• Energy Research

The future Internet of Things (IoT) landscape includes not only low-latency and low-payload machine-type communications (MTC), but it is also expected to support the growing demand of multimedia data traffic to be communicated in smart environments. Emerging IoT use cases address the delivery of the same content from the network to a large number of devices. In such scenarios, Point-to-Multipoint(PTM) technology is seen as an efficient enabler of massive IoT (mIoT) in downlink direction. In this paper, we review the capabilities of the cellular-based PTM solution and propose different paging and data delivery strategies with the aim to improve the energy and latency efficiency of group-oriented mIoT communications. The performance of the proposed solutions is evaluated through an extensive simulation campaign.

Fifth generation (5G) networks are expected to connect a huge number of Internet of Things (IoT) devices in many usage scenarios. The challenges of typical massive IoT applications with sporadic and short packet uplink transmissions are well studied, while not enough attention is given to the delivery of content of common interest, such as software/firmware updates and remote control, towards IoT devices in emerging point-to-multipoint scenarios. Moreover, the delivery of delay-sensitive IoT traffic is not sufficiently addressed in the literature. In this work we (i) identify the drawbacks of the current Single-Cell Point-to-Multipoint (SC-PTM) solution for unplanned critical traffic delivery in cellular IoT (cIoT) networks, and (ii) propose paging and multicast schemes for a fast distribution of critical updates after, e.g., bug fixes or system failures. We benchmark the performance of the proposed paging scheme against similar solutions available in the literature. Our extended SC-PTM framework is energy efficient and guarantees low service latency, as demonstrated both analytically and by simulations.

RFID tags will really become smart objects of the Internet of Things (IoT) if they will be able to exploit the passive nature of the communication also for exchanging data with any other networked devices in the Internet. To this aim, an adaptation layer, named 6lo-RFID, has been specifically designed to run IPv6 over the RFID link technology. In this paper we draw the design principles for the development of a fully passive, IPv6-compliant, and energy-efficient 6lo-RFID tag platform. In particular, we discuss the block's design of an RF energy harvester and evaluate the simulated performance of a fully-passive 6lo-RFID tag when GET/PUT CoAP methods are used to execute operations on the tag memory.

The forthcoming fifth generation (5G) networks are claimed to deliver the large amount of traffic generated by the huge number of heterogeneous devices that constitute the Internet of Things (IoT). This unprecedented volume of both human- and machine-generated traffic to be managed imposes 5G network operators to move the focus from throughput-optimized to energy-efficiency-optimized resource allocation solutions. Device-to-device (D2D) communications are recognized as an effective offloading technique that the 5G network can exploit to boost the capacity and energy efficiency of future 5G networks. In this paper, we design a technique to efficiently deliver multicast traffic in a 5G New Radio (NR) network by exploiting the benefits of D2D communication and single-frequency operation in order to improve the overall network energy efficiency. In the designed solution, the subset of devices in better channel conditions are served through a conventional multicast transmission, while cell-edge devices receive the multicast service from relay nodes that simultaneously transmit in D2D mode the same content. The dimension of the multicast serving area and the set of D2D connections to establish are chosen in order to maximize the overall network energy efficiency. Performed simulation results show the effectiveness of the proposed solution under varying frame configurations and number of multicast devices.