Bosch ISW-BHB1-WX Technical Bulletin

TECHNICAL BULLETIN
Intrusion
Signal-to-Noise Ratio Values
Issue Severity:
High: Act immediately
Medium: Bosch Security Systems, Inc.
strongly recommends you take the action(s)
described below.
Low: Advisory
1.0 Issue
The Signal-to-Noise Ratio (SNR) recommendations that are shown in the wLSN Reference Guide
(P/N: F01U009440) do not adequately ensure a trouble-free wireless installation in certain European markets
where multi-path signal fading might be present. Table 1 shows the SNR values that are currently published in
the reference guide.
Table 1:
Signal-to-Noise Ratio
< 9 dB
9 dB
13 dB
16 dB
20 dB
22 dB
When the SNR values shown in Table 1 are used to measure signal strength, signal strength can fluctuate
significantly in locations where multi-path signal fading is present. As a result, the device might not be able to
communicate with the hub. If a communication failure occurs and is not resolved within the defined supervision
window, the control panel sends a missing device report to the central monitoring station.
SNR Values using wLSN Hub (ISW-BHB1-WX)
Signal Strength
Unacceptable
Marginal (not recommended)
Acceptable
Good
Very good
Excellent
wLSN Wireless Devices
Products Affected:
• wLSN Hub (ISW-BHB1-WX)
• wLSN Installation Tool
(ISW-BIT1-HAX, -HBX, -HCX)
• Compatible wLSN Devices
March 4, 2010