UMTS
Universal Mobile Telecommunications Systems (UMTS) is a third-generation technology being developed into a 4G technology. It is standardized by the 3GPP and is the European answer to the requirements for 3G cellular radio systems.
For effective, efficient communications, standardization is critical, and nowhere is this more evident than in the areas of mobile computing and cellular telephony.
If you need data access or e-mail through your cell phone, you are likely to be using one of two different technologies. In the US the main approach for voice communication is called Code Division Multiple Access (CDMA), and it is the basis for the major network services offered by Verizon Wireless and Sprint Nextel Corp., among others.
In Europe and most of the rest of the world, however, a very different technology called global System for Mobile Communication has dominated the market. GSM uses a Time Division Multiple Access approach to frame structure. GSM service is available in the US primarily through T-Mobile USA Inc., and Cingular Wireless LLC. These carriers maintain GSM networks that are distinct from their other digital networks. Both CDMA and GSM are 2G technologies, and they have co-existed for several years. Each technology has its supporters. CDMA phones are engineered specifically for an individual carrier, whereas GSM phones make use of a removable memory card call the Subscriber Identity Module (SIM). Physically smaller than a secure digital flash memory card, a SIM card contains all the key information required to activate a phone, including the user’s telephone number, personal identification number, address book and encoded network identification details. A user can easily move a SIM from one phone to another.
Though GSM phones are interoperable with one another, different countries use different parts of the frequency spectrum, so “world phones” typically must be capable of using several frequencies.
Today, the fastest-growing use of cellular network is for the transmission of all kinds of data and rich media, including Web sites, video, music, images, and maps and driving directions. The older 2G network simply couldn’t handle the volume of traffic, and they couldn’t offer the speed needed for transmitting large files. The answer was to make the services faster and build out the networks to deal with more traffic.
Here, too, the CDMA and GSM paths continued their separate but parallel development. CDMA brought us CDMA 2000 and 1xRTT networks. The most recent developments are 1x Evolution Data Optimized, or EV-DO, and 1x Evolution Data/Voice, or EV-DV.
Similarly, GSM begat General Packet Radio Service, or GPRS, which begat enhanced data rates for GSM evolution, or EDGE. EDGE was developed to enable the transmission of large amounts of data at a high speed, 384Kbit/sec. The latest generation is called Wideband Code Division Multiple Access (WCDMA).
And this finally brings us to Universal Mobile Telecommunication System. The International Telecommunication Union (ITU), a specialized agency for the United Nations, has attempted to coordinate these competing technologies to improve throughput and increase interoperability. The International Mobile Telecommunications 2000 standard is a 3G digital communications specification from the ITU. And the European implementation of IMT-2000 is UMTS, which is based on WCDMA. Previous cellular telephone data systems were mostly circuit-switched, requiring a dedicated connection. WCDMA is packet-switched, using Internet Protocol. The first commercial WCDMA network was launched in Japan in 2001.
Technical Details
UMTS has been specified as an integrated application for mobile voice and data systems with wide-area coverage. Using globally harmonized spectrum in paired and unpaired bands, early implementations of UMTS offer theoretical bit rates of up 384Kbit/sec. In situations where the mobile device is actually moving. The current goal is to achieve 2Mbit/sec when both ends of the connection are stationary.
UMTS operates on radio frequencies identified by the ITU IMT-2000 specification document and licensed to operator, using a 5 MHz wide channel that simplifies deployment for network providers that have been granted large, contiguous blocks of spectrum. Most UMTS systems use frequencies between 1885 and 2025 MHz.
UMTS assigns separated carrier frequencies to incoming and outbound signals, a process called frequency division duplexing (FDD). For symmetric traffic, allowing uplink and download data rates to be equal, in contrast to technologies such as Asymmetric Digital Subscriber Line service.
Ongoing work within the 3rd Generation Partnership Project promises increased throughput speeds over the WCDMA Radio Access Network. High-Speed Downlink Packet Access and High-Speed Uplink Packet Access technologies are already standardized, and commercial operators in Asia and North America are putting them through network trials. With theoretical download speed as high as 14.4 Mbit/sec and uplink speed of up to 5.8 Mbit/Sec., these technologies will make it possible for UMTS to offer data transmission speed comparable to those of hard-wired Ethernet-based networks.
Universal Mobile Telecommunications Systems (UMTS) is a third-generation technology being developed into a 4G technology. It is standardized by the 3GPP and is the European answer to the requirements for 3G cellular radio systems.
For effective, efficient communications, standardization is critical, and nowhere is this more evident than in the areas of mobile computing and cellular telephony.
If you need data access or e-mail through your cell phone, you are likely to be using one of two different technologies. In the US the main approach for voice communication is called Code Division Multiple Access (CDMA), and it is the basis for the major network services offered by Verizon Wireless and Sprint Nextel Corp., among others.
In Europe and most of the rest of the world, however, a very different technology called global System for Mobile Communication has dominated the market. GSM uses a Time Division Multiple Access approach to frame structure. GSM service is available in the US primarily through T-Mobile USA Inc., and Cingular Wireless LLC. These carriers maintain GSM networks that are distinct from their other digital networks. Both CDMA and GSM are 2G technologies, and they have co-existed for several years. Each technology has its supporters. CDMA phones are engineered specifically for an individual carrier, whereas GSM phones make use of a removable memory card call the Subscriber Identity Module (SIM). Physically smaller than a secure digital flash memory card, a SIM card contains all the key information required to activate a phone, including the user’s telephone number, personal identification number, address book and encoded network identification details. A user can easily move a SIM from one phone to another.
Though GSM phones are interoperable with one another, different countries use different parts of the frequency spectrum, so “world phones” typically must be capable of using several frequencies.
Today, the fastest-growing use of cellular network is for the transmission of all kinds of data and rich media, including Web sites, video, music, images, and maps and driving directions. The older 2G network simply couldn’t handle the volume of traffic, and they couldn’t offer the speed needed for transmitting large files. The answer was to make the services faster and build out the networks to deal with more traffic.
Here, too, the CDMA and GSM paths continued their separate but parallel development. CDMA brought us CDMA 2000 and 1xRTT networks. The most recent developments are 1x Evolution Data Optimized, or EV-DO, and 1x Evolution Data/Voice, or EV-DV.
Similarly, GSM begat General Packet Radio Service, or GPRS, which begat enhanced data rates for GSM evolution, or EDGE. EDGE was developed to enable the transmission of large amounts of data at a high speed, 384Kbit/sec. The latest generation is called Wideband Code Division Multiple Access (WCDMA).
And this finally brings us to Universal Mobile Telecommunication System. The International Telecommunication Union (ITU), a specialized agency for the United Nations, has attempted to coordinate these competing technologies to improve throughput and increase interoperability. The International Mobile Telecommunications 2000 standard is a 3G digital communications specification from the ITU. And the European implementation of IMT-2000 is UMTS, which is based on WCDMA. Previous cellular telephone data systems were mostly circuit-switched, requiring a dedicated connection. WCDMA is packet-switched, using Internet Protocol. The first commercial WCDMA network was launched in Japan in 2001.
Technical Details
UMTS has been specified as an integrated application for mobile voice and data systems with wide-area coverage. Using globally harmonized spectrum in paired and unpaired bands, early implementations of UMTS offer theoretical bit rates of up 384Kbit/sec. In situations where the mobile device is actually moving. The current goal is to achieve 2Mbit/sec when both ends of the connection are stationary.
UMTS operates on radio frequencies identified by the ITU IMT-2000 specification document and licensed to operator, using a 5 MHz wide channel that simplifies deployment for network providers that have been granted large, contiguous blocks of spectrum. Most UMTS systems use frequencies between 1885 and 2025 MHz.
UMTS assigns separated carrier frequencies to incoming and outbound signals, a process called frequency division duplexing (FDD). For symmetric traffic, allowing uplink and download data rates to be equal, in contrast to technologies such as Asymmetric Digital Subscriber Line service.
Ongoing work within the 3rd Generation Partnership Project promises increased throughput speeds over the WCDMA Radio Access Network. High-Speed Downlink Packet Access and High-Speed Uplink Packet Access technologies are already standardized, and commercial operators in Asia and North America are putting them through network trials. With theoretical download speed as high as 14.4 Mbit/sec and uplink speed of up to 5.8 Mbit/Sec., these technologies will make it possible for UMTS to offer data transmission speed comparable to those of hard-wired Ethernet-based networks.
No comments:
Post a Comment