Essay: Networks And Data Transmission: An Overview.

Task 1.1: Networks and Data Transmission

Task 1.1: Networks and data transmission, in general, have helped us cross the boundaries that are characterised with distance and time. Moreover, these technologies have facilitated a new multimedia dimension where in conjunction with the digital environment physical cues are now used in the electronic world of communication (Goleniewski, 2011). Consider the internet, for instance, it has revolutionised our life by introducing a real-time form of communication that again interconnects various global networks. Moreover, its diversity and versatility are seen in communications that include mobile networks that are facilitated by handheld devices. Through these networks, users can actively participate in everyday communication at their convenience which is efficient and flexible (Openmind, 2014). In addition to this, technologies such as cloud computing have enabled users to share resources and services through the implemented global network i.e. the internet. Through this service (resource sharing), users can lease resources and solutions that they would otherwise not afford.

Task 2.1: Plain old telephone service (POT) is the basic analogue telephone (voice) service implemented using twisted copper wires. It’s generally based on the Bell systems that can connect homes and businesses (Forouzan, 2009). Moreover, it’s highly reliable thus its wide application. Furthermore while applying digital subscriber lines, POT can be used to transmit digital data. In essence, the telephone is connected to the central exchange station using a local loop, this loop which is made of copper wires is meant to transmit audio data but through a modem, analogue to digital signal conversion is done. This conversion allows the local loops to turn into long data trunks that are capable of transmitting data over the voice band (300 to 3400 hertz).

Task 2.2: Modem (Modulation-Demodulation) – The operation of a modem is dependent on signal modulation which is a technical term of referring to the process used to alter the shape of a signal wave. Two techniques can be used amplitude modulation or frequency modulation, through these techniques a computer can transmit its data signal to a modem which adds them to the audio signal by modulating it. Once the signal is received, demodulation takes place where the audio signal is separated from the digital signal to obtain the data (Woodford, 2016).

Task 3.1: Regardless of the outlook, computers in any network must be connected in a logical form. This logical pattern in which computers are interconnected is what is known as a network topology. In a nutshell, its represent the virtual structure of the connection.

1. Star – As shown in the diagram, each computer is connected to the central hub or station. The central hub/station can be another computer or a server that provide administration i.e. control. This topology is cheap to implement and add new items.

1. Bus – A common cable (BUS) connects all the computers i.e. all the computers are connected to the central cable. This cable acts as the backbone of the network making it easy to add new components.
2. Ring – As the name suggests, all computers are connected in a circular fashion and similarly, the data is transmitted in one direction across the network. Every computer is connected to the next computer forming a single connection for data transmission. This topology makes it easier to identify faults and transmit large volumes of data.

1. Mesh – This topology has every computer or node connected to each other, therefore, each computer is connected to all other computers. It’s expensive to implement and has many redundant connections. However, it’s robust and can handle large volumes of data which also adds to its improved security features (Zandbergen, 2017).

Task 4.1: Several network technologies are used to connect computers such as local area network (LAN), wide area network (WAN) and Metropolitan area network (MAN) to mention a few.

LAN: These networks are restricted to small areas such as businesses, schools and houses. Moreover, they are based on Ethernet connections having higher transfer speeds than WAN (10 Mbps to even 1 Gbps).

WAN: These networks cover wider geographical area than LAN and are usually interconnections of different LANs. They provide the solution of transferring data over large areas using common network locations. Furthermore, they are owned by internet service providers who connect different LANs together.

Task 2.1: Plain Old Telephone Service (POT)

MAN: Networks that cover a wider geographical area than LANs but smaller than WANs. They are built for cities and towns but are owned by a single organisation.

(Malik, 2014).

Task 4.2: Fibre optic – Also known as optical fibres, these are long and very thin glass strands that are used to transmit data over long distances. This operation is accomplished by transforming electrical signals to light/optical signals. They have the highest transmission capacities and speeds (THz) (Torlak, 2016).

Coaxial – A copper cable that consists of one communication channel (central wire) surrounded by an insulation and a second physical channel across the same axis. It’s the most common cable used in television systems where data transfer ranges in the

CAT6 – This is an Ethernet cable standard (EIA/TIA) that uses a pair of twisted copper wires to transmit data. These cables are designed to carry gigabit size data (per second0 however, they can also carry 10 Gbps and over a short distance (Mitchell, 2016).

Task 4.3: Switch – A network device that connects two different network devices together. They are sometimes referred to as network bridges because they connect different router together using their multiple ports to enhance the processing of packets across the data link layer. They also handle data transmission differently as compared to hub because they receive and transmit information to the appropriate destination. Moreover, their transmission speeds depend on the module ranging from 10/100 Mbps to 40/100 Gbps.

Router – a network device that connects two or more networks together. Moreover, this device is used to determine the best path (route) to be followed by a data packet when being transmitted. Their operation depends on their routing table, cost algorithms and distance. Through these components, data transmission is coordinated and regulated to meet the network requirements. Similar to switches their performance will depend on brand and module ranging within the same speeds as switches (Linux, 2017).

Network card – A hardware component that connects a computer to a computer network such as a local area network. A detailed review of its function sees it serve as an interface where data is exchanged from the PC to the network and vice versa hence the name network interface card. Its functions are achieved by using standard protocols such as CSAM/CD.

Task 5.1: The internet is an open and public space where computer networks are interconnected globally using the standard internet protocols (TCP/IP). On the other hand, the intranet is a private connection or space of computer networks that uses the same operational protocols as the internet. Therefore, the major difference between the two is accessibility where one is open to the masses while the other is protected and used by certain individuals within an organisation (All business, 2017). However, since they both use the same operation protocols (TCP/IP) it’s easy to integrate the intranet into the internet. Moreover, a user can access intranet resources e.g. in a college through a protected channel known as a virtual private network, designated as a student portal where authentication is needed (username and password).

Task 5.2: Two computers using a common Ethernet cable in a LAN will have to share the common resource. Therefore, a sharing medium mechanism is used known as carrier sense multiple access with collision detection (CSMA/CD). Essentially, this technique allows a computer to check the transmission medium for activity before transmitting. One computer will assess the medium if no transmission is identified it proceeds with its transmission. However, if a transmission is already in place, the computer holds off until the channel is clear. This technique prevents congestion facilitating a smooth and convenient transmission (Rouse, 2017). Ethernet cables come in different variation but the 100 Base-T is the most common, where twisted pair cables are used to transfer data at a maximum speed of 100Mbps. Others types do exist that can transfer at 1000Mbps (1 Gbps), 10 Gbps and so on.

Task 6.1:

(HNA, 2017)

Task 6.2:

Name of Network (SSID)

A service set identifier (SSID), is a unique set of characters that identifiers a wireless network thus allowing stations to connect to the right network in an event of many existing wireless networks. Moreover, it can be hidden to act as an extra layer of security where only authenticated members with its identity can connect to it.

Unlike wired network, wireless networks (e.g. Wi-Fi) do not end at the office boundary. Therefore, even unauthorised people can connect to it through their WLAN-enabled devices. A password consisting of a unique set of characters will serve as the necessary security (authentication) for those who are allowed to use your connection.

AES is an encryption technique that ensures the password is encrypted (hidden) from its true text value, instead, the password appears as an incomprehensible set of characters. This procedure ensures the password is protected from prying eyes of third parties who are not allowed to use the network.

References

All business. (2017). what’s the Difference between an Intranet and the Internet? Retrieved 22 March, 2017, from: https://www.allbusiness.com/whats-the-difference-between-an-intranet-and-the-internet-639-1.html

Goleniewski. L. (2001). Understanding the Telecommunications Revolution. Inform IT, Pearson. Retrieved 22 March, 2017, from: https://www.informit.com/articles/article.aspx?p=24667

Home network admin (HNA). (2017). Top 5 wireless routers. Retrieved 22 March, 2017, from: https://homenetworkadmin.com/wireless-b-vs-g-vs-n-vs-ac-difference/

Linux. (2017). Network switch: Purpose and function. Retrieved 22 March, 2017, from: https://www.yourownlinux.com/2013/07/network-switch-purpose-and-functions.html

Malik. U. (2014). Introduction to LAN, WAN and MAN: Networking Tutorial. Retrieved 22 March, 2017, from: https://blog.udemy.com/lan-wan-man/

Mitchell. B. (2016). CAT6 - Category 6 Ethernet Cables Explained. Internet and network. Retrieved 22 March, 2017, from: https://www.lifewire.com/cat6-ethernet-cable-standard-817553

Open mind. (2014). How the Internet Has Changed Everyday Life. Retrieved 22 March, 2017, from: https://www.bbvaopenmind.com/en/article/internet-changed-everyday-life/

Rouse. M. (2017). Ethernet. Tech target. Retrieved 22 March, 2017, from: https://searchnetworking.techtarget.com/definition/Ethernet

Torlak. M. (2016). Fibre optic communication. Telecom, switching and transmission. Retrieved 22 March, 2017, from: https://www.utdallas.edu/~torlak/courses/ee4367/lectures/FIBEROPTICS.pdf

Woodford. C. (2016). Modems. Retrieved 22 March, 2017, from: https://www.explainthatstuff.com/modems.html

Zandbergen. P. (2017). How Star, Bus, Ring & Mesh Topology Connect Computer Networks in Organizations. Retrieved 22 March, 2017, from: https://study.com/academy/lesson/how-star-topology-connects-computer-networks-in-organizations.html