Frequency planning method for wireless LANs
View Patent ↗A method may include allocating channels of a wireless local area network (WLAN) including a plurality of access points to the plurality of access points based on a load of each access point. The load of each access point may include a user load and/or an interference load. The user load may be generated by each user of the access point. The interference load may be based on interference caused by transmissions between the remainder of the plurality of access points and users of the remainder of the plurality of access points.
1. A method comprising: allocating, by a computer, channels of a wireless local area network (WLAN) including a plurality of access points to the plurality of access points based on a load of each access point, the load of each access point including a user load based on each user of the access point and an interference load based on interference caused by transmissions between a remainder of the plurality of access points and users of the remainder of the plurality of access points, and the allocating further creating, for each access point of the plurality of access points, a number of regions based on the user load of the access point.
2. The method of claim 1 , wherein the allocating the channels of the WLAN is based on a time required to send one unit of data to each user in the WLAN.
3. The method of claim 1 , wherein the creating for each access point of the plurality of access points the number of regions includes locating a selected access point in a given region of another access point if an interference coefficient between the selected access point and the another access point multiplied by the user load of the selected access point is greater than zero and less than or equal to the user load of the selected access point in the given region.
4. The method of claim 3 , further comprising: calculating the interference coefficient based on a channel quality condition between the selected access point and the another access point, the channel quality condition based on at least one of a distance between the selected access point and the another access point and obstacles between the selected access point and the another access point.
5. The method of claim 4 , wherein the calculating the interference coefficient between the selected access point and the another access point is calculated in accordance with the following equation:
α
a
,
b
=
{
1
if
d
(
a
,
b
)
≤
sr
,
0
if
d
(
a
,
b
)
≥
2
tr
+
sr
,
(
1
-
d
(
a
,
b
)
-
sr
2
tr
)
K
otherwise
.
wherein d(a, b) is the distance between the selected access point and the another access point, tr is a transmission range of the selected access point and the another access point, sr is a sensing range of the selected access point and the another access point, and K is a constant.
6. The method of claim 3 , wherein the allocating the channels of the WLAN comprises:
finding a number of time slots with lowest indexes for each region of the selected access point which are not assigned to access points in the region of the selected access point for each of the plurality of channels, the number of the time slots for each region based on a user load of the region, and allocating a channel resulting in a lowest congestion load of the WLAN to the selected access point, the congestion load of the WLAN a summation of the loads of each of the access points in the WLAN.
7. The method of claim 6 , wherein the allocating the channels of the WLAN includes fmding the number of time slots with lowest indexes and allocating the channel resulting in the lowest congestion load of the WLAN for each of the plurality of access points, wherein the selected access point is selected according to a decreasing order of expected loads of the plurality of access points.
8. The method of claim 7 , further comprising: calculating the interference coefficient based on at least one of a distance between the selected access point and the another access point and obstacles between the selected access point and the another access point.
9. The method of claim 8 , wherein the calculating the interference coefficient between the selected access point and the another access point is calculated in accordance with the following equation:
α
a
,
b
=
{
1
if
d
(
a
,
b
)
≤
sr
,
0
if
d
(
a
,
b
)
≥
2
tr
+
sr
,
(
1
-
d
(
a
,
b
)
-
sr
2
tr
)
K
otherwise
.
wherein d(a, b) is the distance between the selected access point and the another access point, tr is a transmission range of the selected access point and the another access point, sr is a sensing range of the selected access point and the another access point, and K is a constant.
10. The method of claim 1 , wherein the WLAN is any IEEE 802.11 WLAN.
11. The method of claim 1 , wherein the allocating the channels of the WLAN is not based on information received from the users.
12. The method of claim 1 , wherein different types of interference cause different amounts of interference load.
13. The method of claim 1 , wherein the load of each access point is an average load over a period of time.
14. The method of claim 1 , wherein the allocating the channels of the WLAN includes allocating a channel resulting in a lowest congestion load of the WLAN to each of the access points, the congestion load of the WLAN a summation of the loads of each of the access points in the WLAN.
15. The method of claim 14 , wherein
the allocating the channel resulting in the lowest congestion load of the WLAN to each of the access points includes selecting a selected access point from the plurality of access points according to a decreasing order of expected loads of the plurality of access points and allocating the channel resulting in the lowest congestion load of the WLAN to a currently selected access point based on a channel allocation of previously selected access points.
16. A wireless local area network (WLAN), comprising:
a plurality of channels allocated, by a computer, to a plurality of access points, the plurality of channels allocated to the plurality of access points based on a load of each access point, the load of each access point including a user load based on each user of the access point and an interference load based on interference caused by transmissions of the remainder of the plurality of access points and users of a remainder of the plurality of access points, and the plurality of access points each having a number of regions, the number of regions based on the user load of the access point.
17. A method comprising: providing a wireless local area network (WLAN) including a plurality of access points, the WLAN configured to allocate channels, by a computer, to the plurality of access points based on a load of each access point, the load of each access point including a user load based on each user of the access point and an interference load based on interference caused by transmissions between the remainder of the plurality of access points and users of the remainder of the plurality of access points, and create for each access point of the plurality of access points, a number of regions based on the user load of the access point.
18. A method comprising: ensuring a level of service above a threshold level to each users of a wireless local area network (WLAN) including a plurality of access points while maximizing a throughput of the WLAN by allocating channels, by a computer, of the WLAN to the users based on a load of each access point of the plurality of access points, the load of each access point including a user load based on each of the users of the access point, and creating for each access point, a number of regions based on the user load of the access point.