# Patent

## Title
Method, apparatus, and computer readable medium for multi-user scheduling in wireless local-area networks

## Abstract

Methods, apparatuses, and computer readable media are shown for multi-user scheduling in wireless local-area networks (WLANs). A wireless communication device is shown including circuitry to determine a plurality of schedules for each of a plurality of channels for an orthogonal frequency division multiple access (OFDMA) communication in a wireless local-area network (WLAN). Each of the plurality of schedules may include a frequency allocation for one or more communication devices. The circuitry may be further configured to transmit the corresponding schedule of the one or more schedules on each of the one or more channels. Each of the plurality of schedules may include a schedule type and a user association identification (AID) list. A number of user AIDs in the user AID list may be based on the schedule type.

## Background
PRIORITY CLAIM
This application is a U.S. National Stage Application under 35 U.S.C. 371 from International Application No. PCT/US2014/057751, filed Nov. 18, 2014, which claims the benefit of priority to the following U.S. Provisional Patent Applications:
Ser. No. 61/906,059, filed Nov. 19, 2013,
Ser. No. 61/973,376, filed Apr. 1, 2014,
Ser. No. 61/976,951, filed Apr. 8, 2014,
Ser. No. 61/986,256, filed Apr. 30, 2014,
Ser. No. 61/986,250, filed Apr. 30, 2014,
Ser. No. 61/991,730, filed May 12, 2014, and
Ser. No. 62/024,801, filed Jul. 15, 2014,
each of which is incorporated herein by reference in its entirety.


TECHNICAL FIELD
Some embodiments relate to low overhead schedules for high-efficiency wireless communications including high-efficiency wireless local-area network (HEW) devices, and some embodiments relate to low overhead schedules in 802.11ax.
BACKGROUND
One issue with wireless local-area networks (WLANs) is throughput and delay time. The resources of the wireless medium are limited, and users of the wireless medium continue to demand better performance from the WLAN. Thus one technical problem with WLANs is improving the throughput and/or the delay time of the WLAN.



BRIEF DESCRIPTION OF THE DRAWINGS
The present disclosure is illustrated by way of example and not limitation in the figures of the accompanying drawings, in which like references indicate similar elements and in which:
FIG. 1 illustrates a wireless network, in accordance with some embodiments;
FIG. 2 illustrates a method for multiple-user scheduling in a WLAN operating according to orthogonal frequency division multiple access (OFDMA), according to example embodiments;
FIG. 3 illustrates a schedule type table for indicating a schedule type in OFDMA, according to example embodiments;
FIG. 4 illustrates a variable-length schedule with a type and variable STA association identification (AID) list;
FIG. 5 illustrates a schedule that is an example of the variable-length schedule of FIG. 4;
FIG. 6 illustrates a schedule that is an example of the variable-length schedule 400 of FIG. 4;
FIG. 7 illustrates a schedule that is an example of the variable-length schedule of FIG. 4;
FIG. 8 illustrates a fixed-length schedule where the schedule includes a fixed length STA AID list;
FIG. 9 illustrates a schedule that is an example of a fixed-length schedule, according to example embodiments;
FIG. 10 illustrates a schedule that is an example of a fixed-length schedule, according to example embodiments;
FIG. 11 illustrates a schedule that is an example of a fixed-length schedule, according to example embodiments;
FIG. 12 illustrates a schedule type table for indicating a schedule type in OFDMA, according to another example embodiment;
FIG. 13 illustrates a method for multiple-user scheduling in a WLAN operating according to OFDMA;
FIG. 14 illustrates a schedule type table for indicating a schedule type in OFDMA, according to example embodiments;
FIG. 15 illustrates a fixed-length schedule with a type and variable STA AID list; and
FIG. 16 illustrates a HEW device, in accordance with some embodiments.



DESCRIPTION
The following description and the drawings sufficiently illustrate specific embodiments to enable those skilled in the art to practice them. Other embodiments may incorporate structural, logical, electrical, process, and other changes. Portions and features of some embodiments may be included in, or substituted for, those of other embodiments. Embodiments set forth in the claims encompass all available equivalents of those claims.
FIG. 1 illustrates a wireless network, in accordance with some embodiments. The wireless network may comprise a basic service set (BSS) 100 that may include an access point (AP) 102, a plurality of HEW devices 104, and a plurality of legacy devices 106.
The AP 102 may be an access point (AP) using the Institute of Electrical and Electronics Engineers (IEEE) 802.11 to transmit and receive. The AP 102 may be a base station. The AP 102 may use other communications protocols as well as the 802.11 protocol as described below. The 802.11 protocol may be 802.11ax. The 802.11 protocol may include using OFDMA. The 802.11 may include using multi-user (MU) multiple-input and multiple-output (MIMO)(MU-MIMO), space division multiplexing (SDM), and/or space division multiple access (SDMA). The HEW devices 104 may operate in accordance with 802.11ax and/or DensiFi. The legacy devices 106 may operate in accordance in accordance with one or more of 802.11 a/g/ag/n/ac, or another legacy wireless communication standard.
The HEW devices 104 may be wireless transmit and receive devices such as cellular telephones, handheld wireless devices, wireless glasses, wireless watches, wireless personal devices, tablets, or other devices that may be transmitting and receiving using the 802.11 protocol such as 802.11 ax or another wireless protocol.
The BSS 100 may operate on a primary channel and one or more secondary channels or sub-channels. The BSS 100 may include one or more APs 102. In accordance with embodiments, the AP 102 may communicate with one or more of the HEW devices 104 on one or more of the secondary channels or sub-channels or the primary channel. In example embodiments, the AP 102 communicates with the legacy devices 106 on the primary channel. In example embodiments, the AP 102 may be configured to communicate concurrently with one or more of the HEW devices 104 on one or more of the secondary channels and a legacy device 106 utilizing only the primary channel and not utilizing any of the secondary channels.
The AP 102 may communicate with legacy devices 106 in accordance with legacy IEEE 802.11 communication techniques. In example embodiments, the AP 102 may also be configured to communicate with HEW devices 104 in accordance with legacy IEEE 802.11 communication techniques. Legacy IEEE 802.11 communication techniques may refer to any IEEE 802.11 communication technique prior to IEEE 802.11ax.
In some embodiments, a HEW frame may be configurable to have the same bandwidth, and the bandwidth may be one of 20 MHz, 40 MHz, 80 MHz, or 160 MHz contiguous bandwidths or an 80+80 MHz (160 MHz) non-contiguous bandwidth. In some embodiments, a 320 MHz contiguous bandwidth may be used. In some embodiments, bandwidths of 1 MHz, 1.25 MHz, 2.5 MHz, 5 MHz and 10 MHz or a combination thereof may also be used. In these embodiments, an HEW frame may be configured for transmitting a number of spatial streams.
In other embodiments, the AP 102, HEW device 104, and/or legacy device 106 may implement additional or different technologies such as code division multiple-access (CDMA)2000, CDMA2000 lX, CDMA2000 EV-DO, Interim Standard 2000 (IS-2000), Interim Standard 95 (IS-95), Interim Standard 856 (IS-856), Global System for Mobile communications (GSM), Long-Term Evolution (LTE), a standard from the 3 Generation Partnership Project (3GPP), Enhanced Data rates for GSM Evolution (EDGE), GSM EDGE (GERAN), IEEE 802.16 (i.e., Worldwide Interoperability for Microwave Access (WiMAX)), WiFi®, BlueTooth®, BlueTooth® Low Energy (BLE), 802.15.4, neighbor aware networking (NAN) program, Near-field communication (NFC), and/or a wireless personal area network (WPAN) wireless technology.
In an OFDMA system such as 802.11ax, an associated HEW device 104 may operate on any 20 MHz sub-channel of the BSS 100 (that can operate, for example, at 80 MHz). In example embodiments, an AP 102, HEW devices 104, and legacy devices 106 use carrier sense multiple access/collision avoidance (CSMA/CA). In some embodiments, the media access control (MAC) layer 1606 (see FIG. 16) controls access to the wireless media.
In example embodiments, an AP 102, HEW devices 104, and legacy devices 106 perform carrier sensing and can detect whether or not the channel is free. For example, an AP 102, HEW device 104, or legacy device 106 may use clear channel assessment (CCA), which may include a determination as to whether the channel is clear based on a Decibel-milliwatts (dBm) level of reception. In example embodiments, the physical layer (PHY) 1604 is configured to determine a CCA for an AP 102, HEW devices 104, and legacy devices 106.
After determining that the channel is free, an AP 102, HEW device 104, and legacy devices 106 defer their attempt to access the channel during a back-off period to avoid collisions. In example embodiments, an AP 102, HEW device 104, and legacy devices 106 determine the back-off period by first waiting a specific period of time and then adding a random back-off time, which, in some embodiments, is chosen uniformly between 0 and a current contention window (CS) size. A period of time may also be called a duration.
In example embodiments, an AP 102, HEW devices 104, legacy devices 106, access the channel in different ways. For example, in accordance with some IEEE 802.11ax embodiments, an AP 102 may operate as a master station which may be arranged to contend for a wireless medium (e.g., during a contention period) to receive exclusive control of the medium for an HEW control period (i.e., a transmission opportunity (TXOP)). The AP 102 may transmit an HEW master-sync transmission at the beginning of the HEW control period. During the HEW control period, HEW devices 104 may communicate with the AP 102 in accordance with a non-contention based multiple access technique. This is unlike conventional Wi-Fi communications in which legacy devices 106 and, optionally, HEW devices 104 communicate in accordance with a contention-based communication technique, rather than a non-contention multiple access technique. During the HEW control period, the AP 102 may communicate with HEW devices 104 using one or more HEW frames. During the HEW control period, legacy devices 106 refrain from communicating. In some embodiments, the master-sync transmission may be referred to as an HEW control and schedule transmission.
In some embodiments, the multiple-access technique used during the HEW control period may be a scheduled OFDMA technique, although this is not a requirement. In some embodiments, the multiple access technique may be a time-division multiple access (TDMA) technique or a frequency division multiple access (FDMA) technique. In some embodiments, the multiple access technique may be a SDMA technique or uplink MU-MIMO (UL MU-MMIO).
The AP 102 may also communicate with legacy devices 106 in accordance with legacy IEEE 802.11 communication techniques. In some embodiments, the master station, which may be the AP 102, may also be configured to communicate with HEW stations outside the HEW control period in accordance with legacy IEEE 802.11 communication techniques, although this is not a requirement.
In example embodiments, the AP 102 is configured to perform one or more of the functions and/or methods described herein such as determining whether or not to adapt the channel contention settings, select new a CCA value and at least one additional new setting, transmit an indication to change a CCA threshold, and transmit a new CCA value and at least one additional new setting to a HEW device 104. In example embodiments, the HEW devices 104 are configured to perform one or more of the functions and/or methods described herein, such as generating and transmitting a low over-head schedule and receiving and operating according to the schedule.
FIG. 2 illustrates a method 200 for multiple-user scheduling in a WLAN operating according to OFDMA, according to example embodiments.
Illustrated along the horizontal axis is time 252 and along the vertical axis is frequency 270. Along the top 272 is an indication of which device is transmitting. The frequency 270 may be divided into channels or sub-channels having a bandwidth. As illustrated, there are two channels 274, 276, which may be called sub-channels, and the bandwidth for each of the channels is 20 MHz. In example embodiments, the bandwidth of the channels 274, 276 may be a different bandwidth such as 10 MHz, 40 MHz, 80 MHz, or 160 MHz, and the bandwidth of the channels 274, 276 may not be the same size. In example embodiments, there may be more channels 274, 276. For example, the number of channels 274, 276 may correspond to one or more standards such as an 802.11 standard or 802.11ax. For example, there may be eight channels of 20 MHz each. In example embodiments, no STA can be allocated in more than one 20 MHz channel unless the STA is allocated the entirety of the 20 MHz channels. In example embodiments, there may be multiple spatial streams in accordance with MU-MIMO on one or more the channels 274 276.
The method 200 begins at time 254 with the AP 102 transmitting a signal field (SIG) 202.1 on the channel 276, and SIG 202.2 on channel 274. The SIG 202 may be a SIG that includes information such as modulation and coding information. The SIG 202.1 includes a schedule (SCH) 204.1, and SIG 202.2 includes a SCH 204.2. The SCHs 204 indicate a schedule for how the channels 274, 276 are allocated to the HEW devices 104. In example embodiments, the SCHs 204 are for a HEW control period, and in some embodiments for 802.11ax. The AP 102 determines the schedules 204.
The method 200 continues at time 256 with the HEW devices 104 transmitting in the uplink according to the SCHs 204.1, 204.2. HEW devices 104.1, 104.2, 104.3, and 104.4 interpret the SCH 204.1, and each transmits on a 5 MHz band in channel 276 according to the SCH 204.1. HEW device 104.5 interprets the SCH 204.4, and transmits on the entire 20 MHz on channel 274 according to the SCH 204.2. The transmission period for the HEW devices 104 ends.
The method 200 continues at time 258 with the AP 102 transmitting SIG 202.3 on channel 276 and SIG 202.4 on channel 274. SIG 202.3 includes SCH 204.3, and SIG 202.4 includes SCH 204.4. The SCHs 204 indicate a schedule for how the channels 274, 276, are allocated to the HEW devices 104. In example embodiments, the AP 102 acquires the wireless medium through a contention period before time 258.
The method 200 continues at time 260 with the HEW devices 104 transmitting in the uplink according to the SCHs 204.3, 204.4. HEW devices 104.1, and 104.2 interpret the SCH 204.3, and each transmits on a 10 MHz band in channel 276 according to the SCH 204.3. HEW devices 104.5, 104.6, 104.7, and 104.8 interpret the SCH 204.4, and transmit each on their allocated 5 MHz on channel 274 according to the SCH 204.4. The transmission period for the HEW devices 104 ends.
The method 200 continues at time 262 with the AP 102 transmitting SIG 202.5 on channel 276 and SIG 202.6 on channel 274. SIG 202.5 includes SCH 204.5, and SIG 202.6 includes SCH 204.6. The SCHs 204 indicate a schedule for how the channels 274, 276, are allocated to the HEW devices 104. In example embodiments, the AP 102 acquires the wireless medium through a contention period before time 262.
The method 200 continues at time 264 with the HEW device 104.2 transmitting in the uplink according to the SCHs 204.5, 204.6. HEW device 104.2 interprets the SCH 204.5 and SCH 20.6, and transmits on channel 274 and channel 276, according to the SCH 204.5 and SCH 204.6. The transmission period for the HEW devices 104 ends. The SIGs 202 may be called MAP-SIGs 202 because of the inclusion of the SCHs 204. In example embodiments, the SCHs 204 are included in a different packet than the SIGs 202.
FIG. 3 illustrates a schedule type table 300 for indicating a schedule type in OFDMA, according to example embodiments. Table 300 has two columns: a schedule type 302 and an allocation 304. The schedule type 302 indicates the allocation 304 to the HEW devices 104 for a 20 MHz channel. Schedule 1 indicates that one STA is allocated the entire 20 MHz schedule. Schedule 2 indicates that two STAs are each allocated 10 MHz of the 20 MHz channel. Schedule 3 indicates that 2 STAs are each allocated 5 MHz and one STA is allocated 10 MHz of the 20 MHz channel. Schedule 4 indicates that four STAs each receive 5 MHz of the 20 MHz channel. The schedule type 302 may be represented by two bits in a packet as described herein. The STAs may be represented by an AID that includes an address that uniquely identifies the STA within the BSS 100 (see FIG. 1). The HEW devices 104 may be STAs. In example embodiments, the schedule type may be represented by 2 bits. One skilled in the art will recognize that the schedule types 302 can correspond to different allocations 304. One skilled in the art will recognize that the schedule types 302 may be extended to divide the channel into smaller bandwidths such as 2.5 MHz and 1.25 MHz.
In example embodiments, the AP 102 and HEW devices 104 may interpret the schedules differently depending on whether there is more than one active spatial stream. In example embodiments, the AP 102 and HEW devices 104 interpret the type differently if there multiple active spatial streams on the channel. In example embodiments, the schedule may be limited to four HEW devices 104 or STAs. In example embodiments, the type 402 includes an indication of whether the allocation is for a single stream or multiple streams.
FIGS. 4-7 illustrate variable-length schedules for a channel in OFDMA, according to example embodiments. Illustrated in FIG. 4 is a variable-length schedule 400 with a type 402 and variable STA AID list 404. The type 402 may be as described in relation to FIG. 3. The variable STA AID list 404 may be a STA AID list where the number of STA AIDs in the list depends on the type 402.
Illustrated in FIG. 5 is a schedule 500 that is an example of the variable-length schedule 400 (FIG. 4). The type 502 is 4, which indicates four STAs each receiving 5 MHz, according to the schedule type table 300 of FIG. 3. The order of the STA AIDs may indicate which part of the 20 MHz channel the STA is allocated. For example, schedule 500 may be schedule 204.1 of FIG. 2. The STA1 AID 504 may indicate HEW Device 104.1, STA2 AID 506 may indicate HEW device 104.2, STA3 AID 508 may indicate HEW device 104.3, and STA4 AID 510 may indicate HEW device 104.4. Similarly, schedule 500 may be schedule 204.4 with a different correspondence between the STAs and HEW devices 104.
Illustrated in FIG. 6 is a schedule 600 that is an example of the variable-length schedule 400 (FIG. 4). The type 602 is 1, which indicates one STA receiving the entire 20 MHz channel, according to the schedule type table 300 of FIG. 3. The schedule 600 may be schedule 204.2 where STA5 AID 604 indicates HEW device 104.5. Similarly, schedule 600 may be schedule 204.5 and schedule 204.6 with a STA5 AID 604 corresponding to HEW device 104.2.
Illustrated in FIG. 7 is a schedule 700 that is an example of the variable-length schedule 400 (FIG. 4). The type 702 is 7, which indicates two STAs each receiving 10 MHz, according to the schedule type table 300 of FIG. 3. The order of the STA AIDs may indicate which part of the 20 MHz channel the STA is allocated. For example, schedule 700 may be schedule 204.3 of FIG. 2. The STA1 AID 704 may indicate HEW Device 104.1, and STA2 AID 706 may indicate HEW device 104.2.
FIGS. 8-11 illustrate fixed-length schedules for a channel in OFDMA, according to example embodiments. Illustrated in FIG. 8 is a fixed-length schedule 800 where the schedule includes a fixed length STA AID list 802. The fixed length STA AID list 802 may indicate a portion of the channel allocated to the corresponding STA.
Illustrated in FIG. 9 is a schedule 900 that is an example of a fixed-length schedule, according to example embodiments. The schedule 900 may not have a type field. The allocation of each of four 5 MHz of the channel may be indicated by the position of the AID within the schedule 900. For example, schedule 900 may be schedule 202.1 (FIG. 2) where STA1 AID 902 indicates HEW device 104.1, STA2 AID 904 indicates HEW device 104.2, STA3 AID 906 indicates HEW device 104.3, and STA4 908 indicates HEW device 104.4. As another example, schedule 900 may be schedule 202.4 where STA1 AID 902 indicates HEW device 104.5, STA2 AID 904 indicates HEW device 104.6, STA3 AID 906 indicates HEW device 104.7, and STA4 908 indicates HEW device 104.8. As one skilled in the art would recognize, the order of the STAs may indicate allocation of different portions of the channel.
Illustrated in FIG. 10 is a schedule 1000 that is an example of a fixed-length schedule, according to example embodiments. The schedule 1000 may not have a type field. The allocation of each of four 5 MHz of the channel may be indicated by the position of the AID within the schedule 1000. For example, schedule 1000 may be schedule 204.3 (FIG. 2) where STA1 AIDs 1002, 1004 indicate HEW device 104.1 and STA2 AIDs 1006, 1008 indicate HEW device 104.2. As one skilled in the art would recognize the order of the STAs may indicate allocation of different portions of the channel.
Illustrated in FIG. 11 is a schedule 1100 that is an example of a fixed-length schedule, according to example embodiments. The schedule 1100 may not have a type field. The allocation of each of four 5 MHz of the channel may be indicated by the position of the AID within the schedule 1000. For example, schedule 1100 may be schedule 204.2 (FIG. 2) where STA1 AIDs 1102, 1104, 1106, 1108 indicate HEW device 104.5. Similarly, schedule 1100 may be schedules 204.5, 204.6 where STAT AIDs 1102, 1104, 1106, 1108 indicate HEW device 104.2.
FIG. 12 illustrates a schedule type table 1200 for indicating a schedule type in OFDMA, according to another example embodiment. Table 1200 has two columns: a schedule type 1202 and an allocation 1204. The schedule type 1202 indicates the allocation 1204 to the HEW devices 104 for a 20 MHz channel. Schedule 1 indicates that one STA is allocated the entire 20 MHz schedule. Schedule 2 indicates that two STAs are each allocated 10 MHz of the 20 MHz schedule. The allocations 1204 in table 1200 are limited to a minimum of 10 MHz. The STAs may be represented by an AID that includes an address that uniquely identifies the STA within the BSS 100 (see FIG. 1). The HEW devices 104 may be STAs. The schedule type 1202 may be represented by one bit. One skilled in the art will recognize that the schedule types 1202 can correspond to different allocations 1204.
FIG. 13 illustrates a method 1300 for multiple-user scheduling in a WLAN operating according to OFDMA in which an alternative schedule to schedule 204.1 in FIG. 2 is used.
The method 1300 begins at time 1354 with the AP 102 transmitting a SIG 1302.1 on channel 276, and SIG 1302.2 on channel 274. The SIG 1302.1 includes a SCH 1304.3, and SIG 1302.2 includes a SCH 1304.4. The SCHs 204 indicate a schedule for how the channels 274, 276, are allocated to the HEW devices 104. In example embodiments, the SCHs 1304 are for a HEW control period. The AP 102 may determine the schedules 1304 based on information regarding the operation bandwidth of the HEW devices 104. Moreover, the HEW devices 104 may interpret the SCHs 1304 in terms of their operation bandwidth. For example, HEW device 104.1 may not operate in all the tone of its allocation in channel 276. In example embodiments, the HEW device 104.1 will interpret the allocation as meaning the HEW device 104.1 is allocated the tones within the allocation that are part of its operation bandwidth. Moreover, the AP 102 may determine the schedules 204 based on information regarding the operation bandwidth of the HEW devices 104. For example, the AP 102 may allocate HEW device 104.1 to the lower end of channel 276 (as in FIG. 13) rather than at the upper end of channel 276 (as in FIG. 2) because HEW device 104.1 may have more operating tones at the lower end than at the higher end. Alternatively, the AP 102 may have scheduled the HEW device 104.1 on the lower end so as to permit HEW device 104.4 to be scheduled on the higher end of channel 276, where HEW device 104.4 may have more tones than on the lower end of the channel 276.
The method 1300 continues at time 1356 with the HEW devices 104 transmitting in the uplink according to the SCHs 1304.3, 1304.4. HEW devices 104.1, 104.2, 104.3, and 104.4 interpret the SCH 1304.3, and each transmits on a 5 MHz band in channel 276 according to the SCH 1304.3. HEW device 104.5 interprets the SCH 1304.4, and transmits on the entire 20 MHz on channel 274 according to the SCH 1304.4. In example embodiments, the HEW devices 104 interpret the SCHs 1304.3, 1304.4 based on their operation bandwidth.
In example embodiments, the AP 102 and HEW devices 104 may interpret the schedules differently depending on whether there is more than one active spatial stream. In example embodiments, the AP 102 and HEW devices 104 interpret the type differently if there are multiple active spatial streams on the channel. In example embodiments, the schedule may be limited to four HEW devices 104 or STAs. In example embodiments, the type 402 (FIG. 4) includes an indication of whether the allocation is for a single stream or multiple streams.
FIG. 14 illustrates a schedule type table 1400 for indicating a schedule type in OFDMA, according to example embodiments. Table 1400 has three columns: a schedule type 1402, an allocation 1404, and a number of spatial streams 1406. The schedule type 1402 indicates the allocation 1404 to the HEW devices 104 for a 20 MHz channel. Schedule A indicates that one STA is allocated the entire 20 MHz schedule per spatial stream 1406. Schedule A may indicate a number of STAs where each STA receives one or more 20 MHz allocation of an entire spatial stream. In example embodiments, the number of STAs may be limited to four in the schedule. Schedule B indicates that two STAs are each allocated 10 MHz of one or more spatial streams of the 20 MHz channel. Schedule B may indicate two pairs of STAs, in which case each pair of STAs is allocated one or more spatial streams of the 20 MHz channel and each pair of STAs are each allocated 10 MHz of the spatial stream. In example embodiments, schedule A and schedule B may be mixed. For example, four STAs may be indicated in the schedule type, and there may be four active spatial streams. Two STAs may each be allocated the entire 20 MHz channel of a spatial stream, and two other STAs may be allocated 10 MHz in each of two spatial streams.
Schedule C indicates that 2 STAs are each allocated 5 MHz and one STA is allocated 10 MHz of the 20 MHz channel. Schedule D indicates that four STAs each receive 5 MHz of the 20 MHz channel. Schedule C and D may only be valid for one spatial stream. The schedule type 1402 may be represented by bits in a packet as described herein. The STAs may be represented by an AID that includes an address that uniquely identifies the STA within the BSS 100 (see FIG. 1). The HEW devices 104 may be STAs. In example embodiments, the schedule type may be represented by 2 bits. One skilled in the art will recognize that the schedule types 1402 can correspond to different allocations 1404. One skilled in the art will recognize that the schedule types 1402 may be extended to divide the channel into smaller bandwidths such as 2.5 MHz and 1.25 MHz, or extended to use one or more schedule types 1402 for different spatial streams. In some embodiments, a packet similar to SCH 400 may be used for indicating the schedule according to table 1400. In some embodiments, a fixed sized packet with a type similar to the SCH 1500 may be used for indicating the schedule according to table 1400.
In example embodiments, the AP 102 and HEW devices 104 may interpret the schedules differently depending on whether there is more than one active spatial stream. In example embodiments, the AP 102 and HEW devices 104 interpret the type differently if there are multiple active spatial streams on the channel. In example embodiments, the schedule may be limited to four HEW devices 104 or STAs. In example embodiments, the type 402 includes an indication of whether the allocation is for a single stream or multiple streams.
Illustrated in FIG. 15 is a fixed-length schedule 1500 with a type 1502 and fixed length STA AID list 1504. The type 1502 may be as described in relation to FIG. 3, 12, or 14. The STA AID list 1504 may be a STA AID list where the number of STA AIDs in the list is a fixed number of STAs, which may be, for example, four STAs.
FIG. 16 illustrates a HEW device, in accordance with some embodiments. HEW device 1600 may be an HEW compliant device that may be arranged to communicate with one or more other HEW devices, such as HEW devices 104 (FIG. 1), or AP 102 (FIG. 1), as well as communicate with legacy devices 106 (FIG. 1). HEW devices 104 and legacy devices 106 may also be referred to as HEW STAs and legacy STAs, respectively. HEW device 600 may be suitable for operating as AP 102 (FIG. 1) or an HEW device 104 (FIG. 1). In accordance with embodiments, HEW device 1600 may include, among other things, a transmit/receive element (for example an antenna) 1601, a transceiver 1602, PHY 1604 circuitry, and MAC 1606 circuitry. PHY 1604 and MAC 1606 may be HEW compliant layers and may also be compliant with one or more legacy IEEE 802.11 standards. MAC 1606 may be arranged to configure PHY layer convergence procedure (PLCP) protocol data units (PPDUs) and arranged to transmit and receive PPDUs, among other things. HEW device 1600 may also include other hardware processing circuitry 1608, and memory 1610 may be configured to perform the various operations described herein. The processing circuitry 1608 may be coupled to the transceiver 1602, which may be coupled to the transmit/receive element 1601. While FIG. 16 depicts the processing circuitry 1608 and the transceiver 1602 as separate components, the processing circuitry 1608 and the transceiver 1602 may be integrated together in an electronic package or chip.
In example embodiments, the HEW device 104 is configured to perform one or more of the functions and/or methods described herein such as the methods, apparatuses, and functions described in conjunction with FIGS. 2 through 15; and in particular to schedules 400, 500, 600, 700, 800, 900, 1000, 1100, and 1500; and to descriptions of schedule types 300, 1200, and 1400.
The PHY 1604 may be arranged to transmit the HEW PPDU. The PHY 1604 may include circuitry for modulation/demodulation, upconversion/downconversion, filtering, amplification, and the like. In some embodiments, the hardware processing circuitry 1608 may include one or more processors. The hardware processing circuitry 1608 may be configured to perform functions based on instructions being stored in a RAM or ROM, or based on special purpose circuitry. In some embodiments, the hardware processing circuitry 1608 may be configured to perform one or more of the functions described herein for sending and receiving schedules.
In some embodiments, two or more antennas may be coupled to the PHY 1604 and arranged for sending and receiving signals including transmission of the HEW packets. The HEW device 1600 may include a transceiver 1602 to transmit and receive data such as HEW PPDU and packets that include an indication that the HEW device 1600 should adapt the channel contention settings according to settings included in the packet. The memory 1610 may store information for configuring the other circuitry to perform operations for configuring and transmitting BAR and BA packets and performing the various operations described herein including sending and responding to BARs and BAs.
In some embodiments, the HEW device 1600 may be configured to communicate using OFDM communication signals over a multicarrier communication channel. In some embodiments, HEW device 1600 may be configured to communicate in accordance with one or more specific communication standards, such as the IEEE standards including IEEE 802.11-2012, 802.11n-2009, 802.11ac-2013, 802.11ax, standards and/or proposed specifications for WLANs, although the scope of the example embodiments is not limited in this respect as they may also be suitable to transmit and/or receive communications in accordance with other techniques and standards. In some embodiments, the HEW device 1600 may use 4× symbol duration of 802.11n or 802.11ac.
In some embodiments, a HEW device 1600 may be part of a portable wireless communication device, such as a personal digital assistant (PDA), a laptop or portable computer with wireless communication capability, a web tablet, a wireless telephone, a smartphone, a wireless headset, a pager, an instant messaging device, a digital camera, an access point, a television, a medical device (e.g., a heart rate monitor, a blood pressure monitor, etc.), an AP, a base station, a transmit/receive device for a wireless standard such as 802.11 or 802.16, or other device that may receive and/or transmit information wirelessly. In some embodiments, the mobile device may include one or more of a keyboard, a display, a non-volatile memory port, multiple antennas, a graphics processor, an application processor, speakers, and other mobile device elements. The display may be an liquid crystal display (LCD) screen including a touch screen.
The transmit/receive element 1601 may comprise one or more directional or omnidirectional antennas, including, for example, dipole antennas, monopole antennas, patch antennas, loop antennas, microstrip antennas or other types of antennas suitable for transmission of radio-frequency (RF) signals. In some MIMO embodiments, the antennas may be effectively separated to take advantage of spatial diversity and the different channel characteristics that may result.
Although the device 1600 is illustrated as having several separate functional elements, one or more of the functional elements may be combined and may be implemented by combinations of software-configured elements, such as processing elements including digital signal processors (DSPs), and/or other hardware elements. For example, some elements may comprise one or more microprocessors, DSPs, field-programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), radio-frequency integrated circuits (RFICs) and combinations of various hardware and logic circuitry for performing at least the functions described herein. In some embodiments, the functional elements may refer to one or more processes operating on one or more processing elements.
Example embodiments have the technical effect of increasing the efficiency of the wireless medium as disclosed in conjunction with FIGS. 1-16. The HEW device 104, thus, may increase both the throughput of the HEW device 104 and the throughput of other HEW devices 104 and/or legacy devices 106, and may decrease the delay time.
Embodiments may be implemented in one or a combination of hardware, firmware and software. Embodiments may also be implemented as instructions stored on a computer-readable storage device, which may be read and executed by at least one processor to perform the operations described herein. A computer-readable storage device may include any non-transitory mechanism for storing information in a form readable by a machine (e.g., a computer). For example, a computer-readable storage device may include ROM, RAM, magnetic disk storage media, optical storage media, flash-memory devices, and other storage devices and media. Some embodiments may include one or more processors and may be configured with instructions stored on a computer-readable storage device.
Example embodiments have the technical effect of improving efficiency by providing a low-overhead schedule for the channels during a multi-user OFDMA up-link period.
Example embodiments have the technical effect of improving efficiency by sending a separate schedule for the channel in each channel rather than sending a combined schedule.
The following examples pertain to further embodiments. Example 1 is a wireless communication device comprising circuitry. The circuitry to: determine a plurality of schedules for each of a plurality of channels for an orthogonal frequency division multiple access (OFDMA) communication in a wireless local-area network (WLAN), wherein each of the plurality of schedules comprise a frequency allocation for one or more communication devices; and transmit the schedule of the one or more schedules on the corresponding channel of the plurality of channels.
In Example 2, the subject matter of Example 1 can optionally include where the circuitry is further to: transmit the corresponding schedule of the one or more schedules on the corresponding channel of the plurality of channels as a portion of a signal field frame.
In Example 3, the subject matter of Examples 1 or 2 can optionally include where a number of user association identifications (AIDs) in a user AID list is based on the schedule type.
In Example 4, the subject matter of any of Examples 1-3 can optionally include where the number of user AIDs is limited to at most four; and wherein a smallest bandwidth allocation is 5 mega-Hertz (MHz).
In Example 5, the subject matter of any of Examples 1-4 can optionally include where the schedule type further indicates the schedule for each of one or more spatial streams associated with the each of the plurality of channels.
In Example 6, the subject matter of any of Examples 1-5 can optionally include where each of the plurality of schedules comprises a fixed number of user association identifications (AIDs), and a bandwidth allocation is indicated by a position of each of the AIDs of the fixed number of AIDs.
In Example 7, the subject matter of Example 6 can optionally include where each of the plurality of schedules is a schedule for each of the plurality of channels and for each of one or more spatial streams associated with the each of the plurality of channels.
In Example 8, the subject matter of any of Examples 1-7 can optionally include wherein the circuitry is further configured to: transmit the corresponding schedule of the one or more schedules on each of the one or more channels in accordance with 802.11ax.
In Example 9, the subject matter of any of Examples 1-8 can optionally include where each of the plurality of schedules comprises a schedule type and a user association identification (AID) list.
In Example 10, the subject matter of any of Examples 1-9 can optionally include where the circuitry is further to: determine the plurality of schedules for each of the plurality of channels based at least on an operation bandwidth of the one or more wireless communication devices.
In Example 11, the subject matter of any of Examples 1-10 can optionally include where the communication is a transmit opportunity (TXOP).
In Example 12, the subject matter of any of Examples 1-11 can optionally include wherein each of the plurality of schedules comprises a fixed number of user association identifications (AIDs) and a type that indicates a bandwidth allocation for each of the one or more wireless communication devices.
In Example 13, the subject matter of any of Examples 1-12 can optionally include memory and a transceiver coupled to the circuitry.
In Example 14, the subject matter of Example 13 can optionally include one or more antennas coupled to the transceiver.
Example 15 is a method for multi-user scheduling performed on a high-efficiency wireless local-area network (HEW) device. The method may include determining a plurality of schedules for each of a plurality of channels for an orthogonal frequency division multiple access (OFDMA) communication in a wireless local-area network (WLAN), wherein each of the plurality of schedules comprise a frequency allocation for one or more communication devices; and transmitting the schedule of the one or more schedules on the corresponding channel of the one or more channels.
In Example 16, the subject matter of Example 15 can optionally include where the transmitting the corresponding schedule further comprises:
transmitting the schedule of the one or more schedules on the corresponding channel of the one or more channels as a portion of a signal field frame.
In Example 17, the subject matter of Examples 15 or 16 can optionally include where each of the plurality of schedules comprises a schedule type and a user association identification (AID) list.
In Example 18, the subject matter of any of Examples 15-17 can optionally include where each of the plurality of schedules comprises a fixed number of user association identifications (AIDs), and a bandwidth allocation is indicated by a position of each of the AIDs of the fixed number of AIDs.
Example 19 is a wireless communication device comprising processing circuitry to: receive a plurality of schedules, one for each of a plurality of channels for an orthogonal frequency division multiple access (OFDMA) communication in a wireless local-area network (WLAN), wherein each of the plurality of schedules comprises a frequency allocation for one of the plurality of channels for a transmit opportunity (TXOP); determine if the frequency allocation of each of the plurality of schedules indicates that the wireless communication device received the frequency allocation; and transmit simultaneously on each of the plurality of channels where the frequency allocation indicates that the wireless communication device received at least a portion of the frequency allocation.
In Example 20, the subject matter of Example 19 can optionally include where each of the plurality of schedules comprises a schedule type and a user association identification (AID) list.
In Example 21, the subject matter of Example 20 can optionally include where a number of user AIDs in the user AID list is based on the schedule type.
In Example 22, the subject matter of Example 21 can optionally include where the schedule type further indicates the schedule for each of one or more spatial streams associated with the each of the plurality of channels.
In Example 23, the subject matter of Examples 19 or 20 can optionally include where each of the plurality of schedules comprises a fixed number of user association identifications (AIDs), and the bandwidth allocation is indicated by a position of each of the AIDs of the fixed number of AIDs.
Example 24 is a non-transitory computer-readable storage medium that stores instructions for execution by one or more processors to perform operations for high-efficiency Wi-Fi (HEW). The instructions to configure the one or more processors to: determine a plurality of schedules for each of a plurality of channels for an orthogonal frequency division multiple access (OFDMA) communication in a wireless local-area network (WLAN), wherein each of the plurality of schedules comprise a frequency allocation for one or more HEW devices; and transmit simultaneously the corresponding schedule of the one or more schedules on each of the one or more channel.
In Example 25, the subject matter of Example 24 can optionally include where each of the plurality of schedules comprises a schedule type and a user association identification (AID) list.
The Abstract is provided to comply with 37 C.F.R. Section 1.72(b) requiring an abstract that will allow the reader to ascertain the nature and gist of the technical disclosure. It is submitted with the understanding that it will not be used to limit or interpret the scope or meaning of the claims. The following claims are hereby incorporated into the detailed description, with each claim standing on its own as a separate embodiment.

## Claims

1. An apparatus of a high-efficiency (HE) access point (AP), the HE AP comprising: memory; and, processing circuitry coupled to the memory, the processing circuitry to:
determine a plurality of schedules for each of a plurality of channels for an orthogonal frequency division multiple access (OFDMA) communication in a wireless local-area network (WLAN), wherein each of the plurality of schedules comprise a frequency allocation for one or more HE stations, and an allocation for each of one or more spatial streams associated with the each of the plurality of channels; and
configure the HE AP to transmit the schedule of the one or more schedules on the corresponding channel of the plurality of channels.

2. The HE AP of claim 1, wherein the processing circuitry is further to:
transmit the corresponding schedule of the one or more schedules on the corresponding channel of the plurality of channels as a portion of a signal field frame.

3. The HE AP of claim 1, wherein a number of user association identifications (AIDs) in a user AID list is based on a schedule type.

4. The HE AP of claim 1, wherein the number of user AIDs is limited to at most four; and wherein a smallest bandwidth allocation is 5 mega-Hertz (MHz).

5. The HE AP of claim 1, wherein each of the plurality of schedules comprises a fixed number of user association identifications (AIDs), and a bandwidth allocation is indicated by a position of each of the AIDs of the fixed number of AIDs.

6. The HE AP of claim 5, wherein each of the plurality of schedules is a schedule for each of the plurality of channels and for each of one or more spatial streams associated with the each of the plurality of channels.

7. The HE AP of claim 1, wherein the processing circuitry is further configured to:
transmit the corresponding schedule of the one or more schedules on each of the one or more channels in accordance with 802.11ax.

8. The HE AP of claim 1, wherein each of the plurality of schedules comprises a schedule type and a user association identification (AID) list.

9. The HE AP of claim 1, wherein the circuitry is further to:
determine the plurality of schedules for each of the plurality of channels based at least on an operation bandwidth of the one or more wireless communication devices.

10. The HE AP of claim 1, wherein the communication is a transmit opportunity (TXOP).

11. The HE AP of claim 1, wherein each of the plurality of schedules comprises a fixed number of user association identifications (AIDs) and a type that indicates a bandwidth allocation for each of the one or more HE stations.

12. The HE AP of claim 1, the HE AP further comprising: transceiver circuitry coupled to the memory.

13. The HE AP of claim 12, further comprising one or more antennas coupled to the transceiver circuitry.

14. A method for multi-user scheduling performed on a high-efficiency (HE) access point (AP), the method comprising:
determining a plurality of schedules for each of a plurality of channels for an orthogonal frequency division multiple access (OFDMA) communication in a wireless local-area network (WLAN), wherein each of the plurality of schedules comprise a frequency allocation for one or more HE stations, and an allocation for each of one or more spatial streams associated with the each of the plurality of channels; and
configuring the HE AP to transmit the schedule of the one or more schedules on the corresponding channel of the plurality of channels.

15. The method of claim 14, wherein the transmitting the corresponding schedule further comprises:
transmitting the schedule of the one or more schedules on the corresponding channel of the one or more channels as a portion of a signal field frame.

16. The method of claim 14, wherein each of the plurality of schedules comprises a schedule type and a user association identification (AID) list.

17. The method of claim 14, wherein each of the plurality of schedules comprises a fixed number of user association identifications (AIDs), and a bandwidth allocation is indicated by a position of each of the AIDs of the fixed number of AIDs.

18. An apparatus of a high-efficiency (HE) station, the HE station comprising: memory; and, processing circuitry coupled to the memory, the processing circuitry configured to:
decode a plurality of schedules, one for each of a plurality of channels for an orthogonal frequency division multiple access (OFDMA) communication in a wireless local-area network (WLAN), wherein each of the plurality of schedules comprises a frequency allocation for one of the plurality of channels for a transmit opportunity (TXOP) and an allocation for each of one or more spatial streams associated with the each of the plurality of channels;
determine if the frequency allocation of each of the plurality of schedules indicates that the wireless communication device received the frequency allocation; and
configure the HE station to transmit simultaneously on each of the plurality of channels where the frequency allocation indicates that the wireless communication device received at least a portion of the frequency allocation.

19. The HE station of claim 18, wherein each of the plurality of schedules comprises a schedule type and a user association identification (AID) list.

20. The HE station of claim 19, wherein a number of user AIDs in the user AID list is based on the schedule type.

21. The HE station of claim 20, wherein the schedule type further indicates the schedule for each of one or more spatial streams associated with the each of the plurality of channels.

22. The HE station of claim 18, wherein each of the plurality of schedules comprises a fixed number of user association identifications (AIDs), and the bandwidth allocation is indicated by a position of each of the AIDs of the fixed number of AIDs.

23. A non-transitory computer-readable storage medium that stores instructions for execution by one or more processors, the instructions to configure the one or more processors to cause an apparatus of a high-efficiency (HE) access point (AP) to:
determine a plurality of schedules for each of a plurality of channels for an orthogonal frequency division multiple access (OFDMA) communication in a wireless local-area network (WLAN), wherein each of the plurality of schedules comprise a frequency allocation for one or more HE stations, and an allocation for each of one or more spatial streams associated with the each of the plurality of channels; and
configure the HE AP to transmit the schedule of the one or more schedules on the corresponding channel of the plurality of channels.

24. The non-transitory computer-readable storage medium of claim 23, wherein each of the plurality of schedules comprises a schedule type and a user association identification (AID) list.

25. An apparatus of a high-efficiency (HE) access point (AP), the HE AP comprising: memory; and, processing circuitry coupled to the memory, the processing circuitry to:
determine a plurality of schedules for each of a plurality of channels for an orthogonal frequency division multiple access (OFDMA) communication in a wireless local-area network (WLAN), wherein each of the plurality of schedules comprise a frequency allocation for one or more HE stations; and
configure the HE AP to transmit the schedule of the one or more schedules on the corresponding channel of the plurality of channel, wherein each of the plurality of schedules comprises a fixed number of user association identifications (AIDs), wherein a bandwidth allocation is indicated by a position of each of the AIDs of the fixed number of AIDs, and wherein each of the plurality of schedules is a schedule for each of the plurality of channels and for each of one or more spatial streams associated with the each of the plurality of channels.

26. The HE AP of claim 25, the HE AP further comprising: transceiver circuitry coupled to the memory; and, one or more antennas coupled to the transceiver circuitry.