scispace - formally typeset
Search or ask a question

Showing papers by "Deutsche Telekom published in 2018"


Proceedings ArticleDOI
12 Jun 2018
TL;DR: This paper describes an open dataset and software for ITU-T Ree, the first standardized Quality of Experience model for audiovisual HTTP Adaptive Streaming, and shows the significant performance improvements of using bitstream-based models over metadata-based ones for video quality analysis, and the robustness of combining classical models with machine-learning-based approaches for estimating user QoE.
Abstract: This paper describes an open dataset and software for ITU-T Ree. P.1203. As the first standardized Quality of Experience model for audiovisual HTTP Adaptive Streaming (HAS), it has been extensively trained and validated on over a thousand audiovisual sequences containing HAS-typical effects (such as stalling, coding artifacts, quality switches). Our dataset comprises four of the 30 official subjective databases at a bitstream feature level. The paper also includes subjective results and the model performance. Our software for the standard was made available to the public, too, and it is used for all the analyses presented. Among other previously unpublished details, we show the significant performance improvements of using bitstream-based models over metadata-based ones for video quality analysis, and the robustness of combining classical models with machine-learning-based approaches for estimating user QoE.

95 citations


Proceedings ArticleDOI
12 Jun 2018
TL;DR: In this article, the performance of objective video quality assessment metrics for gaming videos considering passive streaming applications is evaluated on a dataset of 24 reference videos and 576 compressed sequences obtained by encoding them at 24 different resolution-bitrate pairs.
Abstract: Video Quality assessment is imperative to estimate and hence manage the Quality of Experience (QoE) in video streaming applications to the end-user. Recent years have seen a tremendous advancement in the field of objective video quality assessment (VQA) metrics, with the development of models that can predict the quality of the videos streamed over the Internet. However, no work so far has attempted to study the performance of such quality assessment metrics on gaming videos, which are artificial and synthetic and have different streaming requirements than traditionally streamed videos. Towards this end, we present in this paper a study of the performance of objective quality assessment metrics for gaming videos considering passive streaming applications. Objective quality assessment considering eight widely used VQA metrics is performed on a dataset of 24 reference videos and 576 compressed sequences obtained by encoding them at 24 different resolution-bitrate pairs. We present an evaluation of the performance behavior of the VQA metrics. Our results indicate that VMAF predicts subjective video quality ratings the best, while NIQE turns out to be a promising alternative as a no-reference metric in some scenarios.

52 citations


Proceedings ArticleDOI
01 Jul 2018
TL;DR: This contribution highlights the perspectives of wideband communication systems for optical networks, providing a realistic roadmap for their deployment and a first analysis to estimate the maximum transmittable capacity over these systems.
Abstract: Optical wideband communication systems aim at transmitting over several, if not all, of the low-loss windows of single-mode fibre, i.e. the O-, E-, S-, C-, and L-band. Recently, there has been a clear trend in the industry to support additional bands beyond C-band. While C+L-band solutions are close to commercialization and first products are emerging, the research focus is shifting to supporting also the S-band and, finally, the whole O- to L-band (resulting in a total transmission bandwidth of 365 nm). This contribution highlights the perspectives of wideband communication systems for optical networks, providing a realistic roadmap for their deployment. Particular emphasis is paid on a first analysis to estimate the maximum transmittable capacity over these systems.

34 citations


Journal ArticleDOI
TL;DR: The evaluation results show that the SR yields close to optimal results while still being deployable with reasonable effort, and the existing SR formulations are extended to consider requirements from network operation and management.
Abstract: Internet Service Providers are challenged by increasing traffic demands Advanced Traffic Engineering (TE) is one way to overcome this challenge Segment Routing (SR) is a relatively new approach for TE To decide whether SR is a good approach for deployment in carrier IP backbone networks, it has to show its benefits in real-world scenarios and still needs to be feasible from the network operation and management point of view In this paper, we analyze traffic data from a European tier one backbone network from 2011 to 2015 The total traffic increases significantly throughout that period We analyze geographic differences to select representative traffic peak times as reference scenarios for an evaluation of TE using SR for real-world topologies and traffic demands Finally, we extend the existing SR formulations to consider requirements from network operation and management Our evaluation results show that the SR yields close to optimal results while still being deployable with reasonable effort

30 citations


Journal ArticleDOI
TL;DR: The testbed proves in a real, large-scale industrial environment that basic features of network slicing, namely slice isolation, flexible slice customization, and multitenancy, are already technically feasible and key for the interaction between mobile service provider and tenants of the network.
Abstract: Driven by a massive surge in digitization and customization, so-called vertical industries are expected to be a major beneficiary of the 5G of mobile networks. The use cases of such vertical industries define qualitative and quantitative requirements unprecedented in the history of mobile network development. Autonomous vehicles, traffic light control, video surveillance, and IIoT, to only name a few, introduce challenging requirements regarding both conventional performance metrics, such as throughput and coverage, as well as formerly rather subordinate system metrics, such as deterministic latency, ultra-high reliability and resilience, high number of devices, multi-tenant networks, and demanding security mechanisms. Nokia, Deutsche Telekom, and Hamburg Port Authority have deployed a largescale 5G trial testbed in the Hamburg port area. The testbed proves in a real, large-scale industrial environment that basic features of network slicing, namely slice isolation, flexible slice customization, and multitenancy, are already technically feasible. Three exemplary communication services have been selected and are demonstrated in the testbed. Multi-connectivity is implemented as a key component to achieve high reliability throughout the testbed area. The testbed shows that all network domains must be involved in the setup of network slices, that is, user terminals, radio access, core network, and enterprise networks, in order to efficiently operate and manage network slices. Therefore, the discussed life cycle management is key for the interaction between mobile service provider and tenants of the network.

25 citations


Proceedings ArticleDOI
15 Apr 2018
TL;DR: The concept of resource elasticity as a key means to make an efficient use of the computational resources in 5G systems is introduced and a succinct analysis of the architectural components that need to be enhanced to incorporate elasticity principles is provided.
Abstract: Vertical markets and industries are addressing a large diversity of heterogeneous services, use cases, and applications in 5G. It is currently common understanding that for networks to be able to satisfy those needs, a flexible, adaptable, and programmable architecture based on network slicing is required. Moreover, a softwarization and cloudification of the communications networks is already happening, where network functions (NFs) are transformed from monolithic pieces of equipment to programs running over a shared pool of computational and communication resources. However, this novel architecture paradigm requires new solutions to exploit its inherent flexibility. In this paper, we introduce the concept of resource elasticity as a key means to make an efficient use of the computational resources in 5G systems. Besides establishing a definition as well as a set of requirements and key performance indicators (KPIs), we propose mechanisms for the exploitation of elasticity in three different dimensions, namely computational elasticity in the design and scaling of NFs, orchestration-driven elasticity by flexible placement of NFs, and slice-aware elasticity via cross-slice resource provisioning mechanisms. Finally, we provide a succinct analysis of the architectural components that need to be enhanced to incorporate elasticity principles.

25 citations


Proceedings ArticleDOI
07 May 2018
TL;DR: It is shown that caching for video streaming can benefit from the proposed look-ahead technique, when replacement decisions can be partly revised due to new requests being encountered during long lasting content updates.
Abstract: We compare web caching strategies based on the least recently used (LRU) and the least frequently used (LFU) replacement principles with optimum caching according to Belady's algorithm. The achievable hit rates of the strategies are shown to improve with the exploited knowledge about the request pattern while the computation effort is also increasing. The results give an overview of performance tradeoffs in the whole relevant range for web caching with Zipf request pattern. In a second part, we study a combined approach of the optimum strategy for a limited look-ahead with LRU, LFU or other non-predictive methods. We evaluate the hit rate gain depending on the extent of the look-ahead for request traces and for the independent reference model (IRM) via simulation and derive an analytic confirmation of the observed behaviour. It is shown that caching for video streaming can benefit from the proposed look-ahead technique, when replacement decisions can be partly revised due to new requests being encountered during long lasting content updates.

24 citations


Proceedings ArticleDOI
01 Sep 2018
TL;DR: In this article, a 5G system architecture for the factory of the future is proposed based on the use cases and the ones by 3GPP, which is set in relation to existing architectural frameworks.
Abstract: Factory automation and production are currently undergoing massive changes, and 5G is considered being a key enabler. In this paper, we state uses cases for using 5G in the factory of the future, which are motivated by actual needs of the industry partners of the “5Gang” consortium. Based on these use cases and the ones by 3GPP, a 5G system architecture for the factory of the future is proposed. It is set in relation to existing architectural frameworks.

24 citations


Journal ArticleDOI
TL;DR: In this paper, the authors address the complexity and dynamism of 5G and the wide-ranging socio-economic impact that its adoption and roll-out will have on the telecommunications industry.

20 citations


Journal ArticleDOI
TL;DR: The results of techno-economic assessment are shown and the structural convergence gain when applying a common transport platform in a FTTH and small-cell roll-out scenario are quantified.
Abstract: Carriers face the challenge of integrating their fixed and mobile infrastructures. In this paper we show the results of techno-economic assessment and quantify the structural convergence gain when applying a common transport platform in a FTTH and small-cell roll-out scenario. Furthermore, we discuss functional convergence, dealing with fixed mobile convergence architectures that are aimed at the combination of previously separated fixed and mobile networking functions such as authentication and data path management.

14 citations


Proceedings ArticleDOI
01 Jan 2018
TL;DR: This work demonstrates for the first time a practical deployment of Random Linear Network Coding with NFV and SDN technologies to improve video quality against packet loss due to congestion at the core network and signal impairment of lossy channels at network edges.
Abstract: The 5G communication system will provide flexible and programmable networks by leveraging softwarization technologies such as NFV and SDN. That advanced feature of 5G networks will be demonstrated in the context of real-time video surveillance for public safety. Specifically, we demonstrate for the first time a practical deployment of Random Linear Network Coding (RLNC) with NFV and SDN technologies to improve video quality against packet loss due to congestion at the core network and signal impairment of lossy channels at network edges. The demonstration implements NFV and SDN applications on COTS devices to prove its flexibility and portability.

Proceedings ArticleDOI
01 Dec 2018
TL;DR: This paper presents an optimization problem to find a rate allocation for the paths that minimizes the interruptions of the stream and uses an FEC code to generate redundant data to compensate for the loss of capacity in individual paths.
Abstract: Many envisioned applications for the Tactile Internet require latencies that cannot be achieved by current wireless networks. In this paper, we present a method to optimize the reliability of a live stream using multiple paths. Compared to other approaches, our method does not rely on feedback to achieve the reliability and thus does not add delay for retransmission attempts. We use the diversity of multiple paths to compensate for the loss of capacity in individual paths. By using an FEC code to generate redundant data the transmission is more robust against fluctuations in capacity of single paths. We present an optimization problem to find a rate allocation for the paths that minimizes the interruptions of the stream. The performance is evaluated in an emulated network based on real-world measurements. The evaluation shows that the theoretical values can be achieved with a small margin. The optimized allocation of rates to the paths increases the reliability by up to 12%. With coding the reliability can be increased by up to 20%, depending on the code rate.

Proceedings ArticleDOI
23 Apr 2018
TL;DR: The in- depth architecture, implementation and experiment on a multi­domain orchestration framework that is able to deploy such multi-operator service as well as monitor the service for SLA compliance are presented.
Abstract: Supporting end-to-end network slices and services across operators has become an important use case of study for 5G networks as can be seen by 5G use cases published in 3GPP, ETSI as well as NGMN. This paper presents the in- depth architecture, implementation and experiment on a multi­domain orchestration framework that is ab le to deploy such multi-operator service as well as monitor the service for SLA compliance. Our implemented architecture allows operators to abstract their sensitive details while exposing the relevant amount of information to support inter-operator slice creation. Our experiment shows that the implemented framework is capable of creating services across operators while fulfilling the respective service requirements.

Posted Content
TL;DR: The competition for space between two cell lines that differ only in the expression of the Ras oncogene is studied, and the transformed cell population with larger collective stresses pushes the wild type cell population.
Abstract: We study the competition for space between two cell lines that differ only in the expression of the Ras oncogene. The two cell populations are initially separated and set to migrate antagonistically towards an in-between stripe of free substrate. After contact, their interface moves towards the population of normal cells. We interpret the velocity and traction force data taken before and after contact thanks to a hydrodynamic description of collectively migrating cohesive cell sheets. The kinematics of cells, before and after contact, allows us to estimate the relative material parameters for both cell lines. As predicted by the model, the transformed cell population with larger collective stresses pushes the wild type cell population.

Patent
31 May 2018
TL;DR: A radio communication network includes: a radio scheduler, configured to schedule radio resources of the at least one logical network based on a scheduling strategy; a monitoring entity, configurable to monitor performance information from the at most one logical networks; and a controller, configuring a controller to determine an SLA metric for each logical network of a plurality of logical networks based on the monitored performance information as discussed by the authors.
Abstract: A radio communication network includes: a network orchestration entity, configured to orchestrate a plurality of network resources to set up at least one logical network of a plurality of logical networks based on a logical network-specific service level agreement (SLA); a radio scheduler, configured to schedule radio resources of the at least one logical network based on a scheduling strategy; a monitoring entity, configured to monitor performance information from the at least one logical network; and a controller, configured to: determine an SLA metric for the at least one logical network based on the monitored performance information from the at least one logical network; detect a threshold violation of the SLA metric with respect to a set of thresholds associated with the at least one logical network; and adjust the scheduling strategy based on the detected threshold violation.

Proceedings ArticleDOI
01 May 2018
TL;DR: This paper studies the impact of download speeds on Key Performance Indicators (KPIs such as initial loading time and stalling events) and user QoE as measured using the ITU-T P.1203 standard, and provides a prediction model for estimating theimpact of download speed on KPIs and userQoE.
Abstract: The available Internet bandwidth has a strong impact on the Quality of Experience of video services In order to manage their network efficiently and prevent customer churn, Internet Service Providers need to constantly monitor the QoE of video services such as YouTube However, they often only rely on simple measurement scenarios that consider only one video being loaded repeatedly In this paper we compare this scenario against a new approach in which multiple videos are being loaded in a session, thereby simulating user behavior Using a testbed, we study the impact of download speeds on Key Performance Indicators (KPIs such as initial loading time and stalling events) and user QoE as measured using the ITU-T P1203 standard We show that the monitoring paradigm has a significant impact on the obtained results We further provide a prediction model for estimating the impact of download speed on KPIs and user QoE

Proceedings ArticleDOI
01 Dec 2018
TL;DR: This paper presents a massive content distribution protocol that combines the benefits of cooperative mobile clouds (CMCs) with Random Linear Network Coding (RLNC) through multicast WiFi links and solves the problem of excessive signaling that oftentimes arises in cooperative approaches by eliminating feedback messages within the CMCs.
Abstract: Massive content delivery in cellular networks is in the spotlight of the research community as data traffic is increasing at an incredibly fast pace. The existing LTE-A implementation for content broadcast presents several issues such as indoor coverage, along with low energy and spectral efficiency. Therefore, novel systems that provide efficient massive content delivery and reduced energy consumption are needed. In this paper we present a massive content distribution protocol that combines the benefits of cooperative mobile clouds (CMCs) with Random Linear Network Coding (RLNC) through multicast WiFi links. Our main goal is to offload data traffic from the LTE-A link and to reduce the energy consumption at the cooperating UEs. We solve the problem of excessive signaling that oftentimes arises in cooperative approaches by eliminating feedback messages within the CMCs. Instead, we provide a simple but accurate analytic model to correctly configure the number of coded transmissions to be performed within the CMCs. Results show that energy savings of more than 37 percent can be achieved with our protocol when compared to direct content download from the cellular base station. Furthermore, bandwidth utilization at the LTE-A link is sharply reduced.

Patent
20 Dec 2018
TL;DR: In this article, the authors proposed a method and architecture for an improved and simplified operation of a central office point of delivery and/or for the establishment of a service path within the central office PO, especially involving a stateless central office POD configuration, within a broadband access network of a telecommunications network.
Abstract: The invention relates to a method and architecture for an improved and simplified operation of a central office point of delivery and/or for the establishment of a service path within the central office point of delivery, especially involving a stateless central office point of delivery configuration, within a broadband access network of a telecommunications network, wherein the central office point of delivery and/or the broadband access network comprises a controller node, at least one repository node and a plurality of line termination nodes, wherein a specific line termination node of the plurality of line termination nodes is connectable - using an access node port of the specific line termination node - to one specific network termination node of a plurality of network termination nodes, wherein the broadband access network or the central office point of delivery comprises a plurality of service edge nodes, wherein - upon activation of the specific network termination node, being connected to the specific line termination node - the service path is set up or is established within or traversing the central office point of delivery, wherein the method to set up or to establish the service path comprises the following steps: ~ in a first step, an identity information of the specific network termination node is transmitted to the specific line termination node, - in a second step, subsequent to the first step, the identity information of the specific network termination node is transmitted to the repository node, - in a third step, subsequent to the second step, a specific service edge node of the plurality of service edge nodes is selected or determined, based on the identity information of the specific network termination node, and thereby the service path for the specific network termination node being established.

Proceedings ArticleDOI
01 Aug 2018
TL;DR: The aim is to estimate the increase of the path lengths and the increase in cost of the required transponders, with respect to simple link disjointness (no-SRLG nor geodiversity constraints) in a fully transparent optical network.
Abstract: The problem of disaster resilience is of paramount importance in today’s telecommunication networks. Here, this problem is tackled by considering 1+1 optical lightpath protection with maximally SRLG-disjoint paths and geodiversity in a transparent backbone network. Geodiversity was added to make the network more resilient to geographically correlated disasters. The aim is to estimate the increase of the path lengths (fibre lengths) and the increase in cost of the required transponders, with respect to simple link disjointness (no-SRLG nor geodiversity constraints) in a fully transparent optical network. The results obtained in a realistic test network show that SRLG-disjointness already ensures an acceptable geodiversity for the considered network.

Proceedings ArticleDOI
01 Feb 2018
TL;DR: A novel approach for preserving privacy in IDaaS is presented by combining Purpose Based Access Control and Attribute-based Encryption with multi-authorities support, suitable for sharing sensitive user information in a large distributed and heterogeneous environment.
Abstract: In Federated Identity Management, providers from different security domains exchange messages containing authentication and authorisation credentials of users. As a result, a user can use his Personal Identifiable Information (PII) from one or more Identity Providers to gain access to other sites. Disseminating PII over intermediaries also requires protecting PII from being misused and unauthorised access. Identity-as-a- Service (IDaaS) provides a federated identity for users to access multiple Cloud services on demand but may preserve user privacy. In this paper, we present a novel approach for preserving privacy in IDaaS by combining Purpose Based Access Control and Attribute-based Encryption with multi-authorities support. Our approach is suitable for sharing sensitive user information in a large distributed and heterogeneous environment.

Proceedings ArticleDOI
01 Aug 2018
TL;DR: This paper presents an exemplary implementation and initial evaluation results of a corresponding interface between DU and CU for an emulation of 5G New Radio based bandwidth part adaptation and related physical layer processing time monitoring in LTE eNBs.
Abstract: Network function virtualization (NFV) and cloud based radio access network (C-RAN) architecture concepts constitute an essential foundation of the 5G mobile radio network design. Especially the envisioned splitting of RAN functionality into distributed units (DUs) at base station sites and centralized units (CUs) running in a centralized cloud offer significant advantages regarding energy efficiency, computational elasticity and cost reduction for mobile network operators (MNOs). This paper presents an exemplary implementation and initial evaluation results of a corresponding interface between DU and CU for an emulation of 5G New Radio (NR) based bandwidth part adaptation and related physical layer processing time monitoring in LTE eNBs. Such an interface will facilitate computational elasticity by means of processing time aware transmission parameter adaptation. The implementation is an extension of the FlexRAN framework for OpenAirInterface.

Proceedings ArticleDOI
01 Sep 2018
TL;DR: This work evaluates the implementation complexity and runtime performance of LRU, Least Frequently Used (LFU), and score based strategies in the class of fast $O(1)$ updates with constant effort per request, and implements Window LFU (W-LFU) within this class and shows that$O( 1)$ update effort can be achieved.
Abstract: To be applicable to high user request workloads, web caching strategies benefit from low implementation and update effort. In this regard, the Least Recently Used (LRU) replacement principle is a simple and widely-used method. Despite its popularity, LRU has deficits in the achieved hit rate performance and cannot consider transport and network optimization criteria for selecting content to be cached. As a result, many alternatives have been proposed in the literature, which improve the cache performance at the cost of higher complexity.In this work, we evaluate the implementation complexity and runtime performance of LRU, Least Frequently Used (LFU), and score based strategies in the class of fast $O(1)$ updates with constant effort per request. We implement Window LFU (W-LFU) within this class and show that $O(1)$ update effort can be achieved. We further compare fast update schemes of Score Gated LRU and new Score Gated Polling (SGP). SGP is simpler than LRU and provides full flexibility for arbitrary score assessment per data object as information basis for performance optimization regarding network cost and quality measures.

Proceedings ArticleDOI
01 Oct 2018
TL;DR: This paper concludes that metrics do in fact play a role in SR optimization, and already push SR close to the optimum with respect to the most common traffic engineering objective of minimizing maximum utilization.
Abstract: Segment Routing (SR) based traffic engineering can be used to avoid network congestion effectively. Most research about SR considers the routing metric as a given constant. The metric defines shortest paths. As shortest paths are essential building blocks of SR paths, the metrics heavily influence SR. In this paper, we evaluate this influence thoroughly using data from a tier one Internet Service Provider (ISP) backbone, as well as other, publicly available topologies. We conclude that metrics do in fact play a role in SR optimization. Simple metrics, however, already push SR close to the optimum with respect to the most common traffic engineering objective of minimizing maximum utilization.

Proceedings ArticleDOI
29 Sep 2018
TL;DR: A smart plant system that notifies the users when the plant needs water as an exemplary smart home application for the usage in in-situ studies and studies the user experience of different strategies and locations to display non-urgent smart home notifications.
Abstract: The present work is a demonstration of a smart plant system that monitors the current water level of a plant. Since related work showed that users are already overwhelmed by notifications in their daily lives, how to design smart home applications that use notifications is an important research question. To study how users experience non-urgent smart home notifications in their daily lives, we decided to use a smart plant system that notifies the users when the plant needs water as an exemplary smart home application. We developed a fully functional smart plant system for the usage in in-situ studies. Our smart plant system can notify the users either using an integrated ambient display in the plant pot or by sending notifications to the users' smartphones. Using these prototypes, we study the user experience of different strategies and locations to display non-urgent smart home notifications.

Proceedings ArticleDOI
01 Oct 2018
TL;DR: A measurement campaign is performed to study the delay introduced by Service Function Chaining, a proposed placement heuristics are proposed and the performance on OpenStack is evaluated.
Abstract: Service Function Chaining allows the flexible and efficient deployment of network functions for different applications. With Network Function Virtualization the elements of the chain can be provisioned in virtual environments on any COTS hardware. This introduces the question of where to position the individual network functions within the virtualization environment. This problem of network function placement has been studied in theory as an optimization problem on a graph. However it is challenging to apply theoretical work on practical deployments. In this paper, we perform a measurement campaign to study the delay introduced by Service Function Chaining. We propose placement heuristics and evaluate the performance on OpenStack. With the proposed heuristics, the service delay can be reduced by more than 20%. We measured the overhead introduced by a network function implemented in user space. The processing delay in user space can be twice as much as the same function in kernel space. More interestingly, we identified a service interruption of more than 1 second after activation of the chain.

Proceedings ArticleDOI
14 Oct 2018
TL;DR: A novel concept for automated refactoring of architecture models in order to meet such requirements by formalizing architectural knowledge using model verification and model transformations is proposed.
Abstract: In the process of software-intensive systems engineering, architectures need to be designed that are compliant to the requirements. For this, architects need to examine those requirements with regard to their architectural impact. Accessing and interpreting the requirements is however not always possible, for instance if custom requirements are yet unknown at the time when the architecture is modeled. Ideally, architectural knowledge as derived from custom requirements could be imposed upon architecture models. This paper proposes a novel concept for automated refactoring of architecture models in order to meet such requirements by formalizing architectural knowledge using model verification and model transformations. Industrial application within a telecommunications service provider is demonstrated in the domain of cloud application orchestration: service providers are enabled to autonomously customize solutions predefined by vendors according to their own internal requirements.

Book ChapterDOI
19 Sep 2018
TL;DR: This paper proposes a method to improve conventional RLNC protocols by making them be able to manage multiple generations simultaneously, and concludes that multigeneration protocols have better behavior in terms of throughput and resilience, but the average latency per packet decoded is higher.
Abstract: In the upcoming era of 5G, the number of devices will increase massively, defining a heterogeneous wireless network. Nodes will be gathered in Mobile Clouds, and communicate between peers to achieve a general benefit. To provide packet resilience, error correction codes will be used. In particular, Random Linear Network Coding is standing out as one of the most successful ones. The interplay between Network Coding and Mobile Clouds creates a mesh network where nodes may receive information from multiple sources. However, RLNC was optimized to provide in-order-delay in D2D communications. RLNC need to adapt to a new heterogeneous mesh network where nodes receive packets from multiple paths. In this paper, we propose a method to improve conventional RLNC protocols by making them be able to manage multiple generations simultaneously. We also identify possible trade-offs between conventional RLNC protocols and our new approach. We conclude that multigeneration protocols have better behavior in terms of throughput and resilience, but the average latency per packet decoded is higher.

Book ChapterDOI
26 Feb 2018
TL;DR: This work designs a Markov state model to analyze and evaluate the hit rate of clairvoyant optimum caching, and defines a strategy for updating cache content in order to achieve the optimum hit rate.
Abstract: Belady’s algorithm defines a strategy for updating cache content in order to achieve the optimum hit rate, based on full information being available about future requests. In this work, we design a Markov state model to analyze and evaluate the hit rate of clairvoyant optimum caching.

Book ChapterDOI
19 Sep 2018
TL;DR: The leading technologies that enable the system to efficiently disseminate data over cellular networks are collected, analyzed and compared, and a race for the control of cellular multicast/broadcast has started by indicating which ones are the most likely to succeed.
Abstract: Cellular networks are undergoing a major shift in their deployment and optimization. Regardless the deployment of LTE led to an overall performance increase in cellular networks, disseminating data to multiple users inside a cell is still under development. This dissemination is currently achieved via unicast connections, which is inefficient in terms of throughput and power consumption because the antenna is sending duplicated data to co-located users. The 3rd Generation Partnership Project (3GPP) proposed a new standard to be able to multicast and broadcast information over cellular networks. However, different studies stated that this solution might have problems related to the spectrum, and new multicasting alternatives which provide better performance have appeared. Since these new alternatives came up, a race for the control of cellular multicast/broadcast has started. In this paper, we collect, analyze and compare the leading technologies that enable the system to efficiently disseminate data over cellular networks, and conclude by indicating which ones are the most likely to succeed.

Proceedings ArticleDOI
01 Nov 2018
TL;DR: This work proposes an adaptive decoding process that alters among Galois fields to decode, which significantly reduces the computation complexity at end devices while simultaneously maintaining a high decoding probability.
Abstract: Fulcrum codes, a variant of random linear network coding (RLNC), especially designed for heterogeneous environment. A Fulcrum encoder combines two codes operating on both small, such as binary and big, such as 28 Galois fields. That allows the Fulcrum decoder to operate on either the smaller or greater field size, depending on whether it has a moderate or stronger computing power. However, setting on one particular Galois field is inefficient for end devices, especially in broadcasting scenarios when feedback to senders is normally impractical. We propose an adaptive decoding process that alters among Galois fields to decode. Our comprehensive evaluation shows that the proposed adaptive decoding significantly reduces the computation complexity at end devices while simultaneously maintaining a high decoding probability.