The disclosed embodiments relate generally to wireless communication, and, more particularly, to methods and apparatus for network controlled small gap (NCSG) configuration.
Mobile networks communication continues to grow rapidly. The mobile data usage will continue skyrocketing. New data applications and services will require higher speed and more efficient. Large data bandwidth application continues to attract more consumers. The efficiency and quick adaptation of new standards are key to the mobile network. With the rapid development of the mobile network, the design of measurement gap, which suspends communication to give the mobile stations a gap period to perform measurement, requires more flexibility and efficiency.
In the current new radio (NR) system, only single measurement gap (MG) pattern can be configured within one measurement period for single UE if the UE supports per-UE MG only, or single frequency range (FR) if the UE supports per-FR MG. The measurement gap length (MGL) will be 3 ms, 4 ms, 6 ms in FR1 and 2.5 ms, 3.5 ms, 5.5 ms in FR2. When UE supports carrier aggregation (CA)/dual connectivity (DC), the UE may have additional RF chains which are not configured. These additional RF chains can be used to perform measurements. Measurements for target intra-frequency, inter-frequency, or Inter-radio access technology (RAT) may not use MG once the UE supports related band combination and has additional RF chains during the measurements. Although no measurement gap is needed, the additional interruption is still there due to RF power on/off before or after the measurement occasions, such as synchronization signal block (SSB)-based Measurement Timing configuration (SMTC) window. The visible interruption length (VIL) can be only 0.5 ms for FR1 and 0.25 ms for FR2. To support concurrent measurements, network control small gap (NCSG) is needed. The configuration of NCSG needs to be addressed to adapt to the large possible configurations of the UE.
Improvements and enhancements are required to configure and perform measurements more efficiently.
Apparatus and methods are provided for network controlled small gap (NCSG) configuration. In one novel aspect, the UE sends UE NCSG capability reports to the wireless network, receives a network NCSG configuration, which is based on the UE NCSG capability reports, and performs one or more measurements based on the one or more NCSG for the corresponding measuring frequency bands. In one embodiment, the UE NCSG capability report indicates whether the NCSG is supported by the UE. The UE NCSG capability reports further include the band combination for supported NCSG. The UE NCSG capability report is based on the current configured one or more frequency layers of the UE and indicates whether NCSG is needed for one or more measuring frequency layers. In yet another embodiment, UE NCSG capability report further comprises a beam management type for each corresponding frequency alyer in frequency range-2 (FR2). The network NCSG configuration is received from a master node (MN) base station or a secondary node (SN) base station. In one embodiment, the UE performs intra-frequency measurements or a L1 measurement without gap in parallel with one or more measurements for inter-frequency layers within corresponding configured NCSG when corresponding frequency layers belong to FR1 or independent beam management (IBM) bands on FR2. In one embodiment, one configured NCSG overlaps with a configured measurement gap of the UE, the UE receives a radio resource control (RRC) signal indicating priority information for the overlapped measurement gap and the NCSG. In another embodiment, one configured NCSG overlaps with a configured measurement gap of the UE, the UE prioritizes the overlapped measurement gap and the NCSG based on predefined rules.
Other embodiments and advantages are described in the detailed description below. This summary does not purport to define the invention. The invention is defined by the claims.
The accompanying drawings, where like numerals indicate like components, illustrate embodiments of the invention.
Reference will now be made in detail to some embodiments of the invention, examples of which are illustrated in the accompanying drawings.
A wireless communications device 101 in wireless communication system 100 is served by base station 102 via uplink 111 and downlink 112. Other UEs 105 and 106 are served by different base stations. UE 105 is served by base station 103. UE 106 is served by base station 104. When UE 101 supports the new capability of NCSG, the UE 101 is configured to perform measurement by a NCSG configuration 182 from base station 102. Accordingly, measurement gap configuration 181 and NCSG configuration 182 can be configured between the UE 101 and the base station 102. Depending on capability of the UE 101, different gap patterns can be configured.
Base station 102 has an antenna 126, which transmits and receives radio signals. A RF transceiver module 123, coupled with the antenna 126, receives RF signals from antenna 126, converts them to baseband signals and sends them to processor 122. RF transceiver 123 also converts received baseband signals from processor 122, converts them to RF signals, and sends out to antenna 126. Processor 122 processes the received baseband signals and invokes different functional modules to perform features in base station 102. Memory 121 stores program instructions and data 124 to control the operations of base station 102. Base station 102 also includes a set of control modules, such as a measurement control circuit 171 that receives UE NCSG capability report, configures NCSG, and communicates with UEs to implement the NCSG measurement gap functions.
UE 101 has an antenna 135, which transmits and receives radio signals. A RF transceiver module 134, coupled with the antenna 135, receives RF signals from antenna 135, converts them to baseband signals and sends them to processor 132. RF transceiver 134 also converts received baseband signals from processor 132, converts them to RF signals, and sends out to antenna 135. Processor 132 processes the received baseband signals and invokes different functional modules to perform features in mobile station 101. Memory 131 stores program instructions and data 136 to control the operations of mobile station 101.
UE 101 also includes a set of control modules that carry out functional tasks. These control modules can be implemented in software, firmware, and hardware. A frequency configuration module 191 configures one or more frequency bands in a wireless network. An NCSG capability module 192 sends a UE NCSG capability report to the wireless network based on the configured one or more frequency bands, wherein the UE NCSG capability report indicates whether NCSG is needed for one or more measuring frequency layers. An NCSG control module 193 receives a network NCSG configuration from the wireless network, wherein one or more NCSGs are configured for corresponding frequency layers that are indicated as need-for-NCSG in the UE NCSG capability report. A measurement module 194 performs one or more measurements based on the one or more NCSGs for the corresponding measuring frequency layers.
In one embodiment, at step 210, UE 201 sends a UE NCSG capability report to MN 202. In one embodiment, the UE NCSG capability report indicates whether the NCSG is supported by the UE. The UE NCSG capability reports further include the band combination for supported NCSG. The UE NCSG capability report is based on the current configured one or more frequency layers of the UE and indicates whether NCSG is needed for one or more measuring frequency layers. In NR system, due to hardware limitation, UE can only support two searchers (two separate resources) for NR measurements. Although UE supports NCSG for some NR bands, UE can only measure at most two NR frequencies at a time. However, there is no limitation for inter-RAT measurements. Thus, UE can measure an additional inter-RAT with NR serving cell measurements at a time. For example, when UE performs intra-frequency measurements for primary cell (PCell) and one secondary cell (SCell), the inter-RAT frequency which belongs to a NCSG band can be measured at the same time. The benefit for NCSG is the network (NW) can still schedule data for active serving cells when UE perform measurements for these NCSG frequency layers. When there is no measurement gap configured among PCell and SCell(s), the NW can explicitly provide a single NCSG pattern with constant repetition period for UE. However, when there is still measurement gap configured for some frequency layers' measurements, if NW doesn't know whether UE will use NCSG or measurement gap to measure the frequency, NW has to schedule the measurement gap. To optimize data scheduling in NCSG, NW shall dedicatedly know the time occasions where UE will perform measurement by using legacy measurement gap or NCSG.
In one embodiment, the NW first configures one or more measurement gaps for UE through either MN 202 at step 220, or through SN 203 at step 250. When UE 201 sends the NCSG capability report at step 230, the NW configures NCSG patterns for NCSG frequency layers' measurements, including the frequency layers to be measured in the NCSG.
In one novel aspect, the UE NCSG capability report is updated dynamically based on the current configured one or more frequency layers. The one or more measuring frequency layers are a subset of the possible configurations for the UE.
In another embodiment 283, UE NCSG capability report further comprises a beam management type for each corresponding frequency band. In one embodiment, the beam management types are independent beam management (IBM) and common beam management (CBM). A potential issue for UE's NCSG capability reporting is how to explain the meaning for multiple bands reporting. Although UE reports to support multiple bands with NCSG, the inter-frequency measurement in these bands can be ‘only interruption’ to active serving cells. Owing to the UE RF implementation between bands, UE cannot guarantee that the inter-frequencies' measurement for these related bands has no impact between each other. Thus, UE cannot measure multiple inter-frequencies per measurement gap even though UE reports NCSG for related bands. The UE is not expected to measure 2 inter-frequencies/RAT layers in parallel even if UE reports the support of NCSG to both corresponding bands. It is assumed only one inter-frequency layer or inter-RAT frequency will be measured in each measurement occasion and no prioritization among layers with NCSG. In FR1, owing to using the omnidirectional antennas, UE can receive data or perform L1/L3 intra-frequency measurement together with inter-frequency measurements for the bands which UE claims to support NCSG. In FR2, when UE reports to support NCSG for some bands, whether UE can measure the frequencies in these bands together with receiving data or performing measurement in active serving cells still depends on the Rx beam reception.
In one embodiment, for FR2 intra-band, it shall assume UE will use the same Rx beam to receive the signals at a time. UE cannot simultaneously receive data or perform L1 measurement together with L3 measurement by NCSG because UE shall use fine beam to receive the data/perform L1 measurement but use rough beam to perform L3 measurement. The UE cannot perform L3 measurement for both intra-frequency and inter-frequency because UE can only receive the signal from one Rx beam at a time, but intra-frequency SMTC and inter-frequency SMTC may come from different directions. Although UE has additional RF chains, UE may still not receive the data, perform L1 or L3 measurement for active serving cells and measure the inter-frequency for related intra-bands in parallel. For FR2 inter-band which only supports CBM, the scenario will be similar as FR2 intra-band. The UE may still not receive the data, perform L1 or L3 measurement for active serving cells and measure the inter-frequency for related inter-bands in parallel because UE will use the same Rx beam to receive the signals for these bands, which have the active serving cells. For FR2 inter-band which supports IBM, UE can receive the data from these two bands with independent Rx beams. When UE claims NCSG for these FR2 bands, UE can receive data, perform L1 or intra-frequency L3 measurement together with inter-frequency L3 measurement for these bands. When the UE reports the band which supports NCSG, it shall also report which type of beam management it will use in this band. Other UE NCSG capability report forms can also be used to indicate, dynamically, NCSG capabilities for the frequency bands/layers based on the frequency configuration.
In another embodiment 632, the measurement configuration is predefined or preconfigured. In one embodiment, the frequency layers measurement can be performed in the MG 610. In another embodiment, the frequency layers measurement can be performed in the NCSG 620.
In yet another embodiment 633, the measurement is performed based on a UE NCSG report. The UE reports the NCSG for current bands. The UE also reports the NCSG scheduling pattern {VIRP (visible interruption reception period), VIL (visible interruption length), offset} by RRC signaling. Subsequently, the NW will know in which time occasion UE will use NCSG to measure frequencies. In another embodiment 634, the measurement is performed based on a UE report of an offset. The UE reports the absolute offset to subframe number SFN #0 to indicate which gap occasion will be used for NCSG frequency layers.
Inter-frequency measurement with NCSG 661, which is partially overlapping or fully non-overlapping with measurement gap can be monitored outside gap. Due to searcher limitation, inter-frequency measurement with NCSG will share the same searcher with secondary component carrier (SCC). These new measurement types shall be considered in CSSFoutside_gap for the measurements conducted outside measurement gaps. A difference with other measurement types is the additional interruption will be still needed. Owing to NW not knowing the dedicated measurement occasions for inter-frequency layers with NCSG, the interruption to active serving cells is always needed. The interruption can always occur before or after the SMTC for the inter-frequency layers with NCSG.
E-UTRA inter-RAT measurements with NCSG 662 is monitored outside gap. These new measurements can be performed together with serving cells' Primary component carrier (PCC) and SCC measurements because no baseband searcher limitation for E-UTRA Inter-RAT measurements, but due to RF combination limitation these measurements cannot be paralleled performed with inter-frequencies and other Inter-RAT measurements. For example, there are 6 frequency layers, including f0—intra-frequency PCC, f1, f2—intra-frequency SCC, f3, f4—inter-frequency with NCSG, f5—E-UTRA inter-RAT with NCSG. When NCSG is partially or fully non-overlapping with MG, the frequency layers with NCSG shall be measured outside the legacy gap as summarized in exemplary table 670.
The measurements within NCSG can be also believed as a new type of gap which is different with measurement without gap and measurement within gap. In NR, when some frequencies can be measured both within gap and outside gap, the measurements of these frequency layers shall be performed outside gap. The reason is the number of measurement gap occasions is relatively smaller than that of SMTC occasions. These measurement gap occasions shall be reserved for the frequencies which can only be measured within the gap. The CSSFwithin_NCSG,i applied for shall be measurement object i (MOi) for the following frequencies which are measured within NCSG, including:
In one embodiment, the measurement with MG, NCSG and other SMTC configured, is performed based on one or more predefined/preconfigured rules as illustrated in diagram 680. The measurement gap (MG) with interruption of MGL, will be reserved for frequencies which can only be measured within the gap. The NCSG, with interruption of VIL, reserved for the frequencies which can only be measured within the NCSG. The measurements of other frequencies, which do not need MG nor NCSG are performed in other SMTC occasions, which don't overlap with MG and NCSG. At step 681, the NW/UE checks if the frequency can only be measured in MG. If step 681 determines yes, the measurement is performed in the MG at step 682. If step 681 determines no, the NW/UE determines if the frequency can only be measured in NCSG at step 691. If step 691 determines yes, the measurement is performed in the NCSG at step 692. If step 691 determines no, the measurement is performed in other SMTC occasions which don't overlap with measurement gap and NCSG. In one embodiment, the predefined/preconfigured set of rules includes:
In one embodiment, a VIRP, VIL, measurement length (ML) pattern for NR is defined. To simplify the design, the first twenty-four NR gap patterns 0-23 of the legacy system are reused for NCSG gap pattern. In NR, VIL may be different due to FR1 and FR2. 3GPP RAN4 had already defined the switching time is 0.5 ms for frequency range FR1 and 0.25 ms for frequency range FR2. Thus, we can define the VIL length is 0.5 ms for FR1 and 0.25 ms for FR2. The overall interruption length depends on aggressor cell's SCS and VIL. When UE reports the supporting gap pattern, only 1 bit for supporting NCSG can be reported. When UE supports the traditional gap patterns, it implies the UE can support the correspondent NCSG gap patterns.
Although the present invention has been described in connection with certain specific embodiments for instructional purposes, the present invention is not limited thereto. Accordingly, various modifications, adaptations, and combinations of various features of the described embodiments can be practiced without departing from the scope of the invention as set forth in the claims.
Number | Date | Country | Kind |
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PCT/CN2021/070160 | Jan 2021 | WO | international |
PCT/CN2021/141576 | Dec 2021 | WO | international |
This application is filed under 35 U.S.C. § 111(a) and is based on and hereby claims priority under 35 U.S.C. § 120 and § 365(c) from International Application No. PCT/CN2021/141576, titled “Methods and apparatus of Network Controlled Small Gap in NR,”, filed Dec. 27, 2021. PCT/CN2021/141576, in turn, claims priority under 35 U.S.C. § 120 and § 365(c) from International Application No PCT/CN2021/070160, titled “Methods and apparatus of Network Controlled Small Gap in NR,” with an international filing date of Jan. 4, 2021. The disclosure of each of the foregoing documents is incorporated herein by reference.
Number | Date | Country | |
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Parent | PCT/CN2021/141576 | Dec 2021 | US |
Child | 18346817 | US | |
Parent | PCT/CN2021/070160 | Jan 2021 | US |
Child | PCT/CN2021/141576 | US |