Narrowbanding

cell_towers_photoA fellow ham operator who, like me, is involved in emergency communications, forward an article that Glen Bischoff of Urgent Communications magazine just published titled What to Do About Narrowbanding? I’ve been too focused on short-range wireless to have followed this, but no longer.

 By the end of 2012, all private land mobile radio users operating below 512 MHz must move to 12.5 kHz narrowband voice channels and highly efficient data channel operations.  If they don’t, they will be in violation of their license and subject to fine by the FCC. In addition, the FCC will not be allowing any new licenses for systems operating with 25 kHz wide channels, or expansion of existing systems, after January 1, 2011. That means after December 31, 2010 operators will need to make decisions regarding how they intend to comply by the end of 2012.

 The purpose of the FCC’s 2003 edict was to clear up congestion in the HF/VHF bands, which this action would clearly do. However the public-safety agencies who have the most to gain from this change now find themselves strapped for the cash to implement it; in the absence of government funding for new equipment it’s essentially become another unfunded mandate. The FCC is hanging tough that it will indeed fine or shut down your local police communications center if they don’t comply, but I find it impossible not to share Bischoff’s view that that there’s no way that’s going to happen. It’s either a Mexican standoff or time to negotiate.

 All new equipment mandated by the DHS must comply with Project 25 (P25) standards set by the Association of Public-Safety Communications Officials ( APCO-25) and other agencies. This standard was developed to insure that first responders nationwide can all communicate with each other when they show up at a disaster site. Current APCO-25 Phase 1 radio systems operate in 12.5 kHz analog, digital or mixed mode using continuous 4-level FM (C4FM) modulation for digital transmissions at 4800 baud and 2 bits per symbol, yielding 9600 bits per second total channel throughput. Receivers designed for the C4FM standard can also demodulate the compatible quadrature phase shift keying (CQPSK) signals. As Bischoff points out, any equipment purchased before 2000 will have to be replaced in order to be interoperable with newer equipment. That represents a real hardship for smaller, rural police and fire departments in particular.

 The solution seems to me to be two-fold: (1) petition the FCC for an extension on compliance; and (2) push the administration to fund the purchase of new equipment, flying the flag of “homeland security”. In this economic environment more money is pretty unlikely, so getting the FCC to back off is the main hope.

 If this burr gets under your saddle you can contact the FCC or the P-25 Technology Interest Group (PTIG).  Or check out the IWCE conference and exhibition to be held in Las Vegas from March 8-12, 2010. In any case thanks to Jay (KA5OST) for bringing the issue to my attention and to Glen Bischoff for keeping it on the front burner.

About John Donovan

Writer, editor, Dad
This entry was posted in FCC, Regulatory issues, RF/Wireless and tagged , , , . Bookmark the permalink.

Leave a Reply