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Device-to-Device (D2D) communication is one of the promising technology for the future 5G networks. Utilizing D2D in cellular networks has advantage in terms of capacity and delay. However, in D2D underlay cellular setting, the main concern is quality of service (QoS) for the cellular user due to the mutual interference between D2D user and the cellular user (CU). To utilize the gain brought by D2D setting without violating QoS of the CU, resource sharing is an important design criteria. To this end, we present an optimization model to investigate a resource sharing problem combined with scheduling in a D2D uplink underlay setting. We have used the proposed model to investigate an example resource sharing scenario, in which multiple D2D pairs share the uplink resource of CU, and identified delay and sum throughput for different parameter settings. We observed that there is a significant gain in terms of sum-throughput in allowing a small number of D2D pairs to re-use the cellular resources. [ABSTRACT FROM AUTHOR]

Electricity production and distribution is facing two major changes. First, production is shifting from classical energy sources such as coal and nuclear power toward renewable resources such as solar and wind. Second, consumption in the low voltage grid is expected to grow significantly due to the expected introduction of electrical vehicles. The first step toward more efficient operational capabilities is to introduce an observability of the distribution system and allow for leveraging the flexibility of end connection points with manageable consumption, generation, and storage capabilities. Thanks to advanced measurement devices, management framework, and secure communication infrastructure developed in the FP7 SUNSEED project, the distribution system operator (DSO) now has full observability of the energy flows in the medium/low voltage grid. Furthermore, the prosumers are able to participate pro-actively and coordinate with the DSO and other stakeholders in the grid. The monitoring and management functionalities have strong requirements for communication latency, reliability, and security. This article presents novel solutions and analyses of these aspects for the SUNSEED scenario, where smart grid ICT solutions are pr [ABSTRACT FROM PUBLISHER]

While LTE has been widely rolled out for human-type services, it is also a promising solution for cost-efficient connectivity of the smart grid monitoring equipment. This is a type of machine-to-machine (M2M) traffic that consists mainly of sporadic uplink transmissions. In such a setting, the amount of traffic that can be served in a cell is not constrained by the data capacity, but rather by the signaling constraints in the random access channel and control channel. In this paper, we explore these limitations using a detailed simulation of the LTE access reservation protocol (ARP). We find that 1) assigning more random access opportunities may actually worsen performance and 2) the additional signaling that follows the ARP has very large impact on the capacity in terms of the number of supported devices; we observed a reduction in the capacity by almost a factor of 3. This suggests that a lightweight access method, with a reduced number of signaling messages, needs to be considered in standardization for M2M applications. Additionally we propose a tractable analytical model to calculate the outage that can be rapidly implemented and evaluated. The model accounts for the features of the random access, control channel, and uplink and downlink data channels, as well as retransmissions. [ABSTRACT FROM PUBLISHER]

The introduction of smart electricity meters with cellular radio interfaces has placed an additional load on wireless cellular networks. Currently, these meters are designed for low duty cycle billing and occasional system check, which generates low-rate sporadic traffic. As the number of distributed energy resources increases, household power will become more variable and thus unpredictable from the viewpoint of the distribution system operator (DSO). Therefore, it is expected that in the near future there will be an increase in the number of wide area measurement system (WAMS) devices with phasor measurement unit (PMU)-like capabilities in the distribution grid, thus allowing utilities to monitor the low voltage grid quality while providing information required for tighter grid control. From a communication standpoint, the traffic profile will change drastically toward higher data volumes and higher rates per device. In this paper we characterize the current traffic generated by smart electricity meters, and we discuss the potential traffic requirements resulting from the introduction of enhanced smart meters, i.e. meters with PMUlike capabilities. Our study shows how GSM/ GPRS and LTE cellular system performance behaves with current generation and next generation smart meter traffic, where it is clearly seen that the PMU data will seriously challenge these wireless systems. We conclude by highlighting the possible solutions for upgrading the cellular standards, in order to cope with the upcoming smart metering traffic. [ABSTRACT FROM PUBLISHER]

Two of the emerging trends in wireless cellular systems are device-to-device (D2D) and machine-to-machine (M2M) communications. D2D enables efficient reuse of the licensed spectrum to support localized transmissions, while M2M connections are often characterized by fixed and low transmission rates. D2D connections can be instrumental in localized aggregation of uplink M2M traffic to a more capable cellular device, before being finally delivered to the base station (BS). In this paper we show that a fixed M2M rate is an enabler of efficient machine-type D2D underlay operation taking place simultaneously with another downlink cellular transmission. In the considered scenario, a BS B transmits to a user U, while there are NM machine-type devices (MTDs) attached to U, all sending simultaneously to U and each using the same rate R_{M}. While assuming that B knows the channel B-U, but not the interfering channels from the MTDs to U, we prove that there is a positive downlink rate that can always be decoded by U. We also consider the case of a simpler, single-user decoder at U with successive interference cancellation. However, with single-user decoder, a positive zero-outage rate exists only when N_{M}=1 and is zero when N_{M} >1$. This implies that joint decoding is instrumental in enabling fixed-rate underlay operation. [ABSTRACT FROM PUBLISHER]

LTE is increasingly seen as a system for serving real-time Machine-to-Machine (M2M) communication needs. The asynchronous M2M user access in LTE is obtained through a two-phase access reservation protocol (contention and data phase). Existing analysis related to these protocols is based on the following assumptions: (1) there are sufficient resources in the data phase for all detected contention tokens, and (2) the base station is able to detect collisions, i.e., tokens activated by multiple users. These assumptions are not always applicable to LTE - specifically, (1) due to the variable amount of available data resources caused by variable load, and (2) detection of collisions in contention phase may not be possible. All of this affects transmission of real-time M2M traffic, where data packets have to be sent within a deadline and may have only one contention opportunity. We analyze the features of the two-phase LTE reservation protocol and asses its performance, when assumptions (1) and (2) do not hold. [ABSTRACT FROM PUBLISHER]

ABSTRACT The random access methods used for support of machine-to-machine, also referred to as Machine-Type Communications, in current cellular standards are derivatives of traditional framed slotted ALOHA and therefore do not support high user loads efficiently. We propose an approach that is motivated by the random access method employed in LTE, which significantly increases the amount of contention resources without increasing the system resources, such as contention subframes and preambles. This is accomplished by a logical, rather than physical, extension of the access method in which the available system resources are interpreted in a novel manner. Specifically, in the proposed scheme, users perform random access by transmitting orthogonal preambles in multiple random access subframes, in this way creating access codewords that are used for contention. We show that, for the same number of random access subframes and orthogonal preambles, the amount of available contention resources is drastically increased, enabling the massive support of Machine-Type Communication users that is beyond the reach of current systems. Copyright © 2013 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The seven articles in this special section focus on agile radio resource management technologies for use in 5G mobile communications (5G). 5G networks will support a wide range of frequency bands, features, and use cases, with native support for efficient operation. 5G is considered as a significant disruptor to traditional mobile networks. Some of the main motivations behind the design, standardization, and deployment of the new generation of mobile networks include: significant increase of the supported data rates for enhanced mobile broadband, support for ultra-reliable and low-latency communications (URLLC), and support for massive machine type communications (mMTC). The combination of these 5G pillars can further enable new use cases, such as virtual or augmented reality (VR/AR), enabled by combining eMBB and URLLC. [ABSTRACT FROM AUTHOR]