用于移动Internet随机接入的一种新方式

介绍了移动通信网络中随机接入的概念，论述了移动Internet随机接入的特点，提出了基站调控的slotted-ALOHA随机接入方式，并从理论分析和计算机仿真两方面与现行的移动通信随机接入方式进行了对比，表明该方式能显著提高随机接入性能，使用代价微小，易于实际应用。     

利用USSD实现移动支付业务

利用USSD （Unstructured Supplementry Service Data)作为移动支付业务的接入方式。分析了目前国内移动支付业务的发展现状现有的业务接入方式。比较了USSD与SMS（Short Messages Service)对移动支付业务的支持能力。讨论了利用USSD实现移动支付业务接入时，移动终端和网络侧应用发起的移动支付业务的业务流程、信令流程以及移动支付业务的易用性和安全性。     

LTE时代分组域的接入方式探讨

从核心网组网及业务疏通方式、分组域业务平台连接方式、分组域支撑系统等方面，对移动分组漫游业务的归属地接入和拜访地接入2种方式进行了对比分析，最后对归属地接入方式改造成拜访地接入方式的主要内容和必要性进行了分析。     

支持多接入方式的手机银行技术

手机银行业务作为一项新兴的移动数据业务,目前已成为移动运营商们关注的热点。本文介 绍了一种支持多接入方式手机银行技术,即能支持SMS,USSD,STK+OTA,WAP,KJava五种接入方式, 并讨论了该手机银行系统的组成和结构。     

WiMAX与McWiLL技术的分析与比较

随着互联网和多媒体业务的迅猛发展，人们对带宽的需求越来越大，并且迫切要求终端设备能够实现自由移动。但传统的接入技术难以同时满足宽带和移动两方面的技术要求，为此业界开发了宽带无线接入技术。这种技术以其低廉的成本、高的传输速率和方便、快捷、灵活的接入方式，受到人们的越来越多的关注。[第一段]     

CDMA网络接入失败的原因探讨

1 前言CDMA网络的接入过程比较复杂,涉及的参数比较多,接入失败比较常见,实际表现形式多,而且难以模拟,是引起用户各种投诉的重要原因,一直困扰着网络运维工作。本文对接入流程进行分析,重点探讨了接入过程中占比例较高的移动台试探失败和基站信道捕获失败原因,以便在CDMA网络日常的运维、优化和投诉处理中,可以针对性地定位问题、解决问题。2 接入流程分析按照cdma2000系列标准规定,当移动台有业务到达或收到基站的寻呼消息时,移动台进入接入系统状态(ACC-mode),其接入流程一般可分为5个不同阶段:(1)移动台接入试探,在接入信道发送…     

CDMA系统中接入信道配置方式的研究

CDMA接入方式对无线网络性能有很大影响。随着用户的不断增加，基站信道负荷也越来越高，部分基站的接入信道负荷超过80％。接入信道负荷过高，影响了无线网络的接入性能。简单介绍了CDMA移动通信系统反向信道及接入信道的工作原理，并据此在VC6．0环境下建立了计算机仿真平台，研究接入参数的设置对接入过程的时延、通过量、信道利用率等性能的影响，分析接入尝试对系统产生的额外干扰。通过分析，提出了改善的接入参数设置方法。     

卫星通信系统两步随机接入技术研究

为了实现卫星通信系统低延迟高可靠接入,研究了两步随机接入技术中的信道设计及接收端检测算法.针对卫星场景提出了一种两步随机接入信道设计方案,对两步随机接入信道中数据部分的信道结构以及前导和数据之间的映射方式进行了设计.针对传统最小均方串行干扰消除(Minimum Mean Squared Error-Successive Interference Cancellation,MMSE-SIC)算法中存在误差传播问题导致解码性能降低的问题,提出了一种多判决排序串行干扰消除(Multi-decision Ordered Successive Interference Cancellation,MD-OSIC)算法,以提升多用户发起接入时数据部分检测的可靠性.仿真结果验证了所设计信道及检测算法在典型卫星通信场景下应用的可行性.     

多波长无源光接入网接入控制的分析研究

描述了基于多波长无源不接入网的（WDM-PON）的体系结构和数据信道非时隙化的接入控制协议，这种方式可大大简化以往复杂的同步功能。分析了在控制信道中选择接入协议的必要条件，这就使得控制信道接入协议的选择不再是盲目的。分析随机访问请求队列的延特性。     

LTE物理随机接入信道规划

LTE接入技术与GSM、CDMA有很大不同,为确保LTE网络正常运行,物理随机接入信道需进行精细规划。介绍了LTE-FDD移动通信系统接入技术,物理接入信道相关参数,物理随机接入信道格式、容量、小区逻辑根序列码复用模式与小区覆盖距离之间关系,以及高速移动场景对接入前导循环位移的影响,总结出物理随机接入信道的规划方法。     

WIRELESS BROADBAND ACCESS: WIMAX AND BEYOND - Investigation of Bandwidth Request Mechanisms under Point-to-Multipoint Mode of WiMAX Networks

The WiMAX standard specifies a metropolitan area broadband wireless access air interface. In order to support QoS for multimedia applications, various bandwidth request and scheduling mechanisms are suggested in WiMAX, in which a subscriber station can send request messages to a base station, and the base station can grant or reject the request according to the available radio resources. This article first compares two fundamental bandwidth request mechanisms specified in the standard, random access vs. polling under the point-to-multipoint mode, a mandatory transmission mode. Our results demonstrate that random access outperforms polling when the request rate is low. However, its performance degrades significantly when the channel is congested. Adaptive switching between random access and polling according to load can improve system performance. We also investigate the impact of channel noise on the random access request mechanism     

Control channel traffic design in a high-capacity land mobile telephone system

Control channel efficiency improvement techniques for an 800-MHz band high-capacity land mobile telephone system are described. Three interesting techniques, 1) the channel capacity increase technique under the random access mode from many mobiles, 2) a control channel division method which takes into account differences of control signal traffic behavior in land originated calls and mobile originated calls, and 3) a control channel frequency assignment method for efficient utilization of the radio frequency band, are studied by using computer simulations. The control channel frequency assignment method proposed decreases the required number of control channel frequencies by more than one half of the number in the existing assignment method.     

An adaptive ISMA-DS/CDMA MAC protocol for third-generation mobilecommunications systems

An inhibit sense multiple access-direct sequence/code division multiple access (ISMA-DS/CDMA) medium access control protocol for a packet transmission mobile radio network is presented. The main feature of this protocol is its ability to retain the inherent flexibility of random access protocols while at the same time reducing to some extent the randomness in the access in order to increase the system capacity. In this framework, the protocol is presented together with some adaptive mechanisms that improve the protocol performance by means of regulating the access and varying the transmission bit rate according to the channel load that is broadcast by the base station. As a result, an adaptive bit rate algorithm is presented that reaches a throughput value close to the theoretical maximum     

Optimization of One-Plane Packet Loss in IP Bearer Networks

The problem of one-plane packet loss of the IP bearer network in an Mc-interface mobile Softswitch system impacts Softswitch services in the active/standby access mode,and in the load balancing access mode. This paper focuses on optimization of the load balancing access mode. It also puts forward detailed suggestions for network optimization,providing a reference for mobile Softswitch network optimization and network security.     

5G Mobile Virtual Reality Optimization Solution for Communication and Computing Integration

5G network is an inevitable trend in the development of mobile communications. Mobile cloud computing is a more promising technology for 5G networks. This paper proposes a hierarchical distributed cloud service network model, which is composed of three layers: “access cloud + distributed micro cloud + core cloud”. On the basis of access to the cloud, a distributed micro cloud system is deployed to migrate the service capabilities of the remote core cloud server to the local area. This paper proposes a task offloading assignment algorithm in a small cell cloud scenario. This algorithm establishes a SCC (Small Cell Cloud) based on the channel quality between small cells and the remaining available computing resources, and allocates the load to each small cell in the SCC according to the channel quality and the remaining available computing resources. Simulation results show that this solution can improve the utilization of wireless and computing resources in the small cell cloud computing scenario, and improve the user QoE (Quality of Experience). In order to make the system operate normally under heavy load, this paper proposes a feedback adaptive random access strategy based on the adaptive random access model. This can ensure that the throughput rate does not decrease under heavy load conditions, and at the same time, the average access delay of the existing system is reduced. When the arrival rate of user requests gradually increases, the throughput rate of RA-RACH access will continue to decrease due to collisions until it approaches below 0.1. In the state where the number of users is low and the load is lighter, both RA-RACH, AC-RACH, and FC-RACH have a higher access success rate. But as the load continues to increase, RA-RACH will quickly drop to 0.

     

基于高速移动环境的LTE上行随机接入前导序列的生成

3GPP长期演进（Long Term Evolution）计划中的随机接入信道是一个基于竞争的上行信道。当某个小区内多个移动台同时发起接入时,可能发生碰撞导致部分移动台接入失败或者移动台之间相互干扰。为避免以上情况,3GLTE为不同用户接入分配了不同的前导序列,利用序列间良好的相关性避免接入冲突和用户间干扰。本论文基于3GPP对LTE上行随机接入受限循环移位前导序列的规范定义,在不改变对RACH结构假设的前提下,讨论高速移动环境下的随机接入受限循环移位前导序列,并针对两种不同的假设给出两种生成公式,并通过仿真结果比较其优劣。     

LTE-Advanced时隙接入中动态帧长选择算法

通过分析LTE-Advanced系统中基于时隙接人信道控制协议(SCACP)的随机接入模型,提出一种时隙接入方法中接入帧长的优化算法.利用网络实时接入负载实现时隙接人中动态帧长的选择,使得优化后的接入帧长更适合当前接入负载,保障了较高的接入成功率,消除了不必要的接入时延,还在一定程度上减少了前导重传次数.最后通过仿真验证了所提动态帧长选择算法的有效性和实用性.     

Evaluation of the Random Token Protocol for High-Speed and Radio Networks

In high-speed communication networks, the ratio between the end-to-end propagation delay to packet transmission time is large, causing increased scheduling overhead in demand assignment protocols and increased collision probabilities in random access schemes. These lead to rapid degradation of the channel utilization in both channel access control approaches. In this paper, we present a "random token" oriented protocol where channel access is scheduled by random, implicit token passing leading to lower channel access control penalty. By optimally balancing the collision and scheduling penalties, the protocol allows the network to reach better performance than that obtained from random access schemes in networks with and without collision detection, without imposing additional system operational assumptions. Specifically, the random token protocol does not require knowledge of the number of stations, their identities, or synchronization in periods of silence. Therefore, the protocol is also suitable for high-speed networks with frequent reconfiguration and for mobile radio networks.