The continuation of active service across devices, or access networks, or both from the user’s point of view. For example, service continuity can apply to single services such as voice, or to composite services such as voice and video along with associated data exchange such as web browsing or instant messaging. Service continuity may be seamless and performed automatically. Alternatively, service continuity may involve some degree of interruption or service modification; it may be governed by user preferences or may be user-initiated or user-approved. Regardless, technical limitations of devices, access networks or the service provider will influence the characteristics of service continuity.