Change is in the Air
I’ve always worked with the state of California, starting in 1973. The first system I worked with was the California Highway Patrol System. It’s a low-band VHF conventional system. It’s gone through a couple of replacements of equipment, but essentially it still operates the same way it did back then.
The pluses are that it provides good wide-area coverage, which fits the needs of the highway patrol. The minuses are that the antennas are large, which makes it not particularly conducive for handheld radios. And due to the waning popularity of low band, it’s becoming more difficult to find equipment anymore — everybody wants to go to the higher-frequency bands, and that’s what the manufacturers are supporting.
We provide all of the engineering, installation and maintenance services for all of the state agencies’ radio systems. The individual agencies do not have their own engineers and technicians — we provide a centralized service. So I still provide support for the highway patrol, but quite frankly, I provide support to a hundred other agencies, too.
It’s very difficult for a large agency like the highway patrol to move to other spectrum because of its size and the geographic area it has to operate across. The number of channels that we would need in any other band is significant, and it’s difficult finding those channels. We’re sort of in a Catch-22: We need to move to another band because it’s more and more difficult to find equipment, but we can’t move to another band because we can’t get enough frequencies.
In theory, we could go to the 700 MHz band because there’s lots of spectrum available there currently. But the cost of building a system with equivalent amounts of coverage is prohibitively expensive, because at 700 MHz you don’t get the same amount of coverage as you get with low band. To cover the same amount of area, it would take at least six to seven times as many radio sites … and [building new radio sites] is not easy.
Quite frankly, the technology has stayed pretty constant for 40 or 50 years. In the 1980s, we saw trunking technologies come along. That introduced a new flavor to it. It was still analog FM and still operated pretty much the same, but now we’re using a computer to assign channels, so we improved spectrum efficiency with that.
We’re now undergoing what is going to be a paradigm change, as the FCC is pushing us toward narrower bandwidths. We’re up against the fact that you can’t narrow the bandwidth anymore and still use analog FM — it’s just not going to work. We have to change technology, which is the movement to digital techniques.
There are a lot of things that become possible with broadband, but public safety will have a big learning curve about what is useful and what isn’t. A lot of people are saying, “It would be wonderful if we could have a video camera in every patrol vehicle and we could shoot continuous video, so the dispatcher sees everything the officer sees.” That might be useful, but do we have enough dispatchers to watch all that video?
When we started to implement mobile data terminal (MDT) systems, a number of agencies started to see a significant increase in the number of queries to a database. It didn’t happen very much before MDTs. But with MDTs, it became the norm for an officer to run a license check and a DMV check on every traffic stop. Overall, it proved to be useful. The number of hits was relatively low, but there were enough of them to make the time and effort it took to do that a useful thing to do.
As we expand into broadband, I think we need to learn what is useful and what isn’t. There is a learning curve that we’re going to go through. We’re going to do some things that sound like great ideas but are not worth the time and effort. — as told to Donny Jackson
Glen Nash is the supervising telecommunications engineer for the California Department of Government Services.
