Resumen de Improving the Server Performance of CAR Systems Based on Mobile Phones

Víctor Fernández, Juan Manuel Orduña Huertas, Pedro Morillo

• Collaborative Augmented Reality(CAR) systems allow multiple users to share a realworld environment including computer-generatedimages in real time. The hardware features of mostcurrent mobile phones include wireless networkcapabilities that offer a natural platform for CARsystems. However, the potential number of clientsin CAR systems based on mobile phones is muchlarger than on CAR systems based on other kindof mobile devices, requiring a system design thattakes into account scalability issues. This paperpresents the experimental comparison of differentCAR systems based on mobile phones with differentserver implementations. The performance evaluationresults show that the best implementation is the onebased on UDP messages instead of classical TCPconnections, in order to improve the system throughput.The UDP-based implementation providesa significant improvement in system throughput,at the cost of loosing a very small percentage ofupdating messages. However, the effects of thesesmall quantities of dropped messages cannot expandbeyond some jitter (bounded within a short periodof time) in a reduced number of clients of the CARapplication. These results validate the proposedUDP-based implementation as the best option forlarge-scale CAR systems based on mobile phones.