Physical layer protocol data unit (PPDU) format for reducing preamble overhead of preemption PPDUs
An embodiment is method performed by a wireless device to allow preemption in a wireless network. The method includes wirelessly transmitting a first preemption physical layer protocol data unit (PPDU) that includes a complete preamble followed by one or more subsequent preemption PPDUs that each include a reduced preamble, wherein the complete preamble includes one or more preamble fields that are omitted in the reduced preamble, wherein the first PPDU and the one or more subsequent preemption PPDUs are transmitted with a predefined interframe space interval between PPDU transmissions during which preemption is allowed.
1 . A method performed by a wireless device to allow preemption in a wireless network, comprising:
wirelessly transmitting a first preemption physical layer protocol data unit (PPDU) that includes a complete preamble followed by one or more subsequent preemption PPDUs that each include a reduced preamble, wherein the complete preamble includes one or more preamble fields that are omitted in the reduced preamble, wherein the first PPDU and the one or more subsequent preemption PPDUs are transmitted with a predefined interframe space interval between PPDU transmissions during which preemption is allowed;
wherein the one or more preamble fields that are included in the complete preamble but omitted in the reduced preamble include a legacy short training field (L-STF) preamble field and a legacy long training field (L-LTF) preamble field, wherein the one or more subsequent preemption PPDUs are to be processed using synchronization and channel estimation information obtained from the L-STF preamble field and the L-LTF preamble field included in the complete preamble.
2 . The method of claim 1 , wherein the one or more preamble fields that are included in the complete preamble but omitted in the reduced preamble further include a legacy signal (L-SIG) preamble field and a repeated legacy signal (RL-SIG) preamble field.
3 . The method of claim 2 , wherein the one or more preamble fields that are included in the complete preamble but omitted in the reduced preamble further include a universal signal (U-SIG) preamble field or a portion of the U-SIG preamble field.
4 . The method of claim 3 , wherein the one or more preamble fields that are included in the complete preamble but omitted in the reduced preamble further include an ultra high reliability short training field (UHR-STF) preamble field.
5 . The method of claim 4 , wherein the one or more preamble fields that are included in the complete preamble but omitted in the reduced preamble further include one or more ultra high reliability long training field (UHR-LTF) preamble fields, wherein the reduced preamble includes a single UHR-LTF preamble field for phase tracking.
6 . The method of claim 1 , further comprising:
detecting a low latency data frame transmitted by another wireless device during the predefined interframe space interval between PPDUs; and
responsive to detecting the low latency data frame, pausing transmission of further preemption PPDUs to receive the low latency data frame.
7 . The method of claim 6 , further comprising:
after receiving the low latency data frame, resuming transmission of preemption PPDUs by transmitting a second preemption PPDU that includes the complete preamble followed by one or more subsequent preemption PPDUs that each include the reduced preamble.
8 . The method of claim 1 , further comprising:
determining that the wireless device has low latency data to transmit; and
responsive to determining that the wireless device has low latency data to transmit, pausing transmission of further preemption PPDUs to transmit a low latency data frame that includes the low latency data.
9 . The method of claim 8 , further comprising:
after transmitting the low latency data frame, resuming transmission of preemption PPDUs by transmitting a second preemption PPDU that includes the complete preamble followed by one or more subsequent preemption PPDUs that each include the reduced preamble.
10 . The method of claim 1 , wherein the predefined interframe space interval is longer than a short interframe space (SIFS) interval but shorter than a distributed coordination function interframe space (DIFS) interval.
11 . The method of claim 10 , wherein the predefined interframe space interval has a duration that that is a multiple of an orthogonal frequency division multiplexing (OFDM) symbol duration.
12 . The method of claim 1 , wherein a last one of the one or more subsequent preemption PPDUs includes a packet extension (PE) field but the first PPDU and others of the one or more subsequent preemption PPDUs do not include the packet extension (PE) field.
13 . A method performed by a wireless device to process preemption physical layer protocol data units (PPDUs), the method comprising:
wirelessly receiving a first preemption PPDU that includes a complete preamble followed by one or more subsequent preemption PPDUs that each include a reduced preamble, wherein the complete preamble includes one or more preamble fields that are omitted in the reduced preamble, wherein the first PPDU and the one or more subsequent preemption PPDUs were transmitted with a predefined interframe space interval between PPDU transmissions to allow preemption; and processing the first preemption PPDU and the one or more subsequent preemption PPDUs;
wherein the one or more preamble fields that are included in the complete preamble but omitted in the reduced preamble include a legacy short training field (L-STF) preamble field and a legacy long training field (L-LTF) preamble field, wherein the one or more subsequent preemption PPDUs are processed using synchronization and channel estimation information obtained from the L-STF preamble field and the L-LTF preamble field included in the complete preamble.
14 . The method of claim 13 , wherein the one or more preamble fields that are included in the complete preamble but omitted in the reduced preamble further include a legacy signal (L-SIG) preamble field and a repeated legacy signal (RL-SIG) preamble field, wherein the one or more subsequent preemption PPDUs are processed using information obtained from the L-SIG preamble field included in the complete preamble.
15 . The method of claim 14 , wherein the one or more preamble fields that are included in the complete preamble but omitted in the reduced preamble further include a universal signal (U-SIG) preamble field or a portion of the U-SIG preamble field, wherein the one or more subsequent preemption PPDUs are processed using information obtained from the U-SIG preamble field or the portion of the U-SIG preamble field included in the complete preamble.
16 . The method of claim 15 , wherein the one or more preamble fields that are included in the complete preamble but omitted in the reduced preamble further include an ultra high reliability short training field (UHR-STF) preamble field, wherein the one or more subsequent preemption PPDUs are processed without performing additional automatic gain control (AGC).
17 . The method of claim 16 , wherein the one or more preamble fields that are included in the complete preamble but omitted in the reduced preamble further include one or more ultra high reliability long training field (UHR-LTF) preamble fields, wherein the one or more subsequent preemption PPDUs are processed using multiple input multiple output (MIMO) channel estimation information obtained from the one or more UHR-LTF preamble fields included in the complete preamble.
18 . The method of claim 17 , wherein the reduced preamble includes a single UHR-LTF preamble field for phase tracking.
19 . A wireless device to allow preemption in a wireless network, the wireless device comprising:
a radio frequency transceiver;
a memory device storing a set of instructions; and
a processor coupled to the memory device, wherein the set of instructions when executed by the processor causes the wireless device to:
wirelessly transmit a first preemption physical layer protocol data unit (PPDU) that includes a complete preamble followed by one or more subsequent preemption PPDUs that each include a reduced preamble, wherein the complete preamble includes one or more preamble fields that are omitted in the reduced preamble, wherein the first PPDU and the one or more subsequent preemption PPDUs are transmitted with a predefined interframe space interval between PPDU transmissions during which preemption is allowed;
wherein the one or more preamble fields that are included in the complete preamble but omitted in the reduced preamble include a legacy short training field (L-STF) preamble field and a legacy long training field (L-LTF) preamble field, wherein the one or more subsequent preemption PPDUs are to be processed using synchronization and channel estimation information obtained from the L-STF preamble field and the L-LTF preamble field included in the complete preamble.