A global architecture for the Wi-family

WiMedia, Wi-Fi, WiMax, Wi-Mobile, WiRAN, the Wi-family is getting bigger; so does the network architecture. It is encouraging to see the fast development of the new IEEE wireless technologies promising the ultimate Internet service deployment on wireless and mobile infrastructures since they would offer larger bandwidth at cheaper price compared to the telecommunication wireless radio resource. However it is disquieting to see that the TCP/IP protocol stack which is supposed to be the heart of the Internet services deployment is not evolving as fast as the wireless technologies do. Here we come up with the hard question which is the network performance of the TCP/IP architecture over wireless networks. It is probably too early to decide to replace TCP/IP by another protocol stack for wireless network support, but it is important to not ignore the problem and analyse the main drawbacks of TCP/IP in wireless networks and think about a new architecture of network communication over the wireless networks. This paper provides a brief survey of what we name here the Wi-family wireless technologies, and emphasizes on new network architecture to optimize the TCP/IP behaviour worsen by the wireless characteristics.     

An authenticated re‐encryption scheme for secure file transfer in named data networks

With the fast progress of the Internet and communication technologies, the digital communication is increasingly based on the architecture of TCP/IP. Nevertheless, in TCP/IP's architecture, there are limitations such as data uncertainty and flow overloading. In response to this, a novel architecture has been proposed, which is known as the named data network (NDN). Named data network is an alternative network architecture based on the data each user accesses. Users gain accesses to the data by using an adjacent router (node) that verifies the correctness of the data. In NDN, the router has the capability to store and search for the data. Hence, this architecture largely improves the disadvantages in TCP/IP's architecture. Named data network is a new proposal and relatively under‐researched now. Thus far, an adequate secure file transfer protocol is still unavailable for NDN. In some cases, files are broken or the source fails to authenticate, which results in the need to discover the owner of the file. Furthermore, we believe that NDN should involve an authentication mechanism in the secure file transfer protocol. In view of the above, this paper presents an authenticated re‐encryption scheme for NDN, which offers sender authentication, data confidentiality, and support for potential receivers. Finally, we also propose a security model for sender authentication and prove that the proposed scheme is secure.     

物联网技术与应用研究

 在解析物联网两层基本涵义的基础上,提出了包括底层网络分布、汇聚网关接入、互联网络融合、终端用户应用四部分的物联网系统架构;设计了由网络通信协议、网络控制平台、应用终端平台组成的面向物联网的网络协议体系,并从硬件和软件两个层面讨论了实现物联网的关键技术;在分析当前物联网标准、技术、安全以及应用方面存在问题的基础上提出了未来物联网发展的六个重要理念.     

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.     

基于作战机群的临近空间通信网体系结构设计

在未来空战中,为实现作战机群之间的超视距通信,提出将临近空间通信平台引入战场。首先结合作战机群战场通信的实际情况,设计了临近空间通信网的网络结构;在此基础上,参考开放系统互连体系(OSI)协议模型和数据链的通信协议模型,设计了临近空间通信网的协议结构;最后对影响临近空间通信网络作战性能的指标进行了评估,结果表明临近空间通信网体系结构的设计具有工程上的可行性。     

System lifetime optimization for heterogeneous sensor networks with a hub-spoke technology

As a specific area of sensor networks, wireless in-home sensor networks differ from general sensor networks in that the network has nodes with heterogeneous resources and dissimilar mobility attributes. For example, sensor with different radio coverage, energy capacity, and processing capabilities are deployed, and some of the sensors are mobile and others are fixed in position. The architecture and routing protocol for this type of heterogeneous sensor networks must be based on the resources and characteristics of their member nodes. In addition, the sole stress on energy efficiency for performance measurement is not sufficient. System lifetime is more important in this case. We propose a hub-spoke network topology that is adaptively formed according to the resources of its members. A protocol named resource oriented protocol (ROP) was developed to build the network topology. This protocol principally divides the network operation into two phases. In the topology formation phase, nodes report their available resource characteristics, based on which network architecture is optimally built. We stress that due to the existence of nodes with limitless resources, a top-down appointment process can build the architecture with minimum resource consumption of ordinary nodes. In the topology update phase, mobile sensors and isolated sensors are accepted into the network with an optimal balance of resources. To avoid overhead of periodic route updates, we use a reactive strategy to maintain route cache. Simulation results show that the hub-spoke topology built by ROP can achieve much longer system lifetime.     

Network Layer Access Control for Context-Aware IPv6 Applications

As part of the Lancaster GUIDE II project, we have developed a novel wireless access point protocol designed to support the development of next generation mobile context-aware applications in our local environs. Once deployed, this architecture will allow ordinary citizens secure, accountable and convenient access to a set of tailored applications including location, multimedia and context based services, and the public Internet. Our architecture utilises packet marking and network level packet filtering techniques within a modified Mobile IPv6 protocol stack to perform access control over a range of wireless network technologies. In this paper, we describe the rationale for, and components of, our architecture and contrast our approach with other state-of-the-art systems. The paper also contains details of our current implementation work, including preliminary performance measurements.     

Energy efficiency of dense wireless sensor networks: to cooperate or not to cooperate

Decentralized detection in a network of wireless sensor nodes involves the fusion of information about a phenomenon of interest (PoI) from geographically dispersed nodes. In this paper, we investigate the problem of binary decentralized detection in a dense and randomly deployed wireless sensor network (WSN), whereby the communication channels between the nodes and the fusion center are bandwidth-constrained. We consider a scenario in which sensor observations, conditioned on the alternate hypothesis, are independent but not identically distributed across the sensor nodes. We compare two different fusion architectures, namely, the parallel fusion architecture (PFA) and the cooperative fusion architecture (CFA), for such bandwidth-constrained WSNs, where each sensor node is restricted to send a I-bit information to the fusion center. For each architecture, we derive expression for the probability of decision error at the fusion center. We propose a consensus flooding protocol for CFA and analyze its average energy consumption. We analyze the effects of PoI intensity, realistic link models, consensus flooding protocol, and network connectivity on the system reliability and average energy consumption for both fusion architectures. We demonstrate that a trade-off exists among spatial diversity gain, average energy consumption, delivery ratio of the consensus flooding protocol, network connectivity, node density, and Poll intensity in CFA. We then provide insight into the design of cooperative WSNs     

A summary of the HORNET project: a next-generation metropolitan area network

Metropolitan area networks are currently undergoing an evolution aimed at more efficiently transport of data-oriented traffic. However, the incoming generation of metro networks is based on conventional technology, which prevents them scaling cost-effectively to ultrahigh capacities. We have developed a new architecture and set of protocols for the next generation of metro networks. The architecture, named HORNET (hybrid optoelectronic ring network), is a packet-over-wavelength-division multiplexing ring network that utilizes fast-tunable packet transmitters and wavelength routing to enable it to scale cost-effectively to ultrahigh capacities. A control-channel-based media access control (MAC) protocol enables the network nodes to share the bandwidth of the network while preventing collisions. The MAC protocol is designed to transport variable-sized packets and to provide fairness control to all network end users. The efficiency and the fairness of the MAC protocol is demonstrated with custom-designed simulations. The implementation of the MAC protocol and the survivability of the network have been demonstrated in a laboratory experimental testbed. The article summarizes the accomplishments of the HORNET project, including the design, analysis, and demonstration of a metro architecture and a set of protocols. The HORNET architecture is an excellent candidate for next-generation high-capacity metro networks.     

IPv6网络路由体系架构的建立

由于IPv6地址更加结构化和层次化,使得IPv6网络的路由协议体系与IPv4相比也更加层次化,可扩展性也较优,如何利用这些路由协议的特点构建独立的、便于演进的IPv6网络是目前IPv6研究的重点.本文在简要介绍IPv6路由协议特点的基础上,从影响IPv6路由体系架构的因素、多种EGP(外部网关协议)和IGP(内部网关协议)的选择等方面,对如何建立IPv6网络的路由体系架构进行了分析和研究.     

On the lifetime of wireless sensor networks

We derive a general formula for the lifetime-of wireless sensor networks which holds independently of the underlying network model including network architecture and protocol, data collection initiation, lifetime definition, channel fading characteristics, and energy consumption model. This formula identifies two key parameters at the physical layer that affect the network lifetime: the channel state and the residual energy of sensors. As a result, it provides not only a gauge for performance evaluation of sensor networks but also a guideline for the design of network protocols. Based on this formula, we propose a medium access control protocol that exploits both the channel state information and the residual energy information of individual sensors. Referred to as the max-min approach, this protocol maximizes the minimum residual energy across the network in each data collection.     

Does the IEEE 802.11 MAC protocol work well in multihop wireless adhoc networks?

The IEEE 802.11 MAC protocol is the standard for wireless LANs; it is widely used in testbeds and simulations for wireless multihop ad hoc networks. However, this protocol was not designed for multihop networks. Although it can support some ad hoc network architecture, it is not intended to support the wireless mobile ad hoc network, in which multihop connectivity is one of the most prominent features. In this article we focus on the following question: can the IEEE 802.11 MAC protocol function well in multihop networks? By presenting several serious problems encountered in an IEEE 802.11-based multihop network and revealing the in-depth cause of these problems, we conclude that the current version of this wireless LAN protocol does not function well in multihop ad hoc networks. We thus doubt whether the WaveLAN-based system is workable as a mobile ad hoc testbed     

Signaling and Control Procedures Using Generalized MPLS Protocol for IP over an Optical Network

This paper reviews the existing research activities on signaling and control procedures for IP over optical networks. We focus on the IP‐centric signaling and control architecture based on the generalized multi‐protocol label switching (GMPLS) protocol and analyze various scenarios and technical issues for deploying the IP over an optical network. We analyze the signaling and operations and administration and maintenance requirements for integrating an IP network and an optical network in order to cope with the high bandwidth and poor resource granularity of the optical network, including the optical cross‐connect system. On the basis of network architecture and a reference configuration model, we investigate the GMPLS‐based control architecture and interconnection model appropriate for controlling IP bandwidth and optical lambda resources. The signaling and control procedure based on GMPLS on optical user‐network interface and network‐network interface are comparatively investigated to provide the optical lightpath. We also study protection and restoration procedures to protect link failure when it applies to GMPLS signaling.     

Safari: A self-organizing, hierarchical architecture for scalable ad hoc networking

As wireless devices become more pervasive, mobile ad hoc networks are gaining importance, motivating the development of highly scalable ad hoc networking techniques. In this paper, we give an overview of the Safari architecture for highly scalable ad hoc network routing, and we present the design and evaluation of a specific realization of the Safari architecture, which we call Masai. We focus in this work on the scalability of learning and maintaining the routing state necessary for a large ad hoc network. The Safari architecture provides scalable ad hoc network routing, the seamless integration of infrastructure networks when and where they are available, and the support of self-organizing, decentralized network applications. Safari’s architecture is based on (1) a self-organizing network hierarchy that recursively groups participating nodes into an adaptive, locality-based hierarchy of cells; (2) a routing protocol that uses a hybrid of proactive and reactive routing information in the cells and scales to much larger numbers of nodes than previous ad hoc network routing protocols; and (3) a distributed hash table grounded in the network hierarchy, which supports decentralized network services on top of Safari. We evaluate the Masai realization of the Safari architecture through analysis and simulations, under varying network sizes, fraction of mobile nodes, and offered traffic loads. Compared to both the DSR and the L+ routing protocols, our results show that the Masai realization of the Safari architecture is significantly more scalable, with much higher packet delivery ratio and lower overhead.     

云网融合PCEP应用及端到端保障方案

随着云计算、大数据等新技术的蓬勃发展以及通信基础设施的不断升级,国内三大运营商均提出以智能牵引网络转型,构建集中控制,灵活编排的云网基础架构的发展战略。PCEP 作为一种广泛应用于 SDN架构的路径计算协议,往往应用于解决复杂网络环境跨层、跨域约束路径的计算。从探讨 PCEP 在云网融合场景应用的角度出发,提出了一种基于PCEP的流量端到端保障方案,可实现在本地IP环境下,面向连接的网络通信及端到端业务保障,有助于提升运营商对网络的实时感知、敏捷响应、智能分析等能力,满足通信资源可全局调度、能力可全面开放、架构可灵活调整的运维管理需求。     

QoSMOS: cross-layer QoS architecture for wireless multimedia sensor networks

Wireless multimedia sensor networks (WMSNs), having inherent features and limited resources, require new quality of service (QoS) protocols for real-time and multimedia applications. In this paper, we present a cross-layer QoS architecture (QoSMOS), that unifies network and link layers into a single communication module for QoS provisioning. Based on QoSMOS architecture, we developed an example reference cross-layer protocol, named cross-layer communication protocol (XLCP), enabling scalable service differentiation in WMSNs. Comprehensive analysis of simulation results indicate that the proposed architecture successfully differentiates service classes in terms of soft delay, reliability and throughput domains. A comparative analysis of XLCP and its counterparts is also given to show the superiority of the cross-layer protocol.     

基于OPNET的海上无线Mesh网络路由协议的研究与仿真

针对船舶移动和海洋特殊环境本文采用了无线Mesh自组网来实现海上通信.本文首先介绍了Mesh网络的关键技术和OPNET网络仿真平台,然后给出了海上无线Mesh网络架构,最后通过OPNET平台对OLSR协议、DSR协议和AODV协议的时延、投递率和吞吐量进行了仿真分析,得出AODV协议的性能优于其他两种协议,更适合应用于海上通信.     

ANT-on-YARDS: FPGA/MPU hybrid architecture for telecommunicationdata processing

This paper presents a novel system architecture that combines tightly coupled field programmable gate arrays (FPGA's) and a microprocessing unit (MPU) that we have developed. This system architecture comprises three main programmable devices which yield high flexibility. These devices are a reduced instruction set computer (RISC)-type MPU with memories, programmable interconnection devices, and FPGA's. This system supports various styles of coupling between the FPGA's and the MPU which makes several data processing operations more effective. Furthermore, we indicate the most suitable applications for the system. They are telecommunication data processes involving complex protocol operations and network control algorithms. In this paper, two applications of the system are given. One is for operation, administration, and management (OAM) cell processing on an asynchronous transfer mode (ATM) network. The other is a dynamic remote reconfiguration protocol that enables the functions of the transport data processing system to be updated or changed on-line     

LTE网络接口的协议一致性测试研究

在研究LTE网络演进进程、网络架构及接口协议特性的基础上提出了一种针对X2和S1接口的协议一致性测试方案.从产品实现的角度介绍了该方案的软硬件平台架构.该方案采用硬件解码技术应对LTE网络中高速网络流所带来的协议数据包处理问题,在软件架构中提供开放的用户接口支持自定义的测试例扩展和自定义协议开发,为不断演进的网络在组网...     

Efficient QoS support in a slotted multihop WDM metro ring

A novel distributed access protocol for a slotted wavelength-division-multiplexing (WDM) metro ring employing all-optical packet switching and supporting quality-of-service (QoS) classes is presented and analyzed. Since we assume that there are more nodes than available wavelengths in the network, we obtain a scalable multihop WDM ring as underlying network architecture. By dividing each channel into several time slots and further applying destination release and slot reuse, data packets can be efficiently transmitted and received in a statistically multiplexed manner. In our architecture, each node is equipped with one tunable transmitter and one fixed-tuned receiver. Furthermore, as we generally consider so-called a posteriori access strategies, different packet selection schemes are proposed and compared. An analytical model based on the semi-Markov process methodology is developed to quantify the performance of one of these schemes. As a key element of the protocol, an efficient QoS support access mechanism is proposed and its performance is evaluated. The new QoS control scheme adopts a frame-based slot reservation strategy including connection setup and termination, which only slightly increases the signaling and node processing overhead. Thus, an efficient hybrid protocol combining connectionless and connection-oriented packet transmissions is proposed