Systems and methods for controlling cell selection in a heterogeneous cellular network based on primary direction of traffic flow

A method of operation of a node in a cellular network to control cell selection for a user equipment, comprising:

• obtaining, from the user equipment, a received signal strength value for a downlink channel from a high power base station to the user equipment and a received signal strength value for a downlink channel from a low power base station to the user equipment;
• determining a primary direction of traffic flow for the user equipment located within a transition zone between a high power base station cell of the high power base station and a low power base station cell of the low power base station that neighbors the high power base station in the cellular network is a downlink direction;
• controlling the cell selection for the user equipment based on the primary direction of traffic flow for the user equipment, the received signal strength value for the downlink channel from the high power base station to the user equipment, and the received signal strength value for the downlink channel from the low power base station to the user equipment comprises:
• upon determining that the primary direction of traffic flow for the user equipment is the downlink direction, setting a user equipment cell selection offset for the user equipment to a value that favors the high power base station cell;
• and
• determining whether to perform a handover for the user equipment based on the user equipment cell selection offset for the user equipment, the received signal strength value for the downlink channel from the high power base station to the user equipment, and the received signal strength value for the downlink channel from the low power base station to the user equipment.

A high power base station in a cellular network comprising:

• a transceiver subsystem;
• and
• a processing subsystem connected to the transceiver subsystem, the processing subsystem being adapted to:
• obtain, from a user equipment, a received signal strength value for a downlink channel from the high power base station to the user equipment and a received signal strength value for a downlink channel from a low power base station to the user equipment;
• determine a primary direction of traffic flow for the user equipment located within a transition zone between a high power base station cell of the high power base station and a low power base station cell of the low power base station that neighbors the high power base station in the cellular network is an uplink direction;
• control cell selection for the user equipment based on the primary direction of traffic flow for the user equipment, the received signal strength value for the downlink channel from the high power base station to the user equipment, and the received signal strength value for the downlink channel from the low power base station to the user equipment, wherein being adapted to control cell selection for the user equipment comprises being adapted to:
• upon determining that the primary direction of traffic flow for the user equipment is the uplink direction, set a user equipment cell selection offset for the user equipment to a value that favors the low power base station cell;
• and
• determine whether to perform a handover for the user equipment based on the user equipment cell selection offset for the user equipment, the received signal strength value for the downlink channel from the high power base station to the user equipment, and the received signal strength value for the downlink channel from the low power base station to the user equipment.

A non-transitory computer-readable medium storing software for instructing a controller of a processing subsystem of a high power base station in a cellular network to:

• obtain, from a user equipment, a received signal strength value for a downlink channel from the high power base station to the user equipment and a received signal strength value for a downlink channel from a low power base station to the user equipment;
• determine a primary direction of traffic flow for a user equipment located within a transition zone between a high power base station cell of the high power base station and a low power base station cell of the low power base station that neighbors the high power base station in the cellular network;
• control cell selection for the user equipment based on the primary direction of traffic flow for the user equipment, the received signal strength value for the downlink channel from the high power base station to the user equipment, and the received signal strength value for the downlink channel from the low power base station to the user equipment, wherein being adapted to control cell selection for the user equipment comprises being adapted to:
• upon determining that the primary direction of traffic flow for the user equipment is an uplink direction, set a user equipment cell selection offset for the user equipment to a value that favors the low power base station cell;
• and
• determine whether to perform a handover for the user equipment based on the user equipment cell selection offset for the user equipment, the received signal strength value for the downlink channel from the high power base station to the user equipment, and the received signal strength value for the downlink channel from the low power base station to the user equipment.