Energy efficient paging procedure for dual-mode user equipment

Abstract

To provide energy efficient paging of dual-mode user equipment (UE).SOLUTION: UE may receive paging configuration information from a first network. The paging configuration information may comprise paging parameter(s) for monitoring a paging channel of a second network. Based on the received paging configuration information, the UE may monitor the paging channel of the second network and receive a paging message associated with the first network from the second network. In response to receiving the paging message from the second network, the UE may transmit a paging response to the first network. Apparatuses, methods, and computer programs are disclosed.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] Various exemplary embodiments generally relate to the field of wireless communication. In particular, some example embodiments relate to paging dual-mode user equipment in a cellular communication network.

Background Art

[0002] A user equipment (UE) such as a mobile phone may be configured with multiple radios for communicating with a base station or access point according to different standards or their profiles, such as 3GPP 5G New Radio (NR), 3GPP LTE (Long Term Evolution), 3GPP LTE-MTC or LTE-M (LTE Machine Type Communications), or 3GPP NB-IoT (Narrowband Internet of Things). Different radios may be associated with different power consumption characteristics, and in some applications, it may be desirable to reduce power consumption while still enabling sufficient communication capabilities.

Summary of the Invention

[0003] This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.

[0004] Exemplary embodiments provide a method for energy-efficient paging of dual-mode user equipment. This advantage can be achieved by the features of the independent claims. Further implementations are provided in the dependent claims, the description, and the drawings.

[0005] According to a first aspect, the apparatus comprises at least one processor and at least one memory including computer program code, the at least one memory and the computer code being configured to cause the apparatus, using the at least one processor, to receive, from a first network, paging configuration information including an indication of at least one paging parameter for monitoring a paging channel of a second network; monitor the paging channel of the second network based on the at least one paging parameter; and in response to receiving a paging message from the paging channel of the second network, transmit a paging response to the first network.

[0006] According to an exemplary embodiment of the first aspect, the at least one memory and the computer code may be further configured to cause the apparatus, using the at least one processor, to transmit to the first network an indication of the ability to receive paging messages related to the first network from the second network.

[0007] According to an exemplary embodiment of the first aspect, the indication of the ability may indicate the ability to receive paging messages from the second network in a narrowband idle mode.

[0008] According to an exemplary embodiment of the first aspect, the at least one paging parameter may comprise at least one of a discontinuous reception cycle, an international mobile subscriber identity, or a non-active radio network temporary identifier.

[0009] According to an exemplary embodiment of the first aspect, the paging configuration information may comprise at least one of an indication of fallback conditions for transitioning to an idle mode with respect to the first network, an indication of cell reselection conditions for the first network, or an indication of a set of neighboring cells of the first network that support paging via the second network.

[0010] According to an exemplary embodiment of the first aspect, at least one memory and computer code are further configured to cause an apparatus, using at least one processor, to perform a step of performing cell reselection on cells of a set of neighboring cells of a first network that supports paging via a second network in response to detection of cell reselection conditions for the first network, and a step of continuing to monitor a paging channel of the second network or starting to monitor a second paging channel of the second network based on paging configuration information received from the reselected cell.

[0011] According to an exemplary embodiment of the first aspect, at least one memory and computer code are further configured to cause an apparatus, using at least one processor, to perform a step of transitioning to an idle mode with respect to the first network in response to detection of fallback conditions.

[0012] According to an exemplary embodiment of the first aspect, at least one memory and computer code are further configured to cause an apparatus, using at least one processor, to perform a step of detecting at least one paging response parameter in paging configuration information or a paging message, and a step of transmitting a paging response to the first network based on the at least one paging response parameter.

[0013] According to an exemplary embodiment of the first aspect, the at least one paging response parameter may include at least one of a cell identifier of the first network or a frequency of the first network.

[0014] According to an exemplary embodiment of the first aspect, the paging configuration information may include a radio resource control connection release message.

[0015] According to an exemplary embodiment of the first aspect, at least one memory and computer code may be further configured to cause the apparatus, using at least one processor, to receive control information from a second network, the control information comprising at least one of an indication of a paging subframe offset for a paging subframe configured for the second network, an indication of a paging radio network temporary identifier, an identifier of a wake-up signal sequence, or an indication of a time location of a wake-up signal.

[0016] According to an exemplary embodiment of the first aspect, at least one memory and computer code may be further configured to cause the apparatus, using at least one processor, to monitor a paging channel of a second network based on at least one of a paging subframe offset, a paging radio network temporary identifier, or a wake-up signal.

[0017] According to an exemplary embodiment of the first aspect, the control information may comprise at least one of an indication of system information of a first network, a system information value tag of the first network, or an indication of an update of a physical cell identifier and / or frequency information of a cell of the first network related to a current cell of the second network, the indication being that a paging message is received from the current cell of the second network.

[0018] According to an exemplary embodiment of the first aspect, the control information may be received in downlink control information, at least one system information block, at least one bandwidth reduction system information block, or at least one narrowband system information block.

[0019] According to an exemplary embodiment of the first aspect, at least one memory and computer code may be further configured to cause the apparatus, using at least one processor, to receive from a first network an indication of at least one of a time-frequency location of at least one common channel of a second network, a time-frequency location of at least one common signal of the second network, or timing information of the second network.

[0020] According to an exemplary embodiment of the first aspect, at least one memory and computer code may be further configured to cause the apparatus, using at least one processor, to detect a paging message based on a type of the paging message and an identifier associated with the first network, wherein the type of the paging message indicates the use of an identifier associated with the first network in the paging message.

[0021] According to a second aspect, the method may include receiving, from a first network, paging configuration information including an indication of at least one paging parameter for monitoring a paging channel of a second network; monitoring the paging channel of the second network based on the at least one paging parameter; and transmitting a paging response to the first network in response to receiving a paging message from the paging channel of the second network.

[0022] According to an exemplary embodiment of the second aspect, the method may further include transmitting, to the first network, an indication of the ability to receive a paging message related to the first network from the second network.

[0023] According to an exemplary embodiment of the second aspect, the indication of the ability may indicate the ability to receive a paging message from the second network in a narrowband idle mode.

[0024] According to an exemplary embodiment of the second aspect, at least one paging parameter may comprise at least one of a discontinuous reception cycle, an international mobile subscriber identity, or a non-active radio network temporary identifier.

[0025] According to an exemplary embodiment of the second aspect, the paging configuration information may comprise at least one of an indication of fallback conditions for transitioning to the idle mode with respect to the first network, an indication of cell reselection conditions for the first network, or an indication of a set of neighboring cells of the first network that support paging via the second network.

[0026] According to an exemplary embodiment of the second aspect, the method may further comprise performing cell reselection for a cell of a set of neighboring cells of the first network that support paging via the second network in response to detecting cell reselection conditions for the first network, and continuing to monitor the paging channel of the second network or starting to monitor a second paging channel of the second network based on paging configuration information received from the reselected cell.

[0027] According to an exemplary embodiment of the second aspect, the method may further comprise transitioning to the idle mode with respect to the first network in response to detecting fallback conditions.

[0028] According to an exemplary embodiment of the second aspect, the method may further comprise detecting at least one paging response parameter in the paging configuration information or a paging message, and transmitting a paging response to the first network based on the at least one paging response parameter.

[0029] According to an exemplary embodiment of the second aspect, at least one paging response parameter may comprise at least one of a cell identifier of the first network or a frequency of the first network.

[0030] According to an exemplary embodiment of the second aspect, the paging configuration information may include a radio resource control connection release message.

[0031] According to an exemplary embodiment of the second aspect, the method may further include receiving, from a second network, control information including at least one of an indication of a paging subframe offset for a paging subframe configured for the second network, an indication of a paging radio network temporary identifier, an identifier of a wake-up signal sequence, or an indication of a time location of a wake-up signal.

[0032] According to an exemplary embodiment of the second aspect, the method may further include monitoring a paging channel of the second network based on at least one of a paging subframe offset, a paging radio network temporary identifier, or a wake-up signal.

[0033] According to an exemplary embodiment of the second aspect, the control information may include at least one of an indication of system information of a first network, a system information value tag of the first network, or an update of a physical cell identifier and / or frequency information of a cell of the first network related to a current cell of the second network, where the paging message is received from the current cell of the second network.

[0034] According to an exemplary embodiment of the second aspect, the control information may be received in downlink control information, at least one system information block, at least one bandwidth reduction system information block, or at least one narrowband system information block.

[0035] According to an exemplary embodiment of the second aspect, the method may further include receiving, from a first network, an indication of at least one of a time-frequency location of at least one common channel of a second network, a time-frequency location of at least one common signal of the second network, or timing information of the second network.

[0036] According to an exemplary embodiment of the second aspect, the method may further include detecting a paging message based on a type of the paging message and an identifier associated with the first network, the type of the paging message indicating the use of an identifier associated with the first network in the paging message.

[0037] According to a third aspect, a computer program may include instructions for causing an apparatus to receive, from a first network, paging configuration information including an indication of at least one paging parameter for monitoring a paging channel of a second network; monitor the paging channel of the second network based on the at least one paging parameter; and transmit a paging response to the first network in response to receiving a paging message from the paging channel of the second network. The computer program may further include instructions for causing the apparatus to execute any exemplary embodiment of the method of the second aspect.

[0038] According to a fourth aspect, an apparatus may include means for receiving, from a first network, paging configuration information comprising an indication of at least one paging parameter for monitoring a paging channel of a second network; means for monitoring the paging channel of the second network based on the at least one paging parameter; and means for transmitting a paging response to the first network in response to receiving a paging message from the paging channel of the second network. The apparatus may further include means for executing any exemplary embodiment of the method of the second aspect.

[0039] According to a fifth aspect, the apparatus may comprise at least one processor and at least one memory including computer program code, the at least one memory and the computer code being configured to cause the apparatus, using the at least one processor, to perform the steps of: transmitting paging configuration information including an indication of at least one first paging parameter to a client node for monitoring a paging channel of a second network; transmitting paging configuration information including at least one second paging parameter to the second network for transmitting a paging message related to a first network to the client node; and receiving a paging response from the client node.

[0040] According to an exemplary embodiment of the fifth aspect, the at least one memory and the computer code may be further configured to cause the apparatus, using the at least one processor, to perform the steps of: receiving, from a client node, an indication of the ability to receive a paging message associated with the first network from the second network; and in response to receiving the indication of the ability of the client node to receive a paging message related to the first network from the second network, transmitting paging configuration information to the second network.

[0041] According to an exemplary embodiment of the fifth aspect, the indication of the ability may indicate the ability to receive a paging message from the second network in a narrowband idle mode with respect to the second network.

[0042] According to an exemplary embodiment of the fifth aspect, at least one of the at least one first paging parameter or the at least one second paging parameter may comprise at least one of a discontinuous reception cycle, an international mobile subscriber identity, or a non-active radio network temporary identifier.

[0043] According to an exemplary embodiment of the fifth aspect, the paging configuration information transmitted to the client node may include at least one of an indication of cell reselection conditions for the first network, an indication of a set of neighboring cells of the first network that support paging via the second network, or an indication of fallback conditions for transitioning to the idle mode for the first network.

[0044] According to an exemplary embodiment of the fifth aspect, the paging configuration information transmitted to the client node or the paging configuration information transmitted to the second network may include at least one paging response parameter.

[0045] According to an exemplary embodiment of the fifth aspect, the at least one paging response parameter may include at least one of an indication of a cell identifier of the first network or an indication of a frequency of the first network.

[0046] According to an exemplary embodiment of the fifth aspect, the paging configuration information transmitted to the client node may include a radio resource control connection release message.

[0047] According to an exemplary embodiment of the fifth aspect, the at least one memory and computer code may be further configured to cause the apparatus to transmit, using at least one processor, to the client node an indication of the time-frequency location of at least one common channel of the second network, the time-frequency location of at least one common signal of the second network, or the timing information of the second network.

[0048] According to a sixth aspect, the method may include transmitting, to a client node, paging configuration information comprising an indication of at least one first paging parameter for monitoring a paging channel of a second network; transmitting, to the second network, paging configuration information including at least one second paging parameter for transmitting a paging message related to the first network to the client node; and receiving a paging response from the client node.

[0049] According to an exemplary embodiment of the sixth aspect, the method may further include receiving, from a client node, an indication of the ability to receive a paging message associated with the first network from the second network; and transmitting, in response to receiving the indication of the ability of the client node to receive a paging message associated with the first network from the second network, paging configuration information to the second network.

[0050] According to an exemplary embodiment of the sixth aspect, the indication of the ability may indicate the ability to receive a paging message from the second network in a narrowband idle mode with respect to the second network.

[0051] According to an exemplary embodiment of the sixth aspect, at least one of the at least one first paging parameter or the at least one second paging parameter may comprise at least one of a discontinuous reception cycle, an international mobile subscriber identity, or a non-active radio network temporary identifier.

[0052] According to an exemplary embodiment of the sixth aspect, the paging configuration information transmitted to the client node may include at least one of an indication of cell reselection conditions related to the first network, an indication of a set of neighboring cells of the first network that support paging via the second network, or an indication of fallback conditions for transitioning to an idle mode related to the first network.

[0053] According to an exemplary embodiment of the sixth aspect, the paging configuration information transmitted to the client node or the paging configuration information transmitted to the second network may include at least one paging response parameter.

[0054] According to an exemplary embodiment of the sixth aspect, at least one paging response parameter may include at least one of a cell identifier of the first network or an indication of a frequency of the first network.

[0055] According to an exemplary embodiment of the sixth aspect, the paging configuration information transmitted to the client node may include a radio resource control connection release message.

[0056] According to an exemplary embodiment of the sixth aspect, the method may further include transmitting to the client node an indication of a time-frequency location of at least one common channel of the second network, a time-frequency location of at least one common signal of the second network, or timing information of the second network.

[0057] According to the seventh aspect, a computer program may include instructions for causing an apparatus to transmit to a client node paging configuration information including an indication of at least one first paging parameter for monitoring a paging channel of a second network, transmit to the second network paging configuration information including at least one second paging parameter for transmitting a paging message related to the first network to the client node, and receive a paging response from the client node. The computer program may further include instructions for causing the apparatus to execute any exemplary embodiment of the method of the sixth aspect.

[0058] According to an eighth aspect, the apparatus may comprise means for transmitting to a client node paging configuration information comprising an indication of at least one first paging parameter for monitoring a paging channel of a second network, means for transmitting to the second network paging configuration information comprising at least one second paging parameter for transmitting to the client node a paging message related to the first network, and means for receiving a paging response from the client node. The apparatus may further comprise means for performing any exemplary embodiment of the method of the sixth aspect.

[0059] According to a ninth aspect, the apparatus may comprise at least one processor and at least one memory including computer program code, the at least one memory and the computer code being configured to, using the at least one processor, cause the apparatus to receive from a first network paging configuration information including at least one paging parameter for transmitting to a client node from a second network a paging message related to the first network, and based on the at least one paging parameter, transmit to the client node a paging message associated with the first network.

[0060] According to an exemplary embodiment of the ninth aspect, the at least one paging parameter may comprise at least one of a discontinuous reception cycle, an international mobile subscriber identity, or a non-active radio network temporary identifier.

[0061] According to an exemplary embodiment of the ninth aspect, the paging message may comprise at least one paging response parameter.

[0062] According to an exemplary embodiment of the ninth aspect, the at least one paging response parameter may comprise at least one of an indication of a cell identifier of the first network or a frequency of the first network.

[0063] According to an exemplary embodiment of the ninth aspect, the type of the paging message may indicate the use of an identifier associated with a first network in the paging message.

[0064] According to an exemplary embodiment of the ninth aspect, at least one memory and computer code may be further configured to cause the device to transmit control information including at least one of an indication of a paging subframe offset for a paging occasion configured for a second network, an indication of a paging radio network temporary identifier, an identifier of a wake-up signal sequence, or an indication of a time location of a wake-up signal to a client node using at least one processor.

[0065] According to an exemplary embodiment of the ninth aspect, the control information may include at least one of an indication of an update of system information of a first network, a system information value tag of the first network, or a physical cell identifier and / or frequency information of a cell of the first network related to a current cell of the second network, where the paging message is to be transmitted in the current cell of the second network.

[0066] According to an exemplary embodiment of the ninth aspect, the control information may be transmitted in downlink control information, at least one system information block, at least one bandwidth reduction system information block, or at least one narrowband system information block.

[0067] According to the tenth aspect, the method may include receiving, from a first network, paging configuration information including at least one paging parameter for transmitting a paging message associated with the first network from the first network to a client node from a second network, and transmitting, based on the at least one paging parameter, the paging message associated with the first network to the client node.

[0068] According to an exemplary embodiment of the tenth aspect, at least one paging parameter may include at least one of a discontinuous reception cycle, an international mobile subscriber identity, or a non-active radio network temporary identifier.

[0069] According to an exemplary embodiment of the tenth aspect, a paging message may include at least one paging response parameter.

[0070] According to an exemplary embodiment of the tenth aspect, at least one paging response parameter may include at least one of an identifier of a cell of the first network or an indication of a frequency of the first network.

[0071] According to an exemplary embodiment of the tenth aspect, the type of the paging message may indicate the use of an identifier associated with the first network in the paging message.

[0072] According to an exemplary embodiment of the tenth aspect, the method may include transmitting, to a client node, control information including at least one of an indication of a paging subframe offset for a paging occasion configured for a second network, an indication of a paging radio network temporary identifier, an identifier of a wake-up signal sequence, or an indication of a time location of a wake-up signal.

[0073] According to an exemplary embodiment of the tenth aspect, the control information is an indication of an update of system information of the first network, a system information value tag of the first network, or a physical cell identifier and / or frequency information of a cell of the first network related to a current cell of the second network, and the paging message may include at least one of an indication of being transmitted in the current cell of the second network.

[0074] According to an exemplary embodiment of the tenth aspect, the control information may be transmitted in downlink control information, at least one system information block, at least one bandwidth reduction system information block, or at least one narrowband system information block.

[0075] According to the eleventh aspect, a computer program may include instructions for causing an apparatus to perform steps of receiving, from a first network, paging configuration information including at least one paging parameter for transmitting a paging message related to the first network from a second network to a client node, and transmitting, based on the at least one paging parameter, the paging message associated with the first network to the client node. The computer program may further include instructions for causing the apparatus to perform any exemplary embodiment of the method of the tenth aspect.

[0076] According to the twelfth aspect, an apparatus may include means for receiving, from a first network, paging configuration information including at least one paging parameter for transmitting a paging message associated with the first network from a second network to a client node, and means for transmitting, based on the at least one paging parameter, the paging message associated with the first network to the client node. The apparatus may further include means for performing any exemplary embodiment of the method of the tenth aspect.

[0077] Many of the attendant features will be more readily understood by reference to the following detailed description, which is to be considered in connection with the accompanying drawings, and so will be more readily understood.

Brief Description of the Drawings

[0078] The accompanying drawings, which are included to provide a further understanding of the exemplary embodiments and constitute a part of this specification, illustrate the exemplary embodiments and, together with the description, serve to explain the exemplary embodiments.

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[0080] In the accompanying drawings, like reference numerals are used to designate like parts.

Best Mode for Carrying Out the Invention

[0081] Reference will now be made in detail to exemplary embodiments, examples of which are illustrated in the accompanying drawings. The detailed description provided below in connection with the accompanying drawings is intended as a description of the examples and is not intended to represent the only form in which the examples may be constructed or utilized. The description explains the functions of the examples and the sequence of steps for constructing and operating the examples. However, the same or equivalent functions and sequences may be achieved by different examples.

[0082] Technologies such as NB (Narrowband) IoT (Internet of Things), LTE-M (Long Term Evolution-Machine Type communication), and eMTC (enhanced Machine Type communication), as defined by 3GPP (3rd Generation Partnership Project), enable low-power communication via a cellular communication network. However, low-power technologies such as NB-IoT or LTE-M may not provide sufficient communication capacity for all current or future applications. 3GPP 5G NR (New Radio), or simply NR, provides another radio access technology for various types of services such as enhanced mobile broadband (eMBB) communication, ultra-reliable low-latency communication (URLCC), and massive machine type communication (mMTC). However, the power consumption of NR user equipment may be too high for some IoT-type applications.

[0083] Therefore, it is desirable to enable lower power consumption within the NR standard, and for that purpose, a low power profile of NR, such as NR-Light, can be provided. However, as another concern, significantly modifying the NR radio for NR-Light purposes causes divergence on the chipset side and is not attractive for chipset development. NR-Light is intended to address new use cases with IoT type requirements that cannot be met by NB-IoT or LTE-M, such as higher data rates, higher reliability, and lower latency than eMTC or NB-IoT. On the other hand, it is intended to address lower cost and complexity than NR eMBB as well as long battery life.

[0084] One concern regarding NR is that its reference signals, such as the Synchronization Signal Block (SSB), may not enable an energy-efficient design of NR radio due to, for example, low measurement opportunities. On the other hand, NB-IoT and LTE-M enable reaching low power consumption by virtue of the LTE cell-specific reference signal (CRS), without the influence of beamforming, and with various UE power saving optimizations added to the LTE design. For example, for good CRS availability, the UE can wake up at any time and quickly access the network. In contrast, in the NR idle mode, the UE may need to wait longer to accumulate sufficient energy due to the less frequent CRS, which results in waste of battery power. For example, the idle power consumption is estimated to be up to 45% higher compared to LTE, and the difference for NB-IoT or eMTC can be even higher.

[0085] Therefore, it is desirable to develop a system that enables reasonable UE power consumption for reduced-capability devices such as NR-Light devices or other low-complexity devices and utilizes the NR physical layer (L1) without significant NR physical layer changes. Low UE power consumption is particularly important in the idle mode and inactive states. NR radio may have higher power consumption than NB-IoT or LTE-M radio, or basic LTE radio. NR-Light devices are intended for IoT-type applications and thus aim to provide a longer battery life than NR eMBB-centric devices. However, NR-Light devices are intended to be IoT-centric devices with higher capabilities than NB-IoT or LTE-M devices. Fundamentally changing the NR system, such as the NR physical layer, can cause problems for legacy devices and thus may not be a desirable approach. Also, NR physical layer changes for UE power optimization need to be made at the expense of NR system performance. The changes can also cost the device design.

[0086] Dual-mode UEs may have the ability to access two networks, e.g., an NR network and an LTE or NB-IoT network, or to operate according to different profiles of the network. Power consumption can be reduced, for example, by using a method in which the dual-mode UE is moved to the NR side when it is registered on the LTE side and paged. However, this may involve moving the UE context from the LTE EPC (Evolved Packet Core) to the 5G core. This can cause additional interactions between the two core networks and may also be difficult to achieve interoperability between different manufacturers. For example, modifications on the EPC side may be required to understand the nature of such dual-mode UEs in order to correctly parameterize the UE. Exemplary embodiments provide a method for reducing the power consumption of dual-mode UEs without requiring UE context transfer between two core networks.

[0087] According to an exemplary embodiment, a UE can receive paging configuration information from a first network. The paging configuration information may include paging parameters for monitoring a paging channel of a second network. A network node of the second network may be configured to transmit a paging message instead of the first network. Based on the received paging configuration information, the UE can monitor the paging channel of the second network and receive a paging message related to the first network from the second network. In response to receiving a paging message from the second network, the UE can transmit a paging response to the first network. The first network can provide a higher communication capacity than the second network. However, monitoring paging in the second network can be more energy efficient. For example, paging can be monitored in the second network using a radio having lower power consumption than the radio used for communicating with the first network. Also, the paging procedure of the second network can be more energy efficient.

[0088] FIG. 1 shows an example of a network 100 according to an exemplary embodiment. The network 100 can include at least one client node, which may also be referred to as a user node, a user equipment (UE), a mobile terminal, a terminal, etc. The UE 110 can communicate with one or more base stations via a wireless radio channel, such as an evolved Node B (eNB) 120 of an LTE or NB-IoT network and a next-generation Node B (gNB) 130 of a 5G (NR) network. Generally, the eNB 120 and the gNB 130 are provided as examples of base stations of the first and second networks, respectively. The first network and the second network may also be referred to as a primary network and a secondary network, respectively. The base station may also be referred to as a radio access network (RAN) node or simply a network node.

[0089] The base station may comprise any suitable wireless access point. Generally, the first network node may be configured to operate according to a first standard, and the second network node may be configured to operate according to a second standard. The standard may also be understood as a profile or subset of a certain specification or group of specifications. For example, the first standard may comprise the NR-Light profile of NR. The second standard may comprise NB-IoT or LTE-M. Thus, the first network may comprise a 5G network, such as an NR or NR-Light network. The second network may comprise an NB-IoT network or an LTE-M network. Exemplary embodiments have been described using these specific standards and networks as examples, but it will be understood that the exemplary embodiments may be applied to networks based on any suitable standard or its profile. For example, in one exemplary embodiment, the first network may be configured to operate according to a wireless local area network standard specified by, for example, the IEEE 802.11 series or the Wi-Fi Alliance, and the second network may be configured to operate according to a cellular standard specified by, for example, 3GPP.

[0090] Network 100 can further include a core network 140. The core network 140 can functionally connect different types of base stations, thereby enabling cooperation between RAN nodes. The core network 140 can be implemented by any suitable means. For example, the core network 140 can be configured according to the service-based architecture (SBA) of a 5G core network (CN) 144, which enables a plurality of interconnected network functions (NFs) to access each other's services via a service-based interface (SBI). The core network 140 can include one or more access and mobility management functions (AMF) 145. The AMF 145 can be responsible for connection and mobility management. For example, the AMF 145 can receive and process connection and session request-related information received from the UE 110 via the eNB 120 or gNB 130. The AMF 145 can include a registration management function (RM) 146 configured to handle the registration and deregistration of the UE to the network.

[0091] Furthermore, the core network 140 can be configured to operate according to the evolved packet core (EPC) 141 of LTE. For example, the core network 140 can include one or more mobility management entities (MME) 142. The MME 142 can be configured to manage, for example, service requests from the UE 110, handle paging procedures for the UE 110, and control the mobility of the UE 110, and can include an EMM (extended packet core mobility management) function 143. The EMM 143 can be configured to allocate, for example, a tracking area for the UE 110. A tracking area can include a plurality of cells in which the UE 110 can move without updating its location at the MME 142. The UE 110 can determine whether it has moved to a new tracking area based on comparing the tracking area code (TAC) received from the current cell with a group of tracking area codes included in the tracking area list.

[0092] Radio Resource Control (RRC) can refer to the provision of radio resource related control data. Radio resource control messages can be transmitted on various logical control channels, such as the Common Control Channel (CCCH) or the Dedicated Control Channel (DCCH). The logical control channel can be mapped to one or more Signaling Radio Bearers (SRBs).

[0093] System information can include information provided by the network 100 to the UE 110 for performing, for example, cell selection, cell reselection, handover, etc. System information can be provided in the Master Information Block (MIB) and one or more System Information Blocks, for example, on the Broadcast Control Channel (BCCH).

[0094] Although some exemplary embodiments have been described using specific RRC messages and System Information Blocks (SIBs) as examples, any suitable message can be configured to carry the paging related signaling information described herein. Although some exemplary embodiments have been described using 4G (LTE) and / or 5G networks as examples, the exemplary embodiments presented herein are not limited to these exemplary networks and can be applied to any current or future communication network, such as other types of cellular networks, short-range wireless networks, broadcast networks, etc.

[0095] FIG. 2 shows an exemplary embodiment of an apparatus 200, such as a client node like UE110, or a network node such as eNB120 or gNB130. The apparatus 200 may comprise at least one processor 202. The at least one processor may include, for example, a coprocessor, a microprocessor, a controller, a digital signal processor (DSP), a processing circuit with or without an accompanying DSP, or various other processing devices such as integrated circuits, for example, application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs), microcontroller units (MCUs), hardware accelerators, dedicated computer chips, etc., and may comprise one or more of the foregoing.

[0096] The apparatus 200 may further comprise at least one memory 204. The memory may be configured to store, for example, computer program code such as, for example, operating system software and application software. The memory may comprise one or more volatile memory devices, one or more non-volatile memory devices, and / or combinations thereof. For example, the memory may be configured as a magnetic storage device (e.g., a hard disk drive, a floppy disk, a magnetic tape, etc.), a magneto-optical storage device, or a semiconductor memory (e.g., mask ROM, programmable ROM (PROM), erasable PROM (EPROM), flash ROM, random access memory (RAM), etc.).

[0097] Device 200 may further include a communication interface 208 configured to enable the device 200 to transmit and / or receive information with other devices. In one example, device 200 can use communication interface 208 to transmit or receive signaling information and data according to at least one cellular communication protocol. The communication interface can be configured to provide at least one wireless connection, such as, for example, a 3GPP mobile broadband connection (such as 3G, 4G, 5G). However, the communication interface can be composed of one or more other types of connections, such as a wireless local area network (WLAN) connection standardized by the IEEE 802.11 series or Wi-Fi Alliance, a short-range wireless network connection such as Bluetooth®, NFC (Near Field Communication), or RFID connection, a local area network (LAN) connection, a wired connection such as a Universal Serial Bus (USB) connection or an optical network connection, or a wired Internet connection. Communication interface 208 can be configured to include or be coupled to at least one antenna for transmitting and / or receiving radio frequency signals. One or more of the various types of connections can also be implemented as a separate communication interface that can be coupled to or configured to be coupled to multiple antennas.

[0098] Device 200 may further include a user interface 210 including an input device and / or an output device. The input device may take various forms such as a keyboard, a touch screen, or one or more embedded control buttons. The output device may include, for example, a display, a speaker, a vibration motor, etc.

[0099] When the device 200 is configured to implement several functions, for example, some components and / or elements of the device, such as at least one processor and / or memory, may be configured to implement this function. Further, when at least one processor 202 is configured to implement several functions, this function may be implemented, for example, using program code 206 included in at least one memory 204.

[0100] The functions described herein may be executed at least in part by one or more computer program product components, such as software components. According to an embodiment, the device comprises a processor or a processor circuit, such as a microcontroller, and the processor or processor circuit is configured by program code to execute embodiments of the described operations and functions when executed. Alternatively or additionally, the functions described herein may be executed at least in part by one or more hardware logic components. For example, without limitation, exemplary types of hardware logic components that may be used include field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), application specific standard products (ASSPs), system on chip systems (SOCs), complex programmable logic devices (CPLDs), and graphics processing units (GPUs).

[0101] The device 200 comprises means for executing at least one method described herein. In one example, the means comprises at least one processor 202 and at least one memory 204 including program code 206 configured to cause the device 200 to execute the method when executed by the at least one processor.

[0102] Device 200 may comprise a computing device such as, for example, a base station, a server, a mobile phone, a tablet computer, a laptop, an Internet of Things (IoT) device, etc. Examples of IoT devices include, but are not limited to, home appliances, wearables, sensors, and smart home appliances. In one example, device 200 may comprise a vehicle such as, for example, an automobile. Although device 200 is shown as a single device, it should be understood that whenever applicable, the functions of device 200 may be distributed among multiple devices, for example, to implement an exemplary embodiment as a cloud computing service.

[0103] FIG. 3 shows an example of a paging procedure for a dual-mode user equipment according to an exemplary embodiment. When UE110 is connected to gNB130 in the idle mode, the monitoring of the NR (Light) carrier can be replaced by the monitoring of the LTE or NB-IoT paging channel (PCH), which can be transmitted, for example, on the LTE physical downlink shared channel (PDSCH) or the NB-IoT narrowband physical downlink shared channel (NPDSCH).

[0104] gNB 130 may send at least one paging configuration message that may include paging configuration information, for example, an instruction to monitor the LTE or NB-IoT PCH for an NR paging message. The paging configuration information may be provided, for example, as part of dedicated signaling and / or broadcast signaling. In response to receiving the paging configuration information, UE 110 may start listening or monitoring the LTE or NB-IoT PCH. For example, UE 110 may be configured to follow the LTE side by the 5G side of the corresponding UE ID (identifier). UE 110 may determine the paging frame and / or paging occasion to be monitored based on its international mobile subscriber identity (IMSI). Alternatively, the network may configure the specific IMSI value to be used. This IMSI value can then determine which UE ID triggers a jump to the LTE side. For example, UE 110 may have additional identifiers other than the additional IMSI value. In response to detecting a paging message for an additional identifier, UE 110 may jump to the 5G side. Another identifier may trigger UE 110 to proceed to the LTE side. Thus, in addition to the S-TMSI (serving temporary mobile subscribed identity), any identifier that may normally be used for paging may be used. UE 110 may also be notified about the discontinuous reception (DRX) cycle for monitoring the LTE or NB-IoT PCH.

[0105] gNB130 can provide NR paging messages via LTE or NB-IoT and provide inter-node signaling information, such as a paging indication, to eNB120 to configure eNB120 to activate the transmission of paging messages accordingly. The paging indication may include paging configuration information with at least one paging parameter for transmitting a paging message related to the NR network to UE110. The paging configuration information provided to eNB120 may include, for example, an identifier related to the NR network, such as an IMSI or an I-RNTI (Inactive Radio Network Temporary Identifier), which is used to page UE110 on the LTE / NB-IoT side. The paging configuration information may further include a DRX cycle configured or to be configured for UE110 to receive NR paging via LTE / NB-IoT.

[0106] eNB120 can generate a paging message based on the received paging parameters. For example, eNB120 may insert the indicated NR identifier into the paging message or determine the transmission time of the paging message based on the indicated DRX cycle of UE110. The paging message for NR can then be transmitted by eNB120 using, for example, the Physical Downlink Shared Channel (PDSCH) or the Narrowband Physical Downlink Shared Channel (NPDSCH).

[0107] When receiving an NR paging message from the LTE / NB-IoT PCH, the UE 110 can directly send a paging response to the gNB 130. After the completion of data transmission via the gNB 130, the UE 110 can return to monitoring the LTE / NB-IoT PCH. This procedure results in the same idle mode power consumption as LTE or NB-IoT thanks to the same Radio Resource Management (RMM) operation. Furthermore, the UE context can be maintained in the 5G Core Network (CN) 144, and thus this procedure enables avoiding UE context transfer between LTE and 5G. Additionally, this procedure enables energy-efficient paging without defining a new narrowband operation for NR that could result in L1 (Layer 1) changes, a new L1 wake-up signal, or a new synchronization signal block structure (e.g., with more frequent DMRS occurrences) to achieve lower idle mode power consumption and thereby longer device standby time.

[0108] FIG. 4 shows an example of a flowchart for paging a dual-mode user equipment according to an exemplary embodiment.

[0109] In operation 401, the gNB 130 may send paging parameters to the UE 110 to configure the UE 110 to receive an NR paging message via LTE or NB-IoT.

[0110] In operation 402, the UE 110 may move to listen on the paging channel of LTE or NB-IoT. Listening on the paging channel may be based on the received paging parameters.

[0111] In operation 403, UE 110 may determine whether the NR paging message is received from the paging channel of LTE or NB-IoT. For example, UE 110 may determine whether the paging message includes a UE ID derived from NR signaling. If the paging message related to NR is not received from the paging channel of LTE or NB-IoT, UE 110 may continue to listen to the paging channel in 402. In response to determining that the paging message associated with NR is received from the paging channel of LTE or NB-IoT, UE 110 may proceed to operation 404.

[0112] In operation 404, UE 110 may respond to the paging message via a 5G (NR) carrier. The paging response may be transmitted based on the paging response parameters received from gNB 130 or eNB 120.

[0113] In operation 405, UE 110 and gNB 130 may transfer data on a 5G (NR) carrier.

[0114] In operation 406, UE 110 and / or gNB 130 may deplete the 5G data to be transmitted. UE 110 and / or gNB 130 may further start a timer to determine whether to continue transferring further data on the 5G (NR) carrier.

[0115] In operation 407, UE 110 and / or gNB 130 may determine whether the timer expires before further 5G data for transmission is received. If further data is received before the timer expires, 5G data transfer may continue in operation 405. In response to detecting the expiration of the timer before receiving further 5G data for transmission, gNB 130 may return to operation 401 to reconfigure UE 110 for 5G (NR) paging via LTE or NB-IoT.

[0116] 5G paging via LTE or NB-IoT enables 5G data rates and low latency while reducing idle mode power consumption due to more energy-efficient paging of LTE or NB-IoT, thereby enabling longer battery life for dual-mode UEs. Another advantage is that the hardware implementation of dual-mode UEs is not affected as simultaneous support for 5G and LTE or NB-IoT is not required. Another advantage is that context transfer between the EPC 141 and the 5G CN 144 can be avoided. Thus, changes to the EPC 141 can be avoided.

[0117] According to an exemplary embodiment, the UE 110 can determine whether it is (substantially) stationary, for example, based on being connected to the same eNB 120 and being within a predetermined range. The UE 110 can determine that it is within the predetermined range if, for example, the signal strength from the eNB 120, such as the reference signal received power (RSRP), exceeds a threshold. While monitoring the LTE or NB-IoT network for NR paging, the UE 110 can be configured to check the availability of the NR signal if the signal strength decreases, for example, below a threshold. If the NR signal is no longer available at a sufficient strength, the UE 110 can determine to perform cell reselection to LTE. A tracking area update can also be performed accordingly.

[0118] UE110 may also be configured to monitor NR signals for cell reselection at preconfigured or signaled time intervals to ensure that NR coverage still exists even when UE110 is monitoring NR paging based on LTE or NB-IoT. Monitoring NR signals when paging is configured to be provided via LTE or NB-IoT can be relaxed compared to normal NR requirements to maintain the benefit of power saving. For example, the time interval set for NR cell reselection monitoring may be longer than the time interval set for monitoring the NR paging channel when NR paging is provided by the NR network itself.

[0119] Figure 5 illustrates an example of a message sequence between a dual-mode user equipment, an NR network node, and an LTE or NB-IoT network node for paging the dual-mode user equipment according to an exemplary embodiment. gNB130 and eNB120 are provided as examples of network nodes of the first and second networks, which in this example are an NR (Light) network and an LTE network or an NB-IoT network, respectively.

[0120] In operation 501, UE 110 may send an indication of its ability to receive paging messages related to the NR network from the LTE or NB-IoT network. The indication may be sent to gNB 130. The indication of ability may indicate the ability to receive paging messages from the NB-IoT network in the narrowband idle mode. The narrowband idle mode may generally refer to an idle mode related to a secondary network that has lower idle mode power consumption and / or lower communication capabilities compared to the primary network that provides paging services. For example, the narrowband idle mode may include the RRC_IDLE mode with respect to the LTE or NB-IoT network when monitoring for NR paging from the LTE or NB-IoT network. However, while in the RRC_IDLE mode with respect to LTE or NB-IoT, UE 110 may be in another mode, such as RRC_INACTIVE, with respect to the NR network. The indication of ability may be provided as a new UE ability entry for "narrowband idle mode", which may generally indicate the ability to receive NR paging messages via a secondary network, such as LTE or NB-IoT. gNB 130 may receive an indication of the ability of UE 110 to receive paging messages related to NR from the LTE / NB-IoT network. In response to receiving this ability indication, gNB 130 may configure eNB 120 to send paging messages related to NR, as described with reference to FIG. 3. For example, gNB 130 may send paging configuration information to eNB 120. The paging configuration information may include, for example, at least one paging parameter for processing NR paging via the LTE or NB-IoT network.

[0121] In operation 502, gNB 130 may send an RRC connection release message to UE 110. The RRC connection release message may include narrowband idle mode assistance information. Thus, the RRC connection release message may include, for example, as narrowband idle mode assistance information, an indication of at least one paging parameter for monitoring the paging channel of the LTE or NB-IoT network. The at least one paging parameter may include, for example, a DRX cycle, an IMSI, or an I-RNTI. The indication of the paging parameter may include a value of the paging parameter, for example, a specific value of the IMSI. Alternatively, the indication of the paging parameter may include an indication of the paging parameter without a value of the parameter. For example, gNB 130 may request UE 110 to monitor the paging channel of LTE or NB-IoT based on the IMSI value pre-configured in UE 110. Alternatively, gNB 130 may provide UE 110 with a special IMSI value for monitoring the LTE or NB-IoT network for NR paging. UE 110 may receive the RRC connection release message from gNB 130.

[0122] The RRC connection release message may further include an indication of fallback conditions for transitioning to the idle mode, for example, the RRC_IDLE mode, with respect to the NR network. The fallback conditions may be associated with radio conditions between UE 110 and gNB 130, for example, the signal strength of gNB 130 such as the RSRP at UE 110. Thus, the fallback conditions may include, for example, an RSRP change threshold for transitioning to the NR idle mode.

[0123] The RRC connection release message is an example of paging configuration information, but it should be understood that similar information can be provided by other control messages or within control information such as one or more system information blocks, for example. Further, even if some messages are described as a single message, it should be understood that similar information can be transmitted using multiple messages. For example, paging parameters can be distributed across multiple paging configuration messages.

[0124] The RRC connection release message may further include an indication of cell reselection conditions for the NR network. The cell reselection conditions can be associated with radio conditions between UE110 and gNB130, such as RSRP. However, the threshold for cell reselection may be different from the threshold for fallback to the idle mode of NR.

[0125] The RRC connection release message may further include an indication of a set of neighboring cells of the NR network that support paging via LTE or NB-IoT, for example, a list of neighboring cells. The indication can be provided to notify UE110 about neighboring NR cells, and UE110 can continue to monitor NR paging on the LTE side or the NB-IoT side.

[0126] Figure 6 shows an example of an NR cell reselection procedure during paging monitoring via LTE according to an exemplary embodiment. This procedure can be applied, for example, in an NR-Light UE110 to perform NR cell reselection during narrowband idle mode. LTE-M is used as an example of a second network that provides paging services to a first network 5G NR. The LTE-M signal (LTE-M-RSRP) and the RSRP of the NR signal (NR-RSRP), as well as the corresponding operations at the UE110, are shown with respect to time t. First, the UE110 may be monitoring the paging channel in a first cell of LTE-M. The UE110 may be in an inactive mode (e.g., RRC_INACTIVE) with respect to the NR network. The UE110 may be located in a first cell of NR (NR Cell-1). The RSRP of LTE-M may be higher than the RSRP of NR. As shown in Figure 6, the received signal strength may begin to decrease, and at a first time point T1, the NR signal may reach a threshold for cell reselection. Thus, the UE110 may determine that cell reselection conditions have been detected.

[0127] At a first time point T1, the UE110 can start NR cell reselection. The cell reselection can be performed for an NR cell belonging to a set of neighboring cells that are indicated to support paging via LTE or NB-IoT. Performing NR cell reselection can respond to detecting that cell reselection conditions are met. If a new NR cell (NR cell-2) is found, the UE110 can complete system acquisition and maintain the new (reselected) cell as a reference cell for the uplink, for example, to transmit a paging response.

[0128] At a second (subsequent) time point T2, UE110 can return to LTE-M to continue monitoring the paging channel in the first LTE-M cell. Alternatively, a new NR cell (NR cell-2) can send an indication of the second LTE-M cell for NR paging. The indication can be provided, for example, in paging configuration information, such as at least one paging configuration message, other control messages, or other control information. In response to receiving such an indication, UE110 can start monitoring the paging channel of the second LTE-M cell at the second time point T2.

[0129] If UE110 does not discover an NR cell that is shown to support NR paging via LTE-M, UE110 can reselect an NR cell that does not support NR paging on LTE-M and interrupt monitoring LTE-M for NR paging messages.

[0130] Referring again to FIG. 5, in operation 503, UE110 can receive an LTE cell-specific reference signal (CRS) transmitted by eNB120.

[0131] In operation 504, UE110 can perform idle mode radio resource management (RRM) based on the LTE-CRS.

[0132] In operation 505, eNB120 can send an indication of the current version of the NR system information, such as control information comprising an NR system information value tag. The control information can be sent, for example, on the physical broadcast channel (PBCH) of LTE. UE110 can receive the control information.

[0133] In operation 506, UE 110 may monitor the LTE network, e.g., PBCH, for changes in NR system information. If an indication of a change or NR system information is detected, e.g., if it is detected that the NR system information value tag has increased, UE 110 may activate its NR radio and receive updated system information from gNB 130. However, if no change is indicated, UE 110 may continue to monitor the paging channel of LTE / NB-IoT for NR paging messages while maintaining the NR radio in a low power state.

[0134] In operation 507, eNB 120 may transmit a paging message. The paging message may be transmitted on the LTE physical downlink control channel (PDCCH). The paging message may be transmitted based on at least one paging parameter configured for UE 110 to receive NR paging via LTE / NB-IoT. For example, the paging message may include a UE identifier related to the NR network, or the paging message may be transmitted on a specific paging occasion (PO) of a paging frame (PF). The paging occasion may be determined by eNB 120 based on the DRX cycle configured for UE 110. As described above, UE 110 may be notified of the paging parameters by gNB 130. Alternatively or additionally, eNB 120 may transmit an indication of at least one paging parameter to UE 110. eNB 120 may receive an indication of the paging parameters from gNB 130 as one or more paging configuration messages, e.g., within inter-node signaling. The paging message transmitted by eNB 120 may also include an indication of the NR carrier to be used for data communication, e.g., a mobile incoming call.

[0135] In operation 508, UE 110 may monitor the paging channel of the LTE or NB-IoT network based on paging parameters. UE 110 may then receive an NR paging message from eNB 120 on the monitored paging channel of the LTE or NB-IoT network. In response to receiving the paging message, UE 110 may switch to NR and transmit a paging response to gNB 130 or generally to the NR network. The paging response may be transmitted based on paging configuration information received from gNB 130 or paging response parameters detected in the paging message received from eNB 120. gNB 130 may directly transmit the paging response parameters to UE 110, for example, in the paging configuration information. Alternatively, or in addition, gNB 130 may transmit the paging response parameters to eNB 120, and the eNB may forward the paging response parameters to UE 110, for example, in the paging message. The paging response parameters may comprise at least one of, for example, a cell identifier of the NR network or a frequency of the NR network. The paging response may be transmitted to the identified cell and / or at the indicated frequency. Generally, the paging message can be decoded using a radio access technology (RAT) different from actual data communication, for example, a mobile incoming call or a mobile outgoing call is executed by UE 110.

[0136] gNB 130 may receive a paging response message from UE 110. In response to receiving the paging response, gNB 130 may establish a connection with UE 110 and start 5G data transfer on the NR carrier.

[0137] In operation 509, for example, while monitoring the paging channel of an LTE or NB-IoT network, UE 110 may monitor the strength of the LTE or NB-IoT signal, such as RSRP. As described above, the RRC connection release message may include an indication of fallback conditions for transitioning to the NR idle mode. In response to detecting a fallback condition, such as an RSRP below a fallback threshold, UE 110 may transition to the idle mode with respect to the NR network. Further, UE 110 may interrupt the LTE / NB-IoT monitoring for NR paging messages.

[0138] In operation 510, UE 110 may receive an NR synchronization signal block (SSB) and / or an NR paging message from gNB 130. This enables the delivery of NR paging messages to dual-mode UE 110 when the radio conditions degrade on the LTE or NB-IoT side.

[0139] FIG. 7 is a diagram illustrating an example of a message sequence between a dual-mode user equipment and an LTE network node for the delivery of paging control information according to an exemplary embodiment. Operations 701 and 702 enable the setting of paging occasions for an NR (Light) UE 110. Operations 703-705 enable the setting of changes for monitoring the physical downlink control channel (PDCCH) and the wake-up signal (WUS). The PDCCH may be a physical layer channel carried in a predetermined location of a downlink subframe, such as a predetermined number of first OFDM symbols of the downlink subframe. The PDCCH may be used to transmit paging messages. Operations 706 and 707 enable LTE paging for an NR (Light) UE 110. Operations 708 and 709 enable LTE system support for NR system information changes. Although the above operations are shown as a single message sequence, it is understood that the operations may be applied separately or in different combinations.

[0140] In operation 701, the eNB 120 may transmit control information to the UE 110. The UE 110 may receive the control information. The control information may be provided as LTE system information, for example, in one or more system information blocks (SIBs). The control information may include paging parameters for configuring the UE 110 for receiving NR paging from the eNB 120. For example, the control information may include an indication of a paging subframe (PS) offset. The UE 110 may be configured to monitor a specific paging occasion for receiving an LTE paging message. The paging subframe offset may be relative to a paging occasion configured for LTE paging. The paging occasion may include a specific subframe in a paging frame (PF). The paging frame may be transmitted on a paging channel. The paging frame may include one or more paging occasions (subframes). For a paging event for the UE 110, the paging occasion may include an identifier of the UE 110, such as a paging radio network temporary identifier (P-RNTI).

[0141] In operation 702, the UE 110 can calculate a paging occasion to be monitored for NR paging using the paging subframe offset information. The paging occasion for NR paging can be calculated based at least on an identifier of the UE 110 related to the NR (Light) network and the indicated paging subframe offset. The paging frame (PF) and the paging occasion (PO) can be derived from the identifier of the UE 110, for example, as follows. - The system frame number (SFN) for the paging frame can be determined based on (SFN PF_offset)mod T=(Tdiv N)*(UE_ID mod N). - The index (i_s) indicating the start of a set of PDCCH monitoring occasions for paging DCI can be determined based on i_s = floor(UE_ID / N) mod Ns.

[0142] In the above formula, T is the DRX cycle of UE110, N is the total number of paging frames in the DRX cycle T, Ns is the number of paging occasions for the paging frame, PF_offset is the offset used for PF determination, and UE ID is, for example, the 5G-S-TMSI of UE110 with a 1024 remainder. The use of the paging subframe offset can ensure that NR paging messages are not transmitted in the same paging occasion as LTE, and can avoid unnecessary wake-up of narrowband IoT devices. Alternatively, UE110 can be configured to monitor the same paging occasion as in the case of LTE paging, but use a different identifier value, such as a different P-RNTI, to avoid incorrect wake-up. To configure UE110 to monitor the same paging occasion, eNB120 can set the paging subframe offset to zero or send another indication of the use of the same paging occasion for both LTE paging and NR paging.

[0143] In operation 703, the eNB 120 may transmit control information to the UE 110, for example, as LTE system information as described above. The control information may include an identifier for detecting an NR paging message on the LTE paging channel, for example, an indication of a P-RNTI. The identifier may be an identifier used for the UE 110 in the NR network, for example, an NR P-PRNTI. The control information may further include information related to a wake-up signal (WUS), for example, an identifier of a wake-up signal sequence and / or an indication of a time location of the wake-up signal. The wake-up signal may be used to wake up the UE 110 from the sleep mode to detect whether the UE 110 is being paged in a paging occasion. The wake-up signal may be received by a low-power wake-up receiver of the UE 110, and thus, the main LTE receiver may be maintained in a low-power state for a longer time than a normal DRX cycle, which reduces power consumption. The time location of the WUS may be signaled, for example, based on an offset with respect to a paging occasion, for example, by indicating how much before the associated paging occasion the WUS occurs. A separate UE capability indicating how much time the UE needs to wake up after receiving the WUS may be provided by the UE 110 to the network, for example, to the gNB 130 or the eNB 120.

[0144] In operation 704, UE 110 may monitor a wake-up signal specific to NR (Light) based on the control information. For example, UE 110 may monitor a wake-up signal at the indicated time location and / or a wake-up signal comprising the indicated wake-up sequence, for example, by monitoring a paging channel on the PDCCH. Alternatively, the wake-up signal may be transmitted on a separate channel, for example, on a narrower-band transmission channel. Thus, UE 110 may first monitor a separate wake-up signal channel instead of the paging channel. In response to receiving the wake-up signal, UE 110 may turn on the main LTE receiver and start monitoring the paging channel on the LTE-PDCCH for the NR paging message.

[0145] In operation 705, UE 110 may monitor a paging channel based on the control information. For example, UE 110 may monitor the paging occasion determined in 702. UE 110 may monitor the paging channel for an identifier indicated in the control information received from eNB 120 in 703, for example, the NR-P-RNTI.

[0146] In operation 706, eNB 120 may transmit a paging message. The paging message may be of a specific type, for example, an RRC-Paging-IRAT (inter-RAT) message. The type of the paging message may indicate the use of an NR identifier in the paging message. Thus, the paging message may include an NR paging identifier for UE 110. The paging message may further include redirection information for transmitting a paging response, for example, one or more paging response parameters. The paging response parameters may indicate, for example, the NR carrier on which UE 110 is required to transmit a paging response. The NR carrier may be identified by a cell identifier and a frequency. UE 110 may receive the paging message. UE 110 may detect the paging message based on the NR identifier. Detecting the paging message may further be based on the type of the paging message. For example, UE 110 may first detect the type of the paging message. If the type of the paging message indicates the use of an NR identifier, UE 110 may determine whether the configured NR identifier is included in the paging message. If the type does not indicate the use of an NR identifier, UE 110 may determine not to check the paging message for the NR identifier. Thus, indicating the type of the paging message enables UE 110 to avoid searching for an NR identifier in a paging message known not to include it.

[0147] In operation 707, UE 110 may switch to a specific NR carrier configured to send a paging response. UE 110 may then transmit a paging response to gNB 130 on the NR carrier.

[0148] In operation 708, the eNB 120 may transmit additional control information to the UE 110, for example, on the LTE-PDCCH. The control information may include information for indicating a change in the NR system information, for example, additional downlink control information (DCI) bits. The DCI may be carried, for example, on the LTE-PDCCH or the MPDCCH (PDCCH of LTE-M). The control information may include an indication of an update to the NR system information. This enables the UE 110 to be notified of changes in the NR system information even if the UE 110 does not access the NR network while monitoring NR paging on the LTE side. When the UE 110 detects a change in the NR system information, it can access the NR network and receive the updated system information from the gNB 130.

[0149] In operation 709, the eNB 120 can transmit additional control information to the UE 110. The control information may be transmitted as part of the LTE system information, for example, in one or more system information blocks such as SIB1 or one or more bandwidth reduction system information blocks such as SIB1-BR (bandwidth reduction). The control information may assist the UE 110 that monitors the LTE paging channel and may include parameters for keeping it synchronized with the latest system information and the cell. For example, the control information may include the NR (Light) physical cell identifier (PCI), frequency information shared by the LTE-M and NB-IoT cells, and the NR (Light) system information value tag.

[0150] The PCI and / or frequency information of the NR network may be used in the UE 110 to determine which cell to connect to after receiving the NR paging message from the eNB 120. The PCI and frequency information of the NR network may be associated with, for example, collocated NR cells associated with the current cell of the LTE network.

[0151] The system information value tag can indicate the currently applicable version of the system information. Based on the system information value tag, the UE110 can detect changes in the NR system information. Then, the UE110 can access the NR network to receive the updated system information from the gNB130.

[0152] The various control information described herein can be provided in any suitable control channel or signal. For example, the control information can be transmitted or received in downlink control information or system information. The downlink control information can be transmitted or received on the PDCCH. The system information can include one or more system information blocks (SIBs) of LTE or one or more bandwidth reduction system information blocks (SIB-BRs) of LTE-M. The control information may also be referred to as paging control information, paging signaling, narrowband paging control information, narrowband paging signaling, etc.

[0153] FIG. 8 is a diagram showing an example of a message sequence between a dual-mode user equipment and an NB-IoT node for the delivery of paging control information according to an exemplary embodiment.

[0154] In operation 801, similar to operation 701, the eNB120 (NB-IoT eNB) can transmit control information to the UE110, and the UE110 can receive the control information. However, the control information may be provided in narrowband system information, for example, one or more narrowband system information blocks (NB-SIBs) of NB-IoT.

[0155] In operation 802, similar to operation 702, the UE110 can calculate a paging occasion for receiving NR paging from the eNB120.

[0156] In operation 803, the eNB 120 can transmit additional control information to the UE 110, similar to operation 703. However, the control information may be provided in the narrowband system information.

[0157] In operation 804, the UE 110 can monitor the NR (Light)-specific wake-up signal before the paging occasion, similar to operation 704.

[0158] In operation 805, the UE 110 can monitor the narrowband PDCCH (NPDDCH) of NB-IoT for the NR paging message, similar to operation 705. Operations 803 to 805 enable the setting of changes for monitoring the NPDCCH and the wake-up signal (WUS).

[0159] In operation 806, the eNB 120 can transmit a paging message, similar to operation 706. However, the paging message can be transmitted on the paging channel of NB-IoT, for example, on the NPDCCH.

[0160] In operation 807, the UE 110 can switch to a specific NR carrier to transmit a paging response, similar to operation 707. The UE 110 can then transmit the paging response to the gNB 130 on the NR carrier.

[0161] In operation 808, the eNB 120 can transmit additional control information to the UE 110, similar to operation 708. However, the control information may be transmitted on the control channel of NB-IoT. For example, the DCI can be carried on the NPDCCH (the PDCCH of NB-IoT). The UE 110 can receive the control information on the corresponding channel.

[0162] In operation 809, the eNB 120 may transmit additional control information to the UE 110, similar to operation 709. However, the control information may be transmitted as part of the NB-IoT system information. The system information may comprise one or more narrowband system information blocks (NB-SIBs) of NB-IoT, such as NB-SIB1. Alternatively or additionally, the control information may be provided in one or more bandwidth reduced system information blocks, such as SIB-BR1.

[0163] According to an exemplary embodiment, the UE 110 can receive control information, such as a system information message, from the gNB 130 that includes information regarding the common signal location with reference to the LTE-M or NB-IoT common channel or the correct network timing in order to enable the UE 110 to switch back to narrowband monitoring. The common channel or signal may comprise a channel or signal addressed to all or a plurality of UEs, such as a broadcast channel or signal. The control information may comprise, for example, the time-frequency location of at least one common channel of the LTE or NB-IoT network, the time-frequency location of at least one common signal of the LTE or NB-IoT network, or an indication of the timing information of the LTE or NB-IoT network. The timing information of the LTE or NB-IoT network may comprise the timing information of an LTE or NB-IoT control signal, such as a paging signal, regarding the (frame) timing of the NR carrier. Based on this information, the UE 110 may receive information regarding the common channel or common signal of the LTE or NB-IoT network. The common channel or signal may carry, for example, various control information described herein. This enables the UE 110 to directly access relevant control information in the LTE or NB-IoT network based on the information received from the NR network.

[0164] As described above, the exemplary embodiments enable energy-efficient paging of dual-mode devices. As a further advantage, they avoid affecting the idle-mode power consumption of LTE, LTE-M, or NB-IoT devices and can maintain the paging capacity independently between LTE-only devices and devices that use LTE for idle-mode operation.

[0165] FIG. 9 shows an example of a method 900 for receiving paging at a client node according to an exemplary embodiment.

[0166] In operation 901, the method may include receiving paging configuration information from a first network, the paging configuration information comprising an indication of at least one paging parameter for monitoring a paging channel of a second network.

[0167] In operation 902, the method may include monitoring the paging channel of the second network based on the at least one paging parameter.

[0168] In 903, the method may include transmitting a paging response to the first network in response to receiving a paging message from the paging channel of the second network.

[0169] FIG. 10 shows an example of a method 1000 for configuring paging of a client node by a network node according to an exemplary embodiment.

[0170] In 1001, the method may include transmitting to the client node paging configuration information comprising an indication of at least one first paging parameter for monitoring a paging channel of a second network.

[0171] In 1002, the method may comprise sending paging configuration information comprising at least one second paging parameter for sending a paging message related to the first network to a client node to a second network.

[0172] In 1003, the method may include receiving a paging response from a client node.

[0173] FIG. 11 shows an example of a method 1100 for paging a client node by a network node instead of another network node, according to an exemplary embodiment.

[0174] In 1101, the method may comprise receiving, from a first network, paging configuration information comprising at least one paging parameter for sending a paging message related to the first network to a client node from a second network.

[0175] In 1102, the method may include sending, to the client node, a paging message related to the first network based on at least one paging parameter.

[0176] Further features of the method arise directly from the functions of a client node, such as UE110, or a network node, such as eNB120 or gNB130, as described throughout this specification and the appended claims, and thus are not repeated here. Different variations of the method can also be applied, as described in connection with various exemplary embodiments.

[0177] An apparatus, such as a client node like UE110, or a network node like eNB120 or gNB130, may be configured to perform or cause the performance of any aspect of the methods described herein. Further, a computer program, when executed, may comprise instructions for causing the apparatus to perform any aspect of the methods described herein. Further, the apparatus may comprise means for performing any aspect of the methods described herein. According to an exemplary embodiment, the means comprises at least one processor and at least one memory including program code, the program code being configured to cause the performance of any aspect of the method when executed by the at least one processor.

[0178] Any range or device value given herein can be extended or changed without losing the desired effect. Also, unless explicitly disclaimed, any embodiment may be combined with another embodiment.

[0179] It should be understood that although the subject matter has been described in terms of structural features and / or acts specific thereto, the subject matter defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the above-described specific features and acts are disclosed as examples of implementing the claims, and other equivalent features and acts are intended to be within the scope of the claims.

[0180] It will be understood that the above advantages and benefits may be associated with one embodiment or may be associated with several embodiments. Embodiments are not limited to those that solve any or all of the described problems or have any or all of the described advantages and benefits. It will further be understood that references to "one" item may refer to one or more of these items.

[0181] The steps or operations of the methods described herein may be performed in any suitable order or, where appropriate, simultaneously. Additionally, individual blocks may be deleted from any of the methods without departing from the scope of the subject matter described herein. Any aspect of any of the above-described embodiments may be combined with any aspect of any of the other described embodiments to form further embodiments without losing the desired effect.

[0182] The term "comprising" as used herein is used to mean including the identified method, block, or element, but such block or element does not include an exclusive list and the method or apparatus may include additional blocks or elements.

[0183] A subject may be referred to as a "first" subject or a "second" subject, but this does not necessarily indicate any order or importance of the subjects. Instead, such attributes may only be used to create a distinction between the subjects.

[0184] As used in this application, the term "circuit" may refer to one or more or all of the following: (a)(i) a combination of analog and / or digital hardware circuits and software / firmware, and (ii) any portion of a hardware processor and software (including a digital signal processor), such as software only circuit implementations (such as implementations in only analog and / or digital circuits). (b) a combination of a hardware circuit and software. (c) a hardware circuit and / or processor, such as a microprocessor or a portion of a microprocessor, that requires software (e.g., firmware) for operation. However, the software may not be present when it is not required for operation. This definition of circuit applies to all uses of this term in this application, including any claims.

[0185] As a further example, when used in this application, the term circuit also encompasses simply a hardware circuit or a processor (or processors), or a part of a hardware circuit or a processor, and its (or their) associated software and / or firmware implementation. The term circuit also encompasses, for example, a baseband integrated circuit or a processor integrated circuit for a mobile device, or a similar integrated circuit within a server, a cellular network device, or other computing or network device, when applicable to an element of a particular claim.

[0186] The foregoing description is provided as merely an example, and it will be understood that various modifications can be made by those skilled in the art. The foregoing specification, examples, and data provide a complete description of the structure and use of exemplary embodiments. Although various embodiments have been described in some detail, or with reference to one or more individual embodiments, those skilled in the art can make numerous changes to the disclosed embodiments without departing from the scope of this specification.

Claims

1. At least one processor; and at least one memory containing computer program code, The at least one memory and the computer program code are configured to cause the at least one processor to transmitting, to the client node, paging configuration information including an indication of at least one first paging parameter for monitoring a paging channel of the second network; transmitting, to the second network, paging configuration information including at least one second paging parameter for transmitting a paging message associated with the first network to the client node; receiving a paging response from the client node; An apparatus configured to cause a

2. The at least one memory and the computer program code are configured to cause the device, using the at least one processor, to: receiving, from the client node, an indication of an ability to receive paging messages associated with the first network from the second network; transmitting at least one second paging configuration message to the second network in response to receiving the indication of the ability of the client node to receive paging messages related to the first network from the second network; 2. The apparatus of claim 1, further configured to:

3. 3. The apparatus of claim 1 or 2, wherein the at least one first paging parameter or the at least one second paging parameter comprises at least one of a discontinuous reception cycle, an international mobile subscriber identity, or an inactive wireless network temporary identifier.

4. The at least one first paging configuration message comprises: indicating a cell reselection condition to the first network; an indication of a set of neighboring cells of the first network that support paging via the second network; an indication of a fallback condition for transitioning to an idle mode with respect to the first network; 4. The device according to claim 1, further comprising at least one of:

5. At least one processor; and at least one memory containing computer program code, The at least one memory and the computer program code are configured to cause the device, using the at least one processor, to: receiving, from a first network, paging configuration information including at least one second paging parameter for transmitting paging messages related to the first network from the second network to a client node; transmitting the paging message associated with the first network based on the at least one second paging parameter to the client node that has received paging configuration information including an indication of at least one first paging parameter for monitoring a paging channel of the second network; An apparatus configured to cause

6. 6. The apparatus of claim 5, wherein the at least one paging parameter includes at least one of a discontinuous reception cycle, an international mobile subscriber identity, or an inactive wireless network temporary identifier.

7. 7. The apparatus according to claim 5 or 6, characterized in that the paging message includes at least one paging response parameter.

8. transmitting, to the client node, paging configuration information including an indication of at least one first paging parameter for monitoring a paging channel of the second network; transmitting, to the second network, paging configuration information including at least one second paging parameter for transmitting paging messages related to the first network to the client node; receiving a paging response from the client node; 23. A method performed by a node of a first network, comprising:

9. receiving paging configuration information from a first network, the paging configuration information including at least one second paging parameter for transmitting paging messages related to the first network from a second network to a client node; transmitting a paging message associated with the first network based on the at least one second paging parameter to the client node that has received paging configuration information including an indication of at least one first paging parameter for monitoring a paging channel of the second network; 23. A method performed by a node of a second network, comprising:

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