GPS World

Tag: NextNav

  • GPS backup demonstration projects explained

    GPS backup demonstration projects explained

    The U.S. Department of Transportation awarded contracts to 11 companies to demonstrate their technologies’ ability to act as a backup for GPS.

    We wanted to know a bit more about what each of them were going to demonstrate, so we asked each for an explanation. Most provided just that, so much of what appears here is in their own words. A couple of companies sent us a whole lot more than 100 words and two did not respond. For those, we did our best with the materials they sent us and other publicly available materials.

    Wi-Fi, Cellular, Ultra-Wideband

    PhasorLab plans to demonstrate its Hyper Sync Net (HSN) technology as a backup to GPS-based PNT solutions. HSN is a self-organizing mobile mesh network capable of maintaining high-precision time (<<1 ns) and frequency (<<1 ppb) synchronization throughout the whole network as well as an instantaneous 3D locational map of the whole mesh network requiring as little as a single master reference node.

    The HSN can be deployed either as a set of fixed reference nodes providing time and positioning references to other mobile UE clients, which is like a terrestrial version of GPS, or as a private ad-hoc mobile mesh network where all members are expected to be mobile.

    Skyhook Technology’s system is powered by an immense database — created and maintained by Skyhook — that contains more than five billion geolocated access points and 200 million cell base station IDs, enabling it to accurately locate phones and devices worldwide. The user is not required to be connected to a Wi-Fi network for the system to work. The scan will simply detect Wi-Fi access points in the local area based on signals sent periodically (or on demand) according to the IEEE 802.11 specifications. Many devices will acquire information on as many as 100 access points in the surrounding area. Skyhook’s Wi-Fi positioning system (WPS) will compute an estimated end-user location based on each of the signal sources independently, and compute an optimal hybrid location estimate from all sources.

    Fiber/Network

    OPNT’s Global Terrestrial Timing Service (GTTS) provides GPS-independent timing-as-a-service over global fiber-based networks. Trading off cost versus service-level agreement (SLA)-backed accuracy, standard network connectivity offerings and bidirectional fibers are combined to meet application needs. As will be demonstrated with simulations of National Institute of Standards and Technology (NIST) and the two U.S. Naval Observatory (USNO) clocks, OPNT’s fully redundant solution receives its core Coordinated Universal Time (UTC) timing directly from the non-maskable interrupts (NMIs).

    The demonstration will include sub-nanosecond stability with fault detection and glitchless recovery. Using the precision-timed fiber base, OPNT will also demonstrate precision monitoring of wireless signals with continuous, real-time corrections to keep the wireless transmissions and its local timing source in sync.

    Seven Solutions’ core technology is called White Rabbit and was born at CERN. In this demonstration, Seven Solutions plans to showcase the performance of this technology, both on local and wide-area deployments, and explain the capabilities in terms of interoperability (integrating multiple synchronization technologies, i.e. IEEE 1588 PTP, NTP, PPS, 10-MHz clocks), scalability and resiliency. The goal is to provide a reference technology that can provide very stable time references over fiber in GPS-denied scenarios as a backup source or to complement other PNT solutions that need timing distribution at their core.

    eLoran

    Hellen Systems’ team said it is excited by its recent contract award to perform a GPS back-up demonstration for the Department of Transportation. Its team plans to demonstrate advanced eLoran technologies and offer resilient PNT services. Its next-generation solution will include a solid-state eLoran transmitter from Continental Electronics Corp. integrated with advanced timing and frequency products from Microsemi, a Microchip company. Hellen Systems also plans to deploy its proprietary receiver and reference systems developed by Microsemi.

    Hellen Systems and program integrator L3Harris will manage the demonstration, with Booz Allen Hamilton providing technical and engineering leadership.

    UrsaNav supplies eLoran, LFPhoenix and low-frequency technology for very wide-area, GPS-independent, PNT data and frequency services. UrsaNav was selected by the Volpe Center to demonstrate wide-area UTC time synchronization and distribution utilizing the former Loran site in Wildwood, New Jersey. UrsaNav will provide innovative new eLoran technology at the site in Wildwood to broadcast a UTC-synchronized eLoran signal. The demonstration will be conducted at one of the Volpe Center demonstration sites at Joint Base Cape Cod in Massachusetts or the Langley Research Center in Langley, Virginia. Either site can be utilized in the demonstration as eLoran signal transmissions from the Wildwood site can easily cover 700 miles or more.

    Serco recently acquired Alion’s Naval Systems Business unit. This included a group working in New London, Connecticut, that has previously worked with and published on eLoran. While we did not get a response from Serco to our inquiry, eLoran is likely the technology the company will demonstrate.

    Satellite

    Globalstar-Echo Ridge’s system is based on Augmented Positioning System (APS) technology that uses ordinary signals from communications satellites (not special positioning/navigation signals, such as those from GPS satellites) to produce accurate position and timing information in compatible user devices. No new infrastructure is needed; Globalstar’s constellation of 24 low-Earth-orbit (LEO) satellites and Echo Ridge software and compatible devices at the user end provide the building blocks for the APS-based system. APS technology has been successfully demonstrated in diverse environments and incorporates multiple features to assure accurate PNT information under circumstances that can challenge or disable GPS/GNSS technology.

    Satelles provides unique timing and location solutions delivered over the Iridium constellation of 66 LEO satellites. These timing and location signals are available anywhere on Earth without the need for local infrastructure, making the system perfect for complementing GPS and other location-based technologies.

    Unlike standard GPS, these high-power signals can reach into many building structures. Most importantly, Satelles has customized the Iridium signal-in-space to provide a location-specific signature that can reliably prove (or authenticate) the location of a mobile device or other equipment, while being virtually impervious to spoofing and other attacks.

    TRX Systems’ NEON Personnel Tracker provides ubiquitous 3D location, tracking and mapping. (Screenshot: TRX Systems)
    TRX Systems’ NEON Personnel Tracker provides ubiquitous 3D location, tracking and mapping. (Screenshot: TRX Systems)

    Other

    TRX Systems is the developer of NEON GPS-denied location solutions, delivering 3D location and mapping for dismount personnel where GPS is not available or is unreliable — including indoors, underground, in dense urban areas, and where GPS is found to be erroneous. NEON delivers ubiquitous, low-cost, GPS-denied location by using advanced sensor fusion, ranging and patented dynamic mapping algorithms that improve safety and situational awareness for military, public safety and industrial personnel.

    NextNav’s Metropolitan Beacon System (MBS) is a 3GPP-compliant, terrestrial network of long-range broadcast beacons, transmitting a “GPS-like” signal in licensed spectrum in the sub-GHz range. The combination of an on-board atomic clock and the ability to self-synchronize allows the system to operate independent of GPS and provide full PNT services in its footprint. The ability to integrate the MBS signal in mass-market GPS and LTE chipsets can provide a seamless ability to provide full PNT services in the presence and absence of GPS. Because of its terrestrial nature, MBS is able to work indoors, in urban environments and outdoors; for barometer-equipped devices, MBS also enables floor-level altitude determination.

  • DOT gets cracking on a new PNT concept

    DOT gets cracking on a new PNT concept

    Congress mandated movement in December 2017.

    U.S. National PNT Architecture from a 2007 Department of Transportation report, updated in 2017. (Graphic: U.S. Department of Transportation)
    U.S. National PNT Architecture from a 2007 Department of Transportation report, updated in 2017. (Graphic: U.S. Department of Transportation)

    The U.S. Department of Transportation (DOT) says it will implement a terrestrial timing system to complement and back up GPS signals, and plans to demonstrate the new system “toward the end of the calendar year.”

    The demo is anticipated to include a range of technologies, including among others local positioning systems such as Locata and NextNav, wide-area coverage by eLoran, and — though the parameters of DOT’s mandate specified terrestrial backup — space-based signals furnished by Satelles.

    The statement came in response to an inquiry in March from the House of Representatives’ Transportation and Infrastructure Committee concerning progress on a GPS Backup Technology Demonstration that was mandated in December 2017. Although funds were appropriated for the project, committee chair Peter DeFazio of Oregon saw little to no evidence of work being done, and so required a status report.

    DOT issued a Request for Information (RFI) on May 3, with a due date of June 3. The RFI asked for “readiness-level six” technologies (bearing demonstrated results in a relevant environment) “capable of providing backup positioning, navigation, and/or timing services to critical infrastructure in the event of a temporary disruption to GPS.

    “This demonstration effort also is expected to encompass technologies capable of providing complementary PNT functions to GPS by either expanding PNT capabilities, including cross checks, or extending them to GPS or Global Navigation Satellite System (GNSS)-denied or degraded user environments.”

    The DOT said it is “interested in leveraging PNT service technology initiatives.” Possibly, the agency intends to contract for a service rather than build a new system.

    Congress first required DOT to establish an operational terrestrial timing system to back up GPS signals, then expanded that definition to include positioning and navigation services.

    Systems or services, or combinations thereof, must now provide all three functions.

  • NASA program for UAVs in cities turns to NextNav

    NextNav’s Metropolitan Beacon System (MBS) service has been accepted for use by NASA. NASA will use NextNav’s MBS network as part of its CERTAIN (City Environment for Range Testing of Autonomous Integrated Navigation) facilities at NASA’s Langley Research Center in Hampton, Virginia.

    CERTAIN supports, among other programs, Urban Air Mobility (UAM), an air transportation system with myriad applications from small package delivery drones to passenger-carrying air taxis.

    The Federal Aviation Administration (FAA) believes that by 2022 there will be more than 700,000 drones delivering packages, monitoring traffic and aiding in search and rescue operations. NASA’s role is to provide research findings to reduce technical barriers associated with integrating unmanned aircraft systems into the national airspace system.

    NextNav’s MBS system facilitates urban drone operations where satellite-based GPS signals may not be available. The need to reliably know a drone’s location horizontally and vertically is critical to ensure safe operations in urban air traffic corridors.

    Uber in the Mix. Uber and Bell (formerly Bell Helicopter) plan to launch an on-demand mobility venture, or flying taxis, nationwide by 2023, so the need to precisely track vehicles moving throughout city airspace is imminent.

    The move to such flying taxis would require a change to current FAA-controlled airspace separation requirements, according to Tom Prevot, Uber’s director of airspace systems. He stated that the Uber venture foresees takeoffs and landings from city vertiports every 24 seconds, requiring a considerable reduction in the minimum-distance standards of 1,000 feet vertically or 3 to 5 nm horizontally, as currently mandated in FAA order JO 7110.65.

    Metro Beacons. “NextNav’s MBS system provides us with new tools for the development of navigation systems in environments where GPS has traditionally been challenged,” said Evan Dill, Safety-Critical Avionics Systems Branch of NASA. “We’re looking forward to working with MBS as we develop new approaches to the operation of unmanned systems in urban environments.”

    NextNav’s wide-area terrestrial positioning network provides accurate and secure location services, critical for unmanned aircraft navigation. In addition, MBS complements and integrates seamlessly with GPS and provides a level of geo-redundancy ensuring a safe and efficient system for future air transportation in cities and urban areas, with particularly difficult challenges at low altitudes where solutions such as radar, GPS and ADS-B are unreliable or insufficient.

    Delivered over a managed network on nationwide licensed spectrum with carrier-grade dependability and metropolitan-wide coverage, NextNav said its services are designed for public safety applications, E911, critical infrastructure, as well consumer, Internet of Things (IoT) and commercial applications that require reliable 3D geolocation indoors and urban areas or precise timing.

    Future city airspace filled with drones and passenger aircraft. (Image: NASA)
    Future city airspace filled with drones and passenger aircraft. (Image: NASA)

    “We are proud to work with NASA and integrate MBS into its urban drone operations,” said Ganesh Pattabiraman, co-founder and CEO of NextNav. “The MBS system is designed for secure, reliable and consistent 3D geolocation capabilities, which are important for autonomous systems such as drones. NASA’s acquisition of the MBS system is an exciting milestone for MBS technology and a great partnership with NASA to address the key challenges in urban drone navigation and make it possible to explore new opportunities in unmanned operations.”

  • Floor-level positioning accuracy demonstrated for indoor mobile calls

    Floor-level positioning accuracy demonstrated for indoor mobile calls

    <b>NextNav Results: </b>Vertical accuracy delivered by various phone models using signals from an installed network of NextNav beacons. (Plots: NextNav, from ex parte FCC filing, Aug. 8)
    NextNav Results: Vertical accuracy delivered by various phone models using signals from an installed network of NextNav beacons. (Plots: NextNav, from ex parte FCC filing, Aug. 8)

    According to NextNav, its altitude service delivered floor-level accuracy in 94 percent of test calls in recent blind industry tests commissioned by the Cellular Telephone Industry Association.

    The Stage Z Tests were designed to develop a proposed Z-axis (vertical) metric for indoor wireless 9-1-1 calls, as required by the Federal Communications Commission (FCC).

    NextNav’s Metropolitan Beacon System (MBS)-based services enable mobile phones and other devices to reliably determine their location and timing in indoor and urban environments where GPS signals cannot be received, the company said. NextNav’s 3D location services include accurate horizontal positioning, floor-level altitude precision, and context and visualization applications.

    <b>Polaris Results: </b>Vertical accuracy delivered by various phone models using signals from an installed network of NextNav beacons. (Plots: NextNav, from ex parte FCC filing, Aug. 8)
    Polaris Results: Vertical accuracy (Plots: Next Nav, from ex party FCC filing, Aug. 9)

    Delivered over a managed network on the licensed spectrum with carrier-grade dependability and metropolitan-wide coverage, NextNav’s services are designed for public safety applications, E911 and critical infrastructure as well as the multitude of consumer, internet of things and commercial applications that require reliable indoor 3D location or precision timing.

    According to NextNav, the Stage Z Tests evaluated the ability of various technologies to accurately locate mobile 911 callers in the vertical dimension in challenging indoor environments spread across an entire metropolitan area. The tests were conducted using popular off-the-shelf iOS and Android devices running a software client provided by NextNav. The tests included more than 70,000 emergency-style calls generating altitude fixes from more than 200 different test locations.

    “Our ability to deliver floor-level height accuracy has the potential to speed up emergency response time and save lives,” said Ganesh Pattabiraman, co-founder and CEO of NextNav. “The ability to precisely locate the exact floor is a significant breakthrough for wireless 9-1-1 location technologies.”

  • Terrestrial beacons bring wide-area location indoors

    Terrestrial beacons bring wide-area location indoors

    Extraordinary though satellite navigation may be, GPS and other satellite-based constellations are limited when there is not a line-of-sight or near-line-of-sight path to at least three (and preferably more) satellites. These systems also do not provide sufficiently accurate and reliable altitude information for most applications, especially indoors. Finally, power consumption is an issue for user equipment.

    It has been easy to overlook these limitations as the enormous benefits of GNSS have become pervasive, but the increasing demand especially for indoor geolocation now requires a robust solution designed for the indoors and urban canyons. Support for Terrestrial Beacon System (TBS) location technologies was incorporated in Release 13 of the Third Generation Partnership Project (3GPP). These technologies are complementary to GNSS, and provide a comprehensive solution to these limitations.

    One of the TBS in development is the Metropolitan Beacon System (MBS) implementation by NextNav, which is the subject of this article. NextNav is deploying the first MBS network in the United States, using spectrum in the 920–928 MHz band, on licenses that cover about 98 percent of the U.S. urban population.

    3GPP is the standards development organization for cellular wireless specifications, and is in part responsible for the popularization of GPS through its standardization in the 3GPP Release ’98 specifications. Release ’98 enabled wireless operators to adopt GPS and bring their economies of scale to GPS positioning.

    Release 13 support has similar potential for MBS, enabling support for MBS in any Release 13-compliant LTE network throughout the world. As with the original standardization of GPS in 1999, incorporation of MBS in this release was driven primarily by the need for wireless carriers to provide accurate indoor geolocation for E911 calls.

    MBS complements GPS by providing precise geolocation and timing indoors, in urban canyons, and other locations where GPS signals are either unreliable or unavailable. MBS receivers work seamlessly with GPS so they are as transparent to the user as satellite-based systems. MBS can provide floor-level altitude and navigation in indoor environments.

    Typical mall experience: green dots show NextNav computed positions relative to ground truth (red line).
    Typical mall experience: green dots show NextNav computed positions relative to ground truth (red line).

    How it works

    MBS transmitters are similar in many respects to GPS satellites that are deployed terrestrially. Unlike communications systems, MBS is deployed with a view toward minimizing dilution of precision (DOP) so that the signals available at any indoor or outdoor location will meet the unique requirements for accurate geolocation. DOP is an indicator of the three-dimensional positioning accuracy of a radio positioning system’s signals as they are “viewed” by a receiver.

    GPS signals are typically 30 dB below the thermal noise floor at the Earth’s surface, and thus GPS receivers require a significant amount of processing resources for acquisition and tracking. Acquisition time can be quite long, up to 12 minutes in the absence of almanac and ephemeris information. Modern commercial implementations with some assistance information is typically closer to 30 seconds.

    Mall store accuracy tests depicting indoor tracking performance in suburban mall environment. Dots show MBS-drive information, with no additional data from inertial or other sensors.
    Mall store accuracy tests depicting indoor tracking performance in suburban mall environment. Dots show MBS-drive information, with no additional data from inertial or other sensors.

    Throughout this time the receiver is running at full bore, drawing a considerable amount of current, the bane of any battery-operated device. MBS mitigates these problems because the 30-Watt radiated power of each terrestrially located transmitter combined with a satellite-like link budget provides greater received signal-to-noise ratio.

    The result is an acquisition time without assistance information of 6 seconds or less, and 1 second if assistance information is available. The ease of acquiring and tracking MBS signals has significant implications for power draw and power management strategies.

    Metropolitan beacon rooftop transmitter.
    Metropolitan beacon rooftop transmitter.

    Although deploying a wireless network of any kind is a complex endeavor, MBS benefits from the ability to cover an area using fewer beacons, thanks to its relatively high RF output power (but much lower than cellular signals) and robust processing gain.

    The transmitters typically share space with existing cellular systems on towers and building rooftops and are compact. The antenna is typically a 5-foot, vertically mounted, omnidirectional element.

    The system provides for redundancy at both the transmitter and network levels, and the signals are encrypted for security. Like GPS, location can be calculated by the user’s device.

    Baseband Change. MBS was designed to be like another constellation on a multi-constellation GNSS processor, and primarily constitutes a firmware change to modern baseband designs. The primary receiver changes are related to the analog components (accommodation for a different frequency band and higher dynamic range).

    Enabling MBS in a smartphone requires a few inexpensive passive components and slight modifications to the antenna. From an RF perspective, NextNav’s MBS operating frequency is sandwiched between bands currently used by wireless carriers, so few if any changes to a standard FR lineup is required.

    Tackling cellular first

    Most of the billions of mobile phones shipped every year incorporate GPS receivers. Because GPS does not work reliably inside a building, however, mobile devices must fall back to ad hoc positioning methods based on communications infrastructure. This has become increasingly important because mobile wireless devices are used predominately indoors at least 70 percent of the time, according to a study by J. D. Power and Associates. This makes reliable indoor geolocation essential for consumer, commercial and public safety interests.

    The MBS architecture was designed to integrate into the GPS ecosystem and integrate organically within modern mobile devices, without the need for separate chips or elaborate reengineering.
    The additional benefit of determining altitude along with horizontal position is also significant. Indoors, context is determined as much by the vertical as the horizontal — for example, in a multi-level shopping mall. In emergency-response scenarios, critical seconds or minutes can be shaved off of response time if the floor in which an emergency is occurring can be reliably determined.

    Control-plane architecture (LTE) for NextNav E2E.
    Control-plane architecture (LTE) for NextNav E2E.

    Power and the IoT. The Internet of Things offers substantial productivity gains. Nevertheless, there have been limitations to the rapid adoption of certain IoT technologies. Among these is a fierce battle among competing low-power wireless communication standards. Lower power operations are the key for many IoT implementations, and location is one area where power savings, especially for wide-area location, are critical.

    While MBS is generally designed to complement GPS, in IoT operations it has the potential to replace GPS in some cases due to power savings available from the system. Due to its terrestrial nature, the MBS signal is much stronger than GPS, enabling significant power savings. Many applications are expected to be enabled by such a system, whether for very long-life applications with intermittent position reporting to always-on location (that is, persistent tracking). Location capabilities on wearable devices are also very desirable, but because of power constraints, provision of location through GPS has been difficult to realize.

    The general benefits of a terrestrial constellation also apply to non-power-limited applications, especially in urban environments and those where altitude is a critical feature. Driverless cars and unmanned aerial systems, for example, rely on GPS but also need precise 3D location accuracy.

    Vertical accuracy performance of mass-market devices.
    Vertical accuracy performance of mass-market devices.
    Vertical accuracy performance of mass-market devices.
    Another example of vertical accuracy performance of mass-market devices.

    Applications in 5G small cells

    The fifth generation of carrier wireless, 5G represents another potentially significant application of MBS technology. Achieving 5G’s ambitious goals — standards are expected to be complete by 2019 — will require a massive infrastructure increase, including small base stations, or femtocells, that must be time-synchronized to avoid interfering with each other. A large percentage of these are expected to be deployed indoors.

    This means wireless carriers, neutral hosts and other infrastructure operators will need to bring timing synchronization signals inside. This typically requires GPS receivers to be placed on rooftops with the received signal fed to multiple indoor locations by running cables throughout the facility.

    To an operator in a metropolitan area with hundreds or even thousands of indoor small cells, this represents a large investment in capital equipment and limits customer-based installation. MBS can provide a timing signal that can be received indoors through the use of a modified multi-constellation GNSS chipset, a low-cost and convenient alternative.

    Beyond cellular

    The enablement of MBS in 3GPP has drawn attention from those seeking geolocation for a range of other devices. EF Johnson Technologies, a provider of radios and other equipment for public safety applications, demonstrated the integration of MBS in its Viking P25 (Project 25) radios. As P25 radios are the standard for mission-critical voice in the public safety community, the ability to carry MBS information could be a key feature for first responders.

    Elder care, monitoring family members, security guards, assets, and hospitality employees: any application that experiences service limitations due to indoor lack of availability is a candidate to augment service with MBS service, or, if power is a very serious issue, simply rely on MBS alone.

    Summary

    MBS complements GNSS systems by providing indoor coverage, altitude positioning and lower power consumption. By leveraging the existing GNSS ecosystem, low-cost, high-volume receivers can be adopted and service become seamless among satellite and terrestrial systems.

    Other indoor PNT technologies

    The 2013 CSRIC Trials administered by the FCC also tested technologies from Qualcomm, Polaris Wireless and True Position.

    GPS World plans to publish articles about these and other alternative technologies in upcoming issues.

  • Expert Opinions: What will help regulators, public accept autonomous vehicles on the road?

    Q: What advance — or, overcoming what challenge — will most enable acceptance of autonomous vehicles on the road with regulators and the public?

    Ganesh Pattabiraman Co-founder, CEO Nextnav
    Ganesh
    Pattabiraman
    Co-founder, CEO
    Nextnav

    A: Similar to airplanes with an autopilot feature, the key issues that must be addressed in autonomous vehicles are redundancy and reliability of systems and appropriate, timely signals to the operator. One key area where this is required is the location of the vehicle. Autonomous location systems have to take into account areas where GPS works fine — but may suffer from an outage — and where GPS does not work, such as in urban canyons.

    Jane Macfarlane Chief Scientist, Head of Research HERE
    Jane
    Macfarlane
    Chief Scientist,
    Head of Research
    HERE

    A: Autonomous vehicles face two key challenges. The first is enabling the vehicle to see beyond its sensors. Autonomous vehicles are composed of two functions: sensing the local environment and controlling the vehicle to operate in the sensed environment. This model must be extended to include the larger environment using cloud-delivered map information informed by a connected vehicle fleet. The second is building intelligence that allows autonomous vehicles to share the road safely with human drivers.

    Kevin Dennehy Contributing Editor, GPS World; Director, Driverless Conference
    Kevin
    Dennehy
    Contributing Editor, GPS World; Director,
    Driverless Conference

    A: The development of autonomous vehicle sensors, artificial intelligence and software is advancing rapidly. Technology is being tested in open-road environments — and in bad weather. Component costs are falling as technology companies and automakers eye specific rollout dates. What could slow this developing industry is bad press, and the resulting government regulation, from a high-profile cyber security breach or an incident like a partially autonomous car getting into a fatal crash.

  • NextNav supports metropolitan beacon system for mobile

    The final specification for 3GPP Release 13 will include messaging support for Terrestrial Beacon System (TBS) location technologies, including the Metropolitan Beacon System (MBS).

    NextNav is deploying the MBS positioning technology across the U.S. to allow mobile phones and other devices to reliably determine their location in indoor and urban environments where GPS signals can’t be received.

    NextNav has adopted MBS for its nationwide deployment, which it calls an innovative “terrestrial constellation” bringing GNSS-like positioning performance to indoor and urban environments where satellite-based positioning is either unavailable or significantly degraded. By standardizing the core network information flow in 3GPP, support for MBS will become available across any Release 13-compliant LTE network platforms globally, similar to previously standardized GNSS systems such as GPS, GLONASS, BeiDou and Galileo satellite signals.

    NextNav’s system is complementary to GPS and delivers high precision latitude, longitude and “floor level” altitude in GPS-challenged areas such as indoors and urban locations across an entire metropolitan area. Unlike cellular positioning in LTE, MBS does not consume expensive wireless spectrum to do so.

    “We are gratified, after an especially intensive effort, to see 3GPP add support for Terrestrial Beacon Systems generically and for supporting the NextNav implementation of it — the Metropolitan Beacon System,” said Ganesh Pattabiraman, president of NextNav. “This speaks to the urgent market requirements for ubiquitous, high-quality indoor positioning. MBS availability as an international standard ensures that our location signals can be used in widely deployed LTE (long-term evolution) networks as part of an end-to-end system. It also opens the doors for multi-vendor systems, a critical consideration for our carrier customers and users worldwide.”

    The 3rd Generation Partnership Project (3GPP) unites seven telecommunications standard development organizations (ARIB, ATIS, CCSA, ETSI, TSDSI, TTA, TTC) and provides their members with a stable environment to produce the reports and specifications that define 3GPP technologies.

     

  • NextNav and Broadcom Partner for Indoor Accuracy

    NextNav and Broadcom Partner for Indoor Accuracy

    A NextNav beacon.
    A NextNav beacon.

    On October 2, NextNav announced that Broadcom Corporation acquired a commercial license to NextNav’s Metropolitan Beacon System (MBS) technology, a so-called terrestrial constellation that brings GNSS-like performance to indoor and urban environments where satellite-based positioning is either unavailable or significantly degraded.

    The agreement enables Broadcom to integrate NextNav’s location technology into its mass-market GNSS connectivity and mobility platforms, used primarily in cell phones and tablets.

    NextNav President and Founder Ganesh Pattabiraman characterized the deal in a conversation with GPS World:  “This is a commercial license to a Tier 1 chipset provider, whose products are in a vast number of smart and feature phones in the country. The partnership enables our technology in a low-cost, high-volume form factor. This is important for us since we don’t make chips. We rely on partners such as Broadcom.  This is the first of many such agreements; we’ll have more through the year.”

    Most wireless companies have a mobility group addressing cellular modems, the central clearinghouse for so-called connectivity: the combination of Wi-Fi, Bluetooth, GNSS, and other technologies. Standard assisted GNSS (A-GNSS) packages to date in such cases generally consist of  ephemeris from all GNSS satellite constellations supported by the wireless company’s chips, cell ID and Wi-Fi ID from base-station databases, and additional proprietary assistance mechanisms.

    The NextNav MBS concept shares many operating principles with GNSS satellite constellations, but because the NextNav beacons are installed terrestrially instead of in space, they transmit sufficient signal strength for reliable reception indoors and in urban canyons where a clear view of the sky is unavailable. MBS is deployed much like a cellular network, to provide consistent indoor positioning to every building within a covered metropolitan area. MBS offers both accurate horizontal positioning and highly accurate altitude information, a particularly important capability for emergency responders in urban and indoor areas where GNSS systems tend to be most challenged.

    NextNav built its MBS network across forty large U.S. markets (see list at end of story) with its own Federal Communications Commission (FCC) licensed spectrum. “We bring more a managed network providing consistency and reliability of position information,” continued Pattabiraman. “Also the vertical component that other systems do not provide.” He characterized Wi-Fi, for example, as “an unmanaged network,” subject to frequent changes without a centralized and continually updated source of certified data.

    NextNav location performance was recently highlighted in side-by-side technology tests conducted by the Communications Security, Reliability, and Interoperability Council (CSRIC) of the FCC, and published in March of this year; see reportage and analysis of these tests at The Inner Edge: Who Holds the Key to Indoor Nav?

    The trial compared the performance of location systems across urban, suburban, and rural areas in the San Francisco Bay Area for determining the location of callers during emergency calls (E911), a critical case for mobile-phone users. NextNav was the only technology capable of reporting a valid height or altitude estimate, enabling floor-level positioning. NextNav’s horizontal accuracy results also reduced first-responder “search rings” by 90 percent over its nearest competitor.

    Don Fuchs, director of business development at Broadcom, added “Nextnav is a metropolitan area location system, which is typically a wider area than that covered by Wi-Fi. Wireless emergency assistance calling (E911) needs a wider venue covered. And across 40 metro areas. Nextnav is wide area, while Wi-Fi is essentially local area.”

    Pattabiraman said that in a typical metro area, NextNav’s terrestrial constellation of beacons is deployed for maximum coverage and minimum GDOP, and is not constrained by capacity like a cellular network. He stated that the San Francisco Bay area covered by NextNav extends to 900 square miles, from South San Jose into Marin County and East Bay. “With a fraction of the beacons required for cellular coverage in the same area, which would be in the neighborhood of a few thousand antenna installations, our deploy and operating costs are much less. Less than 20 percent of that for a cellular network.”

    In comparison with Locata, another recently rolled out terrestrial constellation designed to fill GNSS gaps, Pattabiraman said, “Locata and NextNav are two entirely different systems serving different needs.  We are in the mass-market commercial cell phone wide area use case, filing that gap, providing 5–10 meter accuracy, with vertical as a critical component, and full market coverage. Locata covers centimeter-level precision application in localized environments. The two companies could both eventually get to the other side [of the market-sector spectrum], but currently each of us is focused on the particular requirements of our designated market areas. Also, we operate with licensed spectrum versus the Locata operation in 2.4 GHz unlicensed.”

    “At the highest level, they are both multi-lateration systems.  Time of arrival, time difference of arrival.  We arrive at our core synchronization via GPS, which has its own synchronization, but we’ve got our IP  on top of that to improve it.  Each beacon is autonomous.  You can drop it anywhere with a clear view of the sky, and it is synchronized to the rest of the network, it has its own self-synchronizing mechanisms.  Locata is a synchronized network.

    “Another way of looking at it, they have a replacement for GPS. We do more complementing for GPS, we count on GPS being there.”

    Broadcom’s Fuchs added, “From the perspective of a company designing GPS and GNSS client-side semiconductors, we view NextNav as a terrestrial constellation, no more difficult or challenging than adding support for any new or legacy constellation like BeiDou or GLONASS.  We see this integration as being very straightforward, we have lots of IP in the area of signal processing, these sort of signals, this sort of positioning algorithm. We add NextNav as a secondary technology for challenging urban conditions. We view this as a piece of location technology to develop and integrate as the market demands.

    “In six years at Broadcom and seven before that at Global Locate (acquired by Broadcom in 2007), we have a history of turning support like this, we’ve been able to do this very quickly.  Depending on market demand, in less than a year.  I can’t lay out a roadmap at this point.  We expect to see market demand for this, certainly expect regulatory demand.  We wanted to get to the point where we can react to that in less than a year. That was the motivation to get this agreement into place, and we are now positioned.”

    “We all operate under standard operating environments as specified by the FCC. We’re metro-wide just like paging towers or broadcast TV,” continued Pattabiraman. “We’re not necessarily doing anything different as regards the indoor environment.  We’re not adding anything additional to the noise spectrum or floors. Our maximum transmission is 30 watts, very small compared to cell transmission in kilowatts. It is bits per second by the time it hits the receiver.  Because it’s calibration for navigation, the network design is optimized for location. We take into account GDOP and coverage, maximizing the latter, minimize the former. There is a very low throughput. It’s a tradeoff between power and coding.  We code the heck out of this thing.  We just new a few bits to get our information through, not like cellular that needs to get megabits through.”

    As to any data or issues about the human health impacts of an RF-rich indoor environment, Pattabiraman concluded, “There’s none of this concern about power into your head. We transmit only at the tower, receive only at the user. It is very, very heavily coded, like GPS, and very low-powered.  It’s not even close [to cell transmission power].  We’re a feather, they’re a hammer.”

    List of NextNav Covered Metro Areas

    NextNav characterizes San Francisco as built to “commercial grade” and the other markets as “Initial Builds.”

    • Boston-Worcester-Lawrence, ME
    • Syracuse, NY-PA
    • New York-North New Jersey, NY-NJ
    • Philadelphia-Wilmington-Atlantic City, PA-NJ-DE-MD
    • Washington-Baltimore, DC-MD
    • Greensboro-Winston-Salem-High Point, NC-VA
    • Raleigh-Durham-Chapel Hill, NC
    • Jacksonville, FL-GA
    • Charlotte-Gastonia-Rock Hill, SC
    • Orlando, FL
    • Miami-Fort Lauderdale, FL
    • Tampa-St. Petersburg-Clearwater, FL
    • Atlanta, GA-AL-NC
    • Cincinnati-Hamilton, OH-KY-IN
    • Columbus, OH
    • Pittsburgh, PA-WV
    • Cleveland-Akron, OH-PA
    • Detroit-Ann Arbor-Flint, MI
    • Grand Rapids-Muskegon-Holland, MI
    • Milwaukee-Racine, WI
    • Chicago-Gary-Kenosha, IL-IN-WI
    • Indianapolis, IN-IL
    • Nashville, TN-KY
    • Memphis, TN-AR-MS-KY
    • New Orleans, LA-MS
    • St. Louis, MO-IL
    • Kansas City, MO-KS
    • Oklahoma City, OK
    • Dallas-Fort Worth, TX-AR-OK
    • Houston-Galveston-Brazoria, TX
    • San Antonio, TX
    • Denver-Boulder-Greeley, CO-KS-NE
    • Salt Lake City-Ogden, UT-ID
    • Las Vegas, NV-AZ-UT
    • Phoenix-Mesa, AZ-NM
    • Los Angeles-Riverside-Orange County, CA-AZ
    • San Diego, CA
    • San Francisco-Oakland-San Jose, CA
    • Portland-Salem, OR-WA
    • Seattle-Tacoma-Bremerton, WA

     

  • FCC Order Enables NextNav to Commence Commercial Operations

    NextNav-bldg
    Photo: NextNav

    On June 6, the FCC, following a unanimous vote of the commission, issued an order enabling NextNav, LLC to begin commercial operation of its advanced positioning network, which is designed to support 911 emergency first responders.  NextNav is deploying its nationwide network using Part 90 Multilateration Location and Monitoring Service licenses that are held by its affiliate, Progeny LMS, LLC. NextNav has been operating a fully-deployed location network for trial, testing and other non-commercial purposes in the San Francisco Bay Area for more than three years.

    “We are pleased that the Commission has unanimously approved our ability to enter into commercial service,” said Gary Parsons, CEO of NextNav. “The commission conducted an extremely thoughtful review of the technical characteristics of our innovative system, and this order will allow us to offer location services that have the potential to significantly enhance 911 and public safety applications.”

    NextNav’s high-performance terrestrial positioning network is designed to complement GPS in urban areas and inside structures, places where GPS is significantly degraded or denied due to blockage of the fainter, satellite-based GPS signal. The FCC-chartered Communications Security, Reliability and Interoperability Council Working Group III found that NextNav’s system delivered 90 percent smaller search rings then existing technologies in challenging indoor urban environments, and was the only technology tested capable of providing floor-level height accuracy.

    The operation of this system is significantly enhanced by its use of Part 90 M-LMS spectrum licenses, which are designated for the location of mobile devices.  The spectrum licenses used by NextNav cover nearly all major U.S. urban centers and over 93 percent of the U.S. population.

  • Leadership Awards 2012: Terrestrial-Based Signals

    A GPS Look-Alike to Compensate for Poor Indoor, Urban Availability

    Editor’s Note: This article reproduces the acceptance speeches given by the winners of GPS World’s 2012 Leadership Awards, at the Leadership Dinner in Nashville in September. The Leadership Dinner was sponsored by Lockheed Martin and Deimos Space.

    Remarks by Waldemar Kunysz

    Senior Staff Engineer, winner in the Services category. He works on Wide-Area Positioning System (WAPS) design and implementation in the continental United States. He spent the  previous 16 years with NovAtel, Inc., working on various research projects and novel antenna designs.

     

    I am much honored to receive this award and recognition. It means a lot to me.

    I would like to thank the people who made a difference in my career. Without them it would not be possible for me to be here.

    First I am grateful to Dr. Maurice Meyer, former MIT professor. He taught me the black magic of antenna engineering. I am quite sure that his spirit guided me when I invented the GPS/GNSS Pinwheel antenna when working at NovAtel, for which I received six patents.

    I also would like to thank Prof. Gerard Lachapelle and Dr. AJ Van Dierendock for teaching me GPS technology and Dr. Phillip Ward for providing very useful insight on the subject of interference. That knowledge saved me countless hours when troubleshooting some system-level issues while designing current and past GPS/GNSS products.

    Currently I am working at NextNav LLC, developing technologies related to NextNav’s new terrestrial based Wide Area Positioning System (WAPS). Founded in 2008 and based in Sunnyvale, California, NextNav has designed a new positioning system that is being initially deployed across the United States, although we anticipate taking our technology to global markets in the future. In its short life, in addition to developing the technology necessary for a timing-based, high-accuracy terrestrial positioning system, NextNav has already established a network presence in 40 of the largest U.S. metropolitan areas. This system allows the reception of a GPS-like signal in the areas where satellite coverage is weak or non-existent, such as indoors or in dense urban developments, that is, downtowns, urban canyons, and so on. We already have completed a fully-deployed service capability in the San Francisco Bay area that enables consistently accurate indoor and outdoor positioning anywhere from San Francisco to San Jose, and we are growing our network footprint across the United States. We are also very excited to have developed a height system that has demonstrated consistent floor-level accuracy, a feature that is particularly valuable indoors.

    As we know, all major terrestrial systems, such as Loran, Omega and Decca, have been shut down in the past several years. We have become very dependent on satellite-based services such as GPS and GLONASS without any terrestrially-based back-up. Any major solar storm in the future could be very disruptive to this service, so having a terrestrial-based system that is in sync with the satellite-based system will fill that void. And of course, a terrestrial system can be maintained and improved on a significantly shorter schedule, with significantly lower cost, than a space-based system. NextNav really provides an excellent complement to GPS.

    The future looks very bright for the positioning service industry. In my opinion, by 2020 it will become another ubiquitously-available utility such as phone or power. I’d like to agree with my other awardee and predict that in 2020 we will be able to have a carrier-based positioning accuracy anywhere and anytime, available from any devices including handheld units. You will know where all your assets are and you won’t need to post a question to your wife: “Honey, did you see where my tie is?” Your personal digital assistant will locate it for you.

    Thanks again.

  • Accord Technology Completes Full Suite Advanced GPS for Aviation

    Accord Technology LLC was recently authorized TSO-C145c for its latest receiver/sensor in the NextNav product family, the NextNav MAX GPS WAAS Class Beta-1, -2, -3. This successful GPS development is a key solution in a series of Accord Technology’s affordable civil aviation GPS receivers and sensor, the company said.

    Available as circuit card receivers (CCA) for avionics OEM hosting or as line replaceable sensor units (LRU) for aircraft installations, MAX is affordable and meets the latest standards, worldwide. It supports ADS-B (Automatic Dependent Surveillance-broadcast), all normal GPS procedures, as well as precision approach requirements such as LPV (Localizer Performance with Vertical Guidance) and RNP AR (Required Navigation Performance with Authorization Required).

    The NextNav MAX GPS technology is the most advanced in the world and is compatible with Satellite Based Augmentation System (SBAS) solutions such as the United States’ WAAS, the European EGNOS, Japan’s MTSAT, and GAGAN in India.

    “This TSO authorization for the NextNav MAX gives us greater flexibility to serve our customers with WAAS Beta 1 Only or Beta 1, 2, 3 LRU’s and CCA’s to fit their need,” commented Hal Adams, chief operating officer for Accord Technology. “The NextNav MAX is another important first for Accord Technology and we are anxious to move forward now with our AC 20-165 approved GPS sensor,” added Adams.

    Accord Technology received TSO-C145c for its NextNav mini in 2010. The NexNav mini GPS technology was the first GPS WAAS sensor to be authorized by the Federal Aviation Administration TSO-C145c WAAS Class Beta-1 Only. The NexNav mini solution is a market-breaking hybrid of automotive technology and aviation requirements providing an affordable solution for ADS-B GPS source.

    NextNav MAX’s DO-229D compliant aerospace GPS-SBAS receiver is certified by the FAA for TSO-C145c Class Beta-3 operation and is the enabling technology for several key applications, including:

    • Primary means of navigation
    • Localizer Precision with Vertical guidance approaches (LPV)
    • Airborne spacing assurance
    • Airborne Collision Avoidance (Non-TCAS System)
    • Constant descent approaches
    • Surface area movement management
    • Current and advanced Terrain Avoidance Warning System (TAWS)
    • Advanced Air Traffic Management (ATM)
    • Required Navigation Performance enhancements (RNP AR)

    “Whether it’s a need for LP/LPV approach precision or highly reliable PVT, NextNav MAX offers standard and custom solutions according to what our customers need,” Adams said. Designed around a small form-factor, the NextNav MAX CCA is delivered ready to integrate into host avionics systems, an LRU sensor or as a standalone module to ARINC 743 requirements. “We can even package the CCA in a module, tailored to your application,” Adams said.