A Holistic Survey of Wireless Multipath Video Streaming <s> C. Which is the best path to send the packet? <s> We consider the following natural model: customers arrive as a Poisson stream of rate /spl lambda/n, /spl lambda/<1, at a collection of n servers. Each customer chooses some constant d servers independently and uniformly at random from the n servers and waits for service at the one with the fewest customers. Customers are served according to the first-in first-out (FIFO) protocol and the service time for a customer is exponentially distributed with mean 1. We call this problem the supermarket model. We wish to know how the system behaves and in particular we are interested in the effect that the parameter d has on the expected time a customer spends in the system in equilibrium. Our approach uses a limiting, deterministic model representing the behavior as n/spl rarr//spl infin/ to approximate the behavior of finite systems. The analysis of the deterministic model is interesting in its own right. Along with a theoretical justification of this approach, we provide simulations that demonstrate that the method accurately predicts system behavior, even for relatively small systems. Our analysis provides surprising implications. Having d=2 choices leads to exponential improvements in the expected time a customer spends in the system over d=1, whereas having d=3 choices is only a constant factor better than d=2. We discuss the possible implications for system design. <s> BIB001 </s> A Holistic Survey of Wireless Multipath Video Streaming <s> C. Which is the best path to send the packet? <s> This paper presents pathChirp, a new active probing tool for estimating the available bandwidth on a communication network path. Based on the concept of ''self-induced congestion,'' pathChirp features an exponential flight pattern of probes we call a chirp. Packet chips offer several significant advantages over current probing schemes based on packet pairs or packet trains. By rapidly increasing the probing rate within each chirp, pathChirp obtains a rich set of information from which to dynamically estimate the available bandwidth. Since it uses only packet interarrival times for estimation, pathChirp does not require synchronous nor highly stable clocks at the sender and receiver. We test pathChirp with simulations and Internet experiments and find that it provides good estimates of the available bandwidth while using only a fraction of the number of probe bytes that current state-of-the-art techniques use. <s> BIB002 </s> A Holistic Survey of Wireless Multipath Video Streaming <s> C. Which is the best path to send the packet? <s> Concurrent multipath transfer (CMT) uses the Stream Control Transmission Protocol's (SCTP) multihoming feature to distribute data across multiple end-to-end paths in a multihomed SCTP association. We identify three negative side-effects of reordering introduced by CMT that must be managed before efficient parallel transfer can be achieved: (1) unnecessary fast retransmissions by a sender; (2) overly conservative congestion window (cwnd) growth at a sender; and (3) increased ack traffic due to fewer delayed acks by a receiver. We propose three algorithms which augment and/or modify current SCTP to counter these side-effects. Presented with several choices as to where a sender should direct retransmissions of lost data, we propose five retransmission policies for CMT. We demonstrate spurious retransmissions in CMT with all five policies and propose changes to CMT to allow the different policies. CMT is evaluated against AppStripe, which is an idealized application that stripes data over multiple paths using multiple SCTP associations. The different CMT retransmission policies are then evaluated with varied constrained receive buffer sizes. In this foundation work, we operate under the strong assumption that the bottleneck queues on the end-to-end paths used in CMT are independent. <s> BIB003 </s> A Holistic Survey of Wireless Multipath Video Streaming <s> C. Which is the best path to send the packet? <s> A variety of wireless interfaces are available for today's mobile user to access Internet content. When coverage areas of these different technologies overlap, a terminal equipped with multiple interfaces can use them simultaneously to improve the performance of its applications. In this paper, we motivate the advantages that can be had through simultaneous use of multiple interfaces and present a network layer architecture that enables diverse multiaccess services. In particular, we explore in depth one such service provided by the architecture: Bandwidth Aggregation (BAG) for real-time applications. An important aspect of the architecture when providing BAG services for real-time applications is the scheduling algorithm that partitions the traffic onto different interfaces such that the QoS requirements of the application are met. We propose one such algorithm Earliest Delivery Path First (EDPF), that ensures packets meet their playback deadlines by scheduling packets based on the estimated delivery time of the packets. We show through analysis that EDPF performs close to an idealized Aggregated Single Link (ASL) discipline, where the multiple interfaces are replaced by a single interface with same aggregated bandwidth. A prototype implementation and extensive simulations carried using video and delay traces show the performance improvement BAG with EDPF scheduling offers over using just the Highest Bandwidth Interface (HBI) and other scheduling approaches based on weighted round robin. <s> BIB004 </s> A Holistic Survey of Wireless Multipath Video Streaming <s> C. Which is the best path to send the packet? <s> As mobile and fixed hosts are increasingly equipped with multiple network interfaces that enable multi-homing, there is significant current interest to seek appropriate method for access network selection. To address the presence of asymmetric forward-return path combinations in practice, we propose a simple but novel scheme to determine the one-way path with the lowest delay independently for both directions. This method provides delay sensitive multimedia applications with the lowest possible round-trip time in a multi-homed environment, compared to existing methods which assume path symmetry. <s> BIB005 </s> A Holistic Survey of Wireless Multipath Video Streaming <s> C. Which is the best path to send the packet? <s> Real-time multimedia transport has stringent quality of service requirements, which are generally not supported by current network architectures. In emerging mobile ad hoc networks, frequent topology changes and link failures cause severe packet losses, which degrade the quality of received media. However, in such mesh networks, there usually exist multiple paths between any source and destination nodes. Such path diversity has been demonstrated to be effective in combating congestion and link failures for improved media quality. In this paper, we present a new protocol to facilitate multipath transport of real-time multimedia data. The proposed protocol, the multiflow real-time transport protocol (MRTP), provides a convenient vehicle for real-time applications to partition and transmit data using multiple flows. We demonstrate through analysis that data partitioning, which is an essential function of MRTP, can effectively reduce the short-range dependence of multimedia data, thus improving its queueing performance in underlying networks. Furthermore, we show that a few flows are sufficient for MRTP to exploit most of the benefits of multipath transport. Finally, we present a comprehensive simulation study on the performance of MRTP under a mobile ad hoc network. We show that with one additional path, MRTP outperformed single-flow RTP by a significant margin. <s> BIB006 </s> A Holistic Survey of Wireless Multipath Video Streaming <s> C. Which is the best path to send the packet? <s> In this paper, we propose a novel transport protocol that effectively utilizes available bandwidth and diversity gains provided by heterogeneous, highly lossy paths. Our Multi-Path LOss-Tolerant (MPLOT) protocol can be used to provide significant gains in the goodput of wireless mesh networks, subject to bursty, correlated losses with average loss-rates as high as 50%, and random outage events. MPLOT makes intelligent use of erasure codes to guard against packets losses, and a Hybrid-ARQ/FEC scheme to reduce packet recovery latency, where the redundancy is adaptively provisioned into both proactive and reactive FECs. MPLOT uses dynamic packet mapping based on current path characteristics, and does not require packets to be delivered in sequence to ensure reliability. We present a theoretical analysis of the different design choices of MPLOT and show that MPLOT makes an optimal trade-off between goodput and delay constraints. We test MPLOT, through simulations, under a variety of test scenarios and show that it effectively exploits path diversity in addition to aggregating path bandwidths. We also show that MPLOT is fair to single-path protocols like TCP-SACK. <s> BIB007 </s> A Holistic Survey of Wireless Multipath Video Streaming <s> C. Which is the best path to send the packet? <s> Previous Probe Gap Model (PGM) based available bandwidth (AB) estimation methods all request the "busy assumption" that probing packet pairs should be in the same busy period when transmitted on bottleneck link, which is hard to satisfy especially for the low utilization path. In this paper, we first present a new probabilistic methodology to estimate AB under "non busy assumption". The methodology is quite accurate on the low utilization network path. Secondly, we propose a metric to weigh the busyness of a network path based on the distribution of output probe gap. Using the metric, we combine our new methodology and previous methodology, and present a new AB estimation method called Adaptive Available Bandwidth Estimation (A_ABE) which is fit for both low utilization and high utilization paths. We use NS-2 simulation and reproduce traffic from real Internet links to evaluate A_ABE. Compared with previous methods, A_ABE shows its advantages in terms of accuracy, overhead, and also the robustness when confronted with non-persistent cross traffic in multiple hop situations. <s> BIB008 </s> A Holistic Survey of Wireless Multipath Video Streaming <s> C. Which is the best path to send the packet? <s> Video streaming ranks among the most popular services offered through the Internet today. At the same time, accessing the Internet over public WiFi and 3G networks has become part of our everyday lives. However, streaming video in wireless environments is often subject to frequent periods of rebuffering and characterized by low picture quality. In particular, achieving smooth and quality-adaptive streaming of live video poses a big challenge in mobile scenarios. Building on the observation that the subjective video experience on mobile devices decreases when quality changes are more frequent than every 1 to 2 seconds, we present a client-side scheduler that retrieves segments of several video encodings over heterogeneous network interfaces simultaneously. By extending the DAVVI streaming platform with support for multiple interfaces, the proposed scheduler's performance is experimentally evaluated. The results show that our scheduler reduces the video interruptions and achieves a higher and more stable average quality over multiple, truly heterogeneous wireless interfaces. <s> BIB009 </s> A Holistic Survey of Wireless Multipath Video Streaming <s> C. Which is the best path to send the packet? <s> Devices capable of connecting to multiple, overlapping networks simultaneously are becoming increasingly common. For example, most laptops are equipped with LAN- and WLAN-interfaces, and smart phones can typically connect to both WLANs and 3G mobile networks. At the same time, streaming high-quality video is becoming increasingly popular. However, due to bandwidth limitations or the unreliable and unpredictable nature of some types of networks, streaming video can be subject to frequent periods of rebuffering and characterised by a low picture quality. In this paper, we present a client-side request scheduler that distributes requests for the video over multiple heterogeneous interfaces simultaneously. Each video is divided into independent segments with constant duration, enabling segments to be requested over separate links, utilizing all the available bandwidth. To increase performance even further, the segments are divided into smaller subsegments, and the sizes are dynamically calculated on the fly, based on the throughput of the different links. This is an improvement over our earlier subsegment approach, which divided segments into fixed size subsegments. Both subsegment approaches were evaluated with on-demand streaming and quasi-live streaming. The new subsegment approach reduces the number of playback interruptions and improves video quality significantly for all cases where the earlier approach struggled. Otherwise, they show similar performance. <s> BIB010 </s> A Holistic Survey of Wireless Multipath Video Streaming <s> C. Which is the best path to send the packet? <s> Devices capable of connecting to multiple, overlapping networks simultaneously is becoming increasingly common. For example, most laptops are equipped with LAN- and WLAN-interface, and smart phones can typically connect to both WLANs and 3G mobile networks. At the same time, streaming high-quality video is becoming increasingly popular. However, due to bandwidth limitations or the unreliable and unpredictable nature of some types of networks, streaming video can be subject to frequent periods of rebuffering and characterized by a low picture quality. In this paper, we present a multilink extension to the data retrieval part of the DAVVI adaptive, segmented video streaming system. DAVVI implements the same core functionality as the MPEG DASH standard. It uses HTTP to retrieve data, segments video, provides clients with a description of the content, and allows clients to switch quality during playback. Any DAVVI-data retrieval extensions can also be implemented in a DASH-solution. The multilink-enabled DAVVI client divides video segments into smaller subsegments, which are requested over multiple interfaces simultaneously. The size of each subsegment is dynamic and calculated on the fly, based on the throughput of the different links. This is an improvement over our earlier subsegment approach, which divided segments into fixed size subsegments. The quality of the video is adapted based on the measured, aggregated throughput. Both the static and the dynamic subsegment approaches were evaluated with on-demand streaming and quasi-live streaming. The new subsegment approach reduces the number of playback interruptions and improves video quality significantly for all cases where the earlier approach struggled. Otherwise, they show similar performance. <s> BIB011 </s> A Holistic Survey of Wireless Multipath Video Streaming <s> C. Which is the best path to send the packet? <s> Datagram Congestion Control Protocol (DCCP) is an unreliable transport layer protocol with a congestion control mechanism used for multimedia streaming. In order to use multiple network interfaces to transmit streaming data smoothly, a Multi-Path Datagram Congestion Control Protocol (MP-DCCP) is proposed and presented in this paper. Video streaming transmission through multi-path faces three problems: (1) out-of-ordering packets at the receiver side, (2) conditions of paths are changed anytime, and (3) the importances of frames/packets are different. The first problem may let video streaming data be delivered to the application layer too late, especially for the live streaming data. The second and third problems may let a packet be scheduled to an unsuitable path for transmission. Since importances of video streaming frames/packets are different, it should consider how to schedule the transmission of frames/packets properly. For example, an important frame/packet should be transmitted in the more reliable path. In order to resolve these three problems, a QoS-aware Order Prediction Scheduling (QOPS) scheme for MP-DCCP is proposed in this paper. QOPS estimates packets' arrival orders at the receive side through these multiple paths before packets are scheduled into the transmission at the sender side. From simulation results, we proved that the packets' out-of-ordering problem in MPDCCP can be improved using our proposed QOPS scheme. <s> BIB012 </s> A Holistic Survey of Wireless Multipath Video Streaming <s> C. Which is the best path to send the packet? <s> The increasing number of interfaces using different access technologies in modern devices gives opportunities for enhancing the Quality of Service (QoS) delivered to multimedia and interactive data transfers involved in distributed applications. In the current Internet, the presence of "middleboxes" such as Network Address Translators (NAT) or firewalls hardly lets applications use any Transport protocol but the well-known Transmission Control Protocol (TCP). Currently under standardization at the IETF, the new Multipath-TCP (MPTCP) protocol uses several TCP flows to make use of the multiple interfaces available on the end terminals, thus improving both network availability and QoS, still being capable to cross over middle boxes. Although originally being fully reliable and fully ordered, its two sub-layers architecture gives opportunity to use QoS techniques over fully reliable paths. This paper studies the QoS benefits induced by the implementation of the "partial reliability" concept in MPTCP for interactive video applications. Two different mechanisms are experimented with the aim to enhance global quality of video transmission over paths close to 3G networks characteristics. The Internet Engineering Task Force (IETF) MPTCP working group's ns-2 implementation is used for the experimentations. The Evalvid toolkit over ns-2 is used to measure the QoS benefits expressed in terms of Peak Signal to Noise Ratio (PSNR). <s> BIB013 </s> A Holistic Survey of Wireless Multipath Video Streaming <s> C. Which is the best path to send the packet? <s> Video streaming is gaining popularity among mobile users. The latest mobile devices, such as smart phones and tablets are equipped with multiple wireless network interfaces. How to efficiently and cost-effectively utilize multiple links to improve the video streaming quality needs to be investigated. In order to maintain high video streaming quality while reduce the wireless service cost, in this paper, the optimal video streaming process with multiple links is formulated as a Markov Decision Process (MDP). The reward function is designed to consider the quality of experience (QoE) requirements for video traffic, such as the interruption rate, average playback quality, playback smoothness and wireless service cost. Using dynamic programming, the MDP can be solved to obtain the optimal streaming policy. To evaluate the performance of the proposed multi-link rate adaptation (MLRA) algorithm, we implement a testbed using the Android mobile phone and the open-source X264 video codec. Experimental results demonstrate the feasibility and effectiveness of the proposed MLRA algorithm for mobile video streaming applications, which outperforms the existing state-of-the-art one. <s> BIB014 </s> A Holistic Survey of Wireless Multipath Video Streaming <s> C. Which is the best path to send the packet? <s> This paper investigates mobile video delivery in a heterogeneous wireless network from a video server to a multi-homed client. Joint source-channel coding (JSCC) has proven to be an effective solution for video transmission over bandwidth-limited, error-prone wireless networks. However, one major problem with the existing JSCC approaches is that they consider the network between the server and the client as a single transport link. The situation becomes more complicated in the context of multiple available links because involving a low-bandwidth, highly lossy, or long-delay wireless network in the transmission will only degrade the video quality. To address the critical problem, we propose a novel flow rate allocation-based JSCC (FRA-JSCC) approach that includes three key phases: (1) forward error correction redundancy estimation under loss requirement, (2) source rate adaption under delay constraint, and (3) dynamic rate allocation to minimize end-to-end video distortion. We present a mathematical formulation of JSCC to optimize video quality over multiple wireless channels and provide comprehensive analysis for channel distortion. We evaluate the performance of FRA-JSCC through emulations in Exata and compare it with the existing schemes. Experimental results show that FRA-JSCC outperforms the competing models in improving the video peak signal-to-noise ratio as well as in reducing the end-to-end delay. <s> BIB015 </s> A Holistic Survey of Wireless Multipath Video Streaming <s> C. Which is the best path to send the packet? <s> Mobile devices equipped with multiple network interfaces can increase their throughput by making use of parallel transmissions over multiple paths and bandwidth aggregation, enabled by the stream control transport protocol (SCTP). However, the different bandwidth and delay of the multiple paths will determine data to be received out of order and in the absence of related mechanisms to correct this, serious application-level performance degradations will occur. This paper proposes a novel quality-aware adaptive concurrent multipath transfer solution (CMT-QA) that utilizes SCTP for FTP-like data transmission and real-time video delivery in wireless heterogeneous networks. CMT-QA monitors and analyses regularly each path's data handling capability and makes data delivery adaptation decisions to select the qualified paths for concurrent data transfer. CMT-QA includes a series of mechanisms to distribute data chunks over multiple paths intelligently and control the data traffic rate of each path independently. CMT-QA's goal is to mitigate the out-of-order data reception by reducing the reordering delay and unnecessary fast retransmissions. CMT-QA can effectively differentiate between different types of packet loss to avoid unreasonable congestion window adjustments for retransmissions. Simulations show how CMT-QA outperforms existing solutions in terms of performance and quality of service. <s> BIB016 </s> A Holistic Survey of Wireless Multipath Video Streaming <s> C. Which is the best path to send the packet? <s> We consider the problem of scalable video streaming from a server to multinetwork clients over heterogeneous access networks, with the goal of minimizing the distortion of the received videos. This problem has numerous applications including: 1) mobile devices connecting to multiple licensed and ISM bands, and 2) cognitive multiradio devices employing spectrum bonding. In this paper, we ascertain how to optimally determine which video packets to transmit over each access network. We present models to capture the network conditions and video characteristics and develop an integer program for deterministic packet scheduling. Solving the integer program exactly is typically not computationally tractable, so we develop heuristic algorithms for deterministic packet scheduling, as well as convex optimization problems for randomized packet scheduling. We carry out a thorough study of the tradeoff between performance and computational complexity and propose a convex programming-based algorithm that yields good performance while being suitable for real-time applications. We conduct extensive trace-driven simulations to evaluate the proposed algorithms using real network conditions and scalable video streams. The simulation results show that the proposed convex programming-based algorithm: 1) outperforms the rate control algorithms defined in the Datagram Congestion Control Protocol (DCCP) by about 10-15 dB higher video quality; 2) reduces average delivery delay by over 90% compared to DCCP; 3) results in higher average video quality of 4.47 and 1.92 dB than the two developed heuristics; 4) runs efficiently, up to six times faster than the best-performing heuristic; and 5) does indeed provide service differentiation among users. <s> BIB017 </s> A Holistic Survey of Wireless Multipath Video Streaming <s> C. Which is the best path to send the packet? <s> The Internet infrastructure often supports multiple routes between two communicating hosts and, today, especially mobile hosts usually offer multiple network interfaces, so that disjoint paths between the hosts can be constructed. Having a number of (partly or fully) disjoint paths available may allow applications to distribute their traffic, aggregate capacity of different paths, choose the most suitable subset of paths, and support failover if a path fails. Exploiting multipath characteristics has been explored for TCP, but the requirements for real-time traffic differs notably. In this paper, we devise a multipath communication model for Real-time Transport Protocol (RTP); present minimal set of required protocol extensions; develop algorithms for scheduling RTP traffic across multiple paths at the sender and a corresponding de-jittering algorithm at the receiver side; and evaluate our proposal in varying scenarios using media traffic across different emulated mobile access network setups. <s> BIB018 </s> A Holistic Survey of Wireless Multipath Video Streaming <s> C. Which is the best path to send the packet? <s> Modern mobile devices are equipped with multiple network interfaces, including 3G/LTE and WiFi. Bandwidth aggregation over LTE and WiFi links offers an attractive opportunity of supporting bandwidth-intensive services, such as high-quality video streaming, on mobile devices. However, achieving effective bandwidth aggregation in mobile environments raises several challenges related to deployment, link heterogeneity, network fluctuation, and energy consumption. We present GreenBag, an energy-efficient bandwidth aggregation middleware that supports real-time data-streaming services over asymmetric wireless links, requiring no modifications to the existing Internet infrastructure and servers. GreenBag employs several techniques, including medium load balancing, efficient segment management, and energy-aware mode control, to resolve such challenges. We implement a prototype of GreenBag on Android-based mobile devices which hosts, to the best knowledge of the authors, the first LTE-enabled bandwidth aggregation prototype for energy-efficient real-time video streaming. Our experiment results in both emulated and real-world environments show that GreenBag not only achieves good bandwidth aggregation to provide QoS in bandwidth-scarce environments but also efficiently saves energy on mobile devices. Moreover, energy-aware GreenBag can minimize video interruption while consuming 14-25% less energy than the non-energy-aware counterpart in real-world experiments. <s> BIB019 </s> A Holistic Survey of Wireless Multipath Video Streaming <s> C. Which is the best path to send the packet? <s> The massive proliferation of wireless infrastructures with complementary characteristics prompts the bandwidth aggregation for Concurrent Multipath Transfer (CMT) over heterogeneous access networks. Stream Control Transmission Protocol (SCTP) is the standard transport-layer solution to enable CMT in multihomed communication environments. However, delivering high-quality streaming video with the existing CMT solutions still remains problematic due to the stringent quality of service (QoS) requirements and path asymmetry in heterogeneous wireless networks. In this paper, we advance the state of the art by introducing video distortion into the decision process of multipath data transfer. The proposed distortion-aware concurrent multipath transfer (CMT-DA) solution includes three phases: 1) per-path status estimation and congestion control; 2) quality-optimal video flow rate allocation; 3) delay and loss controlled data retransmission. The term ‘flow rate allocation’ indicates dynamically picking appropriate access networks and assigning the transmission rates. We analytically formulate the data distribution over multiple communication paths to minimize the end-to-end video distortion and derive the solution based on the utility maximization theory. The performance of the proposed CMT-DA is evaluated through extensive semi-physical emulations in Exata involving H.264 video streaming. Experimental results show that CMT-DA outperforms the reference schemes in terms of video peak signal-to-noise ratio (PSNR), goodput, and inter-packet delay. <s> BIB020 </s> A Holistic Survey of Wireless Multipath Video Streaming <s> C. Which is the best path to send the packet? <s> Video streaming is gaining popularity among mobile users. The latest mobile devices, such as smart phones and tablets, are equipped with multiple wireless network interfaces. How to efficiently and cost-effectively utilize multiple links to improve video streaming quality needs investigation. In order to maintain high video streaming quality while reducing the wireless service cost, in this paper, the optimal video streaming process with multiple links is formulated as a Markov Decision Process (MDP). The reward function is designed to consider the quality of service (QoS) requirements for video traffic, such as the startup latency, playback fluency, average playback quality, playback smoothness and wireless service cost. To solve the MDP in real time, we propose an adaptive, best-action search algorithm to obtain a sub-optimal solution. To evaluate the performance of the proposed adaptation algorithm, we implemented a testbed using the Android mobile phone and the Scalable Video Coding (SVC) codec. Experiment results demonstrate the feasibility and effectiveness of the proposed adaptation algorithm for mobile video streaming applications, which outperforms the existing state-of-the-art adaptation algorithms. <s> BIB021 </s> A Holistic Survey of Wireless Multipath Video Streaming <s> C. Which is the best path to send the packet? <s> Load distribution is a key research issue in deploying the limited network resources available to support traffic transmissions. Developing an effective solution is critical for enhancing traffic performance and network utilization. In this paper, we investigate the problem of load distribution for real-time traffic over multipath networks. Due to the path diversity and unreliability in heterogeneous overlay networks, large end-to-end delay and consecutive packet losses can significantly degrade the traffic flow’s goodput , whereas existing studies mainly focus on the delay or throughput performance. To address the challenging problems, we propose a G oodput- A ware L oad distribu T i ON (GALTON) model that includes three phases: (1) path status estimation to accurately sense the quality of each transport link, (2) flow rate assignment to optimize the aggregate goodput of input traffic, and (3) deadline-constrained packet interleaving to mitigate consecutive losses. We present a mathematical formulation for multipath load distribution and derive the solution based on utility theory. The performance of the proposed model is evaluated through semi-physical emulations in Exata involving both real Internet traffic traces and H.264 video streaming. Experimental results show that GALTON outperforms existing traffic distribution models in terms of goodput, video Peak Signal-to-Noise Ratio (PSNR), end-to-end delay, and aggregate loss rate. <s> BIB022 </s> A Holistic Survey of Wireless Multipath Video Streaming <s> C. Which is the best path to send the packet? <s> The growing availability of various wireless access technologies promotes increasing demand for mobile video applications. Stream control transmission protocol (SCTP)-based concurrent multipath transfer (CMT) improves the wireless video delivery performance with its parallel transmission and bandwidth (BW) aggregation features. However, the existing CMT solutions deployed at the transport layer only are not accurate enough due to lower layer uncertainties, such as variations of the wireless channel. In addition, CMT-based video transmission may use excessive BW in comparison with the popular Transmission Control Protocol (TCP)-based flows, which results in unfair sharing of network resources. This paper proposes a novel cross-layer fairness-driven (CL/FD) SCTP-based CMT solution (CMT-CL/FD) to improve video delivery performance, while remaining fair to the competing TCP flows. CMT-CL/FD utilizes a cross-layer approach to monitor and analyze path quality, which includes wireless channel measurements at the data-link layer and rate/BW estimations at the transport layer. Furthermore, an innovative window-based mechanism is applied for flow control to balance delivery fairness and efficiency. Finally, CMT-CL/FD intelligently distributes video data over different paths depending on their estimated quality to mitigate packet reordering and loss, under the constraint of TCP-friendly flow control. Simulation results show how CMT-CL/FD outperforms existing solutions in terms of both video delivery performance and TCP-friendliness. <s> BIB023 </s> A Holistic Survey of Wireless Multipath Video Streaming <s> C. Which is the best path to send the packet? <s> Multipathing in communication networks is gaining momentum due to its attractive features of increased reliability, throughput, fault tolerance, and load balancing capabilities. In particular, wireless environments and datacenters are envisioned to become largely dependent on the power of multipathing for seamless handovers, virtual machine (VM) migration and in general, pooling less proficient resources together for achieving overall high proficiency. The transport layer, with its knowledge about end-to-end path characteristics, is well placed to enhance performance through better utilization of multiple paths. Realizing the importance of transport-layer multipath, this paper investigates the modernization of traditional connection establishment, flow control, sequence number splitting, acknowledgement, and flow scheduling mechanisms for use with multiple paths.Multipath rate control defines the fundamental feature of the transport layer. Thus, we study the restructuring of classical utility maximization framework and analyze its stability and convergence. We also examine the topic of multipath congestion control in the light of TCP fairness. To the best of our knowledge, this is the first in-depth survey paper that has chronicled the evolution of the transport layer of the Internet from the traditional single-path TCP to the recent development of the modern multipath TCP (MPTCP) protocol. Along with describing the history of this evolution, we also highlight in this paper the remaining challenges and research issues. Graphical abstractDisplay Omitted <s> BIB024 </s> A Holistic Survey of Wireless Multipath Video Streaming <s> C. Which is the best path to send the packet? <s> Smart devices equipped with multiple network interfaces are becoming commonplace. Nevertheless, even though multiple interfaces can be used to connect to the Internet, their capabilities have not been fully utilized yet because the default TCP/IP stack supports only a single interface for communication. This situation is now changing due to the emergence of multipath protocols on different network stack layers. For example, many IP level approaches have been proposed utilizing tunneling mechanisms for hiding multipath transmission from the transport protocols. Several working groups under IEEE and IETF are actively standardizing multipath transmission on the link layer and transport layer. Application level approaches enable multipath transmission capability by establishing multiple transport connections and distributing data over them. Given all these efforts, it is beneficial and timely to summarize the state-of-the-art, compare their pros and cons, and discuss about the future directions. To that end, we present a survey on multipath transmission and make several major contributions: 1) we present a complete taxonomy pertaining to multipath transmission, including link, network, transport, application, and cross layers; 2) we survey the state-of-the-art for each layer, investigate the problems that each layer aims to address, and make comprehensive assessment of the solutions; and 3) based on the comparison, we identify open issues and pinpoint future directions for multipath transmission research. <s> BIB025 </s> A Holistic Survey of Wireless Multipath Video Streaming <s> C. Which is the best path to send the packet? <s> Recent technological advancements in wireless infrastructures and handheld devices enable mobile users to concurrently receive multimedia contents with different radio interfaces (e.g., cellular and Wi-Fi). However, multipath video transport over the resource-limited and error-prone wireless networks is challenged with key technical issues: 1) conventional multipath protocols are throughput-oriented, and video data are scheduled in a content-agnostic fashion and 2) high-quality real-time video is bandwidth-intensive and delay-sensitive. To address these critical problems, this paper proposes a bandwidth-efficient multipath streaming (BEMA) protocol featured by the priority-aware data scheduling and forward error correction-based reliable transmission. First, we present a mathematical framework to formulate the delay-constrained distortion minimization problem for concurrent video transmission over multiple wireless access networks. Second, we develop a joint Raptor coding and data distribution framework to achieve target video quality with minimum bandwidth consumption. The proposed BEMA is able to effectively mitigate packet reordering and path asymmetry to improve network utilization. We conduct performance evaluation through extensive emulations in Exata involving real-time H.264 video streaming. Compared with the existing multipath protocols, BEMA achieves appreciable improvements in terms of video peak signal-to-noise ratio, end-to-end delay, bandwidth utilization, and goodput. Therefore, BEMA is recommended for streaming high-quality real-time video to multihomed terminals in heterogeneous wireless networks. <s> BIB026 </s> A Holistic Survey of Wireless Multipath Video Streaming <s> C. Which is the best path to send the packet? <s> The proliferating wireless infrastructures with complementary characteristics prompt the bandwidth aggregation for concurrent video transmission in heterogeneous access networks. Multipath TCP (MPTCP) is an important transport-layer protocol recommended by IETF to integrate different access medium (e.g., Cellular and Wi-Fi). This paper investigates the problem of mobile video delivery using MPTCP in heterogeneous wireless networks with multihomed terminals. To achieve the optimal quality of real-time video streaming, we have to seriously consider the path asymmetry in different access networks and the disadvantages of the data retransmission mechanism in MPTCP. Motivated by addressing these critical issues, this study presents a novel quAlity-Driven MultIpath TCP (ADMIT) scheme that integrates the utility maximization based Forward Error Correction (FEC) coding and rate allocation. We develop an analytical framework to model the MPTCP-based video delivery quality over multiple communication paths. ADMIT is able to effectively integrate the most reliable access networks with FEC coding to minimize the end-to-end video distortion. The performance of ADMIT is evaluated through extensive semi-physical emulations in Exata involving H.264 video streaming. Experimental results show that ADMIT outperforms the reference transport protocols in terms of video PSNR (Peak Signal-to-Noise Ratio), end-to-end delay, and goodput. Thus, we recommend ADMIT for streaming high-quality mobile video in heterogeneous wireless networks with multihomed terminals. <s> BIB027 </s> A Holistic Survey of Wireless Multipath Video Streaming <s> C. Which is the best path to send the packet? <s> Delivering high-definition (HD) wireless video under stringent delay constraint is challenging with regard to the limited network resources and high transmission rate. Concurrent multipath transfer (CMT) using stream control transmission protocol (SCTP) exploits the multihoming feature of mobile devices to establish associations with different access networks. In this paper, we study the multihomed HD video communication with SCTP over heterogeneous wireless networks. The existing CMT schemes mainly treat the traffic data in a content-agnostic fashion, and thus cannot effectively leverage the scarce wireless resources to maximize the perceived video quality. To address this critical issue, we propose a content-aware CMT (CMT-CA) solution that featured by the unequal frame-level scheduling based on estimated video parameters and feedback channel status. First, we develop an analytical framework to model the total distortion of parallel video transmission over multiple wireless access networks. Second, we introduce a joint congestion control and data distribution scheme to minimize the total distortion based on online quality evaluation and Markov decision process (MDP). The performance of CMT-CA is evaluated through extensive semi-physical emulations in Exata involving HD video encoded with H.264 codec. Experimental results show that CMT-CA outperforms the reference schemes in terms of video peak signal-to-noise ratio (PSNR), end-to-end delay, and goodput. Or conversely, CMT-CA achieves the same video quality with $20$ percent bandwidth conservation. <s> BIB028 </s> A Holistic Survey of Wireless Multipath Video Streaming <s> C. Which is the best path to send the packet? <s> In order to improve the Quality-of-Service (QoS) of latency sensitive applications in next-generation cellular networks, multi-path is adopted to transmit packet stream in real-time to achieve high-quality video transmission in heterogeneous wireless networks. However, multi-path also introduces two important challenges: out-of-order issue and reordering delay. In this paper, we propose a new architecture based on Software Defined Network (SDN) for flow aggregation and flow splitting, and then design a Multiple Access Radio Scheduling (MARS) scheme based on relative Round-Trip Time (RTT) measurement. The QoS metrics including end-to-end delay, throughput and the packet out-of-order problem at the receiver have been investigated using the extensive simulation experiments. The performance results show that this SDN architecture coupled with the proposed MARS scheme can reduce the end-to-end delay and the reordering delay time caused by packet out-of-order as well as achieve a better throughput than the existing SMOS and Round-Robin algorithms. <s> BIB029 </s> A Holistic Survey of Wireless Multipath Video Streaming <s> C. Which is the best path to send the packet? <s> End-users in online video services are sensitive to the overall quality of the video at screen, but also, and more importantly, to other factors, including the latency between the video generation and the playback for live videos. If the improvement of the quality of the perceived video has been well investigated by the multimedia community, the impact of delay, latency, and re-buffering has not received a significant attention. Adaptive streaming technologies, which have been widely adopted in the recent years, contribute to this lack of consideration since vendors usually recommend the introduction of significant extra-latency. In this paper, we address the problem of low-latency live video streaming. We propose an implementation of multi-path video delivery at the applicative level, which exploits the information provided in the latest version of the video delivery standards. We present an implementation of a video player, which takes advantage of multi-path networking to enable video playback using TCP with a latency below 100 ms. By initiating the multi-path delivery from the client side, our mechanism is compatible with current network equipments and does not require any change neither at the server nor in the middleboxes. <s> BIB030 </s> A Holistic Survey of Wireless Multipath Video Streaming <s> C. Which is the best path to send the packet? <s> One major concern when applying Multipath TCP (MPTCP) to the real-time multimedia applications is related to MPTCP's fully-reliable and fully-ordered service nature, which will inevitably degrade users' Quality of Experience (QoE) for multimedia streaming services in a heterogeneous wireless network environment because asymmetric wireless links are commonly with different transmission characteristics and sensitive to variations. In this paper, we first discuss the design considerations of partially reliable-MPTCP associated with the real-time constraint of multimedia streaming. Then we propose a context-aware QoE-oriented MPTCP Partial Reliability extension (PR-MPTCP+) for providing partially reliable multimedia streaming service to an upper layer protocol. Finally, we evaluate the proposed PR-MPTCP+ solution using a wide range of multimedia quality metrics. <s> BIB031 </s> A Holistic Survey of Wireless Multipath Video Streaming <s> C. Which is the best path to send the packet? <s> Transport protocols that can exploit multiple paths, especially MPTCP, do not match the requirements of video streaming: high average transmission delay, too strict reliability, and frequent head-of-line phenomenons resulting in abrupt throughput drops. In this paper, we address this mismatch by introducing a cross-layer scheduler, which leverages information from both application and transport layers to re-order the transmission of data and prioritize the most significant parts of the video. Our objective is to maximize the amount of video data that is received in time at the client. We show that current technologies enable the implementation of this cross-layer scheduler without much overhead. We then demonstrate the validity of our approach by studying the performance of an optimal cross-layer scheduler. The gap between the performance of the traditional scheduler versus the optimal scheduler justifies our motivation to implement a cross-layer scheduler in practice. We propose one implementation with basic cross-layer awareness. To evaluate the performance of our proposal, we aggregate a dataset of real MPTCP sessions and we use video stream encoded with HEVC. Our results show that our cross-layer proposal outperforms the traditional scheduler. Viewers not only benefit from the inherent advantages of using MPTCP (such as a better resilience to path failure) but also get a better QoE compared to the traditional scheduler. <s> BIB032 </s> A Holistic Survey of Wireless Multipath Video Streaming <s> C. Which is the best path to send the packet? <s> Making networks aware of applications and vice versa is a current trend in the design of emerging network management and service architectures. Additionally, new protocols and application adaptation approaches have been proposed in order to enhance the transmission of Quality of Service (QoS) sensitive data in the best effort Internet. This paper contributes to the field by studying means to improve the quality and availability of video streaming services in multi-access networks through controlled bitrate adaptation and multipath capabilities. The paper proposes a network management system to achieve advanced control and improved performance for multipath adaptive HTTP video streaming in multi-access networks. The management system builds upon the Distributed Decision Engine (DDE) framework and it is partially implemented and evaluated in the paper using a multi-access network testbed. <s> BIB033 </s> A Holistic Survey of Wireless Multipath Video Streaming <s> C. Which is the best path to send the packet? <s> This paper presents a unique probing scheme, a rate adjustment algorithm, and a modified excursion detection algorithm (EDA) for estimating the available bandwidth (ABW) of an end-to-end network path more accurately and less intrusively. The proposed algorithm is based on the well-known concept of self-induced congestion and it features a unique probing train structure in which there is a region where packets are sampled more frequently than in other regions. This high-density region enables our algorithm to find the turning point more accurately. When the dynamic ABW is outside of this region, we readjust the lower rate and upper rate of the packet stream to fit the dynamic ABW into that region. We appropriately adjust the range between the lower rate and the upper rate using spread factors, which enables us to keep the number of packets low, and we are thus able to measure the ABW less intrusively. Finally, to detect the ABW from the one-way queuing delay, we present a modified EDA from PathChirps’ original EDA to better deal with sudden increase and decrease in queuing delays due to cross traffic burstiness. For the experiments, an Android OS-based device was used to measure the ABW over a commercial 4G/LTE mobile network of a Japanese mobile operator, as well, as real testbed measurements were conducted over fixed and WLAN network. Simulations and experimental results show that our algorithm can achieve ABW estimations in real time and outperforms other stat-of-the-art measurement algorithms in terms of accuracy, intrusiveness, and convergence time. <s> BIB034 </s> A Holistic Survey of Wireless Multipath Video Streaming <s> C. Which is the best path to send the packet? <s> Delivering high-quality mobile video with the limited radio resources is challenging due to the time-varying channel status and stringent Quality of Service (QoS) requirements. Multi-homing support enables mobile terminals to establish multiple simultaneous associations for enhancing transmission performance. In this paper, we study the multi-homed communication of delay-constrained High Definition (HD) video in heterogeneous wireless networks. The low-delay encoded HD video streaming consists exclusively of Intra (I) and Predicted (P) frames. In the capacity-limited wireless networks, it is highly possible the large-size I frames experience deadline violations and induce severe quality degradations. To address the challenging problem, we propose a novel scheduling framework dubbed del A y S tringent CO ded T ransmission (ASCOT) that featured by frame-level data protection and allocation over multiple wireless access networks . First, we perform online video distortion estimation to simulate multi-homed transmission impairments according to the feedback channel status and input video data. Second, we control the frame protection level by adapting the Forward Error Correction (FEC) coding redundancy and video data allocation to achieve target quality. The performance of the proposed ASCOT is evaluated through semi-physical emulations in Exata using real-time H.264 video streaming. Experimental results show that ASCOT outperforms existing transmission schemes in improving the video PSNR (Peak Signal-to-Noise Ratio), reducing the end-to-end delay, and increasing the goodput. Or conversely, ASCOT achieves the same video quality with approximately $20$ percent bandwidth conservation . <s> BIB035 </s> A Holistic Survey of Wireless Multipath Video Streaming <s> C. Which is the best path to send the packet? <s> Compared with using only a single wireless path such as WiFi, leveraging multipath (e.g., WiFi and cellular) can dramatically improve users' quality of experience (QoE) for mobile video streaming. However, Multipath TCP (MPTCP), the de-facto multipath solution, lacks the support to prioritize one path over another. When applied to video streaming, it may cause undesired network usage such as substantial over-utilization of the metered cellular link. In this paper, we propose MP-DASH, a multipath framework for video streaming with the awareness of network interface preferences from users. The basic idea behind MP-DASH is to strategically schedule video chunks' delivery and thus satisfy user preferences. MP-DASH can work with a wide range of off-the-shelf video rate adaptation algorithms with very small changes. Our extensive field studies at 33 locations in three U.S. states suggest that MP-DASH is very effective: it can reduce cellular usage by up to 99% and radio energy consumption by up to 85% with negligible degradation of QoE, compared with off-the-shelf MPTCP. <s> BIB036 </s> A Holistic Survey of Wireless Multipath Video Streaming <s> C. Which is the best path to send the packet? <s> MPTCP (MultiPath TCP) boosts application network performance by aggregating bandwidth over multiple paths. However, it may cause poor performance due to the large number of out-of-order packets especially when the paths have different delays. To resolve this issue, we propose to dynamically add or remove MPTCP paths with the leverage of software-defined networking (SDN). The key idea is to track the available capacity of connected paths and pick the most appropriate paths depending on varying network conditions. To show the feasibility of our approach, we create an SDN platform using Mininet over Wi-Fi networks. Our analysis shows that a faster download and improved quality of experience (QoE) in adaptive rate video streaming is possible with our dynamic MPTCP path control mechanism using SDN. <s> BIB037 </s> A Holistic Survey of Wireless Multipath Video Streaming <s> C. Which is the best path to send the packet? <s> Bandwidth constraints and high end-to-end delays are real challenges for achieving and sustaining high quality mobile video streaming services. Diverse multipath transmission techniques are being investigated as possible solutions, since recent developments have enabled mobile devices users to receive video data simultaneously over multiple interfaces (e.g., LTE and WiFi). While some multipath protocols have been recently standardized for this purpose (e.g., MPTCP), being network layer protocols they cannot properly handle challenging transmission scenarios subject to packet losses and congestion, such as lossy wireless channels. In this work, we adopt the MPEG Media Transport (MMT) protocol to propose an improvement for mobile multipath video streaming solutions. MMT is an application layer protocol with inherent hybrid media delivery properties. We propose a novel path-and-content-aware scheduling strategy for MMT by means of full cooperation between network metrics and video content features. Our strategy provides better models to adaptively cope with unstable communication channel conditions and to improve the final user quality of experience (QoE). For the experimental evaluation, we used NS3-DCE to simulate a realistic multipath network scenario which includes channel error models and background traffic. Results for two video sequences are presented in terms of PSNR, SSIM, goodput, delay and packet loss rates. When compared with a simple scheduling strategy for the traditional multipath MMT, our approach yields significant packet loss rate reductions (~90%) and video quality improvements of around 12 dB for PSNR and 0.15 for SSIM. <s> BIB038
Before discussing how could select the proper path to transfer the packet, it is worthwhile to mention that using many paths for data transmission does not always lead to better QoE, since many paths for video delivery make large overheads due to parallel connections BIB024 . According to BIB001 , it is possible to achieve maximum multipath benefits with just using two paths by using a proper scheduling strategy. The simplest scheduling strategy is Round Robin BIB025 . This strategy sorts paths and sends data to the next available path in circular order without taking into account the heterogeneous paths' characteristics. In Round Robin strategy, slow channels would be overloaded while fast channels remain underutilized (e.g., CMT BIB003 ). Obviously, scheduling strategies that are aware of path characteristics (e.g., RTT, packet loss rate) generate wiser scheduling decisions. These strategies generally referred to pathaware scheduling strategies. For example, Weighted Round Robin (WRR) is a scheduling strategy which assigns weight to each path. Weight shows path capability regarding available bandwidth/delay/packet loss rate. This way, data distribution is proportional to the path transmission capability (e.g., MPTCP and FRA-JSCC BIB015 ). Earliest Delivery Path First (EDPF) is another scheduling strategy that estimates the delivery time of each packet over each path. Then, the packets are transmitted over the fastest path in order to prevent from missing their deadlines and minimizing packet-reordering (e.g., BAG BIB004 and MPLOT BIB007 ). Finding End-to-End path capability of real-time video traffic communication leads to estimate path quality or path reliability BIB038 , BIB026 , BIB027 , BIB016 . Therefore, scheduling strategy could map higher priority packets to the more reliable or qualified paths (assume that it is a combination of content-aware and path-aware scheduling strategy). It is important to note here that mapping many packets to most qualified or reliable paths pushes congestion over that path, and consequently decreases video quality, which is called load imbalance problem BIB020 . Therefore, using a method to balance the data over the available paths is required. In our surveyed works, BEMA BIB026 , BIB017 , ADMIT BIB027 , CMT-CA BIB028 , CMT-DA BIB020 and GALTON BIB022 use load balancing mechanism to avoid imbalance problem. Most network characteristics that are used to find the quality or reliability probability of network channels are RTT/Delay, PLR, Available bandwidth/Throughput/Goodput. There are also some other metrics that lead to better path selection and scheduling decision, such as delay constraint and video distortion at flow level. These network characteristics and metrics will be discussed in this subsection. Tables V, VI, VII, and VIII present each category per protocol layer. 1) RTT/Delay: Round Trip Time (RTT) is the time required for a packet to be sent plus the time it takes to receive an ACK of that packet BIB022 , BIB027 . Therefore, RTT consists of the packet transmission time and path propagation delay BIB027 . In order to avoid sudden variations of RTT, some approaches (e.g., MPTCP and SCTP) apply a smoothing factor to the RTT which is called smooth Round Trip Time (sRTT). In the approaches without ACK method, for example, UDP-based approaches, one-way delay could be considered instead of RTT. Considering RTT/Delay for path scheduling decreases the probability of expired arrival packets, stall or out-of-order packet delivery. In our surveyed works, MARS BIB029 , which is implemented over separate TCP connections, utilized a relative RTT measurement method based on OpenFlow protocol. In this approach, duplicated packets (probes) are sent through different interfaces. The probes would return to the sender through the common reverse path from the edge switch close to the client side. The transfer process can be implemented with the tables of OpenFlow at the edge switch. The approach measures the relative delay of forward paths instead of their absolute delay because, in case of absolute forward path delays, the tight clock synchronization between sender and receiver is required. More information and comparison details between relative and absolute delay can be found at BIB005 . In SCTP protocol, the acknowledgment of the sent packet (SACK) can be transmitted over different paths. Mostly the acknowledgment packet returns through the most reliable path to mitigate the probability of dropped or overdue feedback packets. Since paths have different delay characteristics, the estimated RTT is incorrect and using this estimated RTT to find the path quality leads to the wrong result. For this reason, CMT-QA BIB016 does not use RTT directly. Instead, it uses transmission delay. Transmission delay refers to the time difference between the time of the first chunk entering each path sender buffer from a group of distributed data chunks and the time of the last chunk leaving the path sender buffer. CMT-CL/FD BIB023 utilizes the SCTP heartbeat mechanism to calculate RTT. In this mechanism, the HEARTBEAT-ACKs have to return through the same path used to send the HEARTBEAT messages. Since in RTCP protocol, which is generally used by RTP, is possible to calculate RTT by using sender and receiver reports, the multipath transmission approaches over RTP, such as MRTP BIB006 and MPRTP BIB018 extended RTCP in order to calculate RTT in multipath transmission solutions. FRA-JSCC BIB015 and BAG BIB004 , which are the approaches that use UDP as transport protocol, utilize propagation delay. FRA-JSCC BIB015 calculates propagation delay network characteristic by using the existing time stamp in each header packet. RTT/Delay is also used for packet loss differentiation decision in CMT-QA BIB016 , CMT-CL/FD BIB023 , BEMA BIB026 , ADMIT BIB027 , GALTON BIB022 , and CMT-CA BIB028 . More technical details on packet loss differentiation are provided in Section VI-A. Besides, RTT/Delay can also be used for other tasks. For example, MRTP BIB006 sets retransmission timeout value by RTT, and Greenbag BIB019 utilizes RTT to determine when to send requests for the next segments. Other surveyed works, which consider RTT/Delay network characteristic for their scheduling decision are BIB030 , BIB038 , BIB009 , BIB010 , BIB011 , BIB017 , MPLOT BIB007 , MP-DCCP BIB012 , MPTCP-SD BIB013 , MPTCP-PR BIB013 , PR-MPTCP + BIB031 , CMT-DA BIB020 , BIB032 , and BIB033 . 2) PLR: Packet Loss Rate (PLR) comprises of network transmission lost packets, which are lost/error arrived packets during the communication paths, and the expired arrival packets (overdue) BIB022 . Three basic reasons cause packet losses BIB016 ; 1) congestion due to limited bandwidth or buffer size, 2) noise or interference in the wireless networks, 3) path failure or handover. Therefore, sending highest priority frame packets on the paths with less PLR leads to better QoE. Besides, PLR network characteristic and distinguishing packet loss differentiation are key factors for adaptively FEC protection (Section V-B1), avoiding unnecessary fast retransmission (Section IV-B), and video distortion estimation (Section V-A2 and Section V-C5). PLR is considered for scheduling decision in the following works: MRTP BIB006 , MPRTP BIB018 , BIB038 , BEMA BIB026 , BIB017 , MPLOT BIB007 , MP-DCCP BIB012 , ADMIT BIB027 , CMT-DA BIB020 , CMT-CA BIB028 , BIB032 , GALTON BIB022 , FRA-JSCC BIB015 , and CMT-CL/FD BIB023 . 3) Available bandwidth/Throughput/Goodput: Available bandwidth is defined as the maximum video rate that can be transmitted over End-to-End path BIB027 . Different methods are introduced to estimate available bandwidth in the literature BIB034 ,  , BIB008 . Some approaches utilize throughput or goodput for this purpose. The amount of data that could traverse through a path is known as throughput. Throughput refers to all useful and not useful data, including data retransmissions, and overhead data (e.g., headers). If the scheduler considers only throughput among all network characteristics, it may distribute packets over high loss rate channels, and consequently, serious degrade of goodput performance and video quality occurs BIB035 . Goodput refers to the amount of useful data (exclusive protocol overhead or retransmission) delivered successfully to the destination within the imposed specific deadline BIB022 . Goodput is also known as application level throughput. Regarding BIB027 , the approaches over HTTP/TCP could estimate the available bandwidth by using the observed TCP throughput. In our surveyed works, BIB017 measures bandwidth by using Abing  . GALTON BIB022 and FRA-JSCC BIB015 implement pathChirp algorithm BIB002 for this purpose. CMT-CL/FD BIB023 computes available bandwidth as the ratio between the average packet length and average inter-packet sending time. CMT-CA BIB028 and CMT-DA BIB020 believe that cwnd has effect on bandwidth, therefore, these works calculate it as (cwnd/RT T ). In RTRA BIB021 , once a segment has been successfully downloaded, the transmission bandwidth would be calculated as division of the total size of transmitted data over the transmission time, and then, a Markov channel model is used to estimate future available bandwidth. Other surveyed works, which consider Available bandwidth/Throughput/Goodput network characteristic for their scheduling decision are MRTP BIB006 , MPRTP BIB018 , BIB014 , BIB038 , BIB009 , BIB010 , BIB011 , Greenbag BIB019 , BEMA BIB026 , ADMIT BIB027 , PR-MPTCP + BIB031 , MARS BIB029 , BAG BIB004 , BIB032 , MP-DASH BIB036 , BIB037 .