ICT and Multimedia Fundamentals

Assalammualaikum, today I have assingments to complete. Assingments this time is to make a blog.

Before that, I want to introduce myself in a short time.My name is Norashikin binti Samsuddin. I'm from 6 Rendah Al-Farabi at SMK Tun Habab,Kota Tinggi,Johor. This is my first blog and I hope you all enjoy reding this blog.

What is tranmission media ?

Transmission media is a pathway that carries the information from sender to receiver.We use different types of cables or waves to transmit data. Data is transmitted normally through electrical or electromagnetic signals.

  

Types of Transmission Media

Transmission media is broadly classified into two groups.

1. Wired or Guided Media or Bound Transmission Media

2. Wireless or Unguided Media or Unbound Transmission Media

Wired or Guided Media or Bound Transmission Media: Bound transmission media are the cables that are tangible or have physical existence and are limited by the physical geography. Popular bound transmission media in use are twisted pair cable, co-axial cable and fiber optical cable. Each of them has its own characteristics like transmission speed, effect of noise, physical appearance, cost etc.

Wireless or Unguided Media or Unbound Transmission Media: Unbound transmission media are the ways of transmitting data without using any cables. These media are not bounded by physical geography. This type of transmission is called Wireless communication. Nowadays wireless communication is becoming popular. Wireless LANs are being installed in office and college campuses. This transmission uses Microwave, Radio wave, Infra red are some of popular unbound transmission media.

COMPUTER NETWORK

A computer network or data network is a telecommunications network that allows computers to exchange data. In computer networks, networked computing devices pass data to each other along data connections. The connections (network links) between nodes are established using either cable media or wireless media. The best-known computer network is theInternet.

Network computer devices that originate, route and terminate the data are called network nodes.Nodes can include hostssuch as personal computers, phones, servers as well as networking hardware. Two such devices are said to be networked together when one device is able to exchange information with the other device, whether or not they have a direct connection to each other.

Computer networks support applications such as access to the World Wide Web, shared use of application and storage servers, printers, and fax machines, and use of email and instant messaging applications. Computer networks differ in thephysical media used to transmit their signals, the communications protocols to organize network traffic, the network's size,topology and organizational intent.

WIRED

             In computing terminology, the term "wired" is used to differentiate between wireless connections and those that involve cables. While wireless devices communicate over the air, a wired setup uses physical cables to transfer data between different devices and computer systems.
          
        A wired network is a common type of wired configuration. Most wired networks use Ethernet cables to transfer data between connected PCs. In a small wired network, a single router may be used to connect all the computers. Larger networks often involve multiple routers or switches that connect to each other. One of these devices typically connects to a cable modem, T1 line, or other type of Internet connection that provides Internet access to all devices connected to the network.
         
        Wired may refer to peripheral devices as well. Since many keyboards and mice are now wireless, "wired" is often used to describe input devices that connect to a USB port. Peripherals such as monitors and external hard drives also use cables, but they are rarely called wired devices since wireless options are generally not available.
         
    While many peripherals are now wireless, some users still prefer wired devices, since they have a few benefits over their wireless counterparts. For example, an Ethernet connection is not prone to signal interference that can slow down Wi-Fi connections. Additionally, wired network connections are generally faster than wireless ones, which allows for faster data transfer rates. Some users also prefer wired peripherals since their is no need to replace batteries on a regular basis. Gamers especially prefer wireless keyboards and mice since they have lower latency and can be backlit, thanks to the power provided by the USB connection.

WIRELESS

Wireless communication is the transfer of information between two or more points that are not connected by an electrical conductor.

The most common wireless technologies use radio. With radio waves distances can be short, such as a few meters fortelevision or as far as thousands or even millions of kilometers for deep-space radio communications. It encompasses various types of fixed, mobile, and portable applications, including two-way radios, cellular telephones, personal digital assistants(PDAs), and wireless networking. Other examples of applications of radio wireless technology include GPS units, garage door openers, wireless computer mice, keyboards and headsets, headphones, radio receivers, satellite television, broadcast television and cordless telephones.

Somewhat less common methods of achieving wireless communications includes the use of other electromagnetic wireless technologies, such as light, magnetic, or electric fields or the use of sound.

COMMUNICATION PROTOCOL

A communications protocol defines the rules for sending blocks of data (each known as a Protocol Data Unit (PDU)) from one node in a network to another node. Protocols are normally defined in a layeredmanner and provide all or part of the services specified by a layer of the OSI reference model. A protocol specification defines the operation of the protocol and may also suggest how the protocol should be implemented. It consists of three parts:

1. Definition of Protocol Control Information (PCI) format which forms the PDU header
2. Definition of procedures for transmitting and receiving PDUs
3. Definition of services provided by the protocol layers

A Protocol Data Unit

The PDUs exchanged have two parts: a header (also known as the Protocol Control Information (PCI)) and a payload (also known as a Service Data Unit (SDU)). The protocol does not define or constrain the data carried in the payload part. It does specify the format of the PCI, defining the fields which are present and the way in which the patterns of bits are to be interpreted.
A protocol also defines the procedures which determine how the PDU will be processed at the transmit and receive nodes. The procedures specify the valid values for the PCI fields, and the action be taken upon reception of each PCI value (usually based on stored control information). Examples of procedures which are implemented in protocols include:

• error recovery (e.g. the checkpoint procedure, the go-back-n procedure)
• flow control
• segmentation
• service access point selection
• connection management

The documents which define a protocol procedures are usually large and are seldom concrete (i.e. they may not be directly translated to executable programs). They typically define the actions to be taken when a particular condition is detected, but not how the condition is to be detected. It has been said that "Part of what makes a protocol mature is good implementation guidelines and folklore". The success of the TCP/IP protocol suite is largely due to the "industrial strength" code available in freely distributed reference implementations.