Arrl Seeks Access To Mhz For Packetradio Links

The ARRL has petitioned the Federal Communications Commission for a new spectrum allocation to help replace that at 220-222 MHz which will be lost on Aug 27.

On June 4, the League filed a Petition for Rule Making with the FCC, seeking a secondary, noninterference allocation for the Amateur Radio Service at 216-220 MHz to "provide reaccommodation for those present and future wideband data intercity links and other point-to-point fixed amateur stations which stand... to be displaced from the 220-222 MHz band." The idea of replacement spectrum had its genesis with Congressman Robert E. Wise, Jr, of West Virginia, Chairman of the House Government Information, Justice, and Agri├žulture Subcommittee. During the subcommittee's May 11, 1989 hearings on the FCC's 220-MHz decision (see QST, July 1989, p 44), in calling attention to the fact that 216-220 MHz was underutilized, ARRL Executive Vice President David Sumner, K1ZZ, had testified that "radio amateurs would love to have access to [the 216-220 MHz band] in the rest of the country [where it is not used for waterways communications]. We'd make very good use of it."

Rep. Wise followed up by writing to then-FCC Chairman Dennis Patrick to suggest that the Commission consider some alternative scenarios for 216-222 MHz that would have provided some continued amateur access. The Commission declined to do so in the context of the Docket 87-14 proceeding, but agreed to give such a proposal consideration if submitted separately. In his reply to Rep. Wise, Chairman Patrick said, "We did not consider in any depth amateur use of the 216-220 MHz band in this proceeding. It was not proposed by the Commission, nor was it addressed in the comments. However, ARRL did make a general comment in this regard in its petition for reconsideration. We have, therefore, in our Memorandum Opinion and Order invited the amateur community to make a specific proposal. This would allow full public comment by all interested parties. It is possible that some limited secondary fixed use of this band may be made by the amateur service in reaccommodating the amateur fixed operations from the 220-222 MHz band. The Commission noted that while it is willing to consider this matter, potential impact on other users of this spectrum, particularly potential interference to TV broadcasting, will need to be addressed."

All other avenues for relief having been exhausted, on June 4 the League submitted the specific proposal invited by the Commission.

The 216-220 MHz band currently is occupied by the

If you're tired of hunting for bits and pieces of information on spread spectrum, the ARRL Spread Spectrum Sourcebook is for you. You'll find reprints of most spread spectrum articles from QST and QEX, as well as articles and news items from the AMRAD Newsletter. Also included in this 384-page softcover book is historical information on spread spectrum's beginnings and an introduction by Robert Dixon, a well-known author on this subject.

All the information you want

-in one place-at your fingertips!

The HUNT is over.

Available for $20 plus $3 for shipping and handling ($4 UPS) from ARRL or directly from your dealer. Order #3177

August 1991 15

Maritime Mobile Service and by some fixed and mobile assignments. In addition, part of the range (specifically, 218-218.5 MHz) also is under consideration for use by a new Interactive Video Data Service.

An engineering study by Atlantic Research Corp, commissioned by the League, found that the Amateur Service "could effectively operate in the 216-220 MHz band subject to appropriate frequency and distance separation constraints," even if usage of the band by commercial interests "grows substantially."

Another engineering study conducted by the staff of the ARRL Technical Department Laboratory found that interference to television channels 11 and 13 also could be avoided, particularly if amateur operation were confined above 218 MHz in areas served by channel 13 television stations.

The League's petition notes that despite the apparent constraints that would be presented by sharing arrangements with existing and planned commercial operations, "there appears a significant opportunity for additional operation in segments of the band on certain frequencies in vast areas of the country."

The League's petition notes that the spectrum soon to be lost at 220-222 MHz was generally free of the repeater operations that dominate the band above 222 MHz. For that reason it had been planned, the petition says, that 220-222 MHz would be used for "high-speed, inter-city" packet radio, a system that is regarded as vital to amateurs' continued public service work in the coming years.

The League contends that the FCC's assumption that amateurs could merely move operations from 220-222 MHz "up the band" was incorrect; that such a move is not possible "because of the differences in the technology used in the different segments." The use of 222-225 MHz for voice repeater operation is expected to grow as new Technician class licensees occupy the band, further compounding the problem of finding space for the wideband channels necessary for high speed packet operation.

Most new high-speed modems for packet radio "were designed specifically for the amateur 220 MHz band," the petition says, and notes that while in 1987,30,000 amateur packet stations were thought to exist, the number today is thought to be more than 100,000. In many cases the intercity packet networks envisioned for 216-220 MHz cannot be accommodated elsewhere, above or below those frequencies, because of band loading, sharing, or path length considerations.

The petition notes that the US Department of Defense, on behalf of the National Communications System (NCS), filed reply comments on behalf of amateurs in Docket 87-14 (which reallocated 220-222 MHz to land mobile interests). NCS, in planning to use amateur communications itself, already had signed a memorandum of understanding with the League.

"The deprivation of these types of communication resources, which would be vital in times of emergency or crisis, could significantly hamper the ability of the NCS to carry out its responsibilities in the area of national security," the Secretary of Defense told the FCC at the time of Docket 87-14.

The ARRL Laboratory studied the potential television interference problem. TV channel 13 occupies 210-216 MHz. While the potential for interference would at first

Was this article helpful?

0 0

Post a comment