ABSTRACT
Contents 13.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 351 13.2 Related Work . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 353
13.2.1 Relaying in Intermittently Connected Wireless Networks . . . . . 353 13.2.2 Chemical Computing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 354
13.3 System Model and Framework . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 355 13.4 Fraglets Implementation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 360 13.5 Performance Evaluation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 362 13.6 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 366 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 367
13.1 Introduction Recent advances in microelectronics and information technology are enabling the widespread diffusion of mobile computing devices equipped with short-range wireless communication capabilities. As users get more and more accustomed to
such devices (smartphones, PDAs, gaming consoles, etc.) for accessing a variety of services, opportunities arise for leveraging their proximity communication capabilities in order to provide user-centric and/or location-based services. The resulting systems are variously referred to as delay-tolerant or disruption-tolerant networks (DTNs) or opportunistic communication systems, depending on the specific point of view [1,2].
