RACOM rebanding info

[Radioman96p71]

So I was scanning the 800MHz TRS band last night and came across a few new EDACS control channels that were not there a few days ago. Not sure if they are atmospheric or local but I want to share them to see if anyone else can maybe listen for them. I have a strong suspicion they are the rebanded sites for RACOM, but again, I didn't have much time to monitor them to verify that.

All the below information is as reported by Unitrunker and TrunkMon.

These were all captured around 10:30 PM CDT June 28th

Freq:        LCN:   Sys ID:         Neighbors:     Notes:
854.9375    8            3            1, 4, 19, 22
855.5375    5            1                                 Site is in FailSoft mode
855.8875    1            25          24
856.7875    2            25                               Site in FailSoft mode, listed as 'Island"
856.8375    1            4            1, 2, 3            FailSoft
857.3875    2            2            1, 4, 6, 9        FailSoft
859.3625    8            9            1, 2                FailSoft
860.3875    5            6            2, 5, 7
861.3125                                                     Too weak to decode packets, but was audible

The rest of the hits i got from 861.3125 up can be accounted for in the RR database as RACOM sites. But looking thru the RRDB i cannot find any of the frequencies in Iowa.

Something else i saw was the Des Moines, Osceola, and Ames sites are all announcing a site 22 as their neighbor, when AFAIK there is no site 22. Site 26 is the new one at Collins so maybe they have built another??

More chatter on the radio today about rebanding, but this is the first physical evidence ive heard personally of any LCN changes. They are in Cedar Rapids today doing some reporgramming, so maybe they started in NE Iowa moving this way?

OK enough ranting, I will be monitoring these freqs to see if I can learn any more. I forgot to mention I'm in the Des Moines area. Maybe someone East of me can see if they can hear them better?

When I get some time I would like to speak with someone about the RACOM wiki, I think among all of us here at RR we can make quite an informative page.

KCØGIK

[Radioman96p71]

Ok so my neat table got all smashed when I posted it, maybe I will redo it differently to make it easier to read... grr

KCØGIK

[newsphotog]

Adam, thanks for spending time to take a look at RACOM changes. As it turns out, I am not as familiar with the RACOM system than I thought. I have a few questions.

- What is FailSoft mode? Is it used when they are testing the system?

- When a system announces a site as a neighbor, I assume it "pings" its neighboring tower?

- How are the towers linked then -- RF/microwave or something like fiber optic?

- If the system relies on its neighboring towers to work together and rebanding is going on, should some site failures be expected?

I thought the FCC wasn't mandating that RACOM be rebanded (I might be wrong on this). Is this voluntary?

I know there's a lot of people on this forum that are extremely familiar with RACOM so hopefully someone can shed some more light on this. If they are rebanding all of the sites, it's gonna be a pain in the butt.

[Radioman96p71]

Good questions, I'll try to answer them to the best of my (limited) knowlegde:

Failsoft means the site is operating without connection to the system controller. i.e. if the link between the headend and the site breaks, the site goes into failsoft mode. Which means that it will not check the validity of LIDs against the controller, it cant do advanced features like data, status messages and profile. It essentially turns the site into a non-networked 'island'.

Site neighbors are controlled by the system controller. The site announces who its neighbors are so the radio knows who to scan for when the signal gets low on the current site. It's a handy way for radios to update their roaming list without having to program a new personality. Each site does not actually talk to each other, in the case of RACOM, every site is by itself they just happen to be linked together to share LIDs, GIDs and roaming.

Most towers are linked via a dedicated T1 fiber line. In some cases 2, going opposite directions for redundancy. Some newer sites or sites close together have a microwave link between them then piggybacks over the fiber to the headend. (which in the case of RACOM is in Marshalltown)

In a system like this, all traffic (voice, data) from a site is sent to the headend FIRST, is relayed to all sites that have a user logged in on them on that GID and is sent back to the originating site for transmission. Allowing RACOM to control all aspects of how traffic is handled.

And the rebanding does effect RACOM. According to TA800.org, The entire band over 861 MHz is being allocated to ESMR (Nextel Sprint) while the band from 851-854 is exclusive for NPSPAC, 854-860 is Public Safety, Business and Industrial and low-power SMR. If you look at the RRDB, RACOM is almost exclusively in the 860-865 range.

How all this ties together (in my head) would play out like this:

Set up sites on the new frequencies (temporary or permanent at the same site) with site numbers different than the normal ones. (i.e. 22, 23, 24 etc)
Start to announce these higher site numbers in the neighbor plan being sent to all the radios.
ProFile or manually reprogram the radios with the existing sites, AND the new sites with all the same GIDs they use now.
Test and get the new sites networked in and bring them online.
Fire up the new sites and shut down the old ones, the radios will automatically switch to the closest site in their roam list (which now has the rebanded sites in the list) and auto-affiliate.
Shut down the old site and either re-configure it to replace the temporary site, or take it down completely and use it at the next site to be rebanded.

At least thats how I see it going down to minimize down-time.

Thats what makes me wonder why Des Moines and Ames are both announcing a new site 22 in the neighbor list, when that site does not exist (or i cant hear it).

I really hope that clears something up for someone somewhere! Sorry for the VERY ling-winded post.

KCØGIK

[newsphotog]

Thanks for the info. That all makes sense.

[mws72]

Wirelessly posted (BlackBerry7250/4.1.0 Profile/MIDP-2.0 Configuration/CLDC-1.1 VendorID/105)

In the past I have seen them use higher system numbers to build new sites then when everthing it ready they switched to one of the "normal" site numbers. I have not seen any changes locally but then I need to cruise the band when running unitrunker. Thanks for the info posted.

[KD0BML]

Nothing has changed much here other than some LCNs being re-arranged a bit. I did however manage to get a list of the new frequencies that they will be moving to in the Dubuque area.

[Radioman96p71]

Originally Posted by KD0BML

Nothing has changed much here other than some LCNs being re-arranged a bit. I did however manage to get a list of the new frequencies that they will be moving to in the Dubuque area.

If you would be so kind, I'd love to see them! Do you know what sites they are for? Thanks!

KCØGIK