Smart Infrastructures for Radio Access as a Service (SIRAS) - Software-defined Wireless Access Networks for Future Generations

为了满足无线数据流量的指数增长（预计到2020年全球将超过300艾字节/年），移动的服务提供商正在部署异构网络，该异构网络利用微小区、皮科小区和毫微微小区来增强传统的宏小区，并且正在利用诸如3G/4G蜂窝和802.11n/ac的无线电接入技术（RAT）的混合。然而，RAT的进步尚未与促进其有效部署的系统架构的新开发相匹配。新的无线系统架构应该是可扩展的以提供增加的容量，可编程的以支持新的功能和高级RAT，以及自组织的以实现“即插即用”部署。我们建议填补这些空白，解决重要的研究问题，导致发展的SIRAS，智能网络结构的无线接入即服务（RAaaS），使成本效益和高效的下一代无线接入，利用新兴的云计算和虚拟化技术，这是有前途的，但尚未广泛探索的方法，无线接入网络。 SIRAS将云计算的效率以及软件定义网络（SDN）的可控性和可编程性扩展到无线接入网络，同时利用分布式天线系统和软件定义无线电（SDR）的最新进展。 我们设想SIRAS用采用大规模分布式天线系统和自治小小区的分布式架构来替换当前的集中式蜂窝架构，所述大规模分布式天线系统和自治小小区协作以使用适合于特定环境的若干支持的RAT之一来向个体业务流提供所需的服务质量（QoS），其中分布式交互由采用SDN技术的扩展控制平面来协调，并且在每个流的基础上优化资源分配。这种分布式架构将通过按需利用云计算资源，结合本地资源，以成本效益和可扩展的方式虚拟化管理和信号处理功能，从而实现RAaaS。因此，无论何时何地出现需求，SIRAS都有望能够通过增加基础设施容量和保证QoS来立即有效地提供移动的服务。 为了实现这一愿景，我们建议在无线接入网络研究中寻求一个新的方向，以开发新的架构，协议和管理算法，实现上述SIRAS的潜在优势。本研究项目的总体目标是为这一新的研究方向做出基础性贡献，这将对下一代无线接入网络产生重大影响。具体而言，我们在拟议项目中的工作将分为以下相互关联的研究任务：（A）SIRAS架构设计，以实现用于多RAT的虚拟化RAaaS，（B）算法设计，以增强和优化用于RAaaS的无线电和核心网络资源的分配，（C）基于SDN的协议设计，以实现SIRAS中的业务负载平衡和管理功能虚拟化，（D）设计分布式算法和协议以支持虚拟化SIRAS无线电接入节点之间的认知和协作操作，以及（E）SIRAS测试床开发和实验。这些任务将通过新颖的设计和性能评估，通过理论建模和计算机模拟来完成。利用拟议的微调实验测试平台，将在现实条件下实施和评估为SIRAS中的上述任务提出的有前途的技术，以进行概念验证演示和可能的商业化。

To meet the exponential growth of wireless data traffic, anticipated to exceed 300 Exabytes/year worldwide by 2020, mobile service providers are deploying heterogeneous networks that augment conventional macro-cells with micro-, pico-, and femto-cells, and are utilizing a mix of radio access technologies (RAT) like 3G/4G cellular and 802.11n/ac. However, advances in RAT have not been matched by new development of system architectures that facilitate their efficient deployment. New wireless system architectures should be scalable to provide increased capacity, programmable to support new functions and advanced RAT, and self-organized to enable “plug-and-play” deployment. We propose to fill these gaps by addressing important research problems leading to the development of SIRAS, Smart Infrastructures for Radio Access as a Service (RAaaS) to enable cost effective and efficient future generation wireless access by leveraging emerging cloud computing and virtualization techniques, which are promising but not yet widely explored approaches for wireless access networks. SIRAS extends the efficiency of cloud computing and the controllability and programmability of software-defined networks (SDN) to wireless access networks, while exploiting recent advances in distributed antenna systems and software defined radios (SDR). We envisage that SIRAS replaces the current centralized cellular architecture with a distributed architecture employing massively distributed antenna systems and autonomous small cells that collaborate to provide the required Quality of Service (QoS) to individual traffic stream using one of several supported RAT that is appropriate for the specific environment, where the distributed interactions are coordinated by an extended control plane that employs SDN techniques, and resource allocation is optimized on a per-flow basis. This distributed architecture would enable RAaaS by utilizing cloud computing resources in an on-demand basis, in combination with local resources, to virtualize management and signal processing functions in a cost effective and scalable manner. SIRAS is thus expected to be able to offer mobile services by increased infrastructure capacities and guaranteed QoS instantly and efficiently in cost, energy, complexity and latency wherever and whenever the demand arises. To realize this vision, we propose to pursue a new direction in wireless access networking research to develop new architecture, protocols and management algorithms that realize the potential benefits of SIRAS described above. The overall objective of this research project is to make fundamental contributions to this new research direction, which will have significant impacts on future generation wireless access networks. Specifically, our work in the proposed project will be divided into the following inter-related research tasks: (A) SIRAS architectural design to enable virtualized RAaaS for multi-RAT, (B) Algorithm design to enhance and optimize allocation of radio and core network resources for RAaaS, (C) SDN-based protocol design to enable traffic load balancing and management function virtualization in SIRAS, (D) Design of distributed algorithms and protocols to support cognitive and cooperative operations among virtualized SIRAS radio access nodes, and (E) SIRAS testbed development and experimentations. These tasks will be accomplished through novel design and performance evaluations by means of theoretical modeling and computer simulations. Utilizing the proposed fine-tuned experimental testbed, promising techniques proposed for aforementioned tasks in SIRAS will be implemented and evaluated under realistic conditions for proof-of-concept demonstrations and possible commercialization.