This book constitutes the refereed post-conference proceedings of the Fourth IFIP International Cross-Domain Conference on Internet of Things, IFIPIoT 2021, held virtually in November 2021. The 15 full papers presented were carefully reviewed and selected from 33 submissions. Also included is a summary of two panel sessions held at the conference. The papers are organized in the following topical sections: challenges in IoT Applications and Research, Modernizing Agricultural Practice Using IoT, Cyber-physical IoT systems in Wildfire Context, IoT for Smart Health, Security, Methods.

The seventh edition of the International Conference on Wired/Wireless Int- net Communications (WWIC) was organized by the University of Twente in May 2009. Since the ?rst event in 2002, WWIC has been established as a highly selectiveconferencefocussingonthe rapidlydeveloping?eldof wirelessnetwo- ing, and providing an international forum for the presentation and discussion of cutting-edge research in the ?eld. The WWIC 2009 call for papers attracted 39 submissions from 20 countries, which were subject to thorough review by the Technical Program Committee members and additional experts. The selection process resulted in the acc- tance of 13 papers, organized into 4 technical sessions. The major themes of WWIC this year were energy e?ciency, security, reliability, and routing p- tocols in wireless sensor and ad hoc networks as well as handover and mobility managementin heterogeneousenvironments. We aregratefulto MatthiasGro- glauser (Nokia Research Center, Finland, and EPFL Lausanne, Switzerland), who accepted our invitation to give the WWIC 2009 keynote speech. Further, we would like to thank Hans Appel (Sun Microsystems, The Netherlands), and Remco Litjens (TNO ICT, The Netherlands) for giving invited presentations at this year's event. In addition to the main technical program, the third ERCIM workshop on eMobility took place on the ?rst day of WWIC 2009. We thank the authors for choosing WWIC 2009 as the conference to submit their results to.

WWIC2008wasorganizedbytheTechnicalUniversityofTampere, Finland, and it was the sixth event in a series of InternationalConferenceson Wired/Wireless Internet Communications. Previous events were held in Coimbra (Portugal) in 2007, Berne (Switzerland) in 2006, Xanthi (Greece) in 2005, Frankfurt (G- many) in 2004, and Las Vegas (USA) in 2002. The WWIC 2008 call for papers attracted 67 submissions from 33 co- tries, which were subject to thorough review work by the Technical Program Committee members and additional reviewers. The selection process resulted in acceptance of 18 papers, organized into 6 single-track technical sessions. The WWIC 2008 main technical program covered studies on performance analysis of wireless systems, topics on resource and QoS management, and issues on implementation techniques, mobility, cross-layer design and wireless sensor n- works. The technical program was complemented by two keynote speeches, by Nestor Peccia (European Space Agency, Darmstadt, Germany) on "Interpla- tary Internet," and Arto Karila (Helsinki Institute of Information Technology, Finland), on"Multi-Accessin RegionalNetworks."Inadditionto themainte- nicalprogram, thelastdayoftheconferencewasdedicatedtotheSecondERCIM workshop on eMobility. WWIC has been selected as the o?cial annual conference by COST Action 290 (Wi-QoST-Tra?c and QoS Management in Wireless Multimedia Networks) since 2005, and this time the conference was co-located with the ?nal mana- ment committee meeting of the Action. For that reason, two sessions of WWIC were dedicated to the Action, and in those sessions a distinguished selection of the results of COST Action 290 were presented. Those papers were selected from the submissions to the general call for papers according to the same strict criteria as the other accepted papers.