Patent Description:
Aspects of the present disclosure generally relate to wireless communication, and more particularly to techniques and apparatus for high band access.

NR, which may also be referred to as <NUM>, is a set of enhancements to the LTE mobile standard promulgated by the Third Generation Partnership Project (3GPP). <CIT> describes a method and apparatus for transmitting/receiving data on multiple carriers in mobile communication system. <CIT> describes methods and apparatus for enabling L1 Enhancements in LTE heterogeneous networks.

The scope of the present invention is defined by the scope of the appended claims.

The scope of the present invention is defined by the scope of the appended claims.

A cell may be provided on a band, and may be associated with a frequency on the band.

A UE may be a cellular phone (e.g., a smart phone), a personal digital assistant (PDA), a wireless modem, a wireless communication device, a handheld device, a laptop computer, a cordless phone, a wireless local loop (WLL) station, a tablet, a camera, a gaming device, a netbook, a smartbook, an ultrabook, medical device or equipment, biometric sensors/devices, wearable devices (smart watches, smart clothing, smart glasses, smart wrist bands, smart jewelry (e.g., smart ring, smart bracelet)), an entertainment device (e.g., a music or video device, or a satellite radio), a vehicular component or sensor, a smart meter or sensor, industrial manufacturing equipment, a global positioning system device, or any other suitable device that is configured to communicate via a wireless or wired medium.

Controller/processor <NUM> of base station <NUM>, controller/processor <NUM> of UE <NUM>, and/or any other component(s) of <FIG> may perform one or more techniques associated with high band access for <NUM>/NR, as described in more detail elsewhere herein. For example, controller/processor <NUM> of base station <NUM>, controller/processor <NUM> of UE <NUM>, and/or any other component(s) of <FIG> may perform or direct operations of, for example, process <NUM> of <FIG>, process <NUM> of <FIG>, and/or other processes as described herein. Memories <NUM> and <NUM> may store data and program codes for base station <NUM> and UE <NUM>, respectively.

In some aspects, UE <NUM> may include means for receiving system information for a first cell on a second cell, wherein the UE is camped on the second cell, and wherein the system information for the first cell is received with system information for the second cell; means for accessing an uplink of the first cell using the system information for the first cell; means for establishing a connection on the first cell as a primary cell; means for performing a random access procedure for the first cell using the system information; means for performing a periodic search or measurement of the first cell while the UE is in an idle mode or an inactive mode; means for acquiring a downlink of the first cell; means for initiating a random access procedure on the first cell, wherein downlink and uplink messages associated with the random access procedure are transmitted and received on the first cell; means for acquiring the downlink of the first cell using a first receive chain, wherein a second receive chain is used for communication using the second cell; means for receiving system information for a first cell on a second cell, wherein the UE is camped on the second cell, and wherein the first cell is a lower cell than the second cell; means for selectively accessing an uplink of the first cell, or an uplink of the second cell, based at least in part on a measurement of the first cell; means for configuring the first cell as a secondary cell of the UE based at least in part on a blind handover; and/or the like. In some aspects, such means may include one or more components of UE <NUM> described in connection with <FIG>.

Other examples may differ from what was described with regard to <FIG>.

Each subframe may have a predetermined duration (e.g., <NUM>) and may include a set of slots (e.g., <NUM>m slots per subframe are shown in <FIG>, where m is a numerology used for a transmission, such as <NUM>, <NUM>,<NUM>, <NUM>, <NUM>, and/or the like). In some aspects, a scheduling unit for the FDD may frame-based, subframe-based, slot-based, symbol-based, and/or the like.

As further shown, each SS burst may include one or more SS blocks (identified as SS block <NUM> through SS block (bmax_SS-<NUM>), where bmax_SS is a maximum number of SS blocks that can be carried by an SS burst).

Each resource block may cover a set to of subcarriers (e.g., <NUM> subcarriers) in one slot and may include a number of resource elements.

An interlace structure may be used for each of the downlink and uplink for FDD in certain telecommunications systems (e.g., NR). For example, Q interlaces with indices of <NUM> through Q-<NUM> may be defined, where Q may be equal to <NUM>, <NUM>, <NUM>, <NUM>, or some other value. Each interlace may include slots that are spaced apart by Q frames. In particular, interlace q may include slots q, q + Q, q + 2Q, etc., where q ∈ {<NUM>,. , Q-<NUM>}.

NR may refer to radios configured to operate according to a new air interface (e.g., other than Orthogonal Frequency Divisional Multiple Access (OFDMA)-based air interfaces) or fixed transport layer (e.g., other than Internet Protocol (IP)). In aspects, NR may utilize OFDM with a CP (herein referred to as cyclic prefix OFDM or CP-OFDM) and/or SC-FDM on the uplink, may utilize CP-OFDM on the downlink and include support for half-duplex operation using time division duplexing (TDD).

There may be an imbalance in coverage between the uplink and the downlink. This imbalance may be particularly problematic in <NUM>/NR for reasons such as a power imbalance between the UE (e.g., UE <NUM>) and the BS (e.g., BS <NUM>), sub-optimal BS uplink implementations, and/or the like. Thus, uplink coverage holes may be present in locations where the downlink signal is still strong. For this reason, system selection and inter-radio-access-technology for <NUM>/NR may be configured conservatively to ensure that the UE is within <NUM>/NR uplink coverage. This may reduce or delay the use of <NUM>/NR bands.

One approach for handling high band (e.g., <NUM>/NR, uplink, etc.) coverage holes is using a supplementary uplink (SUL) with a low band and a high band. In SUL, the UE may camp on a high band based at least in part on a downlink signal. A broadcast downlink signal may advertise random access channel (RACH) configuration information for a high band uplink and for a low band uplink. When the UE determines that a RACH procedure is to be performed (e.g., based at least in part on receiving paging and/or the like), the UE may select an uplink (e.g., of the high band uplink and the low band uplink) for the RACH procedure based at least in part on a measurement on the high band. The UE may then begin to determine system information associated with the selected uplink, and may acquire the selected uplink using the system information.

Another approach for handling high band coverage holes is carrier aggregation (CA) using a low band and a high band. In CA, the UE may camp on the low band based at least in part on a downlink signal of the low band. When the UE is to perform the RACH procedure, the UE may use the camped low band carrier for the RACH procedure. After the RACH procedure, a high band component carrier may be added and activated (e.g., by providing configuration information on the low band).

In both SUL and CA, there may be significant delay while the UE determines system information, performs the RACH procedure, and acquires the high band. This may mean that the usage of the large bandwidth associated with the high band is delayed. Thus, the high band may not be usable for some types of traffic (e.g., small traffic, bursty traffic, etc.), which impacts user experience and reduces bandwidth of the UE.

Some techniques and apparatuses described herein may provide system information for acquisition and accessing of a low band and a high band via one of the low band or the high band. In some cases, the UE may camp on a low band, which improves coverage and reduces the number of reselections. The UE may use the system information to acquire and access the high band more quickly than if the UE were to obtain the system information after determining that the high band is to be acquired or accessed. In other cases, the UE may camp on the high band, and may acquire or access the low band using the system information. Thus, the UE may save time associated with acquiring and accessing a high band or a low band, which improves bandwidth of the UE, reduces delay associated with communicating on the high band, and improves user experience.

It should be noted that "band" is used herein to refer to a cell associated with a frequency included in a band. In other words, a UE referred to as camping on a band should be understood to be camping on a cell associated with a frequency included in the band. Similarly, a UE referred to as communicating on a band should be understood to be communicating on a cell associated with a frequency included in the band.

<FIG> is a diagram illustrating an example <NUM> of high band access for <NUM>/NR, in accordance with various aspects of the present disclosure. <FIG> shows a UE <NUM> and a BS <NUM>, and a call flow between the UE <NUM> and the BS <NUM> is illustrated for a high band (in the top half of <FIG>) and for a low band (in the bottom half of <FIG>). For the purpose of <FIG>, assume that a UE <NUM> is camped on a low band, which may provide better coverage and fewer reselections than camping on a high band. Furthermore, by camping on the low band, the UE <NUM> may avoid multi-beam paging in the case when the high band is operated in a multi-beam mode. As used herein, a high band may refer to a <NUM>/NR band, a super-<NUM> band, a mm Wave band, a Frequency Range (FR) <NUM> band, an FR3 band, an FR4 band, and/or the like. As used herein, a low band may refer to a <NUM>/LTE band, a sub-<NUM> band, an FR1 band, and/or the like. In some aspects, a high band may refer to a band that is associated with a higher frequency (e.g., center frequency) than a low band. In some aspects, the high band may have a larger bandwidth than the low band.

As shown in <FIG>, and by reference number <NUM>, the UE <NUM> is configured to receive system information (e.g., a system information block (SIB)) on the low band from the BS <NUM>. For example, the system information may be for the low band and for the high band. In some aspects, the system information may be broadcasted, such as in a physical broadcast channel. In some aspects, the system information may include a subset of all system information for the high band. For example, the subset may include information used for transitioning from an idle mode or an inactive mode to a connected mode with regard to the high band (e.g., a master information block, a SIB0, a frequency location of the high band, security information for the high band, RACH information for the high band, information for acquiring a downlink of the high band, etc.). Thus, the UE <NUM> and the BS <NUM> conserve bandwidth that would otherwise be used to provide all system information of the high band using the low band.

As shown by reference number <NUM>, the UE <NUM> may receive paging on the low band. For example, the UE <NUM> may determine that uplink data is to be provided on the high band based at least in part on receiving the paging on the low band. In some aspects, the UE <NUM> may determine that mobile-originated data is to be provided by the UE <NUM> on the high band.

As shown by reference number <NUM>, the UE <NUM> may acquire a high band synchronization signal block for synchronization, which may be referred to herein as acquiring a downlink of the high band. For example, the UE <NUM> may acquire the high band synchronization signal block based at least in part on the system information received on the low band. In some aspects, the UE <NUM> may immediately acquire the high band downlink (e.g., without obtaining system information after the UE <NUM> receives paging or determines that mobile-originated data is to be transmitted on the high band). In this way, the UE <NUM> conserves time and bandwidth resources that would otherwise be used to obtain system information for the high band after the paging is received or the UE <NUM> determines that the mobile-originated data is to be provided.

In some aspects, the UE <NUM> may perform a search or measurement for the high band. For example, the UE <NUM> may periodically perform the search or measurement based at least in part on the system information (e.g., based at least in part on information identifying the high band in the system information), which may further reduce delay associated with transitioning to connected mode on the high band. For example, performing the search or measurement periodically may allow the UE <NUM> to use a previously-performed search or measurement rather than performing a new search or measurement after the paging to acquire the downlink of the high band, which saves time associated with performing the search or measurement on-demand.

As shown by reference numbers <NUM>, <NUM>, <NUM>, and <NUM>, the UE <NUM> and the BS <NUM> are configured to perform the RACH procedure on the high band, which may be referred to herein as accessing the high band. For example, the UE <NUM> and the BS <NUM> are configured to exchange RACH messages <NUM>, <NUM>, <NUM>, and <NUM> on the high band. In some aspects, the UE <NUM> may enter connected mode with regard to the high band based at least in part on the procedure. In some aspects, the high band may be set as a primary cell (PCell) of the UE <NUM>. For example, the UE <NUM> may receive signaling indicating that the high band is to be set or used as the primary cell of the UE <NUM>, and/or may determine that the high band is to be set as the primary cell. Thus, the UE <NUM> may have quicker access to bandwidth of the high band than if system information is obtained after paging is received.

<FIG> is a diagram illustrating an example <NUM> of high band access for <NUM>/NR, in accordance with various aspects of the present disclosure. <FIG> shows a UE <NUM> and a BS <NUM>, and a call flow between the UE <NUM> and the BS <NUM> is illustrated for a high band (in the top half of <FIG>) and for a low band (in the bottom half of <FIG>). For the purpose of <FIG>, assume that the UE <NUM> is camped on the low band.

As shown in <FIG>, and by reference number <NUM>, the UE <NUM> is configured to receive system information (e.g., a SIB) on the low band from the BS <NUM>, which is described in more detail in connection with block <NUM> of <FIG>, above. As shown by reference number <NUM>, the UE <NUM> may receive paging on the low band. For example, the UE <NUM> is configured to determine that uplink data is to be provided on the high band based at least in part on receiving the paging on the low band. In some aspects, the UE <NUM> is configured to determine that mobile-originated data is to be provided by the UE <NUM> on the high band. As shown by reference number <NUM>, the UE <NUM> is configured to acquire the synchronization signal block of the high band for synchronization (e.g., may acquire the downlink of the high band), which is described in more detail in connection with block <NUM> of <FIG>, above.

As shown by reference numbers <NUM>, <NUM>, <NUM>, and <NUM>, the UE <NUM> is configured to perform part of the RACH procedure using the low band and part of the RACH procedure using the high band in order to access the high band. For example, the UE <NUM> is configured to perform the RACH procedure while the UE <NUM> acquires the synchronization signal block (e.g., the downlink) of the high band. This may be possible because the UE <NUM> may not need to synchronize with the high band to transmit RACH message <NUM> (shown by reference number <NUM>) and RACH message <NUM> (shown by reference number <NUM>) on the high band.

In some aspects, the UE <NUM> is configured to determine that one or more RACH messages are to be provided on the high band. For example, the UE <NUM> is configured to determine whether a downlink measurement (e.g., reference signal received power or another measurement) of the low band satisfies the threshold. When the downlink measurement of the low band satisfies the threshold, the UE <NUM> is configured to determine that coverage of the high band may be sufficient for providing the one or more messages on the high band. In this way, the UE <NUM> is configured to selectively provide the RACH messages on the low band or on the high band based at least in part on a measurement on the low band.

In some aspects, the UE <NUM> is configured to communicate on the low band using a first receive chain, and may acquire the downlink of the high band using a second receive chain (e.g., a receive chain different than the first receive chain). This may conserve resources of the first receive chain and may reduce time associated with retuning the first receive chain. In some aspects, the UE <NUM> may perform a search or measurement for the high band (e.g., periodically), as described in connection with <FIG>, above.

As shown by reference number <NUM>, the BS <NUM> may provide a handover message to the UE <NUM> on the low band. For example, the handover message may indicate that the UE <NUM> is to perform a handover, such as a blind handover, so that the high band is used as the primary cell. As shown by reference number <NUM>, the UE <NUM> may use the high band as the primary cell based at least in part on the handover message. For example, the UE <NUM> and the BS <NUM> may perform the handover to use the high band as the primary cell.

<FIG> is a diagram illustrating an example <NUM> of high band access for <NUM>/NR, in accordance with various aspects of the present disclosure. Some operations of <FIG> (e.g., signaling of the system information for both bands on the low band, paging/mobile-originated data determination, acquiring/synchronizing the downlink, performance of the RACH procedure during acquisition, etc.) are similar to the corresponding operations described in connection with <FIG> and <FIG>, and are not described any further. It should be understood that the operations described in connection with examples <NUM> and <NUM> can be performed similarly for example <NUM>.

As shown in <FIG>, and by reference number <NUM>, in some aspects, the BS <NUM> may provide a handover message in a RACH message. For example, here, the BS <NUM> provides the handover message in RACH message <NUM>. In some aspects, RACH message <NUM> may be modified from a standard format to include the handover message. In some aspects, RACH message <NUM> may be transmitted on particular resources, using a particular encoding scheme, using a particular cyclic prefix, and/or the like, to indicate the handover message. In some aspects, RACH message <NUM> may implicitly indicate the handover message. In some aspects, the handover message may be a blind handover message. By providing the handover message using RACH message <NUM>, the BS <NUM> reduces delay with configuring the high band as the primary cell (shown by reference number <NUM>) and downlink data transfer using the high band.

<FIG> is a diagram illustrating an example <NUM> of high band access for <NUM>/NR, in accordance with various aspects of the present disclosure. <FIG> shows an example wherein a UE <NUM> camped on a high band communicates using the high band and a low band. In this case, the high band and the low band may be configured with frequency division duplexed carriers with an uplink and a downlink.

As shown by reference number <NUM>, the UE <NUM> may receive system information for the high band and the low band from the BS <NUM>. For example, the UE <NUM> may receive the system information on the high band since the UE <NUM> camped on the high band. As shown by reference number <NUM>, the UE <NUM> may receive paging on the high band. For example, the UE <NUM> may determine that uplink data is to be provided based at least in part on receiving the paging on the high band. In some aspects, the UE <NUM> may determine that mobile-originated data is to be provided by the UE <NUM>.

As shown by reference number <NUM>, the UE <NUM> may determine whether to perform a RACH procedure for the low band or for the high band. For example, the UE <NUM> may determine whether to access an uplink on the low band or on the high band. In some aspects, the UE <NUM> may perform this determination based at least in part on a channel measurement (e.g., an RSRP, RSRQ, CQI, etc.) for the high band. For example, when the channel measurement does not satisfy a threshold (e.g., indicating poor coverage in the high band), the UE <NUM> may perform the RACH procedure for the low band, which improves reliability of the RACH procedure in low-coverage situations. When the channel measurement satisfies the threshold (e.g., indicating satisfactory coverage in the high band), the UE <NUM> may perform the RACH procedure for the high band, which increases bandwidth of the UE <NUM> and conserves low band resources.

As shown by reference numbers <NUM>, <NUM>, <NUM>, and <NUM>, the UE <NUM> and the BS <NUM> may perform the RACH procedure. For example, the UE <NUM> may access the selected band, of the low band and the high band. Here, the UE <NUM> provides RACH messages <NUM> and <NUM> (shown by reference numbers <NUM> and <NUM>) using the low band. For example, the UE <NUM> may have determined, in connection with reference number <NUM>, that a channel measurement for the high band does not satisfy a threshold. As further shown, the BS <NUM> provides RACH messages <NUM> and <NUM> (shown by reference numbers <NUM> and <NUM>) using the high band. This may be because the BS <NUM> has sufficient transmit power to provide ample coverage in the downlink on the high band, while UE transmissions in the high band may not be sufficiently powerful for reliable random access.

As shown by reference number <NUM>, the UE <NUM> may use the high band as a primary cell (PCell) and, as shown by reference number <NUM>, the UE <NUM> may use the low band as a secondary cell (SCell). For example, the BS <NUM> may configure the UE <NUM> to use the high band as the primary cell (e.g., based at least in part on a handover command, such as a blind handover command). In some aspects, the BS <NUM> may configure the UE <NUM> to use the high band as the secondary cell (e.g., based at least in part on a handover command, such as a blind handover command). In some aspects, the UE <NUM> may use the low band as an FDD serving cell or a TDD serving cell. In this way, the UE <NUM> may camp on and use the high band as the primary cell for downlink purposes when coverage is poor, and may use the low band for a secondary cell and/or for uplink purposes.

In some aspects, an operation described with regard to example <NUM>, <NUM>, <NUM>, or <NUM> may be performed in any one or more of example <NUM>, <NUM>, <NUM>, <NUM>. For example, an operation described in connection with example <NUM> may be performed in any one or more of example <NUM>, <NUM>, or <NUM>, and so on. Thus, any combination of the operations performed in connection with examples <NUM>, <NUM>, <NUM>, and <NUM> are contemplated herein.

<FIG> is a diagram illustrating an example process <NUM> performed, for example, by a UE, in accordance with various aspects of the present disclosure. Example process <NUM> is an example where a UE (e.g., UE <NUM>) performs high cell access for <NUM>/NR. In some aspects, process <NUM> may correspond to any one of examples <NUM>, <NUM>, or <NUM>.

As shown in <FIG>, in some aspects, process <NUM> includes receiving system information for a first cell on a second cell, wherein the UE is camped on the second cell, and wherein the system information for the first cell is received with system information for the second cell (block <NUM>). The UE (e.g., using antenna <NUM>, DEMOD <NUM>, MIMO detector <NUM>, receive processor <NUM>, controller/processor <NUM>, and/or the like) is configured to receive system information for a first cell (e.g., a high cell) on a second cell (e.g., a low cell). The system information includes system information for the first cell and for the second cell. The system information for the first cell and the system information for the second cell may be received together (e.g., in a same broadcast, in concurrent broadcasts, in consecutive broadcasts, etc.).

As shown in <FIG>, in some aspects, process <NUM> includes accessing an uplink of the first cell using the system information for the first cell (block <NUM>). For example, the UE (e.g., using controller/processor <NUM>, transmit processor <NUM>, TX MIMO processor <NUM>, MOD <NUM>, antenna <NUM>, and/or the like) may access an uplink of the first cell using the system information for the first cell (e.g., may perform a RACH procedure for the first cell). In some aspects, the UE may receive paging indicating that mobile-originated data is to be transmitted or may determine that mobile-originated data is to be transmitted. The UE may access the uplink of the first cell using the system information for the first cell. In some aspects, the UE may perform a RACH procedure for the first cell using at least one of the first cell or the second cell, as described in more detail elsewhere herein.

As shown in <FIG>, in some aspects, process <NUM> includes establishing a connection on the first cell as a serving cell (block <NUM>). For example, the UE (e.g., using controller/processor <NUM> and/or the like) may establish a connection on the first cell (e.g., and/or the second cell). The UE may establish the connection on the first cell as the serving cell (e.g., primary cell) of the UE. In this way, the UE may more quickly and efficiently access bandwidth of the high cell, thereby increasing bandwidth of the UE and reducing latency.

In a first aspect, the first cell is associated with a higher frequency than the second cell. In a second aspect, alone or in combination with the first aspect, the first cell has a larger bandwidth than the second cell. In a third aspect, alone or in combination with the first aspect and/or the second aspect, the first cell and the second cell are duplex cells. In a fourth aspect, alone or in combination with any one or more of the first through third aspects, the first cell and the second cell are associated with a time division duplexing configuration or a frequency division duplexing configuration. In a fifth aspect, alone or in combination with any one or more of the first through fourth aspects, the system information includes a subset of all system information of the first cell, and wherein the subset is to be used to transition the UE to a connected mode. In a sixth aspect, alone or in combination with any one or more of the first through fifth aspects, the UE is configured to access the uplink of the first cell based at least in part on receiving paging on the second cell or to transmit mobile-originated data. In a seventh aspect, alone or in combination with any one or more of the first through sixth aspects, one or more downlink messages associated with a random access procedure are received on the second cell. In an eighth aspect, alone or in combination with any one or more of the first through seventh aspects, one or more uplink messages associated with a random access procedure are transmitted on the first cell based at least in part on a measurement of the second cell. In a ninth aspect, alone or in combination with any one or more of the first through eighth aspects, the UE may perform a periodic search or measurement of the first cell while the UE is in an idle mode or an inactive mode. In a tenth aspect, alone or in combination with any one or more of the first through ninth aspects, the UE may acquire a downlink of the first cell; and initiate a random access procedure on the first cell, wherein downlink and uplink messages associated with the random access procedure are transmitted and received on the first cell.

In an eleventh aspect, alone or in combination with any one or more of the first through tenth aspects, the first cell is used as the serving cell of the UE based at least in part on a received handover message. In a twelfth aspect, alone or in combination with any one or more of the first through eleventh aspects, the received handover message is a modified random access message. In a thirteenth aspect, alone or in combination with any one or more of the first through twelfth aspects, the UE may acquire the downlink of the first cell using a first receive chain, wherein a second receive chain is used for communication using the second cell. In a fourteenth aspect, alone or in combination with any one or more of the first through thirteenth aspects, the first cell and the second cell are configured as frequency division duplexed carriers with respective uplinks and respective downlinks. In a fifteenth aspect, alone or in combination with any one or more of the first through fourteenth aspects, the first cell is on a first band and the second cell is on a second band.

<FIG> is a diagram illustrating an example process <NUM> performed, for example, by a UE, in accordance with various aspects of the present disclosure. Example process <NUM> is an example where a UE (e.g., UE <NUM>) performs high cell access for <NUM>/NR. In some aspects, process <NUM> may correspond to example <NUM>.

As shown in <FIG>, in some aspects, process <NUM> may include receiving system information for a first cell on a second cell, wherein the UE is camped on the second cell, and wherein the first cell is associated with a lower frequency than the second cell (block <NUM>). For example, the UE (e.g., using antenna <NUM>, DEMOD <NUM>, MIMO detector <NUM>, receive processor <NUM>, controller/processor <NUM>, and/or the like) may receive system information for a first cell (e.g., a low cell or a cell associated with a low band) on a second cell (e.g., a high cell or a cell associated with a high band). The UE may be camped on the second cell. The first cell may be associated with a lower frequency than the second cell. For example, the first cell may be associated with a different radio access technology than the second cell.

As shown in <FIG>, in some aspects, process <NUM> may include selectively accessing an uplink of the first cell, or an uplink of the second cell, based at least in part on a measurement of the first cell or system information received for the first cell and the second cell (block <NUM>). For example, the UE may determine whether an uplink of the first cell or an uplink of the second cell is to be accessed. In some aspects, the UE may determine whether a RACH procedure is to be performed using the first cell or the second cell. For example, the UE may determine whether one or more uplink RACH messages are to be transmitted by the UE on the low cell or the high cell. The UE may perform one or more of the above determinations based at least in part on a measurement regarding the high cell or based at least in part on system information received for the first cell and the second cell. The first cell may be established as a time division duplexing serving cell or a frequency division serving cell of the UE.

In a first aspect, the system information for the first cell is received with system information for the second cell. In a second aspect, alone or in combination with the first aspect, the second cell is a primary cell of the UE. In a third aspect, alone or in combination with the first aspect and/or the second aspect, the network may configure, and the UE may use, the first cell as a secondary cell of the UE based at least in part on a blind handover. In a fourth aspect, alone or in combination with any one or more of the first through third aspects, the first cell is on a first band and the second cell is on a second band.

The scope of the present invention is defined by the scope of the appended claims.

Claim 1:
A method of wireless communication performed by a user equipment, UE, comprising:
receiving (<NUM>) system information for a first cell on a second cell, wherein the UE is camped on the second cell, and wherein the system information for the first cell is received with system information for the second cell;
performing a random access channel, RACH, procedure using the first cell and the second cell while the UE acquires a synchronization signal block for the first cell, wherein the performing the RACH procedure includes accessing (<NUM>), based at least in part on whether a channel measurement of the first cell or the second cell satisfies a threshold,
an uplink of the first cell using the system information for the first cell, to transmit at least one RACH message, associated with the RACH procedure, on the first cell; and
a downlink of the second cell to receive at least another RACH message, associated with the RACH procedure, on the second cell; and
establishing (<NUM>) a connection on the first cell as a serving cell.