In addition to the following, abbreviations used in the present document are listed in TR 21.905
For the purposes of the present document, the following definitions apply:
Connection mode (for a bearer service):
characterises the type of association between two endpoints as required by the bearer service for the transfer of information. A bearer service is either connection-oriented or connectionless. In a connection oriented mode, a logical association called connection needs to be established between the source and the destination entities before information can be exchanged between them. Connection oriented bearer services lifetime is the period of time between the establishment and the release of the connection.
Connectionless (for a bearer service):
In a connectionless bearer, no connection is established beforehand between the source and the destination entities; the source and destination network addresses need to be specified in each message. Transferred information cannot be guaranteed of ordered delivery. Connectionless bearer services lifetime is reduced to the transport of one message.
an area where mobile cellular services are provided by a GERAN in accordance with GERAN specifications.
an area where mobile cellular services are provided by a UTRAN in accordance with UTRAN specifications.
Multi mode terminal:
UE that can obtain service from at least one UTRA radio access mode, and one or more different systems such as GERAN bands or possibly other radio systems such IMT-2000 family members.
The process in which the radio access network changes the radio transmitters or radio access mode or radio system used to provide the bearer services, while maintaining a defined bearer service QoS.
Intra PLMN handover:
Handover within the same network, i.e. having the same MCC-MNC regardless of radio access system. Note: this includes the case of UTRAN ↔ GERAN handover where MCC-MNC are the same in both cases.
Inter PLMN handover:
Handover between different PLMNs, i.e. having different MCC-MNC.
Inter system handover:
Handover between networks using different radio systems , e.g. UTRAN - GERAN.
UTRA Radio access mode:
the selected UTRA radio access mode i.e. UTRA-FDD; UTRA-TDD.
the selected 2nd or 3rd generation radio access technology.
The means for maintaining active services during changes in the coverage areas or their characteristics without, as far as possible, the user noticing. Note that Service Continuity can be achieved by handover, cell re-selection or other mechanisms.