Routing and Capacity Optimization Based on Estimated Latent OD Traffic Demand

Telemedicine has been introduced as a new and effective method in dealing with public health challenges, improving access to health care, and reducing healthcare costs in today's world. In order to solve the problems of a single access network and the unknown network status of the telemedicine system in complex environments, a multi-link aggregation algorithm based on link priority (MLA-LP) was proposed. Firstly, the network parameters, such as packet loss rate (PLR) and round-trip time (RTT), of each link were obtained, and then MLA-LP was realized by using the congestion control algorithm based on sender and the traffic allocation algorithm based on link priority. Finally, the MLA-LP algorithm was tested on the test platform based on HoloWAN 1200 network simulator. The comparison algorithm was the multilink aggregation algorithm based on the weightedround-robin algorithm (MLA-WRR). MLA-LP algorithm has higher uplink throughput than MLA-WRR under the same link PLR and delay. When the link is suddenly abnormal (burst packet loss, delay, etc.), the MLA-LP algorithm could quickly avoid the abnormal link and transfer traffic within 2 s; In the mobile scenario, compared with a single network and MLA-WRR algorithm, MLA-LP algorithm has the best video transmission effect, with an average delay of 136 ms, an average bit rate of 2.31 Mbps, an average PLR of 0.04%, and video jamming times close to 0. The MLA-LP algorithm could effectively aggregate link bandwidth and quickly avoid abnormal links, ensuring the robustness of the access network.In order to solve the problems of a single access network and the unknown network status of telemedicine system in complex environment, a MLA-LP was proposed. MLA-LP algorithm has higher uplink throughput and could quickly avoid the abnormal link and transfer traffic within 2 s, ensuring the robustness of the access network.

Multimedia applications have expanded and resulted in huge demands for high resolution videos in order to enhance the end user Quality of Experience (QoE). Therefore, QoE becomes a critical factor that is often addressed in design considerations of Consumer Electronics (CE) devices. Furthermore, error prone transmission conditions can influence the QoE, potentially degrading the end-user multimedia experience. Although video coding standards such as Versatile Video Coding (VVC) take potential mitigation measures to improve the bandwidth reductions, it fails to address other significant network Quality of Service (QoS) parameters that impact transmission based QoE such as transmission delay and Packet Loss Rate (PLR) in the encoding processes. In response, this paper first derives a relationship between QoE that addresses the network QoS parameters and VVC dependent parameters. Subsequently, the derived QoE model is used with the VVC encoding process to adaptively optimize Lagrange parameters as well as the quantization parameter. Extensive experiments report significant improvements to VVC Test Model (VTM) 7.0, achieving superior QoE gains over the state-of-the-art research and up to 3.41% over the anchor implementations.

Recently, with the spread of smart devices and the development of networks, the demand for video streaming has increased, and HTTP adaptive streaming has been gaining attention. HTTP adaptive streaming can guarantee QoE (Quality of Experience) because it selects the video quality according to the network state. However, in wireless networks, delay and packet loss rates are high and the available bandwidth fluctuates sharply. Therefore, QoE is degraded when the quality is selected on the basis of the measured bandwidth. In this paper, we propose an adaptive quality control scheme to improve QoE of video streaming in wireless networks. The proposed scheme calculates two factors, the buffer underflow probability and the instability, by considering the buffer state and the changes of quality level. Using these factors, the proposed scheme defines a quality control region that consists of four sub-regions. The video quality is determined by applying different control strategy to each sub-region. The results of experiments have shown that the proposed scheme improves QoE compared to the existing quality control schemes by minimizing the buffer underflow and the unnecessary quality changes and maximizing the average video quality.

In order to reduce computational complexity and transmission delay in the cooperative transmission system based on digital fountain codes, the paper proposes the cooperative communication scheme based on a distributed Raptor codes .The throughput is treated as the parametric analysis of the system complexity and the link packet loss rate is looked as parametric analysis of the transmission delay of the system.Moreover, the distributed Raptor codes compares with LT codes and other digital fountain codes transmission scheme.Theoretical analysis and simulation results indicate that the Raptor codes in throughput and decoding success rate is more greatly improved than LT codes.When the link packet loss rate is big, this distributed Raptor codes cooperative transmission scheme can greatly improve the performance of the system on the transmission delay and the larger link deletion probability is, obviously the greater advantages is.

Traffic simulation is utilized to solve traffic-related problems. Microscopic simulations can describe individual vehicles and thus reproduce detailed vehicle behavior. To use a simulator, traffic demand should be estimated in the form of an origin-destination (OD) matrix. The simulator and OD estimation models must be consistent. In addition, microscopic models are sensitive to congestion, and can thus easily produce unexpected congestion. Here, we propose a simulator-embedded OD estimation method that uses congestion sensing. We minimize the residual between the observed and simulated link traffic volumes with some constraints regarding congestion. If a link is judged to be congested, we use resistance in a constraint in the optimization problem, which is determined by the number of the stuck vehicles at each link. Use of the resistance prevents excessively large traffic demand for that link. This congestion sensing mitigates unrealistic congestion in the estimated traffic demand.

4 - QoE-based Power Efficient LTE Downlink Scheduler

A heuristic approach to time-dependent origin-destination traffic demand estimation for the development of large-scale dynamic traffic assignment models

Quality of service (QoS) and quality of experience (QoE) are two major concepts for the quality evaluation of video services. QoS analyzes the technical performance of a network transmission chain (e.g., utilization or packet loss rate). On the other hand, subjective evaluation (QoE) relies on the observer’s opinion, so it cannot provide output in a form of score immediately (extensive time requirements). Although several well-known methods for objective evaluation exist (trying to adopt psychological principles of the human visual system via mathematical models), each of them has its own rating scale without an existing symmetric conversion to a standardized subjective output like MOS (mean opinion score), typically represented by a five-point rating scale. This makes it difficult for network operators to recognize when they have to apply resource reservation control mechanisms. For this reason, we propose an application (classifier) that derivates the subjective end-user quality perception based on a score of objective assessment and selected parameters of each video sequence. Our model integrates the unique benefits of unsupervised learning and clustering techniques such as overfitting avoidance or small dataset requirements. In fact, most of the published papers are based on regression models or supervised clustering. In this article, we also investigate the possibility of a graphical SOM (self-organizing map) representation called a U-matrix as a feature selection method.

Mobile Ad-hoc Networks (MANETs) usually suffer from high packet loss and high link failure rates. These challenges usually increase congestion on some links while other links are almost free. In this paper, we propose a novel mechanism to enhance QoS in multipath routing protocols in MANETs based on the InfiniBand (IB) QoS architecture. The basic idea of our approach is to enhance the load balancing and thus reduce congestion on overloaded links. This mechanism has enabled us to (1) give critical applications higher priority when routing their packets across the network, (2) effectively manage frequent connections and disconnections and thus reduce link failures and packet loss rates, and (3) reduce the overall power consumption as a consequence of the previous gains. We have tested the scheme on the (IBsim) simulator and achieved significant improvements in QoS parameters compared to two well- known routing protocols: AODV and AOMDV.

The rapid growth of mobile video traffic and user demand poses a more stringent requirement for efficient bandwidth allocation in mobile networks where multiple users may share a bottleneck link. This provides content providers an opportunity to jointly optimize multiple users’ experiences but users often suffer short connection durations and frequent handoffs because of their high mobility. In this paper, we propose an end-to-end scheme, VSiM, for supporting mobile video streaming applications in heterogeneous wireless networks. The key idea is allocating bottleneck bandwidth among multiple users based on their mobility profiles and Quality of Experience (QoE)-related knowledge to achieve max-min QoE fairness. Besides, the QoE of buffer-sensitive clients is further improved by the novel server push strategy based on HTTP/3 protocol without affecting the existing bandwidth allocation approach or sacrificing other clients’ view quality. VSiM is lightweight and easy to deploy in the real world without touching the underlying network infrastructure. We evaluated VSiM experimentally in both simulations and a lab testbed on top of the HTTP/3 protocol. We find that the clients’ QoE fairness of VSiM achieves more than 40% improvement compared with state-of-the-art solutions, i.e., the viewing quality of clients in VSiM can be improved from 720p to 1080p in resolution. Meanwhile, VSiM provides about 20% improvement of average QoE.

Counteracting economic challenges in the network industry partially resulting from enormous traffic growth rates and the absence of successful Quality of Service (QoS) mechanisms in practice, we propose a novel concept centering price and quality differentiation on customers' quality perceptions, i.e., Quality of Experience (QoE). By fundamentally building on the known Paris Metro Pricing (PMP) concept we iteratively integrate pricing mechanisms with QoE aspects. Our concept also cardinally incorporates the interests of users, Internet Service Providers (ISPs) offering Internet access, and regulatory bodies-e.g., controlling the fraction of premium service class capacity. Our findings demonstrate the economic desirability for ISPs to apply price discrimination based on QoE considerations. The inclusion of QoE aspects in the traffic classification process, moreover, yields a significant increase of user utilities, while further stimulating the overall demand. This may also prepare the scene for involvements in the Net Neutrality (NN) debate.

Community networks (CNs) have gained momentum in the last few years with the increasing number of spontaneously deployed WiFi hotspots and home networks. These networks, owned and managed by volunteers, offer various services to their members and to the public. While Internet access is the most popular service, the provision of services of local interest within the network is enabled by the emerging technology of CN micro-clouds. By putting services closer to users, micro-clouds pursue not only a better service performance, but also a low entry barrier for the deployment of mainstream Internet services within the CN. Unfortunately, the provisioning of these services is not so simple. Due to the large and irregular topology, high software and hardware diversity of CNs, a “careful” placement of micro-clouds services over the network is required to optimize service performance. This paper proposes to leverage state information about the network to inform service placement decisions, and to do so through a fast heuristic algorithm, which is critical to quickly react to changing conditions. To evaluate its performance, we compare our heuristic with one based on random placement in Guifi.net, the biggest CN worldwide. Our experimental results show that our heuristic consistently outperforms random placement by 2x in bandwidth gain. We quantify the benefits of our heuristic on a real live video-streaming service, and demonstrate that video chunk losses decrease significantly, attaining a 37% decrease in the packet loss rate. Further, using a popular Web 2.0 service, we demonstrate that the client response times decrease up to an order of magnitude when using our heuristic. Since these improvements translate in the QoE (Quality of Experience) perceived by the user, our results are relevant for contributing to higher QoE, a crucial parameter for using services from volunteer-based systems and adapting CN micro-clouds as an eco-system for service deployment.

Cellular wirelesses heterogeneous networks (HetNets) have become an important part of the growth of the telecom industry. The rapid growth of cellular networks and widespread use of wireless services have led to a huge increase in energy use. This makes it hard to make cellular networks that use less energy and last longer. In HetNets, load balancing (LB) and energy balance have a big effect on cell range extension (CRE) and network lifetime extension (NLE). optimal energy efficient LB in wireless cellular HetNets is presented in this paper using a self-tuning algorithm. Several self-tuning methods for HetNets have been developed that are driven by the quality of experience (QoE). Unlike earlier heuristic-based approaches, the suggested technique uses a gradient ascending method to ensure that parameter modifications constantly increase overall system QoE, LB, throughput, and energy efficiency. The planned network's packet loss rate is extremely low. The suggested and contemporary models are tested in an experimental investigation, demonstrating the importance of the suggested model in comparison to other contemporary methodologies.

Long Term Evolution (LTE) is the preliminary version of a fourth generation (4G) mobile communication system. Its aim is to support different services with high data rates and strict Quality of Experience (QoE) requirements of users. The main aim of this study is to present a prediction model based on Random Neural Networks (RNNs) for objective, non-intrusive prediction of video quality over LTE for video applications. A three layer feed-forward RNN model with gradient descent training algorithm has been developed. This model uses a combination of objective parameters in the application and network layers, such as Content Type (CT), Sender Bit Rate (SBR), resolution size, Frame Rate (FR), codec, and packet loss rate (PLR). The video quality was predicted in terms of the Mean Opinion Score (MOS). The results show an approximate 50% increase in accuracy using this model, compared to previous models. LTE-Sim software has been used to generate different samples for testing and training RNN model.

Telepresence robots (TPRs) are versatile, remotely controlled vehicles that enable physical presence and human-to-human interaction over a distance. Thanks to improving hardware and dropping price points, TPRs enjoy the growing interest in various industries and application domains. Still, a satisfying experience remains key for their acceptance and successful adoption, not only in terms of enabling remote communication with others, but also in terms of managing robot mobility by means of remote navigation. This paper focuses on the latter aspect of remote operation which has been hitherto neglected. We present the results of an extensive subjective study designed to systematically assess remote navigation Quality of Experience (QoE) in the context of using a TPR live over the Internet. Participants were 'beamed' into a remote office space and asked to perform characteristic TPR remote operation tasks (driving, turning, parking). Visual and control dimensions of their experience were systematically impaired by altering network characteristics (bandwidth, delay and packet loss rate) in a controlled fashion. Our results show that users can differentiate well between visual and navigation/control aspects of their experience. Furthermore, QoE impairment sensitivity varies with the actual task at hand.