The Battle: Hospital telemtry v.s. land mobile interference

[radioservice]

I have a customer that operates security radios for a local hospital . They run in the 466 Mhz band. They have been given the order to cease and discist use of thier two way because of interference ( alleged interference) with the hospitals patient telemetry equipment (operating in the 460-470 Mhz band) Who's right!? Who's wrong!? It's a great big pissin' contest and the telemetry people have that whole 'life or death' club to swing. (rightly so).
Throughout the hospitals paitient floors there are telemetry antennas in the ceiling tiles...they say that they receive "squelch" noise from time to time at random. There may be a two way in the area, and then, there may be no two ways in the area...but there gettin' noise from somewhere....and thier obviose answer...; shut down the two way radios!
Shouldn't the telemetry equipment be filtered well enough to keep out the two ways signal...?could this be a stray harmonic from outside the building?
What should I do to assist my Security chief in his defense of the two way usage?

Help

[k4wtf]

What should I do to assist my Security chief in his defense of the two way usage?

Help

Move him to VHF, 800Mhz or 900Mhz? A friend of mine is the SecOps chief at Cardinal Health (Grant, Riverside, etc in Columbus) and I know that when they recently went to an 800Mhz system, it was to be sure that they didn't cause problems for any of the other systems in operation in the hospitals.

Just a thought.

John

[mastr]

The mentality of most hospital managment never ceases to amaze, and at the same time irritate me. You can't win in this situation from a technical standpoint, because their is no way to prove (to the satisfaction of hospital "neckties") that your radios are not a problem to the telemetry equipment. Instead, let the telemetry vendor find the source of the problem- have the security staff carry "dead" radios while this is done, it is a near pricless thing to see the look on the telemetry tech's face when you say "we are just carrying these inoperative radios for show, until you find the trouble; guess it's not us."

The best way might be to tell the Security chief to meet with the administrator, and tell him that if security is to be provided to the facility, that radios (of some type) will be used. That way they can decide if they want (a.) leave the issue alone (b.) no on-site security. (c.) fund a more "compatible" radio system. This could backfire , as the bottom line is, if they are paying for the service, you do it their way or sometimes not at all.

[tom IL]

The local hospital here uses 464.xxx for security and I have not heard of them having any problems. The Medics also use thier radios (462) in the hospital all the time.

[firemed9]

If it is cost feasable for you security chief, have them look into changing bands. If not, have the chief sit down with the hospital management and the telemetry vendor and hash it out. One of two things need to happen, either the vendor fixs the problem, or you will have to change radio systems.

[mike m]

just to let the hospital administrator know how rediculous his idea is, remind him that the hospitals E.R. also uses 463/465 MHz radios for their EMSCOM system to talk to medics on the ground and or medivac air units.

If they require the security people to stop using their little 1 or 2 watt radios then they surely will want the 25 to 50 watt base station on the hospitals roof that is used by the E.R. nurses and doctors to talk to medics in the field to also be shut off.

Try to explain this to the accident victim who is coming in that the medics cannot give him or her any treatment because they are now not allowed to talk to the E.R. doctors because some bean counter shut the MEDICS only link to the hospital off. I'm sure some accident lawyers or the local media will love to get ahold of this hair brain idea.





Mike

[commtek]

I have never heard of this issue before. Several of my hospital customers use 460 MHz repeaters on the facility roof for their in-house security.

Take your spectrum analyzer to the site and make sure that everything is clean. We had a wierd situation a few years ago where two commercial FM radio stations were beating together with a paging transmitter on the same tower as one of the FMs, and causing spurs on the 460 MHz frequency that the steel mill below the tower site was using for data.

Long story short, we swept the FMs, both were clean, and the problem was caused by water in the hard line for the paging transmitter. We luckily found the water dripping from the connectors at the site.

[motorolamonster911]

I live near 5 or 6 primary treatment hospitals that use a similiar telemetry system... All of our Med channels are in that range and our squad RICK repeater portables are on those channels too and I have NEVER EVER EVER heard of a problem..

How often are these "squelch problems" happening?

Couldnt you all go 1 day without using your radios at all and then see if they are still having the same problems?

Nick

[OX]

#1 problem, the telemetry system is in the 460 band. The tele equipment has several other bands that are dedicated explicitly to it.

The problem could also be coming from stray RF from the CATV system.

[mancow]

Our hospital uses 460.525 and has that telemetry stuff too. They've never had a problem that I know of. They even have a maxtrac sitting on a shelf in the ER area as the main radio! It's funny, they get all worked up about us using our Vhf radios in there then turn around and crank out 40 watts on 465.525.



mancow

[Gerbil]

This issue has come up a couple of times at the county hospital.
The board, basically said word for word what some idiot tech's opinion was. "Nextels interfere with everything, so thats whats causing the problem." So they banned all nextels from any floor with telemerty. Which pissed off the director of telemetry, because he and his staff used... what? Thats right, Nextel.

After pointing out to the board, that
1. the interfearance is new, however started after an expansion of the telemetry system. But, it wasnt in the area of the expansion.
2. the nextels are not the cause because of pre-implimentation testing
3. the city 800 mhz system, including EMS, and unit to hospital channels, including the tower right next to the hospital uses the same frequency band
4. Banning the nextels didnt help
5. The vendor did a full study on the facility, taking into consiteration all frequancies and radio transmissions
6. All hospital departments use 800 mhz radios.

They contacted the vendor to come and figure out the problem.

The cause of the interfearance? A faulty telemetry transmitter.

[Monty]

Hello;

This is a problem I have faced more than once, and
more and more with surveying equipment as well.

The frequencies are " Shared " and as such if both
parties hold a Radio Station License, then in the
majority of the cases its left up to the 2 parties
involved to find a suitable solution to the problem

There are still a number of qualified Two-Way
Consultants that can address the problem, and
come up with a suitable solution as long as both
parties can agree.

And yes, money does have a weight factor, but
who ever was licensed first has a edge over someone
new showing up

In the earlier days when Motorola was selling equipment,
the salespeople ( and FTR's ) paid very close attention to
what frequencies were chosen to prevent issues of this
type.

Now days, it's a Free for all, and I have no idea why they
even coordinate freqs anymore since Trimble
can run there telemetry right on the input freqs of most
repeaters in the 460 ~ 470 Mhz band without any regard
to prior users, not to mention users in Mexico and elsewhere
most of which is not licensed at all !

Its been left up to the user, and me ( in San Diego ) since
I have a lot of UHF Analog Equipment still in servicea to
chase down these dam things, ( when it effects our system )
and get the offending user to go to a alternate freq.

Not a easy task !

Hopefully, they will find such a individual ( or group )
in their area, that can offer the same service.

One thing for sure , check the License Status, and make
sure both parties are Licensed and operating within thier
parameters.

Monty

[RKG]

This post left out some data. What is the security freq? (Note that 466 mHz is not a legitimate freq for simplex or repeater output.) Is the security co. licensed? What is the freq for the medical telemetry equipment? And, most importantly of all, who issued the "cease and desist" order?

If the order was issued by the hospital, this is not a radio issue; the hospital owns the hospital and can order the radios silenced, right or wrong.

If the security co is licensed on the freq, then the FCC will not order it to cease operations, since the telemetry use is secondary to the listed public safety use.

We, too, have had some recent experience with surveying equipment (basically, local GPS differential systems using unlicensed frequencies in the repeater input range to calibrate field measuring instruments). This use is illegal, and the local FCC office shut the operation down within hours (and on a Sunday!). When the same outfit came back up on the same freq one week later (on another Sunday), the FCC fined them and issued a blanket "do not use" order for all of the differential equipment.

[nc5p]

It gets worse, there are some facilities that are banning cell phones in certain areas because of this concern. I would have thought that everybody would know hospitals are high rf environments. They almost always have high power paging transmitters on their roofs, in addition to all kinds of two way radios. I used to work a mile from a hospital, you could point a log periodic antenna towards the place and see all the crap peak up on a spectrum analyzer. There is some kind of politics there though, I once tried to rent rooftop space on a hospital for a 10 watt FM translator and was denied. Good luck to you.

Doug

[Cowthief]

Hello.

Nextels can drive biomed equipment crazy.
If you look at a cardiomon and you see this really sharp set of spikes. you most likely have iDEN.
If you see what looks like a series of "splats", you have TDMA cell-'phone noise.
For a sharp pulse, but only one, look for a talkie.
The biomed units have so-so filtering, and the leads are connected to this large "wet" person.
You can set up an audio amplifer as a very wide band radio and actually listen to the racket.
http://tentec.com/Tk1252.htm

[EngineerZ]

There's more to this story...

In the past, hospitals have been elgible for low power, secondary licenses, on what were known as the "offset" or "splinter" frequencies. These were 12.5 kHz channels sandwiched in between the traditional 25 kHz channels, mainly in the 460-470 MHz portion of the band. Some hospitals didn't even bother to license their equipment, but that's another issue.

When refarming came along, these spliter channels became "real" channels and the FCC planned to assign these to normal (high power) users. Furthermore, FCC regs typically do not allow high power channels to be licensed for telemetry on a primary basis, so many of these telemetry users would be pushed off their existing channels by primary licensees. In other words, refarming was going to increase occupancy of the band and increase the chances of intereference. Of course the medical telemetry people were up in arms over this "life and death" issue.

To address this issue, the FCC gave the medical telemetry people their own primary allocation at 600 MHz and 1400 MHz. The intent being moving these intrahospital patient monitoring systems to these primary allocations. This way hospitals would have their very own spectrum away from the unpredictable nature of operations in an LMR band.

This all transpired back in 1995. What did the medical telemetry folks do? Nearly nothing. The manufacturers (like Agilent) continued to produce the 460 MHz gear and the hospitals continued to buy it. When the FCC was going to start licensing these channels to the high power folks in 2003, the hospitals stepped in and said "hey you can't do that, we haven't had a chance to move!" Since this was a "life and death" issue (mainly to hospital budgets IMHO), the FCC issued a stay in licensing these channels and is trying to figure out what to do. (At least I don't think they've issued a final Report and Order in this matter yet.) You can read a public notice on this at http://hraunfoss.fcc.gov/edocs_public/a ... 3178A1.pdf .

So the interference refered to in the parent message of this thread is very possible, especially if the two-way LMR units are operating on a channel adjacent to the med telemetry channel. By FCC regs, the telemetry system, being a secondary user of the band, is supposed to accept interference from a Primary licensee. Certainly, it is the hospital's perrogative to tell it's own security people to not use 460 MHz radios in the building, but they are just burying their heads in sand. If someone were to use these or any other high power radios just off the hospital's property, there's nothing the hospital can do about it. In fact they may be putting their patients' lives in jeopardy by not addressing this issue.

The medical telemetry industry and users really need to clean up their act on this.

--z

[Cowthief]

Hello.

The case was really exciting in Dallas Texas a few years.
TV station WFAA was put on a new digital TV channel, and promply put half the hospitals in the area in a cardio-fit!
Turns out that FCC gave them something in the 600MHz range.
The 600MHz range was intended as a quick fix, untill we works things out.
Looks like it is going to stay that way.

[Flametamer]

I work in the biomed dept of a 600 bed hospital. We have 106 channels of telemetry in the 610 mhz range (HP/Philips) that was put in place in 9/02. The odd thing to me is that they still use the 460 range for rx. Thankfully we haven't had any rf problems with as many 2-ways in use. ( Maint., Campus Police, Transport, 2 depts. using nexthell, etc) (We have a nice antenna farm on the roof)
I have heard of at least 1 local hospital haveing problems with the local TV stations testing HDTV a year or 2 back. But still, I would love to be able to get a spectrum analyzer for a while to see how much is really there.

DT