Hi, I am not sure whether this is the right place to ask question related to GSM network but anyway here goes my question. 

What software/ coding language is used in GSM network? During the manufacture of mobile handsets, surely some coding or maybe assembly language is used, so I liked to know what they use. I don't know a thing in this regard so my question might be little bit vague. If you know website where I can read about it let me know. Thanks in advance. 

laptop memory

There isn't a language specific to GSM devices. The low level code will be compiled to native machine code for whatever processor architecture the device uses (e.g. ARM). There is a precise specification covering all aspects of GSM to ensure interoperability. So really the answer is - it depends what you are trying to do and on what kinds of devices...

Peter