Pandora, Zynga build network-efficient apps through AT&T's ARO, and 9 tips for developers

Mike Dano

AT&T Mobility recently reported that Pandora, Zynga and other, unnamed top developers have used its "Application Resource Optimizer" to make their apps more network efficient. The announcement represents a culmination of more than two years of work by the wireless operator to encourage mobile app developers to make applications that are not unnecessarily stressful on AT&T's network.

"We need to work with app developers and device makers to make the most of the natural resource we all use, which is spectrum," said AT&T President and CEO Ralph de la Vega during his March 2010 appearance at the CTIA Wireless trade show. "It should be a national imperative."

Also at the CTIA 2010 show, AT&T executive Kris Rinne provided further details on the topic during a FierceWireless event. She said that one streaming video site in particular required eight times the amount of data for a download, compared with the most-efficient site's data requirements--with no visible difference in video quality from the customer standpoint.

Rinne too called for collaboration among carriers, content providers and application developers to create new standards to enable the efficient delivery of content over mobile broadband networks. "Such innovation will enable reduced costs and improved quality for our common end users," she said.

And it appears AT&T has taken the first steps toward this goal via its Application Resource Optimizer, or ARO for short. The technology was announced early this year and made available as an open source download two months ago. AT&T said "several hundreds of developers" have downloaded the tool so far.

So what exactly does AT&T's ARO do? According to the company, it is a "free diagnostic tool for analyzing the performance of your mobile applications. It can help your app run faster and smarter by providing recommendations to help optimize your mobile application's performance, speed, network impact and battery utilization."

To be specific, it's a bit of software that a developer would install into a testing phone that logs that device's performance when it is running the developer's application. A monitoring program then provides data on how that application works with the device's wireless network processor, GPS, Wi-Fi, Bluetooth, camera, screen and battery. The software works across all carriers and devices.

To prove ARO's usefulness, AT&T ran Pandora's streaming radio app through the software. According to AT&T, ARO helped reduce Pandora's battery usage by 40 percent. ARO discovered that while the Pandora app was sending music efficiently, it was also powering up the device's radio every 60 seconds to send information back to Pandora about what the listener was doing. This audience measurement information represented just 0.2 percent of Pandora's overall data load, but due to the app's design the information accounted for 46 percent of Pandora's overall power consumption. The solution was to bundle the small bursts of data into a single transmission.

"We'd like to incorporate AT&T's profiling tool as part of our normal ongoing testing," concluded Tom Conrad, CTO of Pandora, according to AT&T.

As a result of its work in the area of app optimization, AT&T researchers published a list of the top wireless issues that developers should address in order to make their apps more network efficient--a key feature in an age when most wireless carriers charge for data on a per-MB basis and many smartphone platforms allow users to see which apps chew through their cellular data usage.

Here are the top issues AT&T identified:

1.      Unnecessary or inefficient connections. The carrier said that apps sometimes open too many or unnecessary TCP connections to the data network, which chews through devices' battery life and users' data allotments. Such connections also sometimes overuse "periodic transfers" or network pings.

2.      Opening and closing connections quickly. AT&T said a number of the apps it tested would have been more network efficient if they had grouped opening and closing data transmissions together. Such groupings would make the apps run faster (by eliminating the network latency in multiple connections) and ease network strain.

3.      Offload to Wi-Fi when possible. AT&T is not alone in encouraging the use of Wi-Fi; Sprint Nextel, T-Mobile USA and other carriers have made moves to encourage users to move onto Wi-Fi networks when they are available. For its part, AT&T manages more than 30,000 public hotspots in the United States

4.      Connections when the user's screen rotates. "Many apps are written so that the device pings the server each and every time the user rotates the screen, even though there is no change to the data the user is experiencing. Um, hello… Talk about a waste," wrote the AT&T researchers.

5.      Duplicate content. The researchers said one app they tested downloaded an extra 600 KB of content that was already on the device.

6.      Caching issues. AT&T said apps should always cache content on a device when possible, and should only update that cached content when newer content is available.

7.      Pre-fetching. AT&T said apps should download all the information a user would need all at once, rather than downloading it on an as-needed basis. While this might load the network during the initial download, it will result in a better user experience since a user wouldn't have to wait for each image in a list, for example, to load separately.

8.      Accessing peripherals. AT&T said some apps access functions like GPS and Bluetooth when they are unnecessary.

9.      Avoiding HTTP 1.0. AT&T said developers should use TCP connections instead of the outdated HTTP 1.0 standard.

Of course, ARO is just one part of a much larger push by the wireless industry to make more efficient use of spectrum. Indeed, AT&T and most of the rest of the nation's wireless carriers are spending billions of dollars to build LTE networks--LTE technology is far more spectrally efficient than 3G network technology (and AT&T confirmed ARO works just as well on LTE as 3G).

As wireless technology in general matures, I expect an increasing number of developers will begin focusing on the details of the mobile app market, including usability issues like network efficiency. +Mike Dano