Keynote -- QoS Is Still an Issue, Congestion Pricing Is not the Solution -- Session 1: Competition Models -- Optimization of Transmission Power in Competitive Wireless Networks -- On Competition for Market Share in a Dynamic ISP Market with Customer Loyalty: A Game-Theoretic Analysis -- A Pricing Model for a Mobile Network Operator Sharing Limited Resource with a Mobile Virtual Network Operator -- Session 2: Pricing Mechanisms -- Design and Evaluation of a Combinatorial Double Auction for Resource Allocations in Grids -- A User-Influenced Pricing Mechanism for Internet Access -- Price Setting in Two-Sided Markets for Internet Connectivity -- Session 3: Economics of Inter-domain Traffic -- Online Charging for IMS-Based Inter-domain Composite Services -- A New Bilateral Arrangement between Interconnected Providers -- Improvement of BitTorrent Performance and Inter-domain Traffic by Inserting ISP-Owned Peers.

This book constitutes the refereed proceedings of the 6th International Workshop on Internet Charging and QoS Technologies, ICQT 2009, held in Aachen, Germany, in May 2009 collocated with the IFIP Networking 2009 conference. The 9 revised full papers presented together with the extended abstract of a keynote paper were carefully reviewed and selected from a total of 26 submissions. The papers are organized in topical sections on competition models, pricing mechanisms, and economics of inter-domain traffic. Bringing together researchers from the area of technology and economy in both industry and academia to discuss key improvements and to support further progress in these fields, ICQT 2009 features combination of micro-economic models, auctions, game theoretic approaches, peer-to-peer, and IMS-based charging.