Thursday, November 15, 2018

Serval Chat iOS Port finally emerges from the lab

Goodness me, this is probably the single piece of the Serval Project that has taken the longest compared to what was expected.  We have had a number of misadventures along the way with false starts to make a working port of Serval for iOS, but today, we finally have it.

This adventure began back in about 2014 when the NLnet provided us with a grant to achieve this.  Needless to say, we didn't make our original planned timelines.  We had some turn over of engineers and students on the project, and Apple changed from Objective C to Swift, and we hit some early dead ends and speed humps.  But we now have something that works quite nicely on iOS 12.

This port runs the core serval-dna source in a thread in the background, so that it is fully capable and fully compatible.  Getting serval-dna to compile for iOS, and produce binaries that can run on all iPhone CPU types, and that could be sensibly accessed from Swift, and that would behave properly was non-trivial to say the least.  We got to that point earlier in the year, and then the remaining time has been spent making a proof-of-concept app, and working through the remaining issues, like not having the thread die when the app looses focus, and working around a pile of funny little problems, including using the properly containerised paths in strange places we had overlooked it, and discovering that named sockets just don't work on the iPhone.

So today we reached the happy point of having something working, just hours before our French exchange student was due to finish up.  His last great act for us was to help prepare the following short video to celebrate this milestone.

There is still some missing functionality to implement, and then the real fun begins: Trying to get the app approved for release on the Apple App Store.  But that will be an adventure for another day.

Monday, November 12, 2018

Slashing the cost of tsunami (and bushfire) early warning systems

We have just about finished off a project that we have had funded by the Humanitarian Innovation Fund (HIF), which is funded by the UK's foreign aid program.  This has been a bit of a complementary variation on our existing work on the Serval Mesh.  Rather than on-ground peer-to-peer communications, the goal is to get communications out in to very remote locations, in particular, to get earaly warning for tsunamis, cyclones, bush fires and other hazards.

The tragic events in Sulawesi last month are a stark reminder of the need for tsunami early warning systems.  Following the earthquake, a tsunami warning was generated, but there was no way to get the message out to the impacted communities, in part because the earthquake had knocked out the cellular network, and in part, because many of the smaller villages likely lacked cellular coverage to begin with, or in the absence of grid electricity, many phones would have been turned off to conserve power.

These circumstances are not by any means unique to Indonesia -- they occur all around the Indo-Pacific in various forms and permutations.  The question is how to solve the problem.

The traditional approach is big tsunami early warning towers.  However, those are really expensive, especially to install in remote areas, often costing $10,000 or more per tower.  For isolated villages of a hundred or so people, the per-capita cost is simply infeasible.  Maintenance is also problematic both financially, and logistically

We have tackled this problem from the perspective of making a solution that works best in these resource-constrained environments.  In the end, our solution is rather simple:  Use off-the-shelf satellite TV receiver parts combined with some clever signal processing work by, so that no dish is required -- just point it to within about 10 degrees of where the geostationary satellite is.  This gives us a low-bit-rate digital broadcast signal that we can receive over a wide area.  Add to this direct-leasing of satellite capacity, so that the operating cost of the system is low and fixes, i.e., there is no monthly charge per user, so that it can be scaled up region wide.  Then all that is missing is a cheap automotive air-horn, so that the alarm can be heard within a village.  

The result is receiver hardware that costs maybe $200 in modest quantities, i.e., around 100x cheaper than the old approach, and that can be installed by communities themselves.  That is, we don't have to rely on big programs to roll these things out. Once people know about them, they are cheap enough for a village to buy, and easy enough for them to install themselves.

This just leaves the problem of disaster resilience/warning technologies not getting maintained during the year, and thus often having failed before they were needed. Our solution here is to include a low-power FM radio transmitter, so that news, weather, climate change mitigation and other information can be received in each village.  This means when the unit stops working at some point (nothing lasts forever in the tropics), they know immediately (no more radio signal, and the services it was providing them), and they can organise themselves to get it replaced and reinstalled, again, without having to rely on an NGO or aid program to do it.

In short, it is not only way cheaper, it is also way more appropriate to the needs of the Pacific.  It turns out that these characteristics also make it a great potential solution for bush-fire early-warning in Australia, where cell networks are often taken out by large bush fires (= wild fires, for those on the other side of The Pond), being cheap enough for house-holds to install themselves, and simple enough for them to self-install.

We are at the proof-of-concept stage and are looking for ways to fund the next stage.  Hopefully we will find a funder who can help us bring it to operational readiness in the next year or so.