Data Speed ​​Improvement for GSM Evolution ( EDGE ) (also known as Enhanced GPRS ( EGPRS ), or IMT-SC , or Data Speed ​​Enhancement for Global Evolution ) is a digital cell phone technology that enables increased data transmission rates as backward extensions GSM-compatible. EDGE is considered a pre-3G radio technology and is part of the ITU 3G definition. EDGE is deployed on GSM networks starting in 2003 - originally by Cingular (now AT & amp; T) in the United States.
EDGE is also standardized by 3GPP as part of the GSM family. The variant, called Compact-EDGE, was developed for use in the AMPS Digital network spectrum section.
Through the introduction of advanced coding and data delivery methods, EDGE delivers higher bit rates per radio channel, resulting in increased capacity and threefold performance compared to ordinary GSM/GPRS connections.
EDGE can be used for any packet switched application, such as an Internet connection.
Evolved EDGE continues in Release 7 of the 3GPP standard which provides more than twice as much latency and performance overhaul. to complete High Speed ​​Access (HSPA) Access. Peak bit-rate up to 1 Mbit/s and typical bit-rate 400 kbit/s can be expected.
Video Enhanced Data Rates for GSM Evolution
Technology
EDGE/EGPRS is implemented as an improved bolt for the GSM/GPRS 2.5G network, making it easier for existing GSM operators to upgrade it. EDGE is a superset for GPRS and can work on any network with GPRS placed on it, as long as the operator implements the necessary improvements. EDGE does not require any hardware or software changes to be made on the GSM core network. The EDGE-compatible transceiver unit must be installed and the base station subsystem needs to be upgraded to support EDGE. If the carrier already has this in place, which often happens today, the network can be upgraded to EDGE by enabling optional software features. EDGE is now supported by all major chip vendors for GSM and WCDMA/HSPA.
Transmission techniques
In addition to Gaussian minimum-shift keying (GMSK), EDGE uses higher PSK/8 phase shift keying (8PSK) for five of the nine modulation schemes and encodings. EDGE generates a 3-bit word for each change in the carrier phase. This is effectively three times the level of gross data offered by GSM. EDGE, like GPRS, uses a rate adjustment algorithm that adjusts the modulation and coding scheme (MCS) according to the quality of the radio channel, and thus bit rate and data transmission toughness. It introduces a new technology not found in GPRS, Incremental Redundancy, which, instead of transmitting disrupted packets, sends more redundancy information to be combined on the receiver. This increases the probability of the correct decoding.
EDGE can carry bandwidths of up to 236 kbit/s (with end-to-end latency of less than 150 ms) for 4 timeslots (theoretical maximum is 473.6 kbit/s for 8 timeslots) in packet mode. This means it can handle four times as much traffic as a standard GPRS. EDGE complies with the requirements of the International Telecommunication Union for 3G networks, and has been accepted by ITU as part of the 3G IMT-2000 family of standards. It also enhances the data set mode called HSCSD, increasing the data rate of this service.
EDGE modulation and encoding scheme (MCS)
The channel coding process in GPRS and EGPRS/EDGE consists of two steps: first, the cyclic code is used to add parity bits, also called Check Blocks, followed by encoding with convolutional codes that may be punctured. In GPRS, the CS-1 Encoding Scheme to CS-4 determines the number of parity bits generated by the cyclic code and the puncture rate of the convolutional code. In the CS-1 GPRS Encoding Scheme via CS-3, the convolutional code is the 1/2 level, ie each input bit is converted into two encoded bits. In the CS-2 and CS-3 Encoding Schemes, the output of the convolutional code is perforated to achieve the desired code level. In the GPRS CS-4 Coding Scheme, no convolutional coding is applied.
In EGPRS/EDGE, Modulation and Coding Scheme MCS-1 to MCS-9 replaces Coding scheme of GPRS, and additionally determines which modulation scheme is used, GMSK or 8PSK. MCS-1 through MCS-4 using GMSK and has similar performance (but not same) with GPRS, while MCS-5 through MCS-9 uses 8PSK. In all EGPRS Modulation and Code Schemes, 1/3 level convolution codes are used, and piercing is used to achieve the desired code level. Unlike GPRS, Radio Link Control (RLC) headers and Media Access Control (MAC) and charge data are encoded separately in EGPRS. Header is encoded with more powerful than data.
Maps Enhanced Data Rates for GSM Evolution
HIGH swelling
Evolved EDGE , also called EDGE Evolution, is a bolt extension on GSM mobile phone standards, which improves EDGE in several ways. The latency is reduced by lowering the Transmission Time Interval by half (from 20 ms to 10 ms). Bit rate is increased up to 1 Mbit/s peak bandwidth and latency to 80 ms using dual carrier, higher symbol rate and higher order modulation (32QAM and 16QAM instead of 8PSK), and turbo code to correct error correction. This results in real world downlink speeds up to 600kbit/s. Furthermore signal quality is improved using a dual antenna that increases the average bit-rate and spectral efficiency.
The main purpose of increasing EDGE throughput is that many operators want to improve existing infrastructure rather than investing in new network infrastructure. Mobile operators have invested billions of GSM networks, many of which are capable of supporting EDGE data rates of up to 236.8 kbit/s. With upgrades of new software and devices compatible with Evolved EDGE (such as EDGE Evolved phones) for users, this data rate can be increased up to a speed of close to 1 Mbit/s (ie 98.6 kbit/s per timeslot for 32QAM). Many service providers may not be investing in an entirely new technology like 3G networks.
A lot of research and development takes place around the world for this new technology. Successful trials by Nokia Siemens and "one of China's leading operators" have been achieved in the environment. With introductions to more advanced wireless technologies such as UMTS and LTE, which also focus on the network coverage layer at low frequencies and the upcoming phase and closure of 2G cellular networks, it is highly unlikely that Evolved EDGE will ever see any deployment on the live network. Up to now (as of 2016) no commercial networks support the EDGE Evolved standard (3GPP Rel-7).
Technology
Reduce Latency
With Evolved EDGE there are three main features designed to reduce latency through the air interface.
In EDGE, a single RLC data block (ranging from 23 to 148 bytes of data) is sent through four frames, using a single time slot. On average, this takes 20 ms for one-way transmission. Under the RTTI scheme, a data block is transmitted to two frames in two timeslots, reducing the air interface's latency to 10 ms.
Additionally, Latency Reduction also implies support of Piggy-backed ACK/NACK (PAN), where unaccepted block bitmaps are included in normal data blocks. Using the PAN field, the receiver can report the missing data block immediately, rather than waiting to send a special PAN message.
The final increase is a non-persistent RLC mode. With EDGE, the RLC interface can operate in either a recognized mode, or an unrecognized mode. In unrecognized mode, there is no retransmission of the missing data blocks, so a single corrupt block will cause the entire upper layer IP packet to be lost. With non-persistent mode, RLC data blocks can be retransmitted if less than a certain age. After this time is over, it is considered lost, and the next data block can be forwarded to the top layer.
Downlink Dual Carrier
With Downlink Dual Carrier, handhelds can receive on two different frequency channels at the same time, doubling downlink throughput. In addition, if the second receiver is present then the handheld may receive on additional timeslot in single-carrier mode, as it may overlap one receiver tuning with another task.
High Modulation Schemes
Both uplink and downlink throughput are enhanced by using 16 or 32 QAM (Quadrature Amplitude Modulation), along with turbo codes and higher symbol rates.
Network
The Global Mobile Suppliers Association (GSA) states that, by May 2013, there are 604 GSM/EDGE networks in 213 countries, out of a total of 606 mobile network operator commitments in 213 countries.
See also
- Broadband Internet Access
- CDMA2000
- Evolution-Data Optimized
- List of device bandwidths
- Mobile broadband
- Spectral efficiency comparison table
- UMTS
- WiFi
References
External links
- Global Mobile Supplier Association
- Evolved EDGE as an alternative to 3G
- Technical document by the American 3G association
- An opinion on EDGE developed by Martin Sauter
- EDGE Evolution Report by the Visant Strategy
- Feasibility study to evolve GSM/EDGE Radio Access Network by 3GPP
Source of the article : Wikipedia
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