基于用户和信令数据的3G小区接入性能数据分析

针对3G网络优化提出了基于用户和信令数据的小区接入性能分析手段,以实测数据为例进行RRC接入拥塞和PSTAB接入失败的研究,为优化工作的深入开展提供了一个新的思路和方法。     

基于MDT数据优化小区空闲态与连接态 覆盖一致性的方法

本文提出了利用最小化路测数据(MDT)判断小区空闲态、连接态覆盖一致性的优化方法。根据最小化路测中的Logged和Imm数据分别判断某一地理栅格的RRC空闲态和连接态用户归属主服小区否一致。针对空闲态和连接态存在大量不一致栅格的小区,提出通过修改小区参数修改调整不同状态下覆盖区域,最终保证RRC空闲态、RRC连接态覆盖一致以达到降低发起业务后的非必要切换次数,提高户初始业务阶段速率,提升用户感知。     

LTE RRC连接重建比优化探究

RRC重建过程是终端由于某种原因导致RRC连接中断,在源小区或新小区发起的恢复RRC连接,以试图快速重建业务,提升用户感受的一个过程。但RRC重建会使得业务短暂中断,影响用户体验。造成RRC重建的原因有很多,如:无线信号差、参数设置不合理、终端兼容性问题等,定位起来较困难。文章对这些问题定位过程中的经验进行总结。     

神经计算技术在ATM光纤高速智能管理网中的应用(续)

4　呼叫管理级呼叫管理级的主要功能是呼叫连接接纳控制。呼叫连接接纳控制意味着 ,仅当网络节判断得知新的连接将不会降低已接入老用户要求的服务质量时 ,才能允许接纳一个新用户的连接。例如 ,当用户 USE1要求与另一个用户 USE2通话时 ,首先 USE1用户向ATM网络节呼叫级控制器发送一个建立连接请求的信号。表征此连接请求的参数将包括目的用户、请求连接的承诺信息速率 (Commited InformationRate)、要求的服务质量等级 (GOS)以及生成信元信息特征参数等。网络节控制器由传输信息量参数评价各连接的服务质量水平 ,仅当评价表明对其…     

高负荷小区优化方法研究

随着TD-SCDMA业务量飞速发展,TD-SCDMA用户不断增加,部分小区码资源利用率较高、RRC拥塞、双域RAB拥塞等高负荷将影响移动通信的业务承载能力,同时也会引起掉话、用户无法接入、数据连接交换缓慢,客户满意度等直接后果。TD-SCDMA系统主要受限于码资源,所以码资源不足是导致高负荷的最主要原因。解决无线侧高负荷一般采用算法优化和硬件扩容两种方法。本文重点对某市TD-SCDMA网络中高负荷小区进行算法优化,提高网络承载能力,使用优化的手段降低网络负荷。     

TD-SCDMA小区接入异常综合分析

简要论述了TD-SCDMA系统小区接入流程及接入异常的总体分析过程;将TD-SCDMA小区接入异常所涉及的信令分为：建立RRC连接、初始直传NAS消息、安全模式控制、CallProc、建立RAB及上下行直接传输等6组（步骤）,并以大唐移动无线参数为例,逐一详细阐述了小区接入信令异常分析方法。     

5G干扰特征识别及解决方案研究

当5G网络中存在严重的上行干扰信号时,小区内用户上下行业务会受到影响,严重时会导致小区无法接入,影响用户的感知体验.重点介绍了NSA网络下5G各类上行干扰形成的主要原因,并从多个维度分析各干扰类型的时域、频域等典型特征,重点研究不同干扰类型的针对性解决方案,降低网络中的系统内外干扰,提升5G用户的感知体验.     

基于RRC重定向的CSFB算法研究与改进

论述了在TD-LTE与TD—SCDMA共同组网的情况下,双模单待终端常驻在TD—LTE系统中,当用户发起语音业务时,通过基于RRC重定向的CSFB技术回落到TD—SCDMA网络。为了提高TD—LTE系统的语音业务接入成功率和可靠性,文章提出了一种低时延,高可靠性的CSFB技术方案。该方案的关键技术在于当TD—SCDMA系统小区负荷超载时,算法从目标小区邻区中选择较优小区给TD-LTE侧,提高了TD—LTE侧语音业务的接入成功率。     

LTE系统随机接入过载控制的研究

在同一个小区内,由于随机接入资源的有限性,当大量终端同时接入基站时,会造成网络拥塞,这会导致终端接入碰撞的概率增大,使随机接入成功率降低,同时导致随机接入传输时延增大这种情况,提出一种在网络拥堵环境下进行随机接入过载控制的方法。该方法通过对系统负载进行提前估算,根据网络负载情况动态调整随机接入的用户数和随机接入的时频资源,通过仿真得出该方法有效改善系统性能,使得用户接入时延较原有流程减少约35%,同时使用户接入成功率提升约45%。     

4G多频网络中基于大数据平台的智能拆闲优化研究

针对4G多频组网中空闲小区导致网络投资效益降低和资源利用率降低的问题,提出基于大数据平台的智能拆闲优化方案。从自忙时PRB利用率、自忙时PDCP层用户面总流量、自忙时平均RRC连接用户数这三个指标定义闲小区,借助大数据平台进行小区负荷分析、覆盖需求分析和容量需求分析,综合运用功分、劈裂、直放站三种技术,智能选择最佳的拆闲优化方案。在确保用户感知的前提下,盘活现网资源,有效节约建设成本和人力成本,提升投资效益和资源利用率,扩大了对覆盖盲区和热点忙区的覆盖。     

NB-IoT网络容量和优化方法研究

随着物联网技术的不断发展和普及，人类社会正进入“万物互联”的时代。新一代物联网无线接入技术：窄带物联网（Narrow Band-Internet of Things，NB-IoT）具有大连接的特性，但如此大的连接仍对NB-IoT网络容量造成挑战，本文对网络容量进行研究，并提出高并发用户场景下的优化方法，为应对大量用户接入NB-IoT网络而做好准备。     

Protocols for very high-speed optical fiber local area networks using a passive star topology

This paper deals with the problem of interconnection of many high-speed bursty traffic users via an optical passive star coupler. Each user can tune its laser over a range of wavelengths, thus resulting in a wavelength division multiplexed communication. The total number of wavelengths over which user tunability exists could be much smaller than the number of users. Therefore, some form of random access sharing and packet switching may be necessary. We propose several protocols that require each user to have a tunable receiver. The information on "where" and "when" to tune the laser is confined to a control (setup) channel that users tune to when in idle mode. An interconnection between two users lasting for the length of a data packet is set up on the control channel by the transmitting user who informs the receiving user where to tune in order to receive the data packet. No centralized control or coordination is required among the users. After analyzing each protocol, we present the throughput/ delay versus the offered traffic and the delay versus throughput in a sequence of plots. We show that in typical applications an average throughput of up to 0.95 can be achieved at a reasonable average delay using one of these protocols. In our benchmark examples we present an optical local area network (LAN) with a total throughput of 100- Gbit/s in which every user has access to a 1-Gbit/s data rate and the network can support over 1000 users. The protocols can be used in a) large LAN's that do not require a large capacity, b) small LAN's (1 kin) that require a large capacity and c) large LAN's (tens of kilometers) that require a rather large capacity.     

A Noncooperative Game-Theoretic Framework for Radio Resource Management in 4G Heterogeneous Wireless Access Networks

Fourth generation (4G) wireless networks will provide high-bandwidth connectivity with quality-of-service (QoS) support to mobile users in a seamless manner. In such a scenario, a mobile user will be able to connect to different wireless access networks such as a wireless metropolitan area network (WMAN), a cellular network, and a wireless local area network (WLAN) simultaneously. We present a game-theoretic framework for radio resource management (that is, bandwidth allocation and admission control) in such a heterogeneous wireless access environment. First, a noncooperative game is used to obtain the bandwidth allocations to a service area from the different access networks available in that service area (on a long-term basis). The Nash equilibrium for this game gives the optimal allocation which maximizes the utilities of all the connections in the network (that is, in all of the service areas). Second, based on the obtained bandwidth allocation, to prioritize vertical and horizontal handoff connections over new connections, a bargaining game is formulated to obtain the capacity reservation thresholds so that the connection-level QoS requirements can be satisfied for the different types of connections (on a long-term basis). Third, we formulate a noncooperative game to obtain the amount of bandwidth allocated to an arriving connection (in a service area) by the different access networks (on a short-term basis). Based on the allocated bandwidth and the capacity reservation thresholds, an admission control is used to limit the number of ongoing connections so that the QoS performances are maintained at the target level for the different types of connections.     

User scheduling and power allocation for nonfull buffer traffic in NOMA downlink systems

Nonorthogonal multiple access (NOMA) is one of the key technologies for 5G, where the system capacity can be increased by allowing simultaneous transmission of multiple users at the same radio resource. The most of the proportional fairness (PF)–based resource allocation studies for NOMA systems assumes full buffer traffic model, while the traffic in real‐life scenarios is generally nonfull buffer. In this paper, we propose User Demand–Based Proportional Fairness (UDB‐PF) and Proportional User Satisfaction Fairness (PUSF) algorithms for user scheduling and power allocation in NOMA downlink systems when traffic demands of the users are limited and time‐varying. UDB‐PF extends the PF‐based scheduling by allocating optimum power levels towards satisfying the traffic demand constraints of user pair in each resource block. The objective of PUSF is to maximize the network‐wide user satisfaction by allocating sufficient frequency and power resources according to traffic demands of the users. In both cases, user groups are selected first to simultaneously transmit their signals at the same frequency resource, while the optimal transmission power level is assigned to each user to optimize the underlying objective function. In addition, the genetic algorithm (GA) approach is employed for user group selection to reduce the computational complexity. When the user traffic rate requirements change rapidly over time, UDB‐PF yields better sum rate (throughput) while PUSF provides better network‐wide user satisfaction results compared with the PF‐based user scheduling. We also observed that the GA‐based user group selection significantly reduced the computational load while achieving the comparable results of the exhaustive search.     

中国移动高业务场景的TD-LTE扩容改造方案探讨

近年来中国移动大力建设TD-LTE网络,覆盖广度上已经达到较高水平,但目前有部分场景面临容量不足的问题,并可能出现无法接入、速率偏低等导致用户感知下降的情况。因此,为保持4G竞争领先,需对高业务场景进行多载波扩容。本文首先分析容量瓶颈并探讨扩容改造方法,最后提供典型方案实例供参考。     

Network Design: An Algorithm for the Access Facility Location Problem

In any network where a large number of widely dispersed "users" share a limited number of "resources," the strategy for access will play a large part in determining the cost and performance of the network. In this paper we consider a topological design aspect of the access problem. In particular, we consider the problem of locating "access facilities," or concentration points, to obtain an economic connection of users to resources. The problem is formulated as the locating of generic access facilities (GAF's) to obtain an economic connection of nodes (users) to a resource connection point (RESCOP). The nodes may be connected through multipoint lines, but with a constraint on the number of nodes which may share a single line. The GAF's are constrained in capacity, expressed as the number of nodes they can support, and have a cost associated with them. The basic solution technique presented is a heuristic algorithm characterized by the following four steps. 1) Simplify the problem to a point-to-point problem by replacing clusters of nodes by single "center-of-mass" (COM) nodes. 2) Partition the reduced set of COM nodes by applying an Add algorithm, resulting in one of the COM nodes selected as a GAF site. 3) Select one of the original nodes as a real GAF site in each partition by examining the original nodes closest to the COM node selected in the Add algorithm, and selecting the best. 4) Apply a line-layout algorithm to each partition, with its selected GAF site serving as the central node.     

码资源利用率提升方案

TD-SCDMA网络经过4期的建设后,覆盖日臻完善,TD-SCDMA用户快速发展但有相当部分的用户和业务长期驻留和承载在GSM网,导致目前GSM网络利用率持续攀升,峰值网络利用率可以达到80％,而TD-SCDMA网的码资源利用率还不到12％.详细介绍了采取功率提升,2G/3G互操作参数优化及引导用户使用TD网络等三种措施,在保障用户使用感知度和不影响网络KIP指标的基础上,有效提升TD网络码资源利用率的承载能力,达到GSM向TD-SCDMA网分流的效果.     

TD-SCDMA测试仪中Uu接口的RRC消息关联方案研究

在TD无线网络测试中,测试仪表的空中接口的数据解码和分析质量有着举足轻重的作用。RRC子层在空中接口中属于接入层,空中接口的相关功能的实现,如无线承载的建立和实现等都是在RRC信令连接的基础上进行的,因此RRC子层消息的关联是空中接口呼叫合成的关键所在。本文以MOC信令流程为例,根据RRC信令连接是否建立在专用信道上,对专用信道和公共信道上建立的RRC消息分别提出了相应的关联方案。经过测试,该方案确实可行,达到了研究的预期目的。