In February, the Federal Communications Commission published a preliminary Notice of Proposed Rule Making (NPRM) outlining its intent to expand the current 5 GHz ISM band. In March, the fledgling AAMI Wireless Task Force discussed this proposal and decided to bring a group of interested parties together to draft a comment to the FCC. The goal of the comment was to request that the FCC consider potential patient safety issues and provide special considerations in the rules for the new bands to accommodate critical applications in healthcare (or other industries) that may require controlled-interference environments.
We have all seen what has been happening to the 2.4 GHz band. With its success, it has become quite congested and difficult to manage. Patients, visitors, and employees bring their own devices (phones, games, mobile hot spots, personal healthcare devices, networks, etc.) into the hospital and expect them to work. In dense urban environments, the neighbors also add to the cacophony. This is not just a Wi-Fi issue since these bands can be used in any way the user/developer wants. For example, I recently read about a TV soundbar that used frequency-hopping in the 2.4 GHz band to communicate with its sub-woofer. Needless to say, this caused issues for 802.11 b/g users in the vicinity.
While the 5 GHz band is not in danger of the same sort of congestion anytime soon, we are concerned that it may happen in the long term. As a result, it may become difficult for healthcare IT managers to manage the spectrum in their own environments as patients, employees, and neighboring users deploy devices and applications in the 5 GHz bands that may interfere with each other. We expect that medical devices will follow the crowds into this new spectrum, for good reason, and we want hospital IT managers to have control over at least some of the spectrum as another risk mitigation method in their tool belts.
The group started work immediately with the knowledge that once the NPRM was published in the Federal Register, the comment would need to be submitted within 45 days. The NPRM appeared on April 10 with a deadline of May 28 to respond. AAMI filed its comment on behalf of the group on May 24. The specific requests of AAMI in its comment to the FCC are as follows:
- A mechanism be created that allows a healthcare institution to gain vicinity-based prioritized access to either the U-NII-2B or U-NII-4 band in the proposed new 5 GHz spectrum.
- All users within a specified distance from the prioritized institution be prohibited from using this spectrum according to the local priorities for use.
- Whichever mechanism is chosen for coordination of this new spectrum in the 5 GHz band with incumbent users should also be used for coordination with prioritized users. The options proposed in the NPRM are:
- Geo-location-based technology
- Sensing-based technology
- Beaconing/pilot channel technology
The FCC NPRM can be found at http://apps.fcc.gov/ecfs/proceeding/view?z=aj0e9&name=13-49. (Note you need to search for “13-49” to see all 67 comments, including the one from AAMI.) This is only the first round of what may be a long process. This process is open, and I would encourage you or your organization to provide your response (hopefully supportive) to the AAMI proposal. The initial round of responses is due on June 24.
Ken Fuchs, senior principal architect with Mindray North America, is a member of the AAMI Wireless Task Force.