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Emergency Medical Services Radio


Contents

Frequencies

These are the original Special Emergency/Emergency Medical radio service frequencies. Except for the paging frequencies, they are now part of the Public Safety Pool and may be used for other public safety purposes.

VHF Low Band

Frequency Usage
33.0200
33.0600
33.1000
37.9000
37.9400
37.9800
35.6400Medical Paging
35.6800Medical Paging
43.6400Medical Paging
43.6800Medical Paging
45.9200
45.9600
46.0000
46.0400
47.4200American Red Cross
47.4600
47.5000
47.5400
47.5800
47.6200
47.6600

VHF High Band

Frequency Usage
150.7750
150.7900
150.8050
152.0075Medical Paging
155.1600Search and Rescue in many areas
155.1750
155.2050
155.2200
155.2350
155.2650
155.2800
155.2950
155.3250
155.3400EMS to Hospital (known as HEAR in many areas) Interoperability channel VMED28
155.3550
155.3850
155.4000
157.4500Medical Paging
163.2500Medical Paging

UHF

The UHF "Med" channels 1-8 (some regions use different names, such as "Mednet") are used by Emergency Medical Technicians to communicate with the hospital. Information transmitted may be as little as the patient's age, sex, and general condition or as extensive as a full diagnostic workup.

In some areas, Paramedics are only able to give certain treatments under authority of an MD or specially-trained RN. This type of traffic is on the decline as well as Paramedics are given more independent treatment authority.

Analog transmission of electrocardiograms was quite common in the early days of modern EMS, but these modulated 1000 Hz tones are heard less and less as more and more EMS medical traffic is handled via cell phone. The FCC regulations (47 CFR Ch 1 Sec 90.20) reflect the old way in that Med 1-3 (and also Med 11-33) are allocated primarily for transmitting this type of telemetry, although this is rarely done and hence the channels are also used for other purposes (such as voice and paging).

Med channels 9 and 10 (and also Med 91-103) were added later below the original band of 8 and are allocated for dispatch purposes instead of medical control. They also explicitly allow paging, typically the same type as used by fire departments.

The UHF frequencies are assigned in pairs. In semi-duplex mode the higher frequency of the pair is usually used by the mobile while the lower frequency is used by the base (usually a hospital). Some EMS systems have the system configured for full-duplex where both parties can transmit and recieve at the same time. In many areas, they are configured as repeaters on mountaintops with the hospitals transmitting and receiving the same as any mobile. PL tones are selected by the ambulance crew to select which hospital hears the traffic, since many hospitals may be able to hear the same repeater on a particular pair.

Med channels 11-103 are "splinter" frequencies added the most lately. They are situated between the original existing channels. The channel numbers ending in a "2" (which are .0125 step channels) are limited to 11.25 kHz bandwidth (FMN). The channel numbers ending in a "1" or "3" (which are .00625 step channels) are limited to 6 kHz bandwidth. (See: Narrowbanding)

Mobile and portable stations above 2.5 watts, licensed before July 6, 2000 must have Med channels 1-8. Those licensed between July 6, 2000 and December 31, 2005 must have Med channels 1-8, plus Med channels 12-82 (those intermediate splinters ending in "2"). Starting January 1, 2006, they must have all 40 channels. Base stations and portables below 2.5 watts are excepted.

Mobile Rx Mobile Tx Name Primary Allocation Notes
463.00000468.00000Med 1Biomedical Telemetry
463.02500468.02500Med 2Biomedical Telemetry
463.05000468.05000Med 3Biomedical Telemetry
463.07500468.07500Med 4Medical Control (voice)
463.10000468.10000Med 5Medical Control (voice)
463.12500468.12500Med 6Medical Control (voice)
463.15000468.15000Med 7Medical Control (voice)
463.17500468.17500Med 8Medical Control (voice)
462.95000467.95000Med 9Dispatch/Paging
462.97500467.97500Med 10Dispatch/Paging
463.00625468.00625Med 11Biomedical Telemetrybandwidth not to exceed 6 kHz
463.01250468.01250Med 12Biomedical Telemetrybandwidth not to exceed 11.25 kHz
463.01875468.01875Med 13Biomedical Telemetrybandwidth not to exceed 6 kHz
463.03125468.03125Med 21Biomedical Telemetrybandwidth not to exceed 6 kHz
463.03750468.03750Med 22Biomedical Telemetrybandwidth not to exceed 11.25 kHz
463.04375468.04375Med 23Biomedical Telemetrybandwidth not to exceed 6 kHz
463.05625468.05625Med 31Biomedical Telemetrybandwidth not to exceed 6 kHz
463.06250468.06250Med 32Biomedical Telemetrybandwidth not to exceed 11.25 kHz
463.06875468.06875Med 33Biomedical Telemetrybandwidth not to exceed 6 kHz
463.08125468.08125Med 41Medical Control (voice)bandwidth not to exceed 6 kHz
463.08750468.08750Med 42Medical Control (voice)bandwidth not to exceed 11.25 kHz
463.09375468.09375Med 43Medical Control (voice)bandwidth not to exceed 6 kHz
463.10625468.10625Med 51Medical Control (voice)bandwidth not to exceed 6 kHz
463.11250468.11250Med 52Medical Control (voice)bandwidth not to exceed 11.25 kHz
463.11875468.11875Med 53Medical Control (voice)bandwidth not to exceed 6 kHz
463.13125468.13125Med 61Medical Control (voice)bandwidth not to exceed 6 kHz
463.13750468.13750Med 62Medical Control (voice)bandwidth not to exceed 11.25 kHz
463.14375468.14375Med 63Medical Control (voice)bandwidth not to exceed 6 kHz
463.15625468.15625Med 71Medical Control (voice)bandwidth not to exceed 6 kHz
463.16250468.16250Med 72Medical Control (voice)bandwidth not to exceed 11.25 kHz
463.16875468.16875Med 73Medical Control (voice)bandwidth not to exceed 6 kHz
463.18125468.18125Med 81Medical Control (voice)bandwidth not to exceed 6 kHz
463.18750468.18750Med 82Medical Control (voice)bandwidth not to exceed 11.25 kHz
463.19375468.19375Med 83Medical Control (voice)bandwidth not to exceed 6 kHz
462.95625467.95625Med 91Dispatch/Pagingbandwidth not to exceed 6 kHz
462.96250467.96250Med 92Dispatch/Pagingbandwidth not to exceed 11.25 kHz
462.96875467.96875Med 93Dispatch/Pagingbandwidth not to exceed 6 kHz
462.98125467.98125Med 101Dispatch/Pagingbandwidth not to exceed 6 kHz
462.98750467.98750Med 102Dispatch/Pagingbandwidth not to exceed 11.25 kHz
462.99375467.99375Med 103Dispatch/Pagingbandwidth not to exceed 6 kHz

Early on, there were four other frequencies, another 5 MHz below Meds 2, 4, 6, and 8 (458.02500, 458.0750, 458.1250, 458.1750). These were used by Paramedics to relay medical and telemetry traffic from the patient's location to the ambulance or rescue vehicle and then again to the hospital or other medical control. Like the Med channels themselves, they are now all in the public safety frequency pool.



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