Cell reselection based on probabilistic slicing

Abstract

The present invention provides a method of operating a user equipment, UE, in a cellular telecommunications network implementing a plurality of network slices, the method comprising the steps of: determining a UE-specific usage probability for each network slice of each of the plurality of network slices based on an analysis of uplink data traffic; receiving an area specific use probability of each network slice in the plurality of network slices, wherein the area specific use probability of each network slice is specific to an area where the UE is located; modifying a network slice cell reselection priority for one or more of the plurality of network slices based on the region-specific probability of use for each network slice and also based on the UE-specific probability of use for each network slice; and performing a cell reselection process based on the modified network slice cell reselection priority. The invention also provides a method of operating a device in a cellular telecommunications network implementing a plurality of network slices, the method comprising the steps of: determining an area-specific probability of use for each network slice of the plurality of network slices, the area-specific probability of use for each network slice being area-specific; and transmitting the region-specific probability of use for each network slice to at least one UE in the region, where the region-specific probability of use for each network slice is based on an analysis of one or more of a group comprising: downlink data traffic of a plurality of users in the region; a capability of the network slice in the region; subscription data of the plurality of users in the area; and a roaming protocol between network operators covering the area.

Description

Technical Field

[0001] This invention relates to a cellular telecommunications network. Background Technology

[0002] Network slicing is a technology used to create differentiated logical networks over public infrastructure. It allows for the optimization of network infrastructure for specific services, end users, or network operators by deploying specially configured or customized network functions on virtualized hardware, software-controlled networks, and / or custom physical hardware. This can be performed on one or more network functions on one or more nodes in the network, including access networks, backhaul networks, and core networks. In doing so, a collection of logical network functions (and the virtual networks connecting them) can be grouped into network slices that leverage virtualized network functions, software-controlled networks, and / or custom physical hardware on one or more nodes in the network. Each network slice can then be configured (e.g., by configuring each virtual function of the network slice) to optimize it for specific use cases. For example, in a cellular network, a first network slice for autonomous vehicle applications can be configured on one or more nodes in the cellular network to deliver ultra-high reliability and ultra-low latency services, and other network slices configured for other applications can also run on the same nodes via other virtual functions.

[0003] In the 3GPP cellular telecommunications standard, a central network node (such as the Access and Mobility Management Function, AMF) can configure a set of available network slices for a User Equipment (UE), where each network slice can be optimized for a specific use case. The UE can then select a network slice from this set of available network slices. Another concept, "slice-specific cell reselection information," has been proposed and included in 3GPP Technical Specification 38.300. Slice-specific cell reselection information can include reselection priorities per frequency and per network slice, as well as a list of corresponding cells that support or do not support the network slice. These reselection priorities can be used to influence cell selection or reselection when the UE performs a cell reselection process. Summary of the Invention

[0004] According to a first aspect of the present invention, a method for operating a user equipment (UE) in a cellular telecommunications network implementing multiple network slices is provided. The method includes the following steps: determining a UE-specific usage probability for each network slice in the plurality of network slices based on analysis of uplink data services; receiving a region-specific usage probability for each network slice in the plurality of network slices, the region-specific usage probability of each network slice being specific to the region where the UE is located; modifying the network slice cell reselection priority of one or more network slices in the plurality of network slices based on the region-specific usage probability of each network slice and also based on the UE-specific usage probability of each network slice; and performing a cell reselection process based on the modified network slice cell reselection priority.

[0005] According to a second aspect of the present invention, a method for operating a device in a cellular telecommunications network implementing multiple network slices is provided, the method comprising the steps of: determining a region-specific usage probability for each of the plurality of network slices, the region-specific usage probability of each network slice being region-specific; and transmitting the region-specific usage probability of each network slice to at least one UE in the region, wherein the region-specific usage probability of each network slice is based on an analysis of one or more of the following: downlink data services of a plurality of users in the region; the capabilities of the network slice in the region; subscription data of the plurality of users in the region; and roaming agreements between network operators covering the region.

[0006] According to a third aspect of the invention, a computer program including instructions is provided that, when executed by a user device, causes the user device to perform the steps of the first aspect of the invention. The computer program may be stored on a computer-readable media.

[0007] According to a fourth aspect of the invention, a computer program including instructions is provided, which, when executed by a device, cause the device to perform the steps of the second aspect of the invention. The computer program may be stored on a computer-readable media.

[0008] According to a fifth aspect of the present invention, a user equipment (UE) for a cellular telecommunications network is provided, the UE including a processor configured to perform the steps of the first aspect of the present invention.

[0009] According to a sixth aspect of the invention, an apparatus for a cellular telecommunications network is provided, the apparatus comprising a processor configured to perform the steps of a second aspect of the invention.

[0010] According to a seventh aspect of the present invention, a system is provided that includes a user equipment (UE) of the fifth aspect of the present invention and a device of the sixth aspect of the present invention. Attached Figure Description

[0011] To better understand the present invention, embodiments thereof will now be described by way of example only with reference to the accompanying drawings, in which:

[0012] Figure 1 This is a schematic diagram illustrating a cellular telecommunications network;

[0013] Figure 2 It is shown by Figure 1 A flowchart illustrating the process of implementing network slice management nodes in a network.

[0014] Figure 3 It is shown by Figure 1 A flowchart illustrating the process of implementing a network base station;

[0015] Figure 4 It is shown by Figure 1 The flowchart shows the process of implementing user equipment in a network. Detailed Implementation

[0016] Figure 1 A cellular telecommunications network 100 with a first tracking area 110 and a second tracking area 150 is illustrated. The first tracking area 110 includes a first base station 120, a first user equipment (UE) 130, and a second UE 140. The second tracking area 150 includes a second base station 160. The first tracking area 110 and the second tracking area 150 may include more than Figure 1 This indicates more base stations and more UEs. Figure 1 A core network 170 is also shown, which includes a network slice management node 180. The network slice management node 180 is connected to the first base station 120 and the second base station 160 via a suitable connection (e.g., a wireless or wired connection).

[0017] The cellular telecommunications network is configured to implement network slicing. Therefore, one or more nodes in the network (such as the first base station 120 and the second base station 160, and one or more nodes in the core network 170) can implement a Network Function Virtualization (NFV) architecture, allowing virtual machines to be built on one or more of these network nodes and / or including dedicated physical hardware for a specific network slice. These virtual machines and / or dedicated physical hardware can then be customized for specific use cases (such as for a specific service or a specific network operator) through appropriate configuration. Each network slice in network 100 can be identified by a network slice identifier.

[0018] Figure 2 This is a flowchart illustrating the process implemented by the network slice management node 180. In the first step S101, the network slice management node 180 sends instructions to each UE (such as the first UE 130 and the second UE 140) in each tracking area. Figure 1 The network slice configuration message is sent by any other UE (not shown) to the UE. The network slice configuration message is a device-specific Non-Access Stratum (NAS) message and contains a set of network slice identifiers that identify each network slice available to the UE. The network slice configuration message also includes the cell reselection priority for each network slice identified in the set of network slice identifiers. These priorities can be used to influence cell selection or reselection, as described in 3GPP Technical Specification 38.300.

[0019] In step S103, the network slice management node 180 calculates the usage probability of each network slice supported in each tracking region. The usage probability of each network slice can be calculated based on one or more of the following:

[0020] Business Analysis. The core network can store business patterns for each tracking region (e.g., in Application Function (AF), Data Function (DF), and User Plane Function (UPF)), and can analyze them for each tracking region to identify trends in business types. These trends can be identified on one or more time scales (such as hourly, daily, or weekly time scales) and can be combined into a single metric representing multiple (optionally, weighted) time scales. The probability of network slice usage in each tracking region can be based on these identified trends, such as a relatively high usage of a particular type of business in a recurring time window (e.g., between 9 AM and 5 PM each weekday), which may indicate that a network slice supporting that business is likely to have a relatively high probability of usage in future instances within that recurring time window (compared to the probability of usage assigned to network slices supporting business types with relatively low usage in the data).

[0021] Hardware limitations. The core network can store capacity thresholds on the physical hardware (or virtual machines) used by each network slice in the tracking area. These capacity thresholds may indicate, for example, the maximum number of users that the physical hardware or virtual machine can support simultaneously, or they may relate to specific performance attributes such as process load, data rate, etc. If the current conditions of a network slice meet one or more of these capacity thresholds, the probability of using that network slice can be limited (e.g., limited to zero).

[0022] Subscriptions. The core network can store user subscription types in tracking areas, which can indicate whether there is a relatively high demand for service types associated with a particular network slice. For example, if a tracking area has a relatively high demand for autonomous vehicle services (determined based on the user subscription types in the tracking area), then the network slice supporting this service is likely to have a relatively high probability of use (compared to the probability of use assigned to network slices supporting service types with relatively low usage, as determined by subscription data).

[0023] Roaming. The core network can store roaming protocol data for each network slice, indicating whether the roaming partner operator supports that network slice. In the example, if it is determined from the roaming protocol that the roaming partner operator does not support the network slice, the probability of using that network slice can be limited (e.g., limited to zero).

[0024] In step S105, the network slice management node 180 sends the usage probability of each network slice in the determined first tracking area to the first base station 120 (and any other base station in the first tracking area), and sends the usage probability of each network slice in the determined second tracking area to the second base station 160 (and any other base station in the second tracking area).

[0025] Step S101 can then be triggered after the timer expires or when an event is detected.

[0026] Figure 3 The process implemented by the first base station 120 is illustrated. The following process can also be implemented by any other base station in network 100. In step S201, the first base station 120 receives the usage probability of each network slice of the determined first tracking area (as shown in the reference). Figure 2 (Sent in step S105 of the described process). In step S203, the first base station 120 transmits the probability of each network slice of the first tracking area to each UE in the first tracking area (such as the first UE 130 and the second UE 140, as well as any other UEs in the first tracking area). The form of communication depends on the state of the UE and may include:

[0027] System Information Block (SIB) messages (or portions thereof) (such as SIB16 messages) are broadcast to any UE in inactive (INACTIVE) mode that is in idle (IDLE) mode.

[0028] RRC release message (or a portion thereof) for any UE transitioning from CONECTED mode to idle mode.

[0029] RRC hangup message (or a portion thereof) for any UE transitioning from connected mode to inactive mode, and

[0030] The RRC reconfiguration message (or a portion thereof) for any UE in connected mode will be applied when it is subsequently switched to idle or inactive mode.

[0031] Go to Figure 4 This illustrates the process implemented by the first UE 130. The following process can also be implemented by any other UE in network 100 (such as the second UE 140). In step S301, the first UE 130 receives a network slicing configuration message (in reference...) Figure 2 In step S101 of the described process, the network slice configuration message is sent to the first UE 130, identifying the network slices available to the first UE 130 and their corresponding cell reselection priorities. In step S303, the first UE 130 receives the usage probability of each network slice in the first tracking area (as shown in the reference). Figure 3 (Sent in step S203 of the described process). In step S305, the first UE 130 determines whether a change in its cell reselection priority should be implemented based on the received probability. This determination may also be based on data collected by the first UE 130, such as analyzing uplink traffic data to calculate the UE-specific usage probability for each network slice.

[0032] The following example further illustrates step S305. After steps S301 and S303, the first UE 130 stores the following data regarding the network slices available to the first UE 130:

[0033] Network Slice ID Cell reselection priority Tracking the probability of network slices Slice_gaming 7 10% Slice_eMBB 3 70% Slice_bestEffort 1 20%

[0034] Table 1: A table showing the identifiers, priorities, and probabilities of network slices available to the first UE 130 after step S303.

[0035] Applying step S305 to this example, the first UE 130 can determine that the cell reselection priority should be updated to:

[0036] Network Slice ID Cell reselection priority Slice_eMBB 7 Slice_gaming 3 Slice_bestEffort 1

[0037] Table 2: A table showing the identifiers and priorities of the network slices available to the first UE 130 after step S305.

[0038] These priorities can be determined based on tracking area-specific probabilities, such as those received in step S303 (e.g., enhanced mobile broadband eMBB network slices may have the highest relative priority based on their relatively high usage probability), and also based on data collected by the first UE 130 (e.g., although the usage probability of a best-effort network slice is greater than that of a game network slice, the first UE 130 may determine, based on analysis of historical uplink traffic data, that game traffic should take precedence over best-effort traffic, thus allowing game network slices to have a relatively higher priority than best-effort network slices).

[0039] If the first UE 130 determines that its cell reselection priority should be changed, then in step S307, the first UE 130 modifies its cell reselection priority based on the usage probability of each network slice in the first tracking area 110.

[0040] In step S309, the first UE 130 performs a cell reselection process based on the modified cell reselection priority. That is, the first UE 130 will preferentially attach to a cell that supports a network slice with a relatively high cell reselection priority.

[0041] Therefore, the above process advantageously encourages the first UE 130 to: 1) attach to a cell that supports a network slice more likely to be used by the first UE 130, and 2) connect to a network slice more likely to be used by the first UE 130. This reduces the amount of control signaling and associated energy consumption in network 100 that would otherwise incur if the first UE 130 connects to a cell that only supports a network slice less likely to be used by the first UE 130 (which could result in the first UE 130 requesting a redirect to a suitable cell) and / or connects to a network slice less likely to be used by the first UE 130 (which could result in the first UE 130 requesting a change in the network slice). This further reduces the total time required for the first UE 130 to connect to a suitable cell and network slice.

[0042] The above process also advantageously enables the first UE 130 to prioritize its cell reselection process based on information collected by the core network (including downlink service information) and information collected by the first UE 130 (including uplink service information).

[0043] Those skilled in the art will understand that the dedicated node (network slice management node 180) implements Figure 2 The process shown is not mandatory. That is, any other node in the core network can implement this process. Furthermore, one or more base stations can determine the probability of use for each network slice, which can be done collaboratively (allowing multiple base stations to share data to calculate the probability) and then transmit it to each base station in the tracking area.

[0044] Those skilled in the art will also understand that the probability of network slices transmitted to the UE can be determined in a geographical region different from the tracking region. For example, this region could be the coverage area of ​​one or more base stations in the network, or a combined coverage area. However, the example above is consistent with network slicing implementations that achieve network slicing across tracking regions.

[0045] It is not necessary for the first UE 130 to receive the initial network slice reselection priority from the external node. That is, these priorities can be pre-configured on the first UE 130 (e.g., based on the initial configuration of the first UE 130).

[0046] Those skilled in the art will understand that any combination of features is possible within the scope of the claimed invention. Claims (as amended under Article 19 of the Treaty) 1. A method for operating a user equipment (UE) in a cellular telecommunications network, the cellular telecommunications network further comprising a device, the cellular telecommunications network implementing multiple network slices, the method comprising the following steps: The UE-specific usage probability of each network slice in the plurality of network slices is determined based on the analysis of uplink data services. The device receives the region-specific usage probability of each of the plurality of network slices, wherein the region-specific usage probability of each network slice is specific to the region where the UE is located; Based on the region-specific usage probability of each network slice and further based on the UE-specific usage probability of each network slice, modify the network slice cell reselection priority of one or more of the plurality of network slices; and The cell reselection process is performed based on the modified network slice cell reselection priority. 2. A method for operating a device in a cellular telecommunications network, said cellular telecommunications network implementing multiple network slices, said method comprising the following steps: Determine the region-specific usage probability of each of the plurality of network slices, wherein the region-specific usage probability of each network slice is region-specific; and The region-specific usage probability of each network slice is sent to at least one user equipment (UE) in the region, so that the UE modifies the network slice cell reselection priority of one or more of the plurality of network slices based on the region-specific usage probability of each network slice, wherein the region-specific usage probability of each network slice is based on an analysis of one or more of the following: Downlink data services for multiple users in the region; The capabilities of the network slices in the region; The subscription data of the multiple users in the region; and Roaming agreements between network operators covering the area. 3. A computer program comprising instructions that, when executed by a user device, cause the user device to perform the steps of claim 1. 4. A computer program comprising instructions that, when executed by a device, cause the device to perform the steps of claim 2. 5. A computer-readable carrier medium comprising the computer program of claim 3 or claim 4. 6. A user equipment (UE) for a cellular telecommunications network, the UE comprising a processor configured to perform the steps of claim 1. 7. An apparatus for a cellular telecommunications network, the apparatus comprising a processor configured to perform the steps of claim 2. 8. A system comprising a user equipment (UE) as claimed in claim 6 and a device as claimed in claim 7.

Claims

1. A method for operating a user equipment (UE) in a cellular telecommunications network, wherein the cellular telecommunications network implements multiple network slices, the method comprising the following steps: The UE-specific usage probability of each network slice in the plurality of network slices is determined based on the analysis of uplink data services. Receive the region-specific usage probability of each of the plurality of network slices, wherein the region-specific usage probability of each network slice is specific to the region where the UE is located; The network slice cell reselection priority of one or more of the plurality of network slices is modified based on the region-specific usage probability of each network slice and further based on the UE-specific usage probability of each network slice; as well as The cell reselection process is performed based on the modified network slice cell reselection priority.

2. A method for operating a device in a cellular telecommunications network, said cellular telecommunications network implementing multiple network slices, said method comprising the following steps: Determine the region-specific usage probability of each of the plurality of network slices, wherein the region-specific usage probability of each network slice is region-specific; as well as Send the region-specific usage probability of each network slice to at least one UE in the region, wherein the region-specific usage probability of each network slice is based on an analysis of one or more of the following: Downlink data services for multiple users in the region; The capabilities of the network slices in the region; Subscription data of the multiple users in the region; as well as Roaming agreements between network operators covering the area.

3. A computer program comprising instructions that, when executed by a user device, cause the user device to perform the steps of claim 1.

4. A computer program comprising instructions that, when executed by a device, cause the device to perform the steps of claim 2.

5. A computer-readable carrier medium comprising the computer program of claim 3 or claim 4.

6. A user equipment (UE) for a cellular telecommunications network, the UE comprising a processor configured to perform the steps of claim 1.

7. An apparatus for a cellular telecommunications network, the apparatus comprising a processor configured to perform the steps of claim 2.

8. A system comprising a user equipment (UE) as claimed in claim 6 and a device as claimed in claim 7.

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