2012年3月22日星期四

Week 5 Introduction To Networking

Computer Network
-connecting to a computer with other computers or other devices to enables them to communicate together with each other.
-it can be : 1. devices equipment
                 2. transmission media to send/control data/signals
                 3.communication devices to transmit/send data from source to destination
-In the world of computer, NETWORKING is the practice of linking two or more computing devices together for the purpose of SHARING DATA.

Types Of Network
-Local -Area Networks(LAN)
-Wide-Area Networks(WAN)
-Metropolitan Area Network(MAN)
-Personal Area Network(PAN)



Network Component
                                


Network are categories into 3 properties:
*Topology--->geometric arrangement of the network
*Protocol--->common set of rules and signals    
*Architecture---> Peer -to- peer, and client/server





Topology 
4 main types of network structure are :
1. Bus Network Structure
2.Star Network Structure
3Ring Network Structure
4.Hybrid Network Structure


Protocol
1.Ethernet Protocol(most common used today!!!!!)
2.Token Ring Protocol
3.Local Talk Protocol
4.Fiber Distributed Data Interface(FDDI)
5.Asynchronous Transfer Mode(ATM)



Architecture
Two major types of network architecture :
*Peer-to-peer
*Client/server


Transmission Media:
Bounded Media--->got cables, for example:twisted pair wire,co-axial cable,fiber optic cables

Unbounded Media--->air or vacuum, for example: AM and FM radio,TV broadcasting,satellite communication, microwave radio, Infrared signals

AM RADIO
"AM Radio" is a rock song by the band Everclear. The song was recorded circa 2000 for Everclear's fourth album Songs from an American Movie, Vol. 1: Learning How to Smile So. The song was released as the second single from Everclear's album Songs from an American Movie, Vol. 1: Learning How to Smile. It spent 10 weeks on the Billboard Bubbling Under Hot 100 Singles chart, and reached #101. The "AM Radio" single was mistaken by many to be the first single from Everclear's fifth album, Songs from an American Movie, Vol. 2: Good Time for a Bad Attitude because the song was released so soon before Everclear's fifth album's release. The song was later used in a television commercial for General Motors in early 2006. 




FM RADIO

FM broadcasting is a broadcasting technology pioneered by Edwin Howard Armstrong which uses frequency modulation (FM) to provide high-fidelity sound over broadcast radio. The term "FM band" describes the "frequency band in which FM is used for broadcasting". This term is slightly misleading, since it equates a modulation method with a range of frequencies. 







2012年3月16日星期五

Weeks 4: 
  DATA COMMUNICATION
   -to define data communication terminology
   -to detail the type of signal transmit through communication medium
   -describe data transmission mode
   -how network performance work


Communication
-Definition: collection and contribution of the electronic representation of information FROM and TO remote facilities by means of electrical transmission system such as telephone line,satelites or coaxial cable.
-there are two types of signals, analog signal and digital signal:



-frequency is a number of complete wave cycles. It is measured in Hertz(Hz) which is cycle per second.
-Amplitude is the wave height measures in Volt(V) or decible(dB). A strong signal will create higher   amplitude.
-Analogue signal is transmit through PSTN line known commonly as phone line.
-process changing ANALOGUE to DIGITAL =Modulation 
-process changing DIGITAL to ANALOGUE = Demodulation
-hardware used in computer to do this process is called MoDem



Data Transmission Mode
Parallel transmission
   -a group of bits is transmitted simultaneously by using a separate line for each bit.
Serial transmission
   -transmit all the bits one after another on a single line. This style is a bit slower compare to parallel
   -2 types of serial transmission mode:  # synchronous transmission 
                                                            # asynchronous transmission



Simplex
-data transmitted one direction only
-role of transmitted and receiver are fixed
-example: radio, video, tv


Half Duplex
-message can follow in 2 direction but NEVER at same time.
-one station transmit to another without interruption 
-other respon after transmission been complete.
-example: walkie- talkie.



Full Duplex
-both station can transmit and receive simultaneously 
-consists of 2 simplex channel
-phone call




Multiplexig
-a set of techniques that enable more than 1 device to combine and send their signals simultaneously through a single data links at the same time.
-network can transfer several different types of data : voice, video
-latest technology of LINKS=high - bandwidth media, coxial cable,optical fiber,satellite microwaves.
-each of these LINKS has a carrying CAPACITY. 






























2012年3月8日星期四



Week 1: Finally,I start my conversation at my blog. Want write about what ? Erm, lets talks about telecommunication. Telecommunication refer to communication over long distance, covers all forms of distance and conversion of the original communication, including radio, telegraphy, television,telephony,data communication and computer networking. It can also be defined as the process of transmitting or receiving information over a distance by any electrical or electromagnetic medium. The information may take the form of voice, video, or data.   
   Actually i still don"t know what was this subject about. But the first class seems like fun, and i hope my classmate and lecturer can help me to understand better in this subject^^

2012年3月7日星期三

Web Browser

Week 3.
    Hey hey hey..haha...this week i know better what is telecommunication and networking. And this week we are learning about web browser. A web browser is :
     -software application that enables a user to display and interact with text, images,and other              information typically located on a web page at a website on the World Wide Web or a local area network.
    -software that displays web pages.
    -software that gives users a access to the World Wide Web.

Although browser are  primarily intended to access the World Wide Web, they can also be used to access information provided by web servers in private networks or files in file systems . The major web browsers are Firefox, Google Chrome, Internet Explorer, Opera, and Safari.
   And below chart show the percentage of people use the web browser in 2011.