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Transmission media in computer networks

Transmission means the transmission of information by them. Transmission media include electrical wires, coaxial cables, fiber optics, and electromagnetic waves. What is the transmission medium in computer networks? In data communication, a transmission medium in computer networks is a physical path through which the sender transmits data to the receiver. That is, the channel through which data is sent. Transmission media in computer networks are directly controlled by the physical layer and are located below the physical layer. Data is transmitted by signals. These signals are transmitted in the form of electromagnetic energy from one device to another. Types of transmission media Data transfer from one geographical or electronic location to another is called transfer media or communication media. There are two categories of transmission media in network communication: 1. Conductive transmission media (wired): Conducted media are those that provide conduction from one device to another, including twisted pair cable, coaxial cable and fiber optic cable. 2. Unconducted transmission media: Unconducted (unguided) and unrestricted media transmit electromagnetic waves without the use of physical cable. These types of communications are often called wireless. Guided media Restricted or guided media are physical cables that pass signals in a narrow path consisting of an external conductor (usually copper) wrapped in a jacket made of non-conductive material. Limited media are great for in-lab communication because they offer high speed, are more secure than unguided media, and cost less. Types of guided transmission media Three common types of limited media are used in data transmission. These three types are: • Coaxial cable • Twisted pair cable • Fiber optic cable

1. Coaxial cable One of the most widely used transmission media is coaxial cable. One of the most prominent examples is the TV wire, which is usually made of coaxial cable. Coaxial cable (or coax) carries signals with a frequency range higher than those twisted in pairs. The coaxial cable is placed in two parallel conductors parallel to each other. The central conductor in cable is usually copper, which usually has three modes: 1- solid wire 2- filament copper 3- twisted Outside the central conductor is a non-conductive material called a dielectric insulator. Dielectric insulation is used to separate the internal conductor from the external conductor and is made of white plastic material. The other conductor is a delicate mesh made of woven copper. It is used to help protect the cable against electromagnetic interference or EMI. Actual data travels through the center conductor in Kabul. The EMI is captured or redirected by the external copper network. There are different types of coaxial cable that differ in measurement and impedance. The following are the most common coaxial standards: 50-Ohm RG-7 or RG-11: Used for thick Ethernet or "thicknet". 50-Ohm RG-58: Used for thin or "cheap" Ethernet. 75-Ohm RG-59: Used for cable TV. 93-Ohm RG-62: Used for ARCNET Coaxial cables are classified based on their radio state (RG) rating. Each RG number represents a unique set of physical characteristics. Advantages of coaxial cable • Low costs • Easy to install • Easy to expand • Capacity up to 10 Mbps (Mbps data) • Resistant to EMI Disadvantages In addition to its obvious features, it also has disadvantages, such as: single cable failure, which is also known as a failure point and can destroy the entire network. Coaxial cable is an attenuation medium that gradually weakens the transmission of more data from the point of origin. 2. Twisted pair cable The twisted pair cable consists of two conductors (usually copper), each with its own plastic. This cable is very popular among its consumers. Features of this cable include: light weight, easy to install, cheap and supports a variety of networks. Supports data transfer speeds of up to 100 Mbps. Twisted pair cabling is made of pairs of solid copper or twisted strands along each other. These twists are to reduce vulnerability to EMI. The number of cable pairs depends on the type of cable. There are two types of twisted pair cables: • Unprotected twisted pair (UTP) • Twisted pair of shields (STP) UTP wiring is longer than STP. UTP can be audio grade or data grade. The UTP cable typically has an impedance of 100 ohms. UTP costs less than STP and is easily accessible due to its many applications. 3. Fiber optic cable Fiber optic cable is made of glass or plastic and transmits signals in the form of light. In the center of the cable is a filament or core of glass. The laser light travels through this glass to another device. There is a reflective substance around the inner core known as the veneer. Due to the presence of this reflective coating, no light escapes from the glass core. In optical fiber, light travels in only one direction. Therefore, for two-way communication, a second connection must be established between the two devices. Therefore, optical fiber is produced in parallel with two strands of cable. Each discipline is responsible for one direction of communication. Fiber optic cable has a bandwidth of more than 2 Gbps. Its high speed has made it a prominent feature. Features of fiber optic cable Fiber optics are expensive • It is very difficult to install • It has extremely high data transfer speed Very low damping • No EMI interference

Wireless transmission Wireless communication is the transmission of information between two or more points in which no physical wires or cables are used. The data transfer rate in this method is often slow because it is not connected directly to the cable. Microwave transfer method is a wireless method. microwave Microwave transmission is the technology of transmitting information or energy using radio waves whose wavelengths can be easily measured. The data transfer speed using this medium is high. It can be said that the theoretical maximum speed of microwave transmission is much faster than you can get through fiber. Microwave installation costs less than copper leased lines, but is time consuming. Its level of security depends on the strength and frequency of the waves, the width of the beam and the type of information transmitted. last word Data is represented by computers and other telecommunications devices using signals. Signals are transmitted in the form of electromagnetic energy from one device to another. Electromagnetic signals pass through vacuum, air, or other transmission media to travel from one point to another (from transmitter to receiver). You can share your questions and comments about this article with us in the comments section.

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What is a computer network LAN? + Check the types of computer LAN networks

A computer network is a collection of standalone computers and other devices connected by a communication medium, such as coaxial cables, twisted pairs of optical fibers. One type of computer network is the local network. A local area network (LAN) can be defined as a collection of computers and peripherals connected to each other in a limited and small geographical area such as home, office, etc. This area may be a few kilometers from a building or a campus. Local area networks can be introduced as a private property with high speed and low error rate. What is a computer network LAN? LAN stands for Local Area Network. LANs were first used in colleges and universities in the 1960s. These computer networks were used to index library collections, plan classes, record student grades, and share equipment resources. This network is a group of computers and devices located in a specific location. The devices connect to the LAN via Ethernet cable or Wi-Fi. Your home may have a local area network. If your PC, tablet, smart TV, and wireless printer are connected to you via Wi-Fi, these connected devices are part of your LAN. Only devices that you allow access to the local network Each node or computer on the LAN has its own computing power, but depending on its permissions, it can access other devices on the LAN as well. These can include data, processing power, and the ability to communicate or chat with other users on the network. In LAN, a router acts as a gateway, and the remaining nodes are usually hosts and have no routing function.

Local network types A LAN consists of interconnected workstations and PCs, each capable of accessing and sharing data and devices such as printers, scanners, and data storage devices anywhere on the LAN. Local area networks are characterized by higher communications and data transfer rates and no need for leased lines. Local area networks include two types: client / server networks (client / server LANs) and peer-to-peer networks (peer-to-peer LANs) • Client / server network Client / server networks consist of several devices (clients) that are connected to a central server. The server manages activities such as file storage, printer access, and network traffic. The client device (client) can be a personal computer, tablet, or other device that runs programs. Clients connect to the server either by cable or wirelessly. • Peer-to-Peer networks There is no central server in this type of network and they can not handle heavy loads compared to Client / Server LAN. In this type of network, each PC and device share the network performance equally. Devices share resources and data over a wireless or wireless connection to a router. Most home networks are peer-to-peer. According to this concept, every computer and other device is connected in parallel. LAN network components Any LAN workstation, which can include a microcomputer, barcode reader, or word processor; It can work as an independent equipment. But they are connected to a central control unit through which they can communicate. This includes sharing data, sharing software or hardware with other network workstations. Although each workstation can operate independently, they are not able to control the activities of other network stations. Several methods such as Career Sense Multiple Access / Collision Detection (CSMA / CD) and Career Sense Multiple Access / Collision Avoidance are used to control data transfer to prevent data from crashing or colliding during communication. Network components include the following: Communication media: There is a medium for connecting all workstations and other equipment to each other. Low-cost LANs are connected with twisted-pair pairs. Many LANs use coaxial or fiber optic cables. Wireless networks are easily configurable and maintainable. However, their transmission speed is low and there is a limited distance between the two communication devices. NIC: Abbreviation for network interface card. Also known as a network adapter. A network interface card is a device that physically connects each computer to a network. Controls the flow of information between the network and the computer. Some computers have internal network cards. Bridge: A bridge is a device that connects two parts of a network. Used to connect similar types of networks. Router: A device that connects multiple networks using the same or different protocols. It manages the best route between two communication networks. Routers are used when multiple networks are connected. They can connect networks of different countries. They transfer data in less time. Gateway: A computer gateway that allows access to other networks. Two different types of networks need a gateway to communicate with each other. Receives data from one network and converts it according to the protocol of other networks. For example, computers on a LAN need an input port to access the Internet.

Local network benefits The advantages of local area networks include the following: • Resource sharing between all devices • Central control of equipment and data • Easy connection of equipment from different vendors • The local network is reliable in the data sharing process. • Very affordable Other LAN features Local area networks can be distinguished by their short distance from other networks. Total coverage may be from 1 km to 10 km. LAN data transfer speeds are much faster than other types of networks. When WANs operate at 1 mbps, LANs can transmit data at 1 - 10 mbps. The error rate in data transmission is low due to the shorter distance between the equipment. Because LANs are located in a smaller building or area, they belong to a specific organization. This local control provides more flexibility than other local area networks. last word A local area network (LAN) is a computer network that covers a relatively small area. In most cases, a LAN is limited to one room, building, or group of buildings; however, a LAN can be connected to other networks via any telephone or radio waves. If this is useful for you, share it with your friends. Source: What is a computer LAN?

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Types of computer networks and their review

A computer network is a group of computers that connect to each other through a transmission medium such as cable, wire, etc. and share resources and applications. In this article, we will discuss the types of computer networks. Types of computer networks There are many computer network-based applications, and each of the widely shared networks has unique features that must be used appropriately for effective purposes. There are basically four types of computer networks based on their size and function: 1. Local Area Network (LAN) 2. Urban Area Network (MAN) 3. Wide area network (WAN) 4. Personal Area Network (PAN)

Local Area Network (LAN) Local Area Network (LAN) stands for Local Area Network. A local area network is a collection of computers that are connected in small and limited places such as apartments, schools, hospitals, etc. . This computer network connects computers through a communication device such as a coaxial cable, routers and switches and twisted pairs. The LAN is secure because there is no external connection to the LAN. Therefore, the data that is shared on the local network is secure and less prone to hacking and data loss. LAN speed is much more impressive due to its small size. Their speed can be from 100 to 100 Mbps. Local area networks are not limited to wired connection and with the evolution of technology, they also work on the wireless connection platform.

Urban Area Network (MAN) MAN stands for Metropolitan Area Network. By connecting LANs, this network covers a wide geographical area. In the Metropolitan Area network, different local area networks are connected to each other through telephone communication technology. The most widely used protocols in MAN are Frame Relay, ISDN, ATM, ADSL and RS-232. The size of this network is larger than LANs and smaller than WANs (WANs). MANs cover the larger area of ​​a city or town and are mostly based in airline reservations. In the military, connections between the banking sector, in private companies, and so on.

Wide area network (WAN) Wide Area Network Provides a wide area network for remote data transmission. WAN is larger than LAN and MAN. WAN can cover a huge geographical area such as a country, continent or even the whole world. One of the most widely used examples of this network is the Internet connection. Other applications include mobile broadband communications such as 3G, 4G, etc. The security protocols used are WPA and WEP.

Advantages of WAN: Centralized infrastructure: One of the advantages of a WAN is that it does not require backup and data storage on the local system. This is because everything is stored online in a data center and data can be accessed via the WAN. Privacy: In this network, the risk of unauthorized access can be minimized. This is done by encrypting data that is shared online. Increased bandwidth: In the WAN, bandwidth can be selected and changed based on the needs of the location used. A large organization can have more bandwidth that can carry large amounts of data faster and more efficiently.WAN can cover a large area or even the whole world. Disadvantages of WAN: This network also has disadvantages. One of them is that it has a high installation cost and because it covers a large area, its installation takes a long time. Due to its vastness, this network connects many systems, and this can be a threat to our privacy and increase the likelihood of system viruses and the loss of important information. PAN (Personal Area Network) PAN (Personal Area Network) is a short-range network topology that covers a range of about 10 to 30 meters. The purpose of this type of network is to transfer data between devices without an Internet connection.

PANs can also connect to LANs and higher-level network types where a device acts as a gateway. A common example of a PAN is Bluetooth, which is connected to a smart TV. Personal area networks can be wireless or wired There are two types of personal area network: • Personal area wireless network • Wired personal area network 1. Wireless PANs are called WPANs and use telecommunication protocols such as Wi-Fi, ZigBee, Infrared and Bluetooth for data-driven applications. Configure a personal area wireless network based on wireless technologies Like Bluetooth and Wi-Fi, which are on a limited network. 2. Wired area personal network: The area wired personal area network is established using USB. Like other types of networks, not every connection protocol within a PAN is directly compatible with other protocols.

An example of a computer network

Local area networks, such as Wi-Fi, have limited bandwidth and require many nodes to cover a large area. The WAN adopts telecommunications that are more compatible for coverage. Because the WAN simultaneously covers a wider range, it also implements security protocols. Even if it is advanced, it is not a guaranteed option. But few people still use it as insecure networks because they are prone to vulnerable encryption. But even if they use insecure networks, they can receive signals.

Simply put, WAN and MAN use telecommunications while LAN and PAN do not use it for their operation. LAN and PAN work in secure conditions where WAN is not very secure. PAN and LAN are faster than coverage. LAN has DLNA for effective use. If the user wants to connect to the Internet at home, he can choose PAN or LAN, and if he wants to be an Internet service provider, he must choose WAN. Each has its own unique features and is tailored to your needs Effective operation PAN or LAN is imported via WAN. Due to limited constraints, it covers several people and focuses on high-performance performance speed. But it is not related to a network connection whose speed is limited by LAN or WAN networks. PAN or LAN is compatible for moving and hosting files from one device or system to another device and related applications.

Conclusion This article is a guide to different types of computer networks. Over the years, this technological growth has led to the development of different types of networks to meet diverse demands, and more network types are likely to emerge as future technology advances. If this is useful for you, share it with your friends.

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What is a computer network? And network types

Computer networking is a broad term for one of the greatest technological advances in computer science in the last 40 years. The basic definition of a computer network is that a computer network connects parts of a distributed architecture, whether those parts are made of hardware or virtual or logical resources. A computer network is connected to computing devices (such as laptops, desktops, servers, smartphones and tablets) and a set of IoT devices (such as cameras, door locks, doorbells, refrigerators, audio / video systems). , Various thermostats and sensors) that communicate with each other. Computers on a network are called nodes. A multi-purpose network that allows computers to share resources such as printers, file servers, and other resources without an Internet connection. Something that was never even imagined to be possible without the Internet. How does a computer network work? Specialized devices such as switches, routers, and access points form the basis of computer networks. Switches connect to and assist the internal security of computers, printers, servers, and other devices in the networks of homes or organizations. By access points, which are a kind of switch, devices are connected to the network without the use of cables. Routers have the same functionality as distributors that connect each computer network to another. After analyzing the data, the routers select the best route and send it to their route. One of the important tasks of routers is to protect information against external security threats. Today, most switches have some level of routing performance. The MAC address is the number assigned by the device manufacturer to the Network Interface Card (NIC). An IP address is a number assigned to a network connection. These two addresses define network connections uniquely for each device.

How are computer networks evolving? Today's computer networks have provided something beyond connectivity. Organizations are beginning to transform themselves digitally. Their networks are critical to this transformation and their success. Types of network architectures to meet these needs are evolving as follows:

SDN (Software-defined) With the advancement of technology to meet the needs of the present age, network architecture is also evolving, updating, automating and becoming more open. In SDN networks, traffic routing is centrally controlled through software-based mechanisms. This helps the network to react faster to changing conditions. Intent-based Relying on the principles of SDN, Intent-based Network (IBN) not only provides you with more speed, but also with extensive automation of operations, performance analysis, identification of problem areas, comprehensive security and Integration with business processes creates a network to achieve the desired goals. Virtualized The underlying physical network infrastructure can be logically divided to create multiple "overlapping" networks. Each of these logical networks can be configured to provide specific security, quality of service (QoS), and other conditions. Controller-based Network controllers are very important for scaling and securing networks. Controllers automate network operations by translating business goals into device configurations and constantly monitor devices to ensure performance and security. They simplify operations and help organizations respond to changing business requirements. Types of computer networks A computer network is a group of interconnected computers that allow each computer to communicate with other computers and share their data. Networks are usually categorized according to their characteristics. A computer network can be classified by size. There are basically four types of computer networks: • LAN (local area network) • PAN (Personal Area Network) • MAN (urban area network) WAN (Wide Area Network) Local Area Network (LAN)

A LAN is a group of devices connected to a small physical location, such as a building, home, or office. A local area network can be small or large, depending on its application, from a small home network with one user to a large enterprise network with thousands of users. A special feature of a LAN, regardless of size, is that it connects devices that are in a limited and single area. It uses LAN to connect two or more PCs through a communication medium such as twisted pair, coaxial cable and so on. The data transfer speed in this network is very high and provides higher security for users. The cost of setting up this network is low because it requires cheap hardware such as network adapters, hubs, etc.

Wide area network (WAN)

A WAN extends over a wide geographic area and connects separate users or multiple LANs. The Internet can be considered one of the largest WANs. WAN is most used in large organizations, business, educational and government activities. The most common use of this network is in large organizations that use it to connect to their sites, suppliers and data centers to be able to do their program in the best possible way. Wide Area Network is a much larger network than LAN. This type of network is spread over telephone lines, fiber optic cable or satellite links over a wide geographical area.

PAN (Personal Area Network)

A personal area network is a network set up for one person. The range of this network is usually in the range of 10 meters. The idea of ​​a personal network was mooted by the first research scientist, Thomas Zimmermann. Laptops, cell phones, media players, and gaming stations are the basic equipment needed to develop a personal network. Bluetooth is one of the most famous personal networks in the world, and USB is one of the most popular and widely used.

MAN (Urban Area Network)

A metropolitan network is a network that differs from a LAN connection by forming a larger network that covers a larger geographical area. The network is most used in government organizations to connect citizens and private industries. In MAN, different LANs are connected to each other via a telephone exchange line and have a wider range than a local area network. The most widely used protocols in this network are RS-232, Frame Relay, ATM, ISDN, OC-3, ADSL and so on. Conclusion The network provides a multi-purpose connection so that we can share the resources we need with other resources. Today, the use of computer networks has made it possible to transfer our data and resources at high speed without the need for an Internet platform.     If you have any comments on this, let us know.