Fractional frequency reuse in heterogeneous networks

• US 8,559,961 B2
• Filed: 05/18/2011
• Issued: 10/15/2013
• Est. Priority Date: 12/15/2010
• Status: Active Grant

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Boudreau, Gary David, Dimou, Konstantinos, Falconetti, Laetitia, Huschke, Jrg
• Primary Examiner(s): Addy, Anthony
• Assistant Examiner(s): Choo, Munsoon
• Application Number:
  US13/110,385
• Publication Number:
  US 20120157108A1
• Time in Patent Office: 881 Days
• Field of Search: 455/200, 455/266, 455450-455, 455/464, 455/509, 455/516, 455/158.1, 455/161.1, 340/855.7, 370329-330, 370/341, 370/443, 370/468
• US Class Current: 455/447
• CPC Class Codes: H04J 11/005 of intercell interference
• CPC Class Codes: H04W 16/32 Hierarchical cell structures
• CPC Class Codes: H04W 72/0453 Resources in frequency domain, e.g. a carrier in FDMA

Abstract

A base station node (BS) of a heterogeneous radio access network comprises a terminal locator (34) and a scheduler (36). The terminal locator (34) obtains an indication of location of a wireless terminal (30) in a cell served by the base station (BS), e.g., whether the wireless terminal (30) is in a center region (M) or an edge region (E) for the cell served by the base station node (BS). The scheduler (36) uses the indication of location to assign to the wireless terminal (30) a frequency of a frequency bandwidth usable by the heterogeneous radio access network. The scheduler (36) assigns a frequency from a partitioned portion of the frequency bandwidth if the cell served by the base station node is a micro cell and the wireless terminal is in an edge region of a micro cell. The scheduler (36) also assigns a frequency of the frequency bandwidth if the cell served by the base station node is a micro cell and the wireless terminal is in a center portion of the micro cell.

Claims

1. A method of operating a heterogeneous radio access network, the heterogeneous radio access network comprising a macro layer including at least one macro cell served by a macro base station node and a micro layer comprising at least one micro cell served by a micro base station node, the heterogeneous radio access network comprising plural macro cells and plural micro cells within each of the plural macro cells, the method comprising:

dividing a frequency bandwidth usable by the heterogeneous radio access network into a frequency-partitioned portion which is less than the entire frequency bandwidth;

assigning a frequency of the frequency-partitioned portion to a wireless terminal in an edge region of the micro cell;

assigning a frequency of the frequency bandwidth to a wireless terminal which is in a center region of the micro cell or at least within a center region of the macro cell;

dividing the frequency bandwidth usable by the heterogeneous radio access network into plural partitions including a first partition and a second partition;

dividing the plural partitions into plural sub-partitions;

assigning a frequency of a second partition to a wireless terminal in an edge region of one of the plural micro cells by;

assigning a frequency of a first sub-partition of the second partition if the wireless terminal is in an edge region of a micro cell in the first macro cell; and

assigning a frequency of a second sub-partition of the second partition if the wireless terminal is in an edge region of a micro cell in the second macro cell;

assigning a frequency of a first partition to a wireless terminal in one of the plural macro cells by;

assigning a frequency of a first sub-partition of the first partition if the wireless terminal is in a first macro cell and interferes with any micro base station node;

assigning a frequency of a second sub-partition of the first partition if the wireless terminal is in a second macro cell and interferes with any micro base station node.

2. The method of claim 1, wherein in the frequency bandwidth the first sub-partition of the first partition is separated from the first sub-partition of the second partition by at least the second sub-partition of the first partition.

3. A method of operating a heterogeneous radio access network, the heterogeneous radio access network comprising a macro layer including at least one macro cell served by a macro base station node and a micro layer comprising at least one micro cell served by a micro base station node, the heterogeneous radio access network comprising plural macro cells and plural micro cells within each of the plural macro cells, the method comprising:

dividing a frequency bandwidth usable by the heterogeneous radio access network into a frequency-partitioned portion which is less than the entire frequency bandwidth;

assigning a frequency of the frequency-partitioned portion to a wireless terminal in an edge region of the micro cell;

assigning a frequency of the frequency bandwidth to a wireless terminal which is in a center region of the micro cell or at least within a center region of the macro cell;

dividing the frequency bandwidth usable by the heterogeneous radio access network into plural partitions including a first partition and a second partition;

dividing the plural partitions into plural sub-partitions;

assigning a frequency of a second partition to a wireless terminal in and edge region of one of the plural micro cells by;

assigning a frequency of a first sub-partition of the second partition if the wireless terminal is in an edge region of a micro cell in the second macro cell; and

assigning a frequency of the second sub-partition of the second partition if the wireless terminal is in an edge region of a micro cell in the second macro cell;

assigning a frequency of the second partition to a wireless terminal in one of the plural macro cells if the wireless terminal is in a macro cell and does not substantially interfere with any micro base station node.

4. The method of claim 3, further comprising assigning a frequency of to the wireless terminal in one of the plural macro cells by:

assigning a frequency of a first sub-partition of the second partition if the wireless terminal is in a first macro cell and does not substantially interfere with any micro base station node;

assigning a frequency of a second sub-partition of the second partition if the wireless terminal is in a second macro cell and does not substantially interfere with any micro base station node.

5. The method of claim 3, wherein in the frequency bandwidth the first sub-partition of the first partition is separated from the first sub-partition of the second partition by at least the second sub-partition of the first partition.

6. A base station node of a heterogeneous radio access network, the heterogeneous radio access network comprising a macro layer including at least one macro cell served by a macro base station node and a micro layer including at least one micro cell served by a micro base station node, wherein the heterogeneous radio access network comprises plural macro cells and plural micro cells within each of the plural macro cells, wherein a frequency bandwidth usable by the heterogeneous radio access network is divided into plural partitions and the plural partitions are divided into plural sub-partitions, wherein a first partition is associated with the plural macro cells and a second partition is associated with the plural micro cells, wherein the base station node serves a particular macro cell comprising the plural macro cells, the base station node comprising:

a terminal locator configured to obtain an indication of location of a wireless terminal in a cell served by the base station node;

a scheduler configured to use the indication of location to assign to the wireless terminal a frequency of the frequency bandwidth usable by the heterogeneous radio access network, the scheduler being configured to assign a frequency from a frequency-partitioned portion of the frequency bandwidth if the wireless terminal is in an edge region of the cell served by the base station node, the frequency-partitioned portion being less than the entire frequency bandwidth, and wherein the scheduler is further configured to assign to the wireless terminal a frequency of the second partition if the wireless terminal substantially interferes with a macro cell other than the particular macro cell and does not substantially interfere with a micro cell.

7. The base station node of claim 6, wherein the scheduler is further configured to assign to the wireless terminal a frequency of a selected one of the sub-partitions of the second partition, and wherein the selected one of the sub-partitions of the second partition is associated with the particular macro cell.