The organizing committee of the ACM International Symposium on QoS and Security for Wireless and Mobile Networks is glad to welcome you to the 2021 edition of Q2SWinet, that will be held on November 22nd to 26th, 2021, in Alicante, Spain. The Q2SWinet 2021 symposium aims at serving as a meeting point and a forum for exchanging ideas, discussing solutions, and sharing experiences among researchers, professionals, and application developers, both from industry and academia. As with the previous sixteen editions of the Q2SWinet symposium series, the scope of this year's symposium will remain on general issues related to QoS and security in wireless and mobile networks networking and computing. Paper submission and publication: Papers should neither have been published elsewhere nor currently under review by another conference or journal. Accepted papers will appear in the symposium proceedings published by ACM. Please note that all accepted papers will need to have a full registration to the symposium (there will also be a symposium-only registration separated by the main conference registration). In addition, at least one author of each accepted paper is required to present their work at the symposium. No-shows of accepted papers at the symposium will result in those papers NOT being included in the ACM Digital Library. Topics of interest: In recent years, wireless and mobile communication systems have become increasingly popular as an inexpensive and promising means for ubiquitous communications. However, without creating a new set of issues and trade-offs. QoS and Security management of wireless and mobile communication systems are becoming a very crucial phase for future generation of wireless and mobile networks. The symposium focuses on the study of all aspects of QoS and Security, for wireless and mobile networks. Topics of interest include, but are not limited to: - Wireless and mobile network security (WLAN, PCS, Ad hoc and Sensor Networks, Wireless Mesh, etc. ) - QoS for wireless networks, - Intrusion detection in wireless ad hoc and sensor networks - Privacy and authentication - QoS for data analytics and machine learning - QoS for wireless multimedia systems, VoIP QoS - Quality of control of wireless networks - Power and energy management - Wireless video surveillance networks - QoS in the Wireless Internet - QoS in software-defined networking for wireless and mobile systems - QoS and Routing - Data analytics for QoS - QoS Metrics - Security, privacy - QoS in mobile cloud computing, fog computing and edge computing - QoS in Internet of Things (IoT), and mobile cyber-physical networks - Blockchain for QoS - QoS in mobile and next generation vehicular and sensor networks - QoS of Wireless Network Services - Wireless Network Survivability - QoS and Reliability - Image Quality in Wireless Video-Surveillance Networks - QoS provisioning in wireless multmedia systems - Wireless and mobile systems and applications - QoE in wireless multimedia networks - Performance Modeling and Simulation Techniques - QoS/QoE for Vehicular and wireless sensor networks Submission instructions Papers must be submitted electronically through the EDAS system. The complete list of authors' names must be inserted when registering the paper on the EDAS system. All papers will be reviewed by TPC members and other experts active in the field to ensure high quality and relevance to the conference. The maximum page limit for regular papers is 10 pages, double column, in ACM style including tables and figures. Note that the regular paper size will be 8 pages, with the possibility to obtain up to 2 additional pages (total 10 pages) by paying a fee. Only PDF format is accepted for submitted manuscripts.