Anna Calveras Augé

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MQTT-S and CoAP are two protocols able to use the publish/subscribe model in Wireless Sensor Networks (WSNs). The high scalability provided by the publish/subscribe model may incur a high packet loss and therefore requires an efficient reliability mechanism to cope with this situation. The reliability mechanism of MQTT-S and CoAP employs a method which(More)
In this paper, we propose a modification of the observe extension of CoAP to include Quality of Service (QoS) support for timeliness. The proposed QoS support is based on delivery priority. Nodes are able to express the priority order with which they wish to be notified. Furthermore, they are also able to specify which notification they want to receive. We(More)
Wireless Sensor Networks (WSNs) are attracting more and more interest since they offer a low-cost solution to the problem of providing a means to deploy large sensor networks in a number of application domains. We believe that a crucial aspect to facilitate WSN diffusion is to make them interoperable with external IP networks. This can be achieved by using(More)
At present, there is a growing interest in wireless applications, due to the fact that the technology begins to support them at reasonable costs. In this paper, we present the technology currently available for use in wireless environments, focusing on Geographic Information Systems. As an example, we present a newly developed platform for the(More)
3G wireless networks such as UMTS are currently providing wide area Internet access. However, the Internet protocols exhibit a suboptimal performance in such scenarios. In this paper we first characterize a live UMTS link from the IP level. We identify critical features such as high latency, delay spikes, high packet loss probability and connectivity gaps,(More)
In this paper we present the design and implementation of the Constrained Application Protocol (CoAP) for TinyOS, which we refer to as TinyCoAP. CoAP seeks to apply the same application transfer paradigm and basic features of HTTP to constrained networks, while maintaining a simple design and low overhead. The design constraints of Wireless Sensor Networks(More)
Session setup delay in Packet Switched Streaming (PSS) services over Third Generation (3G) wireless networks is impacted by Real-Time Streaming Protocol (RTSP) and Session Description Protocol (SDP) signalling exchange and negotiation, as well as media buffering at the terminal before playback. The paper discusses PSS session setup delay over 3G, and(More)
In this paper, we present the design of a Constrained Application Protocol (CoAP) proxy able to interconnect Web applications based on Hypertext Transfer Protocol (HTTP) and WebSocket with CoAP based Wireless Sensor Networks. Sensor networks are commonly used to monitor and control physical objects or environments. Smart Cities represent applications of(More)