What is GSM, PCS?

GSM: The Global System for Mobile Communications, known as GSM, is the most widely used mobile phone standard at present. More than 6,543.8 billion people in more than 200 countries and regions around the world are using GSM mobile phones. The ubiquity of GSM standard makes it common for mobile phone operators to roam freely through roaming protocols. The biggest difference between GSM and previous standards is that its signaling and voice channels are digital, so GSM is regarded as the second generation (2G) mobile phone system, which shows that digital communication has been built into the system for a long time. GSM is an open standard currently developed by 3GPP. From the user's point of view, the main advantages of GSM are higher digital voice quality and a new low-cost call option (such as SMS). The advantage of network operators is that they can deploy devices from different manufacturers, because GSM, as an open standard, provides easier interoperability. Moreover, the standard allows network operators to provide roaming services, and users can use mobile phones around the world. PCS: The so-called PCS is actually the floorboard of American digital mobile communication system services. Specifically, PCS is a general term for a wider range of communication services, including digital mobile phones, codeless phones and fixed wireless connections (FWA). Although mobile phones, including PHS, are always called "mobile phones" in Japan, PCS is a broader term. 2008-11-0715: 32: 25 Supplement: Others: CDMA is the abbreviation of Code-Division Multiple Access, and it is a digital interface technology that has only recently been applied to business. It has the advantages of high frequency utilization rate and low power consumption. CDMA introduced by China Unicom belongs to 2.5 generation technology. At present, the third generation DMA standards include WCDMA, CDMA2000 and TD-SCDMA. 2008-11-0715: 32: 39 Supplement: W-CDMA is WidebandCDMA, also known as CDMADirectSpread, which means wideband code division multiple access. Its supporters are mainly European manufacturers based on GSM system, including Ericsson, Alcatel and Nokia in Europe and America. This system can be built on the existing GSM network, which can be easily transitioned by system providers. In Asia, where GSM system is quite popular, the acceptance of this new technology is expected to be quite high. Therefore, W-CDMA has inherent market advantages. 2008-11-0715: 32: 51Supplement: TD-SCDMA is a 3G standard independently formulated by Chinese mainland. On June 29th, 1999, China Institute of Telecommunications Science and Technology (Datang Telecom) proposed to ITU. The standard integrates international leading technologies such as smart wireless, synchronous CDMA and software radio, and has unique advantages in spectrum utilization, business support flexibility, frequency flexibility and cost. In addition, due to the huge market in China, the standard has attracted the attention of major telecom equipment manufacturers, and more than half of the equipment manufacturers in the world have announced that they can support the TD-SCDMA standard. 2008-11-0715: 33: 05 supplement: GPRS: GPRS (general packet radio service) means integrated packet radio service in Chinese. It is a set of wireless transmission mode developed by using the concept of "packet switching" and a new packet data bearing service developed on the existing GSM system. We can understand GPRS as a higher level of GSM. The so-called packet exchange is to package data into many independent packets, and then send these packets one by one, which is a bit like sending a parcel in form. The advantage of packet switching is that it only takes up bandwidth when there is data to send, and it can be priced according to the amount of data transmitted, which is a more reasonable charging method for users. 2008-11-0715: 33: 29 Supplement: 2.5G The 2.5G mobile communication technology that has been put into commercial use at present is the integration technology from 2G to 3G. Because 3G is a huge project, it is difficult to connect from the current 2G to 3G at once, so it is between 2G and 3G. Technologies such as HSCSD, WAP, EDGE, Bluetooth and EPOC are all 2.5G technologies. 2008-11-0715: 34: 05 Supplement: HSCSD HSCSD (high-speed circuit-switched data service) This is an upgraded version of GSM network. Hscsd (high speed circuit switched data) can be transmitted at the same time through multiple times, not just a single time, so the transmission speed can be greatly improved to a normal value. At present, both M 1 in Singapore and Telecom Singapore use HSCSD system, and the transmission speed can reach 57.6 kbps. 2008-1-0715: 34:17 Supplement: WAP (Wireless Application Protocol) is the first combination of mobile communication and Internet. This technology allows users to surf the Internet using wireless devices such as mobile phones and navigate between websites through small screens. These websites must also be written in WML (Wireless Markup Language), which is equivalent to HTML (Hypertext Markup Language) on the Internet. 2008-11-0715: 34: 26 supplement: the English full name of EDGE EDGE is enhanced data rate for GSM evolution, which means improving data rate GSM service in Chinese. This technology mainly lies in the ability to use broadband services. Networks using 800, 900, 1800 and 1900MHz bands can provide some functions of the third generation mobile communication network, and can greatly improve the standardized services currently provided on GSM and TDMA/ 136. This technology can provide 384kbps wide-area data communication service and 2Mbps local data communication service, which can fully meet the bandwidth requirements of future wireless multimedia applications. 2008-11-0715: 34: 37 Supplement: Bluetooth is a short-range wireless communication technology. Electronic devices can be connected to each other through Bluetooth, and traditional wires are useless here. Through the wireless receiver on the chip, electronic products equipped with Bluetooth technology can communicate with each other within ten meters, and the transmission speed can reach 1 megabyte per second. In the past, the transmission technology in infrared data association required the distance of electronic equipment in sight. Now, with Bluetooth technology, such troubles can be eliminated. 2008-11-0715: 34: 42 supplement: 3G 3G is the abbreviation of the third generation of English, which refers to the third generation mobile communication technology. Compared with the first generation of analog mobile phones (1G) and the second generation of GSM, TDMA and other digital mobile phones (2G), the third generation of mobile phones generally refers to a new generation of mobile communication systems that combine wireless communication with multimedia communication such as the Internet. It can handle images, music, video streams and other media forms, and provide a variety of information services including web browsing, teleconference, e-commerce and so on. In order to provide this service, the wireless network must be able to support different data transmission speeds, that is, in indoor, outdoor and driving environments, it can support at least 2Mbps (megabits per second), 384kbps (kilobytes per second) and 144kbps respectively.

Reference: Baidu

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Global System for Mobile Communications (GSM) is the most widely used mobile phone standard at present. More than 6,543.8 billion people in more than 200 countries and regions around the world are using GSM mobile phones. The widespread use of GSM standard makes it very common for users to roam internationally after signing roaming agreements between mobile phone operators. The biggest difference between GSM and previous standards is that its signaling and voice channels are digital, so GSM is regarded as the second generation (2G) mobile phone system. The GSM standard is currently formulated and maintained by the 3GPP organization. From the user's point of view, the main advantage of GSM is to provide higher digital voice quality and low-cost new options (such as SMS) to replace calls. From the point of view of network operators, its advantage is that it can deploy devices from different manufacturers, because GSM, as an open standard, provides easier interoperability. Moreover, the standard allows network operators to provide roaming services, and users can use mobile phones around the world. Although the GSM standard is developing (for example, the packet data capability is increased through GPRS in the' 97 version of the standard), it is still backward compatible with the original GSM phone. Higher-speed data transmission was introduced in the' 99 edition standard with EDGE. Zh。 *** /wiki/GSM personal communication service? Personal communication service (personal communication service)

The concept of PCS) is the hottest topic in communication service recently? The so-called personal communication service should at least include the following three aspects: 1. Terminal mobility: when the user's terminal equipment (such as the user's mobile phone) moves, it must still have the ability to obtain service and not lose service? Construction of wireless communication Neork 2. Service profile management: the items and contents of the service can be arranged in various ways, and various functions (such as call forwarding and voice mail) can be selected? Construction of intelligent Neork 3. Personal mobility: the difference of personal mobility and location should not cause the loss of related communication services (for example, using a single number for personal global communication, and any message must be accessible to the user at any time)? Construction and integration of wireless communication network and intelligent network? In order to meet the growing demand of personal mobile communication, in addition to the original early cellular telephone frequency band, countries have also opened up new frequency bands with higher frequencies, which are usually called PCS or PCN (Personal Communication Neork) frequency bands. Ee.nth.edu/cclu/ee110300/lecture/lecture-11.pdf.

1.The full name of GSM is Global System for Mobile Communications, and Chinese is Global System for Mobile Communications, commonly known as "GSM". It is a technical standard of mobile communication originated in Europe, and it is the second generation of mobile communication technology. Its development purpose is to enable all parts of the world to use the same mobile phone network standard, so that users all over the world can use a mobile phone. China introduced this technical standard in the early 1990s, and has been using cellular analog mobile technology, that is, the first generation of GSM technology (China closed the analog mobile network on February 3, 20061day). At present, China Mobile and China Unicom each have a GSM network, which is the largest mobile communication network in the world. The GSM system includes GSM 900:900MHz, GSM 1800: 1800 MHz and GSM 1900: 1900 MHz. GSM (Global System for Mobile Communications) is a digital mobile phone system widely used in Europe and other parts of the world. GSM is a variant of TDMA, which is the most widely used of three digital wireless telephone technologies (TDMA, GSM and CDMA). GSM digitizes the data, compresses the data, and then sends it out of the channel together with two other user data streams, which have their own time slots. . GSM is actually the wireless telephone standard in Europe. According to the report of the Joint Committee of GSM MoU, GSM has 65.438+0.2 billion users all over the world, covering more than 65.438+0.20 countries. Because many GSM network operators have roaming agreements with other foreign operators, users can still use their mobile phones when they go to other countries. As an auxiliary department of Sprint, a famous American communication company, American Personal Communication is using GSM as a broadband personal communication service technology. This personal communication service will eventually build more than 400 base stations for mobile phones being produced by Ericsson, Motorola and Nokia. Mobile phones include telephones, SMS pagers and walkie-talkies. GSM and other technologies are the evolution of wireless mobile communication, including high-speed circuit-switched data, general wireless packet system, data-enhanced mobile communication technology based on GSM network and general mobile communication services. GSM baike.baidu/view/7530? The detailed explanation of Wtp = TT PCS is the abbreviation of personal communication service, which means "personal communication service". This is a term used by the Federal Communications Commission (FCC) to refer to a set of digital cellular technology deployed in the United States. PCS includes CDMA (also known as IS-95), GSM and TDMA (also known as IS- 136), which are mainly used in north America. The frequency of PCS is 1900MHz. PCS baike.baidu/view/6588 1? A detailed description of WTP = TT

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