Saturday, May 17, 2008

Wireless Technology

As name suggest wireless means without wire. It is the technology employing the use of any media (particularly air, even vacuum) without wire or without any conductor, for the transmission of signal. Evaluation of wireless technology can also be defined in generation.

1st Generation(1G)- First generation of wireless technology use the analog technology. It uses FDMA(Frequency Division Multiple Access) for modulation.
Ex. AMPS(Advanced Mobile Phone Service) - in U.S.

2nd Generation(2G)- Second generation uses digital technology. Voice is digitized over circuit. It uses TDMA(Time Division Multiple Access) and FDMA technology.
Ex. GSM (Global System for Mobile communication) technology.

2.5th Generation(2.5G)- Generally similar to 2nd generation, it uses digitized data and known as 2.5G. The only difference is that it uses data in the form of packets over digital networks, but voice is digitized over circuit like 2G.
Ex. GPRS(General Packet Radio Service) technology.

3rd Generation(3G)-Third generation uses spread spectrum technology for media access and encoding. In 3G both data and voice use packets.
Ex. CDMA(Code Division Multiple Access) technology.

Monday, September 17, 2007

Web Application

A web application is an application that is accessed with the web browser throw internet or intranet.

A web application is a self-contained subtree of the web site.

Web applications are deployed to a web server. It uses Servlets, Filters, JSP, and the functionality provided by Resin and any other java code to provide a response to a client that makes an HTTP request.

Web applications are used to implement Webmai, online retail sales, online auctions, wikis, discussion boards, Weblogs, MMORPGs and many other functions.

Tuesday, September 4, 2007

World Wide Web Protocols

Web Protocols:

IP:- Internet Protocol
SSL:- Secure Sockets Layer
SSH:- Secure Shell
DSN:- Data Source Name
FTP:- File Transfer Protocol
DNS:- Domain Name Service
UPD:- User Datagram Protocol
IRC:- Internet Relay Chat Protocol
ARP:- Address Resolution Protocol
TCP:- Transmission Control Protocol
PAR:- Positive Acknowledgment and Retransmission
POP3:- Post Office Protocol version 3
HTTP:- Hypertext Transfer Protocol
SMTP:- Simple Mail Transfer Protocol
IDRP:- ICMP Router-Discovery Protocol
IMAP:- Internet Message Access Protocol
ICMP:- Internet Control Message Protocol
DHCP:- Dynamic Host Configuration Protocol
RLOGIN:- Remote Login
TELNET:- TCP/IP Terminal Emulation Protocol

Monday, September 3, 2007

World Wide Web ( www )

The world wide web (www) is a global information system and it was designed for availability of data and sharing of that data via computers, which are connected to the internet. In sort www is called Web.

The world wide web is a system of interlinked hyper text documents which is accessed through internet with the help of Web Browser. Web Browser show web page which can contain text, images and other multimedia.

World widw web was designed in 1989 by Tim Berners-Lee and Robert Cailliau in Geneva, Switzerland. Since then, Tim Berners-Lee has played an active role in guiding the development of web standards such Markup language in which web pages are composed. In recent years he has advocated his vision of a Semantic Web.