Middleware enhancements for metropolitan area wireless Internet access

The effectiveness of mission critical wireless applications such as those deployed in mobile commerce depends to a large extent on network service quality. Based on the observation that wireless networks, particularly in metropolitan areas, are subject to pockets of lowered quality and disconnectivity, we propose mechanisms to detect and adapt to these 'trouble spots'. In metropolitan area wireless networks, we postulate that the majority of network problem areas are caused by location and environmental factors. End applications that are susceptible to brief disconnectivity when entering these trouble spots can exploit pre-emptive adaptation at the protocol level to overcome potentially serious problems at the application level. Based on this premise, we propose a mechanism that gathers semantic data pertaining to specific geographic areas which cause communication problems. Prior knowledge of such locations can be used by higher-level communication protocols to pre-emptively adapt, thereby avoiding undesirable effects at the application layer. To facilitate the categorization of trouble spots, we propose a series of wireless service evaluation metrics. We report on our experiences with using these metrics and present initial results from an experimental evaluation of their effectiveness. (C) 2002 Elsevier Science B.V. All rights reserved.