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PDT Standard
PDT (short for ''Professional Digital Trunking'' or ''Police Digital Trunking'') is an open industry standard for trunked radio system in China servicing police wireless communications and professional mobile radio. The standard is being maintained by the ''Professional Digital Trunking System Industry Association'', an association of major vendors of wireless communications equipment in China. The association was formed with the help from Information and Communications Bureau of the Ministry of Public Security. The standard was used to facilitate the digital transformation of the Ministry's existing MPT analogue trunking system. Government policy supporting this domestic standard had led to the abolishment of previous GA/T industry standards based on the European TETRA standard. The initial major contributor of the standard were Hytera Communications and Vigor Communications(WANGE). Vigor was also the first enterprise to produce PDT two-way radio products. Features Features of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trunked Radio System
A trunked radio system is a two-way radio system that uses a control channel to automatically assign frequency channels to groups of user radios. In a traditional half-duplex land mobile radio system a group of users (a ''talkgroup'') with mobile and portable two-way radios communicate over a single shared radio channel, with one user at a time talking. These systems typically have access to multiple channels, up to 40-60, so multiple groups in the same area can communicate simultaneously. In a conventional (non-trunked) system, channel selection is done manually; before use the group must decide which channel to use, and manually switch all the radios to that channel. This is an inefficient use of scarce radio channel resources because the user group must have exclusive use of their channel regardless of how much or how little they are transmitting. There is also nothing to prevent multiple groups in the same area from choosing the same channel, causing conflicts and 'cross-talk'. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Police Radio
Police radio is a radio system used by police and other law enforcement agencies to communicate with one another. Police radio systems almost always use two-way radio systems to allow for communications between police officers and dispatchers. Most modern police radio systems are encrypted, and many jurisdictions have made listening to police radio frequencies as a private citizen illegal. History Before police radio systems were first implemented, police officers assigned to their beat could only communicate with police command using telephone booths, call boxes, police boxes, or physical meetings. Calling for help or signaling other officers could only be done by shouting, using a whistle, or hitting things to make sounds. This meant that properly calling for assistance, reporting an incident or arrest, being dispatched to handle a crime, or requesting police resources was only possible if the officer reached a telephone or call box. The first police radio systems were i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Professional Mobile Radio
Professional mobile radio (also known as private mobile radio (PMR) in the UK) are person-to-person two-way radio voice communications systems which use portable, mobile, base station, and dispatch console radios. PMR radio systems are based on such standards as MPT-1327, TETRA, APCO 25, and DMR which are designed for dedicated use by specific organizations, or standards such as NXDN intended for general commercial use. These systems are used by police, fire, ambulance, and emergency services, and by commercial firms such as taxis and delivery services. Most systems are half-duplex, in which multiple radios share a common radio channel, and only one can transmit at a time. Transceivers are normally in receive mode, the user presses a push-to-talk button on his microphone when he wants to talk, which turns on his transmitter and turns off his receiver. They use channels in the VHF and UHF bands, giving them a limited range, usually depending on terrain. Output power is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ministry Of Public Security Of The People's Republic Of China
The Ministry of Public Security () is a government ministry of the People's Republic of China responsible for public and political security. It oversees more than 1.9 million of the country's law enforcement officers and as such the vast majority of the People's Police (). The MPS is a nationwide police force; however, counterintelligence and so-called "political security" remain core functions. The ministry was established in 1949 (after the Chinese Communist Party's victory in the Chinese Civil War) as the successor to the Central Social Affairs Department and was known as "Ministry of Public Security of the Central People's Government" until 1954. Grand General Luo Ruiqing of the People's Liberation Army (PLA) was its first minister. As the ministry's organization was based on Soviet and Eastern Bloc models, it was responsible for all aspects of national security; ranging from regular police work to intelligence, counterintelligence and the suppression of anti-communis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Digital Transformation
Digital transformation is the adoption of digital technology by an organization to digitize non-digital products, services or operations. The goal for its implementation is to increase value through innovation, invention, customer experience or efficiency. History Digitization is the process of converting analog information into digital form using an analog-to-digital converter, such as in an image scanner or for digital audio recordings. As usage of the internet has increased since the 1990s, the usage of digitization has also increased. Digital transformation, however, is broader than just the digitization of existing processes. Digital transformation entails considering how products, processes and organizations can be changed through the use of new, digital technologies. A 2019 review proposes a definition of digital transformation as "a process that aims to improve an entity by triggering significant changes to its properties through combinations of information, computing, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Terrestrial Trunked Radio
Terrestrial Trunked Radio (TETRA; formerly known as Trans-European Trunked Radio), a European standard for a trunked radio system, is a professional mobile radio and two-way transceiver specification. TETRA was specifically designed for use by government agencies, emergency services, (police forces, fire departments, ambulance) for public safety networks, rail transport staff for train radios, transport services and the military. TETRA is the European version of trunked radio, similar to Project 25. TETRA is a European Telecommunications Standards Institute (ETSI) standard, first version published 1995; it is mentioned by the European Radiocommunications Committee (ERC). Description TETRA uses time-division multiple access (TDMA) with four user channels on one radio carrier and 25 kHz spacing between carriers. Both point-to-point and point-to-multipoint transfer can be used. Digital data transmission is also included in the standard though at a low data rate. TETRA Mob ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hytera Communications
Hytera (; previously HYT; ) is a Chinese publicly-traded and partly state-owned manufacturer of radio transceivers and radio systems founded in Shenzhen, Guangdong in 1993. Hytera is listed on the Shenzhen Stock Exchange and is partly owned by Shenzhen Investment Holdings of Shenzhen's municipal government. Hytera is major contributor to the PDT Standard, which is designed for public safety organizations in China. The company is a major supplier to China's Ministry of Public Security. Locations and subsidiaries The company's head office is in Shenzhen, China. Hytera's products are developed at three development sites in total. One of the development sites is located in Bad Münder, Germany. In March 2012 Hytera acquired the German company Rohde & Schwarz Professional Mobile Radio GmbH from the German electronics group Rohde & Schwarz, which is now known as Hytera Mobilfunk. In addition, there are Hytera subsidiaries in the US, UK, Canada, and Spain. United States In June ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Digital Mobile Radio
Digital mobile radio (DMR) is a specification for commercial products so they can interoperate. It is defined by a standard created by the European Telecommunications Standards Institute (ETSI), and is designed to be low-cost and easy to use. DMR, along with P25 phase II and NXDN are the main competitor technologies in achieving 6.25 kHz equivalent bandwidth using the proprietary AMBE+2 vocoder. DMR and P25 II both use two-slot TDMA in a 12.5 kHz channel, while NXDN uses discrete 6.25 kHz channels using frequency division and TETRA uses a four-slot TDMA in a 25 kHz channel. DMR was designed with three tiers. DMR tiers I and II (conventional) were first published in 2005, and DMR III (Trunked version) was published in 2012, with manufacturers producing products within a few years of each publication. The primary goal of the standard is to specify a digital system with low complexity, low cost and interoperability across brands, so radio communications purchasers a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Law Enforcement In China
Law enforcement in China consists of an extensive public security system and a variety of enforcement procedures used to maintain order in the country. Along with the courts and procuratorates, the country's judicial and public security agencies include the Ministry of Public Security (MPS) and the Ministry of State Security (MSS), with their descending hierarchy of departments, bureaus (局, "Jú"), subbureaus (副局, "Fù jú"), and stations (所, "Suǒ"). Hong Kong and Macau have separate law enforcement agencies, different legal systems and are classified as separate jurisdictions under the one country two systems framework. However, Hong Kong Police Force (HKPF) and Public Security Police Force of Macau often cooperate with the mainland MPS on cases involving cross border crime. Overview The national security system is made up of the Ministry of Public Security (MPS) and the Ministry of State Security (MSS), the People's Armed Police (PAP), the People's Liberation A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Standards Of The People's Republic Of China
Standard may refer to: Symbols * Colours, standards and guidons, kinds of military signs * Standard (emblem), a type of a large symbol or emblem used for identification Norms, conventions or requirements * Standard (metrology), an object that bears a defined relationship to a unit of measure used for calibration of measuring devices * Standard (timber unit), an obsolete measure of timber used in trade * Breed standard (also called bench standard), in animal fancy and animal husbandry * BioCompute Standard, a standard for next generation sequencing * ''De facto'' standard, product or system with market dominance * Gold standard, a monetary system based on gold; also used metaphorically for the best of several options, against which the others are measured * Internet Standard, a specification ratified as an open standard by the Internet Engineering Task Force * Learning standards, standards applied to education content * Standard displacement, a naval term describing the wei ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
