PATENT DOCUMENT

Publication Number: US-12022302-B2
Application Number: US-202318098044-A
Country: US
Kind Code: B2

Title: Technologies for measurement reporting in wireless communication system

Abstract:
A method for performing spatial sharing between an existing SP and a candidate SP includes transmitting a first measurement request to an STA involved in the candidate SP carrying measurement configuration information for measurement over primary tier 1 channel of a tier 2 channel. The measurement configuration information includes the method that is to be used for the requested measurement, the measurement start time, the measurement duration, the number of time blocks within the measurement duration, the number of concurrent measurements to be performed using plural RX antenna configurations, and the method for reporting results of plural concurrent measurements, wherein the duration of each time block is the same.

Claims:
What is claimed is: 
     
       1. A first apparatus comprising:
 storage media having a computer program; and 
 integrated circuitry coupled with the storage media to execute the computer program to:
 generate a measurement request message to be transmitted to a second apparatus, the measurement request message including a measurement report method subfield having a value to indicate a report method to be used with respect to a plurality of concurrent measurements, wherein the report method is a first method to report individual measurements of the plurality of concurrent measurements or a second method to report an average of the plurality of concurrent measurements; and 
 process a measurement report message received from the second apparatus, wherein the measurement report message is based at least on the plurality of concurrent measurements obtained by the second apparatus, and the plurality of concurrent measurements are based at least on signals the second apparatus received from a third apparatus. 
 
 
     
     
       2. The first apparatus of  claim 1 , wherein the integrated circuitry is to execute the computer program to:
 schedule a candidate service period to at least partially overlap with an existing service period based at least on the measurement report message, 
 wherein the candidate service period is for communications between the second apparatus and the third apparatus. 
 
     
     
       3. The first apparatus of  claim 1 , wherein the plurality of concurrent measurements are to be obtained based at least on signals received by a respective plurality of receive antenna configurations of the second apparatus. 
     
     
       4. The first apparatus of  claim 3 , wherein the plurality of concurrent measurements are to be obtained based at least on signals received by the respective plurality of receive antenna configurations of the second apparatus over a channel. 
     
     
       5. The first apparatus of  claim 4 , wherein the channel has a bandwidth of approximately 2.16 gigahertz. 
     
     
       6. The first apparatus of  claim 1 , wherein the plurality of concurrent measurements are to be obtained based at least on signals received by the second apparatus over a plurality of channels. 
     
     
       7. The first apparatus of  claim 6 , wherein one or more of the plurality of channels has a bandwidth of approximately 2.16 gigahertz. 
     
     
       8. The first apparatus of  claim 6 , wherein the measurement request message is to indicate the plurality of channels. 
     
     
       9. A method of operating a first apparatus, the method comprising:
 processing a measurement request message received from a second apparatus, the measurement request message including a measurement report method subfield having a value to indicate a report method to be used with respect to a plurality of concurrent measurements, wherein the report method is a first method to report individual measurements of the plurality of concurrent measurements or a second method to report an average of the plurality of concurrent measurements; 
 obtaining the plurality of concurrent measurements based at least on signals received from a third apparatus; and 
 generating a measurement report message based at least on the report method and the plurality of concurrent measurements. 
 
     
     
       10. The method of  claim 9 , further comprising:
 processing an indication of a service period scheduled for communications between the first apparatus and the third apparatus, wherein the service period is a candidate service period for communications between the first apparatus and the third apparatus that at least partially overlaps with an existing service period. 
 
     
     
       11. The method of  claim 9 , wherein the plurality of concurrent measurements are to be obtained based at least on signals received by a respective plurality of receive antenna configurations of the first apparatus. 
     
     
       12. The method of  claim 11 , wherein the plurality of concurrent measurements are to be obtained based at least on signals received by the respective plurality of receive antenna configurations of the first apparatus over a channel. 
     
     
       13. The method of  claim 12 , wherein the channel has a bandwidth of approximately 2.16 gigahertz. 
     
     
       14. The method of  claim 9 , wherein the plurality of concurrent measurements are to be obtained based at least on signals received by the first apparatus over a plurality of channels. 
     
     
       15. The method of  claim 14 , wherein one or more of the plurality of channels has a bandwidth of approximately 2.16 gigahertz. 
     
     
       16. The method of  claim 14 , wherein the measurement request message is to indicate the plurality of channels. 
     
     
       17. Non-transitory storage media having a computer program that, when executed, causes a first apparatus to:
 process a measurement request message received from a second apparatus, wherein the measurement request message includes a measurement report method subfield having a value to indicate a report method to be used with respect to a plurality of concurrent measurements, wherein the report method is a first method to report individual measurements of the plurality of concurrent measurements or a second method to report an average of the plurality of concurrent measurements; 
 obtain the plurality of concurrent measurements based at least on signals received from a third apparatus; and 
 generate a measurement report message based at least on the report method and the plurality of concurrent measurements. 
 
     
     
       18. The non-transitory storage media of  claim 17 , wherein the plurality of concurrent measurements are to be obtained based at least on signals received by a respective plurality of receive antenna configurations of the first apparatus over a channel with a bandwidth of approximately 2.16 gigahertz. 
     
     
       19. The non-transitory storage media of  claim 17 , wherein the plurality of concurrent measurements are to be obtained based at least on signals received by the first apparatus over a plurality of channels. 
     
     
       20. The non-transitory storage media of  claim 19 , wherein the measurement request message is to indicate the plurality of channels.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 16/934,855, filed Jul. 21, 2020, which is a continuation of U.S. patent application Ser. No. 15/945,498, filed Apr. 4, 2018, which is a continuation of U.S. patent application Ser. No. 14/920,751, filed Oct. 22, 2015, which claims priority to Japan Patent Application No. 2014-234374, filed Nov. 19, 2014, which are hereby incorporated by reference in their entireties for all purposes. 
    
    
     BACKGROUND 
     1. Technical Field 
     The present disclosure generally pertains to wireless communications and, more particularly, to a method for achieving spatial sharing in a directional wireless local area network (WLAN) system. 
     2. Description of the Related Art 
     Interest in unlicensed 60 GHz millimeter wave (mmW) networks is increasing. WirelessHD technology is the first 60 GHz mmW industry standard, which enables multi-gigabit wireless streaming of high-definition audio, video, and data among consumer electronics, personal computer, and portable products. Another multi-gigabit wireless communications technology operating over the 60 GHz mmW frequency band is Wireless Gigabit Alliance (WiGig) technology, which has been standardized by the Institute of Electrical and Electronic Engineers (IEEE) as the IEEE 802.11ad standard (see IEEE Std 802.11ad TM-2012, December 2012). 
     The WiGig technology supplements and extends the IEEE 802.11 media access control (MAC) layer and is backward compatible with the IEEE 802.11 WLAN standard. The WiGig MAC supports a centralized network architecture such as an infrastructure basic service set (BSS) or a personal BSS (PBSS), where the central coordinator, e.g., access point (AP) or personal BSS control point (PCP), transmits beacons to synchronize all stations (STAs) in the network. Rather than other IEEE 802.11 WLAN technologies operating over 2.4 GHz or 5 GHz frequency band, the WiGig technology makes extensive use of beamforming (BF) to achieve directional transmissions. 
     SUMMARY 
     In one general aspect, the techniques disclosed here feature a method for performing spatial sharing via PCP/AP between an existing SP and a candidate SP, the method including generating first measurement configuration information used for a first measurement request in the PCP/AP. The first measurement configuration information includes a first requested measurement, a first measurement start time, a first measurement duration, a first number of time blocks within the measurement duration, a first number of concurrent measurements to be performed using plural RX antenna configurations, and a first method for reporting results of plural concurrent measurements. The first measurement duration of each time block is the same. The method includes transmitting the first measurement request to an STA involved in the candidate SP carrying the first measurement configuration information for measurement over primary tier 1 channel of a tier 2 channel. 
     This invention can carry out most suitable SPSH using channel bonding and MIMO. 
     It should be noted that general or specific embodiments may be implemented as a system, a method, an integrated circuit, a computer program, a storage medium, or any selective combination thereof. 
     Additional benefits and advantages of the disclosed embodiments will become apparent from the specification and drawings. The benefits and/or advantages may be individually obtained by the various embodiments and features of the specification and drawings, which need not all be provided in order to obtain one or more of such benefits and/or advantages. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    shows a diagram illustrating an example single-tier channelization in the 60 GHz mmW frequency band; 
         FIG.  2    shows a diagram illustrating an example centralized WiGig network based on the single-tier channelization; 
         FIG.  3    shows a block diagram illustrating example architecture of PCP/AP in the centralized WiGig network based on the single-tier channelization; 
         FIG.  4    shows a block diagram illustrating example architecture of STA in the centralized WiGig network based on the single-tier channelization; 
         FIG.  5    shows a diagram illustrating channel access periods within a BI based on the single-tier channelization; 
         FIG.  6    shows a diagram illustrating an example SPSH scenario between two SPs within a BI based on the single-tier channelization; 
         FIG.  7    shows a flow chart illustrating a method for achieving SPSH between an existing SP and a candidate SP according to the prior art; 
         FIG.  8    shows a diagram illustrating message exchange between PCP/AP and STAs involved in SPSH according to the prior art method; 
         FIG.  9    shows a diagram illustrating the SPSH assessment between an existing SP and a candidate SP according to the prior art method; 
         FIG.  10    shows a diagram illustrating an example format of measurement request message according to the prior art method; 
         FIG.  11    shows a diagram illustrating an example format of measurement report message according to the prior art method; 
         FIG.  12    shows a diagram illustrating an example two-tier channelization in the 60 GHz mmW frequency band; 
         FIG.  13    shows a diagram illustrating an example centralized WiGig network based on the two-tier channelization; 
         FIG.  14    shows a diagram illustrating MIMO transmission between two STAs; 
         FIG.  15    shows a block diagram illustrating example architecture of PCP/AP in the centralized WiGig network based on the two-tier channelization; 
         FIG.  16    shows a block diagram illustrating example architecture of STA in the centralized WiGig network based on the two-tier channelization; 
         FIG.  17    shows a diagram illustrating a potential SPSH scenario between two SPs within a BI based on the two-tier channelization; 
         FIG.  18    shows a flow chart illustrating a method for achieving SPSH between an existing SP and a candidate SP according to a first embodiment of the present disclosure; 
         FIG.  19    shows a diagram illustrating message exchange between the PCP/AP and the STAs involved in SPSH according to the first embodiment of the present disclosure; 
         FIG.  20    shows a diagram illustrating the SPSH assessment between the existing SP and the candidate SP according to the first embodiment of the present disclosure; 
         FIG.  21    shows a diagram illustrating an example format of measurement request message according to the first embodiment of the present disclosure; 
         FIG.  22    shows a diagram illustrating an example format of measurement report message according to the first embodiment of the present disclosure; 
         FIG.  23    shows a diagram illustrating an example format of the Extended Measurement Report subelement according to the first embodiment of the present disclosure; 
         FIG.  24    shows a flow chart illustrating a method for achieving SPSH between an existing SP and a candidate SP according to a second embodiment of the present disclosure; 
         FIG.  25    shows a diagram illustrating message exchange between the PCP/AP and the STAs involved in SPSH according to the second embodiment of the present disclosure; 
         FIG.  26    shows a diagram illustrating the SPSH assessment between the existing SP and the candidate SP according to the second embodiment of the present disclosure; 
         FIG.  27    shows a diagram illustrating an example format of measurement request message according to the second embodiment of the present disclosure; and 
         FIG.  28    shows a diagram illustrating an example format of measurement report message according to the second embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
       FIG.  1    is a diagram illustrating an example single-tier channelization in the 60 GHz mmW frequency band, which divides the 60 GHz mmW frequency band into four channels with a channel bandwidth (CBW)=2.16 GHz. The channels with a channel number (CN)=1, 2, 3 and 4 center at frequencies 58.32 GHz, 60.48 GHz, 62.64 GHz and 64.8 GHz, respectively. 
       FIG.  2    is a diagram illustrating an example centralized WiGig network  200 , which is based on the single-tier channelization shown in  FIG.  1   . The centralized WiGig network  200 , which operates at a tier 1 channel, includes a plurality of STAs  204  and a PCP/AP  202  including STA functionality as well. The PCP/AP  202  can communicate with one of the STAs  204  (e.g.,  204   e ) via a communication link  212 . One of the STAs  204  (e.g.,  204   c ) can also directly communicate with another of the STAs  204  (e.g.,  204   d ) via a communication link  214 . 
       FIG.  3    is a block diagram illustrating example architecture of the PCP/AP  202  in the centralized WiGig network  200 . The PCP/AP  202  comprises a controller  302 , a scheduler  304 , a message generator  308 , a message processor  306 , a PHY processor  310 , and an antenna  312 . The controller  302  is a MAC protocol controller and controls general MAC protocol operations. The scheduler  304  schedules the allocation of channel access periods under the control of the controller  302 . The message generator  308  receives scheduling information from the scheduler  304  and generates corresponding control, data or management messages such as beacons, which are transmitted through the antenna  312  after physical layer (PHY) processing by PHY processor  310 . The antenna  312  may be a single element antenna, an adaptive antenna array, or a switched beam antenna. On the other hand, the message processor  306  analyzes the messages received from the plurality of STAs  204  and provides them to the controller  302 . 
       FIG.  4    is a block diagram illustrating example architecture of the STAs  204  in the centralized WiGig network  200 . Each of the plurality of STAs  204  comprises a controller  402 , a message generator  404 , a message processor  406 , a PHY processor  408 , and an antenna  410 . The controller  402  is a MAC protocol controller and controls general MAC protocol operations. The message generator  404  generates control, data or management messages under the control of the controller  402 , which are transmitted through the antenna  410  after PHY processing by PHY processor  408 . On the other hand, the message processor  406  analyzes control, data or management messages received from the PCP/AP  102  under the control of the controller  402 , and provides them to the controller  402 . 
     In the WiGig network  200  shown in  FIG.  2   , channel access by the plurality of STAs  204  occurs during beacon intervals (BIs) and is coordinated using a schedule, which is generated by the PCP/AP  202  and may be communicated to the STAs  204  using beacons. The STAs  204  receive scheduling information and access the medium during the scheduled periods using the access rules specific to that period. 
       FIG.  5    is a diagram illustrating the channel access periods within a BI  500 . The BI  500  may comprise of three types of access periods: Beacon Transmission Interval (BTI)  502 , announcement transmission interval (ATI)  506 , and data transfer interval (DTI)  508 . The BTI  502  is an access period during which the PCP/AP  202  performs BF training with directional transmission of plural beacons through all sectors of the antenna  312  in order to reach the full extent of transmission coverage of the plurality of STAs  204 . The ATI  506  is a request-response based management access period between the PCP/AP  202  and the plurality of STAs  204 . In the DTI  508 , message exchanges are performed between the plurality of STAs  204  and between the PCP/AP  202  and the individual STAs  204 . The DTI  508  further includes a plurality of access periods, e.g., a service period (SP)  510  and a contention-based access period (CBAP)  512 . The SP  510  is channel time reserved for communications between the PCP/AP  202  and an STA or a pair of STAs (e.g.,  204   a  and  204   b ). STAs involved in a SP should perform BF training with each other before engaging in any other communication or performing any measurements. After BF training is completed, for each STA involved in a SP, a TX antenna configuration and a RX antenna configuration are determined to be used for single stream transmission during the SP. 
     The WiGig MAC introduces a so-called spatial sharing (SPSH) mechanism to maximize PBSS/infrastructure BSS performance. According to the WiGig SPSH mechanism, SPs belonging to different STAs in the same spatial vicinity may be allowed to be scheduled concurrently over the same channel. An SP to be assessed for SPSH with other scheduled (existing) SPs or considered to be reallocated in the BI is termed as a candidate SP. 
       FIG.  6    is a diagram illustrating an example SPSH scenario between two SPs within a BI  600 . The DTI  608  within the BI  600  includes a plurality of access periods, e.g., a first SP  610  and a second SP  614 . The first SP  610  is supposed to be the existing SP and is reserved, for example, for communications between the STAs  204   a  and  204   b . The second SP  614  is supposed to be the candidate SP and is reserved, for example, for communications between the STAs  204   c  and  204   d . The candidate SP  614  is scheduled to be overlapping in time with the existing SP  610  over the same channel within the BI  600 . 
       FIG.  7    is a flow chart illustrating a method  700  for achieving SPSH between the existing SP  610  and the candidate SP  614  according to the prior art. It is supposed that the candidate SP  614  has not been allocated channel time before the SPSH assessment is initiated.  FIG.  8    is a diagram illustrating message exchange between the PCP/AP  202  and the STAs involved in the candidate SP  614  according to the method  700 . 
     The method  700  starts the SPSH assessment at Step  702 . At Step  704 , the PCP/AP  202  transmits a measurement request message  802  to each STA (i.e.,  204   c  and  204   d ) involved in the candidate SP  614  to request performing measurement for the purpose of assessing the possibility for SPSH with the existing SP  610 . The measurement request message  802  carries the measurement configuration information for the requested measurement, which will be detailed later. At Step  706 , after receiving the measurement request message  802 , each requested STA shall carry out the measurement according to the measurement configuration information in the measurement request message  802 . Note that a requested STA (e.g.,  204   c ) shall carry out the measurement employing the same RX antenna configuration as is used when receiving frames from its target STA (e.g.,  204   d ) involved in the candidate SP  614 . At Step  708 , each requested STA feedbacks results of the measurement to the PCP/AP  202  using a measurement report message  804 . At Step  710 , the PCP/AP  202  decides whether to perform SPSH between the existing SP  610  and the candidate SP  614  based on the results of measurement. The method  700  stops at Step  712 . 
       FIG.  10    is a diagram illustrating an example format of the measurement request message  802 , which includes an Operating Class field  1002 , a Channel Number field  1004 , an AID field  1006 , a Measurement Method field  1010 , a Measurement Start Time field  1012 , a Measurement Duration field  1014 , a Number of Time Blocks field  1016  and Optional Subelements field  1018 . The Operating Class field  1002  and the Channel Number field  1004 , respectively, indicate the channel set and the CN for which the requested measurement applies. Namely, the Operating Class field  1002 , together with the Channel Number field  1004 , specifies the measurement channel. The AID field  1006  indicates the target STA, implying which specific RX antenna configuration is to be used for the requested measurement. The Measurement Method field  1010  indicates the method that is to be used by the requested STA to carry out the measurement and report back in the measurement report message  804 , e.g., average noise plus interference power indicator (ANIPI). The Measurement Start Time field  1012  indicates the time at which the requested measurement starts. The Measurement Duration field  1014  indicates the duration of the requested measurement. The relation of the Measurement Start Time field  1012  and the Measurement Duration field  1014  in the measurement request message  802  is shown in  FIG.  9   . The Number of Time Blocks field  1016  indicates the number of time blocks within the measurement duration where the duration of each time block is the same. The Measurement Start Time field  1012 , together with the Measurement Duration field  1014  and the Number of Time Blocks field  1016 , offers measurement timing information for the requested measurement. The Optional Subelements field  1018  contains zero or more subelements and may be used for functional extension. 
       FIG.  11    is a diagram illustrating an example format of the measurement report message  804 , which includes an Operating Class field  1102 , a Channel Number field  1104 , an AID field  1106 , a Measurement Method field  1110 , a Measurement Start Time field  1112 , a Measurement Duration field  1114 , a Number of Time Blocks field  1116 , a plurality of Measurement for Time Block fields  1118  and an Optional Subelements field  1120 . The Operating Class field  1102  and the Channel Number field  1104 , respectively, indicate the channel set and the CN for which the measurement applies. The AID field  1106  indicates the target STA. The Measurement Method field  1110  indicates the method that was used by the STA to carry out the measurement. The Measurement Start Time field  1112  indicates the time at which the measurement started. The Measurement Duration field  1114  indicates the duration of the measurement. The Number of Time Blocks field  1116  indicates the number of time blocks within the measurement duration. Each of the Measurement for Time Block fields  1118  indicates the result of measurement over a specific time block. The format of the Measurement for Time Block fields  1118  is specified by the Measurement Method field  1110 . The Optional Subelements field  1120  contains zero or more subelements and can be used for functional extension. 
       FIG.  12    is a diagram illustrating an example two-tier channelization in the 60 GHz mmW frequency band. In the first tier, the 60 GHz mmW frequency band is divided into four channels with CBW=2.16 GHz each in a same manner as the one-tier channelization shown in  FIG.  1   . In the second tier, the 60 GHz mmW frequency band is segmented into two channels with CBW=4.32 GHz each. The channels with CN=5 and 6 center at frequencies 59.4 GHz and 63.72 GHz, respectively. In terms of frequency range, the tier 1 channels with CN=1 and 2 are covered by the tier 2 channel with CN=5. From the perspective of the tier 2 channel with CN=5, the channel with CN=1 is called primary tier 1 channel and the channel with CN=2 is called secondary tier 1 channel. Similarly, from the perspective of the tier 2 channel with CN=6, the channel with CN=3 is called primary tier 1 channel and the channel with CN=4 is called secondary tier 1 channel. 
       FIG.  13    is a diagram illustrating an example centralized WiGig network  1300  which is based on the two-tier channelization shown in  FIG.  12   . The centralized WiGig network  1300 , which supports multiple input multiple output (MIMO) transmission over a tier 2 channel or its primary tier 1 channel, includes a plurality of STAs  1304  and a PCP/AP  1302  including STA functionality as well. The PCP/AP  1302  can communicate with one of the STAs (e.g.,  1304   e ) via a MIMO communication link  1312  over a tier 2 channel (e.g., CN=5) or a MIMO communication link  1314  over its primary tier 1 channel (i.e., CN=1). Similarly, one of the STAs (e.g.,  1304   c ) can communicate with another of the STAs (e.g.,  1304   d ) via a MIMO communication link  1322  over the tier 2 channel or a MIMO communication link  1324  over its primary tier 1 channel. 
       FIG.  14    is a diagram illustrating an example MIMO transmission between an STA (e.g.,  1304   d ) and its target STA (e.g.,  1304   c ) in the centralized wireless network  1300 , where the STA  1304   c  is supposed to be the transmitter of MIMO signal and the STA  1304   d  is supposed to be the receiver of MIMO signal. The STA  1304   c  transmits multiple spatial streams simultaneously using plural TX antenna configurations, which are received by the STA  1304   d  concurrently using plural RX antenna configurations. The plural TX antenna configurations for the STA  1304   c  and plural RX antenna configurations for the STA  1304   d  that are used for MIMO transmission can be obtained via a prior MIMO antenna beam training between the STA  1304   d  and its target STA  1304   c . Notice that for different channels, plural TX antenna configurations for the STA  1304   c  and plural RX antenna configurations for the STA  1304   d  that are used for MIMO transmission may be also different. 
       FIG.  15    is a block diagram illustrating example architecture of the PCP/AP  1302  in the centralized WiGig network  1300 . The PCP/AP  1302  comprises a controller  1502 , a scheduler  1504 , a message generator  1508 , a message processor  1506 , a PHY processor  1510 , and a plurality of antennas  1512 . The controller  1502  is a MAC protocol controller and controls general MAC protocol operations. The scheduler  1504  schedules the allocation of channel access periods under the control of the controller  1502 . The message generator  1508  receives scheduling information from the scheduler  1504  and generates corresponding control, data or management messages such as beacons, which are transmitted through the plurality of antennas  1512  after PHY processing by PHY processor  1510 . On the other hand, the message processor  1506  analyzes the messages received from the plurality of STAs  1304  and provides them to the controller  1502 . Compared with their counterparts in  FIG.  3   , the functional blocks such as the controller  1502 , the scheduler  1504 , the message generator  1508 , the message processor  1506  and the PHY processor  1510  are functionally extended and enhanced so that they are able to support MIMO transmission and multiple channel bandwidths. 
       FIG.  16    is a block diagram illustrating example architecture of the STAs  1304  in the centralized WiGig network  1300 . Each of the plurality of STAs  1304  comprises a controller  1602 , a message generator  1604 , a message processor  1606 , a PHY processor  1608  and a plurality of antennas  1610 . The controller  1602  is a MAC protocol controller and controls general MAC protocol operations. The message generator  1604  generates control, data or management messages under the control of the controller  1602 , which are transmitted through the plurality of antennas  1610  after PHY processing by PHY processor  1608 . On the other hand, the message processor  1606  analyzes control, data or management messages received from the PCP/AP  1302  under the control of the controller  1602 , and provides them to the controller  1602 . Compared with their counterparts in  FIG.  4   , the functional blocks such as the controller  1602 , the message generator  1604 , the message processor  1606  and the PHY processor  1608  are functionally extended and enhanced so that they are able to support MIMO transmission and multiple channel bandwidths. 
     With this disclosure, the PCP/AP  1302  can obtain accurate information about channel quality over both the tier 2 channel and its primary tier 1 channel, and thus is able to make an appropriate SPSH decision from measurement results. 
     Various embodiments of the present disclosure will be described in detail with reference to the annexed drawings. In the following description, a detailed description of known functions and configurations incorporate herein has been omitted for clarity and conciseness. 
     First Embodiment 
       FIG.  18    is a flow chart illustrating a method  1800  for achieving SPSH between an existing SP  1710  and a candidate SP  1712  according to a first embodiment of the present disclosure. It is supposed that the candidate SP  1712  has not been allocated channel time before the SPSH assessment is initiated.  FIG.  19    is a diagram illustrating message exchange between the PCP/AP  1302  and the STAs involved in SPSH according to the method  1800 . 
     The method  1800  starts the SPSH assessment at Step  1802 . At Step  1804 , the PCP/AP  1302  transmits a first measurement request message  1902  to each STA (i.e.,  1304   e  and  1304   f ) involved in the candidate SP  1712  to request performing measurement over the primary tier 1 channel (i.e., CN=1) of a tier 2 channel (e.g., CN=5) at which the existing SP  1710  is located. The first measurement request message  1902  contains measurement configuration information for measurement over the primary tier 1 channel. In addition to measurement channel, measurement method and measurement timing, the measurement configuration information also includes the number of measurements to be performed concurrently using plural RX antenna configurations and the method for reporting results of plural concurrent measurements in a subsequent first measurement report message  1906 . 
     At Step  1806 , the PCP/AP  1302  transmits a second measurement request message  1904  to each STA (i.e.,  1304   e  and  1304   f ) involved in the candidate SP  1712  to request performing measurement over the secondary tier 1 channel (i.e., CN=2) of the same tier 2 channel. The second measurement request message  1904  contains measurement configuration information for measurement over the secondary tier 1 channel. 
     At Step  1808 , each requested STA (i.e.,  1304   e  and  1304   f ) carries out plural measurements concurrently using plural RX antenna configurations, respectively, during the time blocks allocated for measurement over the primary tier 1 channel, which are corresponding to a part of the existing SP  1710 , as illustrated in  FIG.  20   . Note that a requested STA (e.g.,  1304   e ) shall carry out plural concurrent measurements over the primary tier 1 channel employing the same plural RX antenna configurations as are used when receiving MIMO transmissions from its target STA (i.e.,  1304   f ) over the same channel. 
     At Step  1810 , each requested STA (i.e.,  1304   e  and  1304   f ) carries out plural measurements concurrently using plural RX antenna configurations, respectively, during the time blocks allocated for measurement over the secondary tier 1 channel, which are corresponding to another part of the existing SP  1710 , as illustrated in  FIG.  20   . Note that a requested STA (e.g.,  1304   e ) shall carry out plural measurements over the secondary tier 1 channel employing the same plural RX antenna configurations as are used when receiving MIMO transmissions from its target STA (i.e.,  1304   f ) over the same channel. 
     At Step  1812 , each requested STA feedbacks results of the plural concurrent measurements over the primary tier 1 channel to the PCP/AP  1302  using a first measurement report message  1906  according to the measurement configuration information contained in the first measurement request message  1902 . At Step  1814 , each requested STA feedbacks results of the plural concurrent measurements over the secondary tier 1 channel to the PCP/AP  1302  using a second measurement report message  1908  according to the measurement configuration information carried in the second measurement request message  1904 . 
     According to the present disclosure, there are various ways for reporting results of the plural concurrent measurements. In a first way, results of the plural concurrent measurements during a time block are individually reported. In a second way, the average of results of the plural concurrent measurements during a time block is reported. In a third way, the weighted average of results of the plural concurrent measurements during a time block is reported. In the third way, the weighting factor for a RX antenna configuration depends on received signal quality associated with the RX antenna configuration during MIMO antenna beam training. The better is received signal quality with a RX antenna configuration, and the larger is its weighting factor. Compared with the first way, both the second way and the third way have a much shorter measurement report. But the first way is able to provide much more detailed measurement results. 
     At Step  1816 , the PCP/AP  1302  determines how to achieve SPSH between the existing SP  1710  and the candidate SP  1712  based on the results of measurements which are carried in the first measurement report message  1906  and the second measurement report message  1908 . The method  1800  stops at Step  1818 . 
     According to the first embodiment of the present disclosure, after receiving a measurement request, each requested STA needs to perform plural measurements concurrently using plural RX antenna configurations. So inconsistency in terms of measurement results incurred by the prior method  700  can be avoided. 
     According to the first embodiment of the present disclosure, the PCP/AP  1302  can obtain accurate information about channel quality over both primary tier 1 channel and secondary tier 1 channel of a tier 2 channel, from which it is able to further estimate channel quality over the tier 2 channel, and thus is able to make an appropriate decision on SPSH between the existing SP  1710  and the candidate SP  1712 . 
       FIG.  21    is a diagram illustrating an example format of the measurement request message  1902  (or  1904 ) according to the first embodiment of the present disclosure. The measurement request message  1902  includes an Operating Class field  2102 , a Channel Number field  2104 , an AID field  2106 , a Measurement Configuration field  2108 , a Measurement Method field  2110 , a Measurement Start Time field  2112 , a Measurement Duration field  2114 , a Number of Time Blocks (M) field  2116  and Optional Subelements field  2118 . Except for the Measurement Configuration field  2108 , the other fields can be defined in a similar manner to their counterparts in the measurement request message  802  shown in  FIG.  10   . 
     The Measurement Configuration field  2108  further includes a Number of Concurrent Measurements (N) field  2122  and a Measurement Report Method field  2124 . The Number of Concurrent Measurements (N) field  2122  indicates how many measurements are to be performed concurrently using plural RX antenna configurations for the requested measurement. The Measurement Report Method field  2124  indicates how results of N concurrent measurements are to be reported in the subsequent measurement report message. 
       FIG.  22    is a diagram illustrating an example format of the measurement report message  1906  (or  1908 ) according to the first embodiment of the present disclosure. The measurement report message  1906  includes an Operating Class field  2202 , a Channel Number field  2204 , an AID field  2206 , a Measurement Configuration field  2208 , a Measurement Method field  2210 , a Measurement Start Time field  2212 , a Measurement Duration field  2214 , a Number of Time Blocks (M) field  2216 , a plurality of Measurement for Time Block fields  2218  and an Optional Subelements field  2220 . Except for the Measurement Configuration field  2208 , the other fields can be defined in a similar manner to their counterparts in the measurement report message  804  shown in  FIG.  11   . 
     The Measurement Configuration field  2208  further includes a Number of Concurrent Measurement (N) field  2222  and a Measurement Report Method field  2224 . The Number of Concurrent Measurement (N) field  2222  indicates how many measurements were performed concurrently using plural RX antenna configurations. The Measurement Report Method field  2224  indicates how results of N concurrent measurements are reported in this measurement report message. 
     In case that the Measurement Report Method field  2224  of a measurement report message indicates that results of N concurrent measurements during a time block are individually reported, measurement results corresponding to a first RX antenna configuration will be contained in the plurality of Measurement for Time Block fields  2218  of the same measurement report message. Measurement results corresponding to the remaining (N−1) RX antenna configurations will be carried in a so-called Extended Measurement Report subelement of the same measurement report message. 
     In case that the Measurement Report Method field  2224  of a measurement report message indicates that the average of results of N concurrent measurements during a time block is reported or indicates that the weighted average of results of N concurrent measurements during a time block is reported, measurement results corresponding to N RX antenna configurations will be entirely contained in the plurality of Measurement for Time Block fields  2218  of the same measurement report message. 
       FIG.  23    is a diagram illustrating an example format of the Extended Measurement Report subelement according to the first embodiment of the present disclosure, which includes a Subelement ID field  2302 , a Length field  2304  and a Data field  2306 . The Data field  2306  further includes (N−1) M Measurement for Time Block fields, which can be divided into (N−1) groups with M Measurement for Time Block fields each. Each group corresponds to a specific RX antenna configuration which was used for the measurement. For example, the group  2312  corresponds to the second RX antenna configuration, and the group  2314  corresponds to the N-th RX antenna configuration. 
     With reference to  FIG.  20   , according to the first embodiment of the present disclosure, the Measurement Start Time field  2112  in the second measurement request message  1904  (or the second measurement report message  1908 ) for measurement over the secondary tier 1 channel shall be equal to or larger than Tcs plus the Measurement Start Time field  2112  plus the Measurement Duration field  2114  in the first measurement request message  1902  (or the first measurement report message  1906 ) for measurement over the primary tier 1 channel, where Tcs accounts for time for switching channel and reconfiguring receiver, and the value of Tcs is either predetermined or configurable. Meanwhile, for keeping measurement results consistent among measurements over the primary and secondary tier 1 channels, the Measurement Configuration field  2108 , the Measurement Method field  2110 , the Measurement Duration field  2114  and the Number of Time Blocks (M) field  2116  should be the same in the first measurement request message  1902  (or the first measurement report message  1906 ) and the second measurement request message  1904  (or the second measurement report message  1908 ). The duration of each time block should also be the same in the first measurement request message  1902  (or the first measurement report message  1906 ) and the second measurement request message  1904  (or the second measurement report message  1908 ). 
     According to the first embodiment of the present disclosure, alternatives exist for the SPSH method  1800 . For example, at Step  1806 , the PCP/AP  1302  can request each STA involved in the candidate SP  1712  to perform measurement over the tier 2 channel instead of its secondary tier 1 channel. As a consequence, the PCP/AP  1302  can directly obtain accurate information about channel quality over the tier 2 channel and its primary tier 1 channel, and thus is able to make an appropriate decision on SPSH between the existing SP  1710  and the candidate SP  1712 . However, using the tier 2 channel instead of its secondary tier 1 channel may incur longer Tcs. 
     Second Embodiment 
       FIG.  24    is a flow chart illustrating a method  2400  for achieving SPSH between an existing SP  1710  and a candidate SP  1712  according to a second embodiment of the present disclosure. It is supposed that the candidate SP has not been allocated channel time before the SPSH assessment is initiated.  FIG.  25    is a diagram illustrating message exchange between the PCP/AP  1302  and the STAs involved in SPSH according to the method  2400 . 
     The method  2400  starts the SPSH assessment at Step  2402 . At Step  2404 , the PCP/AP  1302  transmits a measurement request message  2502  to each STA (i.e.,  1304   e  or  1304   f ) involved in the candidate SP  1712  to request performing measurement over both primary tier 1 channel (i.e., CN=1) and secondary tier 1 channel (i.e., CN=2) of a tier 2 channel (e.g., CN=5). The measurement request message  2502  carries measurement configuration information for measurement over the primary and secondary tier 1 channels of the tier 2 channel. In addition to measurement channel, measurement method and measurement timing, the measurement configuration information further includes the method for allocating measurement time blocks between the primary tier 1 channel and the secondary tier 1 channel, the number of measurements to be performed concurrently using plural RX antenna configurations and the method for reporting results of plural concurrent measurements in the subsequent measurement report message  2504 . 
     At Step  2406 , after receiving the measurement request message  2502 , each requested STA shall carry out plural measurements concurrently using plural RX antenna configurations over the primary tier 1 channel during time blocks allocated to the primary tier 1 channel and carry out plural measurements concurrently using plural RX antenna configurations over the secondary tier 1 channel during time blocks allocated to the secondary tier 1 channel. Time blocks are equally allocated to measurement over each channel. Note that a requested STA (e.g.,  1304   e ) shall carry out plural measurements over the primary tier 1 channel (or secondary tier 1 channel) employing the same plural RX antenna configurations as is used when receiving MIMO transmissions from its target STA (i.e.,  1304   f ) over the same channel. 
     At Step  2408 , each requested STA collectively reports back results of plural concurrent measurements over the primary and secondary tier 1 channels to the PCP/AP  1302  using the measurement report message  2504  according to the measurement configuration information indicated in the measurement request message  2502 . 
     At Step  2410 , the PCP/AP  1302  determines how to achieve SPSH among the existing SP  1710  and the candidate SP  1712  based on results of the measurements carried in the measurement report message  2504 . The method  2400  stops at Step  2412 . 
     According to the second embodiment of the present disclosure, the PCP/AP  1302  can obtain accurate information about channel quality over the primary and secondary tier 1 channels of a tier 2 channel, from which it is able to further estimate channel quality over the tier 2 channel, and thus is able to make an appropriate decision on SPSH between the existing SP  1710  and the candidate SP  1712 . 
     Rather than the first embodiment of the present disclosure which involves two pairs of measurement request and report messages, the second embodiment of the present disclosure involves a single pair of measurement request and report messages. As a consequence, the second embodiment of the present disclosure improves channel efficiency compared with the first embodiment. 
     According to the second embodiment of the present disclosure, alternatives exist for the SPSH method  2400 . For example, at Step  2404 , the PCP/AP  1302  can request each STA involved in the candidate SP  1712  to perform measurement over the tier 2 channel and its primary tier 1 channel instead of over its primary and secondary tier 1 channels. As a consequence, the PCP/AP  1302  can directly obtain accurate information about channel quality over the tier 2 channel and its primary tier 1 channel, and thus is able to make an appropriate decision on SPSH between the existing SP  1710  and the candidate SP  1712 . 
       FIG.  27    is a diagram illustrating an example format of the measurement request message  2502  according to the second embodiment of the present disclosure, which can be envisioned as an extension of the format of the measurement request message  1902  shown in  FIG.  21   . 
     The measurement request message  2502  includes an Operating Class field  2702 , a Channel Number field  2704 , an AID field  2706 , a Measurement Configuration field  2708 , a Measurement Method field  2710 , a Measurement Start Time field  2712 , a Measurement Duration field  2714 , a Number of Time Blocks (M) field  2716  and Optional Subelements field  2718 . 
     The Measurement Configuration field  2708  includes a Channel Control field  2722 , a Time Block Allocation Pattern field  2724 , a Number of Concurrent Measurements (N) field  2726  and a Measurement Report Method field  2728 . The Channel Control field  2722  indicates whether measurement is performed over a single tier 1 (or tier 2) channel, over both primary and secondary tier 1 channels of a tier 2 channel, or over a tier 2 channel and its primary tier 1 channel. The Time Block Allocation Pattern field  2724  indicates how time blocks are allocated for measurement over two channels, which is valid when the Channel Control field  2722  indicates that the measurement is performed over two channels. The Number of Concurrent Measurements (N) field  2726  indicates how many measurements are to be performed concurrently using plural RX antenna configurations for the requested measurement. The Measurement Report Method field  2728  indicates how results of N concurrent measurements are to be reported in the subsequent measurement report message. 
     It can be observed that when the Channel Control field  2722  indicates that the measurement is performed over a single tier 1 (or tier 2) channel, the format of the measurement request message  2502  is exactly the same as the format of the measurement request message  1902  shown in  FIG.  21   . The format of the measurement request message  2502  will thereafter be described for the case that the Channel Control field  2722  indicates that measurement is performed over two channels. 
     With reference to  FIG.  27   , the two channels that the measurement applies can be derived from the Operating Class field  2702 , the Channel Number field  2704  and the Channel Control field  2722 . For example, assume that the Operating Class field  2702  and the Channel Number field  2704  specify a tier 2 channel with CN=5. When the Channel Control field  2722  indicates that measurement is performed over both primary and secondary tier 1 channels of a tier 2 channel, it is easy to deduce that the primary and secondary tier 1 channels that the measurement applies are with CN=1 and CN=2, respectively. 
     With reference to  FIG.  27   , the AID field  2706  indicates the target STA. The Measurement Method field  2710  indicates the method that is to be used by the requested STA to carry out the measurement over the two channels and report back in the measurement report message  2504 . 
     The Measurement Start Time field  2712  indicates the time at which the requested measurement over the primary tier 1 channel starts. The Measurement Duration field  2714  indicates the nominal duration of the requested measurement over the two channels. The Number of Time Blocks field  2716  indicates the number of time blocks within the Measurement Duration, where the duration of each time block is the same. The Optional Subelements field  2718  contains zero or more subelements and can be used for functional extension. 
     As mentioned above, how time blocks are allocated to the two channels are specified in the Time Block Allocation Pattern field  2724 . As shown in  FIG.  26    where the two channels that the measurement applies are supposed to be primary and secondary tier 1 channels of a tier 2 channel, in a first way, time blocks allocated to the primary tier 1 channel may be followed by those allocated to the other channel with a separation of Tcs, where Tcs accounts for time for switching channel and reconfiguring receiver and the value of Tcs is either predetermined or configurable. In a second way, grouped time blocks are alternatively allocated to the two channels, with a group for primary tier 1 channel first and with a separation between neighboring groups of Tcs. The number of time blocks in a group can be either predetermined or configurable. In terms of the first way, channel switch during measurement occurs once, and but channel quality estimate may not be accurate since measurement per channel is performed during a part of whole measurement duration. In terms of the second way, channel quality estimate is more accurate since measurement per channel spreads over whole measurement duration. However, channel switch and receiver reconfiguration during measurement is more frequent and thus consumes more power. 
     With reference to  FIG.  26   , the actual measurement duration for measurement over the two channels depends on not only the Measurement Duration but also the Time Block Allocation Pattern. For example, when the Time Block Allocation Pattern indicates that time blocks allocated to the primary tier 1 channel are followed by those allocated to the other channel, the actual measurement duration for measurement over the two channels equals to the Measurement Duration plus Tcs. When the Time Block Allocation Pattern indicates that grouped time blocks are alternatively allocated to the two channels, the actual measurement duration for measurement over the two channels equals to Measurement Duration plus T where T=Tcs (number of time block groups−1). 
       FIG.  28    is a diagram illustrating an example format of the measurement report message  2504  according to the second embodiment of the present disclosure, which can be envisioned as an extension of the format of the measurement report message  1906  shown in  FIG.  22   . 
     The measurement report message  2504  includes an Operating Class field  2802 , a Channel Number field  2804 , an AID field  2806 , a Measurement Configuration field  2808 , a Measurement Method field  2810 , a Measurement Start Time field  2812 , a Measurement Duration field  2814 , a Number of Time Blocks (M) field  2816 , a plurality of Measurement for Time Block fields  2818  and an Optional Subelements field  2820 . 
     The Measurement Configuration field  2808  includes a Channel Control field  2822 , a Time Block Allocation Pattern field  2824 , a Number of Concurrent Measurements (N) field  2826  and a Measurement Report Method field  2828 . The Channel Control field  2822  indicates whether measurement was performed over a single tier 1 (or tier 2) channel, over both primary and secondary tier 1 channels of a tier 2 channel, or over a tier 2 channel and its primary tier 1 channel. The Time Block Allocation Pattern field  2824  indicates how time blocks were allocated for measurement over two channels, which is valid when the Channel Control field  2822  indicates that the measurement is performed over two channels. The Number of Concurrent Measurements (N) field  2826  indicates how many measurements were performed concurrently using plural RX antenna configurations for the measurement. The Measurement Report Method field  2828  indicates how the results of N concurrent measurements are reported in the measurement report message. 
     It can be observed that when the Channel Control field  2822  indicates that the measurement was performed over a single tier 1 (or tier 2) channel, the format of the measurement report message  2504  is exactly the same as the format of the measurement report message  1906  shown in  FIG.  22   . The format of the measurement report message  2504  will thereafter be described for the case that the Channel Control field  2822  indicates that measurement was performed over two channels. 
     With reference to  FIG.  28   , the two channels that the measurement applies can be derived from the Operating Class field  2802 , the Channel Number field  2804  and the Channel Control field  2822 . The AID field  2806  indicates the target STA. The Measurement Method field  2810  indicates the method was used by the requested STA to carry out the measurement over the two channels. The Measurement Start Time field  2812  indicates the time at which the requested measurement over the primary tier 1 channel started. The Measurement Duration field  2814  indicates the total duration of the requested measurement over the two channels. The Number of Time Blocks field  2816  indicates the number of time blocks within the Measurement Duration. The Optional Subelements field  2820  contains zero or more subelements and can be used for functional extension. 
     In case that the Measurement Report Method field  2828  of a measurement report message indicates that the results of N concurrent measurements during a time block are individually reported, results of the measurement corresponding to a first RX antenna configuration is carried in the plurality of Measurement for Time Block fields  2818  of the same measurement report message. Results of the measurement corresponding to remaining (N−1) RX antenna configurations will be carried in an Extended Measurement Report subelement (see  FIG.  23   ) of the same measurement report message. 
     In case that the Measurement Report Method field  2828  of a measurement report message indicates that the average of results of N concurrent measurements during a time block is reported or that the weighted average of results of N concurrent measurements during a time block is reported, results of the measurement corresponding to N RX antenna configuration are carried in the plurality of Measurement for Time Block fields  2818  of the same measurement report message.

Metadata:
Filing Date: 20230117
Publication Date: 20240625
Grant Date: 20240625
Priority Date: 20141119
Inventors: Irie, Masataka
HUANG, LEI
SIM, HONG CHENG MICHAEL
Assignee: APPLE INC
CPC Classifications: [{"code": "H04W16/28", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W24/10", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W24/08", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W84/12", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04W84/12", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04W24/02", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04W24/02", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04W84/12", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04W24/10", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W24/08", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W16/28", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W24/02", "inventive": true, "first": true, "tree": "[]"}]
Family ID: 55962967