January 2011doc.: IEEE 802.11-11/0098r0

IEEE P802.11
Wireless LANs

Bandwidth Specific TXOPLimits
Date: 2011-01-17
Author(s):
Name / Affiliation / Address / Phone / email
Jarkko Kneckt / Nokia Corporation / Itämerenkatu 11 – 13 00180 Helsinki, Finland /
Eng-Hwee Ong / Nokia Corporation / Itämerenkatu 11 – 13 00180 Helsinki, Finland /
Mika Kasslin / Nokia Corporation / Itämerenkatu 11 – 13 00180 Helsinki, Finland /
6.3.6.1.4 Bandwidth Specific TXOPLimits Parameter Set

Instructions to editor:Insert the new field as described below. Renumber the clauses if necessary.

The Bandwidth Specific TXOP Limit Parameter Setindicates the bandwidth specific TXOPLimits.

Element ID / Length (3) / 40 MHz Factor / 80 MHz Factor / 160 MHz Factor
Octets: / 1 / 1 / 1 / 1 / 1

Figure ac1 – Bandwidth Specific TXOP Limits Parameter Set

The 40 MHz Factor is an unsigned integer. The value of 40 MHz Factor is divided by 255 and multiplied by the AC specific TXOP Limit to calculate the value of AC specific TXOPLimit40that limits the medium occupancy of the 40 MHz or wider bandwidth. The TXOPLimit40 value is rounded up to next multiple of 32 micro seconds. Value 0 in 40MHz Factor indicates that medium occupancy is not allowed for 40 MHz or wider bandwidth.

The 80 MHz Factor is an unsigned integer. The value of 80 MHz Factor is divided by 255 and multiplied by the AC specific TXOP limit to calculate the value of AC specific TXOPLimit80that limits the medium occupancy of the 80 MHz or wider bandwidth. The TXOPLimit80value is rounded up to next multiple of 32 micro seconds. Value 0 in 80 MHz Factor indicates that medium occupancy is not allowed for 80 MHz or wider bandwidth.

The 160 MHz Factor is an unsigned integer. The value of 160 MHz Factor is divided by 255 and multiplied by the AC specific TXOP Limit to calculate the value of TXOPLimit160 that limits the medium occupancy of the 160 MHz bandwidth. The TXOPLimit160 is rounded up to next multiple of 32 micro seconds. Value 0 in 160 MHz Factor indicates that medium occupancy is not allowed for 160 MHz bandwidth.

6.10 Bandwidth specific TXOPlimit

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6.10.1 Measuring the TXOP duration

The TXOP holder measures the bandwidth occupancy within a TXOP for the following channels:

  1. The duration when TXOP holder occupies the primary channel
  2. The duration when TXOP holder occupies the secondary channel
  3. The duration when TXOP holder occupies the tertiary and quarternary channels
  4. The duration when TXOP holder occupies the quinary (5), senary (6), septenary (7), and octonary (8) channels

6.10.2Limiting the maximum duration of the TXOP

The EDCAF that won the TXOP shall constraint the medium occupancy according to AC and the occupied bandwidth. The following rules shall limit the medium occupancy for each AC:

  1. The duration when TXOP holder occupies the primary channel shall not exceed the TXOPLimit.
  2. The duration when TXOP holder occupies the secondary channel shall not exceed the TXOPLimit40.
  3. The duration when TXOP holder occupies the tertiary and the quarternary channels shall not exceed the TXOPLimit80.
  4. The duration when TXOP holder occupies the quinary (5), the senary (6), the septenary (7), and the octonary (8) channels shall not exceed the TXOPLimit160.

Submissionpage 1Jarkko Kneckt, Nokia