Controlling processing resources

Abstract

The present disclosure relates to a method of a controller device (101) controlling processing resources of processing units (102-105) allocated to serve wireless communication devices in a radio access network, and a controller device (101) performing the method. In an aspect, a method of a controller device (101) controlling processing resources of a processing unit (102-105) allocated to serve a wireless communication device in a radio access network is provided. The method comprises determining (S101) a traffic load of the served wireless communication device; determining (S102), based on the determined traffic load, whether a subset (103-105) of processing units has sufficient processing capacity to serve the wireless communication device; and if so, setting (S103) at least one selected processing unit (102) not comprised in the subset (103-105) of processing units in a low power mode; and allocating (S104), to one or more processing units (103) comprised in the subset, services to take over any wireless communication device (111, 112) served by at least one selected processing unit (102) set in the low power mode.

Description

Technical Field

[0001] The present disclosure relates to a method of a controller device for controlling processing resources of a processing unit allocated to serve a wireless communication device in a radio access network, and a controller device for performing the method. Background Art

[0002] In mobile communication systems, such as fourth generation (4G) Long Term Evolution (LTE) or fifth generation (5G) New Radio (NR), power consumption is an important metric since energy costs are a significant part of the total cost to the system operator.

[0003] Typically, resources used to handle physical layer processing are dimensioned to handle peak load scenarios. However, from a long-term, average perspective, instantaneous traffic loads are typically much lower than peak conditions. However, processing resources are dimensioned to handle peak scenarios over short periods of time. Summary of the invention

[0004] It is an object to solve or at least alleviate this problem in the art and therefore to provide an improved method of controlling processing resources of a processing unit allocated to serve wireless communication devices in a radio access network.

[0005] In a first aspect, the object is achieved by a method of controlling processing resources of a processing unit of a controller device allocated to serve wireless communication devices in a radio access network. The method comprises determining a traffic load of the served wireless communication devices; determining, based on the determined traffic load, whether a subset of processing units has sufficient processing capacity to serve the wireless communication devices; and if so, setting at least one selected processing unit not included in the subset of processing units in a low power mode; and allocating to one or more processing units included in the subset to take over service of any wireless communication device served by at least one selected processing unit set in a low power mode.

[0006] In a second aspect, the object is achieved by a controller device configured to control processing resources of a processing unit allocated to serve wireless communication devices in a radio access network. The device comprises a processing unit and a memory, the memory containing instructions executable by the processing unit, whereby the device is operable to: determine a traffic load of the served wireless communication devices; based on the determined traffic load, determine whether a subset of the processing units has sufficient processing capacity to serve the wireless communication devices; and if so, set at least one selected processing unit not included in the subset of processing units in a low power mode; and allocate one or more processing units included in the subset to take over the service of any wireless communication device served by at least one selected processing unit set in a low power mode.

[0007] For example, assume that the first processing unit in the subset serves the first and second wireless communication devices in a group of wireless communication devices. Assume also that the other three processing units in the subset are determined to have processing capacity to serve all of the wireless communication devices in the group, then the controller device will advantageously place the first processing unit in a low power mode and allocate to one of the other processing units in the subset to take over the service of the first and second wireless communication devices.

[0008] Advantageously, the total power consumption of the four processing units in the subset is greatly reduced while still providing processing capacity to serve all wireless communication devices.

[0009] In one embodiment, allocating one or more processing units included in the subset to take over service of any wireless communication device served by at least one selected processing unit set in low power mode includes: controlling a switching fronthaul configured to connect the processing unit to the wireless communication device to be served to switch any wireless communication device to the one or more processing units included in the subset that are allocated to take over service.

[0010] In one embodiment, the method further includes: before at least one selected processing unit is set in low power mode, instructing at least one selected processing unit where to write data required by any wireless communication device in a memory shared by the processing units; and instructing the one or more processing units included in the subset that are assigned to take over the services of any wireless communication device where to read required data in the shared memory.

[0011] In an embodiment, if the determined traffic load does not exceed a first load threshold, then the subset of processing units is determined to have sufficient processing capacity to serve the wireless communication device.

[0012] In one embodiment, the method further includes: determining whether the subset of processing units still has sufficient processing capacity to serve the wireless communication devices based on the newly determined traffic load; and if not, reallocating at least one of the selected processing units set in low power mode to serve one or more of the wireless communication devices currently served by one or more processing units included in the subset.

[0013] In an embodiment, if the determined traffic load exceeds a second load threshold, the subset of processing units is determined to still not have sufficient processing capacity to serve the wireless communication device.

[0014] In one embodiment, determining the traffic load of the served wireless communication device includes determining an instantaneous traffic load or an average traffic load over a period of time, or estimating the traffic load based on historical traffic loads.

[0015] In one embodiment, allocating to one or more processing units included in the subset to take over service of any wireless communication device served by at least one selected processing unit placed in low power mode includes allocating to the one or more processing units included in the subset to take over processing of a cell-specific channel.

[0016] In a third aspect, there is provided a computer program comprising computer executable instructions for causing a controller device to perform the steps set out in the method according to the first aspect when the computer executable instructions are executed on a processing unit comprised in the controller device.

[0017] In a fourth aspect, there is provided a computer program product comprising a computer readable medium having embodied thereon the computer program according to the third aspect.

[0018] Generally, all terms used in the claims should be interpreted according to their ordinary meaning in the technical field, unless otherwise explicitly defined herein. All references to "an / the element, device, component, means, step, etc." should be openly interpreted as referring to at least one instance of an element, device, component, means, step, etc., unless otherwise explicitly stated. The steps of any method disclosed herein do not have to be performed in the exact order disclosed, unless explicitly stated. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Various aspects and embodiments will now be described, by way of example, with reference to the accompanying drawings, in which:

[0020] Figure 1 A communication system including a controller device according to an embodiment is illustrated;

[0021] Figure 2 illustrates an average traffic load caused by a wireless communication device over a period of time;

[0022] Figure 3 A flow chart is shown which illustrates a method of controlling processing resources of a processing unit allocated to serve a wireless communication device by a controller device in one embodiment;

[0023] Figure 4 A flow chart illustrating a method in another embodiment is shown;

[0024] Figure 5 shows a flow chart illustrating a method in yet another embodiment; and

[0025] Figure 6 A controller device according to an embodiment is illustrated. DETAILED DESCRIPTION

[0026] Aspects of the present disclosure will now be described more fully hereinafter with reference to the accompanying drawings, in which certain embodiments of the invention are shown.

[0027] However, these aspects can be embodied in many different forms and should not be interpreted as limiting; rather, these embodiments are provided by way of example so that this disclosure will be thorough and complete, and in order to fully convey the scope of all aspects of the invention to those skilled in the art. Throughout the description, like numbers refer to like elements.

[0028] Figure 1 Illustrated is a communication system 100 comprising a controller device 101 according to an embodiment which will be described in more detail below.

[0029] The communication system 100 includes a plurality of processing units 102-105 (PUs) serving a plurality of radio base stations 106-109 (RBSs) in a radio access network (RAN) and wireless communication devices, often referred to as user equipment (UE), via a switched fronthaul 110. The UE may be embodied in the form of a smartphone, a tablet, a connected vehicle, etc.

[0030] Thus, the PUs 102-105 perform baseband processing at the physical layer, also referred to as layer 1 (L1) processing. The PUs 102-105 may be embodied in the form of a microprocessor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), a complex programmable logic device (CPLD), etc. As will be appreciated, the PUs may be separate chips or implemented as a multi-chip module (MCM).

[0031] In the art, the PUs 102 - 105 serving the RBSs 106 - 109 and UEs are selected to have sufficient capacity to perform baseband processing during peak traffic load scenarios for the UEs.

[0032] like Figure 2 As shown, the average traffic load caused by the UEs served by RBSs 106-109 over a week, and the corresponding processing load at PUs 102-105, varies greatly over time. Figure 2 As can be seen in , the processing load varies between slightly less than 10 units and almost 30 units. In other words, during a peak traffic scenario, the processing load of PUs 102-105 may be 3 times the load during low traffic periods.

[0033] Typically, during the night, the traffic load is much lower than the traffic load that occurs during the daytime peak hours.

[0034] Therefore, providing hardware (such as PUs 102-105) that is activated to service traffic peaks that occur in a short period of time may result in high power consumption even if the average utilization is low. Figure 2 , even if the average load on PUs 102-105 is somewhere around 16-17 load units, the PUs are in practice prepared to immediately cope with peak loads of 27-28 load units.

[0035] Generally speaking, the energy consumed by a PU 102-105, such as a microprocessor or ASIC, consists of two parts:

[0036] 1) Dynamic energy, and

[0037] 2) Static energy (e.g. leakage and energy consumption caused by infrastructure-related clock toggles, which are always present regardless of processing load)

[0038] Therefore, even if the dynamic processing load is low, the PUs 102-105 will still consume energy due to static power consumption.

[0039] Reference again Figure 1 , and further reference Figure 3 , which illustrates a method for a controller device 101 to control processing resources of PUs 102-105 allocated to serve UEs in a RAN. In one embodiment, the problem is solved by the controller 101 executing the method.

[0040] As appreciated, while PUs 102-105 operate at L1, controller 102 typically operates at layer 2 (L2), also known as the data link layer.Controller 101 implements a medium access control (MAC) scheduler, as well as backhaul connectivity and user plane data processing.

[0041] In a first step S101 , the controller 101 determines the traffic load of the UEs being served by the PUs 102 - 105 .

[0042] For example, assume that controller 101 determines in step S102 that the traffic load L1 of the UEs being served by PUs 102-105 via RBSs 106-109 does not currently exceed a first load threshold T1, ie, L1≤T1, which corresponds to the maximum traffic load that a subset of PUs (eg, three PUs) has processing capacity to handle.

[0043] In other words, if the determined traffic load L1 of the UE exceeds the first load threshold T1, ie L1>T1, all four PUs will have to participate in baseband processing in order to provide sufficient processing capacity for serving all UEs given the current traffic load L1.

[0044] However, in this embodiment, since the controller 101 determines in step S102 that the traffic load L1 caused by the UE is low enough to require processing resources of only three PUs, the remaining PUs may be set in low power mode in step S103 to reduce energy consumption of the system.

[0045] In this particular example, it is assumed that the first PU 102 serves the first UE 111 and the second UE 112; since the three PUs 103-105 are indeed determined in step S102 to have the processing capacity to serve all UEs given L1≤T1, in step S103, the controller 101 will advantageously set the first PU 102 in low power mode and allocate one of the PUs 103-105 in the subset (such as the second PU 103) to take over the service of the first UE 111 and the second UE 112.

[0046] If it is determined in step S102 that L1>T1, no reallocation of the UE will be performed, and all four PUs 102-105 will continue to serve the UE.

[0047] Advantageously, with this embodiment, the power consumption of the four PUs 102-105 has been greatly reduced while still providing processing capacity for serving all UEs given the current traffic load. Thus, in this particular example, the second, third, and fourth PUs 103-105 can be used by the MAC scheduler of the controller 101 while the first PU 102 is powered off and not used until powered on again.

[0048] If the traffic load L1 of the UE does not exceed a load threshold that is set lower, another PU may be powered off, and so on, until only one PU serves the UE.

[0049] Figure 4 A flow chart of a method in another embodiment is shown. Figure 1 In the specific network structure shown in the figure, the allocation to the second PU 103 in step S104 to take over the services of the first UE 111 and the second UE 112 from the first PU 102 is performed by the controller 101 controlling the switching fronthaul 110 to switch the first UE 111 and the second UE 112 out of the connection with the first PU 102 and to the connection with the second PU 103. Advantageously, the switching fronthaul facilitates any UE to be switched to the connection with any PU 102-105.

[0050] In another embodiment, the PUs 102 - 105 may access the shared memory 113 , wherein the PUs 102 - 105 may write / read useful data to / from the shared memory 113 .

[0051] For example, if the second PU 103 takes over the service of the first UE 111 and the second UE 112 from the first PU 102 and needs to access any current data of the first UE 111 and the second UE 112 processed by the first PU 102 (e.g., cell-specific data or status-type data, such as uplink hybrid automatic repeat request (HARQ) which is UE-specific information), the first PU 102 may store such data in the shared memory 113 for subsequent access by the second PU 103.

[0052] The controller 101 may instruct the first PU 102 where in the shared memory 113 to write data, and unless the second PU 103 already knows where the particular data is stored in the shared memory 113 , the controller 101 will instruct the second PU 102 where in the memory 113 to access the data.

[0053] In practice, when a UE (eg, the first UE 111) is scheduled by a MAC scheduler implemented in the controller 101, the MAC scheduler combines a pointer to UE-specific data (such as the aforementioned HARQ data) stored in the shared memory 113 with the scheduling indication.

[0054] The shared memory 113 may also be used to store data required for generating and receiving cell-specific signals, such as single sideband (SSB) data and physical random access channel (PRACH) signaling data. This allows the processing of cell-specific channels to be taken over by the PU.

[0055] The first PU 102 serving the first UE 111 updates the data in the memory 113 for the particular time slot being scheduled. When the first UE 111 is served by the first PU 102, access to the memory is handed back to the MAC scheduler of the controller 112. In the next time slot, the service of the first UE 111 can be handed over to the second PU, and any required data has been stored in the shared memory 113. As mentioned earlier, the controller 101 can inform the second PU 103 accordingly. With the shared memory 113, there is advantageously no need to transfer data between PUs, as each PU 102-105 can turn to the memory 113 to obtain the required UE data.

[0056] Therefore, reference Figure 3 According to the flowchart of FIG. 1 , before setting the first PU 102 in the low power consumption mode, in step S102a, the controller 101 instructs the first PU 102 where to write any required data for the first UE 111 and the second UE 112 in the shared memory 113.

[0057] Furthermore, before or after the second PU 103 is assigned to take over the services of the first UE 111 and the second UE 112 from the first PU 102 , in step S104 a , the controller 101 instructs the second PU 103 where to read the required UE data previously written to the memory 113 by the first PU 102 .

[0058] In one embodiment, instead of measuring the instantaneous traffic load, the average load is measured or estimated over a suitably selected period of time to avoid any instantaneous peaks.

[0059] like Figure 2 As illustrated, for a given traffic scenario, historical traffic load data can be utilized to estimate any upcoming traffic load. In practice, the average traffic load typically has a periodic or at least semi-periodic variation.

[0060] As will be appreciated, traffic load may be represented by many different parameters, such as data throughput, number of layers used, number of physical resource blocks (PRBs) allocated, and the like.

[0061] Figure 5 A flow chart of a method according to another embodiment is illustrated, in which the controller 101 determines in step S105 whether the service load L1 of the served UE exceeds a second load threshold L2 (the service load L1 of the served UE exceeding the second load threshold L2 indicates that: given the increased service load L1, the subset 103-105 of the PU no longer has the capacity to serve the UE).

[0062] The second threshold T2 is typically set slightly higher than the first threshold T1 in order to introduce some hysteresis and thereby avoid placing the first PU 102 in a low power mode and thereafter reactivating the first PU 102 to serve one or more of the UEs (or new UEs entering the cell provided by the RBS 106-109) if the load increases slightly and exceeds T1.

[0063] Therefore, if the traffic load L1 of the UE is determined by the controller 101 in step S105 to increase above the second threshold T2, the controller 101 will reactivate the currently powered-off first PU 102 in step S106 and reallocate tasks for serving one or more of the UEs to the first PU 102 so as to provide sufficient capacity to cope with the UEs given the increased traffic load L1.

[0064] For example, the first PU may take over the task of serving the first UE 111 and the second UE 112 from the second PU 103 if this would free up sufficient capacity at the second PU 103 .

[0065] Advantageously, using reference Figure 5 In the illustrated embodiment, the hardware utilization (i.e., the number of PUs that are powered off) is dynamically adapted to the actual traffic load, rather than to the peak load that requires the maximum processing capacity of the PUs 102-105, thereby also adapting the energy consumption to the actual network requirements. It can be seen that any PU that is not currently required is placed in a low power mode, resulting in reduced energy consumption, but can be reactivated if the processing requirements are increased.

[0066] Thus, only some PUs are used in low load scenarios, while the full pool of PUs can be used during peak conditions.

[0067] Figure 6A controller device 101 according to an embodiment is illustrated, which is configured to control processing resources of a processing unit allocated to serve wireless communication devices in a radio access network. The steps of the method performed by the device 101 are performed in practice by a processing unit 210 embodied in the form of one or more microprocessors, which are arranged to execute a computer program 211 downloaded to a suitable storage volatile medium 212 (such as a random access memory (RAM)) or a non-volatile storage medium (such as a flash memory or a hard drive) associated with the microprocessor. The processing unit 210 is arranged to cause the device 101 to perform a method according to the embodiments described herein when a suitable computer program 211 including computer executable instructions is downloaded to the storage medium 212 and executed by the processing unit 210. The storage medium 212 may also be a computer program product including the computer program 211. Alternatively, the computer program 211 may be transferred to the storage medium 212 by a suitable computer program product (such as a digital versatile disk (DVD) or a memory stick). As another alternative, the computer program 211 may be downloaded to the storage medium 212 via a network. The processing unit 210 may alternatively be embodied in the form of a DSP, an ASIC, an FPGA, a CPLD, etc. The device 101 further comprises an interface 213 through which data may be received and sent.

[0068] Aspects of the disclosure have mainly been described above with reference to a few embodiments and examples thereof. However, as readily appreciated by a person skilled in the art, other embodiments than the ones disclosed above are equally possible within the scope of the invention as defined by the appended patent claims.

[0069] Therefore, although various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for illustrative purposes and are not intended to be limiting, with the true scope and spirit being indicated by the appended claims.

Claims

1. A method of a controller device (101) for controlling processing resources of a processing unit (102-105) allocated to serve a wireless communication device in a radio access network, the method comprising: Determining (S101) a traffic load of a served wireless communication device; Based on the determined traffic load, determining (S102) whether the subset of processing units (103-105) has sufficient processing capacity to serve the wireless communication device; and if so, placing (S103) at least one selected processing unit (102) not included in said subset (103-105) of processing units in a low power mode; and One or more processing units (103) included in the subset are assigned (S104) to take over the service of any wireless communication device (111, 112) served by the at least one selected processing unit (102) set in low power mode.

2. The method of claim 1, wherein: Allocating (S104) one or more processing units (103) included in the subset to take over the service of any wireless communication device (111, 112) served by the at least one selected processing unit (102) set in low power mode comprises: Control is configured to connect the processing unit (102-105) to a handover fronthaul (110) of a wireless communication device to be served, so as to handover any wireless communication device (111, 112) to the one or more processing units (103) included in the subset that are assigned to take over the service.

3. The method according to claim 1 or 2, further comprising: Before the at least one selected processing unit (102) is placed in a low power mode, indicating (S102a) to the at least one selected processing unit (102) where in a memory (113) shared by the processing units (102-105) to write data required by any wireless communication device (111, 112); and The one or more processing units (103) included in the subset and assigned to take over the service of any wireless communication device (111, 112) are instructed (S104a) where in the shared memory (113) to read the required data.

4. A method as claimed in any one of the preceding claims, wherein: If the determined traffic load does not exceed a first load threshold, the subset (103-105) of the processing units is determined (S102) to have sufficient processing capacity to serve the wireless communication device.

5. The method according to any one of the preceding claims, further comprising: Based on the newly determined traffic load, determining (S105) whether the subset of processing units (103-105) still has sufficient processing capacity to serve the wireless communication device; and if not, then The at least one selected processing unit (102) set in low power mode is reallocated (S106) to serve one or more wireless communication devices among the wireless communication devices currently served by one or more processing units (103-105) included in the subset.

6. The method of claim 5, wherein: If the determined traffic load exceeds a second load threshold T2, the subset of processing units (103-105) is determined (S102) to still not have sufficient processing capacity to serve the wireless communication device.

7. A method as claimed in any one of the preceding claims, wherein: The determining (S101) of the traffic load of the served wireless communication device includes: determining an instantaneous traffic load or an average traffic load over a period of time, or estimating the traffic load based on historical traffic loads.

8. A method as claimed in any one of the preceding claims, wherein: Allocating (S104) one or more processing units (103) included in the subset to take over the service of any wireless communication device (111, 112) served by at least one selected processing unit (102) set in low power mode includes: allocating the one or more processing units (103) included in the subset to take over the processing of a cell-specific channel.

9. A computer program (211) comprising computer executable instructions for causing the controller device (101) to perform the steps of any one of claims 1 to 8 when the computer executable instructions are executed on a processing unit (210) included in the controller device (101).

10. A computer program product comprising a computer readable medium (212) having embodied thereon a computer program (211) according to claim 9.

11. A controller device (101) configured to control processing resources of a processing unit (102-105) allocated to serve a wireless communication device in a radio access network, the device (101) comprising a processing unit (210) and a memory (212), the memory containing instructions (211) executable by the processing unit (210), whereby the device (101) is operable to: determining a traffic load of a served wireless communication device; Based on the determined traffic load, determining whether the subset of processing units (103-105) has sufficient processing capacity to serve the wireless communication device; and if so, then placing at least one selected processing unit (102) not included in the subset (103-105) of processing units in a low power mode; and One or more processing units (103) included in the subset are assigned to take over service of any wireless communication device (111, 112) served by the at least one selected processing unit (102) placed in low power mode.

12. The device (101) of claim 11, further operable to: when allocating to one or more processing units (103) included in the subset to take over service of any wireless communication device (111, 112) served by the at least one selected processing unit (102) placed in low power mode: Control is configured to connect the processing unit (102-105) to a handover fronthaul (110) of a wireless communication device to be served, so as to handover any wireless communication device (111, 112) to the one or more processing units (103) included in the subset that are assigned to take over the service.

13. The apparatus (101) of claim 11 or 12, further operable to: Before the at least one selected processing unit (102) is placed in a low power mode, indicating to the at least one selected processing unit (102) where to write data required by any of the wireless communication devices (111, 112) in a memory (113) shared by the processing units (102-105); and The one or more processing units (103) included in the subset and assigned to take over the service of any wireless communication device (111, 112) are instructed where in the shared memory (113) to read the required data.

14. The device (101) according to any one of claims 11-13, further operable to: if the determined traffic load does not exceed a first load threshold, determine that the subset (103-105) of the processing units has sufficient processing capacity to serve the wireless communication device.

15. The apparatus (101) according to any one of claims 11 to 14, further operable to: determining, based on the newly determined traffic load, whether the subset of processing units (103-105) still has sufficient processing capacity to serve the wireless communication device; and if not, The at least one selected processing unit (102) placed in low power mode is reallocated to serve one or more of the wireless communication devices currently served by one or more processing units (103-105) included in the subset.

16. The device (101) according to any one of claims 11-15 is further operable to: if the determined traffic load exceeds a second load threshold T2, determine that the subset (103-105) of the processing units still does not have sufficient processing capacity to serve the wireless communication device.

17. The device (101) according to any one of claims 11-16 is further operable to: when determining the traffic load of the served wireless communication device, determine the instantaneous traffic load or the average traffic load over a period of time, or estimate the traffic load based on historical traffic load.

18. The device (101) as described in any one of claims 11-16 is further operable to: when one or more processing units (103) included in the subset are assigned to take over the service of any wireless communication device (111, 112) served by at least one selected processing unit (102) set in low power mode, assign the one or more processing units (103) included in the subset to take over the processing of a cell-specific channel.

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