"The scope of the present document is to investigate the various use cases for spectrum and network sharing@ which can enhance the capabilities of public safety organizations in non-mission critical operations. ""Mission critical operations"" for public safety organisations address situations where human life and goods (rescue operations@ law enforcement) and other values for society are at risk@ especially when time is a vital factor. This means we define 'mission critical information' as the vital information for public safety to succeed with the operation. Mission critical communication solutions' therefore means that the public safety organisations need secure@ reliable and available communication and as a consequence cannot afford the risk of having failures in their individual and group communication (e.g. voice and data or video transmissions). Beyond mission critical operations@ public safety officers may be involved in non-mission critical operations and applications for crisis management@ where demand for broadband connectivity and traffic capacity can be very important. As the requirements of mission critical operations can be quite restrictive@ the present document will address only the application of spectrum and network sharing for non-mission critical operations. In this regard the following aspects are covered: ? The public safety operational scenarios@ where spectrum and network sharing can be applied. ? Potential operational and technical requirements for spectrum and network sharing. ? Taxonomy of the use cases for spectrum and network sharing. The scope of the present document is not to suggest changes to the spectrum regulatory framework."