"This Recommendation describes an architecture of mobility management and control functions (MMCFs) for the NGN transport stratum. This architecture includes the definitions of the functional entities of MMCF and the scenarios for interactions with the other NGN functional components: NACF@ RACF@ SCF and the access and core transport functional blocks within the forwarding plane. This Recommendation considers the types of mobility management described in [ITU-T Q.1706]. This version of the Recommendation is limited to mobility of a single device@ as opposed to the movement of sessions from one device to another (session mobility). It is further limited@ as indicated by the Recommendation title@ to support of IP-based mobility in the transport stratum. In this it differs from [ITU-T Q.1707] in that the latter also considers support of mobility in the service stratum. This Recommendation provides mechanisms to achieve seamless mobility if network conditions permit@ but does not provide any mechanism to deal with service adaptation if the post-handover quality of service is degraded from the quality of service before handover. This Recommendation uses the term ""location information"". That information is currently limited to logical location information as defined by clause 6.3.2 of [ITU-T Q.1707]. The management of physical (geographic) location information is for further study. This Recommendation assumes that mobility is a service@ explicitly specified by parameters in the user service profile. This Recommendation makes no assumption as to whether the mobility service parameters are located in the transport user profile or the service user profile@ but assumes that they are accessible to the functional entities that need to use them. This Recommendation is not dependent on specific access technologies@ and supports handover across different technologies."