DeKalb County is About to Make a $4m Blunder on Bad Advice

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Mike Hammett

I was reading my morning news and I saw an article about the county board going to vote on a new radio system. Good, they probably need it. Most counties have rather poor radio systems. Let’s see what they’re proposing to do. Oh, they’re voting on it tonight!

Let’s get into a bit of my background. I started a company 14 years ago (and still run it to this day) building out wireless systems to provide people with Internet. Designing a network that reliably delivers the Internet performance people are looking for is imperative. I have to know some radio fundamentals to do this well. Yes, it is true that the networks I design and the network the county needs have very different requirements, but the fundamentals are the same.

I am asking the county board to postpone any decisions on R2017-97 until further discussion can be had as to the suitability of the proposal.

The system as proposed will not work. The existing system has 17 sites being a mix of transmit-only, receive-only and some that do both. The new system has four sites. Due to only having four Starcom (similar system to what’s proposed) sites in Kane County, the City of Elgin conducted their own study and determined they needed five sites in Elgin in addition to whatever overlap there was from the larger county-wide system to have 95%+ in-building coverage. There are many areas in Kane County where the Starcom system does not work with only four sites.

The outdoor coverage will likely be great. Indoor will suck. Radio communications is a two-way street. From the individual radio out in the field to a receive tower, back to a central controller (likely at the Sheriff’s office), then back out to a transmit tower and finally to everyone’s individual radios.The towers being tall does help clear obstacles such as hills, trees and other buildings, but being tall does not help penetrate buildings. Power does. The more solid the construction, the more power you need. The tower height will help the towers talk down to everybody over a larger area.

The towers are high power. Cars, trucks and ambulances are medium power. Personal radios are low power. That’s why currently they have to go to the car to use a higher powered radio to be heard. The new system would actually be less capable of going through buildings than the current VHF system. VHF is running somewhere around 150 MHz, plus or minus 20 or so. That’s a comparatively lower frequency than the 800 MHz system being proposed. It’s simple physics that 800 MHz goes through things worse than 150 MHz. The high powered towers can reach down to most everybody, but the low powered personal radios cannot reach back to the towers.

That’s where receive-only sites come in. They monitor the air for transmissions and pipe them back to the office. The sites are scattered about the intended coverage area and pick up the low power transmissions from the radios that the officers wear. Eliminating those means when an officer goes into a school in a town without a tower, he’ll be unable to talk back to the tower. That’s why Elgin at only 38 square miles has five sites. They wanted solid in-building coverage. De Kalb County at 635 square miles is looking at only four. That’s a major discrepancy. These sites can be less costly, but still necessary to ensure that officers, fire fighters, and paramedics can still be heard in schools, healthcare institutions, NIU facilities, warehouses, commercial buildings, etc. Any building of substantial construction that isn’t near one of the four towers would have issues.

Also, I would doubt some of the consultant’s work due to the fact that they could not correctly identify all of the existing locations on the map. The Tower Rd. location is off by at least two miles. What else have they gotten wrong?

Please ask questions about this at tonight’s meeting. Please talk to others in the public safety arena to see what coverage is like in their area with similar designs. The only thing worse than not quickly implementing a new system to enhance officer, fire fighter, paramedic, etc. performance and safety is to spend $4m on a new system that isn’t any better (or worse) than the old one.

(Probably not my best literary work, composed over a quick lunch break.)

58 COMMENTS

  1. i know this is kind late to comment on this, but I am a scanner user. DeKalb Police has a repeater, why cant the county do the same instead of being encrypted and all. So that the public who listen to scanners can still know what is going on as it happens. I get more out of listening to now only DeKalb police but listening to county to see what is going on. Don’t take away a hobby from people who listen to scanners.

      • Hey Mike! This a really good write-up and thought provoking! I commend you on your desire to ensure money is spent in the best interest of the County.

        With regards to 800MHz vs VHF… VHF is less impacted by terrain and propagates further (the lower the frequency the better it follows the curvature of the earth). 800MHz is less impacted by clutter i.e. buildings (the higher the frequency, the smaller the wavelength. The smaller the wavelength, the better the in-building penetration). 800MHz designs also use the benefits of Tower Top Amplifiers (TTA’s) to enhance the talkback signal coming from that low power handheld radio. This provides improvement in talkback signalling over VHF designs.

        With regards to the quantity of sites to provide coverage…. A properly designed simulcast system will provide better balanced coverage than that of a gap fixed voted receive/transmit steered system.

    • Towers did move. One thing I didn’t mention… we had coverage predictions run for VHF, UHF and 700 and the computerized predictions showed in building was better. Once the 700 system was built, we did some comparative tests with a VHF system And the 700 system. Both were in the same tower at the same height and antennas with similar gain. In urban areas, 700 was always best. We have mountains and valleys here. The VHF was sometimes better in the valleys but allowing the 700 radio to roam to another site yielded acceptable coverage.

  2. The motion passed. Hopefully my points are taken seriously during implementation.

    I was not impressed by the consultant. He often used terms that I was likely the only one to understand. My points were largely about the ability of the of the handheld radios to reach back to the towers and I spoke of increasing the number of receive sites. He only spoke of 150 watt tower transmitters being loud enough to reach the radios. He didn’t address my point at all and no one asked me to follow up.

  3. This is a huge and very complex issue. I was on the E911 Board for five years while also on the County Board, and the knowledge I gained just scratched the surface of the complexity. It is important to keep the DeKalb County Emergency Telephone System Board and their Coordinator, Glenna Johnson, in the loop along with the actual users.

  4. Also, it should be noted, after a conversation with Mark Pietrowski Jr., he is entirely in favor of the encryption, which will happen with this changeover. In other words, news organizations, will no longer have access to audio from scanner traffic. We will be 100% dependent on the Dekalb County Sheriff for providing information. The citizens will lose access to an important monitoring tool. Dekalb county sheriff’s dept shares department does a poor job of informing the public via social media, unlike, other police entities that are very good (Rockford)

  5. Appreciative of Mike reaching out with his expertise. He also sent an email and the consultant will address the information he has brought up. Please note that the consultant has spent considerable time working with our county sheriff department and testing the current system all over the county and has been in contact with Police, Fire, etc…

    He is also someone that has done many of these projects for police departments and works with the different communication brands so he also has substantial knowledge of these systems and capabilities. My thought is that there just might be some data and information Mike didn’t see from the consultant but again, his questions will be addressed tonight and I invite Mike or anyone else to attend in person if they are able. Otherwise there is a live broadcast of meetings on dekalbcounty.org A special reminder that the meeting tome has changed so it starts at 7 p.m. tonight now instead of 7:30 p.m.

    • I always treat the work of consultants with a healthy dose of skepticism because you pay them to tell you what you want to hear, not what they really think you need to know. Consultants should be paid on a results basis: if what they propose works without additional “oops” expenditures, and under or on budget, you get your fee. We always pay up front and then, when the inevitable cost overruns due to poor recommendations happen, the consultant is long gone … and we’re stuck with having to re-do the work at a higher cost.

    • Mike, Mark no longer listens to constituents, as county board chair, he is more interested in representing the interests of consultants, and county staff, rather than citizens of the county. Mark, before he was elected, was a great advocate, and someone we could all agree with, but, he has turned. Mark used to be a great advocate against the expansion of the county landfill, now he is one of the biggest proponents of it,

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