Communication Channels

 Communication channels are the medium that connects two or more workstations. Workstations can be connected by either wired media or wireless media. It is also known as a transmission medium. The transmission medium or channel is a link that carries messages between two or more devices. We can group the communication media into two categories:

• Guided media transmission
• Unguided media transmission

1. Guided Media:  In this transmission medium, the physical link is created using wires or cables between two or more computers or devices, and then the data is transmitted using these cables in terms of signals. Guided media transmission of the following types:

1. Twisted pair cable: It is the most common form of wire used in communication. In a twisted-pair cable, two identical wires are wrapped together in a double helix. The twisting of the wire reduces the crosstalk. It is known as the leaking of a signal from one wire to another due to which signal can corrupt and can cause network errors. The twisting protects the wire from internal crosstalk as well as external forms of signal interference. Types of Twisted Pair Cable :

• Unshielded Twisted Pair (UTP): It is used in computers and telephones widely. As the name suggests, there is no external shielding so it does not protects from external interference. It is cheaper than STP.
• Shielded Twisted Pair (STP): It offers greater protection from crosstalk due to shield. Due to shielding, it protects from external interference. It is heavier and costlier as compare to UTP. 

2. Coaxial Cable: It consists of a solid wire core that is surrounded by one or more foil or wire shields. The inner core of the coaxial cable carries the signal and the outer shield provides the ground. It is widely used for television signals and also used by large corporations in building security systems. Data transmission of this cable is better but expensive as compared to twisted pair.

3. Optical fibers: Optical fiber is an important technology. It transmits large amounts of data at very high speeds due to which it is widely used in internet cables. It carries data as a light that travels inside a thin glass fiber. The fiber optic cable is made up of three pieces:

1. Core: Core is the piece through which light travels. It is generally created using glass or plastic.
2. Cladding: It is the covering of the core and reflects the light back to the core.
3. Sheath: It is the protective covering that protects fiber cable from the environment.

2. Unguided Media: The unguided transmission media is a transmission mode in which the signals are propagated from one device to another device wirelessly. Signals can wave through the air, water, or vacuum. It is generally used to transmit signals in all directions. Unguided Media is further divided into various  parts :

1. Microwave: Microwave offers communication without the use of cables. Microwave signals are just like radio and television signals. It is used in long-distance communication. Microwave transmission consists of a transmitter, receiver, and atmosphere. In microwave communication, there are parabolic antennas that are mounted on the towers to send a beam to another antenna. The higher the tower, the greater the range.

2. Radio wave: When communication is carried out by radio frequencies, then it is termed radio waves transmission. It offers mobility. It is consists of the transmitter and the receiver. Both use antennas to radiate and capture the radio signal.

3. Infrared: It is short-distance communication and can pass through any object. It is generally used in TV remotes, wireless mouse, etc.

Read More

Types of data communication

 As we know that data communication is communication in which we can send or receive data from one device to another. The data communication is divided into three types:

1. Simplex Communication: It is one-way communication or we can say that unidirectional communication in which one device only receives and another device only sends data and devices uses their entire capacity in transmission. For example, IoT, entering data using a keyboard, listing music using a speaker, etc.
2. Half Duplex communication: It is a two-way communication or we can say that it is a bidirectional communication in which both the devices can send and receive data but not at the same time. When one device is sending data then another device is only receiving and vice-versa. For example, walkie-talkie. 
3. Full-duplex communication: It is a two-way communication or we can say that it is a bidirectional communication in which both the devices can send and receive data at the same time. For example, mobile phones, landlines, etc.

Read More

Components of Data Communication

 A communication system is made up of the following components:

1. Message: A message is a piece of information that is to be transmitted from one person to another. It could be a text file, an audio file, a video file, etc.
2. Sender: It is simply a device that sends data messages. It can be a computer, mobile, telephone, laptop, video camera, or workstation, etc.
3. Receiver: It is a device that receives messages. It can be a computer, telephone mobile, workstation, etc.
4. Transmission Medium / Communication Channels: Communication channels are the medium that connect two or more workstations. Workstations can be connected by either wired media or wireless media.
5. Set of rules (Protocol): When someone sends the data (The sender), it should be understandable to the receiver also otherwise it is meaningless. For example, A sends a message to B. If A writes in Hindi and B cannot understand Hindi, it is a meaningless conversation.

Therefore, there are some set of rules (protocols) that is followed by every computer connected to the internet and they are:

• TCP(Transmission Control Protocol): It is responsible for dividing messages into packets on the source computer and reassembling the received packet at the destination or recipient computer. It also makes sure that the packets have the information about the source of the message data, the destination of the message data, the sequence in which the message data should be re-assembled, and checks if the message has been sent correctly to the specific destination.
• IP(Internet Protocol): Do You ever wonder how does computer determine which packet belongs to which device. What happens if the message you sent to your friend is received by your father? Scary Right. Well! IP is responsible for handling the address of the destination computer so that each packet is sent to its proper destination. 

Read More

Solution for Question 1 :

The traditional ways of providing IT infrastructure are used by both small and large IT organizations. That means that any IT firm requires a server room, which is a basic requirement of the industry. A database server, mail server, networking, firewalls, routers, modem, switches, high net speed, and maintenance engineers should all be present in the server room.
We’ll have to spend a lot of money to build such an IT infrastructure. Cloud Computing was created to address all of these issues while also lowering the cost of IT infrastructure. We have access to a shared pool of computer resources (servers, storage, programs, and so on) in the cloud. All you have to do is ask for more resources when you need them. The cloud makes provisioning resources quickly a piece of cake. When resources are no longer required, they can be released. You just pay for what you use this way. All maintenance will be handled by your cloud provider. 

Solution for Question 2 :

Web Page: A text file produced in any markup language, such as HTML, is referred to as a web page. Hypertext, simple text, sound, photos, videos, and links to other pages are all included on the web page (hyperlinks).
Websites: A collection of similar web pages linked together via hyperlinks.
Browsers: Browsers are computer programs that search for, access, and display various websites on the Internet. Mozilla Firefox, Chrome, and so forth.
URL: Each website’s main page has its own unique address. Uniform Resource Locator is the name given to this one-of-a-kind address.

Solution for Question 3 :

The advantages of cloud computing are:
1. When needed, service is available 24*7.
2. In terms of data loss, security is important. (When critical data is lost, cloud computing provides excellent security.) Because the data is saved in the system, it can be quickly accessible even if your computer fails.).
3. Resource pooling
4. Services- pay- per use model
5. Shared Infrastructure
6. Cost Reduction
7. In the event of a disaster, it is highly advised that firms have an emergency backup plan in place. Businesses can use cloud storage as a backup plan by storing a second copy of crucial files. These files are kept in a remote place and can only be accessed via the internet.

Solution for Question 4 :

Although Wi-Fi and the Internet are closely related and are frequently used interchangeably, there are significant differences between the two. The Internet is a wide area network (WAN) that uses a set of protocols to send data between networks and devices all over the world. Wi-Fi, on the other hand, is only a way to link devices without the use of cables.
If you don’t have a modem or Internet subscription from an ISP, you can have a Wi-Fi connection but no Internet access. As a result, the signal strength of a Wi-Fi network is unrelated to the Internet speed that a user may experience when connected.

Solution for Question 5 :

	Wired Network	Wireless Network
1.	A wired network employs wires to link devices to the Internet or another network, such as laptops or desktop PCs.	“Wireless” means without wire, media that is made up of electromagnetic waves (EM Waves) or infrared waves. Antennas or sensors will be present on all wireless devices
2.	Faster transmission speed	Slow transmission speed
3.	Propagation delay is Low	Propagation delay is high
4.	More Secure & hence Reliable	Less Secure & hence less Reliable
5.	Devices must be hard-wired	Installation is Quick
6.	Less Expensive	More Expensive
7.	High installation & maintenance cost	Low installation & maintenance cost
8.	Hub, Switch, etc. devices are used	Wireless routers, access points, etc. are used.

Read More

Cloud service models

 Cloud solutions come in three primary service models: Infrastructure as a Service (IaaS), Platform as a Service (PaaS), and Software as a Service (SaaS).

IaaS

IaaS gives users access to storage, networking, servers, and other computing resources via the cloud. While the user is still responsible for managing their applications, data, middleware, etc., IaaS provides automated and scalable environments that provide a high degree of control and flexibility for the user.

For example, many businesses use IaaS to support workload spikes during busy seasons (like holidays).

Popular IaaS providers include:

• Amazon Web Services (AWS)
• Microsoft Azure
• Google Compute Engine (GCE), the IaaS component of Google Cloud Platform (GCP)

PaaS

This service layer is primarily geared towards developers and operations professionals. Service providers rent out cloud-based platforms for users to develop and deliver applications. In other words, PaaS provides a framework that makes it easier and more efficient to build, customize, and deploy applications.

SaaS

Cloud application services are the most well-known of the cloud service models. The software is hosted, packaged, and delivered by a third party through the Internet (typically on a browser-based interface). By delivering the software application over the Internet, enterprises can offload the costs of management and maintenance to the vendor(s).

Popular SaaS options include email and customer relationship management software.

Questions for readers :

(Give your answers in the comment section below)

Question 1. Why Cloud Computing was developed ?

Question 2. Define the terms web page, website, browser & URL ?

Question 3. List the advantages of Cloud Computing ?

Question 4. Compare Wi-Fi & internet ?

Question 5. List the differences between wired & wireless networks ?

There is no correct or wrong answers for these questions. So you can give your answers in the comment session below and we will give ours in the next post.

Read More

Types of cloud computing

 There are three main cloud service options: private, public, and hybrid clouds. Each has its own advantages and disadvantages and which one you (or your business) choose will depend on your data as well as the level of security and management you need.

Public

A public cloud is probably the most commonly understood cloud computing option. This is where all the services and supporting infrastructure are managed off-site over the Internet and shared across multiple users (or tenants).

A good example of a public cloud at the individual consumer level is a streaming service like Netflix or Hulu. Users subscribe to the service through an individual account but access the same services across the platform through the Internet.

The advantage of using a public cloud is the increased efficiency and subsequent cost-effectiveness from shared resources. Public clouds are typically cheaper than private and hybrid cloud solutions (as well as traditional on-premise computing) because they rely on economies of scale. Users don’t have to pay for services they aren’t using and don’t have to worry about managing and maintaining the physical infrastructure.

Private

A private cloud provides IT services through the Internet or a private network to select users, rather than to the general public. Instead of having multiple tenants, like a public cloud does, a private cloud typically has only one tenant. All the data is protected behind a firewall. This is a popular choice for many businesses who want the agility of the cloud with greater customization and security.

Private clouds can reside on-site or off-site. The distinguishing feature is the single, private tenant who maintains greater control over the IT services. Private clouds are popular choices for organizations who have high priorities on security and compliance.

Hybrid

A hybrid cloud environment combines both private and public cloud elements to varying degrees. Despite operating independently, the clouds in a hybrid environment communicate over an encrypted connection and allow for the portability of data and applications.

This is an increasingly popular cloud solution because it allows organizations greater flexibility to meet their IT needs. 

Read More

How cloud computing works

 Cloud computing differs from traditional IT hosting services in that the consumer (whether that’s a business, organization, or individual user) generally doesn’t own the infrastructure needed to support the programs or applications they use.

Instead, those elements are owned and operated by a third party, and the end-user pays only for the services they use. In other words, cloud computing is an on-demand, utility-based model of computing.

Characteristics of cloud computing 

On-demand self-service

Users can access computing services via the cloud when they need to without interaction from the service provider. The computing services should be fully on-demand so that users have control and agility to meet their evolving needs.

Broad network access

Cloud computing services are widely available via the network through users’ preferred tools (e.g., laptops, desktops, smartphones, etc.).

Resource pooling

One of the most attractive elements of cloud computing is the pooling of resources to deliver computing services at scale. Resources, such as storage, memory, processing, and network bandwidth, are pooled and assigned to multiple consumers based on demand.

Rapid elasticity

Successful resource allocation requires elasticity. Resources must be assigned accurately and quickly with the ability to absorb significant increases and decreases in demand without service interruption or quality degradation.

Measured service

Following the utility model, cloud computing services are measured and metered. This measurement allows the service provider (and consumer) to track usage and gauge costs according to their demand on resources.

Read More