Irena Trajkovska

Testing a Cloud Provider Network for Hybrid P2P and Cloud Streaming Architectures

The number of online real-time streaming services deployed over network topologies like P2P or centralized ones has remarkably increased in the recent years. This has revealed the lack of networks that are well prepared to respond to this kind of traffic. A hybrid distribution network can be an efficient solution for real-time streaming services. This paper contains the experimental results of streaming distribution in a hybrid architecture that consist of mixed connections among P2P and Cloud nodes that can interoperate together. We have chosen to represent the P2P nodes as Planet Lab machines over the world and the cloud nodes using a Cloud providers network. First we present an experimental validation of the Cloud infrastructures ability to distribute streaming sessions with respect to some key streaming QoS parameters: jitter, throughput and packet losses. Next we show the results obtained from different test scenarios, when a hybrid distribution network is used. The scenarios measure the improvement of the multimedia QoS parameters, when nodes in the streaming distribution network (located in different continents) are gradually moved into the Cloud provider infrastructure. The overall conclusion is that the QoS of a streaming service can be efficiently improved, unlike in traditional P2P systems and CDN, by deploying a hybrid streaming architecture. This enhancement can be obtained by strategic placing of certain distribution network nodes into the Cloud provider infrastructure, taking advantage of the reduced packet loss and low latency that exists among its datacenters.

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.

SDN-based service function chaining mechanism and service prototype implementation in NFV scenario

The fast growing development of Network Function Virtualization (NFV) trends and the remarkable progress of Software Defined Networking (SDN) have yielded a synergy between both, towards the provision of convergent networking solutions. Since the traditional networking principles were not designed according to the NFV principles, a work has emerged dedicated to protocol redesign among the academic fellows and the industry representatives. A typical example that has been introduced in such eco-system is the concept of network service chaining, as a composition of virtual network functions stitched together in a logically ordered fashion, to create an integral networking service that can be owned by network administrators, programmers, cloud- and telco-operators. This appoints SDN as an essential technology enabler in administering advanced traffic steering techniques, thanks to the SDN controllers capability to dynamically manage VNFs virtual connections and underlying dataplane flows. Despite the rapid progression, the strategies for traffic steering in NFV environment, are still facing imminent challenges to be addressed. This paper joins NFV and SDN technology into a novel traffic steering solution based on open source reference implementations (such as SDK for SDN, virtual Traffic Classifier, virtual Media Transcoder, and WAN Infrastructure Connection Manager) designed with performance and network optimizations in mind. We have successfully deployed and tested the system prototype in a real datacenter. The evaluation results of the prototype system: (1) validated the presented chain use cases, (2) affirmed an efficient performance and scalability of the chaining method, and (3) certified good quality of video traffic transmission and transcoding. HighlightsHolistic approach in SFC delivery and OpenFlow-based traffic steering mechanism in OpenDaylight.Set of four components/services delivered, each of them contributing to the open source community.Implementation reference and support for all components.SFC solution deployed in SDN-NFV environment and proof of concept validated.End-to-end service chaining tests over different traffic types, to showcase a chained traffic characterization and performance implications of the same.A thorough State of the Art in standards, academic and industry implementations of SFC.

Videoconference Capacity Leasing on Hybrid Clouds

This paper proposes a new methodology focused on implementing cost effective architectures on Cloud Computing systems. With this methodology the paper presents some disadvantages of systems that are based on single Cloud architectures and gives some advices for taking into account in the development of hybrid systems. The work also includes a validation of these ideas implemented in a complete videoconference service developed with our research group. This service allows a great number of users per conference, multiple simultaneous conferences, different client software (requiring transcodification of audio and video flows) and provides a service like automatic recording. Furthermore it offers different kinds of connectivity including SIP clients and a client based on Web 2.0. The ideas proposed in this article are intended to be a useful resource for any researcher or developer who wants to implement cost effective systems on several Clouds.

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

Service Mapping and Orchestration Over Multi-Tenant Cloud-Enabled RAN

Fifth-generation (5G) envisages a “hyper-connected society” where an enormous number of diverse entities could communicate with each other anywhere and at any time, some of which will demand extremely challenging performance requirements such as sub-millisecond latency, and higher data rates. Cloud-enabled radio access networks (CE-RANs) where intelligence is placed at the edge of the mobile network and in the proximity of end users emerge as a promising solution to improve online experience. To make CE-RAN more flexible and cost-effective, network functions virtualization and software defined networking technologies are employed, enabling features such as resource pooling, scalability, spectral efficiency, and multi tenancy. The accommodation of such technologies in the context of 5G requires multipronged efforts at various levels, in particular at the management and orchestration. Among all topics that falls into this subject, e.g., resource optimization and efficient lifecycle management, this paper focuses on two critical challenges, i.e., service mapping and quality of service assurance. Particularly, the proposed service placement solution takes into account two main constraints, i.e., quality of user experience and limited hardware capabilities available at the network edge. Simulation tools as well as the SESAME testbed have been used to extract results in this paper and a proof-of-concept evaluation is presented.