Shared use of adjacent 2473-2483.5 MHz unlicensed band could raise objections.
Last November, at the urging of Globalstar, Inc., the FCC proposed to modify the Ancillary Terrestrial Component (ATC) of the rules governing the Mobile-Satellite Service (MSS) system operating in the Big Low-Earth Orbit (LEO) S band. Now, after an inexplicable three-month delay, that proposal has made it into the Federal Register, so comment and reply comment deadlines have been set.
Globalstar is the licensee of a Big LEO S band MSS system. It proposes ATC use of its licensed 2483.5-2495 MHz spectrum for a low power broadband network. That is not especially controversial because use of satellite spectrum for ATC service has been approved by the FCC for more than a decade as a way of expanding the use of satellite spectrum for terrestrial communications while maintaining the primary usage for satellite service.
The quirk in Globalstar’s proposal is that it would incorporate the adjacent 2473-2483.5 MHz segment of the 2.4 GHz unlicensed band into its operation. While the 2.4 GHz unlicensed band as a whole is widely used for Wi-Fi and Bluetooth, this particular segment at the upper end is unused by standard Wi-Fi operations in the U.S. because of the need to protect Globalstar’s adjacent satellite operations. Globalstar figured it could appropriate, in a practical sense, that 11.5 MHz in order to give it an effective full 22 MHz of bandwidth for its terrestrial operations.
But there are some complications.
First, the FCC proposes to relieve Globalstar of some of the so-called “gating” requirements that have acted to limit the usefulness of satellite spectrum for terrestrial operations. Specifically, Globalstar would not have to provide dual-mode handsets capable of communicating with both the MSS network and the ATC. The requirement to have such handsets has been a major obstacle in developing a workable business plan since the satellite component adds considerably to the cost of the device and isn’t needed by the normal terrestrial customer. While Globalstar must maintain its status as a primarily satellite operation, the FCC indicated that that obligation could be met by virtue of Globalstar’s considerable satellite operations without the need for extensive additional showings.
(Interestingly, the approach taken by the FCC toward Globalstar differs from the more expansive approach toward DISH Network and its ATC authorizations. The FCC relieved DISH of any obligation to continue providing satellite service at all. To get to that result, the FCC changed the regulatory regime for the DISH spectrum from Part 25 of the FCC Regulations (satellite operations) to Part 27 (normal terrestrial wireless operations). DISH was also relieved of all gating requirements, permitting it to use its spectrum in all respects as terrestrial – a much higher value use. By contrast, the FCC rejected Globalstar’s request for Part 27 treatment akin to DISH’s and instead chained Globalstar firmly to its Part 25 satellite status. That disparate treatment is curious in view of the National Broadband Plan’s policy directive to maximize use of satellite spectrum for terrestrial purposes.)
Second, Globalstar’s proposed use of the unlicensed spectrum has been viewed with alarm by other users of that band, particularly the Bluetooth community. It turns out that, precisely because the 2973-2983.5 band is not used for Wi-Fi, it is much more available, and more widely used, for Bluetooth connectivity. Bluetooth manufacturers and users are concerned that the Globalstar’s use would adversely affect their own operations. According to Globalstar, because of the frequency-hopping characteristic of Bluetooth operation, there would be no adverse effects. This is one of the most important issues the FCC will have to sort out, with the results of tests conducted by Globalstar figuring in the analysis.
Third, the Broadcast Auxiliary Service (BAS) is a long time user of the same 2483.5-2495 band licensed to Globalstar. This overlapping use of the same spectrum has not heretofore been a problem since the relatively few BAS stations in the band could be coordinated with Globalstar’s satellite operations to avoid interference. Wide scale use of this same band by Globalstar for its terrestrial operations would be a different story. The FCC must therefore consider whether to re-farm the BAS stations to a different frequency band – probably at Globalstar’s expense – or come up with some other way to avoid interference.
Finally, the plan to incorporate the 2473-2483.5 MHz unlicensed band into Globalstar’s managed network raises the question of how to handle the equipment that would be operating in the unlicensed band. Such equipment has been certified for operation under Part 15 (unlicensed operation) and has generally been programmed not to operate on the band that Globalstar needs it to be on. Globalstar indicates that the equipment in the field can be rendered usable in the desired band by software upgrades and can then be controlled by equipment certified for Globalstar’s use. Under current FCC procedures, re-certification of the existing equipment would be required before it could be used as proposed. Exactly how to accomplish the certification process with a minimum of re-certification applications by numerous manufacturers is another issue that will have to be addressed.
So while Globalstar’s proposal has now taken a major step forward, a number of technical and regulatory hurdles remain to be resolved before its ambitious plans can come to fruition. The problems do not seem insurmountable at this point, but the comments submitted in the docket will flesh out the situation. Comments from interested parties are due no later than May 5, 2014, with replies due June 4. Comments may be submitted electronically: Go to the FCC’s ECFS filing site and file them under Proceeding Number 13-213.
[Disclosure: Blogger Don Evans has a small ownership interest in Globalstar.]