Zend Framework - Redirecting to IndexController in different module

Question

All,

I have the following project setup in Zend's mvc Framework. Upon accessing the application, I want the user to redirect to "mobile" module instead of going to IndexController in "default" module. How do I do that?

-billingsystem
-application
    -configs
        application.ini
    -layouts
        -scripts
            layout.phtml
    -modules
        -default
            -controllers
                IndexController.php
            -models
            -views
            Bootstrap.php
        -mobile
            -controllers
                IndexController.php
            -models
            -views
            Bootstrap.php
Bootstrap.php
-documentation
-include
-library
-logs
-public
    -design
        -css
        -images
        -js
    index.php
    .htaccess

My index.php has the following code:

require_once 'Zend/Application.php';
require_once 'Zend/Loader.php';


$application = new Zend_Application(
  APPLICATION_ENV,
  APPLICATION_PATH . '/configs/application.ini'
);

$application->bootstrap()->run();