“Don’t bite the hand that feeds you”
It’s not too often that you see a telecom equipment vendor taking a public position that is adverse to the position of its customers. But that’s exactly what is going on in the FCC white spaces proceeding. Motorola is promoting mobile opportunities that will cause harm to its customers in the cable industry.
I’ve written about this contentious FCC proceeding before, but I’ve never focused on Motorola’s role. There are some 35,000 comments in the FCC’s docket file, and I only read some of them. But (only) 17 petitions for reconsideration were submitted in late March, a much more manageable number. The NCTA submitted one, and so did Motorola. They take very different positions.
In summary, the NCTA wants the power levels decreased and other restrictions tightened, while Motorola wants the power levels increased and other restrictions loosened.
The FCC adopted power limits of 4 watts for fixed TV Band Devices (TVBDs) and 100 milliwatts (mW) for portable devices. In addition to power limits, the FCC imposed many operational restrictions on these unlicensed TVBDs. They include requirements to check into a database to identify available frequencies at TVBD transmitting locations, requirements to sense the presence of wireless microphones and limits on antenna heights.
The FCC requirements might be adequate to protect over-the-air TV reception (although broadcasters dispute this), but they are not adequate to protect cable TV reception. Consequently, the NCTA filed a 144-page Petition for Reconsideration. Much of it consists of two new test reports, a study of TV receiver susceptibility to direct pickup (DPU) interference and a study of headend reception interference.
Even though there may be white spaces in the over-the-air TV broadcast environment, there are no white spaces on a cable system – all of the channels are carrying signals. So TVBD signals that leak into a TV receiver can cause interference to cable reception, even on frequencies that are not used for OTA broadcasting. The NCTA hired a test lab to test the shielding effectiveness of seven representative TV receivers (five new digital/analog receivers and two older, analog-only receivers).
The FCC actually has receiver shielding requirements, but the tests showed that many receivers don’t meet those requirements. Worse yet, the tests found that internal cables and F-connectors, even when professionally installed, could contribute to the DPU interference. But most customers use cables and connectors that are far inferior to those used by professional installers. Even Motorola admitted, in a December 2007 FCC filing, that in-home wiring (and the interaction between that wiring and receiver tuners) can be the dominant mode of DPU interference.
In summary, the tests found that DPU interference from a 100 mW portable TVBD could propagate as far as 80 feet into an adjacent apartment, even taking into account the attenuation of an intervening wall. And a fixed 4 W TVBD could interfere into TV sets as far away as 1000 feet. The NCTA asked the FCC to reduce the power limits to 50 mW for portables and 1 W for fixed devices.
The report of headend interference tests showed that interference could result from TVBDs at greater distances and angular separations than the FCC rules will protect. So the NCTA proposed several changes to the FCC’s headend protection rules, including a requirement that all fixed TVBDs must coordinate with all cable headends within 100 km of the TVBD transmit location.
Motorola sees things differently. It wants higher power limits for vehicle-mounted portables and higher antennas for fixed TVBDs.
The power limit for portable TVBDs, whether handheld or vehicle-mounted, is 100 mW. Motorola wants that increased to 4 W, like fixed devices. Motorola listed the supposed benefits “for critical infrastructure industries and other enterprise users: Access to data through low-cost, wide-area mobile broadband connections protect the American public and improve industrial efficiencies and productivity, increase competitiveness globally and, therefore, help build job strength.” Wow! I’m impressed! But Motorola never addressed the increased likelihood of DPU interference that these high-power mobile TVBDs might cause.
The FCC imposed a height limit of 30 meters for fixed TVBDs. Motorola proposed that the height limit be raised to 100 meters. This would, of course, increase the interference distances, so Motorola agreed that the required separation distance between the TVBD and a TV station’s protected service area be increased. While current rules require that a TVBD with a 30-meter-high antenna be at least 14 km outside of a TV station service area, Motorola proposed that the separation distance for a 100-meter-high antenna be 28 km. While that increased separation might protect off-air TV reception, it provides no mitigation for the increased DPU and headend interference that will occur.
It used to be that the NCTA and Motorola (and before that, General Instrument Corp.) were on the same page when it came to FCC proceedings. I find it quite remarkable that the situation has changed so dramatically.
The Motorola business segment that includes cable TV products had sales of $10 billion and profits of nearly $1 billion in 2008. That year, its mobile devices division had sales of $12 billion and losses of $2 billion. Motorola evidently forgot the old adage, “Don’t bite the hand that feeds you.”