Ultra-low-power localization tag uses cellular signals [pdf]

The first questions is at least partly answered in the document, copied below. However, you still need a collection infrastructure to make this useful.

> Communicating locations: Localization trackers often need a communication module to periodically update location to a server or nearby hub. Standalone GPS trackers (e.g., [35] and [95]) often use cellular or satellite communications to do so. LiTEfoot can incorporate an NB-IoT module for relaying location data. Using a low-power NB-IoT transmitter [96], which consumes 76 mW to transmit a 140 kb packet in eDRX mode, the system can intermittently send updates hourly, daily, or monthly depending on the application. This enables LiTEfoot to operate for approximately 10 years on a coin cell. The same antenna frontend can be shared between LiTEfoot and the communication unit, maintaining a compact form factor while providing flexible communication capabilities.

Re: Ultra-low-power localization tag uses cellular signals [pdf]

#5

Post by micw » Thu, Dec 12, 2024, 8:33 PM UTC

Cool. I want this for my cats, my kids, my keys and everything else.

But I wonder: if millions of this are deployed, would this weaken cellular signals (by drawing power from it)?

Re: Ultra-low-power localization tag uses cellular signals [pdf]

#6

Post by davidhyde » Thu, Dec 12, 2024, 8:40 PM UTC

anonu wrote: post #4

I had 2 questions: 1. what about data transmissions 2. what about using this on containers in the open seas? The first questions is at least partly answered in the document, copied below. However, you still need a collection infrastructure to make this useful. > Communicating locations: Localization trackers often need a communication module to periodically update location to a server or nearby hub. Standalone GPS tr…

There are many cheap ultra low power microcontrollers that can keep a time clock going and a small amount (say 32KB) of ram. 30 years on a coin cell. Pair that with a Bluetooth low energy transceiver to automatically transfer the data when the home base is in range (or any number of base stations). Like at a port in your example.

Re: Ultra-low-power localization tag uses cellular signals [pdf]

#7

Post by fellerts » Thu, Dec 12, 2024, 8:59 PM UTC

How are they able to achieve sub-100 meter accuracy? I might be missing something, but In my experience, collecting the cellular parameters is the easy part. The challenge is knowing where the cells actually are. You can ask Google's geolocation API, but that typically returns a fix with ~1000 meter accuracy if it returns a fix at all. These databases are curated based on GPS+cellular information from millions of phones. There is no global source of truth.

If only base stations included location information in their transmissions...

Re: Ultra-low-power localization tag uses cellular signals [pdf]

#8

Post by timerol » Thu, Dec 12, 2024, 9:00 PM UTC

micw wrote: post #5

Cool. I want this for my cats, my kids, my keys and everything else. But I wonder: if millions of this are deployed, would this weaken cellular signals (by drawing power from it)?

Do you currently have tracker tags on those things? If not, why not? Multi-year lifetimes are already available with Tile (3 years), AirTag (>1 year), and Samsung's SmartTag 2 (700 days), using BLE detection instead of 4G detection.

Millions of these would not degrade signal. A random bit of metal (like a quarter, as shown for scale) in between you an a 4G tower should have the same effect as one of these devices. They are detecting existing 4G signal, not using it for energy harvesting.

Re: Ultra-low-power localization tag uses cellular signals [pdf]

#9

Post by timerol » Thu, Dec 12, 2024, 9:01 PM UTC

fellerts wrote: post #7

How are they able to achieve sub-100 meter accuracy? I might be missing something, but In my experience, collecting the cellular parameters is the easy part. The challenge is knowing where the cells actually are. You can ask Google's geolocation API, but that typically returns a fix with ~1000 meter accuracy if it returns a fix at all. These databases are curated based on GPS+cellular information from millions of pho…

FTA: Our localization approach combines open-source databases (OpenCellID [47], Mozilla Location Services [66], and CellMapper [12]) for PCI-to-coordinate mapping of cell towers with a trilateration technique based on relative signal strengths.

Re: Ultra-low-power localization tag uses cellular signals [pdf]

#10

Post by micw » Thu, Dec 12, 2024, 9:11 PM UTC

timerol wrote: post #8

micw wrote: post #5

Cool. I want this for my cats, my kids, my keys and everything else. But I wonder: if millions of this are deployed, would this weaken cellular signals (by drawing power from it)?

Do you currently have tracker tags on those things? If not, why not? Multi-year lifetimes are already available with Tile (3 years), AirTag (>1 year), and Samsung's SmartTag 2 (700 days), using BLE detection instead of 4G detection. Millions of these would not degrade signal. A random bit of metal (like a quarter, as shown for scale) in between you an a 4G tower should have the same effect as one of these devices. Th…

Thanks. I miss-read it and thought it's energy harvesting from celular.

I already have some trackers on important stuff (like keys and school bag of kids if they loose it in the bus). But for other use cases it's either too large (cats) or makes no sense to have too many because then I'd have to replace a battery every few weeks ("everything else").