Nekane Sainz

A Novel Cluster-Based Energy Efficient Routing in Wireless Sensor Networks

Recent development in electronics and wireless communications has enabled the improvement of low-power and low cost wireless sensors networks. Wireless Sensor Networks(WSNs) are a combination of autonomous devices transmitting locally gathered information to a so-called sink node by using multihop wireless routing. One of the most important challenges in WSNs is to design energy efficient routing mechanism to increase the network lifetime due to the limited energy capacity of the network nodes. Furthermore, hot spots in a WSNs emerge as locations under heavy traffic load. Nodes in such areas quickly drain energy resources, leading to disconnection in network services. Cluster based routing algorithms in WSNs have recently gained increased interest, and energy efficiency is of particular interest. A cluster head (CH) represents all nodes in the cluster and collects data values from them. To balance the energy consumption and the traffic load in the network, the CH should be rotated among all nodes and the cluster size should be carefully determined at different parts of the WSNs. In this paper, we proposed an cluster based energy efficient routing algorithm (CBER), CBER elects CH based on nodes near to the optimal cluster head distance and residual energy of the nodes. In WSNs energy is mostly consumed for transmission and reception, it is a non linear function of transmission range. In this paper, the optimal cluster head distance which links to optimal energy consumption is derived. In addition, residual energy is considered in the CH election in order to increase the network lifetime. Furthermore, the energy consumption of being a CH is equally spread among the cluster members. Performance results show CBER scheme reduces the end to end energy consumption and prolong the network lifetime of multi hop network compared to the well-known clustering algorithms LEACH and HEED.

Cluster-based MAC in VANETs for safety applications

Recently, we are witnessing increased interest in the research of Vehicular Ad-hoc Networks (VANETs). Traffic safety applications using VANETs aim to improve traffic safety in the road using messages which have to meet high reliability, low and predictable delay constraints. Moreover, due to characteristics of VANETs, such as high speed, unstable communication link, and network partitioning, information transfer becomes inevitably challenging. The effectiveness of traffic safety applications using VANETs depends up on the performance of medium access protocol (MAC). Vehicles using CSMA/CA (IEEE 802.11p) MAC algorithm the time to channel access increases randomly every time when the channel is sensed busy. The main challenge for the design of MAC protocol for VANETs is to achieve reliable delivery of messages within the time limit even when the density of vehicles varies rapidly in the network. Furthermore, MAC algorithms with good scalability, fairness, and predictable delay are needed to fulfill the requirements of traffic safety applications. Therefore, cluster-based MAC protocols that can avoid or limit channel contention, provide fairness to channel access, increases radio capacity by the spatial reuse of network resources and effectively control the topology of the network. However, due to the high mobility characteristics of VANETS, vehicles frequently join and leave clusters affects the stability of network. Furthermore, the stability become worse if the cluster heads (CH) elected are not stable. Therefore, maintaining cluster stability can increase performance of safety applications in VANETs. Finally, we propose two cluster based MAC protocols (D-CBM) based on contention based carrier sense multiple access (CSMA) and collision free time division multiple access (TDMA) in order to achieve high stability, low communication overhead and real time delivery of safety messages. Simulation results indicate the proposed protocols are able to achieve the above requirements. Furthermore, we analyze the performance of the proposed MAC design with SBCA protocol.

Cross-Layer Cluster-Based Energy-Efficient Protocol for Wireless Sensor Networks

Recent developments in electronics and wireless communications have enabled the improvement of low-power and low-cost wireless sensors networks (WSNs). One of the most important challenges in WSNs is to increase the network lifetime due to the limited energy capacity of the network nodes. Another major challenge in WSNs is the hot spots that emerge as locations under heavy traffic load. Nodes in such areas quickly drain energy resources, leading to disconnection in network services. In such an environment, cross-layer cluster-based energy-efficient algorithms (CCBE) can prolong the network lifetime and energy efficiency. CCBE is based on clustering the nodes to different hexagonal structures. A hexagonal cluster consists of cluster members (CMs) and a cluster head (CH). The CHs are selected from the CMs based on nodes near the optimal CH distance and the residual energy of the nodes. Additionally, the optimal CH distance that links to optimal energy consumption is derived. To balance the energy consumption and the traffic load in the network, the CHs are rotated among all CMs. In WSNs, energy is mostly consumed during transmission and reception. Transmission collisions can further decrease the energy efficiency. These collisions can be avoided by using a contention-free protocol during the transmission period. Additionally, the CH allocates slots to the CMs based on their residual energy to increase sleep time. Furthermore, the energy consumption of CH can be further reduced by data aggregation. In this paper, we propose a data aggregation level based on the residual energy of CH and a cost-aware decision scheme for the fusion of data. Performance results show that the CCBE scheme performs better in terms of network lifetime, energy consumption and throughput compared to low-energy adaptive clustering hierarchy (LEACH) and hybrid energy-efficient distributed clustering (HEED).

Vehicle on board platform: Communications test and prototyping

This paper describes the process of prototyping and testing an in-vehicle embedded system which allows the driver to communicate with his vehicle, with the gadgets inside it (PDAs, cellular, sensor networks, and so on) and with the road infrastructure in order to consume intelligent transport services. The result of the presented work is an on board prototype and two services which have been developed to validate some characteristics of this embedded prototype.

IEEE802.11p Field Operational Test implementation and driver assistance services for enhanced driver safety

This paper describes the work-in-progress that Mobility research group of Deusto Institute of Technology has been doing in the area of Intelligent Transport Systems for the last two years. This work is divided in two main areas: one is focused on the development and test of a real VANET network and the aim of the second one is to provide the services that could be provided over this validated VANET network.

Deterministic MAC Protocol Based on Clustering for VANETs

This chapter proposes a direction aware cluster-based multichannel MAC (DA-CMAC) protocol for Vehicular Ad-Hoc Networks (VANETs) in which vehicles travelling in the opposite direction may result in a short communication period. Clustering based on the direction of travel can reduce the cost of reconfiguration due to the short communication period. Each cluster consists of Cluster Head (CH), Cluster Members (CMs) and Gateway Vehicles (GV). CH calculates priorities of CMs based on the value of eligibility function that is received from the CM and assign each CM a unique priority based on the future position of CM, CM ID, and eligibility function. The eligibility function is calculated using the number of connected neighbors, average speed deviation, and the average distance between neighbors and itself. Clusters are independently managed and locally reconfigured as vehicles travel. Moreover, the proposed DA-CMAC protocol manages the channel access and allocates time slots to its CMs, reducing access and merging collisions in the channel, by grouping the time slots into two sets based on the direction of movement. Each CMs are allocated with one time slot in both control service channel to achieve fairness in channel access. Simulation results of DA-CMAC are compared with HCA protocol. Simulation results show that the DA-CMAC protocol have higher reliability of packets, fewer CH changes and fewer number of access collisions compared with HCA protocol.

Direction aware cluster-based multi channel MAC protocol for vehicular ad hoc networks

This paper proposes a direction based clustering and multi-channel medium access control (DA-CMAC) protocol for Vehicular Ad Hoc Networks (VANETs). Vehicles travelling in the opposite direction may result in a short communication period. Clustering based on the direction of travel can reduce the cost of reconfiguration due to the short communication period. Each cluster consists of Cluster Head (CH), and Cluster Members (CMs). CH calculates priorities based on the eligibility function and assign each CM with a unique priority based on the number of connected neighbours, average speed deviation, and the average distance between neighbours and itself. Clusters are independently managed and locally reconfigured as vehicles travel. Moreover, the CH manages the channel access and allocates time slots to its CMs. DA-CMAC aims to reduce access and merging collisions in the channel, by grouping the time slots into two sets based on the direction of movement. Each CM is allocated with one time slot in both Control Channel Period (CCP) and Service Channel Period (SCP) to achieve fairness in channel access. Simulation results show that the proposed protocol will increase the reliability of packets and reduce the access collisions due to vehicular mobility.

SELICA: Advanced Sensor Identification System for Secure and Sustainable Food Chain Management

In this paper the systems developed in the framework of the SELICA project are described. The project aims to monitor the fresh-food cold chain and control its temperature and humidity levels. After a preliminary analysis of the cold chain, two blackspots were detected: load and unload areas and the means of transport. For this purpose a set of temperature and humidity sensors inte- grated into passive RFID tags are used. The reading of these tags is done by embedded systems which are also in charge of sending these data to the central management system. SELICA project is a work in progress with real industrial experience that has produced the prototypes described in this paper.

An ICT Solution with Real-Time Tracking Capacities for Improving the Incidence Management Timing in the Transportation of Industrial Equipments

This paper explores the use of ICT technologies in good traceability. In fact, it presents a solution for real-time tracking and fleet management which can be applied in the transportation of manufacture equipment. The system can manage routes and operations and provides onboard support to the carriers, enabling an agile response to incidences happened during transport. We describe both through its technical implementation as a test case used to validate the basic functionality of a first developed prototype. Furthermore, some future works are presented in order to improve some capacities of the solution.

A Location-Based Transactional Download Service of Contextualized Multimedia Content for Mobile Clients

This paper explores the new opportunities offered by the emerging technologies of the last generation of mobile phones. Thanks to features like GPS facilities installed in the mobile terminals new value added services can be developed to offer the user the more suitable multimedia content depending on parameters like user’s location and preferences. We describe the development of a contextualized and personalized multimedia content delivery platform using transactional communications for mobile terminals. Furthermore an actual test route has been made to proof the successful working of the platform.