The following disclosure relates to power feeding management and power saving techniques in radio base stations.

BACKGROUND

Figure 1 is a block diagram schematically illustrating a wireless telecommunications system power fed by an external power grid.

The wireless telecommunications system comprises a network comprising Radio Base Stations, RBSs, sites 20. Herein a site is controlled by a physical RBS serving macro and/or small cells (herein areas limited by dashed lines). A cell is an area in which an RBS is capable of supporting wireless radio communication, i.e. radio traffic, with a Mobile Terminal, MT 80. Each RBS site 20, 20A, 20B is electrically powered from an external power feed, e.g. an AC (Alternating Current) power grid or other energy source. As illustrated, each RBS 30 is connected to an external power feed 10.

In the example in figure 1 , RBS 30 in site 20 is connected to the external power feed 10A via a power input connection 12 which may be an electric power cable. Other RBSs in nearby sites 20A, 20B are connected in the same way via an electric power cable 12 to the same power feed or another power feed 10 operated by another power supplier than the first RBS site 20. However, power feeds indicated as 10A and 10 may be the same power grid.

The AC grid transmission lines are located around the country. The RBS nodes are located in different areas/cities, and are powered via (transformer) substations via the power transmission lines.

An RBS node comprises an RBS 30 that comprises at least one antenna and transceiver unit providing wireless access for MTs 80 to the node within the site 20B by means of any standardized Radio Access Technology, RAT, e.g. GSM (Global System for Mobile telecommunication), 3G (Third Generation), 4G (Forth Generation), LTE (Long Term Evolution), enhanced LTE, LTE advanced, 5G etc.

In figure 1 , three RBS sites 20, 20A, 20B are illustrated. RBS sites indicated 20 and 20A are macro sites. RBS site indicated 20B is managing and controlling a small, or micro, cell structure only. RBS sites 20, 20A are therefore denoted RBS macro cell sites, and RBS site 20B is denoted RBS micro cell site. The micro/small cell site 20B comprises an RBS 30B. A micro or small cell may cover a smaller part of a macro cell in a RBS macro cell site. The RBSs 30, 30B are capable of signalling and exchanging information messages via standardized protocols, e.g. at handover procedures. If an MT 80 moves from one cell or site to another cell or site, the RBSs of said cells exchange information to initiate and finalize such a handover procedure. The communication paths 22 between the RBSs are indicated by dash-dot arrows for indicating bi-directional communication.

The RBS radio traffic load and power demand varies over time due to the variating radio traffic. Thus, the capacity of each RBS has to be configured to handle an expected top load, i.e. maximum load. The power management system is therefore adapted to supply the RBS at top loads, even when the radio traffic load is at its lowest level. Further, the change of radio traffic load may change quickly over time and there has been no means for saving energy during short periods of low traffic in RBSs as they are power supplied from the power grid.

SUMMARY

The problem is that there is no known power management features or solutions fast enough for enabling power savings between varying loads in radio traffic. Power management solutions suffer from the absence of power management features between the radio/digital baseband and the power system. The object is to implement a number of power management features enabling power control of an RBS in dependence of the radio traffic load, which power control enabling power saving even at very quick radio traffic load changes.

The proposed solution provides an E2E (End to End, i.e. from radio traffic load to radio unit converter and through the power system) control in the RBS architecture.

According to one aspect, said object is achieved by a method and embodiments thereof. Said method is performed in a power determination unit of a Radio Base Station Controller. Said method enables energy savings in a radio base station, comprising digital unit or radio unit comprising radio devices for handling radio telecommunication traffic and a radio traffic scheduler. The radio traffic scheduler schedules the radio telecommunication traffic and provides the power determination unit with radio traffic information for a coming time interval. Said radio devices are power supplied by at least one power converter and power supply unit for powering said power converters. The method comprises calculating a required power consumption of said radio devices based on radio traffic information for a coming time interval and determining an operation mode or power demand interval for each of said power converters corresponding to said required power consumption. The method further comprises controlling the operation mode or power demand interval of each power converter by signalling operation mode or power demand interval for each power converter.

According to further one aspect, said object is achieved by a power determination unit of a radio base station controller and embodiments thereof. Said power determination unit enables energy savings in a radio base station, in a digital unit or radio unit comprising radio devices for handling radio telecommunication traffic. A radio traffic scheduler schedules radio telecommunication traffic and provides the power determination unit with radio traffic information for a coming time interval. Said radio devices are power supplied by at least one power converter and power supply unit for powering said power converters. The power determination unit comprises a processor being adapted to operate the device to calculate a required power consumption of said radio devices based on radio traffic information for a coming time interval and to determine an operation mode or power demand interval for each of said power converters corresponding to said required power consumption; and to control the operation mode or power demand interval of each power converter by signalling operation mode or power demand interval for each power converter.

According to yet one aspect, said object is achieved by a method and embodiments thereof in a power converter.

Said method is performed in a power converter of a radio base station, in digital units or radio unit comprising radio devices for handling radio telecommunication traffic and a radio traffic scheduler for scheduling the radio telecommunication traffic. Said radio devices are power supplied by at least one power converter and one power supply unit for powering said at last one power converter. The method comprises receiving an operation mode or power demand interval of the power converter, the operation mode or power demand interval being determined based on radio traffic information for a coming time interval, and comparing received operation mode or power demand interval to current operation mode or power demand interval. The method further comprises if operation mode or power demand interval is changed, then determining an operation state from said received operation mode or power demand interval from said received operation mode or power demand interval, else keeping a current frequency setting, and setting the operation state or power demand interval of the power converter.

According to further one aspect, said object is achieved by a power converter and embodiments thereof.

Said power converter is adapted for saving energy in a radio base station, in a digital unit or radio unit comprising radio devices for handling radio telecommunication traffic and a radio traffic scheduler for scheduling the radio telecommunication traffic. Said radio device is power supplied by at least one power converter and power supply unit for powering said power converters, which comprises a controller processor being adapted to operate the power converter to receive an operation mode or power demand interval of the power converter, the operation mode or power demand interval being determined based on radio traffic information for a coming time interval, and comparing received operation mode or power demand interval to current operation mode or power demand interval. The controller processor is further adapted to operate the power converter to, if operation mode or power demand interval is changed, then determining an operation state from said received operation mode or power demand interval from said received operation mode or power demand interval, else keeping a current frequency setting, and setting the operation state or power demand interval of the power converter.

One advantage of the the provided technique is that it enables efficient radio traffic based power savings, for the total RBS system. BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing, and other, objects, features and advantages of the present invention will be more readily understood upon reading the following detailed description in conjunction with the drawings in which:

Figure 1 is a block diagram of an exemplary wireless

telecommunication network in which devices and methods described herein may be implemented;

Figure 2 is a block diagram illustrating an example of a power supply architecture of a Radio Base Station;

Figure 3 is an illustration of a high frequency power converter;

Figure 4 is a block diagram schematically illustrating a Radio Base

Station controller;

Figure 5 is illustrating a powering system of a radio base station;

Figure 6 is a flowchart illustrating a method S100 for enabling power saving;

Figure 7 is a flowchart illustrating an embodiment of the method S100;

Figure 8 is a flowchart of a method S200 performed in a processor of a power converter; Figure 9 is a block diagram illustrating an embodiment of a wireless power supply architecture of a Radio Base Station;

Figure 10 is a block diagram illustrating the two wireless interfaces between a wireless PSU and a load.

DETAILED DESCRIPTION

In the following description, for purposes of explanation and not limitation, specific details are set forth, such as particular circuits, circuit components, techniques, etc. in order to provide a thorough understanding of the present technology. However, it will be apparent to one skilled in the art that the present technology may be practiced in other embodiments that depart from these specific details. In other instances, detailed descriptions of well-known methods, devices, and circuits are omitted so as not to obscure the description of the present technology with unnecessary detail.

A radio base station (RBS) or base transceiver station (BTS) is a piece of equipment that facilitates wireless communication between mobile terminals (MTs) or user equipment (UE) and a network. MTs or UEs are devices like mobile phones (handsets), WLL (Wireless Local Loop) phones, computers with wireless Internet connectivity. The network can be that of any of the wireless communication technologies like GSM (Groupe Special Mobile), CDMA (Code Division Multiplex Access) , wireless local loop, Wi-Fi, WiMAX or other wide area network (WAN) technology.

BTS is also referred to as the node B (in 3G Networks) or, simply, the base station (BS). For discussion of the LTE standard the abbreviation eNB for evolved node B is widely used.

However, the term RBS is generally used in the description as a general term for BTSs, BSs, nodeBs, eNBs, etc.

Figure 2 is a block diagram illustrating an example of a power supply architecture of a Radio Base Station.

The operation and functions of an RBS 30 is handled and controlled by a RBS controller 50, which comprises at least one processor circuitry of digital processors and supporting memory storages for storing computer software and processing data. Said computer software, when executed by the digital processors, implements different functions of a RBS, such as handover of mobile terminals between different RBS sites, communication with the mobile stations and a backbone of the RBS enabling communication with different nodes in the Internet, control of different functional blocks or units in the RBS, etc. Some functions may be implemented as hardware. For said purposes, the RBS comprises a number of digital busses 52 connected to the functions blocks and units. In the example of figure 2, said function blocks and units consume electric power and could therefore be considered as loads 60. Examples of said loads are transceivers, power amplifier circuits and antennas (62, 64 in figure 1 ). The power feeding of said function blocks or units are provided by one or a plurality of power feed circuits or power supply units, PSU, also sometimes denoted as chargers 40. Thus, a PSU 40 may be designated for one or more function blocks and units. The PSUs 40 are connected to the external power feed, most probably an AC grid, via a power cable connection 12 via an AC input interface 32, which distribute different phases provided by the AC grid through connections to the input terminals 14 of the PSUs. The PSUs converts the AC power into DC which is distributed to the loads 60 via wiring 34 to power distribution switches 38 enabling to switch off and on the power to different loads 60, i.e. functional blocks and units. Any disturbance in the external power feeding on connection 12 will propagate through the AC input interface 32 to the input terminals 14 of the PSUs 40.

For securing power feeding to the RBS in case of external power failure, the RBS is provided with an internal power feed 70, e.g. an arrangement of batteries with capacity adapted to provide enough power capacity to the RBS during a pre-set time of external power feed failure. A switch 36 is provided for connecting and disrupting the power feeding from the internal power 70. As illustrated in figure 2, the control buses 52 are connected between the RBS controller 50 and the functional blocks and units 40, 36, 38, 60 enabling control by the RBS controller and two way communications with said functional blocks and units.

The power supply unit 40 comprises a number of electronic components for converting and adjusting the power supply to a load needing electric power for its operation and functionality. The PSU is fed from an external power feed, e.g. an AC (Alternating Current) power grid, to which it is connected via the input terminal 14. On the output 34 of the PSU is a converted and adjusted Direct Current (DC) provided, which power and voltage is adjusted and controlled by means of a PSU controller.

According to prior art, the input terminal 14 is connected to a Power Factor Correction unit (PFC) for converting the provided AC into DC and correct the power factor of the received AC. The result is a rectified DC current which is connected to a DC/DC converter for transforming the DC to the correct voltage level of the load that the PSU is designated to feed. Between the output 34 of the PSU and the DC/DC converter is a diode bridge inserted for prohibiting current to leak through the PSU if the PSU is shut down or the external power feed does not provide any electric power to the PSU. If the PSU has been shut down or the external power feed does not provide any electric power to the PSU, an internal power feed 70 is adapted to be controlled via a switch 36 for securing the operation and function of the RBS.

Figure 3 is an illustration of a generic high frequency power converter. Three different kinds of power converters are of interest: Direct Current- to-Direct Current (DC/DC) converter 200, Alternating Current-to-Direct

Current (AC/DC) converter 201 and Point Of Load (POL) converter 202.

Each kind of converter comprises a controller 260 and a converter unit 270.

The converter unit comprises switching devices, e.g. MOS-FET circuitry. The controller 260 comprises a processor 265. The Point Of Load (POL) converter 202 is located near a small load at a circuit board. The POL 202 converts the DC voltage supplied by a DC/DC converter 200 to correct DC voltage for small loads e.g. processors.

The power converter has a power input 280 and a power output 290. The power input 280 is connected to a power supplier, e.g. a power supply unit PSU. The power output 290 is connected to one or more power loads, e.g. radio devices of radio base station.

The problem with the prior art power converter is that it operates at a pre-set switching frequency regardless if a connected load is operating at its full capacity or at a low capacity usage. At the load low capacity usage, the power converter operates as if the connected load was fully loaded. This is energy consuming and a waste of energy, especially if a plurality of power converters is operated in the same way. Thus, if the power converters could be controlled to operate in a power saving mode when its load is not fully used there would be a possibility to save energy.

In the following, a solution of the problem will be presented. The solution is based on the scheduler, which controls the operation of the transmitters of a radio base station, RBS. The scheduler plans the radio traffic to be sent for a coming time interval based on radio traffic information. By letting a calculating device or unit in connection to the scheduler, said calculating device or unit calculates the needed power consumption condition for the coming time interval, and send Operation mode or Power demand interval to the power converters, it will be possible to control the power consumption and to save energy. Said operation mode or power demand interval is determined from the radio traffic information comprising traffic load information provided by the scheduler 100 to said calculating device or unit, which is capable of calculating the power demand during a coming interval by means of proper calculation software.

It is therefore suggested an adapted calculating device or unit and method for enabling energy savings in a radio base station or remote radio unit comprising radio devices for handling radio telecommunication traffic. The calculating device or unit is adapted to calculate a required power consumption of said radio devices based on radio traffic information for a coming time interval and to control each power supply unit 40 by signalling Operation mode or Power demand interval for each power converter 200, 201 and 202 via a direct, high bandwidth communication link 150. Each power converter 200, 201 and 202 adapts its operation mode and/or switching frequency, within the converter operating area, according to the Operation mode or Power demand interval.

Figure 4 is a schematic illustration of a Radio Base Station controller 50. The functionalities of the Radio Base Station, RBS, controller are implemented as hardwiring and/or software in a processing circuitry comprising one or more processors 102. One of the functionalities of the RBS controller is a scheduler 100. Said scheduler 100 comprises or is connected to a power determination unit and functionality 105. The power determination unit and functionality, PD, 105 is integrated in one embodiment with the scheduler and the scheduler functionality 100. The power determination unit and functionality 105 may in another embodiment be separated from the scheduler and the scheduler functionality 100. However, in both embodiments the scheduler and the scheduler functionality 100 and power determination unit and functionality 105 are adapted to communicate information, such as e.g. radio traffic information for a coming time interval. Said power determination unit 105 is provided with an input interface 120 and an output interface 150, i.e. a direct, high bandwidth communication link 150. The scheduler has an interface 130 for controlling and scheduling the radio traffic of the RBS.

In an ordinary architecture, high bandwidth required in the high bandwidth communication link 150 may be at least 1 .0 to 1 .2 MHz. In Wireless Power Transfer architecture, the required bandwidth in the high bandwidth communication link 150 may be at least 1 .0 to 10 MHz.

Figure 5 is illustrating an example of a powering system of a radio base station. Said powering system 300 includes an RBS controller 50 and a scheduler 100 of the RBS controller 50.

The scheduler 100 and the PD 105 are located in a (baseband) digital unit (DU) 55. The PD 105 is connected via the direct, high bandwidth communication link 150 to a plurality of loads 60, such as Radio Units (RUs), DUs 55 and power supply units (PSUs) 40. Said link 1 50 is connected to the power converters 200, 201 and 202 of the different loads 60 and PSUs 40. The PSU 40 comprises AC/DC converters 201 , which converts AC from the AC grid into DC, which DC is distributed to DC/DC converters of RU/RRUs 60. Said radio devices handle the radio telecommunication traffic in the RBS.

The RBS controller 50 comprises in this embodiment the scheduler 100 and the PD 105. The scheduler 100 and the PD 105 are connected adapted to communicate information, such as e.g. radio traffic information. For enabling energy savings in a radio base station (30 in figure 1 ) or remote radio unit, RRU, is a method S100 provided.

Figure 6 is a flowchart illustrating said method S100. Said method comprises the steps of:

S110: - Calculating a required power consumption of said radio devices based on radio traffic information for a coming time interval;

S120: - Determining an operation mode or power demand interval for each of said power converter corresponding to said required power consumption; and

S130: - Controlling the operation mode or power demand interval of each power converter by signalling operation mode or power demand interval for each power converter.

This method may be performed in a power determination unit 105 in a RBS controller 50. When the PD 105 by means of the radio traffic information received from the scheduler has calculated in step S1 10 the required power consumption or demand of the radio devices based on radio traffic information for a coming time interval, the controller determines in step 120 an operation mode or power demand interval for each of said power converter 200, 201 , 202 corresponding to said required power consumption. Thus, the required power consumption is divided into different power demand intervals from "full power" to "no power".

An example of operation mode table is illustrated table 1 below. Each operation mode or power demand interval corresponds to an operation state of the RU, DU and PSU, and the power converters AC/DC, DC/DC and POL. Each operation mode is coded, e.g. with a code number. Said code number is addressed and signalled in S130 from the PD 105 to the processor of the converter device, in which the operation mode table is stored in a data memory storage. The power converter processor, 265 in figure 3, is then capable by means of the stored table to decode the code number and set the converter device in the corresponding state. Each state also corresponds to a frequency setting of the power converter.

The operation mode table may be upgraded remotely from e.g. a Network Management System (OSS/ENM).

Here follows an example of an operation mode table.

Table 1 : Operation modes

Except for the operation mode corresponding to full power state or full operation state, the other operation modes correspond to different power saving features. At full power demand, normal operation of the RUs, DUs and PSUs, and their power converters AC/DC, DC/DC and POL are required. Thus, at full power there is no power saving. The operation mode full power demand is coded "1 ". Thus, code number " is signalled from the PD 105 to the processors, 265 in figure 3, of the power converter devices 200, 201 , 202. Said processors will receive the code number and they will decode the code number by means of the table and operate the RUs, DUs and PSUs, and their power converters AC/DC, DC/DC and POL in full power mode.

A second mode is coded "2". Said mode is used if the power demand is calculated to be 50% of full power. The duration of the power saving feature is a few microseconds when the RU and/or DU is switched off. The switching frequency of the power converters is reduced from 1 MHz to 500 kHz.

In this example, a third and fourth mode are coded "3" and "4", respectively. Said modes are used if the power demand is calculated to be 50% of full power. At operation mode "3", the duration of the power saving feature is a few milliseconds when the RU and/or DU is switched off. The switching frequency of the power converters is reduced to 300 kHz. At operation mode "4", the power saving feature is a few milliseconds when the RU and/or DU is set into sleep mode or stand by. The switching frequency of the power converters is reduced to 300 kHz.

Operation mode "5", is a low power mode. The power saving feature is achieved by running the RU very short and then shutting it down for the rest of the period. The DU is kept running and the switching frequency of the power converters is 300 kHz.

Operation mode "6" is the ultimate low power mode, wherein all units are kept off.

The method may be applied in configurations with one or more DUs and/or one or more RU/RRU. In such configurations devices serving specific radio access technologies/radio standards and/or radio frequencies may be turned off while others are turned on, or in power saving mode. For example, devices servings GSM may be turned on (power saving mode applied) while devices serving LTE are turned off, in Operation mode 3 or 4, .

The method S100 may comprise an initiation step,

S105: Starting up in a pre-set condition. An example of said pre-set condition may be to set all power converters in a full operation state, i.e. operation mode 1 .

Figure 7 is a flowchart illustrating an embodiment of the method S100. Said embodiment comprises the step of:

The determining step, S120 may in further one embodiment comprise:

S122: - Determining an operating state or power demand interval from a table, which comprises different operation modes based on said radio traffic information, wherein each operation mode corresponds to a certain operation state or power demand interval.

The controlling step, S130, may in further one embodiment comprise:

S132: - Signalling a change of operation mode or power demand interval to each power converter acting as a slave via a direct, high bandwidth

communication link.

The signalling of a change of operation mode or power demand interval may be synchronized to each power converter 200 , 201 and 202 acting as a slave.

Figure 8 is a flowchart of a method S200 performed in a processor of a power converter.

The method S200 saves energy in a radio device 60 and/or in a DU 50 of a radio base station 30 or radio unit, RU. Said radio device 60 is power supplied by at least one power converter 200, 201 and 202 and one power supply unit (PSU) 40 for powering said at last one power converter 200, 201 and 202. The method comprises following steps:

S210: - Receiving an operation mode or power demand interval of the power converter, the operation mode or power demand interval being determined based on radio traffic information for a coming time interval;

S220: - Comparing received operation mode or power demand interval to current operation mode or power demand interval;

S230: - If operation mode or power demand interval is changed, then determining an operation state from said received operation mode or power demand interval from said received operation mode or power demand interval, else keeping a current frequency setting; S240: - Setting the operation state or power demand interval of the power converter.

The method is now discussed with reference to figures 2, 3, 5, and 8. Thus, a power converter 200, 201 , 202 is adapted to save energy in a DU 55 or radio device 60 of a radio base station 30 or remote radio unit, RRU. Said radio device 60 is power supplied by at least one power converter 200, 201 , 202 and a power supply unit, PSU, 40 for powering said power converters 200, 201 , 202. Each power converter comprises a controller 260 comprising a processor 265 being adapted to operate the power converter 200, 201 , 202 to perform the steps of the method S200.

The power converter is adapted to receive, step S210, an operation mode or power demand interval of the power converter 200, 201 , 202 from the PD 105. Said operation mode or power demand interval is determined from the radio traffic information comprising traffic load information provided by the scheduler 100 to the PD 105, which calculates the power demand during a coming interval. The controller 260 is further adapted to compare, in step S220, the received operation mode or power demand interval to current operation mode or power demand interval. The controller is further adapted to determine, in step S230, the switching frequency from said frequency setting or the new operation mode if the operation mode or power demand interval is changed. If the operation mode or power demand interval is changed, then the controller sets the operation mode or power demand interval of the power converter. If the received operation mode or power demand interval is not changed, the controller is adapted to keep current operation mode or power demand interval setting.

The determining step S230 of the method S200 may further comprise the step of:

S232: - Determining the switching frequency from a table, which comprises different states based on said radio traffic information, wherein each state corresponds to a certain switching frequency.

Thus, the controller 260 and its processor 265 are therefore adapted to operate the power converter to determine the switching frequency from a table, e.g. table 1 , which comprises different states based on said radio traffic information, wherein each state correspond to a certain switching frequency.

According to one embodiment of the method, the method may comprise the step of:

S250: - Signalling a change of operation mode or power demand interval to the Network Management System.

A Network Management System is, e.g. OSS/ENM (Operation Support System/Ericsson Network Management).

According to further one embodiment, the method may comprise the step of:

S260: - Is a loss of signal detected?

In the case of signal error, e.g. loss of signal due to connection loss, the controller is adapted to restart from the initiation step S205: Starting up in a pre-set condition. An example of said pre-set condition may be to set all power converters in a full operation state, i.e. operation mode 1 .

The controller 260 and its processor 265 is therefore adapted to operate the power converter 200, 201 , 202 to signal a change of operation mode or power demand interval to the Network Management System (OSS/ENM).

The controller 260 and its processor 265 is further adapted to receive from the Network Management System (OSS/ENM) settings of operation modes, states and switching frequencies in the operating mode table.

Figure 9 and 10 are block diagrams illustrating an embodiment of a wireless power transfer (WPT) architecture of a Radio Base Station (RBS).

A WPT PSU 41 is designated for one or more function blocks and units of an RBS. The WPT PSUs 41 are connected to the external power feed, most probably an AC grid, via a power cable connection 12 via an AC input interface 32, which distribute different phases provided by the AC grid through connections to the input terminals 14 of the WPT PSUs 41 (with an internal PFC 44). The WPT PSUs transmits the wireless power and distributes it to the loads (wireless fed loads, with RX module) 61 via wireless interfaces 82 between TX module 46 and RX module 96. The wireless link 80 enables communication between the PSU Ctrl 42 and Digital 92, of e.g. impedance matching and enables switching off and on the power to different loads 61 , i.e. functional blocks, units and xPA stage(s) 90. For securing power feeding to the RBS in case of external power failure, the RBS is provided with an internal power feed 70, e.g. an arrangement of batteries capacity adapted to provide enough power capacity to the RBS during a pre-set time of external power feed failure.

Control buses 52 are connected between the RBS controller 50 and the loads, e.g. Radio Units (RU) 61 , Digital Unit (DU) 62, and WPT PSUs 41 enabling control by the RBS controller and two way communications with said functional blocks and units.

The RBS controller 50 comprises a scheduler 100 and a power determination, PD, unit 105. Said RBS controller comprises as described above processing circuitry, which comprise the scheduler 100 and an associated power determination unit 105. Said power determination unit is provided with an input interface and an output interface 150, i.e. a direct, high bandwidth communication link 150.

Control bus 52 and communication link 150 may also be implemented as one physical link. The RBS controller 50 comprising the scheduler 1 00 and the power determination, PD, unit 105 are connected to the xPA stage(s) 90 via the control bus 52 and communication link 150 and a connection 94.

The scheduler 100 is connected via the direct, high bandwidth communication link 150 to a plurality of loads, such as radio units (RUs) 61 , digital units (DUs) 62 and WPT power supply units (WPT PSU) 41 . Said link 150 is connected to the power converters 200, 201 , 202 of the different loads, 61 . The WPT PSU 41 comprises an AC/DC converter, a TX module 46 which converts DC to AC which is wireless distributed via the wireless interface 82 sent to the RX module 96 and converted from AC to DC, which DC is distributed to DC/DC converters of RU/RRUs 61 and a DU 62 in the system. Said radio devices handle the radio telecommunication traffic in the RBS. The technique may be implemented in digital electronically circuitry, or in computer hardware, firmware, software, or in combinations of them. Apparatus of the technique may be implemented in a computer program product tangibly embodied in a machine readable storage device for execution by a programmable processor; and method steps of the method may be performed by a programmable processor executing a program of instructions to perform functions of the technique by operating on input data and generating output.

The technique may advantageously be implemented in one or more computer programs that are executable on a programmable system including at least one programmable processor coupled to receive data and instructions from, and to transmit data and instructions to, a data storage system, at least one input device, and at least one output device. Each computer program may be implemented in a high-level procedural or object- oriented programming language, or in assembly or machine language if desired; and in any case, the language may be a compiled or interpreted language.

Generally, a processor will receive instructions and data from a readonly memory and/or a random access memory. Storage devices suitable for tangibly embodying computer program instructions and data include all forms of non-volatile memory, including by way of example semiconductor memory devices, such as EPROM (Erasable Programmable Read Only Memory), EEPROM (Electrically Erasable Programmable Read Only Memory), and flash memory devices; magnetic disks such internal hard disks and removable disks; magneto-optical disks; and CD-ROM (Compact Disc Readonly Memory) disks. Any of the foregoing may be supplemented by, or incorporated in, specially - designed ASICs (Application Specific Integrated Circuits).

The herein described methods and devices provide a number of advantages.

The technique enables efficient radio traffic based power savings, for the total RBS system, RU/DU in combination with PSU, which technique do not exist today. It further enables the traffic based power savings, e2e solution by applying a correct timing of switching frequency between the RU/DU units and the power system via a power mode table corresponding to different RU/DU power savings from PA (power amplifier) to DC/DC to AC/DC on system level.

The technique merges a more dynamic power management, that enables a direct link between the Radio and the Power system in the 19" (inches) RBS.

The innovative arrangement provides a system control method to consume minimum energy at all traffic conditions in the RBS.

The solution applies a variable state/power need interval vs. operation mode table for faster response and timing based on traffic situation in the RAN (radio access network) and RBS.

By sending state/power need interval information from the power determination unit to PSUs to change/adjust the frequency, an e2e (end-to- end) power saving and energy management solution is implemented. Information can be sent to POL, DC/DC and AC/DC in current power system or inside an RRU.

It further increases the energy performance and energy utilization of the RBS.

By adjusting the frequency of the WPT receiver and transmitter power modules, the efficiency of the total 19" RBS system can be increased to levels that do not exist in current RBS designs. Further is ripple control via the frequency adjust is obtained.

A number of embodiments of the present technique have been described. It will be understood that various modifications may be made without departing from the scope of the technique.