This paper presents the methodology for the synthesis of real-time applications working in the "Internet of Things" environment. We propose the client-server architecture, where embedded systems act as smart clients and the Internet application is a server of the system. The architecture of the application conforms to the cloud computing model. Since centralized systems are prone to bottlenecks caused by accumulation of transmissions or computations, we propose the distributed architecture of the server and the methodology that constructs this architecture using Internet resources supported by a cloud provider. We assume that the function of the server is specified as a set of distributed algorithms, and then our methodology schedules all tasks on the available network infrastructure. It takes into account limited bandwidth of communication channels as well as the limited computation power of server nodes. The method minimizes the cost of using network resources that are necessary to execute all tasks in real-time. We also present a sample application for adaptive control of traffic in a smart city, which shows the benefits of using our methodology.

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This paper presents the architecture of embedded real-time web server. Unlike existing web servers, in our approach, requests are processed not in the -first in first out‖ order but according to their deadlines and the expected server load. For this purpose the Least Laxity First scheduling method is used. First, requests with imposed hard real-time constraints are served. Then requests enclosed by soft deadlines are processed. Finally, request without time requirements are served in the order they arrived. We also present real-time extensions to the Hypertext Transfer Protocol. We propose headers that enable defining hard and soft deadlines, as well as responses containing time information, that are being sent to the client application. The experimental results showed that in case of real-time applications our server misses significantly fewer requests, due to time out, then existing solutions. The presented server may be very useful for implementing real-time services supported by embedded systems, e.g. in future real-time -Internet of things‖ applications.

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