Standards/Consortia Leftovers
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Wired ☛ Moon GPS Is Coming
Precision timekeeping is the core innovation that enabled the rise of global navigation satellite systems (GNSS), a category that includes the US’s GPS, China’s BeiDou, Russia’s GLONASS, and Europe’s Galileo constellations. Satellites in these networks carry atomic clocks that resolve time within a few billionths of a second. Positions on Earth are calculated based on the transit times of satellite signals to ground receivers; a time measurement that is off by just one nanosecond produces a distance error of 30 centimeters. For this reason, high temporal accuracy is fundamental to accurate geolocation services provided by GNSS, and it will also be key to any future analogs on the moon.
There’s a catch, however: Clocks tick slightly faster on the moon than they do on Earth. The difference is a consequence of general relativity, which shows that the flow of time is slowed by massive objects. The moon is less massive than Earth, thus atomic clocks on its surface tick faster.
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Arun Raghavan ☛ Arun Raghavan: GStreamer and WebRTC HTTP signalling
The WebRTC nerds among us will remember the first thing we learn about WebRTC, which is that it is a specification for peer-to-peer communication of media and data, but it does not specify how signalling is done.
Or put more simply, if you want call someone on the web, WebRTC tells you how you can transfer audio, video and data, but it leaves out the bit about how you make the call itself: how do you locate the person you’re calling, let them know you’d like to call them, and a few following steps before you can see and talk to each other.
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Tedium ☛ Taking A Mile
The risk of the open internet is that someone will exploit your well-intentioned openness thoughtlessly. That’s how the internet slowly stops being open.
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CNX Software ☛ Bluetooth 6.0 features accurate two-way ranging using Channel Sounding, latency reduction, improved scanning efficiency, and more
The Bluetooth Special Interest Group (SIG) has just announced the release of the Bluetooth 6.0 Core Specification with features and feature enhancements that include Bluetooth Channel Sounding for two-way ranging between BLE devices, decision-based advertising filtering and monitoring advertisers to improve device scanning efficiency, an enhancement to the Isochronous Adaptation Layer (ISOAL) for lower latency and higher reliability, the LL extended feature set, and a frame space update for throughput optimization. Bluetooth 5.4 was released as a minor update mostly adding electronic shelf label (ESL) support in February 2023, or about 18 months ago, but Bluetooth 6.0 is a major update with the most notable feature being Bluetooth Channel Sounding to enable two-way ranging between two Bluetooth LE devices.