Mobility in wireless communication systems
AssigneeNokia Technologies Oy
InventorsShehzad Ali Ashraf, Panagiotis Spapis, Frederic Ratovelomanana, Umur Karabulut, Halit Murat Gürsu
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Abstract
A communication network comprising distributed units for supporting radio coverage via a cell and for providing access to the cell to a user equipment and central units each controlling several distributed units. The distributed units comprise: mobility control circuitry configured: in response to receipt of layer 3 handover information for a user equipment from a central unit and where the mobility control circuitry has access to layer 1 measurements for the user equipment, to select a cell for a handover in dependence upon the layer 3 handover information and the layer 1 measurements.
Claims19
A distributed unit of an access network node, said distributed unit being for supporting radio coverage via a cell and for providing access to said cell to a user equipment, said distributed unit comprising:
- mobility control circuitry configured:
- based at least partially on receipt of layer 3 handover information for the user equipment, from a central unit of said access network node and where said mobility control circuitry has access to layer 1 measurements for said user equipment, to determine whether there is at least one common cell that is indicated as a candidate cell from said layer 3 handover information and as a candidate cell from said layer 1 measurements;
- and
- based on there being the at least one common cell, to select one of the at least one common cell as a cell for a handover in dependence upon said layer 3 handover information and said layer 1 measurements.
A central unit for controlling a plurality of distributed units comprising:
- determining circuitry configured:
- to determine from layer 3 user equipment measurement information, candidate cells for a cell handover for a user equipment;
- and
- based at least partially on receipt of a lower layer triggered mobility required message received from a distributed unit, to determine whether to allow or refuse a lower layer triggered handover;
- message generating circuitry configured:
- to generate a message for transmission to the distributed unit supporting a cell providing radio coverage to said user equipment, said message comprising information relating to said cell handover;
- and
- based at least partially on a determination whether to allow or refuse the lower layer triggered handover, to generate one of a lower layer triggered handover refused message or a lower layer handover confirmed message;
- transmitting circuitry configured to transmit said message to said distributed unit;
- and
- mobility control circuitry configured to initiate layer 3 handover preparations based, at least partially, on a determination to refuse said lower layer triggered handover.
A method performed with a distributed unit of an access network node, said distributed unit being for supporting radio coverage via a cell and for providing access to said cell to a user equipment, said method comprising:
- based at least partially on layer 3 handover information for the user equipment, from a central unit of said access network node and where said distributed unit has access to layer 1 measurements for said user equipment, determining whether there is at least one common cell that is indicated as a candidate cell from said layer 3 handover information and as a candidate cell from said layer 1 measurements;
- and
- based on there being the at least one common cell, selecting one of the at least one common cell as a cell for a handover in dependence upon said layer 3 handover information and said layer 1 measurements.
Dependencies are inferred from the claim text.