In-Building Radio Communications For First Responders 2007 WESTERN REGIONAL CONFERNCE Long Beach, CA Applications, Codes, Technology, and Implementation Presented by: Jack Daniel Jack Daniel Company
Reliable In-Building Communications For First Responders is NOT a LUXURY
Reliable In-Building Communications For First Responders is a NECESSITY!
Reasons Why In-Building Coverage is Important: Every Reason You Have an Outdoor Radio System Applies Equally to In-Building Communications Coverage as well.
Including Provisions for system-wide in-building coverage is becoming common in new system designs But most of us have to work with existing systems that: - Did not anticipate this requirement. - A practical solution wasn't available when designed. - The coverage requirement has changed; - New Buildings, Malls, Airports have been built. - Geo-political boundaries have expanded. - Higher Levels of Enforcement (Homeland Security) - Have to overcome growing Interference levels.
Public Safety Grade In-Building Solutions are Not inexpensive. (Consumer Grade products are cheaper IF you ignore Dependability and Availability) Adding in-building coverage to Public owned structures is funded by: - Conventional tax based funding. - Community Development grants. - Special District assessments. - Homeland Security Grants.
Using Codes and Ordinances to Provide In- Building Wireless Communications For Public Safety Agencies within Privately Owed Structures.
Example Jurisdictions with Signal Booster Codes - City of Burbank CA - City of Folsom CA - City of Roseville CA - City of Ontario ca- City of Scottsdale AZ - City of Tempe AZ - City of Ft. Lauderdale FL - Grapevine TX - Hampshire (Illinois) FPD - City of Sparks NV - City of Broomfield CO - City of Boston MA - City of West Hartford CT - Clark County NV - City/County of Sacramento - City of Riverside CA Orange County CA - Arlington County VA - Montgomery County MD - Edgewater FL - Kirkland WA - Muskego WI - Sarpy County NE - Schaumberg IL
In-Building Coverage Code Milestones Burbank: Oldest known Ordinance, 1991 Dr. Henry Richter, consultant. Folsom: Adds performance measurement methods and periodic tests. Orange County CA: Adds designer/installer qualifications, certifications and pre-approvals
CODE AND ORDINANCE RESOURCES Example codes, white papers and other related material: www.rfsolutions.com
IN - BUILDING COVERAGE TECHNOLOGY AND IMPLEMENTATION
NOTES ON TERMINOLOGY USED: - The FCC Rules identify special in-building amplifiers as Signal Boosters. Within the wireless industry, a signal booster may also be called a Bi-Directional Amplifier or BDA. They are the same device. - Some rf distribution designs may use radiating coaxial cables which are also called leaky coax. - A system that includes multiple inside antennas is called Distributed Antenna System or DAS.
All Emergency Equipment is NOT Equal
All Signal Boosters Are NOT Equal. Cheap Signal Boosters designed for Consumer and Cellular Applications Can and Will Let you Down at the time You Need Them Most!
Common Public Safety Rated Signal Booster Features: - Non-vented housings; NEMA 12, 4, 4X - 4 to 12 hour Battery Back-up Compatibility - Fail-safe redundancy and design. - Remote Failure Alarming. - Historical Performance Data. - Non-Disruptive Testing while in Service. - Factory Certified Training School. - Retuning and Band expansion compatibility. - Radio technology compatibility; i.e. Delay
Class A Versus Class B Signal Boosters Definitions: Class B (band selective) pass a window of multiple channels. Sometimes called broadband. Class A (channel selective) pass single channels. Sometimes called channelized.
Channel selective signal boosters initially appear To be the best choice but in reality they are not. The biggest problem with Class A signal boosters is propagation delay. Class B s have extremely low propagation delay and group delay distortion. This delay increases when channel bandwidth is reduced. At 25 or 12.5 KHz channel selectivity, the delay is incompatible with many system designs. Increasing the channel width to improve the delay makes these Class B signal boosters
Class A signal boosters will work with small analog systems with a few channels but are subject to obsolescence when the system is updated or expanded. Concerns: - Very high delays - Number of channels, growth, interoperability - High power output impacts feedback isolation - Technology still being developed, not mature. Since 99% of all successful deployments of public safety in-building installations are Class B, this presentation will focus on that Type.
THE COVERAGE PROBLEM GOOD COVERAGE POOR COVERAGE
THE STANDARD SOLUTION DONOR SITE
COMMON SYSTEM DESIGN COMPONENTS ROOF ANTENNA SIGNAL BOOSTER COAX CABLES POWER SPLITTERS ANTENNA TAPS ANTENNAS
SYSTEM DESIGN: BEST PRACTICES: Minimum Signal Level to Portable : - 95 dbm or greater Minimum Coverage: 95% overall, 100% in critical areas such as fire control centers. Must Cover areas: Fire Prevention and suppression Facilities. Underground areas Such as parking and basements. Emergency exit routes, especially stairwells in high rise structures. (forget the elevators)
SYSTEM DESIGN: BEST PRACTICES: Use Directional Roof Antennas to reduce interference, Even when close to the repeater site. ALWAYS USE THE MINIMUM GAIN AND LOWEST POWER LEVELS NECESSARY TO MAINTAIN RELIABLE COVERAGE.
NUMBER ONE CAUSE OF DESTRUCTIVE INTERFERENCE TO RADIO SYSTEMS FROM IN-BUILDING SYSTEMS: OSCILLATIONS CAUSED BY FEEDBACK. NUMBER ONE IN-BUILDING SYSTEM DESIGN AND INSTALLTION ERROR: INSUFFICENT ANTENNA-TO-ANTENNA ISOLATION TO PREVENT OSCILLATIONS CAUSED BY FEEDBACK.
FEEDBACK MECHANISM: AUDIO SYSTEMS:
FEEDBACK MECHANISM: IN-BUILDING DONOR SITE
FEEDBACK PREVENTION: BEST PRACTICES. ANTENNA ISOLATION TESTING: SPECTRUM ANALYZER WITH TRACKING GENERATOR ROOF ANTENNA SPECTRUM ANALYZER INDOOR ANTENNA
FEEDBACK PREVENTION : BEST PRACTICES The MINIMUM Roof Antenna to any inside antenna isolation must be at least 15 db greater than the highest operating gain setting of the signal booster: Example: Signal Booster gain = + 70 db + 15 db Minimum Antenna Isolation read on spectrum analyzer should be > 85 db
FEEDBACK PREVENTION SOLUTIONS : Properly Designed and installed system. Follow proven 'Best Practices" Follow manufacturers instructions Use factory certified integrators
Feedback Statistics : 2 year survey results Feedback has been attributed to less than 0.1% in ALL installed systems. 97% of feedbacks caused by untrained installers. ~3 % caused by poorly designed BDA Conclusion: ANY Feedback Interference is TOO MUCH!
INTERFERENCE FROM OTHER SITES
OVER THE AIR INTERFERENCE IMPACT ON YOU: If system is designed properly, external interference is not a problem in all but a few extreme situations. Directional Roof antenna and placement can dramatically reduce interference. Public Safety grade Signal Boosters use high performance filter designs with pass bandwidths that match your radio system. Signal boosters that amplify public safety and cellular at the same time are problematic.
The impact of undesirable signals On Class B (band selective) is often exaggerated. Assuming multiple signal levels of the same level, here is the relative impact on your output levels if you have a 10 channel trunked system: Your 10 channels. Output per channel: + 23 dbm Add 10 unwanted channels: +20 dbm per channel Add 30 unwanted channels: + 17 dbm per channel These are example levels but the impact is the same relationship for any Class B signal booster. The desired signals are reduced 3 db for each doubling of total channels.
BEST PRACTICES - Use filters optimized for your system bandwidth. - Use filters with at least 35 db rejection of adjacent bands. i.e. +/- 1 MHz. - Use directional antennas to reduce signal levels from other directions and increase desired levels. - Use the structure to add blockage from unwanted directions. Tip: The key aspect of controlling the impact of other signals is to obtain high level differential. Undesired channels that are -20 db or more less than yours has minimal impact on Signal booster performance.
INTERFERENCE BEST PRACTICES FROM OTHER SITES
INTERFERENCE TO OTHERS
INTERFERENCE IMPACT ON OTHERS: If system is designed properly, external interference is a non-problem in all but a few extreme situations. Nearby receiver desense biggest potential problem > 500 ft separation eliminates almost all problems. Multi-BDA composite power can only impact nearby sites normally, using minimum gain and low NF. FCC RULE: ALL In-building is 'secondary' and cannot cause OBJECTIONABLE interference.
BEST PRACTICES
DIRECTIONAL ANTENNA CHARACTERISTICS AND TERMINOLOGY
BEST PRACTICES Directional Antenna Use
BEST PRACTICES: IN-BUILDING SYSTEMS - Use minimum reliable gain settings. - Use Directional antenna on roof. - Don t place inside antennas near windows or doors. - Do not use excessive bandwidth, such as public safety + cellular in one signal booster. -Select signal boosters with overall low Noise Figures. ALWAYS HAVE GAIN + 15 db MINIMUM ANTENNA TO ANTENNA FEEDBACK PROTECTION. NEVER USE AGC CIRCUIT OPEARION AS A SUBSITUTE FOR GOOD SYSTEM DESIGN PRACTICE.
COMMENTS ON FCC CLASS B SIGNAL BOOSTERS With an installed base of over 100,000 Class B signal boosters over 15 years, it is obvious they are viable solutions for most in-building requirements. Class B is the most financially practical solution. Class B signal boosters do not change modulation characteristics, regardless of technology. These devices are available with unlimited bandwidth choices, multiple windows, multiple bands and public safety rated models will accommodate future band changes (retuning) and additions (700)
Fill-In Coverage
BEST PRACTICES Fill-In Coverage Optimization
Fill-In Coverage
BEST PRACTICES : FILL-IN COVERAGE - Use minimum gain. - Use Directional antennas for better vertical antenna-to-antenna isolation. -Control service area antenna pattern to reduce out of area signals. -When using Class A (channelized) signal boosters, propagation delay differential in coverage overlap zones can be excessive. Differential delays over 30 us can be problematic. Delay is not a problem when using Class B signal boosters. -Watch total propagation delay in systems with critical turn-around handshakes, such as TDM based systems.
SHARED SYSTEMS a.k.a Neutral Host Systems
Large privately owned buildings may have an elaborate cellular, PCS and WiFi distribution system. These system are designed to make a profit for the system owners based on the air time used by The public (consumers) within the building. There is nothing wrong with this type of system HOWEVER, there can be problems when you try to add public safety coverage to these systems.
Comparison of Priorities: Profit Driven Basic Rule: Use the minimum amount of equipment investment and cover the least amount of area that will provide The maximum income per investment dollar. This means NOT having back-up power or covering areas where there is little routine public travel. After hours maintenance is not required or offered. Tomorrow is considered good repair service for Consumers. System can be altered to make more profit.
Comparison of Priorities: Public Safety Basic Rule: Providing life critical coverage is more Important than costs. Coverage is needed where first responders and citizens go during any emergency. Reliability and survivability requires power back-up, Redundancy, and public safety grade equipment. Serviceability includes 27/7 access to the system. the ability to alter the system in an emergency and pre-incident fault monitoring.
Shared System Technical Incompatibility. The way cellular systems operate is much different than public safety radio systems. Cellular has relatively low power handsets and Some drop-outs are accepted. Public safety handsets are much more powerful and can overload a system designed for cellular. Overloading can generate interference (IM), Distortion and loss of data.
Technical Incompatibilities. The frequencies used can interact. For example, the high end of NPSPAC channels are immediately adjacent to Cellular A band and parallel signal boosters will disrupt both systems. Filters in cellular signal boosters are lower performance than those used in public safety rated signal boosters. (That s one reason cellular boosters are cheaper) Combinations of the two bands can generate destructive intermodulation.
Operational Incompatibilities: Public Safety users on shared systems should: - Be aware of system accessibility. A Shared system may require coordination and approval of multiple carriers, building owners, etc. Immediate access can be crucial during an emergency. - System coverage maintenance. Cellular engineers may change coverage to meet their needs without notification or agreement with the public safety agencies, losing critical public safety coverage. - In an extreme situation, the public safety must be able to shut down the other users to improve coverage or reduce interference.
INTRODUCTION TO RF-OVER-FIBER (Fiber Optic) RF DISTRIBUTION TECHNOLOGY
BASIC FIBER INSTALLATION RF to FO Signal Booster Roof Antenna FO Cables FO to RF Coax Cables
INTERFERENCE FROM YOU WHY USE RF-OVER-FIBER: 1. Lower installation costs compared to coax. Materials Routing Haz Mat avoidance 2. Lower RF loss than coaxial cable: Increases the area of coverage per BDA Can feed distant buildings 3. Very Broadband: Can be RF channel frequency insensitive. Expansions easily accommodated.
RF-OVER-FIBER LIMITATIONS Propagation Delay over long distances can restrict or even stop operation when used in newer digital systems. Because of low propagation delay needs, some manufacturers will not sell fiber for use with over-the-air systems. Delay can also cause 'dead spots' in simulcast systems where multipath occurs. Fiber distribution has much higher noise output. Special design considerations are required. Fiber RF power levels are low and must be amplified.
INTERFERENCE FROM YOU RF-OVER-FIBER LIMITATIONS An in-building fiber based BDA- DAS system does NOT : - Solve the feedback concerns. - Solve Interference issues. And it may not be the most cost effective solution for general applications.
RF-OVER-FIBER APPLICATION EXAMPLE 200 acre site 8,500 ft SM fiber 15,000 ft coax 3 BDA Head-ends 24 Fiber remotes 96 DAS antenna capacity
LA County Sanitation : BDA - FO Head-End ANTENNA Donor Antenna low to minimize unwanted interference. BDA and FO equipment co-located. No coax feeders into underground. FIBER OPTICS SIGNAL BOOSTER
J Paul Getty : DTD Campus Example Direct to Donor DONOR SITE No outside Interference No Blockage No Feedback
J Paul Getty : DTD Campus Example
Los Angeles HOA: Remote BDA Example Resolves Interference Feedback & Blockage
Anheiser Busch : RF - FIBER DTD DAS 3 Nextel BTS 28 Fiber Links 131 F0-DAS Antennas ~ 4 city blocks
Wynn's Las Vegas: DTD DAS Example 96 DAS Antennas 900 MHz two-way & paging First of two towers
Disney Music Center LA: UHF FIBER Example
FINAL CONCLUSIONS: 1. There is NO single in-building technology that solves requirements. However most applications can be served economically and reliably with good quality Class B signal boosters. 2. Every system should be designed and installed by persons specifically trained for in-building systems. 3. 800 MHz rebanding will resolve most interference possibilities. Public safety coordination facilitates the use of Class B signal boosters 4. Potentially, FCC rule changes can reduce bad equipment and practices.
Thank You Jack Daniel 1-800-NON-TOLL (800-666-8655) www.rfsolutions.com
Presenter Credentials > 15 + years In-building experience > Worked on first in-building code > 50 years public safety and LMR > Over 500 system system involvement > Trainer for Motorola, local agencies > Participated in TIA BDA standards > Participating in NPSTC BDA standards > Implemented first non-cellular fibers > Extensive experience in ALL BDA technologies.
Presenter Affiliations: > APCO Life member > Fellow in Radio Club of America > Member of IACP > Member of NPFA > Author: APCO, NPSTC, MRT, etc. > Presenter: APCO, IWCE, IBC, etc. > FCC petitioner for BDA rule changes.