WO2023158349A1

WO2023158349A1 - Determining handover latency

Info

Publication number: WO2023158349A1
Application number: PCT/SE2022/050167
Authority: WO
Inventors: John Walter Diachina; Dhruvin PATEL
Original assignee: Telefonaktiebolaget Lm Ericsson (Publ)
Priority date: 2022-02-15
Filing date: 2022-02-15
Publication date: 2023-08-24

Abstract

A wireless device, WD, configured to communicate at least with a network node is described. The WD includes processing circuitry configured to determine a first time elapsing from a reception of a handover command until the WD becomes ready to transmit, to the network node, a first message associated with the handover command. In addition, the processing circuitry is also configured to at least one of determine a second time elapsing from reception of a second message until the WD becomes ready to transmit a third message to the network node in response to the second message; and determine the third message to be transmitted to the network node. The third message includes at least one of the determined first time and the determined second time.

Description

DETERMINING HANDOVER LATENCY

TECHNICAL FIELD

The present disclosure relates to wireless communications, and in particular to determination of latency associated with handover of wireless devices.

BACKGROUND

The Third Generation Partnership Project (3GPP) has developed and is developing standards for Fourth Generation (4G) (also referred to as Long Term Evolution (LTE)) and Fifth Generation (5G) (also referred to as New Radio (NR)) wireless communication systems. Such systems provide, among other features, broadband communication between network nodes, such as base stations, and mobile wireless devices (WD), as well as communication between network nodes (NNs) and between WDs. Some WDs may include Internet of Thing (loT) devices such as industrial loT devices.

There are Industrial loT use cases that require low deterministic latency, down to zero interruption time even during mobility /handovers. 3GPP, e.g., since 3GPP Release 15 (Rel-15), has defined features to associated with WD mobility performance. Other use cases associated with 3GPP standards such as 5G NR standards include Ultra-Reliable Low-Latency Communication (URLLC). To enable URLLC type of communication, there are several Open Systems Interconnection (OSI) Layer 2 (L2) and Layer 1 (LI) features standardized by 3GPP (e.g., configured grant, Packet Data Convergence Protocol (PDCP) duplication).

3GPP Release 16 (Rel-16) describes a Dual Active Protocol Stack (DAPS) feature where a WD (i.e., a User Equipment (UE)) has dual receive-transmit (Rx-Tx) functionality, thereby allowing for two independent user plane protocol stacks (except for a common PDCP layer). The DAPS feature uses “make before break” principle using two Rx-Tx interfaces but involves the use of a common PDCP layer at the top of the user plane protocol stack. However, the described DAPS feature may be problematic at least when considering Quality of Service (QoS) flow switching during inter-gNB cell change, e.g., since the delay experienced for any given QoS flow between 5G ingress-to-egress points should have a fixed maximum value. Further, using DAPS involves supporting the user plane with an inter-gNodeB (inter-gNB) path for a variable amount of time during inter-gNB cell change (such as a cell change between network nodes):

• During handover to another cell (e.g., a new cell), the QoS flow user plane path = User Plane Function (UPF)- gNBl- gNB2-UE (i.e., UPF- NN1- NN2- WD);

• After handover completion, the QoS flow user plane path = UPF- gNB2-WD (i.e., UPF- NN1- NN2-WD);

• The user plane delay between 5G ingress and 5G egress includes a network portion and a radio portion. Keeping the network portion smaller than a predetermined network portion value increases radio time budget (i.e., packet delay budget) available for user plane payload delivery over a radio interface.

• When using DAPS, the radio resource allocation to the WD in the new cell (i.e., another cell) is based on the network node to network node, e.g., gNBl- gNB2, path (i.e., a path between network nodes) being present, thereby increasing the network portion of allowed 5G ingress to egress delay.

• That is, a network node (e.g., gNB2) allocates radio resources assuming a smaller packet delay budget is available for the radio interface than if the network node (e.g., gNB2) would allocate if the inter network node path (e.g., gNBl- gNB2 path) was not part of the network path. In other words, there is a limited pool of radio resources suitable for supporting radio packet delay budgets.

FIG. 1 shows an example of OSI Layer 3 (L3) handover (HO) process including contention based random access. Some legacy OSI L3 mobility processes (e.g., as shown in FIG. 1) include a procedure where a WD is required to follow the “break before make” principle of operation as the WD is unable to simultaneously support Rx/Tx operation in two different cells. An example legacy OSI L3 mobility process may include the following steps: 1. The WD is in a connected mode with a source network node (e.g., gNB). The source network node (e.g., source gNB) decides based on the L3 Radio Resource Control (RRC) measurement report to handover WD to a target network node (e.g., target gNB);

2. If the target network node (e.g., target gNB) admits the WD, a handover acknowledgement indication is sent to the source network node (e.g., gNB);

3. The source network node (e.g., gNB) sends a HO command (e.g., RRC message) to the WD;

4. The WD performs a procedure for switching the cell, which includes the WD resetting medium access layer, performing Packet Random Access Channel (PRACH), re-establish Radio Link Control (RLC) layer. In addition, the WD may also re-establish PDCP and change security keys (e.g., if needed); and

5. After successful attach (i.e., connection), the WD sends target network node (e.g., target gNB) a HO completed notification using RRC based signaling.

In addition, there are two processes running in the procedure, the first process includes handover triggering, where the WD performs periodical Reference Signal Received Power (RSRP) and/or Reference Signal Received Quality (RSRQ) measurements based on reference signals from the serving and strongest neighboring cells. The second process includes a handover process which is performed independently of data transmission and performed in a manner to avoid an exceeding predetermined mobility related interruption (i.e., excessive mobility related interruption) of the user plane.

FIG. 2 shows an example of latency components (e.g., steps) in an HO process. Assuming the first Random-Access (RA) procedure is successful (i.e., Preamble transmission shown in FIG. 2), a total handover delay (i.e., user plane interruption) can be in the range of 10’s of milliseconds (ms) such as 40-60 ms which can be considered very high for some industrial loT use cases. At least two steps contribute significantly to handover latency as shown in FIG. 2. The first step is the HO preparation and is associated with processing latency experienced by WD: • Once the HO command RRC message sent by the network node (e.g., gNB) is received at the WD, the WD can take up to 16ms to process the HO command RRC message, according to 3GPP Technical Specification (TS) 38.331, Section 12. o The WD may be considered to have processed the HO command RRC message when the WD is ready to transmit the Preamble (i.e., MSG1) on the PRACH resource using a Contention Based Random Access (CBRA) or a Contention Free Random Access (CFRA).

The user plane may be considered as interrupted starting with WD reception of the HO command in the source cell (e.g., a cell of a network node).

• The time between WD reception of the HO command in the source cell and the next instance of the PRACH resource in the target cell is variable since the time until the next instance of PRACH (i.e., used for Preamble transmission - as shown in FIG. 2) in the target cell is variable. In other words, HO preparation time as shown in FIG. 2 is not a constant value and may vary, e.g., depending on WD baseband implementation.

Further, HO processing latency at the WD is chipset implementation dependent, and the network node (e.g., gNB) does not have information regarding latency incurred/caused by WD processing time and PRACH procedure. Instead, the network node (e.g., gNB) uses static WD capability information (e.g., maximum value imposed as requirement for 3GPP TS 38.331) to estimate a total handover latency (i.e., the expected user plane interruption time due to HO). In other words, processes based on “break before make” lead to unfavorable results. More specifically, processes based on “break before make” are unfavorable for use cases such as industrial use cases, (e.g., Industrial loT) where deterministic performance is desired/expected even when radio environment conditions change. In addition, 3 GPP standards such as 3GPP TS 38.314 NR do not describe OSI L2 measurements usable for accurately estimating/determining WD latency associated with processing different HO related signaling events. SUMMARY

Some embodiments advantageously provide methods, systems, and apparatuses for determining (e.g., estimating) at least a handover latency such as OSI L3 handover latency.

Some other embodiments describe a method which allows WD measurement or estimation of HO related processing latency and/or reporting such values to a network node such as a gNB. WD reporting of HO related processing latency enables estimation of WD capabilities, e.g., to further optimize network performance of the industrial applications, thereby allowing for reduction of user plane interruption during HO-based cell change.

In some embodiments, a cell change having zero interruption of a user plane may be based on dual connectivity and 5G System (5GS) user plane paths. Dual connectivity may refer to the WD and the network node (e.g., gNB) being connected (and/or establishing/terminating a connection) using two independent protocol stacks (i.e., one protocol stack in the source cell and another in the target cell). In addition, each user plane path may include one WD-NN link (e.g., UE-gNB) link and one NN- UPF link (e.g., gNB-UPF link).

In some other embodiments, a cell change procedure is described. The cell change procedure may be based on the “break before make” principle where contention based random access (CBRA) in a target cell allows (e.g., only allows) a single user plane protocol stack to be active (e.g., at any point in time). In other words, the active user plane protocol stack is in the source cell or the target cell. In an embodiment, the active user plane protocol stack may be in the source cell and the target cell.

In another embodiment, when the WD is performing the HO procedure, the user plane is interrupted until the task to complete the cell change are completed. In some other embodiments, for this type of cell change (e.g., where some degree of user plane interruption may be tolerated), a serving network node (e.g., serving gNB) determines (e.g., knows) the message processing capability of a WD (e.g., from HO command reception until ready for Preamble transmission), thereby allowing for reduction of user plane interruption time experienced at cell change below a predetermined user plane interruption time.

In some embodiments, a zero-millisecond interruption time may be realized during cell change if the WD is allocated one or more (e.g., two) independent user plane protocol stacks. In some other embodiments, one protocol stack is in the source cell, and the other protocol stack is in the target cell. In other words, the WD may use Data Radio Bearer (DRB) in the source cell until DRB resources are available in the target cell, thereby avoiding any user plane interruption.

In some other embodiments, a starting point for the network (e.g., the network node, WD) to realize (i.e., determine, detect) a reduced user plane (or mobility) interruption time due to WD mobility includes the WD determining (e.g., estimating, measuring) HO latency and/or identifying unknown latency components (e.g., WD processing time between at least two events.

In an embodiment, the first event may include receiving a HO command from network node (e.g., gNB), and the second event may be the WD triggering a PRACH procedure.

In another embodiment, based on the WD sending (e.g., transmitting) such measurements to the network node (e.g., gNB), the network node (e.g., gNB) can adjust a configuration of radio resources, e.g., to minimize the overall cell switching time. Adjusting the configuration of radio resources may include adjusting the transmission of HO command relative to the configured PRACH preamble resources and/or adjusting the configuration of the PRACH preamble resources for future handover process.

In some embodiments, the network node may provide (e.g., transmit) an indication to the WD. The indication may indicate the type of applications running over OSI L3 (e.g., using RRC signaling). Further, the indication may indicate the user plane performance to be supported during handover (e.g., maximum user plane interruption that can be tolerated during handover).

In some other embodiments, the WD confirms that the WD supports (e.g., determines/indicates that the WD supports) the requested performance (e.g., ability to process a HO command within a predetermined time). The WD may also confirm that the WD can then be configured with corresponding radio resources to be used during handover.

According to one aspect, a wireless device (WD) configured to communicate at least with a network node is described. The WD includes processing circuitry configured to: determine a first time elapsing from a reception of a handover command until the WD becomes ready to transmit, to the network node, a first message associated with the handover command; and at least one of determine a second time elapsing from reception of a second message until the WD becomes ready to transmit a third message to the network node in response to the second message; and determine the third message to be transmitted to the network node, the third message including at least one of the determined first time and the determined second time.

In some embodiments, the first time is included in at least one information element in a WD capability message transmittable by the WD.

In some other embodiments, the first time is a first indication of WD message processing capability usable for scheduling at least another handover command.

In one embodiment, the second time is a second indication of WD message processing capability usable for scheduling at least one uplink resource associated with a third message transmission corresponding to a handover process.

In another embodiment, the processing circuitry is further configured to determine a third time. The third time being a third indication of WD message processing capability associated with the second message and usable for a contention based random access, CBRA, handover. The third time is included in the third message.

In some embodiments, the first message is one of a physical random-access channel (PRACH) and a preamble on the PRACH. The second message is a randomaccess response at least indicating a network node reception of the first message. The third message is associated at least with a contention resolution. In some other embodiments, the first time corresponds to a handover preparation time and triggers a random-access channel (RACH) procedure, and the second time corresponds to the RACH procedure.

In one embodiment, the WD further includes a radio interface in communication with the processing circuitry, where the radio interface is configured to at least one of receive at least one of the handover command, the second message, and a fourth message transmitted in response to the third message and associated at least with a connection setup of the WD to the network node; and transmit at least one of the first message and the third message to the network node.

In another embodiment, the fourth message triggers a completion of a handover associated with the handover command, and the handover command is transmitted by one of the network node; and another network node, the handover being from the network node to the other network node. The handover is from a first cell of the network node to a second cell of the network node.

In some embodiments, the processing circuitry is further configured to at least one of determine a mobility interruption time associated with a location change of the WD at least from a first location to a second location based at least in part on one of the first time and the second time; determine a safety distance associated with the WD based at least in part on the determined mobility interruption time; and trigger the network node to expose the mobility interruption time associated with the location change to at least an industrial application. Exposing the mobility interruption time includes transmitting the mobility interruption time.

In another aspect, a method implemented in a wireless device (WD) is described. The WD is configured to communicate at least with a network node. The method includes: determining a first time elapsing from a reception of a handover command until the WD becomes ready to transmit, to the network node, a first message associated with the handover command; and at least one of determining a second time elapsing from reception of a second message until the WD becomes ready to transmit a third message to the network node in response to the second message; and determining the third message to be transmitted to the network node, the third message including at least one of the determined first time and the determined second time.

In another embodiment, the method further includes determining a third time. The third time being a third indication of WD message processing capability associated with the second message and usable for a contention based random access, CBRA, handover. The third time is included in the third message.

In some embodiments, the first message is one of a physical random-access channel (PRACH) and a preamble on the PRACH. The second message is a randomaccess response at least indicating a network node reception of the first message. The third message is associated at least with a contention resolution.

In some other embodiments, the first time corresponds to a handover preparation time and triggers a random-access channel (RACH) procedure, and the second time corresponds to the RACH procedure.

In one embodiment, the method further includes at least one of: receiving at least one of the handover command, the second message, and a fourth message transmitted in response to the third message and associated at least with a connection setup of the WD to the network node; and transmitting at least one of the first message and the third message to the network node.

In another embodiment, the fourth message triggers a completion of a handover associated with the handover command, and the handover command is transmitted by one of: the network node; and another network node, the handover being from the network node to the other network node. The handover is from a first cell of the network node to a second cell of the network node.

In some embodiments, the method further includes at least one of: determining a mobility interruption time associated with a location change of the WD at least from a first location to a second location based at least in part on one of the first time and the second time; determining a safety distance associated with the WD based at least in part on the determined mobility interruption time; and triggering the network node to expose the mobility interruption time associated with the location change to at least an industrial application. Exposing the mobility interruption time includes transmitting the mobility interruption time.

According to one aspect, a network node configured to communicate at least with a wireless device (WD) is described. The network node includes processing circuitry configured to determine at least one of a first time and a second time. The first time elapses from a reception by the WD of a handover command until the WD becomes ready to transmit, to the network node, a first message associated with the handover command. The second time elapsing from reception by the WD of a second message until the WD becomes ready to transmit a third message to the network node in response to the second message. The at least one of the first time and the second time are included in the third message.

In some other embodiments, the processing circuitry is further configured to determine a scheduling of another handover command based at least in part on the first time. The first time is a first indication of WD message processing capability.

In one embodiment, the processing circuitry is further configured to: determine another scheduling of at least one uplink resource associated with a third message transmission corresponding to a handover process based at least in part on the second time. The second time is a second indication of WD message processing. In another embodiment, the processing circuitry is further configured to determine a contention based random access (CBRA) handover based at least in part on a third time included in the third message. The third time is a third indication of WD message processing capability associated with the second message.

In some embodiments, the first message is one of a physical random-access channel (PRACH) and a preamble on the PRACH. The second message is a random access response at least indicating a network node reception of the first message. The third message is associated with at least with contention resolution.

In one embodiment, the network node further includes a radio interface in communication with the processing circuitry, where the radio interface is configured to at least one of: receive at least one of the first message and the third message from the WD, the third message being used by the network node to determine the at least one of a first time and a second time; and transmit, to the WD, at least one of the handover command, the second message, and a fourth message being transmitted in response to the third message and associated at least with a connection setup of the WD to the network node.

In another embodiment, the fourth message triggers a completion of a handover associated with the hand over command, and the handover command is transmitted by one of: the network node, the handover being from a first cell of the network node to a second cell of the network node; and another network node. The handover is from the network node to the other network node.

In some embodiments, the processing circuitry is further configured to at least one of: determine a mobility interruption time associated with a location change of the WD at least from a first location to a second location based at least in part on one of the first time and the second time; determine a safety distance associated with the WD based at least in part on the determined mobility interruption time; and expose the mobility interruption time associated with the location change to at least an industrial application. Exposing the mobility interruption time includes transmitting the mobility interruption time.

In another aspect, a method implemented in a network node configured to communicate at least with a wireless device (WD) is described. The method includes determining at least one of a first time and a second time. The first time elapses from a reception by the WD of a handover command until the WD becomes ready to transmit, to the network node, a first message associated with the handover command. The second time elapsing from reception by the WD of a second message until the WD becomes ready to transmit a third message to the network node in response to the second message. The at least one of the first time and the second time is included in the third message.

In some other embodiments, the method further includes determining a scheduling of another handover command based at least in part on the first time. The first time is a first indication of WD message processing capability.

In one embodiment, the method further includes determining another scheduling of at least one uplink resource associated with a third message transmission corresponding to a handover process based at least in part on the second time. The second time is a second indication of WD message processing.

In another embodiment, the method further includes determining a contention based random access (CBRA) handover based at least in part on a third time included in the third message. The third time is a third indication of WD message processing capability associated with the second message.

In some embodiments, the first message is one of a physical random-access channel (PRACH) and a preamble on the PRACH. The second message is a random access response at least indicating a network node reception of the first message. The third message is associated with at least with contention resolution. In some other embodiments, the first time corresponds to a handover preparation time and triggers a random-access channel (RACH) procedure, and the second time corresponds to the RACH procedure.

In one embodiment, the method further includes at least one of receiving at least one of the first message and the third message from the WD, the third message being used by the network node to determine the at least one of a first time and a second time; and transmitting, to the WD, at least one of the handover command, the second message, and a fourth message being transmitted in response to the third message and associated at least with a connection setup of the WD to the network node.

In another embodiment, the fourth message triggers a completion of a handover associated with the hand over command, and the handover command is transmitted by one of the network node, the handover being from a first cell of the network node to a second cell of the network node; and another network node. The handover is from the network node to the other network node.

In some embodiments, the method further includes at least one of determining a mobility interruption time associated with a location change of the WD at least from a first location to a second location based at least in part on one of the first time and the second time; determining a safety distance associated with the WD based at least in part on the determined mobility interruption time; and exposing the mobility interruption time associated with the location change to at least an industrial application. Exposing the mobility interruption time includes transmitting the mobility interruption time.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete understanding of the present embodiments, and the attendant advantages and features thereof, will be more readily understood by reference to the following detailed description when considered in conjunction with the accompanying drawings wherein: FIG. 1 shows an example of OSI L3 handover process including contention based random access;

FIG. 2 shows an example of latency components (e.g., steps) in handover process;

FIG. 3 is a schematic diagram of an example network architecture illustrating a communication system according to principles disclosed herein;

FIG. 4 is a block diagram of a network node in communication with a wireless device over a wireless connection according to some embodiments of the present disclosure;

FIG. 5 is a flowchart of an example process in a wireless device according to some embodiments of the present disclosure; and

FIG. 6 is a flowchart of an example process in a network node according to some embodiments of the present disclosure;

FIG. 7 shows an example sequence flow for HO latency determination according to some embodiments of the present disclosure;

FIG. 8 shows an example HO latency determination (e.g., optimization) according to some embodiments of the present disclosure; and

FIG. 9 shows an example safety communication scenario according to some embodiments of the present disclosure

DETAILED DESCRIPTION

Before describing in detail exemplary embodiments, it is noted that the embodiments reside primarily in combinations of apparatus components and processing steps related to determining (e.g., estimating) at least a handover latency such as OSI L3 handover latency. Accordingly, components have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein. As used herein, relational terms, such as “first” and “second,” “top” and “bottom,” and the like, may be used solely to distinguish one entity or element from another entity or element without necessarily requiring or implying any physical or logical relationship or order between such entities or elements. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the concepts described herein. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises,” “comprising,” “includes” and/or “including” when used herein, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

In embodiments described herein, the joining term, “in communication with” and the like, may be used to indicate electrical or data communication, which may be accomplished by physical contact, induction, electromagnetic radiation, radio signaling, infrared signaling or optical signaling, for example. One having ordinary skill in the art will appreciate that multiple components may interoperate and modifications and variations are possible of achieving the electrical and data communication.

In some embodiments described herein, the term “coupled,” “connected,” and the like, may be used herein to indicate a connection, although not necessarily directly, and may include wired and/or wireless connections.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the concepts described herein. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises,” “comprising,” “includes” and/or “including” when used herein, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. The term “network node” used herein can be any kind of network node comprised in a radio network which may further comprise any of base station (BS), radio base station, base transceiver station (BTS), base station controller (BSC), Network Element Function (NEF), safety system, positioning system, radio network controller (RNC), g Node B (gNB), evolved Node B (eNB or eNodeB), Node B, multi -standard radio (MSR) radio node such as MSR BS, multi-cell/multicast coordination entity (MCE), relay node, donor node controlling relay, radio access point (AP), transmission points, transmission nodes, Remote Radio Unit (RRU) Remote Radio Head (RRH), a core network node (e.g., mobile management entity (MME), self-organizing network (SON) node, a coordinating node, positioning node, MDT node, etc.), an external node (e.g., 3rd party node, a node external to the current network), nodes in distributed antenna system (DAS), a spectrum access system (SAS) node, an element management system (EMS), etc. The network node may also comprise test equipment. Further, the network node may be an interface to an edge/cloud network (and/or a core network) and/or comprise the edge/cloud network (and/or a core network). In addition, the network node may be an interface to a wireless communication system, e.g., 5G System (5GS), and/or comprise the wireless communication system, e.g., 5G System (5GS). The term “radio node” used herein may be used to also denote a wireless device (WD) such as a wireless device (WD) or a radio network node. Further, the network node may be and/or comprise a source network node such as a source gNB, a target network node such as a target gNB, a grand master network node such as a 5G Grand Master (5G GM), a core network node such as a 5G Core Network (CN) node, an exposure function (EF), and/or an industrial application.

In some embodiments, the non-limiting terms wireless device (WD) or a user equipment (UE) are used interchangeably. The WD herein can be any type of wireless device capable of communicating with a network node or another WD over radio signals, such as wireless device (WD). The WD may also be a radio communication device, target device, device to device (D2D) WD, machine type WD or WD capable of machine to machine communication (M2M), low-cost and/or low-complexity WD, a sensor equipped with WD, Tablet, mobile terminals, smart phone, laptop embedded equipped (LEE), laptop mounted equipment (LME), USB dongles, Customer Premises Equipment (CPE), an Internet of Things (loT) device, or a Narrowband loT (NB-IOT) device, etc. Further, the WD may refer to a vehicle such as any Automated Guided Vehicle (AGV) and/or be part of the vehicle and/or be in communication with the vehicle via a communication interface of the WD and another communication interface of the vehicle. An AGV may be any type of vehicle and may include one or more of each one of a sensor and an actuator. Each sensor and actuator may be in communication with the vehicle, WD, network node, and/or any component/element described herein.

Also, in some embodiments the generic term “radio network node” is used. It can be any kind of a radio network node which may comprise any of base station, radio base station, base transceiver station, base station controller, network controller, RNC, evolved Node B (eNB), Node B, gNB, Multi-cell/multicast Coordination Entity (MCE), relay node, access point, radio access point, Remote Radio Unit (RRU) Remote Radio Head (RRH).

Note that although terminology from one particular wireless system, such as, for example, 3GPP LTE and/or New Radio (NR), may be used in this disclosure, this should not be seen as limiting the scope of the disclosure to only the aforementioned system. Other wireless systems, including without limitation Wide Band Code Division Multiple Access (WCDMA), Worldwide Interoperability for Microwave Access (WiMax), Ultra Mobile Broadband (UMB) and Global System for Mobile Communications (GSM), may also benefit from exploiting the ideas covered within this disclosure.

Note further, that functions described herein as being performed by a wireless device or a network node may be distributed over a plurality of wireless devices and/or network nodes. In other words, it is contemplated that the functions of the network node and wireless device described herein are not limited to performance by a single physical device and, in fact, can be distributed among several physical devices.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. It will be further understood that terms used herein should be interpreted as having a meaning that is consistent with their meaning in the context of this specification and the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

Referring again to the drawing figures, in which like elements are referred to by like reference numerals, there is shown in FIG. 3 a schematic diagram of a communication system 10, according to an embodiment, such as a 3 GPP -type cellular network that may support standards such as LTE and/or NR (5G), which comprises an access network 12, such as a radio access network, and a core network 14. The access network 12 comprises a plurality of network nodes 16a, 16b, 16c (referred to collectively as network nodes 16), such as NBs, eNBs, gNBs or other types of wireless access points, each defining a corresponding coverage area 18a, 18b, 18c (referred to collectively as coverage areas 18). Each network node 16a, 16b, 16c is connectable to the core network 14 over a wired or wireless connection 20. A first wireless device (WD) 22a located in coverage area 18a is configured to wirelessly connect to, or be paged by, the corresponding network node 16a. A second WD 22b in coverage area 18b is wirelessly connectable to the corresponding network node 16b. While a plurality of WDs 22a, 22b (collectively referred to as wireless devices 22) are illustrated in this example, the disclosed embodiments are equally applicable to a situation where a sole WD is in the coverage area or where a sole WD is connecting to the corresponding network node 16. Note that although only two WDs 22 and three network nodes 16 are shown for convenience, the communication system may include many more WDs 22 and network nodes 16.

Also, it is contemplated that a WD 22 can be in simultaneous communication and/or configured to separately communicate with more than one network node 16 and more than one type of network node 16. For example, a WD 22 can have dual connectivity with a network node 16 that supports LTE and the same or a different network node 16 that supports NR. As an example, WD 22 can be in communication with an eNB for LTEZE-UTRAN and a gNB for NR/NG-RAN. Further, each network node 16 (and/or any of its components) may communicate with another network node 16 (and/or any of its components), e.g., via inter-node connection 80 which may be a wired/wireless connection. Further, each network node 16 may communicate (e.g., be connectable) with a cloud communication network 84, such as via connection 82 which may be a wired/wireless connection. Any one of network nodes 16 may be comprised in cloud communication network 84 and/or core network 14.

A network node 16 (e.g., eNB, gNB) is configured to include a node latency estimator unit 24 which is configured to perform any of the steps, tasks, features, and/or processes described herein, e.g., determine a first time and/ a second time and/or determine a mobility interruption time associated with a location change of the WD 22. A wireless device 22 is configured to include a WD latency estimator unit 26 which is configured to perform any of the steps, tasks, features, and/or processes described herein, e.g., determine a first time and/ a second time and/or determine a mobility interruption time associated with a location change of the WD 22.

Example implementations, in accordance with an embodiment, of the WD 22 and network node 16 discussed in the preceding paragraphs will now be described with reference to FIG. 4.

The communication system 10 includes a network node 16 provided in a communication system 10 and including hardware 28 enabling it to communicate with the WD 22. The hardware 28 may include a radio interface 30 for setting up and maintaining at least a wireless connection 32 with a WD 22 located in a coverage area 18 served by the network node 16. The radio interface 30 may be formed as or may include, for example, one or more RF transmitters, one or more RF receivers, and/or one or more RF transceivers. The radio interface 30 includes an array of antennas 34 to radiate and receive signal(s) carrying electromagnetic waves.

In the embodiment shown, the hardware 28 of the network node 16 further includes processing circuitry 36. The processing circuitry 36 may include a processor 38 and a memory 40. In particular, in addition to or instead of a processor, such as a central processing unit, and memory, the processing circuitry 36 may comprise integrated circuitry for processing and/or control, e.g., one or more processors and/or processor cores and/or FPGAs (Field Programmable Gate Array) and/or ASICs (Application Specific Integrated Circuitry) adapted to execute instructions. The processor 38 may be configured to access (e.g., write to and/or read from) the memory 40, which may comprise any kind of volatile and/or nonvolatile memory, e.g., cache and/or buffer memory and/or RAM (Random Access Memory) and/or ROM (Read-Only Memory) and/or optical memory and/or EPROM (Erasable Programmable Read-Only Memory).

Thus, the network node 16 further has software 42 stored internally in, for example, memory 40, or stored in external memory (e.g., database, storage array, network storage device, etc.) accessible by the network node 16 via an external connection. The software 42 may be executable by the processing circuitry 36. The processing circuitry 36 may be configured to control any of the methods and/or processes described herein and/or to cause such methods, and/or processes to be performed, e.g., by network node 16. Processor 38 corresponds to one or more processors 38 for performing network node 16 functions described herein. The memory 40 is configured to store data, programmatic software code and/or other information described herein. In some embodiments, the software 42 may include instructions that, when executed by the processor 38 and/or processing circuitry 36, causes the processor 38 and/or processing circuitry 36 to perform the processes described herein with respect to network node 16. For example, processing circuitry 36 of the network node 16 may include node latency estimator unit 24 which is configured to perform any of the steps, tasks, features, and/or processes described herein, e.g., determine a first time and/ a second time and/or determine a mobility interruption time associated with a location change of the WD 22. Network node 16 may also include a safety unit 72 configured to perform any of the steps, tasks, features, and/or processes described herein, e.g., determine safety parameters associated at least with a vehicle 100 and/or WD 22. Safety unit 72 may refer to a safety system but is not limited as such and may refer to any other unit/component/system. In addition, network node 16 may also include a positioning unit 74 configured to perform any of the steps, tasks, features, and/or processes described herein, e.g., determine a position associated at least with vehicle 100 and/or WD 22. Positioning unit 74 may refer to a positioning system but is not limited as such and may refer to any other unit/component/system.

The communication system 10 further includes the WD 22 already referred to.

The WD 22 may have hardware 44 that may include a radio interface 46 configured to set up and maintain a wireless connection 32 with a network node 16 serving a coverage area 18 in which the WD 22 is currently located. The radio interface 46 may be formed as or may include, for example, one or more RF transmitters, one or more RF receivers, and/or one or more RF transceivers. The radio interface 46 includes an array of antennas 48 to radiate and receive signal(s) carrying electromagnetic waves.

The hardware 44 of the WD 22 further includes processing circuitry 50. The processing circuitry 50 may include a processor 52 and memory 54. In particular, in addition to or instead of a processor, such as a central processing unit, and memory, the processing circuitry 50 may comprise integrated circuitry for processing and/or control, e.g., one or more processors and/or processor cores and/or FPGAs (Field Programmable Gate Array) and/or ASICs (Application Specific Integrated Circuitry) adapted to execute instructions. The processor 52 may be configured to access (e.g., write to and/or read from) memory 54, which may comprise any kind of volatile and/or nonvolatile memory, e.g., cache and/or buffer memory and/or RAM (Random Access Memory) and/or ROM (Read-Only Memory) and/or optical memory and/or EPROM (Erasable Programmable Read-Only Memory).

Thus, the WD 22 may further comprise software 56, which is stored in, for example, memory 54 at the WD 22, or stored in external memory (e.g., database, storage array, network storage device, etc.) accessible by the WD 22. The software 56 may be executable by the processing circuitry 50. The software 56 may include a client application 58. The client application 58 may be operable to provide a service to a human or non-human user via the WD 22.

The processing circuitry 50 may be configured to control any of the methods and/or processes described herein and/or to cause such methods, and/or processes to be performed, e.g., by WD 22. The processor 52 corresponds to one or more processors 52 for performing WD 22 functions described herein. The WD 22 includes memory 54 that is configured to store data, programmatic software code and/or other information described herein. In some embodiments, the software 56 and/or the client application 58 may include instructions that, when executed by the processor 52 and/or processing circuitry 50, causes the processor 52 and/or processing circuitry 50 to perform the processes described herein with respect to WD 22. For example, the processing circuitry 50 of the wireless device 22 may include WD latency estimator unit 26 which is configured to perform any of the steps, tasks, features, and/or processes described herein, e.g., determine a first time and/ a second time and/or determine a mobility interruption time associated with a location change of the WD 22.

In some embodiments, the inner workings of the network node 16 and WD 22 may be as shown in FIG. 4 and independently, the surrounding network topology may be that of FIG. 3.

The wireless connection 32 between the WD 22 and the network node 16 is in accordance with the teachings of the embodiments described throughout this disclosure. More precisely, the teachings of some of these embodiments may improve the data rate, latency, and/or power consumption and thereby provide benefits such as reduced user waiting time, relaxed restriction on file size, better responsiveness, extended battery lifetime, etc. In some embodiments, a measurement procedure may be provided for the purpose of monitoring data rate, latency and other factors on which the one or more embodiments improve.

Although FIGS. 3 and 4 show various “units” such as node latency estimator unit 24, WD latency estimator unit 26, safety unit 72, and positioning unit 74 as being within a respective processor, it is contemplated that these units may be implemented such that a portion of the unit is stored in a corresponding memory within the processing circuitry. In other words, the units may be implemented in hardware or in a combination of hardware and software within the processing circuitry and/or stand alone.

FIG. 5 is a flowchart of an example process in a wireless device 22 according to some embodiments of the present disclosure. One or more blocks described herein may be performed by one or more elements of wireless device 22 such as by one or more of processing circuitry 50 (including the WD latency estimator unit 26), processor 52, and/or radio interface 46. Wireless device 22 such as via processing circuitry 50 and/or processor 52 and/or radio interface 46 is configured to determine (Block SI 00) a first time elapsing from a reception of a handover command until the WD 22 becomes ready to transmit, to the network node 16, a first message associated with the handover command; and at least one of (Block SI 02): determine a second time elapsing from reception of a second message until the WD 22 becomes ready to transmit a third message to the network node 16 in response to the second message; and determine the third message to be transmitted to the network node 16. The third message includes at least one of the determined first time and the determined second time.

In some embodiments, the first time is included in at least one information element in a WD capability message transmittable by the WD 22.

In one embodiment, the method further includes at least one of: receiving at least one of the handover command, the second message, and a fourth message transmitted in response to the third message and associated at least with a connection setup of the WD 22 to the network node 16; and transmitting at least one of the first message and the third message to the network node 16. In another embodiment, the fourth message triggers a completion of a handover associated with the handover command, and the handover command is transmitted by one of: the network node 16; and another network node, the handover being from the network node 16 to the other network node. The handover is from a first cell of the network node 16 to a second cell of the network node 16.

In some embodiments, the method further includes at least one of: determining a mobility interruption time associated with a location change of the WD 22 at least from a first location to a second location based at least in part on one of the first time and the second time; determining a safety distance associated with the WD 22 based at least in part on the determined mobility interruption time; and triggering the network node 16 to expose the mobility interruption time associated with the location change to at least an industrial application. Exposing the mobility interruption time includes transmitting the mobility interruption time.

FIG. 6 is a flowchart of an example process in a network node 16 according to some embodiments of the present disclosure. One or more blocks described herein may be performed by one or more elements of network node 16 such as by one or more of processing circuitry 36 (including the node latency estimator unit 24), processor 38, and/or radio interface 30. Network node 16 such as via processing circuitry 36 and/or processor 38 and/or radio interface 30 is configured to determine (SI 04) at least one of a first time and a second time. The first time elapses from a reception by the WD 22 of a handover command until the WD 22 becomes ready to transmit, to the network node 16, a first message associated with the handover command. The second time elapses from reception by the WD 22 of a second message until the WD 22 becomes ready to transmit a third message to the network node 16 in response to the second message. The at least one of the first time and the second time are included in the third message.

In some embodiments, the first time is included in at least one information element in a WD capability message transmittable by the WD 22. In some other embodiments, the method further includes determining a scheduling of another handover command based at least in part on the first time. The first time is a first indication of WD message processing capability.

In one embodiment, the method further includes at least one of: receiving at least one of the first message and the third message from the WD 22, the third message being used by the network node 16 to determine the at least one of a first time and a second time; and transmitting, to the WD 22, at least one of the handover command, the second message, and a fourth message being transmitted in response to the third message and associated at least with a connection setup of the WD 22 to the network node 16.

In another embodiment, the fourth message triggers a completion of a handover associated with the hand over command, and the handover command is transmitted by one of: the network node 16, the handover being from a first cell of the network node 16 to a second cell of the network node 16; and another network node.

The handover is from the network node 16 to the other network node.

In some embodiments, the method further includes at least one of: determining a mobility interruption time associated with a location change of the WD 22 at least from a first location to a second location based at least in part on one of the first time and the second time; determining a safety distance associated with the WD 22 based at least in part on the determined mobility interruption time; and exposing the mobility interruption time associated with the location change to at least an industrial application. Exposing the mobility interruption time includes transmitting the mobility interruption time.

Having described the general process flow of arrangements of the disclosure and having provided examples of hardware and software arrangements for implementing the processes and functions of the disclosure, the sections below provide details and examples of arrangements for determining handover latency. WD 22 (and/or any of its components) and/or Network node 16 (and/or any of its components) may be configured to transmit/receive one or more messages such as HO command, Preamble, MSG2, MSG3, MSG4, or any other type of message. The one or more messages may be associated with a handover process.

Some embodiments provide a method which includes a WD 22 calculating (i.e., determining) and reporting, such as via processing circuitry 50 and/or radio interface 46, of HO (e.g., estimated, measured) related processing latency associated with components (i.e., steps) of the handover signaling procedure. Further, the reporting of handover related processing latency may be utilized by the network node 16 (e.g., gNB) to tune, such as via processing circuitry 36 and/or radio interface 30, the timing of signaling messages network node 16 sends to a WD 22 during a “break before make” type handover procedure. The handover related processing latency may also be utilized by the network node 16 as the capability indicator exposed towards the industrial applications. In some other embodiments, method is performed to reduce the mobility interruption time. FIG. 7 shows an example sequence flow for HO latency determination (e.g., calculation). WD 22 and network node (e.g., gNB) in the network may be configured to determine time reference information (e.g., accurate time reference information). In step 200, at least one of network node 16b (e.g., target gNB) and network node 16c (e.g., 5G GM) determines a profile such as an International Telecommunication Union (ITU) profile for time distribution. In a first embodiment, an HO latency estimator (i.e., WD latency estimator unit 26) is described. The HO latency estimator (i.e., WD latency estimator unit 26) may reside (i.e., be included) in WD 22 and/or be used to measure WD preparation time following reception of key signaling messages from network node 16 (e.g., gNB). However, the HO estimator is not limited as such and may reside in any other device such as network node 16 and/or may refer to node latency estimator unit 24. In step S202, a reference time delivery method is performed by at least one of WD 22, WD latency estimator unit 26, and network node 16b. Step S202 may refer to steps S204-S222 as shown in FIG. 7 and described as follows:

• S204: Network node 16b (e.g., the target gNB) transmits an HO command to WD 22. The HO command may refer to an HO acknowledgment from network node 16b to network node 16a and/or network node 16a transmitting the HO command to WD 22. That is, the HO command may be transmitted by another network node in response to a message transmitted by network node 16b.

• S206: WD 22 performs HO preparation.

• S208 (and/or S206): when the HO command is received by WD 22, a timer is determined (i.e., triggered), e.g.,. via WD latency estimator unit 26, processing circuitry 50, etc. A timestamp corresponding to the HO command is saved.

• S210 (and/or S206 and/or S208): WD 22 measures the time elapsed from HO command reception until WD 22 is ready to send the Preamble.

S212: WD 22 then triggers the PRACH procedure by sending (e.g., via radio interface 46) the preamble towards network node 16b (e.g., target gNB) using the next available PRACH resource. • MSG3 can be modified (e.g., steps S216, S218, and/or S220) to include the measured elapsed time (i.e., the time elapsed (e.g., at the WD 22) from HO command reception until WD 22 is ready to send (i.e., transmit) the Preamble on PRACH) which may serve as an indication of WD message processing capability and/or be taken into account (i.e., used by the network node) when network node 16 (e.g., gNB) schedules transmission of the HO command (e.g., within the context of future handovers).

• The HO command message processing capability of WD 22 may be sent as one or more information elements in a WD capability message, thereby allowing the WD message processing capability to be known (i.e., determined) by serving network node 16 (e.g., serving gNB) before sending (i.e., transmitting) an HO command such as the first HO command.

• Network node 16 (e.g., gNB) may be configured to time the sending of HO commands (e.g., future HO commands). The timing may be performed to keep the time between WD reception of the HO command (e.g., S204) and WD transmission of Preamble (e.g., S212). Further, the timing may be compared to a predetermined value such as a minimum and/or help reduce the user plane interruption time (e.g., when compared with legacy systems).

Furthermore, when MSG2 (e.g., S214) is received by WD 22 from target network node 16 (e.g., target gNB), another timestamping is triggered by the HO estimator (i.e., WD latency estimator unit 26) at step S216. FIG. 3 further shows the sequence of signaling events involved:

• S214: MSG2 (Random Access Response sent, e.g., on Physical Downlink Control Channel (PDCCH) transmitted within the common search space) which may provide WD 22 with timing advance and uplink grant (Physical Uplink Shared Channel (PUSCH) resources).

• S214 (and/or S216): After processing MSG2, WD 22 determines the time elapsed from MSG2 reception until WD 22 is ready to send MSG3. • S218 (and/or S220): WD 22 may wait to send MSG3 (e.g., S220) using PUSCH resources provided by MSG2 on the same serving cell WD 22 used for sending the PRACH Preamble.

• S218 (and/or S220): MSG3 can be modified to include the determined elapsed time (e.g., from MSG2 reception until WD 22 is ready to send MSG3) which serves as an indication of the WD message processing capability. The WD message processing capability may be taken into account (e.g., used by target network node 16b) when target network node 16 (e.g., target gNB) schedules PUSCH resources required for MSG3 transmission (e.g., within the context of future handovers). S222: target network node 16 (e.g., target gNB) transmits a MSG4 to WD 22, e.g, via OSI LI .

• Target network node 16 (e.g, target gNB) may be configured to time the sending of future MSG2 transmissions so as to keep the time between WD reception thereof and WD transmission of MSG3 to a minimum (e.g, thereby reducing the user plane interruption time).

WD 22 may determine (e.g, estimate, measure) the time WD 22 takes from reception of the HO command until WD 22 is ready to send (i.e, transmit) a Preamble and/or report to target network node 16 (e.g, target gNB) as information (e.g, new information) in OSI L3 measurement report and/or as supplemental information within MSG3. This allows for network node determination of WD message processing capability which network node 16 (e.g, target network node 16b) can take into account (i.e, use) for future HOs. The following are nonlimiting examples of how a network node 16 (e.g, a gNB) may use the information associated with WD message processing capabilities for future handover procedure:

• For intra network node handover (e.g, intra-gNB handover), network node 16 (e.g, gNB) determines (e.g, knows) where PRACH resources are available in each cell network node 16 manages. Network node 16 may use knowledge of PRACH resources and/or the supplemental information such as to reduce the time between sending the HO command and reception of the corresponding Preamble. This allows for potentially realizing a reduction from the maximum 16ms WD processing time currently allowed for by 3GPP TS 38.331, thereby reducing the total user plane interruption resulting from legacy intra network node handover (e.g., intra-gNB handover).

• For inter network node handover (e.g., inter-gNB handover), network node 16 (e.g., target network node 16b) may be configured to include PRACH resource information as part of the information sent back to source network node 16a in an HO acknowledge. Source network node 16a (e.g., source gNB) may be configured to use knowledge of PRACH resources (e.g., received from the target gNB) and WD message processing capability (e.g., received from the WD 22) to reduce the time between (source network node 16a) sending the HO command in the source cell and (target network node 16a) reception of the corresponding Preamble in the target cell. This allows for potentially realizing a reduction from the maximum 16ms WD processing time allowed for by 3GPP TS 38.331 (thereby reducing the total user plane interruption resulting from inter network node handover).

In one example, a network node 16 (e.g., target network node 16) is configured to transmit an HO command a minimum of 16ms in advance of a next PRACH resource, e.g., to ensure WDs 22 have a minimum mobility interruption time.

A second embodiment addresses latency that occurs during PRACH procedure which starts with WD transmission of a Preamble (i.e., MSG1) on the PRACH of the target cell:

• When CBRA is used in a target cell, there is the possibility of increased delay in completing the handover which is dependent upon whether WD collision occurs during Preamble transmission (e.g., determined by a quantity/number of WDs 22 and radio propagation environment).

• Assuming CBRA is used without WD collision on the PRACH, WD 22 may configured to receive MSG2 on the PDCCH of the target cell.

• MSG2 allocates a PUSCH resource WD 22 may use to transmit a RRC Handover Confirm (MSG3). • MSG3 can be enhanced to include an indication of the time the WD 22 takes to process MSG2, thereby allowing network node 16 (e.g., gNB) to evaluate the message processing capability of WD 22 (which network node 16 may use for future Handovers where CBRA is used).

• In other words, a WD 22 indicating its message processing capability in MSG3 allows network node 16 to reduce the time between MSG2 reception and MSG3 transmission, thereby reducing total user plane interruption such as for the case of HO where CBRA is used. For Contention Free Random Access (CFRA), WD may not transmit MSG3 and/or receive MSG4.

FIG. 8 show an example determination of HO latency, e.g., an example 5G system configured to expose HO mobility interruption time during location change of WD 22 and/or a vehicle 100 (AGV).. One or more steps are performed as follows.

In step S224, a common time reference is determined by at least one of WD 22 and WD latency estimator unit 26. The common time reference may include at least on other time reference (TR). A handover procedure may be performed (as described in the present disclosure) may be performed in step S226 such as between steps S226 and S230. In step S226, WD latency estimator unit 26 may determine a time stamp associated with a HO command, and in step S230 WD latency estimator unit 26 may determine and inform WD 22 of another time stamp (e.g., time when WD 22 is ready for Preamble transmission).

In step S232, WD 22 transmits a message to network node 16a including HO latency, e.g., during location change of WD 22. Network node 16a determines and/or transmits, at step S234, dynamic WD capabilities to network node 16b, which may determine and/or transmit, at step S236, handover interruption time of WD 22 to network node 16c. Network node 16c determines handover/mobility interruption time for a predefined location change such as a location change of the WD 22 and/or exposes/transmits (e.g., via an Application Programming Interface (API)) the handover/mobility interruption time.

FIG. 9 shows an example an example safety communication scenario, e.g., associated with mobility interruption time. Communication system 10 may include one or more network node 16 such as network nodes 16a, 16b and/or WD 22. Network node 16a may be comprised in and/or an interface to another network such as a cloud communication network 84. Further, network node 16 may comprise a safety unit 72 such as a safety system. Network node 16a may also include processing circuitry 36 such as a safety AGV controller. Network node 16b may include positioning unit 74 such as a positioning system and communicate with core network 14 such as a 5GS core network. Further, network node 16b may include a network element function 96 configure to communicate with other network nodes such as network node 16a via inter-node connection 80.

WD 22 may be associated with vehicle 100 (e.g., be mounted on vehicle 100) and/or be configured to communicate with vehicle 100 (and/or processing circuitry and/or communication interface of vehicle 100). Vehicle 100 may be configured to receive communicate with sensor 90 (e.g., via a first connection 92 to receive proximity information) and/or actuator 104 (e.g., via a second connection 94 to command the wheels of vehicle 100 to turn and/or the vehicle 100 to move). The first connection 92 and/or second connection 94 may be wired/wireless. Further, WD 22 may communicate with a network node 16 (such as network nodes 16a, 16b) to exchange safety communication such as information associated with vehicle safety.

In some embodiments, a 5G System (5GS) (and/or a network node 16 operating/communicating as part of a 5GS) may be configured to provide determined/estimated mobility interruption time (e.g., in user plane) during a location change of WD 22 (e.g., from position A to position B). Further, an industrial application (e.g., network node 16d shown in FIG. 8) may utilize knowledge of worstcase user plane downtime during a movement of WD 22 (or movement of a vehicle 100 associated with WD 22) from position A to position B. Mobility interruption time may be exposed (e.g., by network node 16c shown in FIG. 8) from the 5GS (and/or a network node 16 operating/communicating as part of a 5GS) to the industrial application.

In some other embodiments, network node 16 comprising/running an industrial application such as a “real-world” industrial application may be configured to determine (e.g.,. ensure) a safe distance for a vehicle 100 such as an Automated Guided Vehicle (AGV). The safety distance may be associated with WD 22 and/or includes a distance of robot/machine/other object in which WD 22 is embedded and/or integrated. Vehicle 100 may be configured to displace, move, change location, etc. in an area such as an industrial shopfloor. A vehicle 100 such as an AGV moving on shopfloor should maintain a safety distance between vehicle 100 and humans/object (e.g., human operators, obstacles, equipment) to avoid collision. The following is an example equation described in a safety standard (i.e., International Electrotechnical Commission (TEC) Technical Report (TR 62998-2:2020 04) that defines a minimum hazard distance:

Equation 1 : S = (K * T) + C + M, where

• S is a minimum safety distance;

• K is a velocity of AGV measured in millimeters per second;

• T is stopping time of overall system; and

• M is the measurement uncertainty and represented by tolerance range.

In factory service based on 5G, a network node 16 (i.e., comprising safety logic such as software executed by network node 16) may be used to monitor distance between a vehicle 100 (e.g., AGV) and a human operator. Network node 16 (and/or the safety logic) may be connectable/connected via a 5GS. According to Equation 1, stopping time of overall system (T) would be a sum of reaction time of the safety sensor (e.g., LIDAR), safety message communication (i.e., wireless connection 32) between safety sensor 102 and network node 16 (such as network node 16a comprising safety logic on an edge/cloud communication network 84), reaction time of vehicle 100 (e.g., AGV enforcing a safety command). In other words, user plane latency over 5G may directly affects parameter T of Equation 1.

Further, an HO latency estimator (i.e., node latency estimator unit 24, WD latency estimator unit 26) and a determination of a path/displacement of vehicle 100 (e.g., position A to position B) may be used to determine mobility interruption time (e.g., user plane interruption time at cell change) for any given location change detected/determined over a wireless connection 32 (e.g., 5G connectivity link). This allows network node 16 (and/or WD 22) to adjust parameters and/or control to ensure a safe distance between vehicle 100 and humans/objects (e.g., a human operator). For example, by determining user plane interruption time (e.g., reduced) at cell change, the embodiments of the present disclosure allow a vehicle such as vehicle 100 to operate at a speed (higher than typical speeds) while still avoiding collisions with human operators.

As will be appreciated by one of skill in the art, the concepts described herein may be embodied as a method, data processing system, computer program product and/or computer storage media storing an executable computer program. Accordingly, the concepts described herein may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects all generally referred to herein as a “circuit” or “module.” Any process, step, action and/or functionality described herein may be performed by, and/or associated to, a corresponding module, which may be implemented in software and/or firmware and/or hardware. Furthermore, the disclosure may take the form of a computer program product on a tangible computer usable storage medium having computer program code embodied in the medium that can be executed by a computer. Any suitable tangible computer readable medium may be utilized including hard disks, CD-ROMs, electronic storage devices, optical storage devices, or magnetic storage devices.

Some embodiments are described herein with reference to flowchart illustrations and/or block diagrams of methods, systems and computer program products. It will be understood that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer (to thereby create a special purpose computer), special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks. These computer program instructions may also be stored in a computer readable memory or storage medium that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer readable memory produce an article of manufacture including instruction means which implement the function/act specified in the flowchart and/or block diagram block or blocks.

The computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks.

It is to be understood that the functions/acts noted in the blocks may occur out of the order noted in the operational illustrations. For example, two blocks shown in succession may in fact be executed substantially concurrently or the blocks may sometimes be executed in the reverse order, depending upon the functionality/acts involved. Although some of the diagrams include arrows on communication paths to show a primary direction of communication, it is to be understood that communication may occur in the opposite direction to the depicted arrows.

Computer program code for carrying out operations of the concepts described herein may be written in an object oriented programming language such as Python, Java® or C++. However, the computer program code for carrying out operations of the disclosure may also be written in conventional procedural programming languages, such as the "C" programming language. The program code may execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer. In the latter scenario, the remote computer may be connected to the user's computer through a local area network (LAN) or a wide area network (WAN), or the connection may be made to an external computer (for example, through the Internet using an Internet Service Provider). Many different embodiments have been disclosed herein, in connection with the above description and the drawings. It will be understood that it would be unduly repetitious and obfuscating to literally describe and illustrate every combination and subcombination of these embodiments. Accordingly, all embodiments can be combined in any way and/or combination, and the present specification, including the drawings, shall be construed to constitute a complete written description of all combinations and subcombinations of the embodiments described herein, and of the manner and process of making and using them, and shall support claims to any such combination or subcombination. It will be appreciated by persons skilled in the art that the embodiments described herein are not limited to what has been particularly shown and described herein above. In addition, unless mention was made above to the contrary, it should be noted that all of the accompanying drawings are not to scale. A variety of modifications and variations are possible in light of the above teachings without departing from the scope of the following claims.

Claims

What is claimed is:

1. A wireless device, WD, (22) configured to communicate at least with a network node (16), the WD (22) comprising processing circuitry (50) configured to: determine a first time elapsing from a reception of a handover command until the WD (22) becomes ready to transmit, to the network node, a first message associated with the handover command; and at least one of: determine a second time elapsing from reception of a second message until the WD (22) becomes ready to transmit a third message to the network node (16) in response to the second message; and determine the third message to be transmitted to the network node (16), the third message including at least one of the determined first time and the determined second time.

2. The WD (22) of Claim 1, wherein the first time is included in at least one information element in a WD capability message transmittable by the WD (22).

3. The WD (22) of any one of Claims 1 and 2, wherein the first time is a first indication of WD message processing capability usable for scheduling at least another handover command.

4. The WD (22) of any one of Claims 1-3, wherein the second time is a second indication of WD message processing capability usable for scheduling at least one uplink resource associated with a third message transmission corresponding to a handover process.

5. The WD (22) of any one of Claims 1-4, wherein the processing circuitry (50) is further configured to: determine a third time, the third time being a third indication of WD message processing capability associated with the second message and usable for a contention based random access, CBRA, handover; and include the third time in the third message.

6. The WD (22) of Claim 5, wherein the first message is one of a physical random-access channel, PRACH, and a preamble on the PRACH, the second message is a random access response at least indicating a network node reception of the first message, and the third message being associated at least with a contention resolution.

7. The WD (22) of any one of Claims 1-6, wherein the first time corresponds to a handover preparation time and triggers a random-access channel, RACH, procedure, and the second time corresponds to the RACH procedure.

8. The WD (22) of any one of Claims 1-7, wherein the WD (22) further includes a radio interface (46) in communication with the processing circuitry (50), the radio interface (46) being configured to at least one of: receive at least one of the handover command, the second message, and a fourth message transmitted in response to the third message and associated at least with a connection setup of the WD (22) to the network node (16); and transmit at least one of the first message and the third message to the network node (16).

9. The WD (22) of Claim 8, wherein the fourth message triggers a completion of a handover associated with the handover command, and the handover command is transmitted by one of: the network node (16), the handover being from a first cell of the network node (16) to a second cell of the network node (16); and another network node, the handover being from the network node (16) to the other network node.

10. The WD (22) of any one of Claims 1-9, wherein the processing circuitry (50) is further configured to at least one of: determine a mobility interruption time associated with a location change of the WD (22) at least from a first location to a second location based at least in part on one of the first time and the second time; determine a safety distance associated with the WD (22) based at least in part on the determined mobility interruption time; and trigger the network node (16) to expose the mobility interruption time associated with the location change to at least an industrial application, exposing the mobility interruption time including transmitting the mobility interruption time.

11. A method implemented in a wireless device, WD, (22) configured to communicate at least with a network node (16), the method comprising: determining (SI 00) a first time elapsing from a reception of a handover command until the WD (22) becomes ready to transmit, to the network node (16), a first message associated with the handover command; and at least one of (SI 02): determining a second time elapsing from reception of a second message until the WD (22) becomes ready to transmit a third message to the network node (16) in response to the second message; and determining the third message to be transmitted to the network node (16), the third message including at least one of the determined first time and the determined second time.

12. The method of Claim 11, wherein the first time is included in at least one information element in a WD capability message transmittable by the WD (22).

13. The method of any one of Claims 11 and 12, wherein the first time is a first indication of WD message processing capability usable for scheduling at least another handover command.

14. The method of any one of Claims 11-13, wherein the second time is a second indication of WD message processing capability usable for scheduling at least one uplink resource associated with a third message transmission corresponding to a handover process.

15. The method of any one of Claims 11-14, wherein the method further includes: determining a third time, the third time being a third indication of WD message processing capability associated with the second message and usable for a contention based random access, CBRA, handover; and including the third time in the third message.

16. The method of Claim 15, wherein the first message is one of a physical random-access channel, PRACH, and a preamble on the PRACH, the second message is a random access response at least indicating a network node reception of the first message, and the third message being associated at least with a contention resolution.

17. The method of any one of Claims 11-16, wherein the first time corresponds to a handover preparation time and triggers a random-access channel, RACH, procedure, and the second time corresponds to the RACH procedure.

18. The method of any one of Claims 11-17, wherein the method further includes at least one of: receiving at least one of the handover command, the second message, and a fourth message transmitted in response to the third message and associated at least with a connection setup of the WD (22) to the network node (16); and transmitting at least one of the first message and the third message to the network node (16).

19. The method of Claim 18, wherein the fourth message triggers a completion of a handover associated with the handover command, and the handover command is transmitted by one of: the network node (16), the handover being from a first cell of the network node (16) to a second cell of the network node (16); and another network node, the handover being from the network node (16) to the other network node.

20. The method of any one of Claims 11-19, wherein the method further includes at least one of: determining a mobility interruption time associated with a location change of the WD (22) at least from a first location to a second location based at least in part on one of the first time and the second time; determining a safety distance associated with the WD (22) based at least in part on the determined mobility interruption time; and triggering the network node (16) to expose the mobility interruption time associated with the location change to at least an industrial application, exposing the mobility interruption time including transmitting the mobility interruption time.

21. A network node (16) configured to communicate at least with a wireless device, WD, (22) the network node (16) comprising processing circuitry (36) configured to: determine at least one of a first time and a second time, the first time elapsing from a reception by the WD (22) of a handover command until the WD (22) becomes ready to transmit, to the network node (16), a first message associated with the handover command, the second time elapsing from reception by the WD (22) of a second message until the WD (22) becomes ready to transmit a third message to the network node (16) in response to the second message, the at least one of the first time and the second time being included in the third message.

22. The network node (16) of Claim 21, wherein the first time is included in at least one information element in a WD capability message transmittable by the WD (22).

23. The network node (16) of any one of Claims 21 and 22, wherein the processing circuitry (36) is further configured to: determine a scheduling of another handover command based at least in part on the first time, the first time being a first indication of WD message processing capability.

24. The network node (16) of any one of Claims 21-23, wherein the processing circuitry (36) is further configured to: determine another scheduling of at least one uplink resource associated with a third message transmission corresponding to a handover process based at least in part on the second time, the second time being a second indication of WD message processing.

25. The network node (16) of any one of Claims 21-24, wherein the processing circuitry (36) is further configured to: determine a contention based random access, CBRA, handover based at least in part on a third time included in the third message, the third time being a third indication of WD message processing capability associated with the second message.

26. The network node (16) of any one of Claims 21-25, wherein the first message is one of a physical random-access channel, PRACH, and a preamble on the PRACH, the second message is a random access response at least indicating a network node reception of the first message, and the third message being associated with at least with contention resolution.

27. The network node (16) of any one of Claims 21-26, wherein the first time corresponds to a handover preparation time and triggers a random-access channel, RACH, procedure, and the second time corresponds to the RACH procedure.

28. The network node (16) of any one of Claims 21-27, wherein the network node (16) further includes a radio interface (30) in communication with the processing circuitry (36), the radio interface (30) being configured to at least one of: receive at least one of the first message and the third message from the WD (22), the third message being used by the network node (16) to determine the at least one of a first time and a second time; and transmit, to the WD (22), at least one of the handover command, the second message, and a fourth message being transmitted in response to the third message and associated at least with a connection setup of the WD (22) to the network node (16).

29. The network node (16) of Claim 28, wherein the fourth message triggers a completion of a handover associated with the hand over command, and the handover command is transmitted by one of: the network node (16), the handover being from a first cell of the network node (16) to a second cell of the network node (16); and another network node, the handover being from the network node (16) to the other network node.

30. The network node (16) of any one of Claims 21-29, wherein the processing circuitry (36) is further configured to at least one of: determine a mobility interruption time associated with a location change of the WD (22) at least from a first location to a second location based at least in part on one of the first time and the second time; determine a safety distance associated with the WD (22) based at least in part on the determined mobility interruption time; and expose the mobility interruption time associated with the location change to at least an industrial application, exposing the mobility interruption time including transmitting the mobility interruption time.

31. A method implemented in a network node (16) configured to communicate at least with a wireless device, WD, (22) the method comprising:

Determining (SI 04) at least one of a first time and a second time, the first time elapsing from a reception by the WD (22) of a handover command until the WD (22) becomes ready to transmit, to the network node (16), a first message associated with the handover command, the second time elapsing from reception by the WD (22) of a second message until the WD (22) becomes ready to transmit a third message to the network node (16) in response to the second message, the at least one of the first time and the second time being included in the third message.

32. The method of Claim 31, wherein the first time is included in at least one information element in a WD capability message transmittable by the WD (22).

33. The method of any one of Claims 31 and 32, wherein the method further includes: determining a scheduling of another handover command based at least in part on the first time, the first time being a first indication of WD message processing capability.

34. The method of any one of Claims 31-33, wherein the method further includes: determining another scheduling of at least one uplink resource associated with a third message transmission corresponding to a handover process based at least in part on the second time, the second time being a second indication of WD message processing.

35. The method of any one of Claims 31-34, wherein the method further includes: determining a contention based random access, CBRA, handover based at least in part on a third time included in the third message, the third time being a third indication of WD message processing capability associated with the second message.

36. The method of any one of Claims 31-35, wherein the first message is one of a physical random-access channel, PRACH, and a preamble on the PRACH, the second message is a random access response at least indicating a network node (16) reception of the first message, and the third message being associated with at least with contention resolution.

37. The method of any one of Claims 31-36, wherein the first time corresponds to a handover preparation time and triggers a random-access channel, RACH, procedure, and the second time corresponds to the RACH procedure.

38. The method of any one of Claims 31-37, wherein method further includes at least one of: receiving at least one of the first message and the third message from the WD (22), the third message being used by the network node (16) to determine the at least one of a first time and a second time; and transmitting, to the WD (22), at least one of the handover command, the second message, and a fourth message being transmitted in response to the third message and associated at least with a connection setup of the WD (22) to the network node (16).

39. The method of Claim 38, wherein the fourth message triggers a completion of a handover associated with the hand over command, and the handover command is transmitted by one of: the network node (16), the handover being from a first cell of the network node (16) to a second cell of the network node (16); and another network node, the handover being from the network node (16) to the other network node.

40. The method of any one of Claims 31-39, wherein the method further includes at least one of: determining a mobility interruption time associated with a location change of the WD (22) at least from a first location to a second location based at least in part on one of the first time and the second time; determining a safety distance associated with the WD (22) based at least in part on the determined mobility interruption time; and exposing the mobility interruption time associated with the location change to at least an industrial application, exposing the mobility interruption time including transmitting the mobility interruption time.