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Encoder Receiver Transmitter
Encoder receiver transmitter (ERT) is a packet radio protocol developed by Itron for automatic meter reading. The technology is used to transmit data from utility meters over a short range so a utility vehicle can collect meter data without a worker physically inspecting each meter. The ERT protocol was first described in . More technical detail is explained in later . Technical details ERT is an OOK modulated radio signal which is transmitted in the unlicensed 900-920 MHz band. The message is transmitted in the clear and uses Manchester encoding. The protocol uses frequency-hopping, a multiple access method to avoid interference with other nearby meters. SCM and IDM packet formats are described in SCM packet SCM messages are 12 bytes. Each message contains single, cumulative meter reading value along with the meter serial number, commodity type and checksum and tamper flags. IDM packet IDM messages are 92 bytes and contain time of use consumption data. La ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Packet Radio
In digital radio, packet radio is the application of packet switching techniques to digital radio communications. Packet radio uses a packet switching Communication protocol, protocol as opposed to circuit switching or message switching protocols to transmit digital data via a radio communication link. Packet radio is frequently used by amateur radio operators. The AX.25 (Amateur X.25) protocol was derived from the X.25 data link layer protocol and adapted for amateur radio use. Every AX.25 packet includes the sender's amateur radio callsign, which satisfies the US FCC requirements for amateur radio station identification. AX.25 allows other stations to automatically repeat packets to extend the range of transmissions. It is possible for any packet station to act as a digipeater, linking distant stations with each other through ad hoc networks. This makes packet radio especially useful for emergency communications. Packet radio can be used in mobile communications. Some mobile pa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Itron
The ITRON project was the first sub-project of the TRON project. It has formulated and defined Industrial TRON (ITRON) specification for an embedded real-time OS (RTOS) kernel. Originally undertaken in 1984, ITRON is a Japanese open standard for a real-time operating system initiated under the guidance of Ken Sakamura. This project aims to standardize the RTOS and related specifications for embedded systems, particularly small-scale embedded systems. The ITRON RTOS specification is targeted for consumer electronic devices, such as mobile phones and fax machines. Various vendors sell their own implementations of the RTOS. Details ITRON, and μITRON (sometimes also spelled uITRON or microITRON) are the names of RTOS specifications derived from ITRON projects. The 'μ' character indicates that the particular specification is meant for the smaller 8-bit or 16-bit CPU targets. Specifications are available for free. Commercial implementations are available, and offered under many diff ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Automatic Meter Reading
Automatic meter reading (AMR) is the technology of automatically collecting consumption, diagnostic, and status data from water meter or energy metering devices (gas, electric) and transferring that data to a central database for billing, troubleshooting, and analyzing. This technology mainly saves utility providers the expense of periodic trips to each physical location to read a meter. Another advantage is that billing can be based on near real-time consumption rather than on estimates based on past or predicted consumption. This timely information coupled with analysis can help both utility providers and customers better control the use and production of electric energy, gas usage, or water consumption. AMR technologies include handheld, mobile and network technologies based on telephony platforms (wired and wireless), radio frequency (RF), or powerline transmission. Technologies Touch technology With touch-based AMR, a meter reader carries a handheld computer or data colle ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electricity Meter
file:Hydro quebec meter.JPG, North American domestic analog signal, analog (Galileo Ferraris, Ferraris disk) electricity meter. file:Transparent Electricity Meter found in Israel.JPG, Electricity meter with transparent plastic case (Israel) file:West Bengal State Electricity Distribution Company Limited electricity meter – Purulia, West Bengal, India.jpg, Electricity meter in West Bengal, IndiaAn electricity meter, electric meter, electrical meter, energy meter, or kilowatt-hour meter is a device that measures the amount of electric energy consumed by a House, residence, a business, or an electrically powered device over a time interval. Electric utility, Electric utilities use electric meters installed at customers' premises for electricity pricing, billing and monitoring purposes. They are typically calibrated in billing units, the most common one being the kilowatt hour (''kWh''). They are usually read once each billing period. When energy savings during certain periods ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Public Utility
A public utility company (usually just utility) is an organization that maintains the infrastructure for a public service (often also providing a service using that infrastructure). Public utilities are subject to forms of public control and regulation ranging from local community-based groups to statewide government monopolies. Public utilities are meant to supply goods and services that are considered essential; water, gas, electricity, telephone, waste disposal, and other communication systems represent much of the public utility market. The transmission lines used in the transportation of electricity, or natural gas pipelines, have natural monopoly characteristics. A monopoly can occur when it finds the best way to minimize its costs through economies of scale to the point where other companies cannot compete with it. For example, if many companies are already offering electricity, the additional installation of a power plant will only disadvantage the consumer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
On-off Keying
On-off or Onoff may refer to: * On-off control, a type of feedback controller * On-off keying, a type of line modulation * On-off relationship, a form of personal relationship * On-Off Singles, a type of tennis game * On-off switch, a type of electric switch * Onoff (retailer), an electronics retailer in Estonia, formerly also active in Sweden and Finland Music * Onoff (Irish band), an Irish punk-rock band * On/Off (Japanese band), a Japanese j-pop band * ''On/Off'' (ONF EP), 2017 * ''On/Off'' (Run On EP), 1995 * ''On-Off'' (album), a 2006 album by Marcin Rozynek See also * On and Off (other) * " Off & On", a song by Sophie Ellis-Bextor * "Off/On", a 2022 song by Collar * '' OffOn'', a film by Scott Bartlett {{disambiguation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
33-centimeter Band
The 33-centimeter or 900 MHz band is a portion of the UHF radio spectrum internationally allocated to amateur radio on a secondary basis. It ranges from 902 to 928 MHz and is unique to ITU Region 2 (Americas). It is primarily used for very local communications as opposed to bands lower in frequency. However, very high antennas with high gain have shown 33 centimeters can provide good long-range communications almost equal to systems on lower frequencies such as the 70 centimeter band. The band is also used by industrial, scientific, and medical (ISM) equipment, as well as low-powered unlicensed devices. Amateur stations must accept harmful interference caused by ISM users but may receive protection from unlicensed devices. The 900 MHz frequency is also used as a reference band e.g. to express the total power or impact of the electric field "E" - expressed in V/m - or the power density "S" - expressed in W/m2 - of the overall cellular frequencies emission caused by al ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Manchester Encoding
In telecommunications and data storage, Manchester code (also known as phase encoding, or PE) is a line code in which the encoding of each data bit is either low then high, or high then low, for equal time. It is a self-clocking signal with no DC component. Consequently, electrical connections using a Manchester code are easily galvanically isolated. Manchester code derives its name from its development at the University of Manchester, where the coding was used for storing data on the magnetic drums of the Manchester Mark 1 computer. Manchester code was widely used for magnetic recording on 1600 bpi computer tapes before the introduction of 6250 bpi tapes which used the more efficient group-coded recording. Manchester code was used in early Ethernet physical layer standards and is still used in consumer IR protocols, RFID and near-field communication. It was and still is used for uploading commands to the Voyager spacecraft. Features Manchester coding is a spec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frequency-hopping
Frequency-hopping spread spectrum (FHSS) is a method of transmitting radio signals by rapidly changing the carrier frequency among many frequencies occupying a large spectral band. The changes are controlled by a code known to both transmitter and receiver. FHSS is used to avoid interference, to prevent eavesdropping, and to enable code-division multiple access (CDMA) communications. The frequency band is divided into smaller sub-bands. Signals rapidly change ("hop") their carrier frequencies among the center frequencies of these sub-bands in a determined order. Interference at a specific frequency will affect the signal only during a short interval. FHSS offers four main advantages over a fixed-frequency transmission: # FHSS signals are highly resistant to narrowband interference because the signal hops to a different frequency band. # Signals are difficult to intercept if the frequency-hopping pattern is not known. # Jamming is also difficult if the pattern is unknown; the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Multiple Access Method
In telecommunications and computer networks, a channel access method or multiple access method allows more than two terminals connected to the same transmission medium to transmit over it and to share its capacity. Examples of shared physical media are wireless networks, bus networks, ring networks and point-to-point links operating in half-duplex mode. A channel access method is based on multiplexing, which allows several data streams or signals to share the same communication channel or transmission medium. In this context, multiplexing is provided by the physical layer. A channel access method may also be a part of the multiple access protocol and control mechanism, also known as medium access control (MAC). Medium access control deals with issues such as addressing, assigning multiplex channels to different users and avoiding collisions. Media access control is a sub-layer in the data link layer of the OSI model and a component of the link layer of the TCP/IP model. Fundam ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
BCH Code
In coding theory, the Bose–Chaudhuri–Hocquenghem codes (BCH codes) form a class of cyclic error-correcting codes that are constructed using polynomials over a finite field (also called a '' Galois field''). BCH codes were invented in 1959 by French mathematician Alexis Hocquenghem, and independently in 1960 by Raj Chandra Bose and D. K. Ray-Chaudhuri. The name ''Bose–Chaudhuri–Hocquenghem'' (and the acronym ''BCH'') arises from the initials of the inventors' surnames (mistakenly, in the case of Ray-Chaudhuri). One of the key features of BCH codes is that during code design, there is a precise control over the number of symbol errors correctable by the code. In particular, it is possible to design binary BCH codes that can correct multiple bit errors. Another advantage of BCH codes is the ease with which they can be decoded, namely, via an algebraic method known as syndrome decoding. This simplifies the design of the decoder for these codes, using small ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Net Metering
Net metering (or net energy metering, NEM) is an electricity billing mechanism that allows consumers who generate some or all of their own electricity to use that electricity anytime, instead of when it is generated. This is particularly important with renewable energy sources like Wind power, wind and Solar power, solar, which are Variable renewable energy, non-dispatchable (when not coupled to storage). Monthly net metering allows consumers to use solar power generated during the day at night, or wind from a windy day later in the month. Annual net metering rolls over a net kilowatt-hour (kWh) credit to the following month, allowing solar power that was generated in July to be used in December, or wind power from March in August. Net metering policies can vary significantly by country and by state or province: if net metering is available, if and how long banked credits can be retained, and how much the credits are worth (retail/wholesale). Most net metering laws involve mont ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
