EGSM (Extended GSM)

Introduction:

The Global System for Mobile communications (GSM) is a digital cellular communication system that was developed in the 1980s and widely used throughout the world today. GSM was designed to provide voice and data services to mobile devices, such as mobile phones and tablets. Over time, the system has evolved to provide faster data transfer rates, increased capacity, and improved security. One of the more significant developments in the GSM standard is the introduction of EGSM, or Extended GSM.

EGSM Overview:

Extended GSM, or EGSM, is a modification of the original GSM standard that increases the frequency range used for GSM transmissions. The EGSM frequency range extends the original GSM frequency range by adding 10 MHz of bandwidth to the existing 900 MHz band, and operates in the 900 MHz band. EGSM is also sometimes referred to as GSM 900 Phase 2+ or GSM 900 Enhanced.

The increased frequency range of EGSM provides several benefits, including increased capacity and better coverage in areas where the original GSM frequency range was not sufficient. EGSM is particularly useful in rural areas where there are fewer base stations, and in areas with dense foliage, which can reduce the strength of signals in the original GSM frequency range. The use of EGSM also reduces the cost of deploying GSM networks in areas with low population density.

EGSM Implementation:

EGSM is implemented through the use of additional frequency bands within the existing 900 MHz band. Specifically, EGSM uses the 880-915 MHz frequency range for uplink transmissions (from mobile devices to base stations) and the 925-960 MHz frequency range for downlink transmissions (from base stations to mobile devices). This represents an increase of 10 MHz over the original 900 MHz frequency range used by GSM.

EGSM uses a variety of techniques to provide better coverage and capacity. One of the most important of these techniques is power control. In GSM, power control is used to adjust the power of the mobile device's transmitter to ensure that the signal received by the base station is strong enough for reliable communication, but not so strong that it interferes with other signals. In EGSM, power control is used to increase the range of the signal by allowing the mobile device to transmit at higher power levels.

EGSM also uses a technique called frequency hopping to reduce interference between different transmissions. In frequency hopping, the frequency used for transmission is changed rapidly, in a predetermined pattern, to avoid interference from other signals on nearby frequencies. This technique is particularly useful in areas where there are many base stations, as it helps to reduce interference between adjacent cells.

EGSM Advantages:

EGSM provides several advantages over the original GSM standard. The most significant of these advantages is increased capacity. The additional 10 MHz of bandwidth provided by EGSM allows more mobile devices to connect to the network simultaneously, which reduces the likelihood of congestion and dropped calls. The use of EGSM also reduces the cost of deploying GSM networks in areas with low population density, as it allows a greater area to be covered with fewer base stations.

EGSM also provides better coverage than the original GSM standard. The increased frequency range of EGSM allows signals to penetrate buildings and foliage more easily, which improves coverage in areas where the original GSM frequency range was not sufficient. The use of power control and frequency hopping also helps to improve coverage by reducing interference between transmissions.

EGSM Disadvantages:

Despite its advantages, EGSM also has some disadvantages. One of the most significant of these disadvantages is that EGSM is not compatible with the original GSM standard. This means that mobile devices that are designed for GSM may not be able to connect to EGSM networks. This can be a problem in areas where both types of networks are available, as mobile devices may need to be manually switched between networks in order to maintain connectivity.

Another disadvantage of EGSM is that it requires additional equipment and infrastructure to be deployed. This can increase the cost of deploying and maintaining a network, which can be a barrier to adoption in some regions. Additionally, the use of EGSM can result in increased interference with other radio frequencies, which can negatively impact other wireless communication systems in the area.

Conclusion:

Extended GSM, or EGSM, is a modification of the original GSM standard that increases the frequency range used for GSM transmissions. EGSM provides several advantages over the original GSM standard, including increased capacity and better coverage in areas where the original frequency range was not sufficient. However, EGSM also has some disadvantages, such as incompatibility with the original GSM standard and increased cost of deployment. Overall, EGSM is an important development in the evolution of the GSM standard, and it has helped to improve the reliability and coverage of mobile communications networks in many regions of the world.