Enhancing the quality of service of mobile video technology by increasing multimodal synergy

ABSTRACT

Bandwidth is still a limiting factor for the Quality of Service (QoS) of mobile communication applications. In particular, for Voice over IP the QoS is not yet as good as for common, well-engineered, public-switched telephone networks. Multisensory communication has been identified as a possibility to moderate this limitation. One of the strengths of mobile video technology lies in its combination of visual and auditory modalities. However, one of the most salient features of mobile video applications is its small screen size. To test the potential of multimodal synergy for mobile devices, we assessed to what extent small screens affect multimodal synergy. This potential was assessed in an experiment with 54 participants, who conducted a standardised video-listening test for three talking-heads videos with a signal-to-noise ratio of –9 dB. The videos were presented on three different screen sizes, whilst keeping the video and auditory signals equal. Compared to a ground truth based on 359 participants, intelligibility was found to be significantly higher when using a large screen than when using a small screen. This indicates that mobile video technology has the potential for a significant multimodal synergy to which screen size is a substantial constraint. To optimally benefit from their multimodal potential, we offer suggestions on how to increase the effective screen size for small screen (e.g. mobile) devices and applications through elaborating the most relevant (visual) features. We conclude that knowledge about human sensory processing can alleviate the identified constraint and maximise the potential QoS of mobile video technology.

KEYWORDS:

• Multimodal
• multisensory
• mobile
• screen size
• quality of service (QoS)
• voice over IP (VoIP)
• field of view (FOV)
• signal-to-noise ratio (SNR)

Acknowledgments

The CITO (2018), in particular Jan van Thiel, is gratefully acknowledged for their generous cooperation in selecting and, subsequently, preparing suitable video-listening tests. In addition, we thank Ronald van Eijk, Johan de Heer, and Sorin Iacob for their cooperation and fruitful discussions during this study. Last, we thank all subjects for their participation in this study.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

The Dutch organisation for scientific research (NWO) is gratefully acknowledged for funding the IPPSI-KIEM project Adaptive Text-Mining (ATM) (project-number: 628.005.006), in which Frans van der Sluis and Egon L. van den Broek cooperate.