Good point, according to the Apple documentation only the following usages are allowed in background and each service should be registered:
- audio—The app plays audible content to the user while in the background. (This content includes streaming audio or video content
using AirPlay.)- location—The app keeps users informed of their location, even while it is running in the background.
- voip—The app provides the ability for the user to make phone calls using an Internet connection.
- newsstand-content—The app is a Newsstand app that downloads and processes magazine or newspaper content in the background.
- external-accessory—The app works with a hardware accessory that needs to deliver updates on a regular schedule through the External
Accessory framework.- bluetooth-central—The app works with a Bluetooth accessory that needs to deliver updates on a regular schedule through the
CoreBluetooth framework.
Other than this services, you can create a Finite-Length Task in the Background that actually give you the possibility to end a network process.
This can be important if your app is performing some important task,
such as writing user data to disk or downloading an important file
from a network server.
Regarding your question, it’s not really clear if you can or not can do a quick network connection if you’ve a location service running in background. I would say YES for a short connection, but not totally sure. Since iOS 4.0 this usage was denied and clear in documentation, now that part has been removed.