portable communication term

1, GSM

Used mobile phone users must be aware of what is meant by the representative of GSM, in fact, GSM is the Global System for Mobile Communications acronym, which means Global System for Mobile Communications, is the world's major cellular systems in the world. GSM is used for narrow-band TDMA, allows a radio frequency (that is, 'Cellular') at the same time 8-to-call group. It is based on European standards and to determine the frequency range between 900 ~ 1800MHz digital mobile telephone system, a frequency of 1800MHz system has been adopted by the United States. GSM was the beginning of 1991, the use of. By the end of 1997, has operations in more than 100 countries, Europe and Asia to become the de facto standard.

2, CDMA

CDMA and GSM, are also a mobile communication system, its full name in English is the Code Division Multiple Address (CDMA), which is based on the standards of the United States (IS-95) designed in the frequency range of 900 ~ 1800MHz Digital mobile telephone system. This is the adoption of a Spread-Spectrum's digital cellular technology. And the use of Time-Division Multiplexing (TDM) competitors (such as GSM) different, CDMA does not talk to each person to determine the allocation of a frequency, but allow each channel can be used to provide the full spectrum. CDMA calls for each group used to be a random sequence of numbers encoded.

3, Cellular

Cellular is a wireless communication technology. The technology to a geographical area is divided into several small areas, referred to as the "Cellular" (Cell), cellular technology be named. Phone (or cell phone) using this technology, often referred to as cellular phones (Cellular Phone). A large geographical area divided into a number of "Cellular" is designed to take full advantage of the limited radio frequency transmission. Each connection (for wireless phone conversations each group is concerned) will need a special frequency, and can use the frequency of a total of only about 1,000. In order to be able to more conversation at the same time, the cellular systems to each "cell" (that is, each small region) has been allocated a certain amount of frequency. Different cellular can use the same frequency, so that limited resources can be wireless full advantage of. Common cellular systems, including GSM and CDMA, they are second-generation communication technology.

4, CDPD

CDPD's full name in English is Cellular Digital Packet Data, which is dedicated to a cellular telephone data transmission technology. CDPD use of unused cellular channels (in between 800 to 900MHz), to transmit data packets. The technology provides for the transfer rate of 19.2Kbps, and through the use of analog cellular modem channel, connected to the time required for a shorter, stronger error correction. CDPD, but not the all-digital transmission of data, it is analog transmission and digital transmission between the transition. Compared with the all-digital, and its advantage is the use of existing analogue transmission infrastructure, relatively small investment. CDPD began in 1993, mainly for the United States, Canada, Mexico, as well as some in the Pacific Rim.

5, PCS

PCS is an acronym for Personal Communications Service, which means "personal communication services." This is the Federal Communications Commission (FCC) to use a term, the correction in the United States to deploy a set of digital cellular technology. PCS, including CDMA (also known as IS-95), GSM and for the North American TDMA (also called IS-136). The PCS frequency of 1900MHz.

6, TDMA

TDMA is Time Division Multiple Access acronym, with a Time-Division Multiplexing (Time Division Multiple Access) to provide digital wireless services, technology, it represents a kind of mobile phone systems, digital signal transmission technology. TDMA is divided into a number of radio slot, and then slot these sub-groups to call. In this way, a radio-frequency data can support multiple channels at the same time, the current technology has become today's D-AMPS and GSM systems.

7, GPRS

GPRS is General Packet Radio Service's acronym for "general packet radio service." This is a wireless communications standard, the speed of 150Kbps, the GSM than 15 times faster 9.6Kbps. GPRS can support a variety of bandwidth is limited and efficient use of bandwidth. This technology is particularly suitable for sending a small amount of data, such as send and receive E-mail, Internet browsing, can also be used for transmission of large amounts of data. It is the second-generation mobile communications technology transition to 3G, also known as the 25 people on behalf of communications technology.

8,3 G

3G is referred to as the Third Generation, is the third-generation mobile communications. The first generation of mobile communications is analog wireless network, the second generation is the widely used GSM and CDMA. 3G will have a broader bandwidth, the transmission speed of a minimum of 384Kbps, up to 2Mbps, not only voice transmission but also to transmit data to provide fast, convenient wireless applications, such as wireless access to Internet. 3G is still in its pilot phase, in 2002 is expected to be fully operational.

9, TACS

TACS is the full name in English Total Access Communications System, it is a system-wide communications network technology. The technology in accordance with British Standard designed analog mobile phone system, the frequency range of 900MHz.

10, Net Device

It literally means "network equipment" or "network device", but in reality it was not referring to the router or switch means, but with the realization of Internet networking equipment for small, does not include desktop and notebook computers. Net Device including handheld computers, two-way pager, set-top boxes, smart phones, car PC, as well as send and receive E-mail specialized small tools. It was also known as Net Device to Information Appliance (IA).

11, WCDMA

WCDMA is Wideband Code Division Multiple Access abbreviation. This is the third-generation wireless communication (3G) of a standard that can provide sufficient bandwidth to enable wireless multimedia applications possible.

12, DAMPS

DAMPS full name is the Digital AMPS, which is a high-AMPS mobile phone service technology for analog cellular systems, the use of 800MHz spectrum in the United States dominated. Correspond to, Digital AMPS is the representative of the digital advanced mobile phone system. This digital network solutions based on the IS-136 digital standard. 900 ~ 1800MHz spectrum in the implementation.

13, CMTS

CMTS on behalf of the Cellular Mobile Telephone System, is the meaning of the Chinese - cellular mobile telephone system. The system within each area covered by one base station. An area known as a cell. Each cell phone through the Department of base stations to achieve communication. If the Department of another cell phone call is automatically transferred to the new cell within the base station.

14, UMTS

UMTS represents Universal Mobile Telecommunications System, Chinese is the meaning of the Universal Mobile Telecommunications System, specifically the next generation of cellular technology. By the European Telecommunications Standards Institute to protect a group of companies currently developing its standards.

15, NMT450/NMT900

NMT is the Nordic Mobile Telephone System's initials, specifically the Nordic Mobile Telephone System technology. It is based on the Nordic standards established by the analog mobile phone system, the spectrum in the range of 450 and 900MHz.

16, PDC

PDC's full name in English is the Personal Digital Cellular, on behalf of the personal digital cellular phone. Japan in accordance with the standards established by the cellular mobile telephone system, the frequency range of 800 and 1500MHz.