A repeater in a computer network is a networking device used to extend the reach of a network’s signal, particularly in wired networks. It operates at the physical layer of the OSI (Open Systems Interconnection) model, which deals with the actual transmission and reception of data over the physical medium, such as cables or fibre optics. Repeaters are used to overcome the limitations of signal degradation and attenuation that occur as data travels over long distances.
What are Repeaters in Computer Networks?
In computer networks, a repeater is a device that amplifies and regenerates signals as they pass through the network. The primary purpose of a repeater is to extend the distance of a network by increasing the strength and quality of signals over long distances or through dense blocks. Repeaters are often used in LANs (Local Area Networks) and WANs (Wide Area Networks) to improve the performance and reliability of the network. They can help prevent data loss, reduce errors, and ensure that the signal arrives at its intended destination with sufficient strength and quality.
How does a Repeater work in a Computer Network?
Here’s how a repeater works:
- A signal is transmitted from a source, such as a radio or a cell phone.
- The signal travels through the air or a cable, but its strength weakens as it gets farther from the source.
- The weakened signal is received by the repeater, which amplifies it to increase its strength.
- The amplified signal is transmitted from the repeater to its destination, such as another radio or cell phone.
- The signal is now stronger and can travel a greater distance without losing quality.
- Repeaters are commonly used in wireless networks, such as cellular and Wi-Fi networks, to extend their range and improve signal strength.
- They can also be used in wired networks, such as Ethernet networks, to extend the length of a cable run.
Why are Repeaters needed?
When an electrical signal is transmitted via a channel, it gets attenuated depending on the nature of the track or the technology. This poses a limitation upon the length of the LAN or coverage area of cellular networks. This problem is alleviated by installing repeaters at specific intervals.
Repeaters amplify the attenuated signal and then retransmit it. Digital repeaters can even reconstruct signals distorted by transmission loss. So, repeaters are popularly incorporated to connect between two LANs thus forming a large single LAN.
Types of Repeaters
There are primarily two types of repeaters
Analog Repeaters
These are used in analog networks, such as analog telephone lines, to regenerate and amplify analog signals. They help maintain the quality of the signal over long distances.
Digital Repeaters
These are used in digital networks, like Ethernet, to regenerate and retime digital signals. Digital repeaters essentially take the incoming signal, clean it up, and retransmit it at its original strength.
Uses of Repeaters
Repeaters are used for various purposes in computer networks
Extending Network Range
The primary use of repeaters is to extend the reach of a network’s signal. In wired networks, signals can weaken and degrade over long distances, so repeaters are placed at strategic points to boost the signal and maintain its integrity.
Cable Length Limitations
Different network media (like Ethernet cables) have specific length limitations for signal propagation due to attenuation. Repeaters allow network segments to be extended beyond these limitations.
Network Topology
Repeaters are useful in bus and star topologies. In a bus topology, for instance, each end of the bus may require a repeater to prevent signal degradation.
Functions of Repeaters
Repeaters serve several functions in a network
Signal Regeneration
As data travels along a network cable, the signal weakens due to factors like cable quality, interference, and distance. Repeaters receive the weakened signal, amplify it, and then transmit it again, effectively regenerating the signal’s strength.
Noise Elimination
Repeaters can help eliminate or reduce signal noise that might have been introduced during transmission. They clean up the signal before retransmitting it.
Signal Timing
In digital networks, timing becomes crucial to data integrity. Repeaters retime the signal, ensuring that it maintains its original timing characteristics.
Interconnection of Segments
Repeaters allow different network segments to be connected while maintaining signal quality. This is especially important in large networks where segments need to be interconnected.
Advantages of Repeaters
- Repeaters are simple to install and can easily extend the length or the coverage area of networks.
- They are cost-effective.
- Repeaters don’t require any processing overhead. The only time they need to be investigated is in case of degradation of performance.
They can connect signals using different types of cables.
Disadvantages of Repeaters
- Repeaters cannot connect dissimilar networks.
- They cannot differentiate between actual signals and noise.
- They cannot reduce network traffic or congestion.
- Most networks have limitations on the number of repeaters that can be deployed.
Repeaters Manufacturing Companies?
Here are some well-known companies that were involved in manufacturing networking equipment, including repeaters, up to that point:
- Cisco Systems: Cisco is one of the largest and most well-known companies in the networking industry. They manufacture a wide range of networking equipment, including switches, routers, and repeaters.
- Hewlett-Packard (HP): HP offers a variety of networking products, including switches, routers, and network accessories like repeaters.
- Juniper Networks: Juniper specializes in networking and security solutions. They provide products such as switches, routers, and related networking equipment.
- D-Link: D-Link is known for producing networking and connectivity products, including switches, routers, and repeaters.
- NETGEAR: NETGEAR manufactures a range of networking equipment for home and business use, including switches, routers, and repeaters.
- TP-Link: TP-Link is a global provider of networking devices and accessories, including switches, routers, and repeaters.
- Linksys: A division of Belkin International, Linksys offers networking solutions for home and small business users, including switches, routers, and range extenders that function similarly to repeaters.
- Ubiquiti Networks: Ubiquiti is known for its wireless networking products, including access points, routers, and other network devices.
- Zyxel: Zyxel offers networking solutions for both home and business environments, including switches, routers, and repeaters.
- TRENDnet: TRENDnet manufactures a variety of networking hardware, including switches, routers, and access points.
There may be newer players in the market that have emerged since my last update.
Conclusion
It’s important to note that with the advancement of technology and the widespread use of switches and routers, the need for traditional repeaters has decreased. Switches and routers not only extend the reach of networks but also provide additional functionality like segmentation, traffic management, and higher levels of control. Repeaters are more commonly encountered in legacy systems or specialized scenarios where they serve a specific purpose in signal extension and regeneration.
Frequently Asked Questions(FAQs)
Q1. What is a repeater in a computer network?
Ans: A repeater is a device used in computer networks to regenerate and amplify signals as they pass through the network. The primary function of a repeater is to extend the distance of a network by increasing the strength and quality of signals over long distances or through dense obstacles.
Q2. What is the difference between an analog repeater and a digital repeater?
Ans: An analog repeater amplifies the incoming signal and regenerates it at the output, while a digital repeater regenerates the digital signal without amplifying it. Analog repeaters are used in older network technologies that operate on analog signals, while digital repeaters are used in modern network technologies that operate on digital signals.
Q3. Where are repeaters typically used in a computer network?
Ans: Repeaters are typically used in Local Area Networks (LANs) and Wide Area Networks (WANs) to improve the performance and reliability of the network. They can help prevent data loss, reduce errors, and ensure that the signal arrives at its intended destination with sufficient strength and quality.
Q4. How many repeaters can be used in a network?
Ans: The number of repeaters that can be used in a network depends on the specific technology being used, the distance between devices, and other factors such as both the signal’s strength and the cable’s quality. In general, it is recommended to limit the number of repeaters in a network to ensure optimal performance.