Monday, 15 August 2016

mobile communication


                                                    MOBILE COMMUNICATION
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 In olden days we communicated by smoke signals ,carrier pigeons
what is mobile communication?
      a wireless form of communication in which voice and data information is emitted, transmitted and received via microwaves. This type of communication allows individuals to converse with one another and transmit and receive data while moving from place to place.
some examples: cellular and digital cordless telephones,pagers,air to ground telecommunication and satellite based communications.
what is a mobile?
        A cellular phone is a portable telephone that does not use a wired connection. It connects to a wireless carrier network using radio waves.
what is a mobile phone?
        The mobile phone or cell phone is a long range ,portable electronic device used for mobile communication. In addition to the standard voice function of a telephone, current mobile phones can support many additional services such as SMS for text messaging, email, packet switching for access to the Internet, and MMS for sending and receiving photos and video. Most current mobile phones connect to a cellular network of base stations ,which is in turn interconnected to the public switched telephone network
Inside a cell phone
         parts of a cell phone

  • A microscopic microphone
  • A speaker
  • An LCD or plasma display
  • A keyboard 
  • An antenna
  • A battery
  • An amazing circuit board containing the guts of the phone
main uses of cell phone
   voice calling ,voice mail, E-mail, Messaging, Mobile content, Gaming, Play music, Take photos or video, Download and view images, Shop, Bank, Location based services
cellular fundamentals
    First Generation cellular system

  • Introduction of analog cellular systems in the late 1970s and 1980s
  • analog system
  • incompatible system
  • limited to voice service
  • no encryption
  • FM modulation
  • FDMA transmission technology
  • suffer from capacity saturation

Second Generation cellular system

  • Introduction of digital cellular systems
  • development of unified international standards for mobile communication
  • pan-national roaming
  • digital encryption
  • enhanced range of services
  • low power consumption
  • light weight, compact and pocket size terminals
  • TDMA transmission technology
  • huge capacity

Third generation cellular system


  • Multimedia services 
  • W-CDMA transmission technology
  • large BW
  • Higher bit rate
  • more services
The cellular structure


  • area divided into small zones (cells)
  • cells grouped into clusters
  • this gives less power usage
  • enable frequency reuse
GSM system
components in GSM:
       3 main components 
  1. Mobile station(MS) -UE,SIM
  2. Base Station Subsystem(BSS)-BTS,BSC
  3. Network and Switching Subsystem(NSS)-MSC,VLR,HLR
 MSC is the heart of the GSM Network
 In GSM- 900
Uplink frequency      :890-915MHz
Downlink frequency  : 935-960 MHz









Sunday, 14 August 2016

PHP & MYSQL

PHP is a server scripting language and a powerful tool for making dynamic and interactive web pages. PHP is  a widely - used, free and efficient alternative to competitors such as Microsoft's ASP.
  • PHP is an acronym for "PHP: Hypertext Preprocessor"
  • PHP is a widely-used, open source scripting language
  • PHP scripts are executed on the server
  • PHP is free to download and use
Basic PHP Syntax:
A PHP script can be placed anywhere in the document.

A PHP script starts with <?php and ends with ?>:
<?php
//php code goes here
?>
The default file extension for PHP files is ".php".
A PHP file normally contains HTML tags, and some PHP scripting code.
Below, we have an example of a simple PHP file, with a PHP script that uses a built-in PHP function "echo"  used to get output on a web page:
<html>
<body>
<h1>My first page</h1>
<?php
echo"Good Morning GPT Addanki";
?>
</body>
</html>

PHP supports the following data types:
  • String
  • Integer
  • Float (floating point numbers - also called double)
  • Boolean
  • Array
  • Object
  • NULL
  • Resource
With PHP  you can connect to and manipulate databases.
MySQL is the most popular database system used with PHP.
  • MySQL is a database system used on the web
  • MySQL is a database system that runs on a server
  • MySQL is ideal for both small and large applications
  • MySQL is very fast, reliable, and easy to use
  • MySQL uses standard SQL
PHP-AJAX

AJAX = Asynchronous JavaScript and XML.
AJAX is a technique for creating fast and dynamic web pages.
AJAX allows web pages to be updated asynchronously by exchanging small amounts of data with the server behind the scenes. This means that it is possible to update parts of a web page, without reloading the whole page.
Classic web pages, (which do not use AJAX) must reload the entire page if the content should change.
Examples of applications using AJAX: Google Maps, Gmail, Youtube, and Facebook tabs.

AJAX FLOW CHART

AJAX

Monday, 11 July 2016

ADVANCED COMMUNICATION


 RADAR COMMUNICATION:

Radar is a contraction of words radio detection and ranging.
It was first developed as a detection device to warn of the approach of the hostile aircraft and for directing anti aircraft weapons.
Radars are classified into 2 types
according to function 1. civilian radars 2. military radars
according to wave forms 1. cw radars 2. pulsed radars.

SATELLITE COMMUNICATION:

A Satellite is simply any body that moves around another one in a mathematically predictable path called orbit.
a communication satellite is a microwave repeater station in space that is used for telecommunication, radio and television signals.
working:
two stations on earth want to communicate through radio broadcast but are too far away to use conventional repeaters.the two stations to use satellite as relay station for their communication.
one earth station transmits the signals to the satellite that transmitted frequency is called uplink frequency.
the satellite transponder converts the signals and sends it down to the second earth station. this frequency is called down link frequency.
types of orbits:
GEO: ~360000Km from the earth.
MEO: 6000 TO 20000Km.
LEO: 500-1500 Km.

SEMICONDUCTOR MICROWAVE DEVICES:

component                               operating frequency
PIN Diode                                          700GHz
GUNN Diode                                     4-100GHz
IMPATT Diode                                   3-100GHz
SHOTTKY Diode                               3-100GHz
TRAPATT Diode                                3-50GHz


posted by onteru mamatha L/ECE

Monday, 27 June 2016

Oracle - SQL& PL/SQL

Dear all,
              I am to glad to inform you that we participated in "Oracle-SQL & PL/SQL" at NITTTR Chennai from 20-06-2016 to 24-06-2016.

A database is basically a collection of information organized in such a way that a computer program can quickly access desired pieces of data. Example for a data base is address book in your phone.

To access information from a database, you need a database management system (DBMS). This is a collection of programs that enables you to enter, modify, and select data in a database.

A Relational database management system (RDBMS) is a DBMS that is based on the relational model. Data is stored in the form of rows and columns .i.e Tables. Data is created and retrieved using SQL.Some of famous RDBMS softwares are Oracle, MS SQL Server, IBM DB2, Oracle, MySQL, Sybase, Informix, postgres  and Microsoft Access.

Oracle is RDBMS software developed by Oracle Corporation from 70s. The latest version of the database is Oracle 12c. (c means Cloud). Oracle Database 11g XE is free to use for Educational institutions and students & developers.

SQL(Structured Query Language) is a database computer language designed for the retrieval and management of data in relational database. All RDBMS software uses SQL. SQL includes commands for database creation, deletion, fetching rows and modifying rows etc.

Following statements would create a record in customer table
INSERT INTO CUSTOMERS (ID,NAME,AGE,ADDRESS,SALARY) VALUES (1, 'Ramesh', 32, 'Ahmedabad', 2000.00 );

Following is an example which would fetch ID, Name and Salary fields from the CUSTOMERS table where salary is greater than 2000
SQL> SELECT ID, NAME, SALARY FROM CUSTOMERS WHERE SALARY > 2000;

Some examples of SQL commands are
SELECT * FROM CUSTOMERS ORDER BY NAME, SALARY;
SELECT COUNT(*)FROM employees;
SELECT SUM(Salary) FROM employees;

PL/SQL is a combination of SQL along with the procedural features of programming languages.
PL/SQL supports conditional statements, loops, arrays, functions, procedures, functions, Cursors, Exceptions, Triggers, Packages. 

With Regards
BVS.Naga Raju & L.Mohana Tirumala,
Lecturers in CME,
GPT, Addanki

Saturday, 25 June 2016

Software Engineering
Dear All,   

         I am glad to inform you that I participated in short term training programme on “Software Engineering” at NITTTR Chennai from 13.06.2016 to 17.06.2016. Major topics covered in the course are

     1.      Introduction to Software Engineering
     2.      Software Project planning and Management
     3.      Requirement Analysis and Specification
     4.      Software Design, Coding & Testing
     5.      Software Metrics
     6.      Documentation

Formal Definition of Software Engineering: Application of systematic, disciplined, quantifiable approach to the development, operation, and maintenance of software.

Software engineering teaches how software should be constructed. The software engineering industry evolves faster than any other industry and of increasing importance to our economy and standard of living. It is a vast field. Its scope is extremely broad. It covers a wide range of professions such as scientific and numeric computing, ERP/HR and accounts, telecom industry, business applications, graphic designs, video game developmentdefense industry etc. So, software job became one of the most important jobs of today.

It is relatively young discipline by comparison with most other engineering disciplines. The main focus is on how to build and maintain high quality software systems in a controlled, predictable way. Software Engineer must have a sound knowledge of mathematics, science, economic and social issues to build software within given budget and time constraints.

I am very much pleased to be part of this course as it helped all the participants in understanding software engineering practices in the Industry perspective.

With Regards
Dr.K.Ratna Babu, L/CME GPT Addanki.

Tuesday, 22 March 2016

Python Programming


Dear All,

            I am glad to inform you that I participated in short term training programme on “Python Programming” at NITTTR Chennai from 07.03.2016 to 11.03.2016. I believe that Python is very much useful for software development. While there are more powerful languages (Lisp, C, Java etc.), Python gets a lot of different things right, and right in a combination that no other language I know of has done so far.

            Python is an easy to learn, powerful programming language. It has efficient high-level data structures and a simple but effective approach to object-oriented programming. It’s elegant syntax and dynamic typing, together with its interpreted nature, make it an ideal language for scripting and rapid application development in many areas on most platforms. Its design philosophy emphasizes code readability, and its syntax allows programmers to express concepts in fewer lines of code than would be possible in languages such as C++ or Java.

           The most up-to-date and current source code, binaries, documentation, news, etc., is available on the official website of Python: https://www.python.org/. The same site also contains distributions of and pointers to many free third party Python modules, programs and tools, and additional documentation.

Installation

Installing Python is generally easy, and nowadays many Linux and UNIX distributions include a recent Python. Even some Windows computers now come with Python already installed.
Here are the simple steps to install Python:

Unix & Linux Installation

  • Open a Web browser and go to http://www.python.org/download/
  • Follow the link to download zipped source code available for Unix/Linux.
  • Download and extract files.
  • Editing the Modules/Setup file if you want to customize some options.
  •  run ./configure script
  •  make
  • make install
This install python in a standard location /usr/local/bin and its libraries at/usr/local/lib/pythonXX where XX is the version of Python that you are using.

Windows Installation


  • Open a Web browser and go to http://www.python.org/download/
  • Follow the link for the Windows installer python-XYZ.msi file where XYZ is the version you need to install.
  • To use this installer python-XYZ.msi, the Windows system must support Microsoft Installer 2.0. Just save the installer file to your local machine and then run it to find out if your machine supports MSI.
  • Run the downloaded file. This brings up the Python install wizard, which is really easy to use. Just accept the default settings, wait until the install is finished, and you are done.



Execution

A Python script can be executed at command line by invoking the interpreter on your application, as in the following:

$python script.py # Unix/Linux

Another website which is useful in learning python is http://www.tutorialspoint.com/python.


With Regards

Dr.K.Ratna Babu, L/CME GPT Addanki.