System and method for suppressing transmission from a wireless device

Abstract

When several devices communicate through a wireless network, a device may transmit an unacceptable high level of traffic, for example as a result of being endangered, which may prevent other devices from communicating through the network, and this may impose a burden on the processing resources of the device receiving the traffic. Therefore, a system and method for suppressing transmissions from wireless devices are provided.

Description

Technical Field

[0001] This application claims the benefit of U.S. Provisional Application No. 63 / 368,804, filed on July 19, 2022, entitled "System and Method for Suppressing Transmissions from a Wireless Device", which is hereby incorporated by reference in its entirety.

[0002] One or more aspects of the examples according to the present disclosure relate to wireless networking, and more particularly, to systems and methods for suppressing transmissions from wireless devices.

Background Art

[0003] When several devices communicate through a wireless network, one device may transmit an unacceptable high level of traffic, for example as a result of endangering, which may prevent other devices from communicating within the network and may burden the processing resources of the devices receiving the traffic.

[0004] Aspects of the present disclosure relate to this general technical environment.

Summary of the Invention

[0005] This summary is provided to introduce a selected simplification of concepts that are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.

[0006] In one aspect, a wireless network interface circuit and related methods are provided. In one aspect, a wireless interface; and a processing circuit are provided, the processing circuit being configured to receive a shutdown command through the wireless interface; transition to a limited activity state in response to the receipt of the shutdown command; and operate in the limited activity state, the operation in the limited activity state including generating wireless transmissions at a rate that does not exceed a threshold. A wireless network interface circuit is provided.

[0007] In another aspect, a host interface; a wireless interface; a processing circuit; and a memory including instructions are provided, the instructions, when executed by the processing circuit, cause the wireless network interface circuit to receive a shutdown command through the wireless interface; transition to a limited activity state in response to the receipt of the shutdown command; and operate in the limited activity state, the operation in the limited activity state including generating wireless transmissions at a rate that does not exceed a threshold, and the instructions are not modifiable by commands or data received through the wireless interface or through the host interface. A wireless network interface circuit is provided.

[0008] In one aspect, a method comprises receiving, by a wireless network interface circuit, a shutdown command through a wireless interface of the wireless network interface circuit; transitioning, by the wireless network interface circuit, to a limited activity state in response to the receipt of the shutdown command; and operating, by the wireless network interface circuit, in the limited activity state, the operation in the limited activity state including not generating wireless transmissions or generating wireless transmissions at a rate that does not exceed a threshold. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The above and other features and advantages of the present disclosure will be recognized and understood by reference to the specification, claims, and the following accompanying drawings.

[0010]

Figure 1

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Figure 2A

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Figure 2B

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Figure 2C

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Figure 2D

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Figure 2E

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Figure 3

DETAILED DESCRIPTION OF THE INVENTION

[0017] Hereinafter, examples will be described in more detail with reference to the accompanying drawings. In the accompanying drawings, like reference numerals refer to like elements throughout. However, the present disclosure may be embodied in various different forms and should not be construed as limited to only the examples shown herein. Rather, these examples are provided so that this disclosure will be thorough and complete, and will fully convey the aspects and features of the disclosure to those skilled in the art. Accordingly, processes, elements, and techniques that are not necessary for a complete understanding of the aspects and features of the disclosure by those skilled in the art may not be described. Unless otherwise noted, like reference numerals indicate like elements throughout the accompanying drawings and the described description, and thus, the redundant description may not be repeated. The aspects shown or described may be combined without departing from the disclosure, other aspects may be utilized, and structural changes may be made. The examples may be implemented as a method, system, or device. Accordingly, the examples may take the form of a hardware implementation, a completely software implementation, or an implementation combining software and hardware aspects. Further, all systems described with respect to the figures may include one or more machines or devices operably connected to cooperate to provide the functionality of the described systems. Accordingly, the following detailed description should not be construed in a limiting sense, and the scope of the present disclosure is defined by the appended claims and their equivalents.

[0018] Figure 1 is a block diagram of a network in some examples. Each of a plurality of devices or "stations" 105a, 105b, 105c (collectively referred to as "device 105") is connected to a connection device 110, for example, by a wired or wireless connection. The connection device 110 may have an external connection 115 to one or more other networks 120 (e.g., the Internet). The device 105 may include, as shown, one or more Internet of Things (IoT) devices, one or more mobile phones, and one or more computing devices (e.g., laptops); the device 105 may also include, for example, file storage systems, printers, and the like. The connection device 110 may be a hub, gateway (as shown, a combination of a router / modem), modem, router, WiFi extender device, or the like. When the connection device 110 and the device 105 are connected via a WiFi network, each device 105 may be a non-access point station (non-AP STA, or simply "station" or STA), and the connection device 110 may be an access point station (AP STA, or simply AP).

[0019] During operation, it may occur that the first device 105a begins to transmit unacceptable traffic, for example, traffic that places an unacceptable burden on the connection device 110 or its external connection 115, or traffic that interferes with the transmission of other devices 105b and / or 105c. Such behavior may be caused by, for example, a programming error in the code executed on the first device, or by malicious code executed on the device as a result of the device being compromised or "infected" with dangerous or malicious software (or "malware"). If the device 105a is compromised, the unacceptable traffic may also be directed to other devices 105b and / or 105c, or to an external remote device 125 (e.g., to interfere with their operation or attempt to infect them).

[0020] If the connection between the first device 105a and the connection device 110 is a wired connection, the connection device 110 may fix this problem by simply ignoring all traffic received from the first device 105a. However, if the connection between the devices 105 and the connection device 110 is a wireless connection (e.g., a WiFi connection), (i) the connection device 110 may not be able to completely ignore transmissions from the first device 105a, because it may be necessary to decode some such transmissions to identify the source, and (ii) unacceptable traffic may interfere with transmissions from other devices 105b, 105c.

[0021] Therefore, in some examples, one or more of the devices 105 may be configured to receive a control command (sometimes called a "shutdown command") from the connection device 110 and, in response, stop transmitting wirelessly or reduce the rate of wireless transmission to an acceptable level. During normal operation, the threat intelligence and mitigation system 130 (or "threat monitor") may monitor communications within the network and, when it detects that unacceptable traffic has been transmitted by one of the devices 105, transmit a shutdown command for this malicious device or cause the connection device 110 to transmit it. The threat intelligence and mitigation system 130 may be implemented at least partially on the connection device 110, or it may be separate external hardware, or it may be distributed, for example, it may include a plurality of network-connected devices that share information about traffic flows and indications of abnormal activity on the network. Further, the threat intelligence and mitigation system 130 may comprise a threat intelligence system and a separate threat mitigation system.

[0022] When it detects that unacceptable traffic has been transmitted by one of the devices, the threat intelligence and mitigation system 130 may initiate processing to restore that device to normal operation and take additional means to avoid infecting other devices on the network. For example, the threat intelligence and mitigation system 130 may log evidence that unacceptable traffic has been transmitted and the transmission of a shutdown command, and may alert an operator, such as a system administrator, about this event, whereby the operator may (i) determine whether other devices have been infected, (ii) implement measures to prevent further infection, and (iii) notify and assist the user of the malicious device 105. The threat intelligence and mitigation system 130 may also send other notifications, such as a notification to an upstream Internet service provider (e.g., if the connected device is part of a home network).

[0023] As mentioned above, upon receiving a shutdown command, device 105 may reduce the level of its wireless transmission. As shown in FIG. 2A, each device 105 may include a wireless network interface circuit 205 (or a wireless “network interface card” (NIC)), and a host 210. The host 210 may include a processing circuit (e.g., a central processing unit (CPU)) that executes an operating system and one or more applications (the code therefor may be stored in a memory 220), and may be connected to the wireless network interface circuit 205 by a host interface 225. The host interface may be, or may include, a communication link (e.g., a plurality of conductors, or one or more optical fibers) through which the host 210 can communicate with the wireless network interface circuit 205. The wireless network interface circuit 205 may be connected to a connection device 110 through a wireless interface 230. The wireless interface may be, or may include, a radio frequency (RF) transceiver.

[0024] When the shutdown command is received by device 105, it may be interpreted by wireless network interface circuit 205, and in response, wireless network interface circuit 205 may transition to a state (which may be referred to as a "limited activity state") of generating at a sufficiently low rate that does not significantly interfere with the operation of the wireless network or significantly burden connected device 110, whether or not generating a wireless transmission. For example, in the limited activity state, wireless network interface circuit 205 may (i) completely stop generating wireless transmissions, (ii) generate wireless transmissions at a frame rate less than a frame rate threshold (e.g., transmitting less than 100 frames per second), or (iii) generate wireless transmissions at a duty cycle less than a duty cycle threshold (e.g., a duty cycle of less than 1%). The frame rate threshold and the duty cycle threshold may be fixed (e.g., hard-coded in wireless network interface circuit 205) or selectable (e.g., specified in the shutdown command).

[0025] This state transition may be performed in a manner that cannot be interfered with by host 210. For example, wireless network interface circuit 205 may include a controller 235 (which may be a processing circuit), and this controller 235 may be implemented as a state machine that performs the transition to the limited activity state without fetching and executing instructions stored in memory (the limited activity state corresponds to a subset of the states of the state machine), or may operate as a program embedded computer that reads and executes instructions from memory 240 (e.g., read-only memory or memory 240 that host 210 does not have write access to) that cannot be modified by host 210. These safeguards may be an obstacle to any malicious code that may infect device 105 and, if possible, prevent wireless network interface circuit 205 from transitioning to the limited activity state.

[0026] Upon receiving a shutdown command, the wireless network interface circuit 205 may notify the host 210 (through the host interface 225) that it is transitioning to a limited activity state. The shutdown command may include an explanation of why it was sent, or information or advice for the user of the device 105, and the wireless network interface circuit 205 may relay this explanation, information, or advice to the host. For example, the shutdown command may include a payload having a text string containing such an explanation. In other examples, the shutdown command may include a code in a dedicated explanation field of the shutdown command, and this code may correspond to a predefined explanation known to the wireless network interface circuit 205 and / or the host 210. If the operation of the host 210 is still in a sufficiently normal state (e.g., an application on the host 210 is infected or sending unacceptable traffic due to a programming error in that application, but the operating system continues to operate normally), the host may cause an explanation or advice for the user to be displayed on the device. Such an explanation may, for example, inform the user that the wireless connection has been disabled because the device was generating unacceptable network traffic, and advise the user to contact the support center (e.g., at a specified phone number) or the system administrator to assist in restoring the device to normal operation. The display of a message to the user may be done as a system message by the operating system, or rather, when the user attempts to browse websites using a browser, the browser may be provided with a page (generated internally by the device) notifying the user that the wireless connection of the device has been disabled, and displaying advice to the user regarding the steps to take to restore normal operation.

[0027] Upon receiving a shutdown command, the wireless network interface circuit 205 may authenticate the command before transitioning to the limited activity state. This authentication may take the form of (i) verifying that a secret shared only by the wireless network interface circuit 205 and the identified potential sender of the shutdown command exists in the shutdown command, or (ii) encrypting a portion of the shutdown command with a secret key known only to the identified potential sender of the shutdown command (verified by decryption using the public key by the wireless network interface circuit 205). In the latter case, the encrypted portion of the shutdown command may include a timestamp to facilitate prevention of replay attacks.

[0028] The shutdown command may be transmitted as a single frame (e.g., a single WiFi frame that may have a maximum payload size of 2304 bytes); use of a single frame may avoid any reliance on reassembly, reordering, or retransmission. The shutdown command may include, as mentioned above, an explanation (or a short code for the explanation) regarding the transmission of the shutdown command, or a message having advice for the user of the device 105. In some examples, the shutdown command includes the text of such a message; in other examples, instead, the shutdown command includes code that the wireless network interface circuit 205 may convert to a message or relay to the host 210, which may convert it to a message to be displayed to the user.

[0029] After receiving the shutdown command, device 105 may remain in a limited activity state for a certain period of time (e.g., 5 minutes or 10 minutes), and then may automatically transition back to the normal operating state, in which the wireless network interface circuit 205 does not suppress the rate of wireless transmission. In other examples, the device may remain in a limited activity state until the power of the wireless network interface circuit 205 cycles (e.g., is turned off and then back on), or until a command (which may be referred to as a "restart command") is received by the wireless network interface circuit 205.

[0030] Before the wireless network interface circuit 205 executes the corresponding state transition, the restart command may be authenticated by the wireless network interface circuit 205 in the same manner as the shutdown command. The restart command may be transmitted, for example, by an operator who has determined that (i) the device 105 has not been transmitting traffic that is actually unacceptable, or (ii) the cause of the unacceptable traffic has been repaired, or (programmatically) by a threat intelligence / mitigation system 130 or other automated system, etc., through the wireless interface 230 and received by the wireless network interface circuit 205. In some situations, the restart command may instead be received by the wireless network interface circuit 205 through the host interface 225. This may enable, for example, a user running an appropriate application on the device 105 to key in an authentication code (received, for example, from an operator of a help center), and then the application may generate a restart command and transmit it to the wireless network interface circuit 205 to restore it to normal operation.

[0031] Figures 2B - 2E are flowcharts of the method in some examples. Referring to Figure 2B, in some examples, at 250, a shutdown command is received through the wireless interface of the wireless network interface circuit; at 252, the wireless network interface circuit transitions to a limited activity state in response to receiving the shutdown command; and at 254, the wireless network interface circuit operates in the limited activity state, and the operation in the limited activity state includes a stage where no wireless transmission is generated, or a stage where wireless transmission is generated at a rate not exceeding a threshold. Referring to Figure 2C, the operation in the limited activity state (at 254 in Figure 2B) may include, at 256, a stage where no wireless transmission is generated. Referring to Figure 2D, the operation in the limited activity state (at 254 in Figure 2B) may include, at 258, a stage where wireless transmission is generated at a rate not exceeding a threshold, and the stage where wireless transmission is generated at a rate not exceeding a threshold includes a stage where transmission is generated with a duty cycle less than the duty cycle threshold. Referring to Figure 2E, the operation in the limited activity state (at 254 in Figure 2B) may include, at 260, a stage where wireless transmission is generated at a rate not exceeding a threshold, and the stage where wireless transmission is generated at a rate not exceeding a threshold includes a stage where transmission is generated with an average frame rate less than the frame rate threshold.

[0032] Figure 3 shows an example of a suitable operating environment 300 that may be used in part to implement the device 105, connection device 110, threat intelligence and mitigation system 130, user computing device, or other computing device within the system contemplated herein. In its most basic configuration, the operating environment 300 typically includes at least one processing circuit 302 and memory 304. The processing circuit may be a processor, which is hardware. Depending on the exact configuration and type of computing device, the memory 304 (which stores instructions for performing the methods disclosed herein) may be volatile (such as RAM), non-volatile (such as ROM, flash memory, etc.), or some combination of the two. This most basic configuration is shown in Figure 3 by the dashed line 306. The memory 304 stores instructions that, when executed by the processing circuit 302, perform the processes and operations described herein. Additionally, the environment 300 may also include a storage (removable 308 or non-removable 310) including, but not limited to, solid state, magnetic disk, optical disk, or tape. Similarly, the environment 300 may also have input devices 314 such as, for example, a keyboard, mouse, pen, voice input, etc., or output devices 316 such as, for example, a display, speaker, printer, etc. Additional communication connections 312 may also be included to enable further communication such as LAN, WAN, point-to-point, etc. The operating environment 300 may also include a geolocation device 320 such as a global positioning system (GPS) device.

[0033] The operating environment 300 typically includes at least some form of computer-readable medium. The computer-readable medium can be any available medium that can be accessed by the processing circuit 302 or other devices including the operating environment. By way of example and not limitation, the computer-readable medium may include computer storage media and communication media. Computer storage media includes volatile and nonvolatile media, removable and nonremovable media implemented in any method or technology for storing information such as computer-readable instructions, data structures, program modules or other data. Computer storage media includes RAM, ROM, EEPROM, flash memory, or other memory technologies, CD-ROM, digital versatile disk (DVD), or other optical storage, magnetic cassettes, magnetic tape, magnetic disk storage, or other magnetic storage devices, or any other non-transitory medium that can be used to store the desired information. Computer storage media is non-transitory and does not include communication media.

[0034] Communication media includes any information delivery media that embodies computer-readable instructions, data structures, program modules, or other data in a modulated data signal, such as a carrier wave or other transport mechanism. The term "modulated data signal" means a signal that has one or more of its characteristics set or changed in such a manner as to encode information in the signal. By way of example and not limitation, communication media includes wired media such as a wired network or direct-wired connection, and wireless media such as acoustic, RF, infrared, microwave, and other wireless media. Any of the foregoing combinations should also be included within the scope of computer-readable media.

[0035] Although several examples are described herein in the context of a WiFi network, the present disclosure is not limited to such networks. For example, the systems and methods described herein may be utilized for similar or identical effects in other wireless networks. As used herein, the term "or" is inclusive, such that for example, "A or B" means (i) A, (ii) B, or (iii) any one of A and B. As used herein, when a method (e.g., an adjustment) or a first quantity (e.g., a first variable) is referred to as being "based on" a second quantity (e.g., a second variable), it means that the second quantity is input into the method or affects the first quantity. For example, the second quantity may be an input (e.g., the only input, or one of several inputs) to a function that calculates the first quantity, or the first quantity may be equal to the second quantity, or the first quantity may be the same as the second quantity (e.g., stored in the same one or more locations in memory as the second quantity). As used herein, when an operation is performed "in response to" an event or condition, that event or condition may or may not be necessary to trigger the performance of the operation, and that event or condition may or may not be sufficient to trigger the performance of the operation. For example, if the occurrence of a first event and a second event trigger the performance of an operation, the operation may be said to be performed in response to the first event and further in response to the second event.

[0036] As used herein, the term "processing circuit" is used to mean any combination of hardware, firmware, and software utilized to process data or digital signals. Processing circuit hardware may include, for example, programmable logic devices such as application specific integrated circuits (ASICs), general-purpose or special-purpose central processing units (CPUs), digital signal processors (DSPs), graphics processing units (GPUs), and field programmable gate arrays (FPGAs). In a processing circuit, as used herein, each function is either executed by hardware configured, i.e., wired, to perform that function or by more general-purpose hardware such as a CPU configured to execute instructions stored on a non-transitory storage medium. The processing circuit may be fabricated on a single printed circuit board (PCB) or may be distributed across several interconnected PCBs. The processing circuit may include other processing circuits; for example, the processing circuit may include two processing circuits, an FPGA, and a CPU interconnected on a PCB.

[0037] When specific examples may be implemented in different manners, the specific processing order may be different from the order described. For example, two processes described in sequence may be executed simultaneously or substantially simultaneously, or may be executed in an order opposite to the order described.

[0038] The terminology used herein is for the purpose of describing particular examples and is not intended to be limiting of the disclosure. As used herein, the singular forms "a" and "an" are intended to include the plural forms as well, unless the context clearly dictates otherwise. The terms "comprises," "comprising," "includes," "including," "has," "have," and "having," when used herein, specify the presence of the recited feature, integer, step, operation, element, and / or component, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items. For example, the expression "A and / or B" means A, B, or A and B. Expressions such as "at least one of" when following a list of elements modify the entire list of elements and do not modify the individual elements of the list. For example, the expression "at least one of a, b, or c" means only a, only b, only c, both a and b, both a and c, both b and c, all of a, b, and c, or variations thereof.

[0039] As used herein, the terms "substantially," "about," and similar terms are used as terms of approximation and not of degree, and are intended to account for the inherent variations in measured or calculated values recognized by those of ordinary skill in the art. Further, the use of "may" in describing examples of the disclosure refers to "one or more examples of the disclosure." As used herein, the terms "use," "using," and "used" may each be considered synonymous with the terms "utilize," "utilizing," and "utilized," respectively.

[0040] The electronic or electrical devices, and / or any other related devices or components, according to the examples of the present disclosure described herein, may be implemented using any suitable hardware, firmware (e.g., application specific integrated circuit), software, or a combination of software, firmware, and hardware. For example, the various components of these devices may be formed on one integrated circuit (IC) chip or on separate IC chips. Further, the various components of these devices may be implemented on a flexible printed circuit film, a tape carrier package (TCP), a printed circuit board (PCB), or may be formed on one substrate. Further, the various components of these devices may be a process or thread executed on one or more processors in one or more computing devices that execute computer program instructions to perform the various functions described herein and interact with other system components. The computer program instructions may be stored in a memory implemented in a computing device using a standard memory device such as random access memory (RAM). The computer program instructions may also be stored on other non-transitory computer-readable media such as, for example, a CD-ROM, a flash drive, or the like. Also, those skilled in the art should recognize that, without departing from the spirit and scope of the exemplary embodiments of the present disclosure, the functions of various computing devices may be combined or integrated into a single computing device, or the functions of a particular computing device may be distributed across one or more other computing devices.

[0041] Unless otherwise defined, all terms (including technical and scientific terms) used herein shall have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. Terms such as those defined in commonly used dictionaries shall be interpreted as having a meaning consistent with their meaning in the context of the relevant art and / or this specification, and should not be interpreted in an idealized or overly formal sense unless explicitly so defined herein.

[0042] Although several examples have been described, those of ordinary skill in the art will readily recognize that various modifications are possible in the examples without departing from the spirit and scope of the disclosure. It is understood that, unless otherwise stated, the description of features or aspects within the scope of each example should typically be considered applicable to similar other features or aspects in other examples. Thus, as will be apparent to those of ordinary skill in the art, unless specifically indicated otherwise, the features, characteristics, and / or elements described in connection with a particular example may be used alone or in combination with the features, characteristics, and / or elements described in connection with other examples. Accordingly, the foregoing are illustrative of various examples and should not be construed as limitations to the specific examples disclosed herein, and it is intended that various modifications to the disclosed examples and other exemplary embodiments be included within the spirit and scope of the disclosure as defined in the appended claims and their equivalents.

Claims

1. A wireless interface; and A processing circuit comprising, wherein the processing circuit Receiving a shutdown command through the wireless interface; Transitioning to a limited activity state in response to the receipt of the shutdown command; Operating in the limited activity state, wherein the operation in the limited activity state includes generating wireless transmissions at a rate that does not exceed a threshold, configured to perform A wireless network interface circuit.

2. The operation in the limited activity state includes not generating wireless transmissions, the wireless network interface circuit according to claim 1.

3. Generating the wireless transmissions at a rate that does not exceed a threshold includes generating transmissions with a duty cycle less than a duty cycle threshold, the wireless network interface circuit according to claim 1.

4. Generating the wireless transmissions at a rate that does not exceed a threshold includes generating transmissions with an average frame rate less than a frame rate threshold, the wireless network interface circuit according to claim 1.

5. Further comprising a host interface, wherein the processing circuit is configured not to modify the response to the shutdown command in response to a command or data received through the wireless interface or through the host interface, the wireless network interface circuit according to claim 1.

6. The processing circuit has a state machine configured to operate in either the limited activity state or the normal state, the wireless network interface circuit according to claim 5.

7. Further comprising a memory for storing instructions that, when executed by the processing circuit, cause the processing circuit to transition the wireless network interface circuit to the limited activity state, the instructions not being modifiable by a command or data received through the wireless interface or through the host interface, the wireless network interface circuit according to claim 5.

8. The transitioning to the limited activity state is further in response to authenticating the shutdown command, the wireless network interface circuit according to claim 1.

9. The processing circuit is configured to transition the wireless network interface circuit from the limited activity state to the normal state when the power of the wireless network interface circuit is turned off and then turned on, the wireless network interface circuit according to claim 1.

10. The processing circuit receives a restart command; and is further configured to transition from the limited activity state to the normal state in response to the reception of the restart command the wireless network interface circuit according to claim 1.

11. Receiving the restart command includes receiving the restart command through the wireless interface, the wireless network interface circuit according to claim 10.

12. Further comprising a host interface, and receiving the restart command includes receiving the restart command through the host interface, the wireless network interface circuit according to claim 10.

13. Further comprising a host interface, the processing circuit is further configured to send a notification through the host interface in response to receiving the shutdown command, the wireless network interface circuit according to claim 1.

14. The shutdown command includes a message, and the notification includes an indication of the message, the wireless network interface circuit according to claim 13.

15. A wireless network interface circuit, a host interface; a wireless interface; a processing circuit; and a memory for storing instructions wherein the instructions, when executed by the processing circuit, cause the wireless network interface circuit to receive a shutdown command through the wireless interface; transition to a limited activity state in response to the reception of the shutdown command; operate in the limited activity state, where operating in the limited activity state includes generating wireless transmissions at a rate that does not exceed a threshold, and the instructions are not modifiable by commands or data received through the wireless interface or through the host interface, the wireless network interface circuit.

16. Receiving a shutdown command through a wireless interface of the wireless network interface circuit by the wireless network interface circuit; Transitioning to a limited activity state in response to the reception of the shutdown command by the wireless network interface circuit; and Operating in the limited activity state by the wireless network interface circuit, the operating in the limited activity state including generating wireless transmission at a rate that does not exceed a threshold. A method comprising the steps.

17. The method according to claim 16, wherein the step of operating in the limited activity state includes a step of not generating wireless transmission.

18. The method according to claim 16, wherein the step of generating wireless transmission at a rate that does not exceed a threshold includes a step of generating transmission with a duty cycle less than a duty cycle threshold.

19. The method according to claim 16, wherein the step of generating wireless transmission at a rate that does not exceed a threshold includes a step of generating transmission with an average frame rate less than a frame rate threshold.

20. The method according to claim 16, wherein the wireless network interface circuit is configured not to modify a response to a shutdown command in response to a command or data received through the wireless interface of the wireless network interface circuit or through a host interface of the wireless network interface circuit.

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