Ethernet is a family of wired computer networking technologies commonly used in local area networks (LAN), metropolitan area networks (MAN) and wide area networks (WAN). It was commercially introduced in 1980 and first standardized in 1983 as IEEE 802.3. Ethernet has since been refined to support higher bit rates, a greater number of nodes, and longer link distances, but retains much backward compatibility. Over time, Ethernet has largely replaced competing wired LAN technologies such as Token Ring, FDDI and ARCNET.
100BaseVG is a 100 Mbit/s Ethernet standard specified to run over four pairs of Category 3 cable. It is also called 100VG-AnyLAN because it was defined to carry both Ethernet and Token Ring frame types.
Ethernet over twisted-pair technologies use twisted-pair cables for the physical layer of an Ethernet computer network. They are a subset of all Ethernet physical layers.
Carrier-sense multiple access with collision detection (CSMA/CD) is a medium access control (MAC) method used most notably in early Ethernet technology for local area networking. It uses carrier-sensing to defer transmissions until no other stations are transmitting. This is used in combination with collision detection in which a transmitting station detects collisions by sensing transmissions from other stations while it is transmitting a frame. When this collision condition is detected, the station stops transmitting that frame, transmits a jam signal, and then waits for a random time interval before trying to resend the frame.
Carrier-sense multiple access (CSMA) is a medium access control (MAC) protocol in which a node verifies the absence of other traffic before transmitting on a shared transmission medium, such as an electrical bus or a band of the electromagnetic spectrum.
In computer networking, Fast Ethernet physical layers carry traffic at the nominal rate of 100 Mbit/s. The prior Ethernet speed was 10 Mbit/s. Of the Fast Ethernet physical layers, 100BASE-TX is by far the most common.
In the seven-layer OSI model of computer networking, the physical layer or layer 1 is the first and lowest layer: the layer most closely associated with the physical connection between devices. The physical layer provides an electrical, mechanical, and procedural interface to the transmission medium. The shapes and properties of the electrical connectors, the frequencies to transmit on, the line code to use and similar low-level parameters, are specified by the physical layer.
In IEEE 802 LAN/MAN standards, the medium access control (MAC), also called media access control, is the layer that controls the hardware responsible for interaction with the wired 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, while the MAC provides flow control and multiplexing for the transmission medium.
IEEE 802.11e-2005 or 802.11e is an approved amendment to the IEEE 802.11 standard that defines a set of quality of service (QoS) enhancements for wireless LAN applications through modifications to the media access control (MAC) layer. The standard is considered of critical importance for delay-sensitive applications, such as voice over wireless LAN and streaming multimedia. The amendment has been incorporated into the published IEEE 802.11-2007 standard.
Distributed coordination function (DCF) is the fundamental medium access control (MAC) technique of the IEEE 802.11-based WLAN standard. DCF employs a carrier-sense multiple access with collision avoidance (CSMA/CA) with the binary exponential backoff algorithm.
IEEE 802.15.4 is a technical standard which defines the operation of a low-rate wireless personal area network (LR-WPAN). It specifies the physical layer and media access control for LR-WPANs, and is maintained by the IEEE 802.15 working group, which defined the standard in 2003. It is the basis for the Zigbee, ISA100.11a, WirelessHART, MiWi, 6LoWPAN, Thread, Matter and SNAP specifications, each of which further extends the standard by developing the upper layers which are not defined in IEEE 802.15.4. In particular, 6LoWPAN defines a binding for the IPv6 version of the Internet Protocol (IP) over WPANs, and is itself used by upper layers like Thread.
Beacon frame is one of the management frames in IEEE 802.11 based WLANs. It contains all the information about the network. Beacon frames are transmitted periodically, they serve to announce the presence of a wireless LAN and to synchronise the members of the service set. Beacon frames are transmitted by the access point (AP) in an infrastructure basic service set (BSS). In IBSS network beacon generation is distributed among the stations. For the 2.4 GHz spectrum, when having more than 15 SSIDs on non-overlapping channels, beacon frames start to consume significant amount of air time and degrade performance even when most of the networks are idle.
Point Coordination Function (PCF) is a media access control (MAC) technique used in IEEE 802.11 based WLANs, including Wi-Fi. It resides in a point coordinator also known as access point (AP), to coordinate the communication within the network. The AP waits for PIFS duration rather than DIFS duration to grasp the channel. PIFS is less than DIFS duration and hence the point coordinator always has the priority to access the channel.
Autonegotiation is a signaling mechanism and procedure used by Ethernet over twisted pair by which two connected devices choose common transmission parameters, such as speed, duplex mode, and flow control. In this process, the connected devices first share their capabilities regarding these parameters and then choose the highest performance transmission mode they both support.
The physical-layer specifications of the Ethernet family of computer network standards are published by the Institute of Electrical and Electronics Engineers (IEEE), which defines the electrical or optical properties and the transfer speed of the physical connection between a device and the network or between network devices. It is complemented by the MAC layer and the logical link layer. An implementation of a specific physical layer is commonly referred to as PHY.
Token Ring is a physical and data link layer computer networking technology used to build local area networks. It was introduced by IBM in 1984, and standardized in 1989 as IEEE 802.5. It uses a special three-byte frame called a token that is passed around a logical ring of workstations or servers. This token passing is a channel access method providing fair access for all stations, and eliminating the collisions of contention-based access methods.
PME Aggregation Function (PAF) is a computer networking mechanism defined in Clause 61 of the IEEE 802.3 standard, which allows one or more Physical Medium Entities (PMEs) to be combined to form a single logical Ethernet link.
In computer networking, an Ethernet frame is a data link layer protocol data unit and uses the underlying Ethernet physical layer transport mechanisms. In other words, a data unit on an Ethernet link transports an Ethernet frame as its payload.
The 5-4-3 rule, also referred to as the IEEE way, is a design guideline for Ethernet computer networks covering the number of repeaters and segments on shared-medium Ethernet backbones in a tree topology. It means that in a collision domain there should be at most 5 segments tied together with 4 repeaters, with up to 3 mixing segments. Link segments can be 10BASE-T, 10BASE-FL or 10BASE-FB. This rule is also designated the 5-4-3-2-1 rule with there being two link segments and one collision domain.
Time-Sensitive Networking (TSN) is a set of standards under development by the Time-Sensitive Networking task group of the IEEE 802.1 working group. The TSN task group was formed in November 2012 by renaming the existing Audio Video Bridging Task Group and continuing its work. The name changed as a result of the extension of the working area of the standardization group. The standards define mechanisms for the time-sensitive transmission of data over deterministic Ethernet networks.
