Vesa Luukkala

Enhancing a smart space with answer set programming

The background for this work lies in the visions of ubiquitous systems and semantic web. To realize this vision in embedded domains we have implemented an interoperability platform called Smart-M3, which allows sharing of RDF information. In this paper we investigate integrating reasoning capabilities to this platform for solving problems arising from resource allocation and conflict resolution under preferences in dynamic context sensitive environments. Additional goals for our work is to take into account requirements for efficiency, scalability and localized reasoning. For this we are investigating Answer Set Programming (ASP) techniques in particular. We present an integration framework for using an ASP solver Smodels with Smart-M3 and we demonstrate its use within a use case. Both the framework and the rules described in this paper are available for trial.

Verifying Reliable Data Transmission over UMTS Radio Interface with High Level Petri Nets

Standard specifications of telecommunication protocols are mainly written using informal language. Therefore testing the standard, i.e. the definition of the core functionality, requires formal modelling of the protocol. In this article we describe the modelling and verification of a third generation mobile telecommunication protocol. We take the SDL description of the protocol as a starting point for our High Level Petri Net model. Since the size of the real-life protocols is enormous, we apply various abstraction techniques in the modelling phase. Basing on these and our previous experience, we introduce several heuristics for intelligent protocol modelling. Next we describe in detail the verification and modelling task, and derivation of the properties to be verified from the protocol specification. We are able to verify the most essential properties for reliable data transmission. Before executing the actual verification task, we plan a verification strategy, where for example the verification order of the properties and the appropriate configurations for the protocol and channel components for each run are considered.

Meta programming with answer sets for smart spaces

A smart space is an ecosystem of interacting computational objects embedded in some environment. The space seamlessly provides users with information and services using the best available resources. In this paper, the interoperability of heterogeneous objects participating in a smart space is enhanced by publishing their behavioral rules as RDF triples, i.e., in the same way as any other information in the space. This enables the use of answer-set programming (ASP) as the underlying paradigm for rule-based reasoning. The main idea of this paper is to apply meta programming techniques to reified ASP rules published in the smart space. Such techniques enable syntactic and semantic transformations of rules without essentially changing the underlying computational platform so that standard ASP tools can be used to implement inference over rules. These ideas are illustrated in several ways. In addition to basic meta evaluation tasks, we describe a meta grounder for ASP rules involving variables. Moreover, we demonstrate how the qualitative aspects of reasoning can be taken into account in our approach and how meta programming techniques are made available to users.

Integration of an answer set engine to smart-M3

We present our work in integrating an answer-set engine smodels to Smart-M3 interoperability platform. This gives user a possiblity of programming and trialing logic program reasoning in Smart-M3 environment. The smodels programming model guarantees that evaluation of rules is terminating. We add reactive features on top of the answer-set programming model and discuss its implications.

Experiences in implementing a cross-domain use case by combining semantic and service level platforms

We describe experiences of implementing a mash-up of two independent use cases, one operating in the embedded domain and the other in the internet messaging domain. We combine these service implementations on an existing Service Oriented Architecture (SOA) system with agents executing on a novel smart space architecture. Based on the lessons learned from this work, we sketch an approach for implementing similar use cases in a scalable and future proof manner by defining simple ontological concepts and associated behavior.

An SDL Implementation Framework for Third Generation Mobile Communications System

This paper presents an SDL implementation framework for the third generation mobile communication system protocols. The framework includes specific stylistic notations of SDL and extensive usage of ASN.1. Furthermore the framework requires that all protocols should define certain packages and combine certain functionalities into one process. This framework has allowed creation of a prototype implementation of third generation mobile system protocol stacks. This prototype implementation contains nearly all protocols from mobile station, radio access network and some protocols from the core network side. This implementation has and will be used in multiple prototype and validation system implementations within Nokia.

Model based testing of an embedded session and transport protocol

We describe an experience in applying model based testing in verifying especially the parallel behavior of a device level service and discovery protocol. Our approach is two phased: we first define a high level domain model in B and use cases in CSP that can be verified and then create a more detailed reference model that we use for testing the implementation on-the-fly. The use cases are used to drive both the B model and the reference model.