Msc project: Low-Bandwith Semantic Web

[This post is based on the Information Sciences MSc. thesis by Onno Valkering]

To make widespread knowledge sharing possible in rural areas in developing countries, the notion of the Web has to be downscaled based on the specific low-resource infrastructure in place. In this paper, we introduce SPARQL over SMS, a solution for exchanging RDF data in which HTTP is substituted by SMS to enable Web-like exchange of data over cellular networks.

SPARQL in an SMS architecture
SPARQL over SMS architecture

The solution uses converters that take outgoing SPARQL queries sent over HTTP and convert them into SMS messages sent to phone numbers (see architecture image). On the receiver-side, the messages are converted back to standard SPARQL requests.

The converters use various data compression strategies to ensure optimal use of the SMS bandwidth. These include both zip-based compression and the removal of redundant data through the use of common background vocabularies. The thesis presents the design and implementation of the solution, along with evaluations of the different data compression methods.

Test setup with two Kasadakas
Test setup with two Kasadakas

The application is validated in two real-world ICT for Development (ICT4D) cases that both use the Kasadaka platform: 1) An extension of the DigiVet application allows sending information related to veterinary symptoms and diagnoses accross different distributed systems. 2) An extension of the RadioMarche application involves the retrieval and adding of current offerings in the market information system, including the phone number of the advertisers.

For more information:

  • Download Onno’s Thesis. A version of the thesis is currently under review.
  • The slides for Onno’s presentation are also available: Onno Valkering
  • View the application code at


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MSc Project: The Implications of Using Linked Data when Connecting Heterogeneous User Information

[This post describes Karl Lundfall‘s MSc Thesis research and is adapted from his thesis]

sms phoneIn the realm of database technologies, the reign of SQL is slowly coming to an end with the advent of many NoSQL (Not Only SQL) alternatives. Linked Data in the form of RDF is one of these, and is regarded to be highly effective when connecting datasets. In this thesis, we looked into how the choice of database can affect the development, maintenance, and quality of a product by revising a solution for the social enterprise Text to Change Mobile (TTC).

TTC is a non-governmental organization equipping customers in developing countries with high-quality information and important knowledge they could not acquire for themselves. TTC offers mobile-based solutions such as SMS and call services and focuses on projects implying a social change coherent with the values shared by the company.

We revised a real-world system for linking datasets based on a much more mainstream NoSQL technology, and by altering the approach to instead use Linked Data. The result (see the figure on the left) was a more modular system living up to many of the promises of RDF.

Overview of the Linked Data-enabled tool to connect multiple heterogeneous databases developed in the context of this Msc Project.
Overview of the Linked Data-enabled tool to connect multiple heterogeneous databases developed in the context of this Msc Project.

On the other hand, we also found that there for this use case are some obstacles in adopting Linked Data. We saw indicators that more momentum needs to build up in order for RDF to gradually mature enough to be easily applied on use cases like this. The implementation we present and demonstrates a different flavor of Linked Data than the common scenario of publishing data for public reuse, and by applying the technology in business contexts we might be able to expand the possibilities of Linked Data.

As a by-product of the research, a Node.js module for Prolog communication with Cliopatria was developed and made available at . This module might illustrate that new applications usingRDF could contribute in creating a snowball effect of improved quality in RDF-powered applications attracting even more practitioners.

Read more in Karl’s MSc. Thesis 

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