|
Motorola Trunked Radio
Motorola Trunked Radio for telecommunications is a trunked radio system developed by Motorola. Types * Motorola Type I, Type I * Motorola Type II, Type II * Motorola Type IIi Hybrid, Type IIi Hybrid * Motorola Type II SmartZone, Type II SmartZone * Motorola Type II SmartZone OmniLink, Type II SmartZone OmniLink * Motorola Type II VOC, Type II VOC Motorola Type I and Type II systems achieve the same thing in a slightly different way. One important distinction between these systems is the amount of data transmitted by each radio when the operator pushes the PTT button. A Type I system transmits the radio's ID, its fleet information, and the subfleet information. A Type II system only transmits the radio's ID. What’s the difference? In Type I systems, each radio in the trunk group individually transmits its own affiliation. In Type II systems the trunk system maintains a database that determines each radio's affiliation. Another difference between the systems is that Type I systems ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Telecommunications
Telecommunication, often used in its plural form or abbreviated as telecom, is the transmission of information over a distance using electronic means, typically through cables, radio waves, or other communication technologies. These means of transmission may be divided into communication channels for multiplexing, allowing for a single medium to transmit several concurrent Session (computer science), communication sessions. Long-distance technologies invented during the 20th and 21st centuries generally use electric power, and include the electrical telegraph, telegraph, telephone, television, and radio. Early telecommunication networks used metal wires as the medium for transmitting signals. These networks were used for telegraphy and telephony for many decades. In the first decade of the 20th century, a revolution in wireless communication began with breakthroughs including those made in radio communications by Guglielmo Marconi, who won the 1909 Nobel Prize in Physics. Othe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trunked Radio System
A Trunked Radio System (TRS) 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 'c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Motorola
Motorola, Inc. () was an American multinational telecommunications company based in Schaumburg, Illinois. It was founded by brothers Paul and Joseph Galvin in 1928 and had been named Motorola since 1947. Many of Motorola's products had been radio-related communication equipment such as two-way radios, consumer walkie-talkies, cellular infrastructure, mobile phones, satellite communicators, pagers, as well as cable modems and semiconductors. After having lost $4.3 billion from 2007 to 2009, Motorola was split into two independent public companies: Motorola Solutions (its legal successor) and Motorola Mobility (spun off), on January 4, 2011. Motorola designed and sold wireless network equipment such as cellular transmission base stations and signal amplifiers. Its business and government customers consisted mainly of wireless voice and broadband systems (used to build private networks), and public safety communications systems like Astro and Dimetra. Motorola's h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Motorola Type I
Motorola Type I Is the original type of Motorola Motorola, Inc. () was an American multinational telecommunications company based in Schaumburg, Illinois. It was founded by brothers Paul and Joseph Galvin in 1928 and had been named Motorola since 1947. Many of Motorola's products had been ...'s Trunked radio system; it is based on Fleets and Subfleets. Each system had a certain number of Fleets assigned, and then each Fleet had a certain number of Subfleets and radio IDs. The distribution of Fleets and Subfleets on a Type I system is determined by the system Fleetmap. Motorola Type I systems are not scalable because they limit the amount of IDs any fleet or subfleet can support. Each Type I ID appears as a three or four digit number, followed by a hyphen, followed by a one or two digit number (example 200-14). The term "Privacy Plus" refers to a Type I system. Privacy Plus systems are normally older public safety systems and SMRs. {{Trunked radio systems Trunked rad ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Motorola Type II
Motorola Type II refers to the second generation Motorola trunked radio systems that replaced fleets and subfleets with the concept of talkgroups and individual radio IDs. There are no dependencies on fleetmaps, therefore there are no limitations on how many radio IDs can participate on a talkgroup. This allows for greater flexibility for the agency. When scanning Motorola IDs, each Type II user ID appears as an even 4- or 5-digit number without a dash (example 2160). With the introduction of Type II, the "System ID" was also introduced. This is a four digit identifier unique to each trunking system. The purpose of the System ID is to allow radios to operate only on that specific system, and to identify each system. The System ID also allows for enhanced security because a radio now requires a System Key, unique to the System ID in order to be programmed onto any given system. Type I systems do not use unique System IDs, thus the possibility exists for overlapping coverage in b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Motorola Type IIi Hybrid
A Motorola Type IIi Hybrid system is a type of trunked radio system A Trunked Radio System (TRS) 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'') w ... that mixes "blocks" of Type I Fleets/Subfleets with Type II talkgroups. In some cases, all radios support Type II, but in some cases, Type I radios might be used exclusively in subfleets while the Type IIs are used exclusively in talkgroups. The most common reason that an agency sets up a Type IIi Hybrid system is because they have newer Type II radios that they want to interoperate with older Type I radios, without having to create new Type II talkgroups. {{DEFAULTSORT:Motorola Type Iii Hybrid Trunked radio systems ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Motorola Type II SmartZone
Motorola Type II refers to the second generation Motorola trunked radio systems that replaced fleets and subfleets with the concept of talkgroups and individual radio IDs. There are no dependencies on fleetmaps, therefore there are no limitations on how many radio IDs can participate on a talkgroup. This allows for greater flexibility for the agency. When scanning Motorola IDs, each Type II user ID appears as an even 4- or 5-digit number without a dash (example 2160). With the introduction of Type II, the "System ID" was also introduced. This is a four digit identifier unique to each trunking system. The purpose of the System ID is to allow radios to operate only on that specific system, and to identify each system. The System ID also allows for enhanced security because a radio now requires a System Key, unique to the System ID in order to be programmed onto any given system. Type I systems do not use unique System IDs, thus the possibility exists for overlapping coverage in b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Motorola Type II VOC
The introduction of Motorola Type II SmartZone Motorola Type II refers to the second generation Motorola trunked radio systems that replaced fleets and subfleets with the concept of talkgroups and individual radio IDs. There are no dependencies on fleetmaps, therefore there are no limitations ... introduced the IntelliRepeater. An IntelliRepeater, or IR, site is a bare-bones trunked site which has no database of users or talkgroups. It is simply sophisticated software running on a Quantar repeater. It is meant to be controlled by the Zone Controller and to be commanded as to who has permission and who does not. There are some very basic restrictions in the event Site Trunking (a site loses its link to the Zone Controller) does occur but for all intents and purposes once an IR site is in Site Trunking mode it's a free-for-all site. IR sites are generally used for a small geographic area or to fill in holes. For sites that are used to fill in coverage traffic is very limited. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
VSELP
Vector sum excited linear prediction (VSELP) is a speech coding method used in several cellular standards. The VSELP algorithm is an analysis-by-synthesis coding technique and belongs to the class of speech coding algorithms known as CELP (Code Excited Linear Prediction).ETSIEN 300 969 - Half rate speech transcoding (GSM 06.20 version 8.0.1 Release 1999) Retrieved on 2009-07-11 Variations of this codec have been used in several 2G cellular telephony standards, including IS-54, IS-136 (D-AMPS), GSM (Half Rate speech) and iDEN. It was also used in the first version of RealAudio for audio over the Internet. The IS-54 VSELP standard was published by the Telecommunications Industry Association in 1989. D-AMPS (IS-54 and IS-136) VSELP specifies an encoding of each 20 ms of speech into 159-bit frames, thus achieving a raw data rate of 7.95 kbit/s. In an actual TDMA cell phone, the vocoder output is packaged with error correction and signaling information, resulting in an over-th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vocoder
A vocoder (, a portmanteau of ''vo''ice and en''coder'') is a category of speech coding that analyzes and synthesizes the human voice signal for audio data compression, multiplexing, voice encryption or voice transformation. The vocoder was invented in 1938 by Homer Dudley at Bell Labs as a means of synthesizing human speech. This work was developed into the channel vocoder which was used as a voice codec for telecommunications for speech coding to conserve bandwidth in transmission. By encrypting the control signals, voice transmission can be secured against interception. Its primary use in this fashion is for secure radio communication. The advantage of this method of encryption is that none of the original signal is sent, only envelopes of the bandpass filters. The receiving unit needs to be set up in the same filter configuration to re-synthesize a version of the original signal spectrum. The vocoder has also been used extensively as an electronic musical instrument ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IMBE
Multi-Band Excitation (MBE) is a series of proprietary speech coding standards developed by Digital Voice Systems, Inc. (DVSI). Overview In 1967 Osamu Fujimura (MIT) showed basic advantages of the multi-band representation of speech ("An Approximation to Voice Aperiodicity", IEEE 1968). This work gave a start to development of the "multi-band excitation" method of speech coding, that was patented in 1997 (now expired) by founders of DVSI as "Multi-Band Excitation" (MBE). All consequent improvements known as ''Improved Multi-Band Excitation'' (IMBE), ''Advanced Multiband Excitation'' (AMBE), AMBE+ and AMBE+2 are based on this MBE method. AMBE is a codebook-based vocoder that operates at bitrates of between 2 and 9.6 kbit/s, and at a sampling rate of 8 kHz in 20-ms frames. The audio data is usually combined with up to 7 bit/s of forward error correction data, producing a total RF bandwidth of approximately 2,250 Hz (compared to 2,700–3,000 Hz for an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
