GPRS Function Test using TTCN

Functional and conformance testing of new standardized services and protocols is a challenging task as standards may change during implementation and the test system has to be adapted to the system under test continuously. This paper describes how modular and concurrent TTCN was deployed for validation of the GPRS support nodes and reports on the experience collected

Ensuring interoperability between network elements in next generation networks

Next Generation Networks (NGNs), based on the Internet Protocol (IP), implement several services such as IP-based telephony and are beginning to replace the classic telephony systems. Due to the development and implementation of new powerful services these systems are becoming increasingly complex. Implementing these new services (typically software-based network elements) is often accompanied by unexpected and erratic behaviours which can manifest as interoperability problems. The reason for this caused by insufficient testing at the developing companies. The testing of such products is by nature a costly and time-consuming exercise and therefore cut down to what is considered the maximum acceptable level. Ensuring the interoperability between network elements is a known challenge. However, there exists no concept of which testing methods should be utilised to achieve an acceptable level of quality. The objective of this thesis was to improve the interoperability between network elements in NGNs by creating a testing scheme comprising of three diverse testing methods: conformance testing, interoperability testing and posthoc analysis. In the first project a novel conformance testing methodology for developing sets of conformance test cases for service specifications in NGNs was proposed. This methodology significantly improves the chance of interoperability and provides a considerable enhancement to the currently used interoperability tests. It was evaluated by successfully applying it to the Presence Service. The second report proposed a post-hoc methodology which enables the identification of the ultimate causes for interoperability problems in a NGN in daily operation. The new methods were implemented in the tool IMPACT (IP-Based Multi Protocol Posthoc Analyzer and Conformance Tester), which stores all exchanged messages between network elements in a database. Using SQL queries, the causes for errors can be found efficiently. Overall the presented testing scheme improves significantly the chance that network elements interoperate successfully by providing new methods. Beyond that, the quality of the software product is raised by mapping these methods to phases in a process model and providing well defined steps on which test method is the best suited at a certain stage

Using formal methods to support testing

Formal methods and testing are two important approaches that assist in the development of high quality software. While traditionally these approaches have been seen as rivals, in recent years a new consensus has developed in which they are seen as complementary. This article reviews the state of the art regarding ways in which the presence of a formal specification can be used to assist testing

Quality assessment technique for ubiquitous software and middleware

The new paradigm of computing or information systems is ubiquitous computing systems. The technology-oriented issues of ubiquitous computing systems have made researchers pay much attention to the feasibility study of the technologies rather than building quality assurance indices or guidelines. In this context, measuring quality is the key to developing high-quality ubiquitous computing products. For this reason, various quality models have been defined, adopted and enhanced over the years, for example, the need for one recognised standard quality model (ISO/IEC 9126) is the result of a consensus for a software quality model on three levels: characteristics, sub-characteristics, and metrics. However, it is very much unlikely that this scheme will be directly applicable to ubiquitous computing environments which are considerably different to conventional software, trailing a big concern which is being given to reformulate existing methods, and especially to elaborate new assessment techniques for ubiquitous computing environments. This paper selects appropriate quality characteristics for the ubiquitous computing environment, which can be used as the quality target for both ubiquitous computing product evaluation processes ad development processes. Further, each of the quality characteristics has been expanded with evaluation questions and metrics, in some cases with measures. In addition, this quality model has been applied to the industrial setting of the ubiquitous computing environment. These have revealed that while the approach was sound, there are some parts to be more developed in the future

A Model for Emergency Service of VoIP through Certification and Labeling

Voice over Internet Protocol (VoIP) will transform many aspects of traditional telephony service, including the technology, the business models, and the regulatory constructs that govern such service. Perhaps not unexpectedly, this transformation is generating a host of technical, business, social, and policy problems. In attempting to respond to these problems, the Federal Communications Commission (FCC) could mandate obligations or specific solutions to VoIP policy issues; however, it is instead looking first to industry initiatives focused on the key functionality that users have come to expect of telecommunications services. High among this list of desired functionality is user access to emergency services for purposes of summoning fire, medical, and law enforcement agencies. Such services were traditionally required to be implemented (and subsequently were implemented) through state and federal regulations. An emergency service capability is a critical social concern, making it particularly important for the industry to propose viable solutions for promoting VoIP emergency services before regulators are compelled to mandate a solution. Reproducing emergency services in the VoIP space has proven to be a considerable task, mainly due to the wide and diverse variety of VoIP implementations and implementers. While technical and business communities have, in fact, made considerable progress in this area, significant uncertainty and deployment problems still exist. The question we ask is this: Can an industry-based certification and labeling process credibly address social and policy expectations regarding emergency services and VoIP, thus avoiding the need for government regulation at this critical time? We hypothesize that the answer is “yes.” In answering this question, we developed a model for VoIP emergency service compliance through industry certification and device labeling. This model is intended to support a wide range of emergency service implementations while providing users with sufficient verification that the service will operate as anticipated. To this end, we first examine possible technical implementations for VoIP emergency services. Next, we summarize the theory of certification as self-regulation and examine several relevant examples. Finally, we synthesize a specific model for certification of VoIP emergency services. We believe that the model we describe provides both short-term and long-term opportunities. In the short term, an industry-driven effort to solve the current problem of VoIP emergency services, if properly structured and overseen as we suggest, should be both effective and efficient. In the long term, such a process can serve as a self-regulatory model that can be applied to social policy goals in the telecommunications industry, making it an important tool to have as the industry becomes increasingly diverse and heterogeneous