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The FCC Changes The Rules on 915 and 2400 MHz Bands

PR Docket No. 93-61:

Adopted on February 3, 1995 and released February 6, 1995, in Report and Order form, this rulemaking virtually destroys the 915 MHz ISM band as we know it. In short, the FCC established a new service: the Location and Monitoring Service (LMS) that encompasses the old Automatic Vehicle Monitoring Service (AVM) and future advanced transportation related services. The impact of this step by FCC is significant. The FCC adopted rules for the future licensing and continued development of a number of services, including Amateur Radio, in the 902 to 928 MHz band.

Radio Amateurs will continue to have access to 902 to 928 MHz, on a secondary basis to the new LMS systems -- as will industrial, scientific, and medical (ISM) systems and government users. Unlicensed low power "Part 15" users are now restricted to a secondary basis to all the above, including amateurs.

The FCC will adopt a plan to afford both amateurs and Part 15 users "a greater degree of protection to their operations" (from interference from other services). The FCC also will clarify what constitutes harmful interference to LMS licensees by Part 15 devices and by amateurs.

The FCC also said it would use a "negative definition" to clearly establish the parameters under which amateurs and Part 15 users may operate without risk of being considered sources of interference to services with a higher allocation status.

Some highlights from the FCC docket follow:

  1. Multilateration and non-multilateration LMS systems, amateur operations, and Part 15 devices will all play an important role in providing valuable services to the American public in the coming years. We believe that our decisions in this proceeding recognize this importance and will enable all of these services to make continued use of this spectrum. As detailed in our later discussion, commenters representing each of these services indicate the need for varying amounts of spectrum and varying degrees of interference protection from each other's operations in the band. We have therefore developed a spectrum plan that attempts to accommodate all of these users' requirements. The plan: 1) continues to permit secondary operations by unlicensed Part 15 and amateurs across the entire band, but affords users in these services a greater degree of protection to their operations: 2) enables non-multilateration LMS systems to operate on spectrum separate from multilateration systems; and 3) allocates spectrum on an exclusive basis for multilateration LMS licensees.

  2. In this Report and Order we have therefore made the following decisions:

    • Charge the name of this services from the Automatic Vehicle Monitoring (AVM) to the Location and Monitoring service (LMS) (see paragraph 1).

    • Change the terminology used to refer to the two general categories of LMS technologies from "wideband" and "narrowban" to multilateration and "non-multilateration," respectively, (see paragraph 14).

    • Permit multilateration LMS systems to locate any object -- animate or inanimate-- ancillary to their primary vehicular location and monitoring services (see paragraph 24).

    • Permit LMS systems to transmit and receive status and instructional informational, both non-voice and voice, related to the location and monitoring of a mobile unit and permit LMS systems to interconnect with the Public Switched Network (PSN) on a restricted basis (see paragraphs 26-27).

    • Expand LMS license eligibility to all entities eligible to be licensed under Part 90 of our Rules and allow services in the 902-928 MHz band to be provided by LMS licensees to both individuals and the Federal Government on a commercial basis to paying subscribers (see paragraph 28).

    • Clarify what constitutes harmful interference to multilateration licensees by unlicensed Part 15 devices and amateur operations (see paragraphs 35 - 36).

    • Allocate an additional 8 MHz of spectrum in the 902-928 MHz band for LMS use, permitting the entire band to be used for this purpose. Adopt a spectrum allocation scheme for the 902-928 MHz band that assigns separate sub-bands for multilateration and non-multilateration operations as follows:

      Band (MHz) System License
      902.000-904.000 Non Multilateration
      904.000 - 909.750 Multilateration
      909.750 - 919.750 Non Multilateration
      919.750 - 921.750 Multilateration and Non Multilateration
      921.750 -927.250 Multilateration
      927.250 - 928.000 Multilateration

    • License exclusive multilateration LMS systems within each Major Trading Area (MTA) and four additional MTA like service areas in three sub-bands designated above, and resolve mutually exclusive applications through competitive bidding (see paragraph 50-57).

    • Grandfather base stations of multilateration system licensee authorized as of February 3, 1995 and constructed and in operation by April 1, 1996 (see paragraphs 61-64).

    • License non-multilateration systems on a shared basis in the three sub-bands designated above (see paragraphs 69-70).

    • Allow multilateration licenses to commence operations only after demonstrating interference with Part 15 operations is minimized (see paragraphs 81-82).


This proceeding also set new definitions for "interference free" levels of transmitter power output for both amateurs and Part 15 users. Be careful with design, installation or operation of any new SS systems in this Band in the future!

ET Docket No. 94-32:

The FCC has now ruled on various proposals for the 2390-2400, 2402-2417 and 4660-4685 MHz frequency bands. The major changes resulting from this proceeding are:

  • Adoption of 2390 to 2400 MHz as an additional Part 15 ISM frequency band.

  • Elevation of Radio Amateur operations at 2390 to 2400 MHz and 2400 to 2483.5 MHz to the Primary service.

It seems that the NTIA sponsored moves behind this Docket were only partly successful. The FCC widened the 2.4 GHz band by 10 MHz, but allowed amateurs primary status over Part 15 users. We don't think all the battles for this band or some of the higher frequency bands are over yet! SSS looks forward to continued "haggling" on frequency assignments at these frequencies -- since the commercial auction value of telecommunication spectrum is now a proven commodity.

The FCC also has made several changes to Part 15 rules, including adding new sections covering Unlicensed PCS Devices. Be sure you get an up to date copy of part 15 before spending any time or money on decsions regarding ISM band equipment or system regulations.

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