Monday, August 14, 2017

Assembling injection moulded Mesh Extenders

After various delays on various fronts, we now have in our possession enough components to assemble 40 Mesh Extenders, sufficient for the remaining activities for the Vanuatu Pilot.

Yesterday, the RFD900+ radios, antennae and Mesh Extender PCBs arrived:

 We already had the injection-moulded housings on hand (in the boxes behind the radios and PCBs):

First step of assembly is to fit the reverse SMA bulk-head connectors to the cases, and also install the o-rings.  While not particularly glamorous, this represents some number of hours of work to do.  Karthik, a work placement student, has been placed with us over the next few months, and gets to be the lucky one to do this task:

 The first afternoon's work, we have 16 units with seals and 2 of the 3 RSMA leads in place:

After these have been all prepared, we will then proceed with getting the firmware  on the PCBs, and radios and bulk storage fitted.

Our original plan was to use microSD cards, as they are lower power consumption than USB memory sticks, and probably handle power loss better than memory sticks.  However, there is a problem with the kernel driver for the microSD card interface, which we have yet to resolve, so we are probably going to stick with USB memory sticks for now. 

Fortunately we were able to get the USB port working in the Mesh Extenders, after a bunch of earlier problems with signal integrity of the USB data traces.

The only side effect is that we probably won't be able to reliably run these units on solar without a battery connected -- we'll find out for sure as we proceed with testing.

Thursday, August 3, 2017

Education in Emergencies challenge

Just a quick post to say that we have been short-listed in this challenge to find solutions for sustaining education during emergencies:

We feel that Serval is an ideal match for this use-case, especially if an online education system, like Moodle, were extended to support mesh delivery and interaction.

Please feel free to take a look at our entry, and hit the "love it" button, to help raise the profile of our entry.

Sunday, July 30, 2017

OpenWRT firmware building/installing problem

I'm currently working on the firmware for the Mesh Extenders, and have hit an unexpected problem:

Whereas we have previously been able to easily build and flash OpenWRT firmware images onto the Domino Core modules (Atheros 71xx based, Chaos Chalmer derived firmware), it has suddenly stopped working with nasty errors from uboot, like this:

uboot> boot
Booting image at: 0x9F050000

   Image name:   MIPS OpenWrt Linux-3.18.45
   Created:      2017-07-10  23:59:50 UTC
   Image type:   MIPS Linux Kernel Image (lzma compressed)
   Data size:    5328879 Bytes = 5.1 MB
   Load address: 0x80060000
   Entry point:  0x80060000

Uncompressing kernel image... ## Error: LZMA error num: 1

Anyone who can provide some assistance or suggestions as to how to go about tracking the problem down and fixing it would be greatly appreciated.

Some clues so far:

1. The firmware file from, and that works, so I presume that both uboot and the hardware are working.

2. We used to build and flash firmware from an Ubuntu VM in a Mac.  This problem has come about since moving to a native Ubuntu 16.04 based machine.

3. Firmware built on the Mac, which we believe used to work, doesn't seem to worrk now.

4. When this first occurred, it looked like we might have had a problem with a USB power plug, so we have ditched that, and are now running the boards from a USB port on the laptop.  It is in this configuration that we have successfully installed the firmware file mentioned in (1).

5. I *did* manage to build some working firmware images on Friday with the Linux laptop, and apart from using old versions of Serval packages, they seemed to work, before putting updated versions on stopped working.

I'll likely update this post with progress of things as I try them.

UPDATE 01AUG17: It looks like the problem is that we can't flash from uboot while a microSD card is inserted.


1. gl-inet openwrt-domino-2.261.bin installed from Linux laptop via "run lf" + tftp

2. Freshly built openwrt image built from Linux laptop without Mesh Extender package, and on an older test board, that was never powered by the presumed faulty USB power plug, and with no microSD card inserted. [01AUG17]

3. Freshly built openwrt image built from Linux laptop without Mesh Extender package, on one previously powered by the presumed faulty USB power plug, and without a microSD card inserted. [01AUG17]

Doesn't Work

1. openwrt-ar71xx-generic-uImage-initramfs-lzma.bin built on Ubuntu 16.04 laptop from

2. Freshly built openwrt image built from Linux laptop without Mesh Extender package, on one previously powered by the presumed faulty USB power plug, and with a microSD card inserted. [01AUG17]

Thursday, July 6, 2017

First visit to Vanuatu

It has been a rather busy couple of months, so I am only just catching up with sharing what we have been up to. All going well, there will be a burst of posts describing our recent activities.

But first in this post, I want to talk about our first visit to Vanuatu as part of our Pacific Humanitarian Challenge (PHC) award from the Australian Department of Foreign Affairs and Trade (DFAT).

Basically, DFAT have commissioned us to run a pilot of the Serval Mesh in Vanuatu, to be concluded and reported on by the end of 2017. I can assure you, that that timeline is feeling very tight right now.

The lead up to the first visit was busy with getting the very first prototype Mesh Extenders built.  The circuit boards were still under active development, as we tried to fix a few niggling issues around the USB port and power/radio port pinout. We were also waiting on the first injection-moulded shells for the Mesh Extenders.

Part of the busy-ness was also that we had timed our first visit to Vanuatu to coincide with the Pacific ICT Days, which gave us a very firm deadline.

Part of our motivation in being there for the ICT days, was that I would be able to present to representatives from a number of nations in the region, to raise awareness and seek input from them on what we are doing.  This broader socialisation of Serval is one of the goals of the PHC award, to help gauge the regional interest and demand for our work.

Another motivation in being there for the ICT days was to be able to see what other initiatives are underway in Vanuatu, and work out who we could partner with for the pilot project.

We also arranged to stay for about a week after, to allow plenty of time to meet with various stake-holders.  Some meetings were pre-arranged, but the majority were arranged once in country, as this is still the easiest way.  I really can't emphasise how important it is to allow time in-country when working in Pacific island nations.  You can often achieve in a week or so, what would otherwise take a month or more to try to arrange remotely. Finally, the time in country gave us the chance to better understand the local context, and begin to understand the local culture first-hand.

Now to follow the visit in pictures:

 First, it was presentations at the Pacific ICT Days.  Matthew Lloyd, who has been our key contact in NZ Red Cross for almost seven years has resigned and is now a volunteer with NZ Red Cross, and an independent consultant offering his considerable humanitarian, innovation and related experience.  Matthew accompanied me on this trip to assist with the project, and will also help out on upcoming visits to Vanuatu as well.  If you are looking for someone with considerable experience and insight into the region, I'd suggest getting in touch with him (poke me for contact details).

Matthew also presented on behalf of NZ Red Cross while there with us, talking about Succinct Data, another of our joint projects:

Then it was my turn to present about Serval and the PHC pilot in Vanuatu:

We had some of the freshly-minted new Mesh Extenders with us to pass around for the audience to look at and interact with.  Having a professionally designed and manufactured injection-moulded case makes a massive difference to first impressions: Suddenly people think of it as a product and want to know how much they cost! It might have been expensive to do the tooling, but it is already paying dividends, by removing psychological barriers.

Then it was a visit to the National Disaster Management Organisation (NDMO) as part of the ICT Days activities.  This was convenient, as the NDMO one of the organisations on our list to visit.  We are arranging with NDMO to put a Mesh Extender on their building as part of a local network in Port Vila as part of the project.  Here I am outside the door waiting to go in:

Then back at the convention centre it was time to speak as part of a panel looking at the role of ICT and telecommunications in facilitating opportunity and growth.  Two places to the right of me is Salma Farouque, who has been based in the UN World Food Programme (UNWFP) in Fiji, and has also been a huge help in connecting us in with various folks in the region:

After the ICT Days were over, it was time to start meeting with other people.  One of the first visits was to the Telecommunications & Radiocommunications Regulator (TRR), the Vanuatu equivalent of the FCC in the US, or ACMA in Australia.

I cannot overstate just how supportive they have been of us, and the practical assistance that they have given us already.  The regulator staff clearly understand the communications and social challenges facing Vanuatu, and see that we have a missing piece that can help in ways that complement the existing mobile carriers and other initiatives in Vanuatu.

In particular, the regulator sees that technologies like the Serval Mesh have the potential to provide at least basic telecommunications services in locations where conventional cellular communications will never be cost-effective to provide, because of the small, low-income isolated communities living in hilly, mountainous and/or remote locations.   So it was lovely to finally give them the opportunity to try out the Serval Mesh, and see the Serval Mesh Extenders for themselves:

Speaking of the Mesh Extenders, time was so tight before I flew out (my lovely wife even had to help me cut out the holes to pack the Mesh Extenders in the foam blocks in our shipping crate in the hours before I flew out), that I didn't have time to make up the power cables for them.  So this had to happen in Vanuatu.  Sadly my old soldering iron is no longer really up to the job, so this ended up being much more of a hassle than it should have been:

(I have since bought a really nice little AA-battery powered soldering iron, so that for future visits, including to Maewo where there is very limited mains power, I don't have a repeat of this problem.)

TRR also helped us choose a couple of Villages on the same island as Port Vila where we could conduct the pilot, and then made us the necessary introduction to the chief of the first of those villages, and came out with us and helped translate into Bislama (the local Vanuatu pidgin language that almost everyone speaks):

Speaking of Bislama, here is the crate of water we bought.  Translation: "Number #1 water / Good water, good life":

Back to the village, once they understood what we were offering, they were very interested, understanding the value of communications, and given the reality of the lack of cellular coverage in most of the village.

In this particular village, most of the buildings are still rather informal structures, and the surrounding vegetation is quite thick jungle:

Speaking of the jungle and vegetation, there are some quite impressive trees around.  The canopy typically is 10m -- 20m once you get away from the road.  This means that UHF packet radio will really only work if the Mesh Extenders are lofted high enough to clear the vegetation.  This will be one of the challenges going forward.  I expect that a lot of traffic will still deliver using store-and-forward transport in people's phones.

The main highway around Efate island has been sealed, but there are still interesting features, like this wooden bridge. One presumes that a more permanent structure doesn't exist because it would be (or has been) washed away following flooding.

Below, there are number of edible plants visible, primarily bananas and taro (I think) plants.  It seemed like days before we saw any banana trees with fruit on them, and then suddenly we saw them everywhere, so I assume it just took my eye a while to get in the zone.

I have an interest in bananas, because I grow them at home in Adelaide, where the climate really is very marginal for them.  This has come in handy before when we needed a shot showing how Mesh Extenders might be installed in the tropics, but while I was at home. Having the banana plants at home came in handy for taking the following shot:

Not in Vanuatu
But bananas aren't the only fruit on hand.  From a road-side stall we were able to buy 20 large and yummy passion for a total of A$1.20:

Then it was around to the next village, who helpfully have a nice map painted on the side of a building:

This village also has a presence from the US Peace Corp, and generally seems to have more built infrastructure than the first village we visited.  There are apparently a lot of families that are spread between these two villages, which is part of why we are looking at them for the pilot, as we will have intra-village and inter-village communications.  The villages are about 10km apart -- too far for a single Mesh Extender UHF hop, so the inter-village communications will most likely be store-and-forward by people's phones for the most part.

Disaster awareness is something that is taken seriously in Vanuatu:

Then it was back to our accommodation to do some paper work and organise more meetings, with the help of the resident cat in the accommodation.  The cat was very happy to have some extra people around

Next stop was the Office of the Government Chief Information Officer (OGCIO) to keep them informed of what we were planning, and to ask for their assistance to finalise our human ethics approval acceptance in Vanuatu.  This process is still continuing, while we wait for the final sign-off from the Vanuatuan side. This is one of many processes that would have been much harder and taken even longer if we had not been able to spend time in country to talk with the appropriate people.

Then it was time to meet with representatives from the local mobile telephone carriers with the TRR.  This was a really interesting and productive meeting. We communicated our belief that in Vanuatu it makes a lot of sense for the carriers to leverage Serval to improve customer satisfaction (and that of the TRR!) by finding low-cost ways to plug coverage holes, and having an additional capacity that can be used to support communications when towers fail following cyclone or other adverse events.

In particular, we spoke with them about the possibility of creating a two-way SMS/MeshMS gateway, that would enable them to generate revenue from traffic that is delivered between their existing networks and Serval Mesh networks.  We might not be able to achieve anything by the end of the year in the immediate pilot, however we will keep exploring this, as it has considerable potential to help remote communities in Vanuatu and elsewhere.

Speaking of telecommunications service, where we were staying was about 15km out of Port Vila.  Voice calls were easy enough by mobile phone, but getting a usable 3G data signal was not easy.  We had to resort to putting my phone out in a plastic tub to keep out the rain and slobber (see below), in a vantage point where it had clear line of sight back across the bay to Port Vila. However, even then we were at the mercy of various atmospheric effectcs.  Internet would come and go on a minute by minute basis. In the end, we had to spend a lot of time camping in the offices of the lovely people at the TRR to make use of their reliable internet.

The box could stop the slobber of wet noses, but not being knocked about.

Here is a bit more context. The fruit on the tree are pawpaw.  Most mornings we had fresh pawpaw with our breakfast, very yum.

Here is the view from the house we stayed in down to the coast.  Port Vila is out of frame to the left.

And closer down to the coast:

The private stretch of coast was rocky, with lots of interesting little critters to see in the rock pools. There are many worse places to have to work.

Back up by the house, we setup one of the Mesh Extenders with a solar panel to do some testing, and took this little shot to give an idea of just how simple an independent Mesh Extender installation can be:

Then more meetings! This time with the organisers of the Smart ICT Sistas programme. We hope to involve this group that helps young ni-Vanuatu women to learn ICT skills in the deployment of the pilot, as part of our knowledge-transfer objectives.

Then it was time to meet with some folks we met through the Pacific ICT Days, who are planning to roll out a small telecommunications network on Maewo island.  This is one of those connections that could only happen because we were in-country.  They are already planning to put in a couple of 10m high masts, so have the ideal solution for mounting a Mesh Extender clear of the jungle canopy.

Alexis (far left) has been a real gem, helping us with all sorts of further connections, including the Ministry of Health, as well as being a key driver in this Maewo part of the pilot.  Here she is with myself, and a couple of the other folks who are part of that project. The mast sections in the background will be installed on the island, and were built largely with volunteer effort by someone who builds them for one of the local mobile operators.

A quick fit-test with a Mesh Extender revealed a (totally coincidental) perfect fit!

Thursday, June 1, 2017

Initial testing of the new Mesh Extenders with NZ Red Cross in Dunedin

As I have hinted at previously, I went to Dunedin with NZ Red Cross last month to participate in their field exercise there, and to bring the new Mesh Extender prototypes with me for initial socialisation and testing with the NZ RC IT&Telecommunications Emergency Response Unit.

The exercise was run over a weekend, with myself and the ERU arriving a couple of days in advance to establish VHF communications and internet access in advance for them.  Here is the white board listing the task list.  Serval Mesh and RAMP+ (another project we have with NZ RC) are on the list! (I'll talk a bit more about RAMP+ later in this post).

To give a feel for the exercise, here are some shots from around the Emergency Operations Centre (EOC), which was located in a Scout camp site near Dunedin.

First, internet from two places, the satellite dish in the foreground providing VSAT internet, and the ubiquiti router (easier to see in the second image below) pulling in internet from a nearby wireless ISP.  The ISP link required activating and a fair bit of work to get going.  The ERU folks then setup an automatic fail-over between them.  The mast in the field to the right was for VHF radio. They also setup a couple of repeaters on nearby hills.

Here is the communications desk in the EOC itself, staffed by the wonderful ERU folks in their very nice new jackets that Kathmandu kindly donated:

Then here I am sitting down trying to flash and debug some teething problems on the Mesh Extenders with Steve from the ERU to the left:

Here is Andrew from the ERU taking a Mesh Extender and battery pack walk-about as part of a multi-hop over UHF test.

And another of the ERU out during the exercise collecting data using RAMP+, which is a combination of and the Succinct Data extreme compression and satellite uplink tool designed and built by Matthew Lloyd and ourselves, which can exceed 99% compression when uploading the XML records for Magpi, making satellite SMS practical as a transport.

The week turned out to be extremely busy for me, as the Mesh Extender prototypes were still very new, and I only managed to get them packed in time, and the firmware was very raw, and required considerable work to get to the point of having the Mesh Extenders booting quickly and reliably, including formatting their microSD cards.

This was complicated by problems we encountered with RAMP+, where the interface between the Succinct Data application on the tablets and the Garmin inReaches would break if tracking were enabled. Used separately, both work fine, but together a bug in the inReach communications library for Android gets tickled, causing an uncatchable force-quit.  This combined with a minor comedy of errors in trying to get access to the Succinct Data server back home at the University (it was now after close of business in Australia on the Friday), culminating in completely reimplementing the Succinct Data server on Amazon Web Services (for which it is much the better) from in the field, consuming a valuable 36 hour period, which I really needed to use to get the Mesh Extender firmware shaken down.

The result was that we got RAMP+ mostly operational, but the Mesh Extenders had a couple of firmware issues that prevented us from completing any multi-hop UHF tests, which was disappointing.  We also quickly discovered a critical bug in the new Serval Chat application for Android, which rendered the application unresponsive on first load in certain circumstances.  This was of course rather disappointing for myself and the ERU team, as we had hoped to be able to carry out more sophisticated and extensive tests.

The good news is that we have since isolated and corrected the faults that we encountered in both the Mesh Extenders and Serval Chat, and are now gearing up to making an updated firmware image in preparation for the next visit to Vanuatu, and, hopefully, with enough time before landing to perform more extensive testing (in the process we now have more extensive test cases for the firmware image, which means that we are able to automate regression testing of the faults we encountered in NZ).  But before I do that, I need to write about the first visit to Vanuatu...

Prototype Mesh Extender Fly-away kit with NZ Red Cross

As part of the exercise in NZ with NZ Red Cross (NZRC), I pulled together the first attempt at a Serval Mesh fly-away kit for humanitarian use by NZRC.  The contents will be sure to evolve over time, so my focus was just on getting the Mesh Extenders safely in the box for transit, and all of the cables, tools and other bits and pieces that I would be likely to need while in NZ, and later in Vanuatu.

First step was to start with the big Zargs case, which is the standard fare used by NZRC, and make sure it would be big enough:

Step 2 was to get some foam sheets of various thicknesses, so that I could keep everything safe in there, so that enthusiastic baggage handlers wouldn't be a problem.  Clark's Rubber in Australia is the convenient retailer for that sort of thing.  Of course, retail price is not ideal, and it cost about AU$400 for enough foam to fill the box completely.

From one of the 75mm thick layers, my wife and I cut the holes to fit the eight prototype Mesh Extenders that currently exist, as can be seen below, while unpacking the kit in NZ:

Thinner foam layers were above and below in the box, and had solar panels, cables and tools interleaved among them.

My feeling is that we should be able to easily fit 16 units and two solar panels and all associated cables and bits and pieces in one of these cases without great difficulty. If we forgo the solar panels, then 24 or 32 would be possible.  However, that is: (a) a lot of Mesh Extenders; and (b) you still need some way to power them.  

Thus my feeling is that 8 or 16 units per case, with a richer set of accessories will be the norm. This also allows each fly-away kit to be more affordable, and for Mesh Extenders to be more easily distributed, rather than having to split the contents of a single case.

With a 40W and 20W regular glass solar panel, the eight Mesh Extenders and other parts, the whole thing weights <23kg, making it easy to ship as an extra bag by commercial airline, which is an important design goal.

One thing I did discover when traveling with a huge metal box that says "Emergency Response Unit" in large friendly type, is that it didn't exactly have the same effects as the word "Don't Panic" on the Hitch-hiker's Guide to the Galaxy.  Basically they viewed it as being Not Personal Effects and wanted to see appropriate paperwork on reentry to Australia, to see if they could charge me import duties.

Because the kit was only out of the country briefly, it is in principle possible to export and re-import without any customs liabilities, which I managed, however, if I am going to do it confidently repeatedly in the future, there is a pile of magic paperwork that I need to explore.  Exporting to Vanuatu for the pilot similarly requires some special paperwork on the Vanuatuan side, to ensure we are able to use their customs exemption for foreign aid projects.  Another whole interesting world that I am slowly becoming acquainted with...

Injection-moulded Mesh Extender cases

It has been a bit delayed with everything going on to report it, but we have the new Mesh Extender prototypes in their shiny injection-moulded cases. Here is Mesh Extender 2.0 serial number #1 (thanks to Rachael from Second Muse for the shots):

These prototypes are almost, but not quite complete.  The main outstanding issue is that the D-SUB connectors are not the correct IP67 ones with the seals around them.  Thus, while they are ostensibly complete, with the revision 4 PCBs, they are not weather proof enough for deployment.  We will fix this with the upcoming revision 5 PCB.

Also, when those shots were taken, we didn't have the correct reverse-SMA connectors with built-in seals to seal the antenna inputs. I am still not at ease that they will seal completely.  The other niggling concern I have is that humid air will pass through the goretex seal on the bottom (the black disc in the top image), i.e., only liquid phase water will be excluded. I hadn't previously realised this limitation.  Our current approach to these problems is to apply a conformal coating to the revision 5 PCBs, so that with the housing limiting water ingress, and hopefully excluding the ants and other foreign bodies, that the conformal coating will be up to the task.  I am confident it will all work out in the end, but this is representative of the many details that come into play when trying to make hardware, and especially if it is to be used in a hostile environment, such as in the middle of a tropical jungle.

I'll also shortly post about their first excursions to New Zealand to a Red Cross exercise, and to Vanuatu, as the first stage of our pilot there.