Cross-layer design of ad hoc networks for real-time video streaming

Cross-layer design breaks away from traditional network design where each layer of the protocol stack operates independently. We explore the potential synergies of exchanging information between different layers to support real-time video streaming. In this new approach information is exchanged between different layers of the protocol stack, and end-to-end performance is optimized by adapting to this information at each protocol layer. We discuss key parameters used in the cross-layer information exchange along with the associated cross-layer adaptation. Substantial performance gains through this cross-layer design are demonstrated for video streaming.     

A New Systematic Framework for Autonomous Cross-Layer Optimization

Cross-layer optimization solutions have been proposed in recent years to improve the performance of wireless users that operate in a time-varying, error-prone network environment. However, these solutions often rely on centralized cross-layer optimization solutions that violate the layered network architecture of the protocol stack by requiring layers to provide access to their internal protocol parameters to other layers. This paper presents a new systematic framework for cross-layer optimization, which allows each layer to make autonomous decisions to maximize the wireless user's utility by optimally determining what information should be exchanged among layers. Hence, this cross-layer framework preserves the current layered network architecture. Since the user interacts with the wireless environment at various layers of the protocol stack, the cross-layer optimization problem is solved in a layered fashion such that each layer adapts its own protocol parameters and exchanges information (messages) with other layers that cooperatively maximize the performance of the wireless user. Based on the proposed layered framework, we also design a message-exchange mechanism that determines the optimal cross-layer transmission strategies, given the user's experienced environment dynamics.     

Demultiplexed architectures: a solution for efficient STREAMS-basedcommunication stacks

This article analyzes the efficiency of various high-performance implementation techniques for the communication system of UNIX workstations. Using an open system implies that a certain compatibility level is required from the protocol, user interface, and implementation framework. These constraints limit the opportunities to design a high-performance communication system. The authors have designed an experimental platform around the TCP/IP protocol suite, using the STREAMS environment. A BSD TCP/IP stack and a classic STREAMS-based TCP/IP stack serve as reference implementations for performance comparisons. The article explains why the efficiency of some high-performance implementation techniques the authors have applied to this platform is limited. The impacts of the hardware architecture, operating system, and communication stack architecture on performances are analyzed. It is shown that the efficiency of data transmission would benefit from more simplicity and more synchronism in the communication environment, direct data paths between the applications and the device drivers, and a limited ILP integration     

基于协议栈的移动性技术对比分析

传统的协议栈没有对实现移动性的层次进行准确定位，所以几乎协议栈中的每一层都有实现移动性的方案，但对于移动互联网这种异质网络。分层的协议栈效率很低。根据协议栈和移动互联网移动性的特点，从协议栈的链路层、网络层、传输层和应用层上具体分析了各个层实现移动性的优缺点，通过这些分析可见，要给移动互联网中的移动节点提供良好的移动性支持，跨层实现动性是未来移动性发展的趋势。     

下一代无线网络中的跨层设计

下一代无线通信系统必须能够与互联网实现信息交互,这就需要利用通信协议来实现系统与其他通信系统间的互连互通。但是,现有通信协议基于OSI标准,其协议栈按照严格的分层方式工作,很难适应快速变化的无线通信环境。通过对现有协议栈进行改进,加入跨层设计方案则有助于改善下一代无线系统性能。文章简要分析了分层协议栈局限性,讨论了跨层设计原理,并系统地阐述了跨层设计时物理层、链路层、网络层、传输层和应用层协议应考虑的因素。     

基于LTE-A技术无线资源管理的跨层联合博弈

提出了一种在LTE-A(long term evolution advanced,长期演进技术增强)技术下的无线资源管理跨层模型,阐述了模型的基本功能特征。以博弈论为依据,分析了无线网络资源的分配方式,并根据无线网络资源和系统协议栈中各层之间的联系,通过设计跨层结构,使各层博弈的目标统一。提出的理论模型面向多种无线网络资源,涉及多个无线网络协议栈层,实现了无线资源的综合管理以及各层之间的联合优化。     

ad hoc网络中跨层设计方法的研究

ad hoc网络与传统有线和无线蜂窝网络有着显著的区别,基于传统的分层协议栈的设计方法不再适合ad hoc网络,而应采用一种新型的跨层协议栈和跨层设计方法.本文首先阐述了ad hoc网络的特点和传统的分层协议栈的弊端,介绍了跨层设计的概念.然后,详细分析了ad hoc网络中跨层设计的方法,包括策略、体系结构和信令交互方式,探讨了跨层设计的相关技术和面临的挑战.最后,总结了全文并指出了今后的工作方向.     

UPS: Universal Protocol Stack for emerging wireless networks

Recent devices developed for emerging wireless networks, such as 4G cellular networks, wireless mesh networks, and mobile ad hoc networks, support multiple communication substrates and require execution of multiple protocols within a layer, which cannot be supported efficiently by traditional, layered protocol stack approaches. While cross-layer approaches can be designed to support these new requirements, the lack of modularity makes cross-layer approaches inflexible and hence difficult to adapt for future devices and protocols. Thus, there is a need for a new protocol architecture to provide universal support for cross-layer interactions between layers, while also supporting multiple communication substrates and multiple protocols within a stack. In this paper, we propose Universal Protocol Stack (UPS), which provides such support in a modular way through packet-switching, information-sharing and memory management. To show that UPS is realizable with very low overhead and that it enables concurrent and independent execution of protocols of the same stack layer, first, we present a wireless sensor network test-bed evaluation, where UPS is implemented in TinyOS and installed on individual sensor motes. Two cross-layer routing protocols are implemented and evaluated with UPS and without UPS. We also implemented UPS in the OPNET simulator, where the IP (e.g., Routing Information Protocol (RIP)) and AODV routing protocols are executed concurrently to support networks with both static and mobile wireless nodes. Our implementation shows that the overhead incurred to implement UPS is very low, and little or no modification is required to adapt existing protocols to the UPS framework. Both studies also show the advantage of enabling concurrent protocol execution within a stack layer, improving the successful packet delivery ratio or the total number of packets sent for the investigated scenarios.     

轻量级WSN分层协议栈的设计与实现

传统无线网络协议栈存在硬件兼容性弱、内存和CPU占用率高、函数接口复杂等问题,采用此类协议栈将提高项目开发的软硬件成本。设计一种轻量级分层协议栈,通过协议栈架构的分层设计、底层的开放式设计、函数的可重入设计等,使其具有低系统资源占用率、高可移植性和多网卡协同工作的特点。采用IAR EW8051,KEIL MDK,STM32CUBE等作为软件平台,进行协议栈程序的开发与测试。测试结果表明,该协议栈代码量小,可应用于CC1100,CC2500,SI4463, SX1278等无线芯片,且能有效应对复杂环境下的信号干扰,提升点对多通信效果,有较高的实用价值。     

移动WiMAX网络下行链路TCP吞吐量公平性的跨层优化

该文提出了一种移动WiMAX网络中的TCP公平性跨层优化模型,设计了基于此模型的cross-layer TCP改进协议。利用端节点链路层的速率信息和在基站BS(Base Station)处预分配ACK分组所需带宽的策略改善了下行终端的QoS (Quality of Service)指标,保证了下行终端和上行终端的吞吐量公平性。仿真结果表明cross- layer-TCP改进协议能够在保持原有系统吞吐量的前提下改善下行终端的公平性。     

Quanta data storage: an information processing and transportation architecture for storage area networks

A new architecture for storage area networks (SANs) is proposed for providing efficient information processing and transportation. We deviate from the byte stream oriented transmission control protocol (TCP) transport mechanism to more storage friendly block oriented transport. Data is processed, encrypted, error checked, redundantly encoded, and stored in fixed size blocks called quanta. Each quantum is processed by an effective cross-layer protocol that collapses the protocol stack for security, iWARP and iSCSI functions, transport control, and even redundant arrays of inexpensive disk (RAID) storage. This streamlining produces a highly efficient protocol with fewer memory copies and places most of the computational burden and security safeguard on the client, while the target stores quanta from many clients with minimal processing. We propose a new network RAID storage method using the quantum concept. Also, we unify error control and flow control of the iSCSI and TCP protocols in a manner we believe is more suitable for high data rate and low latency storage applications.     

Cross-layer design: a survey and the road ahead

Of late, there has been an avalanche of cross-layer design proposals for wireless networks. A number of researchers have looked at specific aspects of network performance and, approaching cross-layer design via their interpretation of what it implies, have presented several cross-layer design proposals. These proposals involve different layers of the protocol stack, and address both cellular and ad hoc networks. There has also been work relating to the implementation of cross-layer interactions. It is high time that these various individual efforts be put into perspective and a more holistic view be taken. In this article, we take a step in that direction by presenting a survey of the literature in the area of cross-layer design, and by taking stock of the ongoing work. We suggest a definition for cross-layer design, discuss the basic types of cross-layer design with examples drawn from the literature, and categorize the initial proposals on how cross-layer interactions may be implemented. We then highlight some open challenges and new opportunities for cross-layer design. Designers presenting cross-layer design proposals can start addressing these as they move ahead.     

A Cross-Layer Architecture of Wireless Sensor Networks for Target Tracking

We propose the Low Energy Self-Organizing Protocol (LESOP) for target tracking in dense wireless sensor networks. A cross-layer design perspective is adopted in LESOP for high protocol efficiency, where direct interactions between the Application layer and the Medium Access Control (MAC) layer are exploited. Unlike the classical Open Systems Interconnect (OSI) paradigm of communication networks, the Transport and Network layers are excluded in LESOP to simplify the protocol stack. A lightweight yet efficient target localization algorithm is proposed and implemented, and a Quality of Service (QoS) knob is found to control the tradeoff between the tracking error and the network energy consumption. Furthermore, LESOP serves as the first example in demonstrating the migration from the OSI paradigm to the Embedded Wireless Interconnect (EWI) architecture platform, a two-layer efficient architecture proposed here for wireless sensor networks     

Fast Handoff in SIP-Based Next Generation Mobile Networks

It is commonly held that next generation mobile systems will be developed on the Internet in combination with diverse access technologies, as the future network architecture will be the coming together of various overlapping wireless access networks. Integrating various wireless networks in future heterogeneous networking environments poses many difficulties, the most critical challenge of which is efficient support for seamless mobility. SIP is a promising nominee for managing mobility in heterogeneous networks as it provides mobility within the application layer and the characteristics of the lower layer protocols are invisible to it. However, the performance of SIP-based mobility management is downgraded, resulting from its adoption of TCP/UDP for signaling and its strict separation between the lower layers and the application layer of the protocol stack. In this paper, a SIP-based cross-layer design for fast handoffs is proposed to shorten the service interruption time when a mobile node crosses the overlapped area of a WLAN/3G cellular system. As will be shown by the simulation results, the SIP-based solution proposed in this paper effectively lessens the handoff delays caused by either the horizontal handoff or vertical handoff in future all-IP heterogeneous wireless networks.     

VSPLIT: A Cross-Layer Architecture for V2I TCP Services Over 802.11

This article proposes VSPLIT, a new architecture based on TCP cross-layering and splitting techniques for optimizing the transport layer performance in vehicular networks for Internet-based Vehicle-to-Infrastructure (V2I) communications. Our architecture mainly pretends to enhance the performance of TCP handovers in 802.11 networks. VSPLIT includes a cross-layer TCP protocol, called VSPLIT-TCP, that adapts the congestion control during the handover, learning the new characteristics of the network after the handover using the mechanisms provided by the IEEE 802.21 Media Independent Handover (MIH) services. VSPLIT has been implemented and tested in the NS-3 simulator. We include the some of the most interesting performance evaluation results, which show a good performance of our proposal for the intended scenario.     

A high-performance network architecture for a PA-RISC workstation

With current low-cost high-performance workstations, application-to-application throughput is limited more by host memory bandwidth than by the cost of protocol processing. Conventional network architectures are inefficient in their use of this memory bandwidth, because data is copied several times between the application and the network. As network speeds increase further, network architectures must be developed that reduce the demands on host memory bandwidth. The authors discuss the design of a single-copy network architecture, where data is copied directly between the application buffer and the network interface. Protocol processing is performed by the host, and transport layer buffering is provided on the network interface. They describe a prototype implementation for the HP Apollo Series 700 workstation family that consists of an FDDI network interface and a modified 4.3BSD TCP/IP protocol stack, and report some early results that demonstrate twice the throughput of a conventional network architecture and significantly lower latency     

仿真研究无线多跳网络跨层协议设计的优劣

为了改善无线多跳网络的性能，很多研究表明跨层协议设计比OSI模型更适合无线网络。本文分析了无线多跳网络的特征及对各协议层的影响，给出了跨层协议设计对网络性能的改善以及它可能带来的问题，并针对速率自适应MAC协议和网络层路由协议之间的相互影响给出了仿真实例，结果证明跨层协议设计要充分考虑不同协议之间的相互影响，合理规划、谨慎实施，否则网络的性能不升反降。     

Transmission control protocol performance enhancement for mobile broadband interactive satellite communication system: a cross‐layer approach

Mobile broadband interactive satellite communication system is of great interest in both academic and industrial communities. However, the conventional strict‐layered protocol stack architecture and the standard TCP version perform poorly over satellite link. In this paper, we propose a comprehensive cross‐layer Transmission Control Protocol (TCP) optimization architecture while considering the main factors that affect the TCP performance. In our proposed architecture, we adopt two TCP split connection performance enhancing proxies to isolate the satellite link from the terrestrial part of the broadband satellite communication system. Then, based on the proposed cross‐layer architecture, we present an analytical model for the TCP throughput by taking the modulation and coding (ModCod) mode and the allocated bandwidth into account. In addition, we put forward a TCP‐driven bandwidth sharing and ModCod mode optimization algorithm to maximize the TCP throughput in satellite link. Extensive simulation results illustrate that our proposed comprehensive cross‐layer TCP optimization approach is able to improve the TCP throughput significantly. Copyright © 2014 John Wiley & Sons, Ltd.     

嵌入式TCP/IP协议栈的设计与实现

详细描述了TCP/IP协议栈的裁剪、设计和实现方案.该协议栈以PHILIPS LPC2294微处理器、以太网控制器RTL8019AS为硬件平台,采用模块化层次化的结构设计,实现了ARP、IP、ICMP、UDP等协议模块.经过精简后的协议栈代码量小,结构合理,易于移植和扩充.     

Advocating a Remote Socket Architecture for Internet Access Using Wireless LANs

One challenge in the development of telecommunication networks is the seamless integration of wireless devices into the global Internet. Although it is well known that the Internet protocols were designed for heterogeneous networks an end-system with the usual Internet protocol stack will suffer an inefficient communication while connected via a wireless link. The protocol mechanisms of the transport layer can lead to poor performance in case of TCP and a high loss rate in case of UDP. In this paper we advocate a Remote Socket Architecture (ReSoA) which is a kind of proxy-oriented architecture for wireless Internet access in Wireless LAN environment. This approach allows the use of a thin protocol stack on the wireless end-system to save scarce resources and a tailored protocol for the wireless link without breaking the original TCP semantics. We show the suitability of ReSoA by comparing its performance with that of pure TCP and Berkeley Snoop through actual measurements in a test environment.