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1915 research outputs found
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QoS-Aware CAPEX Minimization in Urban Off-Grid Radio Access Networks
Get PDFNetwork densification is currently seen as one of the key techniques enabling Radio Access Networks (RANs) to meet the performance and functional requirements of the 5G paradigm in urban areas. Avoiding the connection of small cells to the power grid facilitates their deployment and reduces both capital and operational expenditures (CAPEX and OPEX). In this paper, we propose an approach to enable net-Zero Energy Networking (ZEN) in urban scenarios, based on dynamically managing the operating point of Base Stations (BSs), so as to drastically decrease their overall energy requirements. More specifically, we formalize the problem of optimizing the CAPEX of a ZEN, while guaranteeing quality of service (QoS) and a given level of service availability. Optimization is over power system parameters (solar panel area, battery capacity) as well as over BS power levels and user association over time. We propose a practical algorithm for the derivation of QoS-aware spatio-temporal strategies in terms of user association and BS power allocation, which, for a given expected pattern of renewable power generation, minimize the probability of service unavailability due to power shortage. Through extensive simulations using measured data, and realistic BS deployments, we show that our algorithm leads to substantial reduction in CAPEX, and to feasible power system requirements.TRUEpu
Architectural aspects of mm-wave radio access integration with 5G ecosystem
Get PDFThe following white paper discusses a range of architectural aspects that are crucial for the integration of mm-wave Radio Access Technology (RAT) in 5G mobile networks. While radio spectrum above 6 GHz offers contiguous high bandwidth resources for high capacity radio links; it gives rise to new challenges in terms of user mobility and reliability due to the harshness of the mobile radio environment, necessitating the deployment of highly directional links. To overcome these challenges, we propose architectural solutions based on tight integration of mm-wave RAT with RAT(s) operating in frequencies below 6 GHz with the intention to diversify the control plane and data split, and the duplication of the user plane.
The paper outlines initial architectural concepts envisioned for 5G mm-wave systems designed to operate in frequencies between 6-100 GHz, and discuss some crucial aspects of its integration within the 5G networks. The proposed concepts include: i) network slicing to address needs of 5G use cases with highly divergent requirements, ii) multiconnectivity with multiple mm-wave base stations and as a way to integrate multiple RATs; iii) mobility related aspects such as mm-wave cell clustering to make small scale mobility of the UE transparent to the CN, and the introduction of a novel inactive RRC state, iv) multi-RAT multi-layer management scheme which introduces abstraction at different layers of the protocol stack for flexible and scalable multi-RAT management, vi) control and user plane aspects for low-band integration, and finally vii) architectural aspects of self-backhauling
Measuring the Impact of Adversarial Errors on Packet Scheduling Strategies
Get PDFIn this paper we explore the problem of achieving efficient packet transmission over unreliable links with worst case occurrence of errors. In such a setup, even an omniscient offline scheduling strategy cannot achieve stability of the packet queue, nor is it able to use up all the available bandwidth. Hence, an important first step is to identify an appropriate metric to measure the efficiency of scheduling strategies in such a setting. To this end, we propose an asymptotic throughput metric which corresponds to the long term competitive ratio of the algorithm with respect to the optimal. We then explore the impact of the error detection mechanism and feedback delay on our measure. We compare instantaneous with deferred error feedback, which requires a faulty packet to be fully received in order to detect the error. We propose algorithms for worst-case adversarial and stochastic packet arrival models, and formally analyze their performance. The asymptotic throughput achieved by these algorithms is shown to be close to optimal by deriving lower bounds on the metric and almost matching upper bounds for any algorithm in the considered settings. Our collection of results demonstrate the potential of using instantaneous feedback to improve the performance of communication systems in adverse environments.pu
Analyzing students' intentionality towards badges within a case study using Khan academy
Get PDFDOI: 10.1145/2883851.2883947.One of the most common gamification techniques in education is the use of badges as a reward for making specific student actions. We propose two indicators to gain insight about students’ intentionality towards earning badges and use them with data from 291 students interacting with Khan Academy courses. The intentionality to earn badges was greater for repetitive badges, and this can be related to the fact that these are easier to achieve. We provide the general distribution of students depending on these badge indicators, obtaining different profiles of students which can be used for adaptation purposes.TRUEpu
Network-assisted Outband D2D-clustering in 5G Cellular Networks: Theory and Practice
Get PDFWe introduce a channel-opportunistic architecture that enhances the user experience in terms of throughput, fairness, and energy efficiency. Our proposed architecture leverages D2D communication and it is built on top of the forthcoming D2D features of 5G networks. In particular, we focus on outband D2D where cellular users are allowed to exploit both cellular (i.e., LTE-A) and WLAN (i.e., WiFi Direct) technologies to establish a D2D connection. In this architecture, cellular users form clusters, in which only the user with the best channel condition communicates with the base station on behalf of the entire cluster. Within the cluster, the unlicensed spectrum is utilized to relay traffic. In this article, we provide analytical models for the proposed system and study the impact of several payoff distribution methods commonly adopted in the literature on coalitional game theory. We then introduce an operator-controlled relay protocol based on the D2D features of LTE-A and WiFi Direct, and demonstrate the feasibility and the advantages of D2D-assisted cellular communication with our SDR prototype.pu
"I Can’t Get No Satisfaction": Helping Autonomous Systems Identify Their Unsatisfied Inter-domain Interests
Get PDFGiven the distributed and business-driven nature of the Internet, economic interests of Autonomous Systems (ASes) may be incompatible. Previous works studied specific effects of incompatible interests, especially BGP policy conflicts leading to routing and forwarding anomalies. In this paper, we rather focus on the effects of incompatible interests that do not trigger such anomalies. We take the perspective of a single AS: We show that incompatible interests can have a tangible impact on its business, and provide a classification of its unsatisfied interests. Since incompatible interests cannot be solved automatically, our effort is directed to support network managers in their business decisions. Hence, we describe algorithms to identify and assess their impact, as well as a prototype of a warning system aimed at signaling the most relevant unsatisfied interests. We evaluate our prototype on real data from two operational networks. In addition to illustrate the potential of our system, our evaluation shows that unsatisfied interest are relatively frequent and likely affect a significant amount of traffic in practice.TRUEpu
Flexible connectivity and QoE/QoS management for 5G Networks: The 5G NORMA view
Get PDFDOI: 10.1109/ICCW.2016.7503816The goal envisioned by 5G NORMA is to develop a novel, adaptive and future-proof 5G mobile network architecture. In order to fulfill these requirements, 5G NORMA envisions an extremely flexible architecture to be deployed in a multi-tier distributed data-center. In this paper we focus on the novel mobility management schemes, QoE/QoS, Control and Orchestration mechanisms that are being developed in 5G NORMA. These modules, that follow the software-defined principle, jointly optimize core and access functions. The final result is a modular architecture that adapts to the requirements of very heterogeneous services, while allowing multiple tenants to share network resources among them, providing hence the flexible connectivity needed by future 5G Networks.TRUEpu
An overview of the CPRI specification and its application to C-RAN-based LTE scenarios
Get PDFThe CPRI specification has been introduced to enable the communication between radio equipment and radio equipment controllers, and is of particular interest for mobile operators willing to deploy their networks following the novel cloud radio access network approach. In such a case, CPRI provides an interface for the interconnection of remote radio heads with a baseband unit by means of the so-called fronthaul network. This article presents the CPRI specification, its concept, design, and interfaces, provides a use case for fronthaul dimensioning in a realistic LTE scenario, and proposes some interesting open research challenges in the next-generation 5G mobile network.pu
Revisiting 802.11 Rate Adaptation from Energy Consumption's Perspective
Get PDFDOI: http://dx.doi.org/10.1145/2988287.2989149Rate adaptation in 802.11 WLANs has received a lot of at-
tention from the research community, with most of the pro-
posals aiming at maximising throughput based on network
conditions. Considering energy consumption, an implicit
assumption is that optimality in throughput implies opti-
mality in energy efficiency, but this assumption has been
recently put into question. In this paper, we address via
analysis and experimentation the relation between through-
put performance and energy efficiency in multi-rate 802.11
scenarios. We demonstrate the trade-off between these per-
formance figures, confirming that they may not be simulta-
neously optimised, and analyse their sensitivity towards the
energy consumption parameters of the device. Our results
provide the means to design novel rate adaptation schemes
that takes energy consumption into account.TRUEpu