Push to talk app in android that allows unicasting,broadcasting and multicasting.Its is implemented using socket programming and UDP datagram.

1. Anjali Jain (9910103580)
Nitin Bansal (9910103589)

2. Push-to-talk (PTT), also known as Press-to-
Transmit, is a method of having conversations
or talking on half-duplex communication lines,
including two-way radio, using a momentary
button to switch from voice reception mode to
transmit mode.

3. Push to Talk over Cellular (PoC)
is a service option for a cellular
phone network that enables
subscribers to use their phones
as walkie-talkies with unlimited
range. A typical Push-to-Talk
connection connects almost
instantly. A significant advantage
of PoC / PTT is the ability for a
single person to reach an active
talk group with a single button
press; users need not make
several telephone calls to
coordinate with a group.

5. THREE WAYS OF TRANSMISSION ::

7. INTERFACE FOR USERS ::
Screen 1 Settings Communication

8. WHAT’S NEW??
• Low Noise
• Behaves same as
telephonic
conversation
not as Walkie -
Talkie

9. LIMITATION
• Within a building that means low range and
less distance covered

10. IMPLEMENTATION::
Sender: UDP Socket programming
1. Create UDP Socket for sending datagram
DatagramSocket socket = new DatagramSocket();
2. Prepare datagram for sending
byte[] data = new byte[256];
InetAddress address = InetAddress.getByName("192.168.1.8");
DatagramPacket pack = null;
pack = new DatagramPacket(data, data.length, address, 8888);
3. Send
socket.send(pack);
4. Receive
Prepare new datagram first for holding the incoming packet. The array of byte must be clear in
advance.
socket.receive(pack);

11. Receiver: UDP Socket programming
1.Start listening for datagram on a certain socket
DatagramSocket socket = new DatagramSocket(Server_Port);
2. Prepare datagram for receiving
byte[] data = new byte[256];
DatagramPacket pack = new DatagramPacket(data, data.length);
3. Start listening for a datagram
socket.receive(pack);
4. Obtaining the data and address and port of sender
int port = pack.getPort();
InetAddress address = pack.getAddress();
String content = new String(pack.getData, 0, pack.getLength());

12. RESEARCH PAPER
1. A Client-Side Design and Implementation for Push to Talk
over Cellular Service
http://ir.lib.nctu.edu.tw/bitstream/987654321/32034/1/A+Client-
Side+Design+and+Implementation+for+Push+to+Talk+over+Cellular+Se
rvice.pdf
2. Practical Voice Communications in Challenged Networks
www.netlab.tkk.fi/~jo/papers/2009-08-dt-talkie.pdf