Power-saving base station switching device, radio access system, and power-saving base station switching method

Abstract

A base station switching controller (200) is a power-saving base station switching device for switching base stations that process a wireless access signal, the base station switching controller (200) being provided with: a base station optimal allocation / switching determination unit (220) for selecting, on the basis of traffic information collected by a traffic information collection unit (210), one suitable base station from a base station pool (100A) in which a plurality of base stations differing in characteristics are pooled and arranged in advance in accordance with prescribed requirements; and a network switching control unit (240) for switching between a network that is connected to a switching-source base station and a network that is connected to a switching-destination base station.

Description

Technical Field

[0001] The present invention relates to a power-saving base station switching device, a radio access system, and a power-saving base station switching method.

Background Art

[0002] In a radio access system for mobile communication, the transmission timing of radio signals between a terminal and a base station is managed by a MAC (Medium Access Control) Scheduler in the base station as a resource multiplexed in the time domain and the frequency domain, and is realized by allocating a RE (Resource Element) suitable for each terminal.

[0003] An overview of the radio access system will be described. FIG. 10 is a diagram for explaining an overview of the radio access system. As shown in FIG. 10, the radio access system 1 includes a terminal (UE: User Equipment) 10, an antenna (base station antenna) 20, a base station (BBU: Base Band Unit) 30, and a core network 40.

[0004] The UE 10 is a plurality of UEs 1, UE2, UE3,..., UEn (n is an arbitrary natural number), and the base station 30 allocates and manages a RE (refer to the hatching or shading in FIG. 10. The hatching or shading pattern represents the REs separately). When collectively referring to UEs 1, UE2, UE3,..., UEn, it is called UE10. The antenna 20 is an antenna and a transceiver that performs wireless communication with the UE 10 (hereinafter, the "antenna" collectively refers to the antenna, the transceiver, and its power supply unit). The transmitted and received data is connected to the base station 30 by, for example, a dedicated cable.

[0005] The base station 30 is a fixed wireless station established on land that communicates with the UE 10. The base station 30 is dedicated hardware (a dedicated device) that performs radio signal processing. Alternatively, the base station 30 is a vRAN (virtual Radio Access Network) that processes radio signal processing in a radio access system such as LTE (Long Term Evolution) or 5G (five generation) using a general-purpose server. In vRAN (described later), a general-purpose server that is inexpensive and can be obtained in large quantities can be used as the hardware of the base station 30. The base station 30 includes hardware (HW) 31, an OS etc. 32, and a base station processing application 33.

[0006] The core network 40 is an EPC (Evolved Packet Core) / (in the following description, " / " represents "or") 5GC (5G Core Network) or the like.

[0007] <vran> Describe vRAN. In a wireless access system for mobile communication, since high latency requirements and throughput are demanded, it has generally been the case that a base station (BBU) that performs radio signal processing is handled by dedicated hardware (a dedicated device). In recent years, with the widespread adoption of general-purpose servers (IA: Intel Architecture servers (Intel: trademark)), the performance of general-purpose servers has improved dramatically, and it has become possible to obtain them at low cost through mass production. As a result, consideration is underway for vRAN, which performs the radio signal processing of the BBU in wireless access systems such as LTE and 5G, using general-purpose servers.

[0008] In vRAN, since it is possible to use general-purpose servers that are inexpensive and available in large quantities as the hardware of the BBU, a BBU pool can be constructed by aggregating regional DCs (Data Centers) and communication buildings within a radius of several tens of kilometers from the antenna, setting up server racks, and installing multiple general-purpose servers in advance (this concept may be referred to as C-RAN (Centralized-RAN)).

[0009] Since it is possible to prepare multiple base station hardwares (general-purpose servers) in advance in the BBU pool, it has potential advantages that enable flexible operations such as rapid hardware replacement (switching) in case of hardware failure and dynamic scale-out / in according to the increase or decrease in traffic.

[0010] FIG. 11 is a diagram for explaining an overview of resource scheduling in the base station 30 of the wireless access system 1 of FIG. 10. As shown in FIG. 11, the carrier timing of the signals exchanged between the base station 30 and the UE 10 is managed by the base station 30 by allocating resources multiplexed in the time domain (horizontal axis) × frequency domain (vertical axis) for each UE 10. The number of REs can be set in various ways depending on the numerology, radio band, etc. Also, in order to enable efficient transmission, the base station measures the noise level of the signals received from the UE and performs control such as allocating suitable REs for each UE (for example, feedback loop control by HARQ (Hybrid Automatic Repeat Request)).

[0011] In a radio access system for mobile communication, base stations (BBUs) that perform radio signal processing include base station devices aimed at meeting different requirements, such as performance-oriented types aiming to achieve high performance and power-saving-oriented types aiming to achieve power saving when traffic is low. For example, it is conceivable to deploy performance-oriented base stations in urban areas with high traffic and power-saving-oriented base stations in rural areas with low traffic.

[0012] Describe the types of base stations and the advantages and disadvantages according to traffic. A performance-oriented base station is a device aiming for high performance, such as processing all L1 processing (forward error correction (FEC) and front hole (FH) functions, etc. of L1 baseband processing) with an accelerator. The accelerator may consume a large amount of power even when there is no data processing (see Non-Patent Document 1). Among accelerators such as (Field-Programmable Gate Array) / GPU (Graphics Processing Unit) / ASIC (Application-Specific Integrated Circuit), there are those that consume more than 100 W of power even when there is no data to be processed. The advantage is that when the traffic is high, high throughput and simultaneous UE connection can be realized. The disadvantage is that when the traffic is low, power saving may not be achieved because it aims for high performance.

[0013] The power-saving type base station is a device that can reduce power consumption by hardware to the greatest extent by putting the processing to sleep while there is no arriving data to be processed (see Non-Patent Document 2). The merit is that when the traffic is high, since it aims at power saving, high throughput and simultaneous UE connection may not be achievable. When the traffic is low, power saving such as stopping unused resources such as the CPU is possible.

[0014] In a single base station of a performance-oriented base station or a power-saving type base station, it may be difficult to achieve both high performance when the traffic is high and power saving when the traffic is low.

Prior Art Documents

Non-Patent Documents

[0015]

Non-Patent Document 1

Non-Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0016] Even in the prior art, the base station operator can respond by switching to a suitable base station (performance-oriented / power-saving type) according to traffic fluctuations by moving to the site manually and replacing the base station manually as the traffic fluctuates. However, it is necessary to take measures such as the operator having to visit the site and the need for procedures such as transferring settings and switching NW settings in order to physically replace the device. For this reason, there are problems that it takes a great deal of time and requires manpower.

[0017] In view of such a background, the present invention has been made, and an object of the present invention is to simultaneously achieve high performance when traffic is heavy and power saving when traffic is light.

Means for Solving the Problems

[0018] A power-saving base station switching device that switches a base station that processes a radio access signal, comprising: a traffic information collection unit that collects, as traffic information, the amount of traffic flowing into the base station in operation; and a switching determination unit that selects, from a base station pool in which a plurality of base stations with different characteristics are pooled and arranged in advance according to a predetermined requirement, one of the suitable base stations based on the traffic information collected by the traffic information collection unit; and a network switching control unit that switches between the network connected to the base station before switching and the network connected to the base station after switching.

Effects of the Invention

[0019] According to the present invention, it is possible to simultaneously achieve high performance when traffic is heavy and power saving when traffic is light.

Brief Description of the Drawings

[0020]

Figure 1

Figure 2

Figure 3

Figure 4A

Figure 4B

Figure 4C

Figure 4D

Figure 4E

Figure 4F

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Embodiment for Carrying Out the Invention

[0021] Hereinafter, a radio access system and the like in an embodiment for carrying out the present invention (hereinafter referred to as "this embodiment") will be described with reference to the drawings. [Overview] FIG. 1 is a schematic configuration diagram of a radio access system according to an embodiment of the present invention. This embodiment is applicable to a radio access system for EPC / 5GC mobile communication. The same reference numerals are given to the same constituent parts as in FIG. 10. As shown in FIG. 1, the radio access system 1000 includes a terminal (UE) 10, an antenna 20, a base station pool 100A that stores a plurality of base stations (BBUs) with different orientations, a base station switching controller (power-saving base station switching device) 200 that selects and switches one base station (BBU) from the base stations (BBUs) pooled (stored) in the base station pool 100A, and a core network 40.

[0022] <Base Station Pool 100A> The base station pool 100A pre-pools and arranges a plurality of base stations with different characteristics according to predetermined requirements. For example, the base station pool 100A includes a plurality of base stations (BBUs) with different orientations, here, a performance-oriented base station 110 and a power-saving-oriented base station 120. One base station (BBU) selected and switched by the base station switching controller 200 from the performance-oriented base station 110 and the power-saving-oriented base station 120 stored in the base station pool 100A becomes the currently operating base station 100. The base station 100 in FIG. 1 is either the performance-oriented base station 110 or the power-saving-oriented base station 120 in the base station pool 100A.

[0023] The base station pool 100A pools and arranges a performance-oriented base station 110 aiming to achieve high performance and a power-saving-oriented base station 120 aiming to achieve power saving.

[0024] When the base station pool 100A separates the base station function into an RU (Radio Unit), a DU (Distributed Unit), and a CU (Centralized Unit), it pools them in units of separation of the RU, DU, or CU (the functions of the RU, DU, and CU will be described later).

[0025] In EPC / 5GC mobile communication, the function of the BBU is arranged in the DU and CU, and the function of the RRH (Remote Radio Head) that processes radio frequency (RF) is arranged in the RU. Most general base stations are installed as slave stations having only the RU as equipment, and base stations equipped with the DU and CU are called master stations and are connected to the slave stations by a network called a fronthaul.

[0026] Also, the base station pool 100A can be pooled in units of CPU cores, accelerators, and NIC (Network Interface Card) in a server, which are units smaller than the separation units of the RU, DU, or CU.

[0027] In the following description, when referring to the base station 100, it means one base station (BBU) selected and switched by the base station switching controller 200 from among the base stations (performance-oriented base station 110 or power-saving-oriented base station 120) pooled in the base station pool 100A of FIG. 1.

[0028] <Base Station 100> The performance-oriented base station 110 includes hardware 111, an OS etc. 112, a traffic collection unit 113, a resource scheduler 114, a synchronization unit 115, and a base station processing application 116. The power-saving-oriented base station 120 includes hardware 121, an OS etc. 122, a traffic collection unit 123, a resource scheduler 124, a synchronization unit 125, and a base station processing application 126.

[0029] The traffic collection units 113 and 123 periodically observe the amount of traffic flowing into the base station 100 (the performance-oriented base station 110 or the power-saving-oriented base station 120) and detect changes in traffic characteristics. The traffic collection units 113 and 123 transmit the change information of the traffic characteristics to the base station switching controller 200 (see arrow a in Fig. 1).

[0030] The resource schedulers 114 and 124 are MAC schedulers that allocate the RE multiplexed in the time domain and the frequency domain to each UE10 (see Fig. 11) and schedule the radio access signal between the UE10 and the base station 100.

[0031] The synchronization units 115 and 125 synchronize when copying the RE allocation information managed by the resource schedulers 114 and 124 (MAC schedulers) from the source to the destination.

[0032] <Base station switching controller 200> The base station switching controller 200 includes a traffic information collection unit 210, a base station optimal allocation / switching determination unit 220, a resource allocation information synchronization control unit 230, and a network switching control unit 240.

[0033] The traffic information collection unit 210 collects the amount of traffic flowing into the operating base station as traffic information. Specifically, the traffic information collection unit 210 collects the change information of the traffic characteristics collected by the traffic collection units 113 and 123 of the base station 100 and determines whether it is a situation of low traffic or high traffic.

[0034] The traffic information collection unit 210 also utilizes the traffic information collected in the past to predict future traffic. At this time, the traffic information collection unit 210 may predict future traffic using machine learning or the like.

[0035] The base station optimal allocation / switching determination unit 220 (switching determination unit) selects one suitable base station from the base station pool 100A in which a plurality of base stations with different characteristics are pre-pooled and arranged according to a predetermined requirement based on the traffic information collected by the traffic information collection unit 210. For example, when the traffic is large, the base station optimal allocation / switching determination unit 220 selects the performance-oriented base station 110, and when the traffic is small, it selects the power-saving-oriented base station 120. The base station (BBU) selected by the base station optimal allocation / switching determination unit 220 from the base station pool 100A becomes the suitable base station 100.

[0036] The base station optimal allocation / switching determination unit 220 determines whether there is a change from the currently used base station 100, and if the power of the base station 100 to be switched to is OFF / power-saving mode, it is restored.

[0037] The base station optimal allocation / switching determination unit 220 may perform control (scaling out / scaling in) to increase / decrease the number of base stations 100 to be used according to the increase or decrease in traffic. The base station optimal allocation / switching determination unit 220 may also control the air conditioning (an example of power saving) of the data center where the hardware is arranged (Fig. 3) according to the increase or decrease in traffic.

[0038] The resource allocation information synchronization control unit 230 synchronizes the resource allocation information of the base station to be switched to and the base station to be switched from selected by the base station optimal allocation / switching determination unit 220, and performs data transfer of the resource allocation information from the base station to be switched from to the base station to be switched to. Specifically, the resource allocation information synchronization control unit 230 synchronizes resource allocation information with the synchronization unit 115 of the resource scheduler 114 of the source base station 100 (for example, the performance-oriented base station 110), and also synchronizes resource allocation information with the synchronization unit 125 of the resource scheduler 124 of the target base station 100 (for example, the power-saving-oriented base station 120), so as to transfer the data of the resource allocation information from the base station 100 before the switch (for example, the performance-oriented base station 110) to the base station 100 after the switch (for example, the power-saving-oriented base station 120) (see arrow b in FIG. 1). Here, the resource allocation information synchronization control unit 230 may periodically synchronize the resource allocation information with the synchronization unit 115 of the resource scheduler 114 of the base station 100.

[0039] In this way, the resource allocation information synchronization control unit 230 transfers the data of the resource allocation information from the base station 100 before the switch to the base station 100 after the switch. That is, the resource allocation information synchronization control unit 230 transfers the resource allocation information at the time of the switch so that no reallocation of radio resources occurs due to the base station switch.

[0040] The network switch control unit 240 switches the network connected to the source base station and the network connected to the target base station. Specifically, the network switch control unit 240 switches the network between the antenna 20 and the base station 100, and between the core network 40 and the base station 100 (see arrow c in FIG. 1). Also, the network switch control unit 240 causes the source base station 100 to transition to the power-off / power-saving mode for power saving. The network switch control unit 240 switches the base station 100 to be used by switching the network between the antenna 20 and the base station 100, and between the core network 40 and the base station 100 (see the thick double-headed arrow d in FIG. 1).

[0041] In this way, the network switch control unit 240 switches the base station 100 to be used according to the magnitude of the traffic. The switching of the base station 100 is handled by switching the NW.

[0042] [RU / DU / CU Configuration] <Separation into RU / DU / CU> In the wireless access system 1000, it may be possible to separate the base station function into RU (Radio Unit) / DU (Distributed Unit) / CU (Centralized Unit).

[0043] Describe each function of RU / DU / CU. The functions of RU are LOW PHY, AD / DA conversion, iFFT, analog beamforming, digital beamforming, etc. The functions of DU are HIGH PHY, modulation / demodulation, encoding / decoding, scrambling, and MAC, and these processes are executed by the DU server. The functions of CU are the execution of packet data convergence protocol, radio resource control, and service data adaptation protocol. A configuration in which the RU and DU are functionally split and connected by a fronthaul is a common configuration. If the DU and CU are each configured with dedicated devices, there are problems such as vendor lock-in, which is being tied to a specific vendor, and difficulty in flexibly changing or expanding functions. vRAN can support multi-vendor and flexible function expansion by implementing functions with software on general-purpose hardware such as servers. Also, if the hardware has extremely high performance, it becomes possible to mount both DU and CU on a single server (or virtualize only the CU that does not handle modulation / demodulation, virtualize the CU and DU on different general-purpose hardware).

[0044] [RU / DU / CU Configuration Example] Explain the configuration example of RU / DU / CU. Figure 2 is a diagram for explaining the configuration example of RU / DU / CU. As shown in Figure 2, the antenna 20 and RU that wirelessly communicate with the terminal (UE) 10 are installed in a high-place facility 51 such as the rooftop of a building or a tower. The DU is installed in communication equipment facilities 52 such as regional data centers (DCs) and regional communication buildings. The communication equipment facilities 52 are often arranged in communication equipment facilities owned by communication carriers within approximately 20 km from the facilities 51 where the antennas 20 and RUs are arranged. The CU is installed in representative communication facilities 53 such as DCs and representative communication buildings. The representative communication facilities 53 are often arranged in representative communication facilities at the prefecture level or the like.

[0045] An arrangement example of the DU server will be described. The DU is composed of DU servers. FIG. 3 is a diagram for explaining an arrangement example of the DU server. As shown in FIG. 3, the DU (DU server) is composed of, for example, general-purpose servers and is housed in the server rack 55 of the communication equipment facility 52 shown in FIG. 2. The server rack 55 is maintained at a predetermined environmental temperature by the air conditioner 56. A DU application is installed in the general-purpose server and operated as a DU server.

[0046] [Variations of switching targets] The base station pool 100A shown in FIG. 1 stores a plurality of base stations (BBUs) with different orientations, and the switching targets exemplified the switching between the base stations. However, the switching targets are not limited to the switching between the base stations. Hereinafter, the variations of the switching targets will be described.

[0047] As a system for pooling and switching according to traffic, a plurality of variations as shown in FIGS. 4A to 4F are assumed by these separation units of RU / DU / CU. The present invention can be applied to any unit. Further, by pooling with RU / DU / CU as the separation unit, it is possible to change the 1:1 relationship between the antenna 20 and the base station 100 to M:N (M and N are arbitrary natural numbers).

[0048] [Separation into units smaller than RU / DU / CU] The switching target may be pooled and switched in units smaller than RU / DU / CU. Units smaller than RU / DU / CU are, for example, CPU cores, accelerators, NICs (Network Interface Cards), etc. in a server.

[0049] <Type of switching target> The switching target may be not only hardware but also software installed on the hardware of base station 100. For example, it may be switched between base station software with a power-saving mode and base station software specialized for performance. Also, without switching the software itself, the settings of the software may be changed to switch between the power-saving mode / performance specialization mode.

[0050] FIG. 4A is a diagram showing base station pool A in which all base station functions are pooled. Base station pool 100A shown in FIG. 4A pools all base station functions (i.e., base stations). Base station switching controller 200 (FIG. 1) selects and switches one base station 100 from among base station pool 100A. Base station switching controller 200 responds to the switching of base station 100 by switching the NW.

[0051] FIG. 4B is a diagram showing DU pool B in which base station functions are separated into RU / DU / CU and pooled in DU units. DU pool 100B shown in FIG. 4B separates base station functions into RU / DU / CU, and among them, functions in DU units are pooled in multiple. DU pool 100B shown in FIG. 4B has two DUs pooled. Base station switching controller 200 selects and switches a suitable DU from among DU pool 100B. Base station switching controller 200 realizes the switching by resetting the address (MAC address) of the destination DU server to the RU. Also, in the case of VLAN connection, it can be dealt with by changing the VLAN tag.

[0052] FIG. 4C is a diagram showing a DU+CU pool C in which the base station functions are separated into RU / DU / CU and pooled in units of DU and CU. The DU+CU pool 100C shown in FIG. 4C separates the base station functions into RU / DU / CU, and a plurality of functions in units of DU and CU are pooled. The DU+CU pool 100C shown in FIG. 4C has a total of four DUs and CUs pooled in units of DU and CU. The base station switch controller 200 selects and switches a suitable DU or CU from the DU+CU pool 100C. The base station switch controller 200 realizes the switching by resetting the address (MAC address) of the DU server (server that executes the functions of the DU, i.e., HIGH PHY, modulation / demodulation, encoding / decoding, scrambling, and MAC processing) of the switching destination to the RU (see FIGS. 5 and 6).

[0053] FIG. 4D is a diagram showing a CU pool D in which the base station functions are separated into RU / DU / CU and pooled in units of CU. The CU pool 100D shown in FIG. 4D separates the base station functions into RU / DU / CU, and a plurality of functions in units of CU are pooled. The CU pool 100D shown in FIG. 4D has two CUs pooled in units of CU. The base station switch controller 200 selects and switches a suitable CU from the CU pool 100D. The base station switch controller 200 realizes the switching by resetting the address (MAC address) of the DU server of the switching destination to the RU.

[0054] FIG. 4E is a diagram showing an RU pool D in which the base station functions are separated into RU / DU / CU and pooled in units of RU. The RU pool 100E shown in FIG. 4E separates the base station functions into RU / DU / CU, and among them, the functions of the RU units are pooled in multiple. The RU pool 100E shown in FIG. 4E has two RUs in the RU unit pooled. The base station switch controller 200 selects and switches a suitable RU from the RU pool 100E. The base station switch controller 200 realizes the switching by resetting the address (MAC address) of the target DU server to the RU for the RU switching.

[0055] FIG. 4F is a diagram showing an RU+DU pool in which the base station functions are separated into RU / DU / CU and pooled in RU and DU units. The RU+DU pool 100F shown in FIG. 4F separates the base station functions into RU / DU / CU, and among them, the functions of the RU and DU units are pooled in multiple. The RU+DU pool 100F shown in FIG. 4F has a total of four RUs and DUs in the RU and DU units pooled. The base station switch controller 200 selects and switches a suitable RU or DU from the RU+DU pool 100F. The base station switch controller 200 realizes the switching of the RU and DU by resetting the address (MAC address) of the target DU server to the RU (see FIGS. 5 and 6).

[0056] [Switching of RU / DU / CU] An example of resetting the address of the DU server (FIG. 3) to the RU will be described. [Example of inputting and switching the setting to the RU] FIG. 5 is a diagram showing an example of inputting and switching the setting to the RU. As shown in FIG. 5, the RU 150 includes an NW function unit 151 for switching the NW function. The DU 160 includes an NW function unit 161 for switching the NW function. The network switching control unit 240 of the base station switching controller 200 inputs (rewrites the NW address) a setting for switching the NW address of the destination DU to the NW function unit 151 of the RU150 (reference sign e in Fig. 5). In response to the input of the setting from the network switching control unit 240, the NW function unit 151 of the RU150 switches, for example, NW address1 to NW address2.

[0057] <Example of inputting a setting to the NW switch and performing a switch> Fig. 6 is a diagram showing an example of inputting a setting to the NW switch and performing a switch. As shown in Fig. 6, an NW switch 170 is arranged between the RU150 and the DU160. The NW switch 170 has a correspondence table (table) 171 of the destination NW address and the device. The network switching control unit 240 of the base station switching controller 200 inputs a setting for switching the connection NW address between the RU and the DU to the NW switch 170 (reference sign e in Fig. 6). In response to the input of the setting from the network switching control unit 240, the NW switch 170 refers to the correspondence table 171 and switches, for example, NW address1 to NW address2. When using the NW switch 170, there is an advantage that the setting (NW address3) on the RU150 side does not need to be changed.

[0058] Hereinafter, the operation of the radio access system 1000 configured as described above will be described. Fig. 7 is a flowchart showing the power-saving base station switching process of the base station 100 and the base station switching controller 200 of the radio access system 1000. Taking as an example the case where the performance-oriented base station 110 arranged in a pooled manner in the base station pool 100A in Fig. 1 is the base station before switching, and the power-saving-oriented base station 120 is the base station after switching.

[0059] In step S11, the traffic collection unit 113 of the base station 100 (performance-oriented base station 110) periodically observes the amount of traffic flowing into the base station 100 and the like, and detects changes in traffic characteristics.

[0060] In step S12, the traffic collection unit 113 determines whether there is a change in the traffic characteristics. If there is no change in the traffic characteristics (S12: No), the process returns to step S11.

[0061] If there is a change in the traffic characteristics (S12: Yes), in step S13, the traffic collection unit 113 transmits the change information of the traffic characteristics to the base station switching controller 200 (see arrow a in FIG. 1).

[0062] In step S14, the traffic information collection unit 210 of the base station switching controller 200 collects the change information of the traffic characteristics collected by the traffic collection unit 113 of the base station 100, and determines whether it is a situation of low traffic or high traffic. The traffic information collection unit 210 also utilizes the traffic information collected in the past to predict future traffic. At this time, the traffic information collection unit 210 may predict future traffic using machine learning or the like.

[0063] In step S15, the base station optimal allocation / switching determination unit 220 of the base station switching controller 200 selects a suitable base station from the base station pool 100A according to the traffic situation collected by the traffic collection unit 113 of the base station 100 (performance-oriented base station 110). The base station optimal allocation / switching determination unit 220, for example, selects the performance-oriented base station 110 in the case of high traffic, and selects the power-saving-oriented base station 120 in the case of low traffic. In addition, the base station optimal allocation / switching determination unit 220 may perform control (scale out / scale in) to increase / decrease the number of base stations 100 to be used according to the increase or decrease of traffic. The base station optimal allocation / switching determination unit 220 may also control the air conditioning of the data center where the hardware is arranged in accordance with the increase or decrease of traffic.

[0064] In step S16, the base station optimal allocation / switching determination unit 220 determines whether there is a change from the currently used base station 100 (performance-oriented base station 110). If there is no change from the currently used base station 100 (performance-oriented base station 110) (S16: No), the processing of this flow ends.

[0065] If there is a change from the currently used base station 100 (performance-oriented base station 110) (S16: Yes), in step S17, if the power of the target base station 100 (power-saving-oriented base station 120) is OFF / in the power-saving mode, the base station optimal allocation / switching determination unit 220 restores it.

[0066] In step S18, the resource allocation information synchronization control unit 230 of the base station switch controller 200 transfers the data of the resource allocation information from the base station 100 (performance-oriented base station 110) before switching to the base station 100 (power-saving-oriented base station 120) after switching (see arrow b in FIG. 1). Here, the resource allocation information synchronization control unit 230 may periodically synchronize the resource allocation information among the synchronization units 115 of the resource scheduler 114 of the base station 100.

[0067] In step S19, the network switching control unit 240 of the base station switch controller 200 switches the network between the antenna 20 and the base station 100, and between the core network 40 and the base station 100 (see arrow c in FIG. 1), thereby switching the used base station 100 from the performance-oriented base station 110 to the power-saving-oriented base station 120 after switching (see the thick double-headed arrow d in FIG. 1).

[0068] In step S20, the network switching control unit 240 causes the base station 100 (performance-oriented base station 110) before switching to transition to the power-off / power-saving mode for power saving, and ends the processing of this flow.

[0069] <Network switching example> As the networks to be switched, connections by Layer 2 Ethernet (communication by MAC address) or connections by VLAN are often used between RU and DU, between DU and CU, and between CU and 5GC. Therefore, for network switching, for example, if switching between RU and DU in DU pool 100B (Figure 4B), the address (MAC address) of the target DU server can be reset to the RU to achieve the switching. Also, in the case of VLAN connection, it can be handled by changing the VLAN tag.

[0070] <Specific examples of large / small traffic as a switching trigger> Illustrate the traffic conditions when switching between the performance-oriented base station 110 (Figure 1) and the power-saving-oriented base station 120 (Figure 1). · Tidal Scale (day and night) The traffic flowing into the base station is known to be regular on a daily basis. During the daytime when people are actively communicating, the traffic volume is large, and during the nighttime when people are sleeping, the traffic volume tends to be small. Utilizing this regularity, when the traffic volume increases beyond a predetermined threshold in the morning time period, the base station is switched from the power-saving-oriented base station 120 to the performance-oriented base station 110. Conversely, when the traffic volume decreases below the predetermined threshold at night, it is assumed that the base station is switched from the performance-oriented base station 110 to the power-saving-oriented base station 120.

[0071] Here, the above-mentioned predetermined threshold may be manually set by the operator based on past performance, or may be calculated by machine learning. Also, depending on the installation location of the base station, if there are characteristics for each day of the week, thresholds may be set for each day of the week.

[0072] · Planned event If there is an event where the traffic is expected to increase / decrease, the event activation information may be held in advance and the base station may be switched to the performance-oriented base station / power-saving-oriented base station. The above events are, for example, fireworks displays and baseball games (traffic increase), and the closure of shopping malls (traffic decrease).

[0073] · Sudden events Different from the above-mentioned diurnal variations and planned events, the performance-oriented base station / power-saving-oriented base station may be switched due to sudden events such as disasters and network failures. For example, the increase and decrease behavior of traffic when a network failure occurs is pre-learned by machine learning in advance. When it matches the traffic pattern, it may be switched to the appropriate performance-oriented base station / power-saving-oriented base station.

[0074] <Example of RE allocation information synchronization> The example of RE allocation information synchronization will be described. FIG. 8 is a diagram for explaining an example of RE allocation information synchronization. The upper diagram in FIG. 8 is an example of the RE allocation information before switching, and the lower diagram in FIG. 8 is an example of the RE allocation information after switching. Taking the case where the performance-oriented base station 110 arranged in a pooled manner in the base station pool 100A of FIG. 1 is the base station before switching and the power-saving-oriented base station 120 is the base station after switching as an example. In the performance-oriented base station 110 shown in FIG. 1, the resource scheduler 114 uses the RE allocation information before switching shown in the upper diagram of FIG. 8 to allocate RE for each UE10 (FIG. 1) and schedule the radio access signal between the UE10 and the base station 100.

[0075] The resource allocation information synchronization control unit 230 of the base station switching controller 200 (FIG. 1) copies the RE allocation information (the upper diagram of FIG. 8) managed by the resource scheduler 114 (MAC scheduler) from the base station before switching to the resource scheduler 124 of the power-saving-oriented base station 120 after switching. Thereby, the data of the resource allocation information can be inherited from the performance-oriented base station 110 before switching to the power-saving-oriented base station 120 after switching.

[0076] [Hardware configuration] The base station switching controller (power-saving base station switching device) 200 according to the above embodiment is realized by a computer 900 having a configuration as shown in FIG. 9, for example. FIG. 9 is a hardware configuration diagram showing an example of a computer 900 that realizes the functions of the base station switching controller (power saving base station switching device) 200. The computer 900 includes a CPU 901, a ROM 902, a RAM 903, an HDD 904, a communication interface (I / F) 906, an input / output interface (I / F) 905, and a media interface (I / F) 907.

[0077] The CPU 901 operates based on a program stored in the ROM 902 or the HDD 904, and controls each part of the base station switching controller 200 shown in FIG. 1. The ROM 902 stores a boot program executed by the CPU 901 when the computer 900 is started up, a program dependent on the hardware of the computer 900, and the like.

[0078] The CPU 901 controls an input device 910 such as a mouse and a keyboard, and an output device 911 such as a display via the input / output I / F 905. The CPU 901 acquires data from the input device 910 via the input / output I / F 905, and outputs the generated data to the output device 911. Note that, together with the CPU 901, a GPU (Graphics Processing Unit) or the like may be used as a processor.

[0079] The HDD 904 stores programs executed by the CPU 901 and data used by the programs. The communication I / F 906 receives data from other devices via a communication network (for example, NW (Network) 920) and outputs it to the CPU 901, and transmits data generated by the CPU 901 to other devices via the communication network.

[0080] The media I / F 907 reads the program or data stored in the recording medium 912 and outputs it to the CPU 901 via the RAM 903. The CPU 901 loads the program related to the target process from the recording medium 912 onto the RAM 903 via the media I / F 907 and executes the loaded program. The recording medium 912 is an optical recording medium such as a DVD (Digital Versatile Disc) or PD (Phase change rewritable Disk), a magneto-optical recording medium such as an MO (Magneto Optical disk), a magnetic recording medium, a conductor memory tape medium, or a semiconductor memory, etc.

[0081] For example, when the computer 900 functions as a base station switching controller (power-saving base station switching device) 200 configured as one device according to this embodiment, the CPU 901 of the computer 900 realizes the functions of the base station switching controller 200 by executing the program loaded onto the RAM 903. Also, the HDD 904 stores the data in the RAM 903. The CPU 901 reads and executes the program related to the target process from the recording medium 912. In addition, the CPU 901 may read the program related to the target process from another device via the communication network (NW920).

[0082] [Effect] As described above, the base station switching controller 200 is a power-saving base station switching device that switches the base station that processes the radio access signal, and includes a traffic information collection unit 210 that collects the amount of traffic flowing into the base station in operation as traffic information, and based on the traffic information collected by the traffic information collection unit 210, a switching determination unit (base station optimal allocation / switching determination unit 220) that selects one of the suitable base stations from the base station pool 100A in which a plurality of base stations with different characteristics are pre-pooled and arranged according to predetermined requirements, and a network switching control unit 240 that switches the network connected to the base station before switching and the network connected to the base station after switching.

[0083] By doing so, it is possible to select a suitable base station 100 according to the increase or decrease of traffic (for example, day / night traffic fluctuations due to user behavior, etc.) and dynamically switch and use it. As a result, it is possible to simultaneously achieve high performance when traffic is high and power saving when traffic is low.

[0084] As described above, it is possible for the machine to autonomously respond without the intervention of an operator. Therefore, no manpower by the operator is required, and it is possible to realize high-frequency switching of the base station 100 on the order of minutes / hours.

[0085] Also, in planned facility renovation, etc., by switching the base station and performing the renovation work, it is possible to eliminate the service interruption time or reduce the service interruption time.

[0086] In the radio access system 1000, the base station switch controller 200 includes a resource allocation information synchronization control unit 230 that synchronizes the resource allocation information of the target base station selected by the base station optimal allocation / switch determination unit 220 and the source base station, and transfers the data of the resource allocation information from the source base station to the target base station.

[0087] In this way, since the resource allocation information synchronization control unit 230 synchronizes the base station states, there is no need to synchronize the base station states, and the present invention can be applied to cases where it operates only by switching the NW. For example, it can be applied when it is necessary to switch without synchronization during a failure, when the UE does not belong and there is no need to inherit the state, etc.

[0088] In the radio access system 1000, the base station pool 100A pools and arranges a performance-oriented base station 110 aiming to achieve high performance and a power-saving-oriented base station 120 aiming to achieve power saving.

[0089] By doing so, base station devices with different characteristics are deployed in the base station pool, and by switching the network to a suitable base station device (performance-oriented / power-saving-oriented, etc.) according to the traffic situation, dynamic switching control can be realized. For example, in the case of high traffic, a performance-oriented type is used, and in the case of low traffic, a power-saving-oriented type is used. Also, by turning off the power / setting the unused base station device to the power-saving mode, power saving can be achieved.

[0090] In the radio access system 1000, when the base station pool 100A separates the base station function into an RU (Radio Unit), a DU (Distributed Unit), and a CU (Centralized Unit), it is pooled in units of separation of the RU, DU, or CU.

[0091] By doing so, through the pooling of the base stations 100, the relationship between the antenna 20 and the base stations 100 can be changed from 1:1 to M:N, and it becomes possible to assign only the necessary base station resources from the pool, thus improving the resource utilization efficiency.

[0092] In the radio access system 1000, the base station pool 100A is pooled in units of CPU cores, accelerators, and NIC (Network Interface Card) in the server, which are units smaller than the separation units of the RU, DU, or CU.

[0093] By doing so, not only can the switching target be switched in units of RU / DU / CU, but also in units of server components (CPU cores / accelerators / NICs, etc.), enabling more fine-grained switching control and achieving further power saving.

[0094] In the radio access system 1000, the network switching control unit 240 re-sets the MAC address of the target DU server to the RU and switches the network.

[0095] By doing so, when switching between base stations, it is possible to inherit the resource allocation information held by the resource scheduler (MAC Scheduler) of the base station so that terminal reconnection processing and the like due to the reallocation of radio resources do not occur.

[0096] In the radio access system 1000, the network switching control unit 240 changes the VLAN (Virtual LAN) tag to switch the network in the case of VLAN connection.

[0097] By doing so, in the case of VLAN connection, the network can be switched. That is, the switching target may be not only the hardware but also the software installed in the base station hardware. For example, it is possible to switch between base station software equipped with a power saving mode and performance-specialized base station software. Also, without switching the software itself, the settings of the software may be changed to switch between the power saving mode / performance specialization mode.

[0098] Note that, among the processes described in the above embodiments, all or part of the processes described as being automatically performed can also be performed manually, or all or part of the processes described as being performed manually can be automatically performed by a known method. In addition, regarding the processing procedures, control procedures, specific names, and information including various data and parameters shown in the above documents and drawings, they can be arbitrarily changed unless otherwise specified. In addition, each component of each illustrated device is conceptually functional and does not necessarily have to be physically configured as shown in the figure. That is, the specific form of distribution and integration of each device is not limited to that shown in the figure, and all or part of it can be functionally or physically distributed and integrated in any unit according to various loads and usage situations.

[0099] In addition, each of the above-described configurations, functions, processing units, processing means, etc. may be implemented in hardware by designing part or all of them using, for example, an integrated circuit. Further, each of the above-described configurations, functions, etc. may be implemented by software for a processor to interpret and execute a program for realizing each function. Information such as a program, table, file, etc. for realizing each function can be held in a memory, a recording device such as a hard disk, SSD (Solid State Drive), or a recording medium such as an IC (Integrated Circuit) card, SD (Secure Digital) card, or optical disk.

Explanation of Signs

[0100] 10 UE (Terminal) 20 Antenna 40 Core Network 100 Base Station (BBU) 100A Base Station Pool 100B DU Pool (Base Station Pool) 100C DU+CU Pool (Base Station Pool) 100D CU Pool (Base Station Pool) 100E RU Pool (Base Station Pool) 100F RU+DU Pool (Base Station Pool) 110 Performance-Oriented Base Station 111, 121 Hardware 112, 122 OS, etc. 113, 123 Traffic Collection Unit 114, 124 Resource Scheduler 115, 125 Synchronization Unit 116, 126 Base Station Processing Application 120 Power-Saving Oriented Base Station 150 RU 160 DU 170 NW Switch 200 Base Station Switching Controller (Power-Saving Base Station Switching Device) 210 Traffic Information Collection Unit 220 Base Station Optimal Allocation / Switching Judgment Unit (Switching Judgment Unit) 230 Resource Allocation Information Synchronization Control Unit 240 Network Switching Control Unit 1000 Wireless Access System< / vran>

Claims

1. A power-saving base station switching device for switching a base station that processes a wireless access signal, comprising: A traffic information collection unit that collects, as traffic information, the amount of traffic flowing into an operating base station; A switching determination unit that selects one suitable base station from a base station pool in which a plurality of base stations with different characteristics are pre-pooled and arranged according to predetermined requirements based on the traffic information collected by the traffic information collection unit; A network switching control unit that switches between a network connected to the source base station and a network connected to the destination base station. A power-saving base station switching device characterized by the above.

2. A resource allocation information synchronization control unit that synchronizes the resource allocation information of the destination base station selected by the switching determination unit with that of the source base station and transfers the data of the resource allocation information from the source base station to the destination base station. The power-saving base station switching device according to claim 1, characterized by the above.

3. The base station pool pools and arranges a performance-oriented base station aiming to achieve high performance and a power-saving-oriented base station aiming to achieve power saving. The power-saving base station switching device according to claim 1, characterized by the above.

4. When the base station pool separates the base station functions into RU (Radio Unit), DU (Distributed Unit), and CU (Centralized Unit), it pools them in units of separation of the RU, the DU, or the CU. The power-saving base station switching device according to claim 1, characterized by the above.

5. The base station pool pools them in units of CPU cores, accelerators, and NIC (Network Interface Card) in a server, which are units smaller than the separation units of the RU, the DU, or the CU. The power-saving base station switching device according to claim 4, characterized in that

6. The network switching control unit re-sets the MAC address of the DU server at the switching destination to the RU and switches the network. The power-saving base station switching device according to claim 4, characterized in that

7. When the network switching control unit is in a VLAN (Virtual LAN) connection, it changes the VLAN tag to switch the network. The power-saving base station switching device according to claim 1, characterized in that

8. A radio access system including a base station that processes radio access signals, A base station pool that pre-pools and arranges a plurality of base stations with different characteristics according to predetermined requirements, A power-saving base station switching device that switches a base station that processes radio access signals, and The power-saving base station switching device includes A traffic information collection unit that collects the traffic volume flowing into the operating base station as traffic information, A switching determination unit that selects one of the suitable base stations from the base station pool based on the traffic information collected by the traffic information collection unit, A network switching control unit that switches the network connected to the base station at the switching source and the network connected to the base station at the switching destination. A radio access system characterized by the above.

9. A power-saving base station switching method for a power-saving base station switching device that switches a base station that processes radio access signals, The power-saving base station switching device includes A step of collecting the traffic volume flowing into the operating base station as traffic information, Based on the collected traffic information, selecting one suitable base station from a base station pool in which a plurality of base stations with different characteristics are pre-pooled and arranged according to predetermined requirements; switching the network connected to the source base station and the network connected to the target base station; and performing the above steps. A power-saving base station switching method characterized by the above.

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