The architecture for seamless mobile information access in connected/disconnected environment

Accessing digital information in many enterprises is increasingly relied on mobile devices such as web-phones, PDAs, Pocket PCs and laptops. The experience of such access is affected by many factors. First, mobile network connections are inferior to their stationary counterparts with more frequent spurious disconnections and greater variation of network bandwidths. Second, the portability requirement of mobile devices limits the resources, which usually results in smaller display and storage sizes. Third, wireless communications are usually more costly for devices moving in a large area than the wired network. Last but not the least, the security risk for mobile devices is higher than stationary ones due to the nature of wireless communication, portability of the devices, disconnection/reconnection and migration of the devices between different service networks. Substantial research efforts are needed to help shape the corporate practices of secure, cost-effective and user-friendly access to enterprise information from mobile devices. In this paper, we focus on an important operation mode in which mobile devices are not always connected. Instead, devices are connected whenever possible and necessary, and disconnected at anytime involuntarily when the communication is interrupted or voluntarily when connection is no longer required or desirable. Clearly, devices operated in this mode usually require less connection time, which in turn results in less security risk and communication cost.