Difference between UMTS and GSM

1. Universal Mobile Telecommunications System (UMTS) :
UMTS stands for Universal Mobile Telecommunications System, developed based on 3GPP standards. Its network composed of three main parts UE (User Equipment), Radio Access Network (RAN) and Core Network. There are various technologies which fall under UMTS based on different releases from 3GPP community. It is also referred as 3G.

2. Global System for Mobile communication (GSM) :
GSM stands for Global System for Mobile communication. It is majorly used mobile communication system in the world. It uses time division multiple access i.e TDMA to send down the digitized and reduced data through a channel with two different streams of client data, each in its own particular time slot.

Difference between UMTS and GSM :

S.No.	UMTS	GSM
1.	UMTS is already 3G.	GSM is 2G and 2.5G.
2.	It is mainly CDMA-based.	It is typically based on TDMA .
3.	There channels are divided into logical, transport and physical based on where they are used along with their functions.	There channels are divided into traffic channel and control channel based on functionality of use in the system.
4.	Its frame duration is about 10ms,	Its frame duration is about 4.615ms,
5.	It is newer.	It is a rather old technology.
6.	It has various bands from Band-I to Band-VI, Each band specifies frequency and UARFCN.	It has various bands, the major among them are 850MHz, 900MHz, 1800MHz and 1900MHz.
7.	It has various documents specified by ETSI and 3GPP, 3GPP™TS 45-series.	It has various releases such as R99(WCDMA), R5 (HSDPA), R6(HSUPA) etc.
8.	The modulation efficiency is 1.0 b/s/Hz .	The modulation efficiency is 1.35 b/s/Hz.