Page 1 of 1

AMTS 217 band reallocation issues

Posted: Fri Dec 15, 2017 6:20 am
by Bill_G
Anyone else having issues with new AMTS 217Mhz block B auction winners interfering with unlicensed patient monitoring products in healthcare facilities?

Re: AMTS 217 band reallocation issues

Posted: Fri Dec 15, 2017 12:24 pm
by Astro Spectra
Hi Bill, interested in your observations can you post more? Are the medical devices Part 15? The 'interferers' Part 80?

Re: AMTS 217 band reallocation issues

Posted: Sat Dec 16, 2017 9:00 am
by Bill_G
I'm not going to get very specific because I think this is the cusp of a bigger problem, and big players are involved. There are a number of patient monitoring systems that utilize the low power unlicensed portion of the 220 band from 216-217Mhz. These things transmit periodic data bursts at around -35dbm to multiple receivers spread around the care unit. Each receiver is supposed to cover about 2000sq ft. RSSI's are typically in the -110/100dbm range depending on patient location in reference to the receivers. Very low level stuff.

Along comes an AMTS block B winner (217-217.5mhz) license winner building their first of many linked trunked DMR systems with 1000W EIRP less than five miles away with a clear line of sight to the care unit. RSSI for the control channel in the unit is -80dbm or better. All the rcvrs are faulting reporting interference. The nurse's station PC is going nuts as all patient links drop out.

Their IT dept and local vendor support can't figure it out. You get called in. You trace down the interferer, contact them, and they agree to mute the new transmitter as a test. Bingo. The healthcare system is working again.

All the managers at the healthcare place say "Oh, thank you so much. You're brilliant."
And you say "Uh, guys, tick tock - this bomb is going to go off again. You need to act."

Indeed, the kind hearted block B system owner is being generous. He wants his new shiny radio system working, and he is the licensed owner of a chunk of spectrum, not them. They need to move if they think he parties too loud. Got his mind on his money, and his money on his mind. Whose neighborhood? His neighborhood. And he may be coming to your neighborhood soon.

Re: AMTS 217 band reallocation issues

Posted: Sun Dec 17, 2017 5:18 pm
by com501
I'm gonna pass this on to our sales team. Something to investigate.

Did you find other devices that won't be in this spectrum to use?

Re: AMTS 217 band reallocation issues

Posted: Mon Dec 18, 2017 4:19 am
by Bill_G
Yes, there is alternative product from the same manufacturers that utilize wifi, 900, or deeper into 216 away from 217.

Re: AMTS 217 band reallocation issues

Posted: Mon Dec 18, 2017 8:57 am
by fineshot1
This must be why I noticed that the local area GSP DOT Trunking Freqs were now totally inactive.

NJGSP - NJDOT 220Mhz Trunking Freqs
in Toms River (Ocean County)

Toms River NJ: (Exit 82)
217.6000,
217.7000,
217.8000,
217.9000

Re: AMTS 217 band reallocation issues

Posted: Mon Dec 18, 2017 9:22 am
by Bill_G
New Jersey Transit has the 218.0-218.5mhz block A license WQZH741. No one has the 217 blocks yet. Just a handful of freq specific users.

Re: AMTS 217 band reallocation issues

Posted: Mon Dec 18, 2017 9:26 am
by fineshot1
Bill - these NJ DOT freqs were actively being used years ago. I have not listened recently and after reading
your post I noticed those freqs were inactive. When they vacated I have no idea.

Re: AMTS 217 band reallocation issues

Posted: Mon Dec 18, 2017 9:33 am
by Bill_G
You can check the ULS to see if those freqs are still active.

Re: AMTS 217 band reallocation issues

Posted: Mon Dec 18, 2017 9:45 am
by fineshot1
Bill_G wrote:You can check the ULS to see if those freqs are still active.
Did that already with nothing listed.

I remember years ago the heavy pulsing causing problems on the
220Mhz ham band repeaters receivers and also if you were in close
proximity while mobile on your mobiles receiver.

http://forums.radioreference.com/new-je ... tem-2.html

Re: AMTS 217 band reallocation issues

Posted: Mon Dec 18, 2017 1:03 pm
by motorola_otaku
fineshot1 wrote:Bill - these NJ DOT freqs were actively being used years ago. I have not listened recently and after reading
your post I noticed those freqs were inactive. When they vacated I have no idea.
NJDOT's 220 system has been taken down, and the radios have surfaced through various surplus channels. Think they're on the new 700 P25 system.

Re: AMTS 217 band reallocation issues

Posted: Tue Dec 19, 2017 11:22 am
by fineshot1
motorola_otaku wrote:
fineshot1 wrote:Bill - these NJ DOT freqs were actively being used years ago. I have not listened recently and after reading
your post I noticed those freqs were inactive. When they vacated I have no idea.
NJDOT's 220 system has been taken down, and the radios have surfaced through various surplus channels. Think they're on the new 700 P25 system.
I won't and don't get on RR anymore since they went the same way of qrz dot com(lousy mods & jackels) so i missed that info. Thanks