MiLAN: Middleware Linking Applications and Networks

Wireless sensor networks are growing in popularity due to the availability of low-power sensing devices and to their flexibility for a large number of applications ranging from environmental monitoring to security and surveillance. Designing and building applications for wireless sensor networks is complex because of (1) the distributed nature of the environment, (2) the fact that the available sensors change over time, and (3) the nature of the applications themselves, which typically require quality of service (e.g., data accuracy) that changes over time as the state of the system being monitored changes. As wireless sensors are typically battery powered, energy management is a critical task to extend application lifetime. Many low level protocols address energy management but typically ignore application needs, providing only a best effort quality level to the application.

We have developed a middleware for sensor networks, called MiLAN (Middleware Linking Applications and Networks) that not only understands the needs of sensor network applications, but also reaches down into the network, adjusting network characteristics to optimize application lifetime while maintaining the needed quality of service. MiLAN receives from the application a specification of its needed quality of service, parameterized by the state of the application. At the network level, it employs a plug-in architecture that identifies the potential "hooks" of the protocols being used by the sensor network and, based on the application requirements over time, optimally adjusts these parameters to best suit the application. By combining the application and network information, MiLAN ensures that the network is optimally configured to support the application and dynamically reconfigures the network in response to changes in the environment and in the high-level state of the application.

For more information on this project, please contact: Wendi Heinzelman.