US 9,813,952 B2
Method for transmitting downlink signal of user equipment having dual connectivity in heterogeneous cell environment
Hyeyoung Choi, Seoul (KR); Jaehoon Chung, Seoul (KR); Ilmu Byun, Seoul (KR); Eunjong Lee, Seoul (KR); Heejeong Cho, Seoul (KR); and Genebeck Hahn, Seoul (KR)
Assigned to LG ELECTRONICS INC., Seoul (KR)
Appl. No. 14/776,515
Filed by LG ELECTRONICS INC., Seoul (KR)
PCT Filed Apr. 7, 2014, PCT No. PCT/KR2014/002984
§ 371(c)(1), (2) Date Sep. 14, 2015,
PCT Pub. No. WO2014/163450, PCT Pub. Date Oct. 9, 2014.
Claims priority of provisional application 61/808,638, filed on Apr. 5, 2013.
Claims priority of provisional application 61/815,229, filed on Apr. 23, 2013.
Claims priority of provisional application 61/835,622, filed on Jun. 16, 2013.
Prior Publication US 2016/0044548 A1, Feb. 11, 2016
Int. Cl. H04W 36/00 (2009.01); H04W 36/04 (2009.01); H04W 40/24 (2009.01); H04W 92/20 (2009.01); H04W 36/02 (2009.01); H04W 76/02 (2009.01)
CPC H04W 36/0061 (2013.01) [H04W 36/04 (2013.01); H04W 36/02 (2013.01); H04W 40/24 (2013.01); H04W 76/025 (2013.01); H04W 92/20 (2013.01)] 10 Claims
OG exemplary drawing
 
1. A method for transmitting a downlink (DL) signal of a user equipment (UE) with dual connectivity by a small cell in a heterogeneous cell deployment in which a macro cell and the small cell coexist, the method comprising:
checking, by the small cell, that the UE performs handover to a second macro cell from a first macro cell;
determining whether the small cell supports dual connectivity of the UE together with the second macro cell, upon the checking that the UE performs the handover;
when an X2 interface with the second macro cell is capable of being formed and dual connectivity of the UE is not capable of being supported, transmitting, by the small cell, a first data forwarding request message for requesting the second macro cell to transmit DL data of the small cell to the UE;
receiving from the second macro cell, by the small cell, a first data forwarding response message for configuring a radio bearer with the second macro cell;
transmitting to the second macro cell, by the small cell, a serial number (SN) status transfer message including information about a count value of a first packet to be transmitted to the UE by the second macro cell; and
transmitting, by the small cell, the DL data to the second macro cell through the radio bearer configured based on the first data forwarding response message.