FIRMS ON DIFFERENT WAVELENGTHS ABOUT EXPANDED BANDWIDTH FOR WIRELESS DEVICES

The FCC is considering whether to expand available radio frequency (RF) for implanted and body-worn wireless devices, but manufacturers disagree on whether additional RF is needed.

At issue is a proposed rule under which additional RF would be made available for certain classes of advanced wireless devices, including implantable pacemakers and defibrillators, vagus nerve stimulators, insulin pumps and artificial limbs, the commission said in a notice.

Medtronic advocates allocating one RF for particular devices, a move being resisted by rival Biotronik.

• The FCC is considering a modification of its rules to:
  Allocate two megahertz (MHz) of RF, 401-402 and 405-406, for use by low-power, low-duty-cycle (minimal and/or infrequent use time) implanted and body-worn devices that operate without "listen-before-talk" (LBT) capability, as recommended by Medtronic.
• Address two current waivers to FCC rules that permit Biotronik and DexCom to operate low-power, low-duty-cycle devices with LBT in the existing 402-405 MHz RF. The DexCom waiver is effective until the later date of Jan. 19, 2009, or one year after the FCC sets new rules on the issue. The Biotronik waiver is effective until Feb. 26, 2007.

An LBT transmitting device will "sniff the air" to see if an RF is clear before initiating communication with the implanted device. While this is acceptable for some devices, firms like Medtronic want an RF available that allows automatic contact between devices without the need to wait for it to become free of interference from other users.