This document discusses best practices for efficient data transfer in Android applications. It covers topics like radio states, bundling data transfers, prefetching data, optimizing download patterns, using SyncAdapters, and Google Cloud Messaging. The document provides resources for analyzing data usage and references papers and guides from AT&T and Google on implementing efficient data strategies.

1. Efficient Data
Transfer in Android
Ralph Pina

2. Topics
- Radio state machine
- Big vs small cookie model
- Best practices
- Analyze your data transfer
- Resources for those interested

3. Radio State Machine
Full power: Used when a connection is active, allowing the device to transfer data at its highest possible rate.
Low power: An intermediate state that uses around 50% of the battery power at the full state.
Standby: The minimal energy state during which no network connection is active or required.
- AT&T timing for 3G

6. And then… show the user

7. Bundle Data Transfers

8. More graphs!

9. Wow power!

10. Prefetch!
“The single most important
measure: transmit as much data as
possible in a single burst and then
end the connection.”
- AT&T Labs

11. Parallelize!
- Parallelize requests

12. Download Patterns!
- Optimize download patterns based on data
connection.
- Prefetch more in 4G since you have higher
speed and it takes more power for the antenna
to come back.

14. More stuff!
- In Android, use SyncAdapter. Let the OS do
the the sync!
- Variable data transfers depending on usage.
- Sync when device is connected to power.

15. How GCM Works
- Phone connected via TCP port 5228
- Periodic heartbeat keeps the connection alive.
15 min on Wifi and 28 min on cell

16. Cotap Device Msging?
- Build our own MQTT server - invented by
IBM, very low power/bandwidth
- Current examples:
Eclipse Paho
Facebook Messenger and main app

17. Show and tell
- AT&T ARO
- supports second rate OS like
iOS and WP8!
- Android Monitor - <sdk location>/tools/monitor

18. Resources/Citations
- AT&T: A Call For More Energy Efficient Apps - http://www.research.att.
com/articles/featured_stories/2011_03/201102_Energy_efficient?fbid=Fp7Al9yFu9_
- AT&T ARO: https://github.com/attdevsupport/ARO
- Android Root Push Notification Fixer: https://play.google.com/store/apps/details?id=com.andqlimax.pushfixer&hl=en
- MQTT in Android: http://mqtt.org/wiki/doku.php/mqtt_on_the_android_platform
- Facebook: Building Facebook Messanger - https://www.facebook.com/notes/facebook-engineering/building-facebook-
messenger/10150259350998920
- DevBytes: Efficient Data Transfers - Understanding the Cell Radio (8/21/13): http://www.youtube.com/watch?v=cSIB2pDvH3E
- DevBytes: Efficient Data Transfers - Analyzing Your Transfer Profile (8/28/13): https://www.youtube.com/watch?
v=cLqWYeQcG94
- DevBytes: Efficient Data Transfers - Effective Prefetching (9/4/13): http://www.youtube.com/watch?v=Rk1u7VVmadE
- Using connectivity patterns: http://developer.android.com/training/efficient-downloads/connectivity_patterns.html
- Using Sync Adapters: http://developer.android.com/training/sync-adapters/index.html

19. Resources/Citations
- DevBytes: Efficient Data Transfers - Batching, Bundling, and SyncAdapters (9/11/13): http://www.youtube.com/watch?
v=5onKZcJyJwI
- DevBytes: Efficient Data Transfers - Eliminating Polling with Google Cloud Messaging (9/20/13): https://www.youtube.
com/watch?v=cJbGK6cVmSM
- DevBytes: Efficient Data Transfers - Variable Update Frequencies (9/25/13): https://www.youtube.com/watch?v=9z1BfyqmsyA
- DevBytes: Efficient Data Transfers - Minimizing Payloads (10/2/13): http://www.youtube.com/watch?v=OfYLG6FXtqE
- AT&T Research - Tail Optimization Protocol: http://www.research.att.com/export/sites/att_labs/techdocs/TD_100036.pdf
- Google I/O 2014 App: https://github.com/google/iosched
- Analyzing ARO Data: https://developer.att.com/static-assets/documents/aro/ATT_ARO_Analysis_Guide_3-2.pdf
- LTE Long and Short DRX Cycles to Save Power: http://mobilesociety.typepad.com/mobile_life/2009/12/lte-long-and-short-drx-
cycles-to-save-power.html