User's Manual

User
AN-100U/UX Base Station
Manual
70-00058-01-04 Proprietary Redline Communications © 2010 Page 116 of 136 April 19, 2010
Table 57: Op. Notes - Base Station Advanced Privacy Settings
Parameter
Defaul
t (sec)
Description
AKLifetime:
60480
0
Period the subscriber is authenticated (168 hours).
TEKLifetime:
180
Period during which each key is valid.
AuthGraceTime:
600
Period allowed to obtain reauthorization before current session
ends.
TEKGraceTime:
60
Period allowed for remote device to process the request for a
new TEK.
ReauthWaitTime:
10
Period to wait for confirmation of reauthorization request.
AuthRejWaitTime:
10
Period to wait after rejection of authorization request.
OpWaitTime:
1
Retransmission interval when requesting new TEK.
7.3.3 Configuring Subscribers
Each wireless subscriber modem contains one built-in certificate for itself and one for the
manufacturer. Encryption must be enabled separately for each participating subscriber.
The mode of authentication must be configured on the base station (see TrustAll
parameter).
Table 58: Op. Notes - Privacy Settings
privacySS
Description
0 (No)
Privacy is enabled -- authentication is required.
1 (Yes)
Privacy is disabled -- authentication is not required.
Example: Enable privacy for subscriber:
SUO#> privacySS
SUO(privacySS ->)#> set Enabled 1
To disable privacy module in SS follow these steps:
SUO#> privacySS
SUO(privacySS ->)#> set Enabled 0
7.4 Co-Channel Operation
Greater complexity in the modulation technique requires a greater (C/N) ratio to
maintain adequate throughput. In the presence of an interferer, the useful signal is
degraded. The ratio of 'useful signal' to 'interfering signal' is called the carrier-to-
interference ratio. If the interferer signal power is additional noise power, and the overall
C/I+N ratio can be estimated as:
)1010log(10//
10
/
10
/ NCIC
NCICCINR
, where all variables are in decibels.
This formula corresponds with an expectation that a very strong signal (high C/N) is able
to withstand higher levels of interference (low C/I). If the signal is weak, even low
interference levels will significantly degrade the useful signal. Consider the following
examples:
Case 1: The threshold CINR for 64 QAM 3/4 is around 23.25 dB. If the C/N ratio is 24
dB, the system will operate at 64 QAM 3/4 (signal is close to the 64 QAM 3/4 threshold,
but still above it). If we introduce an interferer with a signal 30 dB weaker than the