BySteve Lowry 2018-08-07 16673
GSM stands for Global System for Mobile Communication, is a standard developed by the European Telecommunications Standards Institute (ETSI) to describe the protocols for second-generation (2G) digital cellular networks used by mobile phones, first deployed in Finland in July 1991. Is is developed based on cellular system and it has several frequency bands, including GSM900MHz, GSM1800MHz, and GSM1900MHz, etc.
As of 2014, it has become the de facto global standard for mobile communications, and it is widely used by over 200 countries and territories and over 1 billion people all over the world.
3G is short for 3GPP, with its full name is the 3rd Generation Partner Project, so it is also referred to as the third generation. 3G refers to a set of standards used for mobile devices and mobile telecommunications use services and networks that comply with the International Mobile Telecommunications-2000 (IMT-2000) specifications . The third generation, as the name suggests, follows two earlier generations.
The International Telecommunication Union (ITU) has identified three major wireless interface standards for 3G: W-CDMA, CDMA2000 and TDS-CDMA.
In short, 3G is loosely defined, but generally includes high data speeds, always-on data access, and greater voice capacity. The high data speeds are possibly the most prominent feature, and certainly the most hyped. They enable such advanced features as live, streaming video.
Code Division Multiple Access (CDMA) is a digital technology for transmitting data. It is a new and mature wireless communication technology developed from spread spectrum technology.
CDMA is used as the access method in many mobile phone standards. IS-95, also called "cdmaOne", and its 3G evolution CDMA2000, are often simply referred to as "CDMA", but UMTS, the 3G standard used by GSM carriers, also uses "wideband CDMA", or W-CDMA, as well as TD-CDMA and TD-SCDMA, as its radio technologies.
WCDMA, that is, Wideband Code Division Multiple Access, is an air interface standard found in 3G mobile telecommunications networks. It supports conventional cellular voice, text and MMS services, but can also carry data at high speeds, allowing mobile operators to deliver higher bandwidth applications including music-on-demand, TV and video streaming and broadband Internet access. .
It allows use of both voice and data and offers data speeds of up to 384Kbps. The frequency bands for WCDMA are as follows: Europe and Asia - 2100MHz, North America - 1900MHz and 850MHz.
WCDMA is also called UMTS and the two terms have become interchangeable.
Some parts of the WCDMA are based on GSM technology and the networks are designed to integrate the GSM networks at some levels.
TD-SCDMA, an acronym for Time Division-Synchronous Code Division Multiple Access, is a 3G format of choice for the national standard of 3G mobile telecommunication in China as an alternative to W-CDMA.
TD-SCDMA uses the TDMA channel access method combined with an adaptive synchronous CDMA component on 1.6 MHz slices of spectrum, allowing deployment in even tighter frequency bands than TD-CDMA. It is standardized by the 3GPP and also referred to as "UTRA-TDD LCR".
TD-SCDMA network is incompatible with W-CDMA / UMTS-FDD and TD-CDMA / UMTS-TDD (HCR) networks.
4G is the short name for fourth-generation wireless, the stage of broadband mobile communications that will supercede the third generation (3G).
According to the ITU, a 4G network requires a mobile device to be able to exchange data at 100M bit/Sec. A 3G network, on the other hand, can offer data speeds as slow as 3.84 Mbit/Sec.
Long Term Evolution (LTE) standard (a 4G candidate system) is another name for 4G. LTE systems are available in two formats: FDD-LTE and TDD-LTE, that is, Frequency Division Duplex LTE system and Time Division Duplex LTE system.
In terms of speed, TD-LTE’s downlink and uplink network bandwidth are 100Mbps and 50Mbps, respectively, while the FDD-LTE’s downlink and uplink network bandwidth are 150Mbps and 40Mbps, respectively. The two standard has little difference in the speed.
5G is the coming fifth-generation wireless broadband technology based on the IEEE 802.11ac standard.
5G will provide better speeds and coverage than the current 4G. 5G operates with a 5GHz signal and is set to offer speeds of up to 1Gb/s for tens of connections or tens of Mb/s for tens of thousands of connections.
The signal technology of 5G has also been improved for greater coverage as well as spectral and signaling efficiency. These improvements stand to further enable changes like pervasive computing and the Internet of Things (IoT).
Although 5G is not scheduled for launch until 2020, some manufacturers are already incorporating elements of the coming standard's specifications into their products.
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