GB2499445A

GB2499445A - Inter device interference measurement and transmission power control (TPC) for devices operating in unlicensed frequency bands

Info

Publication number: GB2499445A
Application number: GB1202796.7A
Authority: GB
Inventors: Timo Koskela; Sami-Jukka Hakola; Anna Pantelidou; Samuli Turtinen
Original assignee: Renesas Mobile Corp
Current assignee: Renesas Electronics Corp
Priority date: 2012-02-20
Filing date: 2012-02-20
Publication date: 2013-08-21
Also published as: GB201202796D0

Abstract

A number of different communication systems A,B,C can operate within unlicensed frequency bands.(eg. 2.4GHz ISM band) using various protocols (eg. IEEE 802.11). Some devices (eg. access point (AP) 11,station (STA) 17 of System A) can use TPC and detect interference power levels from devices 15,19,21,23,25 in other systems B and C. If the interference detected is below a threshold system A may employ TPC. Interference may be detected based upon beacon transmissions from devices. If interference is detected, devices (eg. 11) may transmit messages to other systems/devices (eg. 15) to request that they reduce their power levels and thence reduce interference. Devices (15) may accede to or refuse these requests, or may enter into power setting negotiations. The request may be included in beacon messages.

Description

1

Methods and Apparatuses for Transmission Power Management In a Shared Band Technical Field

Embodiments of the present invention relate generally to wireless 5 communication technology and, more particularly, to transmission power management in a shared band of a communications system.

Background

Mobile terminals routinely communicate within a licensed spectrum via 10 networks supervised by various cellular operators. The licensed spectrum, however, has a finite capacity and may become somewhat scarce as the number of mobile terminals that are configured to communicate within the licensed spectrum increases at fairly dramatic rates. As the demands placed upon the licensed spectrum by the various mobile terminals begin to saturate the licensed spectrum, the mobile terminals 15 may experience increasing levels of interference with the licensed spectrum potentially eventually becoming a bottleneck for such communications.

An increasing number of other network topologies are being integrated with cellular networks. These other network topologies include, for example, wireless local area networks (WLANs), wireless fidelity (WiFi) networks, ad hoc networks and 20 various other local area networks. The terminals, either mobile or fixed, supported by these other network topologies may communicate with one another in a shared frequency band(s) such as an unlicensed spectrum. For example, the unlicensed spectrum may be a licensed-exempt industrial scientific medical (ISM) radio band. The ISM radio band supports other non-cellular systems, such as WLAN systems, 25 WiFi systems operating in accordance with the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard, ZigBee systems operating in accordance with the IEEE 802.15 standard, Bluetooth systems and universal serial bus (USB) wireless systems. In this regard, the ISM radio band may include the 2.4 GHz ISM band in which WiFi 802.1 lb and 802.1 lg systems operate and the 5 GHz ISM band in which 30 WiFi 802.1 la systems operate. Though cellular technologies have not generally been deployed in the ISM band, such deployment could be considered for local-area Long

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Term Evolution (LTE) cellular networks as long as they meet the regulatory requirements in country-specific ISM bands, e.g. Federal Communications Commission (FCC) in the United States. Another example of a license exempt band is TV White Space (TVWS), which has been investigated widely in the recent years 5 due to the large available bandwidths at suitable frequencies for different radio applications. In the United States, the FCC has regulated licensed or license-exempt TV bands for the secondary-system applications, e.g., cellular, WiFi, WiMax, etc., on TV Band Devices (TVBD).

Currently, WLANs are deployed on an unlicensed band which typically has a 10 very dynamic interference environment. For instance, the operation channel may suddenly be affected by an unknown/known interferer. The nature of the interference environment on unlicensed bands and the typical uncoordinated deployments related therein generally dictates the transmission power utilization of a system. For example, with low transmission power the system typically causes less interference to 15 other systems and also saves energy by using only the necessary amount of power for reaching the performance target. However, utilizing low power also means that other, usually sensing-based systems, operating on the channel may not be aware of the ongoing transmission since the sensing function may be unable to detect the low power transmission. Based on the sensing result, the corresponding system may 20 utilize high transmission power and may unknowingly induce interference to another system and the interference may undesirably affect the transmissions of the system.

Summary

A method, apparatus and computer program product are therefore provided in 25 accordance with an example embodiment to facilitate management of transmission power in a shared spectrum of an unlicensed band (e.g., a license-exempt band.) In this regard, some example embodiments may determine whether devices (e.g., access points (APs), stations (STAs), etc.) of systems (e.g., adjacent systems) cause interference in a shared spectrum (e.g., a shared frequency band (e.g., a shared 30 channel)) of an unlicensed band. The shared spectrum of the unlicensed band may operate in a local area network which may be part of (e.g., deployed within) a Long

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Term Evolution system. The interference may be based on detected transmissions of the devices of the systems at high (e.g., maximum) transmit powers.

In an instance in which a communication device (e.g., an AP and/or a STA) of an example embodiment detects a high power transmission of another device(s) on the 5 shared spectrum, the communication device may send a generated message to the device(s) indicating to the device(s) that the communication device utilizes transmission power control (TPC) with reduced or low transmit power. In some example embodiments, in response to receipt of the generated message, the device(s) may optionally decide to utilize TPC to reduce the transmit power of its 10 communications to avoid or minimize interference on the shared spectrum of the unlicensed band.

As such, some example embodiments may alleviate or remove undesirable interference and may conserve energy (e.g., increased battery capacity, etc.) of devices operating in a communications system.

15 In one example embodiment, a method for managing transmission power is provided that includes determining whether one or more devices of respective systems of a local area network (LAN) are detected as communicating via a shared spectrum of an unlicensed band. The method of this embodiment also obtains a plurality of sensing results indicating a power in which at least a set of communication devices 20 including at least a first communication device and a second communication device of a first system of the LAN are transmitting data via the shared spectrum. The method of this embodiment also compares the sensing results to a predetermined threshold to determine whether to utilize transmission power control (TPC) to reduce transmission power for transmissions between the communication devices.

25 In another example embodiment, an apparatus for managing transmission power is provided that includes a processing system, which may be embodied by at least one processor and at least one memory including computer program code. The processing system is arranged to cause the apparatus to at least determine whether one or more devices of respective systems of a local area network are detected as 30 communicating via a shared spectrum of an unlicensed band. The processing system is also arranged to cause the apparatus to obtain a plurality of sensing results

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indicating a power in which at least a set of communication devices including the apparatus and at least one first communication device of a first system of the local area network are transmitting data via the shared spectrum. The processing system is arranged to cause the apparatus to compare the sensing results to a predetermined 5 threshold to determine whether to utilize transmission power control to reduce transmission power for transmissions between the communication devices.

In yet another example embodiment, a computer program product is provided, the computer program product comprising a set of instructions, which, when executed by a computing system, cause the computing system to determine whether one or 10 more devices of respective systems of a local area network are detected as communicating via a shared spectrum of an unlicensed band. The set of instructions, when executed by the computing system, also cause the computing system to obtain a plurality of sensing results indicating a power in which at least a set of communication devices including at least a first communication device and a second 15 communication device of a first system of the local area network are transmitting data via the shared spectrum. The set of instructions, when executed by the computing system, also cause the computing system to compare the sensing results to a predetermined threshold to determine whether to utilize transmission power control (TPC) to reduce transmission power for transmissions between the communication 20 devices.

In a further example embodiment, an apparatus is provided that includes means for determining whether one or more devices of respective systems of a local area network are detected as communicating via a shared spectrum of an unlicensed band. The apparatus of this embodiment also includes means for obtaining a plurality 25 of sensing results indicating a power in which at least a set of communication devices including the apparatus and at least one first communication device of a first system of the local area network are transmitting data via the shared spectrum. The apparatus of this embodiment also includes means for comparing the sensing results to a predetermined threshold to determine whether to utilize transmission power control to 30 reduce transmission power for transmissions between the communication devices.

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Brief Description of the Drawings

Having thus described the invention in general terms, reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, and wherein:

5 FIG. 1 is one example of a communications system according to an embodiment of the invention;

FIG. 2 is a diagram of a system according to an example embodiment of the invention;

FIG. 3 is a schematic block diagram of an apparatus from the perspective of a 10 base station in accordance with an example embodiment of the invention;

FIG. 4 is a block diagram of an apparatus from the perspective of a terminal in accordance with an example embodiment of the invention;

FIG. 5 is a diagram of a communications system for managing transmission power in a shared spectrum of an unlicensed band according to an example 15 embodiment of the invention;

FIG. 6 is a diagram illustrating a structure of a management frame according to an example embodiment of the invention;

FIG. 7 is a diagram illustrating a frame body of a management frame according to an example embodiment of the invention;

20 FIG. 8 is a diagram illustrating a frame control field including subfield values of a frame control field of a management frame according to an example embodiment of the invention; and

FIG. 9 illustrates a flowchart for managing transmission power in a shared spectrum on an unlicensed band according to an example embodiment of the 25 invention.

Detailed Description

Some embodiments of the present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which some, but not all 30 embodiments of the invention are shown. Indeed, various embodiments of the invention may be embodied in many different forms and should not be construed as

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limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements. Like reference numerals refer to like elements throughout.

As used in this application, the term 'circuitry' refers to all of the following: 5 (a) hardware-only circuit implementations (such as implementations in only analog and/or digital circuitry) and (b) to combinations of circuits and software (and/or firmware), such as (as applicable): (i) to a combination of processor(s) or (ii) to portions of processor(s)/software (including digital signal processor(s)), software, and memory(ies) that work together to cause an apparatus, such as a mobile phone or 10 server, to perform various functions) and (c) to circuits, such as a microprocessor(s) or a portion of a microprocessor(s), that require software or firmware for operation, even if the software or firmware is not physically present.

This definition of 'circuitry' applies to all uses of this term in this application, including in any claims. As a further example, as used in this application, the term 15 "circuitry" would also cover an implementation of merely a processor (or multiple processors) or portion of a processor and its (or their) accompanying software and/or firmware. The term "circuitry" would also cover, for example and if applicable to the particular claim element, a baseband integrated circuit or applications processor integrated circuit for a mobile phone or a similar integrated circuit in server, a cellular 20 network device, or other network device.

As defined herein a "computer-readable storage medium," which refers to a non-transitory, physical or tangible storage medium (e.g., volatile or non-volatile memory device), may be differentiated from a "computer-readable transmission medium," which refers to an electromagnetic signal.

25 As referred to herein, in some example embodiments, a victim system may,

but need not, refer to a system in which devices of the system experience interference based in part on transmission power (e.g., a high transmission power) of other devices transmitting on a shared spectrum of an unlicensed band.

As referred to herein, transmission power control (TPC) may denote a 30 mechanism utilized in order to minimize undesirable interference between devices in a network or system in a shared spectrum (also referred to herein as shared band) of

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an unlicensed band. Utilization of TPC by one or more devices of the example embodiments may automatically reduce the transmit power of the devices. The reduced transmit power may reduce interference in the shared spectrum (e.g., a shared channel) on an unlicensed band.

5 Referring now to FIG. 1, an example embodiment of a system is provided.

The system of FIG. 1 may be a WLAN system deployed on an unlicensed band. The system may include an AP 1, an AP 5 and stations (STAs) 2, 4, 6, and 8. The STA 6 and STA 8 may be part of an independent basic service set (IBSS) in which the STAs 6 and 8 are capable of communicating directly with each other.

10 In the system of FIG. 1, the APs 1 and 5 may transmit beacons with a configured transmission power. Additionally, the STAs 6, and 8 of the IBSS may transmit beacons having a transmission power to devices of the system of FIG. 1. Currently, in many existing deployments, the configured transmission power among devices in a WLAN system is a high power (e.g., the maximum allowed power). In 15 FIG. 1, this is depicted by AP 5 and STA 4 communicating with a high (e.g., maximum) transmission power (e.g., 20 dBm) via a shared spectrum (e.g., a shared band). However, in cases where a STA and AP are close to each other, a more energy-efficient approach may be to limit the transmission power to a value which is lower than a high (e.g., maximum) transmission power but still sufficient to support 20 the data-rate. An example of such an energy efficient approach is to utilize transmission power control which implements a low transmission power. Upon receiving an Association Request from a STA (e.g., STA 2), the AP (e.g., AP 1) may determine the sufficient transmission power for the communication link and may signal the value to the STA (e.g., STA 2). Alternatively, an AP (e.g., AP 1) may 25 already be under a certain power constraint for example in a 5 GHz radar band(s) which may only be used with limited power.

On the shared spectrum the utilization of TPC typically poses a problem since there is generally no guarantee that every other device, even of the same radio access technology (RAT) would be operating in such a mode. This problem is illustrated in 30 FIG. 1. For example, in FIG. 1 STA 2 and AP 1 are using TPC to transmit with a low power which is sufficient for communication. However, as pointed out above, the AP

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5 and STA 4 are communicating with a high (e.g., maximum) power across the same shared spectrum as AP 1 and STA 2. Since AP 1 and STA 2 are communicating with low power, and the AP 5 and STA 4 are communicating with a high power (e.g., maximum power), the AP 5 and STA 4 may not sense or detect the transmissions 5 between the AP 1 and STA 2. As such, the AP 5 and STA 4 may mistakenly determine that the shared spectrum (e.g., a shared channel) is free or available even though the shared spectrum is not free, in this example embodiment. As such, the high transmission power used by the AP 5 and STA 4 may cause interference on the shared spectrum to the AP 1 and STA 2 which are utilizing a low transmission 10 according to TPC. In other words, AP 1 and STA 2 may be overrun by AP 5 and STA 4 which may be unable to detect AP 1 and STA 2 operating on the same channel. As such, the transmissions of AP 1 and STA 2 may be jammed by the high power transmissions of AP 5 and STA 4.

Due to this problem, the safest operation mode for operating and 15 communicating in a local area network (e.g., a WLAN) on a license-exempt band(s) (e.g., a shared spectrum) may be to use the highest (e.g., maximum) allowed power to avoid interference. However, this may be an overkill solution in some situations. For example, the approach of using the highest (e.g., maximum) allowed power to transmit may have drawbacks associated draining battery capacity of the devices of 20 the system and undesirably increasing the overall power usage of the system which may be an inefficient use of power in the system.

In view of the foregoing drawbacks and problems, it may be beneficial to provide an efficient and reliable mechanism of managing transmission power of devices operating on a shared spectrum of an unlicensed band.

25 Referring now to FIG. 2, a schematic block diagram of a communications system according to an example embodiment is provided. In the example embodiment of FIG. 2, the base station, an evolved node B (eNB) 12 (also referred to herein as a base station 12) or the like, may communicate with a plurality of terminals in the licensed spectrum and may optionally communicate in a license-exempt band 30 18 (also referred to herein as unlicensed band 18), such as within the ISM band or the TVWS band. While a communications system that provides coordination of

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communication using carrier aggregation in a licensed band and an unlicensed band may be configured in various different manners, FIG. 2 illustrates a generic system diagram in which a terminal(s) (e.g., first terminal 14), such as a mobile terminal(s), may communicate in a licensed spectrum as well as license-exempt band 18 with the 5 network 10, such as by the exchange of cellular signals as shown in the solid lightening bolts in FIG. 2. Additionally, the terminal, such as a mobile terminal may communicate in a license-exempt band 18, such as, but not limited to, the ISM band and/or TVWS, and in the license-exempt band 18 there may be other terminals/network(s) communicating with each other as shown in the dashed 10 lightening bolts. As shown in FIG. 2, an embodiment of a system 7 in accordance with an example embodiment of the invention may include a set of first terminals 14 and a set of second terminals 16. The first terminals 14 may each be capable of communication, such as cellular communication, in the licensed band, as well as the license-exempt band, with a network 10 (e.g., a cellular network). In some example 15 embodiments, the first terminals 14 may communicate with the eNB 12 and/or an access point (AP) 3 (e.g., a WLAN AP, a WiFi AP, etc.) in the license-exempt band 18. Some terminals 16 may form another network, which may be a cellular system(s) or a non-cellular system(s). The first terminals 14 may be configured to communicate (e.g., directly) with one or more of the second terminals 16 (e.g., WiFi stations, 20 WLAN stations, etc.) as well as the AP 3 in a license-exempt band 18. The first terminals 14 may be configured to listen to signaling on the license-exempt band 18. While each set of the first and second terminals is shown to include multiple terminals, either set or both sets may include a single terminal in other embodiments. While the cellular network may be configured in accordance with Long Term 25 Evolution (LTE), the network may employ other mobile access mechanisms such as wideband code division multiple access (W-CDMA), CDMA2000, global system for mobile communications (GSM), general packet radio service (GPRS), LTE-Advanced (LTE-A) and/or the like. The non-cellular network (e.g., unlicensed band 18) may, but need not, be configured in IEEE 802.11 systems or other shared band 30 technologies.

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The network 10 may include a collection of various different nodes, devices or functions that may be in communication with each other via corresponding wired and/or wireless interfaces. As such, the illustration of FIG. 2 should be understood to be an example of a broad view of certain elements of the system and not an all-5 inclusive or detailed view of the system or the network. One or more communication terminals such as the first terminals 14 and second terminals 16 may be in communication with each other or other devices via the licensed band of the network 10 and/or the unlicensed band 18. In some cases, each of the communication terminals may include an antenna or antennas for transmitting signals to and for 10 receiving signals from an access point (e.g., AP 3), base station, node B, eNB (e.g., eNB 12) or the like. Although one eNB 12 and one AP 3 is shown as part of the system of FIG. 2, it should be pointed out that any suitable number of eNBs 12 and APs 3 may be part of the system of FIG. 2 without departing from the spirit and scope of the invention. The eNB may be, for example, part of one or more cellular or 15 mobile networks or public land mobile networks (PLMNs). In turn, other devices such as processing devices (e.g., personal computers, server computers or the like) may be coupled to the terminals via the network.

In some example embodiments, the first terminals 14 may be one or more mobile communication devices (e.g., user equipment (UE)) such as, for example, a 20 mobile telephone, portable digital assistant (PDA), pager, laptop computer, or any of numerous other hand held or portable communication devices, computation devices, content generation devices, content consumption devices, or combinations thereof. Alternatively, the first terminals may be fixed communication devices that are not configured to be mobile or portable. In either instance, the terminals may include one 25 or more processors that may define processing circuitry either alone or in combination with one or more memories. The processing circuitry may utilize instructions stored in the memory to cause the terminals to operate in a particular way or execute specific functionality when the instructions are executed by the one or more processors. The first terminals may also include communication circuitry and corresponding 30 hardware/software to enable communication with other devices.

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The second terminals 16 may be communication devices such as, for example, a WiFi station, a WLAN station (according to a WLAN technique such as, for example, IEEE 802.11 techniques), a Bluetooth station or the like(s)).

Referring now to FIG. 3, a schematic block diagram of an apparatus according 5 to an example embodiment is provided. In the example embodiment of FIG. 3, the eNB 12 may be embodied as or otherwise include an apparatus 20 as generically represented by the block diagram of FIG. 3. In this regard, the apparatus may be configured to communicate with the sets of first and second terminals 14, 16. While one embodiment of the apparatus is illustrated and described below, it should be noted 10 that the components, devices or elements described below may not be mandatory and thus some may be omitted in certain embodiments. Additionally, some embodiments may include further or different components, devices or elements beyond those shown and described herein.

As shown in FIG. 3, the apparatus 20 may include or otherwise be in 15 communication with a processing system including, for example, processing circuitry 22 that is configurable to perform actions in accordance with example embodiments described herein. The processing circuitry may be configured to perform data processing, application execution and/or other processing and management services according to an example embodiment of the invention. In some example 20 embodiments, the apparatus or the processing circuitry may be embodied as a chip or chip set. In other words, the apparatus or the processing circuitry may comprise one or more physical packages (e.g., chips) including materials, components and/or wires on a structural assembly (e.g., a baseboard). The structural assembly may provide physical strength, conservation of size, and/or limitation of electrical interaction for 25 component circuitry included thereon. The apparatus or the processing circuitry may therefore, in some cases, be configured to implement an embodiment of the present invention on a single chip or as a single "system on a chip." As such, in some cases, a chip or chipset may constitute means for performing one or more operations for providing the functionalities described herein.

30 In an example embodiment, the processing circuitry 22 may include a processor 24 and memory 26 that may be in communication with or otherwise control

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a device interface 28. As such, the processing circuitry may be embodied as a circuit chip (e.g., an integrated circuit chip) configured (e.g., with hardware, software or a combination of hardware and software) to perform operations described herein in relation to the eNB 12.

5 The device interface 28 may include one or more interface mechanisms for enabling communication with other devices, such as the sets of first and second terminals 14, 16. In some cases, the device interface may be any means such as a device or circuitry embodied in either hardware, or a combination of hardware and software that is configured to receive and/or transmit data from/to a network and/or 10 any other device or module in communication with the processing circuitry 22. In this regard, the device interface may include, for example, an antenna (or multiple antennas) and supporting hardware and/or software for enabling communications with a wireless communication network and/or a communication modem, such as a cellular modem 21 (e.g., an LTE modem), and/or an optional non-cellular modem 23 (e.g., a 15 WLAN modem, a WiFi modem, etc.) for enabling communications with the sets of first and second terminals. In an example embodiment, the cellular modem 21 may be configured to facilitate communications via a primary cell (PCell) on a licensed band (for example, of network 10) and the optional non-cellular modem 23 may be able to facilitate communications via a secondary cell (SCell) on the unlicensed band 18. 20 In an example embodiment, the memory 26 may include one or more non-

transitory memory devices such as, for example, volatile and/or non-volatile memory that may be either fixed or removable. The memory may be configured to store information, data, applications, instructions or the like for enabling the apparatus 20 to carry out various functions in accordance with example embodiments of the present 25 invention. For example, the memory could be configured to buffer input data for processing by the processor 24. Additionally or alternatively, the memory could be configured to store instructions for execution by the processor. As yet another alternative, the memory may include one of a plurality of databases that may store a variety of files, contents or data sets. Among the contents of the memory, 30 applications may be stored for execution by the processor in order to carry out the functionality associated with each respective application. In some cases, the memory

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may be in communication with the processor via a bus for passing information among components of the apparatus.

The processor 24 may be embodied in a number of different ways. For example, the processor may be embodied as various processing means such as one or 5 more of a microprocessor or other processing element, a coprocessor, a controller or various other computing or processing devices including integrated circuits such as, for example, an ASIC (application specific integrated circuit), an FPGA (field programmable gate array), or the like. In an example embodiment, the processor may be configured to execute instructions stored in the memory 26 or otherwise accessible 10 to the processor. As such, whether configured by hardware or by a combination of hardware and software, the processor may represent an entity (e.g., physically embodied in circuitry - in the form of processing circuitry 22) capable of performing operations according to embodiments of the present invention while configured accordingly. Thus, for example, when the processor is embodied as an ASIC, FPGA 15 or the like, the processor may be specifically configured hardware for conducting the operations described herein. Alternatively, as another example, when the processor is embodied as an executor of software instructions, the instructions may specifically configure the processor to perform the operations described herein.

In one example embodiment, the first terminals 14 (also referred to herein as 20 user equipment (UE) 14), the second terminals 16 and/or the AP 3 may be embodied as or otherwise include an apparatus 30 as generically represented by the block diagram of FIG. 4. In this regard, the apparatus may be configured to provide for communications in the licensed spectrum, such as cellular communications, with the eNB 12 or another terminal and communications in the license-exempt band, such as 25 non-cellular communications, with another terminal. While the apparatus may be employed, for example, by a mobile terminal, it should be noted that the components, devices or elements described below may not be mandatory and thus some may be omitted in certain embodiments. Additionally, some embodiments may include further or different components, devices or elements beyond those shown and 30 described herein.

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As shown in FIG. 4, the apparatus 30 may include or otherwise be in communication with a processing system including, for example, processing circuitry 32 that is configurable to perform actions in accordance with example embodiments described herein. The processing circuitry may be configured to perform data 5 processing, application execution and/or other processing and management services according to an example embodiment of the present invention. In some embodiments, the apparatus or the processing circuitry may be embodied as a chip or chip set. In other words, the apparatus or the processing circuitry may comprise one or more physical packages (e.g., chips) including materials, components and/or wires on a 10 structural assembly (e.g., a baseboard). The structural assembly may provide physical strength, conservation of size, and/or limitation of electrical interaction for component circuitry included thereon. The apparatus or the processing circuitry may therefore, in some cases, be configured to implement an embodiment of the present invention on a single chip or as a single "system on a chip." As such, in some cases, a chip or 15 chipset may constitute means for performing one or more operations for providing the functionalities described herein.

In an example embodiment, the processing circuitry 32 may include a processor 34 and memory 36 that may be in communication with or otherwise control a device interface 38 and, in some cases, a user interface 44. As such, the processing 20 circuitry may be embodied as a circuit chip (e.g., an integrated circuit chip) configured (e.g., with hardware, software or a combination of hardware and software) to perform operations described herein. However, in some embodiments taken in the context of the mobile terminal, the processing circuitry may be embodied as a portion of a mobile computing device or other mobile terminal.

25 The optional user interface 44 may be in communication with the processing circuitry 32 to receive an indication of a user input at the user interface and/or to provide an audible, visual, mechanical or other output to the user. As such, the user interface in the context of a mobile terminal may include, for example, a keyboard, a mouse, a joystick, a display, a touch screen, a microphone, a speaker, and/or other 30 input/output mechanisms.

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The device interface 38 may include one or more interface mechanisms for enabling communication with other devices and/or networks. In some cases, the device interface may be any means such as a device or circuitry embodied in either hardware, or a combination of hardware and software that is configured to receive 5 and/or transmit data from/to a network and/or any other device or module in communication with the processing circuitry 32. In this regard, the device interface may include, for example, an antenna (or multiple antennas) and supporting hardware and/or software for enabling communications with a wireless communication network and/or a communication modem or other hardware/software for supporting 10 communication via cable, digital subscriber line (DSL), universal serial bus (USB), Ethernet or other methods. In the illustrated embodiment, for example, the device interface includes an optional cellular modem 40 (e.g., an LTE modem) for supporting communications in the licensed spectrum, such as communications with the eNB 12, and an optional non-cellular modem 42 (e.g., a WLAN modem, WiFi modem, 15 Bluetooth (BT) modem, etc.) for supporting communications in the license exempt band 18, such as non-cellular communications, e.g., communications in the ISM band and/or the TVWS band, with other terminals.

In an example embodiment, the memory 36 may include one or more non-transitory memory devices such as, for example, volatile and/or non-volatile memory 20 that may be either fixed or removable. The memory may be configured to store information, data, applications, instructions or the like for enabling the apparatus 30 to carry out various functions in accordance with example embodiments of the present invention. For example, the memory could be configured to buffer input data for processing by the processor 34. Additionally or alternatively, the memory could be 25 configured to store instructions for execution by the processor. As yet another alternative, the memory may include one of a plurality of databases that may store a variety of files, contents or data sets. Among the contents of the memory, applications may be stored for execution by the processor in order to carry out the functionality associated with each respective application. In some cases, the memory 30 may be in communication with the processor via a bus for passing information among components of the apparatus.

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The processor 34 may be embodied in a number of different ways. For example, the processor may be embodied as various processing means such as one or more of a microprocessor or other processing element, a coprocessor, a controller or various other computing or processing devices including integrated circuits such as, 5 for example, an ASIC, an FPGA or the like. In an example embodiment, the processor may be configured to execute instructions stored in the memory 36 or otherwise accessible to the processor. As such, whether configured by hardware or by a combination of hardware and software, the processor may represent an entity (e.g., physically embodied in circuitry - in the form of processing circuitry 32) capable of 10 performing operations according to embodiments of the present invention while configured accordingly. Thus, for example, when the processor is embodied as an ASIC, FPGA or the like, the processor may be specifically configured hardware for conducting the operations described herein. Alternatively, as another example, when the processor is embodied as an executor of software instructions, the instructions 15 may specifically configure the processor to perform the operations described herein.

Referring now to FIG. 5, a communications system for managing transmission power in a shared band according to an example embodiment is provided. In an example embodiment, the communications system 9 of FIG. 5 may be a local area network (LAN) system (e.g., a WLAN system, a WiFi system, a 3GPP LTE system, 20 etc.) operating on a shared spectrum (e.g., a shared band (e.g., a shared channel)) of an unlicensed band (e.g., unlicensed band 18). An example of the shared band may include but is not limited to a 3.5 GHz time-division duplex, (TDD) band, a 2.4 GHz band, a 5 GHz band, TVWS, a sub-1 GHz band and any other suitable frequency bands. In the example embodiment of FIG. 5, the communications system 9 may 25 include an access point (AP) 11 (e.g., AP 3), an AP 15 (e.g., AP 3), a station (STA) 17 (e.g., first terminal 14), a STA 19 (e.g., first terminal 14), a STA 21 (e.g., second terminal 16), a STA 23 (e.g., second terminal 16) and a STA 25 (e.g., first terminal 14). Although one AP 11, one AP 15, five STAs 17, 19, 21, 23 and 25 are shown as part of the system 9 of FIG. 5 any suitable number of APs 11, 15 and STAs 17, 19, 30 21, 23 and 25 may be part of the system 9 without departing from the spirit and scope of the invention. In the example embodiment of the communications system 9, the

17

AP 11 and STA 17 may be part of a system A and AP 15 and STAs 19, 21 may be part of a system B. Additionally, in the communications system 9, the STA 23 and the STA 25 may be part of a system C. The STAs 23 and 25 of system C may be part of a basic service set (BSS) in which the STAs 23 and 25 may communicate directly 5 with each other as well as devices of other systems (e.g., system A, system B, etc.) In one example embodiment, the BSS of the system C may be an independent BSS (IBSS) and may not necessarily include an AP in system C. In an alternative example embodiment, the BSS may be any suitable type of BSS including but not limited to an infrastructure BSS.

10 In one example embodiment, consider an instance in which the AP 11 and the

STA 17 of system A may operate/communicate by using TPC with low power. The AP 15 and the STA 19 and/or STA 21 of system B may, but need not, operate/communicate with a high transmission power causing interference to the AP 11 and STA 17 of system A on a shared spectrum (e.g., a shared channel) of an 15 unlicensed band (e.g., unlicensed band 18). In addition, the STAs 23 and 25 of system C may, but need not, operate/communicate with high transmission power which may cause interference to the AP 11 and STA 17 of system A (e.g., a victim system in this example). In other example embodiments, the devices (e.g., AP 11, STA 17, AP 15, STA 19, STA 21, STA 23, STA 25) of FIG. 5 may operate/transmit 20 with any other suitable transmit powers and in some instances some or all of the devices of system of FIG. 5 may not necessarily be currently transmitting data on a shared spectrum of an unlicensed band. In an instance in which a device(s) of the system 9 may not be currently transmitting on the shared spectrum, the device may be undetected on the shared spectrum, as described more fully below.

25 In the example embodiment of FIG. 5, the AP 11 and/or the STA 17 may first determine whether to use transmission power control based in part on determining whether other systems (e.g., system B, system C, etc.) may cause interference on a shared spectrum (e.g., a shared channel of an unlicensed band (e.g., unlicensed band 18)). Additionally, in an instance in which the AP 11 and/or STA 17 determines that 30 one or more systems may cause interference based in part on their corresponding

18

transmit power, the AP 11 and/or STA 17 may attempt to resolve the interference, as described more fully below.

Initially, a processor (e.g., processor 34) of AP 11 and/or the STA 17 of system A may sense the environment to determine whether there are other 5 transmissions of other devices in the communications system 9 or even another communications system (e.g., other LAN systems). Additionally or alternatively, a processor (e.g., processor 34) of the AP 11 and/or STA 17 may determine whether there are other transmissions from other devices by detecting one or more preambles being transmitted from other devices and/or detecting energy in the shared band (e.g., 10 a shared channel) of an unlicensed band (e.g., unlicensed band 18). In this regard, in an example embodiment, the AP 11 and/or STA 17 may scan the shared spectrum (e.g. a channel (e.g., a shared radio channel) to detect whether other devices of systems (e.g., system B, system C, other systems, etc.) are transmitting on the shared spectrum. The detection via the scan by the AP 11 and/or STA 17 may be based on 15 identifying energy on the shared spectrum. Additionally, a processor (e.g., processor 34) of the AP 11 and/or STA 17 may attempt to detect one or more preambles (e.g., WLAN preambles) and thus detect any beacon messages that may be transmitted by other APs (e.g., AP 15) in order to determine whether there are devices transmitting on the shared spectrum.

20 In an instance in which the AP 11 and/or STA 17 determines that there are no transmissions by other devices detected, the AP 11 and/or STA 17 may operate with transmission power control and may communicate with each other using low power transmissions of data. In one example embodiment, in an instance in which no other system is detected by the AP 11 and/or STA 17 and a detected sensing result by the 25 AP 11 and/or STA 17 is determined to be below a predetermined threshold for both the AP 11 and the STA 17, the processor (e.g., processor 34) of the AP 11 may determine to use TPC to limit the transmit power for the communications between the AP 11 and STA 17. Alternatively, in an instance in which no other system is detected by the AP 11 and/or the STA 17, and the sensing result is below a predetermined 30 threshold at the AP 11 but not at the STA 17, the processor (e.g., processor 34) of the AP 11 may determine to use TPC to limit the transmit power of the STA 17. In this

19

example embodiment, the transmit power of the AP 11 may, but need not, be higher (e.g., a maximum transmit power) than the transmit power associated with the TPC. In an alternative example embodiment, in an instance in which no other system is detected by the AP 11 and/or STA 17 and the sensing result is below a predetermined 5 threshold at the STA 17 but not at AP 11, the AP 11 may decide to use TPC to limit its own transmit power for transmissions to the STA 17. In this alternative example embodiment, the AP 11 may not necessarily limit the transmit power of the STA 17. As such, the STA 17 may but need not transmit data with a power that is higher (e.g., a maximum transmit power) than the low power associated with TPC. 10 The sensing result may be determined by the processor (e.g., processor 34) of the AP 11 and/or STA 17 based in part on one or more power levels detected for transmissions of the AP 11 and/or STA 17 as well as power levels received from other devices transmitting data on the shared spectrum. As such, the processor (e.g., processor 34 of the AP 11 and/or STA 17) may evaluate the received power levels to 15 determine whether the corresponding power of each of the received power levels is below a predetermined threshold. In addition, the sensing result may be determined by the processor (e.g., processor 34) of the AP 11 and/or STA 17 based in part on one or more preambles received from other devices (e.g., AP 15) transmitting data on the shared spectrum of the unlicensed band (e.g., unlicensed band 18). In this regard, the 20 processor (e.g., processor 34) of the AP 11 and/or STA 17 may evaluate the data of the received preambles to identify and determine power levels of the preambles indicating the power in which respective devices (e.g., AP 15) may be transmitting data on the shared spectrum of the unlicensed band. In this manner, the processor (e.g., processor 34) of the AP 11 and/or STA 17 may compare the indicated power to 25 the predetermined threshold to determine whether the received power is below the predetermined threshold. In one example embodiment, the processor (e.g., processor 34) of the AP 11 and/or STA 17 may determine that another device(s) is detected as being on a shared spectrum of an unlicensed band in an instance in which the detection of the received power level exceeds the predetermined threshold. On the 30 other hand, when the processor of the AP 11 and/or STA 17 determines that the detection of the received power level is below the predetermined threshold, the

20

processor of the AP 11 and/or STA 17 may determine that power corresponds to background noise (e.g., white noise) and may not denote detection of another device. In an instance in which the AP 11 and/or STA 17 detects other devices on the shared spectrum of the unlicensed band (e.g., unlicensed band 18), the AP 11 and the STA 17 5 may convey the information indicating the detection of these devices (e.g., AP 15, STA 19, STA 21, STA 23, STA 25, etc.), to each other. As described above, the AP 11 and/or STA 17 may detect other devices of systems on the shared spectrum of the unlicensed band (e.g., unlicensed band 18) by scanning the shared spectrum (e.g., a shared channel) to detect energy on the spectrum and/or by detecting preambles, 10 beacon messages and any other suitable data that is transmitted by other devices (e.g., AP 15) on the shared spectrum of the unlicensed band and comparing the detected energy or detected power levels to a predefined threshold.

In an example embodiment, the STA 17 may convey information identifying an AP(s) (e.g., AP 15) and/or device(s) (e.g., STA 19, STA 21) that are detected on 15 the shared spectrum in an association phase to the AP 11. Alternatively, the STA 17 may convey information identifying detection of an AP(s) and/or device(s) on the shared spectrum to the AP 11 via one or more generic advertisement service (GAS) frames. Additionally or alternatively, the AP 11 may use one or more GAS frames to convey information indicating an AP(s) (e.g., AP 15) and/or device(s) that the AP 11 20 detected on the shared spectrum to the STA 17.

Upon the AP 11 and/or STA 17 detecting that other devices (e.g., devices of systems (e.g., system B, system C, etc.)) are on the shared spectrum of the unlicensed band, the AP 11 and/or STA 17 may detect beacon transmissions of one or more other APs (e.g., AP 15) or other transmissions of devices (e.g., STA 19, STA 21, STA 23, 25 STA 25), and the AP 11 and/or STA 17 may measure the signal strength of the transmissions and may determine whether the transmissions may interfere with the communications of the AP 11 and/or STA 17 on the shared spectrum of the unlicensed band. In an example embodiment, the processor (e.g., processor 34) of the AP 11 and/or the STA 17 may determine that the transmissions may interfere with 30 their communications in an instance in which the signal strength indicates that the AP(s) (e.g., AP 15) and/or device(s) (e.g., STA 19, STA 21, STA 23, STA 25) are

21

transmitting data with a power above a predetermined threshold (e.g., a power higher than a power associated with TPC (e.g., a maximum transmit power)) on the shared spectrum of the unlicensed band (e.g., unlicensed band 18).

In response to determining that one or more devices (e.g., AP 15, STA 19, 5 STA 21, STA 23, STA 25) on the shared spectrum may cause interference, the AP 11 may generate a beacon message(s) and may include information in the beacon message(s) indicating that the AP 11 is utilizing TPC to communicate with reduced power on the shared spectrum of the unlicensed band. The processor (e.g., processor 34) of the AP 11 may include the data indicating the utilization of TPC in a TPC 10 indication within control information of the generated beacon message(s). In another example embodiment, the processor (e.g., processor 34) of the AP 11 may include the data indicating utilization of TPC in a TPC flag within the generated beacon message(s) or any other portion of the beacon message(s). The AP 11 may send the generated beacon message(s) to the one or more devices (e.g., STA 19, etc.) that may 15 cause the interference on the shared spectrum of the unlicensed band.

Upon receipt of the beacon message(s) by a device(s), the device (e.g., STA 19, etc.) may evaluate the data of the beacon message and may determine that the AP 11 sending the message is using TPC. In this regard, the device(s) receiving the beacon message may determine whether to use TPC to reduce its transmission power. 20 As such, the device(s) may optionally use TPC to reduce its transmission power which may avoid or alleviate interference on the shared spectrum of the unlicensed band.

In an alternative example embodiment, upon hearing or receiving beacon messages or flagged transmissions from an AP (e.g., AP 11) indicating that the 25 corresponding AP (e.g., AP 11) is using TPC, the devices (e.g., AP 15, STA 19, STA 21, STA 23, STA 25) receiving the beacon messages or TPC flagged transmissions may immediately decide to use TPC to avoid interference or may perform a negotiation (e.g., a TPC negotiation) with the AP (e.g., AP 11) to agree on a transmission power for utilization. In this regard, the receipt of the beacon messages 30 or TPC flagged transmissions may cause or trigger the devices to utilize TPC with reduced transmit power.

22

In an alternative example embodiment, the processor (e.g., processor 34) of the AP 11 may generate a TPC request that includes information suggesting another device(s), which may cause interference on the shared spectrum of the unlicensed band, to utilize TPC in order to reduce the transmission power of the device(s). In an 5 example embodiment, the AP 11 may include the TPC request in a beacon message(s) or any other suitable message. In response to generating the TPC request, the processor of the AP 11 may send a beacon message(s) that includes the TPC request to one or more devices (e.g., an adjacent device (e.g., AP 15, STA 19, 21, 23, 25, etc.)) that the processor of the AP 11 may determine causes interference on the shared 10 spectrum of the unlicensed band. As described above, the processor of the AP 11 may determine that one or more devices may cause interference on the shared spectrum of the unlicensed band in an instance in which the AP 11 determines that the devices are transmitting data with a power above a predetermined threshold. In response to receiving the beacon message(s) including the TPC request from the processor of the 15 AP 11, the receiving devices (e.g., AP 15, STA 19, STA 21, STA 23, STA 25, etc.) may evaluate the data of the TPC request. Upon evaluating the data of the TPC request, the devices may determine that the AP 11 is currently utilizing TPC and is suggesting or requesting the devices to also utilize TPC to reduce their transmission power. In some example embodiments, the devices (e.g., AP 15, STA 19, STA 21, 20 STA 23, STA 25, etc.) may automatically utilize TPC in response to detection of the TPC request in a received beacon message(s). However, in some alternative example embodiments, even in an instance in which the AP 11 actively requests the devices to utilize TPC, the devices (e.g., AP 15, STA 19, STA 21, STA 23, STA 25) may still have discretion as to whether or not to use TPC for transmissions. As such, one or 25 more of the devices may utilize TPC in response to the suggestion by the AP 11 in the TPC request of a beacon message(s). On the other hand, one or more of the devices may determine not to use TPC in some instances even when requested by the AP 11 in the TPC request. For example, one or more of the devices (e.g., STA 23, STA 25, etc.) may be performing a task(s) that needs a higher transmit power (e.g., to reduce 30 bit error rate). In this regard, the corresponding devices may, but need not, negotiate with the AP 11 regarding the transmission power to utilize for communications.

23

In an instance, in which the processor of the AP 11 does not receive a response from a device(s), within a predetermined time period, indicating whether the corresponding device(s) (e.g., STA 21, etc.) may utilize TPC, the AP 11 may set its transmit power to a power that is higher (e.g., a maximum transmit power (e.g., 20 5 dBm)) than a power associated with TPC.

In another alternative example embodiment, an explicit request response message in reply to a TPC request of a beacon message(s), generated by the AP 11, may be defined for a corresponding protocol (e.g., a request-response protocol for the TPC). In one example embodiment, the processor (e.g., processor 34) of the AP 11 10 may define the explicit request response message for the protocol.

In this example embodiment, in which an explicit request response message may be defined for the protocol, the devices receiving the TPC request from the AP 11 may not necessarily need to send a response message indicating whether they are going to utilize TPC to reduce transmission power. Instead, the devices may 15 automatically utilize TPC to reduce transmission power upon receipt of the TPC request. In this regard, the processor of the AP 11 may determine that the devices are utilizing TPC in response to sending the TPC request in a beacon message(s) to the devices based in part on the defined protocol. For instance, the defined protocol may specify or instruct the devices to begin using TPC upon receipt of a TPC request. 20 Although it may not be necessary for a device(s) (e.g., STA 19, etc.) receiving a TPC request in a beacon message(s) to respond to the AP 11, the corresponding device(s) may optionally send a reply message to the AP 11 to confirm receipt of the TPC request and may indicate that the device(s) is using TPC to reduce transmission power.

25 In another alternative example embodiment, the protocol may be defined to allow devices (e.g., AP 15, STA 19, STA 21, STA 23, STA 25) receiving a TPC request in a beacon message(s), and the AP 11 to negotiate for the TX power. As such, receipt of a TPC request by the devices may not necessarily result in usage of TPC to reduce transmission power. In this regard, upon receipt of the TPC request by 30 a device(s) (e.g., AP 15, etc.), the device(s) may respond to the AP 11 confirming receipt of the TPC request and may send a message to the AP 11 to negotiate for a

24

transmission power in which to utilize. The negotiated transmission power may be different than the low transmit power associated with TPC.

In some other alternative example embodiments, a STA such as, for example, STA 17 may generate the TPC request including in a beacon message(s) requesting 5 other devices (e.g., an adjacent device(s) (e.g., AP 15, STA 19, STA 21, STA 23, STA 25)) to utilize TPC to lower or reduce transmission power. The STA 17 may generate the TPC request that may be included in the beacon message(s) in a manner analogous to that of AP 11 described above. The STA 17 may send the TPC request in the beacon message(s) to the devices.

10 In one example embodiment of FIG. 5, an AP (e.g., AP 11, AP 15) may select to transmit one or more beacon messages with full power to guarantee the reception of a frame and advertise its presence to one or more new STAs communicating on the shared spectrum of the unlicensed band. However, other messages or frames (e.g., data frames) may be transmitted utilizing TPC with reduced transmission power. 15 It should be pointed out that even though the system 9 of the example embodiment of FIG. 5 shows a single interfering AP (e.g., AP 15), the system 9 may include any suitable number of interfering APs without departing from the spirit and scope of the invention.

Referring now to FIG. 6, a diagram of a management frame structure 20 including TPC information according to an example embodiment is provided. The structure of the management frame may relate to a local area network management frame structure. The TPC related information of an example embodiment may be transmitted in a management frame 31 (e.g., a media access control (MAC) layer management frame(s)). In one example embodiment, the management frame 31 may 25 include frames such as, for example, beacon frames, public action frames, action frames and any other suitable frames. The TPC information (e.g., a TPC request, a response to a TPC request, etc.) of some example embodiments may be included in new information elements of a frame body, as described more fully below.

The management frame 31 of an example embodiment may include a Frame 30 control (CRTL) field 29. The Frame Control field 29 may indicate for example, a protocol version, a frame type, a frame subtype, etc. The management frame 31 may

25

also include a Duration field. The Duration field may include a Duration value of the management frame. The management frame 31 may also include a Destination Address (DA) (also referred to herein as Receiver Address (RA)) field. The DA field may include a Destination MAC address. The management frame 31 may also 5 include a Sender Address (SA) (also referred to herein as Transmitter Address (TA)) field. The SA field may include a Sender MAC address. The management frame 31 may also include a basic service set (BSS) identifier (ID) (BSSID) field. The BSSID field may include a basic service set ID. The management field 31 may also include a Sequence (Seq) Control (ctl) (Seq-ctl) field. The Seq-ctl field may include a 10 Sequence Control (e.g., detection of duplicates). The management frame 31 may also include a Frame Body field 33. The Frame Body field 33 may include the information elements associated with the TPC information and one or more fixed fields. The management frame 31 may also include a Frame Check Sequence (FCS) field. The FCS field may include a Frame Check Sequence (e.g., a Cyclic 15 Redundancy Check (CRC) checksum of the management frame).

Referring now to FIG. 7, a diagram of a frame format of a Frame Body field of a management frame of an example embodiment is provided. The Frame Body field 35 (e.g., Frame Body field 33) of a management frame (e.g., management frame 31) may include one or more fixed-length information element fields and one or more 20 variable-length information element fields. An example embodiment of a structure of an Information element field 37 of the Frame Body field 35 is shown in FIG. 7.

In an example embodiment, the TPC requests and/or the responses to TPC requests (also referred to herein as TPC responses) may be included in the Information element field 37 by a processor (e.g., processor 34) of an AP(s) (e.g., AP 11, AP 15) and/or a 25 STA(s) (e.g., STA 17, STA 19, STA 21, STA 23, STA 25).

Referring now to FIG. 8, a frame control field including subfield values of a Frame Control field of a management frame according to an example embodiment is provided. The frame control field subfield values 39 may be part of a Frame Control field (e.g., Frame Ctrl field 29) of a management frame (e.g., management frame 31). 30 The frame control field subfield values 39 may include a new frame subtype 41 for TPC transmissions. In this regard, the new frame subtype 41 may include one or

26

more fields (e.g., a four bit field) in which the fields may interpreted as being associated with a TPC indication. Additionally, the new subtype field may be associated or linked to a power management (PwrMgt) bit 43 to indicate a Power Control Operation.

5 In an example embodiment, in an instance in which the new subtype 41 is set,

by a device (e.g., AP 11, STA 17, etc.) to TPC indication and the power management bit 43 is set to 1, this may indicate that TPC is active and may indicate a suggestion or request to another device to use TPC upon receipt of the corresponding management frame (e.g., management frame 31). Additionally or alternatively, a device (e.g., AP 10 15, STA 19, STA 21, etc.) may set the new subtype 41 to TPC indication and the power management bit to 1 to respond to a received TPC request.

In one example embodiment, an AP (e.g., AP 11) may activate a power control phase for one or more corresponding STA(s) (e.g., STA 17, etc.) by setting a More Data bits field to 1 as well as power management bit 43 to 1, in a management frame 15 (e.g., management frame 31), during which a power management information field (also referred to herein as power management field) (e.g., a field which is generally used for power sleeping) is utilized for transmission power control and not for sleep mode signaling. In other words, in an instance in which the specific subtype field 41 is not used or not defined in the management frame, for example, and the power 20 management bit 43 is set to 1, an AP (e.g., AP 11) may activate a power control phase for one or more corresponding STAs (e.g., STA 17).

In an alternative example embodiment, in an LTE-type system, the TPC information may be conveyed, by a network device (e.g., eNB 12), in the system information such as, for example, in a Master Information Block (MIB) and/or a 25 System Information Block (SIB). Alternatively, the network device (e.g., eNB 12) may configure the UE specific parameters via dedicated Radio Resource Control (RRC) signaling.

Additionally, the TPC information may be carried, for example, via a direct device-to-device communication interface in LTE or via Over The Air 30 Communication (OTAC) interface between local LTE access points. The implementation of such interfaces and the conveying of the aforementioned TPC

27

information may not necessarily depend on the exact format of the utilized transmission.

Referring now to FIG. 9, a flowchart of an example embodiment of managing transmission power in a shared spectrum of an unlicensed band is provided. At 5 operation 900, an apparatus (e.g., AP 11) may include means, such as the processing circuitry 32, the processor 34, or the like, for determining whether one or more devices (e.g., AP 15, STA 19, STA 21, STA 23, STA 25) of respective systems (e.g., system B of FIG 5, system C of FIG. 5, etc.) of a local area network are detected as communicating via a shared spectrum of an unlicensed band (e.g., unlicensed band 10 18). At operation 905, an apparatus (e.g., AP 11) may include means, such as the processing circuitry 32, the processor 34, or the like, for obtaining a plurality of sensing results indicating a power in which at least a set of communication devices (e.g., AP 11, STA 17, etc.) of a first system (e.g., system A of FIG. 5) of the local area network are transmitting data via the shared spectrum. At operation 910, an apparatus 15 (e.g., AP 11) may include means, such as the processing circuitry 32, the processor 34, or the like, for comparing the sensing results to a predetermined threshold to determine whether to utilize transmission power control to reduce transmission power for transmissions between the communication devices.

Optionally, at operation 915, an apparatus (e.g., AP 11) may include means, 20 such as the processing circuitry 32, the processor 34, or the like, for determining whether a transmission of a device(s) (e.g., AP 15, STA 19, etc.) of the respective systems interferes with communications of the apparatus via the shared spectrum in response to detecting the device(s). The apparatus (e.g., AP 11) may determine that the transmissions of the device(s) interfere with the communications of the apparatus 25 in an instance in which a signal strength of the transmissions(s) of the device(s) exceeds a predefined threshold. Optionally, at operation 920, the apparatus (e.g., AP 11) may include means, such as the processing circuitry 32, the processor 34, or the like, for sending a generated message (e.g., a TPC request) to the device(s) (e.g., AP 15, STA 19, etc.) to enable the device(s) to determine whether to utilize TPC to 30 reduce a transmission power for communications of the device(s). The generated message may include information indicating that the apparatus utilizes TPC and

28

currently operates with reduced transmit power. In response to receipt of the generated message the device(s) may, but need not, utilize TPC to transmit with reduced power.

It should be pointed out that FIG. 9 is a flowchart of a system, method and 5 computer program product according to an example embodiment of the invention. It will be understood that each block of the flowchart, and combinations of blocks in the flowchart, can be implemented by various means, such as hardware, firmware, and/or a computer program product including one or more computer program instructions. For example, one or more of the procedures described above may be embodied by 10 computer program instructions. In this regard, in an example embodiment, the computer program instructions which embody the procedures described above are stored by a memory device (e.g., memory 26, memory 36) and executed by a processor (e.g., processor 24, processor 34). As will be appreciated, any such computer program instructions may be loaded onto a computer or other programmable 15 apparatus (e.g., hardware) to produce a machine, such that the instructions which execute on the computer or other programmable apparatus cause the functions specified in the flowchart blocks to be implemented. In one example embodiment, the computer program instructions are stored in a computer-readable memory that can direct a computer or other programmable apparatus to function in a particular manner, 20 such that the instructions stored in the computer-readable memory produce an article of manufacture including instructions which implement the function specified in the flowchart blocks. The computer program instructions may also be loaded onto a computer or other programmable apparatus to cause a series of operations to be performed on the computer or other programmable apparatus to produce a computer-25 implemented process such that the instructions which execute on the computer or other programmable apparatus implement the functions specified in the flowchart blocks.

Accordingly, blocks of the flowchart support combinations of means for performing the specified functions. It will also be understood that one or more blocks 30 of the flowchart, and combinations of blocks in the flowchart, can be implemented by

29

special purpose hardware-based computer systems which perform the specified functions, or combinations of special purpose hardware and computer instructions. In an example embodiment, an apparatus for performing the methods of FIG. 9 above may comprise a processor (e.g., the processor 24, the processor 34) configured to 5 perform some or each of the operations (900 - 920) described above. The processor may, for example, be configured to perform the operations (900 - 920) by performing hardware implemented logical functions, executing stored instructions, or executing algorithms for performing each of the operations. Alternatively, the apparatus may comprise means for performing each of the operations described above. In this 10 regard, according to an example embodiment, examples of means for performing operations (900 - 920) may comprise, for example, the processor 24 (e.g., as means for performing any of the operations described above), the processor 34 and/or a device or circuit for executing instructions or executing an algorithm for processing information as described above.

15 Many modifications and other embodiments of the inventions set forth herein will come to mind to one skilled in the art to which these inventions pertain having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the inventions are not to be limited to the specific embodiments disclosed and that modifications and other embodiments are 20 intended to be included within the scope of the appended claims. Moreover, although the foregoing descriptions and the associated drawings describe example embodiments in the context of certain example combinations of elements and/or functions, it should be appreciated that different combinations of elements and/or functions may be provided by alternative embodiments without departing from the 25 scope of the appended claims. In this regard, for example, different combinations of elements and/or functions than those explicitly described above are also contemplated as may be set forth in some of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.

30

Claims

Claims

1. A method for managing transmission power comprising:

determining whether one or more devices of respective systems of a local area 5 network (LAN) are detected as communicating via a shared spectrum of an unlicensed band;

obtaining a plurality of sensing results indicating a power in which at least a set of communication devices comprising at least a first communication device and a second communication device of a first system of the LAN are transmitting data via 10 the shared spectrum; and comparing the sensing results to a predetermined threshold to determine whether to utilize transmission power control (TPC) to reduce transmission power for transmissions between the communication devices.

15 2. The method of claim 1, further comprising:

determining to utilize TPC to reduce a transmission power for communications between the communication devices via the shared spectrum in response to determining that a first sensing result corresponding to the first communication device of the set and a second sensing result corresponding to the 20 second communication device of the set are below the predetermined threshold in an instance in which the devices of the respective systems are undetected.

3. The method of claim 1, further comprising:

determining to utilize TPC to reduce a transmission power for transmissions of 25 the second communication device of the set in response to determining that a first sensing result corresponding to the first communication device of the set is below the predetermined threshold and that a second sensing result corresponding to the second communication device is above the predetermined threshold in an instance in which the devices of the respective systems are undetected.

30

4. The method of claim 1, further comprising:

31

determining to utilize TPC to reduce a transmission power for transmissions of a first communication device of the set in response to determining that a first sensing result corresponding to the first communication device is above the predetermined threshold and that a second sensing result corresponding to a second communication 5 device of the set is below the predetermined threshold in an instance in which the devices of the respective systems are undetected.

5. The method of any one of claims 1 to 4, wherein determining whether the devices of the respective systems are detected comprises determining whether

10 energy is detected on the shared spectrum or whether one or more messages are detected from at least one of the devices of the respective systems.

6. The method of claim 1, further comprising:

determining whether a transmission of at least one of the devices of the

15 respective systems interferes with communications of the first communication device via the shared spectrum in response to detecting the at least one device.

7. The method of claim 6, wherein detecting the at least one device comprises detecting a beacon transmission of the device.

20

8. The method of any one of claims 6 or 7, further comprising:

determining that the transmission of the device interferes with the communications of the first communications device in an instance in which a signal strength of the transmission of the device exceeds a predefined threshold.

25

9. The method of claim 6, further comprising:

generating a message comprising information indicating that the first communication device of the set utilizes TPC and is currently operating with reduced power in response to determining that the transmission of the device interferes with

30 the communications of the first communication device; and

32

directing provision of the generated message to the device to enable the device to determine whether to utilize TPC to reduce a transmission power for communications of the device.

5 10. The method of claim 6, further comprising:

directing provision of a message, indicating that the first communication device utilizes TPC, to the device to cause the device to determine to utilize TPC to reduce a transmission power for communications of the device,

wherein the message is generated in response to determining that the 10 transmission of the device interferes with the communications of the first communication device via the shared spectrum.

11. The method of claim 6, further comprising:

generating a message comprising information indicating that the first 15 communication device utilizes TPC, is currently operating with reduced power, and suggests the device to utilize TPC, in response to determining that the transmission of the device interferes with communications of the first communication device via the shared spectrum; and directing provision of the generated message to the device to enable the device 20 to determine whether to utilize TPC to reduce a transmission power for communications of the device.

12. The method of claim 11, further comprising:

setting a transmission power, for at least one of the first communication device 25 or the second communication device, to a high transmit power in an instance in which the device does not respond to the generated message, that suggested utilization of TPC, within a predetermined time period.

13.

The method of claim 11, further comprising:

33

receiving a response message from the device indicating that the device agrees to utilize TPC to reduce the transmission power of the device in response to the provision of the generated message.

5 14. The method of claim 11, further comprising:

receiving a response message from the device negotiating utilization of a transmit power other than a reduced transmit power associated with TPC in response to the provision of the generated message.

10 15. The method of claim 11, further comprising:

automatically determining that the device agrees to utilize TPC in response to the provision of the generated message, based in part on a defined protocol.

16. The method of claim 6, wherein the first communication device 15 comprises a first access point and the at least one device comprises a second access point or a mobile phone.

17. The method of claim 1, wherein the unlicensed band is deployed in a Long Term Evolution (LTE) system or a LTE-Advanced (LTE-A) system.

20

18. An apparatus for managing transmission power comprising a processing system arranged to cause the apparatus to:

determine whether one or more devices of respective systems of a local area network (LAN) are detected as communicating via a shared spectrum of an unlicensed 25 band;

obtain a plurality of sensing results indicating a power in which at least a set of communication devices comprising the apparatus and at least one first communication device of a first system of the LAN are transmitting data via the shared spectrum; and compare the sensing results to a predetermined threshold to determine whether to 30 utilize transmission power control (TPC) to reduce transmission power for transmissions between the communication devices.

34

19. The apparatus of claim 18, wherein the processing system is arranged to cause the apparatus to:

determine to utilize TPC to reduce a transmission power for communications 5 between the communication devices via the shared spectrum in response to determining that a first sensing result corresponding to the apparatus and a second sensing result corresponding to the first communication device of the set are below the predetermined threshold in an instance in which the devices of the respective systems are undetected.

10

20. The apparatus of claim 18, wherein the processing system is arranged to cause the apparatus to:

determine to utilize TPC to reduce a transmission power for transmissions of the first communication device of the set in response to determining that a first 15 sensing result corresponding to the apparatus of the set is below the predetermined threshold and that a second sensing result corresponding to the first communication device is above the predetermined threshold in an instance in which the devices of the respective systems are undetected.

20 21. The apparatus of claim 18, wherein the processing system is arranged to cause the apparatus to:

determine to utilize TPC to reduce a transmission power for transmissions of the apparatus of the set in response to determining that a first sensing result corresponding to the apparatus is above the predetermined threshold and that a second 25 sensing result corresponding to the first communication device of the set is below the predetermined threshold in an instance in which the devices of the respective systems are undetected.

22. The apparatus of any one of claims 18 to 21, wherein the processing 30 system is arranged to cause the apparatus to:

35

determine whether the devices of the respective systems are detected by determining whether energy is detected on the shared spectrum or whether one or more messages are detected from at least one of the devices of the respective systems.

5 23. The apparatus of claim 18, wherein the processing system is arranged to cause the apparatus to:

determine whether a transmission of at least one of the devices of the respective systems interferes with communications of the apparatus via the shared spectrum in response to detecting the at least one device.

10

24. The apparatus of claim 23, wherein the processing system is arranged to cause the apparatus to:

detect the at least one device by detecting a beacon transmission of the device.

15 25. The apparatus of any one of claims 23 or 24, wherein the processing system is arranged to cause the apparatus to:

determine that the transmission of the device interferes with the communications of the apparatus in an instance in which a signal strength of the transmission of the device exceeds a predefined threshold.

20

26. The apparatus of claim 23, wherein the processing system is arranged to cause the apparatus to:

generate a message comprising information indicating that the apparatus utilizes TPC and is currently operating with reduced power in response to determining

25 that the transmission of the device interferes with the communications of the apparatus via the shared spectrum; and direct provision of the generated message to the device to enable the device to determine whether to utilize TPC to reduce a transmission power for communications of the device.

30

36

27. The apparatus of claim 23, wherein the processing system is arranged to cause the apparatus to:

direct provision of a message, indicating that the apparatus utilizes TPC, to the device to cause the device to determine to utilize TPC to reduce a transmission power 5 for communications of the device wherein,

the message is generated in response to determining that the transmission of the device interferes with the communications of the apparatus via the shared spectrum.

10 28. The apparatus of claim 23, wherein the processing system is arranged to cause the apparatus to:

generate a message comprising information indicating that the apparatus utilizes TPC, is currently operating with reduced power and suggests the device to utilize TPC, in response to determining that the transmission of the device interferes 15 with communications of the apparatus via the shared spectrum; and direct provision of the generated message to the device to enable the device to determine whether to utilize TPC to reduce a transmission power for communications of the device.

20 29. The apparatus of claim 28, wherein the processing system is arranged to cause the apparatus to:

set a transmission power, for at least one of the apparatus or the first communication device, to a high transmit power in an instance in which the device does not respond to the generated message, that suggested utilization of TPC, within a 25 predetermined time period.

30. The apparatus of claim 28, wherein the processing system is arranged to cause the apparatus to:

receive a response message from the device indicating that the device agrees 30 to utilize TPC to reduce the transmission power of the device in response to the provision of the generated message.

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31. The apparatus of claim 28, wherein the processing system is arranged to cause the apparatus to:

receive a response message from the device negotiating utilization of a 5 transmit power other than a reduced transmit power associated with TPC in response to the provision of the generated message.

32. The apparatus of claim 28, wherein the processing system is arranged to cause the apparatus to:

10 automatically determine that the device agrees to utilize TPC in response to the provision of the generated message to the device, based in part on a defined protocol.

33. The apparatus of claim 23, wherein the apparatus comprises a first 15 access point and the at least one device comprises a second access point or a mobile phone.

34. The apparatus of claim 18, wherein the unlicensed band is deployed in a Long Term Evolution (LTE) system or a LTE-Advanced (LTE-A) system.

20

35. A computer readable medium for managing transmission power comprising a set of instructions, which, when executed on an apparatus causes the apparatus to perform the steps of:

determining whether one or more devices of respective systems of a local area 25 network (LAN) are detected as communicating via a shared spectrum of an unlicensed band;

obtaining a plurality of sensing results indicating a power in which at least a set of communication devices comprising the apparatus and at least one first communication device of a first system of the LAN are transmitting data via the 30 shared spectrum; and

38

comparing the sensing results to a predetermined threshold to determine whether to utilize transmission power control (TPC) to reduce transmission power for transmissions between the communication devices.

5 36. The computer readable medium of claim 35, further comprising instructions, which, when executed on the apparatus causes the apparatus to perform the additional steps of:

determining to utilize TPC to reduce a transmission power for communications between the communication devices via the shared spectrum in 10 response to determining that a first sensing result corresponding to the apparatus and a second sensing result corresponding to the first communication device of the set are below the predetermined threshold in an instance in which the devices of the respective systems are undetected.

15 37. The computer readable medium of claim 35, further comprising instructions, which, when executed on the apparatus causes the apparatus to perform the additional steps of:

determining to utilize TPC to reduce a transmission power for transmissions of the first communication device of the set in response to determining that a first 20 sensing result corresponding to the apparatus of the set is below the predetermined threshold and that a second sensing result corresponding to the first communication device is above the predetermined threshold in an instance in which the devices of the respective systems are undetected.

25 38. The computer readable medium of claim 35, further comprising instructions, which, when executed on the apparatus causes the apparatus to perform the additional steps of:

determining to utilize TPC to reduce a transmission power for transmissions of the apparatus of the set in response to determining that a first sensing result 30 corresponding to the apparatus is above the predetermined threshold and that a second sensing result corresponding to the first communication device of the set is below the

39

predetermined threshold in an instance in which the devices of the respective systems are undetected.

39. The computer readable medium of any one of claims 35 to 38, further 5 comprising instructions, which, when executed on the apparatus causes the apparatus to perform the additional steps of:

determining whether the devices of the respective systems are detected by determining whether energy is detected on the shared spectrum or whether one or more messages are detected from at least one of the devices of the respective systems.

10

40. The computer readable medium of claim 35, further comprising instructions, which, when executed on the apparatus causes the apparatus to perform the additional steps of:

determining whether a transmission of at least one of the devices of the 15 respective systems interferes with communications of the apparatus via the shared spectrum in response to detecting the at least one device.

41. The computer readable medium of claim 40, further comprising instructions, which, when executed on the apparatus causes the apparatus to perform

20 the additional steps of:

detecting the at least one device by detecting a beacon transmission of the device.

42. The computer readable medium of any one of claims 40 or 41, further 25 comprising instructions, which, when executed on the apparatus causes the apparatus to perform the additional steps of:

determining that the transmission of the device interferes with the communications of the apparatus in an instance in which a signal strength of the transmission of the device exceeds a predefined threshold.

30

40

43. The computer readable medium of claim 40, further comprising instructions, which, when executed on the apparatus causes the apparatus to perform the additional steps of:

generating a message comprising information indicating that the apparatus 5 utilizes TPC and is currently operating with reduced power in response to determining that the transmission of the device interferes with the communications of the apparatus via the shared spectrum; and causing directing of provision of the generated message to the device to enable the device to determine whether to utilize TPC to reduce a transmission power for 10 communications of the device.

44. The computer readable medium of claim 40, further comprising instructions, which, when executed on the apparatus causes the apparatus to perform the additional steps of:

15 causing directing of provision of a message, indicating that the apparatus utilizes TPC, to the device to cause the device to determine to utilize TPC to reduce a transmission power for communications of the device wherein,

the message is generated in response to determining that the transmission of the device interferes with the communications of the apparatus via the shared 20 spectrum.

45. The computer readable medium of claim 40, further comprising instructions, which, when executed on the apparatus causes the apparatus to perform the additional steps of:

25 generating a message comprising information indicating that the apparatus utilizes TPC, is currently operating with reduced power and suggests the device to utilize TPC, in response to determining that the transmission of the device interferes with communications of the apparatus via the shared spectrum; and causing directing of the provision of the generated message to the device to 30 enable the device to determine whether to utilize TPC to reduce a transmission power for communications of the device.

41

46. The computer readable medium of claim 45, further comprising instructions, which, when executed on the apparatus causes the apparatus to perform the additional steps of:

5 setting a transmission power, for at least one of the apparatus or the first communication device, to a high transmit power in an instance in which the device does not respond to the generated message, that suggested utilization of TPC, within a predetermined time period.

10 47. The computer readable medium of claim 45, further comprising instructions, which, when executed on the apparatus causes the apparatus to perform the additional steps of:

causing receipt of a response message from the device indicating that the device agrees to utilize TPC to reduce the transmission power of the device in 15 response to the provision of the generated message.

48. The computer readable medium of claim 45, further comprising instructions, which, when executed on the apparatus causes the apparatus to perform the additional steps of:

20 causing receipt of a response message from the device negotiating utilization of a transmit power other than a reduced transmit power associated with TPC in response to the provision of the generated message.

49. The computer readable medium of claim 45, further comprising 25 instructions, which, when executed on the apparatus causes the apparatus to perform the additional steps of:

automatically determining that the device agrees to utilize TPC in response to the provision of the generated message to the device, based in part on a defined protocol.

30

42

50. The computer readable medium of claim 40, wherein the apparatus comprises a first access point and the at least one device comprises a second access point or a mobile phone.

5 51. The computer readable medium of claim 35, wherein the unlicensed band is deployed in a Long Term Evolution (LTE) system or a LTE-Advanced (LTE-A) system.