A Harmful Interference Model for Unlicensed Device Operation in Licensed service Bands

Abstract

Recent FCC proceedings have considered the notion of unlicensed device operation in licensed bands. Licensed users are concerned about harmful interference while unlicensed device manufacturers are concerned that harmful interference is an imprecise design concept. This paper addresses two elements to these concerns. First, it develops an explicit model of harmful interference to be included in unlicensed device rules. Such a model provides explicit bounded protection to the licensed user while providing assurances and performance goals to the unlicenseddevice manufacturers. Second, it presents an analytic model for assessing harmful interference that not only provides quantitative analysis, but, also provides insight into how factors such as directional antennas, power control, and licensed channel avoidance strategies affect the aggregate interference. Further, it suggests that complex factors such as unlicensed device modulation schemes can be captured in a simple measurement. These ideas are applied to the notice of proposed rulemaking on Unlicensed Operation in the TV Broadcast Bands.