Efficient signaling in non-terrestrial and terrestrial network deployments

Abstract

Methods, apparatuses, and systems are disclosed for reducing signaling overhead and power consumption while ensuring mobility of a communication device in non-terrestrial network deployments as well as terrestrial network deployments. In one example aspect, a method of wireless communication includes receiving, by a communication device from a wireless communication node, information including a configuration parameter corresponding to a length of a discontinuous reception cycle of the communication device. The method further includes performing, by the communication device, an operation based on the configuration parameter.

Description

Technical Field

[0001] This patent application is generally directed to wireless communication. Background Technology

[0002] Mobile communication technology is propelling the world towards an increasingly interconnected and networked society. The rapid growth of mobile communications and technological advancements have led to greater demands for capacity and connectivity. Other factors, such as energy consumption, device cost, spectrum efficiency, and latency, are also important for meeting the needs of various communication scenarios. Various technologies are being discussed, including new methods for providing higher quality service, longer battery life, and improved performance. Summary of the Invention

[0003] This patent application specifically describes techniques related to reducing signaling overhead and power consumption while ensuring the mobility of communication equipment in both non-terrestrial and terrestrial network deployments.

[0004] In one embodiment, a wireless communication method is disclosed. The method includes: receiving information including configuration parameters from a wireless communication node by a communication device, the configuration parameters corresponding to the length of a discontinuous reception period of the communication device. The method also includes performing operations by the communication device based on the configuration parameters.

[0005] In another embodiment, a wireless communication method is disclosed. The method includes: a wireless communication node transmitting information including configuration parameters corresponding to the length of a discontinuous reception period of the communication device, so that the communication device can perform operations based on the configuration parameters.

[0006] In another embodiment, a wireless communication method is disclosed. The method includes: receiving information from a wireless communication node by a communication device specifying conditions associated with an operation to be performed by the communication device. The method further includes: initiating the operation by the communication device when the conditions are met.

[0007] In another embodiment, a wireless communication method is disclosed. The method includes: a wireless communication node sending operation-related information to a communication device, enabling the communication device to initiate the operation based on the information.

[0008] In another example, a communication device is disclosed. This device includes a processor configured to implement the methods described above.

[0009] In another embodiment, a computer program storage medium is disclosed. The computer program storage medium includes code stored thereon. When executed by a processor, the code causes the processor to perform the described methods.

[0010] This patent application describes these and other aspects. Attached Figure Description

[0011] Figure 1 An example scenario of a non-terrestrial network (NTN) deployment providing access to user equipment according to one or more embodiments of the present technology is shown.

[0012] Figure 2A This is a flowchart representation of a method for wireless communication according to one or more embodiments of the present technology.

[0013] Figure 2B This is a flowchart representation of another method for wireless communication according to one or more embodiments of the present technology.

[0014] Figure 3A This is a flowchart representation of another method for wireless communication according to one or more embodiments of the present technology.

[0015] Figure 3B This is a flowchart representation of yet another method for wireless communication according to one or more embodiments of the present technology.

[0016] Figure 4 Examples of wireless communication systems in which one or more embodiments of the present technology can be applied are shown.

[0017] Figure 5 This is a block diagram representation of a wireless station in which one or more embodiments of the present technology can be applied. Detailed Implementation

[0018] The use of section headings in this patent application is solely for readability purposes and not to limit the scope of the embodiments and techniques disclosed in each section to that section. Certain features are described using examples of fifth-generation (5G) wireless protocols. However, the applicability of the disclosed techniques is not limited to 5G wireless systems or satellite wireless systems.

[0019] In terrestrial deployments such as 5G terrestrial communication systems, network systems are primarily located in densely populated areas. In sparsely populated areas, network deployment can be extremely expensive. Due to cost, some areas may lack network availability. However, there is a significant need to collect data in remote areas (e.g., collecting meteorological data in mountainous or desert regions). Such high demand can be met through non-terrestrial deployments, where satellites can provide greater coverage in remote areas. Non-terrestrial network deployments can serve as an extension of terrestrial network coverage.

[0020] Figure 1 An example scenario 100 of a non-terrestrial network (NTN) deployment providing access to user equipment according to one or more embodiments of the present technology is illustrated. Figure 1As shown, NTN gateway 101 is a site or gateway deployed on the surface of the Earth. NTN gateway 101 can provide sufficient radio frequency (RF) power and RF sensitivity to the access satellite 103. In some embodiments, NTN gateway 101 can be a transport network layer (TNL) node. The wireless link between NTN gateway 101 and satellite 103 can be referred to as feed link 111. The wireless link between satellite 103 and user equipment (communication equipment) 105 can be referred to as service link 113. Satellite (or UAS platform) 107 generates several beams over a given service area defined by its field of view. The coverage area of ​​the beams typically has an elliptical shape 115.

[0021] Satellite 103 can be placed in either Low Earth Orbit (LEO) or Geostationary Earth Orbit (GEO). A GEO is a circular orbit 35,786 km above the Earth's equator and in the direction of the Earth's rotation. GEOs in this orbit have an orbital period equal to the Earth's rotation period, and therefore appear as a fixed point in the sky to ground observers. The typical beam coverage area of ​​a GEO satellite is 200 to 3,500 km. A LEO is an orbit around the Earth with an altitude between 300 km and 1,500 km. LEO satellites in such orbits orbit the Earth at a speed of 7.56 km / s. The typical beam coverage area of ​​a LEO satellite is 100 to 1,000 km.

[0022] With advancements in wireless communication technology, the use of the Internet of Things (IoT) (a system of interconnected computing devices) has become more widespread. IoT systems require extensive coverage areas for connectivity. Therefore, off-terrestrial network deployments can serve as an extension of terrestrial networks to ensure stable connectivity for IoT devices.

[0023] However, non-terrestrial network deployments present new challenges to existing narrowband Internet of Things (NB-IoT) or enhanced machine-type communication (eMTC) systems. For example, due to the rapid movement of LEO satellites, the satellite beams or cells providing coverage for fixed communication devices on the Earth's surface change frequently. If a communication device is served by an NTNLEO cell with a diameter between 50 km and 1000 km, the device can only maintain a connection for a maximum of 6.61 seconds to 132.38 seconds due to satellite movement. As a result, the fixed communication device must continuously perform cell updates in both idle (e.g., RRC_idle) and connected (e.g., RRC_connected) states. Continuous updates increase the signaling overhead and power consumption of the communication device. This patent application discloses techniques that can be implemented in various embodiments of communication devices (e.g., user equipment) to reduce signaling overhead and power consumption while allowing the communication device to maintain mobility. These techniques are suitable for NTN deployments, but they can be similarly applied to terrestrial networks.

[0024] Figure 2A This is a flowchart representation of a method 200 for wireless communication according to one or more embodiments of the present technology. Method 200 includes, at operation 202, a communication device receiving information from a wireless communication node including configuration parameters corresponding to the length of a discontinuous reception period of the communication device. Method 200 includes, at operation 204, the communication device performing an operation based on the configuration parameters.

[0025] In some embodiments, the configuration parameter is part of a plurality of configuration parameters included in information from the wireless communication node. The method further includes: the communication device selecting the configuration parameter from the plurality of configuration parameters based on the communication device's discontinuous reception period.

[0026] Figure 2B This is a flowchart representation of a method 250 for wireless communication according to one or more embodiments of the present technology. Method 250 includes, at operation 252, a wireless communication node transmitting information including configuration parameters corresponding to the length of a discontinuous reception period of the communication device, so that the communication device can perform operations based on the configuration parameters.

[0027] In some embodiments, the operation includes a cell reselection process. In some embodiments, the operation includes intra-frequency or inter-frequency measurements. In some embodiments, the configuration parameter is part of a plurality of configuration parameters included in information corresponding to the lengths of a plurality of discontinuous reception periods. In some embodiments, the configuration parameter indicates a condition corresponding to a discontinuous reception period that triggers the operation. In some embodiments, the configuration parameter includes at least one of the following: a cell reselection timer value, a frequency priority, or an offset to be used for cell reselection. In some embodiments, the cell reselection timer value or the offset to be used for cell reselection is negatively correlated with the length of the discontinuous reception period of the communication device. In some embodiments, the configuration parameter includes a list of neighboring cells.

[0028] In some embodiments, the configuration parameters are part of a plurality of sets of configuration parameters used in the cell reselection process, each set of configuration parameters corresponding to the length of a discontinuous reception period, which includes a threshold length of the discontinuous reception period or includes discontinuous reception periods supported by the communication device. In some embodiments, each discontinuous reception period is associated with an index, and at least one set of configuration parameters corresponds to one or more indices associated with one or more discontinuous reception periods. In some embodiments, each discontinuous reception period is associated with an index, and the plurality of sets of configuration parameters correspond to a bitmap including bits ordered according to the index of the discontinuous reception period. In some embodiments, the configuration parameters indicate invalid values ​​associated with the discontinuous reception periods of the communication device.

[0029] Figure 3A This is a flowchart representation of a method 300 for wireless communication according to one or more embodiments of the present technology. Method 300 includes, at operation 302, a communication device receiving information from a wireless communication node specifying conditions associated with an operation to be performed by the communication device. Method 300 includes, at operation 304, the communication device initiating the operation if the conditions are met. In some embodiments, the method includes the communication device sending a notification to a base station indicating completion of the operation.

[0030] Figure 3B This is a flowchart representation of a method 350 for wireless communication according to one or more embodiments of the present technology. Method 350 includes, at operation 352, a wireless communication node sending operation-related information to a communication device, enabling the communication device to initiate the operation based on the information.

[0031] In some embodiments, the operation includes one of the following: (1) intra-frequency or inter-frequency measurement, (2) Radio Resource Control (RRC) reconstruction process, or (3) carrier handover process. In some embodiments, the information includes a timing advance threshold associated with the operation, a signal-to-interference-plus-noise ratio (SIR) threshold associated with the operation, a connection time threshold associated with the operation, a distance threshold between the communication device and the serving cell or serving carrier associated with the operation, or an angle threshold between the communication device and a neighboring cell or candidate carrier. In some embodiments, the information is carried in a Radio Resource Control (RRC) message or broadcast in system information. In some embodiments, information sent to multiple communication devices is multiplexed in a single RRC message, which also includes multiple identifiers corresponding to the multiple communication devices. In some embodiments, information sent to multiple communication devices is carried in multiple RRC messages, each of the multiple RRC messages corresponding to one communication device, and the multiple RRC messages are multiplexed in a single Medium Access Control (MAC) Protocol Data Unit (PDU), which also includes multiple identifiers corresponding to the multiple communication devices.

[0032] Note that in some embodiments, the wireless communication node can be implemented as follows: Figure 1 Satellite 103 is shown. The communication equipment can be implemented as follows: Figure 1 User equipment 105 is shown.

[0033] As further described in this application, the above-described techniques provide efficient use of discontinuous reception to reduce power consumption while ensuring that communication devices can maintain their mobility when the serving cell changes. The techniques also allow communication devices to autonomously initiate cell reselection or carrier handover procedures, thereby avoiding mobility problems caused by additional latency in the network. These techniques can further reduce signaling overhead by multiplexing information for multiple communication devices in a single message. Some examples of the disclosed techniques are also described in the following example embodiments.

[0034] Example 1

[0035] Communication equipment (e.g., user equipment) can use discontinuous reception (DRX) in idle mode to reduce its power consumption. During each DRX cycle, when the communication equipment is idle or inactive, it monitors the Physical Downlink Control Channel (PDCCH) for paging messages. For example, when a neighboring cell meets the conditions for cell reselection, the communication equipment can perform cell reselection and camp on the neighboring cell. The conditions used to trigger the cell reselection process can be signal quality or a priority frequency associated with the cell. For example, when the signal quality of the serving cell is below a threshold for a certain duration (e.g., set by a cell reselection timer), a neighboring cell with a lower priority frequency can be considered a candidate cell for the cell reselection process. As another example, when the signal quality of a neighboring cell is above a threshold for a certain duration (e.g., set by a cell reselection timer), the neighboring cell can be considered a candidate cell for the cell reselection process. As yet another example, when determining cell ranking, frequency priority can be used to determine the absolute priority of a cell, and additional offsets can be added to the cell ranking criteria of neighboring cells to adjust the priorities of neighboring and serving cells.

[0036] When a communication device is configured with a short DRX period (e.g., 1.28s), it can detect changes in the serving cell's signal strength caused by satellite movement and reselect another cell. However, when the device is configured with a long DRX period, such as 34 minutes or 12 days, it cannot receive signals from the serving cell during the DRX period if the serving satellite has changed. In these scenarios, the device needs to trigger a cell reselection process in each DRX period to find a new suitable cell to camp on. Traditional cell reselection techniques (such as channel quality assessment of the serving cell or neighboring cells, or priority of neighboring cells) can take a long time for the device to find a new suitable cell. Therefore, different conditions need to be provided for triggering the cell reselection process corresponding to different DRX periods. For UEs with long DRX periods, a faster cell reselection process can be introduced.

[0037] In some embodiments, a wireless node (e.g., a base station or satellite) can configure parameters indicating different conditions for triggering cell reselection processes for different DRX cycles. These parameters can be included in Radio Resource Control (RRC) messages or broadcast in system information. These parameters can include frequency priority, cell reselection timer values, or additional offsets to be used for cell selection or reselection. For communication devices with long DRX cycles, one or more neighboring cells can be prioritized for cell reselection. In some embodiments, a shorter cell reselection timer value can be set for a longer DRX cycle. Similarly, a smaller offset for neighboring cells can be set for a longer DRX cycle. The communication device can select and apply these parameters based on its own DRX cycle. The communication device's DRX cycle can be broadcast or configured by the wireless node. In some embodiments, a specific DRX cycle for the communication device can be configured by the network (e.g., the core network).

[0038] In some embodiments, parameters can be organized as multiple sets of parameters in an RRC message or system information. Each set of parameters corresponds to a DRX cycle of a specific length. Multiple sets of parameters can be configured in the RRC message or system information. A set of parameters can correspond to one or more DRX cycles. In some embodiments, a DRX cycle is assigned an index, and each set of parameters is associated with one or more indices. In some embodiments, a DRX cycle is assigned an index, and multiple sets of parameters are associated with a bitmap having bits ordered according to the index of the DRX cycle. When a bit in the bitmap has a predetermined value (e.g., 1), the bit indicates that the corresponding set of parameters can be applied to a communication device operating using DRX cycles.

[0039] In some embodiments, each of the multiple sets of parameters corresponds to a threshold length of the DRX period. The communication device may select a set of parameters based on comparing its DRX period with the threshold length. For example, ParamSet1 corresponds to the DRX... t1 ParamSet2 corresponds to DRX t2 When the communication equipment has a lower DRX t1 During the DRX cycle, ParamSet1 is used by the communication device during cell reselection. When the communication device has a DRX value below the DRX value... t2 But greater than or equal to DRX t1 During the DRX cycle, ParamSet2 is used by the communication device during the cell reselection process.

[0040] In some embodiments, indicators disabling parameters corresponding to a DRX cycle or a DRX cycle threshold may be included in an RRC message or system information. The communication device may determine one or more invalid parameters based on its DRX cycle or by comparing its DRX cycle length to one or more threshold lengths. For example, the indicator may indicate InvalidParamSet1 and InvalidParamSet2, where InvalidParamSet1 corresponds to a DRX cycle. t1 InvalidParamSet2 corresponds to DRX t2 When the communication equipment has a lower DRX t1 During the DRX cycle, the communication device prohibits the use of InvalidParamSet1 in the cell reselection process. When the communication device has a DRX value below the specified value... t2 But greater than or equal to DRX t1 During the DRX cycle, communication equipment is prohibited from using InvalidParamSet2 for the cell reselection process.

[0041] Example 2

[0042] In-frequency or inter-frequency measurements help communication equipment determine when to reselect a more suitable cell. When the communication equipment is within the coverage area of ​​the serving cell, it can perform in-frequency or inter-frequency measurements. However, due to satellite movement, if the communication equipment has a long DRX cycle, the cell covering the communication equipment in the next DRX cycle may be different. The measurement the communication equipment just performed now becomes useless. Therefore, it is necessary to perform in-frequency or inter-frequency measurements differently depending on the DRX cycle. For example, the conditions for triggering in-frequency / inter-frequency measurements can be different for different DRX cycles.

[0043] In some embodiments, a wireless node (e.g., a base station or satellite) may include configuration information in an RRC message or system information broadcast to a communication node. This configuration information may include parameters indicating one or more conditions that trigger intra-frequency or inter-frequency measurements. In some embodiments, the parameter may indicate whether inter-frequency / intra-frequency measurements should be disabled for one or more DRX cycles. In some embodiments, the parameter may also indicate the duration associated with the inter-frequency / intra-frequency measurement. For example, a timer may be used to track the duration for which the communication device camps in the serving cell or the duration for which the communication device measures neighboring cells. If the timer value exceeds a threshold indicated by the one or more parameters, the intra-frequency / inter-frequency measurement may be disabled. In some embodiments, the configuration information may indicate a duration corresponding to a DRX cycle of the communication device, such that the communication device can disable intra-frequency or inter-frequency measurements for that duration and then re-enable the measurements thereafter.

[0044] In some embodiments, parameters can be organized as multiple sets of parameters in an RRC message or system information. Each set of parameters corresponds to a DRX cycle of a specific length. The RRC message or system information can configure multiple sets of parameters based on the DRX cycle. When a communication device operates using a specific DRX cycle, the corresponding set of parameters can be used to determine whether intra-frequency / inter-frequency measurements should be enabled / disabled or triggered. In some embodiments, a set of parameters can correspond to one or more DRX cycles. In some embodiments, a DRX cycle is assigned an index, and each set of parameters is associated with one or more indices. In some embodiments, a DRX cycle is assigned an index, and multiple sets of parameters are associated with a bitmap having bits ordered according to the index of the DRX cycle. When a bit in the bitmap has a predetermined value (e.g., 1), the bit indicates that the corresponding set of parameters can be applied to a communication device operating using a DRX cycle.

[0045] In some embodiments, each of the multiple sets of parameters corresponds to a threshold length of the DRX period. The communication device may select a set of parameters based on comparing its DRX period with the threshold length. For example, ParamSet1 corresponds to the DRX... t1 ParamSet2 corresponds to DRX t2 When the communication equipment has a lower DRX t1 During the DRX cycle, the communication device uses ParamSet1 to determine whether inter-frequency / intra-frequency measurements should be enabled / disabled or triggered. When the communication device has a DRX value below... t2 But greater than or equal to DRX t1 During the DRX cycle, the communication device uses ParamSet2 to determine whether inter-frequency / intra-frequency measurements should be enabled / disabled or triggered.

[0046] In some embodiments, the conditions for triggering or enabling / disabling measurements may be the same or different for intra-frequency and / or inter-frequency measurements. In some embodiments, a first condition is configured for intra-frequency measurements, while a different second condition is configured for inter-frequency measurements. The communication device can trigger appropriate measurements based on different conditions. In some embodiments, the same condition applies to both intra-frequency and inter-frequency measurements. Both measurements can be triggered by the communication device if the condition is met.

[0047] Example 3

[0048] As described above, due to satellite movement, when a communication device has a long DRX cycle, the cell covering the communication device in the next DRX cycle may become different. Measurements just performed by the communication device become useless. Therefore, it is necessary to perform intra-frequency and / or inter-frequency measurements in different ways depending on the different DRX cycles. In some embodiments, if the communication device has a long DRX cycle, it can perform intra-frequency and / or inter-frequency measurements immediately after it wakes up or immediately after a duration specified by the wireless node. In some embodiments, the communication device can perform or stop intra-frequency and / or inter-frequency measurements every DRX cycle or every few DRX cycles.

[0049] In some embodiments, a wireless node (e.g., a base station or satellite) may include configuration information in an RRC message or system information broadcast to a communication node. This configuration information may include parameters indicating one or more conditions that trigger intra-frequency and / or inter-frequency measurements. In some embodiments, the parameter may indicate the number of one or more DRX cycles, one or more specific DRX cycles, or the duration corresponding to a DRX cycle that can trigger a measurement. For example, an intra-frequency and / or inter-frequency measurement may be triggered after the number or duration of one or more DRX cycles indicated by the parameter. Intra-frequency or inter-frequency measurements may be triggered every DRX cycle or every N DRX cycles, where N is a positive integer. As another example, a communication device may perform intra-frequency and / or inter-frequency measurements when the communication device's DRX cycle is the same as the DRX cycle indicated by one or more parameters.

[0050] In some embodiments, parameters can be organized as multiple sets of parameters in an RRC message or system information. Each set of parameters corresponds to a DRX period of a specific length. The communication device can select a set of parameters based on comparing its DRX period length with one or more threshold lengths. For example, ParamSet1 corresponds to DRX. t1 ParamSet2 corresponds to DRX t2 When the communication equipment has a lower DRX t1 During the DRX cycle, ParamSet1 is used by the communication device (e.g., the duration after the communication device wakes up) to determine whether intra-frequency and / or inter-frequency measurements should be turned on / off or triggered. When the communication device has a DRX below... t2 But greater than or equal to DRX t1During the DRX cycle, ParamSet2 is used by the communication device to determine whether intra-frequency / inter-frequency measurements should be enabled / disabled or triggered. ParamSet1 and / or ParamSet2 may include indications that the communication device may trigger intra-frequency or inter-frequency measurements thereafter. Alternatively, ParamSet1 and / or ParamSet2 may include information indicating a duration after which the communication device should stop intra-frequency and / or inter-frequency measurements. In some embodiments, one or more individual durations may be used for intra-frequency and inter-frequency measurements. In some embodiments, the same duration may be used for both intra-frequency and inter-frequency measurements.

[0051] Example 4

[0052] Communication nodes (e.g., user equipment) can utilize neighbor cell lists to reduce the time required to find a more suitable cell. In NTN deployments, neighbor cell lists are predictable because satellites move along predictable paths. Accurate neighbor cell lists allow communication nodes to determine the next suitable cell efficiently. Due to satellite movement, communication nodes with different DRX cycles may search for different cells and require different neighbor cell lists. For example, two communication devices, UE1 and UE2, camp on cell 1. UE1 has a DRX cycle of 10.24s. Its neighbor cell list includes cells adjacent to cell 1. UE2 has a much longer DRX cycle of 34m. UE2's neighbor cell list includes cells far from cell 1. Therefore, neighbor cell lists corresponding to different DRX cycles are needed.

[0053] In some embodiments, a wireless node (e.g., a base station or satellite) can configure different neighbor cell lists for different DRX cycles. This configuration information can be included in interface messages (e.g., paging messages), Radio Resource Control (RRC) messages, or broadcast in system information. The configuration information may carry a communication device identifier (such as a serving temporary mobile subscriber identity) and a list of neighbor cell information (e.g., frequency and / or physical cell identifier, PCI) corresponding to different DRX cycles. For example, list 1 is configured for DRX cycle 1, and list 2 is configured for DRX cycle 2. More specifically, list 1 may include elements such as T1: cell 1, cell 2, cell 3, where T1 is associated with the length of a DRX cycle. Similarly, list 2 may include elements such as T2: cell 4, cell 5, cell 6, where T2 is associated with the length of another DRX cycle. The communication node can select an appropriate neighbor cell list based on its DRX cycle.

[0054] In some embodiments, the neighboring cell list can be organized into multiple sets. Each set of parameters corresponds to one or more DRX cycles. When a communication device operates using a specific DRX cycle, the corresponding set of neighboring cell lists can be used for cell search. In some embodiments, a set of parameters can correspond to one or more DRX cycles. In some embodiments, a DRX cycle is assigned an index, and each set of parameters is associated with one or more indices. In some embodiments, a DRX cycle is assigned one index, and multiple sets of parameters are associated with a bitmap having bits sorted according to the index of the DRX cycle. When a bit in the bitmap has a predetermined value (e.g., 1), the bit indicates that the corresponding set of parameters can be applied to a communication device operating using the DRX cycle.

[0055] In some embodiments, each of the multiple groups corresponds to a threshold length of the DRX period. The communication device can select a set of one or more neighboring cell lists based on comparing its DRX period with one or more threshold lengths. For example, CellListSet1 corresponds to the DRX period. t1 And a single CellListSet corresponds to a DRX t2 When the communication equipment has a lower DRX t1 During the DRX cycle, CellListSet1 is used by the communication device to perform cell search. When the communication device has a DRX below the threshold... t2 But greater than or equal to DRX t1 During the DRX cycle, CellListSet2 is used by the communication device to perform cell search.

[0056] Example 5

[0057] Measurements of the serving cell and neighboring cells consume power from communication devices, particularly NB-IoT and eMTC communication devices in RRC connection mode. To reduce power consumption, these devices do not always perform measurements. However, the measurement results help the communication device or one or more wireless nodes determine whether a handover process should occur. To balance power consumption and communication device mobility, it is desirable to send configuration information to the communication device indicating one or more conditions under which the communication device can trigger operations such as intra-frequency or inter-frequency measurements. The results of intra-frequency or inter-frequency measurements can also help wireless nodes or communication devices determine whether a handover process is necessary.

[0058] In some embodiments, when the timing advance (TA) value of the serving cell reaches a threshold, the communication device can trigger intra-frequency and / or inter-frequency measurements. A wireless node (e.g., a base station or satellite) can configure one or more TA thresholds in an RRC message or broadcast them in system information. When the TA value reaches or exceeds one or more TA thresholds, the communication node can trigger intra-frequency and / or inter-frequency measurements.

[0059] In some embodiments, due to satellite movement, when the duration of the connection between the communication device and the serving cell reaches a threshold, the communication device may trigger intra-frequency and / or inter-frequency measurements. A wireless node (e.g., a base station or satellite) may broadcast configuration information, such as one or more time thresholds or one or more durations, in an RRC message or in system information. When the connection time (e.g., the time since the communication device entered the RRC connected state) reaches the threshold or duration specified in the configuration information, the communication device may trigger intra-frequency or inter-frequency measurements. In some embodiments, a single threshold may be used for both intra-frequency and inter-frequency measurements. For example, a first timer tracking the connection time may be compared to a first threshold to determine whether an intra-frequency measurement should be triggered. A second timer tracking the connection time may be compared to the first threshold to determine whether an inter-frequency measurement should be triggered. In some embodiments, a single threshold may be used for both intra-frequency and inter-frequency measurements. For example, a timer tracking the connection time may be compared to a threshold to determine whether both intra-frequency and inter-frequency measurements should be triggered. One or more timers may start after the communication device enters the connected state and stop when the communication device enters the idle state.

[0060] Example 6

[0061] When the serving cell changes, some communication devices may not support the handover process. For example, when the signal of the serving cell deteriorates, NB-IoT communication devices cannot perform the handover process and instead rely on the RRC reconstruction process to other cells. Traditionally, the RRC reconstruction process is triggered by a Radio Link Failure (RLF). However, detecting an RLF takes a considerable amount of time. For NTN deployments, due to satellite movement, communication devices may already be within the coverage area of ​​a neighboring cell when the RRC reconstruction process has just been triggered. Therefore, for certain types of communication devices, the RRC reconstruction process needs to be triggered in advance.

[0062] In some embodiments, a wireless node (e.g., a base station or satellite) can be configured with one or more conditions to trigger the reconstruction process and candidate target cells. For example, configuration information can be carried in an RRC message or broadcast in system information. The configuration information may include one or more thresholds that can trigger the reconstruction process and information about neighboring cells, including but not limited to PCI, radio resource configuration, etc.

[0063] In some embodiments, one or more thresholds are associated with the signal-to-interference-plus-noise ratio (SINR). For example, the communication device may trigger a reconstruction process when the measured SINR of the serving cell is below or equal to a threshold. As another example, the communication device may trigger a reconstruction process when the measured SINR of a neighboring cell is equal to or greater than a threshold. In some embodiments, the communication device may trigger a reconstruction process when the measured SINR of a neighboring cell is equal to or greater than a threshold of the measured SINR of the serving cell.

[0064] In some embodiments, one or more thresholds are associated with the connection time of the communication device. For example, when the communication device maintains an RRC connection with the serving cell for a duration that reaches or exceeds a threshold, the communication device may trigger a reconstruction process.

[0065] In some embodiments, one or more thresholds are associated with the TA value of a cell. For example, a communication device may trigger a reconstruction process when the TA value of the serving cell is equal to or greater than a threshold. As another example, a communication device may trigger a reconstruction process when the TA value of a neighboring cell is equal to or less than a threshold. In some embodiments, a communication device may trigger a reconstruction process when the TA value of a neighboring cell is equal to or less than the TA value of the serving cell but higher than a threshold.

[0066] In some embodiments, one or more thresholds are associated with the distance between the communication device and one or more cells. The distance between the communication device and the cell can be determined by comparing the location of the communication device with the distance between a satellite or a reference point of the cell. For example, the communication device may trigger a reconstruction process when the distance between the communication device and the serving cell is equal to or greater than a threshold. As another example, the communication device may trigger a reconstruction process when the distance between the communication device and a neighboring cell is equal to or less than a threshold. In some embodiments, the communication device may trigger a reconstruction process when the distance between the communication device and a neighboring cell is equal to or less than the distance between the communication device and the serving cell, but exceeds a threshold.

[0067] In some embodiments, one or more thresholds are associated with the angle between the communication device and one or more cells. The angle between the communication device and the cell can be determined by comparing the location of the communication device with a satellite or cell reference point. For example, the communication device can trigger a reconstruction process when the angle between the communication device and the serving cell is equal to or less than a threshold. As another example, the communication device can trigger a reconstruction process when the angle between the communication device and a neighboring cell is equal to or greater than a threshold. In some embodiments, the communication device can trigger a reconstruction process when the angle between the communication device and a neighboring cell is equal to or greater than the angle between the communication device and the serving cell, and is above a threshold.

[0068] In some embodiments, one or more thresholds may be associated with a combination of SINR, connection time, TA value, distance and / or angle between communication devices and cells.

[0069] Example 7

[0070] When a communication device communicates with a multi-carrier cell, it can switch from one carrier to another based on an instruction from a wireless node (e.g., a base station or satellite). For example, an NB-IoT communication device can switch to another carrier when the wireless node indicates this in an RRC reconfiguration message. However, due to the large propagation delay, the communication device may spend too much time receiving the RRC reconfiguration. Therefore, the communication node needs to trigger the carrier switch in a timely manner.

[0071] In some embodiments, a wireless node (e.g., a base station or satellite) can be configured with one or more conditions to trigger carrier switching, allowing the communication device to determine whether carrier switching should be performed. For example, configuration information can be carried in an RRC message or broadcast in system information. The configuration information may include one or more thresholds that can trigger carrier switching, as well as additional information about one or more candidate carriers, including but not limited to carrier frequency, radio resource configuration, etc. In some embodiments, candidate carriers can be sorted according to various factors. For example, candidate carriers can be sorted based on descending SINR, ascending TA values, ascending distance between each carrier and the communication device, or descending angle between each carrier and the communication device. Based on the sorting, the communication device can select the optimal carrier for switching. If the communication device fails to switch to the optimal carrier, it can switch to the next optimal carrier based on the sorting.

[0072] In some embodiments, one or more thresholds are associated with the signal-to-interference-plus-noise ratio (SINR). For example, a communication device may trigger a carrier handover process when the measured SINR of the serving carrier is below or equal to a threshold. As another example, a communication device may trigger a carrier handover process when the measured SINR of a candidate carrier is equal to or greater than a threshold. In some embodiments, a communication device may trigger a carrier handover process when the measured SINR of a candidate carrier is equal to or greater than the measured SINR of the serving carrier and is above a threshold.

[0073] In some embodiments, one or more thresholds are associated with the connection time of the communication device. For example, when the communication device remains in an RRC connection state with the serving carrier for a duration that reaches or exceeds a threshold, the communication device may trigger a carrier switching process to switch to a target carrier.

[0074] In some embodiments, one or more thresholds are associated with the TA value of a carrier. For example, a communication device may trigger a carrier handover process when the TA value of the serving carrier is equal to or greater than a threshold. As another example, a communication device may trigger a carrier handover process when the TA value of a candidate carrier is equal to or less than a threshold. In some embodiments, a communication device may trigger a carrier handover process when the TA value of a candidate carrier is equal to or less than a threshold value of the serving carrier's TA value.

[0075] In some embodiments, one or more thresholds are associated with the distance between the communication device and one or more candidate carriers. The distance between the communication device and the carrier can be determined by comparing the location of the communication device with a reference point of the carrier. For example, the communication device may trigger a carrier handover process when the distance between the communication device and the serving carrier is equal to or greater than the threshold. As another example, the communication device may trigger a carrier handover process when the distance between the communication device and the candidate carrier is equal to or less than the threshold. In some embodiments, the communication device may trigger a carrier handover process when the distance between the communication device and the candidate carrier is equal to or less than the distance between the communication device and the serving carrier, but greater than the threshold.

[0076] In some embodiments, one or more thresholds are associated with the angle between the communication device and one or more carriers. The angle between the communication device and the carrier can be determined by comparing the position of the communication device with a reference point of the carrier. For example, the communication device may trigger a carrier handover process when the angle between the communication device and the serving carrier is equal to or greater than a threshold. As another example, the communication device may trigger a carrier handover process when the angle between the communication device and the candidate carrier is equal to or less than a threshold. In some embodiments, the communication device may trigger a carrier handover process when the angle between the communication device and the candidate carrier is equal to or greater than the angle between the communication device and the serving carrier.

[0077] In some embodiments, one or more thresholds may be associated with a combination of SINR, connection time, TA value, or distance and / or angle between the communication device and the carrier.

[0078] Example 8

[0079] The aforementioned technology allows communication nodes to automatically trigger a carrier switching process when one or more conditions are met. When the communication device completes the carrier switching process, the wireless node needs to be aware of the change; otherwise, the wireless node might transmit incorrect scheduling information about the old carrier. To ensure transmission consistency between the wireless node and the communication device, the communication device can notify the wireless node of the carrier switching once the switching process is complete.

[0080] In some embodiments, the communication device may transmit uplink (UL) signals to the wireless node on candidate / target carriers. UL signals may include a random-access channel (RACH) preamble, a sounding reference signal (SRS), signals on the Physical Uplink Shared Channel (PUSCH), a demodulation reference signal (DMRS), etc. In some embodiments, the wireless node may configure one or more dedicated UL resources on one or more candidate / target carriers for transmitting UL signals. Information about the dedicated UL resources may be carried in RRC messages (such as RRC reconfiguration messages). One or more dedicated UL resources may include resources for preamble indexing, SRS sequences, DMRS sequences, RACH resources in the frequency and time domains, SRS resources in the frequency and time domains, PUSCH resources in the frequency and time domains, or DMRS resources in the frequency and time domains, etc.

[0081] In some embodiments, one or more resources may be scheduled periodically in the time domain. In some embodiments, one or more resources may be scheduled in a non-periodic manner (e.g., one-time use). In some embodiments, a valid time domain location or a valid duration may be configured for transmitting a UL signal. For example, after a communication device receives the configuration of a dedicated resource, one or more dedicated resources become valid and remain valid until a valid time domain location is reached. In some embodiments, once the communication device receives the configuration of one or more dedicated resources, a timer with a valid duration is started. Once the timer expires, the one or more dedicated resources become invalid for the communication device. In some embodiments, the timer stops when the communication device receives a message from a wireless node or completes a handover process.

[0082] Upon receiving a UL signal, the wireless node may, in response, send a downlink (DL) signal such as a Downlink Control Indicator (DCI) message. If one or more dedicated UL resources become available, or if the communication device fails to receive a response from the wireless node, the communication device may attempt to send the UL signal again. The communication device may keep track of the number of UL transmission attempts it makes for sending the UL signal. When the number of UL transmission attempts reaches a threshold, the carrier handover process may be considered to have failed. In some embodiments, the communication device may maintain a timer to track the time between sending the first UL signal and receiving a response from the wireless node. If the timer reaches a threshold, the carrier handover process may be considered to have failed. Alternatively, a timer duration may be given. When the timer expires, the carrier handover process may be considered to have failed. One or more thresholds and / or durations may be configured by the wireless node. Upon detecting a failure in the carrier handover process, the communication device may initiate a reconstruction process.

[0083] Example 9

[0084] The configuration information transmitted by wireless nodes to implement the aforementioned cell reselection or carrier handover processes can result in significant signaling overhead. To reduce or minimize the signaling overhead associated with these processes, information from multiple communication devices can be multiplexed into one or fewer messages.

[0085] In some embodiments, a wireless node can multiplex multiple RRC messages into a single Protocol Data Unit (PDU) in the Media Access Control (MAC) layer, with each RRC message carrying information about the corresponding communication device. For example, a wireless node may need to initiate an RRC reconfiguration message for each transmission among multiple communication devices to initiate a handover process. The RRC reconfiguration message may carry a communication device identifier, such as a Cell Radio Network Temporary Identifier (C-RNTI), for the communication device. When a communication device receives a MAC PDU, each communication device can demultiplex the PDU and decode the RRC message based on its own identifier.

[0086] In some embodiments, a wireless node can multiplex multiple RRC messages into a single Protocol Data Unit (PDU) in the Media Access Control (MAC) layer, with each RRC message carrying information about the corresponding communication device. For example, a wireless node may need to initiate an RRC reconfiguration message for each transmission among multiple communication devices to initiate a handover process. The MAC PDU may carry a communication device identifier, such as a Cell Radio Network Temporary Identifier (C-RNTI), for the communication device. When a communication device receives a MAC PDU, each device can demultiplex the PDU and decode the RRC message based on its own identifier.

[0087] In some embodiments, a wireless node can multiplex information from multiple communication devices into a common RRC message. Each part of the information is associated with a communication device identifier, such as a Cell Radio Network Temporary Identifier (C-RNTI). When a communication device receives a common RRC message, each communication device can decode the RRC message based on its own identifier.

[0088] Figure 4 An example of a wireless communication system 400 in which one or more embodiments of the present technology can be applied is shown. The wireless communication system 400 may include one or more base stations (BS) 405a, 405b, one or more wireless devices 410a, 410b, 410c, 410d, and a core network 425. Base stations 405a, 405b may provide wireless services to wireless devices 410a, 410b, 410c, and 410d in one or more wireless sectors. In some embodiments, base stations 405a, 405b include directional antennas to generate two or more directional beams, thereby providing wireless coverage in different sectors.

[0089] Core network 425 can communicate with one or more base stations 405a, 405b. Core network 425 provides connectivity with other wireless communication systems and wired communication systems. Core network may include one or more service subscription databases to store information related to subscribed wireless devices 410a, 410b, 410c, and 410d. First base station 405a can provide wireless services based on a first wireless access technology, while second base station 405b can provide wireless services based on a second wireless access technology. Depending on the deployment scenario, base stations 405a and 405b can be quasi-coordinated or can be installed separately in the field. Wireless devices 410a, 410b, 410c, and 410d can support a variety of different wireless access technologies. The technologies and embodiments described herein can be implemented by base stations of the wireless devices described herein.

[0090] Figure 5This is a block diagram representation of a portion of a wireless station to which one or more embodiments of the present invention may be applied. Wireless station 505, such as a base station or wireless device (or communication device), may include processor electronics 510, such as a microprocessor implementing one or more of the wireless technologies presented herein. Wireless station 505 may include transceiver electronics 515 for transmitting and / or receiving wireless signals via one or more communication interfaces, such as an antenna 520. Wireless station 505 may include other communication interfaces for transmitting and receiving data. Wireless station 505 may include one or more memories (not explicitly shown) configured to store information such as data and / or instructions. In some embodiments, processor electronics 510 may include at least a portion of transceiver electronics 515. In some embodiments, wireless station 505 is used to implement at least some of the disclosed technologies, modules, or functions. In some embodiments, wireless station 505 may be configured to perform the methods described herein.

[0091] It should be understood that this application discloses techniques that can be embodied in various embodiments to reduce signaling overhead and power consumption in both non-terrestrial and terrestrial network deployments, while ensuring the mobility of communication devices. The disclosed and other embodiments, modules, and functional operations described in this application can be implemented in digital electronic circuits, or in computer software, firmware, or hardware that includes the structures disclosed in this application and their structural equivalents, or in a combination of one or more of these. The disclosed and other embodiments can be implemented as one or more computer program products, i.e., one or more modules of computer program instructions encoded on a computer-readable medium for execution by a data processing apparatus or for controlling the operation of a data processing apparatus. The computer-readable medium can be a machine-readable storage device, a machine-readable storage substrate, a memory device, a composition of substances that implement machine-readable propagation signals, or a combination of one or more of these. The term "data processing apparatus" includes all means, devices, and machines for processing data, including, for example, a programmable processor, a computer, or multiple processors or computers. In addition to hardware, the apparatus may include code that creates an execution environment for the computer program in question, such as code constituting processor firmware, a protocol stack, a database management system, an operating system, or a combination of one or more of these. The transmitted signal is an artificially generated signal, such as a machine-generated electrical signal, optical signal, or electromagnetic signal, which is generated to encode information for transmission to a suitable receiver device.

[0092] Computer programs (also referred to as programs, software, software applications, scripts, or code) can be written in any programming language (including compiled or interpreted languages) and can be deployed in any form, including as standalone programs or as modules, components, subroutines, or other units suitable for use in a computing environment. A computer program does not necessarily correspond to a file in a file system. A program can be stored as a portion of a file that holds other programs or data (e.g., one or more scripts stored in a markup language document), as a single file dedicated to the program in question, or as multiple co-located files (e.g., a file storing portions of one or more modules, subroutines, or code). A computer program can be deployed to execute on a single computer or on multiple computers located at a single site or distributed across multiple sites and interconnected by a communication network.

[0093] The processes and logic flows described herein can be executed by one or more programmable processors, which execute one or more computer programs to perform functions by processing input data and generating outputs. The processes and logic flows can also be executed by dedicated logic circuits, and the devices can be implemented as dedicated logic circuits, such as FPGAs (field programmable gate arrays) or ASICs (application-specific integrated circuits).

[0094] As an example, processors suitable for executing computer programs include both general-purpose microprocessors and special-purpose microprocessors, as well as any one or more processors in any type of digital computer. Typically, a processor receives instructions and data from read-only memory or random access memory, or both. The basic unit of a computer is a processor for executing instructions and one or more memory devices for storing instructions and data. Typically, a computer will also include, or be operatively coupled to, one or more mass storage devices (e.g., magnetic disks, magneto-optical disks, or optical disks) for storing data, to receive data from, transfer data to, or both of these mass storage devices. However, a computer does not require such devices. Computer-readable media suitable for storing computer program instructions and data include all forms of non-volatile memory, media, and memory devices, including, as examples, semiconductor memory devices (e.g., EPROM, EEPROM, and flash memory devices); magnetic disks (e.g., internal hard disks or removable disks); magneto-optical disks; and CD-ROMs and DVD-ROMs. The processor and memory may be supplemented by or incorporated into special-purpose logic circuitry.

[0095] Although this patent application contains numerous details, these details should not be construed as limiting the scope of any invention or what may be claimed, but rather as descriptions of features specific to particular embodiments of a particular invention. Certain features described in the context of individual embodiments in this patent application may also be implemented in combination in a single embodiment. Conversely, various features described in the context of a single embodiment may also be implemented individually or in any suitable sub-combination in multiple embodiments. Moreover, although features may be described above as functioning in certain combinations, or even initially claimed in this way, in certain circumstances one or more features from a claimed combination may be excluded from that combination, and the claimed combination may be for sub-combinations or variations thereof.

[0096] Similarly, although the operations are depicted in a specific order in the accompanying drawings, this should not be construed as requiring the operations to be performed in the specific order shown or in a sequential order, or to perform all of the shown operations to obtain the desired result. Furthermore, the separation of various system components in the embodiments described in this patent application should not be construed as requiring such separation in all embodiments.

[0097] Only a few implementation methods and examples have been described, and other implementation methods, enhancements and variations may be made based on the content described and shown in this patent application.

Claims

1. A method for wireless communication, comprising: receiving, by a communication device, information from a wireless communication node, the information comprising a plurality of configuration parameters corresponding to different lengths of discontinuous reception cycles, the plurality of configuration parameters comprising a neighbor cell list for a cell reselection procedure, the neighbor cell list corresponding to different lengths of discontinuous reception cycles; and performing, by the communication device, the following: selecting, by the communication device, a configuration parameter from the plurality of configuration parameters based on a discontinuous reception cycle configured for the communication device; triggering the cell reselection procedure based on a triggering condition corresponding to the selected configuration parameter; and performing the cell reselection procedure based on the selected configuration parameter and a neighbor cell list corresponding to a length of the discontinuous reception cycle of the communication device.

2. The method of claim 1, wherein, The operations comprise intra- or inter-frequency measurements.

3. The method of claim 1 or 2, wherein, The selected configuration parameter indicates a condition corresponding to the discontinuous reception cycle that triggers the operations.

4. The method of claim 1 or 2, wherein, The selected configuration parameter further comprises at least one of a cell reselection timer value, a priority of a frequency, or an offset to be used for cell reselection.

5. The method of claim 4, wherein, The cell reselection timer value or the offset to be used for cell reselection is inversely related to a length of the discontinuous reception cycle of the communication device.

6. The method of claim 1 or 2, wherein, The information comprises a plurality of sets of configuration parameters, each configuration parameter of the plurality of configuration parameters being part of one of the plurality of sets of configuration parameters for the cell reselection procedure, and each set of configuration parameters corresponding to a different triggering condition of the cell reselection procedure associated with a threshold length of a respective discontinuous reception cycle supported by the communication device.

7. The method of claim 6, wherein, Each discontinuous reception cycle is associated with an index.

8. The method of claim 7, wherein, The plurality of sets of configuration parameters correspond to a bitmap, the bitmap comprising bits ordered according to indices of discontinuous reception cycles.

9. The method of claim 1 or 2, wherein, The selected configuration parameter indicates an invalid value related to the discontinuous reception cycle of the communication device.

10. The method of claim 1 or 2, wherein, The information is carried in a radio resource control, RRC, message or broadcast in system information.

11. The method of claim 10, wherein, The information transmitted to a plurality of communication devices is multiplexed in a single RRC message, the single RRC message further comprising a plurality of identifiers corresponding to the plurality of communication devices.

12. The method of claim 10, wherein, The information transmitted to a plurality of communication devices is carried in a plurality of RRC messages, each RRC message of the plurality of RRC messages corresponding to one communication device, and wherein the plurality of RRC messages are multiplexed in a single medium access control, MAC, protocol data unit, PDU, the MAC PDU further comprising a plurality of identifiers corresponding to the plurality of communication devices. 13.A method for wireless communication, comprising: transmitting, by a wireless communication node, information to a communication device, the information comprising a plurality of configuration parameters corresponding to different lengths of discontinuous reception cycles, the plurality of configuration parameters comprising a neighbor cell list for a cell reselection procedure, the neighbor cell list corresponding to different lengths of discontinuous reception cycles, to enable the communication device to perform the following based on the plurality of configuration parameters: selecting a configuration parameter from the plurality of configuration parameters based on a discontinuous reception cycle configured for the communication device, triggering the cell reselection procedure based on a trigger condition corresponding to the selected configuration parameter, and performing a cell reselection procedure based on the selected configuration parameter and a neighbour cell list corresponding to a length of a discontinuous reception cycle of the communication device.

14. The method of claim 13, wherein, The operation comprises intra- or inter-frequency measurements.

15. The method of claim 13 or 14, wherein, The selected configuration parameter indicates a condition corresponding to a discontinuous reception cycle triggering the operation.

16. The method of claim 13 or 14, wherein, The selected configuration parameter further comprises at least one of: a cell reselection timer value, a priority of a frequency, or an offset to be used for cell reselection.

17. The method of claim 16, wherein, The cell reselection timer value or the offset to be used for cell reselection is inversely related to a length of a discontinuous reception cycle of the communication device.

18. The method of claim 13 or 14, wherein, The information comprises a plurality of sets of configuration parameters, each configuration parameter of the plurality of configuration parameters being part of one of the plurality of sets of configuration parameters for the cell reselection procedure, and each set of configuration parameters corresponding to a different trigger condition of the cell reselection procedure associated with a threshold length of a respective discontinuous reception cycle supported by the communication device.

19. The method of claim 18, wherein, Each discontinuous reception cycle is associated with an index.

20. The method of claim 19, wherein, The plurality of sets of configuration parameters correspond to a bitmap, the bitmap comprising bits ordered according to indices of discontinuous reception cycles.

21. The method of claim 13 or 14, wherein, The selected configuration parameter indicates an invalid value related to a discontinuous reception cycle of the communication device.

22. The method of claim 13 or 14, wherein, The information is carried in a radio resource control, RRC, message or broadcast in system information.

23. The method of claim 22, wherein, The information transmitted to a plurality of communication devices is multiplexed in a single RRC message, the single RRC message further comprising a plurality of identifiers corresponding to the plurality of communication devices.

24. The method of claim 22, wherein, The information transmitted to a plurality of communication devices is carried in a plurality of RRC messages, each RRC message of the plurality of RRC messages corresponding to one communication device, and wherein the plurality of RRC messages are multiplexed in a single medium access control, MAC, protocol data unit, PDU, the MAC PDU further comprising a plurality of identifiers corresponding to the plurality of communication devices.

25. A communication device comprising a processor configured to implement the method of any one or more of claims 1 to 24.

26. A computer program product having code stored thereon, which, when executed by a processor, causes the processor to implement the method of any one or more of claims 1 to 24.

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