This article gives an overview of the different location services an iPhone and iPod touch can use to determine your location. For information on using Location Services to track your location in Maps and other applications, see the iPhone User Guide or iPod touch User Guide.

Virtual Private Networks (VPNs) are often used within organizations to allow you to communicate private information securely over a nonprivate network. You may need to configure VPN, for example, to access your work email on iPhone or iPod touch. VPN works over both Wi-Fi and cellular data network connections.
iPhone and iPod touch support VPNs that use the L2TP, PPTP, or Cisco IPSec VPN protocols. For a complete list of supported VPN protocols, see this article.

If you need to send your iPhone in for service, please remove your SIM card before sending it in for repair.

When using a Wi-Fi network with your iPhone or iPod touch, you may occasionally encounter the following issues:

Unable to locate a nearby Wi-Fi network
Weak or low Wi-Fi signal strength
Unable to access the Internet

This article outlines basic troubleshooting tips and techniques for Wi-Fi on the iPhone and iPod touch. For information on enabling or configuring a Wi-Fi connection, see the iPhone User Guide or iPod touch User Guide.
Note: The features and troubleshooting steps below may not be applicable to devices sold in certain countries, including China. Please see iPhone or iPod touch technical specifications and this article for more information.

Try the following troubleshooting steps on your iPhone or iPod touch in order to resolve an application’s issue.