WO2022049084A1

WO2022049084A1 - Technique for controlling radio access provided by cells of a radio access network

Info

Publication number: WO2022049084A1
Application number: PCT/EP2021/074050
Authority: WO
Inventors: Bartosz NAWROT; Demia DELLA PENDA
Original assignee: Telefonaktiebolaget Lm Ericsson (Publ)
Priority date: 2020-09-04
Filing date: 2021-08-31
Publication date: 2022-03-10

Abstract

A technique for controlling radio access provided by cells of a radio access network, RAN (500), to radio devices (802) is described. As to a method aspect of the technique, the method (300) comprises or initiates a step of selectively sending (304), depending on an overload status of a first cell (100) of the RAN (500), a message (502) to at least one second cell (200) in the RAN (500). The at least one second cell (200) is a neighbor cell of the first cell (100). The message (502) comprises blocking information configured to trigger the at least one second cell (200) to refrain from sending, to the first cell (100), a request for providing radio access to at least one of the radio devices (802).

Description

TECHNIQUE FOR CONTROLLING RADIO ACCESS PROVIDED BY CELLS OF A RADIO ACCESS NETWORK

Technical Field

The present disclosure relates to radio access provided by cells of a radio access network (RAN). More specifically, and without limitation, methods and devices for controlling radio access provided by cells of the RAN to radio devices are provided.

Background

Cellular radio communication systems, such as Fourth Generation Long Term Evolution (4G LTE) and Fifth Generation New Radio (5G NR) specified by the Third Generation Partnership Project (3GPP), are designed to offer significantly higher data rates, higher system throughput, and lower latency for delay critical services. This improved performance has to be provided and guaranteed under various mobility conditions. Hence, handover (HO) and dual connectivity (DC) are of high importance.

HO procedures continuously assign ongoing radio access (i.e., radio connections) to radio devices (i.e., user equipments or UEs) from one cell (i.e., a source cell) to another (i.e., a target cell) in order to support mobility of the radio device (also referred to as user mobility).

An access control functionality at the target cell might reject incoming HO requests, depending on a current load status and request type.

Similarly, in the DC between E-UTRAN (i.e., the RAN of LTE) and N R (EUTRAN-N R- DC or EN-DC), the access control functions in the candidate secondary node and relative or associated cell (i.e., the secondary cell) might reject a DC request from a master node. The rejection decision depends on the current load status and request type.

The access control mechanism at the target and secondary nodes continue rejecting incoming HO and DC requests, respectively, as long as the load measurements indicate that there are not enough resources available for admitting a further request of that type.

However, multiple rejections of HO and/or DC requests performed by overloaded cells lead to waste of resources for the processing and signaling involved in the connection procedures that eventually fail.

Additionally, mobility in connected mode and DC procedures are often assisted by radio device measurements (e.g., of the target cell or secondary cell). The network configures the radio device measurements and the radio device performs the measurements by monitoring the strength of the signals (e.g., reference signals) transmitted by both serving and neighbor cells (potential target cells and secondary cells). The radio device reports this information to its serving cell, which then decides whether to trigger the HO or DC procedure, depending on the use case. Too many radio device measurements contribute to battery consumption and potential throughput degradation.

Summary

Accordingly, there is a need for a technique that allows controlling radio access provided by cells of a RAN in case of an overload status of a first cell of the RAN.

As to a first method aspect, a method of controlling radio access is provided. The radio access is provided by cells of a RAN to radio devices. The method comprises or initiates the step of selectively sending, depending on an overload status of a first cell of the RAN, a message to at least one second cell in the RAN. The at least one second cell being a neighbor cell of the first cell. The message comprising blocking information configured to trigger the at least one second cell to refrain from sending, to the first cell, a request for providing radio access to at least one of the radio devices.

In at least some embodiments, by selectively sending the message, depending on the overload status, from the first cell (e.g., a first node) to the at least one second cell (e.g., at least one second node), the first node can indicate its overload status and cause the at least one second cell to refrain from sending a request for providing radio access to at least one of the radio devices. For example, the request that cannot be performed due to the overload status and/or the request that would have been conventionally rejected by the first cell is not sent from the at least one second node to the first node based on the message.

Embodiments can reduce signaling overhead, use radio resources for the signaling more efficiently, and/or avoid processing rejections at the first cell in an overload status. Same or further embodiments may prevent rejections of the request and/or may prevent releases of the at least one radio device.

The first method aspect may be implemented alone or in combination with any one of the claims 1 to 20.

The refraining from sending the message to the first cell may comprise waiting for a backoff time (also referred to as a connection wait time) at the at least one second cell (e.g., a source node) before sending the request. Alternatively or in addition, the refraining from sending the message to the first cell may comprise waiting for a second message indicative of a regular status of the first cell at the at least one second cell (e.g., a source node) before sending the request.

The first cell may also be referred to as a (e.g., temporarily) overloaded cell. Alternatively or in addition, the second cell may also be referred to as a requesting cell.

Herein, "neighbor" and "neighboring" may encompass cells that are "partially or fully overlapping" (e.g., in terms of coverage area). For example, the at least one second cell may be or comprise a micro cell or nano cell within the first cell.

The at least one second cell may encompass one second cell (e.g., referred to as the second cell) or at least two second cells, e.g., a plurality of second cells. Whenever referring to the at least one second cell may encompass referring to one or each of the at least one second cell.

The at least one of the radio devices may encompass one radio device (e.g., referred to as the radio device) or at least two of the radio devices, e.g., a plurality of radio devices. The at least one of the radio devices may be briefly referred to as the at least one radio device. Whenever referring to the at least one radio device may encompass referring to one or each of the at least one radio device.

The blocking information may also be referred to as barring information. Herein, "to refrain from sending the request" (or "to refrain from transmitting the measurement request") may also be referred to as "blocking the request" or "barring the request". The request that is to be refrained (e.g., according to the blocking information) may also be referred to as the blocked request or barred request.

Providing radio access to a radio device may encompass serving the radio device.

Herein, referring to the first and second cells may encompass referring to first and second network nodes providing the radio access in the respective cells.

The message may be sent according to the step of selectively sending the message, if the overload status is determined.

The at least one radio device (e.g., according to the first and/or second method aspect) may be served by or connected to the at least one second cell.

The blocking information (e.g., according to the first and/or second method aspect) may be further configured to trigger the at least one second cell to refrain from transmitting, to the at least one radio device, a measurement request for the first cell.

The blocking information (e.g., according to the first and/or second method aspect) may be indicative of a criterion for the request that is to be refrained. Alternatively or in addition, the blocking information may further be indicative of a criterion for the at least one radio device underlying the request that is to be refrained. Alternatively or in addition, the blocking information may further be indicative of a criterion for a service or application underlying the request that is to be refrained.

The criterion may specify one or more user categories and/or service categories and/or network slices of the RAN. The blocking information (e.g., according to the first and/or second method aspect) may apply to one or more request priorities. Alternatively or in addition, the blocking information may apply to one or more user categories. Alternatively or in addition, the blocking information may apply to one or more service categories. Alternatively or in addition, the blocking information may apply to one or more network slices of the RAN.

The blocking information may apply only to one or more user categories and/or one or more service categories and/or one or more network slices of the RAN.

The overload status of the first cell (e.g., according to the first and/or second aspect) may relate to an overload of the first cell in providing the radio access to radio devices.

The first cell may be overloaded in providing the radio access to radio devices served by or connected to the first cell. Alternatively or in addition, the first cell may be overloaded in processing (e.g., rejecting) radio accesses from radio devices.

The method (e.g., according to the first method aspect) may further comprising or initiating determining the overload status of the first cell.

The message comprising the blocking information may be sent responsive to the determining of the overload status of the first cell (e.g., according to the selectivity in the step of selectively sending the message).

The overload status (e.g., according to the first and/or second method aspect) may be determined for the first cell, if the first cell is using a portion of resources available for providing the radio access in the first cell, the portion being greater than a predefined threshold.

For example, the portion of resources available for providing the radio access in the first cell may be available for (e.g., may be available only for, or exclusively associated with) one or more user categories and/or service categories and/or network slices of the RAN. In other words, the portion of resources and/or the predefined threshold may be specific for the one or more user categories and/or the service categories and/or the network slices of the RAN. The portion being greater than the predefined threshold may correspond to, or may be indicative of, a shortage and/or an overload of the portion of resources (e.g., a partition of resources of the first cell) reserved only for the one or more user categories and/or the service categories and/or the network slices of the RAN. Thus, the blocking information may be applicable only to those one or more user categories and/or service categories and/or network slices of the RAN.

The available resources may be allocated to the first cell for providing the radio access (e.g., at deployment of the cell or by a core network of the RAN).

Alternatively or in addition, the available resources may correspond to a capability of the first cell in providing radio access.

The portion may correspond to a ratio between the used resources and the available resources. The predefined threshold may be 80% to 90% or 95% of the available resources.

The resources (e.g., according to the first and/or second method aspect) may comprise or correspond to a number of radio devices to which the first cell is capable to provide radio access. Alternatively or in addition, the resources may comprise or correspond to radio resources for providing the radio access in the first cell. Alternatively or in addition, the resources may comprise or correspond to processing resources used for providing the radio access in the first cell. Alternatively or in addition, the resources may comprise or correspond to a data throughput or channel capacity of a data link between the first cell and a data network or a core network of the RAN.

The radio resources may comprise radio resources in the time domain, the frequency domain, and/or the spatial domain. The processing resources may comprise computational resources for performing (e.g., any layer of) a radio communication protocol when providing the radio access.

Alternatively or in addition, the processing resources may comprise memory resources for performing (e.g., any layer of) a radio communication protocol when providing the radio access. The available resources may comprise or correspond to at least one of a maximum number of radio devices to which the first cell is capable to provide radio access; radio resources available for providing the radio access in the first cell; processing resources available for providing the radio access in the first cell; and a maximum data throughput or channel capacity of a data link between the first cell and a data network or a core network of the RAN.

The used resources may comprise or correspond to at least one of a number of radio devices to which the first cell is providing radio access; radio resources used for providing the radio access in the first cell; processing resources used for providing the radio access in the first cell; and a data throughput or used channel capacity of a data link between the first cell and a data network or a core network of the RAN.

The first cell (e.g., according to the first and/or second method aspect) may be overloaded in terms of a number of radio devices to which the first cell is providing the radio access.

The message (e.g., according to the first and/or second method aspect) may be sent from the first cell of the RAN.

The message may be sent from a first network node providing the radio access in the first cell.

The method (e.g., according to the first method aspect) may be performed by a first network node providing the radio access in the first cell.

The method may be performed by a first network node providing the radio access in the first cell.

The overload status of the first cell may be an overload status of the first network node. The message comprising the blocking information may be sent if the first network node is overloaded.

The request (e.g., according to the first and/or second method aspect) may be a connection request or the request relates to providing radio access to the at least one radio device served by or connected to the first cell. Based on the message, the at least one second cell may refrain from providing radio access to the at least one radio device.

The request (e.g., according to the first and/or second aspect) may relate to a handover of the at least one radio device. The at least one second cell may be a source cell of the handover and the first cell may be target cell of the handover.

Based on the message, the at least one second cell may refrain from performing or initiating the handover of the at least one radio device from the at least one second cell to the first cell.

Since the blocking information is configured to trigger the at least one second cell to refrain from sending the handover request to the first cell, the at least one second cell refrains from performing or initiating the handover and/or the first cell may also be referred to as a candidate target cell.

The request relates to transmitting reference signals from the at least one second cell to the at least one radio device.

Based on the message, the at least one second cell may refrain from transmitting the reference signals to the at least one radio device.

The request (e.g., according to the first and/or second method aspect) may relate to a dual connectivity of the at least one radio device. The at least one second cell may be a master cell of the dual connectivity or may be in a master cell group of the dual connectivity. The first cell may be a secondary cell of the dual connectivity or is in a secondary cell group of the dual connectivity.

Based on the message, the at least one second cell may refrain from performing or initiating the dual connectivity of the at least one radio device radio involving the first cell.

The request (e.g., according to the first and/or second method aspect) may relate to an E-UTRAN-New Radio-Dual Connectivity (EN-DC). The at least one second cell may be a master cell of the EN-DC or may be in a master cell group of the EN-DC. The first cell may be a secondary cell of the EN-DC or may be in a secondary cell group of the EN-DC. Alternatively or in addition, the "dual connectivity" may encompass carrier aggregation (CA), wherein the at least one of the radio devices is simultaneously connected with the first cell and the second cell of a serving base station.

The at least one second cell may be an evolved Node B (eNB). The first cell may be a next generation Node B (gNB) or an eNB.

The blocking information (e.g., according to the first and/or second method aspect) may be indicative of a cell identifier of the first cell.

The refraining from sending the request (e.g., according to the first and/or second method aspect) may comprise waiting for a backoff time before sending the request.

The blocking information (e.g., according to the first and/or second method aspect) may be indicative of at least one of a blocking probability for the request and a backoff time before sending the request.

As to a second method aspect, a method of controlling radio access is provided. The radio access is provided by cells of a RAN to radio devices. The method comprises or initiates a step of receiving, at a second cell of the RAN, a message that is indicative of an overload status of a first cell of the RAN. The first cell is a neighbor cell of the second cell. The message comprises blocking information configured to trigger the second cell to refrain from sending, to the first cell, a request for providing radio access to at least one of the radio devices.

The second method aspect may be implemented alone or in combination with any one of the claims of the second method aspect.

The second method aspect may further comprise any feature and any step disclosed in the context of the first method aspect, or a feature or step corresponding thereto, e.g., a receiver counterpart to a transmitter feature or step.

The method (e.g., according to the second method aspect) may further comprise or initiate a step of determining if the blocking information applies to the request and selectively sending the request to the first cell depending the determination. The request may be generated or triggered by a layer of a communication protocol, e.g., a non-access stratum (NAS) layer or a radio resource control (RRC) layer or a layer 3 of the communication protocol. The determining step may be performed responsive to the request being generated or triggered.

The message (e.g., according to the second method aspect) may be received from the first cell of the RAN.

The method (e.g., according to the second method aspect) may be performed by a second network node providing the radio access in the second cell.

The method according to the second method aspect may further comprises any of the steps or features of the first method aspect or any step or feature corresponding thereto.

In any aspect, the technique may be implemented as a method of congestion control or access barring or admission control, preferably within the RAN and/or at cell level. Embodiments of the technique may be transparent for the at least one radio device.

The request may relate to dual connectivity, e.g., in Non-Stand-Alone (NSA) scenarios. Alternatively or in addition, the request may relate to a handover.

The first method aspect may be performed by the first cell, e.g., an overloaded network node (e.g., a potential Secondary gNB or a potential target cell).

Depending on the current load situation of the first cell (e.g., the gNB), the first cell (e.g. gNB) sends to the at least one second cell as its one or more neighbor cells (e.g. a neighbor nodes, which may comprise eNBs and/or gNBs) information related to the blocking (i.e., the blocking information in the message).

The blocking information may be indicative of a blocking probability and/or a backoff time (also referred to as blocking time) for the request, e.g., (new or further or future) DC and HO requests.

The blocking information may apply only to specific user categories and/or service categories (e.g., in case of network slicing is supported in a RAN). For example, the second cell may refrain from sending the request (e.g., wait for the backoff time to send the request again) and also any other request of the same user category and/or the same service category arriving within the backoff time. For example, requests (e.g. a handover request) may be blocked for the category "mobile broadband" (MBB) according to the blocking information. Then, a request in the category "voice" may sent. In other words, the blocking information may distinguish user categories and/or service categories (e.g., in case of network slicing is supported in a RAN).

Alternatively or in addition, the blocking information may apply only to specific request priorities, which may be explicitly indicated (e.g., in the blocking information) by the first cell (e.g., the overloaded node) to the at least one second cell (e.g., the neighbor nodes).

The second method aspect may be performed by the at least one second cell, e.g. a requesting network node (e.g., a Master gNB or a source cell).

Requests to which the blocking information are to be applied may be identified by one or a combination of the standardized user indicators and/or service indicators, e.g., Public Land Mobile Network Identifier (PLMN ID), Single-Network Slice Selection Assistance Information (S-NSSAI), Subscriber Profile ID (SPID) or RAT/Frequency Selection Priority (RFSP), QoS Class Identifier (QCI) or 5G QoS Identifier (5QI), allocation and retention priority (ARP).

The blocking information in the message may also be referred to as barring information. The message may also be referred to as blocking information message or barring information message.

Alternatively or in addition, the blocking information (or the blocking information message) may include a Cell Identification (cell-ID or CID) of the first cell or the cells experiencing overload. The request (e.g., further or new connection requests) intended for those cells (e.g., the first cell) may be subject to the blocking actions according to the step of refraining from sending the request.

The blocking information or the blocking information message may be indicative of at least one of a barring factor and a backoff time to use for the request, (e.g., to wait after generation of the request at the second cell or after rejection of the request by the first cell) before sending the request (e.g., a new or further or future request) towards the first cell (e.g., the overloaded cells). The blocking information may be indicative of one or more barring factors. The barring factors may represent the probability that the request (i.e., the connection attempt) would be allowed if the request is sent. The backoff time may be the minimum time to wait before the request (e.g., a new attempt) can be performed (i.e., sent) towards the same cell (i.e., the first cell) after being barred or rejected by the first cell.

The blocking information may be included in a proprietary messages. Alternatively or in addition, the message may be a standardized messages that the first cell (e.g., the overloaded network node, e.g., gNB) sends to the at least one second cell (e.g., neighbor network nodes), e.g., eNBs and/or gNBs, over inter-node interfaces, e.g., X2 and/or Xn interfaces, respectively.

Based on the received blocking information from overloaded neighbor network nodes (e.g., neighbor cells), each requesting network node (e.g., a source node or a master node) shall backoff the request (e.g., HO and DC requests) towards the overloaded neighbor network (e.g., congested cells) accordingly.

Moreover, serving cells shall remove the overloaded cells from the set of cells towards which the UE performs signal strength measurements, to avoid waste of resources and performance degradation at the UE side for UE measurements that are not needed/used.

The first method aspect may be performed at or by the first cell or a first network node providing the radio access in the first cell. The second method aspect may be performed at or by the at least one second cell or a second network node providing the radio access in the at least one second cell.

In any aspect, the first cell, the first network node, the at least one second cell, and/or the second network node may form, or may be part of, the RAN, e.g., according to the Third Generation Partnership Project (3GPP) or according to the standard family IEEE 802.11 (Wi-Fi). The first and second method aspects may be performed by one or more embodiments of the first and second cells, respectively, in the RAN. The RAN may comprise one or more network nodes (e.g., base stations), acting or serving the first and second cells. Alternatively or in addition, the RAN may be a vehicular, ad hoc, and/or mesh network comprising the first and second cells. Any of the radio devices may be a 3GPP user equipment (UE) or a Wi-Fi station (STA). The radio device may be a mobile or portable station, a device for machinetype communication (MTC), a device for narrowband Internet of Things (NB-loT) or a combination thereof. Examples for the UE and the mobile station include a mobile phone, a tablet computer and a self-driving vehicle. Examples for the portable station include a laptop computer and a television set. Examples for the MTC device or the NB-loT device include robots, sensors and/or actuators, e.g., in manufacturing, automotive communication and home automation. The MTC device or the NB-loT device may be implemented in a manufacturing plant, household appliances and consumer electronics.

Any of the radio devices may be wirelessly connected or connectable (e.g., according to a radio resource control, RRC, state or active mode) with any of the first and second cells. For example, in the overload status of the first cell, the radio device may be wirelessly connected only to the at least one second cell.

Herein, any cell may encompass a network node (e.g., a base station). Any network node may encompass a station that is configured to provide radio access to any of the radio devices. The base stations may also be referred to as transmission and reception point (TRP), radio access node or access point (AP). The base station or one of the radio devices functioning as a gateway (e.g., between the radio network and the RAN and/or the Internet) may provide a data link to a host computer providing the user data.

Examples for the network nodes may include a 3G base station or Node B, 4G base station or eNodeB, a 5G base station or gNodeB, a Wi-Fi AP and a network controller (e.g., according to Bluetooth, ZigBee or Z-Wave).

The RAN may be implemented according to the Global System for Mobile Communications (GSM), the Universal Mobile Telecommunications System (UMTS), 3GPP Long Term Evolution (LTE) and/or 3GPP New Radio (NR).

The technique may be implemented in accordance with a 3GPP specification, e.g., for 3GPP release 16 or 17. Particularly, the technique may be implemented in accordance with, or by enhancing, at least one of the 3GPP document TS 22.261 (e.g., on Service requirements for the 5G system), version 17.3.0; the 3GPP document TS 23.501 (e.g., on System architecture for the 5G System), version 16.5.1; the 3GPP document TS 38.331 (e.g., on NR; Radio Resource Control (RRC)), version 16.1.0; the 3GPP document TS 38.423 (e.g., on NG-RAN; Xn Application Protocol (XnAP)), version 16.2.0; the 3GPP document TS 36.331 (e.g., on E-UTRA; Radio Resource Control (RRC)), version 16.1.1; and the 3GPP document TS 36.423 (e.g., on E-UTRAN; X2 Application Protocol (X2AP)), version 16.2.0. Alternatively or in addition, the message comprising the blocking information may be sent at the first cell and received at the at least one second cell according to an amendment of the Xn interface or XnAP specified in the 3GPP document TS 38.423 (on NG-RAN; XnAP) and/or an amendment of the X2 interface or X2AP specified in the 3GPP document TS 36.423 (on E-UTRAN; X2AP).

Any aspect of the technique may be implemented on a Physical Layer (PHY), a Medium Access Control (MAC) layer, a Radio Link Control (RLC) layer and/or a Radio Resource Control (RRC) layer of a protocol stack for the radio communication and/or a non-access stratum (NAS) layer (e.g., in a core network connected to the RAN).

As to another aspect, a computer program product is provided. The computer program product comprises program code portions for performing any one of the steps of the first and/or second method aspect disclosed herein when the computer program product is executed by one or more computing devices. The computer program product may be stored on a computer-readable recording medium. The computer program product may also be provided for download, e.g., via the radio network, the RAN, the Internet and/or the host computer.

Alternatively, or in addition, the method may be encoded in a Field-Programmable Gate Array (FPGA) and/or an Application-Specific Integrated Circuit (ASIC), or the functionality may be provided for download by means of a hardware description language.

First device aspects may be provided or implemented alone or in combination with any one of the claims 27 to 32. Furthermore, any of the first device aspects may be provided or implemented alone or in combination with any one of the embodiments described hereinbelow.

The device may be configured to perform any one of the steps of the first method aspect. As to a first device aspect, a device for controlling radio access is provided. The radio access is provided by cells of a RAN to radio devices. The device comprises memory operable to store instructions and processing circuitry operable to execute the instructions, such that the device is operable to selectively send, depending on an overload status of a first cell of the RAN, a message to at least one second cell in the RAN. The at least one second cell is a neighbor cell of the first cell. The message comprises blocking information configured to trigger the at least one second cell to refrain from sending, to the first cell, a request for providing radio access to at least one of the radio devices.

The device according to the first device aspect may be further operable to perform any of the steps of the first method aspect.

As to a further first device aspect, a device for controlling radio access is provided. The radio access is provided by cells of a RAN to radio devices. The device is configured to selectively send, depending on an overload status of a first cell of the RAN, a message to at least one second cell in the RAN. The at least one second cell is a neighbor cell of the first cell. The message comprises blocking information configured to trigger the at least one second cell to refrain from sending, to the first cell, a request for providing radio access to at least one of the radio devices.

The device according to the further first device aspect may be further configured to perform any of the steps of the first method aspect.

As to a still further first device aspect, a network node for controlling radio access is provided. The radio access is provided by cells of a RAN to radio devices. The network node is configured to communicate with a UE and comprises a radio interface and processing circuitry configured to selectively send, depending on an overload status of a first cell of the RAN, a message to at least one second cell in the RAN. The at least one second cell is a neighbor cell of the first cell. The message comprises blocking information configured to trigger the at least one second cell to refrain from sending, to the first cell, a request for providing radio access to at least one of the radio devices.

The processing circuitry according to the still further first device aspect may be further configured to execute any of the steps of the first method aspect. Second device aspects may be provided or implemented alone or in combination with any one of the claims 33 to 38. Furthermore, each of the second device aspects may be provided or implemented alone or in combination with any one of the embodiments described hereinbelow.

The device may be configured to perform any one of the steps of the second method aspect.

As to a second device aspect, a device for controlling radio access is provided. The radio access is provided by cells of a RAN to radio devices. The device comprises memory operable to store instructions and processing circuitry operable to execute the instructions, such that the device is operable to receive, at a second cell of the RAN, a message that is indicative of an overload status of a first cell of the RAN. The first cell is a neighbor cell of the second cell. The message comprises blocking information configured to trigger the second cell to refrain from sending, to the first cell, a request for providing radio access to at least one of the radio devices.

The device according to the second device aspect may be further operable to execute any of the steps of the second method aspect.

As to a further second device aspect, a device for controlling radio access is provided. The radio access is provided by cells of a RAN to radio devices. The device is configured to receive, at a second cell of the RAN, a message that is indicative of an overload status of a first cell of the RAN. The first cell is a neighbor cell of the second cell. The message comprises blocking information configured to trigger the second cell to refrain from sending, to the first cell, a request for providing radio access to at least one of the radio devices.

The device according to the further second device aspect may be further configured to perform any of the steps of the second method aspect. As to a still further second device aspect, a network node for controlling radio access is provided. The radio access is provided by cells of a RAN to radio devices. The network node is configured to communicate with a UE and comprises a radio interface and processing circuitry configured to receive, at a second cell of the RAN, a message that is indicative of an overload status of a first cell of the RAN. The first cell is a neighbor cell of the second cell. The message comprises blocking information configured to trigger the second cell to refrain from sending, to the first cell, a request for providing radio access to at least one of the radio devices.

The processing circuitry according to the still further second device aspect may be further configured to execute any of the steps of the second method aspect.

As to another device aspect, a communication system including a host computer is provided. The host computer comprising processing circuitry configured to provide user data. The host computer further comprises a communication interface configured to forward user data to a RAN for transmission to a UE. The RAN further comprises network nodes. The network nodes are configured to communicate with the UE and to execute any of the steps of the first method aspect and/or the second method aspect.

The communication system may further include the UE. The UE may comprise a radio interface and processing circuitry. Alternatively, or in addition, the cellular network may further include one or more base stations (i.e., cells or network nodes) configured for radio communication with the UE and/or to provide a data link between the UE and the host computer using the first and/or second method aspects.

The RAN may comprise a first network node comprising processing circuitry configured to execute the any of the steps of the first method aspect. The RAN may further comprise a second network node comprising processing circuitry configured to execute any of the steps of the second method aspect.

The processing circuitry of the host computer may be configured to execute a host application, thereby providing the user data and/or any host computer functionality described herein. Alternatively, or in addition, the processing circuitry of the UE may be configured to execute a client application associated with the host application. Any one of the devices, the first cell, the at least one second cell, the first network node (e.g., a base station), the at least one second network node, the communication system or any node or station for embodying the technique may further include any feature disclosed in the context of the method aspects, and vice versa. Particularly, any one of the units and modules disclosed herein may be configured to perform or initiate one or more of the steps of the method aspects.

Brief Description of the Drawings

Further details of embodiments of the technique are described with reference to the enclosed drawings, wherein:

Fig. 1 shows a schematic block diagram of an embodiment of a device for controlling radio access provided by cells of a RAN, which may be embodied by an overloaded network node;

Fig. 2 shows a schematic block diagram of an embodiment of a device for controlling radio access provided by cells of a RAN, which may be embodied by a requesting network node;

Fig. 3 shows a flowchart for an implementation of a method of controlling radio access provided by cells of a RAN, which method may be implementable by the device of Fig. 1;

Fig. 4 shows a flowchart for an implementation of a method of controlling radio access provided by cells of a RAN, which method may be implementable by the device of Fig. 2;

Fig. 5 schematically illustrates an exemplary RAN for implementing the devices of Figs. 1 and 2;

Fig. 6 schematically illustrates an exemplary signaling diagram resulting from embodiments of the devices of Figs. 1 and 2 in signaling communication;

Fig. 7 shows a flowchart for an implementation of a determining step of the method of Fig. 4; Fig. 8 schematically illustrates an exemplary signaling diagram resulting from embodiments of the device of Fig. 2 and a radio device in radio communication;

Fig. 9 shows a schematic block diagram of an overloaded cell or overloaded network node embodying the device of Fig. 1;

Fig. 10 shows a schematic block diagram of a requesting cell or requesting network node embodying the device of Fig. 2;

Fig. 11 schematically illustrates an example telecommunication network connected via an intermediate network to a host computer;

Fig. 12 shows a generalized block diagram of a host computer communicating via a base station or radio device functioning as a gateway with a user equipment over a partially wireless connection; and

Figs. 13 and 14 show flowcharts for methods implemented in a communication system including a host computer, a base station or radio device functioning as a gateway and a user equipment.

Detailed Description

In the following description, for purposes of explanation and not limitation, specific details are set forth, such as a specific network environment in order to provide a thorough understanding of the technique disclosed herein. It will be apparent to one skilled in the art that the technique may be practiced in other embodiments that depart from these specific details. Moreover, while the following embodiments are primarily described for a New Radio (NR) or 5G implementation, it is readily apparent that the technique described herein may also be implemented for any other radio communication technique, including 3GPP LTE (e.g., LTE-Advanced or a related radio access technique such as MulteFire), a Wireless Local Area Network (WLAN) implementation according to the standard family IEEE 802.11, for Bluetooth according to the Bluetooth Special Interest Group (SIG), particularly Bluetooth Low Energy, Bluetooth Mesh Networking and Bluetooth broadcasting, for Z-Wave according to the Z-Wave Alliance or for ZigBee based on IEEE 802.15.4. Moreover, those skilled in the art will appreciate that the functions, steps, units and modules explained herein may be implemented using software functioning in conjunction with a programmed microprocessor, an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA), a Digital Signal Processor (DSP) or a general purpose computer, e.g., including an Advanced RISC Machine (ARM). It will also be appreciated that, while the following embodiments are primarily described in context with methods and devices, the invention may also be embodied in a computer program product as well as in a system comprising at least one computer processor and memory coupled to the at least one processor, wherein the memory is encoded with one or more programs that may perform the functions and steps or implement the units and modules disclosed herein.

Fig. 1 schematically illustrates a block diagram of an embodiment of a device for controlling radio access provided by cells of a radio access network (RAN) to radio devices. The device is generically referred to by reference sign 100.

The device 100 comprises a message sending unit 104 that, depending on an overload status of a first cell of the RAN, selectively sends a message to at least one second cell in the RAN, the at least one second cell being a neighbor cell of the first cell, the message comprising blocking information configured to trigger the at least one second cell to refrain from sending, to the first cell, a request for providing radio access to at least one of the radio devices.

Optionally, the device 100 comprises a determining unit 102 that determines the overload status of the first cell, e.g., that determines if a load status of the first cell is the overload status.

The device 100 may also be referred to as, or may be embodied by, the first cell or a first network node. The first cell 100 and the second cell may be in direct wired or radio (e.g., microwave) communication, e.g., a backhaul link. The second cell station may be embodied by the device 200.

Fig. 2 schematically illustrates a block diagram of an embodiment of a device for controlling radio access provided by cells of a radio access network (RAN) to radio devices. The device is generically referred to by reference sign 200. The device 200 comprises a message receiving unit 202 that receives, at a second cell of the RAN, a message that is indicative of an overload status of a first cell of the RAN, the first cell being a neighbor cell of the second cell, the message comprising blocking information configured to trigger the second cell to refrain from sending, to the first cell, a request for providing radio access to at least one of the radio devices.

Optionally, the device 200 comprises a determining unit 204 that determines if the blocking information applies to the request (e.g., the request pending at the second cell) and that selectively sends the request to the first cell depending the determination. For example, the request is sent if the determination yields that the blocking information does not apply to the request. Otherwise, the second cell refrains from sent the request, if the determination yields that the blocking information applies to the request, which may comprise that the second cell waits for the blocking time before the request is sent.

The device 200 may also be referred to as, or may be embodied by, the second cell or the second network node. The second cell 200 and the first cell 100 may be in direct wired or radio (e.g., microwave) communication, e.g., via a backhaul link.

Fig. 3 shows an example flowchart for a method 300 according to the first method aspect.

The method 300 may be performed by the device 100. For example, the modules 102 and 104 may perform the steps 302 and 304, respectively.

Fig. 4 shows an example flowchart for a method 400 according to the second method aspect.

The method 400 may be performed by the device 200. For example, the modules 202 and 204 may perform the steps 402 and 404, respectively.

In any aspect, first cell 100 and second cell 200 may be a network node (e.g., a base station). Herein, any radio device may be a mobile or portable station and/or any radio device wirelessly connectable to a base station or RAN, or to another radio device. For example, the radio device may be a user equipment (UE), a device for machine-type communication (MTC) or a device for (e.g., narrowband) Internet of Things (loT). Two or more radio devices may be configured to wirelessly connect to each other, e.g., in an ad hoc radio network or via a 3GPP SL connection. Furthermore, any base station may be a station providing radio access, may be part of a radio access network (RAN) and/or may be a node connected to the RAN for controlling the radio access. For example, the base station may be an access point, for example a Wi-Fi access point.

The technique may be implemented as an extension of the Unified Access Control (UAC) mechanism, to be used in overloaded scenarios (i.e., when the firs cell 100 is in the overload status) to protect the stability of congested cells (e.g., the first cell) and congested network nodes (i.e., the first network node). While the UAC blocks incoming requests to overloaded cells directly at the UEs, the present technique may block the request (e.g., an incoming HO and DC connection request) directly at the cells (e.g., eNBs and gNBs), that is within the RAN.

By means of the message exchanged in the steps 304 and 402, the technique is the capability of sharing an accessibility level information (e.g., in the blocking information) for different types of requests among the neighbor nodes. The technique may further comprise evaluating this accessibility information (e.g., the blocking information), which may take into account both the RAN current load state and/or a prediction for the near future, optionally as well as a configured differentiation between user categories and/or service categories used in access control.

Fig. 5 schematically illustrates an exemplary RAN 500 comprising embodiments of the first cell 100 and the second cell 200. By performing the methods 300 and 400, respectively, the message 502 is exchanged. The message 502 may be exchanged via the Xn or X2 interface between the first and second cells.

The blocking information may be indicative of at least one of: a cell ID of the first cell 100, a cell ID of the second cell 200, a PLMN ID of the RAN or the first cell 100 or the second cell 200, a quality of service required by a service or an application underlying or causing the request, and admission and retention priority (ARP), one or more barring factors, and one or more backoff times.

When a gNB 100 experiences overload and cannot accept more incoming connection requests from certain user/service categories, the gNB 100 informs the neighbor nodes 200 by means of the message 502. This is done by sending the neighbor nodes 200 the blocking information either via proprietary messages 502, or over the standardized Xn interface or X2 interface for other gNBs 200 and eNBs 200, respectively.

This message 502 indicates the user and service categories for which HO and DC connections attempts towards the overloaded cells shall back-off according to the barring factor and backoff time. The barring factors represents the probability that the connection attempt would be allowed, while the backoff time is the minimum time to wait before a new attempt can be performed after being barred.

Fig. 6 schematically illustrates an exemplary signaling diagram resulting from embodiments of the first cell 100 and the second cell 200 in signaling communication.

The first aspect of the technique (e.g., the units 102 and 104) may be implemented at the access control function of the first cell 100 (e.g., the gNB 100). The second aspect of the technique (e.g., the units 202 and 204) may be implemented at the access control function of the second cell 100 (e.g., the eNB or gNB 200).

When a request is available (e.g., generated or received) or pending at the second cell 200 (e.g., in a certain protocol layer of the second network node 200), the, depending on the result of the determination 404, the request is sent directly to the first cell 100 at reference sign 602, if the blocking information does not apply to the request. Otherwise, e.g., as illustrated at reference sign 604, the second cell 200 refrains sending the request, e.g., by waiting for the backoff time.

The backoff time may start when the request becomes available at the second cell 200 or when the request has been sent to the first cell 100 and rejected by the first cell 100. The backoff time may end when the request is sent to the first cell 100.

The blocking information may comprise Access Control parameters. The message 502 comprising the blocking information is exchanged, e.g., between a source node 200 of the RAN 500 and a target node 100 of the RAN via message 502 comprising blocking information, e.g., delivered over X2 or Xn interfaces. Alternatively or in addition, the message 502 may be a proprietary message or a (e.g., future) standardized message.

In an implementation of the determining step 404, when at the source node 200 (e.g., eNB or gNB) there is an indication of handover or dual-connectivity procedure for the at least one radio device (e.g., a UE), the radio device is classified based on its subscription and/or services type, and the possibility to perform the dual connectivity or handover request towards a given cell (i.e., the first cell) is evaluated against the Access Control information (i.e., the blocking information) received from target node (i.e., the first cell) in the message 502.

Alternatively or in addition, Fig. 7 shows a flowchart for an implementation of a determining step 404 of the method 400. In a substep 702 of the step 404, the (e.g., pending) request is classified based on subscription parameters and/or services of the UE underlying the request. In a substep 704 of the step 404, it is determined whether the blocking information applies to the (e.g., pending) request, e.g., by evaluating a blocking condition for the request.

If the request is not blocked (i.e., the blocking information does not apply to the request), the request is sent at reference sign 602. Otherwise, the second cell 200 refrains from sending the request to the first cell 100, e.g., by waiting for the backoff time as indicted at reference sign 604.

The Access Control algorithm 300 and 400 may be implemented as an enhancement and/or similarly to the algorithm evaluated by the UE 802 in case of standardized Unified Access Control procedure 800, which is illustrated in Fig. 8. Based on a classification of the UE 802, an appropriate set of barring factor and backoff time are used to indicate the probability of admission of the UE 802 on target node 200 and based on the decision procedure at the UE, the connection requests can be sent or hold for the time interval indicated in the backoff time.

A main difference as compared to the standardized Unified Access Control procedure, e.g., according to the 3GPP document TS 38.331, version 16.1.0, may be that in the methods 300 and 400, it is the second cell 200 (e.g., a source node) to perform a barring evaluation for the (e.g., pending) request (e.g., a new DC or HO request), instead of the UE 802 for a new connection requests. This may be implemented by exchanging the different message 502 to be exchanged between the involved entities. In standardized Unified Access Control, the barring information is sent to the UE 802 over the RRC System Information Block type 1 (SI Bl) message. The methods 300 and 400 may be implemented by sending the blocking (or barring) information to the neighbor eNBs and/or gNBs 200 in an X2 message or an Xn message as the message 502.

Fig. 8 shows the standardized Unified Access Control procedure 800. In the SIB1 message, the RAN 500 delivers barring information to the UE 802, and the UE 802 is responsible for evaluating barring conditions according to a standardized procedure (e.g., according to the 3GPP document TS 38.331, version 16.1.0).

The technique covers the case when not the UE 802 but the at least one second cell 200 (e.g., another network node of the RAN, e.g., an eNB or gNB) is responsible to decide in the step 404 if the second cell 200 can send the request (case 602), e.g., start handover or dual-connectivity procedure towards the target node 100. Optionally, the determining step 404 comprises determining if it is probable enough (i.e., the barring probability is below a predefined threshold) that the request (i.e., the requested procedure) will be admitted by the first cell 100 (e.g., a target node).

Fig. 9 shows a schematic block diagram for an embodiment of the device 100. The device 100 comprises processing circuitry, e.g., one or more processors 904 for performing the method 300 and memory 906 coupled to the processors 904. For example, the memory 906 may be encoded with instructions that implement at least one of the modules 102 and 104.

The one or more processors 904 may be a combination of one or more of a microprocessor, controller, microcontroller, central processing unit, digital signal processor, application specific integrated circuit, field programmable gate array, or any other suitable computing device, resource, or combination of hardware, microcode and/or encoded logic operable to provide, either alone or in conjunction with other components of the device 100, such as the memory 906, network node functionality or cell functionality. For example, the one or more processors 904 may execute instructions stored in the memory 906. Such functionality may include providing various features and steps discussed herein, including any of the benefits disclosed herein. The expression "the device being operative to perform an action" may denote the device 100 being configured to perform the action. As schematically illustrated in Fig. 9, the device 100 may be embodied by an overloaded cell 900, e.g., an overloaded network node for the first cell. The first cell 900 or first network node 900 comprises a radio interface 902 coupled to the device 100 for wired or radio (e.g., microwave) communication with one or more second cells, e.g., second network nodes.

Fig. 10 shows a schematic block diagram for an embodiment of the device 200. The device 200 comprises processing circuitry, e.g., one or more processors 1004 for performing the method 400 and memory 1006 coupled to the processors 1004.

For example, the memory 1006 may be encoded with instructions that implement at least one of the modules 202 and 204.

The one or more processors 1004 may be a combination of one or more of a microprocessor, controller, microcontroller, central processing unit, digital signal processor, application specific integrated circuit, field programmable gate array, or any other suitable computing device, resource, or combination of hardware, microcode and/or encoded logic operable to provide, either alone or in conjunction with other components of the device 100, such as the memory 1006, network node functionality or cell functionality. For example, the one or more processors 1004 may execute instructions stored in the memory 1006. Such functionality may include providing various features and steps discussed herein, including any of the benefits disclosed herein. The expression "the device being operative to perform an action" may denote the device 200 being configured to perform the action.

As schematically illustrated in Fig. 10, the device 200 may be embodied by a requesting cell 1000, e.g., a requesting network node for the second cell. The second cell 1000 or second network node 1000 comprises a radio interface 1002 coupled to the device 200 for wired or radio (e.g., microwave) communication with the first cell, e.g., the first network node.

With reference to Fig. 11, in accordance with an embodiment, a communication system 1100 includes a telecommunication network 1110, such as a 3GPP-type cellular network, which comprises an access network 1111, such as a radio access network, and a core network 1114. The access network 1111 comprises a plurality of base stations 1112a, 1112b, 1112c, such as NBs, eNBs, gNBs or other types of wireless access points, each defining a corresponding coverage area 1113a, 1113b, 1113c. Each base station 1112a, 1112b, 1112c is connectable to the core network 1114 over a wired or wireless connection 1115. A first user equipment (UE) 1191 located in coverage area 1113c is configured to wirelessly connect to, or be paged by, the corresponding base station 1112c. A second UE 1192 in coverage area 1113a is wirelessly connectable to the corresponding base station 1112a. While a plurality of UEs 1191, 1192 are illustrated in this example, the disclosed embodiments are equally applicable to a situation where a sole UE is in the coverage area or where a sole UE is connecting to the corresponding base station 1112.

Any of the base stations 1112 and the UEs 1191, 1192 may embody the device 100.

The telecommunication network 1110 is itself connected to a host computer 1130, which may be embodied in the hardware and/or software of a standalone server, a cloud-implemented server, a distributed server or as processing resources in a server farm. The host computer 1130 may be under the ownership or control of a service provider, or may be operated by the service provider or on behalf of the service provider. The connections 1121, 1122 between the telecommunication network 1110 and the host computer 1130 may extend directly from the core network 1114 to the host computer 1130 or may go via an optional intermediate network 1120. The intermediate network 1120 may be one of, or a combination of more than one of, a public, private or hosted network; the intermediate network 1120, if any, may be a backbone network or the Internet; in particular, the intermediate network 1120 may comprise two or more sub-networks (not shown).

The communication system 1100 of Fig. 11 as a whole enables connectivity between one of the connected UEs 1191, 1192 and the host computer 1130. The connectivity may be described as an over-the-top (OTT) connection 1150. The host computer 1130 and the connected UEs 1191, 1192 are configured to communicate data and/or signaling via the OTT connection 1150, using the access network 1111, the core network 1114, any intermediate network 1120 and possible further infrastructure (not shown) as intermediaries. The OTT connection 1150 may be transparent in the sense that the participating communication devices through which the OTT connection 1150 passes are unaware of routing of uplink and downlink communications. For example, a base station 1112 need not be informed about the past routing of an incoming downlink communication with data originating from a host computer 1130 to be forwarded (e.g., handed over) to a connected UE 1191. Similarly, the base station 1112 need not be aware of the future routing of an outgoing uplink communication originating from the UE 1191 towards the host computer 1130.

By virtue of the method 100 and/or 200 being performed by any one of the network nodes or cells 1112, the performance or range of the OTT connection 1150 can be improved, e.g., in terms of increased throughput and/or reduced latency. More specifically, the host computer 1130 may indicate to the RAN 500 or the first cell 100 (e.g., on an application layer) a priority or a QoS of the traffic (e.g., of the underlying service or application), which may influence the determination 404.

Example implementations, in accordance with an embodiment of the UE, base station and host computer discussed in the preceding paragraphs, will now be described with reference to Fig. 12. In a communication system 1200, a host computer 1210 comprises hardware 1215 including a communication interface 1216 configured to set up and maintain a wired or wireless connection with an interface of a different communication device of the communication system 1200. The host computer 1210 further comprises processing circuitry 1218, which may have storage and/or processing capabilities. In particular, the processing circuitry 1218 may comprise one or more programmable processors, application-specific integrated circuits, field programmable gate arrays or combinations of these (not shown) adapted to execute instructions. The host computer 1210 further comprises software 1211, which is stored in or accessible by the host computer 1210 and executable by the processing circuitry 1218. The software 1211 includes a host application 1212. The host application 1212 may be operable to provide a service to a remote user, such as a UE 1230 connecting via an OTT connection 1250 terminating at the UE 1230 and the host computer 1210. In providing the service to the remote user, the host application 1212 may provide user data, which is transmitted using the OTT connection 1250. The user data may depend on the location of the UE 1230. The user data may comprise auxiliary information or precision advertisements (also: ads) delivered to the UE 1230. The location may be reported by the UE 1230 to the host computer, e.g., using the OTT connection 1250, and/or by the base station 1220, e.g., using a connection 1260.

The communication system 1200 further includes a base station 1220 provided in a telecommunication system and comprising hardware 1225 enabling it to communicate with the host computer 1210 and with the UE 1230. The hardware 1225 may include a communication interface 1226 for setting up and maintaining a wired or wireless connection with an interface of a different communication device of the communication system 1200, as well as a radio interface 1227 for setting up and maintaining at least a wireless connection 1270 with a UE 1230 located in a coverage area (not shown in Fig. 12) served by the base station 1220. The communication interface 1226 may be configured to facilitate a connection 1260 to the host computer 1210. The connection 1260 may be direct, or it may pass through a core network (not shown in Fig. 12) of the telecommunication system and/or through one or more intermediate networks outside the telecommunication system. In the embodiment shown, the hardware 1225 of the base station 1220 further includes processing circuitry 1228, which may comprise one or more programmable processors, application-specific integrated circuits, field programmable gate arrays or combinations of these (not shown) adapted to execute instructions. The base station 1220 further has software 1221 stored internally or accessible via an external connection.

The communication system 1200 further includes the UE 1230 already referred to. Its hardware 1235 may include a radio interface 1237 configured to set up and maintain a wireless connection 1270 with a base station serving a coverage area in which the UE 1230 is currently located. The hardware 1235 of the UE 1230 further includes processing circuitry 1238, which may comprise one or more programmable processors, application-specific integrated circuits, field programmable gate arrays or combinations of these (not shown) adapted to execute instructions. The UE 1230 further comprises software 1231, which is stored in or accessible by the UE 1230 and executable by the processing circuitry 1238. The software 1231 includes a client application 1232. The client application 1232 may be operable to provide a service to a human or non-human user via the UE 1230, with the support of the host computer 1210. In the host computer 1210, an executing host application 1212 may communicate with the executing client application 1232 via the OTT connection 1250 terminating at the UE 1230 and the host computer 1210. In providing the service to the user, the client application 1232 may receive request data from the host application 1212 and provide user data in response to the request data. The OTT connection 1250 may transfer both the request data and the user data. The client application 1232 may interact with the user to generate the user data that it provides.

It is noted that the host computer 1210, base station 1220 and UE 1230 illustrated in Fig. 12 may be identical to the host computer 1130, one of the base stations 1112a, 1112b, 1112c and one of the UEs 1191, 1192 of Fig. 11, respectively. This is to say, the inner workings of these entities may be as shown in Fig. 12, and, independently, the surrounding network topology may be that of Fig. 11.

In Fig. 12, the OTT connection 1250 has been drawn abstractly to illustrate the communication between the host computer 1210 and the UE 1230 via the base station 1220, without explicit reference to any intermediary devices and the precise routing of messages via these devices. Network infrastructure may determine the routing, which it may be configured to hide from the UE 1230 or from the service provider operating the host computer 1210, or both. While the OTT connection 1250 is active, the network infrastructure may further take decisions by which it dynamically changes the routing (e.g., on the basis of load balancing consideration or reconfiguration of the network).

The wireless connection 1270 between the UE 1230 and the base station 1220 is in accordance with the teachings of the embodiments described throughout this disclosure. One or more of the various embodiments improve the performance of OTT services provided to the UE 1230 using the OTT connection 1250, in which the wireless connection 1270 forms the last segment. More precisely, the teachings of these embodiments may reduce the latency and improve the data rate and thereby provide benefits such as better responsiveness and improved QoS.

A measurement procedure may be provided for the purpose of monitoring data rate, latency, QoS and other factors on which the one or more embodiments improve. There may further be an optional network functionality for reconfiguring the OTT connection 1250 between the host computer 1210 and UE 1230, in response to variations in the measurement results. The measurement procedure and/or the network functionality for reconfiguring the OTT connection 1250 may be implemented in the software 1211 of the host computer 1210 or in the software 1231 of the UE 1230, or both. In embodiments, sensors (not shown) may be deployed in or in association with communication devices through which the OTT connection 1250 passes; the sensors may participate in the measurement procedure by supplying values of the monitored quantities exemplified above, or supplying values of other physical quantities from which software 1211, 1231 may compute or estimate the monitored quantities. The reconfiguring of the OTT connection 1250 may include message format, retransmission settings, preferred routing etc.; the reconfiguring need not affect the base station 1220, and it may be unknown or imperceptible to the base station 1220. Such procedures and functionalities may be known and practiced in the art. In certain embodiments, measurements may involve proprietary UE signaling facilitating the host computer's 1210 measurements of throughput, propagation times, latency and the like. The measurements may be implemented in that the software 1211, 1231 causes messages to be transmitted, in particular empty or "dummy" messages, using the OTT connection 1250 while it monitors propagation times, errors etc.

Fig. 13 is a flowchart illustrating a method implemented in a communication system, in accordance with one embodiment. The communication system includes a host computer, a base station and a UE which may be those described with reference to Figs. 11 and 12. For simplicity of the present disclosure, only drawing references to Fig. 13 will be included in this paragraph. In a first step 1310 of the method, the host computer provides user data. In an optional substep 1311 of the first step 1310, the host computer provides the user data by executing a host application. In a second step 1320, the host computer initiates a transmission carrying the user data to the UE. In an optional third step 1330, the base station transmits to the UE the user data which was carried in the transmission that the host computer initiated, in accordance with the teachings of the embodiments described throughout this disclosure. In an optional fourth step 1340, the UE executes a client application associated with the host application executed by the host computer.

Fig. 14 is a flowchart illustrating a method implemented in a communication system, in accordance with one embodiment. The communication system includes a host computer, a base station and a UE which may be those described with reference to Figs. 11 and 12. For simplicity of the present disclosure, only drawing references to Fig. 14 will be included in this paragraph. In a first step 1410 of the method, the host computer provides user data. In an optional substep (not shown) the host computer provides the user data by executing a host application. In a second step 1420, the host computer initiates a transmission carrying the user data to the UE. The transmission may pass via the base station, in accordance with the teachings of the embodiments described throughout this disclosure. In an optional third step 1430, the UE receives the user data carried in the transmission.

As has become apparent from above description, embodiments of the technique can decrease the occurrence of unsuccessful connection attempts, which leads to an optimized resource utilization, e.g., on both UE side and RAN side. When neighbor cells (e.g., the first cell and the at least one second cell) share their accessibility level for different types of requests, the network (e.g., the RAN) can more efficiently steer the traffic within the area (e.g., an area covered by both the first cell and the second cell), e.g., improving the load balancing between the cells (e.g., between the network nodes).

Moreover, the UEs may benefit from not performing measurements towards cells (i.e., embodiments of the first cell) that are not able to receive more requests. This can translate in less battery consumption and potential throughput degradation.

Many advantages of the present invention will be fully understood from the foregoing description, and it will be apparent that various changes may be made in the form, construction and arrangement of the units and devices without departing from the scope of the invention and/or without sacrificing all of its advantages. Since the invention can be varied in many ways, it will be recognized that the invention should be limited only by the scope of the following claims.

Claims

33 Claims

1. A method (300) of controlling radio access provided by cells of a radio access network, RAN (500), to radio devices (802), the method (300) comprising or initiating: depending on an overload status of a first cell (100) of the RAN (500), selectively sending (304) a message (502) to at least one second cell (200) in the RAN (500), the at least one second cell (200) being a neighbor cell of the first cell (100), the message (502) comprising blocking information configured to trigger the at least one second cell (200) to refrain from sending, to the first cell (100), a request for providing radio access to at least one of the radio devices (802).

2. The method (300) of embodiment 1, wherein the at least one radio device (802) is served by or connected to the at least one second cell (200).

3. The method (300) of claim 1 or 2, wherein the blocking information is further configured to trigger the at least one second cell (200) to refrain from transmitting, to the at least one radio device (802), a measurement request for the first cell (100).

4. The method (300) of any one of claims 1 to 3, wherein the blocking information is indicative of at least one of: a criterion for the request that is to be refrained; a criterion for the at least one radio device (802) underlying the request that is to be refrained; and a criterion for a service or application underlying the request that is to be refrained.

5. The method (300) of any one of claims 1 to 4, wherein the blocking information applies to at least one of: one or more request priorities; one or more user categories; one or more service categories; one or more network slices of the RAN (500); and 34 requests identified by one or a combination of Public Land Mobile Network Identifier, PLMN ID; Single-Network Slice Selection Assistance Information, S- NSSAI; Subscriber Profile ID, SPID; RAT/Frequency Selection Priority, RFSP; QoS Class Identifier, QCI; or 5G QoS Identifier, 5QI; allocation and retention priority, ARP.

6. The method (300) of any one of claims 1 to 5, wherein the overload status of the first cell (100) relates to an overload of the first cell (100) in providing the radio access to radio devices (802).

7. The method (300) of any one of claims 1 to 6, further comprising or initiating: determining (302) the overload status of the first cell (100).

8. The method (300) of any one of claims 1 to 7, wherein the overload status is determined for the first cell (100), if the first cell (100) is using a portion of resources available for providing the radio access in the first cell (100), the portion being greater than a predefined threshold.

9. The method (300) of claim 8, wherein the resources comprise or correspond to at least one of: a number of radio devices (802) to which the first cell (100) is capable to provide radio access; radio resources for providing the radio access in the first cell (100); processing resources used for providing the radio access in the first cell (100); and a data throughput or channel capacity of a data link between the first cell (100) and a data network or a core network of the RAN (500).

10. The method (300) of any one of claims 1 to 9, wherein the first cell (100) is overloaded in terms of a number of radio devices (802) to which the first cell (100) is providing the radio access.

11. The method (300) of any one of claims 1 to 10, wherein the message (502) is sent from the first cell (100) of the RAN (500).

12. The method (300) of any one of claims 1 to 11, wherein the method (300) is performed by a first network node providing the radio access in the first cell (100).

13. The method (300) of any one of claims 1 to 12, wherein the request is a connection request or the request relates to providing radio access to the at least one radio device (802) served by or connected to the first cell (100).

14. The method (300) of any one of claims 1 to 13, wherein the request relates to a handover of the at least one radio device (802), wherein the at least one second cell (200) is a source cell of the handover and the first cell (100) is target cell of the handover.

15. The method (300) of any one of claims 1 to 14, wherein the request relates to transmitting reference signals from the at least one second cell (200) to the at least one radio device (802).

16. The method (300) of any one of claims 1 to 15, wherein the request relates to a dual connectivity of the at least one radio device (802), wherein the at least one second cell (200) is a master cell of the dual connectivity or is in a master cell group of the dual connectivity, and the first cell (100) is a secondary cell of the dual connectivity or is in a secondary cell group of the dual connectivity.

17. The method (300) of any one of claims 1 to 16, wherein the request relates to an E-UTRAN-New Radio-Dual Connectivity, EN-DC, wherein the at least one second cell (200) is a master cell of the EN-DC or is in a master cell group of the EN- DC, and the first cell (100) is a secondary cell of the EN-DC or is in a secondary cell group of the EN-DC.

18. The method (300) of any one of claims 1 to 17, wherein the blocking information is indicative of a cell identifier of the first cell (100).

19. The method (300) of any one of claims 1 to 18, wherein refraining from sending the request comprises waiting for a backoff time before sending the request.

20. The method (300) of any one of claims 1 to 19, wherein the blocking information is indicative of at least one of a blocking probability for the request and a backoff time before sending the request.

21. A method (400) of controlling radio access provided by cells of a radio access network, RAN (500), to radio devices (802), the method (400) comprising or initiating: receiving (402), at a second cell (200) of the RAN (500), a message (502) that is indicative of an overload status of a first cell (100) of the RAN (500), the first cell (100) being a neighbor cell of the second cell (200), the message (502) comprising blocking information configured to trigger the second cell (200) to refrain from sending, to the first cell (100), a request for providing radio access to at least one of the radio devices (802).

22. The method (400) of claim 21, further comprising or initiating: determining (404) if the blocking information applies to the request and selectively sending the request to the first cell (100) depending the determination.

23. The method (400) of claim 21 or 22, wherein the message is received from the first cell (100) of the RAN (500).

24. The method (400) of any one of claims 21 to 23, wherein the method (400) is performed by a second network node providing the radio access in the second cell (200).

25. The method of any one of claims 21 to 24, further comprising the steps or features of any one of claims 2 to 20 or any step or feature corresponding thereto.

26. A computer program product comprising program code portions for performing the steps of any one of the claims 1 to 20, 21 to 25 when the computer program product is executed on one or more computing devices (904; 1004), optionally stored on a computer-readable recording medium (906; 1006).

27. A device (100; 900; 1112; 1220) for controlling radio access provided by cells of a radio access network, RAN (500), to radio devices (802), the device (100; 900; 1112; 1220) comprising memory operable to store instructions and processing circuitry operable to execute the instructions, such that the radio device (100; 900; 1112; 1220) is operable to: 37 depending on an overload status of a first cell (100; 900; 1112; 1220) of the RAN (500), selectively send a message (502) to at least one second cell (200) in the RAN (500), the at least one second cell (200) being a neighbor cell of the first cell (100), the message (502) comprising blocking information configured to trigger the at least one second cell (200) to refrain from sending, to the first cell (100; 900; 1112; 1220), a request for providing radio access to at least one of the radio devices (802).

28. The device (100; 900; 1112; 1220) of claim 23, further operable to perform the steps of any one of claims 2 to 20.

29. A device (100; 900; 1112; 1220) for controlling radio access provided by cells of a radio access network, RAN (500), to radio devices (802), the device (100; 900; 1112; 1220) being configured to: depending on an overload status of a first cell (100; 900; 1112; 1220) of the RAN (500), selectively send a message (502) to at least one second cell (200) in the RAN (500), the at least one second cell (200) being a neighbor cell of the first cell (100), the message (502) comprising blocking information configured to trigger the at least one second cell (200) to refrain from sending, to the first cell (100; 900; 1112; 1220), a request for providing radio access to at least one of the radio devices (802).

30. The device (100; 900; 1112; 1220) of claim 29, further configured to perform the steps of any one of claims 2 to 20.

31. A network node (100; 900; 1112; 1220) for controlling radio access provided by cells of a radio access network, RAN (500), to radio devices (802), the network node (100; 900; 1112; 1220) being configured to communicate with a UE (802) and comprising a radio interface (902; 1227) and processing circuitry (904; 1228) configured to: depending on an overload status of a first cell (100; 900; 1112; 1220) of the RAN (500), selectively send a message (502) to at least one second cell (200) in the RAN (500), the at least one second cell (200) being a neighbor cell of the first cell (100), the message (502) comprising blocking information configured to trigger the at least one second cell (200) to refrain from sending, to the first cell (100; 900; 1112; 1220), a request for providing radio access to at least one of the radio devices (802). 38

32. The network node (100; 900; 1112; 1220) of claim 31, wherein the processing circuitry (904; 1228) is further configured to execute the steps of any one of claims 2 to 20.

33. A device (200; 1000; 1112; 1220) for controlling radio access provided by cells of a radio access network, RAN (500), to radio devices (802), the device (200; 1000; 1112; 1220) comprising memory operable to store instructions and processing circuitry operable to execute the instructions, such that the radio device (200; 1000; 1112; 1220) is operable to: receive (402), at a second cell (200) of the RAN (500), a message (502) that is indicative of an overload status of a first cell (100) of the RAN (500), the first cell (100) being a neighbor cell of the second cell (200), the message (502) comprising blocking information configured to trigger the second cell (200) to refrain from sending, to the first cell (100), a request for providing radio access to at least one of the radio devices (802).

34. The device (200; 1000; 1112; 1220) of claim 33, further operable to perform the steps of any one of claims 22 to 25.

35. A device (200; 1000; 1112; 1220) for controlling radio access provided by cells of a radio access network, RAN (500), to radio devices (802), the device (200; 1000; 1112; 1220) being configured to: receive (402), at a second cell (200) of the RAN (500), a message (502) that is indicative of an overload status of a first cell (100) of the RAN (500), the first cell (100) being a neighbor cell of the second cell (200), the message (502) comprising blocking information configured to trigger the second cell (200) to refrain from sending, to the first cell (100), a request for providing radio access to at least one of the radio devices (802).

36. The device (200; 1000; 1112; 1220) of claim 35, further configured to perform the steps of any one of claims 22 to 25.

37. A network node (200; 1000; 1112; 1220) for controlling radio access provided by cells of a radio access network, RAN (500), to radio devices (802), the network node (200; 1000; 1112; 1220) being configured to communicate with a UE (802) and comprising a radio interface (1002; 1227) and processing circuitry (1004; 1228) configured to: 39 receive (402), at a second cell (200) of the RAN (500), a message (502) that is indicative of an overload status of a first cell (100) of the RAN (500), the first cell (100) being a neighbor cell of the second cell (200), the message (502) comprising blocking information configured to trigger the second cell (200) to refrain from sending, to the first cell (100), a request for providing radio access to at least one of the radio devices (802).

38. The network node (200; 1000; 1112; 1220) of claim 37, wherein the processing circuitry (904; 1228) is further configured to execute the steps of any one of claims 22 to 25.

39. A communication system (1100; 1200) including a host computer (1130; 1210) comprising: processing circuitry (1218) configured to provide user data; and a communication interface (1216) configured to forward user data to a RAN (500; 1110) for transmission to a user equipment, UE, (802; 1191; 1192; 1230), wherein the RAN (500; 1110) further comprises network nodes (100; 200; 900; 1000; 1112; 1220), which are configured to communicate with the UE (100; 1100; 1391; 1392; 1430) and to execute the steps of any one of claims 1 to 20 or the steps of any one of claims 21 to 25.

40. The communication system (1100; 1200) of claim 39, further including the UE (802; 1191; 1192; 1230), wherein the UE (802; 1191; 1192; 1230) comprises a radio interface (1237) and processing circuitry (1238), the processing circuitry (1238) of the UE (802; 1191; 1192; 1230).

41. The communication system (1100; 1200) of claim 39 or 40, wherein the RAN (500; 1110) comprises a first network node (100; 900; 1112; 1220) comprising processing circuitry (904; 1228) configured to execute the steps of any one of claims 1 to 20 and a second network node (200; 1000; 1112; 1220) comprising processing circuitry (1004; 1228) configured to execute the steps of any one of claims 21 to 25.

42. The communication system (1100; 1200) of any one of claims 39 to 41, wherein: the processing circuitry (1218) of the host computer (1130; 1210) is configured to execute a host application (1212), thereby providing the user data; and 40 the processing circuitry (1238) of the UE (802; 1191; 1192; 1230) is configured to execute a client application (1232) associated with the host application (1212).