Radio plan generator

• US 7,315,533 B2
• Filed: 04/08/2005
• Issued: 01/01/2008
• Est. Priority Date: 04/08/2005
• Status: Expired due to Fees

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Theobold, David M., Hart, Brian, Douglas, Bretton Lee, Qian, Lu
• Primary Examiner(s): Urban; Edward F.
• Assistant Examiner(s): Hannon; Christian A.
• Application Number:
  US11/102,509
• Publication Number:
  US 20060227751A1
• Time in Patent Office: 998 Days
• Field of Search: 370/254, 370/255, 370/329, 370/330, 370/338
• US Class Current: 370/338
• CPC Class Codes: H04W 16/18 Network planning tools

Abstract

A method, apparatus, and carrier medium carrying instructions to assign frequency channels and transmit powers for a plurality of access points of a wireless network. The method includes, until there are no more access points to which to assign a transmit power and frequency channel, selecting a next current access point, determining for a set of at least one transmit power for a set of at least one frequency channel a measure of the quality of the sub-network formed by the current access point and all already-assigned access points an evaluation metric indicative of the quality of the sub-network, and assigning to the current access point the transmit power and frequency channel that minimizes the measure of the quality of the sub-network.

Claims

1. A method of assigning frequency channels and transmit powers for a plurality of access points of a wireless network, the method comprising:

accepting a measure of connectivity between the access points of the network, wherein the measure of connectivity between the access points of the network is a set of pairwise path losses from each access point to a different access point of the network; and

repeating until there are no more access points to which to assign a transmit power and frequency channel;

(a) selecting a current access point to which to assign a transmit power and frequency channel;

(b) determining for a set of at least one transmit power for a set of at least one frequency channel a measure of the quality of the sub-network formed by the current access point and all access points to which a transmit power and frequency channel have been assigned, the measure according to an evaluation metric indicative of the quality of the sub-network; and

(c) assigning to the current access point the transmit power and frequency channel that minimizes the measure of the quality of the sub-network wherein assigning frequency channels and transmit powers for an access point includes assigning one or more frequency channels and one or more transmit powers for the access point to communicate with its one or more clients.

2. A method as recited in claim 1, wherein the pairwise path losses are obtained by automatic measurements by the access points of the network.

3. A method as recited in claim 1, wherein the pairwise path losses are obtained by a path loss model.

4. A method as recited in claim 1, wherein the pairwise path losses are obtained by measurements from a walk-through.

5. A method as recited in claim 1, wherein the determining of the measure of quality and the assigning of the transmit power and frequency channel includes:

starting with an initial transmit power for the current access point;

, determining the pairwise connectivity from the pairwise path loss using a path loss criterion based on the transmit power and a receiver sensitivity;

ascertaining whether or not there is any frequency channel unused by any AP connected to the current AP, and if so, assigning to the current AP such an available frequency channel at the transmit power;

if the ascertaining ascertains that no frequency channel is available, repeating lowering the transmit power of the current access point to possibly cause one or more of the other access points to become disconnected to possibly free up a potential frequency channel until a frequency channel not used by any connected access point is available, or no frequency channel is available even at the lowest possible transmit power;

in the case a frequency channel frees as a result of the lowering of transmit power, assigning to the current access point the newly available frequency channel and the highest transmit power level at which the channel becomes available; and

in the case no frequency channel becomes available, assign the initial transmit power to the current access point, considering groups of access points assigned each of the used frequency channels, and assigning the frequency channel of the group of access points already assigned with a frequency channel whose minimum path loss from the current access point is the highest.

6. A method as recited in claim 1, wherein the evaluation metric is the Fast Evaluation Metric.

7. A method as recited in claim 1, wherein some of the access points are managed access points, and one or more other access points are unmanaged access points for which one or both of the transmit power and/or the frequency channel is pre-assigned.

8. A method as recited in claim 1, wherein the wireless network substantially conforms to one of the IEEE 802.11 standards.

9. A method as recited in claim 1, wherein some of the access points also have one or more other adjustable parameters, and wherein the repeating of the selecting, the determining, and the assigning is until there are no more access points to which to assign a transmit power, frequency channel, and the values of the at least one other parameter, wherein the selecting of a current access point selects a current access point to which to also assign a value for each other parameter, wherein the determining of a measure determines the measure also for a value of each other parameter, and wherein the assigning also assigns each of the at least one other parameter for the current access point.

10. A method of assigning frequency channels and transmit powers for a plurality of access points of a wireless network, the method comprising:

accepting a set of pairwise measures of path losses from each access point to a different access point of the network; and

repeating until there are no more access points to which to assign a transmit power and frequency channel;

(a) selecting a current access point to which to assign a transmit power and frequency channel;

(b) starting with an initial transmit power for the current access point;

, determining the pairwise connectivity from the pairwise path loss using a path loss criterion based on the transmit power and a receiver sensitivity;

(c) ascertaining whether or not there is any frequency channel unused by any AP connected to the current AP, and if so, assigning to the current AP such an available frequency channel at the transmit power;

(d) if the ascertaining ascertains that no frequency channel is available, repeating lowering the transmit power of the current access point to possibly cause one or more of the other access points to become disconnected to possibly free up a potential frequency channel until a frequency channel not used by any connected access point is available, or no frequency channel is available even at the lowest possible transmit power;

(e) in the case a frequency channel frees as a result of the lowering of transmit power, assigning to the current access point the newly available frequency channel and the highest transmit power level at which the channel becomes available; and

(f) in the case no frequency channel becomes available, assigning the initial transmit power to the current access point, considering groups of access points assigned each of the used frequency channels, and assigning the frequency channel of the group of access points already assigned with a frequency channel whose minimum path loss from the current access point is the highest wherein assigning frequency channels and transmit powers for an access point includes assigning one or more frequency channels and one or more transmit powers for the access point to communicate with its one or more clients.

11. A computer readable medium encoded with computer program instructions that when executed on a processor of a processing system carry out a method of assigning frequency channels and transmit powers for a plurality of access points of a wireless network, the method comprising:

accepting a measure of connectivity between the access points of the network, wherein the measure of connectivity between the access points of the network is a set of pairwise path losses from each access point to a different access point of the network; and

repeating until there are no more access points to which to assign a transmit power and frequency channel;

(a) selecting a current access point to which to assign a transmit power and frequency channel;

(b) determining for a set of at least one transmit power for a set of at least one frequency channel a measure of the quality of the sub-network formed by the current access point and all access points to which a transmit power and frequency channel have been assigned, the measure according to an evaluation metric indicative of the quality of the sub-network; and

wherein assigning frequency channels and transmit powers for an access point includes assigning one or more frequency channels and one or more transmit powers for the access point to communicate with its one or more clients.

12. A computer readable medium as recited in claim 11, wherein the determining of the measure of quality and the assigning of the transmit power and frequency channel includes:

starting with an initial transmit power for the current access point;

, determining the pairwise connectivity from the pairwise path loss using a path loss criterion based on the transmit power and a receiver sensitivity;

ascertaining whether or not there is any frequency channel unused by any BP connected to the current BP, and if so, assigning to the current BP such an available frequency channel at the transmit power;

if the ascertaining ascertains that no frequency channel is available, repeating lowering the transmit power of the current access point to possibly cause one or more of the other access points to become disconnected to possibly free up a potential frequency channel until a frequency channel not used by any connected access point is available, or no frequency channel is available even at the lowest possible transmit power;

in the case a frequency channel frees as a result of the lowering of transmit power, assigning to the current access point the newly available frequency channel and the highest transmit power level at which the channel becomes available; and

in the case no frequency channel becomes available, assign the initial transmit power to the current access point, considering groups of access points assigned each of the used frequency channels, and assigning the frequency channel of the group of access points already assigned with a frequency channel whose minimum path loss from the current access point is the highest.

13. A computer readable medium as recited in claim 11, wherein the evaluation metric is the Fast Evaluation Metric.

14. A computer readable medium as recited in claim 11, wherein some of the access points are managed access points, and one or more other access points are unmanaged access points for which one or both of the transmit power and/or the frequency channel is pre-assigned.

15. A computer readable medium as recited in claim 11, wherein the wireless network substantially conforms to one of the IEEE 802.11 standards.

16. A computer-readable encoded with computer program instructions that when executed by one or more processors of a processing system to carry out a method of assigning frequency channels and transmit powers for a plurality of access points of a wireless network, the method comprising:

accepting a set of pairwise measures of path losses from each access point to a different access point of the network; and

repeating until there are no more access points to which to assign a transmit power and frequency channel;

selecting a current access point to which to assign a transmit power and frequency channel;

(b) starting with an initial transmit power for the current access point;

, determining the pairwise connectivity from the pairwise path loss using a path loss criterion based on the transmit power and a receiver sensitivity;

(c) ascertaining whether or not there is any frequency channel unused by any BP connected to the current BP, and if so, assigning to the current BP such an available frequency channel at the transmit power;

(d) if the ascertaining ascertains that no frequency channel is available, repeating lowering the transmit power of the current access point to possibly cause one or more of the other access points to become disconnected to possibly free up a potential frequency channel until a frequency channel not used by any connected access point is available, or no frequency channel is available even at the lowest possible transmit power;

(e) in the case a frequency channel frees as a result of the lowering of transmit power, assigning to the current access point the newly available frequency channel and the highest transmit power level at which the channel becomes available; and

(f) in the case no frequency channel becomes available, assign the initial transmit power to the current access point, considering groups of access points assigned each of the used frequency channels, and assigning the frequency channel of the group of access points already assigned with a frequency channel whose minimum path loss from the current access point is the highest wherein assigning frequency channels and transmit powers for an access point includes assigning one or more frequency channels and one or more transmit powers for the access point to communicate with its one or more clients.

17. An apparatus for assigning frequency channels and transmit powers for a plurality of access points of a wireless network, the apparatus comprising a processing system programmed to execute a method comprising:

accepting a measure of connectivity between the access points of the network; and

repeating until there are no more access points to which to assign a transmit power and frequency channel;

(a) selecting a current access point to which to assign a transmit power and frequency channel, wherein the measure of connectivity between the access points of the network is a set of pairwise path losses from each access point to a different access point of the network;

(b) determining for a set of at least one transmit power for a set of at least one frequency channel a measure of the quality of the sub-network formed by the current access point and all access points to which a transmit power and frequency channel have been assigned, the measure according to an evaluation metric indicative of the quality of the sub-network; and

(c) assigning to the current access point the transmit power and frequency channel that minimizes the measure of the quality of the sub-network.

18. An apparatus as recited in claim 17, wherein the determining of the measure of quality and the assigning of the transmit power and frequency channel includes:

starting with an initial transmit power for the current access point;

, determining the pairwise connectivity from the pairwise path loss using a path loss criterion based on the transmit power and a receiver sensitivity;

ascertaining whether or not there is any frequency channel unused by any AP connected to the current AP, and if so, assigning to the current AP such an available frequency channel at the transmit power;

if the ascertaining ascertains that no frequency channel is available, repeating lowering the transmit power of the current access point to possibly cause one or more of the other access points to become disconnected to possibly free up a potential frequency channel until a frequency channel not used by any connected access point is available, or no frequency channel is available even at the lowest possible transmit power;

in the case a frequency channel frees as a result of the lowering of transmit power, assigning to the current access point the newly available frequency channel and the highest transmit power level at which the channel becomes available; and

in the case no frequency channel becomes available, assign the initial transmit power to the current access point, considering groups of access points assigned each of the used frequency channels, and assigning the frequency channel of the group of access points already assigned with a frequency channel whose minimum path loss from the current access point is the highest.

19. An apparatus as recited in claim 17, wherein the evaluation metric is the Fast Evaluation Metric.

20. An apparatus as recited in claim 17, wherein some of the access points are managed access points, and one or more other access points are unmanaged access points for which one or both of the transmit power and/or the frequency channel is pre-assigned.

21. An apparatus as recited in claim 17, wherein the wireless network substantially conforms to one of the IEEE 802.11 standards.

22. An apparatus of assigning frequency channels and transmit powers for a plurality of access points of a wireless network, the apparatus comprising:

means for accepting a measure of connectivity between the access points of the network; and

means for repeating until there are no more access points to which to assign a transmit power and frequency channel;

(a) selecting a current access point to which to assign a transmit power and frequency channel;

(b) determining for a set of at least one transmit power for a set of at least one frequency channel a measure of the quality of the sub-network formed by the current access point and all access points to which a transmit power and frequency channel have been assigned, the measure according to an evaluation metric indicative of the quality of the sub-network; and

(c) assigning to the current access point the transmit power and frequency channel that minimizes the measure of the quality of the sub-network, wherein assigning frequency channels and transmit powers for an access point includes assigning one or more frequency channels and one or more transmit powers for the access point to communicate with its one or more clients.

23. An apparatus as recited in claim 22, wherein the evaluation metric is the Fast Evaluation Metric.

24. An apparatus as recited in claim 22, wherein some of the access points are managed access points, and one or more other access points are unmanaged access points for which one or both of the transmit power and/or the frequency channel is pre-assigned.

25. An apparatus as recited in claim 22, wherein the wireless network substantially conforms to one of the IEEE 802.11 standards.

26. An apparatus as recited in claim 22, wherein the determining of the measure of quality and the assigning of the transmit power and frequency channel includes:

starting with an initial transmit power for the current access point;

, determining the pairwise connectivity from the pairwise path loss using a path loss criterion based on the transmit power and a receiver sensitivity;

ascertaining whether or not there is any frequency channel unused by any AP connected to the current AP, and if so, assigning to the current AP such an available frequency channel at the transmit power;

if the ascertaining ascertains that no frequency channel is available, repeating lowering the transmit power of the current access point to possibly cause one or more of the other access points to become disconnected to possibly free up a potential frequency channel until a frequency channel not used by any connected access point is available, or no frequency channel is available even at the lowest possible transmit power;

in the case a frequency channel frees as a result of the lowering of transmit power, assigning to the current access point the newly available frequency channel and the highest transmit power level at which the channel becomes available; and

in the case no frequency channel becomes available, assign the initial transmit power to the current access point, considering groups of access points assigned each of the used frequency channels, and assigning the frequency channel of the group of access points already assigned with a frequency channel whose minimum path loss from the current access point is the highest.