Method and apparatus for synchronizing apparatuses in wireless network

Abstract

To provide a method for updating a time counter in one user device to synchronize apparatuses in a wireless network, such as a wireless communication network.SOLUTION: A method includes receiving, at a user device, a timing advance command from a base station, and updating a time counter according to the timing advance command in response to receiving the timing advance command.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] SUMMARY The present disclosure relates to methods and devices for synchronizing devices in a wireless network, such as a wireless communication network. [Background technology]

[0002] The use of the Internet of Things (IoT) is increasing with each use coming with certain constraints.

[0003] One application of IoT is in industry, e.g., production plants that use critical machines and multiple sensors and actuators. IoT allows, for example, to accurately track production lines by performing the following functions (non-exhaustive list): predictive maintenance (avoiding production interruptions by identifying early warning signs of failures to proactively schedule maintenance interventions), intelligent diagnostics (by recording operating data and repair history via sensors), production line optimization, production machine optimization, etc.

[0004] With the development of 5G technology, a new generation of IoT is being developed. However, it is still necessary to ensure that 5G networks are compatible with the time-sensitive applications implemented by IoT elements.

[0005] To achieve this, precise time synchronization is required within 5G networks. One reason for synchronization despite the conventional reference system frame is propagation delay. In fact, propagation delay, i.e., the time it takes for a frame such as a reference system frame to reach its destination, can induce desynchronization between user equipment and base stations when the base station provides information for synchronization to the user equipment, such as a reference time linked to the occurrence of the reference system frame.

[0006] Today, one mechanism for improving the synchronization based on the reference system frame is proposed in the standard TS 38.211, section 4.3, and is called the timing advance mechanism, which aims to control the timing of the uplink frames of the user equipment.

[0007] This mechanism provides a timing value in a Timing Advance (TA) command for each user equipment that takes into account the estimated propagation delay for the user equipment.

[0008] To do this, the base station periodically monitors the propagation delay of the uplink frames, knowing their estimated arrival times given the first estimated propagation delay (already shared with the UE). The base station then compares the expected arrival times with the effective arrival times to detect any significant increase in propagation delay compared to the first estimate.

[0009] If a significant increase is identified, the base station sends a TA command to the user equipment to provide updated parameters.

[0010] The user equipment registers the parameters of the command, calculates an updated propagation delay, and waits for the next reference system frame. Upon receiving the next reference system frame, the user equipment determines an updated time counter based on the last calculated propagation delay.

[0011] However, this mechanism has limitations.

[0012] In particular, network conditions and the user equipment's location may change since the last TA command was received, causing the parameters of the last received TA command to no longer accurately reflect the true propagation delay. Such a situation can induce desynchronization of the user equipment's time counter, which persists until a new reference time is transmitted from the base station.

[0013] Therefore, a more accurate synchronization mechanism is needed. Summary of the Invention

[0014] The present invention has been devised to address one or more of the problems set forth above. The present invention relates to a mechanism for updating a time counter in a user equipment (UE) such that, in response to receiving a timing advance command from a base station, the UE uses a timing advance command to update the time counter in the user equipment.

[0015] According to a first aspect of the present invention, there is provided a method for updating a time counter of a user equipment in a wireless network comprising at least one base station and a plurality of user equipments, said method comprising, in said user equipment: receiving a timing advance command from the base station; In response to receiving the timing advance command, updating the time counter using the timing advance command; Includes:

[0016] In that way, it is no longer necessary for the UE to wait for the next reference system frame before adjusting its time counter based on a received TA command. If a TA command is received immediately after a prior art time counter adjustment, the time counter adjustment in response to the TA command will in fact accurately reflect the true propagation delay, taking into account the current UE location and network conditions.

[0017] The present invention therefore enables the UE to take into account the TA command as soon as it is received, and to calculate the propagation delay and use the calculated propagation delay value to adjust the UE's time counter, even after a conventional update of the UE's time counter.

[0018] Correspondingly, the present invention provides a user equipment of a wireless network, comprising a processor, the processor comprising: receiving a timing advance command from the base station; In response to receiving the timing advance command, updating the time counter using the timing advance command; It is configured as follows.

[0019] The user equipment has the same advantages as the method defined above.

[0020] Optional features of the invention are defined in the accompanying claims. Some of these features are described below with reference to a method, but they may also be transformed into features of a system dedicated to user equipment of a wireless network according to the invention.

[0021] According to some embodiments, the timing advance command may include a parameter representing a propagation delay between the base station and the user equipment.

[0022] According to some embodiments, the method further comprises: receiving a previous timing advance command from the base station; receiving a reference system frame sent by the base station; In response to receiving the reference system frame, updating the time counter using the previous timing advance command to obtain a previously updated time counter; may include Updating the time counter using the timing advance command includes updating the previously updated time counter based on the timing advance command.

[0023] According to some embodiments, the method further comprises: determining whether the timing advance command is more accurate than the previous timing advance command based on a comparison criterion; If so, using the timing advance command to trigger an update of the time counter; may include:

[0024] In some embodiments, determining whether the timing advance command is more accurate than the previous timing advance command comprises: comparing a first elapsed time between the reference system frame and the previous timing advance command with a second elapsed time between the reference system frame and the timing advance command; may include:

[0025] According to some embodiments, the method further comprises: receiving a reference time corresponding to the system frame of reference; determining whether the received reference time is a compensated reference time that represents an arrival time of a reference system frame at the user equipment; may include the compensated reference time already includes a value for the propagation delay; The time counter is updated further based on the compensated reference time.

[0026] According to some embodiments, in the case of a positive determination, the method may further include performing the updating of the time counter using the timing advance command independently of the previous timing advance command.

[0027] According to some embodiments, in the case of a negative determination, the method further comprises: determining whether the timing advance command is more accurate than the previous timing advance command based on a comparison criterion; using the timing advance command to trigger the updating of the time counter upon a positive determination that the timing advance command is more accurate; may include:

[0028] According to some embodiments, the timing advance command used to update the time counter may be the first timing advance command received after the reference system frame.

[0029] According to some embodiments, the timing advance command may be received via a protocol data unit from the group of a random access response MAC protocol data unit, an absolute timing advance command MAC control element, a timing advance command MAC control element, all defined in TS 38.321, and a control element conforming to the MAC Control Element format described in TS 38.321, comprising a command field of at least 13 bits for encoding the timing advance command.

[0030] However, the encoding of the TA commands specified in TS 38.321 introduces errors due to the granularity of the represented path delay information.

[0031] Changing the encoding of the transmitted TA commands is one way to reduce the errors caused by the granularity of the TA instructions.

[0032] Another method is to perform path delay compensation by the gNB, in which the TA command is not forwarded before being used for path delay compensation and the error of the TA indication is null.

[0033] According to another aspect of the present invention, there is provided a method for updating a time counter of a user equipment in a wireless network comprising at least one base station and a plurality of user equipments, the method comprising: estimating a propagation delay to and from the user equipment; determining a compensated reference time representing an arrival time of an associated reference system frame at the user equipment, the compensated reference time including a propagation delay; transmitting the compensated reference time and the associated reference system frame to the user equipment for updating the time counter; Includes:

[0034] Therefore, the compensated reference time includes a propagation delay specific to the user equipment, in order to allow the time counter of the user equipment to be updated directly without calculating the propagation delay. In other words, the proposed embodiment aims to integrate the propagation delay in the reference time value provided by the gNB in ​​order to update the time counter of the user equipment.

[0035] Correspondingly, the present invention provides a base station of a wireless network, comprising a processor, the processor comprising: Estimating a propagation delay to and from the user equipment; determining a compensated reference time representing an arrival time of an associated reference system frame at the user equipment, the compensated reference time including a propagation delay; transmitting the compensated reference time and the associated reference system frame to the user equipment for updating the time counter; It is configured as follows.

[0036] The base station has the same advantages as the method defined above.

[0037] Optional features of the invention are defined in the accompanying claims. Some of these features are described below with reference to a method, but they can also be transformed into features of a system dedicated to a base station of a wireless network according to the invention.

[0038] According to some embodiments, the method further comprises: determining whether a new estimate of a propagation delay to and from the user equipment occurs during transmission of the reference system frame; may include:

[0039] According to some embodiments, in the event of a positive determination, the method may further include transmitting a timing advance command regardless of the magnitude of the newly estimated propagation delay.

[0040] According to some embodiments, the timing advance command may be transmitted using a control element conforming to the MAC Control Element format described in TS 38.321, comprising a command field of at least 13 bits for encoding the timing advance command.

[0041] According to some embodiments, in the case of a negative determination, the method may further include transmitting a timing advance command when the new estimate of propagation delay is greater than a predetermined threshold.

[0042] According to some embodiments, the predetermined threshold may be based on the previously estimated propagation delay.

[0043] According to some embodiments, the timing advance command may be transmitted using a protocol data unit selected from a random access response MAC protocol data unit, an absolute timing advance command MAC control element, and a timing advance command MAC control element, all defined in TS 38.321.

[0044] According to another aspect of the present invention, there is provided a method for updating a time counter of a user equipment in a wireless network comprising at least one base station and a plurality of user equipments, the method comprising: determining a reference time representing a transmission time for a reference system frame; transmitting the reference time to the user equipment and transmitting the reference system frame at the transmission time to update the time counter; In response to transmitting the reference system frame, estimating a propagation delay to and from the user equipment; transmitting a timing advance command to the user equipment, the timing advance command including at least a parameter based on the estimated propagation delay; Includes:

[0045] This method therefore allows the UE to adjust its most recently updated time counter upon receipt of a timing advance command immediately after the reference system frame, which allows a more accurate estimation of the propagation delay to be taken into account and therefore allows for better synchronization with the UE's GM clock.

[0046] Correspondingly, the present invention provides a base station of a wireless network, comprising a processor, the processor comprising: determining a reference time representing a transmission time for a reference system frame; transmitting the reference time to the user equipment and transmitting the reference system frame at the transmission time to update the time counter; In response to transmitting the reference system frame, Estimating a propagation delay to and from the user equipment; transmitting a timing advance command to the user equipment, the timing advance command including at least a parameter based on the estimated propagation delay; It is configured as follows.

[0047] The base station has the same advantages as the method defined above.

[0048] Optional features of the invention are defined in the accompanying claims. Some of these features are described below with reference to a method, but they can also be transformed into features of a system dedicated to a base station of a wireless network according to the invention.

[0049] According to some embodiments, the timing advance command may be transmitted using a control element conforming to the MAC Control Element format described in TS 38.321, comprising a command field of at least 13 bits for encoding the timing advance command.

[0050] The invention also provides a computer program product for a programmable device, which comprises sequences of instructions for performing the above-described method when the computer program product is loaded and executed on a programmable device.

[0051] Furthermore, the present invention also provides a non-transitory computer-readable storage medium storing computer program instructions for implementing the above-described method.

[0052] At least part of the methods according to the present invention may be computer-implemented. Accordingly, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment (including firmware, resident software, microcode, etc.), or an embodiment combining software and hardware aspects, all of which may be referred to generally herein as a "circuit," "module," or "system." Furthermore, the present invention may take the form of a computer program product embodied in any tangible medium of expression having computer-usable program code embodied in the medium.

[0053] Since the present invention can be implemented in software, the present invention can be implemented as computer readable code on any suitable carrier medium for provision to a programmable apparatus. A tangible, non-transitory carrier medium may comprise a storage medium such as a floppy disk, a CD-ROM, a hard disk drive, a magnetic tape device, or a solid-state memory device. A transient carrier medium may include a signal such as an electric, electronic, optical, acoustic, magnetic, or electromagnetic signal, e.g., a microwave or RE signal. [Brief explanation of the drawings]

[0054] Embodiments of the present invention will now be described, by way of example only, with reference to the following drawings: [Figure 1] Figure 1 shows a 5G network interconnecting connected objects. [Figure 2] FIG. 2 illustrates an example of a base station architecture for the illustrated 5G network of FIG. [Figure 3] FIG. 3 illustrates an example of a user equipment architecture for the illustrated 5G network of FIG. [Figure 4] Figure 4 shows the system framework of a 5G network. [Figure 5] FIG. 5 shows a prior art mechanism for updating a timer in a user equipment. [Figure 6] FIG. 6 illustrates a method implemented by a base station according to a first embodiment of the present invention. [Figure 7] FIG. 7 illustrates a method implemented by a base station according to a second embodiment of the present invention. [Figure 8] FIG. 8 illustrates a method implemented by a user equipment according to a second embodiment of the present invention. [Figure 9] FIG. 9 illustrates a method implemented by a base station according to a second embodiment of the present invention. [Figure 10] FIG. 10 illustrates a method implemented by a user equipment according to a second embodiment of the present invention. [Figure 11] FIG. 11 illustrates a method implemented by a base station according to a third embodiment of the present invention. [Figure 12] FIG. 12 illustrates a method implemented by a user equipment according to a third embodiment of the present invention. [Figure 13] FIG. 13 shows a protocol data unit in MAC Control Element format for encapsulating the new timing advance command. [Figure 14]FIG. 14 shows an absolute timing advance command for encapsulating a timing advance command. DETAILED DESCRIPTION OF THE INVENTION

[0055] The lists and element (e.g., data element) names provided in the following description are merely examples, and embodiments are not limited thereto, and other names may be used.

[0056] Embodiments of the present invention are intended to be implemented in a 5G network used to interconnect connected objects or terminals, as shown in Figure 1.

[0057] The 5G network 100 includes multiple user equipment (UE) 104a, 104b, also called mobile stations, that are wirelessly connected (indicated by dotted lines) to at least one base station 102 (gNB or gNodeB). The gNB 102 is connected to a core network 101, for example, by wire (using optical fiber) or wirelessly.

[0058] In this 5G network, the common time reference is provided by the Grandmaster Clock (5G GM) 103, precisely defined in clause 5.27 of TS 23.501.

[0059] The 5G GM clock may be connected to the core network 101 as shown in Figure 1, but may also be connected directly to one of the gNBs or UEs. Thus, devices connected to the 5G GM clock share with other devices in the network the common time reference provided by the 5G GM clock.

[0060] According to some embodiments, the common time reference provided by the 5G GM clock may be or be based on a universal time reference, in which case the universal time reference may be obtained by the gNB directly from the satellite system.

[0061] As mentioned above, the 5G network 100 may be used to connect end devices 105a, 105b, and 105c, e.g., connected devices of an IoT network. The end devices may be, for example, devices for industrial equipment, such as sensors and actuators. As seen in FIG. 1 , the end devices 105a, 105b, and 105c are connected to the UEs 104a, 104b or the network core 101 of the 5G network 100. According to some embodiments, the end devices 105a, 105b, and 105c are wired to the UEs 104a, 104b, or the network core 101.

[0062] According to some embodiments, one end device and one UE may be integrated into a device.

[0063] Therefore, the end devices 105a, 105b, and 105c share data using the 5G network. When implementing time-sensitive applications in an IoT network, accurate time synchronization between UEs is essential within a particular 5G network.

[0064] The internal architecture of gNB 102 is shown diagrammatically in Figure 2.

[0065] The gNB 200 comprises a 5G NR interface 205 that enables it to communicate with the UEs 104a, 104b of the 5G network 100. The gNB may also comprise several different types of air interfaces, such as LTE (4G) or other types of air interfaces.

[0066] To communicate with the core network 101, the gNB also comprises a core network interface 204, as defined in section 4.2 of TS 23.501.

[0067] Synchronization between the gNB and the 5G GM clock is handled by the 5G time synchronization manager 203.

[0068] According to some embodiments, the 5G time synchronization manager 203 implements a time counter incremented by a local clock oscillator. The 5G time synchronization manager 203 continuously evaluates the clock difference between the time counter and the 5G GM clock. The evaluation may be performed using the IEEE 1588 precision time synchronization protocol, which is implemented through the exchange of time synchronization packets with the 5G GM via the core network interface 204. The evaluated difference thus allows the 5G time synchronization manager 203 to determine a value to adjust its time counter.

[0069] According to some embodiments, the 5G time synchronization manager 203 continuously evaluates the clock difference between a time counter and a reference time received from a satellite system such as GPS.

[0070] Therefore, the 5G time synchronization manager 203 provides the current time to the UE synchronization manager 201 based on its local time counter.

[0071] The UE synchronization manager 201 is configured to handle the synchronization between the base stations and the UEs 104a, 104b of the network 100 in terms of the time counters of all these devices being synchronized as accurately as possible.

[0072] To that end, the UE synchronization manager 201 may implement several mechanisms, as described below in connection with Figure 5. The UE synchronization manager 201 is also configured to estimate and record the propagation delay between the gNB and each UE 104a, 104b for synchronization purposes.

[0073] The gNB further comprises a control manager 202 in which the gNB control protocols are implemented. The control protocols include at least the following protocols: RLC (Radio Link Control in TS 38.322), PDCP (Packet Replication Control Protocol in TS 38.323), RRC (Radio Resource Control in TS 38.331), and NAS (Network Access Stratum in TS 24.501). Thus, the control manager 202 handles the generation of protocol packets that are exchanged with the core network 101 and the UE via the core network interface 204 and the 5G NR interface 205, respectively.

[0074] In FIG. 3, the internal architecture of the UEs 104a, 104b is shown by way of illustration.

[0075] The UE 300 includes a 5G NR interface 305 that allows the UE 300 to communicate with the gNB 200, 102 via this interface. The UE 300 may include several different types of air interfaces, such as LTE (4G) or other types of air interfaces.

[0076] Synchronization between the UE and the 5G GM clock is handled by the 5G Time Synchronization Manager 303.

[0077] According to some embodiments, the 5G time synchronization manager 303 implements a time counter incremented by a local clock oscillator. When the 5G time synchronization manager 303 receives a time counter correction value from the gNB synchronization manager 301, it can correct or change the time counter value.

[0078] Indeed, the gNB synchronization manager 301 stores the parameters required for synchronization provided by the gNB 102 and determined by the UE synchronization manager 201 of the gNB 102. Furthermore, the gNB synchronization manager 301 is also configured to estimate and record the propagation delay between the UE 300 and the gNB 102.

[0079] The UE 300 further comprises a control manager 302 in which the gNB control protocols are implemented. The control protocols include at least the following protocols: RLC (Radio Link Control in TS 38.322), PDCP (Packet Replication Control Protocol in TS 38.323), RRC (Radio Resource Control in TS 38.331), and NAS (Network Access Stratum in TS 24.501). The control manager 302 is responsible for generating protocol packets that are exchanged with the gNB 200, 102 via the 5G NR interface 305.

[0080] Data exchanged between the gNB and the UEs of the network 100 over the 5G NR interface 205, 305 conforms to the frame format specified by the 3GPP NR PHY and MAC protocols defined in clauses 5 and 6 of TS 38.300.

[0081] The exchanged frames (hereinafter referred to as system frames) are organized in time and have a structure as shown in FIG.

[0082] The system frames follow each other in time, each system frame having a duration of 10 ms.

[0083] System frames may be numbered by a system frame number (SFN), also known as the system frame index. As shown in Figure 4, the first system frame numbered #0 is followed by system frames #1, #2, and #3. As shown in Figure 4, the system frame numbering is incremented every 10 ms, i.e., the system frame number can go from 0 to 1023. When it reaches 1023, the numbering starts again from 0.

[0084] Therefore, the gNB numbers its system frames with an SFN, which is signaled to the UE using a system frame synchronization signal, which is periodically transmitted by the gNB to the UE by signaling the SFN using the six most significant bits of a so-called MIB (Master Information Block) field in the transmitted system frame and the four least significant bits of a so-called PBCH field in the transmitted system frame.

[0085] Each system frame contains 10 subframes ranging from 0 to 9.

[0086] Each subframe contains a flexible number of slots, for example, up to 64 slots, each of which comprises several Orthogonal Frequency Division Multiplexing (OFDM) slots, each of which consists of up to 14 OFDM slots.

[0087] The system frames therefore constitute a common reference for the UE and the gNB, and therefore the system frames, and in particular their SFNs, are used for the conventional adjustment of the UE's time counters.

[0088] The conventional adjustment of the time counter of the UE is shown in FIG.

[0089] Conventionally, the adjustment of a time counter requires a reference time (T R ) to the terminal. The reference time value corresponds to the transmission time of the system frame used as a reference, which will be referred to hereafter as the reference system frame.

[0090] After receiving a request from the UE for a reference time value for updating its time counter, or spontaneously, the gNB selects a future reference system frame in which the gNB will force the UE to update its time counter with the reference time value provided by the gNB.

[0091] The reference time value may, for example, be the intended start or end time of transmission by the gNB of the system reference frame.

[0092] According to some embodiments, the reference time value is an estimated or intended value of a time counter of the gNB corresponding to the intended start or end transmission time of a reference system frame by the gNB.

[0093] As can be seen from Figure 5, the reference time is equal to the sum of:

[0094] - Current time of the gNB's hour counter, continuously synchronized with the 5G GM clock thanks to the synchronization manager 203 Duration T representing the delay (in time counter units) that the gNB waits before transmitting a reference system frame to the UE According to some embodiments, the reference time is determined, for example, by the gNB as the sum of:

[0095] - Current time of gNB's hour counter synchronized to the 5G Grandmaster clock thanks to the Synchronization Manager 203 - Time remaining until the start of the next system frame. If a new system frame occurs every 10 ms, the remaining time may be obtained by means of an alarm counter set to 10 ms for each system frame start. - 10ms * (referenceSFN-nextSFN), where reference is the SFN of the specified reference system frame and nextSFN is the SFN of the next system frame. Note that referenceSFN is the reference time calculated just before transmitting the reference system frame, which contains the reference time and is the case when SIB9 messages are used. Usually, referenceSFN refers to a future reference system frame, i.e., referenceSFN-nextSFN > 0. Reference time T Rand an indication of the reference system frame, e.g., referenceSFN, is then provided to the UE. Both of these elements may be transmitted together or separately.

[0096] According to some embodiments, the gNB may R and the referenceSFN. The referenceTimeInfo IE is then encapsulated in a system information (SI) or radio resource control (RRC) message, such as a SIB9 or DLInformationTransfer message.

[0097] The DLInformationTransfer message is sent before the reference system frame, as shown in FIG.

[0098] The SIB9 type reference system frame has a reference time T R Therefore, no other messages related to the reference system frame are previously transmitted by the gNB.

[0099] Thus, as shown in Figure 5, the gNB sends the message to the requesting UE or several UEs if the message is broadcast.

[0100] When the DLInformationTransfer message is sent, later, when its time counter is equal to the reference time, a reference system frame is generated by the gNB and sent to the UE.

[0101] When the reference system frame is detected by the UE thanks to the referenceSFN, the UE (its managers 301 and 302) that previously received the reference time (or retrieved the reference time from the SIB9 reference system frame) sets its time counter to the reference time.

[0102] In the particular case of SIB9, the reference time corresponds to the end boundary of the system frame.

[0103] However, as can be seen in Figure 5, there is a delay between the moment the gNB transmits the reference system frame and the moment the UE receives the reference system frame. This delay, also called the propagation delay, represents the propagation time of the radio signal between the UE and the gNB.

[0104] Therefore, the above synchronization mechanism relies on the assumption that the propagation delay of the reference system frame used as a trigger by the UE to set its local time counter with the reference time provided by the gNB is negligible.

[0105] It can be appreciated that when a UE sets its time counter using the reference time provided by the gNB, a persistent synchronization error due to propagation delay is introduced. This may be incompatible with some applications (e.g., time-sensitive applications), especially applications that require accurate timestamps of the arrival or departure times of some packets. Indeed, the persistent synchronization error due to propagation delay introduces errors into the timestamps of those packets, which may be incompatible with the requirements of time-sensitive applications.

[0106] To overcome this drawback, the timing advance mechanism described in clause 4.3 of TS 38.211 is used to correct or compensate for this error in the adjustment of the UE's conventional time counter.

[0107] A timing advance (TA) mechanism may be used to allow the propagation delay to be calculated by the UE, as shown in FIG.

[0108] Originally, the TA mechanism is used by the gNB to control the timing of UE uplink frames. To do so, the gNB provides the UE with a TA command containing several parameters. These parameters, including the TA parameters, determine the timing until the next gNB downlink frame at which the UE should start transmitting its uplink frame. TA This allows the UE to determine

[0109] The TA command is provided by the gNB to the UE over the 5G NR interface. For transmission, the TA command is encapsulated in different types of protocol data units (PDUs), all defined in TS 38.321: - Random Access Response MAC Protocol Data Unit (PDU) as defined in TS 38.321, clauses 6.1.5 and 6.2.3 - Absolute Timing Advance Command MAC Control Element or Timing Advance Command MAC Control Element as defined in TS 38.321 clauses 6.1.3.4 and 6.1.4a Depending on the type of TA command, the parameters provided are of different nature: for random access responses and absolute timing advance commands, the absolute value of the parameter TA is given; for timing advance commands, only the correction of the previously provided TA is included in the TA command.

[0110] Thus, according to some embodiments, the TA command may comprise the absolute value of TA in a TA command field, which then determines the instant T according to the following formula: TA Used by the UE to determine

[0111] T TA =(N TA +N TA,offset )*T C where N TA =TA*16*64*2 μwhere μ is the subcarrier spacing configuration, Δf=2μ*15kHz as defined in TS 38.211, Section 4.2, Table 4.2-1, and N TA,offset is a fixed offset used to calculate the timing advance, and T C is the base time unit for New Radio as defined in TS 38.211 section 4.1.

[0112] According to another embodiment, the TA command is correction The previously provided TA value, called TA previous It can include the correction value of the previous T TA The adjustment applied to (TA correction -31)*16*64 / 2 μ becomes equal to

[0113] Therefore, to control the UE uplink timing, the gNB sends a TA command in a control message to the UE in the network. The TA command is specific to a given UE, as it mirrors the propagation delay to and from this particular UE. The UE then applies the formula detailed above to determine the T TA Calculate.

[0114] Interestingly, member N TA It can be noted that N is proportional to the round trip time between the gNB and the UE. TA can help determine the propagation delay, assuming that the propagation delay is symmetric. For example, the propagation delay between the UE and the gNB is (N TA *Tc) / 2.

[0115] In this way, when receiving a TA command, the UE may be able to determine the propagation delay during transmission of the TA command. The calculated propagation value may then be used when adjusting the time counter as described above using the reference time and reference system frame transmitted by the gNB.

[0116] As shown in Figure 5, a first TA command is received from the gNB and used by the UE to calculate the propagation delay. Then, when a reference system frame is detected, a reference time T adjusted by the calculated propagation delay is calculated. R For example, the time counter is set using T R plus the propagation delay.

[0117] One issue arises when the UE moves between receiving a TA command from the gNB and adjusting its time counter.

[0118] In practice, the gNB continuously monitors the propagation delay of UE uplink frames, and when the arrival time shifts significantly compared to the expected arrival time, i.e., when the propagation delay increases significantly since the last transmitted TA command, the gNB transmits a subsequent TA command. The gNB is also responsible for maintaining uplink synchronization through TA update triggering. Uplink synchronization has different requirements than those required for time synchronization purposes. Thus, for example, a predetermined threshold can be used to determine whether a subsequent TA command should be transmitted to compensate for the increased propagation delay. It can be seen that a TA command cannot be transmitted for some time before the UE moves significantly, significantly correcting the propagation delay and transmitting a subsequent TA command by the gNB.

[0119] However, a subsequent TA command may be sent and received after the UE's previous time counter adjustment while the UE was moving before the reference system frame was transmitted. This situation is shown in Figure 5, where the UE's time counter was adjusted using the old propagation delay and therefore contains a synchronization error because the old propagation delay does not reflect the UE's actual position when it receives the reference system frame from the gNB.

[0120] Therefore, in order to compensate for the propagation delay when updating the UE's time counter, it is necessary to provide the UE or gNB with a way to estimate the propagation delay that best reflects the UE's location when the UE receives a reference system frame from the gNB.

[0121] Therefore, the present invention proposes that the UE uses a timing advance command to update a time counter of the user equipment in response to receiving the timing advance command from the base station.

[0122] In that way, the UE does not need to wait for the next reference system frame before adjusting its time counter based on the received TA command. If the TA command is received immediately after a prior art time counter adjustment, the adjustment of the time counter in response to the TA command will indeed accurately reflect the true propagation delay, taking into account the current UE location and network conditions.

[0123] The present invention therefore enables the UE to take into account the TA command as soon as it is received, even after a conventional update of the UE's time counter, and to calculate the propagation delay and use the calculated value of the propagation delay to adjust the UE's time counter.

[0124] As explained above, the timing advance command includes a parameter TA that represents the propagation delay between the base station and the user equipment, for example, the absolute value of TA or a corrected value of TA that can be used by the UE to determine the propagation delay.

[0125] Several embodiments are proposed herein and are shown in FIGS.

[0126] A first embodiment of the present invention is illustrated in Figure 6. The illustrated method is performed on the UE side when the UE receives a TA command from a gNB.

[0127] In this embodiment, the UE determines based on a comparison criterion whether the timing advance command is more accurate than a previously received timing advance command, and triggers an update of its time counter only in the case of a positive determination.

[0128] First, the UE receives a pre-TA command from the gNB (not shown), as described with reference to Figure 5.

[0129] The UE then receives the reference system frame sent by the gNB. As described above, the reference system frame is used in conventional time counter adjustment to update the UE's time counter.

[0130] As described above, when the UE detects the reference system frame, it counts the time counter to the reference time T R and the estimated propagation time calculated using the previous TA command.

[0131] Next, the UE receives a new TA command in step 500. Upon receiving the TA command, the UE determines in step 501 whether the timing advance command is more accurate than the previous timing advance command based on a comparison criterion.

[0132] According to some embodiments, the comparison criteria may be of different types. For example, the comparison criteria may reflect which of the (previous and new) timing advance commands is closest in time to the reference system frame. For example, the comparison may be to compare a first elapsed time between the reference system frame and the previous timing advance command with a second elapsed time between the reference system frame and the new timing advance command. If the first elapsed time is greater than the second elapsed time, the new TA command is considered to be more accurate than the previous TA command.

[0133] For example, the comparison may be to compare the SFNs of the system frames (the reference frame and the SFN containing the TA command). As mentioned above, the previous TA command may be compared to the SFN, SFN previous In the previous system frame having SFN, SFN is transmitted before the reference system frame. new A new TA command can be sent during the subsequent system frame having the SFN distance between the respective system frames to determine the nearest TA command. reference -SFN new SFN compared to reference -SFN previous , To do so, the SFN of a TA command may be stored by the UE each time a TA command is received and then applied.

[0134] According to other embodiments, the comparison criteria may also include criteria based on the signal strength of the received system frames (including the reference system frames and the frames carrying the timing advance commands). Indeed, based on the measured signal strength, it may be possible to determine which of the provided timing advance TAs more accurately reflects the UE positioning with respect to the base station. Again, the TA command provided in the system frame having the closest signal strength to one of the reference system frames may be considered to be the more accurate one.

[0135] Depending on the outcome of step 501, an update of the time counter may be triggered.

[0136] Therefore, when a new TA command is considered to be more accurate than the previous TA command, the UE must update the previously updated time counter with the new TA command. The update requires the calculation of an adjustment value for the time counter to take into account the new propagation delay (step 502).

[0137] The calculation of the adjustment value depends on the type of new TA command.

[0138] If the new TA command is either a random access response or an absolute timing advance command MAC CE, it therefore comprises the absolute value of TA, and then the adjustment value is T C *(N TA_new -NT A_previous ) / 2, where N TA_new is calculated using the absolute TA value of the new TA command as described above in connection with FIG. TA_previous As explained above, is stored by the UE when it receives the previous TA command. Therefore, the adjustment value represents the difference between the propagation delay calculated in the previous TA command and the new TA command. (As a reminder, the propagation delays corresponding to the previous TA command and the new TA command are (N TA_previous *Tc) / 2 and (N TA_new *Tc) / 2).

[0139] If the new TA command is a timing advance command MAC CE that includes a corrected TA value (not an absolute value of TA), the adjustment value is (TA correction -31)*16*64 / 2 μ where TA correction is the value of the corrected TA value included in the newly received timing advance command.

[0140] In step 503, the UE then adjusts its time counter with the calculated adjustment value. In other words, the UE changes the current value of the time counter by adding the obtained adjustment value. According to some embodiments, the adjustment value is applied according to, for example, a proportional-integral filter, with smaller adjustment values ​​distributed along a predetermined period.

[0141] Then, in step 504, the TA command is applied by the UE. To do so, the UE determines the T TATo determine this, N TA_new Next, calculate N TA_new N TA_old variable and store the SFN of the new command in SFN previous These values ​​are stored as the next reference time T R can be used to compensate for

[0142] In step 501, if the new TA command is not more accurate than the previous timing advance command based on the comparison criterion, the UE directly executes step 504.

[0143] A second embodiment is shown in Figures 7, 8, 9 and 10, in which the gNB estimates the propagation delay to and from the user equipment and then calculates a conventional reference time T R Instead of the gNB, the gNB provides a compensated reference time to the user equipment. Therefore, the compensated reference time includes a propagation delay specific to the UE so that the UE's time counter can be directly updated without calculating the propagation delay. In other words, the proposed embodiment aims to integrate the propagation delay in the reference time value provided by the gNB to update the UE's time counter.

[0144] FIG. 7 shows a gNB-side method performed by the UE synchronization manager 201.

[0145] In optional step 1000, the gNB receives a synchronization request from the UE.

[0146] As previously mentioned, in connection with adjusting a conventional time counter, in step 1002 the gNB calculates the reference time for the next reference system frame.

[0147] Next, the gNB checks whether it should perform pre-compensation of the reference time, i.e., whether it should include the propagation delay in order to obtain a compensated reference time.

[0148] According to some embodiments, this test may include, for example, checking a configuration flag that indicates whether the gNB should perform predistortion.

[0149] According to some embodiments, this test may include checking whether the reference time is intended to be transferred to one UE (unicast) or several UEs (broadcast). Since pre-distortion takes into account different propagation delays from one UE to another, it should only be performed when the reference is intended for one UE.

[0150] If the gNB performs predistortion, then in step 1004 the gNB estimates the propagation delay using the last calculated and transmitted TA and the following equation: (T TA -Tc*N TA,offset ) / 2, where T TA is the timing advance between the downlink and uplink frames. TA is continuously determined by the gNB, and then the gNB calculates the TA, which is transmitted in the TA command. Thus, the determination of the compensated reference time is performed after the transmission of the TA command by the gNB.

[0151] Next, in step 1005, the gNB determines a compensated reference time by adjusting (summing) the reference time with the calculated propagation delay.

[0152] The calculated propagation delay is stored as previousPropagationDelay.

[0153] According to some embodiments, in step 1006, a pre-compensation flag (a Boolean field) associated with the referenceTimeInfo information element of the DLInformationTransfer or SIB9 message may be provided. Thus, if a compensated reference time is determined, the flag is set to TRUE. Otherwise, the flag is set to FALSE, in order to signal to the UE whether the provided reference time is compensated or not.

[0154] Next, in step 1007, a DLInformationTransfer or SIB9 message is sent containing:

[0155] - Reference time when no pre-distortion is performed - Compensated reference time including propagation delay when pre-distortion is performed by gNB Reference system frames are sent as needed (DLInformationTransfer case).

[0156] The UE then receives the messages, which are processed according to the method illustrated in Figure 8, performed by the UE's gNB synchronization manager 301.

[0157] After receiving the DLInformationTransfer or SIB9 message in step 801, the UE checks the pre-compensation flag of the received message to determine whether the message includes a compensated reference time or a reference time.

[0158] Once pre-distortion is performed by the gNB, the UE waits for the reference system frame (step 805) and, upon receiving it, updates its time counter with the provided compensated reference time (806).

[0159] If no predistortion has been performed by the gNB, the conventional process is followed and the UE waits for a reference system frame (step 802). Next, in step 803, the UE determines the propagation delay using the last applied TA command. The propagation delay is calculated as T as described above (in relation to FIG. 6). C *NT A_old / 2, where the value NT A_old is obtained from the UE's storage.

[0160] Using the calculated propagation delay, the gNB synchronization manager 301 instructs the 5G time synchronization manager to set a time counter to the sum of the reference time and the calculated propagation delay (804).

[0161] This pre-compensation mechanism can be used alone or together with the principle of the first embodiment (described in relation to Figure 5), for example as shown in Figure 10, i.e., updating the time counter upon receipt of a TA command from the gNB.

[0162] According to some embodiments, the pre-distortion is performed systematically by the gNB, so that on the UE side, upon receiving the pre-distortion, the UE systematically applies steps 805 and 806 described above with reference to FIG. 8.

[0163] When the gNB transmits the reference time to the UE, it must have a valid TA value to be used for precompensation, which is obtained after random access by the UE and subsequent uplink transmission by the UE.

[0164] If the gNB does not have a valid TA value at the time of pre-distortion, dedicated signaling must be specified to enable the gNB to send a correction value for the path delay information after the reference time has been transmitted.

[0165] The method shown in Figure 9 enables the transmission of propagation delay correction values ​​by a gNB using a TA command according to an embodiment of the present invention.

[0166] Therefore, upon detection of an SFN event, the gNB can use new signaling to transmit a correction value for the propagation delay to the UE.

[0167] This method is performed during the transmission of a reference system frame.

[0168] This method is executed by the UE synchronization manager 201 when a new TA value is determined for the UE. In fact, when the gNB exchanges frames with the UE, it TA These determined T TA is, among other things, the determined T TA When the TA calculated from the previous T has a value close to the TA of the most recently generated TA command, it does not necessarily lead to the generation of the TA command. TA Command and new T TA When the difference between is greater than a predetermined threshold, a new TA command is generated.

[0169] In step 1101, the gNB checks whether pre-distortion has been performed by the gNB for the UE. In other words, the gNB determines whether the transmitted reference time has been compensated.

[0170] If the determination is positive, in step 1102, the gNB checks whether the evaluation of the new TA occurred during the transmission of a reference system frame associated with the compensated reference time.

[0171] If the current system frame is the reference system frame, in step 1103, the gNB uses the new T to calculate a correction value of the propagation delay for the estimated propagation delay previousPropagationDelay when determining the compensated reference time. TA (i.e., step 1005).

[0172] The correction value of the propagation delay (CorrectionPropagationDelay) is calculated using the following formula:

[0173] CorrectionPropagationDelay=(T TA -T c *N TA,offset ) / 2-previousPropagationDelay where previousPropagationDelay is the propagation delay value stored in step 1005 of the method shown in Figure 7. Note that CorrectionPropagationDelay is a signed value because the correction must indicate whether the UE should increase or decrease the current value of its time counter.

[0174] Once the propagation delay correction value is obtained, in step 1104, the gNB transmits the propagation delay correction value to the UE via the 5G NR interface 205.

[0175] To that end, the gNB may use multiple types of TA command PDUs, either the previously introduced timing advance command MAC CE, or a new type of timing command MAC CE, hereafter referred to as delay correction MAC CE message.

[0176] The delay compensation MAC CE is a PDU in a MAC CE format conforming to TS 38.321, and includes a command field of at least 13 bits for encoding a timing advance command (for encoding a TA value).

[0177] An exemplary format of the Delay Compensation MAC CE message is shown in Figure 13 and conforms to the MAC CE format described in TS 38.321, section 6.1.3. The first byte comprises two reserved bits (R) and a logical channel id (LCID), whose value can be any value between 35 and 46. The eight bytes from byte 2 to byte 9 encode the propagation delay compensation value (TA value) as a 64-bit integer.

[0178] Of course, other bit lengths for encoding the TA value are conceivable, preferably 4 or 6 bytes.

[0179] When the timing advance command MAC CE is sent, TA correction The value of is calculated according to the following formula:

[0180] TA correction =(CorrectionPropagationDelay+31)*2 μ / 16*64 When a delay-corrected MAC CE message is sent, the propagation delay correction field of the delay-corrected MAC CE message is set to the propagation delay correction calculated in step 1103. Such a message has the advantage that it can carry the correction value in a larger bit field (64 bits), which allows it to handle a wider range of correction values.

[0181] According to some embodiments, the gNB may decide to send a TA command to the UE independently of the magnitude of the calculated correction value for the propagation delay, i.e., without comparing it to a threshold. According to some embodiments, the calculated correction value for the propagation delay is transmitted to the UE in a Delay Correction MAC CE message.

[0182] According to some embodiments, the TA command is transmitted only when the magnitude of the calculated correction value for the propagation delay is greater than a predetermined threshold, in which case the gNB may transmit the timing command using a PDU selected from the group of a random access response PDU, an absolute timing advance command MAC CE, and a timing advance command MAC CE.

[0183] 9 process advantageously handles the first TA command transmitted after a reference system frame. The use of a delay-compensated MAC CE format for transmitting this first TA command advantageously facilitates recognition of such a TA command by the UE. The latter ensures that the delay-compensated MAC CE format provides a realistic estimate / correction of the propagation delay so that the TA command can be used to systematically apply updates to its time counter.

[0184] The transmitted TA command is then received by the UE and processed according to the method shown in FIG.

[0185] The method is performed by the gNB synchronization manager 301 of the UE upon receipt of a timing advance command (step 900).

[0186] In step 901, the UE first checks whether predistortion has been performed on the last reference system frame by the gNB. This step is similar to step 801 above.

[0187] If no compensation has been performed, the UE determines (902) whether the received timing advance command is more accurate than the previous timing advance command based on a comparison criterion, as described in connection with FIG. 6 (see step 501).

[0188] If the received TA command is less accurate than the previous TA command, the received TA command is not used to update the UE's time counter and is only applied in the conventional manner (step 905).

[0189] If the received TA command is more accurate than the previous timing advance command, an adjustment value is calculated (step 903) and the time counter is updated (904) using the received TA command, similar to steps 502 and 503 described with respect to FIG. 6 .

[0190] If the precompensation is performed by the gNB, the UE updates its time counter using the received TA command if the received TA command is carried through the delay compensation MAC CE. In other words, when the precompensation of the reference time is performed by the gNB, the update using the received TA in the delay compensation MAC CE is performed systematically without checking the relevance of the TA compared to the previous one.

[0191] Returning to the figure, in step 906 it is determined whether the received TA command is a delay correction MAC CE.

[0192] In the affirmative (this is the first TA command received after the reference system frame), the propagation delay correction value CorrectionPropagationDelay included in the TA command is used to adjust the UE's time counter. Thus, in step 907, the adjustment value is set to CorrectionPropagationDelay retrieved from the Delay Correction MAC CE message. During step 908, the UE's gNB synchronization manager 301 instructs the 5G time synchronization manager to modify the time counter value by applying the adjustment value obtained in step 907, typically by adding CorrectionPropagationDelay to the current value of the time counter. Preferably, the adjustment by adding CorrectionPropagationDelay is applied by smaller adjustment values ​​distributed along time, for example according to a proportional-integral filter.

[0193] In the negative (the received TA command is included in the timing advance command MAC CE), the process proceeds to step 902 and applies the TA command only if it is more accurate than the previously used TA command, for which steps 903, 904 and 905 are performed, similar to steps 501, 502, 503 and 504 described in relation to Figure 6.

[0194] Third embodiments of the present invention are shown in Figures 11 and 12. These embodiments rely on the systematic updating of the UE's time counter by the first TA command received after the reference system frame. In fact, this TA command is assumed to be an exact mirroring of the actual propagation delay at the reference time.

[0195] In a third embodiment, when the gNB is transmitting a reference system frame, it automatically calculates a propagation delay correction value (or propagation delay) for the UE, and then provides this correction value (or propagation delay value) to the UE in a TA command to adjust the UE's recently updated time counter (using the reference time of the reference system frame). Thus, such a method allows for systematic correction of the UE's recently updated time counter using the first TA command following the reference system frame.

[0196] Figure 11 shows the method performed by the gNB, and in particular the UE synchronization manager, when the reference time is transmitted to the UE.

[0197] In step 1202, the reference time is determined in the same manner as described in FIG. 7 (steps 1004 and 1005) (or FIG. 5).

[0198] In step 1207, the reference time is transmitted to the UE over the 5G NR interface 205. This can be done using a DLInformationTransfer or SIB9 message.

[0199] The gNB then waits for a reference system frame associated with the reference time.

[0200] As mentioned above, gNB is TA Next, in step 1209, the gNB calculates the last determined T TA The propagation delay (T TA -T c *N TA,offset) / 2. In the best case, T TA may be calculated during the transmission of the reference system frame.

[0201] The calculated propagation delay correction value (or propagation delay) is then transmitted to the UE via the 5G NR interface 205 using a TA command.

[0202] According to some embodiments, a delay correction MAC CE message or an absolute timing advance command MAC CE and random access response may be used.

[0203] When a delay correction MAC CE message is used to transmit relative correction values ​​and absolute TA values, a flag may be signaled within the message to indicate whether the TA value provided is relative or absolute.

[0204] Thus, an example of an absolute timing advance command MAC CE is shown in Figure 14, where the absolute timing advance command MAC CE has a reserved bit (R) and the logical channel id (LCID) set to 34. The EL CID byte is set to code point 252 index 316 as defined in Table 6.2.1-1b of TS 38.321. The timing advance command field is 12 bits long and has TAC = (T TA -Tc*N TA,offset ) / 2*2μ / 16*64.

[0205] According to an alternative example, the four reserved bits in byte 3 of the absolute timing advance command MAC CE can be used to extend the timing advance command field of the absolute timing advance command MAC CE from 12 to 16 bits.

[0206] According to some embodiments, the TAC timing advance command is transmitted using the random access response TS 38.321 clauses 6.1.5 and 6.2.3.

[0207] At the UE side shown in Figure 12, steps 1300-1302 are the same steps as those performed during the conventional time counter adjustment of the UE. In fact, once the reference time is received in step 1300, the UE waits for the reference frame system in step 1302 to update the time counter with the reference time and the last received TA in step 1301.

[0208] The UE then waits for a propagation delay correction value provided by the gNB (step 1303). This is the first TA command following the reference system frame.

[0209] Upon receiving the first timing advance command following the reference system frame (and including the propagation delay correction value), the UE adjusts its time counter accordingly.

[0210] To that end, the propagation delay is obtained directly from this TA command in step 1304. It is then used to adjust the UE's time counter by simple addition (step 1305).

[0211] If what is received is an absolute timing advance command MAC CE or a random access response, then in step 1304 the adjustment value is T C *N TA / 2. Delay Compensation When a MAC CE message is received, the value delay compensation is applied directly.

[0212] In step 130, the gNB synchronization manager of the UE instructs the 5G time synchronization manager to adjust the time counter by applying the obtained adjustment value.

[0213] Also, in step 1305, the UE determines the new N TA Calculate.

[0214] This method therefore allows the UE to adjust its most recently updated time counter when it receives a timing advance command immediately after the reference system frame, allowing it to take into account a more accurate estimate of the propagation delay and therefore obtain better synchronization with the UE's GM clock.

[0215] The present invention also provides a computer program product for a programmable device comprising a set of instructions for carrying out the above-described embodiments of the invention when loaded into and executed by the programmable device.

[0216] Furthermore, the present method also provides a non-transitory computer-readable storage medium storing instructions of a computer program for implementing the aforementioned embodiments of the present invention.

[0217] Any step of an algorithm of the present invention may be implemented in software by execution of a set of instructions or programs by a programmable computing machine such as a PC (Personal Computer), a DSP (Digital Signal Processor) or a microcontroller, or in hardware by a machine or dedicated component such as an FPGA (Field Programmable Gate Array) or an ASIC (Application Specific Integrated Circuit).

[0218] Although the present invention has been described with reference to particular embodiments, the present invention is not limited to those embodiments and modifications will be apparent to those skilled in the art that are within the scope of the present invention.

[0219] Many further modifications and variations will be suggested to those skilled in the art by reference to the exemplary embodiments described above, which are not intended to limit the scope of the invention, which is determined solely by the appended claims. In particular, different features from the various embodiments may be interchanged where appropriate.

[0220] Each of the above-described embodiments of the present invention can be practiced alone or in combination with other embodiments, and features from various embodiments can be combined as needed or where a combination of elements or features from the individual embodiments in a single embodiment is beneficial.

[0221] In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality. The mere fact that different features are recited in mutually different dependent claims does not indicate that a combination of these features cannot be used to advantage.

Claims

1. 1. A method for updating a time counter of a user equipment in a wireless network comprising at least one base station and a plurality of user equipments, the method comprising: receiving a timing advance command from the base station; In response to receiving the timing advance command, updating the time counter using the timing advance command; A method comprising:

2. 2. The method of claim 1, wherein the timing advance command includes a parameter representing a propagation delay between the base station and the user equipment.

3. 3. The method of claim 1 or 2, further comprising: receiving a previous timing advance command from the base station; receiving a reference system frame sent by the base station; In response to receiving the reference system frame, updating the time counter using the previous timing advance command to obtain a previously updated time counter; Including, The method, wherein updating the time counter using the timing advance command includes updating the previously updated time counter based on the timing advance command.

4. 4. The method of claim 3, further comprising: determining whether the timing advance command is more accurate than the previous timing advance command based on a comparison criterion; If so, using the timing advance command to trigger an update of the time counter; A method comprising:

5. 5. The method of claim 4, wherein determining whether the timing advance command is more accurate than the previous timing advance command comprises: comparing a first elapsed time between the system frame of reference and the previous timing advance command and a second elapsed time between the system frame of reference and the timing advance command.

6. 4. The method of claim 3, further comprising: receiving a reference time corresponding to the system frame of reference; determining whether the received reference time is a compensated reference time that represents an arrival time of a reference system frame at the user equipment; Including, the compensated reference time already includes a value for the propagation delay; The method, wherein the time counter is updated further based on the compensated reference time.

7. 7. The method of claim 6, wherein in the event of a positive determination, the method further comprises performing the updating of the time counter using the timing advance command independent of the previous timing advance command.

8. 7. The method of claim 6, in the event of a negative determination, the method further comprises: determining whether the timing advance command is more accurate than the previous timing advance command based on a comparison criterion; using the timing advance command to trigger the updating of the time counter upon a positive determination that the timing advance command is more accurate; A method comprising:

9. 2. The method of claim 1, wherein the timing advance command used to update the time counter is the first timing advance command received after the reference system frame.

10. 10. The method of claim 1, wherein the timing advance command is received via a protocol data unit from the group of a random access response MAC protocol data unit, an absolute timing advance command MAC control element, and a timing advance command MAC control element, all defined in TS 38.321, and a control element conforming to the MAC control element format described in TS 38.321, comprising a command field of at least 13 bits for encoding the timing advance command.

11. 1. A method for updating a time counter of a user equipment in a wireless network comprising at least one base station and a plurality of user equipments, the method comprising, at the base station: estimating a propagation delay to and from the user equipment; determining a compensated reference time representing an arrival time of an associated reference system frame at the user equipment, the compensated reference time including a propagation delay; transmitting the compensated reference time and the associated reference system frame to the user equipment for updating the time counter; A method comprising:

12. 12. The method of claim 11 further comprising: determining whether a new estimate of a propagation delay to and from the user equipment occurs during transmission of the reference system frame.

13. 13. The method of claim 12, wherein, in the event of a positive determination, the method further comprises transmitting a timing advance command regardless of the magnitude of the newly estimated propagation delay.

14. 12. The method of claim 11, wherein the timing advance command is transmitted using a control element conforming to a MAC control element format as described in TS 38.321, comprising a command field of at least 13 bits for encoding the timing advance command.

15. 13. The method of claim 12, wherein in the event of a negative determination, the method further comprises transmitting a timing advance command when the new estimate of propagation delay is greater than a predetermined threshold.

16. 16. The method of claim 15, wherein the predetermined threshold is based on the previously estimated propagation delay.

17. 17. The method of claim 16, wherein the timing advance command is transmitted using a protocol data unit selected from a random access response MAC protocol data unit, an absolute timing advance command MAC control element, and a timing advance command MAC control element, all defined in TS 38.

321.

18. 1. A method for updating a time counter of a user equipment in a wireless network comprising at least one base station and a plurality of user equipments, the method comprising, at the base station: determining a reference time representing a transmission time for a reference system frame; transmitting the reference time to the user equipment and transmitting the reference system frame at the transmission time to update the time counter; In response to transmitting the reference system frame, estimating a propagation delay to and from the user equipment; transmitting a timing advance command to the user equipment, the timing advance command including at least a parameter based on the estimated propagation delay; A method comprising:

19. 20. The method of claim 18, wherein the timing advance command is transmitted using a control element conforming to a MAC control element format as described in TS 38.321, comprising a command field of at least 13 bits for encoding the timing advance command.

20. A device in a wireless network comprising at least one base station and a plurality of user equipments, comprising a processor configured to perform the steps of claim 1, 11 or 18.

21. A computer program product for a programmable device, comprising a set of instructions for carrying out the method of any one of claims 1 to 19 when loaded and executed on said programmable device.

22. A non-transitory computer readable storage medium storing computer program instructions for performing the method of any one of claims 1 to 19.

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