CHP and RCS

[Anderegg]

I frequent traffic accident scenes for my job, meaning I am around CHP officers frequently. I have found that in the last month or so, almost all officers radios and vehicle extenders are the new 700 MHz variety. This is great for my 800 antenna/splitter/filter set-up in my car, but has given me a thought regarding any chance that ORANGE and TAN will go RCS. If money is being put into these new vehicle repeater systems, what are the chances ORANGE or TAN will ever move to the RCS?

The handheld radios the officers have will work on the RCS, it's just that it would seem odd to invest funds into VRS's for something your about to abandon.

Paul

 

[musician2111]

Someone with more knowledge can correct me if I am wrong but:

The CHP is moving over to its own digital 700Mhz system. The conversions from their current VHF freqs to the new system is being done in multiple phases geographically throughout the state. I do not think the Border Region (thats what they call San Diego) has been done yet.

The El Cajon office in San Diego is the only office to use the RCS but interestingly the RCS equipment is only available to a CHP officer via their handheld radio. Their car radios are not RCS compliant/programmed.

Since the CHP is moving over to their own system, it is only a matter of time before the El Cajon office is no longer affiliated with the RCS. This makes the likelihood of the Orange and Tan coming to the RCS obsolete. What I would expect is that the new 700 Mhz system and the current RCS system will have interoperability once the programming is done. Can anyone more technically savy add to this?

 

[SCPD]

The 700 MHz is not really a "system," it is used for their extenders only. As far as I know the 700 MHz base stations are used as extenders for use in offices. Low band is going to remain for almost all of the state, with the exception of the two offices in San Diego County that are using RCS.

 

[hpycmpr]

Smokey's correct on the 700 MHz frequencies.
The Tan is used over a considerable area outside the range of San Diego's RCS, so I don't see that happening. The Orange I can't speak to.

Steve

 

[Anderegg]

I am getting conflicting stories here.........CHP planning a statewide 700 repeater/trunked system, or it will remain just the extenders?

Paul

 

[Mike_G_D]

I am getting conflicting stories here.........CHP planning a statewide 700 repeater/trunked system, or it will remain just the extenders?

Paul

Years ago (I'm thinking five or so, maybe more) there was some "chatter" about the CHP looking into going to a statewide radio system consisting of 700MHz repeaters when those frequencies become available but they nixed it when the cost versus coverage (because of the number of sites needed) became impractical. I think this where some of the rumors about them going to 700MHz dispatching came from that still persist to this day. Combined with the confusion over what the new CHPERS (?) project has wrought plus the new extender system and new local base 700MHz installations and I guess I can understand why many are confused.

Short answer: Low band will remain the main dispatching system throughout the state (the El Cajon office is the sole exception, as far as I know, as it is on the San Diego County RCS trunking system but the cars will still have low band capability as a back up). The new extenders will use 700MHz P25 for portable-to-mobile operation and allow the officers with the new 700MHz handhelds to operate on local 700MHz/800MHz trunking systems and/or mutual aid conventional channels where available and when so programmed. The 700MHz CHP base channels are a little unclear to me as to usage but I get the impression they will only be used in and around CHP offices and not for long distance statewide coverage.

-Mike

 

[K6CDO]

To expand on Mike's answer:

In the late 1990s, the radio managers of 10 state agencies (I was one of them) realized that funding major system overhauls piecemeal would be a losing battle for funding from the Legislature. They gathered and started working on a unified strategy to consolidate on a replacement system. That effort resulted in a concept of a statewide trunked radio system operating on VHF (150) with 700 MHz augmentation in the densely-populated urban counties. CHP El Cajon came on the RCS in 2002 as a pilot study to evaluate the use of trunking and the higher frequencies. All of the studies showed that the concept would work (and I contend that it still would work, today) using the existing VHF frequencies the state already had available, along with the 2.4 MHz of State-use spectrum at 700 MHz.

About that time the political leadership at CHP changed and the new administration decided they didn't want to partner with the other departments, killing the concept. CHP admin went to the legislature and got a 5-year $500M spending plan adopted to totally replace everything at low band along with 700 MHz. That 5-year implementation is now midway through Year 7.

 

[Anderegg]

CHP is annoying me........I have to keep a 5 foot whip in my car just to throw on the roof for pursuits.

OK, so low band is here to stay........what about the narrowband issue, are they not affected?

Paul

 

[SCPD]

To expand just a little more, each of the new radio configurations in CHP vehicles include capability to operate on VHF High, UHF and, as mentioned via the extender, the 700/800 bands as well. I don't know if they can switch between bands remotely using the handheld extender or if the mobile has to be adjusted before the officer leaves the car. Maybe someone on this thread can answer that question.

VHF would have been a good deal for the CHP. I thought another constraint was the unavailability of a sufficient VHF High frequencies statewide. The number of additional sites needed for 700 MHz coverage, especially in rural areas, for maintaining the same coverage that exists for low band would involve at least a 100-200% increase. I read a study done of San Diego County, where topography is less mountainous than other areas of the state, that the additional sites necessary to make the conversion would Involve 3-4 times the sites. I've also heard from others who had worked in the Department of Communications for the state (I've forgotten the current name) that more than 4 times sites would be required statewide. Then there is the north coast where Caltrans and State Parks gave up on using 800 MHz, which they had converted to in the remainder of the state, due to the heavy tree cover. Needles attenuate RF energy at the higher bands due to the shorter wavelengths involved. State Parks is using VHF High and employees sent of out of district assignments would have to pick up 800 MHz radios to communicate in all the other districts.

It is likely that increasing the number of sites even by 200-300% statewide could not be accomplished. Almost all the new sites would involve establishing sites and access roads to locations that have no development. The environmental impacts of this would be very significant. On federal public land (NPS, BLM and USFS), where a significant number of the new sites would be located, involve land in Congressionally designated wilderness, wilderness study areas or non-wilderness roadless areas on National Forest lands. On these latter lands the building of roads is prohibited.

I'm very familiar with the coverage of 800 MHz in the eastern Sierra (Mono County) as a result of working for the Forest Service in two different ranger districts here. I worked with Caltrans during their 800 MHz conversion and the CHP effort to improve coverage in some canyons in the early 80's. Thus I'm familiar with what it would take to get better coverage for the CHP as they need better coverage than Caltrans. They would at least need to install their 700 MHz equipment at 15 existing developed sites, 2 NPS and USFS sites that are only accessible by helicopter where microwave installation could not be made, with even 70 MHz linking would be doubtful and would not be approved by these agencies,1 site on BLM land without power and accessible by 4WD only where approval is doubtful and the development of at least 9 entirely new sites. This is a total of 27 new installations. There are 7 existing sites with low band already installed. This results in an increase of 20 sites, a nearly 300% increase where 7 of those have no developed power, and 5 of those where commercial power is unlikely to be approved. The 3 sites where approval is significantly doubtful would leave some large areas uncovered..

A VHF High conversion would only involve 4 entirely new sites and the 2 sites with the one road accessible BLM site and one NPS site where approval is unlikely and helicopter access is needed. This is nearly a doubling of sites. UHF would involve 3 more additional sites than VHF High. The new installations at both the existing developed sites and those entirely new sites would require more maintenance per site than the existing 7 low band sites, primarily due to more difficult access and distances. Imagine the expense at the 2 sites with helicopter access if the unlikely approval of the 2 agencies managing those lands was given. Apply this statewide and you can see how expensive it would be to depart low band.

 

[Anderegg]

I don't understand the big "Let's move to 800 trunking!" nowadays, since it seems just as easy to go VHF or UHF trunking, as they did in parts of Los Angeles. Was this whole 800 thing just a "fad" because 800 was the only trunking solution for so many years?

Paul

 

[SCPD]

To expand on Mike's answer:

In the late 1990s, the radio managers of 10 state agencies (I was one of them) realized that funding major system overhauls piecemeal would be a losing battle for funding from the Legislature. They gathered and started working on a unified strategy to consolidate on a replacement system. That effort resulted in a concept of a statewide trunked radio system operating on VHF (150) with 700 MHz augmentation in the densely-populated urban counties. CHP El Cajon came on the RCS in 2002 as a pilot study to evaluate the use of trunking and the higher frequencies. All of the studies showed that the concept would work (and I contend that it still would work, today) using the existing VHF frequencies the state already had available, along with the 2.4 MHz of State-use spectrum at 700 MHz.

About that time the political leadership at CHP changed and the new administration decided they didn't want to partner with the other departments, killing the concept. CHP admin went to the legislature and got a 5-year $500M spending plan adopted to totally replace everything at low band along with 700 MHz. That 5-year implementation is now midway through Year 7.

A VHF trunked system would pool frequencies from several other state agencies, most especially Cal Fire. I would bet that State Parks would prefer to standardize their system on VHF high. Had the state waited until narrowbanding was accomplished it would double the number of frequencies on VHF high. Such a system would provide interoperability among a number of agencies that don't have it now, as well as in rural counties where VHF High use is prevalent. As I stated above, the number of additional sites needed would still be significant, but not nearly what 700 MHz would require. I think it would be many times more expensive than they are spending on CHPERS, which is proving hard enough to fund.

I agree that a statewide trunking system for multiple agencies would have worked. Imagine not having to have the Department of Corrections and Rehabilitation on 800 MHz as well as the elimination of the CMARS system that has very spotty coverage in rural and mountainous areas. One agency presently using CMARS that I'm familiar with is the CCC. They don't have 800 MHz coverage in most of the rural areas, such as Mono and Inyo Counties. They work with Cal Fire, the BLM, USFS and NPS on a regular basis. If they had VHF handhelds for the state trunked system they would be able to communicate with these agencies without having to borrow the very limited extra handhelds these agencies can spare. A VHF trunking system would have some "fill in" areas where single conventional frequency sites would be used, similar to what San Bernardino County and SCE have done with their 800/900 MHz systems. Those areas don't have nearly the traffic that other trunked sites have.

All of this has been discussed on a number of other threads. The guess of the use of the 700 MHz base stations was made by a number of people on them. The discussion concluded that they would be used for extenders while the officers were working at the area office. Speculation as to other uses was also talked about. The office extenders would require a base station, similar to the mobile units that could interface 700 MHz and low band.

When I worked for the Inyo National Forest direct communication with a repeater was very spotty for those carrying handhelds in the Lee Vining Ranger Station. The radio tech installed a 400 MHz link to a more powerful base station that already existed in the building. He obtained a number of 400 MHz handhelds so that field going employees could have radios at their desks and be able to leave their desks and operate the nearest repeater. Employees in the ranger station whose duty stations were away from the ranger station, such as fire stations, could pick up one of the 400 MHz handhelds while they were in the office. Typically there are a limited number of base station remote desk units in a ranger station so this was quite an improvement. Perhaps the 700 MHz base stations will be similar.

 

[K6CDO]

-...-

OK, so low band is here to stay........what about the narrowband issue, are they not affected?

Paul

No, the narrowabnding mandate is for the 150 and 450 bands only.

 

[SCPD]

I don't understand the big "Let's move to 800 trunking!" nowadays, since it seems just as easy to go VHF or UHF trunking, as they did in parts of Los Angeles. Was this whole 800 thing just a "fad" because 800 was the only trunking solution for so many years?

Paul

Many departments, in my opinion, did not need trunking at all, whether it was 800 MHz or 400 MHz. When I look at the database for Coconino County, Arizona I see that there is a digital trunking system in place for Northern Arizona University and the Flagstaff Police Department. I used to live there and am familiar with the place. Flagstaff is isolated enough from much larger metro areas that the availability of VHF frequencies should not be a huge obstacle. Both the university and the PD had been operating on VHF and could have gained interoperability by just programming each other's frequencies into their radios. It had probably been accomplished before anyway. They could have obtained a few more tac frequencies and such, but they went 800 trunked. I think they were sold based on the following:

--they cannot be scanned (not true of course)
--they can expand the system for decades to include 10x or more of their existing channels
--if you want to encrypt, it can be done with minimal effort
--soon all your friends and neighbors will be on 800 MHz trunked systems and interoperability will exist for everyone
--it will meet narrowband requirements right now, no need to be concerned with that once we build you this system

Given the huge investment in technology the communications companies had invested the pressure to sell in order to recoup much of this was on as soon as the product was ready for production. I think most of the government admin types that got involved did know the first thing about radio and could easily be sold. There is also the tendency to want to have the latest, the most bells and whistles, and most complex product as a matter of pride. With the growth of all sorts of electronic gadgets available to us, many that we don't need at all or don't need the latest version, admin types and rank and file police officers seem to be caught up in this trend they want to do the same at work.

Its too bad, because almost everything else in the county is on VHF High. The fire departments, the federal agencies, the county sheriff, the Navajo Reservation, etc. The Arizona DPS is on UHF and was the only major player that wasn't on VHF High. Interoperability existed before. The terrain in Northern Arizona is more or less flat so 800 might work OK, but not always with handhelds. I worked for the Forest Service there and handheld coverage was very good back in the 70's, so I would imagine it is excellent now, so staying on VHF High would have made sense.

Yes, 800 MHz trunking has had an element of being trendy.

 

[K6CDO]

I don't understand the big "Let's move to 800 trunking!" nowadays, since it seems just as easy to go VHF or UHF trunking, as they did in parts of Los Angeles. Was this whole 800 thing just a "fad" because 800 was the only trunking solution for so many years?

Paul

The move to 800 was driven by the lack of available frequencies. and equipment limitations. San Diego City was on VHF, with the expanding use of radio in NW Baja California chewing up what little spectrum wasn't being blasted by users in the LA area. The County was on VHF Low, VHF High, and UHF - with no room in VHF High or UHF for expansion. 800 was green space, where all could get onto one level playing field, and allow trunking technology to handle the increased demand for spectrum. Trunking technology is frequency band agnostic; one could trunk lowband, if one wanted to. Of course, the users in Texas, Arkansas, Rhode Island, Georgia, etc. might object when the skip is in ...

 

[SCPD]

The move to 800 was driven by the lack of available frequencies. and equipment limitations. San Diego City was on VHF, with the expanding use of radio in NW Baja California chewing up what little spectrum wasn't being blasted by users in the LA area. The County was on VHF Low, VHF High, and UHF - with no room in VHF High or UHF for expansion. 800 was green space, where all could get onto one level playing field, and allow trunking technology to handle the increased demand for spectrum. Trunking technology is frequency band agnostic; one could trunk lowband, if one wanted to. Of course, the users in Texas, Arkansas, Rhode Island, Georgia, etc. might object when the skip is in ...

Thanks for this explanation, it jogged my memory. I do remember the use of the three bands, but did not realize the problems with frequency availability. It does make sense as San Diego is in a location where interference with portions of L.A. and Orange Counties is possible. The problems with Mexico are well known, not just for legal use of frequencies, but, as hams and natural resource agencies have experienced, the illegal use of frequencies is overwhelming. I've been on fires in southern California where critical fire traffic on tactical frequencies has been blocked by taxi cabs and CB like use. I don't think that San Diego had access to the UHF-T band either, although I'm not sure of this.

Even if VHF Low trunked systems were available there are problems with handhelds. I remember working with some buddies at California State Parks in the early 80's who were wearing VHF Low handhelds. The antennas nearly extended above their shoulders and were getting caught on things. The manufacturers were not building better handhelds on the band either. The 5 watt power didn't seem to work all that well either.

My comments regarding 800 MHz trunking were not specific to San Diego County, rather to other locations I've observed in the last 20 years.