Heterogeneous Networks for the IoT and Machine Type Communications

The Internet of Things promises to be a key-factor in the forthcoming industrial and social revolution. The Internet of Things concept rely on pervasive communications where ’things’ are ’always connected’. The focus of the thesis is on Heterogeneous Networks for Internet of Things and Machine Type Communications. Heterogeneous Networks are an enabling factor of paramount important in order to achieve the ’always connected’ paradigm. On the other hand, Machine Type Communications are deeply different from Human-to-Human communications both in terms of traffic patterns and requirements. This thesis investigate both concepts. In particular, here are studied short and long range solutions for Machine-to-machine applications. For this work a dual approach has been followed: for the short-range solutions analysis an experimental approach has been privileged; meanwhile for the long-range solutions analysis a theoretical and simulation approach has been preferred. In both case, a particular attention has been given to the feasibility of the solutions proposed, hence solutions based on products that already exist in the market have been privileged

Neighbors-Aware Proportional Fair scheduling for future wireless networks with mixed MAC protocols

Abstract In this paper, we consider a beyond-5G scenario, where two types of users, denoted as scheduled and uncoordinated nodes, coexist on the same set of radio resources for sending data to a base station. Scheduled nodes rely solely on a centralized scheduler within the base station for the assignment of resources, while uncoordinated nodes use an unslotted Carrier Sense Multiple Access (CSMA) protocol for channel access. We propose and evaluate through simulations: (a) a novel centralized resource scheduling algorithm, called Neighbors-Aware Proportional Fair (N-PF) and (b) a novel packet length adaptation algorithm, called Channel-Aware (CA) Packet Length Adaptation algorithm for the scheduled nodes. The N-PF algorithm considers the uplink channel state conditions and the number of uncoordinated nodes neighboring each scheduled node in the aggregate scheduling metric, in order to maximize packet transmission success probability. The CA algorithm provides an additional degree of freedom for improving the performance, thanks to the fact that scheduled nodes with lower number of hidden terminals, i.e., having higher packet capture probability, are assigned longer packet transmission opportunities. We consider two benchmark schemes: Proportional Fair (PF) algorithm, as a resource scheduling algorithm, and a discrete uniform distribution (DUD) scheme for packet lengths distribution. Simulation results show that the proposed schemes can result in significant gain in terms of network goodput, without compromising fairness, with respect to two benchmark solutions taken from the literature

D22.1 Definition of EuWIn@CNIT/Bologna testbed interfaces and preliminary plan of activities

Preprin

Scheduling M2M traffic over LTE uplink of a dense small cell network

We present an approach to schedule Long Term Evolution (LTE) uplink (UL) Machine-to-Machine (M2M) traffic in a densely deployed heterogeneous network, over the street lights of a big boulevard for smart city applications. The small cells operate with frequency reuse 1, and inter-cell interference (ICI) is a critical issue to manage. We consider a 3rd Generation Partnership Project (3GPP) compliant scenario, where single-carrier frequency-division multiple access (SC-FDMA) is selected as the multiple access scheme, which requires that all resource blocks (RBs) allocated to a single user have to be contiguous in the frequency within each time slot. This adjacency constraint limits the flexibility of the frequency-domain packet scheduling (FDPS) and inter-cell interference coordination (ICIC), when trying to maximize the scheduling objectives, and this makes the problem NP-hard. We aim to solve a multi-objective optimization problem, to maximize the overall throughput, maximize the radio resource usage and minimize the ICI. This can be modelled through a mixed-integer linear programming (MILP) and solved through a heuristic implementable in the standards. We propose two models. The first one allocates resources based on the three optimization criteria, while the second model is more compact and is demonstrated through numerical evaluation in CPLEX, to be equivalent in the complexity, while it performs better and executes faster. We present simulation results in a 3GPP compliant network simulator, implementing the overall protocol stack, which support the effectiveness of our algorithm, for different M2M applications, with respect to the state-of-the-art approaches

D13.1 Fundamental issues on energy- and bandwidth-efficient communications and networking

Deliverable D13.1 del projecte europeu NEWCOM#The report presents the current status in the research area of energy- and bandwidth-efficient communications and networking and highlights the fundamental issues still open for further investigation. Furthermore, the report presents the Joint Research Activities (JRAs) which will be performed within WP1.3. For each activity there is the description, the identification of the adherence with the identified fundamental open issues, a presentation of the initial results, and a roadmap for the planned joint research work in each topic.Preprin

A multi-service wireless lamp post backbone for smart cities - centralized vs distributed control

This paper proposes an empirically-based methodology for spatial down-scaling of wireless sensor networks (WSNs). WSNs are often deployed in environments not easily accessible, highly unpredictable and where running experiments is generally very expensive and time consuming. The latter calls for the need to develop down-scaled testbeds, deployed in a controlled environment, where tests can be conducted under predictable and replicable conditions. In this paper we present a methodology to realise the down-scaling of a real testbed on an experimental platform developed at the University of Bologna in the framework of the \u201dEuropean Laboratory of Wireless Communications for the Future Internet\u201d (EuWIn). The real testbed we refer to is composed of 24 devices, deployed on the lamp posts of the small town of Casalgrande (Italy), running a smart city application. The proposed procedure for the down-scaling is implemented and results achieved on the real testbed and those achieved on EuWIn are compared. The comparison is performed in terms of network topologies and packet error rate. Results demonstrate the utility of EuWIn for down-scaling purposes and the efficacy of the proposed methodology

Neighbours-aware proportional fair scheduler for future wireless networks

n this paper, we present an uplink scenario where primary and secondary users coexist on the same set of radio resources. The primary users rely solely on a centralised scheduler within the base station for the assignment of resources, and the secondary users rely on an unslotted Carrier Sense Multiple Access (CSMA) protocol for channel access. We propose a novel centralised scheduling algorithm, Neighbours-Aware Proportional Fair (N-PF), which considers the uplink channel state conditions and the number of secondary users neighbouring each primary user in the aggregate scheduling metric. Through simulations we demonstrate that N-PF outperforms the chosen benchmark algorithm, Proportional Fair (PF), in terms of packet delivery rate while maintaining fairness. © ICST Institute for Computer Sciences, Social Informatics and Telecommunications Engineering 2016

Scheduling M2M Traffic over LTE Uplink of a dense Small Cells Network

We present an approach to schedule Long Term Evolution (LTE) uplink (UL) Machine to Machine (M2M) traffic in a densely deployed heterogeneous network, over the lamp posts of a big boulevard for smart city applications. The small cells operate with frequency reuse 1 and Inter-Cell Interference (ICI) is a critical issue to manage. We consider a Release 9 3rd Generation Partnership Project (3GPP) compliant scenario, where Single Carrier Frequency Division Multiple Access (SCFDMA) is selected as the multiple access scheme, which requires that all Resource Block (RB)s allocated to a single user have to be contiguous in frequency within each time slot. This adjacency constraint limits the flexibility of the Frequency-Domain Packet Scheduling (FDPS) and Inter-Cell Interference Coordination (ICIC), when trying to maximize the scheduling objectives, and this is sufficient to make the problem NP-hard. We aim to solve an optimization problem, taking into account criteria such as the maximization of the overall throughput, the minimization of the radio resource usage, and the minimization of ICI. This can be modelled through a Mixed Integer Linear Programming (MILP) and solved through a heuristic implementable in the standards. We present simulation results in a 3GPP compliant network simulator, which support the effectivity of our algorithm, for different M2M applications, with respect to state of the art approaches. \ua9 2015 IEEE

The EuWin Platform: From a Down-Scaled Testbed to the Real Deployment

This paper proposes an empirically-based methodology that can be used for spatial down-scaling of wireless sensor networks (WSNs). WSNs are often deployed in environments not easily accessible, highly unpredictable and where running experiments is generally very expensive and time consuming. The latter calls for the need to develop down-scaled testbeds, deployed in a controlled environment, where tests can be conducted under predictable and replicable conditions. In this paper we present a methodology to realise the down-scaling of a real testbed on a testbed developed at the University in the framework of the Network of Excellence, NEWCOM#, with reference to EuWIn (the "European Laboratory of Wireless Communications for the Future Internet"). The real testbed we refer to is composed of 24 devices, deployed on the lamp posts of the small town of Casalgrande (Italy), and running a smart city application. The proposed procedure for the down-scaling is implemented and the results achieved on the real testbed and on the down-scaled testbed are compared. The comparison is performed in terms of network topologies and average number of hops necessary to reach the gateway. Results demonstrate the utility of EuWIn for down-scaling purposes and the efficacy of the proposed methodology

Testing the impact of Wi-Fi interference on Zigbee networks

Wireless Local Area Networks (WLAN), using IEEE 802.11, and Wireless Personal Area Networks (WPAN), using IEEE 802.15.4/Zigbee standard, share the same unlicensed 2.4 GHz Industrial Scientific Medical band. Co-existence between such wireless technologies within the same frequency spectrum is crucial to ensure that each wireless technology guarantees the desired performance requirements. In this paper we investigate the interference generated by IEEE 802.11 over an 802.15.4/Zigbee network. Results of an extensive measurement campaign are reported to derive the performance of a Zigbee point-to-point network, when different types of traffic are generated and when affected by different levels of interference. Performance is evaluated in terms of packet loss rate, average round trip time and overhead. Tests have been performed on the “European Laboratory of Wireless Communications for the Future Internet” (EuWin) testbed at the University of Bologna, allowing a proper characterization of the environmental conditions during experiments