10BROAD36
Encyclopedia
10BROAD36 is an obsolete computer network
standard in the Ethernet
family. It was developed during the 1980s and specified in IEEE 802.3b-1985.
The standard supported 10 Mbit/s Ethernet
signals over standard 75 ohm cable television
(CATV) cable over a 3600 meter range. The original Ethernet standard 10BASE-T
used a baseband
encoding, where the signal is simply encoded directly on the wire without any sort of carrier wave. Instead, 10BROAD36 modulated its data onto a higher carrier frequency signal, much as an audio signal would modulate a carrier wave to be transmitted in a radio station. This was called broadband
at the time; the term has a different (more meaningless) marketing meaning today.
This provides several advantages over the more traditional baseband signal. Range was greatly extended, (3600 meters, versus 100 meters for 10BASE-T) and multiple signals can be carried on the same cable. 10BROAD36 could even share a cable with standard television channels.
The Institute of Electrical and Electronics Engineers
standards committee IEEE 802
published the standard that was ratified in 1985 as an additional section 11 to the base Ethernet standard.
It was also issued as ISO/IEC 8802-3 in 1989.
10BROAD36 was less successful than its contemporaries because of the high equipment complexity (and cost) associated with it. The individual stations were much more expensive due to the extra radio frequency
circuitry involved, however the primary extra complexity came from the fact that 10BROAD36 was unidirectional. Signals could only travel one direction along the line, so head-end stations must be present on the line to repeat the signals (ensuring that no packets travel through the line indefinitely) on either another, backwards direction frequency on the same line, or another line entirely. This also increased latency and prevented bidirectional signal flow.
The extra complexity outweighed the advantage of reusability of CATV technology for the intended campus networks and metropolitan area network
s. An installer at Boston University
using the Ungermann-Bass
product noted that no installers understood both the digital and analog aspects of the system.
In wide area networks it was quickly replaced by fiber-optic communication
alternatives, such as 100BASE-FX (which provided ten times the data rate). Interest in cable modem
s was revived for residential Internet access
, through later technologies such as the Data Over Cable Service Interface Specification
(DOCSIS) in the 1990s.
Computer network
A computer network, often simply referred to as a network, is a collection of hardware components and computers interconnected by communication channels that allow sharing of resources and information....
standard in the Ethernet
Ethernet
Ethernet is a family of computer networking technologies for local area networks commercially introduced in 1980. Standardized in IEEE 802.3, Ethernet has largely replaced competing wired LAN technologies....
family. It was developed during the 1980s and specified in IEEE 802.3b-1985.
The standard supported 10 Mbit/s Ethernet
Ethernet
Ethernet is a family of computer networking technologies for local area networks commercially introduced in 1980. Standardized in IEEE 802.3, Ethernet has largely replaced competing wired LAN technologies....
signals over standard 75 ohm cable television
Cable television
Cable television is a system of providing television programs to consumers via radio frequency signals transmitted to televisions through coaxial cables or digital light pulses through fixed optical fibers located on the subscriber's property, much like the over-the-air method used in traditional...
(CATV) cable over a 3600 meter range. The original Ethernet standard 10BASE-T
10BASE-T
Ethernet over twisted pair technologies use twisted-pair cables for the physical layer of an Ethernet computer network. Other Ethernet cable standards employ coaxial cable or optical fiber. Early versions developed in the 1980s included StarLAN followed by 10BASE-T. By the 1990s, fast, inexpensive...
used a baseband
Baseband
In telecommunications and signal processing, baseband is an adjective that describes signals and systems whose range of frequencies is measured from close to 0 hertz to a cut-off frequency, a maximum bandwidth or highest signal frequency; it is sometimes used as a noun for a band of frequencies...
encoding, where the signal is simply encoded directly on the wire without any sort of carrier wave. Instead, 10BROAD36 modulated its data onto a higher carrier frequency signal, much as an audio signal would modulate a carrier wave to be transmitted in a radio station. This was called broadband
Broadband
The term broadband refers to a telecommunications signal or device of greater bandwidth, in some sense, than another standard or usual signal or device . Different criteria for "broad" have been applied in different contexts and at different times...
at the time; the term has a different (more meaningless) marketing meaning today.
This provides several advantages over the more traditional baseband signal. Range was greatly extended, (3600 meters, versus 100 meters for 10BASE-T) and multiple signals can be carried on the same cable. 10BROAD36 could even share a cable with standard television channels.
The Institute of Electrical and Electronics Engineers
Institute of Electrical and Electronics Engineers
The Institute of Electrical and Electronics Engineers is a non-profit professional association headquartered in New York City that is dedicated to advancing technological innovation and excellence...
standards committee IEEE 802
IEEE 802
IEEE 802 refers to a family of IEEE standards dealing with local area networks and metropolitan area networks.More specifically, the IEEE 802 standards are restricted to networks carrying variable-size packets. IEEE 802 refers to a family of IEEE standards dealing with local area networks and...
published the standard that was ratified in 1985 as an additional section 11 to the base Ethernet standard.
It was also issued as ISO/IEC 8802-3 in 1989.
10BROAD36 was less successful than its contemporaries because of the high equipment complexity (and cost) associated with it. The individual stations were much more expensive due to the extra radio frequency
Radio frequency
Radio frequency is a rate of oscillation in the range of about 3 kHz to 300 GHz, which corresponds to the frequency of radio waves, and the alternating currents which carry radio signals...
circuitry involved, however the primary extra complexity came from the fact that 10BROAD36 was unidirectional. Signals could only travel one direction along the line, so head-end stations must be present on the line to repeat the signals (ensuring that no packets travel through the line indefinitely) on either another, backwards direction frequency on the same line, or another line entirely. This also increased latency and prevented bidirectional signal flow.
The extra complexity outweighed the advantage of reusability of CATV technology for the intended campus networks and metropolitan area network
Metropolitan area network
A metropolitan area network is a computer network that usually spans a city or a large campus. A MAN usually interconnects a number of local area networks using a high-capacity backbone technology, such as fiber-optical links, and provides up-link services to wide area networks and the...
s. An installer at Boston University
Boston University
Boston University is a private research university located in Boston, Massachusetts. With more than 4,000 faculty members and more than 31,000 students, Boston University is one of the largest private universities in the United States and one of Boston's largest employers...
using the Ungermann-Bass
Ungermann-Bass
Ungermann-Bass, also known as UB and UB Networks, was a computer networking company in the 1980s to 1990s. Located in Santa Clara, California, in Silicon Valley, UB was the first large networking company independent of any computer manufacturer. UB was founded by Ralph Ungermann and Charlie Bass...
product noted that no installers understood both the digital and analog aspects of the system.
In wide area networks it was quickly replaced by fiber-optic communication
Fiber-optic communication
Fiber-optic communication is a method of transmitting information from one place to another by sending pulses of light through an optical fiber. The light forms an electromagnetic carrier wave that is modulated to carry information...
alternatives, such as 100BASE-FX (which provided ten times the data rate). Interest in cable modem
Cable modem
A cable modem is a type of network bridge and modem that provides bi-directional data communication via radio frequency channels on a HFC and RFoG infrastructure. Cable modems are primarily used to deliver broadband Internet access in the form of cable Internet, taking advantage of the high...
s was revived for residential Internet access
Internet access
Many technologies and service plans for Internet access allow customers to connect to the Internet.Consumer use first became popular through dial-up connections in the 20th century....
, through later technologies such as the Data Over Cable Service Interface Specification
DOCSIS
Data Over Cable Service Interface Specification is an international telecommunications standard that permits the addition of high-speed data transfer to an existing cable TV system...
(DOCSIS) in the 1990s.