A method for a device to perform cell reselection, includes: when the device resides in a current serving cell, determining whether a neighboring cell meets a cell reselection condition; if the neighboring cell meets the cell reselection condition, obtaining cell reselection information corresponding to the neighboring cell; determining whether the cell reselection information matches any one of one or more historical ping-pong reselection records; if the cell reselection information matches a first historical ping-pong reselection record of the one or more historical ping-pong reselection records, determining whether a time difference between a current cell reselection time and a historical cell reselection time corresponding to the first historical ping-pong reselection record is greater than a preset time difference; and if the time difference is greater than the preset time difference, reselecting the neighboring cell as a current serving cell.

A method of processing state information relating to user equipment in a communications system comprising a radio access network, the method comprising: maintaining current state information relating to the user equipment; and on the basis of a change of connection of the user equipment from a first cell to a second cell: transmitting a current value associated with a given state information part to the target radio access node in response to detecting at least one of one or more predetermined triggers that indicate that the target radio access node may not have received the current value from the source radio access node; or relying on the target radio access node having received the current value from the source radio access node if said at least one of said one or more predetermined triggers is not detected.

A method and apparatus for accessing a random access channel (RACH) during handover are disclosed. A handover procedure is initiated and a maximum handover interruption timer is activated. A dedicated preamble is transmitted in an attempt to access the RACH on a condition that the dedicated preamble is reserved in a current random access opportunity and the maximum handover interruption timer has not expired. A contention-based preamble is transmitted in an attempt to access the RACH on a condition that a dedicated preamble is not reserved in a current random access opportunity. If the maximum handover interruption timer has expired, a contention-based preamble is transmitted in an attempt to access the RACH.

A method and an apparatus for supporting mobility in a communication system. An operation method for a mobile communication node includes: measuring channel quality between the mobile communication node and at least one adjacent communication node, on the basis of a signal received from the at least one adjacent communication node; transmitting a report message including information on the channel quality to a serving communication node connected to the mobile communication node; receiving, from the serving communication node, a response message including configuration information for a target communication node determined on the basis of the report message; and performing a connection establishment procedure with the target communication node indicated by the response message. Therefore, the performance of a communication system can be improved.

Methods and systems are provided for using virtual base stations in communication systems. A communication system may include a plurality of fixed base stations. A virtual base station may be created in the communication system based on one or more creation conditions or criteria. Operation of the virtual base station may be managed, with the managing including assigning a first fixed base station in the communication system to operate as the virtual base station; concurrently communicating data of the virtual base station to the first fixed base station and to one or more other fixed base stations in the communication system; switching assignment of the virtual base station to a second fixed base station from the one or more other fixed base stations, based on a determination that a switch of assignment of the virtual base station is required. The virtual base station may be deleted based on one or more deletion conditions or criteria.

A method for a conditional handover (CHO) is described in some of the present embodiments. The method may receive from a source base station (e.g., a gNB or an eNB) one or more CHO commands that each is associated with one or more triggering conditions for a CHO to a target cell associated with a target base station (e.g., a target gNB or a target eNB). The method may continuously evaluate the triggering condition(s) associated with each received (and valid) CHO command. When the method determines that at least one of the triggering conditions has been fulfilled, the method may execute the CHO command that is associated with the triggering condition in order to connect to one or more candidate target cells associated with the CHO command.

The present disclosure relates to a method and apparatus for performing random access in a user equipment for a small cell e-NB with a small cell service area in heterogeneous e-NB cell carrier integration (dual connectivity or inter-eNB carrier aggregation) in mobile communication systems. In accordance with an aspect of the present disclosure, a method for performing random access in a mobile communication system is provided. The method includes receiving a configuration request message for configuring a Serving Cell Group (SCG) from a second eNB located in a service area of a first eNB through the first eNB; configuring an SCG cell based on the configuration request message, and sending a configuration response message in response to the configuration request message to the second eNB through the first eNB; and performing random access if there is uplink data present on a logic channel (LCH) relocated into the SCG cell.

Embodiments of the present disclosure provide a mobility management method, apparatus, and system. An HA-C sends a first BA message to an MN, where the first BA message includes an address of a first HA-U; and the HA-C sends a configuration message to the first HA-U, where the configuration message includes an HoA and a CoA that are of the MN, so that the first HA-U performs tunnel communication with the MN according to the configuration message. In this way, an original proxy server or an original gateway completes only tunnel communication with the MN, and a newly-added proxy server completes control signaling interaction with a BU, thereby reducing load of the original proxy server or the original gateway, and resolving a prior-art problem that load of a proxy server or a gateway is relatively heavy.

A method for multiple association includes associating with a first access point (AP) in a primary basic service set (BSS), associating with a second AP in a secondary BSS, informing the first and second APs of an inter-BSS relaying capability of a doubly-associated station, and relaying data between the first AP and the second AP.

Embodiments of the present invention provide a handover method to simplify a cross-base station handover procedure of a WD in a mobile communication scenario, and reduce power consumption of the WD. The method includes: sending, by a first base station, handover group information to a second base station, where the handover group information includes a first association relationship between a first terminal device and a second terminal device, and the second terminal device can communicate with the first base station through the first terminal device; and receiving, by the first base station, handover response information from the second base station, where the handover response information includes a second association relationship, and the second association relationship is established by the second base station between the first terminal device and the second terminal device based on the first association relationship.