Studying Quality of Experience (QoE) over Wireless Networks

Background

As stated earlier, QoE is subjective, user-centric and content-dependent. Now is the time that QoS firstly, and more terms later come into foreground. Under QoS the idea is that transmission rates, error rates and other characteristics can be measured, improved and guaranteed in advance. By using parameters as bit rate, jitter, delay, packet loss, a service can be described and evaluated. Later in this article, the differences between QoS and QoE will be discussed in more detail.

In addition with QoS, the term Class of Service (CoS) can also be found in the literature in order to describe the semantics and parameters of a specific type of QoS. Applications and services are categorized as symmetrical or asymmetrical judging by the equality of the bandwidth in both uplink and downlink directions. Also elastic and non-elastic characterizations where used, based on the minimum level of bandwidth needed and finally interactive and non-interactive depending on the human contact with a service.

Grade of Service (GoS) describes all the phenomena occurring during connection setup, release and maintenance. It appears mostly in circuit switched optical services and is the probability of the service to be blocked or delayed for more than a specific interval due to the high traffic intensity and the lack of available resources.

Finally, Quality of Resilience (QoR) is perceived as one of the dimensions of QoS and covers the gray areas when a service is operational but not fully functional and is characterized as degraded. Approaches related to QoR are not well formalized as the ones in QoS, CoS, or GoS.