https://urgentcomm.com/wp-content/themes/ucm_child/assets/images/logo/footer-new-logo.png
  • Home
  • News
  • Multimedia
    • Back
    • Multimedia
    • Video
    • Podcasts
    • Galleries
    • IWCE’s Video Showcase
    • Product Guides
  • Commentary
    • Back
    • Commentary
    • Urgent Matters
    • View From The Top
    • All Things IWCE
    • Legal Matters
  • Resources
    • Back
    • Resources
    • Webinars
    • White Papers
    • Reprints & Reuse
  • IWCE
    • Back
    • IWCE
    • Conference
    • Special Events
    • Exhibitor Listings
    • Premier Partners
    • Floor Plan
    • Exhibiting Information
    • Register for IWCE
  • About Us
    • Back
    • About Us
    • Contact Us
    • Advertise
    • Terms of Service
    • Privacy Statement
    • Cookie Policy
  • Related Sites
    • Back
    • American City & County
    • IWCE
    • Light Reading
    • IOT World Today
    • Mission Critical Technologies
    • TU-Auto
  • In the field
    • Back
    • In the field
    • Broadband Push-to-X
    • Internet of Things
    • Project 25
    • Public-Safety Broadband/FirstNet
    • Virtual/Augmented Reality
    • Land Mobile Radio
    • Long Term Evolution (LTE)
    • Applications
    • Drones/Robots
    • IoT/Smart X
    • Software
    • Subscriber Devices
    • Video
  • Call Center/Command
    • Back
    • Call Center/Command
    • Artificial Intelligence
    • NG911
    • Alerting Systems
    • Analytics
    • Dispatch/Call-taking
    • Incident Command/Situational Awareness
    • Tracking, Monitoring & Control
  • Network Tech
    • Back
    • Network Tech
    • Interoperability
    • LMR 100
    • LMR 200
    • Backhaul
    • Deployables
    • Power
    • Tower & Site
    • Wireless Networks
    • Coverage/Interference
    • Security
    • System Design
    • System Installation
    • System Operation
    • Test & Measurement
  • Operations
    • Back
    • Operations
    • Critical Infrastructure
    • Enterprise
    • Federal Government/Military
    • Public Safety
    • State & Local Government
    • Training
  • Regulations
    • Back
    • Regulations
    • Narrowbanding
    • T-Band
    • Rebanding
    • TV White Spaces
    • None
    • Funding
    • Policy
    • Regional Coordination
    • Standards
  • Organizations
    • Back
    • Organizations
    • AASHTO
    • APCO
    • DHS
    • DMR Association
    • ETA
    • EWA
    • FCC
    • IWCE
    • NASEMSO
    • NATE
    • NXDN Forum
    • NENA
    • NIST/PSCR
    • NPSTC
    • NTIA/FirstNet
    • P25 TIG
    • TETRA + CCA
    • UTC
Urgent Communications
  • NEWSLETTER
  • Home
  • News
  • Multimedia
    • Back
    • Video
    • Podcasts
    • Omdia Crit Comms Circle Podcast
    • Galleries
    • IWCE’s Video Showcase
    • Product Guides
  • Commentary
    • Back
    • All Things IWCE
    • Urgent Matters
    • View From The Top
    • Legal Matters
  • Resources
    • Back
    • Webinars
    • White Papers
    • Reprints & Reuse
    • UC eZines
    • Sponsored content
  • IWCE
    • Back
    • Conference
    • Why Attend
    • Exhibitor Listing
    • Floor Plan
    • Exhibiting Information
    • Join the Event Mailing List
  • About Us
    • Back
    • About Us
    • Contact Us
    • Advertise
    • Cookie Policy
    • Terms of Service
    • Privacy Statement
  • Related Sites
    • Back
    • American City & County
    • IWCE
    • Light Reading
    • IOT World Today
    • TU-Auto
  • newsletter
  • In the field
    • Back
    • Internet of Things
    • Broadband Push-to-X
    • Project 25
    • Public-Safety Broadband/FirstNet
    • Virtual/Augmented Reality
    • Land Mobile Radio
    • Long Term Evolution (LTE)
    • Applications
    • Drones/Robots
    • IoT/Smart X
    • Software
    • Subscriber Devices
    • Video
  • Call Center/Command
    • Back
    • Artificial Intelligence
    • NG911
    • Alerting Systems
    • Analytics
    • Dispatch/Call-taking
    • Incident Command/Situational Awareness
    • Tracking, Monitoring & Control
  • Network Tech
    • Back
    • Cybersecurity
    • Interoperability
    • LMR 100
    • LMR 200
    • Backhaul
    • Deployables
    • Power
    • Tower & Site
    • Wireless Networks
    • Coverage/Interference
    • Security
    • System Design
    • System Installation
    • System Operation
    • Test & Measurement
  • Operations
    • Back
    • Critical Infrastructure
    • Enterprise
    • Federal Government/Military
    • Public Safety
    • State & Local Government
    • Training
  • Regulations
    • Back
    • Narrowbanding
    • T-Band
    • Rebanding
    • TV White Spaces
    • None
    • Funding
    • Policy
    • Regional Coordination
    • Standards
  • Organizations
    • Back
    • AASHTO
    • APCO
    • DHS
    • DMR Association
    • ETA
    • EWA
    • FCC
    • IWCE
    • NASEMSO
    • NATE
    • NXDN Forum
    • NENA
    • NIST/PSCR
    • NPSTC
    • NTIA/FirstNet
    • P25 TIG
    • TETRA + CCA
    • UTC
acc.com

content


Tower siting gets more difficult

Tower siting gets more difficult

Interference-avoidance plans 'doable' but potentially complex
  • Written by Urgent Communications Administrator
  • 1st August 2005

After years of struggling with a spectrum shortage in the U.S., the wireless industry appears to be on the cusp of getting a great deal of relief from upcoming FCC auctions of airwaves in the 1.7 GHz and 2.1 GHz bands, as well as the possible availability of 700 MHz spectrum in a few years.

All of these new frequencies are relatively close to the 1.9 GHz and 800 MHz bands that host most existing commercial wireless voice services today. In many cases, this means the same towers from an existing network can host transceivers operating in the new spectrum bands because they have similar propagation characteristics as airwaves used for existing services.

However, the proliferation of wireless antennas hanging from a given tower can create co-location interference — an issue that likely will become more significant with the introduction of services on the new spectrum, said David Kiesling, director of marketing and technical services for Radio Frequency Systems. None of the intermodulation problems are expected to be insurmountable, but network operators must consider them and factor the cost of solutions into their plans, he said.

“It may impact a carrier’s deployment strategy,” Kiesling said. “You may just think that you can use all your existing towers, but it may be more complicated than that.”

It’s a sign of the times, as the simplistic “might-is-right” days for tower siting — which was predicated almost solely on height — are long gone, said Ted Abrams, chief technology officer for SpectraSite, which recently agreed to merge with American Tower.

“It is going to be more complicated,” Abrams said. “The siting business is not as simple as it used to be.”

Being able to use existing towers for new networks is economically significant throughout the wireless industry. For carriers and other system operators — including public safety — it means relatively quick deployments without the expenses associated with the politics and delays often inherent in any attempt to build a new base station. For tower owners, it means the potential to realize additional revenue from infrastructure — in this case, towers — for which the most significant costs already have been paid.

Indeed, a typical tower can host antennas from five to eight different operators, said Woodie Williams, district manager in south Florida for tower company Crown Castle.

“It depends on the tower itself … and how willing you are to perform modifications [to reinforce the tower],” Williams said.

These towers are expected to become even more popular as more spectrum becomes available. During the next year, the FCC is expected to auction airwaves at 1.7 GHz and 2.1 GHz, with existing commercial wireless operators expected to be the primary bidders. Meanwhile, government officials hope to clear television broadcasters from the 700 MHz band by the end of the decade and see that prime spectrum used by new wireless players wanting to offer WiMAX and mobile video applications (see news story on page 6).

The potential for using tower sites that currently host 1.9 GHz antennas will be attractive to bidders wanting spectrum at 1.7 GHz and 2.1 GHz, just as 800 MHz sites will be candidates to host 700 MHz antennas if the broadcasting bands are cleared.

But such co-locations can create intermodulation issues, Kiesling said. In particular, spurious emissions — particularly third-order intermodulations (see graphic on page 32) — from antennas operating at the same tower location on close frequencies may interfere with signals from other antennas. In most circumstances, these problems can be anticipated via a mathematical formula and resolved with appropriate co-location filters.

“Filtering is not that hard to do, but you have to plan ahead for it,” RFS’ Kiesling said. “As more and more systems come into play, there will be more of a requirement for filters.”

In addition to filtering, other methods to alleviate co-location interference at tower sites include reducing signal power and altering antenna positions on the tower, which can rectify the problem because spurious emissions are a factor only at very close range, Kiesling said. Focusing antenna energies in a specific direction is another common strategy to combat unwanted intermodulation.

“Rather than using an antenna with an omnidirectional pattern, most operators choose to use antenna elements that are more precisely controlled and directed,” Abrams said.

When RFS carrier clients have been told about the potential impact of spurious emissions, Kiesling said, it surprises many of them.

Indeed, co-location interference at tower sites generally is not a problem today, Crown Castle’s Williams said.

“Right now, we haven’t seen too much of that, except with Nextel and [emergency-services networks],” he said. “In my five years with the company, we’ve only had two occasions, but we were able to remedy those quickly … in one case, with a simple filter. In the other case, we had to change some equipment.”

Although not much of an issue today, Williams acknowledged that co-location interference could increase significantly as more services are provided from a tower at new frequencies.

“I would say that is something we would have to look at,” Williams said. “But we probably won’t be able to address it until we see the applications and how they work with each other on the tower.”

In addition to spurious emissions, subharmonics and cross products are other forms of co-location intermodulation distortion that tower owners and wireless operators need to address, Abrams said. While computers are employed to crunch all the relevant mathematical formulas used in an effort to anticipate interference, there are times it is not found until after various networks are deployed, Kiesling said, noting that activities in unlicensed bands could present some unique problems in the future.

“How does WiMAX at 2.4 [GHz] mix with 1.9 [GHz] and 2.1 [GHz]? … What’s going to happen at 2.4 [GHz]?” Kiesling asked. “We all have a lot of ideas, but the fact is, until you build it, I don’t think anybody really knows.”

Abrams agreed but expressed confidence that the tower industry will be able to work with wireless operators to find solutions that prevent co-location interference from becoming a significant problem.

“It’s a doable thing — the technology challenges are not show-stoppers,” Abrams said, noting that new tower sites inevitably will have to be part of the long-term plan. “It will not be done without effort and a need to communicate well … but the costs will be reasonable.”

Indeed, for all the potential co-location interference issues that the new spectrum may create, Kiesling is quick to note that the circumstances will not negatively impact the value of the spectrum the FCC plans to auction.

“It’s going to clutter up the landscape … but the value of the spectrum far outweighs the risk this brings,” he said.

Tags: Antennas content Operations Tower & Site

Most Recent


  • AT&T wireless growth keyed by FirstNet—now provides 24,000 agencies with 4.4 million connections
    AT&T this week reported that FirstNet ended 2022 supporting more than 24,000 public-safety agencies with “about” 4.4 million connections, including 377,000 connections that were added during the last three months of 2022—a total that represents more than half of the carrier’s post-paid wireless growth for the quarter. AT&T officials released these figures in conjunction with […]
  • Report: Remote work causing offices to empty, but walkable cities still in high demand
    Given the reliance on vehicular transportation in the United States, some American cities historically haven’t prioritized being walkable in past planning and or design. But amid an unprecedented shift in the economy toward remote work, those that have are increasingly desirable for prospective residents. A new report from Smart Growth American and Places Platform, “Foot Traffic Ahead […]
  • AT&T FirstNet unleashes robotic dogs for emergency services
    AT&T is releasing robotic hounds from Ghost Robotics as part of the service provider’s FirstNet emergency responder service. In a blog, AT&T VP Lance Spencer explained that the robotic dogs will be connected to AT&T’s network and deployed for public safety, defense, federal and state agencies, local police and fire departments, and commercial customers. “Network-connected robotic dogs can deliver a […]
  • Federal agencies infested by cyberattackers via legit remote-management systems
    It has come to light that hackers cleverly utilized two off-the-shelf remote monitoring and management systems (RMMs) to breach multiple Federal Civilian Executive Branch (FCEB) agency networks in the US last summer. On Jan. 25, the Cybersecurity and Infrastructure Security Agency (CISA), National Security Agency (NSA), and Multi-State Information Sharing and Analysis Center (MS-ISAC) released […]

Leave a comment Cancel reply

To leave a comment login with your Urgent Comms account:

Log in with your Urgent Comms account

Or alternatively provide your name, email address below:

Your email address will not be published. Required fields are marked *

Related Content

  • Unfinished Business: Why NFPA and IBC fire codes need to kill the fire phone
  • Driverless-tech liability is all in the wording
  • Is an attacker living off your land?
  • New ThroughTek IoT supply-chain vulnerability announced

Commentary


How 5G is making cities safer, smarter, and more efficient

26th January 2023

3GPP moves Release 18 freeze date to March 2024

18th January 2023

Do smart cities make safer cities?

  • 1
6th January 2023
view all

Events


UC Ezines


IWCE 2019 Wrap Up

13th May 2019
view all

Twitter


UrgentComm

AT&T wireless growth keyed by FirstNet—now provides 24,000 agencies with 4.4 million connections dlvr.it/ShY5qH

27th January 2023
UrgentComm

Report: Remote work causing offices to empty, but walkable cities still in high demand dlvr.it/ShXM7Z

27th January 2023
UrgentComm

AT&T FirstNet unleashes robotic dogs for emergency services dlvr.it/ShW7p8

27th January 2023
UrgentComm

Federal agencies infested by cyberattackers via legit remote-management systems dlvr.it/ShVhn3

26th January 2023
UrgentComm

How 5G is making cities safer, smarter, and more efficient dlvr.it/ShVS1h

26th January 2023
UrgentComm

MCPTT interworking for critical communications dlvr.it/ShTm3P

26th January 2023
UrgentComm

Self-driving cars present terrorism risk, FBI director says dlvr.it/ShTTHx

26th January 2023
UrgentComm

UK Home Office officially will cut ESN ties with Motorola Solutions in December dlvr.it/ShNjfN

24th January 2023

Newsletter

Sign up for UrgentComm’s newsletters to receive regular news and information updates about Communications and Technology.

Expert Commentary

Learn from experts about the latest technology in automation, machine-learning, big data and cybersecurity.

Business Media

Find the latest videos and media from the market leaders.

Media Kit and Advertising

Want to reach our digital and print audiences? Learn more here.

DISCOVER MORE FROM INFORMA TECH

  • American City & County
  • IWCE
  • Light Reading
  • IOT World Today
  • Mission Critical Technologies
  • TU-Auto

WORKING WITH US

  • About Us
  • Contact Us
  • Events
  • Careers

FOLLOW Urgent Comms ON SOCIAL

  • Privacy
  • CCPA: “Do Not Sell My Data”
  • Cookie Policy
  • Terms
Copyright © 2023 Informa PLC. Informa PLC is registered in England and Wales with company number 8860726 whose registered and Head office is 5 Howick Place, London, SW1P 1WG.