Repeater

Network Device:Repeater

Ø  Repeater is an electronic device that receives a signal and retransmits it.

Ø  It is networking device

Ø  It operates only at physical layer of OSI reference model

Ø  The basic purpose of a repeater is to extend the length of Local Area Network (LAN)

Ø  It connects two segments of same network, overcoming the distance limitations of transmission media (Generally at Hill stations)

Ø  It has two ports

Ø  A repeater receives a signal and before it becomes too weak or corrupted; regenerates the original bit patterns (0 & 1) and sends the refreshed signal.

Ø  A repeater enables signals to travel longer distances over a network.

Ø  It regenerate analog or digital signals distorted by transmission loss

Ø  According to the types of signals that they regenerate, repeaters can be classified into two types

      ·       Analog repeater

      ·       Digital repeater

Ø  Analog repeaters only amplify the signal without concerning the impurities in signal

Ø  Digital repeaters can reconstruct a signal to near its original quantity

Ø  According to the types of networks that they connect, repeaters can be categorized into two types –

     ·       Wired Repeaters − They are used in wired LANs.

     ·       Wireless Repeaters − They are used in wireless LANs and cellular networks.

Ø  According to the domain of LANs they connect, repeaters can be divided into two categories −

     ·       Local Repeaters − They connect LAN segments separated by small distance.

     ·       Remote Repeaters − They connect LAN segments that are far from each other.

Advantages of Repeaters

Ø  Repeaters are simple to install and can easily extend the length or the coverage area of networks.

Ø  It extends the distance typically covered by wired or wireless medium.

Ø  Repeaters don’t require any processing overhead. The only time they need to be investigated is in case of degradation of performance.

Ø  They can connect signals using different types of cables

Disadvantages of Repeaters

Ø  Repeaters cannot connect dissimilar networks.

Ø  They cannot differentiate between actual signal and noise.

Ø  They cannot reduce network traffic or congestion.

Ø  More repeaters create noise on the wire which results into packet collisions or problems in the packet detection (at the receiver).