| 175 | | This is the first example where we see the interplay of the two types of errors introduced in [#ExampleL.2 Example L.2] and [#ExampleL.3 Example L.3]. |
| | 175 | In this example, we see the error introduced in [#ExampleL.2 Example L.2] taken to its limit when the maximum retransmission limit is reached. After the 4th failure to transmit the long MPDU, the LRC increments to 4. At this point in time, the following excerpt from the standard binds: |
| | 176 | |
| | 177 | '''''Excerpt E of Section 9.3.4.4 of 802.11-2012''''' |
| | 178 | |
| | 179 | ''Retries for failed transmission attempts shall continue until the ... LRC for the MPDU ... is equal to dot11LongRetryLimit. When either of these limits is reached, retry attempts shall cease, and the MPDU ... shall be discarded.'' |
| | 180 | |
| | 181 | As such, the MPDU is discarded since the LRC hit the ''dot11LongRetryLimit''. At the same moment, the SLRC reaches ''dot11LongRetryLimit'' as well, thereby enacting the following passage: |
| | 182 | |
| | 183 | '''''Excerpt G from 9.3.3 of 802.11-2012''''' |
| | 184 | |
| | 185 | ''The CW shall be reset to aCWmin ... when SLRC reaches dot11LongRetryLimit ... .'' |
| | 186 | |
| | 187 | As such, MPDU 2 begins with a minimum contention window. The SLRC, however, remains at a value of 4 at the beginning of MPDU 2. |
