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2,5G
2G is a short notation for second-generation cellular network, a group of technology standards employed for cellular networks. 2G was comercially launched on the GSM standard in Finland by Radiolinja (now part of Elisa Oyj) in 1991. After 2G was launched, the previous mobile wireless network systems were retroactively dubbed 1G. While radio signals on 1G networks are analog, radio signals on 2G networks are digital, though both systems use digital signaling to connect cellular radio towers to the rest of the mobile network system. The most common 2G technology was the time-division multiple access (TDMA)-based GSM standard, used in most of the world outside Japan and North America. In North America, Digital AMPS (IS-54 and IS-136) and cdmaOne (IS-95) were the main systems. In Japan the ubiquitous system was Personal Digital Cellular (PDC) though another, Personal Handy-phone System (PHS), also existed. Three primary benefits of 2G networks over their 1G predecessors were: # D ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
2,75G
2G is a short notation for second-generation cellular network, a group of technology standards employed for cellular networks. 2G was comercially launched on the GSM standard in Finland by Radiolinja (now part of Elisa Oyj) in 1991. After 2G was launched, the previous mobile wireless network systems were retroactively dubbed 1G. While radio signals on 1G networks are analog signal, analog, radio signals on 2G networks are digital data, digital, though both systems use digital signaling to connect Cell site , cellular radio towers to the rest of the mobile network system. The most common 2G technology was the time-division multiple access (TDMA)-based GSM standard, used in most of the world outside Japan and North America. In North America, Digital AMPS (IS-54 and IS-136) and cdmaOne (IS-95) were the main systems. In Japan the ubiquitous system was Personal Digital Cellular (PDC) though another, Personal Handy-phone System (PHS), also existed. Three primary benefits of 2G network ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
UMTS
The Universal Mobile Telecommunications System (UMTS) is a third generation mobile cellular system for networks based on the GSM standard. Developed and maintained by the 3GPP (3rd Generation Partnership Project), UMTS is a component of the International Telecommunication Union IMT-2000 standard set and compares with the CDMA2000 standard set for networks based on the competing cdmaOne technology. UMTS uses wideband code-division multiple access ( W-CDMA) radio access technology to offer greater spectral efficiency and bandwidth to mobile network operators. UMTS specifies a complete network system, which includes the radio access network ( UMTS Terrestrial Radio Access Network, or UTRAN), the core network (Mobile Application Part, or MAP) and the authentication of users via SIM ( subscriber identity module) cards. The technology described in UMTS is sometimes also referred to as Freedom of Mobile Multimedia Access (FOMA) or 3GSM. Unlike EDGE (IMT Single-Carrier, based o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
T-Mobile US
T-Mobile US, Inc. is an American wireless network operator headquartered in Overland Park, Kansas and Bellevue, Washington, U.S. Its largest shareholder is a multinational telecommunications company Deutsche Telekom AG, which , holds 48.4 percent of the common stock. T-Mobile US is the second-largest wireless carrier in the United States, with more than 110 million subscribers . The company was founded in 1994 as VoiceStream Wireless before Deutsche Telekom purchased it in 2001 and renamed it after its T-Mobile brand. T-Mobile US provides wireless voice and data services in the United States under the T-Mobile and Metro by T-Mobile brands (the latter was acquired via the purchase of MetroPCS in a reverse takeover in 2013, resulting in T-Mobile going public on the NASDAQ stock exchange), and also serves as the host network for many mobile virtual network operators. The company has annual revenues of over $40 billion. In 2015, ''Consumer Reports'' named T-Mobile the number ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
General Packet Radio Service
General Packet Radio Service (GPRS) is a packet oriented mobile data standard on the 2G and 3G cellular communication network's global system for mobile communications (GSM). GPRS was established by European Telecommunications Standards Institute (ETSI) in response to the earlier CDPD and i-mode packet-switched cellular technologies. It is now maintained by the 3rd Generation Partnership Project (3GPP). GPRS is typically sold according to the total volume of data transferred during the billing cycle, in contrast with circuit switched data, which is usually billed per minute of connection time, or sometimes by one-third minute increments. Usage above the GPRS bundled data cap may be charged per MB of data, speed limited, or disallowed. GPRS is a best-effort service, implying variable throughput and latency that depend on the number of other users sharing the service concurrently, as opposed to circuit switching, where a certain quality of service (QoS) is guaranteed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
LTE (telecommunication)
In telecommunications, long-term evolution (LTE) is a Technical standard, standard for wireless broadband communication for mobile devices and data terminals, based on the GSM/Enhanced Data Rates for GSM Evolution, EDGE and UMTS/High Speed Packet Access, HSPA standards. It improves on those standards' capacity and speed by using a different radio interface and core network improvements. LTE is the upgrade path for carriers with both GSM/UMTS networks and CDMA2000 networks. Because LTE frequency bands, LTE frequencies and bands differ from country to country, only multi-band phones can use LTE in all countries where it is supported. The standard is developed by the 3GPP (3rd Generation Partnership Project) and is specified in its Release 8 document series, with minor enhancements described in Release 9. LTE is also called 3.95G and has been marketed as "4G LTE" and "Advanced 4G"; but it does not meet the technical criteria of a 4G wireless service, as specified in the 3GPP Relea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mobile Phone
A mobile phone, cellular phone, cell phone, cellphone, handphone, hand phone or pocket phone, sometimes shortened to simply mobile, cell, or just phone, is a portable telephone that can make and receive calls over a radio frequency link while the user is moving within a telephone service area. The radio frequency link establishes a connection to the switching systems of a mobile phone operator, which provides access to the public switched telephone network (PSTN). Modern mobile telephone services use a cellular network architecture and, therefore, mobile telephones are called ''cellular telephones'' or ''cell phones'' in North America. In addition to telephony, digital mobile phones ( 2G) support a variety of other services, such as text messaging, multimedia messagIng, email, Internet access, short-range wireless communications ( infrared, Bluetooth), business applications, video games and digital photography. Mobile phones offering only those capabilities are kn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Time-division Multiple Access
Time-division multiple access (TDMA) is a channel access method for shared-medium networks. It allows several users to share the same frequency channel by dividing the signal into different time slots. The users transmit in rapid succession, one after the other, each using its own time slot. This allows multiple stations to share the same transmission medium (e.g. radio frequency channel) while using only a part of its channel capacity. Dynamic TDMA is a TDMA variant that dynamically reserves a variable number of time slots in each frame to variable bit-rate data streams, based on the traffic demand of each data stream. TDMA is used in the digital 2G cellular systems such as Global System for Mobile Communications (GSM), IS-136, Personal Digital Cellular (PDC) and iDEN, and in the Digital Enhanced Cordless Telecommunications (DECT) standard for portable phones. TDMA was first used in satellite communication systems by Western Union in its Westar 3 communications sat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Digital AMPS
IS-54 and IS-136 are second-generation ( 2G) mobile phone systems, known as Digital AMPS (D-AMPS), and a further development of the North American 1G mobile system Advanced Mobile Phone System (AMPS). It was once prevalent throughout the Americas, particularly in the United States and Canada since the first commercial network was deployed in 1993. D-AMPS is considered end-of-life, and existing networks have mostly been replaced by GSM/ GPRS or CDMA2000 technologies. This system is most often referred to as TDMA. That name is based on the abbreviation for time-division multiple access, a common multiple access technique which is used in most 2G standards, including GSM, as well as in IS-54 and IS-136. D-AMPS competed against GSM and systems based on code-division multiple access (CDMA). D-AMPS uses existing AMPS channels and allows for smooth transition between digital and analog systems in the same area. Capacity was increased over the preceding analog design by dividing ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CdmaOne
Interim Standard 95 (IS-95) was the first ever CDMA-based digital cellular technology. It was developed by Qualcomm and later adopted as a standard by the Telecommunications Industry Association in TIA/EIA/IS-95 release published in 1995. The proprietary name for IS-95 is cdmaOne. It is a 2G mobile telecommunications standard that uses code-division multiple access (CDMA), a multiple access scheme for digital radio, to send voice, data and signaling data (such as a dialed telephone number) between mobile telephones and cell sites. CDMA transmits streams of bits ( PN codes). CDMA permits several radios to share the same frequencies. Unlike TDMA "time division multiple access", a competing system used in 2G GSM, all radios can be active all the time, because network capacity does not directly limit the number of active radios. Since larger numbers of phones can be served by smaller numbers of cell-sites, CDMA-based standards have a significant economic advantage over ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CdmaOne
Interim Standard 95 (IS-95) was the first ever CDMA-based digital cellular technology. It was developed by Qualcomm and later adopted as a standard by the Telecommunications Industry Association in TIA/EIA/IS-95 release published in 1995. The proprietary name for IS-95 is cdmaOne. It is a 2G mobile telecommunications standard that uses code-division multiple access (CDMA), a multiple access scheme for digital radio, to send voice, data and signaling data (such as a dialed telephone number) between mobile telephones and cell sites. CDMA transmits streams of bits ( PN codes). CDMA permits several radios to share the same frequencies. Unlike TDMA "time division multiple access", a competing system used in 2G GSM, all radios can be active all the time, because network capacity does not directly limit the number of active radios. Since larger numbers of phones can be served by smaller numbers of cell-sites, CDMA-based standards have a significant economic advantage over ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spectral Efficiency
Spectral efficiency, spectrum efficiency or bandwidth efficiency refers to the information rate that can be transmitted over a given bandwidth in a specific communication system. It is a measure of how efficiently a limited frequency spectrum is utilized by the physical layer protocol, and sometimes by the medium access control (the channel access protocol). Guowang Miao, Jens Zander, Ki Won Sung, and Ben Slimane, Fundamentals of Mobile Data Networks, Cambridge University Press, , 2016. Link spectral efficiency The link spectral efficiency of a digital communication system is measured in ''bit/ s/ Hz'', or, less frequently but unambiguously, in ''(bit/s)/Hz''. It is the net bit rate (useful information rate excluding error-correcting codes) or maximum throughput divided by the bandwidth in hertz of a communication channel or a data link. Alternatively, the spectral efficiency may be measured in ''bit/symbol'', which is equivalent to ''bits per channel use'' (''bpcu''), implying tha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
