week 4

A computer network is a group of more computers connected to each electronically. This means that the computers can "talk" to each other and that every computer in the network can send information to the others. Usually, this means that the speed of the connection is fast - faster than a normal connection to the Internet.

Network Components

There are three primary components to understanding networks: 1. Physical Connections; 2. Network Operating System; and 3. Application Component. 

The physical components are the network topology and network connecting devices, which include network interface cards (NIC), cabling, connections, and all other hardware to connect the computers. 

Data communication:

Data communication refers to the transmission of the digital signals over a communication channel between the transmitter and receiver computers. Communication is possible only with wired and wireless connectivity of the computers with each other. All the computers, in the logically and physically networks have to follow the same rules known as Protocols such as TCP/IP, IPX/SPX and NETBEUI etc. Today, there are many computer networking technologies such as LAN, MAN, WAN, WLAN, ISDN, ATM, Frame Relay, X.25, Bluetooth, GPRS, CDMA and many others.

 

Analog and digital signal

The analog signal and digital signal are differ in their data format which they carry during the transmission. Let’s see the some difference in both. Analog signal are continues and digital signal is discrete, analog signal are continuously variable and digital signal are based on 1’s an d 0’s, The primary disadvantage of an analog signal is noise and Noise in digital signal is much easier to filter out, Sound waves are a continuous wave and as such are analog in the real world and in digital signal is used in computer which is used in every office, Analog signal required lesser bandwidth capacity and digital signal require greater bandwidth capacity.

session 2  and 3

Session two I took the typical ways of networking computers. Firstly, Communication Channel is to send data through the channel requires. secondly, Network Medium is share access to common network medium that carries signals from one computer to another and so on.

Transmission medium:

 Physical path between transmitter and receiver
May be guided (wired) or unguided (wireless)
Communication achieved by using em waves
Characteristics and quality of data transmission
Dependent on characteristics of medium and signal
Guided medium
Medium is more important in setting transmission parameters







Wifi

Wifi, is a mechanism for wirelessly connecting electronic devices. A device enabled with Wi-Fi, such as a personal computer, video game console, smatphone, or digital audio player, can connect to the Internet via a wireless network access point. An assess point (or hotspot) has a range of about 20 meters (65 ft) indoors and a greater range outdoors. Multiple overlapping access points can cover large areas.