DETAILED ACTION
This Office Action is in response to the Applicants' communication filed on February 23, 2026. Claims 1, 8 and 14 are amended. Claims 1-20 are currently pending and have been examined.
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Response to Arguments
Applicant’s arguments/remarks made in an amendment filed February 23, 2026, have been fully considered and is not persuasive. Applicant argues on pages 12-14 that prior art, U.S. Publication No. 2022/0418018 ("Jang") does not teach or suggest determine that the primary link is experiencing degradation and, in response to determining that the primary link is experiencing degradation, effect a change in the primary link designation. Further, U.S. Publication No. 2021/0409979 ("Wang"), U.S. Publication No. 2022/0287121 ("Hwang") and Broadcom, Inc., "CR-CID-5672-dynamicNSTRbitmap", IEEE 802.11-21 /1547r0, 19 September 2021 ("Fischer") do not cure the above-identified deficiencies of Jang. Applicant further argues that the amended feature “where the MLD capabilities subfield includes a New Primary Link ID field indicating a link ID of the new primary link” is not disclosed or suggested by Hwang. Examiner respectfully disagrees as also can be seen from the detailed office action.
WANG discloses determine that the primary link is experiencing degradation; and in response to determining that the primary link is experiencing degradation and after verification by the associated non-AP MLD at a predetermined time, effect a change in the primary link designation (Fig. 7-10, [0012], “In some examples, the notification frame includes at least one of a notification that the quality of the primary link is below the threshold”. [0040], “In some examples of this disclosure, and as discussed in more detail below, if the quality of link 150a deteriorates, AP MLD 110 and non-AP MLD 120a can quickly switch the low latency communication to a different link (e.g., link 150b) that has a better quality”. [0044], “Since AP MLD 110 and non-AP MLD 120a had established link 150b as the backup link for the notification frame, switching the communication from link 150a to link 150c is fast due to the notification frame containing the information of using 150c as the new link , the link switch time is reduced, and the channel access time may be reduced” (verification by non-AP MLD to switch when quality deteriorates). [0078], “...after the backup link establishment, AP MLD 410 and non-AP MLD 420 commit to be available on the backup link during specific time to assist the data communication on the primary low latency link” (non-AP MLD commit to assist or second link available at a pre negotiated time at which the primary link can be switched when quality deteriorates). [0104], “Additionally, or alternatively, the power save agreement establishment can be negotiated after the initial link setup” (pre negotiated time to switch). [0106], “In some examples, STA 740a (or the non-AP MLD that includes STA 740b) sets power save schedule 711 of STA 740a (e.g., transceiver 540a on link 550a of FIG. 5A) based on power save schedule 701 of STA 740b (e.g., the transceiver configured to operate at the primary low latency link for example, transceiver 540b on link 550b) and possibly some other factors (verification by non AP-MLD). Power save schedule 711 of the STA 740a (e.g., transceiver 540a on link 550a of FIG. 5A) can include awake periods 713a and 713b and sleep or doze periods 715. Awake periods 713 are periods where STA 740a (e.g., the transceiver that operates at the backup link) is in an awake state and able to receive DL data from the AP (and is able to transmit uplink (UL) data to the AP) when the low latency communication occurs on the primary low latency link” (discloses a time to switch based on awake periods).
HWANG discloses where the MLD capabilities subfield includes a New Primary Link ID field indicating a link ID of the new primary link (Fig. 12, Fig. 23, Claim 23, “The operation method according to claim 20, wherein the information of the second link includes an identifier of the second link” (new link ID is included in the MLD subfield)).
Examiner’s note: The claim limitation in independent claims “effect a change in the primary link designation, or implement a channel change procedure to change a channel within the primary link...” makes it a broader interpretation. Limitation can be narrowed to bring out the distinction by selecting only the second option “implement a channel change procedure to change a channel within the primary link, wherein the predetermined time is indicated in an MLD capabilities subfield of a multi-link element as (i) a counter value or (ii) a multiple of a fixed pre-negotiated value, wherein the MLD capabilities subfield further includes a New Primary Link ID field indicating a link ID of the new primary link”.
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
Claims 1-20 are rejected under 35 U.S.C. 103 as being unpatentable over US 20220418018 A1 (JANG et al.)(hereinafter JANG) in view of US 20210409979 A1 (WANG et al.)(hereinafter WANG) and in further view of US 20220287121 A1 (HWANG et al.)(hereinafter HWANG).
In re claims 1, 8 and 14, JANG discloses a method for wireless communication performed by an access point (AP) multi- link device (MLD) ([0005], “A method performed by a transmitting multi-link device (MLD) in a wireless local area network (WLAN) system, wherein the transmitting MLD includes a first and a second stations (STAs), the first STA operates on a first link, and the second STA operates on a second link”), the multi-link device (MLD) comprising: access points (APs) forming a mobile AP MLD, each AP comprising a transceiver configured to form a link with a corresponding station (STA) associated with a non-AP MLD (Fig. 2, [0257], “When one STA supports multiple links, a transceiver supporting each link may operate as one logical STA. For example, one STA supporting two links may be expressed as one Multi Link Device (MLD) including a first STA for the first link and a second STA for the second link”); and a processor operably coupled to the APs (Fig. 1), the processor configured to: instruct the APs to form a first link and a second link with the corresponding STAs ([0257], “For example, one AP supporting two links may be expressed as one AP MLD including a first AP for a first link and a second AP for a second link. In addition, one non-AP supporting two links may be expressed as one non-AP MLD including a first STA for the first link and a second STA for the second link”); designate the first link as a primary link and the second link as a non-primary link ([0428], “It may be configured to perform channel access on the first and second links, wherein the first link is a primary link, and the second link is a non-primary link; defer transmission of a first physical protocol data unit (PPDU) in the second link based on a back-off counter (BC) of the second link being 0 and a BC of the first link being non-zero; and transmit the first PPDU to the second link on the basis that BCs of the first and second links are both 0”); determine that the primary link is experiencing degradation; and in response to determining that the primary link is experiencing degradation and after verification by the associated non-AP MLD at a predetermined time, effect a change in the primary link designation, or implement a channel change procedure to change a channel within the primary link, wherein the predetermined time is indicated in an MLD capabilities subfield of a multi-link element as (
PNG
media_image1.png
11
5
media_image1.png
Greyscale
) a counter value or (ii) a multiple of a fixed pre-negotiated value, wherein the MLD capabilities subfield further includes a New Primary Link ID field indicating a link ID of the new primary link.
JANG does not explicitly disclose determine that the primary link is experiencing degradation; and in response to determining that the primary link is experiencing degradation and after verification by the associated non-AP MLD at a predetermined time, effect a change in the primary link designation, wherein the predetermined time is indicated in an MLD capabilities subfield of a multi-link element as (
PNG
media_image1.png
11
5
media_image1.png
Greyscale
) a counter value or (ii) a multiple of a fixed pre-negotiated value, wherein the MLD capabilities subfield further includes a New Primary Link ID field indicating a link ID of the new primary link.
WANG discloses determine that the primary link is experiencing degradation; and in response to determining that the primary link is experiencing degradation and after verification by the associated non-AP MLD at a predetermined time, effect a change in the primary link designation (Fig. 7-10, [0012], “In some examples, the notification frame includes at least one of a notification that the quality of the primary link is below the threshold”. [0040], “In some examples of this disclosure, and as discussed in more detail below, if the quality of link 150a deteriorates, AP MLD 110 and non-AP MLD 120a can quickly switch the low latency communication to a different link (e.g., link 150b) that has a better quality”. [0044], “Since AP MLD 110 and non-AP MLD 120a had established link 150b as the backup link for the notification frame, switching the communication from link 150a to link 150c is fast due to the notification frame containing the information of using 150c as the new link , the link switch time is reduced, and the channel access time may be reduced” (verification by non-AP MLD to switch when quality deteriorates). [0078], “...after the backup link establishment, AP MLD 410 and non-AP MLD 420 commit to be available on the backup link during specific time to assist the data communication on the primary low latency link” (non-AP MLD commit to assist or second link available at a pre negotiated time at which the primary link can be switched when quality deteriorates). [0104], “Additionally, or alternatively, the power save agreement establishment can be negotiated after the initial link setup” (pre negotiated time to switch). [0106], “In some examples, STA 740a (or the non-AP MLD that includes STA 740b) sets power save schedule 711 of STA 740a (e.g., transceiver 540a on link 550a of FIG. 5A) based on power save schedule 701 of STA 740b (e.g., the transceiver configured to operate at the primary low latency link for example, transceiver 540b on link 550b) and possibly some other factors (verification by non AP-MLD). Power save schedule 711 of the STA 740a (e.g., transceiver 540a on link 550a of FIG. 5A) can include awake periods 713a and 713b and sleep or doze periods 715. Awake periods 713 are periods where STA 740a (e.g., the transceiver that operates at the backup link) is in an awake state and able to receive DL data from the AP (and is able to transmit uplink (UL) data to the AP) when the low latency communication occurs on the primary low latency link” (discloses a time to switch based on awake periods).
It would have been obvious for one of ordinary skill in the art before the effective filing date of the claimed invention to combine the teachings of JANG with WANG to facilitate a primary link changing procedure performed by a multi-link device (MLD) in a wireless local area network system. The advantage of doing so is by specifying the channel access method for other links in a non-STR MLD, collision between links of the non-STR MLD can be prevented and address the blindness issue of other links.
JANG and WANG do not explicitly disclose in response to determining that the primary link is experiencing degradation, implement a channel change procedure to change a channel within the primary link; and wherein the predetermined time for link change is indicated in an MLD capabilities subfield of a multi-link element as (
PNG
media_image1.png
11
5
media_image1.png
Greyscale
) a counter value or (ii) a multiple of a fixed pre-negotiated value, wherein the MLD capabilities subfield further includes a New Primary Link ID field indicating a link ID of the new primary link.
HWANG discloses in response to determining that the primary link is experiencing degradation, implement a channel change procedure to change a channel within the primary link, wherein the MLD capabilities subfield further includes a New Primary Link ID field indicating a link ID of the new primary link ([0142], “In addition, a STA or a STA MLD having a received signal strength indicator (RSSI) less than or greater than a value of a field to which a predetermined RSSI value is set may be designated as the communication node subjected to the link change”. [0143], “The reference value of the RSSI may be set differently according to a band in which the primary link to be moved operates. When the communication node moves to a frequency band lower than the currently operating band (e.g., when the communication node operates in the 6 GHz band and then moves to the 2.4 GHz band), a signal may be delivered smoothly to a wider area according to the frequency characteristics. Accordingly, the AP MLD may move STAs or STA MLDs having a poor reception signal state in the current 6 GHz band by designating them. That is, the AP MLD may instruct STAs having a poor reception signal state to move to the lower frequency band” (move or change the channel within the link based on degradation measured in terms of RSSI values)); and wherein the predetermined time for link change is indicated in an MLD capabilities subfield of a multi-link element as (
PNG
media_image1.png
11
5
media_image1.png
Greyscale
) a counter value or (ii) a multiple of a fixed pre-negotiated value (Fig. 19, [0177], “Referring to FIG. 16, the information element for multi-link operation may include an element ID field, a length field, an element ID extension field, a field indicating the number of links to be used, a primary link field, a secondary link field, a candidate link field, a link appliance timer field, a request result (i.e., result status code) field included in the response frame, a field indicating a request rejection reason (i.e., denial reason), and the like”. [0159], “The STA or STA MLD may perform a primary link change at the appliance time of the link information indicated in the EHT operation element”. [0168], “Through such the procedure, the capability elements (e.g., EHT capability elements including whether multi-link related functions are supported) of the STA MLD and the AP MLD may be exchanged. The STA MLD may receive an EHT operation element including multi-link related information from the AP MLD” (discloses a time for primary link change included in the MLD capability field). [0016], “configuring a first link as a primary link for multi-link transmission to a second communication node; transmitting to the second communication node a first frame including an indicator indicating to change the primary link from the first link to a second link; and transmitting a data frame to the second communication node on the second link”. [0019], “The first frame may further include information on a time at which the primary link is changed from the first link to the second link, and the data frame may be transmitted to the second communication node on the second link at the time at which the primary link is changed” (discloses a pre negotiated time at which the primary link is changed). [0077], “As shown in FIG. 3, an association procedure of a STA in an infrastructure BSS may be generally divided into a probe step of probing an AP, an authentication step for authentication with the probed AP, and an association step of associating with the authenticated AP” (verification by non-AP MLD). [0187], “In addition, the link appliance timer field may include information on a time at which the changed link is to be applied. In this case, the AP MLD may receive the request frame for multi-link operation including the corresponding information from the STA MLD. The AP MLD may transmit the response frame for multi-link operation according to the request frame including information indicating whether to approve or reject the request in the result status code field”. [0139], “When the AP MLD wants to change the primary link, the primary link through which the probe response frame, association response frame, reassociation response frame, or beacon frame is currently transmitted may be different from the primary link indicated by the corresponding field. In addition, a field of an appliance time for the link may include information on a time point for changing the primary link to the link indicated in the corresponding primary link field”. [0193], “the changed link information and the time at which the corresponding link information is to be applied may be transmitted as being included in the corresponding field” (discloses time point at which primary link is to be changed is included in the capability element field)), wherein the MLD capabilities subfield further includes a New Primary Link ID field indicating a link ID of the new primary link (Fig. 23, [0158], “A communication node receiving the trigger frame may be the STAs or STA MLDs subjected to the primary link change, which are included in the EHT operation element. In this case, since the association procedure may not be required for the corresponding STAs or STA MLDs, the AP MLD may transmit the trigger frame by including the AID used in the previous primary link in an AID subfield of the trigger frame”. Claim 23, “The operation method according to claim 20, wherein the information of the second link includes an identifier of the second link” (here the second link may be interpreted as new primary link)).
It would have been obvious for one of ordinary skill in the art before the effective filing date of the claimed invention to combine the teachings of JANG, WANG and HWANG to facilitate a primary link changing procedure performed by a multi-link device (MLD) in a wireless local area network system. The advantage of doing so is by specifying the channel access method for other links in a non-STR MLD, collision between links of the non-STR MLD can be prevented and address the blindness issue of other links.
In re claims 2, 9 and 15, the combination discloses the MLD of Claim 1, the method of claim 14 and the non-AP MLD of Claim 8, wherein HWANG discloses wherein in order to effect the change in the primary link designation: the processor is further configured to indicate, on the non-primary link, availability of the primary link designation, and a corresponding transceiver is further configured to transmit a frame, on the primary link, designating the non-primary link as the primary link and the primary link as the non-primary link ([0184], “Referring to Fig. 17, the information element for multi-link operation may include an element ID field, a length field, an element ID extension field, a field indicating whether or not to perform simultaneous transmission, a field indicating the number of links to be used, a primary link field, a plurality of secondary link fields, a link appliance timer field, a link appliance timeout field, a result status code field included in the response, a denial reason field, a beacon transmission time information field (i.e., beacon information field) transmitted on a changed link when the primary link is changed”. [0154], “The AP MLD may register AID information of the corresponding STA in the changed primary link. On the other hand, the AP MLD may delete the AID information used in the previous primary link, and allocate the deleted AID to another STA using the previous primary link”. [0152], “Referring to Fig. 13, when a primary link is changed through the EHT operation element, the AP MLD may determine the reassociation procedure does not need to be performed. In this case, the STA or STA MLD may transmit an arbitrary frame notifying that the primary link has been changed on the changed primary link after the appliance time of the designated link” (features of claim 2 are design options involving a simple modification of the existing system to communicate the availability of the primary link designation and to swap the designations of the links)).
In re claims 4, 11 and 17, the combination discloses the MLD of Claim 1, the method of claim 14 and the non-AP MLD of Claim 8, wherein HWANG discloses wherein: the primary link designation is changed by setting a bit corresponding to the primary link to 1 in a frame including a non-simultaneous transmit receive (NSTR) indication bitmap subfield of a per-STA profile sub element in a multi-link element, and the designation of the non-primary link as the primary link takes effect after the predetermined time ([0145], “...when the link change target STAs or STA MLDs are designated based on the RSSIs, a field for designating the targets based on the RSSI may include a field with a length of 1 bit indicating whether the change target STA or STA MLD is a STA or STA MLD having an RSSI greater than the predetermined RSSI and a field indicating the predetermined RSSI”. [0146], “For example, when the field with the length of 1 bit is set to 1, the AP MLD may instruct the STA or STA MLD having an RSSI greater than the value of the RSSI field to move to a channel of a designated band, that is, a link. When the field with the length of 1 bit is set to 0, the AP MLD may instruct the STA or STA MLD having an RSSI less than a minimum RSSI to move to a channel of a designated band, that is a link”. [0133], “The communication node may indicate the supported band by setting a bit corresponding to the supported band to ‘1’. The link switching delay may refer to the maximum time required for the STA to switch the link when the STA is instructed by the AP to change the link in use” (setting bit to 1 to change the primary link)).
In re claims 5, 12 and 18, the combination discloses the MLD of Claim 1, the method of claim 14 and the non-AP MLD of Claim 8, wherein HWANG discloses wherein: the change of the primary link designation is indicated using 1 bit in the MLD capabilities subfield of the multi-link element, the designation of the non-primary link as the primary link takes effect after the predetermined time, and the predetermined time is indicated in another MLD capabilities subfield of the multi-link element ([0226], “In this case, the activated link information field may be configured in a form in which IDs of the activated links are listed. As yet another exemplary embodiment, the activated link information field may be configured as a 1-byte bitmap field. In this case, when a link corresponding to a specific link ID is activated, a position of the bitmap corresponding to the link ID may be set to 1. In this case, a bit located at the frontmost place of the bitmap may indicate whether a link having a link ID of 0 is activated. For example, when links having link IDs 1, 4, and 6 are activated, the corresponding bitmap may be set to ‘01001010’”).
In re claims 6, 13 and 19, the combination discloses the MLD of Claim 1, the method of claim 14 and the non-AP MLD of Claim 8, wherein HWANG discloses wherein the processor is configured to receive, from the non- AP MLD, an acknowledgement to the change of the primary link designation ([0116], “The negotiation procedure for performing the multi-link operation may include a step in which the STA MLD transmits a request frame for multi-link operation to the AP MLD, and receives an ACK for the corresponding request frame from the AP MLD, and a step in which the AP MLD transmits a response frame for multi-link operation, and receives an ACK for the response frame from the STA MLD”. [0203], “Alternatively, a process for confirming the procedure for changing the primary link, in which the AP MLD transmits an unrequested AID response frame after the link appliance time and the STA MLD transmits an ACK frame to the AID response frame, and a process for allocating a new AID may be performed”).
In re claims 7 and 20, the combination discloses the MLD of claim 1 and the method of claim 14, wherein HWANG discloses wherein: to indicate the change of the primary link designation, a corresponding transceiver is configured to transmit a primary link change element, and the designation of the non-primary link as the primary link takes effect after the predetermined time indicated in the primary link change element ([0109], “In this case, a channel contention step may be performed on each link, and thus, a time point for transmitting a frame on each link may be different. That is, an operation of transmitting a frame may be performed on a link 1, and an operation of receiving a frame may be performed on a link 2”. [0110], “For example, the STA MLD may receive a data frame from the AP MLD on the link 2 while transmitting a response frame (e.g., an ACK frame for a data frame, a data frame that is a response to a trigger frame, etc.) for a received frame on the link 1”. [0148], “Referring to Fig. 12, after the association procedure between the STA MLD and the AP MLD is completed, if an indicator instructing to change a primary link is included in the EHT operation element of FIG. 11 included in the beacon frame, the STA or the STA MLD may change the primary link at the time indicated in the link appliance timer field of the EHT operation element”).
Claims 3, 10 and 16 are rejected under 35 U.S.C. 103 as being unpatentable over US 20220418018 A1 (JANG et al.)(hereinafter JANG) in view of US 20210409979 A1 (WANG et al.)(hereinafter WANG) in view of US 20220287121 A1 (HWANG et al.)(hereinafter HWANG) and in further view of MATTHEW FISCHER (BROADCOM INC): "CR-CID-5672-dynamic-NSTRbitmap", IEEE 802.11-21 /1547r0, 19 September 2021, pages 1-4 (hereinafter FISCHER).
In re claims 3, 10 and 16, the combination discloses the MLD of Claim 1, the method of claim 14 and the non-AP MLD of Claim 8, but does not explicitly disclose wherein a corresponding transceiver is configured to transmit a primary link designation indication in a frame including a non-simultaneous transmit receive (NSTR) indication bitmap subfield of a per-STA profile sub element in a multi-link element.
FISCHER discloses wherein a corresponding transceiver is configured to transmit a primary link designation indication in a frame including a non-simultaneous transmit receive (NSTR) indication bitmap subfield of a per-STA profile sub element in a multi-link element (page 3, “to indicate a change in the NSTR status of its links, a non-AP MLD may transmit an NSTR Update frame to a peer MLD containing a value in the NSTR Indication Bitmap field including Per-STA Profile sub element that differs from the most recently transmitted NSTR Indication Bitmap field value to that peer”).
It would have been obvious for one of ordinary skill in the art before the effective filing date of the claimed invention to combine the teachings of JANG, WANG and HWANG with FISCHER to facilitate a primary link changing procedure performed by a multi-link device (MLD) in a wireless local area network system. The advantage of doing so is that collision between links of the non-STR MLD can be prevented and address the blindness issue of other links.
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any extension fee pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the date of this final action.
Contact
Any inquiry concerning this communication or earlier communications from the examiner should be directed to SWATI JAIN whose telephone number is (571)270-0699. The examiner can normally be reached Mon - Fri (830 am - 530 pm).
Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Pan Yuwen can be reached on 571-272-7855. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000.
/SWATI JAIN/Examiner, Art Unit 2649 /YUWEN PAN/Supervisory Patent Examiner, Art Unit 2649