Rebanding Question

[rvictor]

Does anyone know from an operational or practical standpoint how rebanding actually occurs? I know that the end goal is to change a group of frequencies to another group of frequencies, but what I'm wondering about is how a complex system with numerous sites, agencies, and users actually goes about making the change?

Is a parallel system setup so that the two systems can operate in parallel during the transition period? Is it done in some way where with a command from a computer everything is commanded to make the change simultaneously? Does some outside provider come in with mobile equipment and setup a temporary system to run parallel during the transition and then pack up and move to the next system to do the same thing? Does everyone transfer communications to secondary channels on other systems during the transition? How long does it take?

Given the need for communication to continue throughout the process, it must be something with a high level of confidence that it will work.

At least one curious mind would like to know.

Thanks.

Dick

 

[OpSec]

Simplified, non-techno version...don't flame me, this is a very skeletal description:

Subscriber units get flashed with a new set of channel maps. Infrastructure gets flashed with a new set of channel maps. TRS controller is told to start using the new channel maps, ergo the system now uses the new channels as assigned by the controller.

I would imagine the the agencies getting rebanded at a particular time would be using a conventional 700/800 MHz channel or would do it in chunks over the course of a day. Smaller agencies may be able to just be off the air for a few hours as all the subscriber units are updated. The bulk of the time needed to "re-band" is the time by a human physically touching each subscriber unit to update it. That's a LOT of radios to be done. Look at Milwaukee County...upwards of 100 separate agencies with 10's, 100's or 1000's of radios for each agency. That's a lot of time and energy needed.

 

[N_Jay]

Lots of different ways depending on how well they planned and how well the negotiated.

In total, probably more ways than you can think of, and many you and I would never dream of,

AND some that make no sense at all!

 

[RevGary]

And to think that if the FCC and Sprint-Nextel would have worked together on their technical standards and original banding/licensing, RE-banding would not have been necessary for many years. Just goes to show once again that once everyone was on the field, someone fumbled the ball and the line judge recovered it and made a touchdown for the head referee... along the sidelines. No extra point !!

 

[N_Jay]

And to think that if the FCC and Sprint-Nextel would have worked together on their technical standards and original banding/licensing, RE-banding would not have been necessary for many years. Just goes to show once again that once everyone was on the field, someone fumbled the ball and the line judge recovered it and made a touchdown for the head referee... along the sidelines. No extra point !!

And if we all had the ability to predict the future perfectly no one would have any excuses for mistakes made. :roll:

There is a lot of history here, and while there were mistakes made, most of the decisions were as good as anyone knew at the time.

 

[mancow]

As for a major system here they just put both the old and new control channels in the radios. When the time comes to change them at the towers the radios will automatically seek what is active.

 

[rvictor]

As for a major system here they just put both the old and new control channels in the radios. When the time comes to change them at the towers the radios will automatically seek what is active.

This sounds almost too simple. The radios could be reprogrammed over a long period of time and the only downtime would be to change the frequencies of the towers. Was this procedure actually used in your area?

73
Dick

 

[OpSec]

Sounds like it...probably the state of Kansas system down there.

Mancow, how are those drug checkpoints going for you?

 

[W9CD]

After talking with the radio techs from Waukesha County, it sounds as though the transition here is going to be a bit more involved. They are currently going around to each subscriber unit and reflashing/reprogramming. The new system will be operating 15MHz lower than before...

So... You can't just change the subscriber units and then flip a switch. The system wouldn't survive for long without retuning the cavities and aligning the transmitters at each repeater site... The way they've explained it is that they will be visiting each individual repeater site up to 3 times for each of the 13 frequencies (so that's what, 6 sites (?) * 13 freqs * 3 visits) and in turn, individual frequencies will be activated in the controllers as these frequencies' transmitters and cans are realigned and tuned. So, it sounds to me as though the subscriber units must receive OTA programming to activate each frequency one at a time and disable the old corresponding freq that is 15MHz higher, until all the new freqs are active.

Does this sound like what other people have heard? My concern is with scanners--many scanner listeners in the FD's around here because not everyone gets a radio. I am trying to help get these units flashed and programmed--but am trying to find out if we will basically have a 6 month period of dead scanners, or if reflashing and programming the new custom band maps will keep the systems monitor-able via the scanners for the duration of the transition... I'm thinking if you load up all the old/new frequencies in the scanner, it's not going to track... Especially since the old freqs would be on the old standard Type II band map, and the new would be using a custom map...

Anyone?!?!?!?

 

[rvictor]

Thanks for the info from the radio techs.

What I've done in anticipation of the rebanding is to set up an additional site for each system using the "new" information for the additional site. I can let the scanner scan for that site now since it doesn't receive a control channel there. I figure that when the switch is made it will receive the control channel on the new site and no longer get one on the old. Anyone see a flaw in this reasoning?

For scanners that don't support multiple sites per system, it would seem that you could just have duplicate systems--one with the existing frequencies and bandplan and one with the new frequencies and bandplan.

Thanks.

73
Dick

 

[mkescan]

I have a conventional system in the BC246 with all the Milwaukee & Waukesha county 851, 852, 853 freqs, So I will know when they start testing
Thats how I heard Milwaukee County Transit is using 853.550 for data now, and 868.550 is silent

 

[Mweiher]

Milwaukee County's Way to Reband

I cannot begin to address how other areas are completing their rebanding, I can only explain how a complicated system like Milwaukee County's is being rebanded.

On December 12, 2008, we finally had an agreement with Sprint after a very very lengthy negotiation and mediation phases. I didn't have the final FRA (Freq Reconfig Agreement), signed, in my hands until April 28! What took so long? A stalling stalling Sprint and unnessary questions from the TA. Less than 1.5 weeks (yes WEEKS) of that period was caused by Milwaukee County needing time to get all the appropriate legal signatures.

We will begin with those agencies that have the most number of mobile replacements. Then we'll move from municipality to municipality finishing each before moving on to the next. We expect to start our first subscriber retune around the end of July (we're ordering and preparing templates at this point) and expect to retune the last one sometime late this year. There are 69 agencies total that use our system as their primary comprising 17 of the 19 municipalities in the county. This is logistical nightmare #1.

Logistical nightmare #2 begins after we're done with the radio retunes/replacements. We will then begin the FNE (tower sites) retune. I've only permitted Motorola to retune one frequency at a time, around all 9 tower sites, because our users require absolute least amount of interuption of service. We expect to have all 19 frequencies retuned before April 2010.

We are adding the new control channels to each radio and redoing the NPSPAC Mutual Aid frequencies (including the newly assigned TG Alias'). We will be taking out the old NPSPAC MA Freqs to avoid the need for a second touch.

The Milwaukee Police Department has in their FRA an promise to keep all 10 NPSPAC MA frequencies available for the duration of rebanding in the entire Midwest. They also agreed to have the old and new patched as needed so that these channels will be fully functional for all users regardless of where their agency (or radio) is in the rebanding project timeline.

I hope this answers your question. If not, feel free to re-post another question, or email me directly. Thanks!

 

[N_Jay]

The last thing anyone should do is assume that how one system rebands is anything like how another system rebands.

There are way too many variables.

 

[rvictor]

Mweiher,

Thanks for taking the time to provide the detailed explanation. Some of us have been doing a lot of speculating about how this project could get done without major interruptions in necessary communication services to the many agencies involved. It's great to hear how it's really being done.

As you proceed through the coming months, take some comfort in knowing that there are those who appreciate the complexity and importance of what you are doing.

73
Dick