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In a hierarchical telecommunications network, the backhaul [1] portion of the network comprises the intermediate links between the core network, or backbone network, and the small subnetworks at the edge of the network (like for example private networks, LANs, etc.[ citation needed ]).
The most common network type in which backhaul is implemented is a mobile network. A backhaul of a mobile network, also referred to as a mobile-backhaul connects a cell site towards the core network. The two main methods of mobile backhaul implementations are fiber-based backhaul and wireless point-to-point backhaul. [2] Other methods, such as copper-based wireline, satellite communications and point-to-multipoint wireless technologies are being phased out as capacity and latency requirements become higher in 4G and 5G networks.
In both the technical and commercial definitions, backhaul generally refers to the side of the network that communicates with the global Internet, paid for at wholesale commercial access rates to or at an Internet exchange point or other core network access location. Sometimes middle mile networks exist between the customer's own LAN and those exchanges. This can be a local WAN connection.
Cell phones communicating with a single cell tower constitute a local subnetwork; the connection between the cell tower and the rest of the world begins with a backhaul link to the core of the internet service provider's network (via a point of presence). A backhaul may include wired, fiber optic and wireless components. Wireless sections may include using microwave bands and mesh and edge network topologies that may use a high-capacity wireless channel to get packets to the microwave or fiber links.
Visualizing the entire hierarchical network as a human skeleton, the core network would represent the spine, the backhaul links would be the limbs, the edge networks would be the hands and feet, and the individual links within those edge networks would be the fingers and toes.
Other examples include:
A telephone company is very often the internet service provider providing backhaul, although for academic research and education networks, large commercial networks or municipal networks, it is increasingly common to connect to public broadband backhaul. See national broadband plans from around the world, many of which were motivated by the perceived need to break the monopoly of incumbent commercial providers. The US plan for instance, specifies that all community anchor institutions should be connected by gigabit fiber optics before the end of 2020. [3]
The choice of backhaul technology must take account of such parameters as capacity, cost, reach, and the need for such resources as frequency spectrum, optical fiber, wiring, or rights of way.
Generally, backhaul solutions can largely be categorized into wired (leased lines or copper/fiber) or wireless (point-to-point, point-to-multipoint over high-capacity radio links). Wired is usually a very expensive solution and often impossible to deploy in remote areas, hence making wireless a more suitable and/or a viable option. Multi-hop wireless architecture can overcome the hurdles of wired solutions to create efficient large coverage areas and with growing demand in emerging markets where often cost is a major factor in deciding technologies, a wireless backhaul solution is able to offer 'carrier-grade' services, whereas this is not easily feasible with wired backhaul connectivity. [4]
Backhaul technologies include:
Backhaul capacity can also be leased from another network operator, in which case that other network operator generally selects the technology being used, though this can be limited to fewer technologies if the requirement is very specific such as short-term links for emergency/disaster relief or for public events, where cost and time would be major factors and would immediately rule out wired solutions, unless pre-existing infrastructure was readily accessible or available. [4]
Wireless backhaul is easy to deploy, cost efficient and can provide high capacity connectivity, e.g., multiple gigabits per second, and even tens of Gbps. Wireline fiber backhaul, on the other hand, can provide practically endless capacity, but requires investment in deploying fiber as well as in optical equipment.
The above-mentioned tradeoff is considered when planning. The type of backhaul for each site is determined taking into consideration the capacity requirement (current and future), deployment timeline, fiber availability and feasibility and budget constraints.
As data rates increase, the range of wireless network coverage is reduced, raising investment costs for building infrastructure with access points to cover service areas. Mesh networks are unique enablers that can reduce this cost due to their flexible architecture.
With mesh networking, access points are connected wirelessly and exchange data frames with each other to forward to/from a gateway point.
Since a mesh requires no costly cable constructions for its backhaul network, it reduces total investment cost. Mesh technology’s capabilities can boost extending coverage of service areas easily and flexibly.
For further cost reduction, a large-scale high-capacity mesh is desirable. For instance, Kyushu University's Mimo-Mesh Project, based in Fukuoka City, Fukuoka Prefecture, Japan, has developed and put into use new technology for building high capacity mesh infrastructure. [7] A key component is called IPT, intermittent periodic transmit, a proprietary packet-forwarding scheme that is designed to reduce radio interference in the forwarding path of mesh networks. In 2010, hundreds of wireless LAN access points incorporating the technology were installed in the commercial shopping and entertainment complex, Canal City Hakata, resulting in the successful operation of one of the world's largest indoor wireless multi-hop backhauls. That network uses a wireless multi-hop relay of up to 11 access points while delivering high bandwidth to end users. Actual throughput is double that of standard mesh network systems using conventional packet forwarding. Latency, as in all multi-hop relays, suffers, but not to the degree that it compromises voice over IP communications.
Many common wireless mesh network hotspot solutions are supported in open source router firmware including DD-WRT, OpenWRT and derivatives. The IEEE 802.21 standard specifies basic capabilities for such systems including 802.11u unknown user authentication and 802.11s ad hoc wireless mesh networking support. Effectively these allow arbitrary wired net connections to be teamed or ganged into what appears to be a single backhaul – a "virtual private cloud". Proprietary networks from Meraki follow similar principles. The use of the term backhaul to describe this type of connectivity may be controversial technically. They invert the business definition, as it is the customer who is providing the connectivity to the open Internet while the vendor is providing authentication and management services.
On very large scale long range networks, including transcontinental, submarine telecommunications cables are used. Sometimes these are laid alongside HVDC cables on the same route. Several companies, including Prysmian, run both HVDC power cables [8] and telecommunications cables [9] as far as FTTx. This reflects the fact that telecommunications backhaul and long range high voltage electricity transmission have many technologies in common, and are almost identical in terms of route clearing, liability in outages, and other legal aspects. [10]
A wireless LAN (WLAN) is a wireless computer network that links two or more devices using wireless communication to form a local area network (LAN) within a limited area such as a home, school, computer laboratory, campus, or office building. This gives users the ability to move around within the area and remain connected to the network. Through a gateway, a WLAN can also provide a connection to the wider Internet.
A wireless network is a computer network that uses wireless data connections between network nodes. Wireless networking allows homes, telecommunications networks and business installations to avoid the costly process of introducing cables into a building, or as a connection between various equipment locations. Admin telecommunications networks are generally implemented and administered using radio communication. This implementation takes place at the physical level (layer) of the OSI model network structure.
Network topology is the arrangement of the elements of a communication network. Network topology can be used to define or describe the arrangement of various types of telecommunication networks, including command and control radio networks, industrial fieldbusses and computer networks.
Wireless communication is the transfer of information (telecommunication) between two or more points without the use of an electrical conductor, optical fiber or other continuous guided medium for the transfer. The most common wireless technologies use radio waves. With radio waves, intended distances can be short, such as a few meters for Bluetooth, or as far as millions of kilometers for deep-space radio communications. It encompasses various types of fixed, mobile, and portable applications, including two-way radios, cellular telephones, personal digital assistants (PDAs), and wireless networking. Other examples of applications of radio wireless technology include GPS units, garage door openers, wireless computer mouse, keyboards and headsets, headphones, radio receivers, satellite television, broadcast television and cordless telephones. Somewhat less common methods of achieving wireless communications involve other electromagnetic phenomena, such as light and magnetic or electric fields, or the use of sound.
Wireless local loop (WLL) is the use of a wireless communications link as the "last mile / first mile" connection for delivering plain old telephone service (POTS) or Internet access to telecommunications customers. Various types of WLL systems and technologies exist.
The last mile, or last kilometer, in the telecommunications, cable television and internet industries refers to the final leg of a telecommunications network that delivers telecommunication services to retail end-users (customers). More specifically, last mile describes the portion of the telecommunications network chain that physically reaches the end-user's premises. Examples are the copper wire subscriber lines connecting landline telephones to the local telephone exchange; coaxial cable service drops carrying cable television signals from utility poles to subscribers' homes, and cell towers linking local cell phones to the cellular network. The word "mile" is used metaphorically; the length of the last mile link may be more or less than a mile. Because the last mile of a network to the user is conversely the first mile from the user's premises to the outside world when the user is sending data, the term first mile is also alternatively used.
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 Web. Internet access is offered for sale by an international hierarchy of Internet service providers (ISPs) using various networking technologies. At the retail level, many organizations, including municipal entities, also provide cost-free access to the general public.
In telecommunications, a point-to-point connection refers to a communications connection between two communication endpoints or nodes. An example is a telephone call, in which one telephone is connected with one other, and what is said by one caller can only be heard by the other. This is contrasted with a point-to-multipoint or broadcast connection, in which many nodes can receive information transmitted by one node. Other examples of point-to-point communications links are leased lines and microwave radio relay.
In telecommunications, point-to-multipoint communication is communication which is accomplished via a distinct type of one-to-many connection, providing multiple paths from a single location to multiple locations.
A wireless Internet service provider (WISP) is an Internet service provider with a network based on wireless networking. Technology may include commonplace Wi-Fi wireless mesh networking, or proprietary equipment designed to operate over open 900 MHz, 2.4 GHz, 4.9, 5, 24, and 60 GHz bands or licensed frequencies in the UHF band, LMDS, and other bands from 6 GHz to 80 GHz.
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.
Local multipoint distribution service (LMDS) is a broadband wireless access technology originally designed for digital television transmission (DTV). It was conceived as a fixed wireless, point-to-multipoint technology for utilization in the last mile. LMDS commonly operates on microwave frequencies across the 26 GHz and 29 GHz bands. In the United States, frequencies from 31.0 through 31.3 GHz are also considered LMDS frequencies.
A metropolitan-area Ethernet, Ethernet MAN, carrier Ethernet or metro Ethernet network is a metropolitan area network (MAN) that is based on Ethernet standards. It is commonly used to connect subscribers to a larger service network or for internet access. Businesses can also use metropolitan-area Ethernet to connect their own offices to each other.
A backbone or core network is a part of a computer network which interconnects networks, providing a path for the exchange of information between different LANs or subnetworks. A backbone can tie together diverse networks in the same building, in different buildings in a campus environment, or over wide areas. Normally, the backbone's capacity is greater than the networks connected to it.
A computer network is a set of computers sharing resources located on or provided by network nodes. Computers use common communication protocols over digital interconnections to communicate with each other. These interconnections are made up of telecommunication network technologies based on physically wired, optical, and wireless radio-frequency methods that may be arranged in a variety of network topologies.
Cambium Networks Corporation is a wireless infrastructure provider that offers fixed wireless and Wi-Fi to broadband service providers and enterprises to provide Internet access. An American telecommunications infrastructure company, it provides wireless technology, including Enterprise WiFi, switching solutions, Internet of Things, and fixed wireless broadband and Wi-Fi for enterprises. Publicly traded on the NASDAQ stock exchange, it spun out of Motorola in October 2011.
Cambridge Broadband Networks Limited (CBNL) is a British telecommunications company which develops and manufactures point-to-multipoint (PMP) wireless backhaul and access solutions.
A residential gateway is a small consumer-grade gateway which bridges network access between connected local area network (LAN) hosts to a wide area network (WAN) via a modem, or directly connects to a WAN, while routing. The WAN is a larger computer network, generally operated by an Internet service provider.
Fixed wireless is the operation of wireless communication devices or systems used to connect two fixed locations with a radio or other wireless link, such as laser bridge. Usually, fixed wireless is part of a wireless LAN infrastructure. The purpose of a fixed wireless link is to enable data communications between the two sites or buildings. Fixed wireless data (FWD) links are often a cost-effective alternative to leasing fiber or installing cables between the buildings.
Carrier Ethernet is a marketing term for extensions to Ethernet for communications service providers that utilize Ethernet technology in their networks.
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