Ethernet over Coax (EoC) is a family of technologies that supports the transmission of

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 ...

frames over

coaxial cable 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 ...

History

The first Ethernet standard, known as 10BASE5 (ThickNet) in the family of IEEE 802.3, specified

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 a ...

operation over 50 ohm coaxial cable, which remained the principal medium into the 1980s, when 10BASE2 (ThinNet) coax replaced it in deployments in the 1980s; both being replaced in the 1990s when thinner, cheaper

twisted pair Twisted pair cabling is a type of wiring used for communications 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 ba ...

cabling came to dominate the market. The use of coaxial cable for Ethernet has been deprecated by 2011. Research in Ethernet transmission over coaxial cable continued, as both consumers and telecommunications operators strive to use existing 75 ohm coaxial cable installations (from cable television or CATV), to carry broadband data into and through the home, and into multiple dwelling unit (MDU) installations. Most EoC technologies are being developed for in home or on premises networking and are expected to be operated within the domain of a single operator.

Standards

The Institute of Electrical and Electronics Engineers (IEEE) maintains all official Ethernet standards in the 802.x family of protocols. Active work in Ethernet over Coax is ongoing.

Homeplug

HomePlug AV HomePlug is the family name for various power line communications specifications under the HomePlug designation, each with unique capabilities and compatibility with other HomePlug specifications. Some HomePlug specifications target broadband a ...

as well as its later extension, HomePlug AV2 both operate in a portion of the RF spectrum directly below what is commonly used for terrestrial FM radio broadcasting. HomePlug AV uses BPSK, QPSK, 16 QAM, 64 QAM, 256 QAM, and 1024 QAM modulation strategies between 2 MHz and 30 MHz while the more recent HomePlug AV2 standard extends the upper bound of its spectral use to 86 MHz.

ITU-T G.hn

The

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 Comm ...

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 n ...

standard provides high-speed (up to 1 Gigabit/s) local area networking over existing home wires, including coaxial cable, power lines and phone lines. It defines an Application Protocol Convergence (APC) layer for encapsulation standard 802.3 Ethernet frames into G.hn MAC Service Data Units (MSDUs). Other ITU-T standards for home networking over coaxial cable include G.9954, also known as

HomePNA The HomePNA Alliance is an incorporated non-profit industry association of companies that develops and standardizes technology for home networking over the existing coaxial cables and telephone wiring within homes, so new wires do not need to be ...

3.1.

MoCA

CATV compatibility

EoC research is focused on the use of existing

cable television Cable television is a system of delivering television programming to consumers via radio frequency (RF) signals transmitted through coaxial cables, or in more recent systems, light pulses through fibre-optic cables. This contrasts with broa ...

(CATV) infrastructure for Internet access or broadband data transmission for the purpose of being compatible with the existing CATV (or sometimes satellite television) broadcast signals simultaneously transmitted on the same cable. The EoC technologies must operate outside the

frequency domain In physics, electronics, control systems engineering, and statistics, the frequency domain refers to the analysis of mathematical functions or signals with respect to frequency, rather than time. Put simply, a time-domain graph shows how a s ...

currently used for CATV or for satellite receiver to set-top box transmissions. Most EoC technologies are designed to operate in

frequency band A frequency band is an interval in the frequency domain, delimited by a lower frequency and an upper frequency. The term may refer to a radio band or an interval of some other spectrum. The frequency range of a system is the range over which i ...

s above 1 GHz, which is the upper bound of television signals and for systems designed to operate in North America using the SCTE 55-1 and SCTE 55-2 CATV transmission systems, as well as in most of Europe and portions of Asia. In many localities CATV systems operate only up to 550 MHz or 750 MHz, wherein some EoC technologies focus on using spectrum between 550 MHz or 750 MHz and 1 GHz. Though less costly, they could potentially conflict with future spectrum expansion up to 1 GHz. Some markets focus on using this 750 MHz to 1 GHz spectrum for EoC, specifically avoiding EoC bands above 1 GHz due to potential ingress noise from over-the-air transmissions and cellular systems.

References

{{Ethernet

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 ...