WO2022111787A1

WO2022111787A1 - Method, apparatus and computer program

Info

Publication number: WO2022111787A1
Application number: PCT/EP2020/083133
Authority: WO
Inventors: Pilar ANDRÉS MALDONADO; Kari Juhani NIEMELÄ; Devaki Chandramouli; Troels Emil Kolding
Original assignee: Nokia Technologies Oy
Priority date: 2020-11-24
Filing date: 2020-11-24
Publication date: 2022-06-02

Abstract

There is provided an apparatus comprising means for: receiving, at an access node from a network entity, configuration information; responsive to the configuration information, providing a clock value associated with the access node to the at least one further access node of a group of at least two access nodes; receiving, from the at least one further access node, respective further clock values associated with each at least one further access node in the group; determining whether the clock value matches a reference value within a timing accuracy requirement based on the received further clock values; and providing, to a network entity, information indicating whether the clock value associated with at least one of the access nodes matches the reference value within the timing accuracy requirement.

Description

METHOD, APPARATUS AND COMPUTER PROGRAM

FIELD

The present application relates to a method, apparatus, and computer program and in particular but not exclusively to determining whether a clock value matches a reference value.

BACKGROUND

A communication system can be seen as a facility that enables communication sessions between two or more entities such as user terminals, base stations and/or other nodes by providing carriers between the various entities involved in the communications path. A communication system can be provided for example by means of a communication network and one or more compatible communication devices. The communication sessions may comprise, for example, communication of data for carrying communications such as voice, video, electronic mail (email), text message, multimedia and/or content data and so on. Non limiting examples of services provided comprise two-way or multi-way calls, data communication or multimedia services and access to a data network system, such as the Internet.

In a wireless communication system at least a part of a communication session between at least two stations occurs over a wireless link. Examples of wireless systems comprise public land mobile networks (PLMN), satellite based communication systems and different wireless local networks, for example wireless local area networks (WLAN). Some wireless systems can be divided into cells, and are therefore often referred to as cellular systems.

A user can access the communication system by means of an appropriate communication device or terminal. A communication device of a user may be referred to as user equipment (UE) or user device. A communication device is provided with an appropriate signal receiving and transmitting apparatus for enabling communications, for example enabling access to a communication network or communications directly with other users. The communication device may access a carrier provided by a station, for example a base station of a cell, and transmit and/or receive communications on the carrier.

The communication system and associated devices typically operate in accordance with a given standard or specification which sets out what the various entities associated with the system are permitted to do and how that should be achieved. Communication protocols and/or parameters which shall be used for the connection are also typically defined. One example of a communications system is UTRAN (3G radio). Other examples of communication systems are the long-term evolution (LTE) of the Universal Mobile Telecommunications System (UMTS) radio-access technology and so-called 5G or New Radio (NR) networks. NR is being standardized by the 3rd Generation Partnership Project (3GPP).

SUMMARY

According to an aspect, there is provided an apparatus comprising means for: receiving, at an access node from a network entity, configuration information; responsive to the configuration information, providing a clock value associated with the access node to the at least one further access node of a group of at least two access nodes; receiving, from the at least one further access node, respective further clock values associated with each at least one further access node in the group; determining whether the clock value matches a reference value within a timing accuracy requirement based on the received further clock values; and providing, to a network entity, information indicating whether the clock value associated with at least one of the access nodes matches the reference value within the timing accuracy requirement.

The means may be for: receiving a signal comprising the reference value; and synchronizing the clock value to the reference value.

The means may be for: determining an average clock value based on the clock value and the received further clock values.

The configuration information may comprise information indicating at least one of: a periodicity for the access node to provide the clock value; the timing accuracy requirement; group member information; and the method to use to provide the clock value.

The means for determining whether the clock value matches a reference value within a timing accuracy requirement may comprise means for: comparing the clock value to the received respective further clock values.

The means may be for at least one of: determining that the clock value does not match the reference value when a result of the comparing indicates that the clock value differs from the received respective further clock values by more than the timing accuracy requirement; and determining that the clock value matches the reference value when the result of the comparing indicates that the clock value differs from the received respective further clock values by less than the timing accuracy requirement. At least one of the access node and at least one of the at least one further access node may be a gNB.

The reference value may be a universal time clock value.

According to an aspect, there is provided an apparatus comprising means for: providing, to a plurality of access nodes in a group, configuration information for causing the access nodes to share respective clock values with the other access nodes in the group; and receiving, from at least one of the access nodes in the group, information indicating whether the clock value associated with the at least one of the access nodes matches a reference value within a timing accuracy requirement.

At least one of the two access nodes may comprise a gNB.

The means may be for: determining the group comprising the at least two access nodes.

The means for determining the group may comprise means for determining the group based on at least one of: a tracking area; a capability of the at least two access nodes; a class of the at least two access nodes; a location of the at least two access nodes; a time synchronization service area; a precision timing protocol network configuration between the at least two access nodes and a core network; and a self organizing network capability.

At least one access node within the group may be located at greater than a threshold distance away from the other access nodes within the group.

The configuration information may comprise information indicating at least one of: a periodicity for the at least two access nodes to share their clock value; the timing accuracy requirement; group member information; and the method to use to provide the clock value.

The means may be for: determining a change in the timing accuracy requirement for at least one of the at least two access nodes; and transmitting the configuration information responsive to determining the change in timing accuracy. According to an aspect, there is provided an apparatus comprising at least one processor and at least one memory including a computer program code, the at least one memory and computer program code configured to, with the at least one processor, cause the apparatus at least to: receive, at an access node from a network entity, configuration information; responsive to the configuration information, provide a clock value associated with the access node to the at least one further access node of a group of at least two access nodes; receive, from the at least one further access node, respective further clock values associated with each at least one further access node in the group; determine whether the clock value matches a reference value within a timing accuracy requirement based on the received further clock values; and provide, to a network entity, information indicating whether the clock value associated with at least one of the access nodes matches the reference value within the timing accuracy requirement.

The at least one memory and at least one processor may be configured to cause the apparatus to: receive a signal comprising the reference value; and synchronize the clock value to the reference value.

The at least one memory and at least one processor may be configured to cause the apparatus to: determine an average clock value based on the clock value and the received further clock values.

The at least one memory and at least one processor may be configured to cause the apparatus to: compare the clock value to the received respective further clock values.

The at least one memory and at least one processor may be configured to cause the apparatus to perform at least one of: determining that the clock value does not match the reference value when a result of the comparing indicates that the clock value differs from the received respective further clock values by more than the timing accuracy requirement; and determining that the clock value matches the reference value when the result of the comparing indicates that the clock value differs from the received respective further clock values by less than the timing accuracy requirement. At least one of the access node and at least one of the at least one further access node may be a gNB.

The reference value may be a universal time clock value.

According to an aspect, there is provided an apparatus comprising at least one processor and at least one memory including a computer program code, the at least one memory and computer program code configured to, with the at least one processor, cause the apparatus at least to: provide, to a plurality of access nodes in a group, configuration information for causing the access nodes to share respective clock values with the other access nodes in the group; and receive, from at least one of the access nodes in the group, information indicating whether the clock value associated with the at least one of the access nodes matches a reference value within a timing accuracy requirement.

At least one of the two access nodes may comprise a gNB.

The at least one memory and at least one processor may be configured to cause the apparatus to: determine the group comprising the at least two access nodes.

The at least one memory and at least one processor may be configured to cause the apparatus to determine the group based on at least one of: a tracking area; a capability of the at least two access nodes; a class of the at least two access nodes; a location of the at least two access nodes; a time synchronization service area; a precision timing protocol network configuration between the at least two access nodes and a core network; and a self organizing network capability.

The at least one memory and at least one processor may be configured to cause the apparatus to: determine a change in the timing accuracy requirement for at least one of the at least two access nodes; and transmitting the configuration information responsive to determining the change in timing accuracy. According to an aspect, there is provided a method comprising: receiving, at an access node from a network entity, configuration information; responsive to the configuration information, providing a clock value associated with the access node to the at least one further access node of a group of at least two access nodes; receiving, from the at least one further access node, respective further clock values associated with each at least one further access node in the group; determining whether the clock value matches a reference value within a timing accuracy requirement based on the received further clock values; and providing, to a network entity, information indicating whether the clock value associated with at least one of the access nodes matches the reference value within the timing accuracy requirement.

The method may comprise: receiving a signal comprising the reference value; and synchronizing the clock value to the reference value.

The method may comprise: determining an average clock value based on the clock value and the received further clock values.

Determining whether the clock value matches a reference value within a timing accuracy requirement may comprise: comparing the clock value to the received respective further clock values.

The method may comprise at least one of: determining that the clock value does not match the reference value when a result of the comparing indicates that the clock value differs from the received respective further clock values by more than the timing accuracy requirement; and determining that the clock value matches the reference value when the result of the comparing indicates that the clock value differs from the received respective further clock values by less than the timing accuracy requirement.

At least one of the access node and at least one of the at least one further access node may be a gNB.

The reference value may be a universal time clock value. According to an aspect, there is provided a method comprising: providing, to a plurality of access nodes in a group, configuration information for causing the access nodes to share respective clock values with the other access nodes in the group; and receiving, from at least one of the access nodes in the group, information indicating whether the clock value associated with the at least one of the access nodes matches a reference value within a timing accuracy requirement.

At least one of the two access nodes may comprise a gNB.

The method may comprise: determining the group comprising the at least two access nodes.

Determining the group may comprise determining the group based on at least one of: a tracking area; a capability of the at least two access nodes; a class of the at least two access nodes; a location of the at least two access nodes; a time synchronization service area; a precision timing protocol network configuration between the at least two access nodes and a core network; and a self organizing network capability.

The method may comprise: determining a change in the timing accuracy requirement for at least one of the at least two access nodes; and transmitting the configuration information responsive to determining the change in timing accuracy.

According to an aspect, there is provided a computer readable medium comprising program instructions for causing an apparatus to perform at least the following: receiving, at an access node from a network entity, configuration information; responsive to the configuration information, providing a clock value associated with the access node to the at least one further access node of a group of at least two access nodes; receiving, from the at least one further access node, respective further clock values associated with each at least one further access node in the group; determining whether the clock value matches a reference value within a timing accuracy requirement based on the received further clock values; and providing, to a network entity, information indicating whether the clock value associated with at least one of the access nodes matches the reference value within the timing accuracy requirement.

According to an aspect, there is provided a computer readable medium comprising program instructions for causing an apparatus to perform at least the following: providing, to a plurality of access nodes in a group, configuration information for causing the access nodes to share respective clock values with the other access nodes in the group; and receiving, from at least one of the access nodes in the group, information indicating whether the clock value associated with the at least one of the access nodes matches a reference value within a timing accuracy requirement.

The apparatus may be caused to perform: receiving a signal comprising the reference value; and synchronizing the clock value to the reference value.

The apparatus may be caused to perform: determining an average clock value based on the clock value and the received further clock values.

The apparatus may be caused to perform at least one of: determining that the clock value does not match the reference value when a result of the comparing indicates that the clock value differs from the received respective further clock values by more than the timing accuracy requirement; and determining that the clock value matches the reference value when the result of the comparing indicates that the clock value differs from the received respective further clock values by less than the timing accuracy requirement.

The reference value may be a universal time clock value. According to an aspect, there is provided a computer readable medium comprising program instructions for causing an apparatus to perform at least the following: providing, to a plurality of access nodes in a group, configuration information for causing the access nodes to share respective clock values with the other access nodes in the group; and receiving, from at least one of the access nodes in the group, information indicating whether the clock value associated with the at least one of the access nodes matches a reference value within a timing accuracy requirement.

At least one of the two access nodes may comprise a gNB.

The apparatus may be caused to perform: determining the group comprising the at least two access nodes.

The apparatus may be caused to perform: determining a change in the timing accuracy requirement for at least one of the at least two access nodes; and transmitting the configuration information responsive to determining the change in timing accuracy.

According to an aspect, there is provided a non-transitory computer readable medium comprising program instructions for causing an apparatus to perform at least the method according to any of the preceding aspects.

In the above, many different embodiments have been described. It should be appreciated that further embodiments may be provided by the combination of any two or more of the embodiments described above. DESCRIPTION OF FIGURES

Embodiments will now be described, by way of example only, with reference to the accompanying Figures in which:

Figure 1 shows a representation of a network system according to some example embodiments;

Figure 2 shows a representation of a control apparatus according to some example embodiments;

Figure 3 shows a representation of an apparatus according to some example embodiments;

Figures 4A and 4B show an example method; and Figure 5 shows an example method.

DETAILED DESCRIPTION

In the following certain embodiments are explained with reference to mobile communication devices capable of communication via a wireless cellular system and mobile communication systems serving such mobile communication devices. Before explaining in detail the exemplifying embodiments, certain general principles of a wireless communication system, access systems thereof, and mobile communication devices are briefly explained with reference to Figures 1, 2 and 3 to assist in understanding the technology underlying the described examples.

Figure 1 shows a schematic representation of a 5G system (5GS). The 5GS may be comprised by a terminal or user equipment (UE), a 5G radio access network (5GRAN) or next generation radio access network (NG-RAN), a 5G core network (5GC), one or more application function (AF) and one or more data networks (DN).

The 5G-RAN may comprise one or more gNodeB (GNB) or one or more gNodeB (GNB) distributed unit functions connected to one or more gNodeB (GNB) centralized unit functions. The 5GC may comprise the following entities: Network Slice Selection Function (NSSF); Network Exposure Function; Network Repository Function (NRF); Policy Control Function (PCF); Unified Data Management (UDM); Application Function (AF); Authentication Server Function (AUSF); an Access and Mobility Management Function (AMF); and Session Management Function (SMF). Figure 2 illustrates an example of a control apparatus 200 for controlling a function of the 5GRAN or the 5GC as illustrated on Figure 1. The control apparatus may comprise at least one random access memory (RAM) 211a, at least on read only memory (ROM) 211b, at least one processor 212, 213 and an input/output interface 214. The at least one processor 212, 213 may be coupled to the RAM 211a and the ROM 211b. The at least one processor 212, 213 may be configured to execute an appropriate software code 215. The software code 215 may for example allow to perform one or more steps to perform one or more of the present aspects. The software code 215 may be stored in the ROM 211b. The control apparatus 200 may be interconnected with another control apparatus 200 controlling another function of the 5GRAN or the 5GC. In some embodiments, each function of the 5GRAN or the 5GC comprises a control apparatus 200. In alternative embodiments, two or more functions of the 5GRAN or the 5GC may share a control apparatus.

Figure 3 illustrates an example of a terminal 300, such as the terminal illustrated on Figure 1. The terminal 300 may be provided by any device capable of sending and receiving radio signals. Non-limiting examples comprise a user equipment, a mobile station (MS) or mobile device such as a mobile phone or what is known as a ’smart phone’, a computer provided with a wireless interface card or other wireless interface facility (e.g., USB dongle), a personal data assistant (PDA) or a tablet provided with wireless communication capabilities, a machine-type communications (MTC) device, an Internet of things (loT) type communication device or any combinations of these or the like. The terminal 300 may provide, for example, communication of data for carrying communications. The communications may be one or more of voice, electronic mail (email), text message, multimedia, data, machine data and so on.

The terminal 300 may receive signals over an air or radio interface 307 via appropriate apparatus for receiving and may transmit signals via appropriate apparatus for transmitting radio signals. In Figure 3 transceiver apparatus is designated schematically by block 306. The transceiver apparatus 306 may be provided for example by means of a radio part and associated antenna arrangement. The antenna arrangement may be arranged internally or externally to the mobile device.

The terminal 300 may be provided with at least one processor 301, at least one memory ROM 302a, at least one RAM 302b and other possible components 303 for use in software and hardware aided execution of tasks it is designed to perform, including control of access to and communications with access systems and other communication devices. The at least one processor 301 is coupled to the RAM 311a and the ROM 311b. The at least one processor 301 may be configured to execute an appropriate software code 308. The software code 308 may for example allow to perform one or more of the present aspects. The software code 308 may be stored in the ROM 311b.

The processor, storage and other relevant control apparatus can be provided on an appropriate circuit board and/or in chipsets. This feature is denoted by reference 304. The device may optionally have a user interface such as key pad 305, touch sensitive screen or pad, combinations thereof or the like. Optionally one or more of a display, a speaker and a microphone may be provided depending on the type of the device.

In Release 17 of 5G, a time synchronization framework within the 5G System (5GS) is described. To enable wider and more flexible use of 5GS for time synchronization, the 5GS is evolving to offer time synchronization as a service (i.e. expose time synchronization network capabilities, allow application to influence the time synchronization service, exchange of time sync capabilities between the UEs and the network, etc.).

For Release 18 of 5G, time synchronization in 5GS is progressing to offer Time Resilience as a service.

Several services may be dependent on having on timing provided by global Navigation Satellite System (GNSS). These include telecoms, finance, transportation, power, utility sector, and banking. Smart Grids rely on microsecond level time-stamping accuracy to reliably trouble-shoot and manage the power grid, which may be provided by GNSS. As another example, for financial markets it may be important to record each transaction with an accurate time stamp to comply with regulatory requirements. Also, for the telecommunication industry, the operation of the cellular networks may require the reliable delivery of precision timing signals.

However, if GNSS timing services are unable to be provided, then these services may not be able to be provided. Thus it may be important to support time-synchronization and the ability to act as a backup for GNSS timing services.

Furthermore, GNSS may not be safe enough for mission critical services. GNSS time delivery may experience several vulnerabilities due to environmental phenomena, malicious or incidental interference, spoofing, adjacent band interference, etc.

GNSS spoofing may be done gradually and as a result may not be detected easily. Cheap devices may just generate a transient interference, but more expensive devices could do more advance spoofing. Additionally, the distribution of a wrong GNSS time reference not only impacts the offered time synchronization service, it may also impact TDD deployments, advanced 3GPP coordination features such as handover procedures and positioning services.

Some methods for detecting GNSS spoofing include spatial processing of GPS signals using complex receiver arrays. For example, when 4 to 8 GPS signals are received, a spoofing of up to 99% may be achieved. However, such a solution requires complex receiver arrays, and may not be practical to install on a large scale.

There may therefore be a need to reliably detect GNSS spoofing to improve the reliability of GNSS timing services.

Additionally, a further consideration in providing a solution to GNSS spoofing is the concept of holdover. Holdover is the period of time during which the gNB is synchronized to the GNSS time with a given timing accuracy. Some example gNBs may have around a 4-6h holdover capability for a timing accuracy of one microsecond, whereas critical industries may require 24h and even at greater accuracy levels.

Upgrading each gNB to 24h capability may require use of more advanced and expensive oscillators compared to current in-use double oven controlled crystal oscillator (DOCXO) solutions, which may be a very expensive solution, and may therefore be impractical and undesirable.

There may therefore be a need to provide extended holdover capabilities at reasonable cost, including robustness to GNSS spoofing and loss of GNSS signal at a radio site.

Reference is made to Figures 4a and 4b, which show a method according to some examples. Referring to the example of Figure 4a, at step 400, the method may comprise receiving, at an access node from a network entity, configuration information.

At step 402, the method may comprise, responsive to the configuration information, providing a clock value associated with the access node to the at least one further access node of a group of at least two access nodes.

At step 404, the method may comprise receiving, from the at least one further access node, respective further clock values associated with each at least one further access node in the group. At step 406, the method may comprise determining whether the clock value matches a reference value within a timing accuracy requirement based on the received further clock values.

At step 408, the method may comprise providing, to a network entity, information indicating whether the clock value associated with at least one of the access nodes matches the reference value within the timing accuracy requirement.

Referring to the example of Figure 4b, at step 410 the method may comprise providing, to a plurality of access nodes in a group, configuration information for causing the access nodes to share respective clock values with the other access nodes in the group.

At step 412, the method may comprise receiving, from at least one of the access nodes in the group, information indicating whether the clock value associated with the at least one of the access nodes matches a reference value within a timing accuracy requirement.

Reference is made to Figure 5, which shows a method according to some examples.

In the example of Figure 5, a wireless network comprises a first access node 500, a plurality of other access nodes 502, and a 5G core network comprising an AMF 504. In some examples, at least one of the access nodes comprises a gNB.

The first access node 500 and the plurality of other access nodes 502 may each have an internal clock that is used to track time at the access node. The access nodes may receive a reference value. For example, the reference value may be a universal time clock (UTC) value. The reference value may be received via a GNSS signal. The access nodes may synchronize their internal clock value based on the received reference value. In some examples, the reference value may be associated with a timing accuracy requirement. For example, the timing accuracy requirement may be that the access node clock matches the reference value to within 1 microsecond. It should be understood that any suitable timing accuracy requirement may be used.

At 506, the AMF determines a group 501 of access nodes comprising the first access node 500 and at least one of the plurality of other access nodes 502. In the example of Figure 5, there are four access nodes in the determined group - first access node 500 and three other access nodes. It should be understood that in other examples, any number of other access nodes may be part of the determined group.

The AMF may determine the group of access nodes based on at least one of a tracking area (TA), access node capabilities, access node class, and access node location. In some examples, at least one access node within the group may be far away from the other access nodes. That is to say, in some examples at least one access node within the group may be greater than a threshold distance away from the other access nodes within the group. Thus if there is a localized interference causing GNSS signals to not be received at the access nodes, the at least one access node further away may be less likely to suffer from the same interference.

Additionally or alternatively, the AMF may determine the group of access nodes based on a time synchronization service area. In some examples, a time synchronization service area may define an area where all access nodes are served by a same time domain. The time synchronization service area may, for example, be a subset of TA or combination of multiple TAs.

Additionally or alternatively, the AMF may determine the group of access nodes based on existing protocols, such as precision timing protocol (PTP) network configuration between the access nodes and the 5GS.

Additionally or alternatively, the AMF may determine the group of access nodes based on self organizing network (SON) capabilities to exploit for exchanging timing information with other access nodes within the group.

Thus, in some examples, the AMF may determine a group comprising at least two access nodes.

At 508, the AMF configures the access nodes comprised within the determined group. The AMF may configure the access nodes within the group to cause each access node to share the respective access node’s internal clock value with all other access nodes in the group.

The AMF may provide configuration information to the access nodes comprised within the determined group. The configuration information may comprise at least one of the periodicity for the access node to provide the clock value; a timing accuracy requirement; group member information; and a method to use to share the clock value with the other access nodes.

In some examples, the access nodes may be configured to share internal clock values periodically. Additionally or alternatively, the access nodes may be configured to share internal clock values based on a trigger event. The trigger event may, for example, be that a new timing accuracy or timing resilience is configured in a particular area served by one or more of the access nodes. The AMF may configure the access nodes to share internal clock values according to the period and/or the trigger event.

At 510, each access node shares its internal clock value with all other access nodes in the group. Thus, for example, the first access node 500 may share its internal clock with the plurality of other access nodes 502. The first access node 500 may also receive internal clock values associated with the plurality of other access nodes 502.

The AMF may configure the access nodes to share their internal clock values by any suitable means. For example, the access nodes may be configured to share their internal clock values by means of a rotating PTP Grand Master (GM) in the group, inter-access node alignment of subframe number (SFN) etc.

In some examples, if the first access node serves as the backhaul for another access node, then the first access node may receive an internal clock value from the other access node via NR Uu broadcast information.

At 512, the first access node determines whether it is aligned with the reference value within the timing accuracy requirement based on the received internal clock values.

For example, the first access node may compare its internal clock value against the internal clock values received from the other access nodes in the group in order to determine whether there is an error in the first access node’s internal clock. The error may due to for example, GNSS spoofing or random error.

If GNSS signal falls out at the first access node due to signal loss, there may be random clock drift between the access nodes. Additionally or alternatively, if the GNSS signal is spoofed the reference clock value received at an access node may not be correct. In some examples the first access node may determine that its internal clock value differs from the internal clock values of the other nodes by more than a threshold value. The threshold value may be the timing accuracy requirement. Thus, the first access node may determine that the first access node internal clock value is incorrect.

At 514, the first access node reports the result of the determination performed at 512 to the network. For example, the first access node may send information indicating that the internal clock of the first access node is aligned with the reference value within the timing accuracy requirement. Alternatively, the first access node may send information indicating that the internal clock of the first access node is not aligned with the reference value within the timing accuracy requirement.

In some examples, the access nodes in the group of access nodes may determine an average clock value. In some examples, a weighting system may be used to determine the average clock value among the group of access nodes. That is to say, in some examples, a first access node clock value may have a first weighting, and a second access node clock value may have a second weighting different to the first weighting. At least one of the access nodes may be configured to replace its clock value with the average clock value.

Thus some examples may provide a method whereby a plurality of access nodes share clock information. This may allow the group of access nodes to detect and compensate for clock drift. Furthermore, in some examples, an average clock value may be determined. This may result in a reduction in error experienced by one access node due to the averaging of the values. As such, some examples may increase holdover capabilities of the plurality of access nodes within the group.

In some examples, an apparatus is provided. The apparatus may comprise means for receiving, at an access node from a network entity, configuration information; responsive to the configuration information, providing a clock value associated with the access node to the at least one further access node of a group of at least two access nodes; receiving, from the at least one further access node, respective further clock values associated with each at least one further access node in the group; determining whether the clock value matches a reference value within a timing accuracy requirement based on the received further clock values; and providing, to a network entity, information indicating whether the clock value associated with at least one of the access nodes matches the reference value within the timing accuracy requirement.

In some examples, an apparatus is provided. The apparatus may comprise means for providing, to a plurality of access nodes in a group, configuration information for causing the access nodes to share respective clock values with the other access nodes in the group; and receiving, from at least one of the access nodes in the group, information indicating whether the clock value associated with the at least one of the access nodes matches a reference value within a timing accuracy requirement.

In some examples, the apparatus comprises at least one processor and at least one memory including a computer program code, the at least one memory and computer program code configured to, with the at least one processor, cause the apparatus at least to: receive, at an access node from a network entity, configuration information; responsive to the configuration information, provide a clock value associated with the access node to the at least one further access node of a group of at least two access nodes; receive, from the at least one further access node, respective further clock values associated with each at least one further access node in the group; determine whether the clock value matches a reference value within a timing accuracy requirement based on the received further clock values; and provide, to a network entity, information indicating whether the clock value associated with at least one of the access nodes matches the reference value within the timing accuracy requirement.

In some examples, the apparatus comprises at least one processor and at least one memory including a computer program code, the at least one memory and computer program code configured to, with the at least one processor, cause the apparatus at least to: provide, to a plurality of access nodes in a group, configuration information for causing the access nodes to share respective clock values with the other access nodes in the group; and receive, from at least one of the access nodes in the group, information indicating whether the clock value associated with the at least one of the access nodes matches a reference value within a timing accuracy requirement.

It should be understood that the apparatuses may comprise or be coupled to other units or modules etc., such as radio parts or radio heads, used in or for transmission and/or reception. Although the apparatuses have been described as one entity, different modules and memory may be implemented in one or more physical or logical entities.

It is noted that whilst some embodiments have been described in relation to 5G networks, similar principles can be applied in relation to other networks and communication systems. Therefore, although certain embodiments were described above by way of example with reference to certain example architectures for wireless networks, technologies and standards, embodiments may be applied to any other suitable forms of communication systems than those illustrated and described herein. It is also noted herein that while the above describes example embodiments, there are several variations and modifications which may be made to the disclosed solution without departing from the scope of the present invention.

In general, the various embodiments may be implemented in hardware or special purpose circuitry, software, logic or any combination thereof. Some aspects of the disclosure may be implemented in hardware, while other aspects may be implemented in firmware or software which may be executed by a controller, microprocessor or other computing device, although the disclosure is not limited thereto. While various aspects of the disclosure may be illustrated and described as block diagrams, flow charts, or using some other pictorial representation, it is well understood that these blocks, apparatus, systems, techniques or methods described herein may be implemented in, as non-limiting examples, hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof.

As used in this application, the term “circuitry” may refer to one or more or all of the following:

(a) hardware-only circuit implementations (such as implementations in only analog and/or digital circuitry) and

(b) combinations of hardware circuits and software, such as (as applicable):

(i) a combination of analog and/or digital hardware circuit(s) with software/firmware and

(ii) any portions of hardware processor(s) with software (including digital signal processor(s)), software, and memory(ies) that work together to cause an apparatus, such as a mobile phone or server, to perform various functions) and

(c) hardware circuit(s) and or processor(s), such as a microprocessor(s) or a portion of a microprocessor(s), that requires software (e.g., firmware) for operation, but the software may not be present when it is not needed for operation.”

This definition of circuitry applies to all uses of this term in this application, including in any claims. As a further example, as used in this application, the term circuitry also covers an implementation of merely a hardware circuit or processor (or multiple processors) or portion of a hardware circuit or processor and its (or their) accompanying software and/or firmware. The term circuitry also covers, for example and if applicable to the particular claim element, a baseband integrated circuit or processor integrated circuit for a mobile device or a similar integrated circuit in server, a cellular network device, or other computing or network device.

The embodiments of this disclosure may be implemented by computer software executable by a data processor of the mobile device, such as in the processor entity, or by hardware, or by a combination of software and hardware. Computer software or program, also called program product, including software routines, applets and/or macros, may be stored in any apparatus-readable data storage medium and they comprise program instructions to perform particular tasks. A computer program product may comprise one or more computer- executable components which, when the program is run, are configured to carry out embodiments. The one or more computer-executable components may be at least one software code or portions of it.

Further in this regard it should be noted that any blocks of the logic flow as in the Figures may represent program steps, or interconnected logic circuits, blocks and functions, or a combination of program steps and logic circuits, blocks and functions. The software may be stored on such physical media as memory chips, or memory blocks implemented within the processor, magnetic media such as hard disk or floppy disks, and optical media such as for example DVD and the data variants thereof, CD. The physical media is a non-transitory media.

The memory may be of any type suitable to the local technical environment and may be implemented using any suitable data storage technology, such as semiconductor based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory and removable memory. The data processors may be of any type suitable to the local technical environment, and may comprise one or more of general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs), application specific integrated circuits (ASIC), FPGA, gate level circuits and processors based on multi core processor architecture, as non-limiting examples.

Embodiments of the disclosure may be practiced in various components such as integrated circuit modules. The design of integrated circuits is by and large a highly automated process. Complex and powerful software tools are available for converting a logic level design into a semiconductor circuit design ready to be etched and formed on a semiconductor substrate.

The scope of protection sought for various embodiments of the disclosure is set out by the independent claims. The embodiments and features, if any, described in this specification that do not fall under the scope of the independent claims are to be interpreted as examples useful for understanding various embodiments of the disclosure.

The foregoing description has provided by way of non-limiting examples a full and informative description of the exemplary embodiment of this disclosure. However, various modifications and adaptations may become apparent to those skilled in the relevant arts in view of the foregoing description, when read in conjunction with the accompanying drawings and the appended claims. However, all such and similar modifications of the teachings of this disclosure will still fall within the scope of this invention as defined in the appended claims. Indeed, there is a further embodiment comprising a combination of one or more embodiments with any of the other embodiments previously discussed.

Claims

1. An apparatus comprising means for: receiving, at an access node from a network entity, configuration information; responsive to the configuration information, providing a clock value associated with the access node to the at least one further access node of a group of at least two access nodes; receiving, from the at least one further access node, respective further clock values associated with each at least one further access node in the group; determining whether the clock value matches a reference value within a timing accuracy requirement based on the received further clock values; and providing, to a network entity, information indicating whether the clock value associated with at least one of the access nodes matches the reference value within the timing accuracy requirement.

2. The apparatus of claim 1 , wherein the means is for: receiving a signal comprising the reference value; and synchronizing the clock value to the reference value.

3. The apparatus of any of claims 1 and 2, wherein the means is for: determining an average clock value based on the clock value and the received further clock values.

4. The apparatus of any preceding claim, wherein the configuration information comprises information indicating at least one of: a periodicity for the access node to provide the clock value; the timing accuracy requirement; group member information; and the method to use to provide the clock value.

5. The apparatus of any preceding claim, wherein the means for determining whether the clock value matches a reference value within a timing accuracy requirement comprises means for: comparing the clock value to the received respective further clock values.

6. The apparatus of claim 5, wherein the means is for at least one of: determining that the clock value does not match the reference value when a result of the comparing indicates that the clock value differs from the received respective further clock values by more than the timing accuracy requirement; and determining that the clock value matches the reference value when the result of the comparing indicates that the clock value differs from the received respective further clock values by less than the timing accuracy requirement.

7. The apparatus of any preceding claim, wherein at least one of the access node and at least one of the at least one further access node is a gNB.

8. The apparatus of any preceding claim, wherein the reference value is a universal time clock value.

9. An apparatus comprising means for: providing, to a plurality of access nodes in a group, configuration information for causing the access nodes to share respective clock values with the other access nodes in the group; and receiving, from at least one of the access nodes in the group, information indicating whether the clock value associated with the at least one of the access nodes matches a reference value within a timing accuracy requirement.

10. The apparatus of claim 9, wherein at least one of the two access nodes comprises a gNB.

11. The apparatus of any of claims 9 and 10, wherein the means is for: determining the group comprising the at least two access nodes.

12. The apparatus of any claim 11, wherein the means for determining the group comprises means for determining the group based on at least one of: a tracking area; a capability of the at least two access nodes; a class of the at least two access nodes; a location of the at least two access nodes; a time synchronization service area; a precision timing protocol network configuration between the at least two access nodes and a core network; and a self organizing network capability.

13. The apparatus of any of claims 9 to 12, wherein at least one access node within the group is located at greater than a threshold distance away from the other access nodes within the group.

14. The apparatus of any of claims 9 to 13, wherein the configuration information comprises information indicating at least one of: a periodicity for the at least two access nodes to share their clock value; the timing accuracy requirement; group member information; and the method to use to provide the clock value.

15. The apparatus of any of claims 9 to 14, wherein the means is for: determining a change in the timing accuracy requirement for at least one of the at least two access nodes; and transmitting the configuration information responsive to determining the change in timing accuracy.

16. An apparatus comprising at least one processor and at least one memory including a computer program code, the at least one memory and computer program code configured to, with the at least one processor, cause the apparatus at least to: receive, at an access node from a network entity, configuration information; responsive to the configuration information, provide a clock value associated with the access node to the at least one further access node of a group of at least two access nodes; receive, from the at least one further access node, respective further clock values associated with each at least one further access node in the group; determine whether the clock value matches a reference value within a timing accuracy requirement based on the received further clock values; and provide, to a network entity, information indicating whether the clock value associated with at least one of the access nodes matches the reference value within the timing accuracy requirement.

17. An apparatus comprising at least one processor and at least one memory including a computer program code, the at least one memory and computer program code configured to, with the at least one processor, cause the apparatus at least to: provide, to a plurality of access nodes in a group, configuration information for causing the access nodes to share respective clock values with the other access nodes in the group; and receive, from at least one of the access nodes in the group, information indicating whether the clock value associated with the at least one of the access nodes matches a reference value within a timing accuracy requirement.

18. A method comprising: receiving, at an access node from a network entity, configuration information; responsive to the configuration information, providing a clock value associated with the access node to the at least one further access node of a group of at least two access nodes; receiving, from the at least one further access node, respective further clock values associated with each at least one further access node in the group; determining whether the clock value matches a reference value within a timing accuracy requirement based on the received further clock values; and providing, to a network entity, information indicating whether the clock value associated with at least one of the access nodes matches the reference value within the timing accuracy requirement.

19. A method comprising: providing, to a plurality of access nodes in a group, configuration information for causing the access nodes to share respective clock values with the other access nodes in the group; and receiving, from at least one of the access nodes in the group, information indicating whether the clock value associated with the at least one of the access nodes matches a reference value within a timing accuracy requirement.

20. A computer readable medium comprising program instructions for causing an apparatus to perform at least the following: receiving, at an access node from a network entity, configuration information; responsive to the configuration information, providing a clock value associated with the access node to the at least one further access node of a group of at least two access nodes; receiving, from the at least one further access node, respective further clock values associated with each at least one further access node in the group; determining whether the clock value matches a reference value within a timing accuracy requirement based on the received further clock values; and providing, to a network entity, information indicating whether the clock value associated with at least one of the access nodes matches the reference value within the timing accuracy requirement.

21. A computer readable medium comprising program instructions for causing an apparatus to perform at least the following: providing, to a plurality of access nodes in a group, configuration information for causing the access nodes to share respective clock values with the other access nodes in the group; and receiving, from at least one of the access nodes in the group, information indicating whether the clock value associated with the at least one of the access nodes matches a reference value within a timing accuracy requirement.