WHAT IS COMPUTER NETWORK?
A computer network is a set of computers sharing resources located on or provided by network nodes. The computers use common communication protocols over digital interconnections to communicate with each other.
Computer Network Types
A computer network is a group of computers linked to each other that enables the computer to communicate with another computer and share their resources, data, and applications.
A computer network can be categorized by their size. A computer network is mainly of four types:
- LAN(Local Area Network)
- PAN(Personal Area Network)
- MAN(Metropolitan Area Network)
- WAN(Wide Area Network)
LAN(Local Area Network)
- Local Area Network is a group of computers connected to each other in a small area such as building, office.
- LAN is used for connecting two or more personal computers through a communication medium such as twisted pair, coaxial cable, etc.
- It is less costly as it is built with inexpensive hardware such as hubs, network adapters, and ethernet cables.
- The data is transferred at an extremely faster rate in Local Area Network.
- Local Area Network provides higher security.
PAN(Personal Area Network)
- Personal Area Network is a network arranged within an individual person, typically within a range of 10 meters.
- Personal Area Network is used for connecting the computer devices of personal use is known as Personal Area Network.
- Thomas Zimmerman was the first research scientist to bring the idea of the Personal Area Network.
- Personal Area Network covers an area of 30 feet.
- Personal computer devices that are used to develop the personal area network are the laptop, mobile phones, media player and play stations.
There are two types of Personal Area Network:
- Wired Personal Area Network
- Wireless Personal Area Network
Wireless Personal Area Network: Wireless Personal Area Network is developed by simply using wireless technologies such as WiFi, Bluetooth. It is a low range network.https://imasdk.googleapis.com/js/core/bridge3.485.1_en.html#goog_1094758684
Wired Personal Area Network: Wired Personal Area Network is created by using the USB.
Examples Of Personal Area Network:
- Body Area Network: Body Area Network is a network that moves with a person. For example, a mobile network moves with a person. Suppose a person establishes a network connection and then creates a connection with another device to share the information.
- Offline Network: An offline network can be created inside the home, so it is also known as a home network. A home network is designed to integrate the devices such as printers, computer, television but they are not connected to the internet.
- Small Home Office: It is used to connect a variety of devices to the internet and to a corporate network using a VPN
MAN(Metropolitan Area Network)
- A metropolitan area network is a network that covers a larger geographic area by interconnecting a different LAN to form a larger network.
- Government agencies use MAN to connect to the citizens and private industries.
- In MAN, various LANs are connected to each other through a telephone exchange line.
- The most widely used protocols in MAN are RS-232, Frame Relay, ATM, ISDN, OC-3, ADSL, etc.
- It has a higher range than Local Area Network(LAN).
Uses Of Metropolitan Area Network:
- MAN is used in communication between the banks in a city.
- It can be used in an Airline Reservation.
- It can be used in a college within a city.
- It can also be used for communication in the military.
WAN(Wide Area Network)
- A Wide Area Network is a network that extends over a large geographical area such as states or countries.
- A Wide Area Network is quite bigger network than the LAN.
- A Wide Area Network is not limited to a single location, but it spans over a large geographical area through a telephone line, fibre optic cable or satellite links.
- The internet is one of the biggest WAN in the world.
- A Wide Area Network is widely used in the field of Business, government, and education.
Examples Of Wide Area Network:
- Mobile Broadband: A 4G network is widely used across a region or country.
- Last mile: A telecom company is used to provide the internet services to the customers in hundreds of cities by connecting their home with fiber.
- Private network: A bank provides a private network that connects the 44 offices. This network is made by using the telephone leased line provided by the telecom company.
Advantages Of Wide Area Network:
Following are the advantages of the Wide Area Network:
- Geographical area: A Wide Area Network provides a large geographical area. Suppose if the branch of our office is in a different city then we can connect with them through WAN. The internet provides a leased line through which we can connect with another branch.
- Centralized data: In case of WAN network, data is centralized. Therefore, we do not need to buy the emails, files or back up servers.
- Get updated files: Software companies work on the live server. Therefore, the programmers get the updated files within seconds.
- Exchange messages: In a WAN network, messages are transmitted fast. The web application like Facebook, Whatsapp, Skype allows you to communicate with friends.
- Sharing of software and resources: In WAN network, we can share the software and other resources like a hard drive, RAM.
- Global business: We can do the business over the internet globally.
- High bandwidth: If we use the leased lines for our company then this gives the high bandwidth. The high bandwidth increases the data transfer rate which in turn increases the productivity of our company.
Disadvantages of Wide Area Network:
The following are the disadvantages of the Wide Area Network:
- Security issue: A WAN network has more security issues as compared to LAN and MAN network as all the technologies are combined together that creates the security problem.
- Needs Firewall & antivirus software: The data is transferred on the internet which can be changed or hacked by the hackers, so the firewall needs to be used. Some people can inject the virus in our system so antivirus is needed to protect from such a virus.
- High Setup cost: An installation cost of the WAN network is high as it involves the purchasing of routers, switches.
- Troubleshooting problems: It covers a large area so fixing the problem is difficult.
WHAT IS COAXIAL CABLE
A coaxial cable is a type of shielded and insulated copper cable that is used in computer networks and to deliver cable TV services to end users. … Coaxial cable is also known as coax, which is derived from the geometric axis created between a shield and insulator.
A coaxial cable is used by cable TV service providers to stretch transmission lines from their branch or control offices to residential and business subscribers.
It consists of four primary components, as follows:
- A core copper wire, which serves as the primary channel
- A dielectric plastic insulator, which surrounds the copper
- A braided copper/aluminum sheath beneath the insulator. This is used to protect from external electromagnetic interference.
- The last layer, which is made of Teflon or plastic coating, is used to protect the inner layers from physical damage, such as fire and water.
Coaxial cables tend to carry signals at a greater distance and are a good choice for weak signals, due to their layered protection. There are several types of coaxial cables, which are classified by the inner copper core diameter and number of protective sheaths.
There are two main types of coaxial cables – ones with an impedance of 75 Ohm (Ω) and ones with an impedance of 50 Ohm. Cables with 75 Ohm are mostly used for video signals, while 50 Ohm cables tend to be used for data and wireless communications.
Coaxial cable types
There are two main types of coaxial cables – ones with an impedance of 75 Ohm (Ω) and ones with an impedance of 50 Ohm.
Cables with 75 Ohm are mostly used for video signals, while 50 Ohm cables tend to be used for data and wireless communications.
In coaxial cables, Ohm refers to the impedance, which is the measure of resistance in the cable to the flow of electrical energy.
What’s RF coaxial cable?
RF coaxial cables are used to carry radio frequency signals. They’re the standard input cable on TVs and feature a single pin which plugs into the RF input on a device.
What’s RG-6 cable?
RG-6 cables have larger conductors, so they provide better signal quality. They have thicker dielectric insulation and are made with a different kind of shielding, allowing them to handle GHz level signals more effectively. As this type of cable is thin, it can also be easily installed in walls or ceilings.
What’s RG-59 cable?
A common cable in domestic settings, RG-59 cable is similar to the RG-6, but it has an even thinner centre conductor. This makes it a good choice for short runs and low-frequency transmissions.
What’s RG-11 cable?
RG-11 cable is easily identifiable as it’s thicker than other types of coaxial cable, which can make it more difficult to work with. However, it offers a lower attenuation level than RG-6 or RG-59, meaning it can carry data for longer distances.
What are Coaxial Cables used for?
Here are some of the different uses for coaxial cable and which type is most suited for the task:
|RG-6 Coaxial Cable||Coaxial cable for TVPoor quality coaxial cable can impact TV reception, so it’s important to choose the best cable for the job.Coaxial cable designed for domestic television should be 75 Ohm, with RG-6 coaxial being ideal for TV.|
|RG-11 coaxial cable|
Coaxial cable for HDTV (high-definition)The best coaxial cable for HDTV is RG-11.This type of cable offers a higher gauge than others, which provides more space for signals to transfer. This makes RG-11 cable adept at transferring strong HD signals at speed.
|RG-6 Coaxial Cable||Coaxial cable for the internetCoaxial cables can be used to carry signals for internet connections, but internet signals run at higher frequencies than traditional analogue video.RG-6 cable was designed to fulfil this requirement. It has a larger conductor, which provides a much better signal quality, and the dielectric insulation is thicker. RG-6 cables are also made with a different kind of shielding, which means they can carry GHz level signals more effectively.|
|RG-59 coaxial cable||Coaxial cable for CCTVRG-59 coaxial cable is the best type for CCTV systems, but RG-6 can also be used.RG-6 can run longer distances than RG-59 without loss to a video signal, however, it’s a thicker, firmer cable which isn’t as convenient to work with.|
|RG-6 coaxial cable||Coaxial cable for videoThe most common types of coaxial cable for video are RG-59 and RG-6. Of these, RG-59 is the industry standard cable, whereas RG-6 is better for digital video signals.|
What is coaxial cable in computer networks?
A coaxial cable is a type of shielded and insulated copper cable that is used in computer networks and to deliver cable TV services to end users. It was first commercially implemented in the early 1940s and is used for both baseband and broadband data communication services.
What is the transmission speed of Coaxial Cable?
The transmission speed of coaxial cable is 10Mbps (megabits per second), and they offer 80 times more transmission capacity than twisted pair cables.
Coaxial and fiber cable each have their place, with their own advantages and characteristics. Depending on the application, there may be no “right” or “wrong” answer when choosing their integration into the network. In fact, hybrid fiber / coax systems can combine the benefits of both.
As businesses become increasingly cost conscious, and costs of fiber optic cable and labor remain high, broadband professionals are starting to take a closer look at ways to squeeze more performance from coaxial cable. But before you decide whether coax or fiber is best for your application, there are a few benefits of coaxial cable that you should know about.
1. Coax Supports High Bandwidth Levels
When it comes to bandwidth, there seems to be no end to the increasing appetite of consumers. DOCSIS®3.1 provides support for up to 10 Gbps downstream and up to 1 Gbps upstream over coaxial cable. CableLabs® is conducting research to extend operating frequencies above the current 1 GHz to 1.8 or 3.0 GHz which will open the door to even higher bandwidth.
It is true that fiber theoretically has almost unlimited bandwidth, but tapping this bandwidth is much more difficult and often more expensive compared to coaxial cable implementations. Previously unknown obstacles, such as optical beat interference (OBI), could plague the rollout of fiber solutions. Coax is inherently OBI free!
2. Coax is Easy to Install
Let’s face it, coaxial cable is relatively easy to install and fiber can be a real pain. Coax can be installed using simple hand tools regardless of the cable size. There is only one conductor to deal with and it is large enough to easily see what you are doing. Fiber, on the other hand, often requires fusion splicing equipment, precise alignment, bulky splice enclosures, etc.
In the home, coaxial cable can be easily split and extended by the home owner. Currently, connected devices have RF (radio frequency) input / outputs, not optical, so higher cost media conversion is not needed. Damaged coaxial cable is easily repaired and weatherproofed without the need of fusion splicing and a splice enclosure.
3. Coax is Easy to Locate
It is often necessary to locate cable buried in the ground or behind walls. Because coaxial cable is metallic, it is easy to attach a tone generator to the shield and locate the cable. Fiber, on the other hand, is non-conductive and very difficult to locate. To avoid expensive digging and accidental damage, some fiber cables have an embedded wire to provide toning capability – but no other purpose. Coaxial cable does not require this baggage.
4. Coax Can Provide Power
Electronic devices require power to operate and coaxial cables can supply that power because they are metallic. Fiber cables, on the other hand, are non-conductive and cannot provide electrical power. Network powered modems for example can keep potentially lifesaving internet phone service working during local power outages or fire.
5. Coax is Rugged
Bad things happen and coaxial cables have superior resistance to cut through, crushing and bending. Hair thin fibers are easily broken so they must have lots of strength members, gels, yarns, armoring, and sheathing around them to resist becoming broken or micro-bent.
Coaxial cable advantages and disadvantages
Advantages of coaxial cable
- Easy to wire and install
- Easy to expand
- Good resistance to EMI
- Up to 10Mbps capacity
Another benefit of coaxial cable is the electromagnetic field carrying the signal exists only in the space between the inner and outer conductors. This means coaxial cable can be installed next to metal objects without losing power, unlike other types of transmission lines.
Disadvantages of coaxial cable
The main disadvantage of using coaxial cable is that single cable failure can take down an entire network.