OpenAGPS

OpenAGPS - Update 3: The first major roadblocks

Mon, 18 Aug 2025 22:00:00 +0000

Hi everyone! Another update from us:

As you may know, the goal of this project is to implement a SUPL-compatiable AGPS assistance server. Now, there are some unexpected technical challenges here that I felt were enough to announce here given that they are basically blocking a lot of testing and development:

SUPL uses ASN.1. This is okay, there are open-source ASN.1 toolchains, but the one we were using (python-asn1tools) seemingly does not properly decode some messages from modern devices. This is a problem, as any decoding errors are, from its perspective, fatal.
Most other ASN.1 toolchains are not featured enough to get close to properly being able to compile the ASN.1 specification for SUPL. There is asn1c, but it is old, and seemingly has problems compiling for me (that or I just couldn’t get it to work properly myself), and I would also personally rather use a programming language like python for things like this.
I wasted a lot of time trying to get the python library to work (I am not super experienced with ASN.1, so I was mostly trying stuff, hoping that it would start working), and a lot more time to being demotivated from it

This means we are (temporarily!) going to try something else: making our own assistance protocol. We already had ideas of doing this - ASN.1 may be standardized, but if someone wants to implement something using it, it can be a huge pain, compared to something like protobuf, or even JSON-encapsulated messages. Hopefully, I can wire something simple up soon, but don’t expect anything too quickly, since any protocol I hammer together will likely be based around the best way to sideload AGPS data into the testing devices I have (basically, a Fairphone 4, and a Volla 22), and I’ll need to look into how to best do that (any help with that is welcome, as always!).

If you are interested in potentially hosting a GPS base station - or are in a position to otherwise contribute GPS frame data - feel free to contact me, my contact info is on my GitLab page..

As always, any updates to code will be posted onto the OpenAGPS gitlab page..

Alexander Richards

OpenAGPS - Update 2: Infrastructure + Porygon (in theory) up!

Sat, 31 May 2025 22:00:00 +0000

Hi everyone! Slightly delayed compared to what we hoped for, but we finally have more things to announce:

We setup some automated infrastructure scripts that create and start our OpenStack instances - hosted on leaf.cloud. Porygon is now also packaged as a Docker container, which makes automatically starting it in the instance relatively simple. The API is still very simple (but enough that pointing a base station at it should not error out), however (when it is up, we give no guarantees, and at the moment, updates take it offline), you can see the API docs here.

If you are interested in potentially hosting a GPS base station - or are in a position to otherwise contribute GPS frame data - feel free to contact me, my contact info is on my GitLab page.. We have also begun writing more documentation in general, this includes some (not yet fully finished) documentation on setting up a base station. The firmware on the base station has been functional for a while now, although it is a bit complicated to setup. We aim to make this easier at some point in the future, although for now, getting the back-end up and running is more of a priority.

As always, any updates to code will be posted onto the OpenAGPS gitlab page..

Things will hopefully ramp up a bit from here - at least when exam season is over for me - so stay tuned!

Alexander Richards

OpenAGPS - Where we have been

Mon, 07 Apr 2025 19:00:00 +0000

Hello - It has been a while! Sorry for the radio silence for a bit…

I (Alexander Richards, the main and currently only developer on this) have been very busy with uni and other projects that have been taking time on this - rest assured, this has not been forgotten.

I personally aim to have more to show within the next week or two - ideally, including some public (but without any guarantees on any uptime or functionality!) APIs regarding positioning via cellular information (and contributing celluar information).

If you are interested in potentially hosting a GPS base station - or are in a position to otherwise contribute GPS frame data - feel free to contact me, my contact info is on my GitLab page..

As always, any updates to code will be posted onto the OpenAGPS gitlab page..

Sorry for things being this slow - as said, I am pretty busy with things, along with other personal things going on - I will however try my best to write blog posts whenever something interesting happens, so stay tuned!

OpenAGPS - Hello and first project update

Fri, 06 Dec 2024 10:57:00 +0000

Welcome to the OpenAGPS website! This post is mostly acting as a placeholder for future content here; we will be making regular blog posts about development and development progress. At time of writing this blog post, we have started work on developing on a simple GNSS base station/receiver using a ESP32-C3 and a UBlox M8N board; expect more updates soon!

We will be hosting our code on GitLab under the openagps organisation, feel free to take a look!

If you don’t know, this project is funded through NGI Mobifree Fund, a fund established by NLnet with financial support from the European Commission’s Next Generation Internet program. Learn more at the NLnet project page. Hosting for this project is geneously sponsored by Leaf Cloud.