Patent Description:
Multiple Subscriber Identity Module (SIM), or "Multi-SIM," devices are devices which enable use of multiple subscriptions in one device by means of more than one Universal Mobile Telecommunications System (UMTS) SIM (USIM). Multi-SIM UE's can support concurrent registration to more than one network simultaneously and, e.g., if a UE has two different radios implemented, such as both dual receive (Rx) and dual transmit (Tx) capability, it would be possible for the UE to behave as two separate UEs and communicate with two networks at the same time.

There are also dual or multi-SIM capable UEs that only have one single radio front-end and baseband processing. In this case, if such a UE is registered to two different Public Land Mobile Networks (PLMNs), it is challenging to manage all situations that may occur. For example, it is challenging to manage simultaneous communication with both systems and communication in one system while the other system wants to reach the UE with pages.

An additional aspect of being paged, potentially in two systems, or being occupied in one system while being paged from the other system is that even if it would be possible to listen to pages from one system while communicating in the other system, or if it would be possible to receive pages from two systems simultaneously, there would need to be enough information provided to the end-user / user of the UE to be able to select what communication to prioritize, unless both are not possible at the same time.

There currently exist certain challenge(s). Multi-SIM UE's have been around for some time, but the technical support for the above situations have been such that there is nothing really standardized. Rather, these Multi-SIM UEs may be violating the standard by, e.g., simply leaving a conversation or a connection in case it prioritizes another or not tuning to receive pages from one of the systems. As a result, the network may continue to schedule data to a UE that is no longer able to receive, which in turn deteriorates network performance.

Further, with the increase in number of situations when a user may have a work-SIM and a private-SIM, the amount of Multi-SIM UE's is increasing. There is also a trend to "Bring Your Own Device" to work (BYOD). In such situations, the work may only provide a SIM instead of doubling the amount of UE's in the world. Another trend is that a user may join a "family plan" subscription while maintaining the user's old subscription, resulting in the user having two personal subscriptions / SIMs.

With this increase in Dual-SIM or even Multi-SIM UE related needs, it would be advantageous if there were robust solutions supported by the Third Generation Partnership (3GPP) standard, solutions that avoid a negative impact to network performance and also offer a better service/user experience are needed.

<CIT> discloses a method of dual access handling. <CIT> discloses a method for operating a secondary station, the secondary station comprising communication means for communicating with a primary station. 3GPP DRAFT R2-<NUM> discloses an overheating problem discussion in higher capability Long-Term Evolution (LTE) UEs. 3GPP DRAFT R2-<NUM> discloses UE access capability retrieval framework. 3GPP DRAFT R2-<NUM> discloses a discussion on UE overheating. 3GPP DRAFT R2-<NUM> discloses an issue with thermal challenges of devices that support high throughput configurations. 3GPP DRAFT RP-<NUM> discloses UE capability signaling. 3GPP DRAFT RP-<NUM> discloses limitations and issues related to UE capability handling. <CIT> discloses an apparatus and a method to reuse wireless circuitry to communicate with multiple wireless networks to support multiple subscriber identities in a wireless communication device. <CIT> discloses connection establishment/ connection release signaling between a user equipment and its radio network.

The invention is defined by all features present in and required by the independent claims which define the scope of the invention. Further features of exemplary embodiments are defined in dependent claims. The subject-matter of <FIG> and its description is according to the invention as defined in the claims. The rest of the following description, even if described or named as "embodiment(s)", "invention(s)", "aspect(s)", "example(s)" or "disclosure(s)" etc., does not or does not fully correspond to the invention as defined in the claims and is therefore not according to the invention as defined in the claims but is considered as useful for understanding the invention.

Radio Access Node: As used herein, a "radio access node" or "radio network node" or "radio access network node" is any node in a radio access network of a cellular communications network that operates to wirelessly transmit and/or receive signals.

Core Network Node: As used herein, a "core network node" is any type of node in a core network or any node that implements a core network function. Some examples of a core network node include, e.g., a Mobility Management Entity (MME), a Packet Data Network Gateway (P-GW), a Service Capability Exposure Function (SCEF), a Home Subscriber Server (HSS), or the like. Some other examples of a core network node include a node implementing a Access and Mobility Function (AMF), a UPF, a Session Management Function (SMF), an Authentication Server Function (AUSF), a Network Slice Selection Function (NSSF), a Network Exposure Function (NEF), a Network Function (NF) Repository Function (NRF), a Policy Control Function (PCF), a Unified Data Management (UDM), or the like.

As discussed above, there has been an increase in Dual- Subscriber Identity Module (SIM) or even Multi-SIM UE related needs, it would be advantageous if there were robust solutions supported by the 3GPP standard. These solutions would avoid a negative impact to network performance and also offer a better service/user experience are needed. To offer such solutions, the following challenges must at least be addressed:.

The above should be possible for different UE types, e.g., UEs with one receiver and one transmitter as well as UEs with two receivers and two transmitters and two receivers and one transmitter, irrespective of what operator / PLMN is involved.

Certain aspects of the present disclosure and their embodiments may provide solutions to the aforementioned or other challenges. In some embodiments, a UE indicates reduced capabilities to the network associated with a first SIM so that the UE can communicate with a second network using spare capabilities.

In one embodiment, the UE indicates reduced capabilities to a first network with an overheating indication that the UE prefers or requires that the first network configures fewer carriers for the UE, so that if the network follows the UE preference or requirement, the UE can use the freed up resources for communication with another network.

In one embodiment, the UE requests a first network to release the connection with the UE. The UE changes its capabilities with respect to that network so that resources or capabilities can be used for communication with another network.

In one embodiment, the UE indicates two capability sets where different capabilities apply for when the UE is operating only using one SIM and different capabilities apply for when the UE operates using two SIMs.

Certain embodiments may provide one or more of the following technical advantage(s). Embodiments disclosed herein may enable a UE to use simultaneous connections using different SIMs.

<FIG> illustrates one example of a cellular communications system <NUM> in which embodiments of the present disclosure may be implemented. In the embodiments described herein, the cellular communications system <NUM> is a <NUM> system (5GS) including a NR RAN or LTE RAN (i.e., E-UTRA RAN) or an Evolved Packet System (EPS) including a LTE RAN. In this example, the RAN includes base stations <NUM>-<NUM> and <NUM>-<NUM>, which in LTE are referred to as eNBs (when connected to EPC) and in <NUM> NR are referred to as gNBs or ng-eNBs (e.g., LTE RAN nodes connected to 5GC are referred to as gn-eNBs), controlling corresponding (macro) cells <NUM>-<NUM> and <NUM>-<NUM>. The base stations <NUM>-<NUM> and <NUM>-<NUM> are generally referred to herein collectively as base stations <NUM> and individually as base station <NUM>. Likewise, the (macro) cells <NUM>-<NUM> and <NUM>-<NUM> are generally referred to herein collectively as (macro) cells <NUM> and individually as (macro) cell <NUM>. The RAN may also include a number of low power nodes <NUM>-<NUM> through <NUM>-<NUM> controlling corresponding small cells <NUM>-<NUM> through <NUM>-<NUM>. The low power nodes <NUM>-<NUM> through <NUM>-<NUM> can be small base stations (such as pico or femto base stations) or Remote Radio Heads (RRHs), or the like. Notably, while not illustrated, one or more of the small cells <NUM>-<NUM> through <NUM>-<NUM> may alternatively be provided by the base stations <NUM>. The low power nodes <NUM>-<NUM> through <NUM>-<NUM> are generally referred to herein collectively as low power nodes <NUM> and individually as low power node <NUM>. Likewise, the small cells <NUM>-<NUM> through <NUM>-<NUM> are generally referred to herein collectively as small cells <NUM> and individually as small cell <NUM>. The cellular communications system <NUM> also includes a core network <NUM>, which in the 5GS is referred to as the <NUM> core (5GC). The base stations <NUM> (and optionally the low power nodes <NUM>) are connected to the core network <NUM>.

In the following description, the wireless communication devices <NUM> are oftentimes UEs and as such referred to as UEs <NUM>, but the present disclosure is not limited thereto.

Different methods which a UE <NUM> may apply when operating in a multi-SIM scenario are described below. In some descriptions herein, an example in which the UE <NUM> has two SIMs is used; however, the methods can be generalized to also apply to scenarios in which the UE <NUM> has more than two SIMs and the person skilled in the art will appreciate how the methods would be performed in scenarios with more than two SIMs.

A UE <NUM> may have multiple SIMs. One use case for multiple SIMs is that the different SIMs are associated with different PLMNs. However, it is also possible that a UE <NUM> has more than one SIM which is associated with the same PLMN, e.g. a UE <NUM> has two SIMs from the same operator. It will in some descriptions of the methods herein be used as example that the multiple SIMs are associated to different PLMNs, but the methods can also be applied for the scenario where multiple SIMs are associated with the same PLMN.

It will be described how UE capabilities may be handled in multi-SIM scenarios. Example capability/-ies which may be affected may comprise and/or relate to, e.g., number of radio frontends, number of carriers, bandwidth, buffer sizes/memories, soft-buffer sizes/memories, processing capacity, number of Packet Data Network (PDN) connections/Protocol Data Unit (PDU) sessions, number and/or types of bearers/flows, and/or Dual/Multi-Connectivity and/or Carrier Aggregation (CA) capabilities. CA capabilities and other capabilities may be the same or different for uplink and downlink, respectively. Embodiments of the present disclosure will particularly address the aspect of multi-SIM that relates to simultaneous communication with two networks at the same time. For example, the UE <NUM> may be in RRC_CONNECTED with both networks and, e.g., engage in Internet Protocol (IP) Multimedia Subsystem (IMS) voice communication through one network/PLMN, while having data transfer in the other network. This is possible if a UE is equipped with enough receive and transmit resources, (e.g., two receivers Rx / two transmitters). However, sometimes, in particular for multi-carrier operation (e.g., Dual-Connectivity (DC) and CA configurations), even a single network may configure a UE <NUM> to utilize two receiver chains and two transmitter chains. If a multi-SIM UE <NUM> is registered with two networks at the same time, it may not always be good to allow for such multi-carrier operation.

Thus, according to one aspect of the present disclosure, a multi-SIM capable UE <NUM> has the capability to communicate with two different PLMNs simultaneously. When the UE <NUM> is registered in a first PLMN (PLMN1) only (i.e., the UE <NUM> needs only to receive/transmit signals with PLMN1), the UE <NUM> provides capability information to PLMN1 that corresponds to a situation when the UE <NUM> is only using one of the SIMs. This means that it corresponds to a single-SIM UE and all capabilities that are available in the UE <NUM> (e.g., frequencies, carrier combinations, features, processing) are available for use with PLMN1. When the UE <NUM> is registered with PLMN1 and a second PLMN (PLMN2) at the same time, the UE <NUM> provides capabilities to PLMN1 that take into consideration that PLMN2 may also require, e.g., processing, features, in any situation when simultaneous communication with PLMN1 and PLMN2 is necessary/desired. For example, a multi-carrier-capable UE <NUM> is registered with two different PLMNs where communication may occur simultaneously with both PLMNs, and the multi-carrier-capable UE <NUM> does not include in its capability information any multi-carrier capability, or only limited multi-carrier capabilities. This is to avoid that one of the PLMNs may configure the UE <NUM> such that not enough radio capability in the UE <NUM> is left for communication with the other PLMN.

Note that, as used herein, the phrase "registered with a PLMN" means that the UE <NUM> receives and/or transmits signals with that PLMN when in connected mode. However, the UE <NUM> may also be registered with a PLMN when in idle mode, in which case the UE <NUM> is at least ready to receive some signals (e.g., paging signals) from that PLMN.

Example implementation: If the UE <NUM> has the possibility to support up to six carriers in total, the UE <NUM> would, if it is operating using only a single SIM, indicate in its capabilities that it supports six carriers. Note that the UE <NUM> indicates the number of carriers in its supported band-combinations. However, if the UE <NUM> is operating using two SIMs, the UE <NUM> may indicate to a first PLMN that it supports only three carriers, while indicating to a second PLMN that it supports only three carriers.

A UE <NUM> may be configured, e.g. by the end user, such that data traffic is preferred or allowed to be communicated only over one SIM, while voice is preferred or allowed to be communicated over another SIM. According to one aspect of the present disclosure, the UE <NUM> considers the expected services its SIMs are configured to use, when indicating capabilities for the SIMs. For example, the UE <NUM> indicates multiple carrier operation by the SIM which is expected to serve data traffic, while single carrier operation is indicated by the SIM which should serve voice traffic. The benefit with this is that more resources could be used for the data-SIM and hence high throughputs can be achieved for data communication, while for the voice-SIM only single carrier operation is used, which likely is sufficient for voice communication.

Example implementation: In the example above, it is described how a UE <NUM> indicates to a first PLMN and to a second PLMN that it supports three carriers. However, if for example the UE <NUM> is configured to perform voice services over a first PLMN and, e.g., data services over a second PLMN, the UE <NUM> may indicate to the first PLMN that it supports only one carrier (which should be sufficient to support voice services) and indicate to the second PLMN that it supports five carriers.

<FIG> illustrates the operation of a wireless communication device <NUM> in accordance with at least some aspects of the embodiments described above. The wireless communication device <NUM> is equipped with two or more SIMs (e.g., the wireless communication device <NUM> is a multi-SIM UE). Optional steps are represented by dashed lines/boxes. As illustrated, the wireless communication device <NUM> optionally obtains a configuration(s) (e.g., from an associated user) of particular service(s) to be used for a particular PLMN(s), as described above (step <NUM>). For example, the wireless communication device <NUM> may be configured such that a first PLMN (PLMN1) is required or preferred to voice service(s) and a second PLMN (PLMN2) is required or preferred for another service(s) (e.g., a data service(s)).

The wireless communication device <NUM> registers with PLMN1 and PLMN2, as described above (steps <NUM> and <NUM>). Thus, the wireless communication device <NUM> is simultaneously registered with PLMN1, which is associated with a first SIM (SIM1), and with PLMN2, which is associated with PLMN2. The wireless communication device <NUM> provides, to a network node associated with PLMN1, first capability information (step <NUM>). As described herein, this first capability information takes into consideration that PLMN2 may also require, e.g., processing, features, in any situation when simultaneous communication with PLMN1 and PLMN2 is necessary/desired, as described above. In some embodiments, the first capability information takes into account any service(s) configured as being preferred or required for PLMN1. The network node associated with PLMN1 may then use the first capability information when, e.g., configuring the wireless communication device <NUM> for communication over PLMN1 (e.g. when deciding whether to configure the wireless communication device <NUM> with CA or DC), as described above (step <NUM>).

The wireless communication device <NUM> may also provide, to a network node associated with PLMN2, second capability information that takes into consideration that PLMN1 may also require, e.g., processing, features, in any situation when simultaneous communication with PLMN1 and PLMN2 is necessary/desired, as described above (<NUM>). In some embodiments, the second capability information takes into account any service(s) configured as being preferred or required for PLMN2. The network node associated with PLMN2 may then use the second capability information when, e.g., configuring the wireless communication device <NUM> for communication over PLMN2 (e.g. when deciding whether to configure the wireless communication device <NUM> with CA or DC), as described above (step <NUM>).

In another aspect of the present disclosure, a UE <NUM> is signaling at least two different capability information profiles to a network. The at least two different capability information profiles are intended to be used by the receiving network based on indications from the UE <NUM>. In certain situations, a first capability profile will be valid, and the network may configure communication to the UE <NUM> according to said first capability profile. In another situation, the UE <NUM> may switch to a second capability profile, at which point the network must re-configure any configuration to the UE <NUM> that is not coherent with said second capability information. The second capability profile may be used by the UE <NUM> towards one PLMN when also registered, in idle mode, or in active communication in another PLMN.

Example implementation: To implement this embodiment, when a UE <NUM> reports its capabilities, the UE <NUM> may send two occurrences of its UE capabilities. For example, the UE <NUM> may report two occurrences of its UE capabilities by having two entries in the UE-CapabilityRAT-ContainerList. There may be an implicit mapping such that the first occurrence of a capabilities are mapped to a first index, e.g. <NUM>, and a second occurrence of the capabilities are mapped to a second index, e.g. <NUM>.

Whether or not the UE <NUM> is allowed to send multiple capability profiles to the network may be indicated to the UE <NUM> by the network. For example, the network may indicate it with a flag in the UE <NUM>. This option is shown below where the flag "allowMultipleProfiles-v15xy' is shown.

The UE <NUM> may, by default, apply a particular profile, i.e. unless otherwise stated the UE <NUM> applies a certain profile. This may be a profile associated with a certain index, for example the lowest index. It may be the first occurring profile.

In another aspect of the present disclosure, the UE <NUM> indicates existence of a second capability profile when sending capability information in the UECapabilityInformation message to the network. This secondary profile may be explicitly requested by the network. For example, the UE capability enquiry message may be extended so that the network can indicate whether the UE <NUM> is to send the primary capability set and/or the secondary capability set.

In another aspect of the present disclosure, a second capability profile may be sent in a separate message (e.g., a separate RRC message) compared to the primary capability profile. The UE <NUM> may indicate in the message if the capabilities that the UE <NUM> transfers are the primary or secondary UE capabilities. Or in general (in case this method would be applied to support more than two sets of capabilities), the UE <NUM> may indicate an identifier for the UE capabilities, for example an index which may be an integer value. The primary capabilities may have a default index, e.g. <NUM> or <NUM>, and this index may be omitted in the UE capabilities. In other words, when the UE <NUM> sends the primary/default capabilities, the UE <NUM> does not indicate an index for them.

Whether or not the UE <NUM> has or supports a second capability profile may be indicated in legacy capability signaling information. This may be a one-bit flag which indicates that this UE <NUM> supports more than one capability profile. The network can then for such a UE request the additional capability profiles. Another approach is that the UE <NUM> indicates the number of capability profiles the UE <NUM> supports (this may be indicated as the number of additional profiles the UE supports in addition to the legacy/initial capability profile, or it may be indicated as the total number of capability profiles the UE supports).

In another aspect of the present disclosure, mechanisms that are used to signal overheating issues in the UE <NUM> are used to switch between different capability profiles. If a UE <NUM> supports X number of carriers in total, it would, if it only considers a single SIM, indicate that it supports X carriers (this in indicated in terms of supported band combinations and a number of carriers within each band in the band combinations). However, if the UE <NUM> in a multi-SIM scenario has to perform communication with respect to multiple SIMs, the UE <NUM> will have to share the UE resources (carriers, capabilities, processing, etc.) between these SIMs. According to this aspect of the present disclosure, the UE <NUM> may indicate towards the network with respect to a first SIM that, even if the capabilities indicate that it supports X carriers, the UE supports fewer carriers. This may then be indicated to the network using an overheating indication which tells the network that the UE <NUM> would require or prefer to use fewer carriers than the UE <NUM> is capable of. If the network associated with the first SIM responds by configuring fewer carriers for the UE <NUM>, the UE <NUM> can use the spare carriers or resources for communication with the second SIM.

In another aspect of the present disclosure, if a UE <NUM> has sent more than one capability profile to the network, the UE <NUM> may switch between these profiles with a switching indication to the network. This may be preceded by a request from the UE <NUM> to switch UE capabilities. The UE <NUM> may, upon needing to connect with a second SIM and hence reserve resources for communication using that second SIM, change the capabilities related to the first SIM so that communication using the first SIM uses less resources.

In another aspect of the present disclosure, the network would reconfigure any connection that is not applicable with a new configuration within a duration that corresponds to a specific reconfiguration timer.

<FIG> illustrates the operation of a wireless communication device <NUM> in accordance with at least some aspects of the embodiments described above. The wireless communication device <NUM> is equipped with two or more SIMs (e.g., the wireless communication device <NUM> is a multi-SIM UE). Optional steps are represented by dashed lines/boxes. As illustrated, a network node (e.g., a base station <NUM>) sends an indication to the wireless communication device <NUM> that indicates whether the wireless communication device <NUM> is allowed to send multiple capability information sets, as described above (step <NUM>). These capability information sets are also referred to herein as capability profiles. The wireless communication device <NUM> sends a first capability profile and a second capability profile (e.g., a first capability profile, e.g., for use when using only a single SIM and a second capability profile, e.g., for use when using (e.g., simultaneous registrations) for two or more SIMs) to the network node, as described above (step <NUM>). In one embodiment, the wireless communication device <NUM> sends the first and second capability profiles in the same message (step 302A). In another embodiment, the wireless communication device <NUM> sends the first and second capability profiles in separate messages. For example, in one embodiment, the wireless communication device <NUM> includes an indication in the first capability profile that indicates availability of the second capability profile (step 302B1). The network node may then request the second capability profile from the wireless communication device <NUM> (step 302B2), and the wireless communication device <NUM> then sends the second capability profile to the network node (step 302B3).

Optionally, the network node selects one of the capability profiles of the wireless communication device <NUM> (e.g., selects a default capability profile) (step <NUM>) and configures the wireless communication device <NUM> in accordance with the selected capability profile (step <NUM>), as described above.

Optionally, the wireless communication device <NUM> decides to use (e.g., switch to) a particular one of its capability profiles, as described above (step <NUM>). For example, upon simultaneous registration with the PLMN associated with the network node and another PLMN, the wireless communication device <NUM> may decides to switch to a particular one of its capability profiles that takes into consideration that the other PLMN may also require, e.g., processing, features, in any situation when simultaneous communication with the two PLMNs is necessary/desired. The wireless communication device <NUM> sends an indication to the network node of a preference or request to switch to the particular capability profile (e.g., selected in step <NUM>), as described above (step <NUM>). In one embodiment, this indication is sent via an overheat indication. The network node re-configures the wireless communication device <NUM> in accordance with the indicated capability profile, as described above (step <NUM>).

In another aspect of the present disclosure illustrated in <FIG>, a UE <NUM> request release from the network in order to update its capabilities. More specifically, the UE <NUM> is in Connected mode (RRC_CONNECTED) with regards to a PLMN A, and the UE <NUM> is registered towards another PLMN B for which the UE <NUM> is in Idle or Inactive mode. However, for some reason, the UE <NUM> may need to enter Connected mode with respect to PLMN B (e.g. arrival of data in the uplink buffer of the UE which should be sent via PLMN B, or based on paging of the UE in PLMN B). In such a case, resources in the UE <NUM> (e.g. RF-transceivers, processing, etc.) which currently are assigned for communication with PLMN A may need to be reallocated for communication with PLMN B. In such a situation, the UE <NUM> sends an indication to PLMN A indicating that the UE <NUM> suggests to the network to release the UE <NUM>. When the UE <NUM> leaves Connected Mode with respect to PLMN A, the UE <NUM> re-enters Connected with respect to PLMN A shortly thereafter and, when doing so, the UE <NUM> indicates less capabilities towards PLMN A so that the UE <NUM> can reserve some resources for communication with PLMN B. This then allows the UE <NUM> to reallocate resources from PLMN A to PLMN B. Such indication is a Release Assistance Info (RAI). The RAI is enhanced to indicate further that the cause for sending the RAI is that the UE <NUM> intends to change its UE capabilities upon returning to the network.

<FIG> illustrates the operation of a wireless communication device <NUM> in accordance with at least some aspects of the embodiments described above. The wireless communication device <NUM> is equipped with two or more SIMs (e.g., the wireless communication device <NUM> is a multi-SIM UE). Optional steps are represented by dashed lines/boxes. Initially, in the example, the wireless communication device <NUM> is registered with a first PLMN (PLMN1) and a second PLMN (PLMN2), the wireless communication device <NUM> is in connected mode with PLMN1, and the wireless communication device <NUM> is in idle or inactive mode with PLMN2. As illustrated, the wireless communication device <NUM> determines that it is to enter connected mode in PLMN2, as discussed above (step <NUM>). Upon making this determination, the wireless communication device <NUM> sends a request or suggestion to a network node associated with PLMN1 that it is to release the wireless communication device <NUM>, as discussed above (<NUM>), wherein the request or suggestion to release the connection comprises release assistance information and wherein the release assistance information comprises an indication that the wireless communication device intends to change its capabilities upon reconnecting to the first network. As discussed above, this indication is profiled by enhanced RAI. The network node associated with the wireless communication device <NUM> releases the connection of the wireless communication device <NUM> with respect to PLMN1 (e.g., via an RRC Release procedure) (step <NUM>). The wireless communication device <NUM> then re-connects to PLMN1 (e.g. via a RRC Resume procedure) and in association therewith indicates less capabilities towards PLMN1, as discussed above (step <NUM>). In other words, the wireless communication device <NUM> indicates capabilities that take into consideration (e.g., reserve) resources needed for PLMN2. The wireless communication device <NUM> connects to PLMN2 and, in association therewith, indicates capabilities that take into consideration resources needed for PLMN1 (step <NUM>).

Some aspects of this present disclosure can be implemented in the RRC protocol. The RRC protocol can be implemented in a cloud environment and hence parts of the present disclosure could be implemented in a cloud environment.

<FIG> is a schematic block diagram of a network node <NUM> according to some embodiments of the present disclosure. Optional features are represented by dashed boxes. The network node <NUM> may be, for example, a radio access node such as, e.g., a base station <NUM> or <NUM> or a network node that implements all or part of the functionality of the base station <NUM>, eNB, or gNB described herein or a core network node. As illustrated, the network node <NUM> includes a control system <NUM> that includes one or more processors <NUM> (e.g., Central Processing Units (CPUs), Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs), and/or the like), memory <NUM>, and a network interface <NUM>. The one or more processors <NUM> are also referred to herein as processing circuitry. In addition, if the network node is a radio access node, the network node <NUM> may include one or more radio units <NUM> that each includes one or more transmitters <NUM> and one or more receivers <NUM> coupled to one or more antennas <NUM>. The radio units <NUM> may be referred to or be part of radio interface circuitry. In some embodiments, the radio unit(s) <NUM> is external to the control system <NUM> and connected to the control system <NUM> via, e.g., a wired connection (e.g., an optical cable). However, in some other embodiments, the radio unit(s) <NUM> and potentially the antenna(s) <NUM> are integrated together with the control system <NUM>. The one or more processors <NUM> operate to provide one or more functions of a network node as described herein. In some embodiments, the function(s) are implemented in software that is stored, e.g., in the memory <NUM> and executed by the one or more processors <NUM>.

<FIG> is a schematic block diagram that illustrates a virtualized embodiment of the network node <NUM> according to some embodiments of the present disclosure. As used herein, a "virtualized" network node is an implementation of the network node <NUM> in which at least a portion of the functionality of the network node <NUM> is implemented as a virtual component(s) (e.g., via a virtual machine(s) executing on a physical processing node(s) in a network(s)). As illustrated, in this example, the network node <NUM> includes one or more processing nodes <NUM> coupled to or included as part of a network(s) <NUM>. Each processing node <NUM> includes one or more processors <NUM> (e.g., CPUs, ASICs, FPGAs, and/or the like), memory <NUM>, and a network interface <NUM>. If the network node <NUM> is a radio access node, the network node <NUM> may include the control system <NUM> and/or the one or more radio units <NUM>, as described above, which may be connected to the processing node(s) <NUM> via the network <NUM>.

In this example, functions <NUM> of a network node described herein are implemented at the one or more processing nodes <NUM> or distributed across the one or more processing nodes <NUM> and the control system <NUM> and/or the radio unit(s) <NUM> in any desired manner. In some particular embodiments, some or all of the functions <NUM> of a network node described herein are implemented as virtual components executed by one or more virtual machines implemented in a virtual environment(s) hosted by the processing node(s) <NUM>.

In some embodiments, a computer program including instructions which, when executed by at least one processor, causes the at least one processor to carry out the functionality of a network node (e.g., network node <NUM>) or a node (e.g., a processing node <NUM>) implementing one or more of the functions <NUM> of the a network node in a virtual environment according to any of the embodiments described herein is provided.

<FIG> is a schematic block diagram of the network node <NUM> according to some other embodiments of the present disclosure. The module(s) <NUM> provide the functionality of a network node described herein.

<FIG> is a schematic block diagram of a wireless communication device <NUM> according to some embodiments of the present disclosure. As illustrated, the wireless communication device <NUM> includes one or more processors <NUM> (e.g., CPUs, ASICs, FPGAs, and/or the like), memory <NUM>, and one or more transceivers <NUM> each including one or more transmitters <NUM> and one or more receivers <NUM> coupled to one or more antennas <NUM>. The transceiver(s) <NUM> includes radio-front end circuitry connected to the antenna(s) <NUM> that is configured to condition signals communicated between the antenna(s) <NUM> and the processor(s) <NUM>, as will be appreciated by on of ordinary skill in the art. The processors <NUM> are also referred to herein as processing circuitry. The transceivers <NUM> are also referred to herein as radio circuitry. In some embodiments, the functionality of the wireless communication device <NUM> described above may be fully or partially implemented in software that is, e.g., stored in the memory <NUM> and executed by the processor(s) <NUM>. Note that the wireless communication device <NUM> may include additional components not illustrated in <FIG> such as, e.g., one or more user interface components (e.g., an input/output interface including a display, buttons, a touch screen, a microphone, a speaker(s), and/or the like and/or any other components for allowing input of information into the wireless communication device <NUM> and/or allowing output of information from the wireless communication device <NUM>), a power supply (e.g., a battery and associated power circuitry), etc..

Claim 1:
A method performed by a wireless communication device (<NUM>) that is simultaneously registered with a first network and a second network, in connected mode with respect to the first network, and in idle or inactive mode with respect to the second network, the method comprising:
determining (<NUM>) that the wireless communication device (<NUM>) is to connect to the second network;
sending (<NUM>), to a network node associated with the first network, a request or suggestion to release a connection of the wireless communication device (<NUM>) with the first network wherein the request or suggestion to release the connection comprises release assistance information and wherein the release assistance information comprises an indication that the wireless communication device (<NUM>) intends to change its capabilities upon reconnecting to the first network;
receiving (<NUM>), from the network node associated with the first network, a request to release the connection of the wireless communication device (<NUM>) with the first network;
reconnecting (<NUM>) with the first network;
providing (<NUM>), to the network node associated with the first network, capability information that takes into consideration resources to be used for a connection with the second network.