Suchergebnisse

The increase of demand for mobile data services requires a massive network densification. A cost-effective solution to this problem is to reduce cell size by deploying a low-cost all-wireless Network of Small Cells (NoS). These hyperdense deployments create a wireless mesh backhaul amongst Small Cells (SCs) to transport control and data plane traffic. The semi-planned nature of SCs can often lead to dynamic wireless mesh backhaul topologies. This paper presents a self-organized backpressure routing scheme for dynamic SC deployments (BS) that combines queue backlog and geographic information to route traffic in dynamic NoS deployments. BS aims at relieving network congestion, whilst having a low routing stretch (i.e., the ratio of the hop count of the selected paths to that of the shortest path). Evaluation results show that, under uncongested conditions, BS shows similar performance to that of an Idealized Shortest PAth routing protocol (ISPA), while outperforming Greedy Perimeter Stateless Routing (GPSR), a state of the art geographic routing scheme. Under more severe traffic conditions, BS outperforms both GPSR and ISPA in terms of average latency by up to a 85% and 70%, respectively. We conducted ns-3 simulations in a wide range of sparse NoS deployments and workloads to support these performance claims. ; Project: SYMBIOSIS TEC2011-29700-C02-01 (MINECO) ; 2009-SGR-940 grant of the Catalan Government.

Service based architecture (SBA) is a paradigm shift from Service-Oriented Architecture (SOA) to microservices, combining their principles. Network virtualization enables the application of SBA in cellular systems. To better guide the software design of this virtualized cellular system with SBA, this paper presents a software perspective and a positional approach to using fundamental development principles for adapting SBA in virtualized Radio Access Networks (vRANs). First, we present the motivation for using an SBA in cellular radio systems. Then, we explore the critical requirements, key principles, and components for the software to provide radio services in SBA. We also explore the potential of applying SBA-based Radio Access Network (RAN) by comparing the functional split requirements of 5G RAN with existing open-source software and accelerated hardware implementations of service bus, and discuss the limitations of SBA. Finally, we present some discussions, future directions, and a roadmap of applying such a high-level design perspective of SBA to next-generation RAN infrastructure. ; This work was supported in part by the European Union (EU) H2020 5GROWTH Project under Grant 856709, in part by the Generalitat de Catalunya under Grant 2017 SGR 1195, and in part by the National Program on Equipment and Scientific and Technical Infrastructure under the European Regional Development Fund (FEDER) under Grant EQC2018-005257-P.

Network slicing is one of the fundamental tenets of Fifth Generation (5G)/Sixth Generation (6G) networks. Deploying slices requires end-to-end (E2E) control of services and the underlying resources in a network substrate featuring an increasing number of stakeholders. Beyond the technical difficulties this entails, there is a long list of administrative negotiations among parties that do not necessarily trust each other, which often requires costly manual processes, including the legal construction of neutral entities. In this context, Blockchain comes to the rescue by bringing its decentralized yet immutable and auditable lemdger, which has a high potential in the telco arena. In this sense, it may help to automate some of the above costly processes. There have been some proposals in this direction that are applied to various problems among different stakeholders. This paper aims at structuring this field of knowledge by, first, providing introductions to network slicing and blockchain technologies. Then, state-of-the-art is presented through a global architecture that aggregates the various proposals into a coherent whole while showing the motivation behind applying Blockchain and smart contracts to network slicing. And finally, some limitations of current work, future challenges and research directions are also presented. ; This work was supported in part by the Spanish Formación Personal Investigador (FPI) under Grant PRE2018-086061, in part by the TRUE5G under Grant PID2019-108713RB-C52/AEI/10.13039/501100011033, and in part by the European Union (EU) H2020 The 5G Infrastructure Public Private Partnership (5GPPP) 5Growth Project 856709. ; Publicado

Proceedings of: 9th ACM SIGCOMM Conference on Internet Measurement Conference (IMC'09), November 4–6, 2009, Chicago, Illinois ; WLAN devices based on CSMA/CA access schemes have become a fundamental component of network deployments. In such wireless scenarios, traditional networking applications, tools, and protocols, with their built-in measurement techniques, are usually run unchanged. However, their actual interaction with the dynamics of underlying wireless systems is not yet fully understood. A relevant example of such built-in techniques is bandwidth measurement. When considering WLAN environments, various preliminary studies have shown that the application of results obtained in wired setups is not straightforward. Indeed, the contention for medium sharing among multiple users inherent to CSMA/CA access schemes has remarkable consequences on the behavior of and results obtained by bandwidth measurement techniques. In this paper, we focus on evaluating the effect of CSMA/CA-based contention on active bandwidth measurement techniques. As a result, it presents the rate response curve in steady state of a system with both FIFO and CSMA/CA-based contending cross-traffic. We also find out that the distribution of access delay shows a transient regime before reaching a stationary state. The duration of such transient regime is characterized and bounded. We also show how dispersion-based measurements that use a short number of probing packets are biased measurements of the achievable throughput, the origin of this bias lying on the transient detected in the access delay of probing packets. Overall, the results presented in this paper have several consequences that are expected to influence the design of bandwidth measurement tools as well as to better understand the results obtained with them in CSMA/CA links. ; European Community's Seventh Framework Program ; This work has been partially funded by the COST Action IC0703 "Data Traffic Monitoring and Analysis", by the Spanish Ministry of Science and Innovation under grant number TEC2008-06826/TEC (project ARTICO), and by the Catalan Regional Government under grants 2009SGR-1140 and 2009SGR-940 ; Publicado

5G is being deployed in major cities across the globe. Although the benefits brought by the new 5G air interface will be numerous, 5G is more than just an evolution of radio technology. New concepts, such as the application of network softwarization and programmability paradigms to the overall network design, the reduced latency promised by edge computing, or the concept of network slicing – just to cite some of them – will open the door to new vertical-specific services, even capable of saving more lives. This article discusses the implementation and validation of an eHealth service specially tailored for the Emergency Services of the Madrid Municipality. This new vertical application makes use of the novel characteristics of 5G, enabling dynamic instantiation of services at the edge, a federation of domains and execution of real on-the-field augmented reality. The article provides an explanation of the design of the use case and its real-life implementation and demonstration in collaboration with the Madrid emergency response team. The major outcome of this work is a real-life proof-of-concept of this system, which can reduce the time required to respond to an emergency in minutes and perform more efficient triage, increasing the chances of saving lives. ; This work was supported in part by the EU H2020 5GROWTH Project under Grant 856709, in part by Madrid Government (Comunidad de Madrid-Spain) through the Multiannual Agreement with University Carlos III of Madrid UC3M in the line of Excellence of University Professors under Grant EPUC3M21, and in part by the Regional Program of Research and Technological Innovation (V PRICIT).

Flexibility and energy efficiency are considered two principal requirements of future fifth generation (5G) systems. From an architectural point of view, centralized processing and a dense deployment of small cells will play a vital role in enabling the efficient and dynamic operation of 5G networks. In this context, reconfigurable hotspots will provide on-demand services and adapt their operation in accordance to traffic re quirements, constituting a vital element of the heterogeneous 5G network infrastructure. In this paper we present a reconfigurable hotspot which is able to flexibly distribute its underlying communication functions across the network, as well as to adapt various parameters affecting the generation of the transmitted signal. The reconfiguration of the hotspot focuses on minimizing its energy footprint, while accounting for the current operative requirements. A real-time hotspot prototype has been developed to facilitate the realistic evaluation of the energy saving gains of the proposed scheme. The development flexibly combines software (SW) and hardware (HW) accelerated (HWA) functions in order to enable the agile reconfiguration of the hotspot. Actual power consumption measurements are presented for various relevant 5G networking scenarios and hotspot configurations. This thorough characterization of the energy footprint of the different subsystems of the prototype allows to map reconfiguration strategies to different use cases. Finally, the energy-aware design and implementation of the hotspot prototype is widely detailed in an effort to underline its importance to the provision of the flexibility and energy efficiency to future 5G systems. ; This work was supported by the European Commission in the framework of the H2020-ICT-2014-2 project Flex5Gware (Grant agreement no. 671563). The work of CTTC was also partially supported by the Generalitat de Catalunya (2017 SGR 891) and by the Spanish Government under project TEC2014-58341-C4-4-R.

5G has a main requirement of highly flexible, ultralow latency and ultra-high bandwidth virtualized infrastructure in order to deliver end-to-end services. This requirement can be met by efficiently integrating all network segments (radio access, aggregation and core) with heterogeneous wireless and optical technologies (5G, mmWave, LTE/LTE-A, Wi-Fi, Ethernet, MPLS, WDM, software-defined optical transmission, etc.), and massive computing and storage cloud services (offered in edge/core data centers). This paper introduces the preliminary architecture aiming at integrating three consolidated and standalone experimental infrastructures at CTTC, in order to deploy the required end-to-end top-to-bottom converged infrastructure pointed out above for testing and developing advanced 5G services. ; Grant numbers : This work has been supported by the Catalan Government under grants 2014 SGR 1567, 2014 SGR 1551.© 2015 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.