Will iPhone 3.0 “Push” Mobile VoIP Forward?


Of the many fixes and enhancements to iPhone software that Apple announced Tuesday, push notification has the potential to completely change the way people use the company’s mobile devices to communicate with one another.

A half-dozen mobile VoIP applications today make outgoing iPhone calls over WiFi possible but none of them can offer incoming calls due to development limitations imposed by the iPhone Software Development Kit. Apps can’t run in the background, nor can a network-aware application send notification to a user that they have a call coming in. The only way for an iPhone user to receive a telephone call today is through the cellular network the phone is registered to.  

Done right, however, push notification could change this, opening the door for companies such as Fring, Jajah, RF.com and Truphone to offer their customers both outgoing and incoming service.

This could radically change the economics of cellular phone service.

Whether such a sea change is really on the horizon remains a mystery, however, because iPhone software developers say the beta release of iPhone 3.0, though containing many of the fixes Apple boasted of on Tuesday, still lacks the push notification the company has been promising for more than a year.

Scott Forstall, Apple’s Senior VP of iPhone software alluded to the nature of the problem during Tuesday’s launch event, describing the problem as one of scale. “We had to completely re-architect the server infrastructure for push notification” in response to the huge number of developers who intend to use push “in volumes we hadn’t considered.”

Because push notification, Apple contends, is itself something of a compromise between the desire for apps that can run in the background and the need for a battery that doesn’t have to be recharged every couple of hours, “how” it works will determine whether communications are going to be transformed in the next phase of iPhone development.

In theory, incoming VoIP calls will announce their presence to Apple’s revamped server infrastructure and an alarm, or a visual indicator will be “pushed” to the iPhone, letting users know they have a call coming in.

Will the latency between the event requiring push notification and the time it arrives on a user’s device be predictable? Will it be manageable? Will it perform similar to SMS, which can take anywhere from seconds to many minutes depending on a variety of factors?

It’s one thing to find out your ESPN sports score notifications five minutes after the game is over, or your SIM City game partner’s activity a few seconds after the fact, but for push notification to help foster the growth of mobile VoIP, the time between a call being placed and an iPhone user being notified needs to be measured in fractions of seconds.

VoIP app developers are going to need dependable, low-latency push notification baked-in to leverage the potential for iPhone 3.0 to truly bring low-cost and free voice calling to the mobile environment.

Until Apple puts the push framework into the OS however, no one knows how that possibility is going to play out.



  1. KOKO says:

    SIAX for iphone (http://www.siax.org) offers incoming VOIP SIP calls and it works well. Furthermore, it is not a very big drain on the battery. Also, backgrounder for jailbroken iPhones provides the option to have background applications too.