> On January 1, 2013, all public safety and business industrial land mobile radio systems operating in the 150-512 MHz radio bands must cease operating using 25 kHz efficiency technology, and begin operating using at least 12.5 kHz efficiency technology. This deadline is the result of an FCC effort that began almost two decades ago to ensure more efficient use of the spectrum and greater spectrum access for public safety and non-public safety users. Migration to 12.5 kHz efficiency technology (once referred to as Refarming, but now referred to as Narrowbanding) will allow the creation of additional channel capacity within the same radio spectrum, and support more users.
> After January 1, 2013, licensees not operating at 12.5 KHz efficiency will be in violation of the Commission's rules and could be subject to FCC enforcement action, which may include admonishment, monetary fines, or loss of license.
You could be faced with a very hard spanking; if you don't spend large amounts of money, up-grading your RTK and/or Robotic setup, and tossing out your old, out-dated expensive system.
Is this just another way for THEM to mine more money out of US? Or is it for the greater good of all mankind?
Radar
PS: Please forgive me if this has already been posted; I have not had much time to pay attention...
> Is this just another way for THEM to mine more money out of US? Or is it for the greater good of all mankind?
It makes more frequencies available. So in that sense it is for the greater good. More frequencies means more licensing fees for the FCC, so in that sense it is a way to et more money.
It has been coming since the Clinton administration, so it's not like they just sprung it on us.
I am wondering when the 6.25 Mhz mandate is coming.
It's one thing to regulate, but just how could they enforce it?
The FCC has spectrum analyzers and directional antennas and field engineers who know how to use them. They also respond to complaints of interference to adjacent channels.
The fines for interference can be quite large. Certainly enough for you to buy new radios and have a lot left over.
FCC enforcement is mainly complaint driven.
The RTK GPS broadcast, which is on for about a quarter of a second every second for hours on end, can certainly generate some complaints.
When the narrowbanding discussion began I was skeptical of the need because it seems that the cellular phone has greatly decreased the use of two-way radio, which would mean less demand for radio frequencies.
A couple of months ago I did some looking in the FCC license database on the frequencies 12.5 kHz above and below the center frequencies of the 13 frequencies most used by RTK GPS users. These are frequencies that are being made available by narrowbanding.
I was surprised how many licensees there already are on those "new" frequencies. Some licenses go back to 2002. Licensees on these frequencies in Wyoming and Montana include municipal governments, engineering firms, investor-owned electric utilities, and a bunch of others.
Those licensees 12.5 kHz away from your center frequencies have had to accept the interference from wideband broadcasts in the past, but after 01 January 2013 they will be complaining to the FCC.
This will be interesting to watch.
GB
How does this affect the PDL 32 watt gps base radios, is there anything that can be done beside purchasing new to make the existing equipment work.
I been a little confused with the information.
I heard that you can still use these freq. if transmitting at 19,200 in a 25 kHz?
Does anyone know?
Scott
> is there anything that can be done beside purchasing new to make the existing equipment work.
I would talk to my dealer, you might even ask the competition, just to keep them honest....;-)
Scott
That's my understanding and my Trimmark3 will work alright at the 19,200 data rate. So that's my plan for now, unless someone tells me different. Google FCC narrowbanding and you will that on data only, 19,200 on the 25 kHz is OK.
Ron
Thanks for the info Ron,
I have been using the same Trimmark-3 @ 19,200 for years. I do not understand why the high baud rate makes a difference, but I am with you, "unless someone tells me different."
Scott
Found some info on FCC
I find the FCC web site VERY unfriendly about straight information. But here is a brochure put out my a Fire Fighter Association that may be helpful.
http://transition.fcc.gov/pshs/docs/clearinghouse/guidelines/Narrowbanding_Booklet.pdf
Some info from it...
Beware:
The FCC expects that licensees ultimately will implement equipment that is designed to
operate on channel bandwidths of 6.25 kHz or less. However, there currently is no deadline set for making this transition.
Baud Rates:
WHAT IS THE “EFFICIENCY STANDARD”?
As noted above, licensees may meet an efficiency standard instead of satisfying the
requirement to operate of channels with a bandwidth of 12.5 kHz or less.
For voice operations, the efficiency standard is satisfied if the equipment is
capable of transmitting at least one voice channel per 12.5 kHz of bandwidth. In
other words, voice equipment operating on a channel bandwidth of up to 25 kHz
will be permitted if the equipment supports two or more voice channels.
For data operations, the efficiency standard is satisfied if the equipment is
capable of supporting a minimum data rate of 4800 bits per second per 6.25 kHz
of channel bandwidth.
ARE THERE ANY EXCEPTIONS TO THE BASIC NARROWBANDING REQUIREMENT?
Apart from the option of satisfying the above efficiency standard, the only general exception is that paging-only channels are not subject to the FCC’s narrowbanding requirements.
So 19,200 looks okay. (4800 x 4 = 19200)
Some have tested the higher baud rate and stated that the there is a loss of distance, I believe. I am going to try it out soon before I spend the big bucks buying a new radio. Still have to upgrade the license though. Don't forget that though.
Yes, I have noticed a loss of distance, but it is rare that I need over a mile and I have been getting about two miles in the rolling terrain where I could get 3 or 4 on the lower rate.
So is there a loss of distance with the new stuff. I have an old Trimble Trimmark IIe and after I rewired the power cord kicks butt for distance. Hate to give it up! Does anyone know if I still will be able to get good range with a new 35 Watt narrow band unit? I suppose I'll need to do some testing in the field before I buy.
