Infrastructure-less Localization

RedNodeLabs’ wireless mesh technology enables breakthrough applications. In this article we introduce one of them: real-time infrastructure-less localization.

Positioning IoT nodes with centimeter accuracy is a big challenge for industries like sport and logistic. Current solutions based on GPS only work outdoors, and the resolution (a few meters) is not enough to satisfy the requirements of many applications. Solutions based on Ultra-wideband (UWB) have excellent precision, but they require costly infrastructure deployment.

As an example, positioning players on a soccer field based on UWB (Kinexon, Catapult) requires the deployment of a ring of fixed nodes (anchors) around the field, which are used to track the players. Anchors need high-bandwidth communication links to successfully locate all the players and report the measurements. In addition, they are sensitive to interference from the large number of radio signals coming from the audience. They need to be accurately distributed, calibrated, and spread around the area of interest where the positioning takes place.

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Anchor-based localization: a ring of anchors surrounding the localization area is required

We perform accurate positioning without infrastructure using our award-winning RedNodeBus technology. Without requiring a ring of static anchors, every node localizes itself with its neighbors, achieving an outstanding number of positions per second, since anchors’ bottleneck is eliminated. Featuring direct node-to-node ranging, it works even in extremely crowded environments, with increased accuracy, scalability and noise resilience compared to anchors-based solutions.

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Infrastructure-less localization: mobile nodes are located using other nodes in the network; no anchor ring needed

RedNodeBus

RedNodeBus efficiently uses in parallel two collision-free and tightly-synchronized time-division multiple access (TDMA) radio buses:

  1. The UWB bus is used to calculate the pairwise distances between the nodes, based on periodically scheduled Time of Flight (ToF) measurements. To optimize scalability, our novel concept uses broadcast positioning beacons and scattered response times.
  2. The Bluetooth Low Energy (BLE) bus enables an extremely quick and reliable dissemination of the node coordinates and sensor data, based on the novel concept of wireless mesh flooding with concurrent transmissions and channel hopping.

RedNodeBus removes the need for an infrastructure. Combining pairwise distance and energy measurements with advanced data analysis techniques, a precise 3D map with real-time positioning of all the nodes is obtained. Concurrent transmissions allow us to reliably and efficiently report all the positions, getting exceptional update rates (thousands of positions per second with tenths of nodes). Localization coverage is extended with every node, since all of them act as a relay, extending the network coverage and the resistance to noise jamming, achieving great path diversity and eliminating single points of failure.

Multiple applications benefit from plug-and-play infrastructureless localization, from industry to sports. While localization schemes based on complex infrastructure are feasible for big events, seamless RedNodeBus localization also scales for quick and inexpensive deployments, everywhere and anytime. Training monitoring of an amateur football team, a group of cyclists racing outdoors or autonomous mobile robots inside a factory; all of them can be localized in real-time, with precise movement tracking and performance monitoring.

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RedNodeBus, winner of the EWSN 2019 Dependability Competition, is a protocol created by RedNodeLabs. If you need an extremely reliable, energy efficient and latency-optimal connectivity solution, including accurate positioning for sport or industrial environments, contact us at info@rednodelabs.com

Visit us at www.rednodelabs.com

developing the next generation of IoT networks

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