Web Services for Smart Objects - Part 2: Performance considerations

9.2 THE PERFORMANCE OF WEB SERVICES FOR SMART OBJECTS
The performance of web services for large-scale servers has been questioned on numerous occasions. Because of this, the performance of web services for smart objects has to be critically examined. Compared to the servers and networks on top of which large-scale web service applications run, smart object systems are severely constrained in both computational resources and bandwidth. Can smart objects maintain a good performance for web services?

In addition to the runtime performance of web services for smart objects, the constrained resources of the smart object nodes also require the implementation complexity of web services to be examined. Can a tiny smart object node bear the complexity of web services?

To answer these questions, we turn to the literature and find two independent studies of web services for smart objects: one by Priyantha et al. [207] from Microsoft Research and one by Yazar and Dunkels [260] from the Swedish Institute of Computer Science. Both studies implement a web services framework for smart objects, but the two studies focus on different aspects of the system.

The study by Priyantha et al. investigates the use of XML transactions enclosed in SOAP messages sent over HTTP and TCP, whereas the study by Yazar and Dunkels uses REST transactions directly over HTTP. Both studies have implemented web services over the uIP TCP/IP stack [64], which is discussed in Chapter 13.