Radio network
A radio network is a computer network in which information is transmitted by means of electromagnetic waves . It is a wireless telecommunication system in which the methods of radio technology are used.
Expressions
Radio networks can be classified in different ways , e.g. B. by:
- the coordination of the network nodes in the infrastructure network or ad hoc network .
- the radio technology used : Bluetooth (IEEE 802.15, WPAN ), WLAN ( IEEE 802.11 ), WiMAX (IEEE 802.16).
- the direction of communication : data can only be transmitted from the sender to one or more receivers ( unidirectional ) or between both (all) communication partners ( bidirectional ).
- the communication relationship between the systems: a sender can send to a recipient ( unicast ), to all possible recipients ( broadcast ), to a defined group of all recipients ( multicast ) or to (at least) any recipient from a group ( anycast ).
- the (typical) intended use / area of application, e.g. B. networks of sensors ( sensor networks ), the home area (e.g. smart home , wireless local area network ), amateur radio , Car2X ,
- the (typically) associated radio service .
When used as backbone technology, the radio links are often designed redundantly . This can improve the capacity of the network and increase reliability. In this configuration one speaks of a meshed radio network .
In other scenarios, individual radio links are preferred , so that one cannot actually speak of a radio network here:
- bridging large distances ( directional radio ),
- mobile data transmission ( cellular network ),
- the authority radio (BOS, trunked radio ),
- the distribution of radio and television (terrestrial and satellite broadcasting ),
- the distribution of time signals ,
- the distribution of satellite signals for positioning ( GNSS ),
- communication between small devices ( Internet of Things ).
The division between the classes is often blurred. For example, one and the same data transmission can be a broadcast transmission on the physical (radio) level, a unicast transmission on the security layer (data link layer, OSI layer 2 ) and a multicast at the same time -Transmission act on the network layer ( OSI layer 3 ).
Current developments in radio networks etc. a. in the following areas of application:
- Vehicle ad hoc network Car2X,
- Communication between small devices ( Internet of Things ),
- Internet for developing and emerging countries
See also
literature
- Christian Lüders: Local radio networks. Wireless LANs (IEEE 802.11), Bluetooth, DECT. Vogel Business Media, Würzburg 2007, ISBN 978-3-8343-3018-5 .
- Jörg Roth: Mobile Computing. Basics, technology, concepts. dpunkt-Verlag, Heidelberg 2002, ISBN 3-89864-165-1 .
Web links
- Freifunk : non-commercial initiative for free wireless networks
- Tegola radio network : Community Broadband Infrastructure in Scotland
- Hardly : experimental Wireless Broadband Mesh Network that has been deployed at the Karlstad University Campus
- SolarMesh (BMBF funding project) : As part of this project, existing technology is to be conceptually and technically adapted, expanded and improved in order to better meet the requirements in sparsely populated areas of the second and third world.
- Alliance for Affordable Internet : Association of private, public and social organizations that promotes Internet access in developing countries
- NET4DC initiative of the Fraunhofer-Gesellschaft : Develops technologies for global communication
- Wireless Networking in the Developing World : A practical guide to planning and setting up wireless networks in local environments