Electromagnetic interference assessment of CDMA and GSM wireless phones to aircraft navigation radios

Abstract

To address the concern for cellular phone electromagnetic interference (EMI) to aircraft radios, a radiated emission measurement process for CDMA (IS-95) and GSM (ETSI GSM 1 1.22) wireless handsets was developed. Spurious radiated emissions were efficiently characterized from devices tested in either a semi-anechoic or reverberation chamber, in terms of effective isotropic radiated power. Eight representative handsets (4 GSM, 4 CDMA) were commanded to operate while varying their radio transmitter parameters (power, modulation, etc.). This report provides a detailed description of the measurement process and resulting data, which may subsequently be used by others as a basis of consistent evaluation for cellularPCS phones, Bluetooth, IEEE802.1 lb, IEEE802.1 la, FRS/GMRS radios, and other portable transmitters. Aircraft interference path loss (IPL) and navigation radio interference threshold data from numerous reference documents, standards, and NASA partnerships were compiled. Using this data, a preliminary risk assessment is provided for CDMA and GSM wireless phone interference to aircraft localizer, Glideslope, VOR, and GPS radio receivers on typical transport airplanes. The report identifies where existing data for device emissions, IPL, and navigation radio interference thresholds needs to be extended for an accurate risk assessment for wireless transmitters in aircraft.

An infrared sensor Tx/Rx electronic card for aerospace applications

“…In fact, the possible interferences with primary signals could lead to catastrophic situations such as to render uncontrollable the aircraft [2,3,4,5].…”

Path Loss From a Transmitter Inside an Aircraft Cabin to an Exterior Fuselage-Mounted Antenna

“…Recently, an evolved measurement methodology for small aircraft has been reported [9]. An example of IPL analysis demonstrating the deleterious impact of IPL uncertainty is presented in [10]. A method for estimating IPL for cabin-to-antenna problems with accuracy comparable to direct measurements is desirable as a means to validate measurements, as a tool for interference vulnerability analysis generally, and for design and assessment of mitigation techniques.…”

Ultrawideband electromagnetic interference to aircraft radios

“…Since the RTCA/DO-199 & DO-233 studies, significant additional work has been performed by Eagles Wings Incorporated (EWI), Delta Airlines and NASA to better understand and quantify IPL. Previous analyses note that there are significant deficiencies in available data to allow estimation of the probability that a particular passenger location will have an IPL below a particular threshold [6]. A need was identified to extend the available IPL database on typical commercial transport aircraft.…”

“…WhileUWBoperation is stated tobe restricted tothe3.1-10. 6 GHzfrequency bandin the FCCFinal Rule, the15.209 limitsbelow960MHz arerelatively highalso. …”