World Informatics

Sep 22, 2010

Encoding Technique EDGE

Encoding Technique EDGE

EDGE 9 types of encoding techniques, the MCS (Modulation Coding Scheme) 1 up to MCS9. While GPRS uses four pieces of encoding technique, ie CS (Coding Scheme) 1 up to SC4. The first four encoding techniques on EDGE, MCS1 until MCS4, using GMSK modulation, the same as that used in GPRS. While five other coding techniques, MCS5 until MCS9, using 8PSK modulation.

Both the GPRS or EDGE, levels higher coding schemes offering higher data speeds too but besides that, the higher the level of encoding scheme, then the lower the resistance to errors. It means that the higher speed packet data, the easier the data packets that have errors in delivery. This is because, the higher level encoding scheme, then the level of mechanisms "error correction" used the lower.

Although MCS1 until MCS4 on EGDE both use GMSK modulation, such as CS1 to CS4 on GPRS, but both have different speeds. This is because the use of the headers are different. In EDGE, the data packet contains a header that allows data packets resegmentasi. That is, if a data packet is sent by using a high-level coding scheme (higher speed, less error correction) and data were not well received at the receiver side.

After a retransmission request (retransmission) packet of data received, at the next delivery, the encoding scheme used can be changed and adapted to conditions of the radio interface. That is, on the next delivery, the data packet will be sent by using a lower coding scheme, which had an error correction mechanism better. Hopefully, in this second delivery data can be well received in the receiver side.

In contrast to the GPRS, resegmentasi packet data can not be done. Therefore, when a data packet has been sent using a particular encoding scheme. So although the data is received either on the receiver side, when the next delivery, the data will still be sent by using the same encoding scheme. Consequently, the possibility that the data packet is received at the receiver side is still as large as when the first shipment. Therefore, it can achieve a balance between speed and quality transfer of data transferred.

Source : http://id.wikipedia.org/wiki/Enhanced_Data_Rates_for_GSM_Evolution#Teknik_Pengkodean_Pada_EDGE

In the EDGE modulation

In the EDGE modulation

To obtain higher transfer speeds than GPRS uses GMSK modulation (Minimum Shift Keying gausian), EDGE uses a different modulation technique with GPRS is 8PSK (8-Phase Shif Keying). Figure below shows the visualization of GMSK modulation on GPRS and EDGE are described 8PSSK Pasa on a diagram of I / Q, where I is the real axis and Q is the imaginary axis.

By using 8PSK modulation, a symbol is encoded using three bits, while in GMSK a symbol is encoded with one bit. Because GMSK and 8PSK symbols have the same level, that is equal to 270 ksimbol / s, then the overall level of 8PSK modulation will be three times larger than GMSK, amounting to 810 kb / s.

Based on the explanation above, the distance between the symbols on the 8PSK is shorter than the distance between the symbols on the GMSK, because in ad 8 8PSK symbol in GMSK sedengkan there are only two symbols. Shorter the distance between the symbol lead to greater levels of signals between one symbol to another symbol is more difficult to distinguish. So that the risk of error is greater.

On the condition of the radio signal is good enough, the difference in the distances between symbols is not very influential on the quality of the data sent. At the time of the radio signal conditions are bad, then the addition of extra bits needed to be used as a correction of errors, so that any data received could be improved. So that the quality of data on EDGE is not inferior to the quality of data on GPRS using MPSK. Besides, the EDGE is also used MPSK modulation used in CS1 to CS4 -, and also in EDGE have a process of "adjustment package" which can change the type of CS used in case of errors in the data being transmitted.

Source : http://id.wikipedia.org/wiki/Enhanced_Data_Rates_for_GSM_Evolution#Modulasi_Pada_EDGE

EDGE Speed Process

EDGE Speed Process

EDGE is a way to increase data speeds on GSM radio link. By using the technique of modulation and coding schemes that are different from the previous GPRS system, and by doing the settings in the radio link protocol, EDGE offers a capacity that is significantly greater than that possessed by the GPRS system. So generally there are three aspects of new techniques if we compare to EDGE to GPRS, which is

* Modulation Technique
* Coding Techniques
* Radio Access Network (RAN)

Source : http://id.wikipedia.org/wiki/Enhanced_Data_Rates_for_GSM_Evolution#Proses_Kecepatan_EDGE

Implementation of EDGE

Implementation of EDGE

As the name suggests, EDGE (Enhanced Data rates for GSM Evolution), is a technology developed with the basic technology for GSM and GPRS. An EDGE system using devices developed with the remains found on GSM / GPRS network. So can not EDGE alone. A GPRS system is comprised of SGSN (Serving GPRS Support Node) and the GGSN (Gateway GPRS Support Node), which is a network corenya, which added to a previous GSM network. While on the radio, a GPRS network requires the addition of PCU in the previous GSM network radio devices. The figure below shows the general diagram of the GPRS network.

EDGE implementation in the existing GPRS network requires only additions to the radio access side only. While the core network side, EDGE uses the same tools and protocols to those used in previous GPRS networks. GPRS and EDGE network differences found only in akssnya radio side only, while the core network side, EDGE and GPRS using the same tools and protocols. A GPRS network could be upgraded into a network with EDGE system by simply adding an EDGE Transceivier Unit (TRU) on the radio side of the access.

Source : http://id.wikipedia.org/wiki/Enhanced_Data_Rates_for_GSM_Evolution#Implementasi_EDGE

Capacity and Capability EDGE Mobile Technology The Third Generation (3G)

Capacity and Capability EDGE Mobile Technology The Third Generation (3G)

As mentioned in the previous points, EDGE has the data transfer, for example, could EDGE technology is three times faster than GPRS technology. That is, if the cellular subscriber wants to download MMS messages using GPRS technology takes tens of seconds, but with EDGE technology, it only takes a few seconds.

Another advantage, if the GPRS technology having data transfer capability up to 114 Kbps, EDGE technology capable of supporting data, multimedia services up to 384 Kbps. EDGE is a new designation for the GSM 384. This technology is called GSM 384, because it has a data transmission capability up to 384 Kbps.

According to the World GSM Association, EDGE and even can reach speeds up to 473.8 kbps. With EDGE, operators can provide mobile data communications service with higher speeds than GPRS, which is only capable of GPRS data transmission speeds of about 25 Kbps. So also when compared to other platforms, the ability to reach 3-4 times the speed of EDGE access telephone lines (usually around 30-40 kbps) and almost two times the speed of CDMA 2000 1x, which is only about 70-80 kbps. About the services provided this technology, namely third-generation service applications namely high quality streaming audio, streaming video, online games, high speed downloading.

Source : http://id.wikipedia.org/wiki/Enhanced_Data_Rates_for_GSM_Evolution#Kapasitas_dan_Kapabilitas_EDGE_Sebagai_Teknologi_Mobile_Generasi_Ketiga_.283G.29

EDGE Capacity For Advanced Technology Data Transfer Rate

EDGE Capacity For Advanced Technology Data Transfer Rate

GPRS offers data speeds of 115 kbps, and can theoretically reach 160 kbps. While at EDGE data speeds sbesar 384 kbps, and in theory can achieve 473.6 kilobits per second. EDGE speeds generally three times higher than GPRS. This is possible because the techniques used in EDGE modulation (EDGE uses 8PSK, GPRS uses GMSK) and different methods of fault tolerance with GPRS, and also an improved link adaptation mechanisms. EDGE also uses a different coding scheme with GPRS. In nine kinds EDGE coding scheme, whereas in only four GPRS coding scheme.

Source : http://id.wikipedia.org/wiki/Enhanced_Data_Rates_for_GSM_Evolution#Kapasitas_EDGE_Sebagai_Teknologi_Data_Transfer_Tingkat_Advance

Enhanced Data Rates for GSM Evolution or EDGE

Enhanced Data Rates for GSM Evolution or EDGE

EDGE or Enhanced Data rates for the GSM Evolution is a technological evolution of the GSM and IS-136. Goal of developing this new technology is to increase the speed of data transmission, spectral efficiency, and allows the use of new applications and increase capacity.

The application of EDGE in GSM phase 2 + such as GPRS and HSCSD done by adding a new physical layer at the side of the Radio Access Network (RAN). So no berubahan on the side of the core network such as MSC, SGSN, or GGSN

Source : http://id.wikipedia.org/wiki/Enhanced_Data_Rates_for_GSM_Evolution

W-CDMA

Wideband Code-Division Multiple Access or Wideband-CDMA usually written or W-CDMA, is third generation technology (3G) to GSM, also called UMTS (Universal Mobile Telecommunication System). This technology is not compatible with CDMA2000 or often known as CDMA only.

WCDMA speed may reach 384 kbps and the future will rise to probably around 10Mbps.

This technology uses the AMR-Wideband (Adaptive Multi-rate) for the codification of sound (voice codec) so that the sound quality got better than the previous generation.

Source : http://id.wikipedia.org/wiki/W-CDMA

EV-DO , Background , How It Works ,

EV-DO

EVDO, is also known as EV-DO, 1xEV-DO 1xEvDO and is a standard in high-speed wireless broadband. EVDO stands for "Evolution, Data-only" or "Evolution, Data Optimized". The term officially issued by the Telecommunication Industry Association of CDMA2000, a high-speed data interface to the air medium. EVDO one of two main kinds of wireless standard 3rd generation or 3G. As for other standards are W-CDMA.

Background

3G designs to increase speed data and voice network using the existing cellular phone. Where, the main obstacle to implementing high-speed wireless networks is the lack of bandwidth, or range of frequencies that can be used. With so many radio frequencies that can be reduced / streamlined on the FM waves, it is not too much data that it can memnfaatkan bandwidt. EVDO which developed the technology developed by Qualcomm could solve this problem.

How It Works

CDMA coded division multiple access, using a mathematical method for multiple wireless devices can be spent for sending data simultaneously on the same frequency. Each device, such as cell phones, are marked with a unique mathematical. Unique sign was applied to the original signal and sent as a signal modified. Recipients are also applying mathematical inverse sign of the signal to send to get the original signal.

Wireless networking was once used a barrier between sender and receiver, like most traditional phone. EVDO, as his successor to adopt a similar approach to the Internet. IP, Internet Protocol, breaking the data on the small fraction which was then called packets. Each packet is sent independently of the other packages. Of course this will save bandwidth used by other devices allow; when no phone conversations are also not sure there's a package that passed because there are no packets sent. or when a web site is accessed, there will be no bandwidth is used to start sending the web site pages.

In theory the EVDO capable of passing 2.4 megabits per second. Of course this is faster than DSL and cable broadband available. In a video conference in America, which is used by someone who resides in a vehicle at a speed of 60 miles per hour (90km/jam), while in another demonstration of a phone from a bullet train to start moving more than 150 miles per hour (240 km / hours).
Advantages of CDMA EVDO than usual, certainly more save frequency spectrum from the regulator and be very expensive indeed, lower the cost of developing and utilizing the new network. in united EVDO used by Verizon and Sprint, in Korea is also used. As this article EVDO made little impact on the European market and most of Asia because the region has been chose 3G as their choice. Similarly in Indonesia, however there are several operators who use the EVDO technology.

Source : http://id.wikipedia.org/wiki/EV-DO

GSM Technology Excellence as Second Generation (2G)

GSM Technology Excellence as Second Generation (2G)

GSM, a digital mobile telecommunications system has the advantage that far more than the analog systems, among them:

* The capacity of larger systems, because it uses digital technology in which usage of a channel not only for just one user. So when the user does not transmit information, the channel can be used by other users.
* Its as an international standard enables international roaming
* With digital technology, not only to deliver voice, but allows other services such as texts, images and video.
* Security system better
* The sound quality is more clear and sensitive.
* Mobile (can be taken anywhere)

However, the benefits of a diverse GSM proper course makes it the largest mobile telecommunications system users worldwide.

Source : http://id.wikipedia.org/wiki/GSM#Keunggulan_GSM_sebagai_Teknologi_Generasi_Kedua_.282G.29

GSM network architecture

GSM network architecture

Overall, the network element in the architecture of a GSM network can be divided into:

1. The Mobile Station (MS)
2. Base Station Sub-system (BSS)
3. Network Sub-system (NSS),
4. Operation and Support System (OSS)

Taken together, the entire network element above would establish a PLMN (Public Land Mobile Network).

MS Mobile Station or a device used by subscribers for talks. Consisting of:

* Mobile Equipment (ME) or a handset, a GSM device which is on the users or customers that serves as a terminal transceiver (transmitter and receiver) to communicate with other GSM devices.
* Subscriber Identity Module (SIM) or the SIM Card, a card that contains all customer information and some information services. ME will not be used without a SIM inside it, except for emergency calls. Data stored in the SIM in general, are:

1. IMMSI (International Mobile Subscriber Identity), is the numbering of the customer.
2. MSISDN (Mobile Subscriber ISDN), the number being the number of customer calls.

Or BSS Base Station System, consisting of:

* Base Transceiver Station BTS, GSM devices that are directly related to MS and functions as sending and receiving signals.
* BSC Base Station Controller, the device that controls base stations BTS working beneath it, and as a liaison BTS and MSC

Network Sub System or NSS, consisting of:

* Mobile Switching Center or MSC, is a central element network in a GSM network. MSC as the core of mobile networks, which serve to interconnect MSC talks relationships, both between cellular and wired networks PSTN, or with a data network.
* Home Location Register or HLR, which serves as a database to store all data and information about customers that is stored permanently.
* Visitor Location Register or VLR, which serves to store data and customer information.
* Authentication Center or AUC, which is required to store all the data needed to examine keabsahaan customers. So the talks are not legitimate customers is inevitable.
* Registration or EIR Equipment Identity, which includes customer data.

Operation and Support System or OSS, is a sub system of the GSM network that serves as a central control, including fault management, configuration management, performance management, and inventory management.

Source : http://id.wikipedia.org/wiki/GSM#Keunggulan_GSM_sebagai_Teknologi_Generasi_Kedua_.282G.29

GSM Technical Specification

GSM Technical Specification

In Europe, GSM was originally designed to operate at a frequency of 900 Mhz. At this frequency, the frequency of its use uplinks 890-915 MHz frequency, while the frequency of 935-960 MHz frequency downlinksnya. Bandwidth used is 25 MHz (915-890 = 960-935 = 25 MHz), and width of the canal amounted to 200 Khz. Of the two, then got 125 channels, in which 124 channels are used for voice and one channel for the signal. In its development, 124 of the channel increasingly inadequate in meeting the needs caused by rapidly growing number of users. To meet the needs of more channels, then the GSM regulators in Europe attempt to use additional frequency bands for GSM at 1800 MHz frequency range with frequency as a frequency of 1710-1785 MHz 1805-1880 MHz frequency uplinks and downlinks as frequency. With the new GSM frequency bands was then known as GSM 1800, which provides a bandwidth of 75 MHz (1880-1805 = 1785-1710 = 75 Mhz). With the wide canal that remains the same ie 200 Khz same, when the GSM at 900 Mhz frequency, then the GSM will be available in 1800 as many as 375 canals. In Europe, the GSM standards and is also used for railway communication, which became known as GSM-R.

Source : http://id.wikipedia.org/wiki/GSM#Spesifikasi_teknis_GSM