http://www.mdpi.com/journal/futureinternet/special_issues/networked-sensors-actuators/ Submission Information All manuscripts should be submitted to futureinternet@mdpi.com with a copy to the Guest Editor. Manuscripts can be submitted until the deadline. Papers will be published continuously (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website. Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are refereed through a peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Future Internet is an international peer-reviewed Open Access quarterly journal published by MDPI. Please visit the Instructions for Authors page before submitting a manuscript. For the first few issues, to be published in 2009 and 2010, the Article Processing Charges (APC) will be waived for well-prepared manuscripts. English correction and/or formatting fees of 250 CHF (Swiss Francs) will be charged in certain cases for those articles accepted for publication that require extensive additional formatting and/or English corrections. http://www.mdpi.com/1999-5903/2/4/469/ In wireless sensor networks, energy efficiency is mainly achieved by making nodes sleep. In this paper, we present the combination of SERENA, a new node activity scheduling algorithm based on node coloring, with TDMA/CA, a collision avoidance MAC protocol. We show that the  combination of these two protocols enables substantial bandwidth and energy benefits for both general and data gathering applications. As a first contribution, we prove that the three-hop node coloring problem is NP-complete. As a second contribution, the overhead induced by SERENA during network coloring is reduced, making possible the use of these protocols even in dense networks with limited bandwidth. The third contribution of this paper is to show that applying any slot assignment algorithmwith spatial reuse based on node neighborhood without taking into account link quality can lead to poor performances because of collisions. The use of good quality links will prevent this phenomenon. The fourth contribution consists of optimizing end-to-end delays for data gathering applications, by means of cross-layering with the application. However, color conflicts resulting from topology changes, mobility and late node arrivals can give rise to collisions. As a fifth contribution, we show how the MAC layer can detect color conflicts, and cope with them at the cost of a slightly reduced throughput. Then, we discuss the tradeoffbetween requesting SERENA to solve the color conflicts and dealing with them at the MAC layer, our third contribution. The combination of SERENA and TDMA/CA is evaluated through simulations on realistic topologies. http://www.mdpi.com/1999-5903/2/4/469/ Wed, 13 Oct 2010 00:00:00 CEST Future Internet 2010-10-13 2 4 Article 469 504 1999-5903 Node Coloring and Color Conflict Detection in Wireless Sensor Networks 2010-10-13 doi: 10.3390/fi2040469 Saoucene Mahfoudh Gerard Chalhoub Pascale Minet Michel Misson Ichrak Amdouni http://www.mdpi.com/1999-5903/2/3/363/ Cooperation between networked mobile sensors, wearable and sycophant sensor networks with parasitically sticking agents, and also having human beings involved in the loop is the “Avatarization” within the robotic research community, where all networks are connected and where you can connect/disconnect at any time to acquire data from a vast unstructured world. This paper extensively surveys the networked robotic foundations of this robotic biological “Avatar” that awaits us in the future. Cooperation between networked mobile sensors as well as cooperation of nodes within a network are becoming more robust, fault tolerant and enable adaptation of the networks to changing environment conditions. In this paper, we survey and comparatively discuss the current state of networked robotics via their critical application areas and their design characteristics. We conclude by discussing future challenges. http://www.mdpi.com/1999-5903/2/3/363/ Tue, 14 Sep 2010 00:00:00 CEST Future Internet 2010-09-14 2 3 Review 363 387 1999-5903 Towards the Robotic “Avatar”: An Extensive Survey of the Cooperation between and within Networked Mobile Sensors 2010-09-14 doi: 10.3390/fi2030363 Sebahattin Topal İsmet Erkmen Aydan M. Erkmen http://www.mdpi.com/1999-5903/2/3/308/ Sensor nodes are characterized by a small size, a low cost, an advanced communication technology, but also a limited amount of energy. Energy efficient strategies are required in such networks to maximize network lifetime. In this paper, we focus on a solution integrating energy efficient routing and node activity scheduling. The energy efficient routing we propose, called EOLSR, selects the route and minimizes the energy consumed by an end-to-end transmission, while avoiding nodes with low residual energy. Simulation results show that EOLSR outperforms the solution selecting the route of minimum energy as well as the solution based on node residual energy. Cross-layering allows EOLSR to use information from the application layer or the MAC layer to reduce its overhead and increase network lifetime. Node activity scheduling is based on the following observation: the sleep state is the least power consuming state. So, to schedule node active and sleeping periods, we propose SERENA that colors all network nodes using a small number of colors, such that two nodes with the same color can transmit without interfering. The node color is mapped into a time slot during which the node can transmit. Consequently, each node is awake during its slot and the slots of its one-hop neighbors, and sleeps in the remaining time. We evaluate SERENA benefits obtained in terms of bandwidth, delay and energy. We also show how cross-layering with the application layer can improve the end-to-end delays for data gathering applications. http://www.mdpi.com/1999-5903/2/3/308/ Tue, 17 Aug 2010 00:00:00 CEST Future Internet 2010-08-17 2 3 Article 308 340 1999-5903 Energy Efficient Routing and Node Activity Scheduling in the OCARI Wireless Sensor Network 2010-08-17 doi: 10.3390/fi2030308 Saoucene Mahfoudh Pascale Minet Ichrak Amdouni