Demonstrating the Serval Rhizome Store-and-Forward MeshMS SMS Service

(Please take a look at our crowd-funding campaign at igg.me/at/speakfreely.)

Update: We trialled Rhizome on a training exercise in New Zealand recently.  Follow the link to read the blog post about it.

SMS messages on a cellular network get delivered via the cell towers and message centre infrastructure.

On a mesh, it is possible for us to deliver messages to other phones that are reachable on the mesh at the same time.  This works great, and we have had this capability in the Serval BatPhone software for a while now.

However, it does have some limitations, in particular, if there is no link all the way from the sender to the receiver on the mesh at the instant the message is sent.  This is rather unfortunate, as we usually think of SMS as being the most reliable fall-back on a mobile communications network.

So we set about replicating this resilience by creating a store-and-forward SMS-like service on top of the Serval Rhizome mesh file distribution framework.  We call this MeshMS, for Mesh Message Service.

This service uses direct mesh links if they are available by making use of the existing SMS capability in the Serval BatPhone software.  However, if there is no direct link, then it uses a store-and-forward scheme, that asks any passing phones to copy the message and distribute it to other phones on the mesh, until it (hopefully) eventually reaches its intended destination.  The cartoon below shows how this works.

The man wishes to send the message "Prepare the Zeppelin" to his hench-person, but there is no direct mesh link at that time due to the challenging topology.  The message gets picked up (stored) by the compatible phone in the pram, without any action on the part of the woman.  The woman then keeps walking along, and eventually the phone in the pram is able to automatically deliver (forward) the message to the ultimate destination, whereupon the minion knows to ready his master's zeppelin, to do the weekly grocery shopping, one trusts. Of course, there could be many intermediate steps, instead of just the one shown here.

The great thing about this approach is that it doesn't require a complete path to the destination at the time of sending, but can propagate progressively across the mesh as it is able, and can make use of nodes that move between otherwise isolated mesh networks, creating an asynchronous link between them where it would not otherwise be possible.

While the delay in such a service is huge, the bandwidth is also great, as potentially gigabytes of data can be transferred between nodes.  One side use of this protocol that we intend to exploit is to provide an efficient means of distributing updates to the Serval software suite, so that field updates can occur without dependence on infrastructure, and with much greater aggregate bandwidth than any single-cast cellular or wireless approach.  In fact, this will even allow the update of software, maps and other resources during a disaster.

We have even demonstrated it to deliver an SMS message between South Africa and Australia, using nothing but compatible phones to carry the message more than 10,000km:

This feature has profound utility in allowing the exchange of messages, files, and all manner of data in what are otherwise very difficult settings.

It also provides the capabilities required to enable disadvantaged communities, perhaps in remote locations, war zones or informal settlements, to create their own infrastructure, carrier and cost-free SMS networks using compatible handsets, so that they can enjoy the benefits of digital communications that many of us take for granted.

A Serval Project Progress Report

It is time to reflect on the past six months of Serval, and where we intend to head in the next six months.

Six months ago we did not have a developer software offering, or even a single Android application that contained all the components for Serval. Today we do.

On-site in South Africa after testing the Serval MeshMS store-and-forward SMS Service, delivering files and SMS messages up to 11,000km without infrastructure, or a continuously connected mesh.

Six months ago we did not have MeshMS (Mesh SMS service), interactive mapping,  Rhizome file distribution or store-and-forward SMS working.  Today, we do, and have even sent photos and SMS messages more then 10,000km between Australia and South Africa using mobile phones as the only infrastructure (more on this in a blog post and video in the next few days).  See this blog entry for an infographic and video showing the sending and receiving of this first inter-continental mesh SMS message.

Demonstration of the Serval Rhizome Mesh-Based Infrastructure-Free File Distribution System, which is also the basis of the store-and-forward MeshMS/SMS service.

Six months ago we had a number of legal issues to work through with regard to giving Flinders University an appropriate holding in the Serval Project's commercial arm, and the Shuttleworth Foundation had not yet come on board.  Today, we have just about finalised the details for these arrangements, with the final execution to occur in the coming weeks.  It will be fantastic to get this settled.

TEDxAdelaide Presentation November 2011. (Video coming soon) “The democratisation of online music is one example where the internet has eroded the monopoly power of music labels returning some portion of that power to the general public, without bankrupting those enterprises.” Paul will explore what is essentially a Napster equivalent that will compete with the mobile telecommunication giants. He believes that the advent of powerful, programmable, portable digital devices (e.g. smartphones) are a key factor in this eventual democratisation of mobile telecommunications.

Six months ago we were not greatly recognised internationally for our work on mesh communications.  Today, we are increasingly recognised as the leaders internationally in this space, which is a tremendous honour and also acts to spur us along to deliver on all the potential that mesh networking offers.  Recognition has included support by the Shuttleworth Foundation (South Africa), reaching the finals of the World Embedded Software Competition for University students (South Korea), strong engagement by and with the IEEE 802.11 standards process (USA and international), presenting at the Adelaide Festival of Ideas and TEDx Adelaide (Australia), and also reaching the finals of the Ashoka Foundation World Changer's Citizen Media competition (international) from a field of more than 400 entrants.  We are also seeing university and other partnership opportunities in Australia, Europe, the Middle East, Africa, the Americas, and Asia begin to take shape.  Now all we need is to be able to clone ourselves a few times over so that we can engage fully with the various opportunities!

Our plans for the next six months are to fill out the feature set that we have generated (voice, SMS, MMS, interactive mapping, file and software distribution), and add in the missing pieces, primarily the security and authenticity components that we have planned from the outset.  This will take us to mid-2012 when we hope to focus on maturing all of this into a general public release, as compared to the early-access developer software we have released to date.

Adelaide Festival of Ideas, 2011, JIM BETTISON ORATION: KICKING THE INFRASTRUCTURE HABIT: [listen to MP3]  "Modern communications systems use extensive and expensive infrastructure to deliver services we could only dream of a few decades ago. This works for those who enjoy peace and sufficient wealth, but fails to reach the last billion people in poorer countries, as well as those in remote, emergency or disaster situations. Now modern mobile phones have the potential to communicate directly, to form networks without reliance on any infrastructure. The Serval Project based at Flinders University is turning this dream into a reality. It is working to make communications available to everyone, anywhere, any time especially to those who need it most."

We are also looking seriously about getting advanced mesh support built into one or more models of mobile phone to offer energy efficiency and/or range improvements over the basic service.

Simultaneously, we are beginning to explore appropriate trials of the technology that if they go ahead will gain us valuable feedback, and refine the software to maximise it's utility for the general community, including in South Africa (assisting in the distribution of educational material without cost or dependence on cellular or school IT infrastructure), North America and Australia.

So all in all, the next six months should keep us fairly busy.

A Simple Illustration of A Multi-Hop Telephone Call

From time to time I get asked to provide a simple explanation of what the Serval Project actually does.

It allows you to make multi-hop phone calls using only phones, with the signal bouncing from phone to phone 

What does a multi-hop mobile mesh telephone call look like?  

Well, it can look a bit like this:

Of course this photo is a bit staged, and in reality the people in the middle of the call don't have to have their phones out, or do anything -- the mesh routing software automatically works out how to get the call between the parties.  

The only limitation is that their be a path between the calling parties.

Also, the phones can be quite a bit further apart than shown here, around 100 - 200m with line of sight at present, and potentially kilometres apart once we get the ISM915 band meshing happening in the future.

In a future post I will explain how we can enable SMS type services, even when there isn't a reliable path.

Opening Mobile Hardware

Over the last few years we have seen the impact and innovation that opening the software on smart phones has enabled.

The key is that the barrier to entry is now so low, that innovation can prosper without significant drag or hindrance.

So why don't we open the hardware on smart phones, by offering a "geek port" that some nice simple interfaces and a really cheap common connector, like a female .156" DIP header?

The port could have some analog and digital input and output lines, and maybe a serial interface or two, perhaps the common SPI interface, and a 3.3v power rail (that the phone can turn on and off to control power consumption).

Such a simple port would be trivial in cost to add to smart phone, probably costing less than $1 in marginal hardware cost, plus a once-of cost developing some nice APIs to access the port.

Creating such a simple interface would allow the creation of cheap dumb devices that can plug into the port.

Really boring stuff, like, say, a digital thermometer, an LED and sensor that can be used to collect pulse oximetry data, and relay it on an infrastructure-independent mesh network like servalproject.org, to a local care provider.  Or maybe it might be a cheap ultrasound transponder to allow mid-wives and maternal health workers to acquire cheap ultrasound imagery.

Each of these plug-ons could probably be made for $5 or less, and yet each has the potential to save many lives in the developing world, and save many billions of dollars in the developed world.

And that is just in one application domain.  Who knows what else people might come up with.

After all, no one anticipated the myriad applications that have been enabled by making smart phones programmable.

I reckon that for perhaps $100,000 it would be possible to get a phone designed and a small manufacture run of such phones to demonstrate the idea.  Anyone want to make a significant impact on the world?