Nokia XPRESSMUSIC 5530 - Manual (Page 122)

Important: Even if the use of certificates makes the risks involved in remote
connections and software installation considerably smaller, they must be used
correctly in order to benefit from increased security. The existence of a certificate
does not offer any protection by itself; the certificate manager must contain correct,
authentic, or trusted certificates for increased security to be available. Certificates
have a restricted lifetime. If "Expired certificate" or "Certificate not valid yet" is
shown, even if the certificate should be valid, check that the current date and time
in your device are correct.
Before changing any certificate settings, you must make sure that you really trust
the owner of the certificate and that the certificate really belongs to the listed
owner.
15. Positioning
Positioning with your device
You can use applications such as GPS data to determine your location, or measure
distances and coordinates. These applications require a GPS connection.
Your device does not have an internal GPS antenna. To use applications that require
a GPS connection, use a compatible GPS receiver (accessory sold separately). Use
Bluetooth connectivity to connect to the GPS receiver.
You can also use network-based positioning with your device.
Network positioning
You can use the mobile network to determine your current location, even indoors.
This is faster but less accurate than with GPS, and you cannot use the location as a
starting point for navigation.
122 Positioning
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