Lab4 : Voice Over IP Using Android

This is an approximation of the grading form that wil be used to grade your project.

Pictures of the demo.

Goal

In this lab you will write an application that will allow communicating two or more phones running Android over the Internet. You will work on teams of 2 to 5 students.

Making the Teams

Make your teams and e-mail to cs290-ta@cs the list of the team members with the name and logins. Please do it before November 19th. Also include the number of Android phones you already have in your team .Once we have all the teams, we will see how to allocate the number of phones in each team.

You should not work individually. One of the goals of this lab is to learn how to work in teams.

Downloading Android

First download the Android SDK. The SDK has a simulator so you do not need to have a phone to develop. Also you should download the Eclipse IDE for Java Developers and the Eclipse Android Plugin since it will make the development easier. Start by writing a simple hello world program that you can run in the emulator and in your phone if available.

Sound Capture and Sound Playback

Look for Sound Capture and Sound Playback examples. See how they work and install them in your phone. You will use these examples as the base for your phone application.

UDP and TCP sockets

Also, look for example applications that use sockets to communicate. You will need TCP to listen for incoming calls and you will need UDP to send the voice packets to avoid any delay. Try running these applications in your emulator/phone.

Architecture:

The Internet phone system will consist of two programs:

The VOIP Program that will be running in the phone for each user using the phone.
A Directory Server that will have the name and IP address of each of the users. This server can be running on any UNIX machine (lore or sslab machines).

When the telephone program starts running, it will tell the directory server its own IP address and user name.

The VOIP program will have the following subsystems:

A Directory Client that will communicate with the Directory Server to add the user and IP address and to get the list of user names.
A Ringer Server that will be waiting for incoming communications and will tell the user if there is an incoming communication. The server will keep the connection open until the telephone hangs up.
A Ringer Client, that will contact the Ringer-Server in the other end when the dial button is pressed.
Voice Capture Client, that will capture voice from the microphone and it will send the voice stream to the Voice Player Server in the other end.
A Voice Player Server, that will receive the voice stream sent by the Voice Capture Client.

The protocol used by the Directory Server/Client, Ringer Server/Client will be TCP to make the lookup and call start/end reliable. The Voice Capture Client and the Voice Player Server will use UDP since the voice samples should arrive on time to be played on time and using TCP/IP may add cumulative delays in the voice due to the retransmission.

Step 1. Android SDK

Download the Andorid SDK, Eclipse, and the Eclipse plugin. Get familial with them. See the sample applications to get familiar with Android.

Step 2. Divide work

You can divide the teams in subteams that will implement the different subsystems:

Directory Server/Directory Client
Ringer Server Ringer Client
Voice Capture Client
Voice Player server
Phone GUI

Look for example programs that can help you start with your own implementation.
To capture and play voice use:

import android.media.AudioRecord;
import android.media.AudioTrack;

Here are some Slides that explain these classes . You can also check the following Android VoIP implementation in SIPDROD for ideas. The sources are available and you can see how they solved some of the problems.
You can also find some examples of Voice recorder/capture as well as UDP in lab4-src. The examples currently do not use AudioRecord and AudioTrack but they may serve as starting point. (Thanks to Rudy Sevile for providing the examples). A program that helps edit and generate the GUI of andorid is here.

Step 3. Source Control

You should use Source Control in this project to allow parallel development in the team.

To use SVN:

1. Create a shared directory in one of the home directories of the team members:

Login to lore
cd ~
mkdir-shared svn-cs290-lab4-repo login1 login2 login3 ...

where login1 login2 login3 are the logins of the member in the team

2. Create repository

svnadmin create ~/svn-cs290-lab4-repo

3. Each user now can access the repository. To create a copy of the repository type:

Login to a different account or machine.

To use the command line svn:

svn co svn+ssh://lore.cs.purdue.edu/homes/<user>/svn-cs290-lab4-repo

Also in windows you can download TortoiseSVN that integrates into the Windows environment.
Also an alternative is to use a SVN plugin in Eclipse.
Google for "svn tutorial" or "svn commands to see how to use it.

Turnin

You will turnin your project on December 9th during your demo time.

Create a directory called lab4-android/ with all the files needed to create your project.

Include also in this directory a README file with the following contents:

Members of the team with Names and Logins
Files used in the project and a small description of what they contain.
Features described in the handout that work.
Features described in the handout that do not work
Extra Features.

To turnin your files login to lore and type:

turnin -c cs290 -p lab4 lab4-android

The projects will be graded 11:30 am - 1:30 pm Thursday December 9th in LWSN B146. I will bring the schedule of times to class on Wednesday December 17th.

About 15 minutes before your presentation setup the environment you need and make sure that your project works. That will make the presentations go faster. We will have only about 15mins per team.