is internet or cell connection required for iPhone to use Skyhook to locate via wifi?

As I understand it when gps or cellular location services are unavailable the iPhone will use Skyhook to locate the device using surrounding wifi networks based on the networks locations that are stored in a Skyhook database.

If the device has no network connection, meaning it can't get at the internet at all, and it has no cell connection so no phone capabilities, can it still find the current l开发者_运维技巧ocation based on surrounding networks?

No, Skyhook is a web service. Your phone does not contain a copy of Skyhook's massive database of the geographic coordinates of every known wireless point in the world.

actually, the answer is not completely correct.

skyhook does utilize web services as part of its system, but it has client side software and a localized subset of the master data cached on the device. so while you don't need to be connected at any specific point and time, if you have been connected recently and in that local area then skyhook has loaded some data on your device and it may well be able to locate you without being connected.

see http://www.skyhookwireless.com/devices/deploymentmodels.php

that said, most apps DO need a connection to render location based content (like maps) so even if you are getting a lat/long calculated by skyhook, the app itself may not be able to render it.