Installing NS2

There are two ways of using NS2:
On Linux Operating System or on Windows Operating System.

On Linux, after downloading NS2 follow these steps:
Copy ns-allinone-2.35.tar.gz file to your home directory.
Run terminal by pressing Ctrl+Alt+T .

Execute “tar -xzvf ns-allinone-2.35.tar.gz” command.
 Execute “cd ns-allinone-2.35” command. Execute “./install” command. Execute “cd ns2.35” command.

TRANSACTION IN DATABASES

Most of the organisations use database to store their information such as bank may use a database to store the balance of all depositors in a bank.
For Example:

DATA LINK CONTROL

 For  effective  digital  data communications,  much  more  is  needed  to  control  and manage  the  exchange.  In  this  chapter,  we  shift  our  emphasis  to  that  of  sending  data over  a  data  communications  link.  To  achieve  the  necessary  control,  a  layer  of  logic  is added  above  the  physical  transmission  layer;  this  logic  is  referred  to  as  data  link control  or  a  data  link  control  protocol.  When  a  data  link  control  protocol  is  used,

What is Net Frameworks and .Net Framework Architecture

.NET FRAMEWORK VERSIONS:

The development of .Net has been started in late 90’s and the first version of framework has been launched in the year 2000 as 1.0 Beta (Trial) and officially it has launched into the market as 1.0 RTM (Release To Manufacturing) in 2002.

2000  ——  .Net Framework 1.0 Beta

2002  ——  .Net Framework 1.0 RTM

2003  ——  .Net Framework 1.1

2005  ——  .Net Framework 2.0

2006  ——  .Net Framework 3.0

2007  ——  .Net Framework 3.5

2009  ——  .Net Framework 4.0

2012  ——  .Net Framework 4.5

2013  ——  .Net Framework 4.5.1

2014  ——  .Net Framework 4.5.2

2015  ——  .Net Framework 4.6

.NET FRAMEWORK ARCHITECTURE:

Following is the figure of .Net Framework Architecture:

MOBILITY MODELS

Node mobility in MIRACLE is ruled by two classes named BMPosition and GMPosition, derived from Position class. The former utilizes a Basic Movement (BM) model and the latter uses a Gauss-Markov (GM) model. 
These models are those we provide with the MIRACLE release, but you can feel free to create your own! 

STATIC KEYWORD

If  a keyword Static is present before a variable or method then it is called as static variable or static method respectively.The keyword static is mainly used for memory management in Java.The variable declared with  static keyword belongs to the class rathar than the object of class .It is also possible to define main() method without the keyword static.

CONSTRUCTORS IN JAVA

Constructor is a special type of method in a class that is used initialise an object, that is a constructor is called automatically when an object of a class is created.A constructor is mainly used to initiallise the values to the variables in the functions.
The constructor has some special  properties that are:

•     Constructor cannot have any return type ,not even void.
• The name of the constructor should be same as the class name.

The most common types of constructors in Java programming are:
Default constructor and
Parameterised constructor