"Radio Navigation and Radio Communication - Synergies and Conflicts"

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Harvey Price
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1 "Radio Navigation and Radio Communication - Synergies and Conflicts" Marconi/SCPNT Panel Panel Moderator: Brad Parkinson Panelists: Irwin Jacobs, Vint Cert, John Coffi, Mar?n Cooper & David Payne

2 Use of Radio Waves - Noteworthy Characteristics Communica?ons Posi?oning & Timing Digital Communica.ons resolving sequence of 0s or 1s Wide RF bandwidth and high power to maximize data bandwidth, constrained by Shannon Limit in the presence of noise Users can be passive (broadcas.ng) or ac.ve (full-duplex) TransmiKng users are usually easily iden.fied Explosive growth in demand for Bandwidth New ac spec may allow precision indoor posi.oning Precision Timing (mul.-latera.on) or Signal Direc2on (or both) are key parameters Key measurement is bit transi2on 2me (for ranging type systems) Signal Sequence already known Wide Bandwidth to achieve.ming (and hence ranging) precision Use of processing gain (an averaging technique) to achieve Jamming Resistance For passive Users (e.g. GPS or eloran), cannot determine number or loca.ons Satellite Naviga.on signals are extremely weak

3 Use of Radio Waves Selected Techniques/Applications Communica?ons Cell Phones (2-way) Fiber Op.c Cable - major distribu.on technique TV both satellite and terrestrial HF/Short Wave long range communica.ons Next Genera.on 5G Posi?oning and Timing Time Synchroniza.on Most applica.ons require mul.ple,.me-synchronized transmiaer loca.ons For GNSS/GPS, signal strength is very weak but gives 24/7 Global coverage GPS receivers now apparently over 3.5 Billion mostly smart phones Hi-precision GPS annual value to US over $35B

4 PNT Applications Major Dependency on Comm is in Red Areas Avia?on Agriculture Automo?ve Emergency & Rescue Services Intelligent Transporta?on Military Recrea?on Robo?cs & Machine Control Scien?fic Survey and GIS Timing Example applica?ons Area naviga.on, approach, landing up to Cat III, WAAS, NextGen AutoFarming: crop spraying, precision cul.va.ng, yield assessment Turn-by-turn guidance, OnStar, driverless cars 911, ambulance, fire, police, rescue helicopters, emergency beacons, airplane and ship locaters, OnStar Train control and management, UAVs, Intelligent highways Rescue, precision weapon delivery, unit and individual loca.on GeoCaching, control of models, hiking, outdoor ac.vi.es Bull dozers, Earth graders, mining trucks, oil drilling Earth movement and shape, atmosphere, weather forecas.ng, climate modeling, ionosphere, space weather, tsunami warning, soil moisture, ocean roughness, wind velocity, snow, ice, and foliage coverage, Mapping, environmental monitoring, tagging disease outbreaks Cell phone towers, banking, power grid Tracking Fleets, assets, equipment, shipments, children, Alzheimer s pa?ents, wild life, animals, law enforcements, criminals, parolees,

5 Major Synergies Nav and Com Cell Phones and Towers Synchronize Time Provide quick GPS Posi.on Air Traffic Control UAVs (Vehicle guidance, Traffic Control, Regulatory Compliance) WAAS (Integrity Verifica.on, Differen.al correc.ons) NextGen (Automa.c dependent Surveilance) First Responders (Police, Fire, Ambulance) Dispatch and Tracking Urban Canyons Challnge Local and Regional Differen.al Correc.on Links

6 Another synergy use of ac for indoor positioning Status of IEEE NGP Study Group Next Generation Positioning (NGP) From July 2015 Mee.ng: Expected Horizontal Accuracy: XY accuracy expected for the use case to succeed, is a requirement is that the computed loca.on be within 1m horizontally of the actual loca.on 90% of the.me Expected Ver.cal Accuracy: Z accuracy expected for the use case to succeed, same floor@99% is a requirement is that the computed loca.on be on the same floor as the actual loca.on 99% of the.me. 0.5m@90% is a requirement is that the computed loca.on be within 0.5m ver.cally of the actual loca.on 90% of the.me Use cases not yet proven

7 Conflicts Scarce Spectrum (FCC Alloca.ons) Inadvertent Interference (OOB) Collateral Damage (e.g. trying to jam Comm and also take out Posi.oning or reverse) Passive Nav (no Comm) versus two-way Nav

$Transmi\ers - - 5 Billion Times GPS Power at ¼ Mile Frequency in MegaHertz GPS Band Problems: Proximity (geographic and RF spectrum) and$

8 Scarce Spectrum Com/Nav Conflict: -Poten.al FCC Authorized repurposing of Spectrum Frequency Alloca2ons in GPS Frequency Vicinity - Proposed: 1-40,000 Terrestrial Broadband Transmi\ers Billion Times GPS Power at ¼ Mile Frequency in MegaHertz GPS Band Problems: Proximity (geographic and RF spectrum) and Power Lo-Performance, Narrow-Band GPS Receivers may be made to cope with Hi- Power Adjacent Transmiaeres Full-Band Exis.ng GPS Hi-Performance, Full- 0? Band GPS Receivers are Jammed X No Known Simple Fix (swapout in 10 years?)

feet drop with 64,750 cubic feet/ second) F e e t GPS - 0.

9 Visualizing the Problem - Equivalent Power Ratio Hi-Power Terrestrial - ¼ mile from GPS 5 Hi Power Terrestrial Niagara ~ 1 Billion Waas (167 feet drop with 64,750 cubic feet/ second) F e e t GPS Waas (1 Tablespoon of water per second through 5 feet ) Same Power Ra?o of 5 Billion to One

10 Major Questions What can cell phones do to cope with jamming of PNT? Does it maaer? Can adjacent band Terrestrial, wide-band Communica.ons (e.g. Ligado) be compa.ble with GPS/GNSS? Will 5G or ac change the synergies between Nav and Com? With the near-future advent of four major GNSS, does the internet or cell phones benefit?

11 Backups

12 Adjacent band interference 12

13 Why the Strong Reaction to changing the adjacent band to high-power applications? GPS users support the introduc?on of Broadband, but not at the expense of the founda?ons of GPS - Hi power neighbors threatens GPS availability, accuracy and (most important) Integrity While Digital Communica?ons and Digital Naviga?on are superficially similar, there are some fundamental differences that must be understood GPS - Accuracy with Integrity 13

14 Summary: Potential Technical Issues and Solutions May be future technical solu.ons good enough to diminish "leakage". (sensi.vity of GPS receivers to transmiaed power in the LightSquared band.) Such solu.ons not implemented in current GPS receivers - some will be ok, and many others will not. Increased future GPS receiver Cost and GPS accuracy degrada.ons TBD Second issue is trespassing. (intrusion of LSQ signals into the GPS band. ) Filtering LSQ modula2on may theore2cally make this type of interference acceptable. Non-linear and other effects ("duc.ng") may negate filter effec.veness Evalua.on requires real data - from real LSQ transmiaers. all ranges, azimuths, and eleva.ons. Also city areas where reflec.ons can reinforce signal power. The big point: Stop the rush to LSQ implementa?on. Objec?vely evaluate: 1. Total impact on current GPS receivers 2. Impact of forcing solu?ons on future GPS receivers No Deployment of LSQ Transmi\ers un?l a full na?onal dialog is complete Once deployment is begun, it will be difficult to reverse it. Note that we are having difficulty in in even forcing a reasonable delay to allow full evalua?on of the situa?on. March 2011 LightSquared Nationwide Interference with GPS 14

Three Wishes. and an elaboration. For Reception of. Professor Bradford Parkinson Stanford University. (these are my personal views)

Three Wishes. and an elaboration. For Reception of. Professor Bradford Parkinson Stanford University. (these are my personal views) Three Wishes and an elaboration For Reception of Professor Bradford Parkinson Stanford University (these are my personal views) Three Wishes - Dr, Parkinson 2017 1 Good News: World-wide dependency on GNSS