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Results from Running an Experiment as a Service Platform for Mobile Broadband Networks in Europe
Get PDFIn this article we present a selection from a vast range of experiments run with MONROE, our open experiment as a service (EaaS) platform for measurements and experimentation in Mobile Broadband Networks. We show that the plat- form can be used to benchmark network performance in a repeatable and con- trolled manner thanks to the collection of a rich set of geotagged metadata and the execution of discretionary user experiments. Indeed, with the sheer amount of data collected from 12 commercial mobile operators across Europe, MON- ROE offers an unprecedented opportunity to monitor, analyze and ultimately improve the status of current and future mobile broadband networks. Besides, we show how flexibly the platform allows combining metadata and experimental data series during the experiments or by means of post-processing, and show results produced by our own experiments as well as comment on results obtained by external research groups and developers that have been granted access to our platform.pu
Analysis of TCP Performance in 5G mm-wave Mobile Networks
Get PDFMillimeter-wave (mm-wave) bands will play an essential role in 5G mobile networks in supporting the increasing
demand for higher data rates. Communications at mm-wave frequencies pose unique challenges. The high propagation loss and unfavorable atmospheric absorption make the channel quality highly variable – short communication ranges and blockage through obstacles may prevent communication altogether. The use of directional antennas helps to achieve higher communication ranges and provides better spatial reuse and lower
interference compared to omni-directional communications. At the same time, this introduces the problem of beam misalignment. Mm-wave research has primarily focused on the PHY and MAC layers, whereas the transport layer aspects of mm-wave systems require further attention. In this article, we analyze the behavior of TCP in mm-wave networks and study its impact on systemlevel performance. Through extensive simulations, we show the effect of different types of blockages on the behavior of the congestion control in the presence of handovers, and when small,
medium and long flows coexist. Protocols like CUBIC that target high throughput benefit significantly when jointly optimizing link layers buffers and timeouts. While the optimization fosters prompt reaction to short-term blockages, the performance of such protocols significantly decreases when obstacles degrade the channel quality for longer time periods. Hybrid-designs like TCP YeAH are more robust to blockage, but fail to recover quickly and to ramp up to the link capacity after timeouts.TRUEpu
Enhanced Connectivity in Wireless Mobile Programmable Networks
Get PDFThe architecture of current operator infrastructures is being challenged by the non-stop growing demand of data hungry services appearing every day. While currently deployed operator networks have been able to cope with traffic demands so far, the architectures for the 5th generation of mobile networks (5G) are expected to support unprecedented traffic loads while decreasing costs associated with the network deployment and operations. Indeed, the forthcoming set of 5G standards will bring programmability and flexibility to levels never seen before. This has required introducing changes in the architecture of mobile networks, enabling different features such as the split of control and data planes, as required to support rapid programming of heterogeneous data planes. Network softwarisation is hence seen as a key enabler to cope with such network evolution, as it permits controlling all networking functions through (re)programming, thus providing higher flexibility to meet heterogeneous requirements while keeping deployment and operational costs low. A great diversity in terms of traffic patterns, multi-tenancy, heterogeneous and stringent trafic requirements is therefore expected in 5G networks.
Software Defined Networking (SDN) and Network Function Virtualisation (NFV) have emerged as a basic tool-set for operators to manage their infrastructure with increased flexibility and reduced costs. As a result, new 5G services can now be envisioned and quickly programmed and provisioned in response of user and market necessities, imposing a paradigm shift in the services design. However, such flexibility requires the 5G transport network to undergo a profound transformation, evolving from a static connectivity substrate into a service-oriented infrastructure capable of accommodating the various 5G services, including Ultra-Reliable and Low Latency Communications (URLLC). Moreover,
to achieve the desired flexibility and cost reduction, one promising approach is to leverage virtualisation technologies to dynamically host contents, services, and applications closer to the users so as to offload the core network and reduce the communication delay. This
thesis tackles the above challenges which are detailed in the following.
A common characteristic of the 5G services is the ubiquity and the almost permanent connection that is required from the mobile network. This really imposes a challenge in the signalling procedures provided to get track of the users and to guarantee session continuity. The mobility management mechanisms will hence play a central role in the 5G networks because of the always-on connectivity demand. Distributed Mobility Management (DMM) helps going towards this direction, by flattening the network, hence improving its scalability, and enabling local access to the Internet and other communication services, like mobile-edge clouds. Simultaneously, SDN opens up the possibility of running a multitude
of intelligent and advanced applications for network optimisation purposes in a centralised network controller. The combination of DMM architectural principles with SDN management appears as a powerful tool for operators to cope with the management and data burden expected in 5G networks.
To meet the future mobile user demand at a reduced cost, operators are also looking at solutions such as C-RAN and different functional splits to decrease the cost of deploying and maintaining cell sites. The increasing stress on mobile radio access performance in a context of declining revenues for operators is hence requiring the evolution of backhaul and fronthaul transport networks, which currently work decoupled. The heterogeneity of the nodes and transmission technologies inter-connecting the fronthaul and backhaul segments makes the network quite complex, costly and ineffcient to manage
flexibly and dynamically. Indeed, the use of heterogeneous technologies forces operators to manage two physically separated networks, one for backhaul and one for fronthaul. In order to meet 5G requirements in a cost-effective manner, a unified 5G transport network that unifies the data, control, and management planes is hence required. Such an integrated fronthaul/backhaul transport network, denoted as crosshaul, will hence carry both fronthaul and backhaul traffic operating over heterogeneous data plane technologies, which are software-controlled so as to adapt to the fluctuating capacity demand of the 5G air interfaces.
Moreover, 5G transport networks will need to accommodate a wide spectrum of services on top of the same physical infrastructure. To that end, network slicing is seen as a suitable candidate for providing the necessary Quality of Service (QoS). Traffic differentiation is usually enforced at the border of the network in order to ensure a proper forwarding of the traffic according to its class through the backbone. With network slicing, the traffic may now traverse many slice edges where the traffic policy needs to be enforced, discriminated and ensured, according to the service and tenants needs. However, the very basic nature that makes this efficient management and operation possible in a flexible way -- the logical centralisation -- poses important challenges due to the lack of proper monitoring tools, suited for SDN-based architectures. In order to take timely and right decisions while operating a network, centralised intelligence applications need to be fed with a continuous stream of up-to-date network statistics. However, this is not feasible
with current SDN solutions due to scalability and accuracy issues. Therefore, an adaptive telemetry system is required so as to support the diversity of 5G services and their stringent traffic requirements.
The path towards 5G wireless networks also presents a clear trend of carrying out computations close to end users. Indeed, pushing contents, applications, and network functions closer to end users is necessary to cope with the huge data volume and low latency required in future 5G networks. Edge and fog frameworks have emerged recently to address this challenge. Whilst the edge framework was more infrastructure-focused and more mobile operator-oriented, the fog was more pervasive and included any node (stationary or mobile), including terminal devices. By further utilising pervasive computational resources in proximity to users, edge and fog can be merged to construct a computing platform, which can also be used as a common stage for multiple radio access technologies (RATs) to share their information, hence opening a new dimension of multi-RAT integrationTelematics EngineeringUniversidad Carlos III de Madrid, Spainpu
Brief Announcement: Implementing Byzantine Tolerant Distributed Ledger Objects
Get PDFThis work provides a proper formalization for Distributed Ledger Objects (as first defined in \cite{DLO_SIGACT18}), when processes may be Byzantine. The formal definitions are accompanied by algorithms to implement Byzantine Distributed Ledgers by utilizing a Byzantine Atomic Broadcast service.TRUEpu
Automated Deployment of an Internet Protocol Telephony Service on Unmanned Aerial Vehicles Using Network Functions Virtualization
Get PDFThe Network Function Virtualization (NFV) paradigm is one of the key enabling technologies in the development of the 5th generation of mobile networks. This technology aims to lessen the dependence on hardware in the provision of network functions and services by using virtualization techniques that allow the softwarization of those functionalities over an abstraction layer. In this context, there is increasing interest in exploring the potential of unmanned aerial vehicles (UAVs) to offer a flexible platform capable of enabling cost-effective NFV operations over delimited geographic areas.
To demonstrate the practical feasibility of utilizing NFV technologies in UAV platforms, a protocol is presented to set up a functional NFV environment based on open source technologies, in which a set of small UAVs supply the computational resources that support the deployment of moderately complex network services. Then, the protocol details the different steps needed to support the automated deployment of an internet protocol (IP) telephony service over a network of interconnected UAVs, leveraging the capacities of the configured NFV environment. Experimentation results demonstrate the proper operation of the service after its deployment. Although the protocol focuses on a specific type of network service (i.e., IP telephony), the described steps may serve as a general guide to deploy other type of network services. On the other hand, the protocol description considers concrete equipment and software to set up the NFV environment (e.g., specific single board computers and open source software). The utilization of other hardware and software platforms may be feasible, although the specific configuration aspect of the NFV environment and the service deployment may present variations with respect to those described in the protocol.pu
50 Ways to Leak Your Data: An Exploration of Apps’ Circumvention of the Android Permissions System
No full textSmartphones are general-purpose computers that store a great deal of sensitive personal information. Apps are prevented from accessing this information at will through the use of a permission system at the operating-system level. These security mechanisms are reasonable because we carry our smartphones alongside us all day, and they can gain access to our intimate communications and social network, our web browsing history, our location at all times—even if the GPS is disabled. When apps are denied permissions, however, they still have options to cheat the permission system by using side and covert channels. In our research we found a small number of such channels being actively exploited when we tested Google Play Store apps.pu
Hybrid Precoding and Combining for Full-Duplex Millimeter Wave Communication
Get PDFFull-duplex (FD) communication is an enabling technology to increase spectral efficiency. The self-interference (SI) resulting from sharing time and frequency resources between different transceivers in FD mode must, however, be managed. At millimeter wave (mmWave) frequencies, FD communication is different than at sub-6 GHz frequencies, because non conventional MIMO architectures and large antenna arrays are often used. In this paper, we address a major challenge for FD mmWave systems: the design of hybrid precoders and combiners that simultaneously maximize the sum spectral efficiency and cancel the SI in the analog domain, to keep control of the signal level at the input of the analog-to-digital converters (ADCs). The optimal joint design is a very difficult problem, since it involves the optimization of eight precoding/combining matrices with several constraints, some of them non convex. We derive two suboptimal solutions which exhibit near-optimum spectral efficiency and significantly outperform prior work in terms of SI cancelation.TRUEpu
Multimedia Networking Technologies, Protocols, and Architectures
No full texthttps://us.artechhouse.com/Multimedia-Networking-Technologies-Protocols-and-Architectures-P2000.aspxThis practical resource provides a survey on the technologies, protocols, and architectures that are widely used in practice to implement networked multimedia services. The book presents the background and basic concepts behind multimedia networking, and provides a detailed analysis of how multimedia services work, reviewing the diverse network protocols that are of common use to implement them. To guide the explanation of concepts, the book focuses on a representative set of networked multimedia services with proven success and high penetration in the telecommunication market, namely Internet telephony, Video-on-Demand (VoD), and live IP television (IPTV). Contents are presented following a stepwise approach, describing each network protocol in the context of a networked multimedia service and making appropriate references to the protocol as needed in the description of other multimedia services.
This book also contains questions and exercises to provide the reader with insight on the practical application of the explained concepts. Additionally, a laboratory practice is included, based on open-source tools and software, to analyze the operation of an Internet telephony service from a practical perspective, as well as to deploy some of its fundamental components.TRUEpu
Analysis, characterization and optimization of the energy efficiency on softwarized mobile platforms
Get PDFThe upcoming 5th Generation of mobile systems (5G) is about to revolutionize the industry, bringing a new architecture oriented to new vertical markets and services. Due to this, the 5G-PPP has specified a list of Key Performance Indicator (KPI) that 5G systems need to support e.g. increasing the 1000 times higher data volume, 10 to 100 times more connected devices or 10 times lower power consumption. In order to achieve these requirements, it is expected to expand the current deployments using more Points of Attachment (PoA) by increasing their density and by using multiple wireless technologies. This massive deployment strategy triggers a side effect in the energy efficiency though, generating a conflict with the “10 times lower power consumption” KPI. In this context, the research community has proposed novel paradigms to achieve the imposed requirements for 5G systems, being materialized in technologies such as Software Defined Networking (SDN) and Network Function Virtualization (NFV). These new paradigms are the first step to softwarize the mobile network deployments, enabling new degrees of flexibility and reconfigurability of the Radio Access Network (RAN). In this thesis, we first present a detailed analysis and characterization of softwarized mobile networking. We consider software as a basis for the next generation of cellular networks and hence, we analyze and characterize the impact on the energy efficiency of these systems. The first goal of this work is to characterize the available software platforms for Software Defined Radio (SDR), focusing on the two main open source solutions: OAI and srsLTE. As result, we provide a methodology to analyze and characterize the performance of these solutions in terms of CPU usage, network performance, compatibility and extensibility of the software. Once we have understood the expected performance for such platformsc, we study an SDR prototype built with hardware acceleration, that employs a FPGA based platform. This prototype is designed to include energy-awareness capabilites, allowing the system to be reconfigured to minimize the energy footprint when possible. In order to validate our system design, we later present an energy characterization platform that we will employ to experimentally measure the energy consumption of real devices. In our approach, we perform two kind of analysis: at short time scale and large time scale. Thus, to validate our approach in short time scale and the energy framework, we have characterized though numerical analysis the Rate Adaptation (RA) algorithms in IEEE 802.11, and then compare our theoretical results to the obtained ones through experimentation. Next we extend our analysis to the hardware accelerated SDR prototype previously mentioned. Our experimental results show that our system can indeed reduce the energy footprint reconfiguring the system deployment. Then, the time scale of our analysis is elevated and we present Resource-on-Demand (RoD) schemes for ultradense network deployments. This strategy is based on dynamically switch on/off the elements that form the network to reduce the overall energy consumption. Hence, we present a analytic model in two flavors, an exact model that accurately predicts the system behaviour but high computational cost and a simplified one that is lighter in complexity while keeping the accuracy. Our results show that these schemes can effectively enhance the energy efficiency of the deployments and mantaining the Quality of Service (QoS). In order to prove the feasibility of RoD, we present a softwarized platform that follows the SDN paradigm, the OFTEN (Open Flow framework for Traffic Engineering in mobile Networks with energy awareness) framework. Our design is based on OpenFlow with energy-awareness functionalities. Finally, a real prototype of this framework is presented, proving the feasibility of the RoD in real deployments.Telematics EngineeringUniversidad Carlos III de Madrid, Spainpu