معماری شبکه بی سیم نرم افزار محور
Abstract
1- Introduction
2- Ethanol architecture
3- Ethanol implementation
4- Case studies
5- Other uses of Ethanol
6- Related work
7- Conclusions
References
Abstract
Wireless Networks have become ubiquitous to support the growing demand from mobile users, and other devices, like in the Internet of Things (IoT). This article proposes a Software-Defined Wireless Networking architecture specialized in 802.11 Wireless LANs, called Ethanol, which provides a more fine-grained control. Ethanol is the first wireless SDN architecture that extends the control to the user devices. Further, Ethanol allows intelligent white-box control with finer grain than the state of the art, since it is optimized for WiFi. The proposed architecture is evaluated on a prototype over three use cases. Ethanol can be deployed in any Access Point (AP) running embedded Linux, since it has a negligible overhead — up to 1% in memory and 0.1% in CPU usage. Our results show that Ethanol dynamically alter the throughput of an application up to 3x during a prioritization period, returning bandwidth to other applications outside this period. Only by controlling the best time to perform the handover, our results show about 45% improvement over the traditional signal-based handover process.
Introduction
Wireless networks have become ubiquitous and dense. More devices will become connected to the network because of IoT. Cisco predicts that 50 billion things will connect to the Internet by 2020.1 Emerging high-speed network standards (e.g. 802.11ad) are migrating to higher frequencies, which are absorbed by walls, thus requiring the densification of APs. Thus, a more refined control of all the network devices is needed to increase future wireless networks scalability in these environments. Current management architectures for Wireless LANs (WLANs) employ proprietary controllers. These controllers perform network-wide optimizations such as adjustment of transmission power at each AP, selection of best operational channels, faster client mobility, and enhanced traceability, as well as Quality of Service (QoS) policy (rate limiting) enforcement, and security. However, those controllers only manage compatible devices, usually from a single manufacturer, since they rely on proprietary interfaces and Management Information Bases (MIBs). Furthermore, current wireless network controllers for WLAN remain (mostly) closed [1] and the industry has little incentive to change. This article presents Ethanol, an Software Defined Networking (SDN) architecture for IEEE 802.11 WLANs. Ethanol refactors the control plane functionalities between the APs, and the controller, creating hooks in the AP implementation that trigger events to be treated by the controller. Also, the controller can use getter/setter methods to change the AP behavior, controlling features such as client mobility, association and disassociation, QoS, link-level parameters and current state, and virtual APs. The key benefit of Ethanol is its flexibility, and the use cases it enables, for example those shown in Sections 4 and 5.