What iPhone needs: Core Location Daemon

By now, most people are aware of many limitations for developing on the iPhone, the most prominent being lack of ability for third-party applications to run in the background. To assuage this situation, Apple proposed a system of “push” messages that could be sent through the cellular network to the phone to notify them of an event.

A common example of this would be IM services: A user logs into the application, whose state is stored on the provider’s server. If the user closes the application, they can remain logged in through the server. If a message is received, the provider server notifies Apple, which notifies the mobile service company, and a notification is sent to the user indicating that a message from the instant messaging application is waiting.

It sounds simple enough, but Apple has yet to deliver on this promise and is far beyond their self-imposed deadline. Something I would like to see as a compliment to this service, actually works in exact reverse order and relies on the fact that  first-party applications already run in the background (such as Mail, Phone, SMS, and iPod).The tool I’d like to see added to this arsenal is Core Location – the software framework for detecting the phone’s location. If Core Location ran as a daemon in the background, along with existing Apple applications, the phone could provide location information to Apple, who can replicate that information to user-selected application providers.

Privacy advocates might balk at the idea as big brother-ish, but as long as the user has complete control over which applications can access the location data (as is currently the case), they need not worry about a change in the status quo. Furthermore, cell tower triangulation - while not as accurate as GPS – is already available to the service provider and services like E911.

What’s the upshoot to this possibility? One of the awesome potential capabilities of the phone is to deliver location-sensitive information, such as nearby friends or a favorite sandwich shop. Unfortunately, these uses are simply not possible unless the application remains opened in the foreground, requiring the user to take specific action, and restricting them from performing any other.

Instead, imagine that you could subscribe to that favorite sandwich chain with a coupon application. If you approve Core Location to send that information to the coupon server, they could detect when you are within a near distance of the store, and send a notification to your phone that a coupon is available if you stop by in the next hour.

The implementation is even more obvious if you consider the functionality of Loopt: You go out downtown with a few friends, but it turns out some other friends are also out. If an application could detect this, a message could be dispatched to everyone, notifying of the close proximity.

In general, this of course, still relies on a notification mechanism that Apple has made no recent mention of providing. A simple workaround, immediately available, is to utilize SMS. Although its capabilities are very limited, just prompting the user to open an application is better than no notification at all. With this situation, the only component to implement is exactly the feature this article recommends: a configurable, always-on Core Location service.

So Apple, where’s it at?