Load-based dynamic fractional frequency reuse in an LTE network

摘要

A services node or central controller or coordinator is provided that dynamically computes fractional frequency reuse allocation among user equipment in a radio access network. The central controller or coordinator communicates the fractional frequency reuse allocation and configures the individual MAC schedulers within each radio node in the radio access network. Inputs to the central coordinator may include its serving radio node, a detected set of radio nodes, and information about user equipment buffer status both in the downlink and uplink. In one implementation, interference graphs are constructed for downlinks and uplink separately and the same are used with a heuristic independent set algorithm to compute the frequency allocation.

主权项

1. A method of allocating frequencies for a plurality of user equipment in a small cell network in which a number of radio nodes are controlled by a services node, the method comprising the steps of:
a. for a plurality of user equipment relative to a set of radio nodes, each radio node associated with a cell and having a cell interior and a cell edge, allocating transmission frequencies such that interfering links or transmissions in adjacent cells are not simultaneously scheduled; b. wherein the allocating is performed by a central services node controlling MAC scheduling of the radio nodes, and not by the radio nodes themselves, and wherein, for a given cell, frequencies allocated to user equipment in the cell interior are different from those allocated to user equipment in the cell edge, and wherein the allocating includes:
i. partitioning the plurality of user equipment into sets, each set associated with a serving radio node and a common set of detected radio nodes; andii. computing a fractional frequency reuse allocation schedule based on the partitioned sets, such that user equipment in different sets that interfere with each other are not simultaneously scheduled; andwherein each set is characterized by the number of user equipment within the set, an aggregate downlink buffer occupancy of all user equipment in the set, and an aggregate uplink buffer occupancy of all user equipment in the set.