Narrowband Analog
Simulcast Workshop
APCO/Minneapolis
August 20, 2012
Ed O’Connor
O Connor – Simulcast Solutions LLC / Fairport,
Fairport NY
Steve Dubberstein – Communications Service / Portage, WI
• FCC requires 12.5 kHz channels by 1/1/2013
Your Towers Aren’t Able
to Reach Everyone
• Some long
g standingg “holes” still need to be
filled
• Consolidation has resulted in a larger
geography
g
g p y than the p
past
This Afternoon’s Workshop
p Topics
p
•
Simulcast Parameters & Narrowband “Coverage”
• System Providers & Available Products
• System Recap – Steve Dubberstein
• Open Discussion of Participant Systems
Simulcast
• Contraction of simultaneous broadcast
• Broadcast the same modulation on the
q
y from multiple
p transmitters
same frequency
at the same time
25kHz Simulcast Technical
Challenges for Intelligible Overlap
((+// 10dB)
• Carrier Accuracy
+// 0.1Hz @800/450/150MHz
• Audio and CTCSS Alignment
+/- 30 degrees (= +/- 70usec)
• Modulation
M d l ti Adjustment
Adj t
t – Recovered
R
dA
Audio
di
+/- 0.2dB
12.5kHz Simulcast Technical
Challenges for Intelligible Overlap
• Carrier Accuracy – same as 25kHz
• Audio and CTCSS Alignment – “more critical” than 25kHz
• Modulation Adjustment – Recovered Audio – “more critical”
Capture effect less pronounced (approx +/- 15 to 20dB)
Narrow IF filters do not handle impulse noise as well
Signal to noise ratio may adversely affect audio recovery
Additional Considerations
12.5kHz Simulcast
• Make sure 12.5 mobiles and portables selected do not have reduced hum,
distortion or performance specifications
• Older test equipment may not have good resolution for narrowband
deviation measurements (it is not as easy to measure 2.5 kHz deviation
on scales of 2, 6, 20, or 40kHz)
• Narrowband area coverage of analog transmissions decrease due to
reduced audio quality and signal-to-noise ratio are approximately
equivalent to a 3 dB decreased power level. Range is reduced because it
t k a hi
takes
higher
h signal
i
l level
l l to
t provide
id the
th same voice
i quality.
lit Th
The actual
t l
received RF signal levels stay the same.
Radio Manufacturers who Provide
Turn-key Conventional Simulcast
• Conventional Analog Simulcast
•Harris PSPC
•Motorola Solutions
•Tait Radio Communications
Simulcast Systems
Installed by Radio Dealers or
g
g End Users
Self-Integrating
• Require specialized equipment
• GPS Master Oscillators
• Audio Delay
•Voters
• Simulcast Capable Base Stations
Voting
g
Talk-In
Voter Comparator
• A shelf handles up to 12 remote receivers
• Idle tones of 2175Hz
2175Hz, 1950Hz or E&M
• Transmitter keying E&M (or EIA tones)
• Model SNV-12 from Raytheon
Frequency
q
y Control
Talk-Out
Master Oscillators
• GPS / OCXO Master Oscillator
• Precisely match carrier frequency
• Synchronize outgoing CTCSS (=PL = CG)
• GPS / Rb available for longer holdover
• SecureSync
S
S
ffrom S
Spectracom
t
Audio Delay
y
• rf linked
Manual
p
digital
g
uwave ((not GE-MDS 900S))
• hub and spoke
Manual
• loop digital uwave
M (2 values)
Dynamic
• Telco T1
Dynamic
•G
GE-MDS
S 900S-FT1
S
Dynamic
y
• SONET
Dynamic
• IP (VLAN, not public internet)
Dynamic
• Telco 4-wire (not recommended)
• Analog uwave
Man or Dyn
(NO)
Manual Audio Delay
y
Talk-Out
Audio Delay - Manual
Audio Delay – Dynamic
• Remote Delay Line
• For paging and rf linked two way systems
• Local RS232 control
• DTMF remote control
• Individually addressable on common channel
• Model VDL-RS from Convex
Dynamic
y
Audio Delay
y
Talk-Out
Audio Delay - Manual
Audio Delay – Dynamic
•
•
•
•
For single VF channels (no VoIP channels)
Cost-efficient for a few channels
Control Timing Unit is installed at Main Site
Requires a GPS Master Oscillator at all sites
• Automatic Delay Line (ADL) from Convex
Dynamic
y
Audio Delay
y
Talk-Out
Audio Delay - Manual
Audio Delay – Dynamic
•
•
•
•
For IP, T1 microwave, telco T1, or SONET
Very cost-effective for multiple channels
Special “simulcast” control cards in muxes
Requires a GPS Master Oscillator at all sites
• SynchroCast3 from Harris Broadcast
Audio Booster Limiter
Talk-Out
Audio Shaping
• Amplifies low volume, does not overdrive channel
• Does not boost noise floor
• Designed for LMR, strips out 2175 and 1950 before
DSP and then reinserts tones after DSP
• Voice Optimizer Model NBL-4
Downloadable from
www.simulcastsolutions.com
Project Recaps from annual Simulcast Forums
Technical Details
Manuals / Data Sheets
Bid Specification Templates
Application Notes
Budgetary Pricing
www.rfstore.com
Project Recaps
Trempealeau County and Columbia County
Wisconsin
Steve Dubberstein
President, Communications Service Inc.
305 East
E t Albert
Alb t Street
St t
Portage WI 53901
608-745-3300
3470 Losey
L
Boulevard
B l
d South
S th
La Crosse WI 54601
608-788-8980
2011 S Stoughton
St ht R
Road
d
Madison WI 53716
608-241-7700
Communications Service
Trempealeau
County
La Crosse
Portage
Columbia County
Madison
Suppliers
pp
•
Motorola Quantar Transceivers
•
Harris T1 Intraplex SynchroCast III and VF-40 Module
•
Aviat TRuepoint and Eclipse 6 & 11 GHz Licensed Microwave
•
GE MDS LEDR 950 MHz Licensed Microwave
•
Raytheon SNV-12 Voters
•
Spectracom GPS Master Oscillators
•
TXRX Filtering
•
RFS Antennas and Cables
•
Convex 2240A-2C with PL/CTCSS Generation
•
NBL4 Narrowband Booster Limiter
T
Trempealeau
l
County
C
t
Trempealeau County
7 Site System
4 Channels
Voted/Simulcast
7 Sites
Strum
Osseo
Whitehall
Arcadia
Blair
Ettrick
Galesville
Trempealeau County
System
Forward Link (talk-out)
Color
C
l
Grey
Dark Green
Light Green
Yellow
Red
Performance
P
f
Pager Coverage with 8 dB building loss
Portable at Hip Coverage
Mobile Coverage
Marginal Mobile Coverage
No coverage
Trempealeau County
System
Reverse Link (talk-in)
Color
Dark Green
Light Green
Yellow
Red
Performance
Portable at Hip Coverage
Mobile Coverage
Marginal Mobile Coverage
No coverage
Trempealeau County
System
Simulcast Time Delay
Before Offset Delay Optimization
• No Time Delay Offset
• Radiosoft ComStudy 2.2
• Reference Simulcast Forum XII
“Simulcast
Simulcast Optimization Techniques”
Techniques
Trempealeau County
System
Simulcast Time Delay
After Offset Delay Optimization
• Time Delay Offset -10 usec to +20 usec
• Radiosoft ComStudy 2.2
• Reference Simulcast Forum XII
“Simulcast
Simulcast Optimization Techniques”
Techniques
Trempealeau County System
Columbia County
Columbia County 9 Site System
5 Channels
Voted/Simulcast
9 Sites
Caledonia
Cambria
Rio
Columbus
Arlington
Lodi
Baraboo Bluff
Portage
Wisconsin Dells
Columbia County
y System
y
Forward Link (talk-out)
Signal Strength
> -76 dBm
> -92 dBm
> -105 dBm
> -116 dBm
Below –116
116 dBm
Color
Grey
Dark Green
Light Green
Yellow
Red
Performance
Pager Coverage with 8 dB building loss
Portable at Hip Coverage
Mobile Coverage
Marginal Mobile Coverage
No coverage
Columbia County
y System
y
Reverse Link (talk-in)
Signal Strength
> -92 dBm
> -105 dBm
> -116 dBm
Below –116 dBm
Color
Dark Green
Light Green
Yellow
Red
Performance
Portable at Hip Coverage
Mobile Coverage
Marginal Mobile Coverage
No coverage
Columbia County System
Simulcast Time Delay
Before Offset Delay
Optimization
• No Time Delay Offset
• Radiosoft ComStudy 2.2
• Reference Simulcast Forum XII
“Simulcast Optimization Techniques”
Columbia County System
Simulcast Time Delay
After Offset Delay
Optimization
• Time Offset 0 to +40 usec
• Radiosoft ComStudy 2.2
• Reference Simulcast Forum XII
“Simulcast Optimization Techniques”
Block Diagram
g
Summary – Simulcast by Communications Service
• Minimize the Variables
Non-Variable Reliable Backhaul (T1 Microwave)
Keep Identical Audio Response
Eliminate Time Delay Changes
Advantages over Self-Adjusting Systems
• Simplified Design and Optimization
Convex 2240A-2C with PL Generation
Harris VF-40 Cards
• Replacement
R l
off Motorola
M
l Quantar
Q
with
i h GTR8000
Same Analog Simulcast Baseband Input and Control as the Quantar
Cannot Mix Quantar and GTR8000 on the Same Channel
•
Si l t Narrowbanding
Simulcast
N
b di Experience
E
i
in
i 2011/2012
Smooth Cutovers. Coverage Loss in Very Low Signal Strength Areas
Other conversion experiences
p
Experience of workshop participants
Discussion about your
y
systems and challenges ….
If We Can Help
p Solve Some of
Your Comm Problems ….
For information on simulcast hardware visit
www.simulcastsolutions.com,
i l t l ti
call 585.223.4927 or email
ed@simulcastsolutions.com