WiFi overcast: Enabling true mobility for realtime applications in the enterprise

Abstract

Enterprises are increasingly deploying wireless local area connections (WLANs) to provide mobile access to users in corporate offices. However, existing enterprise WLANs are far from being truly mobile. In particular, they do not adequately support continuous mobility, where users access the network on-the-go. Furthermore, WLANs that do provide continuous mobility support require client modifications, making them hard to deploy in practice 20. In addition, with the growing interest in realtime applications such as voice and video, users are increasingly placing additional (QoS) demands on the network, which for inadequately designed WLANs, does not scale to large numbers of user 10. In this paper, we propose Overcast, a novel WLAN architecture that targets scenarios demanding continuous mobility and real-time support for 802.11 clients. Overcast does not require client modifications and supports all 802.11 standards. Though Overcast borrows some features from prior WLAN designs, it improves on them by incorporating a novel RF mapping framework (proposed in 3) for accurate online detection of RF interference. We describe the architecture of Overcast in detail and discuss our current efforts in realizing such a system on off-the-shelf commodity hardware. We also describe an example application of Overcast to highlight its usefulness in supporting realtime applications in continuously mobile user environments.