It is our great pleasure to introduce this Special Section of the Journal, focused on self-organising networks. The rapid diffusion of a whole range of devices featuring wireless networking capabilities and a wealth of heterogeneous resources make self-organising networks more and more a premier component of the Future Internet.
It is therefore fundamental to guarantee efficient and effective solutions for building autonomous self-organising networks, able to exploit in the best possible way the huge resource capacity such networks can provide as a whole. Two key areas in this framework are Wireless Sensor Networks (WSN) and Vehicular Ad hoc Networks (VANET). Research in WSN and VANET is generating a very well balanced blend between theoretical results, practical directions, and concrete applications and use cases. Thus, these areas can be considered amongst the most promising to enable self-organising technologies to impact on the mass market.
This Special Section includes extensions of selected papers originally presented at IEEE WoWMoM 2009. The two papers in this special section showcase notable examples of efficient protocols for WSN and VANET, respectively. Interestingly, the common ground of the two papers is how to embed ''distributed intelligence'' in the reference networking environment, so as to make the network self-organised, and efficient in terms of resource usage. The first paper, ''Scheduling Protocols for Homogeneous and Heterogeneous k-Covered Wireless Sensor Networks'' by H.M. Ammari and S.K. Das, proposes two distributed solutions for addressing the problem of k-coverage. In k-coverage problems, each point of a field has to be covered by at least k distinct sensor nodes. Both solutions exploit a slice&schedule approach, by which nodes first slice their sensing region appropriately to guarantee k-coverage, and then decide when to be active and when to stay turned off, in order to perform sensing operations. In the first protocol -named Self-Scheduling driven k-Coverage -nodes autonomously decide their activation patterns, while in the second protocol -named Triggered-Scheduling driven k-Coverage -neighbour nodes can trigger each other to achieve k-coverage. Interestingly, the paper considers the case where nodes can have different sensing ranges, and shows the improvement attained by the proposed protocols over state-of-art solutions. The second paper, ''An Efficient Routing Protocol for Connecting Vehicular Networks to the Internet'', by A. Benslimane, S. Barghi, and C. Assi, tackles the problem of guaranteeing seamless Internet connectivity in VANET. Vehicles in general connect to the Internet through multi-paths to roadside gateways. The challenges addressed by the paper are (i) identify as stable as possible paths to the gateways, and (ii) guarantee seamless handover when gateways have to be changed. To this end, nodes exploit predictions of intermediate hops movements to estimate the stability of a candidate multi-hop path to a gateway, and pick the most stable path amongst the candidates. Based on the same predictions, nodes can also estimate when the current path to a gateway will break, and identify suitable alternative gateways in time.
As a whole, we think this selection of papers represents two very interesting examples showing the potential of selforganising networks in the perspective of the Future Internet. We would like to thank the authors of the selected papers for contributing their high quality work, and the reviewers, who significantly contributed to the quality of this Special Section.