Dynamic Frequency Allocation In Wireless Backhaul Networks

• US 20120307633A1
• Filed: 06/30/2011
• Published: 12/06/2012
• Est. Priority Date: 06/30/2010
• Status: Active Grant

• Current Assignee: Commonwealth Scientific & Industrial Research Organisation (Commonwealth Of Australia As Represented By Department Of Industry, Innovation, Climate Change, Science, Research And Tertiary Education)
• Original Assignee: Commonwealth Scientific & Industrial Research Organisation (Commonwealth Of Australia As Represented By Department Of Industry, Innovation, Climate Change, Science, Research And Tertiary Education)
• Inventors: Collings, Iain Bruce, Ni, Wei
• Granted Patent: US 9,007,900 B2
• Time in Patent Office: Days
• US Class Current: 370/230
• CPC Class Codes: H04W 28/16 Central resource management; Negotiation of resources or communication parameters, e.g. negotiating bandwidth or QoS [Quality of Service]
• CPC Class Codes: H04W 72/0453 Resources in frequency domain, e.g. a carrier in FDMA
• CPC Class Codes: H04W 72/52 based on load
• CPC Class Codes: H04W 72/541 using the level of interference

Abstract

Disclosed is a wireless backhaul network for a communications system. The network comprises a congregate node connected to the communications system; a plurality of access points, each access point having associated amounts of incident bidirectional traffic to be conveyed to and from the congregate node; and a plurality of bidirectional wireless links adapted to convey the traffic between the access points and the congregate node. The congregate node is configured to allocate spectrum to each directional component of each link within a predetermined available spectrum for the conveyance of the traffic, wherein the allocation is dependent on the amounts of traffic at the respective access points.

Claims

1. A wireless backhaul network for a communications system, the network comprising:

a congregate node connected to the communications system;

a plurality of access points, each access point having associated amounts of incident bidirectional traffic to be conveyed to and from the congregate node; and

a plurality of bidirectional wireless links adapted to convey the traffic between the access points and the congregate node;

wherein the congregate node is configured to allocate spectrum to each directional component of each link within a predetermined available spectrum for the conveyance of to the traffic, wherein the allocation is dependent on the amounts of traffic at the respective access points.

2. A network according to claim 1, where the allocation is subject to one or more interference constraints on the links.

3. A network according to claim 1 wherein the wireless backhaul network is a frequency division duplex wireless backhaul network.

4. A method of dynamically configuring a wireless backhaul network for a communications system, the network comprising a congregate node connected to the communications system, a plurality of access points, each access point having associated amounts of incident bidirectional traffic to be conveyed to and from the congregate node, and a plurality of bidirectional wireless links adapted to convey the traffic between the access points and the congregate node, the method comprising:

computing a bandwidth request associated with each link from the traffic amounts associated with each node connected by the link; and

allocating bandwidth within a predetermined available spectrum to each link based on the computed bandwidth requests.

5. A method according to claim 4, wherein the allocating is subject to one or more interference constraints on the links.

6. A method according to claim 4, wherein the computing comprises:

computing a bandwidth request for an uplink component of each link based on the uplink traffic amounts; and

computing a bandwidth request for a downlink component of each link based on the downlink traffic amounts.

7. A method according to claim 4, wherein the wireless backhaul network is a frequency division duplex wireless backhaul network, and the allocating comprises:

allocating bandwidth within a first frequency division duplex band of the predetermined available spectrum to each link in a first sub-network of the network based on the computed bandwidth requests associated with those links; and

allocating bandwidth within a second frequency division duplex band of the predetermined available spectrum to each link in a second sub-network of the network based on the computed bandwidth requests associated with those links.

8. A method according to claim 7, wherein each allocating comprises:

provisionally allocating bandwidth within the band to each link in the sub-network based on the bandwidth requests associated with the links and a provisional guard band amount;

computed a scaling factor that, if applied to the provisional bandwidth allocation, would make the total provisionally allocated bandwidth equal to the available bandwidth of the band;

adjusting the provisional guard band amount depending on a comparison between the provisional guard band amount scaled by the computed scaling factor and a lower limit on the guard band amount;

repeating the provisional allocating, computing, and adjusting until the provisional guard band amount scaled by the computed scaling factor converges; and

scaling the provisional bandwidth allocation by the computed scaling factor.

9. A method according to claim 8, wherein the provisional allocation allocates bandwidth in a plurality of subbands within the band.

10. A method according to claim 9, wherein the provisional allocation shares at least one subband among a plurality of compatible links within the sub-network.

11. A method according to claim 9, wherein the provisional allocation allocates to at least one link at least one subband that is reserved as a guard band for a link in the same sub-network that is interfering with the at least one link.

12. A method according to claim 7, further comprising equalising the satisfaction factor across both sub-networks, wherein the satisfaction factor of a link is the ratio of the bandwidth allocated to the link to the bandwidth request associated with the link.

13. A method according to claim 4, further comprising allocating further bandwidth to links for which the satisfaction factor is less than one, wherein the satisfaction factor of a link is the ratio of the bandwidth allocated to the link to the bandwidth request associated with the link.

14. A congregate node in a wireless backhaul network for a communications system, the network comprising a congregate node connected to the communications system, a plurality of access points, each access point having associated amounts of incident bidirectional traffic to be conveyed to and from the congregate node, and a plurality of bidirectional wireless links adapted to convey the traffic between the access points and the congregate node, the congregate node being adapted to:

compute a bandwidth request associated with each link from the traffic amounts associated with each node connected by the link; and

allocate bandwidth within a predetermined available spectrum to each link based on the computed bandwidth requests.

15. A congregate node according to claim 14, wherein the allocating is subject to one or more interference constraints on the links.