The Tri-Cities Herald recently published the article ‘Built with parts from eBay.’ Tri-Cities leaders rush to replace failing 911 system. It’s a little light on details for the $20+ million project, and the title is a bit inflammatory. What’s important in there?

The article doesn’t go into detail about how much was purchased from eBay, but buying used equipment is not necessarily bad and may have saved the taxpayers quite a bit of money. The main downside of government purchases of used equipment is the possibility of getting compromised equipment, i.e. equipment with software/firmware vulnerabilities or actual Chinese spy chips. The article doesn’t give us any more details than the title, so no determinations can be made about the good or bad of the eBay purchases other than that the Herald wanted something sensational to get people to click on the article.

VHF vs UHF vs 800MHz

Radio jargon. Very High Frequency (VHF) is a range of radio frequencies from 30Mhz to 300MHz. Ultra High Frequency (UHF) is the next step higher, ranging from 300MHz to 3000Mhz (3GHz). You might notice that 800MHz lies within the UHF range. So 800MHz is a UHF frequency. You might even remember that there used to be UHF television stations, and that the UHF televisions had to go away in order for the government to re-allocate that swath of radio spectrum to public service radio in the 700/800MHz (this is actually a range of frequencies in the middle of 700MHz and another range in the first half of the 800MHz range) frequency range. A radio using VHF or UHF does not make it either obsolete or modern. New radio systems in both VHF and UHF come out all the time. That said, sometime in the public service space when people use the terms VHF and UHF they mean analog VHF or analog UHF, and they use 800MHz when they mean specifically digital UHF radios using the public service spectrum — or even more specifically a trunked P25 radio system. The article makes it sound like the VHF radios being replaced are obsolete because they are VHF, but really it is because they are not part of the digital trunking system.

With analog VHF radios (there are digital VHF radios), each agency needs to have a range of frequencies to use for difference purposes. There may be a regular dispatch channel and then several, separate tactical channels so that teams of responders responding to specific incidents can talk with each other outside of the main dispatch channel. This took up a lot of frequency “space.” Using fictional frequencies, Prosser might need to have 100-110MHz to have several channels for police and ambulance and regional county Sheriff cannels. Benton City cannot overlap those channels or it may interfere with Prosser and vice versa, so Benton City needs 112MHz to 122MHz. and so on for Richland, Kennewick, West Richland, and so on. The frequencies were getting full, which was why the federal government allocated the 700/800MHz frequencies in the first place — to give more room for allocating frequencies.

Digital trunking is a method that was created to do an even better job of sharing frequencies but still allowing all of the agencies sharing a system to have their own private channels. As a bonus, if agencies were all sharing the same trunking system, then it is easy to create coordination channels for the agencies to talk to each other. A downside is that it becomes more difficult for users of a digital trunking system to communicate with users of analog radio systems. A trunking radio system over a large area (like a city or county) also requires that all of the radio repeaters (radios typically in high places that retransmit signals in order to cover large areas) be linked to each other with some sort of communication infrastructure. These links may be fiber optic cable or other cable, but in the case of BCES the repeaters are linked with microwave radio links. In 2010, BCES went live with a digital P25 trunking radio system. According to the BCES press release at the time, “The new digital system has more than 1,000 subscribers. Agencies involved in the switchover include Richland Police, West Richland Police, Kennewick Police, Prosser Police, Pasco Police and the Benton County Sheriff’s Office, as well as Benton Public Utilities, Benton County Public Works, the Benton County Jail, Prosser Ambulance and Areva.” BCES was using an 800MHz analog radio system prior to that.

So the article is clear that that one goal of the upgrade is to get all agencies off of the analog VHF systems and onto the digital trunking system. Another goal is to replace all of the microwave links between the “50 different transmitters and receivers…on ridges and mountaintops.” The repeaters that are currently running analog systems which need to join the trunking system will need to be linked into the rest of the system, so there will be expenses for that new equipment. Franklin County agencies will be replacing virtually all of their radio infrastructure. Even if they wanted to stick with analog VHF, it is old and failing and the cost would be about the same as changing to a digital trunking system. In the public service space, the digital trunking systems are more common, so it does make sense to conform the systems that other agencies in the area are using.

How will the counties pay for these upgrades? The article says the counties may implement a 911 sales tax of 0.2%. Benton County, however, does have a 0.3% Public Safety Sales Tax already. So will a 911 tax be added on top of that?