Messungen zum Kommunikationsaufwand für Prozesse in einem lokalen Rechnernetz: Erfahrungen aus einer Implementation. - G. Neumann; Ralf Ackermann; Winfried Grünewald (Implementierungssprachen für nichtsequentielle Programmsysteme, 1981)

Agent-Q - das Diagnose- und Datenqualitätssystem (Ein Praxisbericht). - Thomas Kubela; Ralf Ackermann (Workshop Integration heterogener Softwaresysteme, 1998)

MBone2Tel - Telephone Users Meeting the MBone. - Ralf Ackermann; Jörg Pommnitz; Lars C. Wolf; Ralf Steinmetz (IDMS, 1999)

VDMFA, eine verteilte dynamische Firewallarchitektur für Multimedia-Dienste. - Christoph Rensing; Utz Roedig; Ralf Ackermann; Lars C. Wolf; Ralf Steinmetz (Kommunikation in Verteilten Systemen, 1999)

Using DMIF for Abstracting from IP-Telephony Signaling Protocols. - Ralf Ackermann; Vasilios Darlagiannis; Utz Roedig; Ralf Steinmetz (IDMS, 2000)

Associating network flows with user and application information. - Ralf Ackermann; Utz Roedig; Michael Zink; Carsten Griwodz; Ralf Steinmetz (ACM Multimedia Workshops, 2000)

Vulnerabilities and Security Limitations of current IP Telephony Systems. - Ralf Ackermann; Markus Schumacher; Utz Roedig; Ralf Steinmetz (Communications and Multimedia Security, 2001)

Conditional Access for Business and M-Commerce Applications using Annotation Watermarks. - Jana Dittmann; Petra Wohlmacher; Ralf Ackermann (Communications and Multimedia Security, 2001)

IP-Telefonie und Firewalls, Probleme und Lösungen. - Utz Roedig; Ralf Ackermann; Ralf Steinmetz (Prax. Inf.verarb. Kommun., 2001)

Using a Multi-Layer Approach to Tackle the Service Interaction Problem in Telephony Scenarios. - Manuel Görtz; Ralf Ackermann; Martin Karsten; Ralf Steinmetz (EUROMICRO, 2002)

Digital Watermarks Enabling E-Commerce Strategies: Conditional and User Specific Access to Services and Resources. - Jana Dittmann; Martin Steinebach; Petra Wohlmacher; Ralf Ackermann (EURASIP J. Adv. Signal Process., 2002)

Using Context Information to Avoid Service Interactions in IP Telephony. - Manuel Görtz; Ralf Ackermann; Andreas Mauthe; Ralf Steinmetz (MIPS, 2003)

Gateways and components for supplementary IP telephony services in heterogeneous environments. - Ralf Ackermann (2003)

Enhanced SIP Communication Services by Context Sharing. - Manuel Görtz; Ralf Ackermann; Ralf Steinmetz (EUROMICRO, 2004)

Context-aware Communication Services: A Framework for Building Enhanced IP Telephony Services. - Manuel Görtz; Ralf Ackermann; Johannes Schmitt 001; Ralf Steinmetz (ICCCN, 2004)

The Digital Call Assistant: Determine Optimal Time Slots for Calls. - Manuel Görtz; Ralf Ackermann; Ralf Steinmetz (MIPS, 2004)

Security-Related Issues in Peer-to-Peer Networks. - Luka Divac-Krnic; Ralf Ackermann (Peer-to-Peer Systems and Applications, 2005)

Proof of Possession: Using RFID for Large-Scale Authorization Management. - Eberhard Grummt; Ralf Ackermann (AmI Workshops, 2007)

Routing Mechanism for Secure, Distributed Discovery Services for Global Auto-ID Networks. - Jons-Tobias Wamhoff; Eberhard Grummt; Ralf Ackermann (IWRT, 2008)

Using context information to enhance the functionality and usability of enterprise information systems. - Ralf Ackermann (GI Jahrestagung, 2009)

A service infrastructure for the Internet of Things based on XMPP. - Sven Bendel; Thomas Springer 001; Daniel Schuster 002; Alexander Schill; Ralf Ackermann; Michael Ameling (PerCom Workshops, 2013)