EP4691181A1

EP4691181A1 - User equipment operation when secondary cell is in network energy saving mode

Info

Publication number: EP4691181A1
Application number: EP23936088.6A
Authority: EP
Inventors: Jie Cui; Chunxuan Ye; Dan Wu; Dawei Zhang; Peng Cheng; Yang Tang
Original assignee: Apple Inc
Current assignee: Apple Inc
Priority date: 2023-05-10
Filing date: 2023-05-10
Publication date: 2026-02-11
Also published as: CN121080125A; WO2024229767A1

Abstract

A user equipment (UE) operates in carrier aggregation (CA) mode where a first component carrier (CC) is served by a serving cell and a second CC is served by a secondary cell (SCell) and where the SCell is operating in a network energy saving (NES) mode where the SCell does not transmit Synchronization Signal Blocks (SSBs). The UE is configured to determine whether the CA mode is an inter-band CA where the first CC is served on a first band and the second CC is served on a second band, determine whether the serving cell and the SCell are co-located and determine whether to reuse synchronization information from the serving cell for the SCell based on at least the determination of the inter-band CA and the serving cell and SCell being co-located.

Description

User Equipment Operation When Secondary Cell is in Network Energy Saving Mode

TECHNICAL FIELD

This application relates generally to wireless communication systems, and in particular relates to user equipment operation when secondary cell is in network energy saving mode.

BACKGROUND

Network energy saving (NES) is a mode of operation for New Radio (NR) which reduces signaling and power draw. NES typically involves a base station (e.g., a next generation node B (gNB) ) muting certain transmissions such as reference signals (RSs) . A Synchronization Signal Block (SSB) is an RS transmitted by a base station and used by a user equipment (UE) for time and frequency synchronization with the cell. Thus, muting of such an RS may result in the UE not being synchronized with the cell. However, it would be beneficial for power saving if a secondary cell could mute SSB transmissions when operating in NES without a UE becoming out of synchronization with the secondary cell.

SUMMARY

Some exemplary embodiments are related to a method performed by a user equipment (UE) operating in carrier aggregation (CA) mode where a first component carrier (CC) is served by a serving cell and a second CC is served by a secondary cell (SCell) and where the SCell is operating in a network energy saving (NES) mode where the SCell does not transmit Synchronization Signal Blocks (SSBs) . The method includes determining whether the CA mode is an inter-band CA where the first CC is served on a first band and the second CC is served on a second band, determining whether the serving cell and the SCell are co-located and determining whether to reuse synchronization information from the serving cell for the SCell based on at least the determination of the inter-band CA and the serving cell and SCell being co-located.
Other exemplary embodiments are related to a processor of a user equipment (UE) operating in carrier aggregation (CA) mode where a first component carrier (CC) is served by a serving cell and a second CC is served by a secondary cell (SCell) and where the SCell is operating in a network energy saving (NES) mode where the SCell does not transmit Synchronization Signal Blocks (SSBs) . The processor is configured to determine whether the CA mode is an inter-band CA where the first CC is served on a first band and the second CC is served on a second band, determine whether the serving cell and the SCell are co-located and determine whether to reuse synchronization information from the serving cell for the SCell based on at least the determination of the inter-band CA and the serving cell and SCell being co-located.
Still further exemplary embodiments are related to a user equipment (UE) operating in carrier aggregation (CA) mode having a transceiver communicating with a serving cell using a first component carrier (CC) and communicating with a secondary cell (SCell) using a second CC, where the SCell is operating in a network energy saving (NES) mode where the SCell does not transmit Synchronization Signal Blocks (SSBs) . The UE also includes a processor configured to determine whether the CA mode is an inter-band CA where the first CC is served on a first band and the second CC is served on a second band, determine whether the serving cell and the SCell are co-located and determine whether to reuse synchronization information from the serving cell for the SCell based on at least the determination of the inter-band CA and the serving cell and SCell being co-located.

Brief Description of the Drawings

Fig. 1 shows an exemplary network arrangement according to various exemplary embodiments.
Fig. 2 shows an exemplary user equipment (UE) according to various exemplary embodiments.
Fig. 3 shows an exemplary base station according to various exemplary embodiments.
Fig. 4 shows an exemplary method for reuse of inter-band serving cell coarse information and/or fine information for an SCell in NES mode according to various exemplary embodiments.
Fig. 5a shows a first exemplary arrangement for a UE according to various exemplary embodiments.
Fig. 5b shows a second exemplary arrangement for a UE 110 according to various exemplary embodiments.
Fig. 6 shows an exemplary method for reuse of inter-band serving cell coarse information and/or fine information for an SCell in NES mode based on a UE radio frequency (RF) chain arrangement according to various exemplary embodiments.

Detailed Description

The exemplary embodiments may be further understood with reference to the following description and the related appended drawings, wherein like elements are provided with the same reference numerals. The exemplary embodiments relate to a secondary cell (SCell) of a carrier aggregation (CA) combination operating in NES mode where the SCell mutes transmission of SSBs. More specifically, the exemplary embodiments relate to a UE reusing synchronization information from a serving cell of the CA combination when an SCell is in NES mode.
The exemplary embodiments are described with regard to a UE. However, reference to a UE is merely provided for illustrative purposes. The exemplary embodiments may be utilized with any electronic component that may establish a connection to an accessory device and is configured with the hardware, software, and/or firmware to exchange information and data with accessory devices. Therefore, the UE as described herein is used to represent any electronic component.
The exemplary embodiments are also described with reference to a 5G New Radio (NR) network. However, it should be understood that the exemplary embodiments may also be implemented in other types of networks, including but not limited to LTE networks, future evolutions of the cellular protocol (e.g., 6G networks) , or any other type of network.
The exemplary embodiments are also described with reference to carrier aggregation (CA) . In CA, a UE may communicate in the downlink (DL) or uplink (UL) with multiple cells of a network to increase throughput. CA includes the UE associating with a Primary Cell (PCell) and one or more Secondary Cells (SCells) . Different band combinations of CA may be served by the PCell and SCell, e.g., the PCell may serve. A first component carrier (CC) of a CA band combination (e.g., CC1) to the UE and the SCell may serve a second CC of the CA band combination (e.g., CC2) to the UE. Thus, in CA, both the PCell and the SCell are considered to be serving cells.
The exemplary embodiments are also described with reference to inter-band CA in frequency range 1 (FR1) of NR. FR1 of NR is divided into various frequency bands, e.g., n1, n12, n38, etc. Inter-band CA means that one of the CCs in the CA band combination is from a first one of the frequency bands and the other one of the CCs is from a second one of the frequency bands. In contrast, intra-band CA means that both CCs are from the same frequency band. It should be understood that inter-band CA will typically result in a larger frequency separation between the CCs in inter-band CA than in intra-band CA. This larger separation of frequency may impact the reuse of synchronization information by the UE. It should be understood that the exemplary embodiments are not limited to FR1 of NR and they may be applied to inter-band CA in other frequency ranges, e.g., FR2 of NR, frequency ranges defined in the 6G standards, etc. ) .
The exemplary embodiments provide manners for a UE to reuse synchronization information from a serving cell serving a CC of a CA combination when an SCell of the CA combination is operating in NES mode where the SCell mutes transmission of SSBs. The exemplary embodiments relate to whether the UE may reuse coarse and/or fine synchronization information from the serving cell based on various factors including conditions related to the serving cell and the SCell, conditions related to the frequency separation of the two CCs and capabilities of the UE.Each of these exemplary embodiments will be described in greater detail below.
Fig. 1 shows an exemplary network arrangement 100 according to various exemplary embodiments. The exemplary network arrangement 100 includes a UE 110. Those skilled in the art will understand that the UE 110 may be any type of electronic component that is configured to communicate via a network, e.g., mobile phones, tablet computers, desktop computers, smartphones, phablets, embedded devices, wearables, Internet of Things (IoT) devices, etc. It should also be understood that an actual network arrangement may include any number of UEs being used by any number of users. Thus, the example of one UE 110 is merely provided for illustrative purposes.
The UE 110 may be configured to communicate with one or more networks. In the example of the network arrangement 100, the network with which the UE 110 may wirelessly communicate is a 5G NR radio access network (RAN) 120. However, it should be understood that the UE 110 may also communicate with other types of networks (e.g., 5G cloud RAN, a next generation RAN (NG-RAN) , a legacy cellular network, etc. ) and the UE 110 may also communicate with networks over a wired connection. With regard to the exemplary embodiments, the UE 110 may establish a connection with the 5G NR RAN 120. Therefore, the UE 110 may have a 5G NR chipset to communicate with the NR RAN 120.
The 5G NR RAN 120 may be portions of a cellular network that may be deployed by a network carrier (e.g., Verizon, AT&T, T-Mobile, etc. ) . The RAN 120 may include cells or base stations that are configured to send and receive traffic from UEs that are equipped with the appropriate cellular chip set. In this example, the 5G NR RAN 120 includes the gNB 120A and the gNB 120B. However, reference to a gNB is merely provided for illustrative purposes, any appropriate base station or cell may be deployed (e.g., Node Bs, eNodeBs, HeNBs, eNBs, gNBs, gNodeBs, macrocells, microcells, small cells, femtocells, etc. ) .
Those skilled in the art will understand that any association procedure may be performed for the UE 110 to connect to the 5G NR RAN 120. For example, as discussed above, the 5G NR RAN 120 may be associated with a particular network carrier where the UE 110 and/or the user thereof has a contract and credential information (e.g., stored on a S IM card) . Upon detecting the presence of the 5G NR RAN 120, the UE 110 may transmit the corresponding credential information to associate with the 5G NR RAN 120. More specifically, the UE 110 may associate with a specific cell (e.g., gNB 120A) .
In this example, it may be considered that the UE 110 is operating in CA mode where the gNB 120A is the PCell and the gNB 120B is the SCell that will be operating in NES mode. As described above, CA mode may include multiple SCells but for the purpose of description only a single SCell is shown. In the exemplary embodiments, it may be considered that the PCell and SCell are co-located, e.g., in the same general physical location (e.g., on the same cell tower) . Also, while the PCell and SCell are shown as being different gNBs, those skilled in the art will understand that a single gNB may include multiple cells. Thus, the PCell and SCell may be cells of the same gNB.
The network arrangement 100 also includes a cellular core network 130, the Internet 140, an IP Multimedia Subsystem (IMS) 150, and a network services backbone 160. The cellular core network 130 manages the traffic that flows between the cellular network and the Internet 140. The IMS 150 may be generally described as an architecture for delivering multimedia services to the UE 110 using the IP protocol. The IMS 150 may communicate with the cellular core network 130 and the Internet 140 to provide the multimedia services to the UE 110. The network services backbone 160 is in communication either directly or indirectly with the Internet 140 and the cellular core network 130. The network services backbone 160 may be generally described as a set of components (e.g., servers, network storage arrangements, etc. ) that implement a suite of services that may be used to extend the functionalities of the UE 110 in communication with the various networks.
Fig. 2 shows an exemplary UE 110 according to various exemplary embodiments. The UE 110 will be described with regard to the network arrangement 100 of Fig. 1. The UE 110 may represent any electronic device and may include a processor 205, a memory arrangement 210, a display device 215, an input/output (I/O) device 220, a transceiver 225, and other components 230. The other components 230 may include, for example, an audio input device, an audio output device, a battery that provides a limited power supply, a data acquisition device, ports to electrically connect the UE 110 to other electronic devices, sensors to detect conditions of the UE 110, etc.
The processor 205 may be configured to execute a plurality of engines for the UE 110. For example, the engines may include an NES SCell engine 235 for performing operations related to synchronization operations when an SCell of an inter-band CA combination is operating in NES mode. The operations include, but are not limited to, receiving an NES SCell configuration from the network, evaluating conditions for reusing coarse and fine synchronization information of a serving cell for the SCell, determining RF chain use for the CA combination and reporting UE capabilities related to reuse of coarse and fine synchronization information for the CA combination. Each of these exemplary operations will be described in more detail below.
The above referenced engine being an application (e.g., a program) executed by the processor 205 is only exemplary. The functionality associated with the engines may also be represented as a separate incorporated component of the UE 110 or may be a modular component coupled to the UE 110, e.g., an integrated circuit with or without firmware. For example, the integrated circuit may include input circuitry to receive signals and processing circuitry to process the signals and other information. The engines may also be embodied as one application or separate applications. In addition, in some UEs, the functionality described for the processor 205 is split among two or more processors such as a baseband processor and an applications processor. The exemplary embodiments may be implemented in any of these or other configurations of a UE.
The memory arrangement 210 may be a hardware component configured to store data related to operations performed by the UE 110. The display device 215 may be a hardware component configured to show data to a user while the I/O device 220 may be a hardware component that enables the user to enter inputs. The display device 215 and the I/O device 220 may be separate components or integrated together such as a touchscreen. The transceiver 225 may be a hardware component configured to establish a connection with the 5G-NR RAN 120. Accordingly, the transceiver 225 may operate on a variety of different frequencies or channels (e.g., set of consecutive frequencies) .
Fig. 3 shows an exemplary base station 300 according to various exemplary embodiments. The base station 300 may represent the gNB 120A, the gNB 120B or any other access node through which the UE 110 may establish a connection and manage network operations.
The base station 300 may include a processor 305, a memory arrangement 310, an input/output (I/O) device 315, a transceiver 320, and other components 325. The other components 325 may include, for example, an audio input device, an audio output device, a battery, a data acquisition device, ports to electrically connect the base station 300 to other electronic devices and/or power sources, etc.
The processor 305 may be configured to execute a plurality of engines for the UE 110. For example, the engines may include an NES SCell engine 330 for performing operations related to NES SCell operations. The operations include, but are not limited to, configuring a UE for NES SCell operations for an inter-band CA combination, receiving RF chain information for the CA combination and receiving UE capabilities related to reuse of coarse and fine synchronization information for the CA combination. Each of these exemplary operations will be described in more detail below.
The memory 310 may be a hardware component configured to store data related to operations performed by the base station 300. The I/O device 315 may be a hardware component or ports that enable a user to interact with the base station 300. The transceiver 320 may be a hardware component configured to exchange data with the UE 110 and any other UE in the network arrangement 100. The transceiver 320 may operate on a variety of different frequencies or channels (e.g., set of consecutive frequencies) . Therefore, the transceiver 320 may include one or more components (e.g., radios) to enable the data exchange with the various networks and UEs.
As described above, the exemplary embodiments are related to an SCell operating in NES mode where SSB is muted. SSBs are used by the UE to remain in time and frequency synchronization including downlink automatic gain control (AGC) with a cell. Thus, by muting the SSB, the SCell may be risking the UE becoming out of synchronization with the SCell. The exemplary embodiments provide manners for the UE to reuse synchronization information from a serving cell of a CA combination for the SCell in NES mode that is muting SSBs.
In the exemplary embodiments, it will be described that a UE 110 may reuse synchronization information from a serving cell serving a CC of a CA band combination. Specifically, in the examples provided, it will be considered that the PCell 120A is serving the CC1 and the SCell 120B is serving the CC2 of the CA band combination CC1+CC2. Thus, in the examples, it will be considered that the SCell 120B is operating in NES mode and when referring to the UE 110 reusing the synchronization information from the serving cell, the serving cell is the PCell 120A.
However, it should be understood that the PCell being the inter-band serving cell is only exemplary. As described above, when operating in CA, the PCell and the one or more SCells are considered serving cells. For example, consider a 3 CC band combination where the PCell serves CC1, an SCell 1 serves CC2 and an SCell 2 serves CC3. When the SCell1 operates in NES mode, the UE may reuse synchronization information from either the PCell or the SCell2 (e.g., reference to the inter-band serving cell may be a reference to either the PCell or the SCell2) . Thus, while the exemplary embodiments describe the PCell as the serving cell, the serving cell is not required to be a PCell.
In the exemplary embodiments, the UE may reuse the timing information and the AGC information from the serving cell to remain in synchronization with the SCell. When reusing the timing information and the AGC information from the serving cell, there may be two levels, a coarse level and a fine level (referred to herein as “coarse information” or “coarse synchronization information” that may include coarse timing information and coarse AGC information and “fine information” or “fine synchronization information” that may include fine timing information and fine AGC information. In general, the coarse information may be used for cell level synchronization such as determining symbol boundaries or slot boundaries. Fine information may be used for more detailed operations such as receiving control channel information or data. The exemplary embodiments include scenarios where one or both of the coarse information or fine information of the serving cell timing information and/or AGC information may be reused.
In some exemplary embodiments, when inter-band CA is used for a co-located scenario, the UE may reuse coarse timing and coarse AGC information from the inter-band serving cell, e.g., the UE 110 may use the coarse timing and coarse AGC information from the PCell 120A to apply to the SCell 120B that is not transmitting SSB. This coarse timing/AGC information may be used for Layer 3 (L3) measurements and some aspects of SCell activation. The aspects of SCell activation for which the coarse information may be used is DL synchronization. Other aspects of SCell activation may still use the fine information such as T/F tracking and AGC settling information.
In these exemplary embodiments, it may not even be considered whether the fine information should be reused. For example, when inter-band CA is used for a co-located scenario, the UE 110 may reuse the coarse information without any further consideration or evaluation. In the exemplary embodiments that are described below, the UE 110 may further evaluate as to whether the fine information may be reused but in these exemplary embodiments such further evaluation may be skipped.
In the above exemplary embodiments, there may also be conditions on the reuse of the coarse information, e.g., when inter-band CA is used for a co-located scenario, the coarse information may be reused if the condition is satisfied. One exemplary condition may be that a received time difference (RTD) between the SSB-less SCell (e.g., gNB 120B) and the inter-band serving cell (e.g., gNB 120A) is within a cyclic prefix (CP) length or X*CP, where X<1.
Another exemplary condition may be that a difference of the reception power between the SCell and the inter-band serving cell is within a threshold. For example, the threshold may be a specific value (e.g., 6dB) or may be within a range of values (e.g., Y dB where 6dB<Y<25dB) .
While these conditions are described as conditions for reusing thee coarse information, these conditions may also be applied to reusing the fine information. As will be described in greater detail below, the UE may evaluate conditions to determine whether the fine information may be reused. Some exemplary conditions are provided below. However, the above examples may also serve as exemplary conditions for the fine information determination.
In other exemplary embodiments, when inter-band CA is used for a co-located scenario, the UE may reuse both coarse and fine timing and coarse and fine AGC information from the inter-band serving cell. However, there may be conditions for reusing the fine timing and AGC information. One exemplary condition may be based on the frequency domain (FD) separation between the CC1 and CC2. Specifically, if the FD separation is below a threshold, the UE 110 may reuse both the fine and coarse timing and the fine and coarse AGC information from the inter-band serving cell (e.g., PCell 120A) for the SSB-less SCell (e.g., SCell 120B) . Otherwise only coarse timing/AGC information may be reused. The FD separation threshold may be expressed in terms of Physical Resource Blocks (PRBs) or frequency kHz or MHz. The UE 110 may be configured with the FD separation threshold through network signaling (e.g., Radio Resource Control (RRC) , Medium Access Control (MAC) , etc. ) or the FD separation threshold may be defined in standards (e.g., 3GPP standards) .
Another exemplary condition may be whether the inter-band CCs (e.g., CC1 and CC2) are adjacent in the FD. The UE 110 may reuse fine and coarse timing and fine and coarse AGC information from the inter-band serving cell (e.g., PCell 120A) for the SSB-less SCell (e.g., SCell 120B) when the inter-band CCs are adjacent. Otherwise only coarse timing/AGC information may be reused.
A further exemplary condition may be whether the two bands that contain the two CCs (e.g., CC1 and CC2) are adjacent in the FD. If the two bands are adjacent, the UE 110 may reuse fine and coarse timing and fine and coarse AGC information from inter-band serving cell (e.g., PCell 120A) for the SSB-less SCell (e.g., SCell 120B) . Otherwise only coarse timing/AGC information may be reused.
In further exemplary embodiments, the network may indicate to the UE 110 the level of timing and AGC information that may be reused from one inter-band serving cell for the target SSB-less SCell. For example, as part of the CA configuration (or any other configuration) sent by the network to the UE 110, the network may indicate that if a particular SCell (e.g., SCell 120B) is operating in NES mode, the UE 110 may reuse only the coarse timing/AGC information from the inter-band serving cell (e.g., PCell 120A) or the UE 110 may reuse both fine and coarse timing and fine and coarse AGC information from the inter-band serving cell.
The fine information may be used for the SSB-less SCell operations, including SCell activation, L3 measurements and Layer 1 (L1) measurements. In this case, there is no need for fine T/F tracking or fine AGC settling during SCell activation because fine timing and AGC information is based on the fine T/F tracking and fine AGC settling result for the serving cell, respectively. The coarse information may be used in the same manner as described above.
Fig. 4 shows an exemplary method 400 for reuse of inter-band serving cell coarse information and/or fine information for an SCell in NES mode according to various exemplary embodiments. The method 400 is described with reference to the example where the PCell 120A is serving the CC1 and the SCell 120B is serving the CC2 of the inter-band CA combination CC1+CC2 and the SCell 120B is operating in NES mode.
When the above scenario is active, in 410, the UE 110 will determine whether the UE 110 has received an NES SCell configuration from the network, e.g., has the network indicated to the UE 110 for this band combination whether the coarse information and/or fine information may be reused. If the network has provided this NES SCell configuration information, in 420, the UE 110 will operate in accordance with the configuration. For example, if the network configured the UE 110 that for band combination CC1+CC2 served by PCell 120A and SCell 120B, respectively, the UE 110 may reuse both the coarse information and the fine information of the serving cell (PCell 120A) , the UE 110 will operate in accordance with this configuration and the method is complete.
On the other hand, if the UE 110 has not received an NES SCell configuration from the network related to the specific scenario, in 430, the UE 110 determines whether there are any conditions placed on reusing the coarse information for the inter-band serving cell, e.g., it is assumed that the coarse information may be reused when inter-band CA is used for a co-located scenario unless a condition has been placed on the reuse of the coarse information.
If there is a condition or conditions placed on thee reuse of the coarse information, in 440, the UE 110 evaluates the condition (s) . Some example conditions were described above, e.g., RTD between the NES SCell and the inter-band serving cell, difference of the reception power between the NES SCell and the inter-band serving cell, etc. If the condition is not satisfied, the UE 110 does not reuse the coarse information from the inter-band serving cell and the method 400 ends.
If the condition (s) are satisfied in 440 or if there are no conditions in 430, in 450, the UE 110 evaluates the condition (s) related to reusing the fine information. Again, numerous examples of conditions were described above such as FD separation between the CCs, whether the CCs are adjacent, whether the bands are adjacent, etc. If the condition (s) for using the fine information are satisfied, in 460, the UE 110 may reuse the coarse information and the fine information from the inter-band serving cell, e.g., the coarse timing and coarse AGC and the fine timing and fine AGC.
On the other hand, if the condition (s) for using the fine information are not satisfied, in 470, the UE 110 may reuse only the coarse information from the inter-band serving cell, e.g., the coarse timing and coarse AGC.
Fig. 5a shows a first exemplary arrangement 500 for a UE 110 according to various exemplary embodiments. In the first exemplary arrangement 500, the UE 110 includes two radio frequency (RF) chains, RF chain 1 and RF chain 2. In this arrangement, the UE 110 receives and processes the CC1 from the PCell 120A using the RF chain 1 and receives and processes the CC2 from the SCell 120B using the RF chain 2. In this arrangement, the components of the RF chain 1 and the RF chain 2 are separate, e.g., the AGC, the amplifier, etc.
Fig. 5b shows a second exemplary arrangement 550 for a UE 110 according to various exemplary embodiments. In the second exemplary arrangement 550, the UE 110 includes one RF chain, RF chain 1. In this arrangement, the UE 110 receives and processes the CC1 from the PCell 120A and the CC2 from the SCell 120B using the RF chain 1. and receives and processes the CC2 from the SCell 120B using RF chain 2. In this arrangement, the two CCs are processed using the same components of the RF chain 1, e.g., the AGC, the amplifier, etc.
These two different arrangements 500 and 550 for the UE 110 may be treated differently for the purposes of reusing the coarse information and/or the fine information of the inter-band serving cell. Some examples of this different treatment will be described below.
In some exemplary embodiments, when the UE 110 uses two RF chains for the band-combination of the two CCs as shown in Fig. 5a, the UE may reuse the coarse timing/AGC information from the inter-band serving cell for the SSB-less SCell. Otherwise, when the UE 110 uses a single RF chain for the band-combination of the two CCs as shown in Fig. 5b, the UE may reuse the fine and coarse timing and the fine and coarse AGC information from the inter-band serving cell for the SSB-less SCell. In these exemplary embodiments, the network may not understand whether the UE 110 is reusing the coarse information or both the coarse and fine information because the network is unaware of the configuration of the UE 110 with respect to RF chains.
Thus, in other exemplary embodiments, the UE 110 may indicate to the network the RF chain implementation as a UE capability, e.g., single RF chain or separated RF chain per band-combination. If the UE supports a single RF chain for a band combination, then the UE may reuse the fine and coarse timing and fine and coarse AGC information from the inter-band serving cell within this band combination. Otherwise, the UE 110 may only reuse the coarse timing/AGC information from the inter-band serving cell.
The UE 110 may use the coarse information and/or the fine information for the SCell in the same manner as was described above, e.g., related to the SCell activation, L1 measurements, L3 measurements, etc.
Fig. 6 shows an exemplary method 600 for reuse of inter-band serving cell coarse information and/or fine information for an SCell in NES mode based on a UE radio frequency (RF) chain arrangement according to various exemplary embodiments. The method 600 is described with reference to the example where the PCell 120A is serving the CC1 and the SCell 120B is serving the CC2 of the inter-band CA combination CC1+CC2 and the SCell 120B is operating in NES mode.
When the above scenario is active, in 610, the UE 110 will determine whether the UE 110 supports single RF chain or 2 RF chains for the CA band combination. If the UE supports a single RF chain for the CA band combination, in 620, the UE 110 may reuse the coarse information and the fine information from the inter-band serving cell, e.g., the coarse timing and coarse AGC and the fine timing and fine AGC.
On the other hand, if the UE supports a two RF chains for the CA band combination, in 630, the UE 110 may reuse only the coarse information from the inter-band serving cell, e.g., the coarse timing and coarse AGC.
In still further exemplary embodiments, the UE 110 may report a UE capability on fine or coarse information reuse for inter-band serving CCs. For example, the UE 110n can indicate for the configured serving CCs in the inter-band CA that it can support reuse of fine and coarse timing and fine and coarse AGC information between CCs or band combinations.
To provide a specific example, the network may configure the UE 110 with a CA combination of CC1+CC2+CC3 where CC1 is served by a PCell, CC2 is served by an SCell 1 and CC3 is served by an SCell2. Furthermore, the SCell2 serving the CC3 is the SSB-less SCell. After receiving the CA configuration, the UE 110 may report a capability to the network related to the CA combination. For example, the UE 110 may report a capability where the SCell2 (CC3) can reuse the coarse information from the PCell (CC1) but the SCell2 (CC3) can reuse both the fine and coarse information from the SCell 1 (CC2) . This UE capability information may be reported based on a network request or may be reported without a network request, e.g., whenever a UE receives a CA configuration.
Examples
In a first example, a processor of a user equipment (UE) operating in carrier aggregation (CA) mode where a first component carrier (CC) is served by a serving cell and a second CC is served by a secondary cell (SCell) and where the SCell is operating in a network energy saving (NES) mode where the SCell does not transmit Synchronization Signal Blocks (SSBs) , the processor configured to determine whether the CA mode is an inter-band CA where the first CC is served on a first band and the second CC is served on a second band, determine whether the serving cell and the SCell are co-located and determine whether to reuse synchronization information from the serving cell for the SCell based on at least the determination of the inter-band CA and the serving cell and SCell being co-located.
In a second example, the processor of the first example, further configured to determine a condition related to reusing coarse synchronization information from the serving cell for the SCell is satisfied and reuse the coarse synchronization information from the serving cell for the SCell when the CA is inter-band CA, the serving cell and the SCell are co-located and the condition related to reusing coarse synchronization information is satisfied.
In a third example, the processor of the second example, wherein the condition related to reusing coarse synchronization information is a received time difference (RTD) between the SCell and the serving cell is less than or equal to a cyclic prefix (CP) length or a partial CP length.
In a fourth example, the processor of the third example, wherein the condition related to reusing coarse synchronization information is a difference of a reception power between the SCell and the serving cell is less than a predetermined value.
In a fifth example, the processor of the first example, further configured to reuse coarse synchronization information from the serving cell for the SCell when the CA is inter-band CA and the serving cell and the SCell are co-located.
In a sixth example, the processor of the fifth example, wherein the coarse synchronization information comprises coarse timing information for the serving cell or coarse automatic gain control (AGC) information for the serving cell.
In a seventh example, the processor of the fifth example, wherein the coarse synchronization information is used by the UE for SCell activation or Layer 3 (L3) measurements for the SCell.
In an eighth example, the processor of the fifth example, further configured to determine whether a condition related to reusing fine synchronization information from the serving cell for the SCell is satisfied.
In a ninth example, the processor of the eighth example, further configured to reuse the fine synchronization information from the serving cell for the SCell when the condition related to reusing fine synchronization information is satisfied.
In a tenth example, the processor of the ninth example, wherein the fine synchronization information comprises fine timing information for the serving cell or fine automatic gain control (AGC) information for the serving cell.
In an eleventh example, the processor of the ninth example, wherein the fine synchronization information is used by the UE for SCell activation, Layer 1 (L1) or Layer 3 (L3) measurements for the SCell.
In a twelfth example, the processor of the eighth example, further configured to, when the condition related to reusing fine synchronization information is not satisfied, only use the coarse synchronization information from the serving cell for the SCell.
In a thirteenth example, the processor of the eighth example, wherein the condition related to reusing fine synchronization information is related to a frequency domain (FD) separation between the first CC and the second CC, whether the first CC and the second CC are adjacent on the FD or whether a first frequency band including the first CC is adjacent to a second frequency band including the second CC.
In a fourteenth example, the processor of the first example, further configured to receive, from a network, an NES SCell configuration comprising an indication that coarse synchronization information from the serving cell can be used for the SCell or coarse synchronization information and fine synchronization information from the serving cell can be used for the SCell and reuse the coarse synchronization information or the coarse synchronization information and the fine synchronization information based on the NES SCell configuration when the CA is inter-band CA, the serving cell and the SCell are co-located.
In a fifteenth example, the processor of the first example, further configured to determine whether the UE uses a first radio frequency (RF) chain to receive and process the first CC and the second CC or the first RF chain to receive and process the first CC and a second RF chain to receive and process the second CC.
In a sixteenth example, the processor of the fifteenth example, further configured to reuse coarse synchronization information from the serving cell for the SCell when the CA is inter-band CA, the serving cell and the SCell are co-located and the UE uses the first RF chain to receive and process the first CC and a second RF chain to receive and process the second CC.
In a seventeenth example, the processor of the sixteenth example, further configured to report, to a network, that the UE uses the first RF chain to receive and process the first CC and a second RF chain to receive and process the second CC.
In an eighteenth example, the processor of the fifteenth example, further configured to reuse coarse synchronization information and fine synchronization information from the serving cell for the SCell when the CA is inter-band CA, the serving cell and the SCell are co-located and the UE uses the first RF chain to receive and process the first CC and the second CC.
In a nineteenth example, the processor of the eighteenth example, further configured to report, to a network, that the UE uses the first RF chain to receive and process the first CC and the second CC.
In a twentieth example, the processor of the first example, further configured to report, to a network, the synchronization information supported by the UE for reuse when the CA is inter-band CA and the serving cell and the SCell are co-located, wherein the synchronization information comprises coarse synchronization information from the serving cell for the SCell or coarse synchronization information and fine synchronization information from the serving cell for the SCell.
In a twenty first example, a user equipment comprising a transceiver configured to communicate with a network and the processor of any of the first through twentieth examples communicatively coupled to the transceiver.
Those skilled in the art will understand that the above-described exemplary embodiments may be implemented in any suitable software or hardware configuration or combination thereof. An exemplary hardware platform for implementing the exemplary embodiments may include, for example, an Intel x86 based platform with compatible operating system, a Windows OS, a Mac platform and MAC OS, a mobile device having an operating system such as iOS, Android, etc. The exemplary embodiments of the above described method may be embodied as a program containing lines of code stored on a non-transitory computer readable storage medium that, when compiled, may be executed on a processor or microprocessor.
Although this application described various embodiments each having different features in various combinations, those skilled in the art will understand that any of the features of one embodiment may be combined with the features of the other embodiments in any manner not specifically disclaimed or which is not functionally or logically inconsistent with the operation of the device or the stated functions of the disclosed embodiments.
It is well understood that the use of personally identifiable information should follow privacy policies and practices that are generally recognized as meeting or exceeding industry or governmental requirements for maintaining the privacy of users. In particular, personally identifiable information data should be managed and handled so as to minimize risks of unintentional or unauthorized access or use, and the nature of authorized use should be clearly indicated to users.
It will be apparent to those skilled in the art that various modifications may be made in the present disclosure, without departing from the spirit or the scope of the disclosure. Thus, it is intended that the present disclosure cover modifications and variations of this disclosure provided they come within the scope of the appended claims and their equivalent.

Claims

A method performed by a user equipment (UE) operating in carrier aggregation (CA) mode where a first component carrier (CC) is served by a serving cell and a second CC is served by a secondary cell (SCell) and where the SCell is operating in a network energy saving (NES) mode where the SCell does not transmit Synchronization Signal Blocks (SSBs) , the method comprising:

determining whether the CA mode is an inter-band CA where the first CC is served on a first band and the second CC is served on a second band;

determining whether the serving cell and the SCell are co-located; and

determining whether to reuse synchroni zation information from the serving cell for the SCell based on at least the determination of the inter-band CA and the serving cell and SCell being co-located.
The method of claim 1, further comprising:

determining a condition related to reusing coarse synchronization information from the serving cell for the SCell is satisfied; and

reusing the coarse synchronization information from the serving cell for the SCell when the CA is inter-band CA, the serving cell and the SCell are co-located and the condition related to reusing coarse synchronization information is satisfied.
The method of claim 2, wherein the condition related to reusing coarse synchronization information is a received time difference (RTD) between the SCell and the serving cell is less than or equal to a cyclic prefix (CP) length or a partial CP length.
The method of claim 3, wherein the condition related to reusing coarse synchronization information is a difference of a reception power between the SCell and the serving cell is less than a predetermined value.
The method of claim 1, further comprising:

reusing coarse synchronization information from the serving cell for the SCell when the CA is inter-band CA and the serving cell and the SCell are co-located.
The method of claim 5, wherein the coarse synchronization information comprises coarse timing information for the serving cell or coarse automatic gain control (AGC) information for the serving cell.
The method of claim 5, wherein the coarse synchronization information is used by the UE for SCell activation or Layer 3 (L3) measurements for the SCell.
The method of claim 5, further comprising:

determining whether a condition related to reusing fine synchronization information from the serving cell for the SCell is satisfied.
The method of claim 8, further comprising:

reusing the fine synchronization information from the serving cell for the SCell when the condition related to reusing fine synchronization information is satisfied.
The method of claim 9, wherein the fine synchronization information comprises fine timing information for the serving cell or fine automatic gain control (AGC) information for the serving cell.
The method of claim 9, wherein the fine synchronization information is used by the UE for SCell activation, Layer 1 (L1) or Layer 3 (L3) measurements for the SCell.
The method of claim 8, further comprising:

when the condition related to reusing fine synchronization information is not satisfied, only using the coarse synchronization information from the serving cell for the SCell.
The method of claim 8, wherein the condition related to reusing fine synchronization information is related to a frequency domain (FD) separation between the first CC and the second CC, whether the first CC and the second CC are adjacent on the FD or whether a first frequency band including the first CC is adjacent to a second frequency band including the second CC.
The method of claim 1, further comprising:

receiving, from a network, an NES SCell configuration comprising an indication that coarse synchronization information from the serving cell can be used for the SCell or coarse synchronization information and fine synchronization information from the serving cell can be used for the SCell; and

reusing the coarse synchronization information or the coarse synchronization information and the fine synchronization information based on the NES SCell configuration when the CA is inter-band CA, the serving cell and the SCell are co-located.
The method of claim 1, further comprising:

determining whether the UE uses a first radio frequency (RF) chain to receive and process the first CC and the second CC or the first RF chain to receive and process the first CC and a second RF chain to receive and process the second CC.
The method of claim 15, further comprising:

reusing coarse synchronization information from the serving cell for the SCell when the CA is inter-band CA, the serving cell and the SCell are co-located and the UE uses the first RF chain to receive and process the first CC and a second RF chain to receive and process the second CC.
The method of claim 16, further comprising:

reporting, to a network, that the UE uses the first RF chain to receive and process the first CC and a second RF chain to receive and process the second CC.
The method of claim 15, further comprising:

reusing coarse synchronization information and fine synchronization information from the serving cell for the SCell when the CA is inter-band CA, the serving cell and the SCell are co-located and the UE uses the first RF chain to receive and process the first CC and the second CC.
The method of claim 18, further comprising:

reporting, to a network, that the UE uses the first RF chain to receive and process the first CC and the second CC.
The method of claim 1, further comprising:

reporting, to a network, the synchronization information supported by the UE for reuse when the CA is inter-band CA and the serving cell and the SCell are co-located, wherein the synchronization information comprises coarse synchronization information from the serving cell for the SCell or coarse synchronization information and fine synchronization information from the serving cell for the SCell.