This document discusses various topics in networking and telecommunications including cellular networks, half and full duplex communication, circuit switched networks, radio communication, HTTP, FTP, NAT, DNS, SMTP, and DSL. It provides definitions and examples for each topic with links to additional online resources for further information.

1. Daffodil International University, EEE
Name
Md. Mujahiduzzaman

2. Cellular Network
Half And Full Duplex
Circuit-switched network
Radio Communication
HTTP Protocol
 File Transfer Protocol
NAT
DSL

3.  A cellular network is a radio network made up of a number of radio cells each
served by at least one fixed location transceiver known as a base station.
 Reduced power usage.
 Larger coverage area.
 An example of a simple non-telephone cellular system is an taxi drivers radio
system.

5. Half duplex is a both stations transmit , but only
one at a time.
Example: police radio
Full duplex is a simultaneous transmissions.
Example: telephone

7.  Connection-oriented network is called a circuit-switched network.
 Circuit switched networks did not dynamically recreate dropped circuits.
 Example: telephone network .
Link: http://www.highteck.net/EN/Basic/Internetworking.html

9.  It is wireless communication system.
 The information is being carried by the electromagnetic waves .
 electromagnetic waves are waves that travel at the speed of light
and made up of an electrical field.

11.  Hypertext Transfer Protocol.
HTTP client sends a request message to an HTTP server.
 HTTP is a stateless protocol.
Link:
https://www.ntu.edu.sg/home/ehchua/programming/webprogramm
ing/HTTP_Basics.html

13.  it is very uncommon to share folders over the Internet.
File transfers over the Internet use special techniques, of which
one of the oldest and most widely-used is FTP.
 File Transfer Protocol can transfer files between any
computers that have an Internet connection.
It works between computers using totally different operating
systems.
Link: http://www.deskshare.com/resources/articles/ftp-how-to.aspx

15.  NAT means Network Address Translation.
 The simplest type of NAT provides a one-to-one translation of
IP addresses.
Basic NATs can be used to interconnect two IP networks that
have incompatible addressing.
Network address translation is not commonly used in IPv6
Link:
https://en.wikipedia.org/wiki/Network_address_translation#NAT_i
n_IPv6
https://en.wikibooks.org/wiki/Communication_Networks/NAT_an

17.  DNS means Domain Name System.
The root DNS server maintains information about where a top-
level (.com) DNS server is located and returns this information to
the ISP’s DNS Server.
he ISP’s DNS server redirects the query to a top-level (.com)
DNS server.
Lastly, the ISP’s DNS server sends the IP address to the client
computer so the client can access www.yourcompany.com.
Link: http://www.uxworld.com/?p=384

19.  SMTP means Simple Mail Transfer Protocol.
SMTP sender sends MAIL command indicating the sender of the
mail.
 The SMTP-Sender then sends a command identifying a
recipient of the mail.
Sending machine is operating as a client and the receiving as a
server.
Link:
http://www.ee.surrey.ac.uk/Projects/CAL/networks/Network-
Transport_Application_Layers.htm#smtp

21.  DSL means Digital Subscriber Lines.
 range from 128 kbps to 1.54 Mbps.
 DSL achieves higher data transfer rates by utilizing more of the
available bandwidth spectrum.
 frequency range 0 ~ 3400 Hz.
 larger bandwidth is available, allowing for greater transfer rates.
Link: http://www.infocellar.com/cable-dsl/DSL.htm