煤矿井下异构无线 Mes h感知网络融合研究

在综合分析各感知网络和以太网网络特点及其异构性的基础上,提出了分层的异构网络融合网关结构模型,设计了网间通信统一的数据包格式和全网统一的地址编码方式．具有多切换接口的M esh终端,能够根据自动切换管理技术智能地接入不同网络．网关实现了基于802．11、802．15和802．3等协议的语音业务、视频图像业务以及数据传输业务在不同网络间的无障碍通信,网关的双向通信功能,使其连通的两端网络以对等方式通信,最终实现了井下全网互联互通．     

无线传感网与移动通信网融合业务流模型和预测算法研究

由于移动通信网和无线传感网各有特点,且各自的网络结构和协议栈差别较大,两网异构融合产生的多业务数据流量将同时具备局部性、周期性、随机性、突发性等多重特点,结构复杂,对网络运营能力及安全监测带来了技术难题。文中针对多业务流的场景,分析各类业务流模型的特点,提出一种基于异构网的融合业务流模型,并对业务流量通过预测算法进行预测。仿真结果表明,该模型算法的预测精度较高,为异构网的多业务融合起到了重要的支撑作用。     

基于移动IP的SIP协议

移动IP是3G网络实现各种移动业务的关键技术。SIP是提供和实现IP业务的重要协议。未来移动IP网络由于受到地址空间不足的限制,必然要从IPv4发展到IPv6,本文主要讨论SIP协议在IPv6中的应用,并提出了在IP异构网络中实现SIP协议的方式。     

终端通信接入网网络资源分配策略研究

论文在不改变现有国家电网通信网中各种体制网络结构的前提下,通过增加网络融合网关和终端接入网关两种功能实体,提出了一种双通信代理机制的异构网协同融合传输方案,并由此设计实现了基于时延的负载感知的异构网络资源分配算法,实现了多业务综合接入及多网络动态协同环境下的网络资源分配技术。数据分析表明该算法在平均时延、网络开销及丢包率等方面优于均匀分配算法、定时反馈的负载感知流量分配算法。     

DSLAM传输网技术

无线Mesh网络(Wireless Mesh Network,WMN)是一种新兴的源于移动Ad Hoc网络的宽带无线接入技术.它通过网关节点接入因特网.实际应用中当网络接入业务量很大或网络规模扩大时,一个网关节点将成为网络接入性能的"瓶颈",大量转发的数据包将导致严重的拥塞.针对此问题提出一种基于移动自组网DSR协议的多网关选播路由协议MAMSR,仿真实验表明它能有效解决接入拥塞问题.     

物联网ZigBee网关的设计与实现方法

随着传感器、无线通信等技术的迅速的不断发展,物联网在仓库物理、智能电网等领域都得到了广泛的应用。作为计算机网络及移动通讯设备之后的又一次信息革新,如何设计与实现物联网Zig Bee网关成为我们研究的热点。因为物联网中的Big Zee网关的协议与广泛的TCP/IP协议并不一致,这就为实现两种不同的网络的融合带来了难题。本文就主要对此进行深入的探讨。本文主要从网关的内部构造及Zig Bee在以太网中与其他模块之间的交互作用角度出发,探索如何实现异构网络的融合,以达到数据顺利传输和有效处理。     

H.248协议下T.38传真业务的实现

IP技术的发展和新业务需求驱使传统电路交换网络逐步走向统一、融合的多媒体网络,而传统基于电路方式的传真业务也面临全新基于IP网络的实时传真业务挑战,其中的关键技术是基于IP实时传真的ITU标准T.38协议在下一代网络(NGN)中的应用。文中将深入探讨这一问题,重点讨论如何在H.248协议下实现T.38传真业务中软交换和媒体网关的交互。     

基于NS2的移动自组混合网络模拟平台研究

提出了一种统一的移动自组混合网络模型,并在NS2中实现了该网络模型.首先对NS2中的核心模块进行了扩展,使其支持移动节点的多模通信和多信道;其次,在NS2中添加了新的移动网关选取模块.在扩展后的NS2平台上,通过模拟和比较成组位置更新和传统位置更新,验证了仿真平台的正确性和合理性.研究成果为基于蜂窝Ad hoc混合网络结构的协议研究提供了一个较通用的仿真平台.     

无线移动网络与业务的发展及其关键技术研究

文章探讨了B3G无线移动通信网络的发展方向,指出了以用户为中心,面向市场的多业务智能异构泛在网络是新一代无线移动网络的重要特征。并基于多无线电技术、环境感知技术和协作技术研究了未来无线移动网络和业务融合的体系框架,探讨了AN网络和AUN网络的技术及构建方法,设计了基于多种关键技术的智能多业务的异构协作网络体系。     

面向智能小区的全业务家用网关

面向智能小区的全业务家用网关(FSGW)位于家庭内部,既是家庭各种异构网络互联的中心节点,同时又是家庭的多媒体中心,社区信息服务的节点。一个满足全业务模型需求,并且具备协议一致、升级方便、操作简便、高稳定性等特点的低成本、高质量的家用网关,是构建未来集散型家庭网络的关键。     

QoS routing in ad hoc wireless networks

The emergence of nomadic applications have generated much interest in wireless network infrastructures that support real-time communications. We propose a bandwidth routing protocol for quality-of-service (QoS) support in a multihop mobile network. The QoS routing feature is important for a mobile network to interconnect wired networks with QoS support (e.g., ATM, Internet, etc.). The QoS routing protocol can also work in a stand-alone multihop mobile network for real-time applications. This QoS routing protocol contains end-to-end bandwidth calculation and bandwidth allocation. Under such a routing protocol, the source (or the ATM gateway) is informed of the bandwidth and QoS available to any destination in the mobile network. This knowledge enables the establishment of QoS connections within the mobile network and the efficient support of real-time applications. In addition, it enables more efficient call admission control. In the case of ATM interconnection, the bandwidth information can be used to carry out intelligent handoff between ATM gateways and/or to extend the ATM virtual circuit (VC) service to the mobile network with possible renegotiation of QoS parameters at the gateway. We examine the system performance in various QoS traffic flows and mobility environments via simulation. Simulation results suggest distinct performance advantages of our protocol that calculates the bandwidth information. It is particularly useful in call admission control. Furthermore, “standby” routing enhances the performance in the mobile environment. Simulation experiments show this improvement     

Optimized Access Network Selection in a Combined WLAN/LTE Environment

Multimode terminals equipped with multiple radio access technologies are becoming increasingly popular. At the same time, network operators and service providers seek opportunities to deliver seamless services cost effectively, leveraging a variety of radio access technologies using both licensed and unlicensed spectrum. In order to standardize the operations of such complex environments 3GPP is currently working on IP flow mobility and mobile data offload solutions. This article proposes and evaluates a new access network selection procedure in such a combined WLAN/LTE environment. The proposed solution takes not only parameters available in the mobile node and its current and candidate access networks into account, but performs an optimization on the heterogeneous wireless network level as well. An optimization model based on an approximate solution to the well-known bin packing problem is presented. Also, there is a signaling scheme for distribution handling presented. Results from simulations performed in OPNET Modeler show improvements compared to basing handover decisions on locally available information only.     

改善卫星融合网络随机丢包和间歇性中断的方法研究*1

当移动自组织网用户通过网关经卫星网络发送数据时,存在卫星链路的长传播时延、随机丢包以及移动终端的移动性引起链接的间歇性中断,导致TCP触发拥塞控制机制而降低传输性能降低。针对以上卫星网络的特点,提出了TCP M-Veno方法。在发送端对TCP Veno进行优化改进使得它能够缓解卫星网络中长的传播时延和随机丢包的影响。在网关中结合M-TCP算法来解决卫星融合网络移动终端间歇性中断。仿真表明,所提出的TCP M-Veno比NewReno、Veno以及M-TCP有更好的传输性能。     

基于多因素的Ad Hoc网络连通可靠性仿真方法

移动Ad Hoc网络的连通可靠性对于战场的指挥控制、警察与医疗部门的抢险救灾等众多领域具有重要意义。然而当前的移动Ad Hoc网络连通可靠性评估方法大多建模简单,考虑因素单一,而以OPNET为代表的网络仿真只针对网络普通性能分析而没有可靠性分析。因此,目前缺少一种能够涵盖真实场景中节点移动、无线通信特性和复杂地形环境的移动Ad Hoc网络连通可靠性评价方法。针对此问题提出了多因素模型连通可靠性仿真方法,同时结合可靠性定时标准实验方法给出了系统的移动Ad Hoc网络可靠性仿真实验设计方案。并根据具体移动Ad Hoc网络案例,在OPNET中进行二次开发建模与仿真,验证了该多因素连通可靠性仿真方法的可行性。     

基于IPv6的无线传感网异构通信技术研究

文章提出了一种基于IPv6实现6LoWPAN和Zigbee两种异构协议通信的架构——6LoWPAN-IPv6-Zigbee。6LoWPAN-IPv6-Zigbee架构在分析异构节点互通问题的基础上,设计了协议转换、网关功能以及节点交互流程;基于现有的异构节点互通方案,设计了的异构节点互通场景、系统结构、协议转换模式以及网关功能;基于寻址、服务发现等互联互通关键技术,设计了异构节点交互流程。6LoWPAN-IPv6-Zigbee架构可为同时存在Zigbee节点与6LoWPAN节点的混合传感网络提供良好互通性。     

End-to-end QoS provisioning in mobile heterogeneous networks

The remarkable advances in information technologies bring a heterogeneous environment for mobile users and service providers. This heterogeneity exists in wireless access technologies, networks, user terminals, applications, service providers, and so on. The ability to provide seamless and adaptive quality of service in such a heterogeneous environment is key to the success of next-generation wireless communications systems. There has been a considerable amount of QoS research recently. However, the main part of this research has been in the context of individual architectural components, and much less progress has been made in addressing the issue of an overall QoS architecture for the mobile Internet. This article first summarizes the state-of-the-art QoS techniques and standardization activities, then examines in detail important challenges in building a ubiquitous QoS framework over the heterogeneous environment, and finally proposes a QoS framework integrating a three-plane network infrastructure and a unified terminal cross-layer adaptation platform to provide seamless support for future applications.     

Distributed Mapping Management of Identifiers and Locators in LISP-based Mobile Networks

The Locator Identifier Separation Protocol (LISP) has been proposed as an identifier-locator separation scheme for scalable Internet routing. However, LISP was originally designed in the fixed network environment rather than in the mobile network environment. In particular, the existing LISP mobility schemes are based on a centralized map server that is used as an anchor point for mobile nodes, and thus intrinsically subject to some limitations in mobile environment. In this paper, we propose a distributed mapping management of Endpoint Identifiers (EIDs) and Locators (LOCs) in mobile LISP networks. We use Routing LOC (RLOC) and Local LOC (LLOC) as locators for mobile hosts. RLOC represents the IP address of the domain gateway, and LLOC is the IP address of the access router that a host is currently attached to. For EID-LOC mapping management, each network domain has a Distributed Map Server (DMS) over its gateway. Each DMS keeps track of the EID-LOC mapping information for mobile hosts in the distributed way. The proposed scheme is also a network-based approach, in which each access router, instead of a host, performs the mapping management operations. From the performance analysis, we can see that the proposed distributed scheme can give better performance than the existing schemes in terms of the signaling delays required for EID-LOC mapping update and query operations.     

NetCAPE: Enabling Seamless IMS Service Delivery across Heterogeneous Mobile Networks

An evolving wireless world is constantly providing users with a wider set of access technologies to choose from, each with different capabilities and properties. In this world, IMS as defined by 3GPP provides an enabling, standardized multimedia architecture that is access independent, hence, providing service convergence. This trend is accompanied by an increasing number of multimode terminals so that inter-access- system-service continuity gains relevance. This article presents the architectural framework of NetCAPE (networking context aware policy environment), which addresses the optimization of mobility management in such a heterogeneous environment while interacting with IMS applications to enable seamless service delivery across heterogeneous mobile networks; even as the mobility offered by the underlying network remains transparent to IMS applications. Although the focus is on 3GPP-based mobile networks, the framework also incorporates wired access technologies, hence, taking a further step toward fixed mobile convergence (FMC). First results are presented highlighting the improvements gained by applying NetCAPE concepts.     

A Gateway and Framework for Telematics Systems Independent on Mobile Networks

In this letter, we analyze the problems with the existing telematics service systems that have been dependently developed and provided on a specific mobile network infrastructure. Then, we suggest methods to solve the problems and propose an architecture of the gateway and framework to implement our methods. We also verify the effectiveness of the suggested architecture through a comparison with an existing telematics system. With this architecture, it is possible to develop service applications without knowledge of the underlying mobile network technology and the system integration methods.     

Gateway load balancing using multiple QoS parameters in a hybrid MANET

A Mobile ad hoc network (MANET) is a self configurable wireless network in which mobile nodes communicate with each other in a multihop fashion without any pre-installed infrastructure. A MANET can be considered to be a standalone network. To enhance the connectivity of a MANET it can be connected to the fixed network, thus forming a heterogeneous network. The integration of MANET and the Internet is called a hybrid MANET which is facilitated by special nodes called Internet gateway nodes. Load balancing among gateways is a challenging task when a MANET is connected to Internet. Gateway nodes with higher loads will lead to disconnected networks and depletes the node’s resources which include their batteries, memory and bandwidth quickly. Gateway selection based on the shortest path may increase traffic concentration on one particular gateway which leads to congestion and increases delay in the network. In this paper a QoS based load balancing mechanism has been proposed among multiple gateway nodes that provide communication between mobile nodes and fixed nodes in the Internet to select lightly loaded gateways so that more packets will be delivered to the fixed host in the Internet. The proposed QoS based scheme selects four QoS parameters that are (1) connecting degree, (2) interface queue length, (3) routing table entries and (4) hop count. A weight based method is used to select the gateway which combines all four QoS metrics. Simulation results demonstrate that when compared with individual parameter, the average ETE delay, queue size and traffic load of gateway generated by proposed algorithm is decreased by 17, 25 and 15 % respectively and when compared with existing schemes, the average ETE delay, queue size and traffic load of gateway is decreased by 25, 25 and 16 % respectively.