In this paper, we focus on the radio resource planning in the uplink of licensed Orthogonal Frequency Division Multiple Access (OFDMA) based Internet of Things (IoT) networks. The average behavior of the network is considered by assuming that active sensors and collectors are distributed according to independent random Poisson Point Process (PPP) marked by channel randomness. Our objective is to statistically determine the optimal total number of Radio Resources (RRs) required for a typical cell. On one hand, the allocated bandwidth should be sufficiently large to support the traffic of the devices and to guarantee a low access delay. On the other hand, the over-dimensioning is costly from an operator point of view and induces spectrum wastage. For this sake, we propose statistical tools derived from stochastic geometry to evaluate, adjust and adapt the allocated bandwidth according to the network parameters, namely the required Quality of Service (QoS) in terms of rate and access delay, the density of the active sensors, the collector intensities, the antenna configurations and the transmission modes. The optimal total number of RRs required for a typical cell is then calculated by jointly considering the constraints of low access delay, limited power per RR, target data rate and network outage probability. Different types of networks are considered including Single Input Single Output (SISO) systems, Single Input Multiple Output (SIMO) systems using antenna selection or Maximum Ratio Combiner (MRC), and Multiuser Multiple Input Multiple Output (MU-MIMO) systems using Zero-Forcing decoder.

Vehicle to Everything (V2X) communication has been a topic of great interest for the past decade. Lately, a push from the automotive industry and regulators for inclusion of advanced use cases towards autonomous vehicles, has led to the search for improved solutions that can support the respective features. In this paper, Hybrid Automatic Repeat Request (HARQ) feedback solutions are explored in the context of group communications (groupcast) in cellular V2X. A solution is provided to combine reliability improvements while using the least possible amount of sidelink resources. Furthermore, for the case where members of the group are out of communication range of the transmitter, it is suggested to use the feedback response for selecting another member of the group to forward the message.

Future 5G systems have set a goal to support mission-critical Vehicle-to-Everything (V2X) communications and they contribute to an important step towards connected and automated driving. To achieve this goal, the communication technologies should be designed based on a solid understanding of the new V2X applications and the related requirements and challenges. In this regard, we provide a description of the main V2X application categories and their representative use cases selected based on an analysis of the future needs of cooperative and automated driving. We also present a methodology on how to derive the network related requirements from the automotive specific requirements. The methodology can be used to analyze the key requirements of both existing and future V2X use cases.

In this paper, we consider an IoT dedicated network corresponding to a non licensed LoRa Low Power Wide Area Network. The LoRa network operates in the unlicensed 868 MHz band within a total bandwidth of 1 MHz divided into 8 orthogonal channels of 125 kHz each. Despite the high level of interference, this network offers long range communications in the order of 2 to 5 km in urban areas and 10 to 30 km in rural areas. To efficiently mitigate this high level of interference, LoRa network essentially relies on a Chirp Spread Spectrum (CSS) modulation and on repetition diversity mechanisms. The LoRa CSS modulation spreads the signal within a band of 125 kHz using 6 possible spreading factors (from 7 to 12) to target data rates (starting from 5 kbps for the closest node to 300 bps for the furthest ones). The repetition diversity mechanisms enable the data recovery when the transmission is subject to bad channel conditions or/and high interference levels. Although the CSS modulation protects edge-cell's devices from the high level of interference induced by nodes in the proximity of the gateway, it fails to protect nodes at the edge of a given SF region and several trials are required to recover the packet. In this paper, we propose an adaptive multi-channels allocation policy that attributes multiple adjacent channels of 125 kHz for nodes situated at the edge of SF zones. We study the impact of this adaptive sub-band allocation on the gateways' intensities, the rate distribution and the power consumption. Our results are based on a statistical characterization of the interference in the network as well as the outage probability in a typical cell.

This paper proposes areas of improvement for Low Power Wide Area (LPWA) solutions. After recalling the rationale of these systems, it summarizes the main challenges of existing solutions and proposes various improvements at PHY and MAC layer that were investigated in context of the EPHYL project. NB-IoT and LoRa were mostly considered in the analysis of existing techniques, while proposals for improvement address both waveform design and resource allocation strategy. We propose as well introduction of new paradigm such as network coding to benefit of the sparse characteristic of some LPWA use cases. Some of the proposals are validated experimentally in the FIT/CorteXlab environment, offering to the research community a framework to experiment and compare their improvements of LPWA systems.

In this paper, we consider a Low Power Wide Area Networks (LPWAN) operating in a licensed-exempt band. In order to enhance the receiver sensitivity, low complexity repetition schemes that benefit from the time-varying channel condition are widely used. In this case, successful data recovery requires a significant channel variation from a bad to a good state depending on the data rate. This induces a relatively high decoding latency especially for slow time-varying channel. The main objective of this paper is to reduce the packet recovery latency by exploiting multiple channel states defined with respect to various transmission data rates, that are enabled by a rate-less polar code. We characterize the good channel sequence state of this code, and evaluate its latency performance in a slow and fast-time varying context.

This paper focuses on capabilities enabled by 5G connectivity in the cooperative, connected and autonomous cars, and elaborates on two technical enablers. One of the technical enablers consists of a beamformed broadcast/multicast technology that builds on adaptive and robust beam management techniques at the air interface. The other proposed technical component aims to improve the end-to-end architectural design of 5G networks to enable efficient broadcast and multicast transmissions for vehicle-to-anything services. Finally, the key results of multicast and broadcast technical components are described and ongoing and future areas of work and research are detailed.

The fifth generation of cellular communication systems is foreseen to enable a multitude of new applications and use cases with very different requirements. A new 5G multi-service air interface needs to enhance broadband performance as well as provide new levels of reliability, latency, and supported number of users. In this paper, we focus on the massive Machine Type Communications (mMTC) service within a multi-service air interface. Specifically, we present an overview of different physical and medium access techniques to address the problem of a massive number of access attempts in mMTC and discuss the protocol performance of these solutions in a common evaluation framework.

Cooperative intelligent transport systems (ITS) and connected vehicles are foreseen to change the way mobility is conceived today. Cooperative and connected vehicles will lead to improved road traffic safety and efficiency and will also trigger innovation in the infotainment area. These will foster the design of disruptive new business models for both the telco and automotive industries, triggering a profound impact in society and economy. However, before this can become a reality, many technical challenges still need to be solved. One important challenge relates to the provision of efficient and reliable vehicle-to-anything (V2X) communications for the vehicles. The new emerging generation of Mobile communications, the so-called 5G technology, is aimed at giving an answer to this challenge. Among other coordinated efforts, the European-funded 5GCAR project is looking into such V2X technology components and enablers. This paper aims at presenting and describing the technologies that are being considered in 5GCAR to make the vision of the cooperative and connected vehicle a reality.

Mobile networks will increasingly need to make use of heterogeneous access and spectrum opportunities to realize required capacity and quality of service. Moreover, aggregation of such resources will routinely be necessary, and there will be a clear need to develop a management architecture for that aggregation. Such an architecture should ascertain what can and should be aggregated by particular systems, networks, and terminals in view of better managing the collection of available resources on a heterogeneous system level, taking into account all systems', networks', and terminals' traffic requirements and technical capabilities. This article proposes such a management architecture and assesses its benefits, quantified by some particular examples.

Carrier Aggregation has been included in 4G systems such as 3GPP LTE-Advanced to allow the utilization of larger (up to 100MHz) and fragmented spectrum. Aggregation is happening at the MAC layer and each carrier is using the same PHY layer. Further, given the nature of LTE, each of these carriers must use a licensed frequency band. In the SOLDER project we will go further by aggregating heterogeneous radio access technologies with potentially different spectrum access schemes such as unlicensed or light-licensed. This is an important step towards fulfilling the requirements of spectrum hungry 5G systems. This paper presents the scenarios, vision and possible technical solutions envisioned in the SOLDER project.

This deliverable defines general framework for consequent technical workpackages in TROPIC. First, scenarios from the business point of view are defined and further transformed to more technical representation. Then, abstraction models are introduced for both communication and computation parts of femto-cloud concept. Furthermore, requirements need to be met to ensure efficient and feasible utilization of the femto-cloud are presented. To enable prove of the femto-cloud concept and to compare the developed techniques and algorithms a set of performance indicators to be considered in all technical workpackages are listed and defined. To that end, the models and simulation settings are defied in the last section of the document

LTE and LTE-Advanced have introduced complex system features to improve system capacity. Although exhaustively simulated, it often happens that the simulated capacity figures differ from the actual performance seen in the field. This paper explores the combination of real measurements from LTE devices and realistic propagation models to generate coverage maps that are truly representative of radio performance. The paper illustrates the proposed methodology by forecasting the gain of inter-cell interference mitigation implemented in a UE device.