In August 2014, The Serval Project was awarded a US-AID grant for activities in “Seed Grants for Tech Challenge for Atrocity Prevention”, to develop the Succinct Data concept in collaboration with New Zealand Red Cross.
The grant funds three work units:
In addition, three extra work units will be pursued by means outside the grant, and any surplus grant funds:
We have funding to create a communications channel between the core Serval Mesh software component and the Android software framework required for Serval Mesh to use Android services; specifically the inReach satellite SMS module Android APIs for sending and receiving satellite SMS messages. Work Unit 1 will build on this pre-funded work to create an end-to-end path so the Serval Mesh software can cause satellite SMS messages to be sent and received. Work Unit 1 also includes testing to determine whether messages queued on the inReach pocket satellite terminal are actually transmitted and delivered. This will create the communications path over which secure text messages and other data can be sent.
Work Unit 2 is the core capability we intend to deliver. It involves the reformatting and processing of Serval Mesh data bundles into a form that can be efficiently delivered over low-bandwidth media such as the inReach. This consists of applying data fragmentation, queueing and synchronization methods to the data bundles to create a protocol and stream that can be carried over the inReach transport. Initial focus will be on effectiveness and capability demonstration, with optimization following in future work.
The inReach service charges per message sent or received. Therefore we desire to implement access control mechanisms so that costs can be contained, and only be incurred by authorized parties. This will extend on the access control facilities currently being incorporated into other components of the Serval Mesh software. Initially messages will be rate-limited to control costs.
The ODK digital form system creates XML documents for each completed form. This work unit transforms those XML documents into SMS-like short messages, or Succinct Data. The Succinct Data can then be efficiently transmitted. Where the information content of the completed forms exceeds the capacity of the short message communications channel, a combination of multiple messages and selection of the most salient information from completed forms will be employed. This task has been allocated to a student developer from INSA Lyon (Institute for Telecommunications Applications), France.
Once Succinct Data messages have been received via the satellite SMS message service, the original XML documents will be reconstructed so far as possible. Complete reconstruction of forms that include images and other rich media may not be possible until the original completed form is transmitted via a high-bandwidth uplink at a later time. Importantly however, this reconstruction will allow immediate access to the most salient content. The reconstructed form instances can then be aggregated for analysis and further use according to the users' needs.
In some instances, a Serval Mesh mesh-network will come into range of cellular SMS services either permanently or transiently. Being able to send and receive data via cellular SMS when available is the next most important feature to be added to the Succinct Data project.