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Imbe Station Bizen Okayama Pref Japan03s3
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] |
Speech Coding
Speech coding is an application of data compression to digital audio signals containing speech. Speech coding uses speech-specific parameter estimation using audio signal processing techniques to model the speech signal, combined with generic data compression algorithms to represent the resulting modeled parameters in a compact bitstream. Common applications of speech coding are mobile telephony and voice over IP (VoIP). The most widely used speech coding technique in mobile telephony is linear predictive coding (LPC), while the most widely used in VoIP applications are the LPC and modified discrete cosine transform (MDCT) techniques. The techniques employed in speech coding are similar to those used in audio data compression and audio coding where appreciation of psychoacoustics is used to transmit only data that is relevant to the human auditory system. For example, in voiceband speech coding, only information in the frequency band 400 to 3500 Hz is transmitted but the re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Patent
A patent is a type of intellectual property that gives its owner the legal right to exclude others from making, using, or selling an invention for a limited period of time in exchange for publishing an sufficiency of disclosure, enabling disclosure of the invention."A patent is not the grant of a right to make or use or sell. It does not, directly or indirectly, imply any such right. It grants only the right to exclude others. The supposition that a right to make is created by the patent grant is obviously inconsistent with the established distinctions between generic and specific patents, and with the well-known fact that a very considerable portion of the patents granted are in a field covered by a former relatively generic or basic patent, are tributary to such earlier patent, and cannot be practiced unless by license thereunder." – ''Herman v. Youngstown Car Mfg. Co.'', 191 F. 579, 584–85, 112 CCA 185 (6th Cir. 1911) In most countries, patent rights fall under private la ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Digital Mobile Radio
Digital Mobile Radio (DMR) is a digital radio Technical standard, standard for voice and data transmission in non-public Radio network, radio networks. It was created by the European Telecommunications Standards Institute (ETSI), and is designed to be low-cost and easy to use. DMR, along with Project 25#Phase 2, P25 phase II and NXDN are the main competitor technologies in achieving 6.25 kHz equivalent bandwidth using the proprietary Multi-Band Excitation, AMBE+2 vocoder. DMR and P25 II both use two-slot Time division multiple access, 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 (Unlicensed) and II (Conventional Licensed) 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 t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bruce Perens
Bruce Perens (born around 1958) is an American computer programmer and advocate in the free software movement. He created ''The Open Source Definition'' and published the first formal announcement and manifesto of open source. He co-founded the Open Source Initiative (OSI) with Eric S. Raymond. In 2005, Perens represented Open Source at the United Nations World Summit on the Information Society, at the invitation of the United Nations Development Programme. He has appeared before national legislatures and is often quoted in the press, advocating for open source and the reform of national and international technology policy. Perens is also an amateur radio operator, with call sign K6BP. He promotes open radio communications standards and open-source hardware. In 2016 Perens, along with Boalt Hall (Berkeley Law) professor Lothar Determann, co-authored "Open Cars" which appeared in the Berkeley Technology Law Journal. In 2018 Perens founded the Open Research Institute (ORI), a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Codec2
Codec 2 is a low-bitrate speech audio codec (speech coding) that is patent free and open source. Codec 2 compresses speech using sinusoidal coding, a method specialized for human speech. Bit rates of 3200 to 450 bit/s have been successfully created. Codec 2 was designed to be used for amateur radio and other high compression voice applications. Overview The codec was developed by David Grant Rowe, with support and cooperation of other researchers (e.g., Jean-Marc Valin from Opus). Codec 2 consists of 3200, 2400, 1600, 1400, 1300, 1200, 700 and 450 bit/s codec modes. It outperforms most other low-bitrate speech codecs. For example, it uses half the bandwidth of Advanced Multi-Band Excitation to encode speech with similar quality. The speech codec uses 16-bit PCM sampled audio, and outputs packed digital bytes. When sent packed digital bytes, it outputs PCM sampled audio. The audio sample rate is fixed at 8 kHz. The reference implementation is open source and is f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Digital Mobile Radio
Digital Mobile Radio (DMR) is a digital radio Technical standard, standard for voice and data transmission in non-public Radio network, radio networks. It was created by the European Telecommunications Standards Institute (ETSI), and is designed to be low-cost and easy to use. DMR, along with Project 25#Phase 2, P25 phase II and NXDN are the main competitor technologies in achieving 6.25 kHz equivalent bandwidth using the proprietary Multi-Band Excitation, AMBE+2 vocoder. DMR and P25 II both use two-slot Time division multiple access, 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 (Unlicensed) and II (Conventional Licensed) 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 t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Motorola Solutions
Motorola Solutions, Inc. is an American technology, communications, and security company, headquartered in Chicago, Chicago, Illinois. It is the legal successor of Motorola, Inc., following the spinoff of the mobile phone division into Motorola Mobility in 2011. Motorola Solutions is focused on mission-critical communications including land mobile radio, such as enterprise two-way radios and consumer-grade walkie-talkies and baby monitors, emergency and public safety LTE (telecommunication), LTE devices, video surveillance and security software. History On January 4, 2011 Motorola Inc. split into two companies: Motorola Mobility and Motorola Solutions. Motorola Solutions, the public safety and enterprise security side of the business, began trading as a separate independent company under the NYSE symbol MSI. In April 2011, Motorola Solutions and China’s Huawei Technologies settled a legal dispute over trade secrets, which cleared the way for Motorola Solutions to complete ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
APCO Project 25
Project 25 (P25 or APCO-25) is a suite of standards for interoperable Land Mobile Radio (LMR) systems designed primarily for public safety users. The standards allow analog conventional, digital conventional, digital trunked, or mixed-mode systems. P25 was originally developed for public safety users in the United States but has gained acceptance for public safety, security, public service, and some commercial applications worldwide. P25 radios are a replacement for analog UHF (typically FM) radios, adding the ability to transfer data as well as voice for more natural implementations of encryption and text messaging. P25 radios are commonly implemented by dispatch organizations, such as police, fire, ambulance and emergency rescue service, using vehicle-mounted radios combined with repeaters and handheld walkie-talkie use. Starting around 2012, products became available with the newer Phase II modulation protocol. The older protocol known as P25 became P25 Phase I. P25 Phase ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NXDN
NXDN stands for Next Generation Digital Narrowband, and is an open standard for public land mobile radio systems; that is, systems of two-way radios (transceivers) for bidirectional person-to-person voice communication. It was developed jointly by Icom Incorporated and Kenwood Corporation as an advanced digital system using FSK modulation that supports encrypted transmission and data as well as voice transmission. Like other land mobile systems, NXDN systems use the VHF and UHF frequency bands. It is also used as a niche mode in amateur radio. NXDN is implemented by Icom in their IDAS system and by Kenwood as NEXEDGE; both Kenwood and Icom now offer dual-standard equipment which supports the European dPMR standard. History Icom and Kenwood began their collaboration in 2003. The NXDN protocol was announced in 2005, and NXDN-compatible products first appeared in 2006. The NXDN Common Air Interface (CAI) was accepted at the Study Group 5 (SG5) meeting of the International ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frequency-shift Keying
Frequency-shift keying (FSK) is a frequency modulation scheme in which digital information is encoded on a carrier signal by periodically shifting the frequency of the carrier between several discrete frequencies. The technology is used for communication systems such as telemetry, weather balloon radiosondes, caller ID, garage door openers, and low frequency radio transmission in the VLF and ELF bands. The simplest FSK is binary FSK (BFSK, which is also commonly referred to as 2FSK or 2-FSK), in which the carrier is shifted between two discrete frequencies to transmit binary (0s and 1s) information. Modulating and demodulating Reference implementations of FSK modems exist and are documented in detail. The demodulation of a binary FSK signal can be done using the Goertzel algorithm very efficiently, even on low-power microcontrollers. Variations Multiple frequency-shift keying Continuous-phase frequency-shift keying In principle FSK can be implemented by usin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yaesu (brand)
Yaesu is a Japanese brand of amateur radio equipment, founded as in 1959 by a Japanese radio amateur Sako Hasegawa (call sign JA1MP) in Yaesu, Japan, a district of Tokyo. History Yaesu had initially been formed with the intention to develop and manufacture commercial and amateur radio transceivers for the Japanese market, but only five years after its formation the company had signed foreign sales agreements for export to Australia and Germany. In Europe, the equipment was sold under the Yaesu brand and the Sommerkamp brand. In 1963 the Swiss firm Sommerkamp imported Yaesu equipment and sold it using their own brand. Yaesu's line of equipment was first imported into the US by Spectronics, Inc. located in Signal Hill, California, in 1965. Yaesu became an important presence in the U.S. amateur radio market with the introduction and improvement of its very popular FT-101 line of equipment in the 1970s. In addition, transceiver manufacture was outsourced to Henry Radio in L ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
System Fusion
A system is a group of interacting or interrelated elements that act according to a set of rules to form a unified whole. A system, surrounded and influenced by its open system (systems theory), environment, is described by its boundaries, structure and purpose and is expressed in its functioning. Systems are the subjects of study of systems theory and other systems sciences. Systems have several common properties and characteristics, including structure, function(s), behavior and interconnectivity. Etymology The term ''system'' comes from the Latin word ''systēma'', in turn from Greek language, Greek ''systēma'': "whole concept made of several parts or members, system", literary "composition"."σύστημα" , Henry George Liddell, Robert Scott, ''A Greek–English Lexicon'', on Pers ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
