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A remote radio head (RRH), also called a remote radio unit (RRU) in wireless networks, is a remote radio transceiver that connects to an operator radio control panel via electrical or wireless interface. When used to describe aircraft radio cockpit radio systems, the control panel is often called the radio head.
In wireless system technologies such as GSM, CDMA, UMTS, LTE, 5G NR this radio equipment is remote to baseband units [1] such as BTS/NodeB/eNodeB/gNodeB or gNB. This equipment is used to extend the coverage of a baseband unit in challenging environments such as rural areas or tunnels. RRHs are generally connected to the baseband unit or base station which can be an x86 server [2] on the ground near a cell tower, via a fiber optic cable using Common Public Radio Interface protocols. [3]
RRHs have become one of the most important subsystems of today's new distributed base stations. The RRH contains RF circuitry plus analog-to-digital/digital-to-analog converters and up/down converters, and connects to, and thus drives the cell site's antenna. RRHs also have operation and management processing capabilities and a standardized optical interface to connect to the rest of the base station/baseband unit. This will be increasingly true as LTE and WiMAX are deployed. Remote radio heads make MIMO operation easier; they increase a base station's efficiency and facilitate easier physical location for gap coverage problems. RRHs will use the latest RF component technology including gallium nitride (GaN) RF power devices and envelope tracking technology within the RRH RF power amplifier (RFPA). [4]
Fourth generation (4G) and beyond infrastructure deployments will include the implementation of Fiber to the Antenna (FTTA) architecture. FTTA architecture has enabled lower power requirements, distributed antenna sites, and a reduced base station footprint than conventional tower sites. The use of FTTA will promote the separation of power and signal components from the base station and their relocation to the top of the tower mast in a Remote Radio Head (RRH).
According to the Telcordia industry standard that establishes generic requirements for Fiber to the Antenna (FTTA) protection GR-3177, [5] the RRH shifts the entire high-frequency and power electronic segments from the base station to a location adjacent to the antenna. The RRH will be served by optical fiber and DC power for the optical-to-electronic conversion at the RRH.
RRHs located on cell towers will require Surge Protective Devices (SPDs) to protect the system from lightning strikes and induced power surges. There is also a change in electrical overstress exposure due to the relocation of the equipment from the base station to the top of the mast.
RRHs can be installed in a low-profile arrangement along a rooftop, or can involve a much higher tower arrangement. When installed at the highest point on a structure (whether a building or a dedicated cell tower), they will be more vulnerable to receiving a direct lightning strike and higher induced lightning levels, compared with those installed in a lower profile manner below the upper edges of the building.
As noted in GR-3177, while surges can be induced into the RRH wiring for lightning striking the nearby rooftop or even the base station closure, the worst case will occur when a direct strike occurs to the antenna or its supporting structure. Designing the electrical protection to handle this situation will provide protection for less damaging scenarios... it can also be use in optical fiber communication but different type.
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.
In telecommunications, a network interface device is a device that serves as the demarcation point between the carrier's local loop and the customer's premises wiring. Outdoor telephone NIDs also provide the subscriber with access to the station wiring and serve as a convenient test point for verification of loop integrity and of the subscriber's inside wiring.
In telecommunications, a repeater is an electronic device that receives a signal and retransmits it. Repeaters are used to extend transmissions so that the signal can cover longer distances or be received on the other side of an obstruction. Some types of repeaters broadcast an identical signal, but alter its method of transmission, for example, on another frequency or baud rate.
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.
This is an index of articles relating to electronics and electricity or natural electricity and things that run on electricity and things that use or conduct electricity.
Base station is – according to the International Telecommunication Union's (ITU) Radio Regulations (RR) – a "land station in the land mobile service."
A base transceiver station (BTS) or a baseband unit (BBU) is a piece of equipment that facilitates wireless communication between user equipment (UE) and a network. UEs are devices like mobile phones (handsets), WLL phones, computers with wireless Internet connectivity, or antennas mounted on buildings or telecommunication towers. The network can be that of any of the wireless communication technologies like GSM, CDMA, wireless local loop, Wi-Fi, WiMAX or other wide area network (WAN) technology.
A cellular network or mobile network is a telecommunications network where the link to and from end nodes is wireless and the network is distributed over land areas called cells, each served by at least one fixed-location transceiver. These base stations provide the cell with the network coverage which can be used for transmission of voice, data, and other types of content. A cell typically uses a different set of frequencies from neighboring cells, to avoid interference and provide guaranteed service quality within each cell.
The antennas contained in mobile phones, including smartphones, emit radiofrequency (RF) radiation ; the parts of the head or body nearest to the antenna can absorb this energy and convert it to heat. Since at least the 1990s, scientists have researched whether the now-ubiquitous radiation associated with mobile phone antennas or cell phone towers is affecting human health. Mobile phone networks use various bands of RF radiation, some of which overlap with the microwave range. Other digital wireless systems, such as data communication networks, produce similar radiation.
Microconnect distributed antennas (MDA) are small-cell local area transmitter-receivers usually fitted to lampposts and other street furniture in order to provide Wireless LAN, GSM and GPRS connectivity. They are therefore less obtrusive than the usual masts and antennas used for these purposes and meet with less public opposition.
In a hierarchical telecommunications network, the backhaul 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.
Telecommunications engineering is a subfield of electronics engineering which seeks to design and devise systems of communication at a distance. The work ranges from basic circuit design to strategic mass developments. A telecommunication engineer is responsible for designing and overseeing the installation of telecommunications equipment and facilities, such as complex electronic switching system, and other plain old telephone service facilities, optical fiber cabling, IP networks, and microwave transmission systems. Telecommunications engineering also overlaps with broadcast engineering.
The Open Base Station Architecture Initiative (OBSAI) was a trade association created by Hyundai, LG Electronics, Nokia, Samsung and ZTE in September 2002 with the aim of creating an open market for cellular network base stations. The hope was that an open market would reduce the development effort and costs traditionally associated with creating base station products.
A sector antenna is a type of directional microwave antenna with a sector-shaped radiation pattern. The word "sector" is used in the geometric sense; some portion of the circumference of a circle measured in degrees of arc. 60°, 90° and 120° designs are typical, often with a few degrees 'extra' to ensure overlap and mounted in multiples when wider or full-circle coverage is required. The largest use of these antennas is as antennas for cell phone base-station sites. They are also used for other types of mobile communications, for example in Wi-Fi networks. They are used for limited-range distances of around 4 to 5 km.
The Common Public Radio Interface (CPRI) standard defines an interface between Radio Equipment Control (REC) and Radio Equipment (RE). Oftentimes, CPRI links are used to carry data between cell sites/remote radio heads and base stations/baseband units.
A fiber-optic cable, also known as an optical-fiber cable, is an assembly similar to an electrical cable but containing one or more optical fibers that are used to carry light. The optical fiber elements are typically individually coated with plastic layers and contained in a protective tube suitable for the environment where the cable is used. Different types of cable are used for fiber-optic communication in different applications, for example long-distance telecommunication or providing a high-speed data connection between different parts of a building.
Radio over fiber (RoF) or RF over fiber (RFoF) refers to a technology whereby light is modulated by a radio frequency signal and transmitted over an optical fiber link. Main technical advantages of using fiber optical links are lower transmission losses and reduced sensitivity to noise and electromagnetic interference compared to all-electrical signal transmission.
C-RAN (Cloud-RAN), also referred to as Centralized-RAN, is an architecture for cellular networks. C-RAN is a centralized, cloud computing-based architecture for radio access networks that supports 2G, 3G, 4G and future wireless communication standards. Its name comes from the four 'C's in the main characteristics of C-RAN system, "Clean, Centralized processing, Collaborative radio, and a real-time Cloud Radio Access Network".
Small cells are low-powered cellular radio access nodes that operate in spectrum that have a range of 10 meters to a few kilometers. They are base stations with low power consumption and cheap cost. They can provide high data rates by being deployed densely to achieve high spatial spectrum efficiency.
IEEE 1914.1 is a standard for packet-based fronthaul transport networks developed under IEEE 1914 Next Generation Fronthaul Interface – NGFI (xhaul) Working Group. NGFI (xhaul) working group is sponsored by IEEE Communications Society/Standards Development Board (COM/SDB). IEEE 1914.1 standardizes architecture and requirements for mobile fronthaul network – spanning between cell sites and centralized baseband locations in Centralized, Collaborative, Cloud and Clean Radio Access Network C-RAN.