CN116233936A - First multi-link device and method for switching operation mode thereof - Google Patents

Abstract

The present application relates to a first multilink device and a method of switching operation modes thereof. A method for switching operation modes of a first multi-link device includes establishing multiple links between the first multi-link device and a second multi-link device, and the first multi-link device determining to receive multiple streams via one of the multiple links or via the multiple links according to channel conditions.

Description

First multi-link device and method for switching operation mode thereof

Technical Field

The present invention relates to wireless networks, and more particularly, to a multi-link device and a method for switching operation modes thereof.

Background

The IEEE 802.11be protocol is a new generation Wi-Fi 7 radio access technology, supporting multi-link multi-radio (MLMR), 320MHz bandwidth (bandwidth), 4096 quadrature amplitude modulation (Quadrature Amplitude Modulation, QAM), 16 spatial streams (spatial streams), thereby achieving high transmission rate (speed rate), high throughput (throughput), and low latency (low latency) effects.

Disclosure of Invention

The embodiment of the invention provides a method for switching operation modes of a first multi-link device, which comprises the steps of establishing a plurality of links between the first multi-link device and a second multi-link device, and judging whether to receive a plurality of streaming through one of the links or through the links by the first multi-link device according to channel conditions.

Another embodiment of the present invention provides a first multi-link device comprising a plurality of wireless circuits and a processor. The plurality of wireless circuits are configured to establish a plurality of links with a second multi-link device. The processor is coupled to the wireless circuits for determining whether to receive the plurality of streams via one of the plurality of links or via the plurality of links according to the channel condition.

Drawings

Fig. 1 is a schematic diagram of a multi-link communication system according to an embodiment of the present invention.

Fig. 2 is a schematic diagram of a transmission sequence of the synchronous transceiving mode.

Fig. 3 is a schematic diagram of a transmission sequence of the asynchronous receiving and transmitting mode.

Fig. 4 is a schematic diagram of a transmission sequence of a multilink single radio circuit mode.

Fig. 5 is a block diagram of the non-ap multi-link device of fig. 1.

Fig. 6 is a flow chart of a method of switching operation modes of the non-ap multi-link device of fig. 1.

Detailed Description

Fig. 1 is a schematic diagram of a multi-link communication system 1 according to an embodiment of the present invention. The multilink communication system 1 includes an access point multilink device (access point multi-link device, AP-MLD) 10 and a non-access point multilink device (non-access point multi-link device, non-AP-MLD) 12. The multilink communication system 1 is compatible with IEEE 802.11 protocols, such as IEEE 802.11be protocols.

The AP-multilink device 10 includes APs 101 and 102, and the non-AP-multilink device 12 includes stations 121 and 122. Access points 101 and 102, and stations 121 and 122 may be logical devices and may be implemented in hardware, software, firmware, or a combination thereof. Links 141 and 142 may be established between the ap-multilink device 10 and the non-ap-multilink device 12. For example, ap 101 may communicate with station 121 via link 141 and ap 102 may communicate with station 122 via link 142. The non-ap multi-link device 12 may include 2 sets of complete (full function) radio circuits, and thus may support enhanced multi-link multi-radio (EMLMR) modes, and may switch between multiple modes of operation, such as between a baseline (baseline) mode and a gain (enhanced) mode, depending on channel conditions. The baseline mode may also be referred to as a multi-link multi-radio (MLMR) mode, and the gain mode may also be referred to as an EMLMR mode. The 2 sets of radio circuits of the non-ap multi-link device 12 may be used for 2 data transmissions in the same or different frequency bands, respectively. For example, 2 frequency bands may include channels of 2.4GHz and 5 GHz. In another example, 2 frequency bands may include channels of 5GHz and 6 GHz. When the EMLMR mode is enabled, the non-ap-multilink device 12 may communicate with the ap-multilink device 10 in the gain mode; when the EMLMR mode is disabled, the non-ap multi-link device 12 may communicate with the ap multi-link device 10 in the baseline mode. In baseline mode, non-ap-multilink device 12 may transmit simultaneously over both links 141 and 142 and ap-multilink device 10 using 2 sets of radio circuits, N spatial streams (nss=n) may be transmitted over link 141, N spatial streams (nss=n) may be transmitted over link 142, N being greater than or equal to 1; in gain mode, the non-ap-multilink device 12 may transmit via one of the links 141 and 142 and the ap-multilink device 10 using 1 set of radio circuits, and 2N spatial streams (nss=2n) may be transmitted on one of the links 141 and 142, improving throughput (throughput) by adjusting the spatial stream number of the links (nss=2n). In the baseline mode, the non-ap multi-link device 12 may operate in a synchronized transceiving (simultaneous transmit and receive, STR) mode or a non-simultaneous transmit and receive, NSTR) mode. In gain mode, the non-ap multi-link device 12 may operate in EMLMR mode. When the non-ap-multilink device 12 includes only 1 set (single-function) of radio circuits, referred to as multi-link single-radio (MLSR), 2N spatial streams can be transmitted over one of the links 141 and 142 and the ap-multilink device 10 via an enhanced multi-link single-radio (EMLSR) mode, although no simultaneous transmission is possible via both links 141 and 142 using N spatial streams and the ap-multilink device 10. Since the multilink single radio circuit can only transmit in EMLSR mode, there is no switching of operation modes. Fig. 2 to 4 are schematic diagrams showing transmission sequences of STR mode of the multi-link multi-radio circuit, mode of the multi-link multi-radio circuit NSTR, and gain mode of the multi-link multi-radio circuit, respectively. As will be described in detail in subsequent paragraphs.

Fig. 2 is a schematic diagram of a transmission sequence of an STR mode of a baseline mode of a multi-link multi-radio circuit. When the channel spacing (channel spacing) of the 2 radio channels of the non-ap-multilink device 12 is large, such as the channels operating at 2.4G and 5G respectively, the transmissions on links 141 and 142 do not interfere with each other, so that the non-ap-multilink device 12 can use STR mode for transmissions with the ap-multilink device 10. In STR mode, the non-ap multi-link device 12 uses 2 sets of radio circuits to transmit via links 141 and 142, and Channel accesses (Channel accesses) on links 141 and 142 operate independently of each other, and uplink and downlink transmissions on links 141 and 142 need not be synchronized. For example, in fig. 2, downlink 200 and uplink 202 may be performed on link 141, while downlink 220 may be performed on link 142.

Fig. 3 is a schematic diagram of a transmission sequence of the NSTR mode of the baseline mode of the multi-link multi-radio circuit. When the separation of the channels of the 2 radio circuits of the non-ap-multilink device 12 is insufficient, such as the channels operating in 5G and 6G, respectively, the transmissions on the links 141 and 142 may interfere with each other, so that the non-ap-multilink device 12 can use the NSTR mode for transmission with the ap-multilink device 10. In NSTR mode, the non-AP multi-link device 12 uses 2 sets of radio circuits to transmit via links 141 and 142, and if one of the links 141 and 142 is in the transmit packet phase, the other will not receive packets, so that the links 141 and 142 must transmit either simultaneously or simultaneously. In addition, to avoid coexistence interference (in-device coexistence interference) between links 141 and 142, the uplink and downlink transmissions of links 141 and 142 need to be synchronized and conform to the physical layer protocol data unit end time alignment (physical protocol data unit (PPDU) end time alignment), the PPDU medium access start time synchronization (start time sync PPDU medium access), and the medium access recovery (medium access recovery) specified by the IEEE 802.11be protocol, which results in a lower throughput in the NSTR mode than in the STR mode. For example, in fig. 3, downlink transmission 300 on link 141 and downlink transmission 320 on link 142 may be synchronized, and uplink transmission 302 on link 141 and uplink transmission 322 on link 142 may be synchronized.

Fig. 4 is a schematic diagram of a transmission sequence of gain modes of the multi-link multi-radio circuit. In gain mode, each data transfer limit can only be performed on one of links 141 and 142. For example, in fig. 4, non-ap multi-link device 12 listens for information (400 and 420) on links 141 and 142 and first detects a request to send (MU-RTS) frame 402 on link 141 and prepares to receive data on link 141. When ready, the non-AP multi-link device 12 transmits a Clear To Send (CTS) frame 404 on link 141 and performs a receive radio chain switch 424 to switch the radio chain (radio chain) of link 142 to link 141. In response to the CTS404, the ap multilink device 10 transmits aggregate mac protocol data unit (aggregated media access control protocol data unit, AMPDU) frames 406 in 2N spatial streams over the link 141. After receiving the AMPDU frame 406, the non-ap multi-link device 12 transmits a block acknowledgement (black acknowledgement, BA) frame 408 on link 141 and performs a receive radio link switch 410 to switch the radio link of link 142 back to link 142, and the non-ap multi-link device 12 listens for information again on links 141 and 142 (412 and 426). The use of gain mode allows non-ap multi-link device 12 to transmit on one of links 141 and 142 using all available spatial streams (nss=2n), thereby improving overall throughput.

Fig. 5 is a block diagram of a non-ap multi-link device 12. The non-ap multilink device 12 includes a processor 52, radio circuits 541 and 542, and a timer 56. The processor 52 is coupled to the wireless circuit 541, the wireless circuit 542, and the timer 56.

The wireless circuits 541 and 542 may include respective antennas, transceivers and other radio frequency elements. Wireless circuitry 541 may establish link 141 with access point-multilink device 10 and wireless circuitry 542 may establish link 142 with access point-multilink device 10. Processor 52 may determine to receive multiple streams via one of links 141 and 142 or via links 141 and 142 based on channel conditions. When the channel condition is busy, the probability that links 141 and 142 may transmit simultaneously is reduced, so processor 52 determines to switch to gain mode to receive multiple spatial streams via one of links 141 and 142. When the channel condition is idle, the probability that links 141 and 142 may transmit simultaneously increases, so processor 52 determines to switch to baseline mode to receive multiple streams over links 141 and 142.

In some embodiments, the processor 52 may be configured to measure the period T _m Channel busy time T within and data transfer time T of non-ap multi-link device 12 _tx To generate a channel busy ratio (Channel Busy Ratio, CBR) for the non-ap multi-link device 12, thereby estimating channel conditions. The channel busy ratio CBR of the non-ap multi-link device 12 can be expressed as formula (1):

CBR＝(T _b +T _tx )/T _m formula (1)

Wherein T is _m The measurement time is;

T _b is the channel busy time; a kind of electronic device with high-pressure air-conditioning system

T _tx Is the data transfer time of the non-ap multilink device 12.

Channel busy time T _b May be obtained through physical carrier detection (physical carrier sense) or virtual carrier detection (virtual carrier sense). In physical carrier detection, the non-AP multi-link device 12 may detect whether the channel energy (channel power) exceeds a threshold (threshold) of CCA (Clear Channel Assessment), e.g., the threshold may be-82 dBm, and if so, the processor 52 may determine that the channel is busy and calculate the channel busy time T _b . In virtual carrier detection, the non-AP multi-link device 12 can monitor the value of the network allocation vector (Network Allocation Vector, NAV) in the RTS information, and the processor 52 can determine that the channel is busy and calculate the channel busy time T when the NAV is not 0 _b . When CBR approaches 1When the channel is busy or congestion is detected (channel congestion).

In other embodiments, the ap-multilink device 10 may broadcast beacon (beacon) frames with network load reports periodically, and the processor 52 of the non-ap-multilink device 12 may generate the channel busy rate cbr_obss of the overlapping service set (overlapping basic service set) based on the network load reports of the multilink communication system 1. Since other aps in the vicinity of the system 1 can transmit data simultaneously, the ap-multilink device 10 can collect traffic from other aps in the vicinity to generate network load reports. The network load report may be a Qload report, and the format of the Qload report is shown in table 1:

table 1

Wherein the element identification value represents a Qload report number;

the length represents the length of the Qload report;

the potential single AP traffic represents the longest media time (media time) allocated to the point-to-point multi-link device 10 within a predetermined time, e.g., 7 days;

the allocated single AP traffic represents the current media time allocated by the AP-multilink device 10, including the mean and standard deviation;

the allocated common traffic represents the allocated media time for all access points in the vicinity of the ap-multilink device 10, including the average mu _s Standard deviation sigma _s ；

The enhanced distributed channel access (enhanced distributed channel access, EDCA) factor represents the media time using the EDCA mechanism;

hybrid coordinated channel access (hybrid coordinated channel access, HCCA) peaks represent peak media times using the HCCA mechanism;

HCCA factor represents the media time using HCCA mechanism;

overlapping APs means the number of APs using the same channel;

the sharing policy represents a channel sharing policy used by the AP; a kind of electronic device with high-pressure air-conditioning system

The optional subelements represent other information.

In some embodiments, non-access point multilink device 12 may generate long-term channel busy ratio cbr_obss1 from EDCA factor and HCCA factor in the Qload report, as represented by equation (2):

cbr_obss1= (EDCA factor+hcca factor)/64 formula (2)

Where 64 corresponds to the decimal point accuracy of the EDCA factor and HCCA factor.

In other embodiments, the non-ap multi-link device 12 may generate a short-term channel busy ratio cbr_obss2 from the allocated common traffic in the Qload report, as represented by equation (3):

CBR_OBSS2＝μ _s +2σ _s formula (3)

Wherein mu _s Media time average value recorded by the assigned common flow field; a kind of electronic device with high-pressure air-conditioning system

σ _s The standard deviation of the media time recorded in the assigned common flow field.

When the long-term channel busy ratio cbr_obss1 or the short-term channel busy ratio cbr_obss2 approaches 1, it can be regarded as channel busy or channel congestion. Processor 52 may determine the channel condition based on the channel busy ratio CBR, the long term channel busy ratio cbr_obss1, and/or the short term channel busy ratio cbr_obss2 of non-ap multi-link device 12. Since the short-term channel busy ratio cbr_obss2 reflects the media time to which the overlapping service set was recently allocated, the accuracy of the short-term channel busy ratio cbr_obss2 is greater than the accuracy of the long-term channel busy ratio cbr_obss1.

In some embodiments, the non-access point multilink device 12 may set a timer 56 to periodically check channel conditions to determine whether to switch modes of operation. In some embodiments, if non-access point multi-link device 12 is to enter NSTR mode to perform NSTR operation, processor 52 determines to switch to gain mode to receive 2N spatial streams via one of links 141 and 142, since throughput in NSTR mode is low, improving throughput.

In this way, the non-access point multilink device 12 can switch modes of operation depending on channel conditions while compromising the flexibility of the multilink multiradio circuit and overall throughput.

Fig. 6 is a flow chart of a method 600 of switching modes of operation of the non-ap multilink device 12. The method 600 for switching operation modes includes steps S602 to S624, steps S602 to S608 are used for switching to the gain mode for data transmission after determining that the NSTR mode is to be used for transmission, steps S610 to S618 are used for determining that the data transmission is to be performed in the baseline mode or the gain mode according to the channel condition, and steps S620 to S624 are used for periodically determining the channel condition. Any reasonable modification or adjustment of the steps is within the scope of the present disclosure. The details of steps S602 to S624 are as follows:

step S602: the processor 52 sets up the multilink operation;

step S604: is processor 52 determining that asynchronous transceiving operations are to be performed? If yes, go to step S606; if not, go to step S610;

step S606: processor 52 sets the EMLMR mode to 1;

step S608: processor 52 determines whether a channel switch is required? If yes, go to step S602; if not, executing step S606;

step S610: processor 52 determines whether a network load report was received? If yes, go to step S612; if not, go to step S614;

step S612: is processor 52 determine that channel busy ratio cbr_obss exceeds a predetermined value α? If yes, go to step S616; if not, go to step S618;

step S614: is processor 52 determine that channel busy ratio cbr_obss exceeds a predetermined value β? If yes, go to step S616; if not, go to step S618;

step S616: the processor 52 sets the EMLMR mode to 1, jumping to step S620;

step S618: processor 52 sets the EMLMR mode to 0;

step S620: processor 52 resets timer 56;

step S622: processor 52 determines whether a channel switch is required? If yes, go to step S602; if not, go to step S624;

step S624: processor 52 determines whether timer 56 has expired? If yes, go to step S610; if not, go to step S622.

In step S602, the non-ap multi-link device 12 enters a multi-link operation setting, and the processor 52 sets the EMLMR mode to 0 to switch the non-ap multi-link device 12 to the baseline mode. In step S604, the processor 52 sets the operation mode of the non-ap multi-link device 12 to STR mode or NSTR mode according to the channel interval between the links 141 and 142. For example, when the channel spacing between links 141 and 142 is less than 1GHz, processor 52 sets the operating mode of non-access point multilink device 12 to NSTR mode; processor 52 sets the mode of operation of non-ap multi-link device 12 to STR mode when the channel spacing between links 141 and 142 exceeds 1 GHz. In step S606, if the operation mode is NSTR mode, the processor 52 sets the EMLMR mode to 1 to switch the non-ap multi-link device 12 to gain mode to receive 2N spatial streams via one of the links 141 and 142, thereby improving throughput. In step S608, if one of the wireless circuit 541 and the wireless circuit 542 detects the channel switch notification (channel switch announcement, CSA) information in the beacon, the processor 52 determines to switch channels. Returning to step S602 to cause the non-ap multi-link device 12 to reset the operation mode due to the channel change; if no CSA information is detected, the process returns to step S606 to continue to receive 2N spatial streams from one of links 141 and 142 in gain mode.

If the processor 52 sets the operation mode of the non-ap multi-link device 12 to the non-NSTR mode (i.e., STR mode) in step S604, the processor 52 further determines whether a network load report is received (step S610). If so, the processor 52 generates a channel busy rate cbr_obss for the overlapping service set according to the network load report, and estimates a channel condition according to the channel busy rate cbr_obss (step S612). The channel busy ratio cbr_obss may be a long-term channel busy ratio cbr_obss1 or a short-term channel busy ratio cbr_obss2. In some embodiments, processor 52 generates a short term channel busy ratio cbr_obss2 from the allocated common traffic in the Qload report to improve the accuracy of the channel busy ratio. In some embodiments, processor 52 may also use long-term channel busy ratio cbr_obss1 as the channel busy ratio cbr_obss for the overlapping service set. If the channel busy ratio cbr_obss exceeds a predetermined value α, indicating that the channel condition is busy; if the channel busy ratio cbr_obss is less than the predetermined value α, the channel status is idle. The predetermined value α may be a value between 0 and 1, for example the predetermined value α may be between 0.4 and 0.5.

If, at step S610, processor 52 determines that no network loading report has been received, a channel busy rate CBR for non-AP multi-link device 12 may be generated. If the channel busy ratio CBR exceeds a preset value beta, indicating that the channel condition is busy; if the channel busy ratio CBR is less than the predetermined value β, the channel condition is idle. The predetermined value β may be a value between 0 and 1, for example the predetermined value β may be between 0.4 and 0.5. The predetermined value α and the predetermined value β may be the same or different.

If the processor 52 determines that the channel condition is busy in step S612 or step S614, the EMLMR mode is set to 1 to switch the non-ap multi-link device 12 to the gain mode to receive 2N spatial streams over one of the links 141 and 142, thereby improving throughput (step S616). If the processor 52 determines that the channel condition is idle in step S612 or step S614, the EMLMR mode is set to 0 to switch the non-ap multi-link device 12 to the baseline mode to receive N spatial streams over each of the links 141 and 142 (step S618).

In step S620, the processor 52 resets the timer 56 to a predetermined time. The predetermined time may be greater than dot11QLoadReportIntervalDTIM defined in the 802.11be protocol. In step S622, if the wireless circuit 541 or the wireless circuit 542 detects CSA information in the beacon, the processor 52 determines to switch channels. Returning to step S602 to cause the non-ap multi-link device 12 to reset the operation mode due to the channel change; if no CSA information is detected, step S624 is continued to determine whether the timer 56 has expired. If the timer 56 has not expired, the processor 52 continues to determine whether to switch channels (step S622); if the timer 56 expires, the processor 52 sets the operation mode again according to the channel state (S610 to S618).

In steps S602, S606, S616 and S618, once the operation mode of the non-ap multi-link device 12 changes, for example, the EMLMR mode changes from 1 to 0, or from 0 to 1, the wireless circuit 541 and/or the wireless circuit 542 transmits an Enhanced multi-link (EML) Operating Mode Notification frame with the EMLMR mode setting to the ap multi-link device 10 via the links 141 and/or 142 to notify the ap multi-link device 10 to change its transmission mode.

Although the non-ap-multilink device 12 in the embodiments of fig. 1-6 only includes 2 sets of radio circuits and establishes 2 links, the non-ap-multilink device 12 may also include more sets of radio circuits and establish more links, and those skilled in the art may determine whether the non-ap-multilink device 12 is to receive streams over one of the links or over multiple links based on channel conditions based on the spirit of the present invention. Although non-ap multi-link device 12 in the present embodiment transmits N spatial streams for each of links 141 and 142 in baseline mode, in some embodiments the spatial streams on links 141 and 142 may not be equal, e.g., N1 spatial streams may be transmitted on link 141, N2 spatial streams may be transmitted on link 142, and one of links 141 and 142 may transmit (n1+n2) spatial streams in gain mode. In addition, although the embodiments of the present invention use only downlink transmission, those skilled in the art can apply the present invention to uplink transmission based on the spirit of the present invention.

The non-ap multilink device 12 switches between baseline and gain modes depending on channel conditions while compromising the flexibility of the multilink and overall throughput.

The foregoing description is only of the preferred embodiments of the invention, and all changes and modifications that come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

[ symbolic description ]

1: multilink communication system

10: access point multilink device

101 and 102: access point

12: non-access point multilink device

121, 122: site(s)

141 and 142 links

200,142,300,320: downlink transmission

202,302,322: uplink transmission

400,412,420,426: listening to information

402 to 408: frame for communication

410,424: receiving radio link handover

52: processor and method for controlling the same

541, 542: wireless circuit

56: time-piece

600: method for switching operation modes

S602 to S624: and (3) step (c).

Claims (10)

1. A method of switching modes of operation of a first multilink device, comprising:

establishing a plurality of links between the first multi-link device and a second multi-link device; a kind of electronic device with high-pressure air-conditioning system

The first multi-link device determines whether to receive a plurality of streams via one of the plurality of links or via the plurality of links according to a channel condition.

2. The method of claim 1, wherein the first multi-link device determining to receive a plurality of the streams via one of the links or via a plurality of the links according to the channel condition comprises: when the channel condition is busy, the first multi-link device determines to receive a plurality of the streams via one of the links.

3. The method of claim 1, wherein the first multi-link device determining to receive a plurality of the streams via one of the links or via a plurality of the links according to the channel condition comprises: when the channel condition is idle, the first multi-link device determines to receive a plurality of the streams via a plurality of the links.

4. The method of claim 1, further comprising:

if the first multi-link device is to perform an asynchronous transceiving operation, it is determined to receive a plurality of the streams via one of the plurality of links.

5. The method of claim 1, further comprising:

the first multi-link device estimates the channel condition according to a channel busy time in a measurement period and a data transmission time of the first multi-link device.

6. The method of claim 1, further comprising:

the first multilink device receiving a network load report from the second multilink device; a kind of electronic device with high-pressure air-conditioning system

The first multi-link device estimates the channel condition based on the network load report.

7. A first multilink device comprising:

a plurality of wireless circuits for establishing a plurality of links with a second multi-link device; a kind of electronic device with high-pressure air-conditioning system

The processor is coupled to the wireless circuits and used for judging whether to receive a plurality of streams through one of the links or through the links according to a channel condition.

8. The first multi-link device of claim 7, wherein the processor determines to receive a plurality of the streams via one of the links when the channel condition is busy.

9. The first multi-link device of claim 7, wherein when the channel condition is idle, the processor determines to receive a plurality of the streams via a plurality of the links.

10. The first multilink device of claim 7, wherein:

if the first multilink device is to perform an asynchronous transceiving operation, the processor further determines to receive a plurality of the streams via one of the links.

Images