n services. Scandinavian Journal of Management 18(2): 155-171. Vanhaverbeke, W. and Cloodt, M. 2006. Open innovation in value networks. In Open Innovation: Researching a New Paradigm, Chesbrough, H., Vanhaverbeke, W. and West, J. (Eds.), pp. 258-281. New York, NY: Oxford University Press. Vermeulen, P. and van der Aa, W. 2003. Organizing innovation in services. In Service Innovation, Tidd, J. and Hull, F. M. (Eds.), pp. 35-53. London: Imperial College Press. von Hippel, E. 2005. Democratizing Innovation. Cambridge: MIT Press. West, J. and Lakhani, K. 2008. Getting clear about communities in open innovation. Industry and Innovation (2):223-231. West, J., Vanhaverbeke, W., and Chesbrough, H. 2006. Open innovation: A research agenda. In Open Innovation: Researching a New Paradigm, Chesbrough, H., Vanhaverbeke, W., and West, J. (Eds.), pp. 285-307. Oxford: Oxford University Press. Whinston, A., Choi, S., and Stahl, D. 1997. The Economics of Electronic Commerce. Indianapolis: Macmillan Technical Publishing. Zhou, Q. and Tan, K. C. 2008. A bibliographic analysis of the literature on new service development. In Proceedings of the International Conference on Management of Innovation and Technology (ICMIT '08). IEEE, 872-877. Chapter 8 Service Orchestration in the IP Multimedia Subsystem Richard Spiers, Richard Good, and Neco Ventura Contents Introduction IP Multimedia Subsystem 8.2.1 Architecture and Signaling 8.2.2 Service Triggering in the IMS 8.2.3 Limitations Service Orchestration System Design 8.3.1 Combined Service Examples 8.3.1.1 Presence-Based Simultaneous Ring 8.3.1.2 Enhanced Call Control 8.3.1.3 Rich Media Content Distribution 8.3.2 Service Conflict Detection and Resolution 8.3.3 Requirements 8.3.4 Existing Research 8.3.4.1 Architecture 8.3.4.2 Functionality 8.3.5 Open Research Areas 8.4 Conclusion References Service Delivery Platforms 8.1 Introduction In the past couple of years, a wave of new innovative services has appeared on the Internet. These services, including Skype, YouTube, Facebook, and Twitter ar