to work effectively at any signal-to-noise ratio, both types of modulation are used in EDGE coding schemes.

Coding schemes and packaging

Four coding schemes are defined for GPRS: CS1 – CS4. Each contains a different number of correction bits, optimizing each coding scheme for a specific quality of the radio link. EGPRS uses nine coding schemes, which are designated MCS1 through MSC9. The lower four circuits use GMSK modulation and are designed to operate at the worst S / N ratio. The MSC5-MSC9 schemes use 8PSK modulation. In fig. 3 shows the maximum data rates achievable using different coding schemes. The GPRS user can get a maximum data rate of 20 kbaud, while the EGPRS rate increases up to 59.2 kbaud as the quality of the radio link improves (closer to the base station).

Rice. 3.

Although CS1-CS4 and MSC 1-MSC4 use the same GMSK modulation, EGPRS radio packets have different header lengths and payloads. This allows you to change the coding scheme on the fly for packet retransmission. If a packet with a higher coding scheme (with a lower noise immunity) is received in error, then it can be resent using a lower coding scheme (with a higher noise immunity) to compensate for the degraded parameters of the radio link. Transmission with a different coding scheme (resegmentation) requires a change in the number of useful bits in the radio transmission. GPRS does not provide such a possibility, therefore the GPRS and EGPRS coding schemes have different efficiency.

In GPRS, repetition of a packet is possible only with the original coding scheme, even if this coding scheme has ceased to be optimal due to the deterioration of the quality of the radio link. Let's consider the example of the packet retransmission scheme (Fig. 4).

A. The GPRS terminal receives data from the base station. Based on the previous radio link quality report, the base station controller decides to send the next data block (numbers 1-4) with the CS3 coding scheme. During transmission, the state of the radio link deteriorated (signal-to-noise ratio decreased), as a result, packets 2 and 3 were received with an error. After transmitting a group of packets, the base station requests a new report - an assessment of the quality of the radio link.

B. The GPRS terminal transmits information about incorrectly delivered packets to the base station along with information about the quality of the radio link (in the confirmation report).

WITH. Considering the deterioration of the communication quality, the adaptation algorithm chooses a new, more noise-immune CS1 coding scheme for transmitting packets 5 and 6. However, due to the impossibility of resegmentation in GPRS, retransmission of packets 2 and 3 will occur with the old CS3 coding scheme, which significantly increases the risk of incorrect reception these packets by the GPRS terminal.

The GPRS adaptation algorithm requires very careful selection of the coding scheme to prevent retransmission of packets as much as possible. With resegmentation, EGPRS can use more effective method the choice of the coding scheme, since the probability of packet delivery during retransmission is much higher here.

Table 2. Group of coding schemes

Packet addressing

When a block of packets is transmitted via a radio channel, the packets inside the block are numbered - from 1 to 128. This an identification number included in the header of each packet. In this case, the number of packets in a block transmitted to a specific GPRS terminal should not exceed 64. A situation may arise when the number of the retransmitted packet coincides with the number of the new packet in the queue. In this case, you have to re-transmit the entire block. In EGPRS, the packet address space is increased to 2048, and the sliding window size is 1024 (the maximum number of packets in one block), which significantly reduces the likelihood of such collisions. Reducing retransmissions at the RLC (Radio Link Control) layer ultimately leads to an increase in throughput (Fig. 5).

Measuring the quality of the radio channel

The assessment of the quality of radio link communication in GPRS is carried out by measuring the received signal level, estimating the BER parameter (bit error rate - the relative number of incorrectly received bits), etc. plays a large role in the constant use of one coding scheme. With packet data switching, it is necessary to quickly monitor the quality of the radio link in order to quickly change the coding scheme depending on the state of the radio broadcast. The channel quality estimation procedure in GPRS can only be performed twice in a 240-ms period. It makes it difficult prompt selection correct coding scheme. In EGPRS, measurements are made at each reception by evaluating the bit error probability (BEP). Based on the data from each transmission, the BEP reflects the current signal-to-noise ratio and temporal dispersion of the signal. As a result of this approach, the estimation of the quality parameters of the transmission channel turns out to be quite accurate even over a short measured period. This determines the higher efficiency of the adaptation scheme compared to GPRS.

Radio link monitoring functions and increased redundancy

To ensure the maximum transmission rate under the conditions of the existing quality of the radio channel, the following mechanisms are used in EGPRS:

Adaptation to the quality of the channel. Based on measurements of the quality of the data transmission line (both in the direction mobile terminal and from it), the adaptation algorithm selects a new coding scheme for the next sequence of packets. The coding schemes are grouped into three families - A, B and C. The new coding scheme is selected from the same family to which the previous one belonged (Fig. 5).
Increased code redundancy. Incremental Redundancy is used for older coding schemes in cases where sending is used instead of analyzing radio link parameters and changing the coding scheme. additional information on subsequent transmissions. If errors occurred when receiving a packet, then redundant information may be sent in the next packet, which will help correct the previous incorrectly received bits. This procedure can be repeated until the information in the previously received packet is completely restored.

In Russia, the operators “ big three»Already provide EDGE service in several districts of Moscow and in a number of regions of the country. The introduction of EDGE is happening gradually, as the equipment of the base stations is updated. MegaFon plans to cover about 500 base stations with EDGE technology by the end of 2005. VimpelCom intends to fragmentarily introduce EDGE on the territory of Moscow within the Moscow Ring Road (in areas with increased GPRS traffic), and across Russia - in all regions by the end of 2006 - early 2007. MTS states that "the work is being carried out very intensively: EDGE coverage in the Moscow region is expanding almost daily."

Literature

EDGE. Introduction of high-speed data in GSM / GPRS networks (www.ericsson.com/products/white_papers_pdf/edge_wp_technical.pdf). / link lost /
Materials of the site "Mobile Forum" (http://mforum.ru/news/article/01-5533.htm). / link lost /

Chelyabinsk, after modernizing the equipment, it was possible to increase the data transfer rate four times. What does it give to ordinary subscribers, and what are real speeds mobile Internet, our correspondent understood.

Today, you can access the Internet not only from your home or work computer. Cellular telephone became the most accessible tool for accessing the global network... Alas, until recently, existing networks did not allow mobile operators to transfer data quickly. This was expressed in a very long loading of pages of portals and sites, and only a few risked downloading large files from the Internet [this could take several days]. What else can you say, except how "Brakes" and Glitches.

These "brakes" are technology GPRS[the so-called 2.5G networks are built on it], which at best allows data transmission at a speed of 171.2 Kbps. In real conditions, the channel width is reduced to 20-25 kbps... When this technology appeared almost ten years ago, this was not so critical. But now, as you understand, the speed data cannot be compared.

In order to increase the comfort of working with Internet resources, it was developed new technology- EDGE. EDGE [Enhanced Data rates for GSM Evolution] Is a digital technology for mobile communications that functions as an add-on over 2G and 2.5G networks. This format data transmission allows to develop speeds up to 474.6 kbps.

EDGE technology is available to all subscribers who have phones with EDGE support and are in the EDGE coverage area. The data transfer speed depends on the network congestion and its quality at the point of the subscriber's location and, as a rule, reaches an average 100 - 130 kbps[peak values at the level 200 kbps].

In the TELE2 Chelyabinsk network, EDGE technology compared to GPRS technology allows you to increase the data transfer rate, when viewing WAP pages from a mobile phone, using a cellular device as a modem to a computer and exchanging MMS messages.

The main application of EDGE is high-speed Internet access, organization of a mobile office, which is indispensable for business people. And such opportunities as picture exchange, photos, watching streaming video, Internet radio, fax, mail forwarding is no longer a dream, but a reality.

In order to check the work of EDGE in the TELE2 network in Chelyabinsk, we asked three subscribers of the operator to test mobile Internet services in different parts of the city.

Armed with laptops mobile phones and TELE2 SIM cards, our testers measured the data transfer speed, having driven through different districts of Chelyabinsk. As assistive devices were taken Nokia phones E51 and ReGet deluxe v. 5.2.0 and DU Meter. In order to exclude the possibility of caching in each case, different files were uploaded.

In general, according to the experience of using 128 Kbps anlim at home. shows good results. As a mobile option, it deserves close attention. It's really much faster than GPRS, - says Vyacheslav, one of our testers... - Sometimes errors occur during the transfer of information - not without them. They naturally affect speed.

We each had two points in the city. I got - Sinegorye [Vokzal] and an office building on Revolution Square 7. We took measurements at the height of the working day and therefore the results were very fair, - notes Alexander, second tester of MobiChel.Ru... - At first, the speed of EDGE shows quite standard results, but by the end of the download the speed reaches the maximum downloads.

Measuring point	File size, Mb	File upload time, min: s	Average baud rate kbps	Maximum speed data transmission kbps	Subjective assessment [on a five-point system]
Lenin Ave. 81, editorial office of "Mobile Chelyabinsk"	5,8	4:05	121,0	177,7	Good
Sinegorye [Station]	6,1	4:29	119,2	165,2	Good
pl. Revolution 7	4,9	3:27	125,4	201,0	Fine
TRK Gorki	7,6	8:01	111,9	169,0	Good
Victory Garden [ChTZ]	5,3	4:12	113,1	174,2	Good
Komsomolsky prospect / st. Voroshilov	5,5	4:16	117,0	178,2	Good
ave. Pobedy / st. Chicherina	6,5	7:02	103,4	154,6	Satisfactorily

In general, the quality of data transmission and speed directly depends on many factors... This is the number of subscribers who use communication services; distance from the base station; all kinds of obstacles [buildings and other structures] that interfere with the propagation of the radio signal. Do not forget that the time of access to the Internet plays an important role. For example, at night the speeds will be much higher than during the working day.

Currently, Internet access at higher speeds may be TELE2 subscribers in Chelyabinsk and Kopeysk... By the end of the year, high-speed EDGE Internet will appear in other cities of the region.

For TELE2 subscribers who use their own phone that supports EDGE, there is no need to reconfigure the device to access the Internet and exchange MMS messages. But if the mobile phone is not configured, then you can order automatic settings from the operator's website or call 679.

Technology EDGE does not require additional payment... Browsing WAP pages, downloading melodies, pictures and java games, using the phone as a modem to a computer, as well as exchanging MMS messages are charged in the same way as when using GPRS technology.

Moreover, TELE2 currently allows its customers to cut their mobile Internet costs in half! The cost of one megabyte in this case will be only 2.5 rubles around the clock... To do this, you need to activate the service " Mobile Internet with a 50% discount "by typing a simple USSD request *116*14*1#. Connection cost is 30 rubles. Subscription fee per month - 30 rubles.

According to the summary data of sales of the main Russian retailers, the share of phones with EDGE support in 2008 is about 65%. At the same time, it is predicted that by the end of 2009 this figure will be 75% ... Thus, faster Internet access is already available to most customers.

Thus, the Internet from TELE2 has become not only mobile, but also high-speed. This can be checked by all subscribers of the operator.

Articles and Life Hacks

Every Internet user knows what edge is in a phone. This option is intended to speed up data transmission in GSM networks, and it must be supported by the mobile operator you are using.

The quality of edge work is affected by the network congestion, the operator's signal level, and the amount of free basic network resources.

What is this technology for?

This option first appeared in 2004 in North America. The main purpose of edge is to provide high-speed Internet access to the user of a modern gadget.
Such a function is necessary for business people who need to quickly send information over the network.
Also, this option is needed by ordinary people who cannot imagine their life without the Internet and those who do not have stationary computer to access the worldwide network.
Edge has its advantages over gprs - higher speed and the ability to access the Internet from almost anywhere in the city.
GPRS has an unstable connection, and the data transfer rate rarely exceeds 56 Kbps, which is very slow by modern standards.

How edge works

At the time of the idea, edge was supposed to be just a gprs extension. But later this idea was abandoned. Due to the fact that edge uses 8-PSK, the Internet speed is twice as high as compared to gprs.
In fact, this speed is much lower than the declared almost 400 k / bit per second. It all depends on the settings and capabilities of the cellular operator. When transmitting information through the edge, timeslots are used.
For one stream, edge is capable of transmitting up to 48 Kbps, while the capabilities of gprs in this regard are only 9 Kbps. But this data transfer rate is only possible under ideal conditions.
In cases where there is a failure in the operator's network, then the user cannot access the Internet. Edge is gradually being squeezed out of the global market, as it is being replaced by 3G and 4G networks. Edge is categorized as 2G and 2.5G networks.

The first launch of Microsoft Edge leaves a lasting impression. Of such quick start you have not seen in any browser. It is clear that loaded with extensions, themes and plugins, Chrome and Firefox cannot show such agility, but it still looks very convincing.

The same can be said about the responsiveness of the interface. Opening new tabs and switching between them is just instant. But with the speed of opening pages, the situation is not so straightforward. As numerous comparisons show (,,), the surfing speed in the new browser is practically the same as in the competition. However, this can also be regarded as an achievement, isn't it?

2. Built-in Reading Mode and Reading List

Microsoft Edge is great for anyone who likes to read comfortably. It provides a special view mode, when activated, the page is cleared of all unnecessary and only text and illustrations remain on it. The page background and font size used in reading mode can be selected in the program settings.

In addition, you can save the pages you are interested in in a special reading list, the panel of which appears on the right after clicking the corresponding button on the toolbar. It looks a bit like a Pocket Reading List and contains links to the pages you want with titles and covers.

3. Security

Yes, remembering Microsoft Explorer, this is hard to believe. But, according to the assurances of the developers, they drew conclusions from past mistakes and took all measures to protect their browser from hacking. The built-in SmartScreen security screen checks all sites you open and can block potentially dangerous ones. In addition, all pages are opened in separate processes, each of which is isolated from the rest of the system and is executed in the so-called sandbox. So even if something happens to the browser, operating system and your data will remain safe.

4. Convenient interface

I don’t know about you, but I love the Microsoft Edge interface insanely. It has a minimalist design that fits perfectly into general form Windows 10. The toolbar contains only the most necessary buttons, and everything else is hidden in the panel that appears on the right. By the way, this panel can be fixed permanently, just like the sidebar works in Firefox, and more recently in Opera. Very handy, especially if developers eventually teach this panel to display not only bookmarks, downloads and reading list, but other content as well.

5. Edit mode

And a big fly in the ointment

Despite all these advantages, the new windows browser 10 also has a big drawback. It lacks support for extensions. Yes, the available functions are interesting, the speed is good, the interface is pleasant, but this is not enough! Only full support for extensions can make Microsoft Edge a real competitor. However, Microsoft understands this and promises to present the first extensions for Edge to the world in the fall. So it won't be long to wait.

Would you dare to ditch your favorite browser and switch to Microsoft Edge if it comes with extensions?