Universal Mobile Telecommunications System (UMTS)
Definition - What does Universal Mobile Telecommunications System (UMTS) mean?
An umbrella term that encompasses the third generation (3G) radio technologies developed by the 3GPP (3rd Generation Partnership Project), a collaborative project designed to produce Technical Specifications and Technical Reports for a 3G mobile system based on evolved GSM core networks as well as the radio access technologies associated with them. The most common variant of UMTS employs the W-CDMA air interface. As a result, the two terms are commonly interchanged.
Techopedia explains Universal Mobile Telecommunications System (UMTS)
The Universal Mobile Telecommunications System represents a complete system. That means, it includes cell phones (and other mobile equipment), the radio infrastructure needed to provide call and data session services, the core network equipment for transporting user calls and data, the billing systems, and the security systems, among others.
Because UMTS has deep GSM roots, it is sometimes called 3GSM. However, as the name W-CDMA implies, it also makes extensive use of CDMA technology.
Upgraded UMTS networks around the globe are able to provide fast download speeds of up to 14 Mbps via the HSDPA (High-Speed Downlink Packet Access) protocol. Faster uplink speeds of up to 5.7 Mbps are currently underway via the HSUPA (High-Speed Uplink Packet Access) protocol. Both HSDPA and HSUPA are part of a larger family of protocols known as High Speed Packet Access (HSPA).
Because UMTS is built on GSM networks, it enjoys the same global roaming capabilities. Practically all UMTS phones are capable of switching to GSM mode. That means, if you’re using a UMTS device and happen to wander away from a UMTS network and into a GSM network, you can still avail of cellular services using the same phone (provided of course the necessary roaming agreements are in place).
Like their GSM predecessors, UMTS phones also come with an upgraded SIM (Subscriber Identity Module) known as the USIM (Universal SIM). UTMS phones can work with either SIMs or USIMs.
With the wireless industry now moving from 3G to 4G, UMTS serves as the basis of the 3GPP’s new set of radio technologies, known as Long Term Evolution (LTE).
Networks upgrading from GSM to the Universal Mobile Telecommunications System are able to reuse a number of network elements, including: the Home Location Register, Visitor Location Register, Mobile Switching Center, and the Authentication Center, to name some. However, a new Base Station Controller and Base Transceiver Station is required.
In most cases, 3G and 2G networks will be made to operate side by side.