Energy saving cellular communication system

Abstract

An energy saving cellular communication system is provided. The system includes a plurality of remote antenna units (RAUs) and a distributed antenna system (DAS) head end. The DAS head end is in communication with each RAU of the plurality of RAUs. The DAS head end includes at least one input head end port that is in communication with a base station entity and at least one of a first output head end port and a second output head end port that is in communication with at least some of the RAUs of the plurality of RAUs. A head end controller is configured to implement a scheduler to selectively control at least some of the power consuming functionality of at least one RAU of the plurality of RAUs.

Description

Attorney Docket No.7083 WO W1 / 100.2179WO01 ENERGY SAVING CELLULAR COMMUNICATION SYSTEM

[0001] This Application claims priority to Italy Patent Application No. 102023000025833, same title herewith, filed on December 4, 2023, which is incorporated in its entirety herein by reference. BACKGROUND

[0002] Cellular communication networks may include a distributed antenna system (DAS). A DAS is commonly used to provide enhanced cellular phone coverage in indoor and outdoor environments that frequently have insufficient coverage from outdoor cellular base stations due to increased signal attenuation caused by building structures. A DAS is commonly comprised of multiple radio antennas (remote antenna units) that are distributed throughout the building. A base station downlink wireless signal may be captured and distributed by cables to the multiple remote antenna units of the DAS which then retransmits the signal within the building. Likewise for the cellular uplink, the distributed remote antenna units capture the uplink wireless signal from user equipment, such as mobile phones and these signals are amplified and routed by the cables back to the base station receiver equipment. In some implementations the distribution is achieved between the remote antenna units and the base station equipment using electrical signals on electrically conductive cables either as RF or digital signals. In other implementations distribution is achieved between the remote antenna units and the base station equipment using optical signals carried on optical fiber cables.

[0003] Cellular communication networks require power for operation. Distributed antenna systems (DAS) and small cell remote units typically operate in a “powered on” state, even when there is no traffic in the coverage area. During times of low traffic, power consumption can be reduced by powering down some circuits / functions within the remote unit. However, even when a remote unit is put in a low power idle state, it is still consuming some power. At some point, normal operations need to be restored, so enough of the processing and communication hardware of the remote unit must stay active so communication with the master unit is maintained so the master unit can command the remote unit to resume normal (higher power) operation. With the increasing cost of energy, it is desired for DAS and small cell systems to reduce power consumption.Attorney Docket No.7083 WO W1 / 100.2179WO01

[0004] For the reasons stated above and for other reasons stated below which will become apparent to those skilled in the art upon reading and understanding the present specification, there is a need in the art for a communication system with decreased power consumption. SUMMARY

[0005] The following summary is made by way of example and not by way of limitation. It is merely provided to aid the reader in understanding some of the aspects of the subject matter described. Embodiments provide an energy saving cellular communication system.

[0006] In one embodiment, an energy saving cellular communication system is provided. The system includes a plurality of remote antenna units (RAUs) and a distributed antenna system (DAS) head end. The DAS head end is in communication with each RAU of the plurality of RAUs. The DAS head end includes at least one input head end port that is in communication with a base station entity and at least one of a first output head end port and a second output head end port that is in communication with at least some of the RAUs of the plurality of RAUs. A head end controller is configured to implement a scheduler to selectively control at least some of the power consuming functionality of at least one RAU of the plurality of RAUs.

[0007] In another embodiment, a method of saving energy in a cellular communication system is provided. The method includes tracking at least one of time and communication traffic; determining if the tracked at least one of time and communication traffic warrants change in power consuming functionality of at least one remote antenna unit (RAU) of plurality of RAUs; and implementing a scheduler to selectively change at least some of the power consuming functionality of the at least one RAU of the plurality of RAUs.

[0008] In yet another embodiment, an RAU for an energy saving cellular communication system is provided. The RAU includes RAU circuits and a power control circuit. The RAU circuits include an RAU port that is in communication with a DAS head end, an RAU controller that is in communication with an RAU port, an RAU power supply, a downlink path that is in communication with the RAU controller, the downlink path including a power amplifier and transmitter, and an uplink path that is in communication with the RAU controller, the uplink path including a low-noise amplifier and receiver. The power control circuit is configured to control operational modes of at least some of the RAU circuits through associated control links to the at least some the RAU circuits.Attorney Docket No.7083 WO W1 / 100.2179WO01

[0009] In still another embodiment, a method of operating a RAU in an energy saving cellular communication system is provided, the method includes based on received power control instructions, selecting at least one control link that is communication with at least one RAU circuit; communicating mode control signals through the selected at least one control link to control the mode of an associated RAU circuit with a mode controller that is powered by an independent power source; and controlling the operating mode of the associated RAU circuit with the communicated mode control signal.

[0010] In another embodiment, a remote antenna unit (RAU) for an energy saving cellular communication system is provided. The RAU includes a RAU power supply, RAU circuits, power circuit and an RAU controller. The power circuit is positioned within a connection between the RAU power supply and the RAU circuits. The RAU controller is configured to control the power circuit to selectively couple power from the RAU power supply to the RAU circuits based on one of a schedule and communication traffic.

[0011] In yet another embodiment, a remote antenna unit (RAU) for an energy saving cellular communication system is provided. The RAU includes at least one radio module, at least one power amplifier, a base band controller (BBC) including a field programmable gate array (FPGA). The BBC is in communication with a DAS head end to receive power saving commands from the DAS head end. The BBC is configured to configure the FPGA with a selected load based on a received power saving command. A RAU power supply is coupled to power the at least one radio module and the power amplifier based at least in part on the initialized FPGA.

[0012] In still another embodiment, a method of operating an energy saving cellular communication system is provided. The method includes determining if a power saving mode should be enabled using a remote antenna unit (RAU) controller of at least one RAU; and disconnecting a RAU power source to RAU circuits of the at least one RAU when the RAU controller determines the power saving mode should be enabled.

[0013] In another embodiment, a method of operating an energy saving cellular communication system is provided. The method including generating a power saving command that includes a desired power load with a distributed antenna system (DAS) head end when a power saving mode is desired; communicating the power saving command to a base band controller (BBC) of remote antenna unit (RAU) circuits in at least one RAU; initializing a field programmable gate array (FPGA) of the BBC to the desired power load;Attorney Docket No.7083 WO W1 / 100.2179WO01 and implementing the power saving command with the FPGA to achieve a desired power consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The present invention can be more easily understood and further advantages and uses thereof will be more readily apparent, when considered in view of the detailed description and the following figures in which:

[0015] Figure 1 is a block diagram illustrating one exemplary embodiment of a radio access network communication system that includes a distributed antenna system according to an example aspect of the preset invention.

[0016] Figure 2A is a block diagram of an energy saving cellular communication system in a first configuration according to an example aspect of the present invention.

[0017] Figure 2B is a block diagram of the energy saving cellular communication system of Figure 2A in a second configuration according to an example aspect of the present invention.

[0018] Figure 3A is a block diagram of another energy saving cellular communication system in a first configuration according to an example aspect of the present invention.

[0019] Figure 3B is a block diagram of the energy saving cellular communication system of Figure 3A in a second configuration according to an example aspect of the present invention.

[0020] Figure 4 illustrates a method of implementing a scheduler in a communication system energy saving flow diagram according to an example aspect of the present invention.

[0021] Figure 5 illustrates a block diagram of the remote antenna unit according to an example aspect of the present invention.

[0022] Figure 6 illustrates a block diagram of the remote antenna unit according to an example aspect of the present invention.

[0023] Figure 7 illustrates a block diagram of a sleep clock / timer of the remote antenna unit of Figure 6 according to an example aspect of the present invention.

[0024] Figure 8 illustrates a method of operating a mode controller in a mode controller flow diagram according to an example aspect of the present invention.Attorney Docket No.7083 WO W1 / 100.2179WO01

[0025] Figure 9 illustrates a block diagram of an energy saving cellular communication system according to an example aspect of the present invention.

[0026] Figure 10 illustrates a block diagram of another energy saving cellular communication system according to an example aspect of the present invention.

[0027] Figure 11 illustrates a block diagram of yet another energy saving cellular communication system according to an example aspect of the present invention.

[0028] Figure 12 illustrates a method of operating a remote antenna unit for an energy saving cellular communication system in flow diagram according to example aspects of the present invention.

[0029] In accordance with common practice, the various described features are not drawn to scale but are drawn to emphasize specific features relevant to the present invention. Reference characters denote like elements throughout Figures and text. DETAILED DESCRIPTION

[0030] In the following detailed description, reference is made to the accompanying drawings, which form a part hereof, and in which is shown by way of illustration specific embodiments in which the inventions may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be utilized and that changes may be made without departing from the spirit and scope of the present invention. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is defined only by the claims and equivalents thereof.

[0031] Embodiments of the present invention provide a communication system that selectively turns off multiple input multiple output (MIMO) ports in a communication system. In one example, an express recovery appliance (ERA) backup and restore files (configuration files) and an advanced integrated management and operating system (AIMOS) scheduler are used to turn off MIMO ports and to use the system in single input / single output SISO configuration. The configuration files may include configuration information that contains certain bands to be turned on or off, or MIMO paths to be turned on or off. Examples select an appropriate file to be restored to the system in a given (scheduled) period. This allows saving power and less heat dissipation in the remote antenna units and a head end. Turning off ports can be applied at radio frequency donors (RFDs) (system baseAttorney Docket No.7083 WO W1 / 100.2179WO01 transceiver station (BTS) interfaces), or even at an optical transport (OPT) (head end output), depending on sector / channel choice from a customer. Moreover, in one embodiment further turns-off some bands (so not only MIMO layers, but unused bands (no traffic)). The AIMOS scheduler can be used for day / night shifts or be event-based. The reduced power consumption embodiments provide a green and efficient DAS. Further in an embodiment, one or more circuits of one or more remote antenna units (RAUs) are powered down to conserve energy using a power control circuit that may optionally include a sleep clock / timer with an internal power supply. Further, while the examples provided below focus on DAS remote antenna units, the system may be applied to other wireless systems including repeaters, relays, remote radio heads and non-DAS remote units such as open radio access network (O-RAN) and O-RAN radio units (O-RUs).

[0032] Figure 1 is a block diagram illustrating one exemplary embodiment of a radio access network (RAN) communication system 100 that includes a DAS 130. The DAS 130 further includes RAU 140 that are configured to selectively turn off MIMO ports to conserve energy. Additionally, power amplifiers for a band may be turned off to conserve additional energy. The communication system 100 shown in Figure 1 implements at least one base station entity 102 to serve a cell. Each such base station entity 102 can also be referred to here as a “base station” or “base station system” (and, which in the context of a fourth generation (4G) Long Term Evolution (LTE) system, may also be referred to as an “evolved NodeB”, “eNodeB”, or “eNB” and, in the context of a fifth generation (5G) New Radio (NR) system, may also be referred to as a “gNodeB” or “gNB”).

[0033] In general, each base station 102 is configured to provide wireless service (cellular coverage area) to various items of user equipment (UEs) 150 served by an associated cell in a remote location. Unless explicitly stated to the contrary, references to Layer 1, Layer 2, Layer 3, and other or equivalent layers (such as the physical layer or the media access control (MAC) layer) refer to layers of the particular wireless interface (for example, 4G LTE or 5G NR) used for wirelessly communicating with UEs 150. Furthermore, it is also to be understood that 5G NR embodiments can be used in both standalone and non-standalone modes (or other modes developed in the future) and the following description is not intended to be limited to any particular mode. Moreover, although some embodiments are described here as being implemented for use with 5G NR, other embodiments can be implemented forAttorney Docket No.7083 WO W1 / 100.2179WO01 use with other wireless interfaces and the following description is not intended to be limited to any particular wireless interface.

[0034] In the specific exemplary embodiment shown in Figure 1, each base station 102 is implemented as a respective 5G NR gNB 102 (only one of which is shown in Figure 1 for ease of illustration). In this embodiment, each gNB 102 is partitioned into one or more central unit entities (CUs) 108, one or more distributed unit entities (DUs) 110, and one or more radio units (RUs) 109. In such a configuration, each CU 108 implements Layer 3 and non-time critical Layer 2 functions for the gNB 102. In the embodiment shown in Figure 1, each CU 108 is further partitioned into one or more control-plane entities 114 and one or more user-plane entities 116 that handle the control-plane and user-plane processing of the CU 108, respectively. Each such control-plane CU entity 114 is also referred to as a “CU- CP” 114, and each such user-plane CU entity 116 is also referred to as a "CU-UP" 116. Also, in such a configuration, each DU 110 is configured to implement the time critical Layer 2 functions and, except as described below, at least some of the Layer 1 functions for the gNB 102. In this example, each RU 109 is configured to implement the physical layer functions for the gNB 102 that are not implemented in the DU 110 as well as the RF interface. Also, each RU 109 includes a plurality of base transceiver station (BTS) interface ports 111.

[0035] Each RU 109 is communicatively coupled to the DU 110 serving it (for example, using a switched Ethernet network, in which case each RU 109 and each physical node on which each DU 110 is implemented includes one or more Ethernet network interfaces to couple each RU 109 and each DU physical node to the switched Ethernet network in order to facilitate communications between the DU 110 and the RUs 109). In one implementation, a fronthaul interface promulgated by the O-RAN alliance is used for communication between the DU 110 and the RUs 109. In another implementation, a proprietary fronthaul interface that uses a so-called “functional split 7-2” for at least some of the physical channels (for example, for the PDSCH and PUSCH) and a different functional split for at last some of the other physical channels (for example, using a functional split 6 for the PRACH and SRS).

[0036] In such an example, each CU 108 is configured to communicate with a core network 122 of the associated wireless operator using an appropriate backhaul network 124 (typically, a public wide area network such as the Internet).

[0037] Although Figure 1 (and the description set forth below more generally) is described in the context of a 5G embodiment in which each logical base station entity 102 isAttorney Docket No.7083 WO W1 / 100.2179WO01 partitioned into a CU 108, DUs 110, and RUs 109 and, for at least some of the physical channels, some physical-layer processing is performed in the DUs 110 with the remaining physical-layer processing being performed in the RUs 109, it is to be understood that the techniques described here can be used with other wireless interfaces (for example, 4G LTE) and with other ways of implementing a base station entity (for example, using a conventional baseband band unit (BBU) / remote radio head (RRH) architecture). Accordingly, references to a CU, DU, or RU in this description and associated figures can also be considered to refer more generally to any entity (including, for example, any “base station” or “RAN” entity) implementing any of the functions or features described here as being implemented by a CU, DU, or RU. Further in an example, a DU 110 may connect directly to the MU 135, with no need for the RU 109. In this example, the MU 135 has functions that emulate a RU interface.

[0038] Each CU 108, DU 110, and RU 109, and any of the specific features described here as being implemented thereby, can be implemented in hardware, software, or combinations of hardware and software, and the various implementations (whether hardware, software, or combinations of hardware and software) can also be referred to generally as “circuitry,” a “circuit,” or “circuits” that is or are configured to implement at least some of the associated functionality. When implemented in software, such software can be implemented in software or firmware executing on one or more suitable programmable processors (or other programmable device) or configuring a programmable device (for example, processors or devices included in or used to implement special-purpose hardware, general-purpose hardware, and / or a virtual platform). In such a software example, the software can comprise program instructions that are stored (or otherwise embodied) on or in an appropriate non-transitory storage medium or media (such as flash or other non-volatile memory, magnetic disc drives, and / or optical disc drives) from which at least a portion of the program instructions are read by the programmable processor or device for execution thereby (and / or for otherwise configuring such processor or device) in order for the processor or device to perform one or more functions described here as being implemented the software. Such hardware or software (or portions thereof) can be implemented in other ways (for example, in an application specific integrated circuit (ASIC), etc.).

[0039] Moreover, each CU 108, DU 110, and RU 109, can be implemented as a physical network function (PNF) (for example, using dedicated physical programmable devices and other circuitry) and / or a virtual network function (VNF) (for example, using one or moreAttorney Docket No.7083 WO W1 / 100.2179WO01 general purpose servers (possibly with hardware acceleration) in a scalable cloud environment and in different locations within an operator’s network (for example, in the operator’s “edge cloud” or “central cloud”). Each VNF can be implemented using hardware virtualization, operating system virtualization (also referred to as containerization), and application virtualization as well as various combinations of two or more the preceding. Where containerization is used to implement a VNF, it may also be referred to as a “containerized network function” (CNF).

[0040] For example, in the exemplary embodiment shown in Figure 1, each RU 109 is implemented as a PNF and is deployed in or near a physical location where radio coverage is to be provided and each CU 108 and DU 110 is implemented using a respective set of one or more VNFs deployed in a distributed manner within one or more clouds (for example, within an “edge” cloud or “central” cloud).

[0041] Each CU 108, DU 110, and RU 109, and any of the specific features described here as being implemented thereby, can be implemented in other ways. In the exemplary embodiment shown in Figure 1, each base station 102 is coupled to a distributed antenna system (DAS) 130 in order to improve the wireless coverage provided by the base station 102.

[0042] In the exemplary embodiment shown in Figure 1, each base station 102 is coupled to the DAS 130 in order to improve the wireless coverage provided by the base station 102. More specifically, in the exemplary embodiment shown in Figure 1, a RU 109 of each base station 102 is coupled to the DAS 130 using an analog RF interface. More specifically, the DAS 130 is coupled to the set of BTS interface ports 111 of the RU 109 that would otherwise be used to couple the RU 109 to a set of antennas. In that configuration, the BTS interface ports 111 would be BTS antenna ports. The connection between the base station 102 and the DAS 130, in this example, may occur using one or more coaxial cables and possibly some intermediary attenuators or a point-of-interface (POI) type device connecting the BTS interface ports 111 of the RU 109 to antenna ports 132 of a master unit (MU) 135 in a head end 204 of the DAS 130. In another example a digital interface (e.g., CPRI digital donor and O-RAN donor) may be used.

[0043] In an example DAS 130, radio frequency (RF) signals (or representations of the RF signals) may be transported between a master unit 135 and one or more RAU 140 usingAttorney Docket No.7083 WO W1 / 100.2179WO01 one or more transport cables 136, that are part of the fronthaul of the communication system 100. The transport cables 136 may be part of a fiber distribution network.

[0044] Traditionally, RF signals transmitted from the base stations 102 (also referred to here as "downlink RF signals") are received at the master unit 135 of the DAS head end 204. Master unit 135 uses the downlink RF signals to generate one or more downlink transport signals that are distributed to one or more of the RAUs 140 over the transport cables 136. Each such RAU 140 receives a downlink transport signal and generates a version of the downlink RF signals based on the downlink transport signal and causes the generated downlink RF signals to be radiated from at least one antenna 144 coupled to or included in that RAU 140.

[0045] A similar process is performed in the uplink direction. RF signals transmitted are from user equipment 150 (also referred to here as "uplink RF signals"). Each such uplink RF signal is intended for base station 102 coupled to the master unit 135. Each RAU 140 receives uplink RF signals transmitted from user equipment 150 within its associated coverage area. Each RAU 140 uses the received uplink RF signals to generate an uplink transport signal that is transmitted from the RAU 140 to the master unit 135. The MU 135 receives uplink transport signals from the various RAUs 140 coupled to it. An extension unit (EU) 138 (or extension node) may be used between the MU 135 and one or more RAU 140 to extend the coverage of the DAS 130.

[0046] For each base station 102 coupled to the master unit 135, the master unit 135 ultimately generates uplink RF signals from the combined uplink signals for that base station 102, which are provided to that base station 102. Each RAU 140 can be coupled to each master unit 135 either directly or indirectly via one or more intermediate devices (such as another RAU 140 or an expansion unit (EU) 138). In this way, the coverage of each base station 102 can be expanded using DAS 130. In one example, a master unit 135 of the DAS 130 is in communication with (or coupled to) the antenna ports 111 of the RUs 109 as discussed above.

[0047] As discussed above, some embodiments provide a communication system that selectively turns off MIMO ports. In an example, an express recovery appliance (ERA) backup and restore files and an advanced integrated management and operating system (AIMOS) scheduler are used to turn off MIMO ports and to use the system in single input / single output (SISO) configuration. Examples select an appropriate file to be restoredAttorney Docket No.7083 WO W1 / 100.2179WO01 to the system in a given (scheduled) period. The file may contain configuration information that tells the DAS how many MIMO paths for each channel should be transmitted and whether certain bands should be turned on or off at each RAU. This allows saving power in the remote antenna units and less heat dissipation at remote antenna units and the head-end. Turning off ports can be applied at radio frequency donors (RFDs) (system base transceiver station (BTS) interfaces), or even at an optical transport (OPT) (head-end output), depending on sector / channel choice from a customer. Further in an example, the turning off of ports or bands may also be done at the RAUs. Moreover, in one embodiment further turns-off some bands (so not only MIMO layers, but unused bands (no traffic)). The AIMOS scheduler can be used for day / night shifts or be event-based. The reduced power consumption embodiments provide a green and efficient DAS. Further, while the examples provided below focus on DAS remote antenna units, the system may be applied to other wireless systems including repeaters, relays, remote radio heads and non-DAS remote units such as open radio access network (O-RAN) and O-RAN radio units (O-RUs).

[0048] Figure 2A illustrates an energy saving cellular communication system 200 of one example. The energy saving cellular communication system 200 is illustrated as including a BTS interface port 111 that may be part of the RU 109 of the base station entity 102 discussed above. The BTS interface port 111 is in communication with the head end 204 of DAS 130. The head end 204 may include associated MUs 135. Further illustrated are a first input head end port 206a and a second input head end port 206b. The DAS head end 204 is further in communication with remote antenna units 140a and 140b. In this example, the BTS interface port 111 is configured to communicate in a first channel (channel A) with the first input head end port 206a and a second channel (channel B) with the second input head end port 206a.

[0049] The DAS head end 204 further includes a head end controller 220 that is in communication with a memory 222. In one example, the head end controller 220 is a master unit controller. Memory 222 is used in part to store operating instructions implemented by head end controller 220 and a configuration database 230. In examples, the memory 222 further includes a scheduler 232 that be referred to as a schedular function. The scheduler 232 may instruct the head end controller 220 to implement a configuration file in the backup datafile data base to implement an energy saving strategy.Attorney Docket No.7083 WO W1 / 100.2179WO01

[0050] The example of Figures 2A and 2B illustrate the scheduler 232 and configuration database being internal to the DAS head end 204 (e.g., AIMOS), however, in other examples, the scheduler 232 and / or the configuration database 230 may be external to DAS 130 or the RAU 140. In the external location example, scheduler 232 may instruct the DAS 130 to use a specific configuration file. Accordingly, the configuration files may be stored externally and downloaded to DAS 130 or stored in the DAS 130 and an internal scheduler, such as schedular 232 is used to tell the DAS 130 to use a specific configuration file from multiple configuration files. Further in an example, the scheduler 232 and configuration files are in AIMOS, and the AIMOS is the entity that instructs the DAS 130 to use a different configuration file. In another example, the AIMOS may send the new configuration file to DAS 130 to use. Further in an AIMOS example, one AIMOS system may monitor / control multiple DAS systems at multiple locations. In further still another example, an external scheduler connects to the DAS 130 and directly changes a DAS configuration.

[0051] Further in an example, scheduler 232 may be implemented without changing any configuration file. The scheduler 232, in this example, may simply turn on or off elements of the system according to some predefined criteria such as, but not limited to, time of day, day of week, communication traffic, occupancy, or other internal or external conditions.

[0052] In general, the head end controller 220 may include any one or more of a processor, microprocessor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field program gate array (FPGA), or equivalent discrete or integrated logic circuitry. In some example embodiments, head end controller 220 may include multiple circuits, such as any combination of one or more microprocessors, one or more controllers, one or more DSPs, one or more ASICs, one or more FPGAs, as well as other discrete or integrated logic circuitry. The functions attributed to the head end controller 220 herein may be embodied as software, firmware, hardware or any combination thereof. Head end controller 220 may be part of a system controller or a circuit controller such as a master unit controller. Memory 222 may include computer-readable operating instructions that, when executed by the head end controller 220 provides functions of the energy saving cellular network. Such functions may include the functions of selectively shutting off head ports that are not needed as described below. The computer readable instructions may be encoded within memory 222. Memory 222 is an appropriate non-transitory storage medium or media including any volatile, nonvolatile, magnetic, optical, or electrical media, such as, but notAttorney Docket No.7083 WO W1 / 100.2179WO01 limited to, a random-access memory (RAM), read-only memory (ROM), non-volatile RAM (NVRAM), electrically-erasable programmable ROM (EEPROM), flash memory, or any other storage medium.

[0053] In the example of Figure 2A, both the first input head end port 206a and the second input head end port 206b are turned on and as a result, the BTS 111 is in communication with RAUs 140a using channel A and RAUs 140b using channel B. In Figure 2B, scheduler 232 has turned off input head end port 206b for energy saving purposes. As a result, in this configuration channel A is still used to communicate between the BTS 111 and RAUs 140a but channel B is no longer available, so RAUs 140b are shut down. Hence, in this situation, only RAUs 140a are needed for communications. Further in another example, the RAUs 140 may be turned off directly, leaving the head end unchanged.

[0054] Figures 3A and 3B illustrate another configuration of an energy saving cellular communication system 300, where output head end ports 306a and 306b are selectively turned off in an energy saving mode. In the example of Figures 3A and 3A, one communication channel A is used to communicate between the BTS 202 and RAUs 140a and 140b. In the configuration of Figure 3A, both output head end ports 306a and 306b are turned on so that communications using the single channel A between the BTS 202 and the RAUs 140a and 140b is accomplished. This configuration would be used during high traffic periods. Figure 3B illustrates a configuration where scheduler 232 implemented by the controller 220, has shut off output head end port 306b. As a result, RAUs 140b in communication with output head end port 306b are shut off to conserve energy. In another example, the RAUs 140b may be controlled directly without changing the head end.

[0055] Referring to Figure 4, a method of implementing scheduler 232 in a communication system energy saving flow diagram 400 is illustrated. The energy saving flow diagram 400 is illustrated as a series of sequential blocks. The sequence, however, may occur in a different order or in parallel in other embodiments. Hence, the present invention is not limited to the sequence as set out in the energy saving flow diagram 400 of Figure 4.

[0056] At block 402, the time is tracked. This may be done with a clock or with a received signal that provides a then current time. At block 404 in this example, the communication traffic is tracked. Based on at least one of a current time provided at block 402 and traffic provided at block 404, it is determined if a change in power consumption (power consuming functionality) at one or more RAUs 140 is needed at block 406. In anAttorney Docket No.7083 WO W1 / 100.2179WO01 example that implements different configuration files in changing power consuming functionality at the RAUs 140, it is determined which configuration file is needed to implement the desired change. At block 408 scheduler 232 implements the change. In the configuration file example, the schedular 232 implements a selection configuration file to implement the change. In another example, scheduler 232 may implement enable / disable system directly based on time, day, usage, etc. The process continues at blocks 402 and 404 in this example.

[0057] In embodiments selectively changing at least some of the power consuming functionality of the at least one RAU 140 of the plurality of RAUs 140 may include totally shutting down and turning on the at one RAU 140, enabling and disabling certain functions of the at least one RAU, and turning on and off one or more power amplifiers of the at least one RAU.

[0058] In one example, a customer (user) can customize the configuration files by creating one or more profiles for coverage that are implemented by the scheduler. In one example a customer can use the ERA backup and restore function to turn RF off / on from an ERA access point. Further in an example, a customer can close / open Copper Transport Card (CAT)’s ports to turn off / on ERA copper-feed access points, multiple profiles (all ports, per sector, etc.) can be backed up and restored as appropriate. As discussed above, a customer can benefit from the AIMOS scheduler to apply (restore) the different backup (configuration) files as appropriate.

[0059] In some embodiments, once a port is turned off, the corresponding RAU 140 that is no longer receiving communications with the DAS head end may be powered down to conserve energy as discussed above. A RAU may not be fully turned off and instead be placed in a low power idle state so minimal processing and communication hardware stays active. This maintains communication with the master unit 135 of the DAS head end 204 so the master unit can command the RAU 140 to resume normal higher power operation when desired. A RAU 140 will consume some power in the low idle state. In another example, it is not required that any ports be turned off in the MU 135 before some or all of the functions of an RAU are turned off.

[0060] In one embodiment an RAU 140 is completely turned off when not in use therein further reducing power consumption of the communication system while still retaining the ability to return to normal full power operation with the use of an RAU power supply.Attorney Docket No.7083 WO W1 / 100.2179WO01

[0061] Figure 5 illustrates a simple block diagram of a RAU 140 that can have its power shut down. The RAU 140 includes an RAU port 502 (interface) that is communication with the DAS head end 204. A RAU controller 504 is in communication with the RAU port 502. The RAU controller 504 is in communication with an RAU memory 520.

[0062] In general, the RAU controller 504 may include any one or more of a processor, microprocessor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field program gate array (FPGA), or equivalent discrete or integrated logic circuitry. In some example embodiments, RAU controller 504 may include multiple circuits, such as any combination of one or more microprocessors, one or more controllers, one or more DSPs, one or more ASICs, one or more FPGAs, as well as other discrete or integrated logic circuitry. The functions attributed to the RAU controller 504 herein may be embodied as software, firmware, hardware or any combination thereof. RAU controller 504 may be part of a system controller or a circuit controller. RAU memory 520 may include computer- readable operating instructions that, when executed by the RAU controller 504 provides functions of the energy saving cellular network. Such functions may include communication functions of the RAU 140 as described below. The computer readable instructions may be encoded within the memory. Memory 520 is an appropriate non-transitory storage medium or media including any volatile, nonvolatile, magnetic, optical, or electrical media, such as, but not limited to, a random-access memory (RAM), read-only memory (ROM), non-volatile RAM (NVRAM), electrically-erasable programmable ROM (EEPROM), flash memory, or any other storage medium.

[0063] Other circuits of the RAU 140 in the example of Figure 5 further include in a downlink path a digital-to-analog converter (DAC 506) and a power amplifier / transmitter (PA / TX 508) to convert digital signals from the RAU controller 504 into RF signals and amplify and transmit the RF signals to UE 150. In an uplink path, the RAU 104 includes a low-noise amplifier / receiver (LNA / RX 512) to receive UE 150 generated RF signals and an analog-to-digital converter (ADC 510) to convert the RF signals to digital signals that are communicated to the RAU controller 504. The RAU 104 also includes a RAU power supply 514 that powers the circuits of the RAU 104. The RAU is always enabled, in this example, as long as the power supply 514 is being applied to the RAU’s circuits. The RAU power supply 514 is a separate power supply from a main power supply to allow for select power applications to the RAU circuits as discussed below. Although the RAU power supply 514 isAttorney Docket No.7083 WO W1 / 100.2179WO01 illustrated as being internal to the RAU 140, in another example, the RAU power supply 514 may be external to an associated RAU 140. As discussed above, the power supply 514 of the RAU in an example may be shut down to power down the RAU 140 in an example.

[0064] Figure 6 illustrates an example of a power control circuit 600 to selectively provide power to the circuits of the RAU 140. The power control circuit 600 includes a sleep clock / timer (SCT 602), the power supply 514 and the switch 604. The SCT 602 is a circuit that includes a real time clock 704 (which may be a timer), a mode controller 702 with control links 703, and a SCT power source 708 that is separate from the RAU power supply 514 and the main power. SCT 602 is illustrated in Figure 7.

[0065] The real time clock 704 and the mode controller 702 may be integrated together into a single integrated circuit (IC), or they could be separate ICs. Such circuits consume very little power and can operate for years using a small battery. The power source 708 may be a battery, a capacitor, or other device. In one example, the power source 708 may be rechargeable from the RAU power supply 514 or the main power. If the RAU controller 504 includes a built-in real-time clock function a separate SCT 602 may not be needed.

[0066] The mode controller 702 is used to completely turn off some or all of the circuits of the RAU 140 based on instructions stored in mode memory 710. In general, mode controller 702 may include any one or more of a processor, microprocessor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field program gate array (FPGA), or equivalent discrete or integrated logic circuitry. In some example embodiments, mode controller 702 may include multiple circuits, such as any combination of one or more microprocessors, one or more controllers, one or more DSPs, one or more ASICs, one or more FPGAs, as well as other discrete or integrated logic circuitry. The functions attributed to the mode controller 702 herein may be embodied as software, firmware, hardware, or any combination thereof. Mode controller 702 may be part of a system controller or a circuit controller. Mode memory 710 may include computer-readable operating instructions that, when executed by the mode controller 702 provides functions of shutting down circuits of an associate RAU 140 as described below. The computer readable instructions may be encoded within the memory. Mode memory 710 is an appropriate non-transitory storage medium or media including any volatile, nonvolatile, magnetic, optical, or electrical media, such as, but not limited to, a random-access memory (RAM), read-only memory (ROM), non-volatileAttorney Docket No.7083 WO W1 / 100.2179WO01 RAM (NVRAM), electrically-erasable programmable ROM (EEPROM), flash memory, or any other storage medium.

[0067] The mode controller 702 is in communication with RAU circuits of the RAU 140 that may include the RAU controller 504, the RAU port 502, the ADC 510, the PA / TX 508, the DAC 506, and the LNA / RX 512 via control links 703. Signals passed through the control links 703 to an associated RAU circuit may control whether the circuit is to be fully on, at some reduced power consumption mode or turned off. An illustration of the control links 703 (enable / reset line) used by the mode controller 702 is provided in Figure 7. Each control link is coupled to an associated circuit of the SCT 602. An example of a control link 703a from the SCT 602 to the RAU controller 504 is control link 703a illustrated in Figure 6. Mode controller 702, based on instructions stored in the mode memory 710 or power control instructions received from the RAU controller 504, directs the RAU controller 504 to either shut down, reduce power consumption (low power mode) or turn on. Another example of a control link 703, is control link 703b that directs the RAU power supply 514 to enter an operational mode associated such as a shut down mode, reduce power output mode or full power mode. If the RAU power supply 514 is turned off, (shut down mode) the RAU is turned off (i.e., all circuits are turned off except the SCT 602 that has the independent SCT power source 708).

[0068] In one example, a switch 604, which may be relay or other type of power circuit, is positioned between the main power and the RAU power supply 514 as illustrated in Figure 6. In this example, a control link 703, such as control link 703c is used to selectively activate switch 604 to either shut off power to the RAU power supply 514 (which will either shut down all the RAU circuits of the RAU 140 (except the SCT 602 with its own power supply)) (off power mode) or to allow power from the main power to be used by the RAU power supply 514 to power all the RAU circuits of the RAU 140 (on power mode).

[0069] In one example input / output (I / O) bits are used to control the operating modes of the RAU circuits of the RAU 104. The I / O bits are communicated through the control links 703 to an associated circuit of the RAU 140. The I / O bits may be used in combination or separately by the mode controller 702 to power down circuits of the RAU 140. The SCT 602 may be controlled by the RAU controller 504 via communication link 705 illustrated in Figure 6. The RAU controller 504 may in turn be in communication with a master unit, such as master unit 135 of the DAS head end 204 discussed above. In an example, the DAS headAttorney Docket No.7083 WO W1 / 100.2179WO01 end 204 may generate power control instructions that are passed on to the mode controller 702 through the RAU controller 504. If, in an example, it is determined that an RAU 140 should be put into a low power state or mode, either by the RAU 140, or at the request of the master unit 135, the RAU controller 504 would instruct the SCT 602 to activate specific control links (which may use I / O bits) to specific states at a specific times (Off Times) and a second specific times when the I / O bits would return to their normal states (On Times). If multiple I / O bits are used on a circuit, each I / O bit may have a separate on / off time if the I / O bits need to be sequenced in a specific order or time interval. When specific times are reached, the mode controller 702 may activate the I / O bits according to the programmed schedule, first completely turning off the remote unit, and then waking it up some time later.

[0070] The switching times may be relative (for example, turn off in 10 minutes and return to normal operation three hours later), or specific times (for example, turn off at 1 am and turn on at 5am), or a combination thereof. The SCT 602 could also be enabled / disabled by some other source as well.

[0071] The master unit 135 in an example, may have the ability to assign the same or different on / off schedules to each RAU 140. The schedules could be fixed or adaptive. Other inputs could be used to determine when to enable / disable remote units, including traffic levels in the system or in the remote unit, light sensors, occupancy sensors, either separately or in combination with the scheduler. For instance, an RAU 140 may be scheduled to turn off if the time is between 11:00 pm and 5:00 am if occupancy sensors indicate the coverage area is vacant and turn on at 5:00 am. While the above discussion focuses on DAS RAUs, the power saving described above may also be applied to other wireless systems including repeaters, relays, remote radio heads, and non-DAS remote units (e.g., O-RAN O-RUs).

[0072] Although the scheduler 232 and the configuration database 230 are described above as being located in the DAS head end 204 in other examples, the scheduler 232 and the configuration database 230 may be located outside of the DAS head end 204. For example, the scheduler 232 and configuration database 230 may be in a RAU memory 520 of at least one RAU 140. The RAU controller 504, in this example, may be configured to use the scheduler 232 and the configuration database 230 to control the switch 604 (power circuit). Further, the traffic tracking described above in block 404 may also occur outside of the DAS head end 204 in other embodiments. In one example, the traffic tracking (traffic detection) may occur in at least one RAU 140.Attorney Docket No.7083 WO W1 / 100.2179WO01

[0073] Referring to Figure 8, an example method of operating a mode controller 702 is provided in a mode controller flow diagram 800. The mode controller flow diagram 800 is provided in a series of sequential blocks. The blocks may occur in a different order or in parallel in other examples. Hence, the present invention is not limited to the sequence as set out in the mode controller flow diagram 800.

[0074] At block 802, it is determined if power control instructions have been received at the mode controller 702. The power control instructions may be provided by the RAU controller 504 via communication link 705. The instructions may have originated in DAS head end 204 which may include the MU 135 as discussed above. If no power control instructions have been received, the process continues monitoring for power control instructions at block 802.

[0075] Once power control instructions have been received, the mode controller 702 at block 804, selects control links and mode control signals (I / O bits) needed to implement the instructions. In one example, the mode controller 702 implements RAU circuit operating mode instructions stored in mode memory to implement the power control instructions received by the mode controller 702. In other examples, the power control instructions themselves provide the specific RAU circuit operating mode instructions the mode controller 702 uses. The mode memory 710 may include a control link database of control link - RAU circuit connections. The mode controller 702 uses the control link database when selecting control links 703.

[0076] Once the control links are selected, the mode controller 702 sends the mode control signal(s) to the associated circuit(s) of the RAU 140 at block 806. As discussed above, the number of RAU circuits and the operating mode (level of power down) can be individually regulated or the whole RAU may be powered down with the use of a switch 604. Control of the operating modes of the respective RAU circuits based on the communicated mode control signals occurs at block 808. The process continues at block 802 monitoring for additional instructions.

[0077] As discussed above, since the SCT 602 includes its own power supply (SCT power source 708), circuits of the SCT 602 remains at power up to be able to send mode control signals to the circuits of the RAU 140 when the RAU 140, or RAU circuits of the RAU 140, need to be powered back up. In one example, as described above, the SCT 602 includes a real time clock 704, so that is the mode controller 702 of the SCT 602 knows whenAttorney Docket No.7083 WO W1 / 100.2179WO01 to power up an RAU 140. Instructions on when to power back up an RAU may be provided with the sleep instructions and stored in mode memory 710.

[0078] In another example, a physical circuit / intelligence (i.e., a controller such as a RAU controller as discussed above or a base band controller) that controls power cycles of remote antenna units 140 may be used. The power consumption of a controller in an RAU is low (in the range of a few watts), which is negligible compared to typical DAS and small cell RAU power consumption. The controller in the RAU, in an example, allows a user to turn off a select RAU circuits via software, thus saving the entire RAU’s power consumption with only the RAU controller remaining active during a power saving mode. A local graphic user interface (GUI) may be used to put one or more of the RAUs in and out of a power saving mode in an example. In another example, one or more of the RAUs may be put into and out of a power saving mode remotely. In a remotely operated example, a simple network management protocol version (SNMPv), such as SNMPv3, may be used over a monitoring platform such as the advance integrated management and operating system (AIMOS) platform. The power consumption saving is comparable to a RAU’s power consumption, for each of the remote antenna unit 140, in the DAS 130 system. In an example, based on a user’s interaction or a scheduled event, the user is able to turn on the remote antenna unit 140 via software, thanks to continuous connectivity with the above-mentioned controller (circuit / intelligence), through a master unit 135, or directly to the controller of the RAU itself in another example.

[0079] In a typical DAS application, like a stadium application, there may be 200 medium RAUs 140 per system, serving 20 or more zones in terms of coverage and capacity. An example maximum power consumption for a RAU in this type of application is around 200W and a minimum power consumption for a RAU is around 150W. Therefore, the overall power consumption during a full traffic event (such as a football match, concert, etc.) will be 200W x 200 units = 40,000 W. With the use of controllers in the RAUs for power savings (which consume 2W or less of power), the power consumption in a full traffic scenario will be slightly higher per system: 202 W x 200 remotes = 40,400 W (1% higher). However, in the scenario where no-traffic is present (empty stadium, no event), with the setup for these energy saving enhancements, the DAS typical power consumption is about 2W x 200 remotes = 400W, while the power consumption during a no traffic scenario of the DAS, without the energy saving enhancements, is about 150W x 200 units = 30,000W.Attorney Docket No.7083 WO W1 / 100.2179WO01 Hence, in this example there is a 99% lower power consumption with the energy saving RAUs described herein during the no-traffic scenario.

[0080] In an example, the power consumption of RAUs is done with fiber light coding. In this example, TX disable hardware pins and loss of signal (LOS) hardware pins on a standard small form-factor pluggable (SFP) transceiver may be used. A TX disable hardware pin is used to shut down a transmitter optical output. On a central area node (CAN) / transport extension node (TEN) side (DAS head end 204 side), the optical TX of a SFP transceiver module may be switched on and off via a pin. On a carrier access point (CAP) side (remote antenna unit side), a loss of signal (LOS) pin may be used to determine whether optical power is received or not.

[0081] In one possible implementation on the RAU side, a RAN controller, which may be a simple logic block, is used that disconnects a voltage source in the RAU if a LOS pin goes low for a defined duration, for example, 10 seconds, and connects the RAU voltage source if the LOS pin goes high for a defined duration, for example, 10 seconds.

[0082] In another implementation, a low-speed serial protocol like a universal asynchronous receiver-transmitter (UART) protocol may be used when enabling / disabling SFPs TX disable PIN (light coding). The data rate for communication via light coding could be up to around 500Hz in one example. In this implementation a parity bit or checksum may be implemented providing secure communication / signaling. Further in an example with light coding, a kind of addressing (e.g. using a morse code) and with that just deactivating dedicated CAPs (remote antenna units) that are connected to a CAN or TEN (DAS head end) may be used.

[0083] Figure 9 illustrates a block diagram of an energy saving cellular communication system that includes a DAS head end 902 (CAN / TEN) and a RAU 920 (CAP). The DAS head end 902 in this example includes a backplane with a system processor 904 that is in communication with an optical transport (OPT) card 906 via communication interface 905. The OPT card 906 in this example includes a communication path through a complex programable logic device (CPLD 908), a TX disable 912 (which may be an SFP pin in an example) and SFP module 910. The DAS head end 902 is in communication with the RAU 920 via communication link 918.

[0084] The RAU 920 in this example, includes a power control circuit 921. The power control circuit 921 includes a data and power entry module (DPEM 922). The DPEM 922 isAttorney Docket No.7083 WO W1 / 100.2179WO01 an optical module inside the RAU 920. One of DPEM’s main features is to convert optical signals to digital signals. DPEMs 922, in this example, includes an SPF module 924, a RAU controller 926 and a power circuit 934. Power circuit 934 may be a switch or circuit that enables and disables power. Power circuit 934 further may be a circuit that controls devices to consume the power off and on. Further the power circuit, in an example, may be configured to stop clock(s) to a circuit to minimize current consumption. RAU controller 926 is coupled to a loss of signal (LOS) pin 928 of the SPF module 924 in an example. The RAU controller 926 controls power circuit 934 to selectively couple voltage from a RAU power source (RAU PS 930) to RAU circuit 931. The RAU circuits 931 includes one or more radio modules 932, a base band controller (BBC) 935 and a power amplifier 936. RAU controller 926 may be a simple logic block in one example. In another embodiment, the RAU controller may include one or more processors. Further, RAU controller 926 may be used to implement a low-speed serial protocol discussed above in another embodiment.

[0085] In another embodiment, a combination of the RAU controller 926 and a BBC 1004, or other dedicated processor, may be used for power saving at the RAU 920. An example of this embodiment is illustrated in the power saving block diagram 1000 of Figure 10. In this example, the BBC 1004 receives off-signals directly via a highspeed communication interface 1104 between DAS head end 902 and RAU 920. The off-signal is forwarded to the RAU controller 926 and the BBC 1004. As a result, the FPGA of the BBC 1004 disables itself and the RAU controller 926 selectively disconnects the voltage to the RAU circuits 931 that includes the BBC 1004, radio modules 932 and the power amplifiers 936. An on-signal, in an example, is transmitted via light coding from the DAS head end 902 to the RAU controller 926 of the RAU 920 since the FPGA of the BBC 1004 has disabled itself by the off-signals in this example. The RAU controller in response to the on-signals connects the RAU PS 930 to the TAU circuit 931.

[0086] Figure 11 illustrates a processor only power saving block diagram 1100 of another example of an energy saving cellular communication system that includes a DAS head end 902 and a RAU 920. In this example, communications are accomplished via the high-speed communication interface 1104. The power control circuit 1106 of this embodiment includes a DPEM 1102 that includes the SFP module 924, the high speed communication interface 1104 and a FPGA (controller) of BBC 1108. The DAS head end 902 may send a power saving commands to the BBC 1108 of dedicated RAUs 920. The BBC 1108 initializes itsAttorney Docket No.7083 WO W1 / 100.2179WO01 associated FPGA with a select power load based on a received power saving command from the DAS head end 902. A load can either be a minimum load where just an ethernet high speed communication is enabled with minimum power consumption or it can be a full load which would support the maximum signal processing functionality (max. RF bandwidth, digital filtering, etc.) with maximum power consumption.

[0087] In one example, the BBC 1108 is in communication with the DAS head end 902 to receive off-signals from the DAS head end 902. A field programable gate array (FPGA) of the BBC 1108 is configured to one of disable and remove power from itself upon receiving an off-signal from the DAS head end 902. A RAU controller, such a RAU controller 926, may be configured to one of enable and add power to the RAU circuits 931 upon receiving an on-signal from the DAS head end 902.

[0088] In another example of a processor only power saving embodiment, initialization of the FPGA of the BBC 1108 is done dynamically. In a minimum load example, the BBC 1108 would initialize the FPGA to the minimum load in which just the high-speed communication with the DAS head end 902 is enabled (minimum power consumption). Depending on the use case communicated from the DAS head end 902, the FPGA will initialize exactly that portion of the FPGA which is required to support the dedicated bandwidth of a current active use case. In this example, the power consumption is directly related to the required bandwidth. Further, a combination of this example with the low-speed serial protocol, like the UART example described above, may optimize power consumption.

[0089] Embodiments described above may be helpful in larger deployments (like stadiums) to shut down for example every second remote antenna unit, such as select RAUs 140 of Figure 1 and / or a portion of a remote antenna unit. The remaining active remote units 140 or portion of them are still guaranteeing the base coverage during non-event times. In another use case, selected areas of the building / stadium are disabled completely.

[0090] For larger cities, a dedicated coverage control can be realized. This means that a larger number of RAUs 140 (as illustrated in Figure 1) or radio points are connected to a common sector but only a portion of the RAUs 140 or radio points are enabled. Based on the throughput requirements it can be decided (e.g. by using artificial intelligence (AI)) to disable a certain set of RAUs 140 and enable another set of RAUs 140. With that, the UE 150 can be followed, and the capacity is always exactly present at the right time in the right area.Attorney Docket No.7083 WO W1 / 100.2179WO01

[0091] An application of the example of the processor only power saving embodiment illustrated in Figure 11 may be in train tunnel where the RAUs are enabled and disabled in alignment with the timetable of the train traffic. In other words, this means that the DAS 130 is only active when a train passes through the tunnel.

[0092] Figure 12 illustrates an example method of operating a RAU for an energy saving cellular communication system in flow diagram 1200. Flow diagram 1200 is provided in a series of sequential blocks. The blocks may occur in a different order or in parallel in other examples. Hence, the present invention is not limited to the sequence as set out in low diagram 1200.

[0093] At block 1202 it is determined if a power saving mode has been enabled. Determining if power saving mode is enabled may be based on user interaction or may be based on a set schedule. The determination may be done with a processor / logic located in either the DAS head end 902, such as the CPLD 908 in the DAS head end 902, discussed above, or the RAU controller 926 of RAU 920. User interaction may be based on communication traffic. For example, the LOS pin 928 in the RAU 920 may be monitored by the RAU controller 926 to determine if a power saving mode should be enabled (i.e., a select period of time the LOS pin 928 is low). As discussed above, in an example, the RAU controller 926 (which may be a simple logic block) may determine the desire to enable a power saving mode based on a defined duration of no communication traffic using an output of the LOS pin 928.

[0094] If it is determined at block 1202 that a power saving mode has been enabled, the initiation of the power saving mode occurs at block 1204. In some embodiments, the initiation of the power saving mode is accomplished by activating power circuit 934 with the RAU controller 926 to disconnect power supplied by the RAU PS 930 to the RAU circuits 931. The RAU circuits include the BBC 1004, the radio modules 932 and the power amplifiers 936 in an example. In one example, the processor of the BBC 1004 also receives an off-signal directly from the DAS head end 902 via highspeed communication interface. In yet another embodiment, power commands, that include a desired load, are communicated to the BBC 1108 of the RAU 920 from the DAS head end 902. The BBC 1004 initializes its FPGA with a desired load to save power. In one example, the FPGA is initialized to support a current dedicated bandwidth of an active use case so power consumption is directly related to the then required bandwidth of the communication system.Attorney Docket No.7083 WO W1 / 100.2179WO01

[0095] At block 1206 it is determined if the power saving mode is to be disabled. In one example this is determined based on a schedule. In another example, the determination is based on communication traffic. If it is determined at block 1206 that the power saving mode has not been disabled, the process continues at block 1206. If it is determined at block 1206 that the power saving mode has been disabled, an end of the power saving process occurs at block 1208. In one example, the end of the power saving process occurs by activating the power circuit 934 to connect the RAU power source to the RAU circuits. In one embodiment, an on-signal generated at the DAS head end 902 generates an on-signal that is communicated to the RAU controller 926 via light coding. The RAU controller 926 in this example, controls the switch 934 based on the on-signal. The process then continues at block 1202. EXAMPLE EMBODIMENTS

[0096] Example 1 is an energy saving cellular communication system. The system includes a DAS head end and a plurality of RAUs. The DAS head end is in communication with each RAU of the plurality of RAUs. The DAS head end includes at least one input head end port that is in communication with a base station entity. The DAS head end further includes at least one of a first output head end port and a second output head end port that are in communication with at least some of the RAUs of the plurality of RAUs. Additionally, the DAS head end includes a head end controller that is configured to implement a scheduler to selectively control at least some of a power consuming functionality of at least one RAU of the plurality of RAUs.

[0097] Example 2 includes the system of Example 1, wherein the head end controller is further configured to control the at least some power consuming functionality of the at least one RAU of the plurality of RAUs by selectively turning on and off at least one of the at least one input head end port and at least the first output head end port and the second output head end port to implement an energy saving strategy.

[0098] Example 3 includes the system of any of the Examples 1-2, further including a configuration file database, the scheduler configured to instruct the head end controller to implement a select configuration file from the configuration file database to implement the energy saving strategy.

[0099] Example 4 includes the system of any of the Examples 1-3, wherein the head end controller is a master unit controller of a master unit.Attorney Docket No.7083 WO W1 / 100.2179WO01

[0100] Example 5 includes the system of any of the Examples 1-4, wherein the first output head end port is in communication with at least a first RAU of the plurality of RAUs and the second output head end port is in communication with at least a second different RAU of the plurality of RAUs.

[0101] Example 6 includes the system of any of the Examples 1-5, wherein at least one RAU of the plurality of RAUs includes a sleep clock / timer (SCT) that is in communication with RAU circuits of the RAU to control power consumption of the RAU circuits of the RAU, the SCT including an independent SCT power source.

[0102] Example 7 includes the system of Example 6, wherein the circuits of the RAU further include an RAU port that is in communication with the DAS head end; an RAU controller that is in communication with the RAU port and the SCT; a RAU power supply; a switch that selectively couples power to the RAU power supply; and a power amplifier / transmitter.

[0103] Example 8 includes the system of Example 6, wherein the SCT further includes a mode controller that is in communication with the RAU controller to receive instructions from the RAU controller; and a real time clock in communication with the mode controller.

[0104] Example 9 includes the system of Example 8, further including a plurality of control lines. Each control line of the plurality of control lines communicates mode control signals between the mode controller and an associated RAU circuit of the RAU.

[0105] Example 10 includes a method of saving energy in a cellular communication system, the method including tracking at least one of time and communication traffic; determining if the tracked at least one of time and communication traffic warrants change in power consuming functionality of at least one remote antenna unit (RAU) of plurality of RAUs; and implementing a scheduler to selectively change at least some of the power consuming functionality of the at least one RAU of the plurality of RAUs.

[0106] Example 11 includes the method of Example 10, wherein determining if the tracked at least one of time and communication traffic warrants change in power consuming functionality of at least one remote antenna unit (RAU) of plurality of RAUs further includes determining if a new configuration file should be implemented by a head end controller of the DAS head end based on at one of the tracking of the time and communication traffic; and implementing the new configuration file when it is determined the new configuration fileAttorney Docket No.7083 WO W1 / 100.2179WO01 should be implemented that changes a current operational state of at least one of an input head end port and an output head port of the DAS head end.

[0107] Example 12 includes the method of any of the Examples 10-11, wherein selectively changing the at least some of the power consuming functionality of the at least one RAU of the plurality of RAUs further comprises at least one of shutting down and turning on the at least one RAU, enabling and disabling certain functions of the at least one RAU, and turning on and off one or more power amplifiers of the at least one RAU.

[0108] Example 13 includes the method of any of the examples 10-12, wherein changing the at least some of the power consuming functionality of the at least one RAU of the plurality of RAUs further includes receiving instructions from an RAU controller at a mode controller of a sleep clock / timer (SCT); selecting control links in communication with RAU circuits of the RAU to shut down; and communicating mode control signals between the mode controller and associated RAU circuits of the RAU.

[0109] Example 14 includes the method of Example 13, wherein the mode control signals include input / output bits.

[0110] Example 15 includes the method of any of the Examples 10-13, wherein the circuits of the RAU include a power source switch that selectively provides power to the circuits of the RAU.

[0111] Examples 16 includes an RAU for an energy saving cellular communication system, the RAU includes RAU circuits and a power control circuit. The RAU circuits include an RAU port that is in communication with a DAS head end, an RAU controller that is in communication with an RAU port, an RAU power supply, a downlink path that is in communication with the RAU controller, the downlink path including a power amplifier and transmitter, and an uplink path that is in communication with the RAU controller, the uplink path including a low-noise amplifier and receiver. The power control circuit is configured to control operational modes of at least some of the RAU circuits through associated control links to the at least some the RAU circuits.

[0112] Example 17 includes the RAU of Example 16, wherein the power control circuit further includes a mode controller. The mode controller is in communication with the RAU controller. The mode controller is configured to communicate mode control signals throughAttorney Docket No.7083 WO W1 / 100.2179WO01 the control links to control an operational mode of an associated RAU circuit based on instructions from the RAU controller.

[0113] Example 18 includes the RAU of any of the Examples 16-17, wherein the power control circuit further includes an independent sleep clock / timer (SCT) power source.

[0114] Example 19 includes the RAU of any of the Examples 16-18, further including a switch that selectively couples a main power supply to the RAU power supply.

[0115] Example 20 includes a method of operating a RAU in an energy saving cellular communication system, the method includes based on received power control instructions, selecting at least one control link that is communication with at least one RAU circuit; communicating mode control signals through the selected at least one control link to control the mode of an associated RAU circuit with a mode controller; and controlling the operating mode of the associated RAU circuit with the communicated mode control signal.

[0116] Example 21 includes the method of Example 20, further including generating the power control instructions in a distributed antenna system (DAS) head end; and communicating the power control instructions to the mode controller.

[0117] Example 22 includes the method of Example 20, further including powering the mode controller with an independent power source.

[0118] Example 23 includes a remote antenna unit (RAU) for an energy saving cellular communication system. The RAU includes a RAU power supply, RAU circuits, power circuit and an RAU controller. The power circuit is positioned within a connection between the RAU power supply and the RAU circuits. The RAU controller if configured to control the power circuit to selectively couple power from the RAU power supply to the RAU circuits based on one of a schedule and communication traffic.

[0119] Example 24 includes the RAU of Example 23, wherein the RAU circuits further include a base band controller (BBC), at least one radio module, and at least one power amplifier.

[0120] Example 25 includes the RAU of Example 24, wherein the BBC is in communication with a DAS head end to receive off-signals from the DAS head end, a field programable gate array (FPGA) of the BBC configured to one of disable and remove power from itself upon receiving an off-signal from the DAS head end, the RAU controllerAttorney Docket No.7083 WO W1 / 100.2179WO01 configured to one of enable and add power to the RAU circuits upon receiving an on-signal from the DAS head end.

[0121] Example 26 includes a remote antenna unit (RAU) for an energy saving cellular communication system. The RAU includes at least one radio module, at least one power amplifier, a base band controller (BBC) including a field programmable gate array (FPGA). The BBC is in communication with a DAS head end to receive power saving commands from the DAS head end. The BBC is configured to configure the FPGA with a selected load based on a received power saving command. A RAU power supply is coupled to power the at least one radio module and the power amplifier based at least in part on the initialized FPGA.

[0122] Example 27 includes the RAU of Example 26, wherein the FPGA is configured dynamically based on a then current required bandwidth.

[0123] Example 28 includes a method of operating an energy saving cellular communication system. The method includes determining if a power saving mode should be enable using a remote antenna unit (RAU) controller of at least one RAU; and disconnecting a RAU power source to RAU circuits of the at least one RAU when the RAU controller determines the power saving mode should be enabled.

[0124] Example 29 includes the method of Example 28, further including using one of power saving commands from a distributed antenna system (DAS) head end, a schedule, and communication traffic in determining which power saving mode should be enabled.

[0125] Example 30 includes the method of any of the Examples 28-29, further including using a switch to disconnect the RAU power source to the RAU circuits.

[0126] Example 31 includes the method of Example 28, further including shutting down a base band controller (BBC) of the RAU circuits with an off-signal from a distributed antenna system (DAS) head end.

[0127] Example 32 includes a method of operating an energy saving cellular communication system. The method including generating a power saving command that includes a desired power load with a distributed antenna system (DAS) head end when a power saving mode is desired; communicating the power saving command to a base band controller (BBC) of remote antenna unit (RAU) circuits in at least one RAU; initializing a field programmable gate array (FPGA) of the BBC to the desired power load; andAttorney Docket No.7083 WO W1 / 100.2179WO01 implementing the power saving command with the FPGA to achieve a desired power consumption.

[0128] Example 33 includes the method of Example 32, further including dynamically generating the power saving command to support a dedicated bandwidth of a then current active use case.

[0129] Example 34 includes the method of any of the Examples 32 -33, further including monitoring a loss of signal (LOS) pin in the at least one RAU to determine if the power saving mode is desired.

[0130] Although specific embodiments have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that any arrangement, which is calculated to achieve the same purpose, may be substituted for the specific embodiment shown. This application is intended to cover any adaptations or variations of the present invention. Therefore, it is manifestly intended that this invention be limited only by the claims and the equivalents thereof.

Claims

Attorney Docket No.7083 WO W1 / 100.2179WO01 CLAIMS 1. An energy saving cellular communication system, the system comprising: a plurality of remote antenna units (RAUs); and a distributed antenna system (DAS) head end in communication with each RAU of the plurality of RAUs, the DAS head end including, at least one input head end port in communication with a base station entity, at least one of a first output head end port and a second output head end port in communication with at least some of the RAUs of the plurality of RAUs, and a head end controller configured to implement a scheduler to selectively control at least some of a power consuming functionality of at least one RAU of the plurality of RAUs.

2. The system of claim 1, wherein the head end controller is further configured to control the at least some power consuming functionality of the at least one RAU of the plurality of RAUs by selectively turning on and off at least one of the at least one input head port and at least the first output head end port and the second output head end port to implement an energy saving strategy.

3. The system of claim 1, further comprising: a configuration file database, the scheduler configured to instruct the head end controller to implement a select configuration file from the configuration file database to implement an energy saving strategy.

4. The system of claim 1, wherein the head end controller is a master unit controller of a master unit.

5. The system of claim 1, wherein the first output head end port is in communication with at least a first RAU of the plurality of RAUs and the second output head end port is in communication with at least a second different RAU of the plurality of RAUs.

6. The system of claim 1, wherein at least one RAU of the plurality of RAUs comprises:Attorney Docket No.7083 WO W1 / 100.2179WO01 a sleep clock / timer (SCT) in communication with RAU circuits of the RAU to control power consumption of the RAU circuits of the RAU, the SCT including an independent SCT power source.

7. The system of claim 6, wherein the circuits of the RAU further comprise: an RAU port in communication with the DAS head end; an RAU controller in communication with the RAU port and the SCT; a RAU power supply; a switch that selectively couples power to the RAU power supply; and a power amplifier / transmitter.

8. The system of claim 6, wherein the SCT further comprises: a mode controller that is in communication with the RAU controller to receive instructions from the RAU controller; and a real time clock in communication with the mode controller.

9. The system of claim 8, further comprising: a plurality of control lines, each control line of the plurality of control lines communicating mode control signals between the mode controller and an associated RAU circuit of the RAU.

10. A method of saving energy in a cellular communication system, the method comprising: tracking at least one of time and communication traffic; determining if the tracked at least one of time and communication traffic warrants change in power consuming functionality of at least one remote antenna unit (RAU) of plurality of RAUs; and implementing a scheduler to selectively change at least some of the power consuming functionality of the at least one RAU of the plurality of RAUs.

11. The method of claim 10, wherein determining if the tracked at least one of time and communication traffic warrants change in power consuming functionality of at least one remote antenna unit (RAU) of plurality of RAUs further comprises:Attorney Docket No.7083 WO W1 / 100.2179WO01 determining if a new configuration file should be implemented by a head end controller of a DAS head end based on at one of the tracking of the time and communication traffic; and implementing the new configuration file when it is determined the new configuration file should be implemented that changes a current operational state of at least one of an input head end port and an output head port of the DAS head end.

12. The method of claim 10, wherein selectively changing the at least some of the power consuming functionality of the at least one RAU of the plurality of RAUs further comprises at least one of shutting down and turning on the at least one RAU, enabling and disabling certain functions of the at least one RAU, and turning on and off one or more power amplifiers of the at least one RAU.

13. The method of claim 12, changing the at least some of the power consuming functionality of the at least one RAU of the plurality of RAUs further comprising: receiving instructions from an RAU controller at a mode controller of a sleep clock / timer (SCT); selecting control links in communication with RAU circuits of the RAU to shut down; and communicating mode control signals between the mode controller and associated RAU circuits of the RAU.

14. The method of claim 13, wherein the mode control signals include input / output bits.

15. The method of claim 13, wherein the circuits of the RAU include a power source switch that selectively provides power to the circuits of the RAU.

16. A remote antenna unit (RAU) for an energy saving cellular communication system, the RAU including: RAU circuits that include, an RAU port in communication with a DAS head end, an RAU controller in communication with an RAU port, a RAU power supply,Attorney Docket No.7083 WO W1 / 100.2179WO01 a downlink path in communication with the RAU controller, the downlink path including a power amplifier and transmitter, and an uplink path in communication with the RAU controller, the uplink path including a low-noise amplifier and receiver; and a power control circuit configured to control operational modes of at least some of the RAU circuits through associated control links to the at least some the RAU circuits.

17. The RAU of claim 16, wherein the power control circuit further comprises: a mode controller, the mode controller in communication with the RAU controller, the mode controller configured to communicate mode control signals through the control links to control an operational mode of an associated RAU circuit based on instructions from the RAU controller.

18. The RAU of claim 16, wherein the power control circuit further comprises at least one of: an independent sleep clock / timer (SCT) power source; and a timer.

19. The RAU of claim 16, further comprising: a switch that selectively couples a main power supply to the RAU power supply.

20. A method of operating a remote antenna unit (RAU) in an energy saving cellular communication system, the method comprising: based on received power control instructions, selecting at least one control link that is communication with at least one RAU circuit; communicating mode control signals through the selected at least one control link to control the mode of an associated RAU circuit with a mode controller; and controlling the operating mode of the associated RAU circuit with the communicated mode control signal.

21. The method of claim 20, further comprising: generating the power control instructions in a distributed antenna system (DAS) head end; andAttorney Docket No.7083 WO W1 / 100.2179WO01 communicating the power control instructions to the mode controller.

22. The method of claim 20, further comprising: powering the mode controller with an independent power source.

23. A remote antenna unit (RAU) for an energy saving cellular communication system, the RAU comprising: a RAU power supply; RAU circuits; a power circuit positioned within a connection between the RAU power supply and the RAU circuits; and an RAU controller configured to control the power circuit to selectively couple power from the RAU power supply to the RAU circuits based on one of a schedule and communication traffic.

24. The RAU of claim 23, wherein the RAU circuits further comprise: a base band controller (BBC); at least one radio module; and at least one power amplifier.

25. The RAU of claim 24, wherein the BBC is in communication with a DAS head end to receive off-signals from the DAS head end, a field programable gate array (FPGA) of the BBC configured to one of disable and remove power from itself upon receiving an off-signal from the DAS head end, the RAU controller configured to one of enable and add power to the RAU circuits upon receiving an on-signal from the DAS head end.

26. A remote antenna unit (RAU) for an energy saving cellular communication system, the RAU including: at least one radio module; at least one power amplifier; a base band controller (BBC) including a field programmable gate array (FPGA), the BBC in communication with a DAS head end to receive power saving commands from theAttorney Docket No.7083 WO W1 / 100.2179WO01 DAS head end, the BBC configured to configure the FPGA with a selected load based on a received power saving command; and a RAU power supply coupled to power the at least one radio module and the power amplifier based at least in part on the initialized FPGA.

27. The RAU of claim 26, wherein the FPGA is configured dynamically based on a then current required bandwidth.

28. A method of operating an energy saving cellular communication system, the method comprising: determining if a power saving mode should be enable using a remote antenna unit (RAU) controller of at least one RAU; and disconnecting a RAU power source to RAU circuits of the at least one RAU when the RAU controller determines the power saving mode should be enabled.

29. The method of claim 28, further comprising: using one of power saving commands from a distributed antenna system (DAS) head end, a schedule, and communication traffic in determining which power saving mode should be enabled.

30. The method of claim 28, further comprising: using a switch to disconnect the RAU power source to the RAU circuits.

31. The method of claim 28, further comprising: shutting down a base band controller (BBC) of the RAU circuits with an off-signal from a distributed antenna system (DAS) head end.

32. A method of operating an energy saving cellular communication system, the method comprising: generating a power saving command that includes a desired power load with a distributed antenna system (DAS) head end when a power saving mode is desired; communicating the power saving command to a base band controller (BBC) of remote antenna unit (RAU) circuits in at least one RAU;Attorney Docket No.7083 WO W1 / 100.2179WO01 initializing a field programmable gate array (FPGA) of the BBC to the desired power load; and implementing the power saving command with the FPGA to achieve a desired power consumption.

33. The method of claim 32, further comprising: dynamically generating the power saving command to support a dedicated bandwidth of a then current active use case.

34. The method of claim 32, further comprising: monitoring a loss of signal (LOS) pin in the at least one RAU to determine if the power saving mode is desired.

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