Rap A real-time communication architecture for large-scale wireless sensor networks.pdf

1RAP: A Real-Time Communication Architecture for Large-Scale Wireless Sensor Networks Chenyang Lu Brian M. Blum Tarek F. Abdelzaher John A. Stankovic Tian He Department of Computer Science University of Virginia {chenyang, bmb5v, zaher, stankovic, th7c}@ Abstract Large-scale wireless sensor networks represent a new generation of real-time embedded systems with signifi- cantly different communication constraints from tradi- tional networked systems. This paper presents RAP, a new real-time communication architecture for large- scale sensor networks. RAP provides convenient, high- level query and event services for distributed micro- sensing applications. Novel location-addressed com- munication models are supported by a scalable and light-weight network stack. We present and evaluate a new packet scheduling policy called velocity monotonic scheduling that inherently accounts for both time and distance constraints. We show that this policy is par- ticularly suitable for communication scheduling in sen- sor networks in which a large number of wireless de- vices are seamlessly integrated into a physical space to perform real-time monitoring and control. Detailed simulations of representative sensor network environ- ments demonstrate that RAP significantly reduces the end-to-end deadline miss ratio in the sensor network. 1. Introduction With the advances in MEMS devices and embedded processors and radios, it will soon be feasible to deploy large-scale sensor networks to perform distributed mi- crosensing control of physical environments [10]. For example, a surveillance system may use a large net- work of acoustic sensors to detect and track vehicles in a security area. Similarly, biometric sensors can be deployed in airports and around vital targets to detect harmful bio-agents and issue alarms to command and control centers during potential bio-attacks. These smart sensors and actuators are equipped with low- power processors and short-range radio transceivers [8]. The