A Wi-Fi AP (access point) operating in full-function mode, i.e., with all AP features running at their maximum potential, consumes maximum energy. Enterprises that deploy Wi-Fi networks incur a cost to operate their networks. Energy-saving measures can significantly lower operating costs for a network, while at the same time maintaining QoS (quality of service) to their customers.
An enterprise AP reduces some functionality or capacity typically in response to a reduced power grant from the PoE (Power over Ethernet) switch to which the AP is connected. In such cases, because the AP does not get enough power from the switch, it cannot operate in full-function mode and therefore it reduces its functionality or capacity.
With respect to the discussion to follow and in particular to the drawings, it is stressed that the particulars shown represent examples for purposes of illustrative discussion, and are presented in the cause of providing a description of principles and conceptual aspects of the present disclosure. In this regard, no attempt is made to show implementation details beyond what is needed for a fundamental understanding of the present disclosure. The discussion to follow, in conjunction with the drawings, makes apparent to those of skill in the art how embodiments in accordance with the present disclosure may be practiced. Similar or same reference numbers may be used to identify or otherwise refer to similar or same elements in the various drawings and supporting descriptions. In the accompanying drawings:
In the following description, for purposes of explanation, numerous examples and specific details are set forth in order to provide a thorough understanding of embodiments of the present disclosure. Particular embodiments as expressed in the claims may include some or all of the features in these examples, alone or in combination with other features described below, and may further include modifications and equivalents of the features and concepts described herein.
APs 102 can be wireless communication devices that operate in accordance with the family of IEEE (Institute of Electrical and Electronics Engineers) 802.11 standards or 3GPP (3rd Generation Partnership Project) standards such as Long Term Evolution (LTE) and New Radio (NR). For discussion purposes, details of the present disclosure will use the technology of IEEE 802.11. However, it will be appreciated that one or more aspects of the present disclosure may be applicable to other wireless technologies. Clients (stations) 12 can associate with APs 102 in order to wirelessly communicate with other clients on the same or different AP, with host machines 108 on network 104, with communication network 112, and so on.
Transceiver subsystem 204 can include a power amplifier 242, a radio component 246, IEEE 802.11 logic 248, and RAM 250. Power amplifier 242 can provide power to radio 246, for example, in order to transmit and receive signals via antenna 206. IEEE 802.11 logic 248 can comprise data processing elements such as an ASIC (application specific integrated circuit), FPGA (field programmable array), digital processing unit, and the like. Logic 248 can be configured to process signals (received or for transmission) in accordance with IEEE 802.11 standards. RAM 250 can provide buffers and other data structures to support the transmission and reception of data.
It is noted that AP 200 is illustrative. It will be appreciated that other embodiments of an AP in accordance with the present disclosure can include more or fewer components than are shown in
Enterprises that deploy Wi-Fi networks incur a cost to operate these networks. Energy-saving (ES) measures result in significantly lower operating costs for a network and can reduce the carbon footprint, while maintaining the QoS. Conventional power saving strategies are “reactive.” For example, in a configuration that uses PoE (power over Ethernet) switches (e.g., network device 106 in
APs in accordance with the present disclosure can perform energy-saving (ES) measures in order to proactively lower operating costs. In lightly loaded conditions, for instance, the AP can reduce some of its functionality (e.g., operations, configurations, capacity, etc.) to save energy without compromising the QoS (quality of service) the AP provides to clients. For example, an AP that supports 4×4 parallel streams can reduce the number of supported simultaneous streams to 2×2 when the traffic load and number of clients are suitably low.
In some embodiments, the AP measures (samples) and computes usage and operating parameters (load factors) of the AP. Based on these parameters, one or more AP operating parameters can be proactively adjusted (turn OFF, scaled down) to enter an ES operating mode. Suppose, for example, that the amount of power currently being supplied to the AP does not require scaling back AP operations; for example, if the AP has sufficient power to operate at full functionality then there is no need to reduce its functionality for the purpose of saving power. However, based on the measured/computed parameters, the AP in accordance with the present disclosure may determine that it does not need to provide full functionality to maintain a certain QoS to its clients. As such the AP can “proactively” scale back AP operations for the purpose of reducing power usage without impacting QoS or without compromising on other quality metrics even though scaling back such operations is not required. By comparison, conventional energy management strategies maintain full function (and hence full power) operation in the AP irrespective of the operating environment such as number of clients, AP resources being used, network conditions, etc.
Various usage parameters relating to operation of the AP can contribute to the power load on the AP. Usage parameters can refer to the number of clients (stations) that are associated with the AP, radio usage, etc. Usage parameters can include buffer occupancy of the AP's uplink and downlink queues, utilization of an Ethernet link, channel utilization, and the like. In general, usage parameters can include any parameter pertaining to the utilization of the functionality of the AP in its performance of allowing Wi-Fi devices to connect to a wired network. Merely for discussion purposes, a non-exhaustive list of usage parameters in accordance with the present disclosure can include, but is not limited to:
Various operational aspects of the AP can be controlled to change the power consumed by the AP, whether to decrease power consumption (enter ES mode) or increase power consumption to resume full-function operation (i.e., exit ES mode). These control knobs can be tuned (e.g., increased, decreased, turned ON, turned OFF, etc.) to change the power consumption of the AP in response to changes in the usage parameters. Further in accordance with the present disclosure, the AP's environment (e.g., network conditions) can be monitored to identify opportunities for reducing power consumption.
Merely for discussion purposes, the following non-exhaustive listing of control knobs that can be used by embodiments in accordance with the present disclosure can include, but is not limited to:
Referring to
At operation 302, the AP can receive usage parameters and control knob configurations to configure proactive ES measures in accordance with the present disclosure. The usage parameters can be provided by a user (e.g., network administrator) or an automated system (e.g., central network controller) over a suitable interface. Any number and combination of usage parameters can be used as criteria for triggering ES measures.
The user can specify a control knob configuration to configure the above-described control knobs for ES mode operations. The configuration can specify limits or ranges for the control knobs. For instance, the user may impose a lower limit on the number of Tx/Rx chains, the user may impose a maximum limit on how much power can be requested from a PoE switch, and so on. In some deployments, some AP functions may be deemed to be sufficiently important that they should never be adjusted when looking to reduce power consumption. For example, control (ON/OFF) of radio functionality, Bluetooth usage, etc. may be disabled for purposes of power reduction because those functions may be deemed critical in a given deployment. Accordingly, in accordance with some embodiments, the configuration can disable adjusting some control knobs when looking to reduce consumption.
At operation 304, the AP can receive threshold values for various usage parameters of the AP. The threshold values can be used to determine when to trigger ES mode. Threshold values for a time-of-use parameter, for example, can be used to designate windows of time when ES measures can be enacted or not. As noted above, energy saving measures in accordance with the present disclosure can involve altering the functionality of the AP. Accordingly, in some embodiments, ES measures can be disabled during business hours to avoid disrupting workflow. Conversely, ES measures can be enabled only during certain off-hours (e.g., late evening, weekends, holidays, etc.) when network traffic is expected to be light.
In some embodiments, the time-of-use parameter can be applied on a per function basis. For instance, an ES action of reducing transmission power (Tx power) may be subject to certain windows of time when the action is allowed, while an ES action of disabling USB capability may be subject to other windows of time.
At operation 306, the AP can measure (sample) various usage parameters on a repeated basis. In some embodiments, usage parameters can be monitored and collected periodically, on a user-defined schedule, and so on. In some embodiments, the measurement frequency can vary from one usage parameter to another.
At decision point 308, the AP can evaluate the collected measurements to determine whether to enter ES mode (reduced-power mode, etc.) to reduce power consumption. One consideration, for example, is whether ES mode for the AP is enabled for the current time of the day, day of the week, etc. based on user-provided time-of-use thresholds. Evaluating the collected measurements can include considerations such as comparing various usage parameters against their corresponding threshold values. For example, if the number of active clients exceeds a given threshold value, then ES measures should not be invoked so that the AP has all of its functionality enabled to handle its clients.
In some embodiments, the criteria for switching to ES mode can be based on the most recent measurement (sample) of a given usage parameter. In other embodiments, the last N samples of a parameter can be used as a criterion for determining whether to enter ES mode or not. For example, the last N samples of a usage parameter can be averaged and a decision on ES mode can be based on the average.
In some embodiments, the criteria for deciding ES mode can be based on a per radio basis, or on a per AP basis. Consider the number of clients, for instance. ES mode can be decided based on the number of clients associated with a given radio (e.g., 2.4 GHz radio), or based on the number of clients associated with the AP as a whole (i.e., total number of clients across all radios).
In some embodiments, the criteria to enter ES mode can be based on combinations of usage parameters.
In some embodiments, criteria other than usage parameters can trigger ES mode such as network conditions. For example, if the AP detects some number of neighbor APs, then certain ES measures can be taken.
Merely to illustrate this aspect of the present disclosure, TABLE I below provides a non-exhaustive list of examples of various criteria for scaling back AP functionality to enter ES mode.
At operation 310, the AP can enact ES measures to enter ES operating mode. In some embodiments, the AP can adjust one or more control knobs (non-exhaustive examples listed above) to reduce its power consumption. In some embodiments, certain environmental criteria may be required before entering ES mode. For example, a criterion for turning off a 2.4 GHz radio can be that two or more neighbor APs have their 2.4 GHz radios on. Merely to illustrate this aspect of the present disclosure, TABLE I below provides a non-exhaustive list of examples of ES measures to enter ES mode.
At operation 312, the AP can continue to measure (sample) various usage parameters on a repeated basis when in ES mode. In some embodiments, the AP can restore full-function operation (exit ES mode) based on measurements made subsequent to entering ES mode. In some embodiments, a different set of thresholds can be used to determine when to exit ES mode than were used to enter ES mode.
At decision point 314, the AP can determine whether to resume full AP functionality, thereby exiting ES mode by adjusting one or more control knobs to restore functionality in the AP. In some embodiments, for example, resuming or otherwise restoring full AP functionality can occur in response to the absence of the criterion or criteria that provoked ES mode to begin with. For example, suppose a usage parameter exceeding a threshold invoked ES mode to reduce AP functionality, then when that usage parameter falls below the threshold, the reduced AP functionality can be reversed to exit ES mode. In some embodiments, exiting ES mode can be based on the expiration of a timer; e.g., we can exit ES mode after the passage of some number of minutes subsequent to entering ES mode. TABLE I below provides a non-exhaustive list of some examples of criteria for exiting ES mode by increasing or otherwise restoring AP functionality.
At operation 316, the AP can reverse some ES measures to restore functionality in the AP. In some embodiments, to prevent over-aggressive entry and exit of ES mode, the AP can delay for an amount of time after the criteria (conditions) for ES mode have been met before enacting ES measure, and likewise delay for a period of time after the criteria that triggered ES mode no longer exist before restoring functionality in the AP. In other words, the criteria for entering ES mode may have to persist for a period of time before going into ES mode. In some embodiments, for example, the decision to switch to ES mode can be regulated by timers. For example, when the criteria for switching to ES mode are met, a timer can be started. If the criteria hold when the timer expires, the AP can switch to ES mode.
Conversely, the condition(s) that triggered ES mode may need to be absent for some period of time before switching out of ES mode. In some embodiments, switching out of ES mode (e.g., back to full-function mode) can be regulated by timers. For example, the AP can re-evaluate the criteria that caused ES mode, for example by periodically sampling the usage parameters. If the criteria no longer hold, the AP can switch back to full-function mode.
In some embodiments, some of the control knobs can be adjusted in stepwise fashion. For example, the channel bandwidth may be initially 320 MHz and iteratively reduced to 20 MHz when switching to ES mode. The speed of the iterative reduction can be regulated by timers; e.g., by halving the bandwidth with each iteration every n seconds; for example, from 320 to 160 to 80 to 40 to 20 MHz every five seconds. Conversely, on exiting ES mode, the channel bandwidth may be increased in steps; e.g., by doubling the bandwidth from 20 MHz to 320 MHz every so many seconds.
The following table provides a non-exhaustive illustrative list of criteria for switching to and out of ES mode with corresponding examples of actions to enter and exit ES mode:
Features described above as well as those claimed below may be combined in various ways without departing from the scope hereof. The following examples illustrate some possible, non-limiting combinations:
(A1) A method for reducing power consumption by an access point (AP) device, the method including: making measurements of one or more usage parameters of the AP; based on comparisons between the measurements of the one or more usage parameters and respective threshold values corresponding to the one or more usage parameters, switching from a full-function operating mode to a reduced functionality mode by adjusting one or more operating parameters of the AP from first respective operating states to second respective operating states; making additional measurements of the one or more usage parameters; and based on comparisons between the additional measurements of the one or more usage parameters and the respective threshold values corresponding to the one or more usage parameters, switching from the reduced functionality mode to an increased functionality mode by adjusting the one or more operating parameters of the AP from the second respective operating states to the first respective operating states.
(A2) For the method denoted as (A1), the increased functionality mode is the full-functioning operating mode.
(A3) The method denoted as any of (A1) through (A2), further including switching to the ES operating mode upon passage of a period of time after occurrence of one or more conditions that are determined based on the measurements of the one or more usage parameters.
(A4) For the method denoted as any of (A1) through (A3), switching from the reduced functionality mode to the increased functionality mode occurs upon passage of a period of time after the one or more conditions are no longer present.
(A5) For the method denoted as any of (A1) through (A4), switching between the reduced functionality mode and the increased functionality mode is enabled during one or more predefined times.
(A6) For the method denoted as any of (A1) through (A5), the AP operating in the ES operating mode provides less functionality and/or capacity than in full-function operating mode.
(A7) For the method denoted as any of (A1) through (A6), making measurements of the one or more usage parameters includes obtaining n measurements of a first usage parameter and computing a first value of the first usage parameter based on the n measurements of the first usage parameter, wherein entering ES operating mode is based at least on the first value.
(A8) For the method denoted as any of (A1) through (A7), the one or more usage parameters includes any one or any combination of two or more of: a number of clients associated with the AP, a buffer occupancy of the AP, an Ethernet link utilization of the AP, and a channel utilization of the AP.
(A9) For the method denoted as any of (A1) through (A8), the one or more operating parameters of the AP include any one or any combination of two or more of: radio state, USB state, BLE state, a number of Tx/Rx chains, protocol, software feature, transmit power level, PoE power level, and channel bandwidth.
(B1) An AP (access point) device including: one or more computer processors; and a computer-readable storage medium. The computer-readable storage medium having instructions for controlling the one or more computer processors to: operate the AP device in a first operating mode; make measurements of one or more usage parameters while operating the AP device in the first operating mode; and operate the AP device in a second operating mode in response to a presence of one or more conditions determined based on the one or more usage parameters. wherein the one or more usage parameters comprise parameters that relate to functions that can be performed by the AP and capacity of the AP device.
(B2) For the AP denoted as (B1), switching from the first operating mode to the second operating mode is enabled only during one or more user-defined periods of time.
(B3) For the AP denoted as any of (B1) through (B2), the computer-readable storage medium further includes instructions for controlling the one or more computer processors to switch to the second operating mode subsequent to passage of a period of time after occurrence of the one or more conditions.
(B4) For the AP denoted as any of (B1) through (B3), the computer-readable storage medium further includes instructions for controlling the one or more computer processors to switch back from the second operating mode to the first operating mode in incremental steps.
(B5) For the AP denoted as any of (B1) through (B4), the first operating mode is a full-function operating mode and the second operating mode is an energy-saving operating mode that provides fewer functions and/or less capacity than the full-function mode.
(C1) A method in a network device, the method including: operating the network device in a full-function operating mode; making measurements of one or more usage parameters while operating the network device in the full-function operating mode; operating the network device in an energy-saving (ES) operating mode in response to a presence of one or more conditions determined based on the one or more usage parameters, wherein the one or more usage parameters comprise parameters that relate to functions that can be performed by the network device and capacity of the network device; and switching back to operating the network device in the full-function operating mode when the one or more conditions are no longer present.
(C2) For the method denoted as (C1), operating the network device in the ES operating mode is enabled only during user-defined periods of time.
(C3) The method denoted as any of (C1) through (C2), further including switching from the full-function operating mode to the ES operating mode subsequent to passage of a period of time after determining the presence of the one or more conditions.
(C4) The method denoted as any of (C1) through (C3), further including switching back to operating the network device in the full-function operating mode subsequent to passage of a period of time after the one or more conditions is no longer present.
(C5) For the method denoted as any of (C1) through (C4), the ES operating mode provides fewer functions and/or less capacity than the full-function mode.
(C6) For the method denoted as any of (C1) through (C5), the one or more usage parameters includes any one or any combination of two or more of: a number of clients associated with the AP, a buffer occupancy of the AP, an Ethernet link utilization of the AP, and a channel utilization of the AP.
The above description illustrates various embodiments of the present disclosure along with examples of how aspects of the present disclosure may be implemented. The above examples and embodiments should not be deemed to be the only embodiments, and are presented to illustrate the flexibility and advantages of the present disclosure as defined by the following claims. Based on the above disclosure and the following claims, other arrangements, embodiments, implementations and equivalents may be employed without departing from the scope of the disclosure as defined by the claims.