Operating and Troubleshooting the T504
How Radio Frequency Scanning Works
T504 Strand Mount Concurrent AP with Integrated CM Installation Guide, 800-70610-001 Rev A
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How Radio Frequency Scanning Works
The following steps describe how a DOCSIS-compliant T504 performs radio
frequency scanning:
1
Looks at the last “known good channel” (repeat this every 64 channel checks).
2
Checks the sixteen last known frequencies (repeat this every 32 channel checks).
3
Scans STD standard channels (where the center of the channel is an integer
spaced by 6MHz), first [from 93MHz to 999MHz - 152 channels]).
4
Scans the harmonically related carrier (HRC) channels, which moves the
channels 1.25MHz off the standard frequencies so the video carriers are all
related by 6MHz [from 91.75 to 997.5MHz--152 channels].
A complete frequency scan requires approximately 469 channel checks. Since each
channel takes about 0.6 seconds, a full scan is done every 281 seconds (a little
under 5 minutes).
NOTE
The scanning of generic DOCSIS channels is required the first time the T504
connects to an MSO. After the initial scan, the T504 is able to retrieve the local
country frequency plan without a complete scan during its normal operation.
DRAFT
