Browse Definitions :
Definition

free-space optics (FSO)

Free-space optics (FSO), also called free-space photonics (FSP), refers to the transmission of modulated visible or infrared ( IR ) beams through the atmosphere to obtain Broadband communications. Most frequently, laser beams are used, although non-lasing sources such as light-emitting diodes ( LED s) or IR-emitting diodes (IREDs) will serve the purpose.

The theory of FSO is essentially the same as that for fiber optic transmission. The difference is that the energy beam is collimated and sent through clear air or space from the source to the destination, rather than guided through an optical fiber. If the energy source does not produce a sufficiently parallel beam to travel the required distance, collimation can be done with lenses. At the source, the visible or IR energy is modulated with the data to be transmitted. At the destination, the beam is intercepted by a photodetector, the data is extracted from the visible or IR beam (demodulated), and the resulting signal is amplified and sent to the hardware.

FSO systems can function over distances of several kilometers. As long as there is a clear line of sight between the source and the destination, communication is theoretically possible. Even if there is no direct line of sight, strategically positioned mirrors can be used to reflect the energy. The beams can pass through glass windows with little or no attenuation (as long as the windows are kept clean!).

Although FSO systems can be a good solution for some broadband networking needs, there are limitations. Most significant is the fact that rain, dust, snow, fog, or smog can block the transmission path and shut down the network.

This was last updated in March 2011
SearchNetworking
  • CIDR (Classless Inter-Domain Routing or supernetting)

    CIDR (Classless Inter-Domain Routing or supernetting) is a method of assigning IP addresses that improves the efficiency of ...

  • throughput

    Throughput is a measure of how many units of information a system can process in a given amount of time.

  • traffic shaping

    Traffic shaping, also known as packet shaping, is a congestion management method that regulates network data transfer by delaying...

SearchSecurity
  • Common Body of Knowledge (CBK)

    In security, the Common Body of Knowledge (CBK) is a comprehensive framework of all the relevant subjects a security professional...

  • buffer underflow

    A buffer underflow, also known as a buffer underrun or a buffer underwrite, is when the buffer -- the temporary holding space ...

  • single sign-on (SSO)

    Single sign-on (SSO) is a session and user authentication service that permits a user to use one set of login credentials -- for ...

SearchCIO
  • benchmark

    A benchmark is a standard or point of reference people can use to measure something else.

  • spatial computing

    Spatial computing broadly characterizes the processes and tools used to capture, process and interact with 3D data.

  • organizational goals

    Organizational goals are strategic objectives that a company's management establishes to outline expected outcomes and guide ...

SearchHRSoftware
  • talent acquisition

    Talent acquisition is the strategic process employers use to analyze their long-term talent needs in the context of business ...

  • employee retention

    Employee retention is the organizational goal of keeping productive and talented workers and reducing turnover by fostering a ...

  • hybrid work model

    A hybrid work model is a workforce structure that includes employees who work remotely and those who work on site, in a company's...

SearchCustomerExperience
Close