Public Safety DAS and PIM

Agenda Introduction The Team Approach Passive Intermodulation (PIM)

What is PIM? What causes PIM? What PIM looks like

Public Safety DAS and PIM New FCC Regulations on Part 90 Signal Boosters/Repeaters/BDA Current Public Safety DAS RF Environment New Public Safety DAS Standards Recommendations Conclusion

History

• Established in 1990• Presence throughout US• Services Include:

• Wireless turnkey design and deployment services• In-Building• ODAS• Public Safety• WIFI

• Voice and Data Cabling• Call Center/Help Desk support• Maintenance and Monitoring Services• National rollouts• General Contracting

• Over 300 Techs, Field Managers, and RF design engineers

• Vendor-certified professionals for customer satisfaction

• CTS continues to attract the best and brightest of the in-building wireless industry

• We utilize state-of-the-art tools from Anritsu, JDSU, TEMS, AirMagnet, Ekahau, IBwave, Exceed, ATOL, and others.

CTS offers you the depth and scalability of the largest services organizations with the Quality, Speed, Agility, Customer Appreciation, Customer Service and Price Performance (value) of a small company. It is what separates us from our competition.

CTS Overview Our People

Over 5000 Wireless Systems and CountingEnterprise Venues• Nestle Corporate HQ • EBay HQ• Raytheon• Kia Motors• Qualcomm • Hewlett Packard • Wells Fargo

Hospitals and Universities• Kaiser Hospitals • Loyola University• Clemson University • University of North Carolina • Cedars Sinai Hospital • UCI Medical Center • University of Colorado Hospital

Government Facilities• USPS • Camp Pendleton • Palms Naval Hospital • IRS • State of CA RC

Entertainment•Largest Amusement Parks•Dolphin Stadium•Stanford Stadium •Minute Maid Stadium•Petco Park•NASCAR Tracks •Staples Center/LA Live

Hospitality•Westin Hotels•Marriott Hotels•Marriott Marquis•Millennium Condo San Francisco•Kodak Theatre •Disney Aulani Hotel

Rollouts•Over 150 Radio Shack Stores •100+ Wal-Mart locations•500 McDonald’s restaurants •1000 BDA swap rollout •300 location DAS audit•250 Truckstops

CTS services all types of venues for our clients

Engineering

Teamwork

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ltsProfessionals

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ning

Project Mgmt

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t

Partner

Perf

orm

anc

e

Cost-effective

Accountable

Construction

Industry Veterans

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ects

Carrier R

elationships

• 21 years of Structured cabling experience – We know buildings!• Over 20 RF engineers on staff• We have earned the trust of the nation’s largest wireless carrier and enterprise customers• General contractors on staff to handle the complexities of large scale builds.• Our national presence allows for consistency and large scaling capabilities. • Our experience ensures you get what you need, not just what you asked for!• Uncompromised commitment to quality.

Excellence in the Three Pillars of Large-Scale Wireless Deployments

Our Current Locations Marlborough MA (HQ) Fort Lee NJ (services NYC and NJ) Washington, DC Raleigh, NC Greenville, SC New Orleans , LA Dallas TX, Houston, TX Chicago, ILL Columbus, OH

Las Vegas, NV Phoenix, AZ San Francisco, CA Los Angeles, CA Milwaukee, WI Portland, Oregon Denver, CO Miami, FL Atlanta, GA Orlando, FL

What is PIM?PIM or Passive Intermodulation occur when 2 or more transmitted frequencies (Downlink) combine together resulting in the sum and differences of those frequencies. This becomes an issue when it occurs within the receive band (Uplink) at a level high enough to interfere with the desired signals.

f1 f2

2f1- f2 2f2- f1

3f1- 2f2 3f2- 2f1

4f1- 3f2 4f2- 3f1

f2- f1 f2+ f1

Interference Interference

3rd 3rd 5th

5th

7th

7th

Example of 3rd Order Intermodulationf1 = 769MHzf2 = 860MHz

IM3 = 678MHz & 951MHz

• As signal amplitudes increase, the effect of nonlinearities becomes more pronounced, causing more prominent distortion.

• Third-order PIM — distortion closest to the intended signal — produces the highest level of interference, followed by fifth- and seventh-order.

• Third-order PIM will cause more severe system consequences than fifth or seventh.

• When multiple users with widely spaced Transmit frequencies share a common system, the probability of PIM in one or more Receive bands increases. • In other words, high-power (≥ 37dBm) multi-operator

Neutral Host DAS are particularly susceptible.

What is PIM?

What causes PIM?• PIM can be caused by any nonlinearity in the RF path.

• Possible sources include poor connections, damaged cable or water infiltration. • Weather-proof those donor antenna runs!

• In some cases, PIM can also be caused by objects outside the path, such as machinery, metal conduit/cable trays, or site equipment.• RF producing machinery, elevator equipment and certain

medical devices are known PIM generators.

• In fact, there are so many possible sources, PIM is sometimes known as “the rusty bolt effect.”• Indoor antennas with grounded backplanes, connectors

touching cable trays etc.

What causes PIM?

What PIM actually looks like.

PIM and Public Safety DAS• Majority of Public Safety DAS are passive.

• Public Safety DAS is cost driven, often designed and installed by the lowest bidder.• Only coverage requirements are tested for with minimal

load testing.• Accepted objective is DAQ (Delivered Audio Quality) of 3.4

or better. • DAQ 3.4 is defined as “understandable speech without

repetition. Some noise/distortion can be present.”

• The more passive components in a DAS – splitters, couplers, combiners, jumper cables and connectors, the higher probability of PIM.

• At every passive stage a large variety of detrimental PIM products are generated falling in the uplink (UL) bands.

PIM and Public Safety DAS• Due to the limited uplink (UL) transmit power of mobile

terminals, the Base Station uplink receive sensitivity is a critical parameter to optimize in outdoor scenarios to allow a balanced downlink/uplink maximum path-loss.

• PIM within a Public Safety DAS can cause Mobile Unit transmit failures directly affecting first responder safety. Remember Nextel?

• PIM from adjacent operator high-power DAS can be re-transmitted over Public Safety DAS to serving Base Stations affecting their uplink receive sensitivity.

New FCC Repeater Rules• Report and Order FCC 13-21.

• http://wireless.fcc.gov/signal-boosters/part-90 boosters/index.html

• Part 90 specifically refers to Public Safety Bi-Directional Amplifiers since March 1st, 2014.

• Requires owners/users to:• Obtain wireless service provider/operator consent to

operate the device, and• Register the device with their serving wireless service

provider prior to operation

• Within Part 90 are two classes:• Class A, designed to transmit and receive one or more

specific channels and each passband CANNOT exceed 75kHz.

• Class B, designed to transmit and receive wideband frequencies and each passband exceeds 75kHz. These BDAs must be registered directly with the FCC before use.

• Legacy Public Safety DAS still operate BDAs not approved under Part 90.

• Non-channelized, wideband repeaters will broadcast PIM in the Receive or Uplink signal back to serving Base Stations affecting their uplink receive sensitivity.

• Legacy Public Safety DAS will have significant PIM levels as passive components age.

Current PS DAS Environment

• Increasing number of new construction is being LEED certified – 325 buildings in Denver alone between 2012-2014. • http://www.usgbc.org/articles/usgbc-releases-top-10-states-leed-green-buildi

ng-capita-nation

• Low-E glass in LEED certified buildings is attenuating Public Safety signals in stairwells and fire command centers requiring more DAS be designed and installed.

• Imagine multiple Public Safety DAS installed in a major metro area generating some level of PIM overwhelming a high power donor site uplink receive sensitivity.

Current PS DAS Environment

New PS DAS Standards are needed• Public Safety DAS Site Audits are necessary to ensure all Bi-

directional Amplifiers comply with Part 90 and are Class A.

• Mandatory Part 90 compliant Class A, channelized repeaters with strong filtering to reduce 3rd Order PIM.

• Maximum composite output power of channelized repeaters to be 30dBm.• PIM increases along with channel power

• PIM rated components rated to at least -153 dBc specified• Connectors, Splitters, Hybrid Combiners, Jumpers and

Antennas.

New PS DAS Standards are needed

• Mandatory PIM testing to be part of system design and installation.

• Public Safety DAS design and testing parameters have to be widened to include PIM.• Reducing PIM will improve DAQ to 4.0 or better.• Acceptance testing should include mobile to mobile testing.

• Adjacent high-power operator DAS PIM tested.

Conclusion• Public Safety DAS is necessary and vital.

• Low cost installs can impact system performance due to lack of attention to PIM.

• Adjacent high power operator DAS can also directly impact Public Safety DAS performance.

• As more and more Public Safety DAS is needed, donor signal owners (that’s you) must be more cognizant about poorly designed and installed DAS.

Questions?

Contact Information:Sujeeva RanasinghePrincipal EngineerCommunication Technology Servicessranasinghe@cts1.com303-483-3387

Please visit our website at www.cts1.com

Thank You