【作者】 王斌；

【导师】 田辉；

【作者基本信息】 北京邮电大学 ， 通信与信息系统， 2014， 硕士

【摘要】 随着无线通信技术的迅猛发展,随着智能终端的不断普及,用户的数据业务量正在处于爆炸式的增长,单独的无线接入技术已经不能够满足用户日益增长的带宽需求、速率需求。为了能够为用户真正实现随时随地无缝漫游的QOS保障服务,不同网络协作融合必然成为未来网络的发展趋势。不同的无线接入技术在网络覆盖、数据速率、时延、计费等方面互相补充,可以更加有效地为用户提供多样化的接入服务,未来移动通信的发展必然朝着宽带化、扁平化、全IP的融合方向发展。各种无线接入技术的异构特性,也为网络服务的可靠性、稳定性以及高效性提出了新的挑战。异构网络的融合不仅涉及到业务层面、控制层面的融合,还涉及到空中接口、接入层面的融合。在异构网络的融合中,面临很多的技术挑战,包括：移动性管理、融合网络架构和理论模型、联合无线资源管理、异构的多模终端和无线接入选择、以及垂直切换等问题。本文主要对异构网络中的联合资源管理中的资源分配策略进行相关研究。论文的主要工作包括下面几个方面：异构网络中的不同无线接入技术具有不同的覆盖,有时交叠覆盖,不同的网络覆盖划分出不同的服务区域；另外终端的无线接入能力也存在差异,有的终端能够同时支持多种无线接入技术的传输,有的终端则只能够同时支持一种无线接入技术的数据传输。因此论文首先提出一个分层的资源分配框架,分别从网络级别和用户连接级别进行资源分配。在网络级别,提出一种基于区域公平性的资源分配算法,通过将每一个区域的业务建模成为M/M/1队列,利用最小最大优化模型,使得所有服务区域中阻塞概率最大的区域的阻塞概率最小化,来达到保障各个服务区域用户可用资源公平性的目的。在用户的连接级别,提出一种基于终端接入能力的公平性的资源分配算法。一方面利用动态分流的算法将多模终端的业务尽可能的分流到各个可用的无线网络中,为单模终端间接实现资源预留；另外一方面,基于退让补偿的机制,当单模终端选择的接入网络资源不足时候,占用该网络的多模终端会释放占用的带宽,保障单模终端的享受资源的公平性。因为网络资源分配策略受到众多因素的影响,分析这些因素发现其中一些关键因素与用户的位置信息密切相关,比如接收信号强度。所以,论文接着提出一种基于用户位置信息的资源分配算法。将研究区域划分成网格,以网格为单位,利用终端用户上报的路测信息(包括接收信号强度,以及详细的经度、纬度、高度信息),综合考虑用户位置处的信道质量和网络的负载水平,为用户选择最为合适的网络接入。从而,为用户提供个性化的资源分配。一方面考虑了用户特定位置处的确切的实时信道条件,另外一方面也考虑了网络的当前负载水平,能够有效降低用户的接入阻塞率和切换频率,提高用户的业务体验。更多还原

【Abstract】 With the development of wireless access technology and the popularity of smart mobile terminals, there exists explosive growth of users’ data service bandwidth requirements. Not a single radio access technology can meet their bandwidth demands and provide users with satisfied bandwidth and data rate. The next generation wireless network will be integration of different networks. These networks include WLAN, WMAN and different cellular networks. They differ and complement with each other in coverage, data rate, delay and cost. The cooperation of different radio access networks can help provide users with more diverse service effectively and seamlessly.However, the heterogeneity of radio access technologies also challenges the quality of service, such as its reliability, stability and high efficiency. The network convergence includes convergence on control plane, user data plane and interface technologies. There also exist many challenges in the research of network convergence, including mobility management, convergence framework and research model, common radio resource management, heterogeneity of mobile terminals, network selection and handoff strategy.The resource allocation strategy belonging to resource management is studied in this paper.The main works of this paper include some aspects listed as followings:In this paper, we firstly propose a hierarchical bandwidth allocation algorithm, in which the issue of radio resource allocation is addressed from both network-level and connection-level jointly. In network-level, to enhance the fairness among different areas and achieve area load balancing, we formulate an optimization problem to minimize the maximum call blocking probability in multiple areas. In the connection-level, a terminal-modality fairness based bandwidth reallocation scheme is proposed to balance the available resource among terminals with different capability. For multi-mode MTs, bandwidth allocation is adapted to residual resource of networks available. For single-mode MTs, a compensation based bandwidth reallocation strategy is developed to compensate for their less available resource compared with multi-mode MTs in the same location.Secondly, a location-based resource allocation scheme is proposed to select accurate network for users. We generate grids in the geographical area, and users report channel information to a control node responsible for resource management in every grid. Based on the received signal strength from different available networks and network traffic load information, the control node deployed in each grid will decide their resource allocation strategy. That is to say the control node will combine the channel information and the traffic load belonging to different available network and decide which network to access. The simulation results show that the proposed location-based resource allocation scheme can effectively reduce the call blocking probability and improve user service.更多还原