A generic load balancing framework for cooperative ITS applications

The deployment of cooperative ITS applications is due to start as soon as 2015. Large investments in the roadside unit (RSU) infrastructure will be necessary to create a dense network and accommodate an increasing number of services, leading to a discussion about the trade-off between distributed processing and storage solutions on the RSU nodes and the centralized alternative. A strictly central solution might not be scalable, whereas the decentralized approach faces the problem that load in the form of CPU and memory usage may be unequally distributed among the nodes, causing performance bottlenecks on some of the RSUs. This work presents a solution for this problem, in form of a generic framework that balances the load between the nodes and reduces in this way the RSU costs. The interactions are based on a flexible coordination pattern for load balancing that is realized using customizable containers provided by a distributed systems middleware. This mechanism is applied to a probe data collection scenario in which individual messages are aggregated by RSU nodes, causing both CPU and memory load. Simulation results illustrate the operation in dynamic load situations.