A Model-Based Abstraction Layer for Heterogeneous SDN Applications

Modern controllers for software-defined networks (SDN) enable the execution of arbitrary SDN applications (eg, Network Address Translation (NAT), traffic monitors) that may be exploited by an overarching set of services (eg, application-layer orchestrators) to build even richer services. To this purpose, the above overarching services require a mechanism that allows reading the run-time state and writing the configuration of arbitrary SDN applications, possibly through a uniform API. Unfortunately, most SDN applications are not designed/implemented by taking into account the possibility to be used as part of higher level service workflows (eg, a complex intrusion prevention system that leverages multiple elementary services as individual components), hence they may not provide an adequate interface that would allow overarching services to exploit their features. This paper addresses this problem by proposing an approach to represent the run-time state of arbitrary applications, where data are exported according to high-level model-based structures. Furthermore, the mapping from the high-level data model to the actual data representation within the SDN application is enabled by a suite of algorithms that are generic enough to operate independently of the actual source code of the application, thus avoiding undesired and invasive modifications to existing applications. The paper also presents a software framework and a prototype implementing the proposed approach, characterizes the resulting performance, and discusses pros and cons of the proposed approach

Building Programmable Wireless Networks: An Architectural Survey

In recent times, there have been a lot of efforts for improving the ossified Internet architecture in a bid to sustain unstinted growth and innovation. A major reason for the perceived architectural ossification is the lack of ability to program the network as a system. This situation has resulted partly from historical decisions in the original Internet design which emphasized decentralized network operations through co-located data and control planes on each network device. The situation for wireless networks is no different resulting in a lot of complexity and a plethora of largely incompatible wireless technologies. The emergence of "programmable wireless networks", that allow greater flexibility, ease of management and configurability, is a step in the right direction to overcome the aforementioned shortcomings of the wireless networks. In this paper, we provide a broad overview of the architectures proposed in literature for building programmable wireless networks focusing primarily on three popular techniques, i.e., software defined networks, cognitive radio networks, and virtualized networks. This survey is a self-contained tutorial on these techniques and its applications. We also discuss the opportunities and challenges in building next-generation programmable wireless networks and identify open research issues and future research directions.Comment: 19 page

Will SDN be part of 5G?

For many, this is no longer a valid question and the case is considered settled with SDN/NFV (Software Defined Networking/Network Function Virtualization) providing the inevitable innovation enablers solving many outstanding management issues regarding 5G. However, given the monumental task of softwarization of radio access network (RAN) while 5G is just around the corner and some companies have started unveiling their 5G equipment already, the concern is very realistic that we may only see some point solutions involving SDN technology instead of a fully SDN-enabled RAN. This survey paper identifies all important obstacles in the way and looks at the state of the art of the relevant solutions. This survey is different from the previous surveys on SDN-based RAN as it focuses on the salient problems and discusses solutions proposed within and outside SDN literature. Our main focus is on fronthaul, backward compatibility, supposedly disruptive nature of SDN deployment, business cases and monetization of SDN related upgrades, latency of general purpose processors (GPP), and additional security vulnerabilities, softwarization brings along to the RAN. We have also provided a summary of the architectural developments in SDN-based RAN landscape as not all work can be covered under the focused issues. This paper provides a comprehensive survey on the state of the art of SDN-based RAN and clearly points out the gaps in the technology.Comment: 33 pages, 10 figure