Traffic engineering and fast reroute are the two major applications of constraint based routing Traffic engineering is the process of controlling how traffic flows through a service provider’s network so as to optimize resource utilization and network performance[1]. Traffic engineering is needed in the Internet mainly because the shortest path is used in current intradomain routing protocols (...

In this paper, we present a real-time algorithm that plans mostly optimal trajectories for multiple mobile robots in a dynamic environment. This approach combines the use of a Delaunay triangulation to discretise the environment, a novel efficient use of the A* search method, and a novel cubic spline representation for a robot trajectory that meets the kinematic and dynamic constraints of the r...

The constrained shortest-path problem (CSPP) generalizes the standard shortest-path problem by adding one or more path-weight side constraints. We present a new algorithm for CSPP that Lagrangianizes those constraints, optimizes the resulting Lagrangian function, identifies a feasible solution, and then closes any optimality gap by enumerating nearshortest paths, measured with respect to the La...

We present methods for extracting optimal paths from motion planning roadmaps. Our system enables any combination of optimization criteria, such as collision detection, kinematic/dynamic constraints, or minimum clearance, and relaxed definitions of the goal state, to be used when selecting paths from roadmaps. Our algorithm is an augmented version of Dijkstra’s shortest path algorithm which all...

We consider the resolution by constraint programming of large problems, i.e. involving millions of constraints, which mainly imply arithmetic constraints, like shortest path problems or other related problems. We show that a simple constraint programming model is not competitive with dedicated algorithms (or dedicated constraints). This mainly comes from the propagation mechanism, i.e. the orde...

This paper describes the path selection function in Networking BroadBand Services (NBBS), which is IBMs architecture for high-speed, multimedia networks. The distinguishing feature of a multimedia network is its ability to integrate different applications with different traffic characteristics and service requirements in the network, such as voice, video, and data. In order to meet their servic...

We consider the problem of computing shortest paths subject to an additional resource constraint such as a hard limit on the (positive) height difference of the path. This is typically of interest in the context of bicycle route planning, or when energy consumption is to be limited. So far, the exact computation of such constrained shortest paths was not feasible on large networks; we show that...

Today, providing a good quality of service (QoS) in irregular traffic networks is an important challenge. Besides, the impressive emergence and the important demand of the rising generation of real-time Multi-service (such as Data, Voice VoD, Video-Conference, etc.) over communication heterogeneous networks, require scalability while considering a continuous QoS. This emergence of rising genera...