WNOS Enabling Principled Software-Defined Wireless Networking
Abstract : This article investigates the basic design principles for a new Wireless Network Operating System (WNOS), a radically different approach to software-defined networking (SDN) for infrastructure-less wireless networks. Departing from well understood approaches inspired by Open Flow, WNOS provides the network designer with an abstraction hiding (i) the lower level details of the wireless protocol stack and (ii) the distributed nature of the network operations. Based on this abstract representation, the WNOS takes network control programs written on a centralized, high-level view of the network and automatically generates distributed cross-layer control programs based on distributed optimization theory that are executed by each individual node on an abstract representation of the radio hardware. We first discuss the main architectural principles of WNOS. Then, we discuss a new approach to automatically generate solution algorithms for each of the resulting sub problems in an automated fashion. Finally, we illustrate a prototype implementation of WNOS on software-defined radio devices and test its effectiveness by considering specific cross-layer control problems. Experimental results indicate that, based on the automatically generated distributed control programs, WNOS achieves 18%, 56% and 80.4% utility gain in networks with low, medium and high levels of interference; maybe more importantly, we illustrate how the global network behavior can be controlled by modifying a few lines of code on a centralized abstraction.
? Sensor Open Flow (SOF) also extended Open Flow to support coexisting applications, data aggregation, and in-band control traffic management.
? There exists a radio link and a corresponding edge between nodesi and j if they are in range with each other.
? However, any required functions can be added to the controller as a new module without modifying the existing architecture or reprogramming the sensors.
? We characterize the observed overhead of the SD Sense operation, which most of the existing solutions for software-defined WSNs overlooked.
? We propose an architecture for WNOS by defining three key components: network abstraction, automated network control problem decomposition, and programmable protocol stack.
? We propose the notion of disciplined instantiation, based on which user-defined abstract centralized network control problems can be decomposed into a set of distributed subproblems in an automated fashion.
? This is the interface through which the network designer can define the network control problem to achieve certain application-specific objectives.
? A network control problem comprises of four components: network setting, control variables, network utility and network constraints.
• In this paper, we state that SDN-based design is beneficial in the multihop wireless networks like wireless sensor network (WSN) and propose an architecture called SDSense.
• We propose a novel principled approach of SDN-based WSN design, where we decompose network functions as slow (e.g., topology control) and fast (e.g., congestion control) changing components.
• SDSense bridges these gaps and proposes a principled approach of delegating control tasks to data plane elements.
• We propose an adaptive resource allocation model to manage the congestion within WSNs, where the controller reallocates the available bandwidth in areas where congestion occurs.
? Different decomposition approaches can lead to different structures of the resulting distributed control program with various convergence properties, communication overhead, and achievable network performance.
? Software-defined networking has shown great potential to enhance the performance of wireless access networks, e.g., improving network resource utilization efficiency, simplifying network management, reducing operating costs, and promoting innovation and evolution.
? We base our development on Python to take advantage of its high programming efficiency and high-level expressiveness and the flexible, open-source programming interfaces to GNU Radio for controlling USRPs.
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