"Edge" vs 'Traditional' GPS Devices

Matt Clark-Massera

Modified on: Mon, 12 Sep, 2022 at 12:14 PM

Digital Matter supply an industry leading range of battery powered devices. Check out the entire range here. Industry-leading performance is about optimising several key areas:

Price
Performance - i.e. the accuracy and reliability of data
Power - super long battery life

Selecting the right device for the application is critical in ensuring the best results. Unfortunately we can't have it all in one device. For example a device that has every feature under the sun is going to be too costly to be viable for basic applications. Where not all these features are used/needed.

Our devices are highly configurable and flexible - to suit a variety of applications - but each has specific strengths.

Some of our devices are somewhat similar. We have 10 battery powered asset trackers in our range! All could be used to track unpowered assets - but understanding some key differences helps in making the right selection.

New to our range are the "Edge" devices, which use our Location Engine to resolve positions. A simplified example of how this works is:

The device scans for GNSS and Wi-Fi signals. It collects this 'raw' data.
This raw data is sent to the Location Engine (cloud) for processing
The Location Engine sends the data to various location providers to 'resolve' the raw data into a position.
The resolved position is send to the end server. (Tracking or other platform)

This has a number of benefits in terms of indoor/outdoor tracking performance, and battery life - but there are some caveats.

In contrast, when a device like the Oyster2 gets a GPS fix, it turns on its GPS module. The module then picks up the satellite signals, and spends time processing the data to obtain the lat/long position on the device. This uses more energy to obtain a position, but has a few benefits compared to the Edge range.

Comparison

Summary

	Edge Devices (Yabby Edge and Oyster Edge)	'Traditional' including Oyster3/Yabby3/Remora3
Tracking Performance	Location solved in cloud Indoor/Outdoor Tracking - Track anywhere The device is able to locate based upon GNSS, WiFi, and Cell signals. "Detailed" cell scans triangulate positions, as the device reports which cell towers (multiple) are nearby Positioning from these methods can be in some circumstances much less accurate (i.e. Cell typical accuracy is 300m+) Positions must be filtered based on accuracy on the server side No speed No heading	Location solved ON Device Must have GPS reception - i.e. a view of the sky - outdoors. No indoor tracking Only "Cell ID" cell tower fallback - i.e. the device reports the single tower it is connected to (accuracy of about 2km. Outdoor positions are more accurate. When the device attempts to get a fix, it will turn the GPS module on, and keep getting fixes until: It finds one within the accuracy range set in parameters The timeout is reached (whichever is first) Position is known ON the device it's position and how accurate a fix is. Speed reported with each update Heading reported
Battery Life	10 years once daily updates 2 years hourly updates If a device goes indoors, the device can still get a position on WiFi - battery life is not adversely affected.	7 Years Daily Updates 1 Year Hourly Updates If a device goes indoors, it will attempt to get a GPS fix for the GPS fix timeout - so it will use extra battery than normal, to the detriment of battery life.
Security	Data must be sent securely to an external server for processing to resolve locations. While the transfer is secure - some clients/organisations with high level security requirements do not want any device data going off-site whatsoever	Position data can be sent directly from the device to the end server, with no other 3rd party servers involved. This is typically preferred by defence, law enforcement etc.
Pricing	Low device hardware cost - particularly in volume. Location Engine Lookup charges apply in addition to any platform fees. This will become costly for devices with a very high reporting frequency. So other devices are a better option.	No charge per position update (other than SIM data charges)
Firmware Features	No Geofence Downloads to Device Tracking Modes Periodic Accelerometer Based	Geofence downloads available. Tracking Modes Periodic Accelerometer Based GPS Movement Based Details: Battery Powered Devices - Overview of Operations

The Details:

Tracking Performance:
Each location update, the Edge devices simply scan for GNSS and Wi-Fi signals for a few seconds. At that point, the device has no idea where it is, or how accurate that position is likely to be. The details are passed to the server, which then solves for the position. Ultimately the accuracy is down to the specific location provider. Our Location Engine has implemented various accuracy filters, so inaccurate positions are discarded. Some anomalies can still slip through - but the LE is improved on a daily basis.

Despite this, some location services and types (WiFi and Cell) are inherently less accurate than traditional GPS. We must trade off the getting any fix - with displaying a potentially wrong location.

For example if we drive into a parking garage with an Oyster2 - it will just show us as the last known point OUTSIDE the garage. It fails the fix in the garage altogether. With the Edge, it will fall back to WiFi - and that might put us directly in the garage, or perhaps across the street (30-100m away). This is a good or bad thing depending on the application. In some cases, we might even fall all the way back to Cell location, which is only accurate to around 300m.

We need to know if we are happy with some form of position - or whether to not return one at all if we aren't 100% sure it's in exactly the right spot. The Edge devices fit the former category, the traditional units the latter. In some ways, devices like the Oyster2 'work harder' (at the expense of battery life) for a more accurate fix. The Edge prioritises super-long battery life!

Summary - what to choose

There may be a specific item above which is a deal maker/deal breaker - which may make choosing simple - i.e. the security aspect may be non-negotiable for some. Other scenarios may be a bit more fuzzy - in this case both products would perform well - it is more up to user preference.

The Yabby Edge is suited to a wide variety of applications. It is not the ideal device for applications where we require aggressive update rates, or a high degree of location accuracy (<10m).