Patent Description:
Wireless communication systems are widely deployed to provide various types of communication content, such as voice, data, multimedia, and so on. Typical wireless communication systems are multiple-access systems capable of supporting communication with multiple users by sharing available system resources (e.g., bandwidth, transmit power, etc.). Examples of such multiple-access systems include Code Division Multiple Access (CDMA) systems, Time Division Multiple Access (TDMA) systems, Frequency Division Multiple Access (FDMA) systems, Orthogonal Frequency Division Multiple Access (OFDMA) systems, and others. These systems are often deployed in conformity with specifications such as Long Term Evolution (LTE) provided by the Third Generation Partnership Project (3GPP), Ultra Mobile Broadband (UMB) and Evolution Data Optimized (EV-DO) provided by the Third Generation Partnership Project <NUM> (3GPP2), <NUM> provided by the Institute of Electrical and Electronics Engineers (IEEE), etc..

In cellular networks, "macro cell" access points provide connectivity and coverage to a large number of users over a certain geographical area. A macro network deployment is carefully planned, designed, and implemented to offer good coverage over the geographical region. To improve indoor or other specific geographic coverage, such as for residential homes and office buildings, additional "small cell," typically low-power access points have recently begun to be deployed to supplement conventional macro networks. Small cell access points may also provide incremental capacity growth, richer user experience, and so on.

Small cell LTE operations, for example, have been extended into the unlicensed frequency spectrum such as the Unlicensed National Information Infrastructure (U-NII) band used by Wireless Local Area Network (WLAN) technologies. This extension of small cell LTE operation is designed to increase spectral efficiency and hence capacity of the LTE system. However, it may also overlap with the operations of other Radio Access Technologies (RATs) that typically utilize the same unlicensed bands, most notably IEEE <NUM>. 11x WLAN technologies generally referred to as "Wi-Fi.

Document <CIT> discloses a signaling method for sharing an unlicensed spectrum between different radio access technologies used by a base station and a multi-mode wireless device, a multi-mode wireless device using the same method, and a base station using the same method. According to one of the exemplary embodiments, the disclosure is directed to a signaling method for sharing an unlicensed spectrum between different radio access technologies used by a base station. The method may include not limited to receiving a first transmission via a receiver of a first radio access technology over an unlicensed spectrum, calculating a channel information of the first transmission, configuring a second transmission based on the first channel information of the first transmission, and transmitting the second transmission via a transmitter of a second radio access technology over the unlicensed spectrum.

<CIT> discloses systems and methods for Carrier Sense Adaptive Transmission (CSAT) and related operations in unlicensed spectrum to reduce interference between co-existing Radio Access Technologies (RATs). The parameters for a given CSAT communication scheme may be adapted dynamically based on received signals from a transceiver for a native RAT to be protected and an identification of how that RAT is utilizing a shared re-source such as an unlicensed band. Other operations such as Discontinuous Reception (DRX) may be aligned with a CSAT Time Division Multiplexed (TDM) communication pattern by way of a DRX broadcast/multicast message. Different TDM communication patterns may be staggered in time across different frequencies. Channel selection for a co-existing RAT may also be configured to afford further protection to native RATs by preferring operation on secondary channels as opposed to primary channels.

There is still a need for enhanced management of wireless communication on a shared communication medium.

The present invention provides a solution according to the subject-matter of the independent claims. Optional variants are defined by the dependent claims.

Techniques for managing Radio Access Technology (RAT) aggregation on a shared communication medium are disclosed.

In one example, a communication method is disclosed, as defined in claim <NUM>.

In another example, a communication apparatus is disclosed, as defined in claim <NUM>.

In another example, computer program is disclosed, as defined in claim <NUM>.

The invention made is disclosed in the embodiments referring to <FIG>. The present disclosure relates generally to Radio Access Technology (RAT) aggregation procedures on a communication medium shared with multiple RATs. To better utilize the relative strengths of each RAT under different scenarios and conditions, an access point may selectively switch between the RATs to provide service to one or more access terminals over the shared communication medium. For example, whereas a more robust but narrowband RAT (e.g., a Long Term Evolution (LTE)-based technology) may be used for control signaling and data traffic for some access terminals, a less robust but wideband RAT (e.g., a Wi-Fi technology) may be used for data traffic for other access terminals. The access point may schedule different access terminals for data traffic in accordance with different RATs based on various operating mode criteria, including signal quality, traffic Quality of Service (QoS), mobility, and so on.

In general, data traffic for the different RATs may be scheduled in a Time Division Multiplexing (TDM) manner, although some RATs (e.g., those that permit independent uplink scheduling) may allow for more efficient use of the communication medium in a Frequency Division Multiplexing (FDM) manner as well. Further optimizations of a given RAT aggregation scheme may also be employed, such as power control, limiting beacon signaling, and so on.

More specific aspects of the disclosure are provided in the following description and related drawings directed to various examples provided for illustration purposes. Additionally, well-known aspects of the disclosure may not be described in detail or may be omitted so as not to obscure more relevant details.

It will be recognized that various actions described herein can be performed by specific circuits (e.g., Application Specific Integrated Circuits (ASICs)), by program instructions being executed by one or more processors, or by a combination of both. In addition, for each of the aspects described herein, the corresponding form of any such aspect may be implemented as, for example, "logic configured to" perform the described action.

<FIG> is a system-level diagram illustrating an example wireless network <NUM>. As shown, the wireless network <NUM> is formed from several wireless nodes, including an access point (AP) <NUM> and an access terminal (AT) <NUM>. Each wireless node is generally capable of receiving and/or transmitting over a wireless link <NUM>. The wireless network <NUM> may support any number of access points <NUM> distributed throughout a geographic region to provide coverage for any number of access terminals <NUM>. For simplicity, one access point <NUM> is shown in <FIG> as providing coordination and control among a plurality of access terminals <NUM>, as well as providing access to other access points or other networks (e.g., the Internet) via a backhaul connection <NUM>.

The access point <NUM> may correspond to a small cell access point, for example. "Small cells" generally refer to a class of low-powered access points that may include or be otherwise referred to as femto cells, pico cells, micro cells, Wireless Local Area Network (WLAN) access points, other small coverage area access points, etc. Small cells may be deployed to supplement macro cell coverage, which may cover a few blocks within a neighborhood or several square miles in a rural environment, thereby leading to improved signaling, incremental capacity growth, richer user experience, and so on.

Unless otherwise noted, the terms "access terminal" and "access point" are not intended to be specific or limited to any particular RAT. In general, access terminals may be any wireless communication device allowing a user to communicate over a communications network (e.g., a mobile phone, router, personal computer, server, entertainment device, Internet of Things (IOT) / Internet of Everything (IOE) capable device, in-vehicle communication device, etc.), and may be alternatively referred to in different RAT environments as a User Device (UD), a Mobile Station (MS), a Subscriber Station (STA), a User Equipment (UE), etc. Similarly, an access point may operate according to one or several RATs in communicating with access terminals depending on the network in which the access point is deployed, and may be alternatively referred to as a Base Station (BS), a Network Node, a NodeB, an evolved NodeB (eNB), etc. As an example, the access point <NUM> and the access terminal <NUM> may communicate via the wireless link <NUM> in accordance with a "primary" RAT such as Long Term Evolution (LTE) technology or variants thereof, and (if properly equipped) a "secondary" RAT such as any member of the Institute of Electrical and Electronics Engineers (IEEE) <NUM> wireless "Wi-Fi" protocol family.

Returning to <FIG>, the wireless link <NUM> may operate over a communication medium <NUM> that is shared by multiple RATs such as the aforementioned primary and secondary RATs. A communication medium of this type may be composed of one or more frequency, time, and/or space communication resources (e.g., encompassing one or more channels across one or more carriers). As an example, the communication medium <NUM> may correspond to at least a portion of an unlicensed frequency band. Although different licensed frequency bands have been reserved for certain communications (e.g., by a government entity such as the Federal Communications Commission (FCC) in the United States), some systems, in particular those employing small cell access points, have extended operation into unlicensed and/or lightly licensed frequency bands such as the Unlicensed National Information Infrastructure (U-NII) band and the Citizens Broadband (CB) Radio Service band. Such systems may include operation in unlicensed or lightly licensed spectrum with or without anchor carrier(s) in licensed frequency.

Due to the shared use of the communication medium <NUM>, there is the potential for cross-link interference and some jurisdictions may require contention or "Listen Before Talk (LBT)" for arbitrating access to the communication medium <NUM>. As an example, a Clear Channel Assessment (CCA) protocol may be used in which each device verifies via medium sensing the absence of other traffic on a shared communication medium before seizing (and in some cases reserving) the communication medium for its own transmissions. In some designs, the CCA protocol may include distinct CCA Preamble Detection (CCA-PD) and CCA Energy Detection (CCA-ED) mechanisms for yielding the communication medium to intra-RAT and inter-RAT traffic, respectively. The European Telecommunications Standards Institute (ETSI), for example, mandates contention for all devices regardless of their RAT on certain communication media such as unlicensed frequency bands.

Different RATs may provide different advantages under different circumstances for use in facilitating communication between the access point <NUM> and the access terminal <NUM> over the shared communication medium <NUM>. For example, cellular technologies such as LTE and its variants (including so-called "MuLTEfire" technology) may, in some instances, provide better coverage, mobility, robustness, and access terminal conformance as compared to WLAN technologies such as Wi-Fi. In general, an LTE-based RAT may utilize lower data rates and Hybrid Automatic Repeat Request (HARQ) protocols as well as more robust control channels than a Wi-Fi-based RAT, which even in some variants such as <NUM>. 11ax still utilizes a legacy preamble. An LTE-based RAT may also utilize a more robust pilot design than a Wi-Fi-based RAT. However, an LTE-based RAT may not as readily support wideband operations due to additional carrier aggregation requirements, for example. Wideband operation may be particularly desirable when access terminals operate in close proximity to each other (e.g., near cell-center regions) and under light to moderate loading conditions.

Because different RATs are associated with different advantages and drawbacks, a hybrid approach that leverages the advantages of different RATs while minimizing the effect of their respective drawbacks may be beneficial under certain circumstances. Such an approach may be particularly applicable in shared spectrum where multiple types of RATs may be available for use in the same frequency band. As will be described in more detail below, the access point <NUM> and/or the access terminal <NUM> may be variously configured in accordance with the teachings herein to provide or otherwise support the RAT-aggregation techniques discussed briefly above. For example, the access point <NUM> may include an operating mode controller <NUM> and the access terminal <NUM> may include an operating mode controller <NUM>. The operating mode controller <NUM> and/or the operating mode controller <NUM> may be configured in different ways to aggregate the operations of different RATs on the shared communication medium <NUM>.

<FIG> is a signaling flow diagram illustrating example aspects of RAT aggregation as provided herein. In this example, the access point <NUM> and the access terminal <NUM> are both capable of operation in accordance with a primary RAT such as LTE-based technology or the like that provides particularly robust operation, as well as a secondary RAT such as Wi-Fi-based technology or the like that provides more streamlined wideband operation. It will be appreciated, however, that different RATs in both type and number may be used in different systems as desired.

As shown, control signaling <NUM> may be generally sent and received over the communication medium <NUM> in accordance with the primary RAT for improved robustness. The control signaling <NUM> may include both pre-connection acquisition and discovery signaling as well as post-connection management signaling. For example, the control signaling <NUM> may be associated with system discovery, acquisition, authentication, mobility, Radio Resource Management (RRM), paging, Radio Link Failure (RLF), and/or Discontinuous Reception (DRX), as well other classes of control signaling that may be generally referred to as Discovery Reference Signals (DRS).

For each connected access terminal including the illustrated access terminal <NUM>, the access point <NUM> may (independently) schedule (block <NUM>) data traffic for transmission over either the primary RAT or the secondary RAT. By multiplexing between the two RATs at the scheduler level, the access point <NUM> is able to more tightly couple the aggregation process on a common set of channels making up the communication medium <NUM>, as compared to lightly-coupled approaches in which the RATs are confined to separate communication media (e.g., separate frequency bands). Alternatively, instead of the primary and secondary RATs utilizing a common set of channels, the primary and secondary RATs may utilize different sets of channels in other embodiments of the disclosure. The different sets of channels utilized by the primary and secondary RATs in this alternative implementation may still overlap in part. In an example, the primary RAT (e.g., which may be used for more robust control, mobility, idle mode, etc.) may use fewer channels than the secondary RAT.

The scheduled data traffic <NUM> may then be sent and received over the communication medium <NUM> in accordance with the selected RAT. In the illustrated example, the scheduled data traffic <NUM> is transmitted in accordance with the secondary RAT. In addition or as an alternative, however, the scheduled data traffic <NUM> may also be transmitted in accordance with the primary RAT (shown by dashed lines in <FIG>). In other words, the access terminal <NUM> and access point <NUM> may first perform system search and acquisition procedures and communication of relevant system information using a primary RAT, and then continue using the primary RAT or switch to a secondary RAT for further communications such as data communications, depending on the circumstances.

The scheduling (block <NUM>) may be performed based on one or more operating mode criteria <NUM> for selecting between the RATs. The operating mode criteria may include, for example, a signal quality criterion, a traffic Quality of Service (QoS) criterion, a mobility criterion, or any other criterion for distinguishing between conditions or scenarios in which either the primary or secondary RAT may be more advantageous.

<FIG> is a system-level diagram illustrating the use of example operating mode criteria for facilitating RAT aggregation. In this example, the access point <NUM> is shown as communicating with the access terminal <NUM> over the communication medium <NUM> in an inner coverage region <NUM> (near so called "cell center") where the corresponding wireless link <NUM> is relatively strong. At other times, the access point <NUM> may also serve the access terminal <NUM> in an outer coverage region <NUM> (near so-called "cell edge") where the wireless link <NUM> is in comparison relatively weak.

A signal quality criterion <NUM> may be used to take into account the cell geometry of the access terminal <NUM> (cell center vs. cell edge) in scheduling it for transmission in accordance with either the primary or secondary RAT. In general, when the access terminal <NUM> is near the cell center and has a correspondingly high Signal-to-Interference-plus-Noise Ratio (SINR), for example (e.g., above a threshold), data traffic for the access terminal <NUM> may be scheduled for transmission in accordance with the secondary RAT (e.g., Wi-Fi). The more streamlined wideband operation of the secondary RAT may be advantageous in such a scenario because it allows interference to be mitigated between other nearby access terminals with minimal impact on throughput. Conversely, when the access terminal <NUM> is near the cell edge and has a correspondingly low SINR, for example (e.g., below a threshold), data traffic for the access terminal <NUM> may be scheduled for transmission in accordance with the primary RAT (e.g., LTE).

In addition or as an alternative, a traffic QoS criterion <NUM> may be used to take into account the flow requirements of the access terminal <NUM>. In general, when the access terminal <NUM> requires a high QoS (e.g., above a threshold) such as Real Time (RT) QoS, data traffic for the access terminal <NUM> may be scheduled for transmission in accordance with the primary RAT (e.g., LTE). The more robust operating procedures of the primary RAT such as HARQ may help to provide better data integrity and so on. Conversely, when the access terminal <NUM> requires only a low QoS (e.g., below a threshold) such as Best Effort (BE) QoS, data traffic for the access terminal <NUM> may be scheduled for transmission in accordance with the secondary RAT (e.g., Wi-Fi).

In addition or as an alternative, a mobility criterion <NUM> may be used to take into account the likely handover or reselection needs of the access terminal <NUM>. In general, when the access terminal <NUM> is highly mobile (e.g., above a threshold), data traffic for the access terminal <NUM> may be scheduled for transmission in accordance with the primary RAT (e.g., LTE). The more robust handover and reselection procedures of the primary RAT may help to provide more seamless coverage. Conversely, when the access terminal <NUM> is not highly mobile (e.g., below a threshold), data traffic for the access terminal <NUM> may be scheduled for transmission in accordance with the secondary RAT (e.g., Wi-Fi).

Returning to <FIG>, the access point <NUM> may coordinate the operating mode with the access terminal <NUM> by sending an operating mode identifier <NUM> to the access terminal <NUM> to identify which RAT is being utilized for the scheduled data traffic <NUM>. The access point <NUM> may communicate the operating mode identifier <NUM> to the access terminal <NUM> in different ways, including both dynamically and semi-statically.

As an example, the access point <NUM> may dynamically send the operating mode identifier <NUM> on a packet-by-packet basis as part of a physical layer (layer <NUM>) message such as a channel reservation message preceding data transmission (e.g., as one bit of Wi-Fi preamble). Example channel reservation messages may include, for example, Clear-to-Send-to-Self (CTS2S) messages, Request-to-Send (RTS) messages, Clear-to-Send (CTS) messages, Physical Layer Convergence Protocol (PLCP) Signal (SIG) headers (e.g., a legacy signal (L-SIG), a high throughput signal (HT-SIG), or very high throughput signal (VHT-SIG)), a data packet such as a legacy <NUM>. 11a data packet, and the like for a Wi-Fi-based RAT, or other similar messages defined for other RATs of interest.

As another example, the access point <NUM> may send the operating mode identifier <NUM> semi-statically (e.g., on the order of tens of ms) as part of a Radio Resource Control (RRC) message.

In general, the access point <NUM> may serve access terminals operating in accordance with different RATs utilizing a Time Division Multiplexed (TDM) scheme, subject to any contention procedures for accessing the communication medium <NUM>. While downlink data traffic is typically scheduled by the access point <NUM>, uplink data traffic may or may not be scheduled by the access point <NUM>. For example, the IEEE <NUM>. 11ac protocol does not support uplink data traffic scheduling by an access point whereas the IEEE <NUM>. 11ax protocol does support uplink data traffic scheduling by an access point. The TDM scheme employed may therefore depend on whether or not uplink data traffic is scheduled for a given RAT in addition to downlink data traffic. Two example TDM schemes are described below for illustration purposes, one without secondary RAT uplink scheduling and one with secondary RAT uplink scheduling.

<FIG> is a resource diagram illustrating an example RAT-aggregation TDM scheduling scheme in which only downlink scheduling is supported by the secondary RAT. In this example, the communication medium <NUM> encompasses four blocks of spectrum, including Blocks A-D. The primary RAT generally provides narrowband operation in Block A and the secondary RAT generally provides wideband operation in Blocks A-D. As discussed above, various control signaling may be sent as appropriate for a given implementation, including DRS and a channel-clearing preamble in the illustrated example.

As shown, due to the uplink scheduling limitations of the secondary RAT, each RAT may be generally served sequentially such that all uplink and downlink data traffic for a given RAT is confined within a common time period designated for that RAT. That is, uplink data traffic may be restricted to a time period otherwise scheduled for downlink data traffic of the same RAT to avoid inter-RAT interference.

In the illustrated example, uplink and downlink data traffic for access terminals designated for primary RAT operation may be exchanged in a first period of time <NUM> scheduled for primary RAT transmission. Uplink and downlink data traffic for access terminals designated for secondary RAT operation may be exchanged in a second period of time <NUM> scheduled for secondary RAT transmission. Uplink and downlink data traffic for access terminals designated for primary RAT operation may then again be exchanged in a third period of time <NUM> scheduled for primary RAT transmission, uplink and downlink data traffic for access terminals designated for secondary RAT operation may then again be exchanged in a fourth period of time <NUM> scheduled for secondary RAT transmission, uplink and downlink data traffic for access terminals designated for primary RAT operation may then again be exchanged in a fifth period of time <NUM> scheduled for primary RAT transmission, and so on.

<FIG> is a resource diagram illustrating another example RAT-aggregation TDM scheduling scheme in which both uplink and downlink scheduling are supported by the secondary RAT. In this example, the communication medium <NUM> again encompasses four blocks of spectrum, including Blocks A-D. The primary RAT generally provides narrowband operation in Block A and the secondary RAT generally provides wideband operation in Blocks A-D. As discussed above, various control signaling may be sent as appropriate for a given implementation, including DRS and a channel-clearing preamble in the illustrated example.

As shown, because uplink scheduling is supported by the secondary RAT, uplink data traffic may be separated from downlink data traffic such that primary and secondary RAT traffic may be generally served concurrently. That is, Frequency Division Multiplexing (FDM) may be employed to avoid inter-RAT interference while more efficiently utilizing the communication medium <NUM>.

In the illustrated example, downlink data traffic for both access terminals designated for primary RAT operation and access terminals designated for secondary RAT operation may be transmitted in a first period of time <NUM>. The downlink data traffic for access terminals designated for primary RAT operation may utilize frequency Block A. The downlink data traffic for access terminals designated for secondary RAT operation may utilize the remaining frequency Blocks B-D. Uplink data traffic for access terminals designated for primary RAT operation may then be received in a second period of time <NUM> and uplink data traffic for access terminals designated for secondary RAT operation may then be received in a third period of time <NUM>.

In some scenarios, the downlink data traffic for the different RATs may be transmitted to different access terminals. In other scenarios, however, the downlink data traffic for the different RATs may be transmitted to the same access terminal. For example, the access terminal <NUM> may be scheduled for downlink data traffic in accordance with both the primary RAT and the secondary RAT in the first period of time <NUM>.

Based on the particular scheduling employed, the RAT aggregation scheme may be further optimized in various ways. For example, since the secondary RAT may be used for access terminals with better SINR, the access point <NUM> may perform additional power control operations for those access terminals. In particular, the access point <NUM> may reduce their transmission power and increase their noise tolerance (e.g., a backoff threshold such as a CCA threshold), which will both increase spatial reuse and Medium Access Control (MAC) efficiency. Lowering the transmission power may also help to reduce ACK interference.

As another example, the access point <NUM> may refrain from transmitting any beacon signals associated with the secondary RAT. This may help to reduce signaling noise, since control signaling may be more efficiently exchanged in accordance with the primary RAT.

As another example, the access point <NUM> and the access terminal <NUM> may perform idle, paging, or random access procedures in accordance with the primary RAT when the access terminal <NUM> enters an idle mode. Once again, this may help to reduce signaling noise, since control signaling may be more efficiently exchanged in accordance with the primary RAT, because idle, paging or random access procedures may be more robust over the primary RAT.

As another example, the access point <NUM> may send a Discontinuous Reception (DRX) mode command to the access terminal in accordance with either the secondary RAT or the primary RAT. In one particular example, the DRX mode command may be sent via a MAC header Information Element (IE) defined by the secondary RAT because the DRX cycle on the secondary RAT may be shorter as a function of traffic "burstiness". In this case, if the access terminal is configured in the secondary RAT mode and wakes up for DRX, the access terminal may continue in the secondary RAT mode and thereby receive the DRX mode command over the secondary RAT. However, it is also possible for the DRX mode command to be conveyed over the primary RAT as noted above.

<FIG> is a flow diagram illustrating an example method of communication in accordance with the techniques described above. The method 600A may be performed, for example, by an access point (e.g., the access point <NUM> illustrated in <FIG>) operating on a shared communication medium. As an example, the communication medium may include one or more time, frequency, or space resources on an unlicensed radio frequency band shared between LTE technology and Wi-Fi technology devices.

As shown, the access point may send, over a shared communication medium to an access terminal, control signaling in accordance with a first RAT (block 602A). The access point may also schedule data traffic for transmission to the access terminal based on one or more operating mode criteria for selecting between RATs (block 604A), and transmit, over the shared communication medium to the access terminal, the scheduled data traffic in accordance with a second RAT (block 606A).

As discussed in more detail above, the shared communication medium may include, for example, a common set of channels that are utilized by both the first and second RATs. In an alternative example, as noted above, the primary and secondary RATs may utilize different sets of channels within the shared communication medium. The control signaling may be associated, for example, with system discovery, acquisition, authentication, mobility, RRM, paging, RLF, and/or DRX.

As also discussed in more detail above, the one or more operating mode criteria may include, for example, a signal quality criterion, a traffic QoS criterion, and/or a mobility criterion. As an example, the scheduling (block 604A) may include scheduling the data traffic for transmission to the access terminal in accordance with the second RAT based on a signal quality of the access terminal being above a threshold. As another example, the scheduling (block 604A) may include scheduling the data traffic for transmission to the access terminal in accordance with the second RAT based on a traffic QoS of the access terminal being below a threshold. As another example, the scheduling (block 604A) may include scheduling the data traffic for transmission to the access terminal in accordance with the second RAT based on a mobility of the access terminal being below a threshold.

In some designs, the access point <NUM> may send an operating mode identifier to the access terminal to identify utilization of the second RAT for the scheduled data traffic (optional block 608A). As an example, the operating mode identifier may be sent dynamically as part of a channel reservation message. As another example, the operating mode identifier may be sent semi-statically as part of an RRC message.

In some designs, the access point may also receive, over the shared communication medium, uplink data traffic from the access terminal (optional block 610A). As an example, the access point may receive, over the shared communication medium, uplink data traffic in accordance with the second RAT, with the transmitting and the receiving in accordance with the second RAT being performed in a common time period of a TDM scheme separating first RAT and second RAT traffic. As another example, the access point may schedule uplink data traffic in accordance with the second RAT over the shared communication medium, and transmit downlink data traffic in accordance with the first RAT substantially concurrently with the transmitting in accordance with the second RAT, with the transmitting in accordance with the first RAT and the transmitting in accordance with the second RAT being frequency division multiplexed. Here, the transmitting in accordance with the first RAT and the transmitting in accordance with the second RAT may correspond to transmissions to the same access terminal, or may correspond to transmissions to different access terminals.

In some designs, the access point may perform further RAT-aggregation optimizations (optional block 612A). For example, the access point may perform power control to reduce a transmission power and/or increase a backoff threshold associated with the transmitting in accordance with the second RAT. In addition or as an alternative, the access point may refrain from transmitting any beacon signals associated with the second RAT. In addition or as an alternative, the access point may perform an idle, paging, or random access procedure with the access terminal in accordance with the first RAT in response to the access terminal entering an idle mode. In addition or as an alternative, the access point may send a DRX mode command to the access terminal in accordance with the second RAT (e.g., via a MAC header IE defined by the second RAT).

<FIG> is a flow diagram illustrating another example method of communication in accordance with the techniques described above. The method 600B may be performed, for example, by an access terminal <NUM> (e.g., the access point <NUM> illustrated in <FIG>) operating on a shared communication medium. As an example, the communication medium may include one or more time, frequency, or space resources on an unlicensed radio frequency band shared between LTE technology and Wi-Fi technology devices. In particular, the method 600B may be implemented in conjunction with the method 600A described above with respect to <FIG>, except from the access terminal perspective instead of the access point perspective.

As shown, the access terminal may receive, over a shared communication medium from the access point, control signaling in accordance with a first RAT (block 602B). Block 602B may map to block 602A of <FIG> in an example. While not illustrated expressly in <FIG>, the access point may also schedule data traffic for transmission to the access terminal based on one or more operating mode criteria for selecting between RATs (described above with respect to block 604A). As a result of this scheduling, the access terminal may receive, over the shared communication medium from the access point, the scheduled data traffic in accordance with a second RAT (block 606B). Block 606B may map to block 606A of <FIG> in an example.

In some designs, the access terminal may receive an operating mode identifier from the access point to identify utilization of the second RAT for the scheduled data traffic (optional block 608B). Block 608B may map to block 608A of <FIG> in an example. As an example, the operating mode identifier may be received dynamically as part of a channel reservation message. As another example, the operating mode identifier may be received semi-statically as part of an RRC message.

In some designs, the access terminal may also transmit, over the shared communication medium, uplink data traffic to the access point (optional block 610B). Block 610B may map to block 610A of <FIG> in an example.

In some designs, the access terminal may implement further RAT-aggregation optimizations (optional block 612B). Block 612B may map to block 612A of <FIG> in an example. For example, the access point may perform power control to reduce a transmission power and/or increase a backoff threshold associated with the transmitting in accordance with the second RAT. In addition or as an alternative, the access point may refrain from transmitting any beacon signals associated with the second RAT. In addition or as an alternative, the access terminal may perform an idle, paging, or random access procedure with the access point in accordance with the first RAT in response to the access terminal entering an idle mode. In addition or as an alternative, the access terminal may receive a DRX mode command from the access point in accordance with the second RAT (e.g., via a MAC header IE defined by the second RAT).

For generality, the access point <NUM> and the access terminal <NUM> are shown in <FIG> only in relevant part as including the operating mode controller <NUM> and the operating mode controller <NUM>, respectively. It will be appreciated, however, that the access point <NUM> and the access terminal <NUM> may be configured in various ways to provide or otherwise support the RAT aggregation techniques discussed herein.

<FIG> is a device-level diagram illustrating example components of the access point <NUM> and the access terminal <NUM> of the wireless network <NUM> in more detail. As shown, the access point <NUM> and the access terminal <NUM> may each generally include a wireless communication device (represented by the communication devices <NUM> and <NUM>) for communicating with other wireless nodes via at least one designated RAT. The communication devices <NUM> and <NUM> may be variously configured for transmitting and encoding signals, and, conversely, for receiving and decoding signals in accordance with the designated RAT (e.g., messages, indications, information, pilots, and so on).

The communication devices <NUM> and <NUM> may include, for example, one or more transceivers, such as respective primary RAT transceivers <NUM> and <NUM>, and co-located secondary RAT transceivers <NUM> and <NUM>, respectively. As used herein, a "transceiver" may include a transmitter circuit, a receiver circuit, or a combination thereof, but need not provide both transmit and receive functionalities in all designs. For example, a low functionality receiver circuit may be employed in some designs to reduce costs when providing full communication is not necessary (e.g., a radio chip or similar circuitry providing low-level sniffing only). Further, as used herein, the term "co-located" (e.g., radios, access points, transceivers, etc.) may refer to one of various arrangements. For example, components that are in the same housing; components that are hosted by the same processor; components that are within a defined distance of one another; and/or components that are connected via an interface (e.g., an Ethernet switch) where the interface meets the latency requirements of any required inter-component communication (e.g., messaging).

The access point <NUM> and the access terminal <NUM> may also each generally include a communication controller (represented by the communication controllers <NUM> and <NUM>) for controlling operation of their respective communication devices <NUM> and <NUM> (e.g., directing, modifying, enabling, disabling, etc.). The communication controllers <NUM> and <NUM> may include one or more processors <NUM> and <NUM>, and one or more memories <NUM> and <NUM> coupled to the processors <NUM> and <NUM>, respectively. The memories <NUM> and <NUM> may be configured to store data, instructions, or a combination thereof, either as on-board cache memory, as separate components, a combination, etc. The processors <NUM> and <NUM> and the memories <NUM> and <NUM> may be standalone communication components or may be part of the respective host system functionality of the access point <NUM> and the access terminal <NUM>.

It will be appreciated that the operating mode controller <NUM> and the operating mode controller <NUM> may be implemented in different ways. In some designs, some or all of the functionality associated therewith may be implemented by or otherwise at the direction of at least one processor (e.g., one or more of the processors <NUM> and/or one or more of the processors <NUM>) and at least one memory (e.g., one or more of the memories <NUM> and/or one or more of the memories <NUM>), at least one transceiver (e.g., one or more of the transceivers <NUM> and <NUM> and/or one or more of the transceivers <NUM> and <NUM>), or a combination thereof. In other designs, some or all of the functionality associated therewith may be implemented as a series of interrelated functional modules.

Accordingly, it will be appreciated that the components in <FIG> may be used to perform operations described above with respect to <FIG>. For example, the access point <NUM> may, via the primary RAT transceiver <NUM>, send, over the shared communication medium <NUM> to the access terminal <NUM>, control signaling in accordance with the primary RAT. The access point <NUM> may, via the processor <NUM> and the memory <NUM>, schedule data traffic for transmission to the access terminal <NUM> based on one or more operating mode criteria for selecting between RATs. The access point <NUM> may, via the secondary RAT transceiver <NUM>, transmit, over the shared communication medium <NUM> to the access terminal <NUM>, the scheduled data traffic in accordance with the secondary RAT. The access terminal <NUM> may use its various components to perform complementary functions.

<FIG> illustrates an example apparatus for implementing the operating mode controller <NUM>, or, in some instances, the operating mode controller <NUM> (e.g., when acting as a hotspot) represented as a series of interrelated functional modules. In the illustrated example, the apparatus <NUM> includes a module for sending <NUM>, a module for scheduling <NUM>, a module for transmitting <NUM>, an (optional) module for sending <NUM>, an (optional) module for receiving <NUM>, and an (optional) module for performing <NUM>.

The module for sending <NUM> may be configured to send, over a shared communication medium to an access terminal, control signaling in accordance with a first RAT. The module for scheduling <NUM> may be configured to schedule data traffic for transmission to the access terminal based on one or more operating mode criteria for selecting between RATs. The module for transmitting <NUM> may be configured to transmit, over the shared communication medium to the access terminal, the scheduled data traffic in accordance with a second RAT.

<FIG> illustrates an example apparatus for implementing the operating mode controller <NUM> represented as a series of interrelated functional modules. In the illustrated example, the apparatus <NUM> includes a module for receiving <NUM>, a module for receiving <NUM>, an (optional) module for receiving <NUM>, an (optional) module for transmitting <NUM>, and an (optional) module for implementing <NUM>.

The module for sending <NUM> may be configured to receive, over a shared communication medium from an access point, control signaling in accordance with a first RAT. The module for receive <NUM> may be configured to receive, over the shared communication medium from the access point, scheduled data traffic in accordance with a second RAT.

As also discussed in more detail above, the one or more operating mode criteria may include, for example, a signal quality criterion, a traffic QoS criterion, and/or a mobility criterion. As an example, the module for scheduling <NUM> may be configured to schedule the data traffic for transmission to the access terminal in accordance with the second RAT based on a signal quality of the access terminal being above a threshold. As another example, the module for scheduling <NUM> may be configured to schedule the data traffic for transmission to the access terminal in accordance with the second RAT based on a traffic QoS of the access terminal being below a threshold. As another example, the module for scheduling <NUM> may be configured to schedule the data traffic for transmission to the access terminal in accordance with the second RAT based on a mobility of the access terminal being below a threshold.

The module for sending <NUM> may be configured to send an operating mode identifier to the access terminal to identify utilization of the second RAT for the scheduled data traffic. As an example, the operating mode identifier may be sent dynamically as part of a channel reservation message. As another example, the operating mode identifier may be sent semi-statically as part of an RRC message.

The module for receiving <NUM> may be configured to receive, over the shared communication medium, uplink data traffic from the access terminal. As an example, the module for receiving <NUM> may be configured to receive, over the shared communication medium, uplink data traffic in accordance with the second RAT, with the transmitting and the receiving in accordance with the second RAT being performed in a common time period of a TDM scheme separating first RAT and second RAT traffic. As another example, the module for receiving <NUM> may be configured to schedule uplink data traffic in accordance with the second RAT over the shared communication medium, and transmit downlink data traffic in accordance with the first RAT substantially concurrently with the transmitting in accordance with the second RAT, with the transmitting in accordance with the first RAT and the transmitting in accordance with the second RAT being frequency division multiplexed. Here, the transmitting in accordance with the first RAT and the transmitting in accordance with the second RAT may correspond to transmissions to the same access terminal, or may correspond to transmissions to different access terminals.

The module for performing <NUM> may be configured to perform further RAT-aggregation optimizations. For example, the module for performing <NUM> may be configured to perform power control to reduce a transmission power and/or increase a backoff threshold associated with the transmitting in accordance with the second RAT. In addition or as an alternative, the module for performing <NUM> may be configured to refrain from transmitting any beacon signals associated with the second RAT. In addition or as an alternative, the module for performing <NUM> may be configured to perform an idle, paging, or random access procedure with the access terminal in accordance with the first RAT in response to the access terminal entering an idle mode. In addition or as an alternative, the module for performing <NUM> may be configured to send a DRX mode command to the access terminal in accordance with the second RAT (e.g., via a MAC header IE defined by the second RAT).

The functionality of the modules of <FIG> may be implemented in various ways consistent with the teachings herein. In some designs, the functionality of these modules may be implemented as one or more electrical components. In some designs, the functionality of these blocks may be implemented as a processing system including one or more processor components. In some designs, the functionality of these modules may be implemented using, for example, at least a portion of one or more integrated circuits (e.g., an ASIC). As discussed herein, an integrated circuit may include a processor, software, other related components, or some combination thereof. Thus, the functionality of different modules may be implemented, for example, as different subsets of an integrated circuit, as different subsets of a set of software modules, or a combination thereof. Also, it will be appreciated that a given subset (e.g., of an integrated circuit and/or of a set of software modules) may provide at least a portion of the functionality for more than one module.

In addition, the components and functions represented by <FIG>, as well as other components and functions described herein, may be implemented using any suitable means. Such means also may be implemented, at least in part, using corresponding structure as taught herein. For example, the components described above in conjunction with the "module for" components of <FIG> also may correspond to similarly designated "means for" functionality. Thus, in some aspects one or more of such means may be implemented using one or more of processor components, integrated circuits, or other suitable structure as taught herein, including as an algorithm. One skilled in the art will recognize in this disclosure an algorithm represented in the prose described above, as well in sequences of actions that may be represented by pseudocode. For example, the components and functions represented by <FIG> may include code for performing a LOAD operation, a COMPARE operation, a RETURN operation, an IF-THEN-ELSE loop, and so on.

It should be understood that any reference to an element herein using a designation such as "first," "second," and so forth does not generally limit the quantity or order of those elements. Rather, these designations may be used herein as a convenient method of distinguishing between two or more elements or instances of an element. Thus, a reference to first and second elements does not mean that only two elements may be employed there or that the first element must precede the second element in some manner. Also, unless stated otherwise a set of elements may comprise one or more elements. In addition, terminology of the form "at least one of A, B, or C" or "one or more of A, B, or C" or "at least one of the group consisting of A, B, and C" used in the description or the claims means "A or B or C or any combination of these elements. " For example, this terminology may include A, or B, or C, or A and B, or A and C, or A and B and C, or 2A, or 2B, or 2C, and so on.

In view of the descriptions and explanations above, one skilled in the art will appreciate that the various illustrative logical blocks, modules, circuits, and algorithm steps described in connection with the aspects disclosed herein may be implemented as electronic hardware, computer software, or combinations of both.

Accordingly, it will be appreciated, for example, that an apparatus or any component of an apparatus may be configured to (or made operable to or adapted to) provide functionality as taught herein. This may be achieved, for example: by manufacturing (e.g., fabricating) the apparatus or component so that it will provide the functionality; by programming the apparatus or component so that it will provide the functionality; or through the use of some other suitable implementation technique. As one example, an integrated circuit may be fabricated to provide the requisite functionality. As another example, an integrated circuit may be fabricated to support the requisite functionality and then configured (e.g., via programming) to provide the requisite functionality. As yet another example, a processor circuit may execute code to provide the requisite functionality.

Moreover, the methods, sequences, and/or algorithms described in connection with the aspects disclosed herein may be embodied directly in hardware, in a software module executed by a processor, or in a combination of the two. A software module may reside in Random-Access Memory (RAM), flash memory, Read-only Memory (ROM), Erasable Programmable Read-only Memory (EPROM), Electrically Erasable Programmable Read-only Memory (EEPROM), registers, hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art, transitory or non-transitory. In the alternative, the storage medium may be integral to the processor (e.g., cache memory).

Claim 1:
A communication method, performed by an access point (<NUM>) and comprising:
sending (602A), over a shared communication medium to an access terminal, control signaling in accordance with a first Radio Access Technology, RAT;
thereafter dynamically selecting between the first RAT and a second RAT for transmission of a packet of data traffic to the access terminal based on one or more operating mode criteria, wherein the access terminal is connected to the access point (<NUM>) via both the first RAT and the second RAT;
dynamically scheduling (604A) the packet of data traffic for transmission to the access terminal on the selected RAT; and
transmitting, over the shared communication medium to the access terminal, the scheduled packet of data traffic in accordance with the selected RAT.