Narrowbanding a radio network.

[andrew80]

So... I work for a relatively large company which has multiple base stations across southern California and a few thousand Motorola MCS 2000's in the same area. Currently all are wideband but have to be switched to narrowband to meet FCC standards by 2013. Is there a specific order things should be switched over, and will, for example, a wideband mobile radio still be able to comunicate with a narrowband base station as long as it remains close enough to it's center frequency? The network must remain 100% functional through out the conversion process or as close to it as physically possible. Any information would be much appreciated.

Thanks.

 

[ab3ai]

As long as your on the same frequency you should be fine. A wideband radio will sound overdriven into a narrowband radio and a narrowband radio will sound quieter into a wideband radio. However, from my experience that was minimal at best. When we did our migration, we had radios on narrowband a week prior and nobody noticed a difference (atleast it wasn't brought to my attention). As far as order, that all depends on how your system is setup and what you have available to you.

PS This was a VHF Simplex system.

 

[n5ims]

Step 1, review all radios in the network to see what's required to make them narrowband compliant (simple program change to replace the radio).
Step 2, order the replacement radios, if necessary.
Step 3, submit application with FCC to modify the existing license(s) to add the narrow-band emission code.
Step 4, cycle through the capable radios to duplicate the existing channels, but have the emission set to the correct narrow-band settings (instruct the users to ignore the new channels for now).
Step 5, replace any existing radios with ones that are narrow-band compliant, if necessary.
Step 6, (should be done during a period of minimal activity and when critical communication is also minimized) instruct users to use an alternate channel and reprogram the repeater(s) for that channel to use the narrow-band setting.
Step 7, instruct users to change their radios to use the narrow-band channel number(s) and no longer use the original wide-band one(s).
Step 8, cycle through the radios and remove the wide-band programming.
Step 9, (once all radios are successfully using the narrow-band settings) submit application with the FCC to remove the wide-band emission code settings from the license(s).

This process can be done by frequency, area, or some combination to guarantee functionality as necessary (steps 6 & 7 at least). If you do stagger the conversion, clearly instruct the users on the correct channel to use for which area and stage of the conversion process to reduce the chance that a wide-band user is on a narrow-band channel and vice-versa.

Please be aware that in 99.999% of the cases, the narrow-band channel will be the exact frequency as the wide-band channel. What's required with the change to narrow-band is a modified emission setting, the frequency will not need to change.

In your example, a wide-band mobile and a narrow-band base, both would use the exact same frequency, but the mobile would use a wider bandwidth than the base would (like an 18 wheeler and a Smart Car both driving in the same lane on a highway). They would both probably be able to communicate, but there may be some volume issues or audio distortion during that conversation. If done as I indicated above, they could simply both switch to the same channel setting to remain either both wide or both narrow for that conversation and communicate without issues.

 

[cdknapp]

I don't know what your logistics are, but probably convert 2-3 bases over first, then do maybe 1/2 of the portables. Once those are on-line, do the balance of everything else. Is you service coming to you to do these, or do they have to take them back to the shop? That would make a big difference; hopefully they can come to you.
Can your bases similcast? That would make things a lot easier if you could.
Do you have anything spare, bases or protables? If you do, get them dome first and put those out to use during the process.
Another thing would be to set up a couple (few) places to have everyone bring thier portables to, so you can do them in mass sessions. This is easier than trying to catch up with everyone individually. Is there any day where more of the portables would be off-duty?
It would be real hit-and-miss if you aren't on exact frequencies; I wouldn't trust that myself.
It is all software driven, so once the new stuff is programmed into the software, it should take only a matter of seconds to prgram each radio.

Good luck!

 

[jim202]

So... I work for a relatively large company which has multiple base stations across southern California and a few thousand Motorola MCS 2000's in the same area. Currently all are wideband but have to be switched to narrowband to meet FCC standards by 2013. Is there a specific order things should be switched over, and will, for example, a wideband mobile radio still be able to comunicate with a narrowband base station as long as it remains close enough to it's center frequency? The network must remain 100% functional through out the conversion process or as close to it as physically possible. Any information would be much appreciated.

Thanks.

I am going to be blunt and you probably will not like what I am about to say. The FCC has been pushing the narrow band issue since it first came out with the news some almost ten years ago. If you have to ask for help on a scanner site, your not in the groove of how communications works. Are you sure your the person for this project? It's rather late in the process and by now you should have read all about the process from a number of sources. Have you even checked to see if your MCS2000 radios will operate narrow band? Your radio service shop might be trying to lead you down a big dollar path for them at your expense. You never mentioned what band your radios are on.

I would suggest that you get with the program and start obtaining information from the sources that can provide you with the correct information.You might not even get it from you local radio service shop. Many of them are trying to make hay while the sun still shines and are suckering their customers into actions that they probably shouldn't be taking. Have you even considered searching the FCC site to even obtain the correct steps that you need to modify your company's radio licenses?

It might even be worth the expense to consider using a communications consultant to work with the company to come up with a plan on just what steps might be best. Again I am going to say that there are many consulting companies that are taking advantage of their customers in the narrow banding process. You will need to find some way to weed out the problem children in the business. Maybe trying to obtain a list of their customers that have gone through what you need to have done. Ask for contact information from other clients that have had to narrow band their radio system. Call those listed and ask point blank questions if they were happy with the services provided and if they thought the cost was acceptable. Don't skimp on your homework on this action item. It will cost you your job if you make the wrong choice.

It may seem harsh and too blunt of an answer, but I have been in the business too long to stand on the side and watch people get taken for a ride and still end up no better off than they were to start with. Your almost too late in the process now to sit back and wait. Don't forget that there are thousands of radios that will be needed to be replaced around the country. The radio vendors can only make so many a month. The longer you wait, the harder it will be to obtain any radio replacements you might require. There are also some good new comers to the market to give Motorola a run for their money at a much lower cost.

 

[andrew80]

Thanks for the info, it was pretty much everything i needed to know. the over/underdrvie issue was my primary concern. I'll do a little testing.

Jim, thanks for your concern, but we have everything we need, all equipment/licences are ready and good to go (giving us over a year to make the switch...). I just wanted a little info on the actual change over and issues that we might face if we don't switch over all mobiles on a channel at once. The project is logistically challenging, but we'll manage. (like we really have a choice ) If i had been with the company more than 10 weeks it would have been done by now.

Thanks again, folks.

Andrew

 

[cdknapp]

I am going to be blunt and you probably will not like what I am about to say. The FCC has been pushing the narrow band issue since it first came out with the news some almost ten years ago. If you have to ask for help on a scanner site, your not in the groove of how communications works. Are you sure your the person for this project? It's rather late in the process and by now you should have read all about the process from a number of sources. Have you even checked to see if your MCS2000 radios will operate narrow band? Your radio service shop might be trying to lead you down a big dollar path for them at your expense. You never mentioned what band your radios are on.

I would suggest that you get with the program and start obtaining information from the sources that can provide you with the correct information.You might not even get it from you local radio service shop. Many of them are trying to make hay while the sun still shines and are suckering their customers into actions that they probably shouldn't be taking. Have you even considered searching the FCC site to even obtain the correct steps that you need to modify your company's radio licenses?

It might even be worth the expense to consider using a communications consultant to work with the company to come up with a plan on just what steps might be best. Again I am going to say that there are many consulting companies that are taking advantage of their customers in the narrow banding process. You will need to find some way to weed out the problem children in the business. Maybe trying to obtain a list of their customers that have gone through what you need to have done. Ask for contact information from other clients that have had to narrow band their radio system. Call those listed and ask point blank questions if they were happy with the services provided and if they thought the cost was acceptable. Don't skimp on your homework on this action item. It will cost you your job if you make the wrong choice.

It may seem harsh and too blunt of an answer, but I have been in the business too long to stand on the side and watch people get taken for a ride and still end up no better off than they were to start with. Your almost too late in the process now to sit back and wait. Don't forget that there are thousands of radios that will be needed to be replaced around the country. The radio vendors can only make so many a month. The longer you wait, the harder it will be to obtain any radio replacements you might require. There are also some good new comers to the market to give Motorola a run for their money at a much lower cost.

AMEN to your last line! If anyone is interested, check out Connect Systems equipment. It is EXCELLENT and very reasonable. I will put it up to the big M or anyone else. One agency that I know of just bought 5 portables with speaker mics for LESS THAN the price of one big M without a speaker mic....