1. Android around the clock Authors: Lior Narkis Maxim Chepurnyak Supervisor: Ittay Eyal

2. Agenda  Motivation  Project Goals  CTP algorithm  Application top-level  Main modules overview  Clock synchronization  Membership  Playback command dispatch  Media Player control  GUI  Design environment  Milestones

3. Motivation  Android based smart-phones are very common nowadays. These phones are used by many also as a media device.  We want to let a group of two or more of these phones, play the same song at the same time.  The playback can be controlled by any of group member.

4. Project goals  Creating a distributed Android application which will play a song on different devices all together.  The application will manage the group membership by supporting joining and leaving.  The application will keep all the group members clocks synchronized to each other.  The application will ensure global ordering of users’ commands.

5. Classless Time Protocol  A network clock synchronization protocol  Based on Omer Gurewitz’s work published in IEEE/ACM TRANSACTIONS ON NETWORKING, VOL. 14, NO. 4, AUGUST 2006  Improvement to NTP

6. Application top-level The diagram is neither complete nor final

7. Clock synchronization module  Implements CTP.  Provides a synchronized clock for other modules.  Provides a level of confidence parameter indicating the CTP quality.

8. Clock synchronization module – class diagram

9. Clock synchronization module – sequence diagram for NTP packet life-cycle

10. Membership module  Maintaining a list of active members(“alive” messages).  Support joining and leaving(avoiding partitions and livelocks).  Provides the members list to the rest of the modules.

11. Playback command dispatch (PCD) module  Broadcasts commands list sent by the MPC to all group members(including itself).  Delivers commands list to the MPC if no later commands list was delivered before.

12. Media player control (MPC) module  Drives the Android media player.  Receives commands from the GUI and sends those to the PCD.  Receives commands lists delivered by the PCD.  Processing the commands list.

13. GUI module  Simple.  Provides joining and leaving a group.  Provides basic playback operations.

14. Design Environment  The following tools/packages will be used:  Eclipse  JRE 7+  JDK 1.7+  Android SDK tools for eclipse  Paradigm UML plugin for eclipse – community edition  The project will be written in Java, using Android libraries, and will be checked on the Android emulator and real Android smart- phones.

15. Milestones  Completion of mid semester report.  Basic clock synchronization module  Basic membership module  Basic PCD module  Basic MPC module  Basic GUI module  Basic app