Rx Networks: Commercializing Indoor Location

In the time since my first article on indoor location, I’ve learned that there is a whole lot to this indoor location technology and business. A number of companies are taking on the indoor challenge, but few have so far successfully cracked this nut.

Rx Networks in Vancouver, Canada, is one of those few who have not only found solutions that work and work reliably, but it has also found a way to commercialize their solutions and make money.

Its embedded software and services are used daily in more than 1 billion devices — mostly smartphones, some machine-to-machine (M2M) installations, tablets, laptops, and wearables. That is some claim!

Daily transactions are primarily requests for A-GNSS assistance data, but also include requests for location based on Wi-Fi and Cell-IDs. Devices are using various Rx software and/or services, which include any or all data from a four-constellation reference network (GPStream GRN), extended ephemeris (GPStream PGPS), and Wi-Fi/Cell-ID positioning (XYBRID RT).

Founded in 2006, and still privately held, Rx is currently profitable. The head office is in Vancouver, and the company has a remote office in Atlanta, Georgia. Rx Network provides GNSS assistance-data to nearly all North American mobile operators and to several international carriers, helping those customers comply with current E-911 requirements and also offer other location-based services (LBS). In anticipation of a potential FCC “indoor” E-911 mandate, Rx’s offerings have been expanded to provide the location of devices where GNSS is not available. Its patented IP is also licensed through major GNSS semiconductor vendors and, in several cases, directly to the smartphone manufacturers.

Rx’s global reference network (GPStream GRN) is the foundation of many Rx solutions, including real-time assistance data and predictions. The service supports GPS and GLONASS, and will soon incorporate BeiDou and Galileo — the data is used by mobile operators and service providers and as an input to other products like XYBRID Cloud, where assistance data is supplied to a cloud-based positioning engine. And GPStream PGPS supplies data from the reference network to create seed files that generate extended ephemeris on smartphones.

The Rx worldwide network of GNSS reference stations. Photo: Rx Networks

There may be growing concerns about the status of the nascent Galileo constellation, but back in May, there was good signal coverage at times in Vancouver, Naples, and Prague. This enabled Rx to conduct testing on behalf of the European GNSS Agency (GSA) in challenging signal environments. The tests confirmed that Galileo significantly improved the accuracy of location-based services in urban canyons and indoors. Galileo signals were incorporated in the positioning solution with various combinations of GPS and GLONASS.

A new product known as XYBRID Cloud — a “cloud-based software receiver” — is going to trial shortly with a major U.S. carrier interested in using Rx’s indoor GNSS capability to locate small cells, home phone units, and other assets that carriers have to manage. The latest release of Cloud is providing an acquisition sensitivity of –166 dBm, which is claimed to be the best in the industry. 

The XYBRID Cloud system. Photo: Rx Networks

XYBRID Cloud captures I & Q data transmitted by satellites and sends it to a cloud-based positioning engine to determine location. This is in contrast to sending it to a receiver engine on a chip within the device. This is automatic, but is not really done for a “user” as much as for an asset such as a Wi-Fi access point, small cell, or other device that someone wants to locate.

Because these devices are often deep indoors, they may only see a few milliseconds of GNSS signals every now and then, so a real-time GNSS chip receiver would never get a fix. However, XYBRID Cloud assembles the captured data over time and is eventually able to record the location of the asset. This may take a few minutes or a few days, but a fix comes together eventually. Given that these assets are normally in fixed locations and seldom if ever move, such delays are not an issue, but knowing their location or if they’ve been moved can be quite valuable.

XYBRID RT/Synchro. Photo: Rx Networks

Another Rx product, XYBRID RT/Synchro,provides Wi-Fi and Cell-ID indoor and outdoor positioning using observed Wi-Fi and -tower signals, both with and without an active network connection. The systems works in real time (RT), and Synchro uses local datasets (regions) for Wi-Fi and other radio beacons that are downloaded into the user device whenever their signal is detected. Each “region” can be tailored to best suit a user’s general location, such as a metro area, city or other venue. The system is capable of a fast GNSS fix with improved sensitivity, or can fall back to basic Cell-ID/Wi-Fi positioning. Location is available indoors with an accuracy of 5-10 meters, depending on the quality of the regional datasets. 

Zed provides floor-level detection based on barometric pressure data. Photo: Rx Networks

Zed is able to provide floor-level detection based on barometric pressure data to within a vertical accuracy of 1-3 meters. Zed combines a global pressure reference with crowd-sourced data for fine-grained performance. This improves Wi-Fi location accuracy and supports Wi-Fi crowd sourcing with altitude geo-tagging.

So, Rx indoor solutions can use various combinations of these three products depending on the capabilities of the user devices. XYBRID RT provides location indoors using Cell-IDs, but more often uses Wi-Fi for more accurate positioning. XYBRID Cloud provides location of assets by sending any observed satellite signals to Rx servers for processing. Zed provides a calibration and ground-level reference pressure for a device, typically a smartphone equipped with a barometric sensor. Applications include location determination for smartphones, tablets, and wearables, and XYBRID Cloud finds assets like access points, small cells, Bluetooth beacon gateways, and home phone systems. Three companies are currently using Rx technology in the wearables space — a sports watch, augmented reality glasses, and heads-up display cycling glasses.

Other services supplied by Rx include worldwide Assisted GNSS (A-GNSS):

• GPStream GRN – Relies on data collected from the Rx worldwide grid of reference receivers for GPS, GLONASS, BeiDou and Galileo. Data is compatible with all popular positioning servers from leading vendors such as Ericsson, NEC, NSN, Qualcomm, and TCS.
• GPStream PGPS – Predicted GPS is an efficient handset-based extended ephemeris A-GNSS solution which supports GPS and GLONASS, for both connected and autonomous operation. Galileo is slated to be demonstrated at the Naviteq conference in December and to be available in 2015 along with BeiDou.Each device equipped with the PGPS client accesses Rx servers at least once every 14 days and downloads a small seed file that is used to create extended ephemeris for each constellation for the following 14 days.

The GPStream PGPS software. Photo: Rx Networks

Rx claims that its A-GNSS services have “carrier-level reliability” — that is to say, 99.999% availability per year.

Rx semi-conductor customers use an IP package that is embedded in processor chips for cell phones. They typically go on to supply Rx software (GPStream PGPS) with their GNSS chips, which is then run on a phone’s host processor — designed in at the factory as part of the phone.

OEM customers buy Rx GPStream PGPS software either directly or from the GNSS chip manufacturer and design it into the smartphone at the factory.

Mobile operators and service providers buy A-GNSS data that is delivered to mobile phones using location-based services for 911 caller location and LBS. Rx also supplies these customers with data containing the locations of Cell-IDs and Wi-Fi access points.

It’s good to hear that someone is already making a living with indoor location. And with so many signals of opportunity, inertial and pressure sensors now being used to “help” or actually completely replace GNSS, the era of indoor testing seems to be giving way to everyday consumer use. The average consumer will likely not realize when they seamlessly transition from outdoors GNSS guidance to “indoor” signals driving their smartphone map inside the mall. Or how really difficult it is for GNSS guidance to work in downtown when they automatically get A-GNSS assistance data that keeps their car map guidance on the correct street. Good for consumers, good for the telecoms guys, and good for the GNSS industry.

Tony Murfin
GNSS Aerospace