Traffic differentiation: a basic step towards providing end-to-end QoS on the train-to-wayside wireless communication system

We developed a network platform that is responsible for an uninterrupted and seamless connectivity from the train to the wayside through heterogeneous wireless access technologies. However, limiting the offered services to only an onboard Internet is not a feasible business case. A viable one should extend to a broad spectrum of railway communication services like: train control, diagnostics, real time passenger information, entertainment, security CCTV surveillance etc. In a highly dynamic environment (from the communication link point of view) such a fast moving train, it is neccesary to introduce prioritization among different traffic classes. This will implicitly determine under what conditions a certain flow should get suspended or dropped in order to preserve the flows of a higher priority as long as possible and to ensure that they meet their QoS demands. The first step towards this goal is data traffic differentiation

A novel network architecture for train-to-wayside communication with quality of service over heterogeneous wireless networks

In the railway industry, there are nowadays different actors who would like to send or receive data from the wayside to an onboard device or vice versa. These actors are e.g., the Train Operation Company, the Train Constructing Company, a Content Provider, etc. This requires a communication module on each train and at the wayside. These modules interact with each other over heterogeneous wireless links. This system is referred to as the Train-to-Wayside Communication System (TWCS). While there are already a lot of deployments using a TWCS, the implementation of quality of service, performance enhancing proxies (PEP) and the network mobility functions have not yet been fully integrated in TWCS systems. Therefore, we propose a novel and modular IPv6-enabled TWCS architecture in this article. It jointly tackles these functions and considers their mutual dependencies and relationships. DiffServ is used to differentiate between service classes and priorities. Virtual local area networks are used to differentiate between different service level agreements. In the PEP, we propose to use a distributed TCP accelerator to optimize bandwidth usage. Concerning network mobility, we propose to use the SCTP protocol (with Dynamic Address Reconfiguration and PR-SCTP extensions) to create a tunnel per wireless link, in order to support the reliable transmission of data between the accelerators. We have analyzed different design choices, pinpointed the main implementation challenges and identified candidate solutions for the different modules in the TWCS system. As such, we present an elaborated framework that can be used for prototyping a fully featured TWCS

Patiëntveiligheid in de ziekenhuissector: wat kunnen we leren van de luchtvaartsector?

Mede ingegeven door de bijwijlen schrijnende incidenten die zich voordoen in ziekenhuizen, komt patiëntveiligheid steeds vaker onder de aandacht. Veertig jaar geleden kampte de luchtvaartsector met een gelijkaardig veiligheidsprobleem, tot in de jaren zeventig besloten werd dit niet langer te dulden en proactief het hoofd te bieden aan dit probleem. Doorheen de jaren leverde de sector enorme inspanningen om de luchtvaartveiligheid structureel en duurzaam te verbeteren. En met succes. Intussen is de luchtvaartsector, ondanks enkele recente incidenten, uitgegroeid tot één van de veiligste sectoren. De ervaringen van deze sector met betrekking tot veiligheidsverbeterinitiatieven verschaffen ziekenhuizen belangrijke inzichten wat betreft de aanpak van het patiëntveiligheidsprobleem. Na een algemene duiding van het begrippenkader worden een aantal concrete aanknopingspunten voor meer veiligheid in de zorg aangereikt