There are several different types of 3G wireless technologies that are defined and planned to be up and working today. There are also several that are on their way. These are successors of course, to the previous 2G technologies that dominated the airwaves.
CDMA2000 is the successor to IS-95 systems. CDMA2000 provides a definition for two different options for 3G technologies. IT Differs in the amount of the frequency spectrum that is used. The Spreading Rate (SR1) operates in the 1.25 MHz band and is known as a 1x system. Another proposal exists also which is referred to as 1xEV-DO. The 1xEV-DO (1x Evolution for Data Optimized) solution is a data-only solution that enables a bandwidth of 2Mbps without any mechanism for voice. This is the type of data rate that we are all familiar with, the 3G 2Mbps speed of data connection.
The Universal Mobile Telecommunications System (UMTS)
The Universal Mobile Telecommunications System (UMTS) is a successor to GSM/GPRS systems. There are also two options for the UMTS networks. The Frequency Division Duplex (FDD) option uses spectrum bands which are paired together. For example, two different 5 MHz bands are used for uplink and downlink. The Time Division Duplex (TDD) option uses an unpaired band. In other words, the same 5 MHz band is shared between uplink and downlink for TDD.
Universal Wireless Consortium for IS-136 systems
The UWC-136 (Universal Wireless Consortium for IS-136 systems) was originally considered to be the evolution for IS-136 systems. However, the IS-136 system operators eventually decided to follow the path of CDMA2000 or UMTS.
Why did we need 3G Technology?
Back in the late 1990’s, when most of the readers out there were still playing in the sandbox, the International Telecommunication Union (ITU) set the requirements for the next generation of wireless networks (that is why they are called Third Generation (3G)). One of the many many requirements is to reach peak data rates of at least 2 Mbps. This is more relvant to the Downlink since the majority of traffic comes from the server to the client in the Internet World.
To meet this new high speed requirement, the 2nd generation wireless networks came up with several different evolutions before eventually being replaced. The GSM evolution includes GPRS and EDGE, which provide packet data services and represent intermediate solutions until a UMTS Release 99 System is deployed. The 1xEV-DO is one possible evolution path from 1xRTT, and HSDPA is a Release 5 feature of UMTS.
So how did UMTS Evolve?
UMTS is the network of choice these days. Yes, UMTS is 3G…If you haven’t caught that yet. For those nerds out there that are curious, the evolution of UMTS has progressed over the years in the following fashion:
UMTS Release 99
- 2 Mbps theoretical peak packet data rates
- 384 kbps (practical)
UMTS Release 5
- HSDPA (14 Mbps downlink theoretical)
- IMS (IP Multimedia Subsystem for multimedia)
- UP UTRAN (for scalability and lower cost)
UMTS Release 6
- HSUPA (up to 5.76 Mbps uplink)
- MBMS (Multimedia Broadcast Multicast Service)
UMTS Release 7
- Multiple Input Multiple Output (MIMO) Antenna Systems