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Emergency Medical Services Radio

From The RadioReference Wiki

Frequencies

These are the original Special Emergency/Emergency Medical radio service frequencies. Except for the medical paging and American Red Cross 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
35.6400 Medical Paging
35.6800 Medical Paging
43.6400 Medical Paging
43.6800 Medical Paging
45.9200
45.9600
46.0000
46.0400
47.4200 American 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
152.0075 Medical Paging
155.1600 Search and Rescue in many areas; interoperability channel VSAR16 (PL 127.3)
155.1750
155.2050
155.2200
155.2350
155.2650
155.2800
155.2950
155.3250
155.3400 EMS to Hospital (known as HEAR in many areas); Interoperability channel VMED28 (PL 156.7)
155.3550
155.3850
155.4000
157.4500 Medical Paging
163.2500 Medical 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
463.0000 468.0000 Med 1 Biomedical Telemetry
463.0250 468.0250 Med 2 Biomedical Telemetry
463.0500 468.0500 Med 3 Biomedical Telemetry
463.0750 468.0750 Med 4 Medical Control (voice)
463.1000 468.1000 Med 5 Medical Control (voice)
463.1250 468.1250 Med 6 Medical Control (voice)
463.1500 468.1500 Med 7 Medical Control (voice)
463.1750 468.1750 Med 8 Medical Control (voice)
462.9500 467.9500 Med 9 Dispatch/Paging
462.9750 467.9750 Med 10 Dispatch/Paging
463.00625 468.00625 Med 11 Biomedical Telemetry bandwidth not to exceed 6 kHz
463.0125 468.0125 Med 12 Biomedical Telemetry bandwidth not to exceed 11.25 kHz
463.01875 468.01875 Med 13 Biomedical Telemetry bandwidth not to exceed 6 kHz
463.03125 468.03125 Med 21 Biomedical Telemetry bandwidth not to exceed 6 kHz
463.0375 468.0375 Med 22 Biomedical Telemetry bandwidth not to exceed 11.25 kHz
463.04375 468.04375 Med 23 Biomedical Telemetry bandwidth not to exceed 6 kHz
463.05625 468.05625 Med 31 Biomedical Telemetry bandwidth not to exceed 6 kHz
463.0625 468.0625 Med 32 Biomedical Telemetry bandwidth not to exceed 11.25 kHz
463.06875 468.06875 Med 33 Biomedical Telemetry bandwidth not to exceed 6 kHz
463.08125 468.08125 Med 41 Medical Control (voice) bandwidth not to exceed 6 kHz
463.0875 468.0875 Med 42 Medical Control (voice) bandwidth not to exceed 11.25 kHz
463.09375 468.09375 Med 43 Medical Control (voice) bandwidth not to exceed 6 kHz
463.10625 468.10625 Med 51 Medical Control (voice) bandwidth not to exceed 6 kHz
463.1125 468.1125 Med 52 Medical Control (voice) bandwidth not to exceed 11.25 kHz
463.11875 468.11875 Med 53 Medical Control (voice) bandwidth not to exceed 6 kHz
463.13125 468.13125 Med 61 Medical Control (voice) bandwidth not to exceed 6 kHz
463.1375 468.1375 Med 62 Medical Control (voice) bandwidth not to exceed 11.25 kHz
463.14375 468.14375 Med 63 Medical Control (voice) bandwidth not to exceed 6 kHz
463.15625 468.15625 Med 71 Medical Control (voice) bandwidth not to exceed 6 kHz
463.1625 468.1625 Med 72 Medical Control (voice) bandwidth not to exceed 11.25 kHz
463.16875 468.16875 Med 73 Medical Control (voice) bandwidth not to exceed 6 kHz
463.18125 468.18125 Med 81 Medical Control (voice) bandwidth not to exceed 6 kHz
463.1875 468.1875 Med 82 Medical Control (voice) bandwidth not to exceed 11.25 kHz
463.19375 468.19375 Med 83 Medical Control (voice) bandwidth not to exceed 6 kHz
462.95625 467.95625 Med 91 Dispatch/Paging bandwidth not to exceed 6 kHz
462.9625 467.9625 Med 92 Dispatch/Paging bandwidth not to exceed 11.25 kHz
462.96875 467.96875 Med 93 Dispatch/Paging bandwidth not to exceed 6 kHz
462.98125 467.98125 Med 101 Dispatch/Paging bandwidth not to exceed 6 kHz
462.9875 467.9875 Med 102 Dispatch/Paging bandwidth not to exceed 11.25 kHz
462.99375 467.99375 Med 103 Dispatch/Paging bandwidth 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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