Emergency Medical Services Radio
From The RadioReference Wiki
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
|47.4200||American Red Cross|
VHF High Band
|155.1600||Search and Rescue in many areas; interoperability channel VSAR16 (PL 127.3)|
|155.3400||EMS to Hospital (known as HEAR in many areas); Interoperability channel VMED28 (PL 156.7)|
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)|
|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.
Return to Wiki page: Common Frequencies