May 01, 2010
Following are comments we’ve received from readers about recent online and print news and articles. If you’d like to comment on an article, e-mail edit@RRMediaGroup.com
It is incredible that in the current troubled environment, the FCC would seek to educate, via the online comment system, every potential terrorist group of the vulnerabilities in this nation’s existing as well as planned cellular/broadband national infrastructure. At one time, the commission internally conducted studies such as these using [the commission’s] internal technical resources. The risks of such a public disclosure would appear to far outweigh any perceived benefit.
Dominic F. Tusa
Tusa Consulting Services
I find it hard to believe that this is being discussed, but I think that there are easier, and better, ways of dealing with this type of problem if it can’t be handled by physical security alone.
I would suggest that you might use a Faraday cage approach when building all new facilities. This would, by the nature of the design, take care of the cell phone issue. You could enhance this by using RF absorbing paint or materials on, or in, the walls. This could also be done with existing structures. A mesh screen embedded in the paint might be a cheaper way of accomplishing a Faraday cage result with existing structures. Then, to ensure that the two-way radio system still works for the prison, simply install an indoor distributed antenna system.
This whole thing smells of corruption to me personally. At the very least, why can’t the FCC just amend their rules for prisons? If it seems ridiculous, it probably is. Jamming the signals is a scam, at best, and should be looked at vigorously to determine whether a payoff situation is being developed.
Kenneth B. Moseley (P.E.)
The FCC answers to the “Narrowbanding FAQs” sounds like typical government speak. They have no idea how much this is costing everyone and don't care. They don't want to make any intelligent decisions, just to quote the regulations.
I have been designing radios since I graduated from college in 1964. John Larribeau from the city of Spokane, Wash., asked about modifying a receiver. Changing the IF filters will do nothing to affect the FCC certification, and I would say go ahead and do it. In fact, he should use the radio until he has interference problems and then change the filters.
The FCC requiring re-certification for transmitters modified with kits is ridiculous. The cost is almost as much as a new transceiver. If the deviation is just reduced from 5 to 2.5 kilohertz, it will in all likelihood pass the narrow band spec. The receiver may be wideband, but unless there is an interference problem, it could be left alone. Otherwise the cheap ceramic filters in the second IF can be changed. It would be enough to measure the occupied bandwidth of the transmit signal for verification and nothing else. The harmonic levels will not change.
In reference to the following from the article:
Question: Is it permissible for users to program radios sold after Jan. 1, 2011, with previous versions of programming software and enable 25-kilohertz operations?
Answer: No, it isn’t permissible for users to program or reprogram radios sold after Jan. 1, 2011, to enable the 25-kilohertz mode of operation.
Help! I just returned from the Motorola Channel Partner Expo in Las Vegas. I am pretty sure that Motorola said that radios manufactured before Jan 1, 2011, could still be sold after Jan 1, 2011, and used in the 25-kilohertz mode until Jan 1, 2013. Were they wrong or has this changed?
Director, Technology Sales
Motorola’s Response: After Jan. 1, 2011, Motorola can still sell 25-kilohertz radios until Dec. 31, 2012 if they were manufactured/imported before the start of 2011. Motorola is looking for FCC clarification in the question of shops or self-maintained licensees being able to reprogram 12.5-kilohertz radios manufactured/imported after Jan. 1, 2011, back to 25-kilohertz, in those situations where licensees are adding or replacing a few radios to their 25-kilohertz systems. The intent is to prevent forced mixed-mode 12.5/25-kilohertz operation during the two-year interim period