Patent Application
20240072961
Various examples generally relate to disconnected-mode operation of a wireless communication device. Various examples specifically relate to a transmission of reference signals while the wireless communication device operates in a disconnected mode.
There is a need to reduce power consumption of wireless communication devices (UEs). One strategy to reduce power consumption of a UE is to operate the UE in a disconnected mode. As a general rule, the disconnected mode provides limited connectivity if compared to a connected mode, but enables a reduced power consumption. This is because a data connection is deactivated, at least along a wireless link between the UE and the communications network.
Then, the disconnected mode may include paging operation and/or a random-access procedure, to re-establish the data connection. For example, in the context of the Third Generation Partnership Project (3GPP), example implementations of the disconnected mode include the Radio Resource Control (RRC) idle mode and RRC inactive mode. See 3GPP Technical Specification (TS), 38.304 Version 16.3 (2020 December).
As a general rule, when operating in a disconnected mode, the UE can typically expect transmissions from the communications network to be restricted to active periods of a discontinuous reception (DRX) cycle; accordingly, during inactive periods of the DRX cycle, the UE can transition some parts of its wireless interface into an inactive state (sometimes also called sleep state). For example, an analog front end and/or more parts of a digital front end and/or other parts can be shut down. This helps to reduce the power consumption.
During disconnected mode, the UE monitors one paging occasion (PO) per DRX cycle. In order to be able to receive data during the active duration of the DRX cycle, typically, the wireless interface is (re-)transitioned into an active state some time before the beginning of the active period. This is because the transitioning from the inactive state to the active state requires some time and, furthermore, it is typically required to re-synchronize with the timing reference of the communications network and/or otherwise adapt the wireless interface to be able to receive data.
To re-synchronize—i.e., to maintain synchronization during a further transmission—, the UE can monitor for reference signals (RSs) transmitted by the communications network when attempting to transition the wireless interface to the active state.
For example, according to existing implementations, the UE can monitor for Synchronization Signal Blocks (SSB) that include RSs.
It has been found that sometimes the process of monitoring for the RSs is comparably inefficient in that it requires significant time and consumes significant power.
Accordingly, there is a need for advanced techniques of operating UEs in the disconnected mode using a DRX cycle. In particular, there is a need for advanced techniques of re-acquiring synchronization with a communications network prior to an active period of the DRX cycle.
A method of operating a UE connectable to a communications network may include obtaining configuration information that is indicative of at least one configuration of one or more sporadically-on transmissions of tracking reference signals.
The configuration information may be obtained from a communications network. A respective control message could be indicative of the configuration information.
The configuration information may be obtained while operating in a connected mode or while operating in a disconnected mode.
The method may include obtaining availability information that is indicative of at least one availability of the one or more sporadically-on transmissions of tracking reference signals.
The availability information may be obtained by receiving a message that is indicative of the availability information. One or more signaling modes may be used in order to receive the message. For instance, implicit signaling or explicit signaling could be used.
An activated signaling mode may be determined by the UE. For instance, it would be possible that the activated signaling mode is indicated by the configuration information. The activated signaling mode may change from time to time.
It would also be possible that the at least one availability of the one or more sporadically-on transmissions is inferred, e.g., from one or more states of the communications network and/or operating modes of the UE and/or other signaling.
The UE may monitor for tracking reference signals when operating in a disconnected mode.
A method of operating a UE connectable to a communications network includes receiving, from the communications network and when operating in a disconnected mode, a downlink control information message. The downlink control information message is received on a downlink control channel. The downlink control information message includes availability information. The availability information is indicative of at least one availability of one or more sporadically-on transmissions of tracking reference signals. The method also includes, when operating in the disconnected mode, monitoring for the tracking reference signals that are sporadically transmitted by the communications network in accordance with the at least one availability. The tracking reference signals are suitable for maintaining synchronization with the communications network.
A computer program or a computer-program product or a computer-readable storage medium includes program code. The program code can be loaded and executed by at least one processor. Upon loading and executing the program code, the at least one processor performs a method of operating a UE that is connectable to a communications network. The method includes receiving, from the communications network and when operating in a disconnected mode, a downlink control information message. The downlink control information message is received on a downlink control channel. The downlink control information message includes availability information. The availability information is indicative of at least one availability of one or more sporadically-on transmissions of tracking reference signals. The method also includes, when operating in the disconnected mode, monitoring for the tracking reference signals that are sporadically transmitted by the communications network in accordance with the at least one availability. The tracking reference signals are suitable for maintaining synchronization with the communications network.
A method of operating a UE connectable to a communications network is provided. The method includes, when operating in a disconnected mode, receiving, from the communications network, a downlink control information message on a downlink control channel. The downlink control information message includes scheduling information for a further message. When operating in the disconnected mode, the method also includes receiving, in accordance with the scheduling information from the communications network, the further message on a downlink shared channel. The further message includes availability information indicative of at least one availability of at least one sporadically-on transmission of tracking reference signals. Also, the method includes monitoring for the tracking reference signals that are sporadically transmitted by the communications network in accordance with the at least one availability and when operating in the disconnected mode. The tracking reference signals are suitable for maintaining synchronization with the communications network.
A computer program or a computer-program product or a computer-readable storage medium includes program code. The program code can be loaded and executed by at least one processor. Upon loading and executing the program code, the at least one processor performs a method of operating a wireless communication device that is connectable to a communications network. The method includes, when operating in a disconnected mode, receiving, from the communications network, a downlink control information message on a downlink control channel. The downlink control information message includes scheduling information for a further message. When operating in the disconnected mode, the method also includes receiving, in accordance with the scheduling information from the communications network, the further message on a downlink shared channel. The further message includes availability information indicative of at least one availability of at least one sporadically-on transmission of tracking reference signals. Also, the method includes monitoring for the tracking reference signals that are sporadically transmitted by the communications network in accordance with the at least one availability and when operating in the disconnected mode. The tracking reference signals are suitable for maintaining synchronization with the communications network.
A method of operating an access node of a communications network includes transmitting, to a UE operating in a disconnected mode, a downlink control information message on a control channel. The downlink control information message includes availability information indicative of at least one availability of one or more sporadically-on transmissions of tracking reference signals. Also, the method includes performing the one or more sporadically-on transmissions of the tracking reference signals when the UE operates in the disconnected mode and in accordance with the at least one availability.
A computer program or a computer-program product or a computer-readable storage medium includes program code. The program code can be loaded and executed by at least one processor. Upon loading and executing the program code, the at least one processor performs a method of operating an access node of a communications network. The method includes transmitting, to a UE operating in a disconnected mode, a downlink control information message on a control channel. The downlink control information message includes availability information indicative of at least one availability of one or more sporadically-on transmissions of tracking reference signals. Also, the method includes performing the one or more sporadically-on transmissions of the tracking reference signals when the UE operates in the disconnected mode and in accordance with the at least one availability.
A method of operating an access node of a communications network includes transmitting, to a UE operating in a disconnected mode, a downlink control information message on a downlink control channel. The downlink control information message includes scheduling information for a further message. The method also includes transmitting, in accordance with the scheduling information and to the UE operating in the disconnected mode, the further message on a downlink shared channel. The further message includes availability information that is indicative of at least one availability of one or more sporadically-on transmissions of tracking reference signals. Also, the method includes performing the one or more sporadically-on transmissions of the tracking reference signals when the UE operates in the disconnected mode in accordance with the at least one availability.
A computer program or a computer-program product or a computer-readable storage medium includes program code. The program code can be loaded and executed by at least one processor. Upon loading and executing the program code, the at least one processor performs a method of operating an access node of a communications net-work. The method includes transmitting, to a UE operating in a disconnected mode, a downlink control information message on a downlink control channel. The downlink control information message includes scheduling information for a further message. The method also includes transmitting, in accordance with the scheduling information and to the UE operating in the disconnected mode, the further message on a downlink shared channel. The further message includes availability information that is indicative of at least one availability of one or more sporadically-on transmissions of tracking reference signals. Also, the method includes performing the one or more sporadically-on transmissions of the tracking reference signals when the UE operates in the disconnected mode in accordance with the at least one availability.
A method of operating a UE connectable to a communications network includes obtaining, from the communications network, at least one configuration of one or more sporadically-on transmissions of tracking reference signals. The method also includes, in accordance with one or more predefined rules, inferring at least one availability of the one or more sporadically-on transmissions. When operating in the disconnected mode, the method further includes monitoring for the tracking reference signals sporadically transmitted by the communications network in accordance with the at least one availability. The tracking reference signals are suitable for maintaining synchronization with the communications network.
A computer program or a computer-program product or a computer-readable storage medium includes program code. The program code can be loaded and executed by at least one processor. Upon loading and executing the program code, the at least one processor performs a method of operating a UE that is connectable to a communications network. The method includes obtaining, from the communications network, at least one configuration of one or more sporadically-on transmissions of tracking reference signals. The method also includes, in accordance with one or more predefined rules, inferring at least one availability of the one or more sporadically-on transmissions. When operating in the disconnected mode, the method further includes monitoring for the tracking reference signals sporadically transmitted by the communications network in accordance with the at least one availability. The tracking reference signals are suitable for maintaining synchronization with the communications network.
A method of operating an access node of a communications network includes providing, to a UE operating in a disconnected mode, availability information that is indicative of at least one availability of one or more sporadically-on transmissions of tracking reference signals. The method also includes performing the one or more sporadically-on transmissions of the tracking reference signals when the UE operates in the disconnected mode and in accordance with at least one availability. The method also includes switching between at least two signaling modes used for said providing of the availability information.
A computer program or a computer-program product or a computer-readable storage medium includes program code that can be loaded and executed by at least one processor. Upon loading and executing the program code, the at least one processor performs a method of operating an access node of a communications network. The method includes providing, to a UE operating in a disconnected mode, availability information that is indicative of at least one availability of one or more sporadically-on transmissions of tracking reference signals. The method also includes performing the one or more sporadically-on transmissions of the tracking reference signals when the UE operates in the disconnected mode and in accordance with at least one availability.
The method also includes switching between at least two signaling modes used for said providing of the availability information.
A method of operating a UE that is connectable to a communications network includes determining an activated signaling mode used to provide availability information indicative of at least one availability of one or more sporadically-on transmissions of tracking reference signals. The method also includes, when operating in a disconnected mode, obtaining, from the communications network, the availability information in accordance with the activated signaling mode. The method further includes, when operating in the disconnected mode, monitoring for the tracking reference signal sporadically transmitted by the communications network in accordance with the at least one availability.
The tracking reference signals are suitable for maintaining synchronization with the communications network.
A computer program or a computer-program product or a computer-readable storage medium includes program code. The program code can be loaded and executed by at least one processor. Upon loading and executing the program code, the at least one processor performs a method of operating a UE that is connectable to a communications network. The method includes determining an activated signaling mode used to provide availability information indicative of at least one availability of one or more spo-radically-on transmissions of tracking reference signals. The method also includes, when operating in a disconnected mode, obtaining, from the communications network, the availability information in accordance with the activated signaling mode. The method further includes, when operating in the disconnected mode, monitoring for the tracking reference signal sporadically transmitted by the communications network in accordance with the at least one availability. The tracking reference signals are suitable for maintaining synchronization with the communications network.
A wireless communication device and/or an access node are configured according to the methods as described above.
It is to be understood that the features mentioned above and those yet to be explained below may be used not only in the respective combinations indicated, but also in other combinations or in isolation without departing from the scope of the invention.
Some examples of the present disclosure generally provide for a plurality of circuits or other electrical devices. All references to the circuits and other electrical devices and the functionality provided by each are not intended to be limited to encompassing only what is illustrated and described herein. While particular labels may be assigned to the various circuits or other electrical devices disclosed, such labels are not intended to limit the scope of operation for the circuits and the other electrical devices. Such circuits and other electrical devices may be combined with each other and/or separated in any manner based on the particular type of electrical implementation that is de-sired. It is recognized that any circuit or other electrical device disclosed herein may include any number of microcontrollers, a graphics processor unit (GPU), integrated circuits, memory devices (e.g., FLASH, random access memory (RAM), read only memory (ROM), electrically programmable read only memory (EPROM), electrically erasable programmable read only memory (EEPROM), or other suitable variants thereof), and software which co-act with one another to perform operation(s) disclosed herein. In addition, any one or more of the electrical devices may be configured to execute a program code that is embodied in a non-transitory computer readable medium programmed to perform any number of the functions as disclosed.
In the following, embodiments of the invention will be described in detail with reference to the accompanying drawings. It is to be understood that the following description of embodiments is not to be taken in a limiting sense. The scope of the invention is not intended to be limited by the embodiments described hereinafter or by the drawings, which are taken to be illustrative only.
The drawings are to be regarded as being schematic representations and elements illustrated in the drawings are not necessarily shown to scale. Rather, the various elements are represented such that their function and general purpose become apparent to a person skilled in the art. Any connection or coupling between functional blocks, devices, components, or other physical or functional units shown in the drawings or described herein may also be implemented by an indirect connection or coupling. A coupling between components may also be established over a wireless connection. Functional blocks may be implemented in hardware, firmware, software, or a combi-nation thereof.
Various aspects relate to a communication system. For example, the communication system may be implemented by a UE and an access node of a communications net-work (NW). For example, the access node may be implemented by a base station (BS) of a cellular communications NW (simply, cellular NW hereinafter). Hereinafter, for sake of simplicity various examples will be described in connection with an implementation of the communication system by a UE connectable to a cellular NW. However, similar techniques may be readily employed for other kinds and types of communication systems.
The communication system may include a wireless link between the UE and the BS. Downlink (DL) signals may be transmitted by the BS and received by the UE. Uplink (UL) signals may be transmitted by the UE and received by the BS.
Hereinafter, techniques will be described that facilitate operation of a UE in a disconnected mode. The disconnected mode may restrict connectivity, e.g., in terms of when the UE can receive data and/or in terms of what signals the UE can receive. The disconnected mode can generally enable a UE to shut down partly or fully one or more components of its wireless interface. When a UE operates in the disconnected mode, it is possible that the cellular NW discards certain information associated with the UE, e.g., certain information of the UE context, etc. It would be possible that a UE-specific data connection on the wireless link between the cellular NW and the UE is released; on the other hand, a section of the data connection may be maintained in a core of the communications NW.
As a general rule, the UE operating in the disconnected mode can use a DRX cycle, i.e., iteratively switch the wireless interface between an active state and an inactive state (sometimes referred to as sleep state). When in the inactive state, the wireless interface may be unfit to receive data. When switching from the inactive state to the active state, the UE may monitor for a RS. The UE may also monitor for a further transmission, e.g., a paging signal.
Examples of disconnected modes are 3GPP Idle and 3GPP Inactive modes.
As a general rule, the disconnected mode can be associated with paging operation. Here, one or more paging signals are transmitted by the communications NW to the UE at a paging occasion (PO). The PO is time-aligned with the active duration of the DRX cycle.
There are various tasks that the UE may perform when operating in the disconnected mode that may require that the UE maintains synchronization with the cellular NW.
Some examples are summarized in TAB. 1 below.
An RS generally denotes a signal that has a well-defined transmit property—e-g. amplitude, phase, symbol sequence, and/or precoding, etc.—that is also known to the receiver. Based on a receive (RX) property of the RS—e.g., based on the received amplitude or the received phase of the RS—it is then possible to tune one or more properties of the wireless interface. For instance, a radio-frequency oscillator may be tuned; phase shifts may be compensated. The RS is suitable/configured to be used by the UE to maintain synchronization with the communications NW. It would be possible to sound one or more channels (e.g., pertaining to different spatial streams) on the wireless link, by monitoring receive properties of RSs transmitted and concluding on, e.g., a channel matrix, path loss, fading and/or other properties of the channel based thereon.
Then, the UE can attempt to demodulate a further transmission from the communications NW based on the RX property of the RS. For example, the UE may attempt to demodulate a further transmission during or prior to the active period of the DRX cycle. Alternatively or additionally, the UE can modulate a further transmission to the communications NW based on the RX property of the RS. Thus, as a general rule, the RS can be suitable for maintaining synchronization in a further communication between the UE and the NW. Examples are explained in connection with TAB. 1.
Hereinafter, techniques are described that facilitate efficient—e.g., low-latency and/or energy-efficient and/or low-overhead—synchronization with the cellular NW. The efficient synchronization can be obtained through appropriate strategies for the transmission of the DL RS.
For example, a sporadically-on transmission of the RS may be used. I.e., a transmission of the RS may be relied upon which is not always-on. This means that the UE will not make an assumption on the presence of the RS on the wireless link unless the sporadically-on transmission is configured for the UE and the UE receives respective signaling from the cellular NW (in contrast to an always-on transmission). More specifically, the UE may require (i) a configuration of the sporadically-on transmission, as well as (ii) an indication of the sporadically-on transmission being activated (on-availability). A sporadically-on transmission of the RSs can be configured by the cellular NW on-demand. The sporadically-on transmission of the RS can be activated and then de-activated again, by the cellular NW; i.e., the availability of the sporadically-on transmission may be changed or toggled between an off-availability and an on-availability; this means that for a given configuration the sporadically-on transmission of RSs can be switched on and off, without the configuration changing.
For example, as a general rule, a configuration information of a sporadically-on transmission of RSs may be indicative of time-frequency resources of the time-frequency resource grid on which the RSs are located. The configuration information could be indicative of a timing of the RSs, e.g., a periodicity and/or a time offset with respect to certain reference timings, e.g., a PO or SSB transmission. The configuration information could be indicative of a sequence format of the RSs. The configuration information could be indicative of one or more transmit beams used by the base station to transmit the RSs of the sporadically-on RS transmission.
The sporadically-on transmission of the RS may use time-frequency resources in a time-frequency resource grid that are specifically allocated when configuring the spo-radically-on transmission. A respective configuration can be indicative of such time-frequency resources. This may be different to an always-on transmission where respective re-occurring resources may be statically allocated, e.g., at certain reserved sections of a subframe of the transmission protocol used for communicating on the wireless link.
As a general rule, it would be possible that the RS of the sporadically-on transmission is indicative of a cell identity of the cell of the cellular NW. The RS of the sporadically-on transmission can be sequence-based. For instance, a symbol sequence of, e.g., a Zadoff-Chu sequence or a maximum-length sequence may be used. Scrambling and/or interleaving may be used. The sporadically-on transmission may map the RS to multiple subcarriers within an Orthogonal Frequency Division Multiplexing (OFDM) symbol.
An example implementation of the sporadically-on transmission of the RS may rely on Channel State Information RSs (CSI-RSs) or specifically tracking RSs (TRSs). In contrast, an always-on transmission of a RS may rely on, e.g., one or more of a primary synchronization signal (PSS), a secondary synchronization signal (SSS), or a cell-specific RS. The PSS and/or the SSS signal can be included in a repeatedly broadcasted synchronization signal block (SSB) that also includes other components such as a physical broadcast channel, carrying an information block including cell-specific information, and demodulation reference signals (DMRS), intended to assist UE for the demodulation of physical broadcast channel.
According to various examples, TRSs are transmitted to UEs operating in an idle mode. Due to oscillator imperfections, the UE tracks and compensates for variations in time and frequency to successfully communicate data between the cellular NW and the UE.
For this, TRSs can be used. A TRS generally describes a resource set consisting of multiple periodic non-zero-power CSI-RSs. More specifically, a TRS may consist of four one-port, density-3 CSI-RSs located within two consecutive slots of a communication protocol used by the UE and the cellular NW. TRS are generally described in 3GPP Technical Specification 38.214, Version 16.4, (2020-12).
In legacy systems (e.g., 3GPP New Radio, NR, rel.15 and 16), the TRS is utilized only by the UE operating in connected mode. The configuration of the TRS transmission is specifically provided by the BS to each UE. TRS can be configured with certain periodicity and typically configured with an association with the transmission of SSBs, e.g. quasi-colocated (QCL'ed). An example of TRS resource allocation and its relationship with SSB is shown in
As illustrated in
Because the always-on transmission of a respective further RS is always available, the sporadically-on transmission of the RS is contemporaneous (i.e., available at the same time) with the always-on transmission. Thus, in principle, the UE may select to attempt to receive (monitor) the further RS of the always-on transmission or the RS of the spo-radically-on transmission, or both.
As a general rule, according to the various examples disclosed herein it would be possible that a repetition rate of the sporadically-on transmission of the RS (e.g., TRS) can be higher than a repetition rate of the always-on transmission of a further RS (e.g., PSS). This may have the benefit that a latency until reception of the RS of the sporad-ically-on transmission is comparably short. Thus, a time-to-synchronization can be reduced when the UE monitors for the RS of the sporadically-on transmission when operating in the disconnected mode.
As a further general rule, according to the various examples disclosed herein it would be possible that a bandwidth of the sporadically-on transmission of the RS is larger than a bandwidth of the always-on transmission of the further RS. This means that the sporadically-on transmission may cover a broader frequency range compared to the always-on transmission. Wider bandwidth RS transmission would enable fine fre-quency/time synchronization. For instance, multiple RSs may be scattered across the broader bandwidth, or a single RS may occupy a comparably large bandwidth.
Various techniques are based on the finding that because a sporadically-on transmission of the RS may be used by the UE operating in the disconnected mode using the DRX cycle, the UE—once transitioning the wireless interface back from the inactive state to the active state in preparation for monitoring a PO—may require some addi-tional information regarding whether the sporadically-on transmission of the RS is currently available by the communications NW or not (in particular in contrast to an al-ways-on transmission of the RS for which the UE may simply begin monitoring, because it is always active and the UE makes the respective assumption without dedicated DL signaling from the cellular NW). The UE may generally require availability information indicative of the availability of the sporadically-on transmission. Lack of the availability information can result in the UE using the legacy SSB for synchronization which may increase power consumption; further, lack of the availability information can result in the UE performing blind detection to detect whether TRSs are transmitted or not which may also increase power consumption.
Obtaining the availability information from the cellular NW can be difficult for the UE in disconnected mode, because there is a limited possible communication exchange between UE and the BS. According to various examples described herein, techniques are provided that facilitate a corresponding exchange of the availability information indicative of at least one availability of one or more sporadically-on transmissions of TRS between the cellular NW and the UE.
According to various examples, there are multiple options available for obtaining the availability information, see TAB. 2 below.
In the scenario of
The UE 101 is connectable to a core NW (CN) 115 of the cellular NW 100 via a RAN 111, typically formed by one or more BSs 112 (only a single BS 112 is illustrated in
For example, the BS 112 can provide an always-on transmission of first RSs. The BS 112 can also provide one or more sporadically-on transmissions of second RSs. For this, the BS 112 can configure the respective sporadically-on transmission(s) for one or more UEs that are connected or have been connected to the respective cell of the cellular NW 100, e.g., by maintaining a respective registry.
The wireless link 114 implements a time-frequency resource grid. Typically, OFDM is used: here, a carrier includes multiple subcarriers. The subcarriers (in frequency domain) and the symbols (in time domain) then define time-frequency resource elements of the time-frequency resource grid. Thereby, a protocol time base is defined, e.g., by the duration of frames and subframes including multiple symbols and the start and stop positions of the frames and subframes. Different time-frequency resource elements can be allocated to different logical channels of the wireless link 114. Examples include: Physical DL Shared Channel (PDSCH); Physical DL Control Channel (PDCCH); Physical Uplink Shared Channel (PUSCH); Physical Uplink Control Channel (PUCCH); channels for random access; etc.
The CN 115 includes a user plane (UP) 191 and a control plane (CP) 192. Application data is typically routed via the UP 191. For this, there is provided a UP function (UPF) 121. The UPF 121 may implement router functionality. Application data may pass through one or more UPFs 121. In the scenario of
The cellular NW 100 also includes a mobility-control node, here implemented by an Access and Mobility Management Function (AMF) 131 and a Session Management Function (SMF) 132.
The cellular NW 100 further includes a Policy Control Function (PCF) 133; an Application Function (AF) 134; a NW Slice Selection Function (NSSF) 134; an Authentication Server Function (AUSF) 136; and a Unified Data Management (UDM) 137.
The AMF 131 provides one or more of the following functionalities: connection management sometimes also referred to as registration management; NAS termination for communication between the CN 115 and the UE 101; connection management; reach-ability management; mobility management; connection authentication; and connection authorization. For example, the AMF 131 controls CN-initiated paging of the UE 101, if the respective UE 101 operates in the idle mode. The AMF 131 may trigger transmission of paging signals to the UE 101; this may be time-aligned with POs. The timing of the POs can be determined based on the UE identity 451. I.e., POs are associated with the respective UEs based on their identify. After UE registration to the NW, the AMF 131 creates a UE context 459 and keeps this UE context, at least as long as the UE 101 is registered to the NW. The UE context 459 can hold one or more identities of the UE 101, e.g., temporary identities used for paging as described herein.
A data connection 189 is established by the SMF 132 if the respective UE 101 operates in a connected mode. The data connection 189 is characterized by UE subscription information hosted by the UDM 137. To keep track of the current mode of the UE 101, the AMF 131 sets the UE 101 to CM-CONNECTED or CM-IDLE. During CM-CONNECTED, a non-access stratum (NAS) connection is maintained between the UE 101 and the AMF 131. The NAS connection implements an example of a mobility control connection. The NAS connection may be set up in response to paging of the UE 101.
The SMF 132 provides one or more of the following functionalities: session management including session establishment, modify and release, including bearers set up of UP bearers between the RAN 111 and the UPF 121; selection and control of UPFs; configuring of traffic steering; roaming functionality; termination of at least parts of NAS messages; etc. As such, the AMF 131 and the SMF 132 both implement CP mobility management needed to support a moving UE.
The data connection 189 is established between the UE 101 and the RAN 111 and on to the UP 191 of the CN 115 and towards the DN 180. For example, a connection with the Internet or another packet data NW can be established. To establish the data connection 189, i.e., to connect to the cellular NW 100, it is possible that the respective UE 101 performs an RA procedure, e.g., in response to reception of paging signals.
This establishes at least a RAN-part of the data connection 189. A server of the DN 180 may host a service for which payload data is communicated via the data connection 189. The data connection 189 may include one or more bearers such as a dedicated bearer or a default bearer. The data connection 189 may be defined on the RRC layer, e.g., generally Layer 3 of the OSI model.
The data connection 189 is established in the connected mode 301. In particular, a RAN-part of the data connection 189 is established in the connected mode 301. Data can be communicated between the UE 101 and the BS 112 using PDSCH, PDCCH, PUSCH, PUCCH. RRC control messages can be communicated on PDSCH and/or PUSCH. It is possible to use connected-mode DRX. The connected mode 301 can be implemented by the 3GPP RRC connected mode.
The transition 309 from the idle mode 302 or the inactive mode 303 to the connected mode 301 includes an RA procedure. The RA procedure may be triggered by paging signals, e.g., a paging indicator on PDCCH and a paging message on PDSCH. In the inactive mode 303, paging can be triggered by the RAN; while in the idle mode 302 the paging is triggered by the CN.
The paging signals are transmitted at POs. The timing of the POs is determined depending on the identity 451 of the UE 101. The UE 101 can configure a DRX cycle in accordance with the timing of the POs. In particular, the UE 101 can control its wireless interface such that it is in the active state and ready to receive data—e.g., by blind decoding PDCCH and searching for paging information in which the CRC is masked with a paging indication identifier (Paging-RNTI; herein also referred to as paging indicator, because it points to the paging message)—at the start of the active period of the DRX cycle. Details with respect to the operation of the UE 101 using the DRX cycle are illustrated in
When using the DRX cycle 390, the UE 101 periodically transitions a modem of its wireless interface between an inactive state 391 (during time periods 1801 and 1803 in
The timing of the PO 396 is given (for the example of 3GPP NR) by (i) the Subframe Frame Number (SFN) and (ii) the subframe within this frame and (iii) the UE_ID, which is derived from the respective identity 451 of the UE 101.
The UE 101 cannot receive paging signals when operating the modem in the inactive state 391; for example, an analog front end and/or a digital front end of the modem may be powered down. For example, amplifiers and analog-to-digital converters may be switched off. For example, decoding digital blocks may be switched off. The UE hardware is entering the inactive state 391 when it is possible to save power. When the UE hardware is in the inactive state 391, one or more clocks may be turned off, all radio blocks and most modem blocks may be turned off, just minimum activity with a low frequency (RTC) clock to start the platform when it is time for the next PO 396 may be maintained. Accordingly, the inactive state 391 is associated with a comparably small power consumption.
When operating the modem in the active state 392 during the active periods of the DRX cycle 390, the UE 101 activates its RF components to be able to receive signals. When operating in the active state 392, the UE 101 can monitor for signals transmitted by the BS 112. Specifically, the UE 101 can prepare for the PO 396 by monitoring for RSs, to thereby maintain synchronization with the cellular NW 100. Thus, each active period can include a preparation duration 397 prior to a respective PO 396. When operating in the active state 392, the various hardware components of the modem of the wireless interface are powered up and operating.
For example, the UE 101 can perform blind decoding of the PDCCH to detect a paging indicator or a SIB-update indicator. This is explained in greater detail hereinafter.
Generally speaking, the PDCCH assists transmission of payload data on the PDSCH. The PDCCH includes control messages that enable to receive, demodulate, and decode the payload data communicated on the PDSCH. DL Control Information (DCI) messages are transmitted through the PDCCH and include scheduling information about the resource allocation (the set of resource blocks of the time-frequency resource grid containing the PDSCH), transport format and information related to the Hybrid Automatic Repeat Request (ARQ) protocol.
The DCI undergoes channel coding: a cyclic redundancy checksum (CRC) is added, coding—e.g., convolutional or polar coding—and rate matching is performed, according to PDCCH format capacity. The coded DCI bits form the DCI message communicated on the PDCCH. These coded bits are then converted to complex modulated symbols after performing operations including scrambling, QPSK modulation, layer mapping and precoding. Finally, the modulated symbols are interleaved and mapped to physical Resource Elements (REs) of the time-frequency resource grid.
After performing deinterleaving, de-precoding, symbol combining, symbol demodulation and descrambling, the UE performs blind decoding of the PDCCH payload: The UE is unaware of the structure of the PDCCH, including the number of PDCCHs and the number of control-channel elements (CCEs) to which each DCI message is mapped. Multiple PDCCHs can be transmitted in a single subframe which may or may not be all relevant to a particular UE. The UE finds the relevant PDCCH(s) by monitoring a set of CCEs periodically. The UE uses a Radio Network Temporary Identifier (RNTI) to try to decode candidates (blind decoding). More specifically, the RNTI is used to demask candidate CRCs. If no CRC error is detected the UE determines that PDCCH carries its own control information; otherwise, respective bits can be dis-carded.
The PDCCH carries scheduling information and other control information in the form of DCI messages. There are multiple formats of the DCI defined, depending on the information content. The PDCCH is masked with temporary identifiers to identify the information content. If the PDCCH contains paging information (paging indicator), the CRC will be masked with a paging indication identifier i.e. Paging-RNTI (P-RNTI). This is also referred to as paging DCI message. The DCI then includes scheduling information for the paging message transmitted on the PDSCH. If the PDSCH contains SIB, i.e., a system information-RNTI (SI-RNTI) will be used to mask the CRC. This is referred to as SIB indicator, e.g., used to signal a change of the SIB to that the UE will read the SIB and update its configuration accordingly.
With the possibilities of different RNTIs, PDCCH candidates, DCI and PDCCH formats, a significant number of attempts may be required to successfully decode the PDCCH.
This is the reason why blind decoding can require significant energy. The active state 392 is accordingly associated with a comparably high power consumption, as illustrated in
As illustrated in
In the scenario of
Hereinafter, strategies are described that facilitate shortening the time period 1802 by fast synchronization. In particular, strategies are described that facilitate such shortening of the time period 1802 by providing a transmission of a RS 901 that facilitates fast and/or fine synchronization during the time period 1802. Specifically, the RSs 901 and/or the RSs 902 could be TRSs of a respective sporadically-on transmission 90.
At box 3002, configuration information is communicated between the BS and the UE. This can include the BS transmitting the configuration information and/or the UE receiving the configuration information. The configuration information is indicative of at least one configuration of one or more sporadically-on transmissions of TRSs, cf.
For example, the configuration information of a sporadically-on transmission of TRSs may be indicative of time-frequency resources of the time-frequency resource grid on which the TRSs are located. The configuration information could be indicative of a timing of the TRSs, e.g., a periodicity and/or a time offset with respect to certain reference timings, e.g., a PO or SSB transmission, cf.
According to the various examples, it would be possible that the configuration information is indicative of a signaling mode of availability information, cf. box 3005. For example, one instance of configuration information could state that availability information is signaled using paging DCI; another instance of configuration information could state that availability information is signaled using SIB DCI; another instance of the configuration information could state that the availability information is implicitly signaled. Respective options for signaling modes are discussed in connection with TAB. 2, TAB. 3, and TAB. 7.
According to the various examples, it would be possible that the configuration information is indicative of a codebook that is used to signal the availability information. For instance, the availability information may include an index encoded in one or more bits that is to be interpreted in accordance with the codebook by the UE. Different code-books can result in different interpretations, e.g., define whether a given sporadically-on transmission of TRSs has an on-availability or off-availability, or whether different sporadically-on transmissions of TRSs are available.
There are various options for communicating the configuration information. For instance, the configuration information could be communicated while the UE operates in the connected mode, prior to transitioning to the disconnected mode (as will be explained later in connection with
At box 3005, availability information indicative of the availability of a sporadically-on transmission of TRSs is signaled. The BS may transmit a respective message that comprises the availability information. The UE may receive a respective message. This has been explained in connection with TAB. 2, example I. Also, implicit indication would be possible, cf. TAB. 2: example II. For instance, the UE may determine the availability information based on a respective indication of a signaling mode included in the configuration information of box 3002.
Thus, while the sporadically-on transmission of TRSs may be generally configured in box 3002, it is possible that the sporadically-on transmission is switched on and switched off by the BS. Even when switched off, the UE may retain the configuration information, at least for a certain time duration; so that the BS may, again and later on, switch on the sporadically-on transmission without having to execute box 3002 again.
Thus, the availability information enables the UE to determine if a configured sporadi-cally-on transmission of the TRSs is available at a certain point in time, e.g., at a certain subframe or timeslot. Details with respect to such determining if a configured sporadi-cally-on transmission of the TRSs is available are explained below in connection with
Where the sporadically-on transmission of TRSs is currently switched on, this can define an on-availability; likewise, where the sporadically-on transmission of the TRSs is currently switched off, this can define an off-availability.
As a general rule, according to the various examples, it is possible to utilize a discrep-ancy between the actual availability of the sporadically-on transmission and the availability signaled by the availability information at box 3005. In particular, it would be possible that the availability information is indicative of an off-availability; while the spo-radically-on transmission of the TRSs is, at least for certain duration, active. Such a scenario will be later on explained in connection with
At box 3010, the BS and/or the UE participate in the one or more transmissions of the TRSs in accordance with the at least one configuration of box 3005. The BS can transmit the sporadically-on RSs; and the UE can monitor for the sporadically-on RSs.
As a general rule, it is possible that multiple sporadically-on transmissions are configured at box 3002; likewise, availability information can be provided that is indicative of multiple availabilities of the multiple sporadically-on transmissions at box 3005.
According to various examples, there are multiple options available for communicating the availability information at box 3005. In particular, as explained above in connection with TAB. 1, it is possible to indicate the availability information either explicitly or implicitly.
First, examples will be described in connection with TAB. 3 that enable to explicitly indicate the availability information.
According to the various examples described herein, there are multiple options for implementing the availability information for the one or more TRS transmissions. Some options are summarized in TAB. 4.
Various techniques are based on the finding that care should be taken to keep knowledge of the current availability up-to-date at the UE. In particular, when TRS availability is signaled as “on”, the signaling does not have to be reliable since UEs that do not receive this availability signaling will synchronize using SSB in any case, according to existing implementations. On the other hand, when TRS availability toggles from “on” to “off”, the signaling needs to be more reliable: if a UE was to falsely assume that a TRS transmission is active, the UE may wrongly synchronize and thus may become un-reachable.
There are various options available to facilitate the UE having up-to-date knowledge regarding the current availability of the one or more TRS transmissions, or—more generally—the UE having up-to-date knowledge of any changes to the availability information of the one or more TRS transmissions. Some options are summarized in TAB. 5 below.
Next, an example for the delayed de-activation of the one or more TRS transmissions—cf. TAB. 5, example I—will be explained. When availability of a TRS transmission is signaled as “off”, TRS are only actually turned off after N_TRS POs have elapsed in which the TRS availability remains de-facto on. For example, when N_TRS is 3, after a decision to turn TRS off in PO n_page, the BS would send TRS according to the following pattern of TAB. 6.
Referring again to TAB. 2: above, various examples have been described that facilitate an explicit indication of the availability information of the one or more sporadically-on TRS transmissions, according to TAB. 2: example I. Next, examples will be explained in connection with TAB. 2: example II, i.e., an implicit indication of availability information of the one or more sporadically-on TRS transmissions.
Again, various options are available and such options are summarized in TAB. 7 below.
Above, various examples have been described regarding explicitly or implicitly indicating the availability information of the one or more sporadically-on transmissions of TRSs. According to various examples, it is possible to combine such different implementations. For instance, at a first PO of a plurality of POs, the availability information may be explicitly indicated; while, at a second PO of the plurality of POs, the availability information may be implicitly indicated, or vice versa. An example is explained below.
For example, when the UE comes to a new cell then the UE receives SIB explicitly including an information element specifying the at least one configuration. Then, the UE assumes the TRS transmission is available (cf. TAB. 7, example I) until the UE receives the availability information that the TRS transmission is no longer available. This corresponds to an implicit indication based on prior knowledge based on the initial SIB including the configuration information. In case the BS decides to switch off the TRS transmission for the UE operating in the disconnected mode, the BS may transmit the paging DCI message (cf. TAB. 3, example I) that includes explicit availability information indicating that TRS transmission is no longer available. Also, another DCI message could be used, cf. TAB. 3. Alternatively, the availability can also be included in the SIB (cf. TAB. 3, example III).
As a general rule, according to various examples described herein, the availability that is determined by BS can be influenced by the paging rate of the UEs in a cell. If it is low (e.g., during the night), BS can decide to set availability=0. A mobility-control node such as the AMF can send to the BS the information related to the paging rate of a cell at a given time.
At optional box 3105, the UE obtains a configuration information that is indicative of at least one configuration of one or more sporadically-on TRS transmissions. Details with respect to the configuration information have been explained above in connection with box 3002 of
At box 3110, the UE obtains availability information. For instance, the availability information could be signaled explicitly; but it would also be possible that the availability information is provided implicitly, as explained in connection with TAB. 2 above.
It would be possible that the UE first determines a respective signaling mode and then attempts to obtain the availability information in accordance with the signaling mode, at box 3110. For example, the signaling mode could be indicated by the configuration information obtained at box 3105. The signaling mode could specify whether the availability information is signaled explicitly or implicitly, e.g., as described in connection with TAB. 2 above. It would also be possible that the signaling mode could specify further details of how to explicitly or implicitly signal the availability information, e.g., as discussed above in connection with TAB. 3 and TAB. 7, respectively.
The signaling mode could also be fixed.
A codebook for encoding the availability information could be set in accordance with a predefined codebook. The predefined codebook could be signaled by the communications network, e.g., in the configuration information of box 3105. For instance, the codebook could specify how one or more bits of the availability information are to be interpreted by the UE, e.g., cf. TAB. 4, example VII and example III.
In a case in which the availability information is explicitly signaled, it would be possible that the availability information is included in a paging DCI message (cf. TAB. 3: example I), a system information block DCI message (cf. TAB. 3: example II), in a dedicated DCI message having a specific temporary identifier defined for that purpose (cf. TAB. 3: example IV), or included in the system information block communicated on the PDSCH (cf. TAB. 3: example 3).
In case the availability information is implicitly obtained, it would be possible that the UE infers at least one availability of the one or more sporadically-on transmissions in accordance with one or more predefined rules, e.g., defined relatively with respect to obtaining the configuration information at box 3105. A respective example has been explained above in connection with TAB. 7: example I.
Then, at box 3115, it can be determined—e.g., at a given PO selected from a plurality of POs associated with the UE, upon transitioning from the inactive state 391 to the active state 392, cf.
Depending on such check, i.e., depending on the at least one availability, the UE can then select between monitoring for the TRS at box 3120 and monitoring for an always-on transmission of the SSB including PSS and SSS, at box 3130. This selection can be for a subsequent PO, after obtaining the availability information at box 3110.
While in the illustrated example the selection is mutually exclusive, in some examples, the UE may always monitor for the PSS and SSS, and only optionally monitor for the TRSs depending on the availability. Then both PSS/SSS and TRS may be cumulatively received, which enables a more accurate synchronization.
The selection can, in particular, take into account a validity of the availability information, i.e., whether or not the validity has expired. Options for such implementation of the validity have been explained in connection with TAB. 4: example II.
It would also be possible that such selection depends on whether a trigger event of one or more network-defined—i.e., signaled by the network—or predefined—e.g., in accordance with the communications standard—trigger events for a temporary on-availability of the one or more sporadically-on TRS transmissions are detected.
Such trigger events have been discussed in connection with TAB. 4: example V. Specifically, it would be possible to check whether the current PO is included in a subset of all POs associated with the UE. This has been discussed in connection with TAB. 4: example IV.
It would also be possible that negative trigger events are considered when selecting between monitoring for the TRSs and monitoring for the SSB: an example of negative trigger events has been discussed in connection with TAB. 4: example VI. A further example will be described in connection with
At box 3120, the UE can then monitor for the TRSs. This can be in accordance with the configuration information obtained at box 3105, e.g., at respective time-frequency resources and using a respective timing.
It can then be determined at box 3125 whether there is a change in availability. In particular, the availability information could be indicative of a validity of the at least one availability of the one or more sporadically-on transmissions of TRSs, as discussed in connection with TAB. 4: example II. Then, based on this validity, it can be judged whether the previously received availability information is still up to date; in such a case, the UE can continue at a subsequent PO to monitor for the TRSs, at a further iteration of box 3120. Otherwise, in case the availability information has expired, the UE may obtain new availability information at box 3110, e.g., using one of the options described in TAB. 3 above.
In case the UE determines, at box 3115, that the one or more sporadically-on TRS transmissions are currently unavailable, the UE can proceed to box 3130 and monitor for synchronization signals included in the SSB, e.g., SSS and/or PSS.
At box 3205, the BS provides configuration information including at least one configuration of one or more sporadically-on TRS transmissions. Box 3205 is thus inter-related with box 3105 and respective considerations also apply.
The configuration information could include an activated signaling mode currently used by the BS to provide availability information at box 3210. For example, the BS may determine the activated signaling mode, e.g., based on a current cell load level or other decision criteria. The BS may switch between different signaling modes from time to time, e.g., even while a current TRS transmission is configured.
At box 3210, the BS provides availability information. This can be done in an implicit manner or explicitly, by control signaling, as already explained in connection with box 3110 of the method of
In particular, the BS can transmit to the UE operating in the disconnected mode a DCI message on a control channel, e.g., PDCCH. The DCI message can include availability information indicative of at least one availability of the one or more sporadically-on transmissions of TRSs. It would also be possible that the BS transmits—in accordance with scheduling information included in the DCI message—a further message on a downlink shared channel, e.g., PDSCH; then, the availability information can be included in the further message rather than in the DCI message. The further message could be, e.g., a SIB or a paging message.
The BS may not be required to provide the availability information where the availability information is implicitly obtained by the UE, cf. TAB. 2, example II. Box 3210 is thus optional.
At box 3215, the BS performs an always-on transmission of reference signals, here primary synchronization PSS and SSS included in an SSB.
At box 3220, the BS checks, whether for a current PO, the one or more sporadically-on TRS transmissions are to be available or unavailable. This is in accordance with the availability information that may have been provided to the UE at box 3210.
In the affirmative, the method commences with box 3225 and the BS transmits the TRSs. Otherwise, the method commences with box 3210 where, if applicable, an up-dated availability information can be provided to the UE and at a further iteration of box 3215, the BS again transmits the SSB. Details with respect to the determination of box 3220 will be explained later on in connection with
The BS 112 transmits, at 5000, a downlink message 4021, e.g., a RRC control message on PDSCH (e.g., SIB or dedicated RRC or RRC release message), including an information element indicative of the configuration information 6010 of the sporadically-on transmission. This is while the UE 101 operates in the connected mode 301.
Then, the BS 112 starts performing the sporadically-on transmission of TRSs 4001, at 5001, in accordance with the configuration information 6010.
The UE transmits an UL control message 4022 at 5002, e.g., a RRC control message on PUSCH. This UL control message 4022 is indicative of a capability of the UE 101 to monitor for TRSs when operating in a disconnected mode such as the idle mode 302. Such capability signaling is generally optional and in other examples, it would be possible that, e.g., such capability is implicitly signaled, e.g., associated with a device category of the UE, etc. 5002 could occur before 5001.
At 5003, the BS 112 then transmits a connection release control message 4011 that includes availability information 6110 indicative of the BS 112 continuing to provide the sporadically-on transmission of TRSs 4001 when the UE 101 operates in the disconnected mode 302, 303. This is optional.
Then, the UE 101 performs the transition 309 to the disconnected mode 302, 303. Subsequently, the BS performs the sporadically-on transmission of TRSs 4001, at 5004, 5005, e.g., in connection with a PO 396 or TRS is sporadically transmitted with certain periodicity until it is switched off by the BS; the UE 101 receives a TRS 4001 at 5005. The UE can then proceed to receive, based on the TRS 4001—the UE 101 thus can maintain the synchronization with the cellular NW 100, e.g., by tuning oscillators of its RF interfaces —, e.g., a paging DCI 4050 at 5006, or perform any other task (cf. TAB. 1).
While
It is also possible to signal changes in the availability of the sporadically-on transmission of TRSs. Respective variants are explained in connection with
At 5050, the UE 101 receives a paging indicator 4050, i.e., a paging DCI message 4050. The paging indicator 4050 includes scheduling information 6120 for a paging message 4055 transmitted by the BS 112 at 5055. This is also illustrated in
The paging indicator 4050 also includes availability information 6110 that is indicative of at least one availability of one or more sporadically-on TRS transmissions, e.g., the sporadically-on TRS transmission for which the respective configuration information 6010 has been provided by the BS 112 at 5000 (cf.
At 5100, a SIB DCI message 4051 is transmitted by the BS 112 and received by the UE 101. The SIB DCI message 4051 includes scheduling information 6120 for a SIB message 4060 transmitted by the BS 112 at 5105. Respective aspects have already been explained above in connection with
For instance, it would be possible that the SIB message 4060 includes configuration information for one or more sporadically-on TRS transmissions.
For example, the configuration information could be indicative of a mode of providing availability information to the UE 101. Multiple modes have been discussed in connection with, e.g., TAB. 2, TAB. 3, and TAB. 7. For instance, the mode used for providing the availability information could be selected from: explicit signaling; and implicit signaling (cf. TAB. 2).
The SIB DCI message 4051 also includes the availability information 6110.
At 5110, the BS 112 transmits a SIB DCI message 4051 which includes scheduling information 6120 for a SIB message 4060 transmitted by the BS 112 at 5115. The SIB message 4060—communicated, e.g., on the PDSCH—includes the availability information 6110. The SIB message 4060 may also include the configuration information for the sporadically-on TRS transmission.
The BS 112 initially performs the sporadically-on transmission 90, up and until a PO 396-3. This means that up until and during the PO 396-3 the TRS 4001 are transmitted.
However, the BS previously decides—in between the PO 396-1 and the PO 396-2—to switch off the sporadically-on transmission 90. In response to this decision made at 7601, the BS 112 changes the availability 6119 indicated by the availability information 6110 from an on-availability (signaled at the PO 396-1) to an off-availability (signaled at all subsequent POs 396-2-396-8).
As illustrated in
This temporary extension of the sporadically-on transmission 90—diverging from the availability 6119 indicated by the availability information 6110—could be in accordance with a validity 6111 of the availability information 6110 (cf. TAB. 4, example II). For instance, the UE 101 may read the availability information 6110 at the PO 396-1 and then enter an extended inactive state 392 (cf.
Another reason for continuing to transmit the TRSs at the POs 396-2 and 396-3 is that the UE 101 might not have received the availability information at the POs 396-1 and 396-2. The UE might not have received the availability information for statistical reasons such as instantaneous SINR is too low, BLER is too high. By giving the UE multiple chances to read the change in availability information—i.e., here at the POs 396-1, 396-2, 396-3 —, the UE 101 is more likely to receive the availability information.
Alternatively or additionally to such stopping of the performing of the sporadically-on transmission in accordance with the validity 6111, it would also be possible that the BS 112 takes into account that the PO 396-3 is selected from a subset of all POs 396-1-396-8 (cf. TAB. 5, example II). The availability information 6110 can be indicative of the subset and the UE may decide to wake-up from its inactive state 391 at the PO 396-3 of the subset. This is because the UE 101 may be aware that the BS 112 can toggle between providing the sporadically-on transmission and not providing/stopping the sporadically-on transmission at the POs of the subset. Thus, the selection to monitor for the TRSs at the PO 396-3 depends on whether or not the respective PO 396-3 is included or not included in the subset.
Subsequently, the sporadically-on transmission is generally deactivated and the availability 6119 of the availability information 6110 also indicates that the sporadically-on transmission is unavailable. However, in response to one or more trigger events, the sporadically-on transmission can be temporarily performed (Cf. TAB. 5, example V).
This is, e.g., illustrated in connection with the POs 396-5 and 396-6. A paging message is unsuccessfully transmitted by the BS 112 at the PO 396-5, and accordingly, at the PO 396-6 the BS 112 transmits a further paging message—at 7501—while temporarily performing the sporadically-on transmission. Similarly, at PO 396-8, the BS 112 temporarily commences the sporadically-on transmission, because an update of the SIB is signaled at 7502. These are only two examples of trigger events; other trigger events are possible.
In particular, the illustrated example corresponds to positive trigger events, i.e., trigger events at which the sporadically-on transmission temporarily commences. Also negative trigger events would be conceivable; here, the sporadically-on transmission is temporarily suppressed. Such an example is discussed in connection with
Nonetheless, the BS 112—at the PO 396-3—temporarily suspends said performing of the sporadically-on transmission, because paging is not executed at 7503. This means, that at and during the PO 396-3, TRSs need not to be transmitted by the BS. This corresponds to a negative trigger event, as explained in connection with TAB. 4: example VI. It is possible, but not mandatory, that the availability information 6110 is indicative of one or more such negative trigger events that trigger a temporary off-availability of the sporadically-on transmission of the TRSs. Cf. TAB. 4, example VI.
Summarizing, at least the following EXAMPLES have been described above.
EXAMPLE 1. A method of operating a wireless communication device (101) connectable to a communications network (100), the method comprising:
EXAMPLE 2. The method of EXAMPLE 1,
EXAMPLE 3. The method of EXAMPLE 1 or 2,
EXAMPLE 4. The method of EXAMPLE 1 or 2,
EXAMPLE 5. A method of operating a wireless communication device (101) connectable to a communications network (100), the method comprising:
EXAMPLE 6. The method of EXAMPLE 5,
EXAMPLE 7. The method of EXAMPLE 5 or 6,
EXAMPLE 8. The method of any one of the preceding EXAMPLEs,
EXAMPLE 9. The method of any one of the preceding EXAMPLEs, further comprising:
EXAMPLE 10. The method of EXAMPLE 9,
EXAMPLE 11. The method of EXAMPLE 9 or 10.
EXAMPLE 12. The method of any one of EXAMPLEs 9 to 11,
EXAMPLE 13. The method of any one of EXAMPLEs 9 to 11,
EXAMPLE 14. A method of operating an access node (112) of a communications network (100), the method comprising:
EXAMPLE 15. A method of operating an access node (112) of a communications network (100), the method comprising:
EXAMPLE 16. The method of EXAMPLE 14 or 15,
EXAMPLE 17. The method of EXAMPLE 16,
EXAMPLE 18. The method of any one of EXAMPLEs 14 to 17, further comprising:
EXAMPLE 19. The method of any one of EXAMPLEs 14 to 18,
EXAMPLE 20. The method of any one of EXAMPLEs 14 to 19,
EXAMPLE 21. The method of EXAMPLE 20,
EXAMPLE 22. The method of any one of EXAMPLEs 14 to 21,
EXAMPLE 23. The method according to any one of the preceding EXAMPLEs,
EXAMPLE 24. The method of any one of the preceding EXAMPLEs,
EXAMPLE 25. The method of any one of the preceding EXAMPLEs,
EXAMPLE 26. The method of EXAMPLE 25,
EXAMPLE 27. The method of EXAMPLE 25 or 26,
EXAMPLE 28. The method of any one of EXAMPLEs 25 to 27,
EXAMPLE 29. The method of any one of the preceding EXAMPLEs,
EXAMPLE 30. The method of any one of the preceding EXAMPLEs,
EXAMPLE 31. The method of EXAMPLE 30,
EXAMPLE 32. A method of operating a wireless communication device (101) connectable to a communications network (100), the method comprising:
EXAMPLE 33. A method of operating an access node (112) of a communications network (100), the method comprising:
EXAMPLE 34. The method of EXAMPLE 33,
EXAMPLE 35. The method of EXAMPLE 33 or 34,
EXAMPLE 36. The method of any one of EXAMPLEs 33 to 35, further comprising:
EXAMPLE 37. A method of operating a wireless communication device (101) connectable to a communications network (100), the method comprising:
EXAMPLE 38. A wireless communication device (101) connectable to a communications network (100), the wireless communication device comprising a control circuitry configured to:
EXAMPLE 39. The wireless communication device of EXAMPLE 38,
EXAMPLE 40. A wireless communication device (101) connectable to a communications network (100), the wireless communication device comprising a control circuitry configured to:
EXAMPLE 41. The wireless communication device, wherein the control circuitry is configured to perform the method of EXAMPLE 5.
EXAMPLE 42. An access node (112) of a communications network (100), the access node comprising a control circuitry configured to:
EXAMPLE 43. The access node of EXAMPLE 42, wherein the control circuitry is configured to perform the method of EXAMPLE 14.
EXAMPLE 44. An access node (112) of a communications network (100), the access node comprising a control circuitry configured to:
EXAMPLE 45. The access node of EXAMPLE 44, wherein the control circuitry is configured to perform the method of EXAMPLE 15.
EXAMPLE 46. An access node (112) of a communications network (100), the access node comprising a control circuitry configured to:
EXAMPLE 47. The access node of EXAMPLE 46, wherein the control circuitry is configured to perform the method of EXAMPLE 33.
EXAMPLE 48. A wireless communication device (101) connectable to a communications network (100), the wireless communication device comprising a control circuitry configured to:
EXAMPLE 49. The wireless communication device of EXAMPLE 48, wherein the control circuitry is configured to perform the method of EXAMPLE 37.
Although the invention has been shown and described with respect to certain preferred embodiments, equivalents and modifications will occur to others skilled in the art upon the reading and understanding of the specification. The present invention includes all such equivalents and modifications and is limited only by the scope of the appended claims.
For illustration, various scenarios have been described according to which a UE monitors for reference signals of a sporadically-on transmission in a preparation duration prior to a PO. As a general rule, it is not required that the reference signals are exclu-sively transmitted during the preparation duration. For example, it would be possible that the reference signals are transmitted at a fixed periodicity also after the PO and before the preparation duration.
For further illustration, scenarios have been described according to which availability information is used by the UE to determine whether or not a sporadically-on transmission of reference signals is currently available or not. According to various examples, it would not be required to rely on such availability information. For instance, in connection with TAB. 5 and
For still further illustration, various examples have been described with respect to the tracking reference signals or generally reference signals that are suitable for maintaining synchronization with the communications network. As a general rule, similar techniques as described herein may also be used in connection with reference signals that are used for other purposes than maintaining the synchronization, e.g., for measuring a channel between the UE and the communications network.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2150037-6 | Jan 2021 | SE | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2021/086511 | 12/17/2021 | WO |
