MULTIPLE OPERATOR COORDINATION FOR TRANSMISSIONS IN AN UNLICENSED BAND

TECHNOLOGICAL FIELD

Embodiments of the present invention relate generally to wireless communication technology and, more particularly, to a method and apparatus for enabling coordination of transmissions of one or more operators in an unlicensed band of a communications system.

BACKGROUND

Mobile terminals routinely communicate within a licensed spectrum via 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 may experience increasing levels of interference or limited resources with the licensed spectrum potentially eventually becoming a bottleneck for such communications. Therefore, it may be necessary to enable cellular operations on license-exempt bands as well in suitable situations to help offload the traffic.

An increasing number of other network topologies are being integrated with cellular networks. For instance, there might already be some other network system or other cellular system operating in an unlicensed band. These other network topologies include, for example, wireless fidelity (WiFi) networks, ad hoc networks and various other local area networks. The terminals, either mobile or fixed, supported by these other network topologies may communicate with one another in an unlicensed spectrum, such as a licensed- exempt industrial scientific medical (ISM) radio band. The ISM radio band supports other non-cellular systems, such as 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 WiFi 802.11a systems operate. Though cellular technologies have not generally been deployed in the ISM band, such deployment could be considered for local-area Long 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 due to the large available bandwidths at suitable frequencies (e.g., TV spectrum in the 54 - 698 MHz range in the U.S.) 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).

In an instance in which an LTE system is deployed in a licensed band, the LTE system is typically designed for continuous transmission, since a

corresponding network operator may need to buy a certain spectrum for the network operator's usage. However, in order to deploy an LTE system in an unlicensed band, the spectrum is generally shared by different wireless systems or operators. In this regard, an LTE system may need to turn on/off its transmission on the unlicensed band from time to time to enable resource sharing or to meet a regulatory requirement of an unlicensed band.

Currently, multiple operators may attempt to deploy LTE unlicensed band transmission in the same location of an unlicensed band. As such, even if there are no other radio access techniques (RATs), the resource may be at least shared among base stations belonging to different operators. The sharing may be quite inefficient with the existing LTE structure as base stations of different operators are typically unable to coordinate with each other for usage of the shared spectrum. As such, there may be collisions and interference on the shared spectrum of the unlicensed band.

For instance, the base stations of different operators may virtually simultaneously determine that the shared spectrum of an unlicensed band is released and attempt to transmit on the spectrum at substantially the same time which may result in collisions on the spectrum. In this regard, random backoff, which typically forces a station to defer its access to the spectrum for a time period, may be utilized to reduce the instances in which stations access the spectrum at the same time to minimize potential collisions on the shared spectrum. However, the potential collisions as well as the random backoff typically results in poor spectrum efficiency which may offset the gains of the unlicensed band deployment. For example, in instances in which a number of stations of a communications system increases, there may be multiple stations attempting to access the shared spectrum at the same time even upon expiration of the random backoff time period. As such, one or more collisions may still occur on the shared spectrum of an unlicensed band even after a random backoff time period which typically results in poor spectrum efficiency.

In view of the foregoing drawbacks, it may be beneficial to provide an efficient and reliable mechanism of enabling multiple operator coordination for unlicensed band transmissions to enhance transmission reliability and spectrum sharing efficiency.

BRIEF SUMMARY OF EXAMPLE EMBODIMENTS

A method, apparatus and computer program product are therefore provided in accordance with an example embodiment to facilitate coordinating a plurality of operators' usage of an unlicensed band. In this regard, some example

embodiments may enable provision of broadcast coordination information on a dedicated coordination channel by a network device (e.g., a base station) currently running/operating in an unlicensed band. The broadcast coordination information may include, but is not limited to, data indicating a planned time that the network device is scheduled to be turned off in a medium (e.g., a channel(s)) of an unlicensed band and an indication of an operator of the network device. In some example embodiments, a broadcast coordination technique is provided that allows other network devices of one or more operators to analyze the broadcast

information provided on the dedicated coordination channel and attempt to access the medium of the unlicensed band at the time that the network device is scheduled to turn off.

In some other example embodiments, a virtual master coordination technique may be utilized. In this regard, one or more network devices (e.g., base stations) of one or more different operators may monitor the broadcast

coordination information provided on the dedicated coordination channel and may request a master network device (e.g., a master base station) to schedule access to the medium of the unlicensed band at the time that the network device is scheduled to turn off or a time subsequent to the time in which the network device is scheduled to turn off. In response to receipt of a message from the network device (e.g., the master base station) the one or more network devices (e.g., standby base stations) requesting access to the medium may access and utilize the medium of the unlicensed band at the turn off time of the network device or the time subsequent to the turn off time.

As such, some example embodiments may provide a unique multiple operator coordination protocol for a communications system (e.g., an LTE system) in an unlicensed band to enhance transmission reliability as well as the spectrum sharing efficiency of the unlicensed band.

In one embodiment, a method is provided that includes detecting an apparatus currently operating in a medium of an unlicensed band. The method of this embodiment also identifies at least one planned time that the apparatus is turned off in the medium of the unlicensed band and an indication of an operator of the apparatus. The method of this embodiment also enables provision of a plurality of items of broadcast coordination information to a dedicated

coordination channel. The items of broadcast coordination information include data indicating the planned time that the apparatus is turned off and the indication of the operator of the apparatus, to enable one or more of a plurality of network devices of respective operators to analyze the information on the channel and utilize the information to determine whether to attempt to access the medium of the unlicensed band at the time that the apparatus is turned off.

In another example embodiment, an apparatus is provided that includes at least one processor and at least one memory including computer program code with the at least one memory and the computer program code being configured to, with the processor, cause the apparatus to at least detect that the apparatus currently operates in a medium of an unlicensed band. The at least one memory and the computer program code of this embodiment are also configured to, with the processor, cause the apparatus to identify at least one planned time that the apparatus is turned off in the medium of the unlicensed band and an indication of an operator of the apparatus. The at least one memory and the computer program code of this embodiment are also configured to, with the processor, cause the apparatus to enable provision of a plurality of items of broadcast coordination information to a dedicated coordination channel. The items of broadcast coordination information include data indicating the planned time that the apparatus is turned off and the indication of the operator of the apparatus, to enable one or more of a plurality of network devices of respective operators to analyze the information on the channel and utilize the information to determine whether to attempt to access the medium of the unlicensed band at the time that the apparatus is turned off.

In a further example embodiment, an apparatus is provided that includes means for detecting that the apparatus currently operates in a medium of an unlicensed band. The apparatus of this embodiment also includes means for identifying at least one planned time that the apparatus is turned off in the medium of the unlicensed band and an indication of an operator of the apparatus. The apparatus of this embodiment also includes means for enabling provision of a plurality of items of broadcast coordination information to a dedicated

coordination channel. The items of broadcast coordination information include data indicating the planned time that the apparatus is turned off and the indication of the operator of the apparatus, to enable one or more of a plurality of network devices of respective operators to analyze the information on the channel and utilize the information to determine whether to attempt to access the medium of the unlicensed band at the time that the apparatus is turned off.

In yet another example embodiment, a computer program product is provided that includes at least one non-transitory computer-readable storage medium having computer-readable program instructions stored therein with the computer-readable program instructions including program instructions configured to detect that an apparatus operates in a medium of an unlicensed band. The computer-readable program instructions of this embodiment also include program instructions configured to identify at least one planned time that the apparatus is turned off in the medium of the unlicensed band and an indication of an operator of the apparatus. The computer-readable program instructions of this embodiment also include program instructions configured to enable provision of a plurality of items of broadcast coordination information to a dedicated coordination channel. The items of broadcast coordination information include data indicating the planned time that the apparatus is turned off and the indication of the operator of the apparatus, to enable one or more of a plurality of network devices of respective operators to analyze the information on the channel and utilize the information to determine whether to attempt to access the medium of the unlicensed band at the time that the apparatus is turned off.

In another example embodiment, a method is provided that includes monitoring a plurality of items of broadcast coordination information provided to a dedicated coordination channel by a network device currently operating in a medium of the unlicensed band. The items of broadcast coordination information include data indicating a planned time that the network device is turned off and an indication of an operator of the network device. The method of this embodiment also analyzes the broadcast coordination information to determine whether to attempt to access the medium of the unlicensed band at the time that the network device is turned off.

In another example embodiment, an apparatus is provided that includes at least one processor and at least one memory including computer program code with the at least one memory and the computer code being configured to, with the processor, cause the apparatus to at least monitor a plurality of items of broadcast coordination information provided to a dedicated coordination channel by a network device currently operating in a medium of the unlicensed band. The items of broadcast coordination information include data indicating a planned time that the network device is turned off and an indication of an operator of the network device.

In a further example embodiment, an apparatus is provided that includes means for monitoring a plurality of items of broadcast coordination information provided to a dedicated coordination channel by a network device currently operating in a medium of the unlicensed band. The items of broadcast

coordination information include data indicating a planned time that the network device is turned off and an indication of an operator of the network device. The apparatus of this embodiment also includes means for analyzing the broadcast coordination information to determine whether to attempt to access the medium of the unlicensed band at the time that the network device is turned off.

In yet another example embodiment, a computer program product is provided that includes at least one non-transitory computer-readable storage medium having computer-readable program instructions stored therein with the computer-readable program instructions including program instructions configured to monitor a plurality of items of broadcast coordination information provided to a dedicated coordination channel by a network device currently operating in a medium of the unlicensed band. The items of broadcast coordination information include data indicating a planned time that the network device is turned off and an indication of an operator of the network device. The computer-readable program instructions of this embodiment also include program instructions configured to analyze the broadcast coordination information to determine whether to attempt to access the medium of the unlicensed band at the time that the network device is turned off. BRIEF DESCRIPTION OF THE SEVERAL VIEWS 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:

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 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 illustrating a collision avoidance with broadcast information in an unlicensed band according to an example embodiment of the invention;

FIG. 6 is a diagram illustrating a broadcast information channel of an unlicensed band according to an example embodiment of the invention;

FIG. 7 illustrates a flowchart for coordinating a plurality of operators' usage of an unlicensed band according to an example embodiment of the invention; and

FIG. 8 illustrates a flowchart for coordinating a plurality of operators' usage of an unlicensed band according to another example embodiment of the 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 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 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: (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 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 "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 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.

As referred to herein, in some example embodiments random backoff may, but need not refer to, a time period or time interval that a station (e.g., a base station) defers its transmission on a medium (e.g., a channel(s), a spectrum) of an unlicensed band in response to a detection that the medium is busy or that another station is simultaneously attempting to access the medium of the unlicensed band.

As referred to herein, an operating evolved node B (eNB), or a running eNB may denote an eNB that is currently running or being utilized on a medium of an unlicensed band. Additionally, as referred to herein, a standby eNB(s) may refer to an eNB(s) that may monitor broadcast coordination information on a dedicated coordination channel.

In some example embodiments, in order to provide deployment of a communication system (e.g., a LTE system) in an unlicensed band to minimize the impact of interference or blocking of other systems (e.g., a WiFi system, a WLAN system), an example embodiment may provide a flexible time sharing scheme on an unlicensed band in which a base station may generate planned ON and OFF durations. During the planned ON duration(s), the base station may utilize (e.g., transmit or communicate data) on the unlicensed band. On the other hand, during the planned OFF duration(s), the base station may not communicate or transmit (e.g., an LTE transmission(s)) data in the unlicensed band.

Referring now to FIG. 1, in accordance with an example embodiment of the invention, a communication system is provided in which a network entity, such as, for example, an access point, a base station, an evolved node B (eNB) or the like, may utilize carrier aggregation and in this regard may communicate with a licensed band carrier(s) as well as an unlicensed band carrier(s).

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 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 in a license- exempt band 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 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 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 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 embodiments, the first terminals 14 may communicate with the eNB 12 and/or an access point (AP) 3 (e.g., a WiFi AP, a wireless local area network (WLAN) AP)) 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, 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 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 technologies.

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-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 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 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 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 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 hardware/software to enable communication with other devices.

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 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 and/or one or more other eNBs (e.g., other eNBs 12). While one embodiment of the apparatus is illustrated and described below, 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 described herein.

As shown in FIG. 3, the apparatus 20 may include or otherwise be in 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 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 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.

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 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 (e.g., an LTE eNB).

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 and/or one or more other eNBs (e.g., other eNBs 12). 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 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 WiFi modem, WLAN 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.

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 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, 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 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 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 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 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 user equipment (UE) 14) 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 non-cellular

communications, with another terminal (e.g., second terminal 16, AP 3). 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 described herein.

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 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 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 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 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.

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 input/output mechanisms.

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 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 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 a 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 WiFi modem, WLAN modem, 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 (e.g., second terminals 16 (e.g., a WiFi station, a WLAN station, etc.), as well as AP 3, or any other suitable devices.

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

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, 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 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 may specifically configure the processor to perform the operations described herein. In some example embodiments, operator coordination schemes are provided which enable efficient and reliable coordination of transmissions on an unlicensed band by various different operators to enhance the transmission reliability and the spectrum sharing efficiency. For example, in one example embodiment, a broadcast coordination technique may be utilized by an eNB to coordinate different systems or operators in an unlicensed band. In this regard, a currently running eNB (e.g., eNB 12) may broadcast coordination information on a newly defined dedicated coordination channel on a downlink dedicated or shared physical resource. In this regard, the eNB providing broadcast coordination information to the dedicated coordmation channel may communicate broadcast information to one or more UEs or other eNBs. The currently running eNB may be an eNB currently transmitting/communicating on an unlicensed band (e.g., unlicensed band 18). The broadcast information transmitted to the dedicated channel by the eNB may include, but is not limited to, an operator identifier (ID) of the eNB, uplink link information, the on duration(s) of the eNB remaining in the unlicensed band, a planned off duration(s) of the eNB in the unlicensed band, load information, coordmation related broadcast transmission patterns (e.g., periodicity, pattern(s), etc.), other carriers/channels the eNB is running on or aware of, on/off durations, load or other information of those channels, and any other suitable data.

One or more standby eNBs (e.g., eNBs 12 (e.g., LTE eNBs)) may monitor or read the broadcast information on the dedicated coordination channel and may perform one or more actions based in part on using this information. For example, a standby eNB(s) may utilize the unlicensed band based in part on information on the dedicated coordination channel indicating that the unlicensed band is free/available or at an instance in which the unlicensed band may be free/available upon expiration of a planned on duration of an eNB currently operating on the unlicensed band, as described more fully below.

The uplink link information (also referred to herein as uplink channel information) of the broadcast information provided to the dedicated coordination channel by an eNB currently operating on the unlicensed band may relate to an uplink channel in which one or more standby eNBs may utilize to reply to communications of a master eNB. The on duration left information may denote or specify to one or more other eNBs (e.g., other eNBs 12) a time in which an eNB (e.g., eNB 12) that is currently turned on and using the unlicensed band is scheduled to turn off communications on the unlicensed band (e.g., unlicensed band 18) and may indicate a time in which the eNB may turn back on communications on the unlicensed band after a predefined delay. In this regard, one or more other eNBs may be informed as to instances in which the eNB using the unlicensed band may be turned off and that the unlicensed band (e.g., unlicensed band 18) may be free/available. The information related to the planned off duration of the eNB using the unlicensed band may specify or denote a time(s) in which the eNB is scheduled to be turned off on the unlicensed band. In this regard, one or more eNBs analyzing the planned off duration information on the dedicated coordination channel may be informed regarding an instance(s) in which the eNB occupying the unlicensed band is scheduled to be turned off, which may indicate when the unlicensed band may be free and available for usage.

The load information may indicate to one or more other eNBs the amount of data that an eNB is using or has in a buffer status for transmission, an amount of delay that the eNB has experienced in transmitting data and any other suitable information.

The information indicating the coordination related broadcast transmission patterns may specify or indicate the sequence or patterns (e.g., periodicity) in which the eNB using the unlicensed band is transmitting. In this regard, the coordination related broadcast transmission patterns may indicate the timing of a next broadcast(s). For instance, information of the coordination related broadcast transmission patterns may denote or specify to other eNBs (e.g., other standby eNBs) instances in which a next broadcast transmission, or subsequent broadcasts, by the eNB (e.g., eNB 12) using or occupying the unlicensed band (e.g., unlicensed band 18) may occur. As such, the eNBs monitoring the dedicated coordination channel may be informed of the timing of a next broadcast (e.g., a next

coordination information broadcast). The coordination related broadcast transmission patterns may also denote the type of coding or modulation used by an eNB for broadcasts/transmissions. The information indicating the other carriers/channels that the eNB is running on or utilizing may indicate load information for these carriers/channels. For instance, an entire spectrum may be divided into multiple channels and an eNB (e.g., eNB 12) may be running on/using several of the channels while another eNB may also be running on/using one or more of these channels. In this regard, in an instance in which an eNB (e.g., eNB 12) that is communicating on an unlicensed band is also communicating on one or more different channels, the eNB may provide information related to these multiple channels to the dedicated

coordination channel. As such, broadcasting information may include information related to a current channel of an unlicensed band (e.g., unlicensed band 18) being utilized as well as other channels of the unlicensed band. The eNBs monitoring the dedicated coordination channel may be informed of one or more the conditions of all, or a subset, of the channels of a spectrum.

For purposes of illustration and not of limitation, consider an example in which there are two channels of a spectrum (e.g., of an unlicensed band) and an eNB is communicating on channel 1 but the traffic load may be light so the eNB may not be communicating on channel 2. In this regard, the eNB may broadcast the traffic information on channel 1 and may provide data to the dedicated coordination channel indicating the broadcast on channel 1, but may specify that the eNB is not busy (e.g., not communicating) on channel 2. As such, for example, one or more other standby eNBs may analyze this information on the dedicated coordination channel and may determine that channel 2 may be free/available rather than waiting for channel 1 to become free. In this manner, an eNB operating on an unlicensed band may provide information as to the status of other channels. The standby eNBs may correspond to eNBs of different operators or alternatively at least a subset of the standby eNBs may correspond to eNBs of different operators.

As described above, one or more standby eNBs may monitor or read the broadcast information on the dedicated coordination channel and may perform one or more actions based on the broadcast information. For example, one or more standby eNBs may start transmissions simultaneously at the time in which the broadcast information indicates that the planned on duration of an operating eNB (e.g., eNB 12), communicating on the unlicensed band, ends. In other words, the one or more standby eNBs may start transmissions simultaneously to attempt to communicate on the unlicensed band when the planned on duration for the operating eNB ends. Since the standby eNBs are not communicating with each other but rather monitoring the dedicated coordination channel, each of the standby eNBs may be unaware of the attempt of other standby eNBs to communicate on the unlicensed band.

In this regard, random backoff may be used by each of the standby eNBs to reduce possible collisions on the unlicensed band among operators. For purposes of illustration and not of limitation, consider an example in which an eNB operates/communicates on the unlicensed band and provides broadcast information (also referred to herein as broadcast coordination information) to the dedicated coordination channel. Consider further that two eNBs (e.g., two standby eNBs) are monitoring the dedicated coordination channel and the broadcast information on the dedicated coordination channel indicates an instance in which the operating eNB is scheduled to turn off on the unlicensed band. As such, the two eNBs may determine that the unlicensed band is about to be free when the operating eNB (e.g., eNB 12) turns off its communications on the unlicensed band, although the two eNBs may be unaware of each other.

At the time in which the operating eNB (e.g., eNB 12) turns off its communications on the unlicensed band (e.g., unlicensed band 18), the two eNBs may attempt to use the unlicensed band simultaneously which may cause a collision. The processor (e.g., processor 24) of the two eNBs may detect this collision based in part on a detection of a high power on the unlicensed band, which may denote or indicate a potential collision/interference. In this regard, each of the processors (e.g., processors 24) of the two eNBs may determine that there is another eNB of another operator attempting to use the spectrum of the unlicensed band. As such, the processors of the two eNBs may select a random value/number within a predefined range and may wait a time period associated with the generated random value/number before taking any further action. Upon expiration of the time period, the two eNBs may attempt to utilize the unlicensed band again.

For example, presume that the predefined range is 10 and the first eNB of the two eNBs selects a random number of 4 and that the second of the two eNBs selects a random number of 6. As such, the first eNB may wait, for example, four frames, and the second eNB may wait, for example, six frames before attempting transmission. Since the time period associated with the four frames may expire before the time period associated with six frames, in this example, the first eNB may begin transmissions on the unlicensed band before the second eNB. Upon expiration of the four frames the first eNB may start transmitting on the unlicensed band and may also transmit broadcast information to the dedicated coordination channel. In this regard, the second eNB may analyze the data on the dedicated coordination channel and determine an instance in which the planned on duration of the first eNB is scheduled to end. The second eNB may utilize the unlicensed band in an instance in which the first eNB is turned off on the unlicensed band.

Although random backoff may be utilized to reduce possible collisions among operators (e.g., eNBs of different operators) in this example embodiment, a collision(s) may still occur on the unlicensed band, for example, in instances in which a number of stations (e.g., eNBs, UEs), of a communications system, contending for access to the spectrum of unlicensed band increases. For example, in instances in which a large number of stations contend for usage of the spectrum of the unlicensed band there is a greater chance that the stations may attempt to access the unlicensed band simultaneously even upon expiration of a random backoff time period which may cause a collision on the unlicensed band.

In another example embodiment, a virtual master coordination technique may be utilized to coordinate different operators or systems usage of an unlicensed band in a communications system. The virtual master coordination technique may overcome the potential issue of a collision due to random backoff.

In one example embodiment, a virtual master eNB (also referred to herein as master eNB) may be selected/designated to make a resource allocation for all present standby eNBs of one or more operators based in part on analyzing collective information. The processor (e.g., processor 24) of an eNB may determine whether an eNB is selected/designated as a virtual master eNB based in part on analyzing a current channel and/or a group of carriers or channels aggregated in unlicensed band (e.g., unlicensed band 18). For example, in an instance in which a processor (e.g., processor 24) of an eNB (e.g., eNB 12) determines that the eNB is currently occupying/communicating on an unlicensed band, the processor may designate/select the corresponding eNB as the virtual master eNB. The master eNB (e.g., master eNB 12) may broadcast coordination information to a dedicated coordination channel in a manner analogous to that described above. For instance, the master eNB may broadcast coordination information on the dedicated coordination channel including, but not limited to, an operator DD of the master eNB, uplink link information, an on duration left of the master eNB, a planned off duration of the eNB, load information, coordination related broadcast transmission patterns (e.g., periodicity, a pattern(s) (e.g., a flexible sharing pattern(s)), etc.), other carriers/channels the master eNB is operating running on or aware of, an on/off duration(s), load or other information of the channels/carriers, or any other suitable data. Additionally, the master eNB may broadcast or transmit its uplink resource allocation for potential requests for transmission to the dedicated coordination channel. The uplink resource allocation may correspond to a spectrum resource(s) that the master eNB may utilize for standby eNBs to communicate with the master eNB. For purposes of illustration and not of limitation, the uplink resource allocation may correspond to a 10 MHz uplink resource in which 1 MHz is dedicated for operator coordination of eNBs for using the unlicensed band and the other 9 MHz may be utilized for normal data transmissions, control information or any other suitable purpose(s). In this example, the 1 MHz uplink resource may be utilized by one or more standby eNBs to communicate with the master eNB.

The requests for transmission may be received from one or more standby eNBs (e.g., one or more other eNBs 12) that desire to utilize the unlicensed band. The standby eNBs may correspond to eNBs of different operators or alternatively at least a subset of the standby eNBs may correspond to eNBs of different operators. Each of the standby eNBs may first detect the virtual master eNB 's broadcast information on the dedicated coordination channel and may then transmit a request(s) to the virtual master eNB on the allocated resource (e.g., an uplink resource allocation (e.g., a channel)). The transmitted request(s) of the standby eNBs to the master eNB may include, but is not limited to, content such as for example, load information, requested resource or duration information, an uplink resource of the standby eNB for a request of feedback transmission, an operator ID (e.g., an ED of a cellular operator) of the standby eNB, and any other suitable information. The uplink resource of the standby eNB for the request of feedback transmission may be a channel, spectrum or the like for the master eNB to provide feedback to the standby eNB that the request for using the unlicensed band is received by the master eNB. The feedback transmission may be an acknowledgement from the master eNB that the request, from the standby eNB, to use the unlicensed band is received by the master eNB.

In response to receipt of one or more transmit requests from one or more standby eNBs, the master eNB may collect the requests and may broadcast one or more decisions in reply to the requests. The decision(s) may specify one of the standby eNBs, which is selected by a processor (e.g., processor 24) of master eNB, to be the next master eNB. The decision(s) may include, but is not limited to, the following information: a next master's operator ID (e.g., an ID of a cellular operator); an on duration left for a current transmission of the master eNB; a sharing pattern(s) for a next period (e.g., an operator order, a duration and frequency/time resource sharing pattern(s), etc.); or any other suitable information.

The processor (e.g., processor 24) of the master eNB may determine the broadcast decision based in part on analyzing the received requests from the standby eNBs. For instance, consider an example in which the master eNB receives three requests from respective standby eNBs to utilize the unlicensed band. In this regard, the processor of the master eNB may analyze the data of the received requests and may designate a standby eNB that has the longest planned on duration or the most data to transmit on the unlicensed band as the next master eNB. In this regard, the processor (e.g., processor 24) of the master eNB may provide an acknowledgement to the corresponding standby eNB informing the standby eNB that it may utilize the unlicensed band after an on duration of the master eNB ends and that the standby eNB may be the next master eNB upon expiration of the on duration of the current master eNB.

Although, the master eNB may designate one standby eNB as the next master eNB, the current master eNB may send acknowledgments to one or more standby eNBs denoting to the standby eNBs that they may utilize the unlicensed band upon the expiration of a planned on duration of the current master eNB, For example, in an instance in which the processor of the master eNB determines that there is a sharing pattern(s) among standby eNBs, in which the corresponding standby eNBs are planned to be on in the unlicensed band at different times, the processor of the master eNB may send acknowledgements to one or more of these standby eNBs. The processor of the master eNB may determine that there is a sharing pattern(s) among the standby eNBs by analyzing data in the received requests sent from the standby eNBs.

As an example in which the master eNB may send multiple

acknowledgements to standby eNBs indicating that the standby eNBs may utilize the unlicensed band, consider an instance in which the master eNB analyzes a sharing pattern for a 10 MHz unlicensed band. In this example, the master eNB may specify that multiple eNBs may utilize the unlicensed band upon the expiration of an on duration of the master eNB on the unlicensed band. Moreover, in this example, presume that the master eNB receives two requests from two standby eNBs of two different operators. Based on analyzing data of the sharing pattern, the processor of the master eNB may assign the first standby eNB to utilize 5 MHz of the 10 MHz unlicensed band and the second standby eNB to utilize the other 5 MHz of the 10 MHz unlicensed band. Alternatively, the processor of the master eNB may enable sharing of the spectrum of the unlicensed band by the two standby eNBs based on time multi lexing. For instance, the processor of the master eNB may determine that the first standby eNB may utilize the unlicensed band during a first time period (e.g., a first 10 ms time period) and that the second eNB may utilize the unlicensed band for a second time period (e.g., a second 10 ms time period). In this regard, multiple standby eNBs of different operators (e.g., cellular operators) may share the spectrum of the unlicensed band upon the expiration of the on duration of the master eNB. In some other example embodiments, the master eNB may designate one standby eNB to occupy the spectrum of the unlicensed band upon the expiration of the on duration of the master eNB. As such, in an instance in which the on duration of master eNB ends, the planned candidate eNBs may start transmission based on the determined sharing pattern.

As described above, one of the standby eNBs among the candidate eNBs may be determined by the processor of the master eNB to be the next master eNB. In this regard, the selection of the next master, by the current master eNB, may be based on coverage overlapping, a scheduled on duration (e.g., a standby eNB with the longest scheduled on duration) or any other suitable manner (e.g., a standby eNB with the most data to transmit on the unlicensed band may be selected as the next master eNB). In an example embodiment, the processor of the master eNB may determine that a standby eNB may be the next master eNB based in part on analyzing coverage overlapping by determining which standby eNBs sending requests to the master eNB have a greater coverage overlapping area (also referred to herein as cell coverage overlapping area). For example, consider an instance in which there are three standby eNBs that sent requests to the master eNB. In this example, presume that a first eNB of the standby eNBs is in a cell (e.g., a middle cell) that overlaps the coverage area of the cells (e.g., cells at the edges of the middle cell) of the other two eNBs whereas the other two eNBs cell coverage areas do not overlap any of the cell coverage areas of other standby eNBs. In this regard, the processor of the master eNB may designate the first eNB as the next master eNB. The processor of the master eNB may designate the first eNB as the next master eNB since the two eNBs may listen to the broadcast information of the first eNB given that the coverage area of the first eNB overlaps both of the cell coverage areas of the two eNBs.

In an example embodiment, an eNB operating/communicating on the unlicensed band may also broadcast coordination information to the dedicated coordination channel indicating the status of other carriers/channels that eNB is aware of and/or is utilizing. The status may indicate whether the other

carriers/channels are busy or free/available, for example.

The broadcast coordination technique and the virtual master coordination technique of the example embodiments enable provision of a multiple operator coordination on an unlicensed band based in part on utilizing a new channel dedicated for this multiple operator coordination. Additionally, the example embodiments of the broadcast coordination technique and/or the virtual master coordination technique may provide on/off duration based scheduling, centralized coordination by a virtual master eNB, as well as capability of pattern based sharing for coordinating multiple operators usage of an unlicensed band.

Referring now to FIG. 5, a diagram illustrating a collision avoidance based on utilizing broadcast coordination information is provided according to an example embodiment. In FIG. 5, a broadcast coordination technique according to an example embodiment is utilized to coordinate usage of an unlicensed band (e.g., unlicensed band 18) by eNBs of multiple operators A, B, and C. In the example embodiment of FIG. 5, an eNB (e.g., an eNB 12) of an operator A may be broadcasting information. As such, the eNB of the operator A may provide control information/signaling on a Physical Downlink Control Channel (PDCCH) 9. Additionally, the eNB of operator A may be communicating on an unlicensed band. In this regard, the eNB (e.g., eNB 12) may provide broadcast coordination information in a dedicated coordination channel on a downlink or shared physical resource (e.g., a downlink channel). The eNB of the operator A may include items of broadcast coordination information 3, 5 on the dedicated coordination channel indicating that the eNB of the operator A is planned to utilize the unlicensed band for two subframes (SFs). In this regard, an eNB (e.g., another eNB 12) of operator B and an eNB (e.g., another eNB 12) of operator C may monitor or read the dedicated coordination channel and may analyze the items of broadcast coordination information 3, 5 and may determine that the eNB of operator A is planned to turn off on the unlicensed band after two subframes.

In other words, an eBN of operator B and an eNB of operator C may listen to this broadcast coordination information 3, 5 on the dedicated coordination channel and as such by analyzing the broadcast coordination information 3, 5 the eNB of operator B and the eNB of the operator C may know when operator A turns off in the unlicensed band. After the two subframes the eNB of operator B and the eNB of operator C may sense simultaneous attempts to access the unlicensed band. In this regard, the processor (e.g., processor 24) of the eNB of operator B and the processor (e.g., processor 24) of the eNB of operator C may each select a random backoff value (also referred to herein as random delay). In the example embodiment of FIG. 5, the processor of the eNB of operator B selects a random backoff value of one subframe and the processor of the eNB of operator C selects a random backoff value of three subframes.

As such, the processor of the eNB of operator B plans to start transmitting on the unlicensed band after three subframes (e.g., a random backoff of one subframe after two subframes in which operator A is turned on). Additionally, the processor of the eNB of operator C plans to start transmitting on the unlicensed band after five subframes (e.g., a random backoff of three subframes after two subframes in which operator A is turned on). After the third subframe, the processor of the eNB of operator B may analyze the spectrum of the unlicensed band to ensure that the spectrum is free/available. In this example embodiment, the processor of the eNB of operator B determines that the spectrum of the unlicensed band is free/available and the eNB of operator B starts transmission on the unlicensed band after the third subframe. In this regard, the processor of the eNB of operator B provides items of broadcast coordination information 2, 4 on the dedicated coordination channel on a downlink dedicated or shared physical resource such as, for example, a downlink channel. The items of broadcast coordination information 2, 4 on the dedicated coordination channel may indicate that the eNB of operator B is planned to utilize/transmit on the unlicensed band during subframes four and five. However, after the fifth subframe, the eNB of operator B is scheduled to turn off communications on the unlicensed band.

As such, upon the delay associated with three subframes (e.g., the random backoff) expiring, the processor of the eNB of operator C may listen or monitor the broadcast coordination information 2, 4 provided by the eNB of operator B to the dedicated coordination channel. Based in part on analyzing the broadcast coordination information 2, 4 on the dedicated coordination channel, the processor of the eNB of operator C may determine that the unlicensed band is scheduled to be free/available after a fifth subframe. In an instance in which the processor of the eNB of operator C determines that the unlicensed band is free/available after the fifth subframe, the eNB of operator C may begin transmitting on the unlicensed band.

Referring now to FIG. 6, a diagram illustrating broadcast coordination information on a dedicated control channel according to an example embodiment is provided. In this regard, FIG. 6 illustrates where broadcast coordination information may be placed in a dedicated coordination channel.

In the example embodiment of FIG. 6, a primary synchronization sequence (PSS) signal (also referred to herein as primary synchronization channel (P-SCH) and a secondary synchronization sequence (SSS) signal (also referred to herein as secondary synchronization channel (S-SCH)) may be continuously available (for example, in an LTE communications system) in a downlink carrier(s) or subframe(s). As such, in one example embodiment, an eNB currently occupying an unlicensed band or a master eNB may include the broadcast coordination information 6, 8, 11, 15 next/adjacent to the P-SCH or S-SCH of a downlink carrier(s) or subframe(s) to enable one or more standby eNBs to locate/detect the items of broadcast coordination information 6, 8, 11 and 15 on a dedicated coordination channel. In this manner, one or more standby eNBs may detect the broadcast information after synchronizing to the broadcast eNB by using the P- SCH and/or S-SCH. Synchronizing to the broadcast eNB by using the P-SCH and/or the S-SCH may denote that the standby eNB searches for sequences of

PSS/SSS in order to identify the frame timing of a running eNB. In this regard, the PSS and/or SSS may be seen as a reference of the frame timing. For example, the corresponding communications standard may define that the coordination information is placed two subframes after PSS/SSS. As the coordination information may be unknown to one or more standby eNBs, an eNB (e.g., eNB 12) may be unable to locate the coordination information directly. Instead, an eNB may know the predefined PSS/SSS (e.g., at least partly fixed with a limited number of possibilities). As such, in this example, an eNB may search for PSS/SSS first, then wait two subframes to decode the coordination information. In some other example embodiments, broadcast coordination information may also be transmitted over one or more Physical Downlink Shared Channel (PDSCH) regions, or may be dynamically scheduled by an eNB (e.g., a master eNB). However, dynamically scheduling broadcast coordination information by an eNB may require eNBs of another operator(s) (e.g., operator B or C) to access an operator (e.g., operator A) that may be currently utilizing an unlicensed band.

The example embodiment of FIG. 6 also illustrates two modes of operation corresponding to Time Division Duplex (TDD) and Frequency Division Duplex (FDD). As such, FIG. 6 illustrates an allocation of broadcast coordination information for both the TDD and FDD modes. Regarding FDD, FIG. 6 shows that there are ten subframes from 0 to 9. The items of broadcast coordination information 11 and 15 are next/adjacent to P-SCH and S-SCH in subframe 0 and sub frame 5, respectively. As such, a standby eNB(s) may locate/detect the broadcast information in subf ames 0 and 5. Subframe 1, 2, 3, 4, 6, 7, 8 and 9 may be utilized/taken by an eNB running/operating in the corresponding spectrum of these subframes according to the broadcast coordination technique or may be utilized taken by a master eNB. Although an eNB may be occupying subframes 6, 7, 8 and 9 the broadcast coordination information 15 in subframe 5 may indicate that the eNB may turn off communications in five subframes, which may denote/indicate to one or more standby eNBs that subframes 10 and 11 (not shown) ma be free/available for usage.

As shown in FIG. 6, items of broadcast coordination information 6, 8 may also be deployed, by an eNB of an operator in subframes 0 and 5 in a TDD mode.

Regarding the virtual master coordination technique, one or more standby eNBs may initially listen to the broadcast coordination information of a master eNB on a dedicated coordination channel, as described above. Based in part on analyzing the broadcast information, the standby eNBs may identify an uplink resource (e.g., a channel) reserved for sending transmitting requests to the master eNB. The requests may include data requesting usage of an unlicensed band that the master eNB is currently using to communicate. The broadcast coordination information of a master eNB may be located next adjacent to a P-SCH and or S- SCH in the manner described above with respect to FIG. 5. In one example embodiment, the uplink resource may be a Random Access Channel (RACH) channel, a dedicated Physical Uplink Shared Channel (PUSCH) resource or any other suitable uplink resource. As described above, the request(s) sent by one or more standby eNBs to a master eNB may include an uplink resource (e.g., an uplink channel) for feedback regardmg the request. In this regard, the master eNB may utilize the uplink resource for feedback to acknowledge the request and to indicate whether the corresponding standby eNB may utilize the unlicensed band.

As described above, an eNB currently running or operating in an unlicensed band may be selected as a master eNB. However, when no operator is running yet, an eNB may utilize a Carrier Sense Multiple Access (CSMA) like scheme to occupy the channel, and a successful eNB may initially become the master eNB. For example, in an instance in which there is no eNB

running/operating on an unlicensed band and then an eNB turns on in the unlicensed band, the eNB may attempt to listen to a broadcast, but it may fail to detect any broadcast because there may not be any broadcast available yet on the unlicensed band. However, the processor (e.g., processor 24) of the eNB may sense the spectrum on the unlicensed band and in an instance in which the processor of the eNB detects that the spectrum is free, the eNB may turn on and the processor of the eNB may designate the eNB as the master eNB.

As described above, the virtual master coordination technique of an example embodiment may generate one or more resource sharing decisions. For instance, the master eNB may collect/receive requests f om standby eNBs and make decisions for these multiple standby eNBs. In this manner, the decisions (also referred to herein as response messages) of the master eNB may mclude different formats of information to realize different use cases. For instance, the decisions may include different scheduling options.

In this regard, for example, in one example embodiment, the decisions of the master e-NB may, but need not, include cross- channel scheduling. As such, the decisions of the master eNB may include the scheduling for other channels in the unlicensed band. Thus, a channel such as, for example, a dedicated coordination channel may serve many channels which may reduce a lot of the signaling overhead. In other words, the master eNB may utilize a coordination channel to coordinate all the channels in the unlicensed band (e.g., unlicensed band 18).

Additionally, in some example embodiments, the decisions of the master e- NB may, but need not, include pattern based scheduling. For instance, instead of determining a certain resource allocation for a certain duration, the decision(s) of the master eNB may include one or more sharing patterns for several eNBs (e.g., multiple standby eNBs). For purposes of illustration and not of limitation, two eNBs may be scheduled by a master eNB to use Frequency Division Duplex (FDD), Time Division Duplex (TDD), Code Domain Division (CDD) or a hybrid to share a resource such as, for example, an unlicensed band.

For example, in an instance in which an unlicensed band corresponds to a

10 MHz frequency spectrum (e.g., in FDD) a master eNB may schedule two standby eNBs to share this unlicensed band. One eNB may be scheduled by the master eNB to utilize 5 MHz of the unlicensed band, and the other eNB may be scheduled to utilize the remaining 10 MHz of the unlicensed band. Alternatively, the master eNB may schedule the two eNBs to share the unlicensed band in the time domain (e.g., in TDD). For example, the master eNB may designate one of the eNBs to utilize the unlicensed band for a first 10 milliseconds and the master eNB may schedule the other eNB to utilize the unlicensed band during a second 10 milliseconds. Additionally, in an instance in which the load of one or more standby eNBs changes, the corresponding standby eNB may send an updated request to the master eNB indicating the load change(s). The master eNB may evaluate the information in the updated request associated with the load change(s) and may reschedule a sharing pattern(s). For purposes of illustration and not of limitation in an instance in which one standby eNB turns off or it has no data to transmit, this standby eNB may send another request to the master eNB indicating that it no longer has any load. As such, the master eNB may designate the unlicensed band to another busy standby eNB.

Referring back to FIG. 6, consider an example for the FDD operation mode according to the broadcast coordination technique in which a channel of an unlicensed band is taken by an eNB of operator A and the eNB of operator A plans to turn off at Subframe 10. As such, in subframe 0, the processor (e.g., processor 24) of the eNB of operator A may broadcast that there may be nine durations of on time remaining. The broadcast may be included in the broadcast coordination information 11 of subframe 0. Then at subframe 5, the processor of the eNB of operator A may broadcast information, in the item of broadcast coordination information 15, indicating that there is only four subframe durations on time remaining. As such, at subframe 10, an operator B or an operator C, for example may attempt to access the channel/spectrum of the unlicensed band. In an instance in which a random backoff of one subframe is selected by an eNB of operator B and a random backoff of three subframes is selected by an eNB of operator C, operator B may access/utilize the spectrum in subframe 11 and operator C may access/utilize the spectrum in subf ame 13.

For the virtual master coordination technique, consider an example in which during subframe 0, a master eNB of operator A is aware of operator B and operator C based on received requests from eNBs of operators B and C. The requests may include data requesting the master eNB to allow operators B and C to utilize the spectrum of an unlicensed band. As such, the master eNB may have already determined that operator B is designated to be the next master eNB, and may take the spectrum (e.g., a medium) of the unlicensed band next (e.g., upon expiration of an on time of the current master eNB). In this regard, the master eNB may provide an acknowledgment (e.g., a positive acknowledgement) on an uplink resource to the eNB of operator B indicating that the eNB of operator B may utilize the spectrum at subframe 10. Additionally or alternatively, the master eNB may provide a negative acknowledgment to the eNB of operator C on an uplink resource indicating to the eNB of operator C that it is not allowed to access/utilize the spectrum. As such, the eNB of operator C knows that there is no need to try to attempt access the spectrum. Γη addition, during subframe 0 the master eNB may also broadcast that the eNB of operator B is designated as the next master eNB at subframe 10. The broadcast that the eNB of operator B is designated as the next master eNB at subframe 10 may be included in the broadcast coordination information 11 in subframe 0.

Referring now to FIG. 7, a flowchart of an example embodiment of coordinating a plurality of operators' usage of an unlicensed band is provided. At operation 700, an apparatus (e.g., eNB 12 (e.g., an operating eNB, a master eNB)) may detect that the apparatus is currently operating in a medium of the unlicensed band (e.g., unlicensed band 18). At apparatus 705, an apparatus (e.g., an eNB 12) may identify at least one planned time that the apparatus is turned off (e.g., information indicating an on duration remaining, information indicating a lanned off duration) in the medium (e.g., a channel(s)) of the unlicensed band and an indication of an operator (e.g., operator A) of the apparatus.

At operation 710, an apparatus (e.g., an eNB 12) may provide a plurality of items of broadcast coordination information to a dedicated coordination channel. The items of broadcast coordination information may include, but is not limited to, data indicating the planned time that the apparatus is turned off and the indication of the operator of the apparatus to enable one or more network devices of respective operators to analyze the broadcast information on the channel and utilize the broadcast information to determine whether to attempt access to the medium at the time that the apparatus is turned off.

Referring now to FIG. 8, a flowchart of an example embodiment of coordinating a plurality of operators' usage of an unlicensed band is provided. At operation 800, an apparatus (e.g., an eNB 12 (e.g., a standby eNB)) may monitor a plurality of items of broadcast coordination information provided to a dedicated coordination channel by a network device (e.g., another eNB 12 (e.g., an operating eNB, a master eNB)) currently operating in a medium (e.g., a channel(s)) of the unlicensed band (e.g., unlicensed band 18). The items of broadcast coordination information include, but are not limited to, data indicating a planned time that network device is turned off (e.g., information indicating an on duration remaining, information indicating a planned off duration) and an indication of an operator (e.g., operator A) of the network device. At operation 805, an apparatus (e.g., a standby e B) may analyze the broadcast coordination information to determine whether to attempt to access the medium of the unlicensed band at the time that the network device is turned off.

It should be pointed out that FIGS. 7 and 8 are flowcharts of a system, method and computer program product according to an example embodiment of the invention. It will be understood that each block of the flowcharts, and combinations of blocks in the flowcharts, 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 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 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 flowcharts blocks to be implemented. In one 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, such that the instructions stored in the computer-readable memory produce an article of manufacture including instructions which implement the function specified in the flowcharts 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-implemented process such that the instructions which execute on the computer or other programmable apparatus implement the functions specified in the flowcharts blocks. Accordingly, blocks of the flowcharts support combinations of means for performing the specified functions. It will also be understood that one or more blocks of the flowcharts, and combinations of blocks in the flowcharts, can be implemented by 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 FIGS. 7 and 8 above may comprise a processor (e.g., the processor 24, the processor 34) configured to perform some or each of the operations (700 - 710, 800 - 805) described above. The processor may, for example, be configured to perform the operations (700 - 710, 800 - 805) 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 regard, according to an example embodiment, examples of means for performing operations (700 - 710, 800 - 805) 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.

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 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 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.