scholarly journals Buffer-based rate adaptation scheme for HTTP video streaming with consistent quality

2021 ◽  
pp. 21-21
Author(s):  
Jiwoo Park ◽  
Minsu Kim ◽  
Kwangsue Chung
Keyword(s):  
Queueing System ◽  
Video Quality ◽  
Rate Adaptation ◽  
Network Resources ◽  
Available Bandwidth ◽  
Buffer Occupancy ◽  
Network Bandwidth ◽  
Hypertext Transfer Protocol ◽  
The Difference ◽  
Adaptation Scheme

Recently, HyperText Transfer Protocol (HTTP) based adaptive streaming (HAS) has been proposed as a solution for efficient use of network resources. HAS performs rate adaptation that adjusts the video quality according to the network conditions. The conventional approaches for rate adaptation involve accurately estimating the available bandwidth or exploiting the playback buffer in HAS clients rather than estimating the network bandwidth. In this paper, we present a playback buffer model for rate adaptation and propose a new buffer-based rate adaptation scheme. First, we model the playback buffer as a queueing system that stores video segments. The proposed scheme selects the next video bitrate that minimizes the difference between the current buffer occupancy and the expected value from the playback buffer model. The evaluation results indicated that the proposed scheme achieves higher video quality than conventional algorithms and can cope with various environments without the tuning of the configuration parameters.

scholarly journals Joint Bandwidth and Power Allocation for LTE-Based Cognitive Radio Network Based on Buffer Occupancy

2016 ◽  
Vol 2016 ◽  
pp. 1-23
Author(s):  
Alia Asheralieva ◽  
Yoshikazu Miyanaga
Keyword(s):  
Spectrum Sharing ◽  
Operating Conditions ◽  
Superior Performance ◽  
Network Resources ◽  
Minimal Impact ◽  
Available Bandwidth ◽  
Buffer Occupancy ◽  
Qos Guarantees ◽  
Network Usage

We investigate the problem of resource allocation in a cognitive long-term evolution (LTE) network, where the available bandwidth resources are shared among the primary (licensed) users (PUs) and secondary (unlicensed) users (SUs). Under such spectrum sharing conditions, the transmission of the SUs should have minimal impact on quality of service (QoS) and operating conditions of the PUs. To achieve this goal, we propose to assign the network resources based on the buffer sizes of the PUs and SUs in the uplink (UL) and downlink (DL) directions. To ensure that the QoS requirements of the PUs are satisfied, we enforce some upper bound on the size of their buffers considering two network usage scenarios. In the first scenario, PUs pay full price for accessing the spectrum and get full QoS protection; the SUs access the network for free and are served on a best-effort basis. In the second scenario, PUs pay less in exchange for sharing the bandwidth and get the reduced QoS guarantees; SUs pay some price for their access without any QoS guarantees. Performance of the algorithms proposed in the paper is evaluated using simulations in OPNET environment. The algorithms show superior performance when compared with other relevant techniques.

scholarly journals Available Bandwidth Estimation in Network-Aware Applications for Wireless Campus e-Learning System

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Mohd Faisal Ibrahim ◽  
Masita Jamal ◽  
Saadiah Yahya ◽  
Mohd Nasir Taib
Keyword(s):  
Wireless Network ◽  
Learning System ◽  
Convergence Time ◽  
Bandwidth Estimation ◽  
Network Resources ◽  
Available Bandwidth ◽  
Network Characteristics ◽  
Network Bandwidth ◽  
Application Architecture ◽  
E Learning

The constraint of a wireless network has motivated many researchers to develop network-aware applications that can dynamically adjust the users' demand based on network resources. For this to happen, applications need to have some mechanism that can estimate the network bandwidth by simply adjusting their behavior based on the collected network characteristics information. In the past, there have been several proposals that provide passive and active bandwidth estimation approaches for wired and wireless network. However, little effort has been spent to address the crucial issues of reliability and congestion control especially in a wireless network environment, which stay as a sticking point for the success of network-aware application. This paper focuses on providing accurate, low-intrusiveness, and fast-convergence time bandwidth estimation for network-aware application architecture. The experimental results validate the efficiency of the proposed solution in terms of accuracy, intrusiveness, and timelines.

scholarly journals VCC-DASH: A Video Content Complexity-Aware DASH Bitrate Adaptation Strategy

Electronics ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 230
Author(s):  
Juzheng Duan ◽  
Min Zhang ◽  
Jing Wang ◽  
Shuai Han ◽  
Xun Chen ◽  
...  
Keyword(s):  
Quality Of Experience ◽  
Adaptation Strategy ◽  
Video Content ◽  
Buffer Occupancy ◽  
Network Bandwidth ◽  
Opinion Score ◽  
Hypertext Transfer Protocol ◽  
Simulation Results ◽  
Definition Of

Traditional DASH (dynamic adaptation streaming over HTTP(i.e., HyperText Transfer Protocol)) bitrate strategy cannot differentiate segments with different complexities of video content, resulting in the user’s QoE (quality of experience) of segments with high content complexity as worse than that with low content complexity. In case of this, this paper firstly studies video coding and puts forward the definition of video content complexity. Then the effects of content complexity on user’s QoE is analyzed and the QoE utility function of the segment is formulated based on its MOS (mean opinion score, related to the content complexity and bitrate) and bitrate switching between consecutive segments. Last, in order to maximize user’s QoE, this paper proposes VCC-DASH (video content complexity-aware DASH bitrate adaptation strategy) under the constraints of the network bandwidth and the buffer occupancy. In simulations, we compare VCC-DASH with the classical bitrate adaptation strategy proposed by Liu et al. (LIU’s strategy, for short). The simulation results show that the two strategies have similar performances in bitrate switching numbers, playback interruption times, and buffer lengths. In addition, it is more important for simulation results to reveal that VCC-DASH’s average bitrate is much higher than that of LIU’s strategy, which means that VCC-DASH can make fuller use of the network bandwidth than LIU’s strategy does. Moreover, the MOS distribution of the VCC-DASH is more concentrated on the better scores “4~5”, which profit from its content complexity-aware adaptation to allocate more bandwidth resources to high-complexity segments.

scholarly journals Adaptive Reservation of Network Resources According to Video Classification Scenes

Sensors ◽  
2021 ◽  
Vol 21 (6) ◽  
pp. 1949
Author(s):  
Lukas Sevcik ◽  
Miroslav Voznak
Keyword(s):  
User Satisfaction ◽  
Quality Evaluation ◽  
Spatial Information ◽  
Service Providers ◽  
Video Quality ◽  
Subjective Assessment ◽  
Video Sequences ◽  
Network Resources ◽  
Proposed Model

Video quality evaluation needs a combined approach that includes subjective and objective metrics, testing, and monitoring of the network. This paper deals with the novel approach of mapping quality of service (QoS) to quality of experience (QoE) using QoE metrics to determine user satisfaction limits, and applying QoS tools to provide the minimum QoE expected by users. Our aim was to connect objective estimations of video quality with the subjective estimations. A comprehensive tool for the estimation of the subjective evaluation is proposed. This new idea is based on the evaluation and marking of video sequences using the sentinel flag derived from spatial information (SI) and temporal information (TI) in individual video frames. The authors of this paper created a video database for quality evaluation, and derived SI and TI from each video sequence for classifying the scenes. Video scenes from the database were evaluated by objective and subjective assessment. Based on the results, a new model for prediction of subjective quality is defined and presented in this paper. This quality is predicted using an artificial neural network based on the objective evaluation and the type of video sequences defined by qualitative parameters such as resolution, compression standard, and bitstream. Furthermore, the authors created an optimum mapping function to define the threshold for the variable bitrate setting based on the flag in the video, determining the type of scene in the proposed model. This function allows one to allocate a bitrate dynamically for a particular segment of the scene and maintains the desired quality. Our proposed model can help video service providers with the increasing the comfort of the end users. The variable bitstream ensures consistent video quality and customer satisfaction, while network resources are used effectively. The proposed model can also predict the appropriate bitrate based on the required quality of video sequences, defined using either objective or subjective assessment.

scholarly journals A Proposed Adaptive Bitrate Scheme Based on Bandwidth Prediction Algorithm for Smoothly Video Streaming

2021 ◽  
Vol 27 (1) ◽  
pp. 112-129
Author(s):  
Saba Qasim Jabbar ◽  
Dheyaa Jasim Kadhim
Keyword(s):  
Video Streaming ◽  
Video Quality ◽  
Prediction Algorithm ◽  
Buffer Size ◽  
Video Playback ◽  
Buffer Occupancy ◽  
Simulation Results ◽  
Streaming Technology ◽  
The Impact ◽  
Buffer Structure

A robust video-bitrate adaptive scheme at client-aspect plays a significant role in keeping a good quality of video streaming technology experience. Video quality affects the amount of time the video has turned off playing due to the unfilled buffer state. Therefore to maintain a video streaming continuously with smooth bandwidth fluctuation, a video buffer structure based on adapting the video bitrate is considered in this work. Initially, the video buffer structure is formulated as an optimal control-theoretic problem that combines both video bitrate and video buffer feedback signals. While protecting the video buffer occupancy from exceeding the limited operating level can provide continuous video streaming, it may also cause a video bitrate oscillation. So the video buffer structure is adjusted by adding two thresholds as operating points for overflow and underflow states to filter the impact of throughput fluctuation on video buffer occupancy level. Then a bandwidth prediction algorithm is proposed for enhancing the performance of video bitrate adaptation. This algorithm's work depends on the current video buffer level, video bitrate of the previous segment, and iterative throughput measurements to predict the best video bitrate for the next segment. Simulation results show that reserving a bandwidth margin is better in adapting the video bitrate under bandwidth variation and then reducing the risk of video playback freezing. Simulation results proved that the playback freezing happens two times: firstly, when there is no bandwidth margin used and secondly, when the bandwidth margin is high while smooth video bitrate is obtained with moderate value. The proposed scheme is compared with other two schemes such as smoothed throughput rate (STR) and Buffer Based Rate (BBR) in terms of prediction error, QoE preferences, buffer size, and startup delay time, then the proposed scheme outperforms these schemes in attaining smooth video bitrates and continuous video playback.

scholarly journals PERFORMANCE COMPARISON WITH ACCESSIBILITY PREDICTION AND LINK BREAKAGE PREDICTION IN MANETS

2015 ◽  
pp. 48-54
Author(s):  
TEJAL ARVIND SONAWALE ◽  
SHIKHA NEMA
Keyword(s):  
Ad Hoc ◽  
Power Level ◽  
Performance Comparison ◽  
Delivery Ratio ◽  
Route Discovery ◽  
Network Resources ◽  
Average Delay ◽  
Network Bandwidth ◽  
Multiple Routes ◽  
Hoc Networks

Ad Hoc Networks face a lot of problems due to issues like mobility, power level, load of the network, bandwidth constraints, dynamic topology which lead to link breaks, node break down and increase in overhead. As nodes are changing their position consistently, routes are rapidly being disturbed, thereby generating route errors and new route discoveries. The need for mobility awareness is widely proclaimed. In our dissertation we present a scheme AOMDV-APLP that makes AOMDV aware of accessibility of neighbor nodes in the network. Nodes acquire the accessibility information of other nodes through routine routing operations and keep in their routing table. Based on this information route discovery is restricted to only “accessible” and “start” nodes. Further route with the strongest signal strength is selected from multiple routes using Link life value predicted by Link Breakage prediction technique. Simulation result shows that using accessibility and link life knowledge in route discovery process MAC overhead, routing overhead and average delay is reduced 3 times, and improve the Packet delivery ratio to a large extent than standard AOMDV which reflects effective use of network resources.

Game Theory for Wireless Network Resource Management

Game Theory ◽  
2017 ◽  
pp. 383-399
Author(s):  
Sungwook Kim
Keyword(s):  
Game Theory ◽  
Computer Network ◽  
Limited Resource ◽  
Shared Resources ◽  
Network Resources ◽  
Network Resource ◽  
Network Bandwidth ◽  
Competitive Game ◽  
Network Usage ◽  
Fair Sharing

Computer network bandwidth can be viewed as a limited resource. The users on the network compete for that resource. Their competition can be simulated using game theory models. No centralized regulation of network usage is possible because of the diverse ownership of network resources. Therefore, the problem is of ensuring the fair sharing of network resources. If a centralized system could be developed which would govern the use of the shared resources, each user would get an assigned network usage time or bandwidth, thereby limiting each person's usage of network resources to his or her fair share. As of yet, however, such a system remains an impossibility, making the situation of sharing network resources a competitive game between the users of the network and decreasing everyone's utility. This chapter explores this competitive game.

Denial-of-Service and Botnet Analysis, Detection, and Mitigation

2021 ◽  
pp. 20-48
Author(s):  
Sobana Sikkanan ◽  
Kasthuri M.
Keyword(s):  
Denial Of Service ◽  
The Internet ◽  
Dos Attack ◽  
Dos Attacks ◽  
Network Resources ◽  
Systematic Analysis ◽  
Network Bandwidth ◽  
Research Areas ◽  
History Analysis ◽  
Near Future

The internet is designed for processing and forwarding of any packet in a best effort manner. The packets carried by the internet may be malicious or not. Most of the time, internet architecture provides an unregulated path to victims. Denial-of-service (DoS) attack is the most common critical threat that causes devastating effects on the internet. The Botnet-based DoS attack aims to exhaust both the target resources and network bandwidth, thereby making the network resources unavailable for its valid users. The resources are utilized by either injecting a computer virus or flooding the network with useless traffic. This chapter provides a systematic analysis of the causes of DoS attacks, including motivations and history, analysis of different attacks, detection and protection techniques, various mitigation techniques, the limitations and challenges of DoS research areas. Finally, this chapter discusses some important research directions which will need more attention in the near future to guarantee the successful defense against DoS attacks.

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