Serving Embedded Content via Web Applications: Model, Design and Experimentation

International audienceEmbedded systems such as smart cards or sensors are now widespread, but are often closed systems, only accessed via dedicated terminals. A new trend consists in embedding Web servers in small devices, making both access and application development easier. In this paper, we propose a TCP performance model in the context of embedded Web servers, and we introduce a taxonomy of the contents possibly served by Web applications. The main idea of this paper is to adapt the communication stack behavior to application contents properties. We propose a strategies set fitting with each type of content. The model allows to evaluate the benefits of our strategies in terms of time and memory charge. By implementing a real use case on a smart card, we measure the benefits of our proposals and validate our model. Our prototype, called Smews, makes a gap with state of the art solutions both in terms of performance and memory charge

The Web of Things: interconnecting devices with high usability and performance

International audienceIn this paper, we show that Web protocols and technologies are good candidates to design the Internet of Things. This approach allows anyone to access embedded devices through a Web application, via a standard Web browser. This Web of Things requires to embed Web servers in hardware-constrained devices. We first analyze the traffics embedded Web servers have to handle. Starting from this analysis, we propose a new way to design embedded Web servers, using a dedicated TCP/IP stack and numerous cross-layer off-line pre-calculation (where information are shared between IP, TCP, HTTP and the Web application). We finally present a prototype -- named Smews -- as a proof of concept of our proposals. It has been embedded in tiny devices (smart cards, sensors and other embedded devices), with a requirement of only 200 bytes of RAM and 7 kilo-bytes of code. We show that it is significantly faster than other state of the art solutions. We made Smews source code publically available under an open-source license

Romization: Early Deployment and Customization of Java Systems for Restrained Devices

Memory is the scarcest ressource of embedded and restrained devices. This paper studies the memory footprint benefit of pre-deploying embedded Java systems up to their activation. We find out that the more the system is deployed off-board, the more it can be efficiently and automatically customized in order to reduce its final size. This claim is validated experimentally through the production of memory images that are between 10% and 45% the size of their J2ME CLDC counterparts, while using the J2SE API and being ready-to-run without any further on-board initialization. Embedded solutions like J2ME degrade the Java environment and API right fromtheir specification, limiting their usage perspectives. By contrast, our romization scheme generates and specializes a custom-tailored Java system and API for embedded applications being deployed in a full-fledged J2SE environment

Smews: Smart and Mobile Embedded Web Server

International audienceIn this paper, we show that Web protocols and technologies are good candidates to design the Internet of Things, through a user-centric architecture (the user simply has to use a standard Web browser). We detail how this Web of Things can handle typical embedded devices interaction needs. We discuss the technical feasibility of embedded Web servers, and, thanks to an analysis of the Web protocols, we propose new cross-layer solutions for efficient tiny embedded Web servers design. The problem of event notification for Web applications is also discussed. We finally present a prototype -- named Smews -- as a proof of concept of the Web of Things. Smews implements our proposals and has been embedded in tiny devices (smart cards, sensors and other embedded devices), with a requirement of only 200~bytes of volatile memory and 7~kilo-bytes of code. We show that it is significantly faster than other state of the art solutions. We made Smews source code publically available under an open-source license

Consistency and scalability in event notification for embedded Web applications

International audienceA new way to interact with small devices consists in embedding tiny Web servers, allowing the devices to serve fully-fledged Web applications. When the device needs to keep its users up-to-date of its internal state, the Web application has to use an event publication solution. Several works have recently been conducted in order to evaluate the trade-offs of various Web-based event notification solutions. In this paper, we propose to evaluate the feasibility of event notification in embedded Web applications. We conduct a large set of experiments in order to compare various push and pull based approaches for embedded systems. We show that a push-based approach can be very efficient in most situations, both in terms of client consistency and of scalability

International forum. an investigation of iron status in blood donors

No abstract availabl

Circadian regulation of human cortical excitability

peer reviewe