Professional Android 4 Application Development

220 x CHAPTER 6 USING INTERNET RESOURCES
Every time you create a new connection to download additional data, you risk waking the wireless
radio from standby mode to active mode. In general, it’s good practice to bundle your connections
and associated downloads to perform them concurrently and infrequently.
To use a converse example, creating frequent, short-lived connections that download small amounts
of data can have the most dramatic impact on the battery.
You can use the following techniques to minimize your application’s battery cost.
‰ Aggressively prefetch — The more data you download in a single connection, the less frequently
the radio will need to be powered up to download more data. This will need to be
balanced with downloading too much data that won’t be used.
‰ Bundle your connections and downloads — Rather than sending time-insensitive data
such as analytics as they’re received, bundle them together and schedule them to transmit
concurrently with other connections, such as when refreshing content or prefetching data.
Remember, each new connection has the potential of powering up the radio.
‰ Reuse existing connections rather than creating new ones — Using existing connections
rather than initiating new ones for each transfer can dramatically improve network
performance, reduce latency, and allow the network to intelligently react to congestion
and related issues
‰ Schedule repeated downloads as infrequently as possible — It’s good practice to set the
default refresh frequency to as low as usability will allow, rather than as fast as possible. For
users who require their updates to be more frequent, provide preferences that allow them to
sacrifice battery life in exchange for freshness.