WO 2020/112021
`
`PCT/SG2019/050530
`
`CLAIMS
`
`1.
`
`A communication apparatus operating in at least a first band and a second band, the
`
`communication apparatus comprising:
`
`a receiver which, in operation, receives a signal including a Trigger frame allocating
`
`at least one Random Access Resource Unit (RA-RU); and
`
`a controller which, in operation:
`
`sets a first Orthogonal Frequency Division Multiple Access
`
`(OFDMA)
`
`random access backoff (OBO) counter according to a number of RA-RUs determined to be
`
`eligible in at least one of the first and second bands in the received Trigger frame; and
`
`randomly selects an eligible RA-RUin each of the at least one of the first and
`
`second bands corresponding to the first OBO counter for Triggcr Based (TB) Physical layer
`
`Protocol Data Unit (PPDU)transmission when the first OBO counteris set to 0;
`
`wherein the first OBO counteris initialized according to a firsts OFDMA Contention Window
`
`(OCW).
`
`2.
`
`The communication apparatus of claim 1, wherein an RA-RU is determined to be
`
`eligible if the communication apparatus supports all
`
`transmit parameters indicated in a
`
`Common Info field of the Trigger frame and in a User Info field of the Trigger frame
`
`corresponding to the RA-RU; and if the communication apparatus is not associated with a
`
`Basic Service Set (BSS) it intends to transmit to and a predetermined subfield of the User
`
`Info field of the Trigger frame corresponding to the RA-RUis a first predetermined number.
`
`3.
`
`The communication apparatus of claim 1, wherein an RA-RU is determined to be
`
`eligible if the communication apparatus supports all
`
`transmit parameters indicated in a
`
`Common Info field of the Trigger frame and in a UserInfo field of the Trigger frame
`
`corresponding to the RA-RU; and if the communication apparatus
`
`is an associated
`
`communication apparatus and a Transmitter Address (TA) field of the Trigger frameis set to
`
`a BSS identifierJD) of an associated BSS and a predetermined subfield of the User Info field
`
`of the Trigger frame corresponding to the RA-RUis a second predetermined number.
`
`4,
`
`The communication apparatus of claim 1, wherein the first OBO counter corresponds
`
`to the first and second bands.
`
`25
`
`

`

`WO 2020/112021
`
`PCT/SG2019/050530
`
`5.
`
`The communication apparatus of claim 4, further comprising: a transmitter which, in
`
`operation, transmits a first TB PPDU in the selected eligible RA-RUin the first band and a
`
`second TB PPDUin the selected eligible RA-RU in the second band if both the selected
`
`eligible RA-RUsare considered to be idle, wherein the first and second TB PPDUscarry a
`
`same Medium Access Control Protocol Data Unit (MPDU) or Aggregate MPDU.
`
`6.
`
`The communication apparatus of claim 1, wherein the range of the first OCW is
`
`specific to the type of communication apparatus.
`
`7.
`
`The communication apparatus of claim 1, wherein the first OBO counter corresponds
`
`to the first band.
`
`8.
`
`The communication apparatus of claim 7, wherein the controller circuitry, when in
`
`operation:
`
`sets the second OBO counter according to a numberofeligible RA-RUsin the second
`
`band in the Trigger frame; and
`
`randomly selects one eligible RA-RU in the second band for TB PPDU transmission
`
`when the second OBO counteris set to 0;
`
`wherein the second OBO counteris initialized according to a second OCW.
`
`9.
`
`The communication apparatus of claim 8, wherein the range of the first OCW is
`
`specific to the first band and the range of the second OCW isspecific to the second band.
`
`10.
`
`The communication apparatus of claim 9, further comprising: a transmitter which, in
`
`operation, transmits a first TB PPDU in the selected eligible RA-RU in the first band and a
`
`second TB PPDUin the selected eligible RA-RU in the second band if both the selected
`
`eligible RA-RUsare considered to be idle, wherein the first and second TB PPDUscarry a
`
`same MPDU,or a same A-MPDU,or different MPDUs, or different A-MPDUs.
`
`11.
`
`The communication apparatus of claim 1, wherein the Trigger frame comprises a User
`
`Info field which includes a subfield, and the subfield is set to a first predetermined value to
`
`indicate
`
`the RA-RU(s)
`
`allocated by the User
`
`Info field reserved for
`
`associated
`
`communication apparatuses operating in one ofat least the first band and the second band.
`
`26
`
`

`

`WO 2020/112021
`
`PCT/SG2019/050530
`
`12.
`
`The communication apparatus of claim 11, wherein the subfield is set to a second
`
`predetermined value to indicate the RA-RU(s) allocated by the User Info field reserved for
`
`communication apparatuses which are operating in one of at least the first band and the
`
`second band and are not associated with a BSS it intends to transmit to.
`
`13.
`
`A communication method for uplink Orthogonal Frequency Division Multiple Access
`
`(OFDMA)based random access, the method comprising:
`
`initializing an Orthogonal Frequency Division Multiple Access (OFDMA) random
`
`access backoff (OBO) counter according to a first OFDMA Contention Window (OCW);
`
`receiving a signal including a Trigger frame having at least one Random Access
`
`Resource Unit (RA-RU);
`
`setting the first OBO counter according to a number of RA-RUs determined to be
`
`eligible in at least one of the first and second bands corresponding to a received Trigger
`
`frame; and
`
`randomly selecting an eligible RA-RU in each of the at least one of the first and
`
`second bands corresponding to the firs’ OBO counter for trigger-based Physical
`
`layer
`
`Protocol Data Unit (PPDU) transmission when the first OBO counteris set to O.
`
`14.
`
`The method of claim 13, wherein the first OBO counter corresponds to the first and
`
`second bands and the method further comprises:
`
`transmitting a first TB PPDU carrying a Medium Access Control Protocol Data Unit
`
`(MPDU) or Aggregate MPDUinthe selected eligible RA-RU in the first band and a second
`
`TB PPDU carrying the same MPDU or Aggregate MPDU inthe selected eligible RA-RU in
`
`the second band if both the selected eligible RA-RUsare consideredto be idle.
`
`15.
`
`The method of claim 13, wherein the first OBO counter corresponds to the first band
`
`and the method further comprises:
`
`initializing a second OBO counter according to a second OCW;
`
`setting the second OBO counter according to a number of eligible RA-RUs in the
`
`second bandin the Trigger frame; and
`
`randomly selecting one eligible RA-RU in the second band for TB PPDU
`
`transmission when the second OBO counteris set to 0.
`
`27
`
`