Wireless on-demand network systems and services have become pivotal in shaping our future networked world. Starting as a niche application over Wi-Fi, they can now be found in mainstream technologies like Bluetooth LE, LTE Direct and Wireless LANs, and have become the cornerstone of upcoming networking paradigms including mesh and sensor networks, cloud networks, vehicular networks, disruption tolerant and opportunistic networks, and in-body networks.

The challenges of this exciting research field are numerous. Examples include how to make smart use of these novel technologies when multiple technologies or a mix of permanent services and on-demand networking opportunities are available to a network node, how to provide robust services in highly dynamic environments, how to efficiently employ and operate heavily resource-constrained devices, and how to develop robust and lightweight algorithms for self-organization and adaptation. Finally, there are many application-specific challenges.

WONS, now in its sixteenth edition, is a high quality forum to address these challenges. WONS aims to provide a global platform for rich interactions between experts in their fields, discussing innovative contributions in a stimulating environment.

This announcement solicits original contributions of high-quality research providing novel insights on all aspects of wireless on-demand networks and systems; from protocol and network design, modeling, performance evaluation, energy efficiency, models and mechanisms, practical implementations, service level aspects, application use-cases, to the integration of multiple wireless network technologies.

Accepted and presented papers will appear in the conference proceedings published in the IFIP Open Access Digital Library and will also be submitted to the IEEE Xplore Digital Library as well as other Abstracting and Indexing (A&I) databases.

After having carefully monitored the sanitary evolution, the WONS 2021 organising committee decided to move to a fully virtual conference. This will allow all speakers and participants to join the conference independently of any travel restrictions that might still apply beginning of 2021.

Topics of interest comprise, but are not limited to:

• Cognitive radio networks
• Network management
• Cross-layer design
• Modeling and optimization
• Energy-efficient protocols and power management
• Mobile computing and services
• Heterogeneous wireless networks
• New architectures for on-demand wireless systems
• Implementations and testbeds
• Novel applications and services
• Integration and co-existence of heterogeneous technologies
• Opportunistic, delay-tolerant, and dissemination-based protocols
• Intra-body and biomedical on-demand systems
• Performance evaluation through simulations and experiments
• Green wireless networks
• Pervasive and ubiquitous computing
• Localization and mobility management
• Security, privacy, and trust
• MAC and advanced PHY technologies
• Social and economic aspects
• Middleware aspects
• Underwater on-demand networked systems
• Mobile peer-to-peer systems
• Architectures and protocols for the Internet of Things
• Vehicular networks
• Device-to-device communication for 5G and 6G architectures

This edition will additionally include a special session titled "Smartphone Apps for Contact Tracing - Experiences with COVID-19 Tracing Apps", addressing the issues related to pandemic control and tracing.

Extended versions of selected top papers will be considered for publication on a fast track on special issues in Elsevier Computer Communications (COMCOM) journal.