Time Synchronization Technology

Abstract

[0009] Techniques for determining a time clock value by a communication device using information provided by the network device are described. An exemplary wireless communication method includes receiving, by the communication device, a first signal at a first time period, transmitting, by the communication device, a second signal to the network device at a second time period that is later than the first time period, receiving, by the communication device, a third message including timing information associated with the first time period, the second time period, or a propagation delay value, and determining, by the communication device, a time when the communication device received the first signal based on at least the timing information.

Description

[Technical field]

[0001] Technical Field TECHNICAL FIELD This disclosure relates generally to digital wireless communications. [Background technology]

[0002] background Mobile communication technologies are moving the world towards an increasingly connected and networked society. Compared to existing wireless networks, next generation systems and wireless communication technologies need to support a much wider range of use case characteristics and provide a more complex and sophisticated range of access requirements and flexibility.

[0003] Long Term Evolution (LTE) is a standard for wireless communications for mobile devices and data terminals developed by the 3rd Generation Partnership Project (3GPP®). LTE Advanced (LTE-A) is a wireless communications standard that extends the LTE standard. The fifth generation of wireless systems, known as 5G, is dedicated to advancing the LTE and LTE-A wireless standards to support higher data rates, a large number of connections, ultra-low latency, high reliability, and other emerging business needs. Summary of the Invention [Means for solving the problem]

[0004] overview Techniques are disclosed for determining a time clock value by a communications device, such as a user equipment (UE), using information provided by a network device, such as a base station (BS).

[0005] The first wireless communication method includes receiving, by the communication device, a first signal at a first time period, transmitting, by the communication device, a second signal to the network device at a second time period that is later than the first time period, and receiving, by the communication device, a third message including timing information associated with the first time period, the second time period, or a propagation delay value. Operation 708 includes determining, by the communication device based at least on the timing information, a time at which the communication device received the first signal.

[0006] In some embodiments, the timing information in the third message includes a transmission time of a first period during which the first signal is transmitted by the network device, the third message includes a Timing Advance (TA) value, the communications device determines an updated TA value by using the TA value and a previous TA value or by using the TA value, and the communications device determines the time at which the communications device received the first signal by adding the transmission time of the first period to half the updated TA value. In some embodiments, the timing information in the third message includes a transmission time of a first period during which the first signal is transmitted by the network device, and the communications device determines the time at which the communications device received the first signal by adding the transmission time of the first period to a propagation delay value. In some embodiments, the timing information in the third message includes a transmission time of a first time period during which the first signal is transmitted by the network device and a first time difference value that is a function of at least a difference between the transmission time of the first time period and a receive time of a second time period during which the second signal is received by the network device, and the communications device determines the time at which the communications device receives the first signal by adding the transmission time of the first time period to a propagation delay value, the propagation delay value being determined by the first time difference value and a second time difference value that is a function of at least a difference between the receive time of the first time period and the transmission time of the second time period.

[0007] In some embodiments, the first time difference value is a function of (1) the difference between the transmission time of the first period and the reception time of the second period and (2) a time offset indicating the time difference between the first period and the second period, and the second time difference value is a function of (1) the difference between the reception time of the first period and the transmission time of the second period and (2) a time offset indicating the time difference between the first period and the second period. In some embodiments, the timing information in the third message includes a transmission time of a first time period during which the first signal is transmitted by the network device and a receive time of a second time period during which the second signal is received by the network device, and the communications device determines the time at which the communications device receives the first signal by subtracting a time clock offset value from or adding a time clock offset value to a first time associated with a first boundary of the first time period during which the first signal is received by the communications device, the time clock offset value being a function of the transmission time of the first time period, the receive time of the second time period, the first time associated with the first boundary of the first time period, and the second time associated with a second boundary of the second time period during which the second signal is transmitted by the communications device.

[0008] In some embodiments, the timing information in the third message includes a first sum of (1) a transmission time of a first period during which the first signal is transmitted by the network device and (2) a reception time of a second period during which the second signal is received by the network device, and the communications device determines the time at which the communications device received the first signal by subtracting a value determined by the communications device from a first time associated with a first boundary of the first period during which the first signal is received by the communications device or adding a value determined by the communications device to the first time, the value being a function of a first variable and a second variable, the first variable being the first sum and the second variable being a second sum of (1) the first time associated with the first boundary of the first period and (2) a second time associated with a second boundary of the second period during which the second signal is transmitted by the communications device.

[0009] In some embodiments, the method further includes receiving, by the communication device prior to receiving the first signal, a second message identifying one or more of the first time period or the second time period or indicating a transmission time of the first time period during which the first signal is transmitted by the network device. In some embodiments, the method further includes transmitting, by the communication device, a first message instructing the network device to transmit the second message, the communication device receiving the second message in response to transmitting the first message. In some embodiments, the first message is included in resource control (RRC) signaling, a medium access control (MAC) control element (CE), or uplink control information (UCI). In some embodiments, the transmission time is associated with a starting boundary of the first time period or an ending boundary of the first time period, or the reception time is associated with a starting boundary of the second time period or an ending boundary of the second time period. In some embodiments, the first time period or the second time period includes a system frame, a subframe, a slot, a subslot, or an orthogonal frequency division multiplexing (OFDM) symbol. In some embodiments, the second message or the third message is included in resource control (RRC) signaling, a medium access control (MAC) control element (CE), or downlink control information (DCI).

[0010] In some embodiments, the first signal includes a downlink (DL) reference signal (RS) or a downlink channel. In some embodiments, the DL RS includes a synchronization signal block (SSB) including a synchronization signal (SS) and a physical broadcast channel (PBCH) block, a channel state information reference signal (CSI-RS), a tracking reference signal (TRS), or a positioning reference signal (PRS). In some embodiments, the downlink channel includes a physical downlink control channel (PDCCH) or a physical downlink shared channel (PDSCH). In some embodiments, the second signal includes a physical random access channel (PRACH), a sounding reference signal (SRS), a physical uplink shared channel (PUSCH), or a physical uplink control channel (PUCCH).

[0011] A second wireless communication method includes transmitting, by a network device, a first signal at a first time period; receiving, by the network device, a second signal from the communication device at a second time period that is later than the first time period; and transmitting, by the network device, a third message including timing information associated with the first time period, the second time period, or a propagation delay value, wherein a time at which the communication device received the first signal is determined based at least on the timing information.

[0012] In some embodiments, the timing information in the third message includes a transmission time of a first time period during which the first signal is transmitted by the network device, and the third message includes a timing advance (TA) value. In some embodiments, the timing information in the third message includes a transmission time of a first time period during which the first signal is transmitted by the network device. In some embodiments, the timing information in the third message includes a transmission time of a first time period during which the first signal is transmitted by the network device and a time difference value that is a function of at least a difference between the transmission time of the first time period and a receive time of a second time period during which the second signal is received by the network device. In some embodiments, the time difference value is a function of (1) a difference between a transmission time of the first time period and a receive time of the second time period, and (2) a time offset indicating a time difference between the first time period and the second time period. In some embodiments, the timing information in the third message includes a transmission time of a first time period during which the first signal is transmitted by the network device and a receive time of a second time period during which the second signal is received by the network device. In some embodiments, the timing information in the third message includes a first sum of (1) a transmission time of a first period during which a first signal is transmitted by the network device, and (2) a reception time of a second period during which a second signal is received by the network device.

[0013] In some embodiments, the method further includes transmitting, by the network device prior to transmitting the first signal, a second message identifying one or more of the first period or the second period or indicating a transmission time of the first period during which the first signal is transmitted by the network device. In some embodiments, the method further includes receiving, by the network device, a first message instructing the network device to transmit the second message, the network device transmitting the second message in response to receiving the first message. In some embodiments, the first message is included in resource control (RRC) signaling, a medium access control (MAC) control element (CE), or uplink control information (UCI). In some embodiments, the transmission time is associated with a starting boundary of the first period or an ending boundary of the first period, or the reception time is associated with a starting boundary of the second period or an ending boundary of the second period.

[0014] In some embodiments, the first period or the second period includes a system frame, a subframe, a slot, a subslot, or an orthogonal frequency division multiplexing (OFDM) symbol. In some embodiments, the second message or the third message is included in resource control (RRC) signaling, a medium access control (MAC) control element (CE), or a downlink control information (DCI). In some embodiments, the first signal includes a downlink (DL) reference signal (RS) or a downlink channel. In some embodiments, the DL RS includes a synchronization signal block (SSB) including a synchronization signal (SS) and a physical broadcast channel (PBCH) block, a channel state information reference signal (CSI-RS), a tracking reference signal (TRS), or a positioning reference signal (PRS). In some embodiments, the downlink channel includes a physical downlink control channel (PDCCH) or a physical downlink shared channel (PDSCH). In some embodiments, the second signal includes a physical random access channel (PRACH), a sounding reference signal (SRS), a physical uplink shared channel (PUSCH), or a physical uplink control channel (PUCCH).

[0015] In yet another exemplary aspect, the methods described above are embodied in the form of processor executable code and stored on a non-transitory computer readable storage medium, the code contained on the computer readable storage medium, when executed by a processor, causes the processor to perform the methods described in this patent document.

[0016] In yet another exemplary embodiment, a device configured or operable to perform the above-mentioned method is disclosed.

[0017] These and other aspects and implementations thereof are described in greater detail in the drawings, specification, and claims. The present invention provides, for example, the following: (Item 1) 1. A wireless communication method, comprising: receiving, by a communication device, a first signal during a first time period; transmitting, by the communication device, a second signal to a network device at a second time period that is later than the first time period; receiving, by the communication device, a third message including timing information associated with the first period, the second period, or a propagation delay value; determining, by the communications device, a time when the communications device received the first signal based at least on the timing information; A method comprising: (Item 2) the timing information in the third message includes a transmission time of the first period during which the first signal is transmitted by the network device; the third message including a timing advance (TA) value; The communications device determines an updated TA value by using the TA value and a previous TA value, or by using the TA value; the communications device determines a time at which the communications device received the first signal by adding the transmission time of the first time period to half the updated TA value. The method according to item 1. (Item 3) the timing information in the third message includes a transmission time of the first period during which the first signal is transmitted by the network device; the communications device determining a time at which the communications device received the first signal by adding the transmission time of the first time period to the propagation delay value. The method according to item 1. (Item 4) The timing information in the third message is a transmission time of the first period during which the first signal is transmitted by the network device; a first time difference value that is a function of at least a difference between the transmission time of the first time period and a reception time of the second time period at which the second signal is received by the network device; Including, the communications device determining a time at which the communications device receives the first signal by adding the transmission time of the first time period to the propagation delay value; the propagation delay value is determined by the first time difference value and a second time difference value that is a function of at least a difference between a reception time of the first time period and a transmission time of the second time period. The method according to item 1. (Item 5) The first time difference value is (1) a difference between the transmission time in the first time period and the reception time in the second time period; and (2) a time offset indicating the time difference between the first period and the second period; is a function of The second time difference value is (1) a difference between the reception time in the first time period and the transmission time in the second time period; and (2) the time offset indicating the time difference between the first period and the second period; 5. The method according to claim 4, wherein the function (Item 6) The timing information in the third message is a transmission time of the first period during which the first signal is transmitted by the network device; and a reception time during the second period during which the second signal is received by the network device; Including, the communications device determines a time at which the communications device receives the first signal by subtracting or adding a time clock offset value from or to a first time associated with a first boundary of the first time period at which the first signal is received by the communications device; The above time clock offset value is said transmission time for said first period of time; said receiving time during said second period of time; the first time associated with the first boundary of the first time period; and a second time associated with a second boundary of the second period during which the second signal is transmitted by the communication device; The method according to item 1, wherein the function (Item 7) the timing information in the third message includes a first sum of (1) a transmission time of the first period during which the first signal is transmitted by the network device, and (2) a reception time of the second period during which the second signal is received by the network device; the communications device determines the time at which the communications device received the first signal by subtracting a value determined by the communications device from or adding a value determined by the communications device to a first time associated with a first boundary of the first time period at which the first signal is received by the communications device; the value being a function of a first variable and a second variable, the first variable is the first sum, the second variable is a second sum of (1) the first time associated with the first boundary of the first period of time, and (2) a second time associated with a second boundary of the second period of time during which the second signal is transmitted by the communication device; The method according to item 1. (Item 8) receiving, by the communication device prior to receiving the first signal, a second message, the second message comprising: Identifying one or more of said first time period or said second time period; or the first signal indicates a transmission time of the first period transmitted by the network device; The method of claim 1, further comprising: (Item 9) transmitting, by the communication device, a first message instructing the network device to transmit the second message, the communication device receiving the second message in response to transmitting the first message. The method according to item 8. (Item 10) 10. The method of claim 9, wherein the first message is included in resource control (RRC) signaling, a medium access control (MAC) control element (CE), or uplink control information (UCI). (Item 11) The transmission time is associated with a start boundary of the first period or an end boundary of the first period, or The receiving time is associated with a starting boundary of the second time period or an ending boundary of the second time period. 9. The method according to any one of items 2 to 8. (Item 12) 12. The method according to any one of items 1 to 11, wherein the first period or the second period includes a system frame, a subframe, a slot, a subslot, or an orthogonal frequency division multiplexing (OFDM) symbol. (Item 13) 12. The method according to any one of items 1 to 11, wherein the second message or the third message is included in resource control (RRC) signaling, a medium access control (MAC) control element (CE), or downlink control information (DCI). (Item 14) 12. The method according to any one of items 1 to 11, wherein the first signal includes a downlink (DL) reference signal (RS) or a downlink channel. (Item 15) Item 15. The method according to item 14, wherein the DL RS includes a synchronization signal block (SSB) including a synchronization signal (SS) and a physical broadcast channel (PBCH) block, a channel state information reference signal (CSI-RS), a tracking reference signal (TRS), or a positioning reference signal (PRS). (Item 16) Item 15. The method according to item 14, wherein the downlink channel includes a physical downlink control channel (PDCCH) or a physical downlink shared channel (PDSCH). (Item 17) 8. The method according to any one of items 1, 4, 6, or 7, wherein the second signal includes a physical random access channel (PRACH), a sounding reference signal (SRS), a physical uplink shared channel (PUSCH), or a physical uplink control channel (PUCCH). (Item 18) 1. A wireless communication method, comprising: Transmitting, by a network device, a first signal during a first time period; receiving, by the network device, a second signal from a communication device at a second time period after the first time period; transmitting, by the network device, a third message including timing information associated with the first period, the second period, or a propagation delay value, wherein a time at which the communication device received the first signal is determined based at least on the timing information; A method comprising: (Item 19) the timing information in the third message includes a transmission time of the first period during which the first signal is transmitted by the network device; the third message including a Timing Advance (TA) value; Item 19. The method according to item 18. (Item 20) 20. The method of claim 18, wherein the timing information in the third message includes a transmission time of the first period during which the first signal is transmitted by the network device. (Item 21) The timing information in the third message is a transmission time of the first period during which the first signal is transmitted by the network device; a time difference value that is a function of at least a difference between the transmission time of the first time period and a reception time of the second time period at which the second signal is received by the network device; 19. The method according to item 18, comprising: (Item 22) The above time difference value is (1) the difference between said transmission time in said first period of time and said reception time in said second period of time; and (2) a time offset indicating the time difference between the first period and the second period; 22. The method according to claim 21, wherein the function (Item 23) The timing information in the third message is a transmission time of the first period during which the first signal is transmitted by the network device; a reception time during which the second signal is received by the network device during the second period; 19. The method according to item 18, comprising: (Item 24) the timing information in the third message includes a first sum of (1) a transmit time of a first period during which a first signal is transmitted by the network device, and (2) a receive time of a second period during which a second signal is received by the network device; Item 19. The method according to item 18. (Item 25) transmitting, by the network device prior to transmitting the first signal, a second message, the second message comprising: Identifying one or more of said first time period or said second time period; or the first signal indicates a transmission time of the first period transmitted by the network device; 20. The method of claim 18, further comprising: (Item 26) receiving, by the network device, a first message instructing the network device to transmit the second message, the network device transmitting the second message in response to receiving the first message; Item 26. The method according to item 25. (Item 27) 27. The method of claim 26, wherein the first message is included in resource control (RRC) signaling, a medium access control (MAC) control element (CE), or uplink control information (UCI). (Item 28) The transmission time is associated with a start boundary of the first period or an end boundary of the first period, or The receiving time is associated with a starting boundary of the second time period or an ending boundary of the second time period. 26. The method according to any one of items 19 to 25. (Item 29) 29. The method of any of items 18 to 28, wherein the first period or the second period includes a system frame, a subframe, a slot, a subslot, or an orthogonal frequency division multiplexing (OFDM) symbol. (Item 30) 29. The method according to any of items 18 to 28, wherein the second message or the third message is included in resource control (RRC) signaling, a medium access control (MAC) control element (CE), or downlink control information (DCI). (Item 31) 29. The method according to any of items 18 to 28, wherein the first signal includes a downlink (DL) reference signal (RS) or a downlink channel. (Item 32) Item 32. The method according to item 31, wherein the DL RS includes a synchronization signal block (SSB) including a synchronization signal (SS) and a physical broadcast channel (PBCH) block, a channel state information reference signal (CSI-RS), a tracking reference signal (TRS), or a positioning reference signal (PRS). (Item 33) 32. The method according to claim 31, wherein the downlink channel includes a physical downlink control channel (PDCCH) or a physical downlink shared channel (PDSCH). (Item 34) 29. The method according to any of items 18 to 28, wherein the second signal includes a physical random access channel (PRACH), a sounding reference signal (SRS), a physical uplink shared channel (PUSCH), or a physical uplink control channel (PUCCH). (Item 35) 35. An apparatus for wireless communication comprising a processor configured to perform the method according to one or more of items 1 to 34. (Item 36) A non-transitory computer readable program storage medium having stored thereon code that, when executed by a processor, causes the processor to perform a method according to one or more of items 1 to 34. [Brief description of the drawings]

[0018] [Figure 1] FIG. 1 shows an example flow chart of operations performed by a user equipment (UE) and a network (NW) for the UE to determine a time clock.

[0019] [Diagram 2] FIG. 2 shows an example timing diagram when slots are transmitted by the NW and received by the UE.

[0020] [Diagram 3] 3 and 4 show example timing diagrams when a slot is transmitted by the NW and received by the UE, and when another slot is transmitted by the UE and received by the NW. [Figure 4]3 and 4 show example timing diagrams when a slot is transmitted by the NW and received by the UE, and when another slot is transmitted by the UE and received by the NW.

[0021] [Diagram 5] FIG. 5 illustrates an example block diagram of a hardware platform that may be part of a network device or user equipment.

[0022] [Figure 6] FIG. 6 illustrates an example of a wireless communication including a base station (BS) and user equipment (UE) according to some implementations of the disclosed technology.

[0023] [Figure 7] FIG. 7 illustrates an exemplary flow chart for determining when a communication device receives a signal.

[0024] [Figure 8] FIG. 8 shows an example flow chart for illustrating timing information. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] Detailed Description In wireless communication, strict clock synchronization may be required for some services, for example, in factory automation or smart grids. In some scenarios, the maximum allowable time offset in the synchronization domain between two nodes may be less than 500 nanoseconds. To achieve this, a first node with a time clock should distribute the time clock information to a second node that has only an independent clock. However, propagation delays may affect the accuracy of the acquired time clock when the second node acquires the time clock. In this patent document, several methods are provided for a node to determine an accurate time clock for time synchronization.

[0026] The exemplary headings of the various sections below are used to facilitate understanding of the disclosed subject matter and are not intended to limit the scope of the claimed subject matter in any way. Thus, one or more features of one exemplary section can be combined with one or more features of another exemplary section. Furthermore, although 5G terminology is used for clarity of explanation, the technology disclosed herein is not limited to only 5G technology and may be used in wireless systems implementing other protocols.

[0027] In this disclosure, it is understood that the disclosed techniques can be used for any node to obtain a time clock from another node that has a clock time. For example, a UE obtains a time clock from a network, or the network obtains a time clock from a UE, or a UE obtains a time clock from another UE. In this disclosure, a UE that obtains a time clock from a network is used as an example, where the network is a node that has a clock time and the UE is a node that needs a time clock.

[0028] EMBODIMENT 1

[0029] In some embodiments, the UE transmits a first message (e.g., signal, signaling) to a network (NW), such as a base station (BS). The message signifies (or indicates) that the UE requests the network to transmit time information. The network transmits a second message to the UE, which may be in response to the network receiving the first message. The second message includes at least time information that may indicate a transmission time of a start boundary or an end boundary of a first time unit (also known as a first period) in which the first signal is transmitted by the network, which may be a time when the network transmits the first time unit. For example, when the network transmits the start boundary of the first time unit or the end boundary of the first time unit. The first time unit may be a system frame, a subframe, a slot, a subslot, or an OFDM symbol. The first time unit may also be indicated by the network, for example, via the second message or another message. For example, the system frame number, the subframe number, the slot number, or the OFDM number of the first time unit may be indicated in the second message or another message. In some embodiments, the first time unit is indicated by the UE to the network.

[0030] Within the first time unit, the network transmits a first signal to the UE after the network transmits the second message. The first signal may include at least a downlink (DL) reference signal (RS) or a downlink channel. The DL RS may include at least a synchronization signal / physical broadcast channel block (SS / PBCH block, SSB), a channel state information reference signal (CSI-RS), a tracking reference signal (TRS), or a positioning reference signal (PRS), etc. The downlink channel may include a physical downlink control channel (PDCCH), or a physical downlink shared channel (PDSCH), etc.

[0031] The UE may receive a first signal within a first time unit and detect downlink frame timing based on the first signal. The downlink frame timing may describe the time at which the UE receives the first signal or the first time unit. The UE transmits an uplink (UL) signal (which may also be known as a second signal) based on the detected downlink frame timing and a timing advance (TA) value if there is a valid TA. For example, as shown in FIG. 2, if the UE receives slot Y with an ending boundary at time t2 (which is also the starting boundary of slot Y+1), the UE may transmit a UL signal at a t2-TA value. The UL signal includes at least one of a physical random access channel (PRACH), a sounding reference signal (SRS), a physical uplink shared channel (PUSCH), or a physical uplink control channel (PUCCH), etc.

[0032] The network transmits a third message to the UE. The third message may include at least a propagation delay value, or the third message may include at least a TA command including either a relative TA value by which the UE may adjust (e.g., increase or decrease) the UE's TA value, or an absolute TA value that the UE uses if the UE has no previous TA value before receiving the TA command. In some embodiments in which the third message includes a TA command, after receiving the TA command, the UE obtains an updated TA value by increasing or decreasing the UE's TA value by the relative TA value from the TA command, or the UE obtains an updated TA value from the absolute TA value. The UE may obtain a time clock (also known as a time clock value) at the time when it received the first signal by adding the transmission time of the first time unit (indicated by the time information from the network) with half of the updated TA value. In some embodiments in which the third message includes a propagation delay, after receiving the propagation delay value, the UE may obtain a time clock at the time when the UE received the first signal by adding the transmission time of the first time unit (indicated by the time information from the network) with the indicated propagation delay value.

[0033] In this manner, the UE can determine an accurate time clock from the network.

[0034] 1 shows an example flowchart of operations performed by a UE and a network (NW), such as a base station, for the UE to determine a time clock. The UE sends a first message to the network to request the network to provide time information.

[0035] The network then transmits time information to the UE, which may be carried by RRC signaling. In one example, the time information indicates the transmission time of the end boundary of slot Y in system frame Z, as shown in the timing diagram of Figure 2. Slot Y in system frame Z may also be indicated by the network via a system frame number and a slot number.

[0036] The indicated slot Y is in the first system frame Z after the time information is transmitted. From the UE's perspective, as shown in Figure 2, the indicated slot is in the first system frame Z after receiving the time information from the network.

[0037] The transmission time of the end boundary of the illustrated slot Y is t1 as shown in FIG. 2. A downlink RS, e.g., SSB, CSI-RS, TRS, or PRS, may be transmitted in the indicated slot Y. The UE performs downlink synchronization based on the downlink RS to determine the timing of the downlink frame. The UE detects that the reception time of the end boundary of the indicated slot Y is t2 as shown in FIG. 2. The UE transmits a UL signal to the network based on the detected downlink frame timing by the indicated slot Y and the corresponding downlink RS.

[0038] The network transmits a third message to the UE. In one example, the third message includes a propagation delay value. The UE determines that the time of t2 is the time indicated by the time information from the network (e.g., the transmission time of the end boundary of slot Y) plus the indicated propagation delay value. For example, the time provided by the network (e.g., t1) is 08:52:33, 139 milliseconds, 823 microseconds, and 130 nanoseconds on 18 March 2021. The indicated propagation delay value is 59 nanoseconds. In this example, the UE can determine that the time clock (e.g., t2) at the time of receiving the indicated end boundary of slot Y is 08:52:33, 139 milliseconds, 823 microseconds, and 189 nanoseconds on 18 March 2021.

[0039] In another example, the second message includes a TA command. The UE determines the updated TA value according to the information in the TA command as described above. The UE can then determine that the time of t2 is the time information provided by the network (e.g., the transmission time of the end boundary of slot Y in FIG. 2) plus half the updated TA value. For example, if the time provided by the network (e.g., t1) is 8:52:33, 139 milliseconds, 823 microseconds, and 130 nanoseconds on March 18, 2021, and the updated TA value is 1792 nanoseconds, the UE can determine that the time clock (e.g., t2) when receiving the indicated end boundary of slot Y is 8:52:33, 139 milliseconds, 824 microseconds, and 26 nanoseconds on March 18, 2021.

[0040] EMBODIMENT 2

[0041] In some embodiments, the UE transmits a first message (e.g., signal, signaling) to the network. The message signifies (or indicates) that the UE requests the network to transmit time information. The network transmits a second message to the UE, which may be in response to the NW receiving the first message. The second message indicates or identifies at least a first time unit and a second time unit (also known as a second period), in which the network transmits the first signal within the first time unit and the network receives the UL signal within the second time unit. The network transmits the time information to the UE in the second message or another message. In one example, the time information may indicate at least a transmission time of an end boundary (or a start boundary) of the first time unit in the time domain. The second time unit may be a system frame, a subframe, a slot, a subslot, or an OFDM symbol. The second time unit may also be indicated by the network, for example, via the second message or another message. For example, the system frame number, subframe number, slot number, or OFDM number of the second time unit may be indicated in the second message or another message. In some embodiments, the first time unit and the second time unit are indicated to the network by the UE.

[0042] The first signal is transmitted from the network to the UE in the first time unit after the network transmits the second message. The UE transmits an UL signal to the network in the second time unit, the UL signal being transmitted by the UE in response to receiving the first signal. The network transmits a third message to the UE. The third message includes at least an Rx-Tx time difference. The Rx-Tx time difference is the time difference between the transmission time of the ending boundary (or starting boundary) of the first time unit and the reception time of the ending boundary (or starting boundary) of the second time unit observed by the network. In some embodiments, a time offset between the first time unit and the second time unit can be taken into account when determining the Rx-Tx time difference.

[0043] The UE determines a propagation delay value based on the Rx-Tx time difference. For example, as described further below, the propagation delay may be determined using the following equation: [ka] The UE can obtain the time clock of when the UE received the ending boundary of the first time unit by adding the indicated time (e.g., the transmission time of the ending boundary (or starting boundary) of the first time unit) to the determined propagation delay.

[0044] In this manner, the UE can determine an accurate time clock from the network.

[0045] As shown in Figure 1, the UE sends a first message to the network to request the network to provide time information. The network sends a second message to the UE. In one example, the second message indicates slot 0 in the system frame 37 as a first time unit and slot 8 in the system frame 37 as a second time unit. The network further indicates a transmission time of an ending boundary of slot 0 in the system frame 37. The transmission time of the ending boundary of the first time slot is included in the second message or another message.

[0046] The network transmits a downlink signal in slot 0 of the system frame 37. The UE transmits a UL signal in slot 8 of the system frame 37. The network then transmits a third message to the UE that includes the Rx-Tx time difference observed by the network. [ka] t1-t4) is the time difference, from the network's perspective, between the transmit time of the indicated ending boundary of slot 0 (e.g., t1 shown in FIG. 3) and the receive time of the indicated ending boundary of slot 8 (e.g., t4 shown in FIG. 3). Thus, for example, the Rx-Tx time difference can be (t4-t1) or (t1-t4).

[0047] In some cases, the time offset between slot 0 and slot 8 is taken into account. Thus, for example, the Rx-Tx time difference is (t4-t1-t offset ) or (t1-t4-t offset ), and t offset is the time offset between slot 0 and slot 8.

[0048] From the network's perspective, in one example, the transmit time of the ending boundary of slot 0 in system frame 37 is 08:52:33, 139 ms, 823 microseconds, and 130 nanoseconds on 03 / 18 / 2021, and the receive time of the ending boundary of slot 8 in system frame 37 is 08:52:33, 139 ms, 831 microseconds, and 170 nanoseconds on 03 / 18 / 2021. In this example, the Rx-Tx time difference observed by the network is 8 microseconds and 40 nanoseconds. Continuing the example, if the time offset between slot 0 and slot 8 is taken into account, the Rx-Tx time difference is 40 nanoseconds and the time offset is 8 microseconds, corresponding to slot 8.

[0049] When the UE receives the Rx-Tx time difference, the UE determines a propagation delay value based on the received Rx-Tx time difference. The UE determines the Rx-Tx time difference observed by the UE ( t ), which is the time difference, from the UE's perspective, between the receive time of slot 0 in system frame 37 (e.g., t2 shown in FIG. 3) and the transmit time of the boundary of slot 8 in system frame 37 (e.g., t3 shown in FIG. 3). [ka] In one example, when the time offset between slot 0 and slot 8 is taken into account, the UE [ka] The Rx-Tx time difference observed by is 128 ns. In this example, the UE then determines that the propagation delay value is [ka] In one example, if the provided time information (e.g., t1) is 08:52:33, 139 ms, 823 μs, 130 ns on 03 / 18 / 2021 and the propagation delay value is 44 ns, the UE may determine that the time to receive the ending boundary of slot 0 is 08:52:33, 139 ms, 823 μs, 174 ns on 03 / 18 / 2021.

[0050] In some embodiments, the UE may transmit the Rx-Tx time difference observed by the UE to the network. The Rx-Tx time difference is the time difference between the reception time of the end boundary (or start boundary) of the first time unit observed by the UE and the transmission time of the end boundary (or start boundary) of the second time unit. After receiving the Rx-Tx time difference observed by the UE from the UE, the network can determine the propagation delay value using the same method used by the UE as described above. The network then transmits the propagation delay value to the UE for the UE to determine the accurate time clock.

[0051] EMBODIMENT 3

[0052] In some embodiments, the UE sends a message (e.g., signaling, signal) to the network. The message signifies (or indicates) that the UE requests the network to transmit time information. The network sends a second message (e.g., signaling, signal) to the UE in response to the NW receiving the first message. The second message indicates or identifies at least a first time unit and a second time unit, and the network transmits the first signal within the first time unit and the network receives the UL signal within the second time unit. In Example 3, the time information of the boundary of the first time slot may not be included in the second message. In some embodiments, the first time unit and the second time unit are indicated to the network by the UE.

[0053] The network then transmits DL signals in the first time unit, the DL signals including at least SSB, CSI-RS, TRS, or PRS, etc. The UE transmits UL signals in the second time unit, the UL signals including at least PRACH, or SRS, etc.

[0054] In response to receiving the UL signal, the network transmits a third message to the UE. The third message may include at least a transmission time of the first time unit (e.g., a start or end boundary of the first time unit) and a reception time of the second time unit (e.g., a start or end boundary of the second time unit). The transmission time and the reception time are based on a local time clock of the network.

[0055] The UE determines a time clock offset between the network and the UE based on the information provided in the third message. The UE can further determine a time to receive the DL signal.

[0056] In this manner, the UE can determine an accurate time clock from the network.

[0057] As shown in FIG. 1, the UE transmits a first message to the network to request the network to provide time information. The network sends a second message to the UE, which may be in response to the NW receiving the first message. The second message may indicate slot Y in system frame Z as the first time unit and slot W in system frame X as the second time unit. As shown in FIG. 4, in slot Y, after the network transmits the second message, the network transmits a first signal to the UE. And in slot W, the UE transmits a UL signal to the network.

[0058] The network transmits the transmission time of the ending boundary of the indicated slot Y and the reception time of the ending boundary of the indicated slot W observed by the network. For example, the transmission time of the ending boundary of the indicated slot Y (e.g., t1' shown in FIG. 4) is 08:52:33, 139 ms, 823 μs, 130 ns on 18 Mar 2021. In this example, the reception time of the ending boundary of the indicated slot W is 08:52:33, 139 ms, 847 μs, 278 ns on 18 Mar 2021. Note that these are based on the local clock times of the network.

[0059] From the UE's perspective, it detects that the reception time of the end boundary of the indicated slot Y (e.g., t2 shown in FIG. 4) is, for example, 08:52:33, 191 ms, 528 μs, 377 ns on March 18, 2021. The transmission time of the end boundary of the indicated slot W (e.g., t3 shown in FIG. 4) is, for example, 08:52:33, 191 ms, 552 μs, 313 ns on March 18, 2021. Note that these are based on the UE's clock times and may not be the correct clock times.

[0060] In one example, the UE may determine that the time clock offset between the network and the UE is ((t2+t3)-(t1'+t4')) / 2, which is 51 milliseconds, 705 microseconds, and 141 nanoseconds. The UE may subtract the time clock offset from the t2 value observed by the UE to obtain an updated t2 value. Thus, the UE may determine that the updated time clock at t2 is 08:52:33, 139 milliseconds, 823 microseconds, and 236 nanoseconds on Mar. 18, 2021.

[0061] In another example, the UE may determine that the time clock offset between the network and the UE is ((t1'+t4')-(t2+t3)) / 2, which is -51 milliseconds, -705 microseconds, and -141 nanoseconds. The UE may add the time clock offset to the t2 value observed by the UE to obtain an updated t2 value. Thus, the UE may determine that the updated time clock at t2 is 08:52:33, 139 milliseconds, 823 microseconds, and 236 nanoseconds on Mar. 18, 2021.

[0062] In some embodiments, the third message includes a sum of a transmit time of the indicated first time unit and a receive time of the second time unit observed by the network, where the transmit time and receive time are based on a local time clock of the network.

[0063] The UE determines a time offset between the network and the UE. The UE can further determine a time to receive the DL signal.

[0064] 4, the network indicates the sum of the indicated transmission time of the ending boundary of slot Y and the reception time of the ending boundary of slot W observed by the network, e.g., the sum of 8:52:33, 139 ms, 823 microseconds, and 130 nanoseconds on March 18, 2021 and 8:52:33, 139 ms, 847 microseconds, and 278 nanoseconds on March 18, 2021, based on the network's local time clock. This is denoted by S1 and is equal to t1'+t4' in FIG. 4.

[0065] The UE may obtain the sum of the reception time of the ending boundary of the indicated slot Y and the transmission time of the ending boundary of the indicated slot W observed by the UE, e.g., the sum of 8:52:33, 191 ms, 528 microseconds, and 377 nanoseconds on March 18, 2021 and 8:52:33, 191 ms, 552 microseconds, and 313 nanoseconds on March 18, 2021 based on the UE's local time clock. This is denoted by S2 and is equal to t2+t3 in FIG. 4.

[0066] In one example, the UE may determine that the time clock between the network and the UE is (S2-S1) / 2=51,705, 141 nanoseconds. The UE may subtract the time clock between the network and the UE from the t2 value observed by the UE to obtain an updated t2 value. Thus, the UE may determine that the updated time clock at t2 is 8:52:33, 139 milliseconds, 823 microseconds, and 236 nanoseconds on March 18, 2021.

[0067] In another example, the UE may determine that the time clock between the network and the UE is (S1-S2) / 2=-51,705,141 nanoseconds. The UE may add the time clock between the network and the UE to the t2 value observed by the UE to obtain an updated t2 value. Thus, the UE may determine that the updated time clock at t2 is 8:52:33, 139 milliseconds, 823 microseconds, and 236 nanoseconds on March 18, 2021.

[0068] In some embodiments, the UE may transmit to the network the reception time of the end boundary (or start boundary) of the first time unit and the transmission time of the end boundary (or start boundary) of the second time unit, or the sum thereof observed by the UE. The network may determine a time clock offset between the network and the UE by using a method used by the UE, as described above. The network then transmits the time clock offset to the UE. The UE determines the time to receive the DL signal, as described above.

[0069] In this patent document, if a message (e.g., the second message or the third message) is sent from a network to a UE, or if a message (e.g., the first message) is sent from a UE to a network, the message may be included in resource control (RRC) signaling, medium access control (MAC) control element (CE). If a message is sent from a network to a UE, the message may be included in downlink control information (DCI). In this patent document, if a message (e.g., the first signal) is sent from a UE to a network, the message may be included in uplink control information (UCI). In this patent document, if a message is sent from a UE to another UE, the message may be included in sidelink control information (SCI).

[0070] EMBODIMENT 4

[0071] When the network indicates the first time unit to the UE, the configuration of the DL RS to be transmitted in the first time unit is also indicated to the UE via the second message. For example, an SSB index, a CSI-RS resource index, a TRS resource index, or a PRS index can be indicated to the UE in the second message. Alternatively, when the network or the UE indicates the first time unit, it can mean that one or more DL RSs are triggered to be transmitted in the first time unit. For example, an SSB, an aperiodic CSI-RS, an aperiodic TRS, an aperiodic PRS are triggered. The configuration of the DL RS is configured before the DL RS is triggered.

[0072] When the network indicates the second time unit to the UE, the configuration of the UL RS to be transmitted in the second time unit is also indicated to the UE. For example, the PRACH resource configuration or the SRS configuration can be indicated to the UE. Alternatively, when the network or the UE indicates the second time unit, it can mean that one or more UL RSs are triggered to be transmitted in the first time unit. For example, the PRACH, the aperiodic SRS are triggered. The configuration of the UL RS to be transmitted in the second time unit is configured before the UL RS is triggered.

[0073] In some embodiments, the network indicates a plurality of first time units and / or second time units to the UE. The network indicates a transmission time, a reception time and / or other information (propagation delay value, TA command, Rx-Tx time difference, or a sum thereof) for each first time unit or each second time unit according to the embodiment. When the UE receives each first time unit, the UE determines a corresponding time according to the embodiment. It may obtain a plurality of times for the plurality of first time units, respectively. Then, the time may be obtained by averaging the obtained plurality of times. When performing the averaging, the time offset between the first time units is taken into account.

[0074] It is understood in the present disclosure that some steps of the procedure may not be required. For example, in some embodiments, the first step of the UE sending the first message to the network may not be required. In such embodiments, the network sends the time information to the UE without receiving a request from the UE (e.g., without receiving the first message).

[0075] FIG. 5 illustrates an example block diagram of a hardware platform 500 that may be part of a network device (e.g., a base station) or a communication device (e.g., a user equipment). The hardware platform 500 includes at least one processor 510 and a memory 505 having instructions stored therein. The instructions executed by the processor 510 configure the hardware platform 500 to perform the operations described in FIGS. 1-4 and 7-8 and various embodiments described in this patent document. The transmitter 515 transmits or sends information or data to another device. For example, the network device transmitter can transmit a message to the user equipment. The receiver 520 receives information or data transmitted or sent by another device. For example, the user equipment can receive a message from the network device.

[0076] The above-mentioned embodiment is applied to wireless communication. Figure 6 shows an example of a wireless communication system (e.g., a 5G or NR cellular network) including a base station 620 and one or more user equipments (UEs) 611, 612, and 613. In some embodiments, the UE accesses a BS (e.g., a network) using a communication link to the network (as shown by dashed arrows 631, 632, 633, sometimes referred to as an uplink direction), and then enables subsequent communication from the BS to the UE (as shown by arrows 641, 642, 643, sometimes referred to as a downlink direction). In some embodiments, the BS transmits information to the UE (as shown by arrows 641, 642, 643, sometimes referred to as a downlink direction), and then enables subsequent communication from the UE to the BS (as shown by dashed arrows 631, 632, 633, sometimes referred to as an uplink direction). The UE may be, for example, a smartphone, a tablet, a mobile computer, a Machine-to-Machine (M2M) device, an Internet of Things (IoT) device, and so on.

[0077] 7 illustrates an example flow chart for determining a time when a communication device receives a signal. Operation 702 includes receiving, by the communication device, a first signal at a first time period. Operation 704 includes transmitting, by the communication device, a second signal to the network device at a second time period that is later than the first time period. Operation 706 includes receiving, by the communication device, a third message including timing information associated with the first time period, the second time period, or a propagation delay value. Operation 708 includes determining, by the communication device, based at least on the timing information, a time when the communication device received the first signal.

[0078] In some embodiments, the timing information in the third message includes a transmission time of a first period during which the first signal is transmitted by the network device, the third message includes a Timing Advance (TA) value, the communications device determines an updated TA value by using the TA value and a previous TA value or by using the TA value, and the communications device determines the time at which the communications device received the first signal by adding the transmission time of the first period to half the updated TA value. In some embodiments, the timing information in the third message includes a transmission time of a first period during which the first signal is transmitted by the network device, and the communications device determines the time at which the communications device received the first signal by adding the transmission time of the first period to a propagation delay value. In some embodiments, the timing information in the third message includes a transmission time of a first time period during which the first signal is transmitted by the network device and a first time difference value that is a function of at least a difference between the transmission time of the first time period and a receive time of a second time period during which the second signal is received by the network device, and the communications device determines the time at which the communications device receives the first signal by adding the transmission time of the first time period to a propagation delay value, the propagation delay value being determined by the first time difference value and a second time difference value that is a function of at least a difference between the receive time of the first time period and the transmission time of the second time period.

[0079] In some embodiments, the first time difference value is a function of (1) the difference between the transmission time of the first period and the reception time of the second period and (2) a time offset indicating the time difference between the first period and the second period, and the second time difference value is a function of (1) the difference between the reception time of the first period and the transmission time of the second period and (2) a time offset indicating the time difference between the first period and the second period. In some embodiments, the timing information in the third message includes a transmission time of a first time period during which the first signal is transmitted by the network device and a receive time of a second time period during which the second signal is received by the network device, and the communications device determines the time at which the communications device receives the first signal by subtracting a time clock offset value from or adding a time clock offset value to a first time associated with a first boundary of the first time period during which the first signal is received by the communications device, the time clock offset value being a function of the transmission time of the first time period, the receive time of the second time period, the first time associated with the first boundary of the first time period, and the second time associated with a second boundary of the second time period during which the second signal is transmitted by the communications device.

[0080] In some embodiments, the timing information in the third message includes a first sum of (1) a transmission time of a first period during which the first signal is transmitted by the network device and (2) a reception time of a second period during which the second signal is received by the network device, and the communications device determines the time at which the communications device received the first signal by subtracting a value determined by the communications device from a first time associated with a first boundary of the first period during which the first signal is received by the communications device or adding a value determined by the communications device to the first time, the value being a function of a first variable and a second variable, the first variable being the first sum and the second variable being a second sum of (1) the first time associated with the first boundary of the first period and (2) a second time associated with a second boundary of the second period during which the second signal is transmitted by the communications device.

[0081] In some embodiments, the method further includes receiving, by the communication device prior to receiving the first signal, a second message identifying one or more of the first time period or the second time period or indicating a transmission time of the first time period during which the first signal is transmitted by the network device. In some embodiments, the method further includes transmitting, by the communication device, a first message instructing the network device to transmit the second message, the communication device receiving the second message in response to transmitting the first message. In some embodiments, the first message is included in resource control (RRC) signaling, a medium access control (MAC) control element (CE), or uplink control information (UCI). In some embodiments, the transmission time is associated with a starting boundary of the first time period or an ending boundary of the first time period, or the reception time is associated with a starting boundary of the second time period or an ending boundary of the second time period. In some embodiments, the first time period or the second time period includes a system frame, a subframe, a slot, a subslot, or an orthogonal frequency division multiplexing (OFDM) symbol. In some embodiments, the second message or the third message is included in resource control (RRC) signaling, a medium access control (MAC) control element (CE), or downlink control information (DCI).

[0082] In some embodiments, the first signal includes a downlink (DL) reference signal (RS) or a downlink channel. In some embodiments, the DL RS includes a synchronization signal block (SSB) including a synchronization signal (SS) and a physical broadcast channel (PBCH) block, a channel state information reference signal (CSI-RS), a tracking reference signal (TRS), or a positioning reference signal (PRS). In some embodiments, the downlink channel includes a physical downlink control channel (PDCCH) or a physical downlink shared channel (PDSCH). In some embodiments, the second signal includes a physical random access channel (PRACH), a sounding reference signal (SRS), a physical uplink shared channel (PUSCH), or a physical uplink control channel (PUCCH).

[0083] 8 shows an example flowchart for illustrating timing information. Operation 802 includes transmitting, by the network device, a first signal at a first time period. Operation 804 includes receiving, by the network device, a second signal from the communication device at a second time period that is later than the first time period. Operation 806 includes transmitting, by the network device, a third message including timing information associated with the first time period, the second time period, or a propagation delay value, wherein a time at which the communication device received the first signal is determined based at least on the timing information.

[0084] In some embodiments, the timing information in the third message includes a transmission time of a first time period during which the first signal is transmitted by the network device, and the third message includes a timing advance (TA) value. In some embodiments, the timing information in the third message includes a transmission time of a first time period during which the first signal is transmitted by the network device. In some embodiments, the timing information in the third message includes a transmission time of a first time period during which the first signal is transmitted by the network device and a time difference value that is a function of at least a difference between the transmission time of the first time period and a receive time of a second time period during which the second signal is received by the network device. In some embodiments, the time difference value is a function of (1) a difference between a transmission time of the first time period and a receive time of the second time period, and (2) a time offset indicating a time difference between the first time period and the second time period. In some embodiments, the timing information in the third message includes a transmission time of a first time period during which the first signal is transmitted by the network device and a receive time of a second time period during which the second signal is received by the network device. In some embodiments, the timing information in the third message includes a first sum of (1) a transmission time of a first period during which a first signal is transmitted by the network device, and (2) a reception time of a second period during which a second signal is received by the network device.

[0085] In some embodiments, the method further includes transmitting, by the network device prior to transmitting the first signal, a second message identifying one or more of the first period or the second period or indicating a transmission time of the first period during which the first signal is transmitted by the network device. In some embodiments, the method further includes receiving, by the network device, a first message instructing the network device to transmit the second message, the network device transmitting the second message in response to receiving the first message. In some embodiments, the first message is included in resource control (RRC) signaling, a medium access control (MAC) control element (CE), or uplink control information (UCI). In some embodiments, the transmission time is associated with a starting boundary of the first period or an ending boundary of the first period, or the reception time is associated with a starting boundary of the second period or an ending boundary of the second period.

[0086] In some embodiments, the first period or the second period includes a system frame, a subframe, a slot, a subslot, or an orthogonal frequency division multiplexing (OFDM) symbol. In some embodiments, the second message or the third message is included in resource control (RRC) signaling, a medium access control (MAC) control element (CE), or a downlink control information (DCI). In some embodiments, the first signal includes a downlink (DL) reference signal (RS) or a downlink channel. In some embodiments, the DL RS includes a synchronization signal block (SSB) including a synchronization signal (SS) and a physical broadcast channel (PBCH) block, a channel state information reference signal (CSI-RS), a tracking reference signal (TRS), or a positioning reference signal (PRS). In some embodiments, the downlink channel includes a physical downlink control channel (PDCCH) or a physical downlink shared channel (PDSCH). In some embodiments, the second signal includes a physical random access channel (PRACH), a sounding reference signal (SRS), a physical uplink shared channel (PUSCH), or a physical uplink control channel (PUCCH).

[0087] The following sections describe an exemplary set of operations for time synchronization. The UE may send a request to the network. The network transmits the first time unit and / or the second time unit to the UE. Based on the downlink timing detected by the DL signal, the DL signal is transmitted by the network in a first time unit, and the UL signal is transmitted by the UE in a second time unit. The network sends a message (e.g., the second message and / or the third message) to the UE, the message including: ○ Transmission time of the first time unit ○ Receiving time in the second time unit a time difference value indicating the difference between the transmission time of the first time unit and the reception time of the second time unit the sum of the transmission time of the first time unit and the reception time of the second time unit, and / or ○ Includes propagation delay values. · The UE determines the time at which the UE received the DL signal based on the information in the message.

[0088] The word "exemplary" is used herein to mean "an example of," and does not mean an ideal or preferred embodiment, unless specifically stated otherwise.

[0089] Some of the embodiments described herein are described in the general context of a method or process that may be implemented in one embodiment by a computer program product embodied in a computer-readable medium including computer-executable instructions, such as program code, executed by a computer in a network environment. The computer-readable medium may include removable and non-removable storage devices, including but not limited to read-only memory (ROM), random access memory (RAM), compact discs (CDs), digital versatile discs (DVDs), and the like. Thus, the computer-readable medium may include non-transitory storage media. Generally, program modules may include routines, programs, objects, components, data structures, and the like that perform particular tasks or implement particular abstract data types. Computer or processor executable instructions, associated data structures, and program modules represent examples of program code for executing steps of the methods disclosed herein. A particular sequence of such executable instructions or associated data structures represents examples of corresponding acts for implementing the functions described in such steps or processes.

[0090] Some of the disclosed embodiments can be implemented as devices or modules using hardware circuits, software, or a combination thereof. For example, hardware circuit implementations can include separate analog and / or digital components integrated, for example, as part of a printed circuit board. Alternatively or additionally, the disclosed components or modules can be implemented as application specific integrated circuits (ASICs) and / or field programmable gate array (FPGA) devices. Some implementations may additionally or alternatively include digital signal processors (DSPs), which are dedicated microprocessors with architectures optimized for the operational needs of digital signal processing related to the disclosed functionality of the present application. Similarly, the various components or subcomponents within each module may be implemented in software, hardware, or firmware. Connections between modules and / or components within a module may be provided using any one of the connection methods and mediums known in the art, including, but not limited to, communication via the Internet, wired, or wireless networks using appropriate protocols.

[0091] While this document contains many details, these should not be construed as limitations on the scope of the claimed invention or the invention that may be claimed, but rather as descriptions of features specific to particular embodiments. Certain features described herein in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely, various features described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable subcombination. Furthermore, although features may be described above as acting in a particular combination and initially claimed as such, one or more features from the claimed combination may, in some cases, be cut out of the combination, and the claimed combination may be directed to a subcombination or a variation of the subcombination. Similarly, although operations are shown in the figures in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown, or in the sequential order, or that all of the operations shown be performed, to achieve desirable results.

[0092] Based on what has been described and illustrated in this disclosure, only some implementations and examples have been described, and other implementations, extensions and variations may be made.

Claims

1. 1. A method of wireless communication, the method comprising: receiving, by a communications device, a first signal in a first subframe; transmitting a second signal in a second subframe by the communications device to a network device; receiving, at the communications device, a message including timing information associated with the first subframe or the second subframe; determining a propagation delay based at least on the timing information by the communications device; Including, the timing information in the message includes a first time difference value, the first time difference value being a difference between a transmission time of the first subframe and a receive time of the second subframe at which the second signal is received by the network device; a propagation delay value determined by the first time difference value and a second time difference value, the second time difference value being a difference between a reception time of the first subframe and a transmission time of the second subframe.

2. The method of claim 1 , wherein the message is included in resource control (RRC) signaling.

3. The method of claim 1 , wherein the first signal comprises a tracking reference signal (TRS) or a positioning reference signal (PRS).

4. The method of claim 1 , wherein the second signal comprises a sounding reference signal (SRS).

5. 1. A method of wireless communication, the method comprising: a network device transmitting a first signal in a first subframe; receiving, by the network device, a second signal in a second subframe from a communication device; the network device transmitting a message including timing information associated with the first subframe or the second subframe, a propagation delay based at least on the timing information; Including, 23. The method of claim 22, wherein the timing information in the message includes a time difference value that is a difference between a transmission time of the first subframe and a receive time of the second subframe at which the second signal is received by the network device.

6. The method of claim 5 , wherein the message is included in resource control (RRC) signaling.

7. The method of claim 5 , wherein the first signal comprises a tracking reference signal (TRS) or a positioning reference signal (PRS).

8. 16. An apparatus for wireless communication, the apparatus comprising: a processor configured to perform a method, the processor comprising: The processor, receiving, by a communications device, a first signal in a first subframe; transmitting, by the communication device, a second signal in a second subframe to a network device; receiving, at the communications device, a message including timing information associated with the first subframe or the second subframe; determining a propagation delay based at least on the timing information by the communications device; The device is configured to: the timing information in the message includes a first time difference value, the first time difference value being a difference between a transmission time of the first subframe and a receive time of the second subframe at which the second signal is received by the network device; the propagation delay value is determined by the first time difference value and a second time difference value, the second time difference value being a difference between a reception time of the first subframe and a transmission time of the second subframe.

9. 16. An apparatus for wireless communication, the apparatus comprising: a processor configured to perform a method, the processor comprising: The processor, A network device transmitting a first signal in a first subframe; receiving, by the network device, a second signal in a second subframe from a communication device; the network device transmitting a message including timing information associated with the first subframe or the second subframe, a propagation delay based at least on the timing information; The device is configured to: the timing information in the message includes a time difference value that is a difference between a transmission time of the first subframe and a receive time of the second subframe at which the second signal is received by the network device.

10. The method of claim 5 , wherein the second signal comprises a sounding reference signal (SRS).

11. The apparatus of claim 8 , wherein the message is included in resource control (RRC) signaling.

12. The apparatus of claim 8 , wherein the first signal comprises a tracking reference signal (TRS) or a positioning reference signal (PRS).

13. The apparatus of claim 8 , wherein the second signal comprises a sounding reference signal (SRS).

14. The apparatus of claim 9 , wherein the message is included in resource control (RRC) signaling.

15. The apparatus of claim 9 , wherein the first signal comprises a tracking reference signal (TRS) or a positioning reference signal (PRS).

16. The apparatus of claim 9 , wherein the second signal comprises a sounding reference signal (SRS).

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