Comparison of IP micromobility protocols

We present a performance comparison of a number of key micromobility protocols that have been discussed in the IETF Mobile IP Working Group over the past several years. IP micromobility protocols complement Mobile IP by offering fast and seamless handoff control in limited geographical areas, and IP paging in support of scalability and power conservation. We show that despite the apparent differences between IP micromobility protocols, the operational principles that govern them are largely similar. We use this observation to establish a generic micromobility model to better understand design and performance trade offs. A number of key design choices are identified within the context of the generic model related to handoff quality and route control messaging. We present simulation results for Cellular IP, Hawaii, and Hierarchical Mobile IP, and evaluate the handoff performance of these protocols. Simulation results presented in this article are based on the Columbia IP Micromobility Software (CIMS), which is freely available from the Web (comet.columbia. edu/micromobility) for experimentation.     

CDMA2000标准制式的移动工P协议分析

随着IPv6标准的成熟和试运行,在3G牌照下发之际,能提供随时随地的移动数据通信已成为人们的迫切需求。通过移动IP协议,移动主机可以通过一个永久的IP地址连接到任何链路上,移动主机移动后仍可以保持正常通信。为了探讨移动IP协议在运营商级商用的技术可行性,文中通过剖析移动IP协议的工作原理及主要技术特点,就移动IPv6在CDMA2000网络中的系统结构、协议模型、路由方式及存在问题进行了探讨。     

CDMA2000 分组域核心网移动IP技术

移动IP技术为CDMA2000 系统中的一种基本接入技术.分析了移动IP技术网络架构,介绍了移动IP网络部署下的几种关键技术.为了使只支持简单IP的终端使用移动IP业务,引入了代理移动IP技术.内容计费业务作为一种灵活的计费方式,同样也可以应用在CDMA2000分组网络中.     

Mobility support in IP: a survey of related protocols

This article presents an overview of a set of IP-based mobility protocols mobile IP, HAWAII, cellular IP, hierarchical MIP, TeIeMIP, dynamic mobility agent, and terminal independent MIP - that will play an important role in the forthcoming convergence of IP and legacy wireless networks. A comparative analysis with respect to system parameters such as location update, handoff latency and signaling overhead exposes their ability in managing micro/macro/global-level mobility. We use this observation to relate their features against a number of key design issues identified for seamless IP-based mobility as envisioned for future 4G networks.     

Reliable RSVP path reservation for multimedia communications under an IP micromobility scenario

We focus on how quality of service (QoS) guarantees can be provided for RSVP flows during handoff events in an IP micromobility network. For this purpose, RSVP message delays and signaling overheads should be minimized, and handoff service disruption should also be minimized. By rerouting the RSVP branch path at a crossover router at every handoff event, and establishing the new RSVP path between the CR and new BS in advance while the existing reservation path is maintained, ongoing RSVP flows can be kept with the guaranteed QoS. We propose the seamless switching of an RSVP branch path for soft handoff, and also show that this scheme could provide QoS guarantee with simulation and examples.     

基于OPNET的移动IP在CDMA2000 1X中的仿真

为解决CDMA2000 1X[1]分组网络节点移动问题,本文利用移动Ip[2]技术代替原有的简单IP,使节点可以以一个永久的IP地址连接网络,从而保证链路切换时的正常通信.通过OPNET工具设计了移动IP在CDMA20001X分组网中的仿真模型,并在此基础上对其功能和性能进行了分析,证实了方案的可行性.     

CDMA2000标准化进展

依据演进次序．从CDMA20001X、1X EV—DO和1X EV—DV三个方面对CDMA 2000系列标准进行了概括的介绍，并对各标准的主要特点和新增功能进行了概述。     

基于IP分布式MSC的CDMA2000系统A接口设计与实现

针对传统集中式移动交换中心(MSC)容量小、安全性低、不易扩展的不足,基于IP技术和软交换技术,提出了一种分布式MSC架构.在此架构下对A接口协议进行了分析并给出了基于IP的实现方案:兼顾TCP的可靠性和UDP的简洁性定义了承载A接口中的信令和业务的一个增强性UDP协议(EUDP).此外,也描述了分布式MSC负荷分担的选择原则:轮选、处理最近和资源最近;最后以8 kbit/s语音业务为例,对基于IP传输语音业务的带宽需求进行了简单分析.实践表明,该方案不仅提高了系统的经济性,也改善了网络容量扩展和新业务提供的灵活性.     

Enhanced analytical method for IP mobility handover schemes cost evaluation

Seamless service delivery for mobile users complemented with Quality of Service provisioning for their real-time applications have a hot topic in the field of mobile communication in recent years. Seamless mobility goes hand in hand with Mobile IPv6 protocol. Since many different handover schemes trying to solve the Quality of Service issues have been developed a need for means for comparison has arisen. This paper presents an enhanced universal analytical method for comparison of handover schemes. The method focuses on two important aspects influencing the handover performance—binding update cost and packet delivery cost. The use of the proposed method is presented for comparison of four most common handover schemes—MIPv6, HMIPv6, FMIPv6 and F-HMIPv6.     

CDMA2000标准化进展

依据演进次序,从cdma20001x、1x EV-DO和1x EV—DV三个方面对CDMA2000系列标准进行了概括的介绍,并对各标准的主要特点和新增功能进行了概述。     

CDMA2000的3G之路

前言从技术上来说,CDMA2000、WCDMA和TD-SCDMA这三种制式都能够满足IMT2000的技术要求,可以说是各有长处,其中CDMA2000的商用化程度无疑是最高的,CDMA2000由cdmaOne演进而来,经历了2G、2.5G、2.75G到3G的发展历程,各阶段的产品都有大规模市场商用的经验。在全球多家提供CDMA2000成熟商用产品的厂商中,中兴通讯作为较早研发CDMA产品的厂商之一,遵循CDMA技术演进标准,以其雄厚的研发实力、完整的产品系列和解决方案,其CDMA2000产品在全球范围内近十余个国家得到了广泛的应用,取得了令人瞩目的成就。中兴通讯的CDMA移动通…     

Mechanisms and hierarchical topology for fast handover in wireless IP networks

We propose a mechanism to perform fast handover in IP-based wireless networks for real-time applications such as Internet telephony and videoconferencing. Our proposal is designed to reestablish the communication session traffic flow quickly and to minimize the service disruption delay that occurs during mobile IP handover. In this scheme, we propose two different mechanisms to handle micromobility and inter-subdomain mobility, respectively. Micromobility handover handles movements within the same subdomain. Inter-subdomain handover supports handovers between two adjacent subdomains. The reason for having several subdomains is to deploy the network over a wider area to keep the mobile user in the same network for as long as possible. The novelty of the scheme is to retransmit the buffered packets during micromobility handover and to use multicasting to reestablish traffic flow during inter-subdomain movement. The entire scheme is performed within a hierarchical topology based on next-generation IP networks. We analyze both micromobility and inter-subdomain mobility handovers, and display simulation results for both voice and video over IP for micromobility handover.     

CDMA2000数字中频的设计

在CDMA2000系统中，信道是经过QPSK四相扩频正交调制传输的，数字中频与模拟中频相比能产生严格的幅相平衡正交信号，处理时能保证有严格的线性相位，为此介绍了CDMA2000系统数字中频调制解调实现的方案，对其中抗混叠滤波器，数字频率合成器的设计方法进行了详细的讨论，最后给出了用基于高密度逻辑门电路可编程集成片编辑器（FPGA Compiler)实现的结果。     

Network support for IP traceback

This paper describes a technique for tracing anonymous packet flooding attacks in the Internet back toward their source. This work is motivated by the increased frequency and sophistication of denial-of-service attacks and by the difficulty in tracing packets with incorrect, or “spoofed,” source addresses. We describe a general purpose traceback mechanism based on probabilistic packet marking in the network. Our approach allows a victim to identify the network path(s) traversed by attack traffic without requiring interactive operational support from Internet service providers (ISPs). Moreover, this traceback can be performed “post mortem”-after an attack has completed. We present an implementation of this technology that is incrementally deployable, (mostly) backward compatible, and can be efficiently implemented using conventional technology     

Enhancing the performance of secured handover protocols in UMTS-WiMAX interworking

Interworking UMTS and WiMAX networks offers global roaming and cost effective broadband wireless Internet access. Designing efficient Intra and Inter WiMAX handovers in the interworking architecture is a challenging problem. Handovers must be instantaneous and secure at the same time. We attempt to solve this problem by designing Intra and Inter WiMAX handover protocols which are capable of operating in the UMTS-WiMAX interworking architecture and perform mutual pre-authentication between the mobile station and the target network prior to handover. Due to the pre-authentication procedure, our proposed handover protocols outperform standard handover protocols by dispatching fewer handover signaling messages, experiencing less handover delay and preserving computation resources of critical nodes in the interworking architecture. Furthermore, our proposed handover protocols meet essential security requirements and defend against common attacks affecting handover protocols.     

Performance study of link layer and MAC layer protocols to support TCP in 3G CDMA systems

Providing support for TCP with good quality link connection is a key issue for future wireless networks in which Internet access is going to be one of the most important data services. A number of schemes have been proposed in literature to improve the TCP performance over wireless links. In this paper, we study the performance of a particular combination of link layer protocol (e.g., radio link protocol or RLP) and MAC retransmissions to support the TCP connections over third generation (3G) wireless CDMA networks. We specifically investigate two metrics - the packet error rate and the delay provided by RLP and MAC retransmissions - both of which are important for TCP performance. For independent and identically distributed (i.i.d) error channels, we propose an analytical model for RLP performance with MAC retransmission. The segmentation of TCP/IP packets into smaller RLP frames, as well as the RLP buffering process, is modeled using a Markov chain. For correlated fading channels, we introduce an analytical metric called RLP retransmission efficiency. We show that: 1) the RLP frame size has significant impact on the overall 3G system performance, 2) MAC layer retransmissions significantly improve the TCP performance, and 3) the RLP retransmission scheme performs better in highly correlated channels, while other scheme performs better in low correlated channels. Simulation results also confirm these conclusions.     

CDMA2000前向信道速率判决

速率判决是CDMA系统的重要技术之一。该文首先介绍了CDMA2000前向信道基于CRC校验和反转误码率的传统速率判决,并在此基础上增加了另外两个判决准则;分别描述出了这四个判决准则的实现方法,以及联合使用的判决逻辑;仿真结果表明增加的两个判决依据减小了速率判决的误帧率。     

CDMA2000移动台信令的软件实现

CDMA技术是第三代移动通信的主导技术,而CDMA移动台和基站之间的信令为它们的通信提供了控制作用。从CDMA2000分层结构引出信令可靠传输的各层,介绍了信令各层的传输机制,并提出运用实时多任务操作系统实现移动台信令软件的设计,从而为移动台的综合业务服务提供了软件的可行操作方法。     

CDMA2000终端的应用测试

做为一种码分多址技术,同时也是一种白干扰系统,CDMA终端的测试对于终端本身和网络都有着重要意义。一部良好工作的CDMA终端,能够在提供优良的通讯质量的同时,尽可能的帮助网络提高容量。在早期的测试中,发射功率、功率控制、切换能力、信道解调能力、以及网络兼容性是CDMA终端的测试重点。在测试标准方面,IS-98、IS-898所对应的射频和协议测试一度是认证CDMA终端的主要内容。运营商、芯片终端厂商和认证实验室的工作主要都是围绕达到标准制定的要求展开。