DMR

DMR (Digital Mobile Radio) Digital trunking communication standard is the open standard designed and developed by ETSI (European telecommunications standards institute) in order to meet the need of professional and commercial users at middle and low levels in European countries for mobile communication. In April 2005 the digital mobile wireless system standard was launched, and its latest version was released in December 2007. DMR standard adopts TDMA (double slots) multiple access mode, 12.5 KHz channel spacing, 4 FSK modulation mode, with data transmission rate of 9.6 Kb/s. DMR has advantages such as efficient use of spectrum resources, regional network mode, compatibility with analog conventional, etc. It is rich in business functions: extensibility, backward compatibility, lower cost of system and the terminal, faster network construction, and lower overall operation and maintenance costs.

　　IMS

IP Multimedia Subsystem, a new form of Multimedia services, can meet the demand of present terminal customers for newer, more diversified Multimedia business. Currently, IMS is regarded as the core technology of next generation network, and is also an important way to achieve the integration of mobile and fixed networks and to introduce the differentiation business of the integration of voice, data, and video, etc.

　　PSIP

PSIP is a an application layer signaling control protocol used for all devices to interconnect within the PDT system, with its basic grammar rules based on the standard SIP version 2.0, and with signaling compression and expansion of the protocol increased.

　　HTTP

HTTP–Hypertext transfer protocol is a kind of data transfer protocol that regulation stipulates rules and regulations for the interconnection between the browser and the web server in detail, transferring the world-wide-web documents through the Internet.

　　SNMP

Simple Network Management Protocol (SNMP), composed of a set of Network Management standards, contains an application layer Protocol (application layer Protocol), database schema (the database schema) and a set of data objects. The protocol can support network management system to monitor if there is any management concern caused by the devices connected to the network. The protocol is part of Internet Protocol Suite defined by the Internet Engineering Task Force (IETF).

　　H.248

H.248 Protocol, a media gateway control protocol put forward by ITU-T 16th working group in 2000, is amended on the basis of the early MGCP Protocol. H.248 / MeGaCo protocol is a gateway control protocol used for connecting the MGC (media gateway controller) and MG (media gateway), and applied between the media gateway and soft switch equipment as well as soft switch and H.248/MeGaCo terminal, and is an important protocol soft switch should support.

　　SS7

Signaling System-7, also known as public channel Signaling, namely, is a signaling method transmitting a speech path signal on a high-speed data link in time-division duplex and is often used between regions. Signaling System-7 used in our country is called China’s Signaling System-7. SS-7 network is an out-of-band data communication network. Being superimposed on the exchange network of operators, it is an important part of the supporting network. It completes local, long-distance and international automatic/semi-automatic telephone connections among the fixed telephone networks or among ISDN networks; it provides local, long distance and international calls and other relevant mobile business such as such as SMS among exchange regions within mobile network; it provides mobile intelligent network business and other value-added services for fixed and mobile networks; it provides the transfer and acquisition of information on the operation management and maintenance.

　　G.723.1

The standard of data communications, sampling at a rate of about 8 KHZ, is a 16 pulse code modulation system, compressing 5.3 or 6.3 kilobit data per second.G.723.1

　　G.729 A/B

G.729 A/B is the standard of speech signal coding of the phone bandwidth, sampling analog signals of the input speech on 8 KHZ and quantifying 16 bits linear PCM. G.729A is a simplified version of G.729 speech coding standard launched the latest by ITU.

　　G.711 A/U

G. 711 A/U is a set of voice compression standards set up by the International telecommunication union (ITU), representing the PCM (logarithmic pulse code modulation) sampling standard. It is mainly used for telephone.

　　G.722

G.722, an audio encoding system set up by the international telecommunication union (ITU) in 1988 by set audio encoding, also known as the ITU-T G. 722, is the wideband speech coding algorithm first used for 16 KHZ sampling frequency. It is also the multi-frequency speech coding algorithm used for supporting 64, 56 and 48kbps frequencies.

　　POE

　　Power Over Ethernet is direct current power supply technology used for supplying the power to data signal transmission on some terminals based on IP (e.g., IP telephone, wireless LAN access point AP, webcams, etc.) and to equipment of this kind at the same time in existing Ethernet Cat.5 cabling infrastructure without making any changes.

　　DTMF

Dual Tone Multi Frequency, the user signaling between telephone and switch in the telephone system, is usually used to send called number. It is invented by Bell Labs and the purpose is to automatically complete the long distance call. Dual tone multiple frequency’s dial pad is in the 4 X 4 matrix, with each row representing a low frequency and each column representing a high frequency. A high and a low frequency sine signals are sent by pressing a button, for example "1" is equal to 697 and 1209 Hertz (Hz). Switches can decode these group frequencies and determine the corresponding buttons.

　　OLED

The Organic Light Emitting Diode is also known as Organic Electroluminesence Display (OELD), with its display technology having the self-luminous characteristic. By using coating of very thin organic materials and glass substrates, these organic materials will glow when a current gets through. As the visual angle of OLED’s display screen is big, it can significantly save electricity. Since the display device began to be widely used in the MP3 player in 2003, OLED’s screen has had many advantages incomparable to LED’s, so it has been highly expected by the insiders.

　　IP57

IP protection grade was drafted by the International Electrotechnical Committee, grading electrical appliances according to their dust-proof and wet-proof properties. IP protection grade is composed of two numbers, with the first representing the level of prevention of the external things from invasion and the second the airtight degree of prevention of moisture from invasion. The greater the number is the higher degree of protection is. The 5th of which can prevent the harm of dust and the 7th can prevent the dangers of immersion of between 15 cm – 1 m.

　　TDMA

Time Division Multiple Access, one technique of digital communication, namely, can divide time into cyclical time Frame. Each Frame then is divided into several time slots to send a signal to the base station. Under the condition of meeting timing and synchronization, the base station can receive the signal from each mobile terminal respectively in each time slot and be confused. At the same time, the signals the base station sends to multiple mobile terminals are transmitted in the designated time slot arranged in sequence, and as long as each mobile terminal receive signals within a specified time slot, it can distinguish and receive the signals sent to it in combined signals.

　　FDMA

Frequency Division Multiple Access, one technique of the digital communication, namely, can distribute different users to the channels of the same time slot but different frequencies. FDMA, a basic technique in the analog advanced mobile phone service (AMPS), is a cellular telephone system most widely used in North America. Using frequency division multiple access, each channel can only be assigned to a user every time. FDMA is also used in the total access communication system (TACS).

　　FSK

Frequency shift keying (FSK) transfers digital information by using carrier frequency changes. It is a digital modulation technique using the characteristic of baseband digital signal discrete values to key carrier frequency to convey information.

　　MPT1327

MPT-1327 signaling, a kind of trunking system standard, officially released by the British Ministry of Posts and Telecommunications in 1985, and a private land trunking mobile communication signaling standard, defines signaling rules in space between system controller (TSC) and mobile terminal (RU). It uses a private control channel to transmit signaling.

　　PSTN

Public Switched Telephone Network (PSTN) is a kind of common old Telephone system, namely, telephone system network commonly used in our daily life. The working principle of the PSTN is a global voice communication switched circuit network.

　　PABX

The abbreviation of Private Automatic Branch Exchange. It is the automatic private branch exchange or private automatic branch exchange. It is one of the telephone communication management tools commonly used in modern office business, enabling making the phone manager to manage calls in from outside and calls out from house telephones in groups.