In the seven-layer

OSI model The Open Systems Interconnection model (OSI model) is a conceptual model that 'provides a common basis for the coordination of SOstandards development for the purpose of systems interconnection'. In the OSI reference model, the communications ...

computer network A computer network is a set of computers sharing resources located on or provided by network nodes. The computers use common communication protocols over digital interconnections to communicate with each other. These interconnections are ...

ing, the physical layer or layer 1 is the first and lowest layer; The layer most closely associated with the physical connection between devices. This layer may be implemented by a

PHY PHY is an abbreviation for the physical layer of the OSI model and refers to the circuitry required to implement physical layer functions. PHY or Phy may also refer to: * Phy, the drug methadone * Phetchabun Airport (IATA code), Thailand See al ...

chip. The physical layer provides an electrical, mechanical, and procedural interface to the transmission medium. The shapes and properties of the

electrical connector Components of an electrical circuit are electrically connected if an electric current can run between them through an electrical conductor. An electrical connector is an electromechanical device used to create an electrical connection between ...

s, the frequencies to broadcast on, the

line code In telecommunication, a line code is a pattern of voltage, current, or photons used to represent digital data transmitted down a communication channel or written to a storage medium. This repertoire of signals is usually called a constrained c ...

to use and similar low-level parameters, are specified by the physical layer.

Role

The physical layer defines the means of transmitting a stream of raw

bit The bit is the most basic unit of information in computing and digital communications. The name is a portmanteau of binary digit. The bit represents a logical state with one of two possible values. These values are most commonly represente ...

s over a physical

data link A data link is the means of connecting one location to another for the purpose of transmitting and receiving digital information (data communication). It can also refer to a set of electronics assemblies, consisting of a transmitter and a recei ...

connecting network

nodes In general, a node is a localized swelling (a "knot") or a point of intersection (a Vertex (graph theory), vertex). Node may refer to: In mathematics *Vertex (graph theory), a vertex in a mathematical graph *Vertex (geometry), a point where two ...

. The

bitstream A bitstream (or bit stream), also known as binary sequence, is a sequence of bits. A bytestream is a sequence of bytes. Typically, each byte is an 8-bit quantity, and so the term octet stream is sometimes used interchangeably. An octet may ...

may be grouped into code words or symbols and converted to a physical

signal In signal processing, a signal is a function that conveys information about a phenomenon. Any quantity that can vary over space or time can be used as a signal to share messages between observers. The ''IEEE Transactions on Signal Processing'' ...

that is transmitted over a

transmission medium A transmission medium is a system or substance that can mediate the propagation of signals for the purposes of telecommunication. Signals are typically imposed on a wave of some kind suitable for the chosen medium. For example, data can modulate ...

. The physical layer consists of the

electronic circuit An electronic circuit is composed of individual electronic components, such as resistors, transistors, capacitors, inductors and diodes, connected by conductive wires or traces through which electric current can flow. It is a type of electrical ...

transmission technologies of a network. It is a fundamental layer underlying the higher level functions in a network, and can be implemented through a great number of different hardware technologies with widely varying characteristics. Within the semantics of the OSI model, the physical layer translates logical communications requests from the

data link layer The data link layer, or layer 2, is the second layer of the seven-layer OSI model of computer networking. This layer is the protocol layer that transfers data between nodes on a network segment across the physical layer. The data link layer p ...

into hardware-specific operations to cause transmission or reception of electronic (or other) signals. The physical layer supports higher layers responsible for generation of logical

data packets In telecommunications and computer networking, a network packet is a formatted unit of Data (computing), data carried by a packet-switched network. A packet consists of control information and user data; the latter is also known as the ''Payload ...

Physical signaling sublayer

In a network using

Open Systems Interconnection The Open Systems Interconnection model (OSI model) is a conceptual model that 'provides a common basis for the coordination of SOstandards development for the purpose of systems interconnection'. In the OSI reference model, the communicatio ...

(OSI) architecture, the ''physical signaling sublayer'' is the portion of the physical layer that * interfaces with the data link layer's

medium 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 sublay ...

(MAC) sublayer, * performs

symbol A symbol is a mark, sign, or word that indicates, signifies, or is understood as representing an idea, object, or relationship. Symbols allow people to go beyond what is known or seen by creating linkages between otherwise very different conc ...

encoding,

transmission Transmission may refer to: Medicine, science and technology * Power transmission ** Electric power transmission ** Propulsion transmission, technology allowing controlled application of power *** Automatic transmission *** Manual transmission *** ...

, reception and decoding and, * performs

galvanic isolation Galvanic isolation is a principle of isolating functional sections of electrical systems to prevent current flow; no direct conduction path is permitted.John Huntington ''Show Networks and Control Systems: Formerly Control Systems for Live E ...

Relation to the Internet protocol suite

The

Internet protocol suite The Internet protocol suite, commonly known as TCP/IP, is a framework for organizing the set of communication protocols used in the Internet and similar computer networks according to functional criteria. The foundational protocols in the suit ...

, as defined i
RFC 1122
an
RFC 1123
is a high-level networking description used for the Internet and similar networks. It does not define a layer that deals exclusively with hardware-level specifications and interfaces, as this model does not concern itself directly with physical interfaces.

Services

The major functions and services performed by the physical layer are: The physical layer performs bit-by-bit or symbol-by-symbol data delivery over a physical

. It provides a standardized interface to the transmission medium, including a mechanical specification of

s and

cables Cable may refer to: Mechanical * Nautical cable, an assembly of three or more ropes woven against the weave of the ropes, rendering it virtually waterproof * Wire rope, a type of rope that consists of several strands of metal wire laid into a hel ...

, for example maximum cable length, an electrical specification of

transmission line In electrical engineering, a transmission line is a specialized cable or other structure designed to conduct electromagnetic waves in a contained manner. The term applies when the conductors are long enough that the wave nature of the transmis ...

signal level Signal-to-noise ratio (SNR or S/N) is a measure used in science and engineering that compares the level of a desired signal to the level of background noise. SNR is defined as the ratio of signal power to the noise power, often expressed in deci ...

and impedance. The physical layer is responsible for

electromagnetic compatibility Electromagnetic compatibility (EMC) is the ability of electrical equipment and systems to function acceptably in their electromagnetic environment, by limiting the unintentional generation, propagation and reception of electromagnetic energy whic ...

including

electromagnetic spectrum The electromagnetic spectrum is the range of frequencies (the spectrum) of electromagnetic radiation and their respective wavelengths and photon energies. The electromagnetic spectrum covers electromagnetic waves with frequencies ranging from ...

frequency allocation Frequency allocation (or spectrum allocation or spectrum management) is the allocation and regulation of the electromagnetic spectrum into radio frequency bands, normally done by governments in most countries. Because radio propagation does no ...

and specification of

signal strength In telecommunications, particularly in radio frequency engineering, signal strength refers to the transmitter power output as received by a reference antenna at a distance from the transmitting antenna. High-powered transmissions, such as those us ...

, analog

bandwidth Bandwidth commonly refers to: * Bandwidth (signal processing) or ''analog bandwidth'', ''frequency bandwidth'', or ''radio bandwidth'', a measure of the width of a frequency range * Bandwidth (computing), the rate of data transfer, bit rate or thr ...

, etc. The transmission medium may be electrical or optical over

optical fiber An optical fiber, or optical fibre in Commonwealth English, is a flexible, transparent fiber made by drawing glass (silica) or plastic to a diameter slightly thicker than that of a human hair. Optical fibers are used most often as a means to ...

or a wireless communication link such as

free-space optical communication Free-space optical communication (FSO) is an optical communication technology that uses light propagating in free space to wirelessly transmit data for telecommunications or computer networking. "Free space" means air, outer space, vacuum, or ...

radio Radio is the technology of signaling and communicating using radio waves. Radio waves are electromagnetic waves of frequency between 30 hertz (Hz) and 300 gigahertz (GHz). They are generated by an electronic device called a transmit ...

Line coding In telecommunication, a line code is a pattern of voltage, current, or photons used to represent digital data transmitted down a communication channel or written to a storage medium. This repertoire of signals is usually called a constrained co ...

is used to convert data into a pattern of electrical fluctuations which may be

modulated In electronics and telecommunications, modulation is the process of varying one or more properties of a periodic waveform, called the ''carrier signal'', with a separate signal called the ''modulation signal'' that typically contains informatio ...

onto a

carrier wave In telecommunications, a carrier wave, carrier signal, or just carrier, is a waveform (usually sinusoidal) that is modulated (modified) with an information-bearing signal for the purpose of conveying information. This carrier wave usually has a ...

infrared light Infrared (IR), sometimes called infrared light, is electromagnetic radiation (EMR) with wavelengths longer than those of visible light. It is therefore invisible to the human eye. IR is generally understood to encompass wavelengths from around ...

. The flow of data is managed with

bit synchronization In coding theory, especially in telecommunications, a self-synchronizing code is a uniquely decodable code in which the symbol stream formed by a portion of one code word, or by the overlapped portion of any two adjacent code words, is not a val ...

in synchronous

serial communication In telecommunication and data transmission, serial communication is the process of sending data one bit at a time, sequentially, over a communication channel or computer bus. This is in contrast to parallel communication, where several bits are ...

start-stop signalling Asynchronous serial communication is a form of serial communication in which the communicating endpoints' interfaces are not continuously synchronized by a common clock signal. Instead of a common synchronization signal, the data stream contai ...

and flow control in

asynchronous serial communication Asynchronous serial communication is a form of serial communication in which the communicating endpoints' interfaces are not continuously synchronized by a common clock signal. Instead of a common synchronization signal, the data stream contai ...

. Sharing of the transmission medium among multiple network participants can be handled by simple

circuit switching Circuit switching is a method of implementing a telecommunications network in which two network nodes establish a dedicated communications channel ( circuit) through the network before the nodes may communicate. The circuit guarantees the full b ...

multiplexing In telecommunications and computer networking, multiplexing (sometimes contracted to muxing) is a method by which multiple analog or digital signals are combined into one signal over a shared medium. The aim is to share a scarce resource - a ...

. More complex

protocols for sharing the transmission medium may use

carrier sense 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 s ...

and

collision detection Collision detection is the computational problem of detecting the intersection (Euclidean geometry), intersection of two or more objects. Collision detection is a classic issue of computational geometry and has applications in various computing ...

such as in Ethernet's

Carrier-sense multiple access with collision detection 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 statio ...

(CSMA/CD). To optimize reliability and efficiency, signal processing techniques such as equalization,

training sequence In computer networks, a syncword, sync character, sync sequence or preamble is used to synchronize a data transmission by indicating the end of header information and the start of data. The syncword is a known sequence of data used to identif ...

s and

pulse shaping In electronics and telecommunications, pulse shaping is the process of changing the waveform of transmitted pulses to optimize the signal for its intended purpose or the communication channel. This is often done by limiting the bandwidth of the tran ...

may be used.

Error correction code In computing, telecommunication, information theory, and coding theory, an error correction code, sometimes error correcting code, (ECC) is used for controlling errors in data over unreliable or noisy communication channels. The central idea is ...

s and techniques including

forward error correction In computing, telecommunication, information theory, and coding theory, an error correction code, sometimes error correcting code, (ECC) is used for controlling errors in data over unreliable or noisy communication channels. The central idea is ...

may be applied to further improve reliability. Other topics associated with the physical layer include:

bit rate In telecommunications and computing, bit rate (bitrate or as a variable ''R'') is the number of bits that are conveyed or processed per unit of time. The bit rate is expressed in the unit bit per second (symbol: bit/s), often in conjunction w ...

; point-to-point, multipoint or

point-to-multipoint In telecommunications, point-to-multipoint communication (P2MP, PTMP or PMP) is communication which is accomplished via a distinct type of one-to-many connection, providing multiple paths from a single location to multiple locations. Point-to ...

line configuration; physical

network topology Network topology is the arrangement of the elements ( links, nodes, etc.) of a communication network. Network topology can be used to define or describe the arrangement of various types of telecommunication networks, including command and contro ...

, for example

bus A bus (contracted from omnibus, with variants multibus, motorbus, autobus, etc.) is a road vehicle that carries significantly more passengers than an average car or van. It is most commonly used in public transport, but is also in use for cha ...

ring Ring may refer to: * Ring (jewellery), a round band, usually made of metal, worn as ornamental jewelry * To make a sound with a bell, and the sound made by a bell :(hence) to initiate a telephone connection Arts, entertainment and media Film and ...

mesh A mesh is a barrier made of connected strands of metal, fiber, or other flexible or ductile materials. A mesh is similar to a web or a net in that it has many attached or woven strands. Types * A plastic mesh may be extruded, oriented, ex ...

star network 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 ...

; serial or

parallel Parallel is a geometric term of location which may refer to: Computing * Parallel algorithm * Parallel computing * Parallel metaheuristic * Parallel (software), a UNIX utility for running programs in parallel * Parallel Sysplex, a cluster of IBM ...

communication;

simplex In geometry, a simplex (plural: simplexes or simplices) is a generalization of the notion of a triangle or tetrahedron to arbitrary dimensions. The simplex is so-named because it represents the simplest possible polytope in any given dimension. ...

half 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 ...

full 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 ...

transmission mode; and

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 mode, and flow control. In this process, the connected devices ...

PHY

Elitegroup 761GX-M754 - Realtek RTL8201CL-5493

A PHY, an abbreviation for "physical layer", is an

, usually implemented as an

integrated circuit An integrated circuit or monolithic integrated circuit (also referred to as an IC, a chip, or a microchip) is a set of electronic circuits on one small flat piece (or "chip") of semiconductor material, usually silicon. Large numbers of tiny ...

, required to implement physical layer functions of the

in a

network interface controller A network interface controller (NIC, also known as a network interface card, network adapter, LAN adapter or physical network interface, and by similar terms) is a computer hardware component that connects a computer to a computer network. Ear ...

. A PHY connects a link layer device (often called MAC as an acronym for

) to a physical medium such as an

copper cable Copper has been used in electrical wiring since the invention of the electromagnet and the telegraph in the 1820s. The invention of the telephone in 1876 created further demand for copper wire as an electrical conductor. Copper is the electr ...

. A PHY device typically includes both physical coding sublayer (PCS) and

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 b ...

(PMD) layer functionality. ''-PHY'' may also be used as a suffix to form a short name referencing a specific physical layer protocol, for example

M-PHY M-PHY is a high speed data communications physical layer protocol standard developed by the MIPI Alliance, PHY Working group, and targeted at the needs of mobile multimedia devices. The specification's details are proprietary to MIPI member organ ...

. Modular transceivers for

fiber-optic communication Fiber-optic communication is a method of transmitting information from one place to another by sending pulses of infrared light through an optical fiber. The light is a form of carrier wave that is modulated to carry information. Fiber is pref ...

(like the

SFP SFP may refer to: Organizations * Salton Inc. (former stock symbol: SFP), now part of Russell Hobbs, Inc. * Swedish People's Party of Finland, a Swedish minority and mainly liberal party in Finland * Syrian Free Press, a Syrian social news networ ...

family) complement a PHY chip and form the PMA sublayer.

Ethernet physical transceiver

Micrel KS8721CL on mainboard of Surf@home II-7778

The Ethernet PHY is a component that operates at the physical layer of the OSI network model. It implements the physical layer portion of the Ethernet. Its purpose is to provide analog signal physical access to the link. It is usually interfaced with a

media-independent interface The media-independent interface (MII) was originally defined as a standard interface to connect a Fast Ethernet (i.e., ) media access control (MAC) block to a PHY#Ethernet physical transceiver, PHY chip. The MII is standardized by IEEE 802.3u and ...

(MII) to a MAC chip in a

microcontroller A microcontroller (MCU for ''microcontroller unit'', often also MC, UC, or μC) is a small computer on a single VLSI integrated circuit (IC) chip. A microcontroller contains one or more CPUs (processor cores) along with memory and programmable i ...

or another system that takes care of the higher layer functions. More specifically, the Ethernet PHY is a chip that implements the hardware send and receive function of Ethernet

frame A frame is often a structural system that supports other components of a physical construction and/or steel frame that limits the construction's extent. Frame and FRAME may also refer to: Physical objects In building construction *Framing (con ...

s; it interfaces between the analog domain of Ethernet's line modulation and the digital domain of link-layer packet signaling. The PHY usually does not handle MAC addressing, as that is the link layer's job. Similarly, Wake-on-LAN and

Boot ROM The boot ROM is a type of ROM that is used for booting a computer system. There are two types: a mask boot ROM that cannot be changed afterwards and a boot EEPROM, which can contain an UEFI implementation. Purpose Upon power up, hardware usually ...

functionality is implemented in the

network interface card A network interface controller (NIC, also known as a network interface card, network adapter, LAN adapter or physical network interface, and by similar terms) is a computer hardware component that connects a computer to a computer network. Ear ...

(NIC), which may have PHY, MAC, and other functionality integrated into one chip or as separate chips. Common Ethernet interfaces include fiber or two to four copper pairs for data communication. However, there now exists a new interface, called Single Pair Ethernet (SPE), which is able to utilize a single pair of copper wires while still communicating at the intended speeds.

Texas Instruments Texas Instruments Incorporated (TI) is an American technology company headquartered in Dallas, Texas, that designs and manufactures semiconductors and various integrated circuits, which it sells to electronics designers and manufacturers globall ...

DP83TD510E is an example of a PHY which uses SPE. Examples include the

Microsemi Microsemi Corporation was an Aliso Viejo, California-based provider of semiconductor and system solutions for aerospace & defense, communications, data center and industrial markets. In February 2018, it was announced that Chandler, Arizona-base ...

SimpliPHY and SynchroPHY VSC82xx/84xx/85xx/86xx family, Marvell Alaska 88E1310/88E1310S/88E1318/88E1318S Gigabit Ethernet transceivers, Texas Instruments DP838xx family and offerings from Intel and ICS.

Other applications

Wireless LAN A wireless LAN (WLAN) is a wireless computer network A wireless network is a computer network that uses wireless data connections between network nodes. Wireless networking is a method by which homes, telecommunications networks and bus ...

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 local area networking of devices and Internet access, allowing nearby digital devices to exchange data by radio wave ...

: The PHY portion consists of the RF, mixed-signal and analog portions, that are often called transceivers, and the digital baseband portion that use

digital signal processor A digital signal processor (DSP) is a specialized microprocessor chip, with its architecture optimized for the operational needs of digital signal processing. DSPs are fabricated on MOS integrated circuit chips. They are widely used in audio si ...

(DSP) and communication algorithm processing, including

channel code Coding theory is the study of the properties of codes and their respective fitness for specific applications. Codes are used for data compression, cryptography, error detection and correction, data transmission and data storage. Codes are studied ...

s. It is common that these PHY portions are integrated with the

(MAC) layer in

system-on-a-chip A system on a chip or system-on-chip (SoC ; pl. ''SoCs'' ) is an integrated circuit that integrates most or all components of a computer or other electronic system. These components almost always include a central processing unit (CPU), memory ...

(SOC) implementations. Similar wireless applications include 3G/ 4G/ LTE/ 5G,

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 WiMAX ...

and UWB. *

Universal Serial Bus Universal Serial Bus (USB) is an industry standard that establishes specifications for cables, connectors and protocols for connection, communication and power supply (interfacing) between computers, peripherals and other computers. A broad ...

(USB): A PHY chip is integrated into most USB controllers in hosts or

embedded systems An embedded system is a computer system—a combination of a computer processor, computer memory, and input/output peripheral devices—that has a dedicated function within a larger mechanical or electronic system. It is ''embedded'' as ...

and provides the bridge between the digital and modulated parts of the interface. * IrDA: The

Infrared Data Association The Infrared Data Association (IrDA) is an industry-driven interest group that was founded in 1994 by around 50 companies. IrDA provides specifications for a complete set of protocols for wireless infrared communications, and the name "IrDA" also ...

's (IrDA) specification includes an IrPHY specification for the physical layer of the data transport. *

Serial ATA SATA (Serial AT Attachment) is a computer bus interface that connects host bus adapters to mass storage devices such as hard disk drives, optical drives, and solid-state drives. Serial ATA succeeded the earlier Parallel ATA (PATA) standard t ...

(SATA): Serial ATA controllers use a PHY.

Technologies

The following technologies provide physical layer services: *

1-Wire 1-Wire is a device communications bus system designed by Dallas Semiconductor Corp. that provides low-speed (16.3 kbit/s) data, signaling, and power over a single conductor. 1-Wire is similar in concept to I²C, but with lower data rates and ...

* ARINC 818 Avionics Digital Video Bus *

Bluetooth Bluetooth is a short-range wireless technology standard that is used for exchanging data between fixed and mobile devices over short distances and building personal area networks (PANs). In the most widely used mode, transmission power is limi ...

physical layer *

CAN bus A Controller Area Network (CAN bus) is a robust vehicle bus standard designed to allow microcontrollers and devices to communicate with each other's applications without a host computer. It is a message-based protocol, designed originally for mu ...

(controller area network) physical layer *

DSL Digital subscriber line (DSL; originally digital subscriber loop) is a family of technologies that are used to transmit digital data over telephone lines. In telecommunications marketing, the term DSL is widely understood to mean asymmetric dig ...

EIA Eia or EIA may refer to: Medicine * Enzyme immunoassay * Equine infectious anemia * Exercise-induced anaphylaxis * Exercise-induced asthma * External iliac artery Transport * Edmonton International Airport, in Alberta, Canada * Erbil Internation ...

RS-232 In telecommunications, RS-232 or Recommended Standard 232 is a standard originally introduced in 1960 for serial communication transmission of data. It formally defines signals connecting between a ''DTE'' (''data terminal equipment'') such a ...

EIA-422 RS-422, also known as TIA/EIA-422, is a technical standard originated by the Electronic Industries Alliance that specifies electrical characteristics of a digital signaling circuit. It was meant to be the foundation of a suite of standards that ...

EIA-423 RS-423, also known as TIA/EIA-423, is a technical standard originated by the Electronic Industries Alliance that specifies electrical characteristics of a digital signaling circuit. Although it was originally intended as a successor to RS-232C of ...

RS-449 The RS-449 specification, also known as EIA-449 or TIA-449, defines the functional and mechanical characteristics of the interface between data terminal equipment, typically a computer, and data communications equipment, typically a modem or termi ...

RS-485 RS-485, also known as TIA-485(-A) or EIA-485, is a standard defining the electrical characteristics of drivers and receivers for use in serial communications systems. Electrical signaling is balanced, and multipoint systems are supported. The st ...

Etherloop Etherloop is a kind of DSL technology that combines the features of Ethernet and DSL. It allows the combination of voice and data transmission on standard phone lines. Under the right conditions it will allow speeds of up to 6 megabits per second o ...

Ethernet physical layer 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 t ...

Including

10BASE-T 1 (one, unit, unity) is a number representing a single or the only entity. 1 is also a numerical digit and represents a single unit of counting or measurement. For example, a line segment of ''unit length'' is a line segment of length 1. I ...

10BASE2 10BASE2 (also known as cheapernet, thin Ethernet, thinnet, and thinwire) is a variant of Ethernet that uses thin coaxial cable terminated with BNC connectors to build a local area network. During the mid to late 1980s this was the dominan ...

10BASE5 10BASE5 (also known as thick Ethernet or thicknet) was the first commercially available variant of Ethernet. The technology was standardized in 1982 as IEEE 802.3. 10BASE5 uses a thick and stiff coaxial cable up to in length. Up to 100 stati ...

100BASE-TX 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. Fast Ethern ...

100BASE-FX 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. Fast Ethern ...

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 ...

1000BASE-SX 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 ...

and other varieties *

G.hn G.hn is a specification for home networking with data rates up to 2 Gbit/s and operation over four types of legacy wires: telephone wiring, coaxial cables, power lines and plastic optical fiber. A single G.hn semiconductor device is able to net ...

G.9960 G.hn is a specification for home networking with data rates up to 2 Gbit/s and operation over four types of legacy wires: telephone wiring, coaxial cables, power lines and plastic optical fiber. A single G.hn semiconductor device is able to ...

physical layer *

GSM The Global System for Mobile Communications (GSM) is a standard developed by the European Telecommunications Standards Institute (ETSI) to describe the protocols for second-generation ( 2G) digital cellular networks used by mobile devices such as ...

Um air interface The Um interface is the air interface for the GSM mobile telephone standard. It is the interface between the mobile station (MS) and the Base transceiver station (BTS). It is called Um because it is the mobile analog to the U interface of ISDN. ...

physical layer *

IEEE 802.15.4 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, ...

physical layers *

IEEE 1394 interface IEEE 1394 is an interface standard for a serial bus for high-speed communications and isochronous real-time data transfer. It was developed in the late 1980s and early 1990s by Apple in cooperation with a number of companies, primarily Sony an ...

IRDA The Infrared Data Association (IrDA) is an industry-driven interest group that was founded in 1994 by around 50 companies. IrDA provides specifications for a complete set of protocols for wireless infrared communications, and the name "IrDA" also ...

physical layer *

ISDN Integrated Services Digital Network (ISDN) is a set of communication standards for simultaneous digital transmission of voice, video, data, and other network services over the digitalised circuits of the public switched telephone network. Wo ...

ITU The International Telecommunication Union is a specialized agency of the United Nations responsible for many matters related to information and communication technologies. It was established on 17 May 1865 as the International Telegraph Unio ...

Recommendations: see

ITU-T The ITU Telecommunication Standardization Sector (ITU-T) is one of the three sectors (divisions or units) of the International Telecommunication Union (ITU). It is responsible for coordinating standards for telecommunications and Information Commu ...

I²C I2C (Inter-Integrated Circuit, ), alternatively known as I2C or IIC, is a synchronous, multi-controller/multi-target (master/slave), packet switched, single-ended, serial communication bus invented in 1982 by Philips Semiconductors. It is wide ...

I²S I²S (Inter-IC Sound, pronounced "eye-squared-ess"), is an electrical serial bus interface standard used for connecting digital audio devices together. It is used to communicate PCM audio data between integrated circuits in an electronic devic ...

LoRa Lora is a female given name and family name in the Spanish language of French origin meaning from Lorraine, a region in Northeastern France. As a given name, Lora may also be a variant of Laura or derived from an Italian hypocoristic of either El ...

Low-voltage differential signaling Low-voltage differential signaling (LVDS), also known as TIA/EIA-644, is a technical standard that specifies electrical characteristics of a differential, serial signaling standard. LVDS operates at low power and can run at very high speeds ...

Mobile Industry Processor Interface MIPI Alliance is a global business alliance that develops technical specifications for the mobile ecosystem, particularly smart phones but including mobile-influenced industries. MIPI was founded in 2003 by ARM, Intel, Nokia, Samsung, STMicroele ...

physical layer *

Modulated ultrasound Ultrasound can be modulated to carry an audio signal (like radio signals are modulated). This is often used to carry messages underwater, in underwater diving communicators, and short-range (under five miles) communication with submarines; the re ...

* Optical Transport Network (OTN) * SMB *

SONET/SDH Synchronous optical networking (SONET) and synchronous digital hierarchy (SDH) are standardized protocols that transfer multiple digital bit streams synchronously over optical fiber using lasers or highly coherent light from light-emitting diod ...

* SPI * T1 and other

T-carrier The T-carrier is a member of the series of carrier systems developed by AT&T Bell Laboratories for digital transmission of multiplexed telephone calls. The first version, the Transmission System 1 (T1), was introduced in 1962 in the Bell System ...

links, and E1 and other

E-carrier The E-carrier is a member of the series of carrier systems developed for digital transmission of many simultaneous telephone calls by time-division multiplexing. The European Conference of Postal and Telecommunications Administrations (CEPT) orig ...

links * Telephone network

modems A modulator-demodulator or modem is a computer hardware device that converts data from a digital format into a format suitable for an analog transmission medium such as telephone or radio. A modem transmits data by Modulation#Digital modulati ...

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V.92 V.92 is an ITU-T recommendation, titled ''Enhancements to Recommendation V.90'', that establishes a modem standard allowing near 56 kb/s download and 48 kb/s upload rates. With V.92 PCM is used for both the upstream and downstream connections; prev ...

TransferJet TransferJet is a close proximity wireless transfer technology initially proposed by Sony and demonstrated publicly in early 2008. By touching (or bringing very close together) two electronic devices, TransferJet allows high speed exchange of data. ...

physical layer *

USB Universal Serial Bus (USB) is an industry standard that establishes specifications for cables, connectors and protocols for connection, communication and power supply (interfacing) between computers, peripherals and other computers. A broad v ...

physical layer *

PCI Express PCI Express (Peripheral Component Interconnect Express), officially abbreviated as PCIe or PCI-e, is a high-speed serial computer expansion bus standard, designed to replace the older PCI, PCI-X and AGP bus standards. It is the common ...

physical layer *

802.11 IEEE 802.11 is part of the IEEE 802 set of local area network (LAN) technical standards, and specifies the set of media access control (MAC) and physical layer (PHY) protocols for implementing wireless local area network (WLAN) computer commu ...

physical layer *

Visible light communication In telecommunications, visible light communication (VLC) is the use of visible light (light with a frequency of 400–800 THz/wavelength of 780–375 nm) as a transmission medium. VLC is a subset of optical wireless communications tec ...

co-ordinated under IEEE 802.15.7 * X10

References

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External links

Physical Layer (Layer 1)

OSI model

Role

Physical signaling sublayer

Relation to the Internet protocol suite

Services

PHY

Ethernet physical transceiver

Other applications

Technologies

See also

References

External links