Base station
A base station is a fixed transmission for radio signals from mobile telephone networks, cordless phones and wireless networks.
Landline
In the fixed network, the term base station refers to the stationary part of a cordless phone, which is connected with a wire to the fixed network. The object of the base station is to convert the signals from the phone jack into radio signals and transmit them to the handsets - and vice versa. Previously, the transfer was carried out analogously for the CT1 and CT1 later - Standard ( ct = Cordless telephone ). Later, a digital transmission was introduced with CT2. But send CT1, CT1 and CT2 partly on the frequencies of the GSM standard and there were disturbances of the cellular network, ended on 31 December 2008, the license for the operation of such cordless telephones in Germany. Today, the digital transmission according to the DECT standard is used. In most cases the base station is also a charging station and has an integrated answering machine. At a base station multiple handsets can be registered, with which you can also call each other. Sometimes there are also radio - TAEs that are registered to the base station and allow the connection of corded devices such as fax machines or dialers.
Mobile
In the area of mobile telephony, the term base station a mobile phone base station of a GSM, UMTS, WiMAX, LTE or TETRA network as a network element or location.
Locations
Since in cellular mobile networks for a comprehensive supply many stations are required, they must be implemented at a variety of locations.
Many mobile sites are located on private or public buildings. To this end, antenna carrier or a small steel tube mast - optionally provided with a vertical ladder - is placed on the flat or pitched roof. In some cases, the antennas are installed on the facade. An installation on or to buildings that are subject to the preservation, is only possible in exceptional cases. With appropriate lining made of fiberglass reinforced plastic (FRP ) can be hidden antenna carrier and antennas. Often, this camouflage is executed as a chimney, the color and shape of the building or the existing chimneys adapts.
Also steeples can wear transmitting devices for mobile communication. The antennas are mounted in most cases behind the windows sound of the bell tower, so they are not visible from the outside and do not affect the appearance of the tower. Due to the symbolism of church towers is in some places apart from a list of antennas in God's house, many dioceses and communities have prohibited the leasing of ecclesiastical property for ethical reasons and environmental consideration for the neighborhood. Not infrequently it is counterproductive, since steeples from the perspective of pollution control often would be the better (since higher ) locations and would lead to a reduction of the neighborhood.
At the top of water towers transmission antennas for mobile communications can be installed normally without any problems, as these structures are very massive and are often already designed to accommodate antennas for relay stations of the BOS radio or similar radio services. Sometimes, however, mobile phone antennas must be covered for the sake of preservation, or aesthetic. For worn towers and towers with sufficient space technology unit is housed inside of the tower, otherwise a container adjacent to the tower is necessary.
How to water towers mobile antennas can be installed on observation towers. In particular, when the tower already (eg radio services BOS ) carries antennas for other services, provides its installation is usually not a problem For some lookout towers is important to note that they are listed buildings. In this case, the antenna must be mounted and designed in color so that they do not detract from the appearance of the tower as possible.
In industrial areas and at locations where suitable high roof locations are not available, mobile antennas can be mounted on existing chimneys. Frequently, this is used simultaneously by several mobile network operators, since it is a costly site variant. Often the chimney before attaching the antenna needs to be completely renovated. If the use of the chimney has been abandoned as a fireplace, is the installation of satellite dishes one requiring approval use change represents the main use then transforms itself from a fireplace to an antenna support, in rare cases, these Terms may not be eligible for approval and are prohibited by the authorities.
Mobile BTS increase the capacity on site (see left image). For example, at major events, the existing BTS would be overloaded quickly. Autonomous BTS are independent of supply lines. The picture below shows a BTS - container. Two mobile phone antennas emit slightly inclined in a valley and communicate with mobile phones in the area. Two directional antennas maintain contact BSC upright and forward the calls continue. The diesel generator right of the screen provides the unit with electrical energy.
Mobile antennas on a tower.
Mobile antennas on a church steeple.
BTS to a chimney.
Mobile BTS
Telecom GSM and 3G BTS
Autonomous BTS
As palm disguised antenna
Antenna in the bush village
Transmission towers and masts
Use of existing transmission towers
Mobile end devices can be installed (eg on television ) converter to existing transmission towers ( for example, on television or telecommunication towers ) or transmission towers. In principle, such devices operate on all types of antenna carriers ( also insulated against ground, radiating transmitting masts during transmission under high RF voltage stand ) can be installed, but it will be fit for maintenance no mobile phone base antennas insulated against ground masts. Depending on the design of the antenna carrier and available space, the transmitter unit is housed in an existing control tower or in a building next to the tower. The power supply of mobile antennas insulated against ground poles is the same as the power of the optionally present air safety lights via a misplaced inside the Windungsdrahts a choke coil cable, which choke coil is put together with a capacitor connected in parallel between the mast and the ground and a blocking circuit for the mast applied high-frequency high voltage forms. Occasionally it may happen that the transmission tower on which the mobile antennas are to be mounted, is a listed building. Then the antennas are designed in color and so be mounted so that they detract from the appearance of the tower as little as possible. Basically, the installation of mobile antennas is to be welcomed listed building transmission towers because by renting such structures to mobile operators can very economically their preservation be funded.
Special transmission towers for mobile
New antenna support must often be built for mobile stations. These are usually configured as a free-standing structure made of reinforced concrete prefabricated parts or as a freestanding tubular steel or steel lattice structures. Guyed masts can also be used, but they will not not be used in Germany as a rule, because they have an increased space requirement due to the Pardunenfundamente. When selecting the tower type is to be noted that concrete towers heavier and more expensive than steel towers comparable level, but less maintenance ( rust preventive ) than this need. In addition, they require a smaller footprint and are also as the reinforced concrete telecommunication towers of Deutsche Telekom as an aesthetic than steel towers. The built for mobile radio transmitter towers are generally not higher than 70 meters and are designed so that they can also carry antennas for other radio services in addition to the antennas for mobile communication. The most common here are directional antennas to 3 m in diameter for microwave links to larger radio relay nodes or other base stations. But antennas for radio services that have nothing to do with the mobile, are often found on transmission towers for mobile communications, because often these sites (for example, as a TV converter ) used for underperforming FM and TV stations. Unlike large telecommunications towers cell towers conventional design do not have high-altitude operating rooms. All technical equipment is housed next to the tower either in a container or in one or more technology cabinets. Many antenna support from about 15 meters in height have round or square maintenance platforms for the antenna systems. The shared use of other wireless services or the installation of floodlights or advertising structures is possible.
There are also numerous special designs of mobile towers. While the German Telekom can use for its mobile network its numerous telecommunication towers than larger network nodes had to telecom competitors often build their own towers with greater capacity to fulfill this task. Most of these towers are designed as 80 to 100 meters high, freestanding lattice steel towers. But there are towers made of prefabricated concrete elements for this purpose, such as the Vodafone towers in Stuttgart- Vaihingen and Mannheim, built as a tripod -like structure made of prefabricated concrete parts.
Some transmitting towers for mobile communications were appointed on request of the municipality on whose territory they are connected to a to the public via a staircase accessible viewing platform. In Germany you can find such towers in Schöppingen, in Fort Fun Amusement Park, the Müritz National Park, United Reken Melchenberg, on the Schomberg and on the graves mountain in Alpenrod. In the Czech Republic there are several such towers.
A particular cell tower is also the microwave converter Schongau, because it is in contrast to other cell towers a wooden structure.
There are also cell phone towers, which are modeled in appearance trees. Such designs are available in different versions, depending on the climate of the installation location in various versions ( palm, pine, etc. ) are commercially available.
For large events, such as the World Youth Day 2005 (here only on the Marienfeld near Kerpen) or the Oktoberfest, most network vendors build additional channel capacity by setting up a temporary BTS. Here steel masts are erected, mostly shared by several network providers.
Overhead line masts
Also on pylons transmitting devices are installed for the mobile (usually including radio relay connections to a larger network nodes) often. Mobile stations and 110 kV lines set - As a rule, this masts of 380 kV lines used because of the required height and static reasons, however, are also not uncommon especially on higher and more stable poles of 220. Masts of traction current lines are rarely used for this purpose, as these designed mostly for 4 conductors designs have a lower load capacity than the designed mostly for at least 6 conductors masts of the public grid.
Also on poles of power lines for medium voltage ( 10-30 kV ) and even low voltage ( 0.4 kV) can mobile antennas for small mobile stations will be installed, but it is especially its installation on masts of cables for low voltage because of their very low viability only in special cases, for example, for the realization of micro-cells is carried out.
As a rule, a platform will be set up with the antennas at transmission towers for mobile phone antennas below the conductors. The transmitters usually find a place in a container or a cabinet under or next to the mast.
Occasionally mobile antennas are mounted on top of the mast above the conductors, for which possibly also a small platform will be installed on the mast. The operation of the high voltage line must not be hindered by the mobile end operation. In some cases, individual high- voltage masts decommissioned power lines are converted to cell towers by keeping them - in contrast to the other pole of the line - does not degrade.
Microcells
At certain points in the inner cities, the network utilization is significantly increased. For this reason, some network operators set up so-called microcells. These have a very limited range of rarely more than 200 meters. They merely serve to relieve neighboring radio cells. The antennas are installed at low altitude, for example, on the facades of buildings, neon signs, on street lamps or on hoardings.
So-called indoor micro cells (also known as pico cells ) come in high traffic buildings such as shopping malls, exhibition halls and airport terminals are used.
There are also mobile micro cells that can be transported on a vehicle and are placed on certain occasions (such as at concerts or football matches ).
Tunnel radio coverage
Many network providers want to offer their customers an underground power supply. Here are several metro stations are usually summarized with several antennas to a BTS. The supply is due to the great distance and the associated high attenuation of the cellular signal usually via an optical repeater network. The distribution of ( analog ) cellular signal is not a coaxial cable, but is realized through optical fibers. In a central operations room in which the base stations of the network operator and the master unit are housed, the analog RF signal is electrical / optical converted and distributed from there via fiber optic cable to the individual remote units, the signal optical / electrical re- back convert, amplify and radiate through antennas or cable slot. Another advantage of this technique is that a plurality of remote units can be supplied with the same frequency, ie the radio cell can extend over several subway stations. This makes it possible to save the base stations.
The radiation of the RF signal into the tunnels will be leaky cables along the tube walls or through directional antennas that are usually placed at the entrances, realized.
Other locations
Mobile antennas can be installed even on very unusual locations. For example, the company LS telcom in Lichtenau has built on its premises a mast looks like a conifer. However, this mast is only used as a demonstration and was never used as an antenna carrier. In the U.S., the installation of wireless antennas on artificial trees is widespread.
Criticism
In many cases, criticism of the growing number of masts is loud, on the one hand refer to the image of the masts in the countryside, on the other hand, the transmission energy, which should lead to an increased electric smog. It is often criticized that each mobile operator draws up its own masts and no arrangements to fold several transmitters are performed on a mast. On the other hand, attract potential rental income many to give permission for their land or house to let there be mounted antennas. This can lead to differences with the neighborhood.
Depending on local law, the policy has more or less rights, regulate it. In Austria, the policy of structural or landscape protection relatively little intervention, therefore the province of Lower Austria wanted from 2006 to introduce a so-called " mobile phone mast control ". The delivery, however, was abolished following an agreement with the Austrian network operators before they are first applied again.