BACKGROUND

Wireless communications networks are widely deployed to provide various communication services such as voice, video, packet data, messaging, broadcast, and the like. These wireless networks may be multiple-access networks capable of supporting multiple users by sharing the available network resources.

A wireless communications network may include a number of access points. The access points of a cellular network may include a number of base stations, such as NodeBs (NBs) or evolved NodeBs (eNBs). The access points of a wireless local area network (WLAN) may include a number of WLAN access points, such as WiFi nodes. Each access point may support communication for a number of user equipments (UEs) and may often communicate with multiple UEs at the same time. Similarly, each UE may communicate with a number of access points, and may sometimes communicate with multiple access points and/or access points employing different access technologies. An access point may communicate with a UE via downlink and uplink. The downlink (or forward link) refers to the communication link from the access point to the UE, and the uplink (or reverse link) refers to the communication link from the UE to the access point.

As cellular networks become more congested, operators are beginning to look at ways to increase capacity. One approach may include the use of WLANs to offload some of the traffic and/or signaling of a cellular network. WLANs (or WiFi networks) are attractive because, unlike cellular networks that operate in a licensed spectrum, WiFi networks generally operate in an unlicensed spectrum. However, the use of unlicensed spectrum by both cellular and WiFi devices may require the use of a contention-based protocol to gain access to the unlicensed spectrum. Thus, devices wanting to communicate over the unlicensed spectrum may not be able to capture the unlicensed spectrum over consecutive data frames, and techniques to maximize the use of (e.g., reduce the overhead associated with) those data frames that are captured may be useful.

SUMMARY

The described features generally relate to one or more improved methods, systems, devices, and/or apparatuses for wireless communications. More particularly, the described features relate to the transmission of data frames including data subframes, and the transmission of group hybrid automatic repeat request (HARQ) feedback messages for groups of the data subframes (i.e., messages containing HARQ feedback information for groups of data subframes).

In a first set of illustrative examples, a method for wireless communications is described. In one configuration, a set of one or more data subframes of a data frame may be transmitted over an unlicensed spectrum, to a UE, during a transmission period. A group HARQ feedback message for a plurality of data subframes including at least one of the data subframes in the set of one or more data subframes may then be received over the unlicensed spectrum, from the UE, during the transmission period.

In some examples, the group HARQ feedback message may include an acknowledgment for each of the plurality of data subframes decoded by the UE. The group HARQ feedback message may be received either periodically or in response to a trigger. In some examples, the group HARQ feedback message may include a bitmap that indicates, based on a position in the bitmap, a process identifier for each of the plurality of data subframes being acknowledged by the UE in the group HARQ feedback message. In yet further example, receiving the group HARQ feedback message for the plurality of data subframes may include receiving the group HARQ feedback message after a downlink portion of the transmission period.

In one example, the method may further include transmitting, over the unlicensed spectrum to the UE, a Request to Send message. The method may also include receiving, over the unlicensed spectrum from the UE, a Clear to Send message to reserve an uplink portion of the transmission period to receive the group HARQ feedback message from the UE. In some examples, the group HARQ feedback message may include HARQ feedback information for a subset of the set of one or more data subframes, and the method may further include receiving, over the unlicensed spectrum from the UE, a next group HARQ feedback message including HARQ feedback information for a remaining subset of the set of one or more data subframes. The next group HARQ feedback message may be received during a next transmission period.

Additionally or alternatively, the method may include performing clear channel assessment (CCA) to determine availability of the unlicensed spectrum, and accessing the unlicensed spectrum during the transmission period when a determination is made that the unlicensed spectrum is available. The method may also include transmitting, after the transmission period, an uplink grant to the UE over the unlicensed spectrum. The group HARQ feedback message may be received in response to the uplink grant. Additionally or alternatively, the method may comprise transmitting a CTS signal when the unlicensed spectrum is available.

In a second set of illustrative examples, an apparatus for wireless communications is also described. In one configuration, the apparatus may include a processor and memory communicatively coupled to the processor. The processor may be configured to transmit, over an unlicensed spectrum to a UE, during a transmission period, a set of one or more data subframes of a data frame. The processor may be further configured to receive, over the unlicensed spectrum from the UE, during the transmission period, a group HARQ feedback message for a plurality of data subframes including at least one of the data subframes in the set of one or more data subframes. In certain examples, the apparatus may implement one or more aspects of the method for wireless communications described above with respect to the first set of illustrative embodiments.

In a third set of illustrative examples, another method for wireless communications is described. In one configuration, a set of one or more data subframes of a data frame may be received over an unlicensed spectrum during a transmission period. A group HARQ feedback message for a plurality of data subframes including at least one of the data subframes in the set of one or more data subframes may then be transmitted over the unlicensed spectrum during the transmission period.

In some examples, the method may include identifying which data subframes are correctly decoded after reception, and the group HARQ feedback message may include an acknowledgement for each of the plurality of data subframes correctly decoded. The group HARQ feedback message may be transmitted, over the unlicensed spectrum, either periodically or in response to a trigger. In one example, the method may include identifying which data subframes are correctly decoded after reception, and the group HARQ feedback message may include a bitmap that indicates, based on a position in the bitmap, a process identifier for each of the plurality of data subframes correctly decoded. In some examples, transmitting the group HARQ feedback message for the plurality of data subframes may include transmitting the group HARQ feedback message after a downlink portion of the transmission period.

Additionally or alternatively, the method may include receiving, over the unlicensed spectrum, a Request to Send message, and transmitting, over the unlicensed spectrum, a Clear to Send message to reserve an uplink portion of the transmission period to transmit the group HARQ feedback message. In some embodiments, the group HARQ feedback message may include HARQ feedback information for a subset of the set of one or more data subframes, and the method may include transmitting, over the unlicensed spectrum, a next group HARQ feedback message comprising HARQ feedback information for a remaining subset of the set of one or more data subframes. In such example, the next group HARQ feedback message may be transmitted during a next transmission period. In one example, the method may include receiving, after the transmission period, an uplink grant over the unlicensed spectrum. The group HARQ feedback message may be transmitted in response to the uplink grant.

In a fourth set of illustrative examples, an apparatus for wireless communications is described. In one configuration, the apparatus may include a processor and memory communicatively coupled to the processor. The processor may be configured to receive, over an unlicensed spectrum, during a transmission period, a set of one or more data subframes of a data frame. The processor may be further configured to transmit, over the unlicensed spectrum, during the transmission period, a group HARQ feedback message for a plurality of data subframes including at least one of the data subframes in the set of one or more data subframes. In certain examples, the apparatus may implement one or more aspects of the method for wireless communications described above with respect to the third set of illustrative embodiments.

Further scope of the applicability of the described methods and apparatuses will become apparent from the following detailed description, claims, and drawings. The detailed description and specific examples are given by way of illustration only, since various changes and modifications within the spirit and scope of the description will become apparent to those skilled in the art.

