smartscan™ · stb courtesy of jdsu 55.25 mhz 745.25 mhz low end roll off high end roll off...
TRANSCRIPT
SmartScan™
Finding Problems between
TAP and the Home
Rob Flask
© 2009 JDSU. All rights reserved. JDSU CONFIDENTIAL & PROPRIETARY INFORMATION 2
Finding issues between the TAP and the Home
Technician needs to perform an adequate set of
tests at the TAP to show that the performance is
not meeting specification. • Proper Levels
• Peak to Valley
• Performance of any offending service
SmartScan™ Helps find Issues
SmartScan™ Technology is Patent Pending
© 2009 JDSU. All rights reserved. JDSU CONFIDENTIAL & PROPRIETARY INFORMATION 3
TAP
Drop Cable
House
TV
GROUND
BLOCK
CABLE MODEM
TV
2-Way Splitter
Splitter 3-Way
STB
Courtesy of JDSU
55.25 MHz 745.25 MHz
Low end roll off High end roll off
Resonant Frequency
absorption
Validate tap performance
Min analog Video
Ch 2-78 15.6dBmv
Min QAM
Ch 79-158 8.75 dBmV
1000 MHz system
AMP
1
x
x
x
x
x
x
AMP
2
Tilt and power levels change from TAP to TAP
Mechanical issues cause customer problems
Power Levels must be
maintained for high
frequency losses
© 2009 JDSU. All rights reserved. JDSU CONFIDENTIAL & PROPRIETARY INFORMATION 4
SmartScan™ - Finds RF problems at tap
Finds RF response issues that are out
of spec
Compares against existing limit set plus
peak to valley and max/min tilt
(the peak to valley limit is labeled drop check in the limit set
during this beta version)
Automatically Tilt Compensates and
Normalizes analog and digital
measurements to identify Peak to Valley
issues
Identifies tilt level at tap
SmartScan will be optional upon final release
SmartScan Technology is Patent Pending
© 2009 JDSU. All rights reserved. JDSU CONFIDENTIAL & PROPRIETARY INFORMATION 5
If systems were flat!
Tight limit bands would be a simple solution
Ideal Case
-20
-15
-10
-5
0
5
10
15
20
50 150
250
350
450
550
650
750
850
950
Freq (MHz)
Le
ve
l (d
Bm
V)
Ideal TV
Typ
IdealHLimit
IdealLowLimit
Digital Tiers Analog tiers
© 2009 JDSU. All rights reserved. JDSU CONFIDENTIAL & PROPRIETARY INFORMATION 6
In real systems – tilt happens!
Tilt Affects Limits
-20
-15
-10
-5
0
5
10
15
20
50 150
250
350
450
550
650
750
850
950
Freq (MHz)
Level
(dB
mV
)
Ideal TV
Typ
PosTilt
NegTilt
IdealHLimit
IdealLowLimit
© 2009 JDSU. All rights reserved. JDSU CONFIDENTIAL & PROPRIETARY INFORMATION 7
SmartScan™ Eliminates Interpretation issues
and solves problems
Differences in power levels between analog and digital
carriers may be difficult to interpret for a technician
Tilt isn’t easily known
– Techs can’t input tilt value to compensate
– Wider limits allow bad channels to pass
Adjacent channel comparisons don’t find all problems
– Different digital carriers can be intermixed with analog carriers
– Roll-off can happen across many channels
Applying “Freq Bands” is still affected by tilt and allows bad
channels to pass
© 2009 JDSU. All rights reserved. JDSU CONFIDENTIAL & PROPRIETARY INFORMATION 8
New approach to find issues
Goal is to find network issues that affect customers
– Suckouts
– Bad Channels
– Bad passives (Tap Plates, 750 MHz splitters, etc)
Provide Tech with a view that eliminates tilt
Provide Tech with a view that “compensates” for
channel type
Tighter limit set for tilt and channel compensated
view
© 2009 JDSU. All rights reserved. JDSU CONFIDENTIAL & PROPRIETARY INFORMATION 9
How do we make this Better?
Step 1: Compensate for Tilt
Compensate for Tilt
-20.0-15.0
-10.0-5.00.0
5.010.015.0
20.025.0
50 150
250
350
450
550
650
750
850
950
Freq (MHz)
Level
(dB
mV
)
Typ
PosTilt
NegTilt
SmartScan™ Automatically calculates tilt and compensates for system tilt
© 2009 JDSU. All rights reserved. JDSU CONFIDENTIAL & PROPRIETARY INFORMATION 10
How do we make this better?
Step 2: Compensate for different channel types
Compensate for Channel Type
-20.0-15.0
-10.0-5.00.0
5.010.015.0
20.025.0
50 150
250
350
450
550
650
750
850
950
Freq (MHz)
Level
(dB
mV
)
Typ
Channel Comp
SmartScan™ automatically normalizes carriers based on ch. type trends
e.g. QAM 64 measure -8dB below analog, etc.
© 2009 JDSU. All rights reserved. JDSU CONFIDENTIAL & PROPRIETARY INFORMATION 11
How do we make this better?
Step 3: Normalize and provide tighter limit bands
Normalize And Peak/Valley Limits
-20.0
-15.0
-10.0
-5.0
0.0
5.0
10.0
15.0
20.0
25.0
1 3 5 7 9 11 13 15 17 19
Freq (MHz)
Devia
tio
ns i
n d
Bm
V
Normalized
High Limit
Low Limit
SmartScan™ provides a normalized view so individual
channel issues and system problems are easily identified
© 2009 JDSU. All rights reserved. JDSU CONFIDENTIAL & PROPRIETARY INFORMATION 12
Other Information
SmartScan uses all of the enabled carriers in the channel plan just like Full Scan
SmartScan compares the channels against the active limit set just like Full Scan
SmartScan adds additional limits of Max Tilt, Min Tilt, and Peak to Valley (labeled as Drop Check in limit settings for now)
SmartScan (beta) is still in Beta and is not a released item. Feedback is expected on it’s performance.
SmartScan will be chargeable option on some models once it is completed