GSM stands for Global System for Mobile communications, this is an international standard. What does that mean? What is GSM on a phone? I will answer these questions and more in this blog post.
In the U.S. all cell phone service providers use either CDMA or GSM. However, in Europe and many other parts of the world, GSM is the only service available.
When the term GSM was originally coined it meant Groupe Spécial Mobile. This was a group which was formed by the Conference of European Posts and Telegraphs (CEPT) in 1982.
The group did research for quite a few years before the GSM services were available in 1991 for commercial use.
GSM was presented as a new digital system which uses TDMA technology which provided some advantages over the analog services that were previously used.
What Is TDMA?
TDMA is used for shared-medium, it is a channel access method. TDMA allows multiple users to share the same frequency channel.
This is accomplished by dividing the signal into different time slots. The users transmit one after the other in rapid succession, each user using their own time slot.
This makes it possible for multiple stations to share the same transmission medium.
TDMA is a narrow band which is 30 KHz wide and 6.7 milliseconds long which is split into three time slots.
A narrow band refers to a channel, every conversation gets the radio for one-third of the time.
It’s possible to do this because voice data which has been converted to digital is compressed, therefore, it uses much less transmission space.
As a result of this, TDMA has about three times the capacity of an analog system which uses the same number of channels.
The access method used my GSM and the Telecommunications Industry Association for Interim Standard 54 (IS-54) and the Interim Standard 136 (IS-136) is TDMA.
GSM and IS-136 are two completely different operating systems which work on the same processor.
Some of the useful features offered by the GSM systems are:
- Caller ID
- Data networking
- Encrypting phone calls to make them more secure
- Short Message Service (SMS)
- Call forwarding
- Call waiting
- Multi-party conferencing
- Group III facsimile services
GSM functions on the 1900 MHz or 1.9 GHz band in the United States and the 900 MHz band in Europe and Asia.
GSM is also used in the signalling for the call set-up and mobility management for the Integrated Digital Enhanced Network (iDEN).
This is a popular system which was originally introduced by Motorola and used by Nextel.
Now you have a better understanding of what is GSM on a phone.
GSM has come a long way since it was invented in 1982 and the GSM network will continue to thrive as long as the cell phone industry is thriving.