Emmanouil Kafetzakis

Introducing Mobile Edge Computing Capabilities through Distributed 5G Cloud Enabled Small Cells

Current trends in broadband mobile networks are addressed towards the placement of different capabilities at the edge of the mobile network in a centralised way. On one hand, the split of the eNB between baseband processing units and remote radio headers makes it possible to process some of the protocols in centralised premises, likely with virtualised resources. On the other hand, mobile edge computing makes use of processing and storage capabilities close to the air interface in order to deploy optimised services with minimum delay. The confluence of both trends is a hot topic in the definition of future 5G networks. The full centralisation of both technologies in cloud data centres imposes stringent requirements to the fronthaul connections in terms of throughput and latency. Therefore, all those cells with limited network access would not be able to offer these types of services. This paper proposes a solution for these cases, based on the placement of processing and storage capabilities close to the remote units, which is especially well suited for the deployment of clusters of small cells. The proposed cloud-enabled small cells include a highly efficient microserver with a limited set of virtualised resources offered to the cluster of small cells. As a result, a light data centre is created and commonly used for deploying centralised eNB and mobile edge computing functionalities. The paper covers the proposed architecture, with special focus on the integration of both aspects, and possible scenarios of application.

Technology pillars in the architecture of future 5G mobile networks: NFV, MEC and SDN

This paper analyzes current standardization situation of 5G and the role network softwarization plays in order to address the challenges the new generation of mobile networks must face. This paper surveys recent documentation from the main stakeholders to pick out the use cases, scenarios and emerging vertical sectors that will be enabled by 5G technologies, and to identify future high-level service requirements. Driven by those service requirements 5G systems will support diverse radio access technology scenarios, meet end-to-end user experienced requirements and provide capability of flexible network deployment and efficient operations. Then, based on the identified requirements, the paper overviews the main 5G technology trends and design principles to address them. In particular, the paper emphasizes the role played by three main technologies, namely SDN, NFV and MEC, and analyzes the main open issues of these technologies in relation to 5G.

QoE4CLOUD: A QoE-driven multidimensional framework for cloud environments

Cloud Operators, in order to respond effectively to the QoS requirements of cloud applications, are obliged to apply over-provisioning policies. In general, this tactic leads to severe waste of the available cloud computing resources. Similarly, both Service/Platform Providers and End-Users wish to avoid the extra cost of this over-provisioning tactic and pay only per use, without having to statically reserve extra resources in advance. As a consequence, the cloud community urgently asks for flexible and intelligent management solutions, towards enhanced and efficient utilization of the cloud. The ultimate target of any intelligent cloud management scheme should be the provision of a service at an adequate quality level, creating the need to introduce the notion of Quality of Experience (QoE). In this context, this paper proposes a unified QoE-aware management framework, directly targeting to cloud computing environments. The proposed management system suggests the optimization of cloud resources usage and offered services in terms of QoE, satisfying the different service and resource requirements of all the involved cloud entities. In addition, the proposed novel approach merges together various QoS aspects in a multidimensional framework, referred to as QoE4CLOUD, which considers the perceived quality as the key metric for the management and performance optimization of the cloud environment.

Enabling technologies and benefits of multi-tenant multi-service 5G small cells

In this manuscript, we present the main concepts of the 5G-PPP SESAME project dedicated to the implementation of Cloud-Enabled Small Cells (CESCs), able to support edge cloud computing in a multi-tenant, multi-service ecosystem. More particularly, we give a preview of the SESAME concept at the component/sub-system, system and operation level. At the component/sub-system level, we detail our plan to deploy multi-operator enabled small cells, enhanced with a virtualised execution platform for 5G. At the system level, we present the envisaged architecture to manage and control the cloud-enabled small cell infrastructure. Finally, at the operation level, we explain the potential advantages of adopting the SESAME concept on the 5G access networks.

A Model for an Innovative 5G-Oriented Architecture, Based on Small Cells Coordination for Multi-tenancy and Edge Services

The “core” aim of the SESAME EU-funded research project is to design and develop a novel 5G platform based on the use of Small Cells, featuring multi-tenancy between network operators and also attach to them edge cloud capabilities to be offered to both the network operators and the mobile users. SESAME aims at providing a fresh 5G mobile network architecture so as to support the ambitious goal of small cell virtualization, multitenancy and edge cloud services. In the present work we assess the fundamental SESAME components and their role in the respective systems, while analysing the initial framework of the essential relevant architecture to implement the critical targets of the respective approach. Finally we identify future potential extensions.

A novel Effective Capacity-based framework for providing statistical QoS guarantees in IEEE 802.11 WLANs

This article proposes a performance model of the IEEE 802.11 MAC layer that employs the notion of Effective Capacity. In particular, the paper establishes that an IEEE 802.11 mobile station can be regarded as a Semi-Markovian bursty server of the On/Off type, with known distributions for the On and Off periods, and subsequently applies known results for Semi-Markovian models to derive the Effective Capacity function of this On/Off server. The general Effective Bandwidth/Capacity theory can then be used for computing buffer overflow probabilities and for employing simple traffic control policies to enforce related QoS guarantees. The policies guarantee a soft bound on the buffer overflow probability and are suitable for real-time traffic control over WLANs. The Effective Capacity model of IEEE 802.11 stations is originally developed by assuming that the other competing stations are saturated. This is a conservative assumption that becomes very accurate in a highly loaded network. Subsequently, the model is adapted to encompass lightly loaded networks as well. In the adapted model, each mobile station directly measures a few model parameters, instead of calculating them on the basis of the saturation assumption, and uses these measurements in the computation of its Effective Capacity function. The theoretical results are checked against simulations, validating the appropriateness of the model.

The Impact of Video Transcoding Parameters on Event Detection for Surveillance Systems

The process of transcoding videos apart from being computationally intensive, can also be a rather complex procedure. The complexity refers to the choice of appropriate parameters for the transcoding engine, with the aim of decreasing video sizes, transcoding times and network bandwidth without degrading video quality beyond some threshold that event detectors lose their accuracy. This paper explains the need for transcoding, and then studies different video quality metrics. Commonly used algorithms for motion and person detection are briefly described, with emphasis in investigating the optimum transcoding configuration parameters. The analysis of the experimental results reveals that the existing video quality metrics are not suitable for automated systems and that the detection of persons is affected by the reduction of bit rate and resolution, while motion detection is more sensitive to frame rate.

Effective-capacity-based stochastic delay guarantees for systems with time-varying servers, with an application to IEEE 802.11 WLANs

Many network applications rely on stochastic QoS guarantees. With respect to loss-related performance, the effective bandwidth/capacity theory has proved useful for calculating loss probabilities in queues with complex input and server processes and for formulating simple admission control tests to ensure associated QoS guarantees. This success has motivated the application of the theory for delay-related QoS too. However, up until now this application has been justified only heuristically for queues with variable service rate. The paper fills this gap by establishing rigorously that the effective bandwidth/capacity theory may be used for the asymptotically correct calculation and enforcement of delay tail-probabilities in systems with variable rate servers too. Subsequently, the paper applies the general results to IEEE 802.11 WLANs, by representing each IEEE 802.11 station as an On/Off server and employing the effective capacity function for this model. Comparison of analytical results with simulation validates the effectiveness of the On/Off IEEE 802.11 model for delay-related QoS, complementing earlier results on loss-related performance.

The emergence of operator-neutral small cells as a strong case for cloud computing at the mobile edge

Small cells have emerged as a useful tool for supporting increased network capacity through network densification, but they can also be used to support edge cloud computing services. In this paper, we provide a preview of an innovative concept that tackles the consolidation of multi-tenancy in such type communications infrastructures, as well as the placement of network intelligence and applications in the network edge. After surveing the challenges and the enabling technologies, we present the envisaged architecture to manage and control the Cloud-Enabled Small Cell infrastructure. Also, at the operation level, we explain the potential advantages of adopting the proposed solutions on the long-term evolution access networks. Copyright

Using small cells for enhancing 5G network facilities

The 5G ESSENCE project context is based on the concept of Edge cloud computing and Small Cell-as-a-Service (SCaaS) and further “promotes” their role and/or influences within the related 5G vertical markets. 5G ESSENCEs core innovation is focused upon the development/provision of a highly flexible and scalable platform, offering benefits to the involved market actors. The present work identifies a variety of challenges to be fulfilled by the 5G ESSENCE in the scope of an enhanced architectural framework. The proposed technical approach exploits the profits of the centralisation of Small Cell functions as scale grows through an edge cloud environment based on a two-tier architecture with the first distributed tier being for offering low latency services and the second centralised tier being for the provision of high processing power for computing-intensive network applications. This permits decoupling the control and user planes of the Radio Access Network (RAN) and achieving the advantages of Cloud-RAN without the enormous fronthaul latency restrictions. The use of end-to-end network slicing mechanisms allows for sharing the related infrastructure among multiple operators/vertical industries and customizing its capabilities on a per-tenant basis, creating a neutral host market and reducing operational costs.