The future of UHF trunking
UHF is the place to go for traditional dispatch services to customers that do not want, or need, ESMR service. An interview with ITA’s Mark Crosby examinesthe rapid adoption of this fast-disappearing spectrum.
In the wake of 1997 refarming (the revision of Part 90 rules covering the Private Land Mobile Radio Services [PLMR]) by the FCC, interest in the use of newly authorized trunking in the 150MHz and 450MHz bands has increased. Private carriers and dedicated systems need the capacity trunking can provide, and most of them need it yesterday. Some SMR operators are bringing their experience with multichannel trunked networks down the band from 800MHz by acquiring conventional UHF repeaters and converting to private carrier status. UHF is the place to go to provide traditional dispatch services to customers that do not want, or need, ESMR service at the higher frequencies. At the same time, narrowbanding has been mandated for 450MHz-470MHz. New applications for equipment type acceptance for UHF must comply with 12.5kHz spacing, which will reduce further to 6.25kHz in 2005.
Details affecting UHF trunking are still being hammered out. The FCC’s 1998 Biennial Regulatory Review, issued in October as a Notice of Proposed Rulemaking (NPRM), deals in part with exclusivity and frequency-assignment policies for PLMR. At press time, comments had been filed on the NPRM, although when the FCC will proceed with modification of the rules is uncertain.
One of the lead commenters for the land mobile industry has been the Land Mobile Communications Council (LMCC). In partcular, the LMCC has offered unified comments (see sidebar, page 68) on clarifying centralized vs. decentralized trunking (currently designated as “YG” and “IG” channels, respectively), as well as licensing requirements and maximum allowable channels.
To clear away some of the mist surrounding UHF trunking, MRT interviewed Mark Crosby, one of the evangelists of spectrum for private carriers and dedicated systems, Crosby is president of the Arlington, VA-based Industrial Telecommunications Association and also serves as secretary-treasurer of the LMCC. These two positions put him in a unique place to observe both frequency coordination and the government rulemaking process. Crosby will be a panelist at the IWCE ’99 session “Industry Leaders Meet the Press,” Wed., April 28, at 3 p.m., in Las Vegas.
MRT: What does UHF trunking represent today to the ITA constituency, as far as capabilities?
CROSBY: It’s great. I don’t really care if they’re doing Smartrunk, LTR, Smartzone or other products coming into the 450MHz-470MHz environment. I think it has, for the immediate future, energized activities in the 150MHz-470MHz band. There has been new product and new infrastructure, which creates opportunities for both private wireless dedicated systems and private carrier systems. It’s not as easy as 800MHz was because you have a high level of incumbency, and it’s multidimensional. At 800MHz, everybody was at 25kHz spacing, and it was a two-dimensional thing-actually one-dimensional. “The sites must be at least 53.4 miles away,” you could do engineering beyond that. Everybody’s operating 25kHz equipment, so it’s a very easy [makes stamping sound] “Yes/No, Yes/No, Yes/No.”
Below 800MHz, it’s considerably more complicated. It is 25kHz, 12.5GHz, no minimum and you’re mixing technologies in varying levels of incumbency. Coordinating YGs, and even coordinating IGs-the reverse works, with YGs in the environment, the IGs have to protect-so everything you do in the bands below 800MHz is complicated. You have to plot service and interfering contours for everything, and you have to bounce it off the frequency/spectrum environment. It is not quite as complicated as fixed point-to-point, but almost.
There needs to be an understanding that because of the introduction of narrowband technologies below 800MHz, the frequency selection and certification process is 50 times more complicated than it ever was before.
MRT: When you subdivide the frequencies, you multiply the workload? CROSBY: And it compounds. I have many, many conversations with both licensees and radio service organizations, private carriers, on this subject. I had one the other day that was trying to move things around, and I said, “I understand what you’re suggesting, but your suggested approach throws the 12.5kHz frequencies off channel centers as identified by the rules. So in other words, your approach, while wise, doesn’t work because it’s not in conformance with the rules.”
And he goes “Oh, crud!” And I’m going ‘See, you can’t just move these suckers around.” Everything is now contour-based.
MRT: When do you think we’ll see some action on the changes proposed in the biennial review?
CROSBY: I don’t have the faintest idea. One of the things I liked about the LMCC petition-the LMCC responds in mysterious ways. We (LMCC) filed a lot of letters on refarming in the last 18 months, and a couple of issues came up in the biennial review. For example, one of them was “No more than 10 YG channels.” The FCC didn’t even reference that the LMCC asked for that. So is this in response to our letter? We don’t know. What harm is it to say “We put this here because the LMCC thought it was a good idea.” I think it’s great, and I think most people support “no more than 10,” and some people could support no more than five.
MRT: What is the logic behind that magic number?
CROSBY: There probably isn’t any specific logic. If an application (whether you are a private carrier or private wireless, the two classes below 800MHz-you’re either an “FB4” or an “FB6” or an “FB2” license) asks for more than five YG channels, assuming you could get them, the FCC application will ask a justification statement.
Now, the incongruence of this issue is, in the biennial review, they say “10.” From ITA’s perspective, “Pick a number, and adhere to it.” The magic? Well, 10 is what-1,000 units? That’s a pretty big system. I sort of like them asking for justification for more than five because five YG channels, which is trunking, should be able to support 500 units. That’s a lot of units. So if someone comes in saying “Gimme, gimme, gimme,” I sort of like [the FCC] going “Justify.” Because you don’t want-speculation.
MRT: You don’t want warehousing.
CROSBY: Absolutely not. We don’t have enough spectrum to fool with, and I suspect that the LMCC will suggest that the Frequency Advisory Committees go back in two or three years and verify the loading of some of these systems-and get the spectrum back if it’s not being used. I had someone today say “My customer needs five,” and I go “How many units is he going to have?” He said a little less than 200. I said, “I’m not giving you five; I’ll give you three.” He said, “Yeah. I really don’t need five.”
MRT: The LMCC recommendations for station code identifiers state that they will improve the channel selection process for the FACs. What does that involve? CROSBY: The “FB2P”? Presently, say you have a big manufacturer that wants five channels at YG because they can support 500 or 600 hand-held portables, and it’s going to do an LTR or some other virtual centralized trunking system below 800MHz. If we can’t find him five YGs, but find three YG frequencies after analysis, we give him three YGs and two IGs (non-trunked conventional).
Commission rules do not permit cohabitation on one license, of IGs and YGs, which is crazy. So, the LMCC sits down and says “We need to come up with another plan because it’s stupid to require that company to have two licenses for the same facility, out of a glitch, because it can’t get the YG channels. Somehow, you have to signify that the channels have received a 39dBu service area protection, which made them eligible so they could get the YG. So you label it “FB2P.” …
To find out which YG is the license class, which of the frequencies under the authorization has absolutely received a 39dBu service area contour protection zone, you add a code to the station class, and you can put it all under one license. … The ones that don’t have the “P” tell you that it’s a shared frequency at that site, and all the coordinators’ software can very easily look at the station class and read “FB2P-Ah, there’s a site where the co-channel and adjacent channel 29dBu service contour cannot overlap that 39dBu.” And that’s how you get one license.
We do need the “P” because it solves everybody’s problem. It solves the FCC, which doesn’t have to issue so many call signs; it helps the coordinators; and it helps dealers and private wireless licensees know exactly what they’ve got. You’ve got “C” codes (interconnect) and “I” codes (itinerant)-“P” code means “protected.” It helps clarify what the environment has out there, and you get everything done in one authorization.
MRT: Whatever became of the MoU [Memorandum of Understanding] about interference to service corridors that was discussed last summer?
CROSBY: The LMCC did submit a recommendation to the FCC suggesting “These are the procedures for trunking.” We never heard from the FCC.
The LMCC has probably written the bureau eight or nine letters. The LMCC changed its approach. It now tells the commission what the Frequency Advisory Committees have agreed to. We did! We said “This is what we’re going to do.” And if we don’t hear from them-fine, but we couldn’t wait. We had to move.
The industry-both of the private wireless categories, both the carriers and the dedicated systems-need product, they need to move, they need to expand. We can’t wait for the bureau. So, the coordinators got together, agreed, said “Here are the policies, this is what we’re going to do: 39 to 21s, 21s to 39s. Go! File!” We’re doing it. Because the industry really couldn’t afford to wait and almost demanded the Frequency Advisory Committees get together and come up with consensual procedures so that we can function. And that’s what’s happened.
MRT: Which probably doesn’t really bother the FCC that much, given its “Let industry-anybody but us-do it” philosophy these days?
CROSBY: Absolutely. We would like however, acknowledgment: “Thank you. We got it.” It would be nice to get that, so at least there’s some measure that there’s a heartbeat over there as to our issues. Please let us know: “Hey, thank you for sharing the letter with us.” I don’t care if they go “It stinks!” Tell us something. But we don’t even get that. What we get is, for example, that one issue that comes out in the biennial review, and we go “I guess that’s our issue.” We don’t know, but I think it is. Then you finally throw up your hands and go “Well, it doesn’t matter, ’cause that’s what we asked for, and there it is.”
So, the LMCC, on these types of issues, has been very proactive. I think it’s doing good because there’s a vacuum, and the LMCC had to fill it.
MRT: As far as centralized vs. decentralized trunking among large-scale business and heavy industry, do you see a trend one way or the other?
CROSBY: It’s hard from ITA’s perspective; you just tell us you’re putting in a trunked system.
MRT: I think you remarked last year “We don’t want to know”?
CROSBY: Well, it now makes a difference because if I discover that there is a pure, centralized, trunking product being introduced into the VHF and, say, 450MHz bands, I need to know that. Because that means that every channel must be “FB2P”; it needs the “P,” or a YG code, as we are right now. I’ll give you an example. Somebody came in for 10 channels, and they were going to put in what I think was a pure, centralized system, and we could only find one YG. You don’t purely trunk a centralized system with one YG. It’s like an 800MHz trunking system with one channel. So it didn’t work.
MRT: So, you’d have a control channel, just without any service.
CROSBY: You see, that’s what works for the LTR format. The LTR format is ideal for-all of them are ideal with their proper applications: Smartrunk, Etrunk, Smartzone, LTR-they’re all ideal for the application, depending on where they are, geographically. In certain parts of the country, you cannot get systems for five YGs. You can get a system with say, one or two YGs and three IGs-that’s perfect for LTR because that infrastructure adapts well for that. In other areas, Smartrunk, Etrunk, purely decentralized: If somebody wants to license it IG, great. It’s monitored; that’s fine. But that’ssort of a “shared” type of trunking system. The other ones that come in are a little bit more sophisticated: Smartzone, whatever. We now need to know that. The other ones, you can run with a combination of YGs and IGs.
That’s why the “one frequency, one license” thing was very important, because it adapts to the infrastructure that’s in the marketplace. The commission took its outline from 800MHz down to these bands, and it doesn’t work. Up there, they had GO or YO; it doesn’t work down here.
MRT: They didn’t think through the process; they just took their 800MHz boilerplate and tried to lay it on the bands?
CROSBY: And it doesn’t adapt because the infrastructure that’s sold below 800MHz recognizes the level of incumbency and has adapted. It would be nice to have one, protected control channel, but this will work really well with shared-channel IGs as well. The products adapt well to the below-800MHz environment. However, the licensing outline-doesn’t. That’s why the LMCC is trying to get the FCC to give us a code down there, the “P,” at least.
MRT: Maybe they don’t have a checkbox for it in the Universal Licensing System? CROSBY: Yeah, they do. But what they have to do is write code. If they’ve got an “FB2I” what’s the matter with an “FB2P”? They’ve got the space for it. They’ve got to write the code: “Oh! ‘P’ equals ‘protected.'” How hard is that? They don’t need to do anything with it. They’re not going to verify it. Is it more overly burdensome to do the “P” or the issue two licenses?
MRT: To issue two licenses. CROSBY: Absolutely. So, you can see the licensing outline at 800MHz doesn’t adapt to the bands below 800MHz. But there is infrastructure that adapts very well, and from ITA’s perspective, I don’t particularly care-you just tell me whether you want an IG or a YG.
MRT: You seem to be ahead of the FCC, but was there a learning curve for you, as well, as a Frequency Advisory Committee, in coming down from 800MHz?
CROSBY: Yes. Absolutely. And ITA has had to retool it’s spectrum-management infrastructure throughout 1998, and we’re still doing it: software, hardware and procedures. There’s more on the plate to figure out what people want to do. Yeah, there’s still add-ons to community repeaters. There’s still “Help me relocate my base station,” but even relocating a base station now takes an analysis.
This is part of the education process that I was alluding to earlier. A dealer will go, “Why can’t you just give me the thing?” No, we can’t because now you have YGs in the environment. I have to make sure that the relocated base station, at 21dBu, doesn’t overlap either a co-channel or an adjacent-channel YG system. People are going “Why can’t I get this thing out of here?” The reason is because everything is as complicated as a new YG.
MRT: Do they require sign-offs from users in the overlap areas?
CROSBY: No, it’s an engineering contour here-well, yes and no. I have to do the analysis that goes “Oh, this relocated base station is 21dBu, and its overlapping contour doesn’t overlap any co-channel or adjacent-channel 39dBu. If it does, you can’t have it!
This is what happens when you introduce new, narrowband technologies-and this is all we’ve got. I can tell him who he’s overlapping, and he can go get the consent. Or, what we also do is rerun it, lowering the ERP and/or other technical parameters of the system so that the overlap is gone.
MRT: What do you see in migration to narrowband? We’ve got 6.25kHz spacing mandatory six years down the road, and everybody scrambling to get to 12.5kHz now, but does the contour have a chilling effect on people migrating into narrowband?
CROSBY: No, I don’t think it does because most of the new products are backward-compatible and are adapting to the new narrowband technologies. I think it would be a mistake on the part of the industry if it forestalled integrating new technologies.
For example, if somebody gets an LTR or some other system, and the commission goes “You know, you coordinators are right,”-in other words, they give us the one license-and the guy has five frequencies, two Ps (YG) and three shared, he’s got something. Now he can go, when it’s 6.25kHz, with two channels, at least, that cleared for 12.5kHz. He can now split them into two 6.25s and maybe do something with the other channels, or give them back. The industry needs to go to 12.5kHz with all due pace and diligence because only then can you facilitate the introduction of narrower technologies. If people wait, it would be a mistake.
MRT: Do you think 6.25kHz by 2005 is realistic or achievable?
CROSBY: I’m not an engineer, but the engineers always amaze me. I bet they’ll be there. Some products are already there.
We have hundreds of strategy telephone calls with licensees and radio communications providers weekly, and I say, “Don’t tarry-go! Go, go, go! Refarming is gone. Don’t hold your breath for the FCC to do too much further of significance on refarming. The gun has sounded-Move!” We’ve done hundreds and hundreds of new applications for narrowband.
MRT: How has the coordination load changed over the last calendar year?
CROSBY: It’s heavy. Not only is the volume higher, the work is more complicated. However, I’m working on some things to facilitate “throughput,” which we’ll announce at the ITA press conference at IWCE in Las Vegas [Wednesday, April 28]. MRT: What about intermural cooperation over UHF trunking? There’s a procedure for inter-FAC objections to coordination certification. Have there been many objections to coordinations for UHF?
CROSBY: A few.
MRT: Is there a pattern to the few objections?
CROSBY: All I can tell you is it’s been congenial. There’s only one instance that troubles me somewhat. … The LMCC submitted to the commission, in June of 1997, its low-power pool recommendations. With the exception of one coordinator, all the Frequency Advisory Committees respect those frequencies for low-power use only, even though the commission hasn’t [approved] it.
MRT: It’s another case of “We have to move ahead and do something, so we’ll do this until they tell us to stop”?
CROSBY: I think it’s pretty good. As a matter of fact, the other coordinator says “I only put high power on those low-frequency-designated frequencies if it’s my last choice.” I guess that’s a position they can take, because the FCC hasn’t adopted anything, officially. … We’re standing firm on it. You have to respect the integrity of the LMCC process, and when the LMCC process submits the low-power pool proposal, even though it hasn’t been officially adopted, the coordinators are adhering to it.
MRT: It’s another case of the industry imposing standards on itself, instead of them coming from “Uncle”?
CROSBY: We can’t wait for “Uncle.” We have to function; 800MHz is frozen. All we’ve got is 450MHz to VHF. I’m actually very pleased at the way the industry is working together on this kind of stuff, absent FCC direction. It’s pretty tight.
MRT: You’ve been traveling around the country quite a bit, holding seminars on UHF trunking and re-farming. What message do you hit hardest when you speak to industry groups, providers and private companies?
CROSBY: “It’s already started. Don’t sit there and wait for the commission.” You can do this, this and this. If you have customers that have a low-power requirement and you’re waiting to move them-move them now to the low-power pool. There’s product out there to do trunking. Move. Look at it, at least. You may not get it, but you’ve at least got to look at it. Run it.
Pretty much, my message is, if you haven’t started already to integrate refarming into your business and spectrum strategies, you are about a year-and-a-half late.
MRT: One last thing: How long until we’re licking the spectrum post, instead of dipping out of it?
CROSBY: When we run out? I’d say we’ve got a three-year window. If we don’t get something really innovative-three years at existing bands.
We need new spectrum, too. And the solution isn’t just new spectrum, we also have to have new technology.