The number of mobile Internet users and the volume of traffic generated by them keep increasing every year. In this context, the proliferation of smartphones, tablets, and cheap mobile data tariffs along with the emergence of new media services and the increasing use of 3G and upcoming 4G cellular networks as a substitute for traditional fixed-line connectivity, creates a host of new challenges when it comes to achieving good network performance and a satisfactory user experience. Beyond traditional multimedia applications such as IPTV and video conferencing which have a fairly very well-known set of performance requirements from the network perspective, the increasing uptake of web- and cloud-based services also introduces a new set of requirements for network performance. Furthermore, the evolution of mobile networks towards an all-IP paradigm (e.g., LTE) introduces new challenges for traditionally circuit-switched services such as voice telephony, where it is critical for operators to guarantee minimum levels of performance and improve them where possible.

For these reasons, operators need to understand, measure, and manage both quality and performance of the 3G and 4G services they offer. This has to be fulfilled on the technical quality of service (QoS) as well as on the quality of experience (QoE) level, since ultimately it is the human end-user who decides whether the quality of a given service is inacceptable, sufficient, or even exceeding expectations.

This special issue aims at bringing together the state-of-the-art research on evaluating and improving QoS and QoE in wireless 3GPP networks. We encourage authors to submit recent unpublished work focused on the following topics. Potential topics include, but are not limited to:

• New mobile applications with special requirements in terms of network performance
• Methods for objective and subjective QoS and QoE assessment
• QoE evaluation methodologies for novel emerging mobile services
• Subjective QoE testing of mobile services in the lab and in the field
• Measurement, simulation, and evaluation techniques, tools, and testbeds
• Combining user-, application-, and network-level measurements on different platforms
• Modeling and mapping relationships between QoS and QoE
• QoS and QoE monitoring in 3G and 4G networks
• QoS- and QoE-driven resource control and service optimization in 4G networks, in particular regarding cross-layer approaches, extensions of current standards, and multitechnology connectivity
• Trade-offs in contrast to QoS or QoE requirements (e.g., energy-efficient mechanisms coping with limited battery capacity, security, and reliability issues)

Before submission authors should carefully read over the journal's Author Guidelines, which are located at http://www.hindawi.com/journals/jcnc/guidelines/. Prospective authors should submit an electronic copy of their complete manuscript through the journal Manuscript Tracking System at http://mts.hindawi.com/ according to the following timetable: