CALIPSO builds Internet Protocol (IP) connected smart object networks, but with novel methods to attain very low power consumption, thereby providing both interoperability and long lifetimes. CALIPSO leans on the significant body of work on sensor networks to integrate radio duty cycling and data-centric mechanisms into the IPv6 stack, something that existing work has not previously done. CALIPSO works at three layers: the network, the routing, and the application layer. We also revisit architectural decisions on naming, identification, and the use of middle-boxes.
CALIPSO announces the Ph.D. School on Internet of Things and Smart Cities 2013, which will be held in Lerici (La Spezia), 16-21 September 2013. Register here. The aim of Ph.D. School is to address young researchers to the forefront of … Continue reading
Pere Tuset, Albert Angles, Jose Lopez Vicario, Xavier Vilajosana. “On the suitability of the the 433 MHz band for M2M wireless communications: propagation aspects”. Transactions on Emerging Telecommunications Technologies. Volume: XX: Issue X. aaa–bbb. April 2013 (Accepted – Pending publication) (IF=1.049)
ABSTRACT: The 433 MHz band is gaining relevance as an alternative to the 2.4 GHz band for machine-to-machine communications using low-power wireless technologies. Currently, two standards are being developed that use the 433 MHz band, DASH7 Mode 2 and IEEE 802.15.4f. The article presents propagation models based on measurements conducted at the 433 MHz and 2.4 GHz bands that can be used for link budget calculations in both outdoor and indoor environments depending on node height. The results obtained show that the 433 MHz band has a larger communication range in both indoor and outdoor environments despite the negative effects of having a larger Fresnel zone. In addition, indoor propagation measurements are conducted in line-of-sight and nonline-of-sight conditions to determine the suitability of channel hopping to combat the effects of multipath propagation. Contrary to the 2.4 GHz band, the results show that channel hopping at 433 MHz does not provide any link robustness advantage because the channel coherence bandwidth is larger than the whole band bandwidth, and thus, all channels are highly correlated.