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Frame Aggregation
Frame aggregation is a feature that allows communicating on shared link or channel, typically a TDM shared channel, with minimum time slot that for efficiency reasons benefit from filling the time slot with data, i.e. sending two or more data frames in a single transmission. The feature is an important part of the IEEE 802.11e, 802.11n and 802.11ac wireless LAN standards that increases throughput with frame aggregation. The MoCA protocol used for communication over coaxial networks also implements frame aggregation for the same reason. In protocol standards and implementations, the frame aggregation is usually combined with segmentation and reassembly of frames so that the time slots can be filled to 100%. E.g., an aggregation MAC PDU can be filled with 3.5 frames to ensure the time slot is utilized to 100% and in the next time slot the rest of the fragmented frame is sent together with any additional complete frames. The article uses IEEE 802.11 as a basis for explanations ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Frame (networking)
A frame is a digital data transmission unit in computer networking and telecommunication. In packet switched systems, a frame is a simple container for a single network packet. In other telecommunications systems, a frame is a repeating structure supporting time-division multiplexing. A frame typically includes frame synchronization features consisting of a sequence of bits or symbols that indicate to the receiver the beginning and end of the payload data within the stream of symbols or bits it receives. If a receiver is connected to the system during frame transmission, it ignores the data until it detects a new frame synchronization sequence. Packet switching In the OSI model of computer networking, a frame is the protocol data unit at the data link layer. Frames are the result of the final layer of encapsulation before the data is transmitted over the physical layer. A frame is "the unit of transmission in a link layer protocol, and consists of a link layer header followed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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IEEE
The Institute of Electrical and Electronics Engineers (IEEE) is a 501(c)(3) professional association for electronic engineering and electrical engineering (and associated disciplines) with its corporate office in New York City and its operations center in Piscataway, New Jersey. The mission of the IEEE is ''advancing technology for the benefit of humanity''. The IEEE was formed from the amalgamation of the American Institute of Electrical Engineers and the Institute of Radio Engineers in 1963. Due to its expansion of scope into so many related fields, it is simply referred to by the letters I-E-E-E (pronounced I-triple-E), except on legal business documents. , it is the world's largest association of technical professionals with more than 423,000 members in over 160 countries around the world. Its objectives are the educational and technical advancement of electrical and electronic engineering, telecommunications, computer engineering and similar disciplines. History Ori ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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IEEE 802
IEEE 802 is a family of Institute of Electrical and Electronics Engineers (IEEE) standards for local area networks (LAN), personal area network (PAN), and metropolitan area networks (MAN). The IEEE 802 LAN/MAN Standards Committee (LMSC) maintains these standards. The IEEE 802 family of standards has had twenty-four members, numbered 802.1 through 802.24, with a working group of the LMSC devoted to each. However, not all of these working groups are currently active. The IEEE 802 standards are restricted to computer networks carrying variable-size packets, unlike cell relay networks, for example, in which data is transmitted in short, uniformly sized units called cells. Isochronous signal networks, in which data is transmitted as a steady stream of octets, or groups of octets, at regular time intervals, are also outside the scope of the IEEE 802 standards. The number 802 has no significance: it was simply the next number in the sequence that the IEEE used for standards project ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Wireless LAN
A wireless LAN (WLAN) is a wireless computer network that links two or more devices using wireless communication to form a local area network (LAN) within a limited area such as a home, school, computer laboratory, campus, or office building. This gives users the ability to move around within the area and remain connected to the network. Through a gateway, a WLAN can also provide a connection to the wider Internet. Wireless LANs based on the IEEE 802.11 standards are the most widely used computer networks in the world. These are commonly called Wi-Fi, which is a trademark belonging to the Wi-Fi Alliance. They are used for home and small office networks that link together laptop computers, printers, smartphones, Web TVs and gaming devices with a wireless router, which links them to the internet. Hotspots provided by routers at restaurants, coffee shops, hotels, libraries, and airports allow consumers to access the internet with portable wireless devices. History Norman ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Multimedia Over Coax Alliance
The Multimedia over Coax Alliance (MoCA) is an international standards consortium that publishes specifications for networking over coaxial cable. The technology was originally developed to distribute IP television in homes using existing cabling, but is now used as a general-purpose Ethernet link where it is inconvenient or undesirable to replace existing coaxial cable with optical fiber or twisted pair cabling. MoCA 1.0 was approved in 2006, MoCA 1.1 in April 2010, MoCA 2.0 in June 2010, and MoCA 2.5 in April 2016. The most recently released version of the standard, MoCA 2.5, supports speeds of up to . Membership The Alliance currently has 45 members including pay TV operators, OEMs, CE manufacturers and IC vendors. MoCA's board of directors consists of Arris, Comcast, Cox Communications, DirecTV, Echostar, Intel, InCoax, MaxLinear and Verizon. Technology Within the scope of the Internet protocol suite, MoCA is a protocol that provides the link layer. In the 7-lay ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Segmentation And Reassembly
Segmentation and reassembly (SAR) is the process used to fragment and reassemble variable length packets into fixed length cells so as to allow them to be transported across Asynchronous Transfer Mode Asynchronous Transfer Mode (ATM) is a telecommunications standard defined by American National Standards Institute (ANSI) and ITU-T (formerly CCITT) for digital transmission of multiple types of traffic. ATM was developed to meet the needs o ... (ATM) networks or other cell based infrastructures. Since ATM's payload is only 48 bytes, nearly every packet from any other protocol has to be processed in this way. Thus, it is an essential process for any ATM node. It is usually handled by a dedicated chip, called the SAR. The process is conceptually simple: an incoming packet from another protocol to be transmitted across the ATM network is chopped up into segments that fit into 48-byte chunks carried as ATM cell payloads. At the far end, these chunks are fitted back togeth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Protocol Data Unit
In telecommunications, a protocol data unit (PDU) is a single unit of information transmitted among peer entities of a computer network. It is composed of protocol-specific control information and user data. In the layered architectures of communication protocol stacks, each layer implements protocols tailored to the specific type or mode of data exchange. For example, the Transmission Control Protocol (TCP) implements a connection-oriented transfer mode, and the PDU of this protocol is called a ''segment'', while the User Datagram Protocol (UDP) uses datagrams as protocol data units for connectionless communication. A layer lower in the Internet protocol suite, at the Internet layer, the PDU is called a packet, irrespective of its payload type. Packet-switched data networks In the context of packet switching data networks, a protocol data unit (PDU) is best understood in relation to a service data unit (SDU). The features or services of the network are implemented in dist ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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MAC Service Data Unit
MAC service data unit (media access control service data unit, MSDU) is the service data unit that is received from the logical link control (LLC) sub-layer which lies above the media access control (MAC) sub-layer in a protocol stack. The LLC and MAC sub-layers are collectively referred to as the data link layer (DLL). See also * MAC protocol data unit * Packet segmentation In data communications networks, packet segmentation is the process of dividing a data packet into smaller units for transmission over the network. Packet segmentation happens at layer four of the OSI model; the transport layer. Segmentation m ... * Packet aggregation External links 802.11 Wireless LAN IEEE standard Media access control {{telecomm-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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MAC Protocol Data Unit
In telecommunications, a protocol data unit (PDU) is a single unit of information transmitted among peer entities of a computer network. It is composed of protocol-specific control information and user data. In the layered architectures of communication protocol stacks, each layer implements protocols tailored to the specific type or mode of data exchange. For example, the Transmission Control Protocol (TCP) implements a connection-oriented transfer mode, and the PDU of this protocol is called a ''segment'', while the User Datagram Protocol (UDP) uses datagrams as protocol data units for connectionless communication. A layer lower in the Internet protocol suite, at the Internet layer, the PDU is called a packet, irrespective of its payload type. Packet-switched data networks In the context of packet switching data networks, a protocol data unit (PDU) is best understood in relation to a service data unit (SDU). The features or services of the network are implemented in disti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Header (computing)
In information technology, header refers to supplemental data placed at the beginning of a block of data being stored or transmitted. In data transmission, the data following the header is sometimes called the '' payload'' or '' body''. It is vital that header composition follows a clear and unambiguous specification or format, to allow for parsing. Examples * E-mail header: The text (body) is preceded by header lines indicating sender, recipient, subject, sending time stamp, receiving time stamps of all intermediate and the final mail transfer agents, and much more. * Similar headers are used in Usenet ( NNTP) messages, and HTTP headers. * In a data packet sent via the Internet, the data (payload) are preceded by header information such as the sender's and the recipient's IP addresses, the protocol governing the format of the payload and several other formats. The header's format is specified in the Internet Protocol. * In data packets sent by wireless communication, and i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Media Access Control
In IEEE 802 LAN/MAN standards, the medium access control (MAC, also called media access control) sublayer is the layer that controls the hardware responsible for interaction with the wired, optical or wireless transmission medium. The MAC sublayer and the logical link control (LLC) sublayer together make up the data link layer. The LLC provides flow control and multiplexing for the logical link (i.e. EtherType, 802.1Q VLAN tag etc), while the MAC provides flow control and multiplexing for the transmission medium. These two sublayers together correspond to layer 2 of the OSI model. For compatibility reasons, LLC is optional for implementations of IEEE 802.3 (the frames are then "raw"), but compulsory for implementations of other IEEE 802 physical layer standards. Within the hierarchy of the OSI model and IEEE 802 standards, the MAC sublayer provides a control abstraction of the physical layer such that the complexities of physical link control are invisible to the LLC and upp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Bandwidth (computing)
In computing, bandwidth is the maximum rate of data transfer across a given path. Bandwidth may be characterized as network bandwidth, data bandwidth, or digital bandwidth. This definition of ''bandwidth'' is in contrast to the field of signal processing, wireless communications, modem data transmission, digital communications, and electronics, in which ''bandwidth'' is used to refer to analog signal bandwidth measured in hertz, meaning the frequency range between lowest and highest attainable frequency while meeting a well-defined impairment level in signal power. The actual bit rate that can be achieved depends not only on the signal bandwidth but also on the noise on the channel. Network capacity The term ''bandwidth'' sometimes defines the net bit rate 'peak bit rate', 'information rate,' or physical layer 'useful bit rate', channel capacity, or the maximum throughput of a logical or physical communication path in a digital communication system. For example, bandwidth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |