Seamless multimedia delivery within a heterogeneous wireless networks environment: are we there yet?

The increasing popularity of live video streaming from mobile devices such as Facebook Live, Instagram Stories, Snapchat, etc. pressurises the network operators to increase the capacity of their networks. However, a simple increase in system capacity will not be enough without considering the provisioning of Quality of Experience (QoE) as the basis for network control, customer loyalty and retention rate and thus increase in network operators revenue. As QoE is gaining strong momentum especially with increasing users’ quality expectations, the focus is now on proposing innovative solutions to enable QoE when delivering video content over heterogeneous wireless networks. In this context, this paper presents an overview of multimedia delivery solutions, identifies the problems and provides a comprehensive classification of related state-of-the-art approaches following three key directions: adaptation, energy efficiency and multipath content delivery. Discussions, challenges and open issues on the seamless multimedia provisioning faced by the current and next generation of wireless networks are also provided

Network reputation-based quality optimization of video delivery in heterogeneous wireless environments

The mass-market adoption of high-end mobile devices and increasing amount of video traffic has led the mobile operators to adopt various solutions to help them cope with the explosion of mobile broadband data traffic, while ensuring high Quality of Service (QoS) levels to their services. Deploying small-cell base stations within the existing macro-cellular networks and offloading traffic from the large macro-cells to the small cells is seen as a promising solution to increase capacity and improve network performance at low cost. Parallel use of diverse technologies is also employed. The result is a heterogeneous network environment (HetNets), part of the next generation network deployments. In this context, this thesis makes a step forward towards the “Always Best Experience” paradigm, which considers mobile users seamlessly roaming in the HetNets environment. Supporting ubiquitous connectivity and enabling very good quality of rich mobile services anywhere and anytime is highly challenging, mostly due to the heterogeneity of the selection criteria, such as: application requirements (e.g., voice, video, data, etc.); different device types and with various capabilities (e.g., smartphones, netbooks, laptops, etc.); multiple overlapping networks using diverse technologies (e.g., Wireless Local Area Networks (IEEE 802.11), Cellular Networks Long Term Evolution (LTE), etc.) and different user preferences. In fact, the mobile users are facing a complex decision when they need to dynamically select the best value network to connect to in order to get the “Always Best Experience”. This thesis presents three major contributions to solve the problem described above: 1) The Location-based Network Prediction mechanism in heterogeneous wireless networks (LNP) provides a shortlist of best available networks to the mobile user based on his location, history record and routing plan; 2) Reputation-oriented Access Network Selection mechanism (RANS) selects the best reputation network from the available networks for the mobile user based on the best trade-off between QoS, energy consumptions and monetary cost. The network reputation is defined based on previous user-network interaction, and consequent user experience with the network. 3) Network Reputation-based Quality Optimization of Video Delivery in heterogeneous networks (NRQOVD) makes use of a reputation mechanism to enhance the video content quality via multipath delivery or delivery adaptation

Seamless Dynamic Adaptive Streaming in LTE/Wi-Fi Integrated Network under Smartphone Resource Constraints

Exploiting both LTE and Wi-Fi links simultaneously enhances the performance of video streaming services in a smartphone. However, it is challenging to achieve seamless and high quality video while saving battery energy and LTE data usage to prolong the usage time of a smartphone. In this paper, we propose REQUEST, a video chunk request policy for Dynamic Adaptive Streaming over HTTP (DASH) in a smartphone, which can utilize both LTE and Wi-Fi. REQUEST enables seamless DASH video streaming with near optimal video quality under given budgets of battery energy and LTE data usage. Through extensive simulation and measurement in a real environment, we demonstrate that REQUEST significantly outperforms other existing schemes in terms of average video bitrate, rebuffering, and resource waste.Peer reviewe

Cross-layer energy-efficient schemes for multimedia content delivery in heterogeneous wireless networks

The wireless communication technology has been developed focusing on fulfilling the demand in various parts of human life. In many real-life cases, this demand directs to most types of commonly-used rich-media applications which – with diverse traffic patterns - often require high quality levels on the devices of wireless network users. Deliveries of applications with different patterns are accomplished using heterogeneous wireless networks using multiple types of wireless network structure simultaneously. Meanwhile, content deliveries with assuring quality involve increased energy consumption on wireless network devices and highly challenge their limited power resources. As a result, many efforts have been invested aiming at high-quality and energy-efficient rich-media content deliveries in the past years. The research work presented in the thesis focuses on developing energy-aware content delivery schemes in heterogeneous wireless networks. This thesis has four major contributions outlined below: 1. An energy-aware mesh router duty cycle management scheme (AOC-MAC) for high-quality video deliveries over wireless mesh networks. AOC-MAC manages the sleep-periods of mesh devices based on link-state communication condition, reducing their energy consumption by extending their sleep-periods. 2. An energy efficient routing algorithm (E-Mesh) for high-quality video deliveries over wireless mesh networks. E-Mesh evolves an innovative energy-aware OLSR-based routing algorithm by taking energy consumption, router position and network load into consideration. 3. An energy-aware multi-flow-based traffic load balancing scheme (eMTCP) for multi-path content delivery over heterogeneous wireless networks. The scheme makes use of the MPTCP protocol at the upper transport layer of network, allowing data streams to be delivered across multiple consequent paths. Meanwhile, this benefit of MPTCP is also balanced with energy consumption awareness by partially off-loading traffic from the paths with higher energy cost to others. 4. A MPTCP-based traffic-characteristic-aware load balancing mechanism (eMTCP-BT) for heterogeneous wireless networks. In eMTCP-BT, mobile applications are categorized according to burstiness level. eMTCP-BT increases the energy efficiency of the application content deliveries by performing a MDP-based distribution of traffic delivery via the available wireless network interfaces and paths based on the traffic burstiness level

스마트폰에서의 다속성 기반 다중 네트워크 운용 최적화 기법 연구

학위논문 (박사)-- 서울대학교 대학원 : 전기·컴퓨터공학부, 2015. 2. 최성현.Todays smartphones integrate multiple radio access technologies (multi-RAT), e.g., 3G, 4G, WiFi, and Bluetooth, etc. Moreover, state-of-the-art smartphones can activate multiple RAT interfaces simultaneously for the parallel transmission. Therefore, it is becoming more important to select the best RAT set among the available RATs, and determine how much data to transfer via each selected RAT network. We propose Energy, Service charge, and Performance Aware (ESPA), an adaptive multi-RAT operation policies for smartphone with supporting system design and multi-attribute cost function for smartphones Internet services including multimedia file transfer and video streaming services. ESPAs cost function incorporates battery energy, data usage quota, and service specific performance, simultaneously. These attributes are motivated by the growing sensitivity of todays smartphone users to these attributes. Each time the individual attributes are calculated and updated, ESPA selects the optimal RAT set that minimizes the overall cost. It can activate only the best one RAT interface or exploit multiple RATs simultaneously. The primary benefit of the ESPA is that it enables the smartphone to always operate in the best mode without the need for users manual controlthe energy saving mode if the remaining battery energy is becoming nearly depletedthe cost-saving mode if the remaining data quota is almost running outor, the performance-oriented mode if remaining data quota and battery energy are both sufficient. From Chapter 2 to Chapter 4, we cope with file transfer, video streaming, and standby mode for our proposed algorithms. The proposed algorithms are based on the service specific cost or utility models, which also take into account practical issues related to user satisfaction metrics. First, for file transfer mode, we apply the transfer completion time as the performance metric, and the energy consumption and service charge for downloading a specific size of file are simultaneously considered. Furthermore, we especially take into account a problem that the computational complexity exponentially increases as the number of available RATs increases. We propose a heuristic linear search algorithm to find the optimal RAT set without significant performance degradation. Secondly, for video streaming mode, we consider the HTTP-based video streaming model exploiting multipath with LTE and WiFi networks. Based on analysis of the energy consumption and data usage for the video streaming services, we propose a multi-RAT based video streaming algorithm that balances between the video quality, i.e., the performance metric, and the total playback time with currently given battery energy and data quota. Finally, we cope with the battery energy leakage issue of the smartphone in the standby mode due to intermittent traffic generated by some applications running on background. We analyze the energy-consuming factors in the standby mode and smartphone usage patterns of multiple users, and then, propose a usage pattern-aware deep sleep operation algorithm to save the battery energy in the standby mode. Simulation results based on real measurement data of the smartphone show that the ESPA algorithms indeed choose the best operational mode by maintaining dynamic balance among the performance, energy consumption, and service charge considering the currently provided services and the remaining resources.Abstract i Contents iv List of Tables vii List of Figures viii 1 Introduction 1 1.1 Energy, Service Charge, and Performance aware Multi-RAT Operation Policies for Smartphone 1.2 Overview of Existing Approaches 1.2.1 Multi-attribute based network selection 1.2.2 Energy and quota-aware video streaming services 1.2.3 Multi-path based approaches 1.3 Main Contributions 1.3.1 File transfer mode 1.3.2 Video streaming mode 1.3.3 Standby mode 1.4 Organization of the Dissertation 2 File Transfer Mode 2.1 Introduction 2.2 System Model 2.3 Problem Formulation 2.3.1 T-E-Q cost modeling 2.3.2 Optimization problem 2.4 Numerical Analysis 2.5 Proposed Algorithm 2.5.1 Bi-directional linear search algorithm 2.5.2 Dynamic update algorithm 2.6 Performance Evaluation 2.7 Summary 3 Video Streaming Mode 3.1 Introduction 3.2 System Model 3.2.1 HTTP-based playback model 3.2.2 LTE/WiFi-based multipath video streaming model 3.3 Chunk Download Cycle based Analysis 3.3.1 Data and energy consumption rate 3.3.2 Expected waste of data and energy 3.4 Proposed Scheme 3.4.1 Problem formulation 3.4.2 Subproblem I: Playback time maximization 3.4.3 Subproblem II: Balancing between encoding rate and total playback time 3.5 Performance Evaluation 3.5.1 Maximization of playback time with a single path 3.5.2 Balancing between video quality and playback time with LTE/WiFi multiple networks 3.6 Summary 4 Standby Mode 4.1 Introduction 4.2 Standby Mode Power Anatomy of Smartphones 4.2.1 Low power mode operation 4.2.2 Power consumption for background traffic 4.2.3 WiFi MAC overhead issue 4.3 Usage Log-based Idle Duration Analysis 4.3.1 User-specific daily distribution of idle duration 4.3.2 All-day distribution 4.3.3 Activity/inactivity time separation 4.4 Proposed Algorithm 4.4.1 Learning phase 4.4.2 Deep Sleep Mode (DSM) operation 4.5 Performance Evaluation 4.5.1 Performance comparison 4.5.2 Effect of Tonoff 4.6 Summary 5 Conclusion 5.1 Concluding Remarks Abstract (In Korean)Docto

Exploiting the power of multiplicity: a holistic survey of network-layer multipath

The Internet is inherently a multipath network: For an underlying network with only a single path, connecting various nodes would have been debilitatingly fragile. Unfortunately, traditional Internet technologies have been designed around the restrictive assumption of a single working path between a source and a destination. The lack of native multipath support constrains network performance even as the underlying network is richly connected and has redundant multiple paths. Computer networks can exploit the power of multiplicity, through which a diverse collection of paths is resource pooled as a single resource, to unlock the inherent redundancy of the Internet. This opens up a new vista of opportunities, promising increased throughput (through concurrent usage of multiple paths) and increased reliability and fault tolerance (through the use of multiple paths in backup/redundant arrangements). There are many emerging trends in networking that signify that the Internet's future will be multipath, including the use of multipath technology in data center computing; the ready availability of multiple heterogeneous radio interfaces in wireless (such as Wi-Fi and cellular) in wireless devices; ubiquity of mobile devices that are multihomed with heterogeneous access networks; and the development and standardization of multipath transport protocols such as multipath TCP. The aim of this paper is to provide a comprehensive survey of the literature on network-layer multipath solutions. We will present a detailed investigation of two important design issues, namely, the control plane problem of how to compute and select the routes and the data plane problem of how to split the flow on the computed paths. The main contribution of this paper is a systematic articulation of the main design issues in network-layer multipath routing along with a broad-ranging survey of the vast literature on network-layer multipathing. We also highlight open issues and identify directions for future work

Situation-aware Edge Computing

Future wireless networks must cope with an increasing amount of data that needs to be transmitted to or from mobile devices. Furthermore, novel applications, e.g., augmented reality games or autonomous driving, require low latency and high bandwidth at the same time. To address these challenges, the paradigm of edge computing has been proposed. It brings computing closer to the users and takes advantage of the capabilities of telecommunication infrastructures, e.g., cellular base stations or wireless access points, but also of end user devices such as smartphones, wearables, and embedded systems. However, edge computing introduces its own challenges, e.g., economic and business-related questions or device mobility. Being aware of the current situation, i.e., the domain-specific interpretation of environmental information, makes it possible to develop approaches targeting these challenges. In this thesis, the novel concept of situation-aware edge computing is presented. It is divided into three areas: situation-aware infrastructure edge computing, situation-aware device edge computing, and situation-aware embedded edge computing. Therefore, the concepts of situation and situation-awareness are introduced. Furthermore, challenges are identified for each area, and corresponding solutions are presented. In the area of situation-aware infrastructure edge computing, economic and business-related challenges are addressed, since companies offering services and infrastructure edge computing facilities have to find agreements regarding the prices for allowing others to use them. In the area of situation-aware device edge computing, the main challenge is to find suitable nodes that can execute a service and to predict a node’s connection in the near future. Finally, to enable situation-aware embedded edge computing, two novel programming and data analysis approaches are presented that allow programmers to develop situation-aware applications. To show the feasibility, applicability, and importance of situation-aware edge computing, two case studies are presented. The first case study shows how situation-aware edge computing can provide services for emergency response applications, while the second case study presents an approach where network transitions can be implemented in a situation-aware manner