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，全球无线数据流量将超过300艾字节/年，移动服务提供商正在部署各种网络，使用微小区、微微小区和毫微微小区来增强传统的宏蜂窝，并利用3G/4G蜂窝和802.11n/ac等无线电接入技术(RAT)的混合。然而，RAT的进步并没有与促进其有效部署的系统体系结构的新发展相匹配。新的无线系统架构应可扩展以提供更大的容量，可编程以支持新功能和高级RAT，并可自组织以实现“即插即用”部署。我们建议通过解决导致SIRAS(无线接入智能基础设施即服务)开发的重要研究问题来填补这些空白，通过利用新兴的云计算和虚拟化技术来实现具有成本效益和高效的下一代无线接入，这些技术是无线接入网络的有前途但尚未广泛探索的方法。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，同时利用了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用分布式体系结构取代当前的集中式蜂窝体系结构，该分布式体系结构采用大规模分布式天线系统和自治小小区，所述分布式体系结构使用适用于特定环境的几个支持的RAT中的一个协作来向各个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，并且基于每个流来优化资源分配。这种分布式架构将使RAaaS能够按需利用云计算资源，并结合本地资源，以经济高效且可扩展的方式实现管理和信号处理功能的虚拟化。因此，无论何时何地出现需求，SIRAS都有望通过增加基础设施容量和在成本、能源、复杂性和延迟方面即时和高效地保证服务质量来提供移动服务。为了实现这一愿景，我们建议在无线接入网络研究中追求一个新的方向，以开发新的体系结构、协议和管理算法，以实现上述SIRAS的潜在好处。本研究项目的总体目标是为这一新的研究方向做出根本性的贡献，这将对下一代无线接入网络产生重大影响。具体地说，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)支持多RAT的虚拟RAAS的SIRAS架构设计；(B)为RAAAS增强和优化无线电和核心网络资源分配的算法设计；(C)基于SDN的协议设计，以实现SIRAS中的流量负载均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SIRAS无线接入节点之间的认知和协作操作；以及(E)SIRAS试验台的开发和实验。这些任务将通过新的设计和性能评估来完成，方法是理论建模和计算机模拟。利用拟议的微调实验试验台，将在现实条件下实施和评估在SIRA中为上述任务提出的有前景的技术，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.