New Jersey Transit Debate Continues with Questions About Emission Mask Requirements

Several  entities weighed in on the debate surrounding the use of TETRA-modified equipment in public-safety spectrum. Following a Harris petition for a rulemaking regarding emissions mask requirements in 800 MHz public-safety spectrum, PowerTrunk, Alcatel-Lucent and Nielson Communications came out in opposition to the request. Harris and the National Public-Safety Telecommunications Council (NPSTC) filed comments supporting the request. Motorola Solutions said the issues deserve the FCC’s consideration, but questioned whether a rulemaking proceeding was necessary.

The proposed rulemaking requested that the FCC restrict digital devices used in the public-safety spectrum to only H-Mask certified devices. Harris said allowing operation of lower emission devices, particularly B-Mask certified devices, could cause system interference to others operating on the spectrum.

In addition, Harris asked that pending the final FCC resolution, the commission prohibit any digital technology not meeting the H-Mask emissions requirement from operating in the spectrum, essentially asking for a freeze of all non-H-Mask devices operating in the 800 MHz spectrum. The third part of the request asked the FCC to “adopt equipment certification ‘technical’ mandates for operations on the mutual aid channels designated in §90.203(i) and §90.203(j)(1).” All commenters, aside from Harris, disagreed with the second two requests.

The emissions mask debate was spurred after New Jersey Transit (NJT) in March awarded a contract to Alcatel-Lucent for a system that included PowerTrunk’s Digital Land Mobile Radio (D-LMR) equipment. The equipment, which some referred to as “modified TETRA,” is a digital technology that meets the B-Mask emissions certification, rather than the H-Mask. Harris argued that use of the lower classification could lead to harmful interference in the public-safety spectrum.

In Section 90.210 of the FCC rules, devices operating in these frequencies must be compliant with the H-Mask if no audio low-pass filter is used, the Motorola Solutions filing said. However, if an audio low-pass filter is used, the device may show compliance with the emission limits specified as the B-Mask, the filing stated.

The FCC-certified PowerTrunk technology contains an audio low-pass filter, which PowerTrunk argued makes the digital technology suitable for use in the spectrum. The D-LMR equipment was awarded type acceptance for Part 90 in July 2010. “In the staff’s response, the chief of the equipment authorization branch agreed, after consultations with the Wireless Bureau, that it was appropriate to certify PowerTrunk’s equipment using the Mask B precisely because it has such a filter,” the filing said.

Click here to read the full article written by Michelle Zilis.

Source: www.radioresourcemag.com