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Bridging the Gap Between Operations and Technology.®

An Implementation Guide for Technicians

Narrowbanding

Updated with the latest FCC rules as of June 2010

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ADCOMM Engineering Co. ©2010 www.adcommeng.com

Bridging the Gap Between Operations and Technology.®

FCC Schedule

This process started in the mid 1990s. Covers VHF Hi h-band (150-160 MHz) and UHF (450-470 MHz) C HighHigh b d (150MH ) d (450MH ) Previous FCC ruling was in 2003 with the following dates:

­ January 1, 2011 ­ January 1, 2013

No new licenses for wideband channels unless part of an existing system system. No new wideband capable equipment imported or manufactured. All systems converted to narrowband operation.

Latest FCC ruling June, 2010, relaxed the equipment availability June 2010 date to January 1, 2013. Wideband equipment can continue to be manufactured and imported until then. No other requirements have been relaxed. E Exceptions ti

­ Paging only channels such as 152.0075 MHz are excluded. ­ Non-Part 90 channels, Marine Channels, Part 22 channels Non-

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Bridging the Gap Between Operations and Technology.®

Implementation Schedule

No N more new wideband system id b d t licenses or modifications

You are here!

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ADCOMM Engineering Co. ©2010 www.adcommeng.com

Bridging the Gap Between Operations and Technology.®

What's the big deal? What s

A big deal or not? Big Deal

­ E i ti equipment not narrowband capable Existing i t t b d bl ­ Areas where coverage is not adequate

No Big Deal

­ Existing equipment narrowband capable ­ Coverage good to excellent in all areas

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Bridging the Gap Between Operations and Technology.®

Narrowband Channel Plan

VHF Channel Plan C a e a

­ 7.5 kHz channel spacing ­ 11.25 kHz occupied bandwidth ­ It doesn't all fit

UHF Channel Plan

­ 12 5 kHz channel spacing 12.5 ­ 11.25 kHz occupied bandwidth ­ It all fits

What about 6.25 kHz?

­ Allowed now but no mandatory date set

ADCOMM Engineering Co. ©2010 www.adcommeng.com

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Bridging the Gap Between Operations and Technology.®

Current Situation

20kHz Bandwidth 20kHz Bandwidth

20K0F3E

20kHz Bandwidth

20K0F3E 20K0F3E

Overlap Overlap

Adjacent channels

15kHz Channel Spacing 15kHz Channel Spacing

155.745

155.760

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155.775

ADCOMM Engineering Co. ©2010 www.adcommeng.com

Bridging the Gap Between Operations and Technology.®

Interim Period nter m er od

20kHz Bandwidth 20kHz Bandwidth

20K0F3E

20kHz Bandwidth

20K0F3E 20K0F3E

Overlap

11.25kHz Bandwidth 11K0F3E

11.25kHz Bandwidth 11K0F3E

Overlap

155.745

155.7525

155.760

7

7.5kHz Channel Spacing S i

155.7675

155.775

ADCOMM Engineering Co. ©2010 www.adcommeng.com

Bridging the Gap Between Operations and Technology.®

After 2013 ­ Analog Modulation

11.25kHz Bandwidth 11K0F3E

11.25kHz Bandwidth 11K0F3E

11.25kHz Bandwidth 11K0F3E

11.25kHz Bandwidth 11K0F3E

11.25kHz Bandwidth 11K0F3E

7.5KHz Channel Spacing p g

155.745

155.7525

155.760

8

155.7675

155.775

ADCOMM Engineering Co. ©2010 www.adcommeng.com

Bridging the Gap Between Operations and Technology.®

After 2013 ­ Narrowband Digital

8.1 kHz Bandwidth 8K1F1D P25 C4FM

8.1 kHz Bandwidth 8K1F1D P25 C4FM

8.1 kHz Bandwidth 8K1F1D P25 C4FM

8.1 kHz Bandwidth 8K1F1D P25 C4FM

8.1 kHz Bandwidth 8K1F1D P25 C4FM

Slight Overlap

11.25kHz Bandwidth 11K0F3E

7.5KHz Channel Spacing p g

155.745

155.7525

155.760

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155.7675

155.775

ADCOMM Engineering Co. ©2010 www.adcommeng.com

Bridging the Gap Between Operations and Technology.®

Equipment Compatibility

Changing to narrowband equipment using existing channels should be ok. Not all equipment can use the new narrowband channels.

­ Diff Different models of equipment h t d l f i t have diff different t frequency steps (e.g., 15 kHz, 7.5 kHz, 5 kHz, 2.5 kHz) 25 ­ Only radios with 2.5 kHz steps or .5 kHz steps will work on all narrowband channels

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ADCOMM Engineering Co. ©2010 www.adcommeng.com

Bridging the Gap Between Operations and Technology.®

Equipment Compatibility

Transmitters

­ 2.5 kHz deviation ­ Improved frequency control ­ FCC Requires

VHF

­ Mobile 5.0 ppm (750 Hz worst case) ­ Base 2.5 ppm (325 Hz worst case) pp ( ) ­ Mobile 2.5 ppm (1175 Hz worst case) ­ Base 1.5 ppm (705 Hz worst case)

UHF

­ R di likely not work well at maximum frequency Radios lik l t k ll t i f error. Purchase radios with better tolerances than the FCC requires.

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ADCOMM Engineering Co. ©2010 www.adcommeng.com

Bridging the Gap Between Operations and Technology.®

Equipment Compatibility

Receivers

­ Adjacent channel protection may not be as g good as before.

Brand Brand Brand Brand A ­ 30 kHz 78 dB B ­ 30 kHz 70 dB C ­ 30 kHz 80 dB D ­ 30 kHz 80 dB 12.5 12.5 12.5 12 5 12.5 kHz kHz kHz kHz 67 60 63 80 dB dB dB dB

­ Be careful when checking out specifications ­ Hum and noise generally not as good as with wideband

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ADCOMM Engineering Co. ©2010 www.adcommeng.com

Bridging the Gap Between Operations and Technology.®

Equipment Compatibility

Receivers

­ Sensitivity may be better, worse, or the same depending on the receiver design. ­ Other noise effects such as ignition, fast fading, etc. can be magnified in narrowband receivers.

Companding C di

­ Some vendors have an audio companding option. These are generally vendor proprietary and should not be used in public safety for interoperability.

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ADCOMM Engineering Co. ©2010 www.adcommeng.com

Bridging the Gap Between Operations and Technology.®

Coverage

Radio coverage will change. change

­ Generally reduced for analog systems ­ May remain consistent if converting to digital ­ Users may not notice the coverage reduction if coverage is good or primarily terrain limited ­ Best "guess" is coverage reduced by 6 dB ­ Due to wide variation in user equipment coverage may change more for some users

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ADCOMM Engineering Co. ©2010 www.adcommeng.com

Bridging the Gap Between Operations and Technology.®

Coverage

Why does coverage change?

­ Transmitter power is the same

RF levels at any given location are not affected by the transmitted deviation

­ Some receive sensitivities may be increased y

Narrower IF filters means less noise Less noise = better signal-to-noise ratio signal-to-

­ Seems like coverage should get better!

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ADCOMM Engineering Co. ©2010 www.adcommeng.com

Bridging the Gap Between Operations and Technology.®

Coverage

Coverage changes because the modulation changes

­ Deviation is the key for FM

Commercial FM ­ 75 kHz Old 2-way FM (1950s) ­ 15 kHz 2Existing FM ­ 5 kHz Narrowband ­ 2.5 kHz

­ As the deviation gets less

Quieting gets less (ability to overcome noise) Capture effect gets less Audio recovery more difficult

ADCOMM Engineering Co. ©2010 www.adcommeng.com

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Bridging the Gap Between Operations and Technology.®

Coverage

Coverage should be measured using audio quality not signal strength Reduced range based on Circuit Merit 3.03.03.4 as the desired audio recovery It is all based on Modulation Index

­ Modulation Index ( = Dev/Max Audio) ( ­ Commercial FM = 5 ­ 5 kHz deviation = 1.67 ­ 2.5 kHz deviation = .69

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Bridging the Gap Between Operations and Technology.®

Coverage

Coverage terrain limited

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ADCOMM Engineering Co. ©2010 www.adcommeng.com

Bridging the Gap Between Operations and Technology.®

Coverage

Coverage signal strength limited

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ADCOMM Engineering Co. ©2010 www.adcommeng.com

Bridging the Gap Between Operations and Technology.®

Coverage

Additional Examples

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Bridging the Gap Between Operations and Technology.®

Implementation

System adjustments

­ More critical, frequency, deviation, etc. ­ Service Monitors may not have right scale for 2.5 kHz y g deviation ­ CTCSS deviation 300 Hz or so

Consider using some type of audio processing for repeat audio and transmitted audio to make audio more consistent. (See ADCOMM consistent presentation from last year on audio processing.)

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Bridging the Gap Between Operations and Technology.®

Implementation

Coordination with neighbors and other users.

­ Wide/narrowband equipment will not work / q p effectively together. ­ When will your neighbors change? ­ What about wide area mutual aid channels such as LERN, Rednet, HEAR, WHEER? ­ Oth users such as public works, etc. Other h bli k t ­ How will you program your radio? Dual sets of channels for wide and narrowband?

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ADCOMM Engineering Co. ©2010 www.adcommeng.com

Bridging the Gap Between Operations and Technology.®

Implementation

Evaluate your syste a d use equ p e t a uate you system and user equipment. Evaluate your coverage and estimated new coverage. Determine if new sites are required. If so, start site location and development. Coordinate ith i hb C di t with neighbors to develop t d l coordinated transition plan. Work with users to determine when they can upgrade their equipment. Costs could be significant.

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ADCOMM Engineering Co. ©2010 www.adcommeng.com

Bridging the Gap Between Operations and Technology.®

Implementation

Develop a coordinated transition plan. p p Procure equipment. Carefully compare vendor specifications. Consider if initial installation will be in wideband mode or if slash cut will be required. Develop schedule for user equipment replacement. Resources for subscriber unit installations may be limited R f b ib it i t ll ti b li it d due to rebanding and volume of work required. Pick a cut over date and develop final cut over plan. p p Now you are talking narrowband.

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Bridging the Gap Between Operations and Technology.®

Considering Digital?

Going digital may mitigate some coverage issues. Going digital is a major decision with many ramifications including

­ Cost ­ Maintenance p y ­ Interoperability ­ Functionality

Subject for another presentation! j p

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ADCOMM Engineering Co. ©2010 www.adcommeng.com

Bridging the Gap Between Operations and Technology.®

Questions?

Thank you!

Joe Blaschka Jr. PE [email protected] j [email protected] com 425-821425-821-8827 www.adcommeng.com

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ADCOMM Engineering Co. ©2010 www.adcommeng.com

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