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Thread: Single Channel Rural Solar Site: P25 Roaming from Urban Trunking to Boonies - How?

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    Default Single Channel Rural Solar Site: P25 Roaming from Urban Trunking to Boonies - How?

    Hi all,

    When roaming from site to site in a single vendor, single agency multisite P25 trunking system, you expect not to have to switch the knob as you pass from tower to tower. It should be automatic.

    But how do you maintain that "automatic-ness" when you pass from an area with full trunking coverage into a rural region which has only one tower with a single repeater.

    I'm looking at keeping power consumption down because the site only has two solar panels running it right now and a low power legacy analog repeater at it. I want to upgrade the site staying as "minimal" as possible, but allowing users to ignore the fact that they've roamed off the trunking system and onto the minimalist system.

    Running grid to the site would be millions. Not an option.

    Increasing the panel count is an option to a degree.

    But the radio part is a conundrum. A trunking solution requires constant transmit on a control channel and one or two more voice channels. The power needs start to spin up too much.

    This is not something the "big boys" (ie. large system vendors) want to pursue - a solution likely represents too much engineering effort and too little return on that effort for a one-off like this.

    Channel scanning schemes was met with considerable disapproval (based on one vendor's years of experience) and I'm inclined to respect that opinion, but I can't believe this is something that someone more niche hasn't tackled before and been successful.

    Backhaul options are wide open but landline of any sort is out. We could go with the (in-stock) reasonably low power microwave (basically a really long ethernet cable, when you look at it's functionality) or another channel with a Yagi, but the chalkboard is bare at the moment and any ideas would be great!

    Thanks!
    --
    Jim
    "Prepare: The time to win the battle is before it starts." - Frederick W. Lewis


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    FWIW, Moto does have a "Power Efficiency Package" in UHF (only) that lowers standby power consumption but it uses a modified transceiver, PA, power supply, fan kits and requires no 29 V Aux power loads.

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    Efj also offers a hybrid solution that can function on solar.

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    You should look into simply installing an in-band Futurecom DVRS at the tower site. Two antennas...one for the XTL/APX mobile radio for your connection back to the system, and another for the "conventional" DVR side for local coverage. I put "conventional" in quotes because the new P25 units are built to 'mimic' the trunking operation for the field radios as if they were still on the system (proper programming of XTS/APX radios needed, of course). The radios affiliate through the DVRS exactly as though they were on the system...in fact the system doesn't know the difference. The radios generate talk permit tones, proper affiliated talkgroup audio is passed though...emergency calls are handled through it...encryption passes through...etc. They really are phenomenal units in P25 mode.

    You still need to physically change the channel selector to the DVRS channel, so it doesn't give you the 'roaming' you're looking for, but otherwise it's practically a single channel site extension of the system.

    http://www.motorolasolutions.com/US-...tem-DVRS_US-EN

    http://www.futurecom.com/products/di...epeater-system

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    I know of a few systems doing this using Intellirepeaters (one or multiple) as fill-ins on top of a big simulcast layer or two. However, those are all on utility power... I'm not aware of anything specifically designed for solar ops.

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    We have used the future comes and work well! But have to change channels. Low Power consumption also compared to a site.

    Run the CC at 10 watts, plus site router, one Site controller instead of two and backhaul equipment at 4.9Ghz. Migt consider a hydrogen full cell technology to supplement your solar never priced it might be expensive also condider a wind generator. A lot of things come into play when running solar.

    Basically if they want roaming capabilty gonna have to have a CC running 24/7 and spend some money to upgrade your Green energy capacity.

    Since it sounds like you are st***** for cash to do what you need/want to do, sounds like changing channels may be the only solution.

    I am sure I am way off the cost of the futurecom system, but I believe it will be over 10k for it. Keep in mind you will have to supply a XTL5000 mobile to interface to the futurecom. But they do work pretty slick, the future come site will have to in range of the donor site. Which is just a yagi antenna aiming at the donar. And an Omni for the coverage area in question.

    If you go this route XTS and XTL should already have the capabilty for DVRS. If using APX, DVRS is an flash option that has to be purchase, not very expensive though.

    Sounds like you have a lot of work ahead of you, goodluck!
    Radio Referenced...Those who think they know it all are very annoying to those of use who do.

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    You might want to check out Daniels Electronics. They are known for engineering low power consumption applications for off-grid and I've heard they are willing to work with unique situations.

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    +1 on Daniels (now called Codan). The stuff they make is bullet proof and extremely low power consumption, and highly customizable.