BMERS: Resilient Email Communications System for Health Facilities

In the event of widespread infrastructure loss during a disaster, NLM’s BHEPP Military Auxiliary Radio System (MARS) Emergency Radio System (BMERS, pronounced "beamers") can provide resilient communication services to medical facilities.

  • BMERS provides email services without a live internet connection, using off-the-shelf amateur radio and IT equipment (computer, Wi-Fi routers, etc.), and free software provided by NLM.
  • A trained BMERS radio operator manages the amateur radio station.
  • BMERS users access a familiar webmail interface from any Wi-Fi capable device—i.e., almost no training is needed to send and receive emails.
  • Remote correspondents in unaffected areas do not need special software or equipment to communicate with BMERS users.

BMERS was originally designed to support the preparedness activities of the Bethesda Hospitals' Emergency Preparedness Partnership (BHEPP), but it can be used in other settings to support the work of Incident Command System and other staff during emergencies.



Many technologies exist today that can supply telecommunications to a medical facility isolated during a disaster, from satellite phones to cellular internet balloons, but we determined that a solution designed specifically for disasters, which tend to happen infrequently in the same location, are far more likely to be adopted if they are simple to use and deploy, and affordable. The service being tested by NLM supplies long-haul wireless Internet email access, enabled by the volunteer work of amateur radio operators.

NLM teamed up with experienced emergency communicators and determined that amateur radio offers excellent opportunities to build a solution for this problem. Throughout its more than 100 years of history, amateur radio has played a support role during all major disasters and continues to do so today (see Further Reading, below). Additionally, NLM is surrounded by a vibrant ham radio community that is constantly looking for volunteering opportunities to assist during emergency events and preparedness activities. Amateur radio technology is easy to obtain, inexpensive, and easy to integrate in other solutions.

Although BMERS was originally designed to support the Hospital Command Centers (HCC, also called Incident Command Centers, or Emergency Operations Centers) of BHEPP hospitals, BMERS was designed with a broader scope. BMERS supports the roles of the Incident Command System (ICS, or the hospital version HICS), which is used by hospitals and other organizations in the United States and many abroad to manage threats, planned events that present significant risks to the facility and its occupants, or emergency incidents. Additionally, BMERS is flexible enough to be useful in other settings were supplementary or backup telecommunications services can be useful.

BMERS Objectives 

The overarching objective of NLM’s BMERS project is to provide a cost-effective, easy-to-use, and flexible telecommunications solution that can be used by incident command staff at a medical facility to exchange information efficiently and accurately during disaster events that can affect their telecommunications resources. BMERS also:

  • Minimizes communication errors and delays by eliminating the need for radio operators to transcribe messages.
  • Accommodates the roles and information tools (standard ICS forms) used by teams using the Incident Command System.
  • Allows radio operators to focus on maintaining radio communications flowing instead managing individual messages.
  • Implements techniques to optimize the limited bandwidth provided by the radio link.
  • Allows end-users to manage their own email traffic.
  • Removes the need of end-users to know or have an FCC license to operate amateur radio.
  • Requires almost no training of end-users, since the service interface looks like traditional electronic mail.
  • Makes possible local communications via email or instant messaging among local staff distributed throughout the isolated facility.
  • Provides the local radio station operator tools to manage the communications service, such as creating user accounts, setting or relaxing email attachment restrictions, monitoring message queues, etc.

BMERS was not designed to replace higher-performance telecommunications services, but to supplement other methods or provide a last-resort communications alternative while other services are either not available or highly degraded.

BMERS is sufficiently compact to be included in the toolbox of amateur radio emergency communications volunteers deployed to disaster areas (see Further Reading section).

The effectiveness of BMERS has been demonstrated during field exercises at the National Institutes of Health, Walter Reed Hospital, Fort McNair, Suburban Hospital-Johns Hopkins Medicine, emergency preparedness fairs, and other venues.

Understanding the Amateur Radio Station 

Amateur (ham) radio is constantly evolving. One of its digital radio communications modalities offer new interesting opportunities for disaster relief. Particularly, the amateur radio system “Winlink 2000” (see references) allows radio operators to send and receive Internet email through wireless links using “radio-modems”, and it was chosen as the basis for our solution. However, BMERS has extended the Winlink 2000 amateur radio service model in several key ways to produce an integrated solution for hospitals and other facilities.

BMERS modifies the traditional amateur radio model used for emergency management support. The traditional model requires radio operators to manually handle individual messages. BMERS, on the other hand, provides end-user to end-user direct email communications. An amateur radio operator is still required to manage the radio station, but the operator does not need to be involved in handling individual messages.

With BMERS, medical staff exchange emails and instant messages within their institution using any Wi-Fi capable device. With the addition of a portable amateur radio station, the same participants can exchange a subset of these emails to any Internet address, even if the nearest Internet connection is tens or hundreds of miles away.

The BMERS technology is portable, inexpensive, deployable on short notice, and does not require a payment for use. With some preparation, BMERS stations can operate on available power, including car batteries or gasoline powered generators. The BMERS software and hardware designs are openly available for non-commercial use.

Technology Description 

System Components and Functionality 

The BMERS base station (Figure 1) has the following high-level components:

  • A high-speed, wireless Local Area Network that enables end-users to access the email application with any Wi-Fi capable computer or mobile device and a regular web browser.
  • A mobile computer that provides access to the email services and runs all the software that enables local email and text messaging, and remote email communications. This server also provides administrative tools for the radio operator and runs software to control the radio station.
  • A radio station with radio transceivers, radio modems, and antennas.
  • Additionally, a licensed radio operator must manage radio communications. Often, amateur radio enthusiast in the local community can provide this kind of support during crisis events.

BMERS high level components: WiFi, email server, radio station, HF/VHF
Figure 1: BMERS high-level components

The BMERS software can support almost any radio station design that is adequate for Winlink 2000 operation (see and therefore it supports a variety of hardware configurations. See the next section for additional details.

To use BMERS, authorized HCC staff must follow the following steps:

  1. The HCC staff will receive email credentials and a local URL from the BMERS radio operator.
  2. The HCC staff connects their computer device (laptop, smart phone, tablet, etc.) to the BMERS Wi-Fi access point and point a web browser to the supplied local URL.
  3. Login to the email account provided by the radio operator
  4. Use the email interface to send and receive email

End users do not need an FCC amateur radio license. HCC personnel can access BMERS with any Wi-Fi or Ethernet-capable device that can run a standard web browser. No additional software or special equipment are needed, only the BMERS email credentials and other data provided by the station operator. The BMERS user interface is shown in Figure 2.

BMERS text messaging interface
Figure 2: BMERS email user interface

Local users that are dispersed throughout the same local facility can use a single BMERS system to communicate with each other via email or text messaging (see Figure 3). Text messages sent through BMERS can be broadcasted to everyone using the system or sent privately to specific people.

BMERS text messaging interface
Figure 3: Text messaging interface

When messages need to go outside of the facility, BMERS users must click the “New Radio Message” button. Incoming messages from the outside will show up in the inbox as any regular email message.

The radio operator has access to a system administration webpage (Figure 4) on the BMERS server that allows him to manage local users, the email service and the radio station. Users of the system can communicate with the radio operator via local email or text messaging.

BMERS operator interface
Figure 4: Operator Interface

BMERS Software

The software was developed for MS Windows computers and can be obtained from the NIHRAC website at: It has been tested on Windows XP, 7, 8 and 10.

The BMERS 6.3.0 Download Information & Release Notes.pdf explains how to download the software and lists release notes.

The DIMRC Radiomail Installation Instructions V6.2_20180308.pdf explains how to install and configure this software: 

IMPORTANT: BMERS was originally designed to work with Paclink to manage the radio traffic. The preferred software is now Winlink Express (

BMERS Hardware 

BMERS works with any radio station design that is compatible with the Winlink 2000 system’s Winlink Express client software ( The following diagrams (Figures 5 and 6) show two designs that have been successfully tested at NLM. Figure 5’s design has a single all-mode VHF + HF radio transceiver (modified to support MARS frequencies), a single Pactor + Packet modem and an optional VHF transceiver and modem as a backup radio. Figure 6 shows a slightly updated design that was normally used with a software modem. Both designs allow the systems to be operated remotely from a computer that can access the radio station via W-Fi or a wired Ethernet connection.

BMERS hardware design 2015
Figure 5: BMERS hardware design 2015

BMERS hardware design 2016
Figure 5: BMERS hardware design 2016

All the hardware components can be obtained commercially off-the shelf from multiple sources. Documents describing these hardware design in more detail are in development and will be made available on this webpage. Picture 1 shows a portable station based on the design depicted on Figure 5.

example of a BMERS implementation
Picture 1: implementation of a BMERS portable station

Detailed parts and materials will be listed on the page soon. Also, check the NIHRAC webpage for additional BMERS information from our ham radio collaborators.


BMERS has been possible by the contributions of many individuals and organizations:

Further Reading 

BMERS System

Use of Amateur Radio in Disasters

  • Nollet KE, Ohto H. When all else fails: 21st century amateur radio as an emergency communications medium. Transfusion and apheresis science. 2013 Dec;49(3):422-7. doi: 10.1016/j.transci.2013.08.00
  • Farnham JW. Disaster and emergency communications prior to computers/Internet: a review. Crit Care. 2006 Feb;10(1):207.

Frequently Asked Questions

Q. Can I obtain the BMERS system from NLM?

A. The software and documentation is openly available for download from NLM and the NIH Radio Amateur Club, but NLM does not provide the hardware. The software can be obtained from the NIHRAC website at If you’d like to build a BMERS radio station, please refer to the Technical Specifications section on this webpage.

Q. Who can I contact to obtain more information about BMERS?

A. For more information, please contact