Communication device, communication method, and program

Abstract

To improve the efficiency of a communication service using a network slice.SOLUTION: A communication device requests a network to allocate a first network slice for executing predetermined processing required in executing a communication service to be executed by the communication device and to allocate a second network slice for the communication service, supplies a result of the predetermined processing executed in the first network slice for communication in the second network slice, and performs communication using the result of the predetermined processing in the second network slice.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to advanced communication technology using network slices. [Background technology]

[0002] The Third Generation Partnership Project (3GPP) specifies that communication should be carried out using network slices, which are virtually divided networks for each service requirement (Non-Patent Document 1). [Prior art documents] [Non-patent literature]

[0003] [Non-Patent Document 1] 3GPP TS23.501, V15.1.0, March 2018 Summary of the Invention [Problem to be solved by the invention]

[0004] Communication using a network slice allows resources to be secured for each service, enabling communication suited to each individual service. However, it may take some time for each service to start after the network slice is provided, which may result in inefficiency.

[0005] The present invention provides a technology for improving the efficiency of communication services using network slices. [Means for solving the problem]

[0006] A communication device according to one embodiment of the present invention is a communication device that performs wireless communication compliant with the 3GPP standard, and includes a requesting means for requesting the allocation of a first network slice for performing a predetermined processing required when executing a communication service performed by the communication device and the allocation of a second network slice for the communication service, a supplying means for supplying a result of the predetermined processing performed in the first network slice for communication in the second network slice, and in the second network slice: The predetermined processing is not performed in the first network slice. and a communication means for performing communication using the result of the predetermined processing. [Effects of the Invention]

[0007] According to the present invention, communication services using network slices can be made more efficient. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 illustrates an example of the configuration of a communication system. [Figure 2] FIG. 10 is a diagram illustrating an example of the flow of time synchronization processing executed by a communication device. [Figure 3] FIG. 1 is a diagram illustrating the configuration of NSSAI. [Figure 4] FIG. 1 is a diagram illustrating an example of 5G QoS settings. [Figure 5] FIG. 10 is a diagram illustrating the flow of a grandmaster selection process performed by the BMCA. [Figure 6] FIG. 1 is a diagram showing the flow of a procedure for estimating transmission delay in PTP. [Figure 7] FIG. 10 is a diagram illustrating an example of a change in error over time when time synchronization processing is performed using PTP. [Figure 8] A diagram showing an example of communication flow using a network slice for a service. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the scope of the invention claimed. Although multiple features are described in the embodiments, not all of these multiple features are necessarily essential to the invention, and multiple features may be combined arbitrarily. Furthermore, in the accompanying drawings, the same reference numerals are used to designate the same or similar components, and redundant explanations will be omitted.

[0010] (System Configuration) FIG. 1 shows an example of the configuration of a communication system according to this embodiment. The communication system includes, for example, a communication device 101, a 5G network 102, and a data network 103. The 5G network 102 is a network of a fifth-generation (5G) cellular communication system and includes a radio access network (RAN) and a core network. The core network includes a user plane function (UPF) and a control plane function (CPF). The communication device 101 is configured to be able to establish a wireless connection with the RAN of the 5G network 102 and perform wireless communication. The 5G network 102 can connect the communication device 101, which is a terminal device of the cellular communication system, to a data network 103 external to the cellular communication system network via the UPF. The communication device 101 is configured to be able to access the data network 103 via the 5G network 102, obtain information from the data network 103, and transmit information to the data network 103.

[0011] In this embodiment, in such a configuration, a network slice 104 for time synchronization is set in accordance with a request from the communication device 101, and the communication device 101 synchronizes its internal time with the time of a highly reliable time server present on the network. A network slice is a virtualized unit of a network for providing services according to the purpose of communication. The communication device 101 then provides the time information for which time synchronization has been established in the network slice 104 for time synchronization to the network slice for another service executed by the communication device 101. This eliminates the need to establish time synchronization for each slice, thereby shortening the time until the start of a communication service in the network slice for the service. Note that time synchronization is an example. The communication device 101 may establish a dedicated network slice for performing predetermined processing (e.g., user authentication) required to execute (and, in some cases, start) multiple communication services, and provide the results of the predetermined processing for communication in other network slices. Note that the predetermined processing may be processing that requires continuous communication.

[0012] For this processing, the communication device 101 has, for example, a configuration as shown in FIG. 1. The communication device 101 includes one or more processors, such as a CPU or an MPU, and can realize each function shown in FIG. 1 by executing a program stored in any storage device, such as a memory, such as a ROM or RAM. CPU is an acronym for Central Processing Unit, and MPU is an acronym for Micro Processing Unit. ROM is an acronym for Read Only Memory, and RAM is an acronym for Random Access Memory. The communication device 101 may include, for example, circuits for wireless communication, such as an antenna, a baseband chip, and a radio frequency (RF) chip, and may also include circuits for wired communication. It may also have dedicated hardware that realizes some or all of the functions shown in FIG. 1. It is sufficient for the communication device 101 to have a configuration capable of executing the following processing, and it does not necessarily have the configuration shown in FIG. 1. In other words, the communication device 101 may not have some or all of the configuration of FIG. 1, but may have an alternative configuration.

[0013] The communication device 101 includes a 5G slice controller 105 that controls the setting of a slice within the device. The 5G slice controller 105 requests the network side to set up a network slice, receives a response indicating that the network slice has been set up on the network side, and sets up the network slice within the communication device 101. The communication device 101 also includes a user network device 106 and a network control device such as a router 108 for communicating with each device in the 5G network 102 and the data network 103. The communication device 101 also has a grandmaster device 107 and a clock synchronizer 109 for time synchronization functions. After the network slice 104 for time synchronization is set up, the clock synchronizer 109 establishes time synchronization via the 5G network 102 using, for example, PTP, based on the grandmaster clock on the data network 103. PTP stands for Precision Time Protocol. The grandmaster device 107 operates as a grandmaster clock in accordance with an internal clock and oscillator within the communication device 101 based on the time synchronization established by the clock synchronizer 109. The grandmaster device 107 can output time information based on the oscillator within the communication device 101. The clock synchronizer 109 supplies time information to applications 110, sensors 111, actuators 112, etc. that require time synchronization within the communication device 101 based on the established time synchronization. Note that, for example, after the communication device 101 is disconnected from the 5G network 102, the clock synchronizer 109 establishes time synchronization using the grandmaster device 107 within the communication device 101 as the grandmaster and supplies time information.

[0014] The 5G network 102 is a network that provides RAN and core network functions in accordance with a general 5G cellular communication standard. In one example, the 5G network 102 includes a 5G orchestrator 114 and a mobile controller 115. The 5G orchestrator 114 manages network slices 116 for various services. The mobile controller 115 configures network slices appropriate for each service under the control of the 5G orchestrator 114. For example, in FIG. 1, the network slice 116 is configured for a time synchronization service so that error rates, such as frame error rates, can be extremely low and highly reliable communications can be performed. The 5G network 102 further includes a 5G grandmaster device 113. The 5G grandmaster device 113 establishes time synchronization based on, for example, a grandmaster clock (e.g., a PTP grandmaster 118) in the data network 103 and distributes time information within the 5G network 102. The 5G grandmaster device 113 may provide time information to the communication device 101 as needed. The data network 103 includes a network 119, and is configured to include a network controller 117, a PTP grandmaster device 118, a cloud server 120, and the like, all connected to the network 119.

[0015] (Processing flow) Next, an example of the flow of time synchronization processing will be described with reference to FIG. 2. In this processing, the communication device 101 determines whether an application requiring QoS control is installed (S201). If an application requiring QoS control is not installed (NO in S201), the communication device 101 ends the processing without executing the following processing. Note that here, the communication device 101 may also determine whether an application requiring time synchronization is installed, for example. That is, if an application requiring QoS control but not time synchronization is installed, the communication device 101 may end the processing without executing the following processing. On the other hand, if an application requiring QoS control is installed (YES in S201), the communication device 101 requests the 5G network 102 to allocate a network slice for time synchronization (S202). For example, the 5G slice controller 105 uses NSSAI (Network Slice Selection Assistance Information) to request the 5G orchestrator 114 to allocate a network slice.

[0016] Here, the NSSAI will be explained using FIG. 3. The NSSAI is identification information of the network side (such as the 5G network 102) that provides the service used by the network slice. The NSSAI includes one or more S-NSSAI (Single NSSAI). The S-NSSAI is composed of an Slice / Service Type (SST) and a Slice Differentiator (SD). The SST stores a value indicating the service type. Service types include enhanced mobile broadband (eMBB), which requires broadband, URLLC, which requires high reliability and low latency, and MIoT, which requires the connection of a massive number of terminals, and the SST stores a value indicating one of these. The SD is used to manage the NSSAI on the network side. In this way, in communications in the 5G network 102, communication characteristics are set according to the service type, and the 5G orchestrator 114 instructs the mobile controller 115 and the network controller 117 to make settings according to these communication characteristics. The 5G orchestrator 114 can determine communication policies (control of bandwidth, delay, priority, etc.) on a slice-by-slice or packet-by-packet basis, and can manage consistency between policies in the 5G network 102 and the data network 103, enabling efficient operation. The mobile controller 115 sets QoS for each network slice within the 5G network 102.

[0017] FIG. 4 shows an example of QoS settings in a 5G network. In the example of FIG. 4, for each 5QI (5G QoS Identifier), in addition to a priority that sets the priority, delay, packet loss rate, packet length, etc. are specified as QoS settings. Note that the network slice for time synchronization requested in S202 (hereinafter referred to as a synchronization slice) does not require a wide frequency bandwidth, but does require highly reliable and low-latency communication characteristics. In the data network 103, the network controller 117 performs QoS settings. Since data networks are generally IP networks, for example, DSCP (Differentiated Service Code Point) is used for QoS control, and transmission control is performed based on priority.

[0018] When the 5G orchestrator 114 completes the setting of the synchronization slice in response to an instruction to the mobile controller 115 and the network controller 117, it transmits a response indicating this to the communication device 101. The communication device 101 determines whether the allocation of the synchronization slice is complete depending on whether the 5G slice controller 105 has received a response (S203). When the allocation of the synchronization slice is complete (YES in S203), for example, PTP communication is performed between the PTP grandmaster 118 and the clock synchronizer 109 (S204).

[0019] PTP is a protocol standardized by IEEE 1588. First, a grandmaster, which will serve as the clock synchronization source, is selected using a method called BMCA (Best Master Clock Algorithm). An example of the grandmaster selection process using BMCA is described below with reference to FIG. 5. In BMCA, the best candidate is selected as the grandmaster from among multiple grandmaster candidates within the network. To achieve this, in PTP, a grandmaster candidate broadcasts a packet called an Announce Packet within the network at regular intervals (S301). When the clock synchronizer 109 of the communication device 101, operating as a slave, receives an Announce Packet from multiple grandmaster candidate devices, it analyzes the contents of the Announce Packet. The clock synchronizer 109 then compares the priority, clock quality (Class), time accuracy (Accuracy), precision, and other parameters described in the packet (S502 to S505). If two candidates have the same performance, the device identifiers may be compared (S506). Then, based on these comparisons, the clock synchronizer 109 selects as the grandmaster the candidate that is expected to be the best (S507, S508). In this embodiment, it is assumed that the clock synchronizer 109 selects the PTP grandmaster 118 as the grandmaster. As described above, Announce Packets are sent at regular intervals, but the clock synchronizer 109 may not receive Announce Packets from the selected grandmaster if, for example, the power to the selected grandmaster is turned off. In this case, the clock synchronizer 109 reselects a grandmaster based on Announce Packets from other grandmaster candidates in the network. For example, if the clock synchronizer 109 is no longer able to receive Announce Packets from the PTP grandmaster 118 due to degradation of the communication environment, it may reselect a grandmaster.Then, through this reselection, the clock synchronizer 109 can select, as the grandmaster, for example, the grandmaster device 107 or the 5G grandmaster device 113. In other words, the clock synchronizer 109 can establish synchronization according to reference time information supplied within the device or within the network of the cellular communication system, and supply time information.

[0020] The clock synchronizer 109 executes a process of establishing time synchronization with the selected PTP grandmaster 118 by exchanging packets with the PTP grandmaster 118. This process will be explained using FIG. 6. A Sync Packet, a Delay Request Packet, and a Delay Response Packet are used to calculate the communication delay between the grandmaster and the slave. The Sync Packet from the grandmaster contains a timestamp T1 indicating the transmission time, and the slave records this T1 and a timestamp T2 indicating the reception time of this packet. The slave records a timestamp T3 indicating the transmission time of the Delay Request Packet that will be transmitted subsequently. When the grandmaster receives the Delay Request Packet, it includes a timestamp T4 indicating the reception time of the Delay Request Packet in a Delay Response Packet and transmits this to the slave. The slave receives the Delay Response Packet and records the timestamp T4, thereby retaining all of the timestamps T1 to T4. The slave can estimate the transmission delay by using the times indicated by these timestamps to calculate "transmission delay = ((T4 - T1) - (T3 - T2)) / 2". The slave then adjusts its own internal time based on the reference time information sent from the grandmaster and the transmission delay. This procedure counts as one time correction, and this delay correction is repeated at regular intervals. Figure 7 shows the measurement results of the time difference between the grandmaster time and the corrected slave time when this time correction is repeated. As this example shows, with PTP, it takes a certain amount of time for the time error to converge to a sufficiently small value.

[0021] 2, the communication device 101 repeatedly executes time synchronization processing by PTP and determines whether the time has converged by, for example, determining whether a predetermined time has elapsed while the correction amount is equal to or less than a predetermined value (S205). If the communication device 101 determines that the time has converged (YES in S205), it transitions to a state in which time synchronization has been completed and starts regenerating the time synchronization, i.e., outputting time information (S206).

[0022] Next, an example of a processing flow when the communication device 101 starts communication for a service will be described with reference to FIG. 8. First, when communication for a service should be started (for example, when a user operation is performed or when communication is initiated by a predetermined application), the communication device 101 requests the 5G orchestrator 114 to allocate a network slice for the service (S801). Similar to the process for allocating a synchronization slice, the communication device 101 requests slice allocation from the 5G orchestrator 114 using an NSSAI for the service. Then, the communication device 101 determines whether the allocation of the network slice for the service has been completed based on a response from the 5G orchestrator 114 (S802). If the allocation of the network slice for the service has been completed (YES in S802), the communication device 101 confirms that time synchronization has been completed in the synchronization slice (S803). Then, when the communication device 101 confirms that time synchronization has been completed (YES in S803), it starts communication using the network slice for the service (S804).

[0023] As shown in FIG. 4, QoS control such as required bandwidth, delay, bit error rate (or packet error rate), and priority control can be defined as characteristics of communication for a service. This allows different QoS controls to be applied to video distribution services that tolerate large delays, and video communication services associated with operating heavy machinery or surgical robots that do not tolerate delays, among other video communications. As shown in FIG. 4, the required bandwidth, delay, bit error rate, etc. are associated with 5QI, which is identification information. By including the 5QI in packets, QoS control can be performed on a packet-by-packet basis. When time synchronization is established at the start of communication for these services, the communication device 101 cannot start the service and must wait until the time synchronization has converged. In contrast, in this embodiment, a network slice for time synchronization is provided, and the time synchronization is converged in advance, allowing the communication device 101 to quickly start the service.

[0024] The present invention can also be realized by supplying a program that realizes one or more functions of the above-described embodiments to a system or device via a network or a storage medium, and having one or more processors in the computer of the system or device read and execute the program.The present invention can also be realized by a circuit (e.g., ASIC) that realizes one or more functions.

[0025] The invention is not limited to the above-described embodiments, and various changes and modifications can be made without departing from the spirit and scope of the invention. Accordingly, the following claims are appended to apprise the public of the scope of the invention. [Explanation of symbols]

[0026] 101: Communication device, 104: Network slice for time synchronization, 105: 5G slice controller, 109: Clock synchronization device

Claims

1. A communication device that performs wireless communication in accordance with the 3GPP standard, a requesting means for requesting allocation of a first network slice for executing a predetermined process required when executing a communication service executed by the communication device and allocation of a second network slice for the communication service; a supplying means for supplying a result of the predetermined processing executed in the first network slice for communication in the second network slice; a communication means for performing communication using a result of the predetermined processing executed in the first network slice without performing the predetermined processing in the second network slice; A communication device comprising:

2. The communication device according to claim 1 , wherein the supplying means supplies the results of the predetermined processing to a plurality of the second network slices.

3. The communication device according to claim 1 or 2, characterized in that, when there is no communication service requiring the specified processing, the requesting means requests allocation of the second network slice without requesting allocation of the first network slice.

4. 4. The communication device according to claim 1, wherein the predetermined process is a time synchronization process, and the result of the predetermined process is time information.

5. The communication device according to claim 4, wherein the communication means starts communication via the second network slice after the time synchronization process is completed.

6. A communication device as described in claim 4 or 5, characterized in that when a specified packet is no longer received from a device that supplies a reference time in the time synchronization process in the first network slice, the supplying means supplies internal time information of the communication device.

7. A communication device described in any one of claims 4 to 6, characterized in that when a specified packet is no longer received from a first device that supplies a reference time in the time synchronization process in the first network slice, the supplying means supplies time information based on a reference time from a second device that transmits the specified packet and from which the communication device is receiving the specified packet.

8. 8. The communication device according to claim 7, wherein the communication device is a terminal device of a cellular communication system, the second device is located inside the network of the cellular communication system, and the first device is located outside the network of the cellular communication system.

9. A communication method executed by a communication device that performs wireless communication in accordance with the 3GPP standard, Requesting allocation of a first network slice for performing a predetermined process required when executing a communication service executed by the communication device and allocation of a second network slice for the communication service; Providing a result of the predetermined processing performed in the first network slice for communication in the second network slice; In the second network slice, performing communication using a result of the predetermined processing executed in the first network slice without performing the predetermined processing; A communication method comprising:

10. A program for causing a computer to function as the communication device according to any one of claims 1 to 8.

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