InitRech 2015/2016, sujet 24

Summary

This article is talking about Integrating wireless sensor networks with the web.

The paper describes the design and development of an end-to-end IP based architecture integrating a Constrained Application Protocol (CoAP) over 6LowPAN Contiki based Wireless Sensor Network (WSN) with an HTTP over IP based application and showing the benefits of COAP compared to HTTP. The idee is to allow a user to access WSN data simply from a Web browser.

The Authors introduces first the subject, the use of the Internet Protocol in resource constrained devices has radically changed the Internet landscape and the number of connected object is increasingly growing.
Then, they explain some new standards like 6LoWPAN , RPL, the terms WOT and M2M and the architectures REST to show the major benefits and advantages of this one’s. The article show different works which propose differents architectures and after this, they will present their work concerning a RESTful WSN based on CoAP.

Firstly, it describes the major difference between CoAP and HTTP and compares the two protocols in terms of power consumption and overhead.

Secondly, the paper describes the design and development of an end-to-end IP based architecture integrating a CoAP over 6LowPAN Contiki based WSN with an HTTP over IP based application.

After an explanation of the a RESTful WSN based on CoAP, the paper describes the major functionalities of CoAP highlighting the differences with HTTP.

Then, they explains the results of an experiment illustrating the benefit of CoAP in terms of power consumption compared to HTTP.

Finally, We can see that CoAP offers the same methods for the resource manipulation as HTTP but supports additional functionalities typical of IoT and M2M applications, such as multicast, asynchronous communication and subscriptions. The gateway is still in prototype phase and it requires the development of proxy and observation functionalities. Nearly, the application will be deployed and tested in a greenhouse monitoring testbed.

Main contribution

The main contribution of the paper is to discuss the integration of WSNs with the Web. This is being facilitated by the development of CoAP, an IETF protocol providing LLNs with a RESTful architecture.

The wireless sensor is still a device with limited resources do not allow to use Internet data publication systems applied to other entities such as Smartphones.
But the paper show how the introduction of UDP and the packet overhead compression drastically reduce the mote’s power consumption and consequently increase the battery lifetime.
They also explain that the application allows a user to access WSN data directly from a Web browser and described the main building blocks of the gateway connecting the Web client with the WSN.
This work aims to make access to small wireless sensors as easy as access to Web servers.
These works are the result of the confluence of two factors: the proven performance, low power consumption and high reliability and efforts on existing IP standards for smooth integration into Internet.

The combination of these factors will result in relatively small and low power consumption that communicate reliably and sensors are compatible IP.Unfortunatly, the application hasn’t been deployed yet.

Applications

The aim of the paper is to discussed about the connection of wireless sensor network to the web.

The Internet of Things will connect physical (analogic) environments to the (digital) Internet, unleashing exciting possibilities and challenges for a variety of application domains, such as smart metering, e-health logistics, building and home automation ,provide database solutions across the firms for data storage and software tools for business processes such as asset tracking, process control systems and building management systems.
Web designers will be able to apply real-time sensor data with web requests to the IP address of a sensor and the underlying wireless sensor network will support this type of communication with a rate of high reliability of data.
By making the sensors as easily accessible as web servers, wireless sensor networks transmit information in real time to the Internet of Things.

To conclude, it's must be more easier to integrate WSN to the web by reducing energy consumption with the use of CoAP.