Efficient water management is a fundamental pillar of sustainable agriculture and one of the main goals of precise agriculture. Indeed, due to the worsening of environmental conditions, the reduction of water resources, the increased deser-tification of some areas of the world, and the huge water usage by agriculture activities, water management is critical to promote a more sustainable agriculture and to support the food production, especially in poorest and most populated areas of the world. This paper presents an extended smart irrigation system that enhances a sensor-based automation framework with real-time water flow monitoring to allow a prompt detection of leaks. The new system is based on a centralized monitoring of water use that allows its application even in extensive crops where the widespread distribution of a dense network of sensors over large areas is not possible, making it feasible also for developing countries thanks to its low cost. This proactive approach, that can be integrated with fine-tuned and distributed monitoring systems, ensures optimal water usage, minimizes waste, and contributes to the reduction of operational costs and to the environmental sustainability of agricultural activities. The paper details the implementation, integration, and benefits of this new system, demonstrating its value in sustainable crops management.

Water scarcity and resource (water, soil, energy) efficient management are critical challenges in modern agriculture. This paper proposes a novel sensor-based smart irrigation system for nurseries, describing its design and experimentation. The system utilizes real-time data from soil moisture sensors and environmental sensors to optimize irrigation based on plant needs and available green energy, activating irrigation only when necessary, minimizing water waste and energy consumption. A software program analyzes sensor data alongside user-defined parameters and factors such as weather and renewable energy availability. The paper demonstrates how this approach can improve plant health, production yield, and product quality, while also achieving significant cost savings for nursery operators. This research contributes to sustainable agricultural practices by promoting efficient water and energy use.

Agriculture is one of the main human activities and plays an important role in answering to the increasing need of food due to the growing of population. However, agriculture is responsible of pollution of natural resources and Climate-Smart Agriculture can contribute to the increase of productivity limiting the negative effects on the natural environment. In this paper an experimentation of a sustainable smart greenhouse is illustrated. Its components suitable to support the crops increasing the percentage of survival of the young plants and to efficiently use water and energy are described along with the intelligent subsystem that deals with the monitoring, management, and automation of the different subsystems.

In the context of sport assessment, the evaluation and monitoring of the referees decisions is of interest for several sports in order to avoid disputes and assist the referees in their activity. Some current solutions are based on video recording, third referee, etc. In this paper, a new wireless wearable system, result of the Italian research project REC-VISIO, is described suitable to assess the referees actions when they are on the move. The system is able to collect the referee staff visual perspective of a sport match, whose subjective is recorded, preprocessed and sent by a wireless network to a sideline workstation for final stabilization. The system architecture design and implementation are described along with the experimentation on the field, considering as use case a football match. The experimentation has shown the successful integration of all the different system components, where the cooperation of sensor-based subsystem, processing unit, and communication subsystem allows to collect and stabilize the video streaming reducing the effects of the movement of the referee, and send in real-time the video content to the sideline workstation without video quality degradation.

The spreading diffusion of wireless devices and the crowded coexistence of multimedia applications greedy of bandwidth and with strict requirements stress the service provisioning offered by wireless technologies. WiFi is a reference for wireless connectivity and it requires a continuous evolution of its mechanism in order to follow increasingly demanding service needs. In particular, despite the evolution of physical layer, some critical contexts, such as industrial networks, telemedicine, telerehabilitation, and virtual training, require further refined improvements in order to ensure the respect of strict real-time service requirements. In this paper an in-depth analysis of Dynamic TXOP HCCA (DTH) MAC enhanced centralized scheduler is illustrated and it is further refined introducing a new improvement, DTH with threshold. DTH and DTH with threshold can be integrated with preexisting centralized schedulers in order to improve their performances, without any overprovisioning that can negatively impact on the admission control feasibility test. Indeed, without modifying the centralized scheduler policy, they combine together the concepts of reclaiming transmission time and statistical estimation of the traffic profile in order to provide, at each polling, an instantaneous transmission time tailored to the variable traffic requirements, increasing, when necessary, the service data rate. These mechanisms can coexist with advanced physical layer-based solutions, providing the required service differentiation. Experimental results and theoretical analysis, based on elastic scheduler theory, show that they are effective especially in the case of Variable Bit Rate traffic streams in terms of transmission queues length, packets loss, delay, and throughput.

IEEE 802.11e HCCA reference scheduler guarantees Quality of Service only for Constant Bit Rate traffic streams, whereas its assignment of scheduling parameters (transmission time TXOP and polling period) is too rigid to serve Variable Bit Rate (VBR) traffic.

Quality of Service (QoS) provided by the IEEE 802.11e amendment and by the proposed HCF Controlled Channel Access (HCCA) reference scheduler is tailored for Constant Bit Rate traffic streams. Moreover the numerous alternative scheduling algorithms are not suitable to serve Variable Bit Rate (VBR) traffic streams with the required QoS and real-time guarantees. This paper presents Immediate Dynamic TXOP HCCA (IDTH), a new scheduling algorithm based on a bandwidth reclaiming mechanism suitable to cooperate with a HCCA real-time scheduler. IDTH recovers the portion of the transmission time unused by the scheduled stations to provide a further capacity for the next variable bit rate traffic streams. The transmission opportunity of the next scheduled station is assigned considering the available spare resources and the previously used ones. The scheduling analysis and the simulations results show that IDTH is suitable to reduce the delay experienced by VBR traffic streams, to efficiently deal with the variability of multimedia traffic and to avoid waste of resources.

The IEEE 802.11e standard introduces Quality of Service (QoS) support for wireless local area networks and suggests how to design a tailored HCF Controlled Channel Access (HCCA) scheduler. However the reference scheduling algorithm is suitable to assure service guarantees only for Constant Bit Rate traffic streams, whereas shows its limits for Variable Bit Rate traffic. Despite the numerous alternative schedulers proposed to improve the QoS support for multimedia applications, in the case of VBR traffic satisfactory real-time performance has not been yet achieved. This paper presents a new scheduling algorithm, Unused Time Shifting Scheduler (UTSS). It integrates a mechanism for bandwidth reclaiming into a HCCA real-time scheduler. UTSS assigns the unused portion of each transmission opportunity to the next scheduled traffic stream. Thanks to such feature, traffic variability is absorbed, reducing the waste of resources. The analytical evaluation, corroborated by the simulation results, shows that UTSS is suitable to reduce the delay experienced by VBR traffic streams and to increase the maximum burstiness sustainable by the network.

Abstract The IEEE 802.11 standard for wireless networks has been recently enhanced with the IEEE 802.11e amendment which introduces Quality of Service support. It provides differentiation mechanisms at the Medium Access Control layer, using two additional access functions: the Enhanced Distributed Channel Access (EDCA) function and the HCF Controlled Channel Access (HCCA) function. Only the HCCA mechanism is suitable for serving traffic streams with real‐time requirements such as multimedia applications and Voice Over IP. The IEEE 802.11e standard does not specify a mandatory HCCA scheduling algorithm, but it offers a reference scheduler as the guideline in the resources scheduling design. In this paper we analyze four HCCA alternative schedulers to the reference one. They offer real‐time guarantees proposing different solutions to the request of QoS and real‐time support expressed by the increasing diffusion of multimedia applications. A performance evaluation is conducted to show the main differences between the considered schedulers, including the reference one. The results show that under several scenarios there is not a unique best scheduler, but there exists a variety of solutions depending on the specified requirements. The conclusions of the paper offer some guidelines in the choice of the scheduler tailored for a particular scenario of interest. Copyright © 2010 John Wiley & Sons, Ltd.

This paper presents a new scheduling algorithm, the Wireless Constant Bandwidth Server (W-CBS) for the Access Points of an IEEE 802.11e wireless networks to support traffic streams with Quality of Service guarantees, in particular in the case of multimedia applications which present variable bit rate traffic. The performance of W-CBS is compared to that of the reference scheduler defined in 802.11e standard using the ns2 simulator. The results show that the W-CBS outperforms the reference scheduler with VBR traffic, in terms of resource utilization and maximum admitted flows.