Remote Access Devices

Topic:
Remote Access Devices
Submitted to:
Sir Saleem Raza
Submitted by:
Saira Nawz F10BB030

Repeaters
The term "repeater" originated with telegraphy in the 19th century, and referred to an electromechanical device used to regenerate telegraph signals.[1] Use of the term has continued in telephony and data communications.Hence we can define it as:
“A repeater is an electronic device that receives a signal and retransmits it at a higher level or higher power, or onto the other side of an obstruction, so that the signal can cover longer distances”.
Or
“A repeater is the simplest facility used for network interconnection, whose major function is to receive a network signal from one LAN terminal cable segment and to regenerate and retransmit the signal as it is in its original strength over a one or more other cable segment. Basically repeater regenerates the strength of the signal before transmitting” it
In telecommunication, the term repeater has the following standardized meanings:
  * An analog device that amplifies an input signal regardless of its nature (analog or digital).
  * A digital device that amplifies, reshapes, retimes, or performs a combination of any of these functions on a digital input signal for retransmission.[2]
Funtionality of repeaters
Repeaters operate in the OSI model Physical layer and are transparent to all the protocols operating in the layers above the Physical layer.
Repeaters allow a network to be constructed to exceed the size limit of a single, physical, cable segment. The number of repeaters that can be used intandem is generally limited by a particular LAN implementation. Using a repeater between two or more LAN cables segment requires that the same physical layer protocol be used to send signal over all the cable segments
A repeater receives a signal on one frequency and simultaneously retransmits (repeats) it on another frequency. The frequency it receives on is called the input frequency, and the frequency it...