Subjective assessment of the perceived quality of video calling services over a real LTE/4G network

Abstract

The rapid growth of wireless mobile communications raises the critical issue of meeting user expectations and requirements. This paper deals with the subjective assessment of the perceived quality of video calling services delivered on a real LTE/4G network. The main goal is to determine the list of parameters that are predominantly impacting the Quality of Experience (QoE). The influencing parameters considered here include the video sequence content, coding technology and both core and radio access networks. Following the ITU-T Recommendations, subjective quality assessment experiments were conducted. Subjects were shown different representative sequences of video-calling services transmitted using different network conditions. The outcomes of these experiments show that the QoE is mainly affected by packets loss, jitter. However the impact of these parameters, which vary over time and in case of user mobility, seems to be different from that observed with simulated networks.

Towards Individual QoE for Multiparty Videoconferencing

“…Passive tests are conducted by letting users rate the quality of video clips using video conferencing related content, for example [26], [27], [28]. As these tests have limited ecological validity, active studies have been proposed, where participants actually interact through the system.…”

1Mbps is enough: Video quality and individual idiosyncrasies in multiparty HD video-conferencing

“…Each bitrate level was further combined with either of two levels of packet loss, i.e. (1) no packet loss, as would occur on a wired connection and (2) 0.5% packet loss, likely over an impaired wireless network [3]. This resulted in a full factorial design with 6 conditions.…”

“…In passive tests, participants assess the quality of video clips [1] or recordings from video-conferencing sessions [2] [3]. While 1 http://www.cisco.com/c/en/us/solutions/collateral/service-provider/visualnetworking-index-vni/VNI_Hyperconnectivity_WP.html 2 http://blogs.skype.com/2016/01/12/ten-years-of-skype-video-yesterdaytoday-and-something-new/ easy to setup, these tests suffer from limited ecological validity: the focus in a video-conferencing session is on effectively interacting with the other participants via audiovisual communication; the level to which system factors impair this ability is not accounted for in passive tests.…”

“…Nevertheless, it is unclear whether this bound still holds for higher resolution video, such as HD. Popular video delivery services encode their 720p videos within 2Mbps and 4Mbps 3 . A multiparty conference, with such bitrates, easily maxes out the typical broadband connections available at households 4 .…”

“…We use a desktop-based 4-way videoconferencing scenario with WQHD screens and 720p videostreams encoded in H.264. We test the effect of encoding the 3 http://www.lighterra.com/papers/videoencodingh264/ 4 https://www.stateoftheinternet.com/resources-connectivity-2015-q3-stateof-the-internet-report.html 978-1-5090-0354-9/16/$31.00 ©2016 IEEE 978-1-5090-0354-9/16/$31.00 ©2016 IEEE video streams to bitrate levels fitting the bandwidth delivered by different internet access technologies typical for domestic households: broadband, DSL and mobile. We inject packet-loss in the videostreams, simulating typical slightly impaired wireless networks.…”