User guide

Raven EDGE/GPRS for Cingular - User Guide, version 2.31 120
APPENDIX 6 Frequently Asked Questions and
Technical Support
Many of these questions and solutions in the following sections come from AirLink Support.
FAQ Topics
Power, Antennas, and Signal Strength . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .page 120
What is RSSI? Why is the RSSI for my Raven negative?
What is the Proper RF Coverage for my Raven?
What Type of Antenna is Best for my Raven?
What do I need to power my Raven ?
Can I use a portable battery to power my Raven ?
The Raven’s IP Addresses and Local Networking . . . .
.
. . . . . . . . . . . . . . . . . . . . . . . .page 122
Why Can’t I reach my Raven from the Internet? What is
a Restricted or Private IP?
What is the difference between Privat
e and Public mode?
How do I set up Private Mode? How do I connect to my Raven to my router or to Linux?
Security for the Raven . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .page 124
Does EDGE/GPRS provide any security?
If I change the password in my Raven and forget it later, can I
still access the modem?
Power, Antennas, and Signal Strength
RSSI (Received Signal Strength Indication) is a measurement of the strength or intensity, not nec-
essarily the quality, of the received signal.
The RSSI is measured in dBm which is t
h
e power ratio in decibel (dB) of the measured power ref-
erenced to one milliwatt (mW). One milliwatt is zero, therefore less than a milliwatt, common and
ideal for cellular communication, is expressed as
a negative interger.
Caution: Solutions should only be performed if you are experiencing the specific
problem indicated and have the specific modem model number indicated. Some
solutions are very specific to model numbers due to differing internal hardware.
What is RSSI? Why is the RSSI for my Raven negative?