A Survey on Cross-Layer Design Frameworks for Multimedia Applications over Wireless Networks
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paper_title: Cross-layer QoS support for multimedia delivery over wireless internet

paper_content:

Delivering multimedia over wireless Internet is a very challenging task. Multimedia delivery inherently has strict quality-of-service (QoS) requirement on bandwidth, delay, and delay jitter. However, the current Internet can only support best-effort service, which imposes varying network conditions during multimedia delivery. The advent of wireless networks further exacerbates the variance of network conditions and brings greater challenges for multimedia delivery. To improve perceived media quality by end users over wireless Internet, QoS supports can be addressed in different layers, including application layer, transport layer, link layer, and so forth. This paper presents a framework, which provides QoS support, for multimedia delivery over wireless Internet, across different layers. To provide efficient QoS support for different types of media over the best-effort networks, we first propose a cross-layer architecture, which combines the application-level, transport-layer, as well as link-layer controls, and then review recent advances in each individual component. Specifically, dynamic estimation of varying channel and network, adaptive and energy-efficient application and link-level error control, efficient congestion control, header compression, adaptive automatic repeat request (ARQ) and priority-based scheduling, as well as QoS-adaptive proxy caching technologies are explicitly reviewed in this paper.
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paper_title: Cross-layer design for resource allocation in 3G wireless networks and beyond

paper_content:

Cross-layer design approaches are critical for efficient utilization of the scarce radio resources with QoS provisioning in the third-generation wireless networks and beyond. Better system performance can be obtained from information exchanges across protocol layers, which may not be available in the traditional layering architecture. This article provides an overview of cross-layer design approaches for resource allocation in 3G CDMA networks, summarizes state-of-the-art research results, and suggests further research issues. In addition, a cross-layer design approach for real-time video over time-varying CDMA channels is proposed, where link layer resource allocation benefits from information in both the application and physical layers. Simulations results are given to demonstrate the effectiveness of the proposed approach.
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paper_title: A cross-Layer quality-of-service mapping architecture for video delivery in wireless networks

paper_content:

Providing quality-of-service (QoS) to video delivery in wireless networks has attracted intensive research over the years. A fundamental problem in this area is how to map QoS criterion at different layers and optimize QoS across the layers. In this paper, we investigate this problem and present a cross-layer mapping architecture for video transmission in wireless networks. There are several important building blocks in this architecture, among others, QoS interaction between video coding and transmission modules, QoS mapping mechanism, video quality adaptation, and source rate constraint derivation. We describe the design and algorithms for each building block, which either builds upon or extend the state-of-the-art algorithms that were developed without much considerations of other layers. Finally, we use simulation results to demonstrate the performance of the proposed architecture for progressive fine granularity scalability video transmission over time-varying and nonstationary wireless channel.
---
paper_title: Cross-layer QoS support for multimedia delivery over wireless internet

paper_content:

Delivering multimedia over wireless Internet is a very challenging task. Multimedia delivery inherently has strict quality-of-service (QoS) requirement on bandwidth, delay, and delay jitter. However, the current Internet can only support best-effort service, which imposes varying network conditions during multimedia delivery. The advent of wireless networks further exacerbates the variance of network conditions and brings greater challenges for multimedia delivery. To improve perceived media quality by end users over wireless Internet, QoS supports can be addressed in different layers, including application layer, transport layer, link layer, and so forth. This paper presents a framework, which provides QoS support, for multimedia delivery over wireless Internet, across different layers. To provide efficient QoS support for different types of media over the best-effort networks, we first propose a cross-layer architecture, which combines the application-level, transport-layer, as well as link-layer controls, and then review recent advances in each individual component. Specifically, dynamic estimation of varying channel and network, adaptive and energy-efficient application and link-level error control, efficient congestion control, header compression, adaptive automatic repeat request (ARQ) and priority-based scheduling, as well as QoS-adaptive proxy caching technologies are explicitly reviewed in this paper.
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paper_title: TCP Performance Issues over Wireless Links

paper_content:

This article discusses the problems arising when the TCP/IP protocol suite is used to provide Internet connectivity over existing and emerging wireless links. Due to the strong drive toward wireless Internet access through mobile terminals, these problems must be carefully studied in order to build improved systems. We review wireless link characteristics using wireless LANs and cellular communications systems as examples. We then outline the performance problems of the TCP/IP protocol suite when employed over those links, such as degraded TCP performance due to mistaking wireless errors for congestion. We present various proposals for solving these problems and examine their benefits and limitations. Finally, we consider the future evolution of wireless systems and the challenges that emerging systems will impose on the Internet protocol suite.
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paper_title: Cross-layer design for resource allocation in 3G wireless networks and beyond

paper_content:

Cross-layer design approaches are critical for efficient utilization of the scarce radio resources with QoS provisioning in the third-generation wireless networks and beyond. Better system performance can be obtained from information exchanges across protocol layers, which may not be available in the traditional layering architecture. This article provides an overview of cross-layer design approaches for resource allocation in 3G CDMA networks, summarizes state-of-the-art research results, and suggests further research issues. In addition, a cross-layer design approach for real-time video over time-varying CDMA channels is proposed, where link layer resource allocation benefits from information in both the application and physical layers. Simulations results are given to demonstrate the effectiveness of the proposed approach.
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paper_title: A cross-layer scheduling algorithm with QoS support in wireless networks

paper_content:

Scheduling plays an important role in providing quality of service (QoS) support to multimedia communications in various kinds of wireless networks, including cellular networks, mobile ad hoc networks, and wireless sensor networks. The authors propose a scheduling algorithm at the medium access control (MAC) layer for multiple connections with diverse QoS requirements, where each connection employs adaptive modulation and coding (AMC) scheme at the physical (PHY) layer over wireless fading channels. Each connection is assigned a priority, which is updated dynamically based on its channel and service status; the connection with the highest priority is scheduled each time. The authors' scheduler provides diverse QoS guarantees, uses the wireless bandwidth efficiently, and enjoys flexibility, scalability, and low implementation complexity. Its performance is evaluated via simulations.
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paper_title: Cross-layer design for resource allocation in 3G wireless networks and beyond

paper_content:

Cross-layer design approaches are critical for efficient utilization of the scarce radio resources with QoS provisioning in the third-generation wireless networks and beyond. Better system performance can be obtained from information exchanges across protocol layers, which may not be available in the traditional layering architecture. This article provides an overview of cross-layer design approaches for resource allocation in 3G CDMA networks, summarizes state-of-the-art research results, and suggests further research issues. In addition, a cross-layer design approach for real-time video over time-varying CDMA channels is proposed, where link layer resource allocation benefits from information in both the application and physical layers. Simulations results are given to demonstrate the effectiveness of the proposed approach.
---
paper_title: Cross-layer QoS support for multimedia delivery over wireless internet

paper_content:

Delivering multimedia over wireless Internet is a very challenging task. Multimedia delivery inherently has strict quality-of-service (QoS) requirement on bandwidth, delay, and delay jitter. However, the current Internet can only support best-effort service, which imposes varying network conditions during multimedia delivery. The advent of wireless networks further exacerbates the variance of network conditions and brings greater challenges for multimedia delivery. To improve perceived media quality by end users over wireless Internet, QoS supports can be addressed in different layers, including application layer, transport layer, link layer, and so forth. This paper presents a framework, which provides QoS support, for multimedia delivery over wireless Internet, across different layers. To provide efficient QoS support for different types of media over the best-effort networks, we first propose a cross-layer architecture, which combines the application-level, transport-layer, as well as link-layer controls, and then review recent advances in each individual component. Specifically, dynamic estimation of varying channel and network, adaptive and energy-efficient application and link-level error control, efficient congestion control, header compression, adaptive automatic repeat request (ARQ) and priority-based scheduling, as well as QoS-adaptive proxy caching technologies are explicitly reviewed in this paper.
---
paper_title: Cross-layer design for resource allocation in 3G wireless networks and beyond

paper_content:

Cross-layer design approaches are critical for efficient utilization of the scarce radio resources with QoS provisioning in the third-generation wireless networks and beyond. Better system performance can be obtained from information exchanges across protocol layers, which may not be available in the traditional layering architecture. This article provides an overview of cross-layer design approaches for resource allocation in 3G CDMA networks, summarizes state-of-the-art research results, and suggests further research issues. In addition, a cross-layer design approach for real-time video over time-varying CDMA channels is proposed, where link layer resource allocation benefits from information in both the application and physical layers. Simulations results are given to demonstrate the effectiveness of the proposed approach.
---
paper_title: Cross-layer design for wireless networks

paper_content:

As the cellular and PCS world collides with wireless LANs and Internet-based packet data, new networking approaches will support the integration of voice and data on the composite infrastructure of cellular base stations and Ethernet-based wireless access points. This article highlights some of the past accomplishments and promising research avenues for an important topic in the creation of future wireless networks. We address the issue of cross-layer networking, where the physical and MAC layer knowledge of the wireless medium is shared with higher layers, in order to provide efficient methods of allocating network resources and applications over the Internet. In essence, future networks will need to provide "impedance matching" of the instantaneous radio channel conditions and capacity needs with the traffic and congestion conditions found over the packet-based world of the Internet. Furthermore, such matching will need to be coordinated with a wide range of particular applications and user expectations, making the topic of cross-layer networking increasingly important for the evolving wireless buildout.
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paper_title: Effective capacity: A wireless link model for support of quality of service

paper_content:

To facilitate the efficient support of quality of service (QoS) in next-generation wireless networks, it is essential to model a wireless channel in terms of connection-level QoS metrics such as data rate, delay, and delay-violation probability. However, the existing wireless channel models, i.e., physical-layer channel models, do not explicitly characterize a wireless channel in terms of these QoS metrics. In this paper, we propose and develop a link-layer channel model termed effective capacity (EC). In this approach, we first model a wireless link by two EC functions, namely, the probability of nonempty buffer, and the QoS exponent of a connection. Then, we propose a simple and efficient algorithm to estimate these EC functions. The physical-layer analogs of these two link-layer EC functions are the marginal distribution (e.g., Rayleigh-Ricean distribution) and the Doppler spectrum, respectively. The key advantages of the EC link-layer modeling and estimation are: 1) ease of translation into QoS guarantees, such as delay bounds; 2) simplicity of implementation; and 3) accuracy, and hence, efficiency in admission control and resource reservation. We illustrate the advantage of our approach with a set of simulation experiments, which show that the actual QoS metric is closely approximated by the QoS metric predicted by the EC link-layer model, under a wide range of conditions.
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paper_title: Channel-adaptive resource allocation for scalable video transmission over 3G wireless network

paper_content:

The paper addresses the important issues of resource allocation for scalable video transmission over third generation (3G) wireless networks. By taking the time-varying wireless channel/network condition and scalable video codec characteristic into account, we allocate resources between source and channel coders based on the minimum-distortion or minimum-power consumption criterion. Specifically, we first present how to estimate the time-varying wireless channel/network condition through measurements of throughput and error rate in a 3G wireless network. Then, we propose a new distortion-minimized bit allocation scheme with hybrid unequal error protection (UEP) and delay-constrained automatic repeat request (ARQ), which dynamically adapts to the estimated time-varying network conditions. Furthermore, a novel power-minimized bit allocation scheme with channel-adaptive hybrid UEP and delay-constrained ARQ is proposed for mobile devices. In our proposed distortion/power-minimized bit-allocation scheme, bits are optimally distributed among source coding, forward error correction, and ARQ according to the varying channel/network condition. Simulation and analysis are performed using a progressive fine granularity scalability video codec. The simulation results show that our proposed schemes can significantly improve the reconstructed video quality under the same network conditions.
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paper_title: A cross-Layer quality-of-service mapping architecture for video delivery in wireless networks

paper_content:

Providing quality-of-service (QoS) to video delivery in wireless networks has attracted intensive research over the years. A fundamental problem in this area is how to map QoS criterion at different layers and optimize QoS across the layers. In this paper, we investigate this problem and present a cross-layer mapping architecture for video transmission in wireless networks. There are several important building blocks in this architecture, among others, QoS interaction between video coding and transmission modules, QoS mapping mechanism, video quality adaptation, and source rate constraint derivation. We describe the design and algorithms for each building block, which either builds upon or extend the state-of-the-art algorithms that were developed without much considerations of other layers. Finally, we use simulation results to demonstrate the performance of the proposed architecture for progressive fine granularity scalability video transmission over time-varying and nonstationary wireless channel.
---
paper_title: Cross-layer design for resource allocation in 3G wireless networks and beyond

paper_content:

Cross-layer design approaches are critical for efficient utilization of the scarce radio resources with QoS provisioning in the third-generation wireless networks and beyond. Better system performance can be obtained from information exchanges across protocol layers, which may not be available in the traditional layering architecture. This article provides an overview of cross-layer design approaches for resource allocation in 3G CDMA networks, summarizes state-of-the-art research results, and suggests further research issues. In addition, a cross-layer design approach for real-time video over time-varying CDMA channels is proposed, where link layer resource allocation benefits from information in both the application and physical layers. Simulations results are given to demonstrate the effectiveness of the proposed approach.
---
paper_title: Cross-layer design for wireless networks

paper_content:

As the cellular and PCS world collides with wireless LANs and Internet-based packet data, new networking approaches will support the integration of voice and data on the composite infrastructure of cellular base stations and Ethernet-based wireless access points. This article highlights some of the past accomplishments and promising research avenues for an important topic in the creation of future wireless networks. We address the issue of cross-layer networking, where the physical and MAC layer knowledge of the wireless medium is shared with higher layers, in order to provide efficient methods of allocating network resources and applications over the Internet. In essence, future networks will need to provide "impedance matching" of the instantaneous radio channel conditions and capacity needs with the traffic and congestion conditions found over the packet-based world of the Internet. Furthermore, such matching will need to be coordinated with a wide range of particular applications and user expectations, making the topic of cross-layer networking increasingly important for the evolving wireless buildout.
---
paper_title: Cross-layer QoS support for multimedia delivery over wireless internet

paper_content:

Delivering multimedia over wireless Internet is a very challenging task. Multimedia delivery inherently has strict quality-of-service (QoS) requirement on bandwidth, delay, and delay jitter. However, the current Internet can only support best-effort service, which imposes varying network conditions during multimedia delivery. The advent of wireless networks further exacerbates the variance of network conditions and brings greater challenges for multimedia delivery. To improve perceived media quality by end users over wireless Internet, QoS supports can be addressed in different layers, including application layer, transport layer, link layer, and so forth. This paper presents a framework, which provides QoS support, for multimedia delivery over wireless Internet, across different layers. To provide efficient QoS support for different types of media over the best-effort networks, we first propose a cross-layer architecture, which combines the application-level, transport-layer, as well as link-layer controls, and then review recent advances in each individual component. Specifically, dynamic estimation of varying channel and network, adaptive and energy-efficient application and link-level error control, efficient congestion control, header compression, adaptive automatic repeat request (ARQ) and priority-based scheduling, as well as QoS-adaptive proxy caching technologies are explicitly reviewed in this paper.
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paper_title: An image transport protocol for the Internet

paper_content:

Images account for a significant and growing fraction of Web downloads. The traditional approach to transporting images uses TCP, which provides a generic reliable, in-order byte-stream abstraction, but which is overly, restrictive for image data. We analyze the progression of image quality at the receiver with time and show that the in-order delivery abstraction provided by a TCP-based approach prevents the receiver application from processing and rendering portions of an image when they, actually, arrive. The end result is that an image is rendered in bursts interspersed with long idle times rather than smoothly. This paper describes the design, implementation, and evaluation of the Image Transport Protocol (ITP) for image transmission over loss-prone congested or wireless networks. ITP improves user-perceived latency using application level framing (ALF) and out-of-order pplication data unit (ADU) delivery achieving significantly better interactive performance as measured by the evolution of peak signal-to-noise ratio (PSNR) with time at the receiver ITP runs over UDP, incorporates receiver-driven selective reliability uses the congestion manager (CM) to adapt to network congestion, and is customizable for specific image formats (e.g., JPEG and JPEG2000). ITP enables a variety of new receiver post-processing algorithms such as error concealment that further improve the interactivity and responsiveness of reconstructed images. Performance experiments using our implementation across a variety of loss conditions demonstrate the benefits of ITP in improving the interactivity of image downloads at the receiver.
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paper_title: The Addition of Explicit Congestion Notification (ECN) to IP

paper_content:

This memo specifies the incorporation of ECN (Explicit Congestion Notification) to TCP and IP, including ECN's use of two bits in the IP header.
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paper_title: Equation-based congestion control for unicast applications

paper_content:

This paper proposes a mechanism for equation-based congestion control for unicast traffic. Most best-effort traffic in the current Internet is well-served by the dominant transport protocol, TCP. However, traffic such as best-effort unicast streaming multimedia could find use for a TCP-friendly congestion control mechanism that refrains from reducing the sending rate in half in response to a single packet drop. With our mechanism, the sender explicitly adjusts its sending rate as a function of the measured rate of loss events, where a loss event consists of one or more packets dropped within a single round-trip time. We use both simulations and experiments over the Internet to explore performance.
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paper_title: Adaptive packet video streaming over IP networks: a cross-layer approach

paper_content:

There is an increasing demand for supporting real-time audiovisual services over next-generation wired and wireless networks. Various link/network characteristics make the deployment of such demanding services more challenging than traditional data applications like e-mail and the Web. These audiovisual applications are bandwidth adaptive but have stringent delay, jitter, and packet loss requirements. Consequently, one of the major requirements for the successful and wide deployment of such services is the efficient transmission of sensitive content (audio, video, image) over a broad range of bandwidth-constrained access networks. These media will be typically compressed according to the emerging ISO/IEC MPEG-4 standard to achieve high bandwidth efficiency and content-based interactivity. MPEG-4 provides an integrated object-oriented representation and coding of natural and synthetic audiovisual content for its manipulation and transport over a broad range of communication infrastructures. In This work, we leverage the characteristics of MPEG-4 and Internet protocol (IP) differentiated service frameworks, to propose an innovative cross-layer content delivery architecture that is capable of receiving information from the network and adaptively tune transport parameters, bit rates, and QoS mechanisms according to the underlying network conditions. This service-aware IP transport architecture is composed of: 1) an automatic content-level audiovisual object classification model; 2) a reliable application level framing protocol with fine-grained TCP-Friendly rate control and adaptive unequal error protection; and 3) a service-level QoS matching/packet tagging algorithm for seamless IP differentiated service delivery. The obtained results demonstrate, that breaking the OSI protocol layer isolation paradigm and injecting content-level semantic and service-level requirements within the transport and traffic control protocols, lead to intelligent and efficient support of multimedia services over complex network architectures.
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paper_title: Real-time constrained TCP-compatible rate control for video over the Internet

paper_content:

This paper describes a rate control algorithm that captures not only the behavior of TCP's congestion control avoidance mechanism but also the delay constraints of real-time streams. Building upon the TFRC protocol , a new protocol has been designed for estimating the bandwidth prediction model parameters. Making use of RTP and RTCP, this protocol allows to better take into account the multimedia flows characteristics (variable packet size, delay ...). Given the current channel state estimated by the above protocol, encoder and decoder buffers states as well as delay constraints of the real-time video source are translated into encoder rate constraints. This global rate control model, coupled with an H.263+ loss resilient video compression algorithm, has been extensively experimented with on various Internet links. The experiments clearly demonstrate the benefits of 1/ the new protocol used for estimating the bandwidth prediction model parameters, adapted to multimedia flows characteristics, and of 2/ the global rate control model encompassing source buffers and end-to-end delay characteristics. The overall system leads to reduce significantly the source timeouts, hence to minimize the expected distortion, for a comparable usage of the TCP-compatible predicted bandwidth.
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paper_title: Cross-layer design of source rate control and congestion control for wireless video streaming

paper_content:

Cross-layer design has been used in streaming video over the wireless channels to optimize the overall system performance. In this paper, we extend our previous work on joint design of source rate control and congestion control for video streaming over the wired channel, and propose a cross-layer design approach for wireless video streaming. First, we extend the QoS-aware congestion control mechanism (TFRCC) proposed in our previous work to the wireless scenario, and provide a detailed discussion about how to enhance the overall performance in terms of rate smoothness and responsiveness of the transport protocol. Then, we extend our previous joint design work to the wireless scenario, and a thorough performance evaluation is conducted to investigate its performance. Simulation results show that by cross-layer design of source rate control at application layer and congestion control at transport layer, and by taking advantage of the MAC layer information, our approach can avoid the throughput degradation caused by wireless link error, and better support the QoS requirements of the application. Thus, the playback quality is significantly improved, while good performance of the transport protocol is still preserved.
---
paper_title: Cross-layer design for resource allocation in 3G wireless networks and beyond

paper_content:

Cross-layer design approaches are critical for efficient utilization of the scarce radio resources with QoS provisioning in the third-generation wireless networks and beyond. Better system performance can be obtained from information exchanges across protocol layers, which may not be available in the traditional layering architecture. This article provides an overview of cross-layer design approaches for resource allocation in 3G CDMA networks, summarizes state-of-the-art research results, and suggests further research issues. In addition, a cross-layer design approach for real-time video over time-varying CDMA channels is proposed, where link layer resource allocation benefits from information in both the application and physical layers. Simulations results are given to demonstrate the effectiveness of the proposed approach.
---
paper_title: Joint Design of Source Rate Control and QoS-Aware Congestion Control for Video Streaming over the Internet

paper_content:

Multimedia streaming over the Internet has been a very challenging issue due to the dynamic uncertain nature of the channels. This paper proposes an algorithm for the joint design of source rate control and congestion control for video streaming over the Internet. With the incorporation of a virtual network buffer management mechanism (VB), the quality of service (QoS) requirements of the application can be translated into the constraints of the source rate and the sending rate. Then at the application layer, the source rate control is implemented based on the derived constraints, and at the transport layer, a QoS-aware congestion control mechanism is proposed that strives to meet the send rate constraint derived from VB, by allowing temporary violation of transport control protocol (TCP)-friendliness when necessary. Long-term TCP-friendliness, nevertheless, is preserved by introducing a rate-compensation algorithm. Simulation results show that compared with traditional source rate/congestion control algorithms, this cross-layer design approach can better support the QoS requirements of the application, and significantly improve the playback quality by reducing the overflow and underflow of the decoder buffer, and improving quality smoothness, while maintaining good long-term TCP-friendliness
---
paper_title: Cross-layer QoS support for multimedia delivery over wireless internet

paper_content:

Delivering multimedia over wireless Internet is a very challenging task. Multimedia delivery inherently has strict quality-of-service (QoS) requirement on bandwidth, delay, and delay jitter. However, the current Internet can only support best-effort service, which imposes varying network conditions during multimedia delivery. The advent of wireless networks further exacerbates the variance of network conditions and brings greater challenges for multimedia delivery. To improve perceived media quality by end users over wireless Internet, QoS supports can be addressed in different layers, including application layer, transport layer, link layer, and so forth. This paper presents a framework, which provides QoS support, for multimedia delivery over wireless Internet, across different layers. To provide efficient QoS support for different types of media over the best-effort networks, we first propose a cross-layer architecture, which combines the application-level, transport-layer, as well as link-layer controls, and then review recent advances in each individual component. Specifically, dynamic estimation of varying channel and network, adaptive and energy-efficient application and link-level error control, efficient congestion control, header compression, adaptive automatic repeat request (ARQ) and priority-based scheduling, as well as QoS-adaptive proxy caching technologies are explicitly reviewed in this paper.
---
paper_title: ARC: the analytical rate control scheme for real-time traffic in wireless networks

paper_content:

Next-generation wireless Internet (NGWI) is expected to provide a wide range of services including real-time multimedia to mobile users. However, the real-time multimedia traffic transport requires rate control deployment to protect shared Internet from unfairness and further congestion collapse. The transmission rate control method must also achieve high throughput and satisfy multimedia requirements such as delay or jitter bound. However, the existing solutions are mostly for the wired Internet, and hence, they do not address the challenges in the wireless environments which are characterized by high bit error rates. In this paper, a new analytical rate control (ARC) protocol for real-time multimedia traffic over wireless networks is presented. It is intended to achieve high throughput and multimedia support for real-time traffic flows while preserving fairness to the TCP sources sharing the same wired link resources. Based on the end-to-end path model, the desired behavior of a TCP source over lossy links is captured via renewal theory. The resulting asymptotic throughput equation is designated as the driving equation for the proposed rate control method. Performance evaluation via simulation experiments reveals that ARC achieves high throughput and meets multimedia traffic expectations without violating good citizenship rules for the shared Internet.
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paper_title: Cross-layer design of source rate control and congestion control for wireless video streaming

paper_content:

Cross-layer design has been used in streaming video over the wireless channels to optimize the overall system performance. In this paper, we extend our previous work on joint design of source rate control and congestion control for video streaming over the wired channel, and propose a cross-layer design approach for wireless video streaming. First, we extend the QoS-aware congestion control mechanism (TFRCC) proposed in our previous work to the wireless scenario, and provide a detailed discussion about how to enhance the overall performance in terms of rate smoothness and responsiveness of the transport protocol. Then, we extend our previous joint design work to the wireless scenario, and a thorough performance evaluation is conducted to investigate its performance. Simulation results show that by cross-layer design of source rate control at application layer and congestion control at transport layer, and by taking advantage of the MAC layer information, our approach can avoid the throughput degradation caused by wireless link error, and better support the QoS requirements of the application. Thus, the playback quality is significantly improved, while good performance of the transport protocol is still preserved.
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paper_title: Cross layer optimization for wireless multi-user video streaming

paper_content:

A cross-layer optimization concept for wireless multi-user video streaming is proposed. We describe a cross layer optimizer that interfaces the video streaming application and the radio link layer by means of parameter abstraction. The optimizer maximizes the end-to-end quality of the video streaming service jointly for all users while efficiently using the wireless resources. Our simulation results for video streaming in a multi-user environment show the performance improvements achievable with this concept. We demonstrate that even for a small number of users and a small number of degrees of freedom in the optimization significant quality improvements can be obtained.
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paper_title: Robust Error Handling for Video Streaming over Mobile Networks

paper_content:

The quality of video streaming in an error-prone environment suffers from packet loss. Since the loss of a packet typically affects a rather large picture area, the performance of error concealment is limited, too. In order to avoid the huge overhead caused by using smaller packet sizes, in this paper we propose and analyze a scheme utilizing the residual redundancy of the encoded video stream. This scheme has two components -(i) syntax analysis implemented at the decoder, allowing exacter localization of errors within the packet and (ii) entropy code resynchronization mechanism based on the out-of-band signalized length indicators. We show that the proposed approach provides substantial improvement in PSNR for the same rate, compared to the standard packet size reduction.
---
paper_title: Cross-layer design for resource allocation in 3G wireless networks and beyond

paper_content:

Cross-layer design approaches are critical for efficient utilization of the scarce radio resources with QoS provisioning in the third-generation wireless networks and beyond. Better system performance can be obtained from information exchanges across protocol layers, which may not be available in the traditional layering architecture. This article provides an overview of cross-layer design approaches for resource allocation in 3G CDMA networks, summarizes state-of-the-art research results, and suggests further research issues. In addition, a cross-layer design approach for real-time video over time-varying CDMA channels is proposed, where link layer resource allocation benefits from information in both the application and physical layers. Simulations results are given to demonstrate the effectiveness of the proposed approach.
---
paper_title: Joint Design of Source Rate Control and QoS-Aware Congestion Control for Video Streaming over the Internet

paper_content:

Multimedia streaming over the Internet has been a very challenging issue due to the dynamic uncertain nature of the channels. This paper proposes an algorithm for the joint design of source rate control and congestion control for video streaming over the Internet. With the incorporation of a virtual network buffer management mechanism (VB), the quality of service (QoS) requirements of the application can be translated into the constraints of the source rate and the sending rate. Then at the application layer, the source rate control is implemented based on the derived constraints, and at the transport layer, a QoS-aware congestion control mechanism is proposed that strives to meet the send rate constraint derived from VB, by allowing temporary violation of transport control protocol (TCP)-friendliness when necessary. Long-term TCP-friendliness, nevertheless, is preserved by introducing a rate-compensation algorithm. Simulation results show that compared with traditional source rate/congestion control algorithms, this cross-layer design approach can better support the QoS requirements of the application, and significantly improve the playback quality by reducing the overflow and underflow of the decoder buffer, and improving quality smoothness, while maintaining good long-term TCP-friendliness
---
paper_title: Cross-layer QoS support for multimedia delivery over wireless internet

paper_content:

Delivering multimedia over wireless Internet is a very challenging task. Multimedia delivery inherently has strict quality-of-service (QoS) requirement on bandwidth, delay, and delay jitter. However, the current Internet can only support best-effort service, which imposes varying network conditions during multimedia delivery. The advent of wireless networks further exacerbates the variance of network conditions and brings greater challenges for multimedia delivery. To improve perceived media quality by end users over wireless Internet, QoS supports can be addressed in different layers, including application layer, transport layer, link layer, and so forth. This paper presents a framework, which provides QoS support, for multimedia delivery over wireless Internet, across different layers. To provide efficient QoS support for different types of media over the best-effort networks, we first propose a cross-layer architecture, which combines the application-level, transport-layer, as well as link-layer controls, and then review recent advances in each individual component. Specifically, dynamic estimation of varying channel and network, adaptive and energy-efficient application and link-level error control, efficient congestion control, header compression, adaptive automatic repeat request (ARQ) and priority-based scheduling, as well as QoS-adaptive proxy caching technologies are explicitly reviewed in this paper.
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paper_title: Overview of Fine Granularity Scalability in MPEG-4 Video Standard

paper_content:

Streaming video profile is the subject of an Amendment of MPEG-4, and is developed in response to the growing need on a video coding standard for streaming video over the Internet. It provides the capability to distribute single-layered frame-based video over a wide range of bit rates with high coding efficiency. It also provides fine granularity scalability (FGS), and its combination with temporal scalability, to address a variety of challenging problems in delivering video over the Internet. This paper provides an overview of the FGS video coding technique in this Amendment of the MPEG-4.
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paper_title: Adaptive Streaming of MPEG-based Audio/Video Content over Wireless Networks

paper_content:

This paper describes a method for robust streaming of combined MPEG audio/video content (encoded either with MPEG-2 or MPEG-4/H.264) over in-home wireless networks. We make use of currently used content distribution format (MPEG Transport Stream) and network protocols (either RTP or TCP/HTTP). The transmitted bit-rate is constantly adapted to the available network bandwidth, such that audio and video artifacts caused by packet loss are avoided. Bit-rate adaptation is achieved by using a packet scheduling technique called I-Frame Delay (IFD), which performs priority-based frame dropping upon insufficient bandwidth. We show an implementation using RTP and an implementation using TCP. Measurements on a real-life demonstrator set-up demonstrate the effectiveness of our approach.
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paper_title: Channel-adaptive resource allocation for scalable video transmission over 3G wireless network

paper_content:

The paper addresses the important issues of resource allocation for scalable video transmission over third generation (3G) wireless networks. By taking the time-varying wireless channel/network condition and scalable video codec characteristic into account, we allocate resources between source and channel coders based on the minimum-distortion or minimum-power consumption criterion. Specifically, we first present how to estimate the time-varying wireless channel/network condition through measurements of throughput and error rate in a 3G wireless network. Then, we propose a new distortion-minimized bit allocation scheme with hybrid unequal error protection (UEP) and delay-constrained automatic repeat request (ARQ), which dynamically adapts to the estimated time-varying network conditions. Furthermore, a novel power-minimized bit allocation scheme with channel-adaptive hybrid UEP and delay-constrained ARQ is proposed for mobile devices. In our proposed distortion/power-minimized bit-allocation scheme, bits are optimally distributed among source coding, forward error correction, and ARQ according to the varying channel/network condition. Simulation and analysis are performed using a progressive fine granularity scalability video codec. The simulation results show that our proposed schemes can significantly improve the reconstructed video quality under the same network conditions.
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paper_title: Video transport over ad hoc networks: Multistream coding with multipath transport

paper_content:

Enabling video transport over ad hoc networks is more challenging than over other wireless networks. The wireless links in an ad hoc network are highly error prone and can go down frequently because of node mobility, interference, channel fading, and the lack of infrastructure. However, the mesh topology of ad hoc networks implies that it is possible to establish multiple paths between a source and a destination. Indeed, multipath transport provides an extra degree of freedom in designing error resilient video coding and transport schemes. In this paper, we propose to combine multistream coding with multipath transport, to show that, in addition to traditional error control techniques, path diversity provides an effective means to combat transmission error in ad hoc networks. The schemes that we have examined are: 1) feedback based reference picture selection; 2) layered coding with selective automatic repeat request; and 3) multiple description motion compensation coding. All these techniques are based on the motion compensated prediction technique found in modern video coding standards. We studied the performance of these three schemes via extensive simulations using both Markov channel models and OPNET Modeler. To further validate the viability and performance advantages of these schemes, we implemented an ad hoc multiple path video streaming testbed using notebook computers and IEEE 802.11b cards. The results show that great improvement in video quality can be achieved over the standard schemes with limited additional cost. Each of these three video coding/transport techniques is best suited for a particular environment, depending on the availability of a feedback channel, the end-to-end delay constraint, and the error characteristics of the paths.
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paper_title: Medium Access Control protocols for ad hoc wireless networks : A survey

paper_content:

Studies of ad hoc wireless networks are a relatively new field gaining more popularity for various new applications. In these networks, the Medium Access Control (MAC) protocols are responsible for coordinating the access from active nodes. These protocols are of significant importance since the wireless communication channel is inherently prone to errors and unique problems such as the hidden-terminal problem, the exposed-terminal problem, and signal fading effects. Although a lot of research has been conducted on MAC protocols, the various issues involved have mostly been presented in isolation of each other. We therefore make an attempt to present a comprehensive survey of major schemes, integrating various related issues and challenges with a view to providing a big-picture outlook to this vast area. We present a classification of MAC protocols and their brief description, based on their operating principles and underlying features. In conclusion, we present a brief summary of key ideas and a general direction for future work.
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Title: A Survey on Cross-Layer Design Frameworks for Multimedia Applications over Wireless Networks

Section 1: Introduction
Description 1: Provide an overview of the evolution of wireless networks, the increasing complexity of traffic, and the resultant quality of service (QoS) requirements. Discuss the challenges and the need for cross-layer design to meet diverse QoS needs.

Section 2: Different QoS Classes of Multimedia Applications
Description 2: Describe the various QoS classifications for multimedia applications over wireless networks, focusing on bit-level, packet-level, call-level, and application-level QoS. Discuss the challenges of mapping QoS parameters across different layers.

Section 3: Cross-Layer Design and Architecture
Description 3: Introduce the concept of cross-layer design and present various frameworks and algorithms in the literature. Highlight their main features, contributions, and areas of application.

Section 4: A Cross-Layer QoS Support Architecture for Multimedia over Wireless Networks
Description 4: Discuss a general architecture based on UMTS for delivering multimedia over wireless networks. Explain the role of each layer and the specific functionalities in the cross-layer architecture.

Section 5: A Cross-Layer Resource Allocation Mechanism for 3G Wireless Networks
Description 5: Elaborate on a proposed cross-layer design framework over CDMA-based networks, focusing on channel-aware scheduling, adaptive TCP, and joint video source/channel coding and power allocation.

Section 6: A Cross-Layer Scheduling Algorithm
Description 6: Describe a scheduling algorithm at the MAC layer for handling multiple connections with diverse QoS requirements, utilizing adaptive modulation and coding schemes.

Section 7: A PHY-MAC Cross-Layer Optimization for Wireless Broadband Network
Description 7: Present a cross-layer optimization mechanism for multimedia traffic over IEEE 802.16 networks. Discuss the combination of adaptive modulation capabilities and multi-rate data encoding.

Section 8: Adaptations at Different Layers of the Protocol Stack
Description 8: Detail the adaptations required at different layers of the protocol stack, including link layer, transport layer, and application layer mechanisms. Discuss issues such as error protection, congestion control, and power saving.

Section 9: Link Layer Adaptation Mechanisms
Description 9: Describe specific link layer adaptation mechanisms such as application adaptive ARQ, priority-based scheduling, and channel-aware scheduling.

Section 10: Transport Layer Adaptation Mechanisms
Description 10: Explain transport layer mechanisms, including Snoop TCP and TCP with Explicit Congestion Notification (ECN), for addressing packet losses and improving TCP performance over wireless networks.

Section 11: Application Layer Adaptation Mechanisms
Description 11: Discuss the application layer QoS control mechanisms, joint source rate control and congestion control, joint source coding and link layer FEC/retransmission, and other relevant approaches.

Section 12: Conclusion
Description 12: Summarize the need for cross-layer adaptations to guarantee QoS for real-time multimedia traffic over wireless networks. Highlight the reviewed mechanisms and discuss the challenges and complexities in designing efficient cross-layer protocols.