Astad approached Recursive to develop an innovative audio tour system that would allow people visiting the Qatar National Library to listen to the audio of each exhibit, video wall and interactive installation through headphones so as not to disturb other users. An important feature of the brief was the need to deliver this audio in real time and using the existing Wi-Fi network in place within the building. This was particularly relevant due to the need to support live presentations within the auditorium and special events space, alongside multiple language support, interfacing directly with the real time interpretation system. An additional requirement for the system was that this should be delivered in a hands free way with no user intervention required. This last requirement meant there was a need to carry out indoor tracking of the individual users location to automatically determine their exact location and then use this to decide the exact moment to switch audio channels, cross-fading the audio, to ensure they always receive the correct audio for the exhibit or space in which they are in. A final requirement was the creation of a roaming “guest speaker” feature which would allow a tour to be conducted around the library with the tour guide simply using a roaming radio microphone with the audio from this being delivered to the users in real time via the application wherever they are.
To transmit audio from exhibit to audio device, Recursive proposed the use of an audio over Wi-Fi device that would allow audio to be streamed over the a wireless network directly to each mobile device. In order to track the position of people throughout the building, Recursive developed bespoke directional beacon devices especially for the project. Standard beacons are omnidirectional meaning that the RF signal is propogated in all directions equally. This approach does not work well when mutliple beacons are required in close proximity, as was the case in the library with multiple exhibits often less than 2m apart. In addition the large number of RF reflections which occur from the surrounding surfaces, especially in an modern architectural environment, skew the readings of the RF signals recieved, leading to false positioning and triggering. To match the bespoke beacon design, Recursive also developed bespoke code to detect the proximity of the mobile device from each Beacon within the building. This is built on the iOS platform and is run from a custom cloud based Content Management System (CMS) which runs and manages all devices and beacon settings, allowing real time diagnostics and changes across the site.