Cumulative Interference to Aircraft Radios from Multiple Portable Electronic Devices

Abstract

Cumulative interference effects from portable electronic devices (PEDs) located inside a passenger cabin are conservatively estimated for aircraft radio receivers. PEDs' emission powers in an aircraft radio frequency band are first scaled according to their locations' interference path loss (IPL) values, and the results are summed to determine the total interference power. The multiple-equipment-factor (MEF) is determined by normalizing the result against the worst case contribution from a single device. Conservative assumptions were made and MEF calculations were performed for Boeing 737's Localizer, Glide-slope, Traffic Collision Avoidance System, and Very High Frequency Communication radio systems where full-aircraft IPL data were available. The results show MEF for the systems to vary between 10 and 14 dB. The same process was also used on the more popular window/door IPL data, and the comparison show the multiple-equipment-factor results came within one decibel (dB) of each other.

Assessing the interference of transmitting portable electronic devices to distance measurement equipment

“…The interference path loss (IPL, item 18) is taken from the TCAS entry in [7, Table 5-4], as measured DME values are not reported. The multiple equipment factor (MEF) is taken from [10]. The result in item 19 shows a significant margin with respect to narrowband T-PED emissions falling in the DME band.…”

“…Using the pro forma spreadsheet, the values derived in this sheet have been combined with other values from [7], DO-YYY, and [10] as shown in Table 1.…”

“…These thresholds will become the values used in Table 6-2 of DO-294B [7]. Finally, we will apply these thresholds with typical values from [7,10] and the draft DO-YYY document to the process defined in [7, Section 6] to assess the likelihood of T-PEDbased interference to DME systems.…”

An analysis of the effects of RFID tags on narrowband instrument landing systems

“…The net effective single entry value for the NIRA power spectral density (PSD) is -112.3 dBm (line 26). The multiple equipment factor of 14 dB is conservatively based on the cabin measurements in the GS band provided by Nguyen in [12].…”

On the requirements of secondary access to 960–1215 MHz aeronautical spectrum

“…The susceptibility of DME equipments to interference can be found in [18], [21]. The impact of onboard electronic devices to DME performance was investigated in [21], [22]. In [23], interference from UMTS cellular base stations in nearby frequency band was studied.…”