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Introduction
9
© Nokia Corporation 2004. All rights reserved.
Roaming – As the radio card user moves from one WLAN access point coverage
area or GSM network cell to another, the signal strength of the channel drops. As
a consequence, the network may hand the user over to a coverage area and
frequency where the signal is stronger. Due to varying network traffic loads,
roaming may also occur when the user is stationary. Such roaming may cause
slight delays in transmission.
Electrostatic discharge – A discharge of static electricity from a finger or a
conductor may cause erroneous functions in electrical devices. The discharge may
result in unstable software operation. Network connections may become
unreliable, data may become corrupted, and transmission halted. In those cases,
end the existing connection (if any), stop the radio card, and remove it from
the PC card slot. Then re-insert the radio card into the PC card slot and try
connecting again.
Dead spots and dropouts – Dead spots are areas where radio signals cannot be
received. Dropouts occur when the radio card user passes through an area where
the radio signal is blocked or reduced by geographical or structural obstructions,
such as concrete walls.
Signal impairment – Distance and obstacles can cause signals to become out-of-
phase. They can also cause reflected signals. Both situations result in a loss of
signal strength.
Low signal strength – Due to either distance or obstacles, the radio signal
strength from a WLAN access point or GSM cell site may not be strong or stable
enough to provide a reliable connection for communication. Therefore, to ensure
the best possible communication, remember to consider the following points:
• Data connection works best when the radio card is in a stationary position.
Attempting wireless data communication while in a moving vehicle is not
recommended. Fax transmission is more easily impaired than data or text
message transmission.
• Do not place the radio card on a metal surface.
General Packet Radio Service (GPRS)
GPRS is a packet data technology where information is sent in short bursts of data
over the mobile network. The benefit of sending data in packets is that the
network is occupied only when sending or receiving data. GPRS as such is a data
bearer that enables wireless access to data networks like the Internet. The
applications that use GPRS are SMS messaging and GPRS dial-up (for example,
the Internet and e-mail).
Before you can use GPRS technology:
• You need to subscribe to GPRS service.
For availability and subscription to GPRS service, contact your service provider
or network operator.