The 2nd IEEE WoWMoM Workshop
on Video Everywhere
June 4, 2013 - Madrid, Spain
(just before the IEEE International Conference on Communications, ICC 2013, in Budapest)
The enormous popularity of smart phones and other mobile hand-held devices has led to a dramatic increase in wireless video traffic. Until just recently, there were very few mobile devices with any capability for video reception. Today, the number of mobile video subscribers worldwide is estimated at 140 million. According to recent estimations, mobile video traffic is expected to be two-thirds of the global mobile traffic by 2014. However, a number of significant challenges need to addressed and overcome before the full potential of mobile video networking is reached. Such challenges include, among others:
- New sets of traffic control procedures must be implemented in order for networks to cope with the high variance in video traffic Quality of Service (QoS) requirements. Efficient video traffic control also prevents new users from overloading the network and prevents malevolent users from violating their traffic contract obligations. This would otherwise lead to the deterioration of the Quality of Experience (QoE) for existing users.
- The small display size, limited battery and processing capabilities of mobile devices are constraints which can negatively influence user QoE.
- The pricing of video services (by using fixed tiers depending on bandwidth usage, or by using dynamic/flexible pricing depending on the current network traffic load).
- User discomfort in holding their phones at a set distance from their faces for the time of a video conference.
- Compatibility issues between the equipment and the software of mobile video users.
All of the challenges related to mobile video networking are further hindered by user mobility and by the high error rates in wireless networks. Given the small display size, even a low video packet dropping probability may considerably deteriorate the viewer’s QoE. Additionally, errors due to packet loss in a reference frame propagate to all of the dependent difference frames (propagation of errors). Depending on the effectiveness of the encoding/decoding scheme, this phenomenon can have a very important impact on the quality of the received video sequence.