RKG
Member
When I first spotted this thread, I determined not to get involved. As it has progressed, I find I cannot resist. So here goes:
By way of background, I am an independent radio communications consultant. I don’t sell any radios or anything else other than my time. Most of my clients are police chiefs or fire chiefs who have concluded that they are not equipped and would therefore not be wise to deal with vendor shops on their own. Interestingly, some of my clients are radios shops, either who have encountered esoteric issues they don’t want to take the time to learn on their own or who want their best customers to be well advised.
Though no two systems are exactly the same (nor should they be), my public safety concentration means that I deal mostly with voted, repeated, wireline-controlled FM (primarily UHF) systems, which typically will have two transmitters, between five and ten receivers, one or two console-based dispatch points, and between 25 and 2,500 subscriber units. If cost is no object, I’ll start out recommending to anyone Quantar stations, XTL and XTS subscribers, a JPS voter and a Zetron console.
My experience with MotoTRBO is limited, but not nil. A couple of years ago, a Motorola shop for whom I do some work asked me to take a hard look at MotoTRBO; the owner wanted to know what it was so that he could decide in which situations it would make a competent recommendation to a customer. (Yes, there are reputable radio shops.) So he acquired a repeater, a couple of mobiles, and a couple of portables. We set the repeater up, first in the staging area and then at one of his sites, and put it through its paces.
MotoTRBO is a cross between a dedicated channel (“conventional”) radio and a trunked radio. It utilizes two digital data channels that share one 12.5 KHz F1D RF channel. If used for digital voice, both channels can be employed simultaneously.
User “channels” are entirely “logical channels.” That is to say, as with a trunked system, selecting a “channel” (sometimes a/k/a “talkgroup”) means selecting a group of users who’s equipment has been programmed such that when Subscriber A keys, all of the radios of the other members of the logical group will hear what he says and can, if they like, push the button and respond. Unlike a true trunked system, however, each “logical channel” is locked to one of the two TDM slots on the MotoTRBO RF channel, so that if you have two logical channels on Slot A, when one of them is using the channel, the other will get a busy signal. Also unlike a true trunked system, all of the talkgroup programming is done in the subscriber units; there is no “system controller.” This means that in order to added talkgroup members, one has to touch all of the subscriber units to update their programming.
When I looked at it, the MotoTRBO “repeater” was just a box containing a mobile radio, a power supply, and some backplane connections. By no means was this the equal of a Quantar or MTR2000, the minimum that I would specify for a police or fire radio system. At that time (I believe this has now changed), there was no provision for wireline control; all dispatch input was done via a control station. At that time (and I don’t know if this has changed), MotoTRBO had no capacity for multiple, voted receivers. Likewise, when I looked at them, MotoTRBO subscriber units were comparatively low end: certainly lower than Spectras/MCS2000s/XTLs or MTS2000s, XTSs. In fact, they appeared to be lower in build quality than the CDM/HT1250 line (which has proved to be far more rugged and reliable than anyone expected when they first came out).
MotoTRBO “repeaters” and subscribers have the capacity to employ analog F3E emission. This appears to have been provided to ease cutover, and when employed the analog function occupies the entirety of the 12.5 KHz FM RF channel. When used in data mode, MotoTRBO can be used to convey both digital voice and data, and the aspiration of the MotoTRBO “System Planner” is clearly that a MotoTRBO system would be used and useable for data functions such as AVL, POS, inventory control and who knows what else. I seem to recall that the data functions were limited to Slot B, and, as above, when they were using Slot B, no one else could use it (either for data or voice).
When used in digital mode, MotoTRBO makes no provision for “direct” (i.e., short range simplex communications, such as on the fireground), and for that reason its application in the fire service seems to conflict with NFPA 1221. The 1221 admonition against using digital voice on the fireground grew out of the experience of FDNY (and others, I believe), and may prove to be limited to Astro 25-based systems. However, the lack of access to “direct” ability, either for technical reasons or as the result of system planning, has cost the lives of firefighters and is something I would never recommend.
So, how does MotoTRBO work in the field? As with all radio systems, this depends hugely on the competence of system design, which is why I guffawed a tad at the OP’s solicitation of “in the box” quotes for equipment, sort of like buying a stereo system. In the tests we ran, a MotoTRBO “repeater” was hooked to a competent (albeit single site) antenna system located at a premier radio high site in the greater Boston area. We found area coverage was pretty good, particularly with the mobile radios (out to more than 20 miles with 99% DAQ voice). The sound of the digital voice (given an adequate signal) was excellent, much better than that of IMBE voice. Subscriber units were, however, a bit complicated for people (including some radio savvy people) to use, more like cellular telephones than two-way radios. And there was a distinct delay between key press and talk permit tone.
My opinion at the time (and I have no basis for changing it now, though I do acknowledge that some particulars may have changed) is that MotoTRBO was intended for a commercial or industrial application, covering a relatively compact and well-defined campus, trading a multiplicity of logical channels for some cumbersomeness in system programming and user interface. In such an application, and given competent system design, I thought (and think) MotoTRBO can perform quite well. I did not (and do not) believe that MotoTRBO was intended to be used in a public safety application – where you must be able to get through right now, where training has to conform to all of the other demands on the users, and where we radio guys have to remember that the radio is not a piece of artwork to be ogled and drooled over, but just a tool that, unless it makes the user’s job easier and safer, is useless.
End of diatribe; sorry for taking so much of your time.
By way of background, I am an independent radio communications consultant. I don’t sell any radios or anything else other than my time. Most of my clients are police chiefs or fire chiefs who have concluded that they are not equipped and would therefore not be wise to deal with vendor shops on their own. Interestingly, some of my clients are radios shops, either who have encountered esoteric issues they don’t want to take the time to learn on their own or who want their best customers to be well advised.
Though no two systems are exactly the same (nor should they be), my public safety concentration means that I deal mostly with voted, repeated, wireline-controlled FM (primarily UHF) systems, which typically will have two transmitters, between five and ten receivers, one or two console-based dispatch points, and between 25 and 2,500 subscriber units. If cost is no object, I’ll start out recommending to anyone Quantar stations, XTL and XTS subscribers, a JPS voter and a Zetron console.
My experience with MotoTRBO is limited, but not nil. A couple of years ago, a Motorola shop for whom I do some work asked me to take a hard look at MotoTRBO; the owner wanted to know what it was so that he could decide in which situations it would make a competent recommendation to a customer. (Yes, there are reputable radio shops.) So he acquired a repeater, a couple of mobiles, and a couple of portables. We set the repeater up, first in the staging area and then at one of his sites, and put it through its paces.
MotoTRBO is a cross between a dedicated channel (“conventional”) radio and a trunked radio. It utilizes two digital data channels that share one 12.5 KHz F1D RF channel. If used for digital voice, both channels can be employed simultaneously.
User “channels” are entirely “logical channels.” That is to say, as with a trunked system, selecting a “channel” (sometimes a/k/a “talkgroup”) means selecting a group of users who’s equipment has been programmed such that when Subscriber A keys, all of the radios of the other members of the logical group will hear what he says and can, if they like, push the button and respond. Unlike a true trunked system, however, each “logical channel” is locked to one of the two TDM slots on the MotoTRBO RF channel, so that if you have two logical channels on Slot A, when one of them is using the channel, the other will get a busy signal. Also unlike a true trunked system, all of the talkgroup programming is done in the subscriber units; there is no “system controller.” This means that in order to added talkgroup members, one has to touch all of the subscriber units to update their programming.
When I looked at it, the MotoTRBO “repeater” was just a box containing a mobile radio, a power supply, and some backplane connections. By no means was this the equal of a Quantar or MTR2000, the minimum that I would specify for a police or fire radio system. At that time (I believe this has now changed), there was no provision for wireline control; all dispatch input was done via a control station. At that time (and I don’t know if this has changed), MotoTRBO had no capacity for multiple, voted receivers. Likewise, when I looked at them, MotoTRBO subscriber units were comparatively low end: certainly lower than Spectras/MCS2000s/XTLs or MTS2000s, XTSs. In fact, they appeared to be lower in build quality than the CDM/HT1250 line (which has proved to be far more rugged and reliable than anyone expected when they first came out).
MotoTRBO “repeaters” and subscribers have the capacity to employ analog F3E emission. This appears to have been provided to ease cutover, and when employed the analog function occupies the entirety of the 12.5 KHz FM RF channel. When used in data mode, MotoTRBO can be used to convey both digital voice and data, and the aspiration of the MotoTRBO “System Planner” is clearly that a MotoTRBO system would be used and useable for data functions such as AVL, POS, inventory control and who knows what else. I seem to recall that the data functions were limited to Slot B, and, as above, when they were using Slot B, no one else could use it (either for data or voice).
When used in digital mode, MotoTRBO makes no provision for “direct” (i.e., short range simplex communications, such as on the fireground), and for that reason its application in the fire service seems to conflict with NFPA 1221. The 1221 admonition against using digital voice on the fireground grew out of the experience of FDNY (and others, I believe), and may prove to be limited to Astro 25-based systems. However, the lack of access to “direct” ability, either for technical reasons or as the result of system planning, has cost the lives of firefighters and is something I would never recommend.
So, how does MotoTRBO work in the field? As with all radio systems, this depends hugely on the competence of system design, which is why I guffawed a tad at the OP’s solicitation of “in the box” quotes for equipment, sort of like buying a stereo system. In the tests we ran, a MotoTRBO “repeater” was hooked to a competent (albeit single site) antenna system located at a premier radio high site in the greater Boston area. We found area coverage was pretty good, particularly with the mobile radios (out to more than 20 miles with 99% DAQ voice). The sound of the digital voice (given an adequate signal) was excellent, much better than that of IMBE voice. Subscriber units were, however, a bit complicated for people (including some radio savvy people) to use, more like cellular telephones than two-way radios. And there was a distinct delay between key press and talk permit tone.
My opinion at the time (and I have no basis for changing it now, though I do acknowledge that some particulars may have changed) is that MotoTRBO was intended for a commercial or industrial application, covering a relatively compact and well-defined campus, trading a multiplicity of logical channels for some cumbersomeness in system programming and user interface. In such an application, and given competent system design, I thought (and think) MotoTRBO can perform quite well. I did not (and do not) believe that MotoTRBO was intended to be used in a public safety application – where you must be able to get through right now, where training has to conform to all of the other demands on the users, and where we radio guys have to remember that the radio is not a piece of artwork to be ogled and drooled over, but just a tool that, unless it makes the user’s job easier and safer, is useless.
End of diatribe; sorry for taking so much of your time.
