# US 2017/0289879 A1 · Method for user equipment to switch base station, base station and user equipment > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2017/0289879 A1 - Document ID: US20170289879A1 - Status: Published application - Kind: A1 - Application number: 15/508,194 - Filed: 2015-03-19 - Published: 2017-10-05 - Earliest claimed: 2014-09-02 - Assignees: Zte Corporation - Applicants: Zte Corporation - Inventors: Xin WANG; Feng HE - Web page: https://patentgrep.com/patent/US20170289879A1 ## CPC - H04W 36/08: Reselecting an access point - H04L 5/0055: {Physical resource allocation for ACK/NACK (for physical mapping arrangements in ARQ protocols H04L1/1861)} - H04W 76/15: Setup of multiple wireless link connections - H04W 76/27: Transitions between radio resource control [RRC] states - H04W 36/00692: {using simultaneous multiple data streams, e.g. cooperative multipoint [CoMP], carrier aggregation [CA] or multiple input multiple output [MIMO] (allocation of physical resources in CoMP or in CA H04L5/0035)} - H04W 88/06: adapted for operation in multiple networks {or having at least two operational modes}, e.g. multi-mode terminals - H04W 88/08: Access point devices - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract Methods for switching an eNB by a user equipment, eNBs and user equipments relate to a mobile communication system deployed in a heterogeneous network. The embodiments of the present disclose a method for switching an eNB by a UE, including: when a master eNB of the UE in dual connectivity is switched, a target eNB determining that the UE keeps a connection and configuration with a secondary eNB; and the target eNB establishing a connection with the UE when the UE keeps the connection and configuration with the secondary eNB. The embodiments of the present disclosure further disclose other three methods for switching the eNB by the UE and corresponding eNBs and user equipments. ## Claims ### Claim 1 A method for switching an evolved node B, eNB, by a user equipment, UE, comprising: when a master eNB of the UE in dual connectivity is switched, determining, by a target eNB, that the UE keeps a connection and configuration with a secondary eNB; and establishing, by the target eNB, a connection with the UE while the UE keeps the connection and configuration with the secondary eNB. ### Claim 2 (depends on 1) The method according to claim 1, wherein the target eNB determining that the UE keeps the connection and configuration with the secondary eNB comprises: receiving, by the target eNB, a switching request and secondary eNB information of the UE sent by the master eNB, judging whether the UE keeps the connection and configuration with the secondary eNB after switching the eNB according to the secondary eNB information of the UE, and determining that the UE keeps the connection and configuration with the secondary eNB if yes. ### Claim 3 (depends on 2) The method according to claim 2, wherein the target eNB receiving the switching request and the secondary eNB information of the UE sent by the master eNB comprises: receiving, by the target eNB, a switching request message sent by the master eNB, wherein the switching request message carries the secondary eNB information of the UE. ### Claim 4 (depends on 2) The method according to claim 2, further comprising: if the target eNB determines that the UE keeps the connection and configuration with the secondary eNB after switching the eNB, then the target eNB first establishing an interface connection with the secondary eNB, and then feeding a switching request acknowledgment and indication information for allowing the UE to retain the connection and configuration with the secondary eNB back to the master eNB. ### Claim 5 (depends on 4) The method according to claim 4, wherein the target eNB feeding the switching request acknowledgment and the indication information for allowing the UE to retain the connection and configuration with the secondary eNB back to the master eNB comprises: feeding, by the target eNB, a switching request acknowledgment message back to the master eNB, wherein the switching request acknowledgment message carries the indication information for allowing the UE to retain the connection and configuration with the secondary eNB. ### Claim 6 (depends on 4) The method according to claim 4, further comprising: establishing, by the target eNB, a connection with the UE, and performing data scheduling of a user plane for the UE after the UE has accessed to a target cell and enabled a new configuration, wherein the target eNB performing the data scheduling of the user plane for the UE comprises: the target eNB sending data through a Uu interface between the target eNB and the UE, and the target eNB sending part of packet data convergence protocol, PDCP, data units, PDUs, to the UE though the secondary eNB. ### Claim 7 (depends on 4) The method according to claim 4, further comprising: after receiving the indication information for allowing the UE to retain the connection and configuration with the secondary eNB sent by the target eNB, continuing to deliver, by the master eNB, originally configured data packets of a shunting bearer to the secondary eNB according to the indication for allowing the UE to retain the connection and configuration with the secondary eNB. ### Claim 8 (depends on 7) The method according to claim 7, further comprising: sending, by the master eNB, data packets to the target eNB when the master eNB continues to deliver the originally configured data packets of the shunting bearer to the secondary eNB; or stopping, by the master eNB, sending data packets to the secondary eNB and beginning to send the data packets to the target eNB when the master eNB continues to deliver the originally configured data packets of the shunting bearer to the secondary eNB until information of the UE enabling a new configuration already is received. ### Claim 9 (depends on 7) The method according to claim 7, further comprising: receiving, by the secondary eNB, the originally configured data packets of the shunting bearer from the master eNB, and then receiving the newly configured data packets of the shunting bearer from the target eNB; and sending in order, by the secondary eNB, the received data packets to the UE, wherein, when the secondary eNB receives newly configure data packets of the shunting bearer sent by the target eNB and there are still data packets which are not sent in a cache, the secondary eNB discards the data packets in the cache. ### Claim 10 A method for switching an evolved node B, eNB, by a user equipment, UE, comprising: when a master eNB of the UE in dual connectivity is switched, keeping, by the UE, a connection and configuration with a secondary eNB while establishing a connection with a target eNB. ### Claim 11 (depends on 10) The method according to claim 10, wherein the UE keeping the connection and configuration with the secondary eNB while establishing the connection with the target eNB comprises: receiving, by the UE, a radio resource control, RRC, connection reconfiguration and an indication for keeping the connection and configuration with the secondary eNB sent by the master eNB; and leaving, by the UE, a source primary cell, and accessing to a target cell according to the RRC connection reconfiguration, while keeping the connection and configuration with the secondary eNB according to the indication for keeping the connection and configuration with the secondary eNB. ### Claim 12 (depends on 10) The method according to claim 10, wherein the UE receiving the RRC connection reconfiguration and the indication for keeping the connection and configuration with the secondary eNB sent by the master eNB comprises: receiving, by the UE, an RRC connection reconfiguration message, wherein the RRC connection reconfiguration message contains the indication for keeping the connection and configuration with the secondary eNB. ### Claim 13 (depends on 10) The method according to claim 10, further comprising: after the UE accesses to the target cell, feeding, by the UE, information of enabling a new configuration already back to the master eNB and/or the secondary eNB. ### Claim at position 14 14-28. (canceled) ### Claim 29 A user equipment, comprising: a first unit, arranged to keep a connection and configuration with a secondary eNB in dual connectivity when a master eNB of the user equipment is switched; and a second unit, arranged to establish a connection with a switched target eNB while the first unit keeps the connection and configuration with the secondary eNB. ### Claim 30 (depends on 29) The user equipment according to claim 29, further comprising: a receiving and transmitting unit, arranged to receive a radio resource control, RRC, connection reconfiguration and an indication for keeping the connection and configuration with the secondary eNB sent by the master eNB; wherein the first unit is arranged to, when the master eNB of the user equipment is switched, keep the connection and configuration with the secondary eNB in dual connectivity according to the indication for keeping the connection and configuration with the secondary eNB; and the second unit is arranged to leave a source cell and access to a target cell according to the RRC connection reconfiguration while the first unit keeps the connection and configuration with the secondary eNB. ### Claim 31 (depends on 30) The user equipment according to claim 30, wherein the receiving and transmitting unit receiving the RRC connection reconfiguration and the indication for keeping the connection and configuration with the secondary eNB sent by the master eNB comprises: the receiving and transmitting unit receiving an RRC connection reconfiguration message, wherein the RRC connection reconfiguration message carries the indication for keeping the connection and configuration with the secondary eNB. ### Claim 32 (depends on 31) The user equipment according to claim 31, wherein the receiving and transmitting unit is further arranged to, after the user equipment accesses to the target cell, feed information of enabling a new configuration already back to the master eNB and/or the secondary eNB. ### Claim at position 19 33-38. (canceled) ### Claim 39 (depends on 1) A computer storage medium storing computer executable instructions which are used for executing the method according to claim 1. ### Claim 40 (depends on 10) A computer storage medium storing computer executable instructions which are used for executing the method according to claim 10. ### Claim at position 22 41-42. (canceled) ### Claim 43 (depends on 3) The method according to claim 3, further comprising: if the target eNB determines that the UE keeps the connection and configuration with the secondary eNB after switching the eNB, then the target eNB first establishing an interface connection with the secondary eNB, and then feeding a switching request acknowledgment and indication information for allowing the UE to retain the connection and configuration with the secondary eNB back to the master eNB.