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Opportunity-Driven Multiple Access
Opportunity-Driven Multiple Access (ODMA) is a UMTS communications relaying protocol standard first introduced by the European Telecommunication Standards Institute (ETSI) in 1996. ODMA has been adopted by the 3rd-Generation Partnership Project, 3GPP to improve the efficiency of UMTS networks using the TDD mode. One of the objectives of ODMA is to enhance the capacity and the coverage of radio transmissions towards the boundaries of the cell. While mobile stations under the cell coverage area can communicate directly with the base station, mobile stations outside the cell boundary can still access the network and communicating with the base station via multihop transmission. Mobile stations with high data rate inside the cell are used as multihop relays. The initial concept of Opportunity Driven Multiple Access (ODMA) was conceived and patented in South Africa by David Larsen and James Larsen of SRD Pty Ltd in 197 The ODMA standard was tabled by the 3GPP committee in 1999 due to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
UMTS
The Universal Mobile Telecommunications System (UMTS) is a third generation mobile cellular system for networks based on the GSM standard. Developed and maintained by the 3GPP (3rd Generation Partnership Project), UMTS is a component of the International Telecommunication Union IMT-2000 standard set and compares with the CDMA2000 standard set for networks based on the competing cdmaOne technology. UMTS uses wideband code-division multiple access (W-CDMA) radio access technology to offer greater spectral efficiency and bandwidth to mobile network operators. UMTS specifies a complete network system, which includes the radio access network (UMTS Terrestrial Radio Access Network, or UTRAN), the core network (Mobile Application Part, or MAP) and the authentication of users via SIM (subscriber identity module) cards. The technology described in UMTS is sometimes also referred to as Freedom of Mobile Multimedia Access (FOMA) or 3GSM. Unlike EDGE (IMT Single-Carrier, based on GSM) and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Time-division Duplex
A duplex communication system is a point-to-point system composed of two or more connected parties or devices that can communicate with one another in both directions. Duplex systems are employed in many communications networks, either to allow for simultaneous communication in both directions between two connected parties or to provide a reverse path for the monitoring and remote adjustment of equipment in the field. There are two types of duplex communication systems: full-duplex (FDX) and half-duplex (HDX). In a full-duplex system, both parties can communicate with each other simultaneously. An example of a full-duplex device is plain old telephone service; the parties at both ends of a call can speak and be heard by the other party simultaneously. The earphone reproduces the speech of the remote party as the microphone transmits the speech of the local party. There is a two-way communication channel between them, or more strictly speaking, there are two communication channel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Multi-hop Routing
Multi-hop routing (or multihop routing) is a type of communication in radio networks in which network coverage area is larger than radio range of single nodes. Therefore, to reach some destination a node can use other nodes as relays. Since the transceiver is the major source of power consumption in a radio node and long distance transmission requires high power, in some cases multi-hop routing can be more energy efficient than single-hop routing. Typical applications of multi-hop routing: * Wireless sensor networks * Wireless mesh networks * Mobile ad hoc networks * Smart phone ad hoc network Smartphone ad hoc networks (SPANs; also ''smart phone ad hoc networks'') are wireless ad hoc networks that use smartphones. Once embedded with ad hoc networking technology, a group of smartphones in close proximity can together create an ad hoc ...s * Mobile networks with stationary multi-hop relays References {{reflist Wireless networking ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ODMA
The Open Document Management API is an API that simplifies the communication of desktop applications with document management systems (DMS). ODMA standardizes the access to the DMS, which makes getting to these files as easy as if the files were in the actual local file system. ODMA was an effort to standardize the API to be used by desktop applications on Microsoft Windows to interface with back-end, server based document management systems (DMS). Version 1.0 of the API specification was completed in 1994, and went on to be supported by many of the major DMS vendors. Version 2.0 of the specification was completed in 1997. ODMA has subsequently been superseded by other, more standard ways of interfacing, such as WebDAV or CMIS. See also *Enterprise content management Enterprise content management (ECM) extends the concept of content management by adding a timeline for each content item and, possibly, enforcing processes for its creation, approval and distribution. Systems u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ODMA Route
The Open Document Management API is an API that simplifies the communication of desktop applications with document management systems (DMS). ODMA standardizes the access to the DMS, which makes getting to these files as easy as if the files were in the actual local file system. ODMA was an effort to standardize the API to be used by desktop applications on Microsoft Windows to interface with back-end, server based document management systems (DMS). Version 1.0 of the API specification was completed in 1994, and went on to be supported by many of the major DMS vendors. Version 2.0 of the specification was completed in 1997. ODMA has subsequently been superseded by other, more standard ways of interfacing, such as WebDAV or CMIS. See also *Enterprise content management Enterprise content management (ECM) extends the concept of content management by adding a timeline for each content item and, possibly, enforcing processes for its creation, approval and distribution. Systems u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Code-division Multiple Access
Code-division multiple access (CDMA) is a channel access method used by various radio communication technologies. CDMA is an example of multiple access, where several transmitters can send information simultaneously over a single communication channel. This allows several users to share a band of frequencies (see bandwidth). To permit this without undue interference between the users, CDMA employs spread spectrum technology and a special coding scheme (where each transmitter is assigned a code). CDMA optimizes the use of available bandwidth as it transmits over the entire frequency range and does not limit the user's frequency range. It is used as the access method in many mobile phone standards. IS-95, also called "cdmaOne", and its 3G evolution CDMA2000, are often simply referred to as "CDMA", but UMTS, the 3G standard used by GSM carriers, also uses "wideband CDMA", or W-CDMA, as well as TD-CDMA and TD-SCDMA, as its radio technologies. It can be also used as a channel or m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Time-division Multiple Access
Time-division multiple access (TDMA) is a channel access method for shared-medium networks. It allows several users to share the same frequency channel by dividing the signal into different time slots. The users transmit in rapid succession, one after the other, each using its own time slot. This allows multiple stations to share the same transmission medium (e.g. radio frequency channel) while using only a part of its channel capacity. Dynamic TDMA is a TDMA variant that dynamically reserves a variable number of time slots in each frame to variable bit-rate data streams, based on the traffic demand of each data stream. TDMA is used in the digital 2G cellular systems such as Global System for Mobile Communications (GSM), IS-136, Personal Digital Cellular (PDC) and iDEN, and in the Digital Enhanced Cordless Telecommunications (DECT) standard for portable phones. TDMA was first used in satellite communication systems by Western Union in its Westar 3 communications satellite ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frequency-division Multiple Access
Frequency-division multiple access (FDMA) is a channel access method used in some multiple-access protocols. FDMA allows multiple users to send data through a single communication channel, such as a coaxial cable or microwave beam, by dividing the bandwidth of the channel into separate non-overlapping frequency sub-channels and allocating each sub-channel to a separate user. Users can send data through a subchannel by modulating it on a carrier wave at the subchannel's frequency. It is used in satellite communication systems and telephone trunklines. FDMA splits the total bandwidth into multiple channels. Each ground station on the earth is allocated a particular frequency group (or a range of frequencies). Within each group, the ground station can allocate different frequencies to individual channels, which are used by different stations connected to that ground station. Before the transmission begins, the transmitting ground station looks for an empty channel within the fre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mobile Telecommunications Standards
Mobile may refer to: Places * Mobile, Alabama, a U.S. port city * Mobile County, Alabama * Mobile, Arizona, a small town near Phoenix, U.S. * Mobile, Newfoundland and Labrador Arts, entertainment, and media Music Groups and labels * Mobile (band), a Canadian rock band * Mobiles (band), a 1980s British band Other uses in music * ''Mobile'' (album), a 1999 album by Brazilian Paulinho Moska * "Mobile" (song), a 2003 song by Avril Lavigne from ''Let Go'' * "Mobile", a song by Gentle Giant from the album ''Free Hand'' Other uses in arts, entertainment, and media * Mobile (sculpture), a kinetic sculpture constructed to take advantage of the principle of equilibrium * ''Mobile'' (TV series), a British ITV drama * "Mobile", a short story by J. G. Ballard, later renamed "Venus Smiles" * Mobile, a feature of the game ''GunBound'' * ''Mobile Magazine'', a publication on portable electronics Military and law enforcement * ''Garde Mobile'', historic French military unit * Mobile Briga ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
