WO2022002354A1

WO2022002354A1 - Resumption processing of connection states

Info

Publication number: WO2022002354A1
Application number: PCT/EP2020/068278
Authority: WO
Inventors: Ethiraj Alwar; Subramanya CHANDRASHEKAR; Andres ARJONA
Original assignee: Nokia Technologies Oy
Priority date: 2020-06-29
Filing date: 2020-06-29
Publication date: 2022-01-06

Abstract

There are provided measures for resumption processing of connection states. Such measures exemplarily comprise receiving a radio resource connection resumption request for resumption of a suspended radio resource control connection, analyzing whether said radio resource connection resumption request includes a predetermined urgency indicator in relation to said resumption of said suspended radio resource control connection, and checking, if said radio resource connection resumption request includes said predetermined urgency indicator, whether at least one predetermined criterion indicative of at least one bearer non-re-establishment is fulfilled.

Description

Title

Resumption processing of connection states

Field

The present invention relates to resumption processing of connection states. More specifically, the present invention exemplarily relates to measures (including methods, apparatuses and computer program products) for realizing resumption processing of connection states and in particular for realizing resumption processing from an inactive state to a connected state.

Background

The present specification generally relates to management of terminals intending to switch from a dormant state to an active, connected state.

Third Generation Partnership Project (3GPP) 5^th Generation (5G) allows two connection management (CM) states, namely, CM-IDLE and CM- CONNECTED. Radio resource control (RRC) states RRC_CONNECTED and RRC_IN ACTIVE belong to the CM-CONNECTED state, while RRC state RRC_IDLE is part of the CM-IDLE state.

Figure 9 is a schematic diagram illustrating connection management concepts. Specifically, Figure 9 illustrates 5G Connection Management and in particular transitions among CM states and among RRC states.

There is an inherent benefit of having a user equipment (UE) keep CM- CONNECTED state when there is no data being transmitted, as both the UE and gNodeB (gNB) keep necessary configurations and information exchanged. This can significantly reduce signaling towards the core network, as well as allow a UE to have very little delay incurred when it needs to transmit/ receive data. These are enhancements that were introduced with 5G with the introduction of the dormant state RRC_IN ACTIVE state.

For a UE in RRC_INACTIVE state, in response to a request to resume the RRC connection, the network may

- resume the suspended RRC connection and send the UE to

RRC_CONNECTED state, or

- reject the request to resume the RRC connection and keep the UE in RRC_INACTIVE state (with a wait timer), or

- directly re-suspend the RRC connection and send the UE to

RRC_IN ACTIVE state, or

- directly release the RRC connection and send the UE to RRC_IDLE state, or

- instruct the UE to initiate Non-Access-Stratum (NAS) level recovery (in this case, the network sends an RRC setup message).

The above-mentioned resumption supports only "All or Nothing", i.e., either all signaling radio bearers (SRB) and data radio bearers (DRB) are resumed (the UE moves to RRC_CONNECTED state), or none of the bearers is resumed (the UE continues to remain in RRC_INACTIVE state or moves to RRC_IDLE state). This behavior is defined in 3GPP technical specification (TS) 38.331.

An UE in RRC_INACTIVE state (with multiple bearers) is forced to do a RRC setup from scratch when one or more of the suspended bearers cannot be resumed.

This potentially causes latency overhead, since the UE has to setup an RRC Connection and has to establish Access Stratum (AS) security again. This becomes critical, if the RRC setup fallback is forced when the UE is resuming the connection for emergency/high priority access. Furthermore, there is no guarantee that a re-attempt of the UE will succeed, given that the re-attempt would again try to establish all the bearers that were previously inactive. Hence, the problem arises that the call setup time needed for emergency or high priority calls (e.g. Ultra-Reliable Low-Latency Communication (URLLC)) when a UE comes back from RRC_INACTIVE state to RRC_CONNECTED state is to be accelerated/quickened. In other words, call setup time for emergency or high priority calls when moving from RRC_INACTIVE state to RRC_CONNECTED state is to be optimized. The problem does not only arise for emergency or high priority calls. Instead, emergency or high priority calls or any other service for similar matter is just an example, and the above- mentioned objects are preferably also to be achieved independent of the type of call the solution according to exemplary embodiments of the present invention is applied upon.

Hence, there is a need to provide for resumption processing of connection states.

Various exemplary embodiments of the present invention aim at addressing at least part of the above issues and/or problems and drawbacks.

Various aspects of exemplary embodiments of the present invention are set out in the appended claims.

According to an exemplary aspect of the present invention, there is provided a method comprising detecting necessity for resumption of a suspended radio resource control connection, determining whether a predetermined condition for announcement of a predetermined urgency indicator in relation to said resumption of said suspended radio resource control connection is fulfilled, and transmitting a radio resource connection resumption request for said resumption of said suspended radio resource control connection, wherein if said predetermined condition is fulfilled, said radio resource connection resumption request includes said predetermined urgency indicator. According to an exemplary aspect of the present invention, there is provided a method comprising receiving a radio resource connection resumption request for resumption of a suspended radio resource control connection, analyzing whether said radio resource connection resumption request includes a predetermined urgency indicator in relation to said resumption of said suspended radio resource control connection, and checking, if said radio resource connection resumption request includes said predetermined urgency indicator, whether at least one predetermined criterion indicative of at least one bearer non-re-establishment is fulfilled.

According to an exemplary aspect of the present invention, there is provided a method comprising receiving an initial uplink radio resource control message from a base station distributed unit, and verifying whether said initial uplink radio resource control message is indicative of at least one bearer non-re-establishment in relation to resumption of a suspended radio resource control connection.

According to an exemplary aspect of the present invention, there is provided an apparatus comprising detecting circuitry configured to detect necessity for resumption of a suspended radio resource control connection, determining circuitry configured to determine whether a predetermined condition for announcement of a predetermined urgency indicator in relation to said resumption of said suspended radio resource control connection is fulfilled, and transmitting circuitry configured to transmit a radio resource connection resumption request for said resumption of said suspended radio resource control connection, wherein if said predetermined condition is fulfilled, said radio resource connection resumption request includes said predetermined urgency indicator.

According to an exemplary aspect of the present invention, there is provided an apparatus comprising receiving circuitry configured to receive a radio resource connection resumption request for resumption of a suspended radio resource control connection, analyzing circuitry configured to analyze whether said radio resource connection resumption request includes a predetermined urgency indicator in relation to said resumption of said suspended radio resource control connection, and checking circuitry configured to check, if said radio resource connection resumption request includes said predetermined urgency indicator, whether at least one predetermined criterion indicative of at least one bearer non-re establishment is fulfilled.

According to an exemplary aspect of the present invention, there is provided an apparatus comprising receiving circuitry configured to receive an initial uplink radio resource control message from a base station distributed unit, and verifying circuitry configured to verify whether said initial uplink radio resource control message is indicative of at least one bearer non-re establishment in relation to resumption of a suspended radio resource control connection.

According to an exemplary aspect of the present invention, there is provided an apparatus comprising at least one processor, at least one memory including computer program code, and at least one interface configured for communication with at least another apparatus, the at least one processor, with the at least one memory and the computer program code, being configured to cause the apparatus to perform detecting necessity for resumption of a suspended radio resource control connection, determining whether a predetermined condition for announcement of a predetermined urgency indicator in relation to said resumption of said suspended radio resource control connection is fulfilled, and transmitting a radio resource connection resumption request for said resumption of said suspended radio resource control connection, wherein if said predetermined condition is fulfilled, said radio resource connection resumption request includes said predetermined urgency indicator.

According to an exemplary aspect of the present invention, there is provided an apparatus comprising at least one processor, at least one memory including computer program code, and at least one interface configured for communication with at least another apparatus, the at least one processor, with the at least one memory and the computer program code, being configured to cause the apparatus to perform receiving a radio resource connection resumption request for resumption of a suspended radio resource control connection, analyzing whether said radio resource connection resumption request includes a predetermined urgency indicator in relation to said resumption of said suspended radio resource control connection, and checking, if said radio resource connection resumption request includes said predetermined urgency indicator, whether at least one predetermined criterion indicative of at least one bearer non-re-establishment is fulfilled.

According to an exemplary aspect of the present invention, there is provided an apparatus comprising at least one processor, at least one memory including computer program code, and at least one interface configured for communication with at least another apparatus, the at least one processor, with the at least one memory and the computer program code, being configured to cause the apparatus to perform receiving an initial uplink radio resource control message from a base station distributed unit, and verifying whether said initial uplink radio resource control message is indicative of at least one bearer non-re-establishment in relation to resumption of a suspended radio resource control connection.

According to an exemplary aspect of the present invention, there is provided a computer program product comprising computer-executable computer program code which, when the program is run on a computer (e.g. a computer of an apparatus according to any one of the aforementioned apparatus-related exemplary aspects of the present invention), is configured to cause the computer to carry out the method according to any one of the aforementioned method-related exemplary aspects of the present invention.

Such computer program product may comprise (or be embodied) a (tangible) computer-readable (storage) medium or the like on which the computer- executable computer program code is stored, and/or the program may be directly loadable into an internal memory of the computer or a processor thereof.

Any one of the above aspects enables an efficient optimization of call setup time for a terminal/UE when moving from RRC_IN ACTIVE state to RRC_CONNECTED state to thereby solve at least part of the problems and drawbacks identified in relation to the prior art.

By way of exemplary embodiments of the present invention, there is provided resumption processing of connection states. More specifically, by way of exemplary embodiments of the present invention, there are provided measures and mechanisms for realizing resumption processing of connection states.

Thus, improvement is achieved by methods, apparatuses and computer program products enabling/realizing resumption processing of connection states.

Brief description of the drawings

In the following, the present invention will be described in greater detail by way of non-limiting examples with reference to the accompanying drawings, in which

Figure 1 is a block diagram illustrating an apparatus according to exemplary embodiments of the present invention,

Figure 2 is a block diagram illustrating an apparatus according to exemplary embodiments of the present invention,

Figure 3 is a block diagram illustrating an apparatus according to exemplary embodiments of the present invention, Figure 4 is a block diagram illustrating an apparatus according to exemplary embodiments of the present invention,

Figure 5 is a block diagram illustrating an apparatus according to exemplary embodiments of the present invention,

Figure 6 is a schematic diagram of a procedure according to exemplary embodiments of the present invention,

Figure 7 is a schematic diagram of a procedure according to exemplary embodiments of the present invention,

Figure 8 is a schematic diagram of a procedure according to exemplary embodiments of the present invention,

Figure 9 is a schematic diagram illustrating connection management concepts,

Figure 10 shows a schematic diagram of signaling sequences according to exemplary embodiments of the present invention, and

Figure 11 is a block diagram alternatively illustrating apparatuses according to exemplary embodiments of the present invention.

Detailed description of drawings and embodiments of the present invention

The present invention is described herein with reference to particular non limiting examples and to what are presently considered to be conceivable embodiments of the present invention. A person skilled in the art will appreciate that the invention is by no means limited to these examples, and may be more broadly applied. It is to be noted that the following description of the present invention and its embodiments mainly refers to specifications being used as non-limiting examples for certain exemplary network configurations and deployments. Namely, the present invention and its embodiments are mainly described in relation to 3GPP specifications being used as non-limiting examples for certain exemplary network configurations and deployments. In particular, emergency or high priority calls and the transition between RRC_IN ACTIVE state to RRC_CONNECTED state are used as non-limiting use case examples for the applicability of thus described exemplary embodiments. As such, the description of exemplary embodiments given herein specifically refers to terminology which is directly related thereto. Such terminology is only used in the context of the presented non-limiting examples, and does naturally not limit the invention in any way. Rather, any other communication or communication related system deployment, etc. may also be utilized as long as compliant with the features described herein.

Hereinafter, various embodiments and implementations of the present invention and its aspects or embodiments are described using several variants and/or alternatives. It is generally noted that, according to certain needs and constraints, all of the described variants and/or alternatives may be provided alone or in any conceivable combination (also including combinations of individual features of the various variants and/or alternatives).

According to exemplary embodiments of the present invention, in general terms, there are provided measures and mechanisms for (enabling/realizing) resumption processing of connection states.

In brief, it is assumed that the F1AP: Initial uplink (UL) RRC message transfer carries initial messages like RRC Setup Request, RRC Resume Request etc. This is sent on common channel, CCCH. According to exemplary embodiments of the present invention, the gNB-DU (gNB-DU: gNB distributed unit) identifies and decodes the RRC message and performs the following actions.

Namely, on the one hand, admission control is performed in the distributed unit (DU) before the message is forwarded to the central unit (CU).

Further, on the other hand, the CellGroupConfig RRC container that is owned and encoded by the DU but needs to be sent to the UE by the CU is encoded. This is an important aspect because, if the CellGroupConfig RRC container is not sent, then an additional FI procedure (UE Context modification) needs to be executed over the FI interface to get the container from DU.

Such actions are currently not possible nor foreseen because, if the DU is only able to partially admit DRBs (because e.g. any data radio bearer cannot be resumed), the DU cannot perform the above-outlined two steps. It is either all DRBs or no DRB. This implies that the above-mentioned additional FI procedure becomes mandatory.

Figure 1 is a block diagram illustrating an apparatus according to exemplary embodiments of the present invention. The apparatus may be a terminal 10 such as a user equipment UE comprising a detecting circuitry 11, a determining circuitry 12, and a transmitting circuitry 13. The detecting circuitry 11 detects necessity for resumption of a suspended radio resource control connection. The determining circuitry 12 determines whether a predetermined condition for announcement of a predetermined urgency indicator in relation to said resumption of said suspended radio resource control connection is fulfilled. The transmitting circuitry 13 transmits a radio resource connection resumption request for said resumption of said suspended radio resource control connection. Here, if said predetermined condition is fulfilled, said radio resource connection resumption request includes said predetermined urgency indicator. Figure 6 is a schematic diagram of a procedure according to exemplary embodiments of the present invention. The apparatus according to Figure 1 may perform the method of Figure 6 but is not limited to this method. The method of Figure 6 may be performed by the apparatus of Figure 1 but is not limited to being performed by this apparatus.

A determination whether a predetermined condition for announcement of a predetermined urgency indicator in relation to said resumption of said suspended radio resource control connection is fulfilled may be a terminal- side decision whether e.g. an emergency case is present or high-priority access is desired, i.e., whether a call the terminal (UE) is initiating or resuming is emergency or high priority (and similar urgency (requiring) cases).

Said predetermined urgency indicator may be transported as or in a resume cause or establishment cause information element.

As shown in Figure 6, a procedure according to exemplary embodiments of the present invention comprises an operation of detecting (S61) necessity for resumption of a suspended radio resource control connection, an operation of determining (S62) whether a predetermined condition for announcement of a predetermined urgency indicator in relation to said resumption of said suspended radio resource control connection is fulfilled, and an operation of transmitting (S63) a radio resource connection resumption request for said resumption of said suspended radio resource control connection, wherein, if said predetermined condition is fulfilled, said radio resource connection resumption request includes said predetermined urgency indicator.

In an embodiment at least some of the functionalities of the apparatus shown in Figure 1 may be shared between two physically separate devices forming one operational entity. Therefore, the apparatus may be seen to depict the operational entity comprising one or more physically separate devices for executing at least some of the described processes. According to exemplary embodiments of the present invention, said radio resource connection resumption request is a request for transition from a radio resource control inactive state to a radio resource control connected state.

According to further exemplary embodiments of the present invention, said predetermined urgency indicator is indicative of at least one of an emergency call and a high priority call.

Figure 2 is a block diagram illustrating an apparatus according to exemplary embodiments of the present invention. The apparatus may be a network node 20 such as (a component of) an access node, e.g. a gNB-DU, comprising a receiving circuitry 21, a analyzing circuitry 22, and a checking circuitry 23. The receiving circuitry 21 receives a radio resource connection resumption request for resumption of a suspended radio resource control connection. The analyzing circuitry 22 analyzes whether said radio resource connection resumption request includes a predetermined urgency indicator in relation to said resumption of said suspended radio resource control connection. The checking circuitry 23 checks, if said radio resource connection resumption request includes said predetermined urgency indicator, whether at least one predetermined criterion indicative of at least one bearer non-re establishment is fulfilled. Figure 7 is a schematic diagram of a procedure according to exemplary embodiments of the present invention. The apparatus according to Figure 2 may perform the method of Figure 7 but is not limited to this method. The method of Figure 7 may be performed by the apparatus of Figure 2 but is not limited to being performed by this apparatus.

As shown in Figure 7, a procedure according to exemplary embodiments of the present invention comprises an operation of receiving (S71) a radio resource connection resumption request for resumption of a suspended radio resource control connection, an operation of analyzing (S72) whether said radio resource connection resumption request includes a predetermined urgency indicator in relation to said resumption of said suspended radio resource control connection, and an operation of checking (S73), if said radio resource connection resumption request includes said predetermined urgency indicator, whether at least one predetermined criterion indicative of at least one bearer non-re-establishment is fulfilled.

Figure 3 is a block diagram illustrating an apparatus according to exemplary embodiments of the present invention. In particular, Figure 3 illustrates a variation of the apparatus shown in Figure 2. The apparatus according to Figure 3 may thus further comprise controlling circuitry 31 and/or transmitting circuitry 32.

In an embodiment at least some of the functionalities of the apparatus shown in Figure 2 (or 3) may be shared between two physically separate devices forming one operational entity. Therefore, the apparatus may be seen to depict the operational entity comprising one or more physically separate devices for executing at least some of the described processes. Such shared architecture, may comprise a remote control unit (RCU), such as a host computer or a server computer, operatively coupled (e.g. via a wireless or wired network) to a remote radio head (RRH) located in the base station or eNB, for example. In an embodiment, at least some of the described processes may be performed by the RCU. In an embodiment, the execution of at least some of the described processes may be shared among the RRH and the RCU. In practice, any digital signal processing task may be performed in either the RRH or the RCU and the boundary where the responsibility is shifted between the RRH and the RCU may be selected according to implementation.

According to a variation of the procedure shown in Figure 7, exemplary additional operations are given, which are inherently independent from each other as such. According to such variation, an exemplary method according to exemplary embodiments of the present invention may comprise an operation of controlling, if said at least one predetermined criterion indicative of said at least one bearer non-re-establishment is fulfilled, continuation of processing for said resumption of a suspended radio resource control connection.

According to further exemplary embodiments of the present invention, a set of at least one suspended data radio bearer is associated with said suspended radio resource control connection, wherein said at least one bearer non-re establishment includes that no one of said at least one suspended data radio bearer or only a subset of said at least one suspended data radio bearer less than said set of said at least one suspended data radio bearer is re established.

According to further exemplary embodiments of the present invention, said at least one predetermined criterion signifies that no one of said at least one suspended data radio bearer or only said subset of said at least one suspended data radio bearer less than said set of said at least one suspended data radio bearer is re-established.

According to further exemplary embodiments of the present invention, said at least one predetermined criterion signifies that admission control for a source of said radio resource connection resumption request has failed, wherein a case that said admission control for a source of said radio resource connection resumption request has failed is deemed as that no one of said at least one suspended data radio bearer is re-established.

According to still further exemplary embodiments of the present invention, a set of at least one service type each corresponding to a specific suspended data radio bearer of said at least one suspended data radio bearer is associated with said suspended radio resource control connection, and said at least one predetermined criterion signifies that no one of said at least one service type or only a subset of said at least one service type less than said set of said at least one service type is admitted. Further, in a case that no one of said at least one service type is admitted, no one of said at least one suspended data radio bearer is re-established, and in a case that only said subset of said at least one service type less than said set of said at least one service type is admitted, only said subset of said at least one suspended data radio bearer corresponding to said admitted at least one service type is re established.

According to a variation of the procedure shown in Figure 7, exemplary additional operations are given, which are inherently independent from each other as such. According to such variation, an exemplary method according to exemplary embodiments of the present invention may comprise an operation of transmitting, if said at least one predetermined criterion indicative of said at least one bearer non-re-establishment is fulfilled, an initial uplink radio resource control message indicative of that said at least one predetermined criterion indicative of said at least one bearer non-re establishment is fulfilled towards a base station central unit.

According to further exemplary embodiments of the present invention, if no one of said at least one suspended data radio bearer is re-established, said initial uplink radio resource control message includes a first information element indicating that no one of said at least one suspended data radio bearer is re-established and a second information element indicative of each of said at least one suspended data radio bearer.

According to still further exemplary embodiments of the present invention, if only said subset of said at least one suspended data radio bearer less than said set of said at least one suspended data radio bearer is re-established, said initial uplink radio resource control message includes a first information element indicating that only said subset of said at least one suspended data radio bearer less than said set of said at least one suspended data radio bearer is re-established, a second information element indicative of each of said at least one suspended data radio bearer not being in said subset of said at least one suspended data radio bearer, and a third information element (CellGroupConfig) used to configure a master cell group.

According to still further exemplary embodiments of the present invention, said initial uplink radio resource control message is a layer 3 message transmitted over an FI interface.

According to still further exemplary embodiments of the present invention, a set of at least one suspended signaling radio bearer is associated with said suspended radio resource control connection, wherein in a case of said at least one bearer non-re-establishment, at least one suspended signaling radio bearer of said set of at least one suspended signaling radio bearer is re established.

Figure 4 is a block diagram illustrating an apparatus according to exemplary embodiments of the present invention. The apparatus may be a network node 40 such as (a component of) an access node, e.g. a gNB-CU, comprising a receiving circuitry 41 and a verifying circuitry 42. The receiving circuitry 41 receives an initial uplink radio resource control message from a base station distributed unit. The verifying circuitry 42 verifies whether said initial uplink radio resource control message is indicative of at least one bearer non-re establishment in relation to resumption of a suspended radio resource control connection. Figure 8 is a schematic diagram of a procedure according to exemplary embodiments of the present invention. The apparatus according to Figure 4 may perform the method of Figure 8 but is not limited to this method. The method of Figure 8 may be performed by the apparatus of Figure 4 but is not limited to being performed by this apparatus.

As shown in Figure 8, a procedure according to exemplary embodiments of the present invention comprises an operation of receiving (S81) an initial uplink radio resource control message from a base station distributed unit, and an operation of verifying (S82) whether said initial uplink radio resource control message is indicative of at least one bearer non-re-establishment in relation to resumption of a suspended radio resource control connection.

Figure 5 is a block diagram illustrating an apparatus according to exemplary embodiments of the present invention. In particular, Figure 5 illustrates a variation of the apparatus shown in Figure 4. The apparatus according to Figure 5 may thus further comprise checking circuitry 51, notifying circuitry 52, selecting circuitry 53, and/or controlling circuitry 54.

In an embodiment at least some of the functionalities of the apparatus shown in Figure 4 (or 5) may be shared between two physically separate devices forming one operational entity. Therefore, the apparatus may be seen to depict the operational entity comprising one or more physically separate devices for executing at least some of the described processes. Such shared architecture, may comprise a remote control unit (RCU), such as a host computer or a server computer, operatively coupled (e.g. via a wireless or wired network) to a remote radio head (RRH) located in the base station or eNB, for example. In an embodiment, at least some of the described processes may be performed by the RCU. In an embodiment, the execution of at least some of the described processes may be shared among the RRH and the RCU. In practice, any digital signal processing task may be performed in either the RRH or the RCU and the boundary where the responsibility is shifted between the RRH and the RCU may be selected according to implementation.

According to exemplary embodiments of the present invention, a set of at least one suspended data radio bearer is associated with said suspended radio resource control connection, wherein said at least one bearer non-re establishment includes that no one of said at least one suspended data radio bearer or only a subset of said at least one suspended data radio bearer less than said set of said at least one suspended data radio bearer is re established. According to further exemplary embodiments of the present invention, if no one of said at least one suspended data radio bearer is re-established, said initial uplink radio resource control message includes a first information element indicating that no one of said at least one suspended data radio bearer is re-established and a second information element indicative of each of said at least one suspended data radio bearer.

According to a variation of the procedure shown in Figure 8, exemplary details of the verifying operation (S82) are given, which are inherently independent from each other as such.

Such exemplary verifying operation (S82) according to exemplary embodiments of the present invention may comprise an operation of checking whether said initial uplink radio resource control message includes said first information element indicating that no one of said at least one suspended data radio bearer is re-established or indicating that only said subset of said at least one suspended data radio bearer less than said set of said at least one suspended data radio bearer is re-established.

According to a variation of the procedure shown in Figure 8, exemplary additional operations are given, which are inherently independent from each other as such. According to such variation, an exemplary method according to exemplary embodiments of the present invention may comprise an operation of notifying, if said initial uplink radio resource control message includes said first information element indicating that no one of said at least one suspended data radio bearer is re-established or indicating that only said subset of said at least one suspended data radio bearer less than said set of said at least one suspended data radio bearer is re-established, an access and mobility management function to release quality of service flows corresponding to suspended data radio bearers indicated by said second information element.

According to a variation of the procedure shown in Figure 8, exemplary additional operations are given, which are inherently independent from each other as such. According to such variation, an exemplary method according to exemplary embodiments of the present invention may comprise an operation of selecting candidate suspended data radio bearers from suspended data radio bearers indicated by said second information element, and an operation of controlling attempting to re-establish connections to said candidate suspended data radio bearers.

In more specific terms, according to exemplary embodiments of the present invention, the UE's resumption from RRC_IN ACTIVE state to RRC_CONNECTED state is allowed for emergency, high-priority calls (i.e. the above-mentioned exemplary emergency, high-priority cases and similar) or based on specific UE capabilities, even if none or only a partial set of DRBs are successfully re-established at the target gNB (the target gNB may be the same as source gNB).

Having a partial success is beneficial both when only some of the DRBs are re-established as well as when none of the DRBs can be re-established.

Namely, in case of partial success, i.e., when only some of the DRBs are re established, (high priority) DRBs can be established, and the UE's resumption (and the successful re-establishment of the (high priority) DRBs) would not be affected by re-establishment failure on other DRBs (e.g. of lower priority). The other way round, a lower priority DRB may also be used for transmission of the higher priority data rather than letting all the DRBs fail, thereby impeding that the higher priority data is transmitted at all. Furthermore, even the assumption that a subsequent re-attempt by the UE to re-establish the connection (and hence all the DRBs) would succeed after accepting that all the DRBs fail with could not be guaranteed (i.e., the all or nothing approach (failing all the DRBs) has no guarantee that a re-attempt by the UE to re establish the connection (and hence all the DRBs) will succeed when attempted afterwards).

Further, in case that none of the DRBs succeed to be re-established, i.e., when none of the DRBs can be re-established, it can also be beneficial to keep the connection even if it corresponds only to the signaling bearers (SRBs). This is because in such case afterwards the CU would have the flexibility to decide whether to make subsequent attempts only for the high priority/emergency/special service DRBs, and the high priority/emergency/special service DRBs could be established as soon as the resources become available. Such approach would increase the probability that a subsequent attempt succeeds, opposed to a re-attempt from scratch from the UE requesting all the bearers that were initially established. Keeping the connection even if it corresponds only to the signaling bearers (SRBs) also depends on the resource availability for SRB-only connection.

In view of the above, according to exemplary embodiments of the present invention, when an inactive UE (i.e. UE in RRC_INACTIVE state) has to resume the connection and sends a RRC RESUME REQUEST to the gNB, if a resume cause or establishment cause is e.g. "emergency" or "highPriorityAccess", i.e., indicates urgency, e.g. is indicated by or constitutes a predetermined urgency indicator, even if none or (only) a subset of the suspended bearers can be resumed, it is continued with the resumption so that a new emergency session (urgent session or high priority session or similar) can be setup faster.

Thus, according to exemplary embodiments of the present invention, the UE is allowed to move to RRC_CONNECTED state immediately.

Further, according to exemplary embodiments of the present invention, it is allowed to alternatively transmit/ receive data over lower priority bearers immediately, while the gNB can still continue to attempt to setup a new bearer with the characteristics which were not immediately accessible upon the resume request (RRC RESUME REQUEST) from the UE. Similarly, in case that no bearer is possible to be initially resumed, CU can make subsequent attempts only for the high priority/emergency bearers, and not necessarily for all bearers simultaneously as in the initial UE request.

Thus, according to exemplary embodiments of the present invention it is ensured that for extremely low latency services and high-priority users, the call establishment is not (unnecessarily) delayed.

Figure 10 shows a schematic diagram of signaling sequences according to exemplary embodiments of the present invention. As is illustrated in Figure 10, once a UE transmits an RRC RESUME REQUEST to the gNB-DU, the gNB-DU determines whether the resume cause or establishment cause is e.g. "EMERGENCY" or "HIGH PRIORITY ACCESS", i.e., indicates urgency, e.g. is indicated by or constitutes a predetermined urgency indicator. If not, the gNB-DU proceeds with the resumption as previously known as discussed above.

If so, the gNB-DU determines whether none or (only) some suspended bearers can be resumed. If not, the gNB-DU proceeds with the resumption as previously known as discussed above.

Consequently, according to exemplary embodiments of the present invention, if a predetermined condition for indication is fulfilled, the UE indicates the urgency.

If the gNB-DU determines that none or (only) some suspended bearers can be resumed, an initial uplink message RRC MESSAGE is transferred to the gNB-CU via the F1AP interface.

The message includes a CellGroupConfig IE (IE: information element), if some suspended bearers can be/are resumed. The message does not include the CellGroupConfig IE, if none of the suspended bearers can be/is resumed.

Further, the message includes an IE indicating partial resumption ("Partial Resume Indication"), which is set to "none" (which may correspond to "false") or "some" (which may correspond to "true").

Further, the message includes an IE indicating the DRBs not resumed ("DRB Not Resumed List"), which is which is a list of DRBs which are not resumed.

Based on the content of the message (i.e. information elements), the gNB- CU identifies the resumption level (none, (only) some). In case of none/some, the gNB decides to notify the access and mobility management function (AMF) to release the corresponding quality of service (QoS) flows.

Hence, the gNB-CU transmits, via the NG application protocol (NGAP) a packet data unit (PDU) session resource notification to the AMF.

Once the RRC Connection is resumed, the involved entities are ready for setting up the new sessions.

Besides the above-illustrated causes or principles, exemplary embodiments of the present invention can be implemented in the following way.

Namely, on the one hand, an admission control based partial resumption may be implemented. According to such implementation, the same concept of prioritizing low latency or high-priority or specific UE-capabilities is also be extended to admission control performed at gNB-DU when a RRC resume request is received at the gNB-DU. According to the above-discussed previously known principles, there is no other option than to release a UE when admission control fails. Contrary thereto, according to exemplary embodiments of the present invention, the specific UE in question is admitted even without any DRBs (because admission control has failed).

Further, on the other hand, a service type based partial resumption may be implemented. This is another criterion to allow RRC resumption of a UE. In particular, according to exemplary embodiments of the present invention, resumption of a UE is partially allowed based on its services. For example, if a UE had one enhanced Mobile Broadband (eMBB) bearer and one URLLC bearer in RRC_CONNECTED state and when it resumes from RRC_INACTIVE, only the URLLC bearer is admitted or successfully re-established, then, according to the exemplary embodiments of the present invention, the UE could still be allowed to complete its resume process. Criteria for the gNB on when the partial resumption of a UE is allowed can be configurable via operator, e.g., in order to minimize service impact to specific services (e.g., URLLC as mentioned above).

Hence, in other words, according to exemplary embodiments of the present invention, the gNB-DU checks if the ResumeCause or establishment cause in the RRCResumeRequest (RRC resume request) is (for example, as explained above) emergency or highPriorityAccess (i.e., indicates urgency).

If all the suspended bearers are resumed, the gNB-DU proceeds with the resumption as per the previously known behavior (resume all).

If none or only a subset of the suspended bearers are resumed and all the above discussed selection criteria are met, the gNB-DU proceeds with the resumption and notifies the gNB-CU about the bearers that have failed to be re-established or admitted at gNB-DU.

The gNB-CU releases the corresponding QoS Flows and also notifies AMF accordingly.

The above-discussed initial uplink RRC message (INITIAL UL RRC MESSAGE TRANSFER) is sent by the gNB-DU to transfer the initial layer 3 message to the gNB-CU over the FI interface.

According to exemplary embodiments of the present invention, this message includes the following structure. However, the structure included is not limited to that given below.

According to exemplary embodiments of the present invention, in contrast to the previously known approaches, the latency is reduced by avoiding the complete RRC Connection Setup and AS Security Establishment.

Further, faster response is enabled in case of e.g. "emergency" or "high priority access" scenarios (or similar urgent scenarios as discussed above).

Still further, admission control in DU is enabled to be flexible by resuming even with partial set of currently suspended bearers.

The above-described procedures and functions may be implemented by respective functional elements, processors, or the like, as described below.

In the foregoing exemplary description of the network entity, only the units that are relevant for understanding the principles of the invention have been described using functional blocks. The network entity may comprise further units that are necessary for its respective operation. However, a description of these units is omitted in this specification. The arrangement of the functional blocks of the devices is not construed to limit the invention, and the functions may be performed by one block or further split into sub-blocks.

When in the foregoing description it is stated that the apparatus, i.e. network entity (or some other means) is configured to perform some function, this is to be construed to be equivalent to a description stating that a (i.e. at least one) processor or corresponding circuitry, potentially in cooperation with computer program code stored in the memory of the respective apparatus, is configured to cause the apparatus to perform at least the thus mentioned function. Also, such function is to be construed to be equivalently implementable by specifically configured circuitry or means for performing the respective function (i.e. the expression "unit configured to" is construed to be equivalent to an expression such as "means for").

In Figure 11, an alternative illustration of apparatuses according to exemplary embodiments of the present invention is depicted. As indicated in Figure 11, according to exemplary embodiments of the present invention, the apparatus (terminal) 10' (corresponding to the terminal 10) comprises a processor 1111, a memory 1112 and an interface 1113, which are connected by a bus 1114 or the like. Further, according to exemplary embodiments of the present invention, the apparatus (network node) 20' (corresponding to the network node 20) comprises a processor 1121, a memory 1122 and an interface 1123, which are connected by a bus 1124 or the like. Further, according to exemplary embodiments of the present invention, the apparatus (network node) 40' (corresponding to the network node 40) comprises a processor 1141, a memory 1142 and an interface 1143, which are connected by a bus 1144 or the like. The apparatuses may be connected via links 111a, 111b, respectively.

The processor 1111/1121/1141 and/or the interface 1113/1123/1143 may also include a modem or the like to facilitate communication over a (hardwire or wireless) link, respectively. The interface 1113/1123/1143 may include a suitable transceiver coupled to one or more antennas or communication means for (hardwire or wireless) communications with the linked or connected device(s), respectively. The interface 1113/1123/1143 is generally configured to communicate with at least one other apparatus, i.e. the interface thereof.

The memory 1112/1122/1142 may store respective programs assumed to include program instructions or computer program code that, when executed by the respective processor, enables the respective electronic device or apparatus to operate in accordance with the exemplary embodiments of the present invention. In general terms, the respective devices/apparatuses (and/or parts thereof) may represent means for performing respective operations and/or exhibiting respective functionalities, and/or the respective devices (and/or parts thereof) may have functions for performing respective operations and/or exhibiting respective functionalities.

When in the subsequent description it is stated that the processor (or some other means) is configured to perform some function, this is to be construed to be equivalent to a description stating that at least one processor, potentially in cooperation with computer program code stored in the memory of the respective apparatus, is configured to cause the apparatus to perform at least the thus mentioned function. Also, such function is to be construed to be equivalently implementable by specifically configured means for performing the respective function (i.e. the expression "processor configured to [cause the apparatus to] perform xxx-ing" is construed to be equivalent to an expression such as "means for xxx-ing").

According to exemplary embodiments of the present invention, an apparatus representing the terminal 10 comprises at least one processor 1111, at least one memory 1112 including computer program code, and at least one interface 1113 configured for communication with at least another apparatus. The processor (i.e. the at least one processor 1111, with the at least one memory 1112 and the computer program code) is configured to perform detecting necessity for resumption of a suspended radio resource control connection (thus the apparatus comprising corresponding means for detecting), to perform determining whether a predetermined condition for announcement of a predetermined urgency indicator in relation to said resumption of said suspended radio resource control connection is fulfilled (thus the apparatus comprising corresponding means for determining), and to perform transmitting a radio resource connection resumption request for said resumption of said suspended radio resource control connection, wherein, if said predetermined condition is fulfilled, said radio resource connection resumption request includes said predetermined urgency indicator (thus the apparatus comprising corresponding means for transmitting).

According to exemplary embodiments of the present invention, an apparatus representing the network node 20 comprises at least one processor 1121, at least one memory 1122 including computer program code, and at least one interface 1123 configured for communication with at least another apparatus. The processor (i.e. the at least one processor 1121, with the at least one memory 1122 and the computer program code) is configured to perform receiving a radio resource connection resumption request for resumption of a suspended radio resource control connection (thus the apparatus comprising corresponding means for receiving), to perform analyzing whether said radio resource connection resumption request includes a predetermined urgency indicator in relation to said resumption of said suspended radio resource control connection (thus the apparatus comprising corresponding means for analyzing), and to perform checking, if said radio resource connection resumption request includes said predetermined urgency indicator, whether at least one predetermined criterion indicative of at least one bearer non-re-establishment is fulfilled (thus the apparatus comprising corresponding means for checking).

According to exemplary embodiments of the present invention, an apparatus representing the network node 40 comprises at least one processor 1141, at least one memory 1142 including computer program code, and at least one interface 1143 configured for communication with at least another apparatus. The processor (i.e. the at least one processor 1141, with the at least one memory 1142 and the computer program code) is configured to perform receiving an initial uplink radio resource control message from a base station distributed unit (thus the apparatus comprising corresponding means for receiving), and to perform verifying whether said initial uplink radio resource control message is indicative of at least one bearer non-re-establishment in relation to resumption of a suspended radio resource control connection (thus the apparatus comprising corresponding means for verifying). For further details regarding the operability/functionality of the individual apparatuses, reference is made to the above description in connection with any one of Figures 1 to 10, respectively.

For the purpose of the present invention as described herein above, it should be noted that

- method steps likely to be implemented as software code portions and being run using a processor at a network server or network entity (as examples of devices, apparatuses and/or modules thereof, or as examples of entities including apparatuses and/or modules therefore), are software code independent and can be specified using any known or future developed programming language as long as the functionality defined by the method steps is preserved;

- generally, any method step is suitable to be implemented as software or by hardware without changing the idea of the embodiments and its modification in terms of the functionality implemented;

- method steps and/or devices, units or means likely to be implemented as hardware components at the above-defined apparatuses, or any module(s) thereof, (e.g., devices carrying out the functions of the apparatuses according to the embodiments as described above) are hardware independent and can be implemented using any known or future developed hardware technology or any hybrids of these, such as MOS (Metal Oxide Semiconductor), CMOS (Complementary MOS), BiMOS (Bipolar MOS), BiCMOS (Bipolar CMOS), ECL (Emitter Coupled Logic), TTL (Transistor-Transistor Logic), etc., using for example ASIC (Application Specific IC (Integrated Circuit)) components, FPGA (Field-programmable Gate Arrays) components, CPLD (Complex Programmable Logic Device) components or DSP (Digital Signal Processor) components;

- devices, units or means (e.g. the above-defined network entity or network register, or any one of their respective units/means) can be implemented as individual devices, units or means, but this does not exclude that they are implemented in a distributed fashion throughout the system, as long as the functionality of the device, unit or means is preserved;

- an apparatus like the user equipment and the network entity /network register may be represented by a semiconductor chip, a chipset, or a (hardware) module comprising such chip or chipset; this, however, does not exclude the possibility that a functionality of an apparatus or module, instead of being hardware implemented, be implemented as software in a (software) module such as a computer program or a computer program product comprising executable software code portions for execution/being run on a processor;

- a device may be regarded as an apparatus or as an assembly of more than one apparatus, whether functionally in cooperation with each other or functionally independently of each other but in a same device housing, for example.

In general, it is to be noted that respective functional blocks or elements according to above-described aspects can be implemented by any known means, either in hardware and/or software, respectively, if it is only adapted to perform the described functions of the respective parts. The mentioned method steps can be realized in individual functional blocks or by individual devices, or one or more of the method steps can be realized in a single functional block or by a single device.

Generally, any method step is suitable to be implemented as software or by hardware without changing the idea of the present invention. Devices and means can be implemented as individual devices, but this does not exclude that they are implemented in a distributed fashion throughout the system, as long as the functionality of the device is preserved. Such and similar principles are to be considered as known to a skilled person.

Software in the sense of the present description comprises software code as such comprising code means or portions or a computer program or a computer program product for performing the respective functions, as well as software (or a computer program or a computer program product) embodied on a tangible medium such as a computer-readable (storage) medium having stored thereon a respective data structure or code means/portions or embodied in a signal or in a chip, potentially during processing thereof.

The present invention also covers any conceivable combination of method steps and operations described above, and any conceivable combination of nodes, apparatuses, modules or elements described above, as long as the above-described concepts of methodology and structural arrangement are applicable.

In view of the above, there are provided measures for resumption processing of connection states. Such measures exemplarily comprise receiving a radio resource connection resumption request for resumption of a suspended radio resource control connection, analyzing whether said radio resource connection resumption request includes a predetermined urgency indicator in relation to said resumption of said suspended radio resource control connection, and checking, if said radio resource connection resumption request includes said predetermined urgency indicator, whether at least one predetermined criterion indicative of at least one bearer non-re establishment is fulfilled.

Even though the invention is described above with reference to the examples according to the accompanying drawings, it is to be understood that the invention is not restricted thereto. Rather, it is apparent to those skilled in the art that the present invention can be modified in many ways without departing from the scope of the inventive idea as disclosed herein.

List of acronyms and abbreviations

3GPP Third Generation Partnership Project

5G 5th Generation AMF access and mobility management function

AS Access Stratum

CM connection management

CU central unit DRB data radio bearer DU distributed unit eMBB enhanced Mobile Broadband gNB gNodeB gNB-CU gNB central unit gNB-DU gNB distributed unit IE information element

NAS Non-Access-Stratum NGAP NG application protocol PDU packet data unit QoS quality of service RCU remote control unit RRC radio resource control RRH remote radio head SRB signaling radio bearer TS technical specification UE user equipment UL uplink

URLLC Ultra-Reliable Low-Latency Communication

Claims

1. A method comprising detecting necessity for resumption of a suspended radio resource control connection, determining whether a predetermined condition for announcement of a predetermined urgency indicator in relation to said resumption of said suspended radio resource control connection is fulfilled, and transmitting a radio resource connection resumption request for said resumption of said suspended radio resource control connection, wherein if said predetermined condition is fulfilled, said radio resource connection resumption request includes said predetermined urgency indicator.

2. The method according to claim 1, wherein said radio resource connection resumption request is a request for transition from a radio resource control inactive state to a radio resource control connected state.

3. The method according to claim 1 or 2, wherein said predetermined urgency indicator is indicative of at least one of an emergency call and a high priority call.

4. The method according to any of claims 1 to 3, wherein the method is operable at or by a terminal, user equipment, mobile station or modem, and/or the method is operable in at least one of a LTE, a LTE-A, and a 5G cellular system.

5. A method comprising receiving a radio resource connection resumption request for resumption of a suspended radio resource control connection, analyzing whether said radio resource connection resumption request includes a predetermined urgency indicator in relation to said resumption of said suspended radio resource control connection, and checking, if said radio resource connection resumption request includes said predetermined urgency indicator, whether at least one predetermined criterion indicative of at least one bearer non-re-establishment is fulfilled.

6. The method according to claim 5, further comprising controlling, if said at least one predetermined criterion indicative of said at least one bearer non-re-establishment is fulfilled, continuation of processing for said resumption of a suspended radio resource control connection.

7. The method according to claim 5 or 6, wherein a set of at least one suspended data radio bearer is associated with said suspended radio resource control connection, wherein said at least one bearer non-re-establishment includes that no one of said at least one suspended data radio bearer or only a subset of said at least one suspended data radio bearer less than said set of said at least one suspended data radio bearer is re-established.

8. The method according to claim 7, wherein said at least one predetermined criterion signifies that no one of said at least one suspended data radio bearer or only said subset of said at least one suspended data radio bearer less than said set of said at least one suspended data radio bearer is re-established.

9. The method according to claim 7, wherein said at least one predetermined criterion signifies that admission control for a source of said radio resource connection resumption request has failed, wherein a case that said admission control for a source of said radio resource connection resumption request has failed is deemed as that no one of said at least one suspended data radio bearer is re-established.

10. The method according to claim 7, wherein a set of at least one service type each corresponding to a specific suspended data radio bearer of said at least one suspended data radio bearer is associated with said suspended radio resource control connection, and said at least one predetermined criterion signifies that no one of said at least one service type or only a subset of said at least one service type less than said set of said at least one service type is admitted, wherein in a case that no one of said at least one service type is admitted, no one of said at least one suspended data radio bearer is re-established, and in a case that only said subset of said at least one service type less than said set of said at least one service type is admitted, only said subset of said at least one suspended data radio bearer corresponding to said admitted at least one service type is re-established.

11. The method according to any of claims 7 to 10, further comprising transmitting, if said at least one predetermined criterion indicative of said at least one bearer non-re-establishment is fulfilled, an initial uplink radio resource control message indicative of that said at least one predetermined criterion indicative of said at least one bearer non-re-establishment is fulfilled towards a base station central unit.

12. The method according to claim 11, wherein if no one of said at least one suspended data radio bearer is re established, said initial uplink radio resource control message includes a first information element indicating that no one of said at least one suspended data radio bearer is re-established and a second information element indicative of each of said at least one suspended data radio bearer.

13. The method according to claim 11, wherein if only said subset of said at least one suspended data radio bearer less than said set of said at least one suspended data radio bearer is re established, said initial uplink radio resource control message includes a first information element indicating that only said subset of said at least one suspended data radio bearer less than said set of said at least one suspended data radio bearer is re-established, a second information element indicative of each of said at least one suspended data radio bearer not being in said subset of said at least one suspended data radio bearer, and a third information element (CellGroupConfig) used to configure a master cell group.

14. The method according to any of claims 11 to 13, wherein said initial uplink radio resource control message is a layer 3 message transmitted over an FI interface.

15. The method according to any of claims 5 to 14, wherein a set of at least one suspended signaling radio bearer is associated with said suspended radio resource control connection, wherein in a case of said at least one bearer non-re-establishment, at least one suspended signaling radio bearer of said set of at least one suspended signaling radio bearer is re-established.

16. The method according to any of claims 5 to 15, wherein the method is operable at or by a base station distributed unit of a cellular system, and/or the method is operable in at least one of a LTE, a LTE-A, and a 5G cellular system.

17. A method comprising receiving an initial uplink radio resource control message from a base station distributed unit, and verifying whether said initial uplink radio resource control message is indicative of at least one bearer non-re-establishment in relation to resumption of a suspended radio resource control connection.

18. The method according to claim 17, wherein a set of at least one suspended data radio bearer is associated with said suspended radio resource control connection, wherein said at least one bearer non-re-establishment includes that no one of said at least one suspended data radio bearer or only a subset of said at least one suspended data radio bearer less than said set of said at least one suspended data radio bearer is re-established.

19. The method according to claim 18, wherein if no one of said at least one suspended data radio bearer is re established, said initial uplink radio resource control message includes a first information element indicating that no one of said at least one suspended data radio bearer is re-established and a second information element indicative of each of said at least one suspended data radio bearer.

20. The method according to claim 18, wherein if only said subset of said at least one suspended data radio bearer less than said set of said at least one suspended data radio bearer is re established, said initial uplink radio resource control message includes a first information element indicating that only said subset of said at least one suspended data radio bearer less than said set of said at least one suspended data radio bearer is re-established, a second information element indicative of each of said at least one suspended data radio bearer not being in said subset of said at least one suspended data radio bearer, and a third information element (CellGroupConfig) used to configure a master cell group.

21. The method according to claim 19 or 20, wherein in relation to said verifying, the method further comprises checking whether said initial uplink radio resource control message includes said first information element indicating that no one of said at least one suspended data radio bearer is re-established or indicating that only said subset of said at least one suspended data radio bearer less than said set of said at least one suspended data radio bearer is re-established.

22. The method according to claim 21, further comprising notifying, if said initial uplink radio resource control message includes said first information element indicating that no one of said at least one suspended data radio bearer is re-established or indicating that only said subset of said at least one suspended data radio bearer less than said set of said at least one suspended data radio bearer is re-established, an access and mobility management function to release quality of service flows corresponding to suspended data radio bearers indicated by said second information element.

23. The method according to claim 21 or 22, further comprising selecting candidate suspended data radio bearers from suspended data radio bearers indicated by said second information element, and controlling attempting to re-establish connections to said candidate suspended data radio bearers.

24. The method according to any of claims 17 to 23, wherein said initial uplink radio resource control message is a layer 3 message transmitted over an FI interface.

25. The method according to any of claims 17 to 24, wherein a set of at least one suspended signaling radio bearer is associated with said suspended radio resource control connection, wherein in a case of said at least one bearer non-re-establishment, at least one suspended signaling radio bearer of said set of at least one suspended signaling radio bearer is re-established.

26. The method according to any of claims 17 to 25, wherein the method is operable at or by a base station central unit of a cellular system, and/or the method is operable in at least one of a LTE, a LTE-A, and a 5G cellular system.

27. An apparatus comprising detecting circuitry configured to detect necessity for resumption of a suspended radio resource control connection, determining circuitry configured to determine whether a predetermined condition for announcement of a predetermined urgency indicator in relation to said resumption of said suspended radio resource control connection is fulfilled, and transmitting circuitry configured to transmit a radio resource connection resumption request for said resumption of said suspended radio resource control connection, wherein if said predetermined condition is fulfilled, said radio resource connection resumption request includes said predetermined urgency indicator.

28. The apparatus according to claim 27, wherein said radio resource connection resumption request is a request for transition from a radio resource control inactive state to a radio resource control connected state.

29. The apparatus according to claim 27 or 28, wherein said predetermined urgency indicator is indicative of at least one of an emergency call and a high priority call.

30. The apparatus according to any of claims 27 to 29, wherein the apparatus is operable as or at a terminal, user equipment, mobile station or modem, and/or the apparatus is operable in at least one of a LTE, a LTE-A, and a 5G cellular system.

31. An apparatus comprising receiving circuitry configured to receive a radio resource connection resumption request for resumption of a suspended radio resource control connection, analyzing circuitry configured to analyze whether said radio resource connection resumption request includes a predetermined urgency indicator in relation to said resumption of said suspended radio resource control connection, and checking circuitry configured to check, if said radio resource connection resumption request includes said predetermined urgency indicator, whether at least one predetermined criterion indicative of at least one bearer non-re establishment is fulfilled.

32. The apparatus according to claim 31, further comprising controlling circuitry configured to control, if said at least one predetermined criterion indicative of said at least one bearer non-re establishment is fulfilled, continuation of processing for said resumption of a suspended radio resource control connection.

33. The apparatus according to claim 31 or 32, wherein a set of at least one suspended data radio bearer is associated with said suspended radio resource control connection, wherein said at least one bearer non-re-establishment includes that no one of said at least one suspended data radio bearer or only a subset of said at least one suspended data radio bearer less than said set of said at least one suspended data radio bearer is re-established.

34. The apparatus according to claim 33, wherein said at least one predetermined criterion signifies that no one of said at least one suspended data radio bearer or only said subset of said at least one suspended data radio bearer less than said set of said at least one suspended data radio bearer is re-established.

35. The apparatus according to claim 33, wherein said at least one predetermined criterion signifies that admission control for a source of said radio resource connection resumption request has failed, wherein a case that said admission control for a source of said radio resource connection resumption request has failed is deemed as that no one of said at least one suspended data radio bearer is re-established.

36. The apparatus according to claim 33, wherein a set of at least one service type each corresponding to a specific suspended data radio bearer of said at least one suspended data radio bearer is associated with said suspended radio resource control connection, and said at least one predetermined criterion signifies that no one of said at least one service type or only a subset of said at least one service type less than said set of said at least one service type is admitted, wherein in a case that no one of said at least one service type is admitted, no one of said at least one suspended data radio bearer is re-established, and in a case that only said subset of said at least one service type less than said set of said at least one service type is admitted, only said subset of said at least one suspended data radio bearer corresponding to said admitted at least one service type is re-established.

37. The apparatus according to any of claims 33 to 36, further comprising transmitting circuitry configured to transmit, if said at least one predetermined criterion indicative of said at least one bearer non-re establishment is fulfilled, an initial uplink radio resource control message indicative of that said at least one predetermined criterion indicative of said at least one bearer non-re-establishment is fulfilled towards a base station central unit.

38. The apparatus according to claim 37, wherein if no one of said at least one suspended data radio bearer is re established, said initial uplink radio resource control message includes a first information element indicating that no one of said at least one suspended data radio bearer is re-established and a second information element indicative of each of said at least one suspended data radio bearer.

39. The apparatus according to claim 37, wherein if only said subset of said at least one suspended data radio bearer less than said set of said at least one suspended data radio bearer is re established, said initial uplink radio resource control message includes a first information element indicating that only said subset of said at least one suspended data radio bearer less than said set of said at least one suspended data radio bearer is re-established, a second information element indicative of each of said at least one suspended data radio bearer not being in said subset of said at least one suspended data radio bearer, and a third information element (CellGroupConfig) used to configure a master cell group.

40. The apparatus according to any of claims 37 to 39, wherein said initial uplink radio resource control message is a layer 3 message transmitted over an FI interface.

41. The apparatus according to any of claims 31 to 40, wherein a set of at least one suspended signaling radio bearer is associated with said suspended radio resource control connection, wherein in a case of said at least one bearer non-re-establishment, at least one suspended signaling radio bearer of said set of at least one suspended signaling radio bearer is re-established.

42. The apparatus according to any of claims 31 to 41, wherein the apparatus is operable as or at a base station distributed unit of a cellular system, and/or the apparatus is operable in at least one of a LTE, a LTE-A, and a 5G cellular system.

43. An apparatus comprising receiving circuitry configured to receive an initial uplink radio resource control message from a base station distributed unit, and verifying circuitry configured to verify whether said initial uplink radio resource control message is indicative of at least one bearer non-re establishment in relation to resumption of a suspended radio resource control connection.

44. The apparatus according to claim 43, wherein a set of at least one suspended data radio bearer is associated with said suspended radio resource control connection, wherein said at least one bearer non-re-establishment includes that no one of said at least one suspended data radio bearer or only a subset of said at least one suspended data radio bearer less than said set of said at least one suspended data radio bearer is re-established.

45. The apparatus according to claim 44, wherein if no one of said at least one suspended data radio bearer is re established, said initial uplink radio resource control message includes a first information element indicating that no one of said at least one suspended data radio bearer is re-established and a second information element indicative of each of said at least one suspended data radio bearer.

46. The apparatus according to claim 44, wherein if only said subset of said at least one suspended data radio bearer less than said set of said at least one suspended data radio bearer is re established, said initial uplink radio resource control message includes a first information element indicating that only said subset of said at least one suspended data radio bearer less than said set of said at least one suspended data radio bearer is re-established, a second information element indicative of each of said at least one suspended data radio bearer not being in said subset of said at least one suspended data radio bearer, and a third information element (CellGroupConfig) used to configure a master cell group.

47. The apparatus according to claim 45 or 46, further comprising checking circuitry configured to check whether said initial uplink radio resource control message includes said first information element indicating that no one of said at least one suspended data radio bearer is re-established or indicating that only said subset of said at least one suspended data radio bearer less than said set of said at least one suspended data radio bearer is re-established.

48. The apparatus according to claim 47, further comprising notifying circuitry configured to notify, if said initial uplink radio resource control message includes said first information element indicating that no one of said at least one suspended data radio bearer is re-established or indicating that only said subset of said at least one suspended data radio bearer less than said set of said at least one suspended data radio bearer is re-established, an access and mobility management function to release quality of service flows corresponding to suspended data radio bearers indicated by said second information element.

49. The apparatus according to claim 47 or 48, further comprising selecting circuitry configured to select candidate suspended data radio bearers from suspended data radio bearers indicated by said second information element, and controlling circuitry configured to control attempting to re-establish connections to said candidate suspended data radio bearers.

50. The apparatus according to any of claims 43 to 49, wherein said initial uplink radio resource control message is a layer 3 message transmitted over an FI interface.

51. The apparatus according to any of claims 43 to 50, wherein a set of at least one suspended signaling radio bearer is associated with said suspended radio resource control connection, wherein in a case of said at least one bearer non-re-establishment, at least one suspended signaling radio bearer of said set of at least one suspended signaling radio bearer is re-established.

52. The apparatus according to any of claims 43 to 51, wherein the apparatus is operable as or at a base station central unit of a cellular system, and/or the apparatus is operable in at least one of a LTE, a LTE-A, and a 5G cellular system.

53. An apparatus comprising at least one processor, at least one memory including computer program code, and at least one interface configured for communication with at least another apparatus, the at least one processor, with the at least one memory and the computer program code, being configured to cause the apparatus to perform: detecting necessity for resumption of a suspended radio resource control connection, determining whether a predetermined condition for announcement of a predetermined urgency indicator in relation to said resumption of said suspended radio resource control connection is fulfilled, and transmitting a radio resource connection resumption request for said resumption of said suspended radio resource control connection, wherein if said predetermined condition is fulfilled, said radio resource connection resumption request includes said predetermined urgency indicator.

54. The apparatus according to claim 53, wherein said radio resource connection resumption request is a request for transition from a radio resource control inactive state to a radio resource control connected state.

55. The apparatus according to claim 53 or 54, wherein said predetermined urgency indicator is indicative of at least one of an emergency call and a high priority call.

56. An apparatus comprising at least one processor, at least one memory including computer program code, and at least one interface configured for communication with at least another apparatus, the at least one processor, with the at least one memory and the computer program code, being configured to cause the apparatus to perform: receiving a radio resource connection resumption request for resumption of a suspended radio resource control connection, analyzing whether said radio resource connection resumption request includes a predetermined urgency indicator in relation to said resumption of said suspended radio resource control connection, and checking, if said radio resource connection resumption request includes said predetermined urgency indicator, whether at least one predetermined criterion indicative of at least one bearer non-re-establishment is fulfilled.

57. The apparatus according to claim 56, wherein the at least one processor, with the at least one memory and the computer program code, being further configured to cause the apparatus to perform : controlling, if said at least one predetermined criterion indicative of said at least one bearer non-re-establishment is fulfilled, continuation of processing for said resumption of a suspended radio resource control connection.

58. The apparatus according to claim 56 or 57, wherein a set of at least one suspended data radio bearer is associated with said suspended radio resource control connection, wherein said at least one bearer non-re-establishment includes that no one of said at least one suspended data radio bearer or only a subset of said at least one suspended data radio bearer less than said set of said at least one suspended data radio bearer is re-established.

59. The apparatus according to claim 58, wherein said at least one predetermined criterion signifies that no one of said at least one suspended data radio bearer or only said subset of said at least one suspended data radio bearer less than said set of said at least one suspended data radio bearer is re-established.

60. The apparatus according to claim 58, wherein said at least one predetermined criterion signifies that admission control for a source of said radio resource connection resumption request has failed, wherein a case that said admission control for a source of said radio resource connection resumption request has failed is deemed as that no one of said at least one suspended data radio bearer is re-established.

61. The apparatus according to claim 58, wherein a set of at least one service type each corresponding to a specific suspended data radio bearer of said at least one suspended data radio bearer is associated with said suspended radio resource control connection, and said at least one predetermined criterion signifies that no one of said at least one service type or only a subset of said at least one service type less than said set of said at least one service type is admitted, wherein in a case that no one of said at least one service type is admitted, no one of said at least one suspended data radio bearer is re-established, and in a case that only said subset of said at least one service type less than said set of said at least one service type is admitted, only said subset of said at least one suspended data radio bearer corresponding to said admitted at least one service type is re-established.

62. The apparatus according to any of claims 58 to 61, wherein the at least one processor, with the at least one memory and the computer program code, being further configured to cause the apparatus to perform : transmitting, if said at least one predetermined criterion indicative of said at least one bearer non-re-establishment is fulfilled, an initial uplink radio resource control message indicative of that said at least one predetermined criterion indicative of said at least one bearer non-re-establishment is fulfilled towards a base station central unit.

63. The apparatus according to claim 62, wherein if no one of said at least one suspended data radio bearer is re established, said initial uplink radio resource control message includes a first information element indicating that no one of said at least one suspended data radio bearer is re-established and a second information element indicative of each of said at least one suspended data radio bearer.

64. The apparatus according to claim 62, wherein if only said subset of said at least one suspended data radio bearer less than said set of said at least one suspended data radio bearer is re established, said initial uplink radio resource control message includes a first information element indicating that only said subset of said at least one suspended data radio bearer less than said set of said at least one suspended data radio bearer is re-established, a second information element indicative of each of said at least one suspended data radio bearer not being in said subset of said at least one suspended data radio bearer, and a third information element (CellGroupConfig) used to configure a master cell group.

65. The apparatus according to any of claims 62 to 64, wherein said initial uplink radio resource control message is a layer 3 message transmitted over an FI interface.

66. The apparatus according to any of claims 56 to 65, wherein a set of at least one suspended signaling radio bearer is associated with said suspended radio resource control connection, wherein in a case of said at least one bearer non-re-establishment, at least one suspended signaling radio bearer of said set of at least one suspended signaling radio bearer is re-established.

67. An apparatus comprising at least one processor, at least one memory including computer program code, and at least one interface configured for communication with at least another apparatus, the at least one processor, with the at least one memory and the computer program code, being configured to cause the apparatus to perform: receiving an initial uplink radio resource control message from a base station distributed unit, and verifying whether said initial uplink radio resource control message is indicative of at least one bearer non-re-establishment in relation to resumption of a suspended radio resource control connection.

68. The apparatus according to claim 67, wherein a set of at least one suspended data radio bearer is associated with said suspended radio resource control connection, wherein said at least one bearer non-re-establishment includes that no one of said at least one suspended data radio bearer or only a subset of said at least one suspended data radio bearer less than said set of said at least one suspended data radio bearer is re-established.

69. The apparatus according to claim 68, wherein if no one of said at least one suspended data radio bearer is re established, said initial uplink radio resource control message includes a first information element indicating that no one of said at least one suspended data radio bearer is re-established and a second information element indicative of each of said at least one suspended data radio bearer.

70. The apparatus according to claim 68, wherein if only said subset of said at least one suspended data radio bearer less than said set of said at least one suspended data radio bearer is re established, said initial uplink radio resource control message includes a first information element indicating that only said subset of said at least one suspended data radio bearer less than said set of said at least one suspended data radio bearer is re-established, a second information element indicative of each of said at least one suspended data radio bearer not being in said subset of said at least one suspended data radio bearer, and a third information element (CellGroupConfig) used to configure a master cell group.

71. The apparatus according to claim 69 or 70, wherein in relation to said verifying, the at least one processor, with the at least one memory and the computer program code, being further configured to cause the apparatus to perform: checking whether said initial uplink radio resource control message includes said first information element indicating that no one of said at least one suspended data radio bearer is re-established or indicating that only said subset of said at least one suspended data radio bearer less than said set of said at least one suspended data radio bearer is re-established.

72. The apparatus according to claim 71, wherein the at least one processor, with the at least one memory and the computer program code, being further configured to cause the apparatus to perform : notifying, if said initial uplink radio resource control message includes said first information element indicating that no one of said at least one suspended data radio bearer is re-established or indicating that only said subset of said at least one suspended data radio bearer less than said set of said at least one suspended data radio bearer is re-established, an access and mobility management function to release quality of service flows corresponding to suspended data radio bearers indicated by said second information element.

73. The apparatus according to claim 71 or 72, wherein the at least one processor, with the at least one memory and the computer program code, being further configured to cause the apparatus to perform : selecting candidate suspended data radio bearers from suspended data radio bearers indicated by said second information element, and controlling attempting to re-establish connections to said candidate data radio suspended bearers.

74. The apparatus according to any of claims 67 to 73, wherein said initial uplink radio resource control message is a layer 3 message transmitted over an FI interface.

75. The apparatus according to any of claims 67 to 74, wherein a set of at least one suspended signaling radio bearer is associated with said suspended radio resource control connection, wherein in a case of said at least one bearer non-re-establishment, at least one suspended signaling radio bearer of said set of at least one suspended signaling radio bearer is re-established.

76. A computer program product comprising computer-executable computer program code which, when the program is run on a computer, is configured to cause the computer to carry out the method according to any one of claims 1 to 4, 5 to 16 or 17 to 26.

77. The computer program product according to claim 76, wherein the computer program product comprises a computer-readable medium on which the computer-executable computer program code is stored, and/or wherein the program is directly loadable into an internal memory of the computer or a processor thereof.