Ethernet Physical Layer
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Ethernet 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 198 ...
family of
computer network A computer network is a collection of communicating computers and other devices, such as printers and smart phones. In order to communicate, the computers and devices must be connected by wired media like copper cables, optical fibers, or b ...
standards are published by the
Institute of Electrical and Electronics Engineers The Institute of Electrical and Electronics Engineers (IEEE) is an American 501(c)(3) public charity professional organization for electrical engineering, electronics engineering, and other related disciplines. The IEEE has a corporate office ...
(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 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, mechani ...
. The Ethernet physical layer has evolved over its existence starting in 1980 and encompasses multiple physical media interfaces and several
orders of magnitude In a ratio scale based on powers of ten, the order of magnitude is a measure of the nearness of two figures. Two numbers are "within an order of magnitude" of each other if their ratio is between 1/10 and 10. In other words, the two numbers are wi ...
of speed from to . The physical medium ranges from bulky
coaxial cable Coaxial cable, or coax (pronounced ), is a type of electrical cable consisting of an inner Electrical conductor, conductor surrounded by a concentric conducting Electromagnetic shielding, shield, with the two separated by a dielectric (Insulat ...
to
twisted pair Twisted pair cabling is a type of communications cable in which two conductors of a single circuit are twisted together for the purposes of improving electromagnetic compatibility. Compared to a single conductor or an untwisted balanced ...
and
optical fiber An optical fiber, or optical fibre, is a flexible glass or plastic fiber that can transmit light from one end to the other. Such fibers find wide usage in fiber-optic communications, where they permit transmission over longer distances and at ...
with a standardized reach of up to 80 km. In general, network
protocol stack The protocol stack or network stack is an implementation of a computer networking protocol suite or protocol family. Some of these terms are used interchangeably but strictly speaking, the ''suite'' is the definition of the communication protoc ...
software will work similarly on all physical layers. Many Ethernet adapters and
switch In electrical engineering, a switch is an electrical component that can disconnect or connect the conducting path in an electrical circuit, interrupting the electric current or diverting it from one conductor to another. The most common type o ...
ports support multiple speeds by using
autonegotiation 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_(telecommunications), duplex mode, and Flow_control_(data), flow ...
to set the speed and duplex for the best values supported by both connected devices. If autonegotiation fails, some multiple-speed devices sense the speed used by their partner, but this may result in a
duplex mismatch On an Ethernet connection, a duplex mismatch is a condition where two connected devices operate in different duplex modes, that is, one operates in half duplex while the other one operates in full duplex. The effect of a duplex mismatch is a li ...
. With rare exceptions, a
100BASE-TX In computer networking, Fast Ethernet physical layers carry traffic at the nominal rate of . The prior Ethernet speed was . Of the Fast Ethernet physical layers, 100BASE-TX is by far the most common. Fast Ethernet was introduced in 1995 as t ...
port (''
10/100 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. Early Ethernet used various grades of coaxial cable, but in 1984, StarL ...
'') also supports
10BASE-T 1 (one, unit, unity) is a number, numeral, and glyph. It is the first and smallest positive integer of the infinite sequence of natural numbers. This fundamental property has led to its unique uses in other fields, ranging from science to sp ...
while a
1000BASE-T In computer networking, Gigabit Ethernet (GbE or 1 GigE) is the term applied to transmitting Ethernet frames at a rate of a gigabit per second. The most popular variant, 1000BASE-T, is defined by the IEEE 802.3ab standard. It came into use i ...
port (''
10/100/1000 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. Early Ethernet used various grades of coaxial cable, but in 1984, StarLA ...
'') also supports 10BASE-T and 100BASE-TX. Most
10GBASE-T 10 Gigabit Ethernet (abbreviated 10GE, 10GbE, or 10 GigE) is a group of computer networking technologies for transmitting Ethernet frames at a rate of 10  gigabits per second. It was first defined by the IEEE 802.3ae-2002 standard. Unli ...
ports also support 1000BASE-T, some even 100BASE-TX or 10BASE-T. While autonegotiation can practically be relied on for
Ethernet over twisted pair 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. Early Ethernet used various grades of coaxial cable, but in 1984, Star ...
, few optical-fiber ports support multiple speeds. In any case, even multi-rate fiber interfaces only support a single wavelength (e.g. 850 nm for 1000BASE-SX or 10GBASE-SR).
10 Gigabit Ethernet 10 Gigabit Ethernet (abbreviated 10GE, 10GbE, or 10 GigE) is a group of computer networking technologies for transmitting Ethernet frames at a rate of 10  gigabits per second. It was first defined by the IEEE 802.3ae-2002 standard. Unlik ...
was already used in both enterprise and carrier networks by 2007, with and
100 Gigabit Ethernet 40 Gigabit Ethernet (40GbE) and 100 Gigabit Ethernet (100GbE) are groups of computer networking technologies for transmitting Ethernet frames at rates of 40 and 100 gigabits per second (Gbit/s), respectively. These technologies offer significantly ...
ratified. In 2024, the fastest additions to the Ethernet family were variants.


Naming conventions

Generally, layers are named by their specifications: * ''10, 100, 1000, 10G, ...'' – the nominal, usable speed at the top of the physical layer (no suffix = , ''G'' = ), excluding
line code In telecommunications, a line code is a pattern of voltage, current, or photons used to represent digital data transmission (telecommunications), transmitted down a communication channel or written to a storage medium. This repertoire of signal ...
s but including other physical layer overhead ( preamble, SFD, IPG); some WAN PHYs (''W'') run at slightly reduced bitrates for compatibility reasons; encoded PHY sublayers usually run at higher bitrates * ''BASE, BROAD, PASS'' – indicates
baseband In telecommunications and signal processing, baseband is the range of frequencies occupied by a signal that has not been modulated to higher frequencies. Baseband signals typically originate from transducers, converting some other variable into ...
,
broadband In telecommunications, broadband or high speed is the wide-bandwidth (signal processing), bandwidth data transmission that exploits signals at a wide spread of frequencies or several different simultaneous frequencies, and is used in fast Inter ...
, or
passband A passband is the range of frequency, frequencies or wavelengths that can pass through a Filter (signal processing), filter. For example, a radio receiver contains a bandpass filter to select the frequency of the desired radio signal out of all t ...
signaling respectively * ''-T, -T1, -S, -L, -E, -Z, -C, -K, -H ...'' – medium ( PMD): ''T'' =
twisted pair Twisted pair cabling is a type of communications cable in which two conductors of a single circuit are twisted together for the purposes of improving electromagnetic compatibility. Compared to a single conductor or an untwisted balanced ...
, ''-T1'' = single-pair twisted pair, ''S'' = 850 nm short wavelength (
multi-mode fiber Multi-mode optical fiber is a type of optical fiber mostly used for communication over short distances, such as within a building or on a campus. Multi-mode links can be used for data rates up to 800 Gbit/s. Multi-mode fiber has a fairly ...
), ''L'' = 1300 nm long wavelength (mostly
single-mode fiber In fiber-optic communication, a single-mode optical fiber, also known as fundamental- or mono-mode, is an optical fiber designed to carry only a single mode of light - the transverse mode. Modes are the possible solutions of the Helmholtz equ ...
), ''E'' or ''Z'' = 1500 nm extra long wavelength (single-mode), ''B'' = bidirectional fiber (mostly single-mode) using WDM, ''P'' = passive optical ( PON), ''C'' = copper/ twinax, ''K'' =
backplane A backplane or backplane system is a group of electrical connectors in parallel with each other, so that each pin of each connector is linked to the same relative pin of all the other connectors, forming a computer bus. It is used to connect s ...
, ''2'' or ''5'' or ''36'' =
coax Coaxial cable, or coax (pronounced ), is a type of electrical cable consisting of an inner conductor surrounded by a concentric conducting shield, with the two separated by a dielectric ( insulating material); many coaxial cables also have a p ...
with 185/500/3600 m reach (obsolete), ''F'' = fiber, various wavelengths, ''H'' =
plastic optical fiber Plastic optical fiber (POF) or polymer optical fiber is an optical fiber that is made out of polymer. Similar to glass optical fiber, POF transmits light (for illumination or data) through the core of the fiber. Its chief advantage over the gl ...
* ''X, R'' – PCS encoding method (varying with the generation): ''X'' for 8b/10b block encoding (
4B5B In telecommunications, 4B5B is a form of data communications line code. 4B5B maps groups of 4 bits of data onto groups of 5 bits for transmission. These 5-bit words are predetermined in a dictionary and they are chosen to ensure that there will b ...
for Fast Ethernet), ''R'' for large block encoding ( 64b/66b) * ''1, 2, 4, 10'' – for LAN PHYs indicates number of lanes used per link; for WAN PHYs indicates reach in kilometers For , no encoding is indicated as all variants use
Manchester code 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 ...
. Most twisted pair layers use unique encoding, so most often just ''-T'' is used. The ''reach'', especially for optical connections, is defined as the maximum achievable link length that is guaranteed to work when all channel parameters are met (
modal bandwidth Modal may refer to: * Modal (textile) * Modal (drug) * Modal (company) See also * Mode (disambiguation) Mode ( meaning "manner, tune, measure, due measure, rhythm, melody") may refer to: Arts and entertainment * MO''D''E (magazine), a def ...
,
attenuation In physics, attenuation (in some contexts, extinction) is the gradual loss of flux intensity through a Transmission medium, medium. For instance, dark glasses attenuate sunlight, lead attenuates X-rays, and water and air attenuate both light and ...
,
insertion loss In telecommunications, insertion loss is the loss of signal power resulting from the insertion of a device in a transmission line or optical fiber and is usually expressed in decibels (dB). If the power transmitted to the load before insertio ...
es etc.). With better channel parameters, often a longer, stable link length can be achieved. Vice versa, a link with worse channel parameters can also work but only over a shorter distance. ''Reach'' and ''maximum distance'' have the same meaning.


Physical layers

The following sections provide a brief summary of official Ethernet media types. In addition to these official standards, many vendors have implemented proprietary media types for various reasons—often to support longer distances over
fiber optic An optical fiber, or optical fibre, is a flexible glass or plastic fiber that can transmit light from one end to the other. Such fibers find wide usage in fiber-optic communications, where they permit transmission over longer distances and at ...
cabling.


Early implementations and

Early Ethernet standards used
Manchester coding 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 ...
so that the signal was
self-clocking In telecommunications and electronics, a self-clocking signal is one that can be decoded without the need for a separate clock signal or other source of Synchronization (computer science), synchronization. This is usually done by including embedd ...
and not adversely affected by
high-pass filter A high-pass filter (HPF) is an electronic filter that passes signals with a frequency higher than a certain cutoff frequency and attenuates signals with frequencies lower than the cutoff frequency. The amount of attenuation for each frequency ...
s.


All ''Fast Ethernet'' variants use a star topology and generally use
4B5B In telecommunications, 4B5B is a form of data communications line code. 4B5B maps groups of 4 bits of data onto groups of 5 bits for transmission. These 5-bit words are predetermined in a dictionary and they are chosen to ensure that there will b ...
line coding.


1 Gbit/s

All Gigabit Ethernet variants use a star topology. 1000BASE-X variants use 8b/10b PCS encoding. Initially, half-duplex mode was included in the standard but has since been abandoned. Very few devices support gigabit speed in half-duplex.


2.5 and

2.5GBASE-T and 5GBASE-T are scaled-down variants of 10GBASE-T and provide longer reach over pre- Cat 6A cabling. These physical layers support twisted-pair copper cabling and backplanes only.


10 Gbit/s

10 Gigabit Ethernet is a version of Ethernet with a nominal data rate of , ten times as fast as Gigabit Ethernet. The first 10 Gigabit Ethernet standard, IEEE Std 802.3ae-2002, was published in 2002. Subsequent standards encompass media types for single-mode fiber (long haul), multi-mode fiber (up to 400 m), copper backplane (up to 1 m) and copper twisted pair (up to 100 m). All 10-gigabit standards were consolidated into IEEE Std 802.3-2008. Most 10-gigabit variants use 64b/66b PCS code (''-R''). 10 Gigabit Ethernet, specifically 10GBASE-LR and 10GBASE-ER, enjoys significant market shares in carrier networks.


25 Gbit/s

Single-lane 25-gigabit Ethernet is based on one 25.78125 GBd lane of the four from the 100 Gigabit Ethernet standard developed by the P802.3by task force.IEEE 802.3by 25 Gb/s Ethernet Task Force
/ref> 25GBASE-T over twisted pair was approved alongside
40GBASE-T 40 Gigabit Ethernet (40GbE) and 100 Gigabit Ethernet (100GbE) are groups of computer networking technologies for transmitting Ethernet frames at rates of 40 and 100 gigabits per second (Gbit/s), respectively. These technologies offer significantl ...
within IEEE 802.3bq.


40 Gbit/s

This class of Ethernet was standardized in June 2010 as IEEE 802.3ba. The work also included the first generation, published in March 2011 as IEEE 802.3bg. A twisted-pair standard was published in 2016 as IEEE 802.3bq-2016.


50 Gbit/s

The IEEE 802.3cd task force developed along with next-generation 100 and standards using lanes.


100 Gbit/s

The first generation of 100 Gigabit Ethernet using 10 and lanes was standardized in June 2010 as IEEE 802.3ba alongside 40 Gigabit Ethernet. The second generation using lanes was developed by the IEEE 802.3cd task force along with 50 and standards. The third generation using a single lane was standardized in September 2022 as IEEE 802.3ck along with 200 and Ethernet.


200 Gbit/s

First generation have been defined by the IEEE 802.3bs task force and standardized in 802.3bs-2017. The IEEE 802.3cd task force has developed 50 and next-generation 100 and standards using one, two, or four lanes respectively. The next generation using lanes was standardized in September 2022 as IEEE 802.3ck along with 100 and PHYs and attachment unit interfaces (AUI) using lanes.


400 Gbit/s

An Ethernet standard capable of 200 and is defined in IEEE 802.3bs-2017. may be a further goal. In May 2018, IEEE 802.3 started the 802.3ck task force to develop standards for 100, 200, and PHYs and attachment unit interfaces (AUI) using lanes. The new standards were approved in September 2022. In 2008,
Robert Metcalfe Robert "Bob" Melancton Metcalfe (born April 7, 1946) is an American engineer and entrepreneur who contributed to the development of the internet in the 1970s. He co-invented Ethernet, co-founded 3Com, and formulated Metcalfe's law, which desc ...
, one of the co-inventors of Ethernet, said he believed commercial applications using
Terabit Ethernet Terabit Ethernet (TbE) is Ethernet with speeds above 100 Gigabit Ethernet. The 400 Gigabit Ethernet (400G, 400GbE) and 200 Gigabit Ethernet (200G, 200GbE) standard developed by the IEEE P802.3bs Task Force using broadly similar technol ...
may occur by 2015, though it might require new Ethernet standards. It was predicted this would be followed rapidly by a scaling to 100 Terabit, possibly as early as 2020. These were theoretical predictions of technological ability, rather than estimates of when such speeds would actually become available at a practical price point.


800 Gbit/s

The Ethernet Technology Consortium proposed an Ethernet PCS variant based on tightly bundled 400GBASE-R in April 2020. In February 2024, the ''IEEE 802.3df Task Force'' defined variants for Ethernet over twinaxial copper, electrical backplanes, single-mode and multi-mode optical fiber along with new 200 and variants using lanes.


1.6 Tbit/s

In December 2022, IEEE started the ''P802.3dj Task Force'' to define variants for 200, 400, 800 and over twinaxial copper, electrical backplanes, single-mode and multi-mode optical fiber along with new variants using 100 and 200 Gbit/s lanes.


First mile

Ethernet in the first mile Ethernet in the first mile (EFM) refers to using one of the Ethernet family of computer network technologies between a telecommunications company and a customer's premises. From the customer's point of view, it is their first mile, although from t ...
provides
Internet access Internet access is a facility or service that provides connectivity for a computer, a computer network, or other network device to the Internet, and for individuals or organizations to access or use applications such as email and the World Wide ...
service directly from providers to homes and small businesses.


Sublayers

Starting with Fast Ethernet, the physical layer specifications are divided into three sublayers in order to simplify design and interoperability: * PCS (
Physical Coding Sublayer The physical coding sublayer (PCS) is a networking protocol sublayer in the Fast Ethernet, Gigabit Ethernet, and 10 Gigabit Ethernet standards. It resides at the top of the physical layer (PHY), and provides an interface between the physical medium ...
) - This sublayer performs auto-negotiation and basic encoding (e.g., 8b/10b), lane separation and recombination. For Ethernet, the bit rate at the top of the PCS is the ''nominal bit rate'', e.g. for classic Ethernet or for Gigabit Ethernet. * PMA ( Physical Medium Attachment sublayer) - This sublayer performs PMA framing, octet synchronization/detection, and polynomial scrambling/descrambling. * PMD (
Physical Medium Dependent Physical medium dependent sublayers or PMDs further help to define the physical layer of computer network protocols. They define the details of transmission and reception of individual bits on a physical medium. These responsibilities encompass bi ...
sublayer) - This sublayer consists of a transceiver for the physical medium.


Twisted-pair cable

Several varieties of Ethernet were specifically designed to run over 4-pair copper
structured cabling In telecommunications, structured cabling is building or campus cabling infrastructure that consists of a number of standardized smaller elements (hence structured) called subsystems. Structured cabling components include twisted pair and opt ...
already installed in many locations. In a departure from both 10BASE-T and 100BASE-TX, 1000BASE-T and above use all four cable pairs for simultaneous transmission in both directions through the use of
echo cancellation Echo suppression and echo cancellation are methods used in telephony to improve voice quality by preventing echo from being created or removing it after it is already present. In addition to improving subjective audio quality, echo suppression i ...
. Using point-to-point copper cabling provides the opportunity to deliver electrical power along with the data. This is called
power over Ethernet Power over Ethernet (PoE) describes any of several technical standard, standards or ad hoc systems that pass electric power along with data on twisted-pair Ethernet cabling. This allows a single cable to provide both a data connection and en ...
and there are several variations defined in IEEE 802.3 standards. Combining 10BASE-T (or 100BASE-TX) with ''Mode A'' allows a hub or a switch to transmit both power and data over only two pairs. This was designed to leave the other two pairs free for analog telephone signals. The pins used in ''Mode B'' supply power over the spare pairs not used by 10BASE-T and 100BASE-TX. ''4PPoE'' defined in IEEE 802.3bt can use all four pairs to supply up to 100 W. The cable requirements depend on the transmission speed and the employed encoding method. Generally, faster speeds require both higher-grade cables and more sophisticated encoding.


Minimum cable lengths

Some fiber connections have minimum cable lengths due to maximum level constraints on received signals. Fiber ports designed for long-haul wavelengths may require a signal attenuator if used within a building. 10BASE2 installations, running on RG-58 coaxial cable, require a minimum of 0.5 m between stations tapped into the network cable to minimize reflections. 10BASE-T, 100BASE-T, and 1000BASE-T installations running on twisted pair cable use a
star topology A star network is an implementation of a spoke–hub distribution paradigm in computer networks. In a star network, every host is connected to a central hub. In its simplest form, one central hub acts as a conduit to transmit messages. The ...
. No minimum cable length is required for these networks.


Related standards

Some networking standards are not part of the IEEE 802.3 Ethernet standard, but support the Ethernet frame format, and are capable of interoperating with it. *
LattisNet LattisNet was a family of computer networking hardware and software products built and sold by SynOptics Communications (also rebranded by Western Digital) during the 1980s. Examples were the 1000, 2500 and 3000 series of LattisHub network hubs. ...
—A
SynOptics SynOptics Communications, Inc., was a Santa Clara, California-based early computer network equipment vendor from 1985 until 1994. SynOptics popularized the concept of the modular Ethernet hub and high-speed Ethernet networking over copper twisted ...
pre-standard twisted-pair variant. *
100BaseVG 100BaseVG is a 100 Mbit/s Ethernet standard specified to run over four pairs of Category 3 cable (cable also known as voice grade, hence the "VG"). It is also called 100VG-AnyLAN because it was defined to carry both Ethernet and Token Ring f ...
—An early contender for Ethernet. It runs over four pairs of
Category 3 cable Category 3 cable, commonly known as or station wire, and less commonly known as VG or voice-grade (as, for example, in 100BaseVG), is an unshielded twisted pair (UTP) cable used in telephone wiring. It is part of a family of standards defin ...
but was not commercially successful. *TIA 100BASE-SX—Promoted by the
Telecommunications Industry Association The Telecommunications Industry Association (TIA) is accredited by the American National Standards Institute (ANSI) to develop voluntary, consensus-based industry standards for a wide variety of information and communication technology (Informat ...
. 100BASE-SX is an alternative implementation of Ethernet over fiber; it is incompatible with the official 100BASE-FX standard. Its main feature is interoperability with 10BASE-FL, supporting autonegotiation between 10 and operation – a feature lacking in the official standards due to the use of differing LED wavelengths. It was targeted at the installed base of fiber networks. *TIA
1000BASE-TX In computer networking, Gigabit Ethernet (GbE or 1 GigE) is the term applied to transmitting Ethernet frames at a rate of a gigabit per second. The most popular variant, 1000BASE-T, is defined by the IEEE 802.3ab standard. It came into use i ...
—Promoted by the
Telecommunications Industry Association The Telecommunications Industry Association (TIA) is accredited by the American National Standards Institute (ANSI) to develop voluntary, consensus-based industry standards for a wide variety of information and communication technology (Informat ...
, it was a commercial failure. 1000BASE-TX uses a simpler protocol than the official 1000BASE-T standard so the electronics can be cheaper, but requires
Category 6 cable Category 6 cable (Cat 6) is a standardized twisted pair cable for Ethernet and other network physical layers that is backward compatible with the Category 5/5e and Category 3 cable standards. Cat 6 must meet more stringen ...
. *
G.hn Gigabit Home Networking (G.hn) is a specification for wired home networking that supports speeds up to 2 Gbit/s and operates over four types of legacy wires: telephone wiring, Coaxial cable, coaxial cables, Power line, power lines and pla ...
—A standard developed by
ITU-T The International Telecommunication Union Telecommunication Standardization Sector (ITU-T) is one of the three Sectors (branches) of the International Telecommunication Union (ITU). It is responsible for coordinating Standardization, standards fo ...
and promoted by HomeGrid Forum for high-speed (up to )
local area network A local area network (LAN) is a computer network that interconnects computers within a limited area such as a residence, campus, or building, and has its network equipment and interconnects locally managed. LANs facilitate the distribution of da ...
s over existing home wiring ( coaxial cables,
power lines Electric power transmission is the bulk movement of electrical energy from a generating site, such as a power plant, to an electrical substation. The interconnected lines that facilitate this movement form a ''transmission network''. This is ...
and phone lines).
G.hn Gigabit Home Networking (G.hn) is a specification for wired home networking that supports speeds up to 2 Gbit/s and operates over four types of legacy wires: telephone wiring, Coaxial cable, coaxial cables, Power line, power lines and pla ...
defines an Application Protocol Convergence (APC) layer that accepts Ethernet frames and encapsulates them into G.hn MSDUs. Other networking standards do not use the Ethernet frame format but can still be connected to Ethernet using MAC-based bridging. *
802.11 IEEE 802.11 is part of the IEEE 802 set of local area network (LAN) technical standards, and specifies the set of medium access control (MAC) and physical layer (PHY) protocols for implementing wireless local area network (WLAN) computer c ...
—Standards for wireless
local area network A local area network (LAN) is a computer network that interconnects computers within a limited area such as a residence, campus, or building, and has its network equipment and interconnects locally managed. LANs facilitate the distribution of da ...
s (LANs), sold as
Wi-Fi Wi-Fi () is a family of wireless network protocols based on the IEEE 802.11 family of standards, which are commonly used for Wireless LAN, local area networking of devices and Internet access, allowing nearby digital devices to exchange data by ...
* 802.16—Standards for wireless
metropolitan area network A metropolitan area network (MAN) is a computer network that interconnects users with computer resources in a geographic region of the size of a metropolitan area. The term MAN is applied to the interconnection of local area networks (LANs) in ...
s (MANs), sold as
WiMAX Worldwide Interoperability for Microwave Access (WiMAX) is a family of wireless broadband communication standards based on the IEEE 802.16 set of standards, which provide physical layer (PHY) and media access control (MAC) options. The WiMA ...
Other special-purpose physical layers include
Avionics Full-Duplex Switched Ethernet Avionics Full-Duplex Switched Ethernet (AFDX), also ARINC 664, is a data network, patented by international aircraft manufacturer Airbus, for safety-critical applications that utilizes dedicated bandwidth while providing deterministic quality of ...
and TTEthernet.


References


External links


IEEE GET Program GET 802(R) StandardsIEEE 802.3 Ethernet Working Group
{{DEFAULTSORT:Ethernet Physical Layer Physical layer protocols
Physical Layer 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, mechani ...