An Assessment of a Mobile Communication Link for a System to Navigate Visually Impaired People

A performance assessment was carried out to establish the suitability of 2G, 2.5G, and 3G mobile communication links for application in a system for the navigation of visually impaired pedestrians. The assessment is intended to enable the implementation of the system using standard telecommunication infrastructure. Thus, the system will be made available to the end user in a wide geographical area, anytime, anyplace. In the mobile link performance assessment, the tests were concentrated on the main link characteristics: bandwidth, latency, link outages, and packet losses - as these link characteristics directly influence the navigation system performance. While the navigation system requires a transmission link that can guarantee the delivery of data with the least delay, losses, and link outages (disconnections), the link also has to support enough bandwidth to simultaneously accommodate video, voice, and Global Positioning System (GPS) location data. The assessment results show that the 2G link is not suitable for the system due to the low bandwidth. The 2.5G link cannot be used because of the high and variable latency, link outages, signal fluctuations, low bandwidth, and high packet loss. The 3G link can be deemed suitable; however, more tests are needed to fully define the appropriate settings for the use of this link in the system.