AoC number

249

Primary domain

ENV

Secondary domain

OP

Description

The current spectrum of available radio frequencies for use by commercial and government entities is limited by physics and international regulations. Most aircraft use low bandwidths and weak Wi-Fi signals, but even these require modifications such as antennae, which can interfere with aerodynamics and aircraft performance. New high frequencies can interfere with radio signals on existing equipment, and overuse of mobile devices on flights can spread already-marginal signals thin.
Despite these drawbacks, the demands for public-use, commercial wireless services and government services are increasing exponentially with time. Proposed models to correct the issue include a 4G LTE model, with full air-to-ground networks streaming at up to 75 Mb/s, and broadcasting signals cheaply over the air via millimeter waves. These technologies carry their own issues of cost and signal stability, as full A2G networks can be expensive to maintain and millimeter waves will scatter in bad weather conditions.

Potential hazard

  1. Decreased frequency separation between users
  2. Unpredictable effects of closely-spaced frequencies utilized by different applications
  3. Potential interference by digital packets serving different applications transmitted on same frequency; prioritzation failure
  4. UWB devices will likely generate enough interference to disrupt transmissions of other frequency users
  5. If UWB does proliferate, its aggregate emissions could wreak havoc across the spectrum. Increased mobile device use on flights spreads existing Wi-Fi thin and interferes with radio signals from older equipment.

Corroborating sources and comments

http://www.masshightech.com/stories/2011/07/04/weekly8-Mobile-bandwidth-crunch-causing-concern-for-innovation-extra-pay.html

http://www.pnt.gov/interference/lightsquared/

This page provides information about potential interference to GPS receivers from the LightSquared communications network. The main text below was updated July 7, 2011.

This problem may be partially ameliorated by the use of laser data links that are in experimental demonstration.

Special Report: Ultra Wideband: Killer App or App Killer?

An intriguing wireless digital technology offers to redefine how spectrum is used, but could its interference cripple other spectrum users?

http://www.aviationtoday.com/av/military/Special-Report-Ultra-Wideband-Killer-App-or-App-Killer_12557.html

UWB emissions will negatively impact GPS and FAA radar, and possibly other vital services. Tests and calculations reveal the deleterious impact UWB will have on restricted band users. GPS operates at a very low margin above the thermal noise floor and is very susceptible to UWB impulses upsetting its moderate bandwidth raw data. That is a very serious problem. The proliferation of UWB systems will compromise the functionality of the Global Positioning System.
https://www.faa.gov/about/office_org/headquarters_offices/ato/service_units/techops/safety_ops_support/spec_management/engineering_office/rfb.cfm (The most recent regulations by the FAA as to which frequencies can be used when.)

http://gizmodo.com/every-major-airlines-wifi-service-explained-and-ranked-1701017977 (A look at the current state of in-air Wi-Fi, by airline. Most are quite slow, with low bandwidths, but new technology aims to increase that connectivity. Note in particular that Wi-Fi-equipped airlines require an antenna, which leads to wonky aerodynamics, which causes increased fuel burn and other issues.)

https://apex.aero/2017/02/15/wireless-interrupted-overcoming-radio-frequency-interference-connected-cabin

(Massive amounts of mobile devices not only spread Wi-Fi thin, but they can cause radio signal interference. Older equipment can’t deal with the crowding, and new high frequencies [i.e. 60 GHz speeds] pose even greater challenges.)

http://www.tmcnet.com/tmc/whitepapers/documents/whitepapers/2015/11529-using-air-to-ground-lte-in-flight-ultra.pdf (Proposal to increase broadband connectivity on flights, meeting consumer demand, using a 4G LTE model. The goal is to establish a full air-to-ground [A2G] network with speeds of up to 75 Mb/s. The technology was tested successfully in 2008 and 2012.)

https://www.theverge.com/2016/1/29/10868232/starry-high-speed-internet-millimeter-wave (Starry, a new startup, aims to broadcast signals over the air to bring cheap, limitless Wi-Fi to consumers. Millimeter waves can deliver such speeds, but market forces could be a limiting factor. Reliability is also an issue, as millimeter waves can easily be scattered.)

http://aviationweek.com/connected-aerospace/anatomy-two-would-be-mesh-network-startups (Idea for a “mesh network”, wherein aircraft would come with their own wireless antennae which could stream forward, above, and beneath them. Essentially, the planes would become carriers and routers themselves. It was difficult making a business case for this a decade ago, but recent financing by Ireland and the advent of startups Aeronet and Airborne Wireless Network have reopened the technology, so to speak.)

Last update

2017-08-28