A coalition of industry organizations has urged the Federal Communications Commission (FCC) to revise draft rules on 800 MHz interstitial channels. The Enterprise Wireless Alliance, APCO International, Forest Industries Telecommunications, and Utilities Technology Council filed the ex parte letter together, commenting upon two items: the placement and currency of the “Adjacent Channel Reciprocal Interference Matrix” and a recommendation by the Land Mobile Communications Council (LMCC) to use an F(50/50) curve for the interference contour.
In the draft Report and Order and Order, the FCC has placed the matrix, developed by the LMCC in 2015, within the body of the rules instead of as an appendix. This action departs from the process used in several recent proceedings that have involved coordination protocols, such as that for vehicular repeater systems. If the matrix remains within the body of the rules, any change—however minimal—may be made only through a rulemaking proceeding, which can take years.
Further, whether or not the Commission accepts the recommendation to remove the matrix from the rules, the coalition urges the FCC to adopt the LMCC’s recommended use of an F(50/50) curve for the interference contour, a factor that will be specified in the rules. The frequency advisory committees (FACs) that constitute the LMCC represent all users of 800 MHz spectrum and, after careful consideration, determined that an F(50/50) curve, with appropriate derating factors, would allow the use of interstitial channels in areas where spectrum is needed, while still providing appropriate protection for adjacent 25 kHz bandwidth licensees. If the Commission chooses to retain the F(50,10) curve, the parties strongly encourage the Commission to allow for the modification of the matrix, before it can be implemented by the 800 MHz FACs due to the matrix values no longer being correct since they were based on the LMCC recommendation of use of the F(50/50) curve.