Method and apparatus for discovering small cell in heterogeneous communication network

A method, in a user equipment of a heterogeneous communication network, of discovering small cells, the method comprising:

• receiving a first signaling from a macro base station, the first signaling being used to instruct the user equipment to perform a periodical measurement on one or more candidate small cells in a target region to discover small cells, wherein the first signaling includes cell identifiers of the one or more candidate small cells in the target region and an interval for the periodical measurement;
• in response to the received first signaling, performing the periodical measurement with the interval to discover small cells;
• and
• transmitting a second signaling to the macro base station, the second signaling including cell identifiers of the discovered small cells.

A method, in a base station of a small cell covered by a macro base station of a macro cell of a heterogeneous communication network, of assisting a user equipment in discovering small cells, the method comprising:

• receiving an offloading request from the macro base station, the offloading request being used to request all small cells covered by the macro base station to report whether to be able to offload traffic of the macro cell;
• judging whether the small cell is able to offload the traffic of the macro cell based upon traffic of the small cell according to a predetermined criterion;
• and
• when a result of the judgment in the step ii is that the small cell is able to offload the traffic of the macro cell, transmitting an offloading reply to the macro base station to indicate that the small cell is able to offload the traffic of the macro cell, the offloading reply including a cell identifier of the small cell.

An apparatus, in a macro base station of a macro cell of a heterogeneous communication network, for assisting a user equipment in discovering small cells, the apparatus comprising:

• a first judging unit configured to judge whether the user equipment has approached to a target region that includes one or more candidate small cells based upon stored location range information of all candidate small cells in the macro cell and estimated position information of the user equipment;
• a second judging unit configured to judge based upon a result of the judgment of the first judging unit whether to instruct the user equipment to perform a periodical measurement on the one or more candidate small cells in the target region to discover small cells;
• and
• a first obtaining unit configured, when a result of the judgment of the second judging unit is to instruct the user equipment to perform the periodical measurement, to obtain density information that indicates a density of the candidate small cells in the target region;
• a first determining unit configured to determine an interval for the periodical measurement of the user equipment based upon the density information obtained by the first obtaining unit;
• and
• a first transmitting unit configured to transmit a first signaling to the user equipment to instruct the user equipment to perform the periodical measurement, wherein the first signaling includes cell identifiers of the one or more candidate small cells in the target region and the determined interval.

An apparatus, in a user equipment of a heterogeneous communication network, for discovering small cells, the apparatus comprising:

• a first receiving unit configured to receive a first signaling from a macro base station, the first signaling being used to instruct the user equipment to perform a periodical measurement on one or more candidate small cells in a target region to discover small cells, wherein the first signaling includes cell identifiers of the one or more candidate small cells in the target region and an interval for the periodical measurement;
• a first measuring unit configured, in response to the received first signaling, to perform the periodical measurement at the interval to discover small cells;
• and
• a second transmitting unit configured to transmit a second signaling to the macro base station, the second signaling including cell identifiers of the discovered small cells.

An apparatus, in a base station of a small cell covered by a macro base station of a macro cell of a heterogeneous communication network, for assisting a user equipment in discovering small cells, the apparatus comprising:

• a second receiving unit configured to receive an offloading request from the macro base station, the offloading request being used to request all small cells covered by the macro base station to report whether to be able to offload traffic of the macro cell;
• a third judging unit configured to judge whether the small cell is able to offload the traffic of the macro cell based upon traffic of the small cell;
• and
• a third transmitting unit configured, when a result of the judgment of the third judging unit is that the small cell is able to offload the traffic of the macro cell, to transmit an offloading reply to the macro base station to indicate that the small cell is able to offload the traffic of the macro cell, the offloading reply including a cell identifier of the small cell.