WO2019090559A1

WO2019090559A1 - Macro diversity communication

Info

Publication number: WO2019090559A1
Application number: PCT/CN2017/110109
Authority: WO
Inventors: Jie Mao; Zhanyi Liu; Congchong Ru
Original assignee: Qualcomm Incorporated
Priority date: 2017-11-09
Filing date: 2017-11-09
Publication date: 2019-05-16

Abstract

Methods, systems, and devices for wireless communications are described. Approaches described herein include transmitting two copies of a packet, each using a distinct radio access technology (RAT), which may be a type of macro diversity transmission. A transmitting node in a wireless communications system, such as a base station or user equipment (UE), may determine whether to use a macro diversity transmission based on a number of factors. A receiving node, such as a base station or UE, may consider a packet to have been successfully received so long as the receiving node is able to successfully decode at least one copy of the packet.

Description

MACRO DIVERSITY COMMUNICATION

BACKGROUND

The following relates generally to wireless communication, and more specifically to macro diversity communication.

Wireless communications systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, and so on. These systems may be capable of supporting communication with multiple users by sharing the available system resources (e.g., time, frequency, and power) . Examples of such multiple-access systems include fourth generation (4G) systems such as a Long Term Evolution (LTE) systems or LTE-Advanced (LTE-A) systems, and fifth generation (5G) systems which may be referred to as New Radio (NR) systems. These systems may employ technologies such as code division multiple access (CDMA) , time division multiple access (TDMA) , frequency division multiple access (FDMA) , orthogonal frequency division multiple access (OFDMA) , or discrete Fourier transform-spread-OFDM (DFT-S-OFDM) . A wireless multiple-access communications system may include a number of base stations or network access nodes, each simultaneously supporting communication for multiple communication devices, which may be otherwise known as user equipment (UE) .

Techniques for improving the reliability or latency with which a wireless communications system may transmit and receive data are desired.

SUMMARY

The described techniques relate to improved methods, systems, devices, or apparatuses that support macro diversity communication. Generally, the described techniques provide for transmitting one copy of a packet using one radio access technology (RAT) or two copies of the packet using two RATs, with each of the two copies of the packet transmitted via a distinct RAT. Transmitting one copy of a packet using one RAT may be referred to as a first transmission mode, and transmitting two copies of the packet using two RATs, with each of the two copies of the packet transmitted via a distinct RAT may be referred to as a second transmission mode. A transmitting node in a wireless communications system, such as a base station or user equipment (UE) , may determine whether to transmit a packet using the first transmission mode or the second transmission mode based on a number of factors.

For example, the transmitting node may determine to use the second transmission mode based at least in part on the packet comprising real-time data, such as voice data. One or more retransmission procedures, such as automatic repeat request (ARQ) procedures, may be unavailable or otherwise undesirable for voice or other types of audio or real-time data, such as videoconferencing data. The second transmission mode may provide certain benefits, such as, for example, avoiding dropped packets (e.g., dropped voice packets) or otherwise improving reliability due to redundancy or diversity between the two RATs (e.g., diversity between transmission resources used by the first RAT and transmission resources used by the second RAT) . A receiving node in a wireless communications system, such as a base station or UE, may consider a packet to have been successfully received by the receiving node as long as the receiving node is able to successfully decode at least one copy of the packet.

A method of wireless communication is described. The method may include identifying a first transmission mode that comprises wireless transmission of one copy of a packet using a first RAT, identifying a second transmission mode that comprises wireless transmission of a first copy of the packet using the first RAT and a second copy of the packet using a second RAT, selecting, from the first transmission mode or the second transmission mode, a transmission mode for wireless transmission of the packet, and transmitting the packet in accordance with the transmission mode.

An apparatus for wireless communication is described. The apparatus may include means for identifying a first transmission mode that comprises wireless transmission of one copy of a packet using a first RAT, means for identifying a second transmission mode that comprises wireless transmission of a first copy of the packet using the first RAT and a second copy of the packet using a second RAT, means for selecting, from the first transmission mode or the second transmission mode, a transmission mode for wireless transmission of the packet, and means for transmitting the packet in accordance with the transmission mode.

Another apparatus for wireless communication is described. The apparatus may include a processor, memory in electronic communication with the processor, and instructions stored in the memory. The instructions may be operable to cause the processor to identify a first transmission mode that comprises wireless transmission of one copy of a packet using a first RAT, identify a second transmission mode that comprises wireless transmission of a first copy of the packet using the first RAT and a second copy of the packet using a second RAT, select, from the first transmission mode or the second transmission mode, a transmission mode for wireless transmission of the packet, and transmit the packet in accordance with the transmission mode.

A non-transitory computer-readable medium for wireless communication is described. The non-transitory computer-readable medium may include instructions operable to cause a processor to identify a first transmission mode that comprises wireless transmission of one copy of a packet using a first RAT, identify a second transmission mode that comprises wireless transmission of a first copy of the packet using the first RAT and a second copy of the packet using a second RAT, select, from the first transmission mode or the second transmission mode, a transmission mode for wireless transmission of the packet, and transmit the packet in accordance with the transmission mode.

In some examples of the method, apparatus, and non-transitory computer-readable medium described above, transmitting the packet in accordance with the second transmission mode comprises: creating the first copy of the packet and the second copy of the packet at a shared processing layer common to at least the first RAT and the second RAT. Some examples of the method, apparatus, and non-transitory computer-readable medium described above may further include processes, features, means, or instructions for passing the first copy of the packet to a first lower processing layer, the first lower processing layer specific to the first RAT. Some examples of the method, apparatus, and non-transitory computer-readable medium described above may further include processes, features, means, or instructions for passing the second copy of the packet to a second lower processing layer, the second lower processing layer specific to the second RAT.

In some examples of the method, apparatus, and non-transitory computer-readable medium described above, the shared processing layer common to at least the first RAT and the second RAT may be common to at least a first base station that supports the first RAT and a second base station that supports the second RAT. In some examples of the method, apparatus, and non-transitory computer-readable medium described above, the first lower processing layer may be specific to the first base station. In some examples of the method, apparatus, and non-transitory computer-readable medium described above, the second lower processing layer may be specific to the second base station.

In some examples of the method, apparatus, and non-transitory computer-readable medium described above, the shared processing layer common to at least the first RAT and the second RAT may be common to a UE that supports the first RAT and the second RAT.

In some examples of the method, apparatus, and non-transitory computer-readable medium described above, the shared processing layer comprises a packet data convergence protocol (PDCP) layer.

Some examples of the method, apparatus, and non-transitory computer-readable medium described above may further include processes, features, means, or instructions for selecting the transmission mode may be based at least in part on a data type of the packet. In some examples of the method, apparatus, and non-transitory computer-readable medium described above, selecting the transmission mode further comprises: determining that the data type for the packet may be a real-time data type. Some examples of the method, apparatus, and non-transitory computer-readable medium described above may further include processes, features, means, or instructions for determining the transmission mode as the second transmission mode. In some examples of the method, apparatus, and non-transitory computer-readable medium described above, the real-time data type comprises voice data, videoconferencing data, or any combination thereof.

Some examples of the method, apparatus, and non-transitory computer-readable medium described above may further include processes, features, means, or instructions for selecting the transmission mode may be based at least in part on a permissible transmit power for the packet. In some examples of the method, apparatus, and non-transitory computer-readable medium described above, selecting the transmission mode comprises: determining the transmission mode as the first transmission mode based at least in part on the permissible transmit power being less than a transmission mode power threshold. In some examples of the method, apparatus, and non-transitory computer-readable medium described above, transmitting the packet in accordance with the first transmission mode comprises: transmitting the one copy of the packet using the permissible transmit power.

Some examples of the method, apparatus, and non-transitory computer-readable medium described above may further include processes, features, means, or instructions for selecting the transmission mode may be based at least in part on a channel quality for at least one of the first RAT and the second RAT.

Some examples of the method, apparatus, and non-transitory computer-readable medium described above may further include processes, features, means, or instructions for determining a channel quality associated with at least one of the first RAT and the second RAT. Some examples of the method, apparatus, and non-transitory computer-readable medium described above may further include processes, features, means, or instructions for determining to transmit the second copy of the packet using the second RAT based at least in part on the channel quality.

In some examples of the method, apparatus, and non-transitory computer-readable medium described above, one of the first RAT and second RAT comprises a long-term evolution (LTE) RAT and another of the first RAT and the second RAT comprises a fifth generation (5G) RAT.

A method of wireless communication is described. The method may include receiving a first copy of a packet via a first RAT, receiving a second copy of the packet via a second RAT, and determining a successful receipt of the packet based at least in part on a successful decode of at least one copy of the packet.

An apparatus for wireless communication is described. The apparatus may include means for receiving a first copy of a packet via a first RAT, means for receiving a second copy of the packet via a second RAT, and means for determining a successful receipt of the packet based at least in part on a successful decode of at least one copy of the packet.

Another apparatus for wireless communication is described. The apparatus may include a processor, memory in electronic communication with the processor, and instructions stored in the memory. The instructions may be operable to cause the processor to receive a first copy of a packet via a first RAT, receive a second copy of the packet via a second RAT, and determine a successful receipt of the packet based at least in part on a successful decode of at least one copy of the packet.

A non-transitory computer-readable medium for wireless communication is described. The non-transitory computer-readable medium may include instructions operable to cause a processor to receive a first copy of a packet via a first RAT, receive a second copy of the packet via a second RAT, and determine a successful receipt of the packet based at least in part on a successful decode of at least one copy of the packet.

Some examples of the method, apparatus, and non-transitory computer-readable medium described above may further include processes, features, means, or instructions for receiving, at a shared processing layer common to at least the first RAT and the second RAT, the first copy of the packet from a first lower processing layer specific to the first RAT and the second copy of the packet from a second lower processing layer specific to the second RAT. Some examples of the method, apparatus, and non-transitory computer-readable medium described above may further include processes, features, means, or instructions for determining the successful decode of at least one copy of the packet. Some examples of the method, apparatus, and non-transitory computer-readable medium described above may further include processes, features, means, or instructions for discarding at least one other copy of the packet.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an example of a system for wireless communication that supports macro diversity communication in accordance with aspects of the present disclosure.

FIG. 2 illustrates an example of a wireless communications system that supports macro diversity communication in accordance with aspects of the present disclosure.

FIG. 3 illustrates an example of a process that supports macro diversity communication in accordance with aspects of the present disclosure.

FIG. 4 illustrates an example of a process that supports macro diversity communication in accordance with aspects of the present disclosure.

FIGs. 5 through 7 show block diagrams of a device that supports macro diversity communication in accordance with aspects of the present disclosure.

FIG. 8 illustrates a block diagram of a system including a user equipment (UE) that supports macro diversity communication in accordance with aspects of the present disclosure.

FIG. 9 illustrates a block diagram of a system including a base station that supports macro diversity communication in accordance with aspects of the present disclosure.

FIGs. 10 through 11 illustrate methods for macro diversity communication in accordance with aspects of the present disclosure.

DETAILED DESCRIPTION

Some wireless communications systems may comprise aspects of multiple generations of networks, including generations utilizing different radio access technologies (RATs) . For example, a system may comprise a fourth generation (4G) network, which may utilize a Long Term Evolution (LTE) RAT, as well as a fifth generation (5G) network, which may utilize a 5G RAT, which may also be referred to as a New Radio (NR) RAT. Different RATs may be supported by different radio access networks (RANs) . For example, an LTE RAN may support an LTE RAT, and a 5G RAN may support a 5G RAT.

In some deployments, a base station may support multiple RATs and be included within multiple RANs, or base stations corresponding to different RANs may be physically collocated or otherwise near one another, such that a single user equipment (UE) may be able to communicate with more than one RAN, and thus use more than one RAT, simultaneously. Such deployments may be referred to as non-standalone (NSA) deployments. For example, a UE may support multiple RATs and be able to simultaneously communicate with an eNodeB (eNB) using an LTE RAT and with a gNodeB (gNB) using a 5G RAT.

Base stations or aspects of a base station corresponding to different RANs may in some cases share processing resources, such as hardware, software, or firmware resources. For example, a first base station may perform some amount of processing for the benefit of a second base station. As one example, the first base station may partially process data, transmit the partially processed data to the second base station, and the second base station may further process the data before transmitting to a UE. As another example, the second base station may receive data from a UE, partially process the received data, transmit the partially processed received data to the first base station, and the first base station may further process the received data. In logical terms, shared resources between base stations may comprise one or more shared processing layers.

Base stations or aspects of a base station corresponding to different RANs may also in some cases share a core network. For example, in some NSA deployments, a first base station that supports a first RAT may be communicatively coupled to a core network, a second base station that supports a second RAT may be communicatively to the first base station, and the second base station may rely on the first base station for access to the core network. In such an NSA deployment, the first base station may be referred to as a primary or master base station and the second base station may be referred to as a secondary or slave base station. For example, the core network may be an evolved packet core (EPC) network, a master eNB (MeNB) may be communicatively to the EPC as well as to a secondary gNB (SgNB) , and the SgNB may lack a direct communication interface with the EPC.

Depending on a variety of factors, such as a data type of a packet, a base station or a UE may determine whether to transmit one copy of the packet using one RAT or two copies of the packet using two RATs, with each of the two copies of the packet transmitted via a distinct RAT. Transmitting one copy of a packet using one RAT may be a first transmission mode, which may be referred as a single-RAT transmission mode. Transmitting two copies of the packet using two RATs, with each of the two copies of the packet transmitted via a distinct RAT, may be a second transmission mode, which may be referred to as macro diversity transmission mode. When a transmitting node uses a macro diversity transmission mode for a packet, a receiving node may consider the packet to have been successfully received by the receiving node so long as the receiving node is able to successfully decode at least one copy of the packet.

In a macro diversity transmission mode, the two copies of the packet are diverse from one another in terms of their respective RATs, and thus may be diverse from each other in any domain in which the two RATs differ (e.g., different frequency resources, different spatial resources, different code resources, different modulation and encoding techniques, etc. ) . Macro diversity communication may provide certain benefits. For example, macro diversity communication may improve the reliability with which a packet may be transmitted and received-e.g., due to redundancy or diversity between the two RATs. As another example, macro diversity communication may provide latency benefits, as it may obviate the need for retransmission of a packet. As another example, macro diversity communication may provide reliability benefits in circumstances in which retransmission of a packet is not viable due to latency requirements, which may, for example, translate into voice quality or other quality benefits. One or more retransmission procedures, such as automatic repeat request (ARQ) procedures, may be unavailable or otherwise undesirable for voice or other types of audio or real-time data, such as videoconferencing data, and macro diversity communication may in some cases avoid dropped packets (e.g., dropped voice packets) . And as yet another example, macro diversity communication may obviate the need for various inter-RAT handover or random access procedures-e.g., because a UE engaged in macro diversity communications is already communicating via two or more RATs, the UE may switch to one of the RATs (atarget RAT) simply by discontinuing communication via the other RATs, avoiding procedures which may otherwise be required to establish initial communications using the target RAT. Obviating the need for various inter-RAT handover or random access procedures may provide further reliability, latency, and quality benefits (e.g., may avoid interruption in a voice call) .

Aspects of the disclosure are initially described in the context of a wireless communications system. Further examples are then provided that illustrate macro diversity communication and related processes. Aspects of the disclosure are further illustrated by and described with reference to apparatus diagrams, system diagrams, and flowcharts that relate to macro diversity communication.

FIG. 1 illustrates an example of a wireless communications system 100 in accordance with various aspects of the present disclosure. The wireless communications system 100 includes base stations 105, UEs 115, and a core network 130. In some examples, the wireless communications system 100 may be an LTE network, an LTE-Advanced (LTE-A) network, or a 5G or NR network. In some cases, wireless communications system 100 may support enhanced broadband communications, ultra-reliable (e.g., mission critical) communications, low latency communications, or communications with low-cost and low-complexity devices.

Base stations 105 may wirelessly communicate with UEs 115 via one or more base station antennas. Base stations 105 described herein may include or may be referred to by those skilled in the art as a base transceiver station, a radio base station, an access point, a radio transceiver, a NodeB, an eNB, a next-generation Node B or giga-nodeB (either of which may be referred to as a gNB) , a Home NodeB, a Home eNodeB, or some other suitable terminology. Wireless communications system 100 may include base stations 105 of different types (e.g., macro or small cell base stations) . The UEs 115 described herein may be able to communicate with various types of base stations 105 and network equipment including macro eNBs, small cell eNBs, gNBs, relay base stations, and the like. In some cases base stations 105 and UEs 115 may support both single-RAT communication and macro diversity communication techniques.

Each base station 105 may be associated with a particular geographic coverage area 110 in which communications with various UEs 115 is supported. Each base station 105 may provide communication coverage for a respective geographic coverage area 110 via communication links 125, and communication links 125 between a base station 105 and a UE 115 may utilize one or more carriers. Communication links 125 shown in wireless communications system 100 may include uplink transmissions from a UE 115 to a base station 105, or downlink transmissions, from a base station 105 to a UE 115. Downlink transmissions may also be called forward link transmissions while uplink transmissions may also be called reverse link transmissions.

The geographic coverage area 110 for a base station 105 may be divided into sectors making up only a portion of the geographic coverage area 110, and each sector may be associated with a cell. For example, each base station 105 may provide communication coverage for a macro cell, a small cell, a hot spot, or other types of cells, or various combinations thereof. In some examples, a base station 105 may be movable and therefore provide communication coverage for a moving geographic coverage area 110. In some examples, different geographic coverage areas 110 associated with different technologies (e.g., different RATs) may overlap, and overlapping geographic coverage areas 110 associated with different technologies may be supported by the same base station 105 or by different base stations 105. The wireless communications system 100 may include, for example, a heterogeneous LTE/LTE-Aor NR network in which different types of base stations 105 provide coverage for various geographic coverage areas 110. Some base stations 105 may be deployed in NSA deployments.

The term “cell” refers to a logical communication entity used for communication with a base station 105 (e.g., over a carrier) , and may be associated with an identifier for distinguishing neighboring cells (e.g., a physical cell identifier (PCID) , a virtual cell identifier (VCID) ) operating via the same or a different carrier. In some examples, a carrier may support multiple cells, and different cells may be configured according to different protocol types (e.g., machine-type communication (MTC) , narrowband Internet-of-Things (NB-IoT) , enhanced mobile broadband (eMBB) , or others) that may provide access for different types of devices. In some cases, the term “cell” may refer to a portion of a geographic coverage area 110 (e.g., a sector) over which the logical entity operates.

UEs 115 may be dispersed throughout the wireless communications system 100, and each UE 115 may be stationary or mobile. A UE 115 may also be referred to as a mobile device, a wireless device, a remote device, a handheld device, or a subscriber device, or some other suitable terminology, where the “device” may also be referred to as a unit, a station, a terminal, or a client. A UE 115 may also be a personal electronic device such as a cellular phone, a personal digital assistant (PDA) , a tablet computer, a laptop computer, or a personal computer. In some examples, a UE 115 may also refer to a wireless local loop (WLL) station, an Internet of Things (IoT) device, an Internet of Everything (IoE) device, or an MTC device, or the like, which may be implemented in various articles such as appliances, vehicles, meters, or the like.

Some UEs 115, such as MTC or IoT devices, may be low cost or low complexity devices, and may provide for automated communication between machines (e.g., via Machine-to-Machine (M2M) communication) . M2M communication or MTC may refer to data communication technologies that allow devices to communicate with one another or a base station 105 without human intervention. In some examples, M2M communication or MTC may include communications from devices that integrate sensors or meters to measure or capture information and relay that information to a central server or application program that can make use of the information or present the information to humans interacting with the program or application. Some UEs 115 may be designed to collect information or enable automated behavior of machines. Examples of applications for MTC devices include smart metering, inventory monitoring, water level monitoring, equipment monitoring, healthcare monitoring, wildlife monitoring, weather and geological event monitoring, fleet management and tracking, remote security sensing, physical access control, and transaction-based business charging.

Some UEs 115 may be configured to employ operating modes that reduce power consumption, such as half-duplex communications (e.g., a mode that supports one-way communication via transmission or reception, but not transmission and reception simultaneously) . In some examples half-duplex communications may be performed at a reduced peak rate. Other power conservation techniques for UEs 115 include entering a power saving “deep sleep” mode when not engaging in active communications, or operating over a limited bandwidth (e.g., according to narrowband communications) . In some cases, UEs 115 may be designed to support critical functions (e.g., mission critical functions) , and a wireless communications system 100 may be configured to provide ultra-reliable communications for these functions. For example, some ultra-reliable communications may utilize macro diversity communication techniques as described herein.

In some cases, a UE 115 may also be able to communicate directly with other UEs 115 (e.g., using a peer-to-peer (P2P) or device-to-device (D2D) protocol) . One or more of a group of UEs 115 utilizing D2D communications may be within the geographic coverage area 110 of a base station 105. Other UEs 115 in such a group may be outside the geographic coverage area 110 of a base station 105, or be otherwise unable to receive transmissions from a base station 105. In some cases, groups of UEs 115 communicating via D2D communications may utilize a one-to-many (1: M) system in which each UE 115 transmits to every other UE 115 in the group. In some cases, a base station 105 facilitates the scheduling of resources for D2D communications. In other cases, D2D communications are carried out between UEs 115 without the involvement of a base station 105. For example, some D2D communications may utilize macro diversity communication techniques as described herein.

Base stations 105 may communicate with the core network 130 and with one another. For example, base stations 105 may interface with the core network 130 through backhaul links 132 (e.g., via an S1 or other interface) . Base stations 105 may communicate with one another over inter-base station 134 (e.g., via an X2 or other interface) either directly (e.g., directly between base stations 105) or indirectly (e.g., via core network 130) . Base stations 105 may also communicate with the core network 130 either directly (e.g., via backhaul links 132) or indirectly (e.g., via one or more other base stations 105) .

The core network 130 may provide user authentication, access authorization, tracking, Internet Protocol (IP) connectivity, and other access, routing, or mobility functions. The core network 130 may be an EPC, which may include at least one mobility management entity (MME) , at least one serving gateway (SGW) , and at least one Packet Data Network (PDN) gateway (PGW) . The MME may manage non-access stratum (e.g., control plane) functions such as mobility, authentication, and bearer management for UEs 115 served by base stations 105 associated with the EPC. User IP packets may be transferred through the S-GW, which itself may be connected to the PGW. The PGW may provide IP address allocation as well as other functions. The PGW may be connected to the network operators IP services. The operators IP services may include access to the Internet, Intranet (s) , an IP Multimedia Subsystem (IMS) , or a Packet-Switched (PS) Streaming Service.

At least some of the network devices, such as a base station 105, may include subcomponents such as an access network entity, which may be an example of an access node controller (ANC) . Each access network entity may communicate with UEs 115 through a number of other access network transmission entities, which may be referred to as a radio head, a smart radio head, or a transmission/reception point (TRP) . In some configurations, various functions of each access network entity or base station 105 may be distributed across various network devices (e.g., radio heads and access network controllers) or consolidated into a single network device (e.g., a base station 105) .

Wireless communications system 100 may operate using one or more frequency bands, typically in the range of 300 MHz to 300 GHz. Generally, the region from 300 MHz to 3 GHz is known as the ultra-high frequency (UHF) region or decimeter band, since the wavelengths range from approximately one decimeter to one meter in length. UHF waves may be blocked or redirected by buildings and environmental features. However, the waves may penetrate structures sufficiently for a macro cell to provide service to UEs 115 located indoors. Transmission of UHF waves may be associated with smaller antennas and shorter range (e.g., less than 100 km) compared to transmission using the smaller frequencies and longer waves of the high frequency (HF) or very high frequency (VHF) portion of the spectrum below 300 MHz.

Wireless communications system 100 may also operate in a super high frequency (SHF) region using frequency bands from 3 GHz to 30 GHz, also known as the centimeter band. The SHF region includes bands such as the 5 GHz industrial, scientific, and medical (ISM) bands, which may be used opportunistically by devices that can tolerate interference from other users.

Wireless communications system 100 may also operate in an extremely high frequency (EHF) region of the spectrum (e.g., from 30 GHz to 300 GHz) , also known as the millimeter band. In some examples, wireless communications system 100 may support millimeter wave (mmW) communications between UEs 115 and base stations 105, and EHF antennas of the respective devices may be even smaller and more closely spaced than UHF antennas. In some cases, this may facilitate use of antenna arrays within a UE 115. However, the propagation of EHF transmissions may be subject to even greater atmospheric attenuation and shorter range than SHF or UHF transmissions. Techniques disclosed herein may be employed across transmissions that use one or more different frequency regions, and designated use of bands across these frequency regions may differ by country or regulating body.

In some cases, wireless communications system 100 may utilize both licensed and unlicensed radio frequency spectrum bands. For example, wireless communications system 100 may employ License Assisted Access (LAA) , LTE-Unlicensed (LTE-U) technology, or NR technology in an unlicensed band such as the 5 GHz ISM band. When operating in unlicensed radio frequency spectrum bands, wireless devices such as base stations 105 and UEs 115 may employ listen-before-talk (LBT) procedures to ensure a frequency channel is clear before transmitting data. In some cases, operations in unlicensed bands may be based on a CA configuration in conjunction with CCs operating in a licensed band (e.g., LAA) . Operations in unlicensed spectrum may include downlink transmissions, uplink transmissions, peer-to-peer transmissions, or a combination of these. Duplexing in unlicensed spectrum may be based on frequency division duplexing (FDD) , time division duplexing (TDD) , or a combination of both.

In some examples, base station 105 or UE 115 may be equipped with multiple antennas, which may be used to employ techniques such as transmit diversity, receive diversity, multiple-input multiple-output (MIMO) communications, beamforming, or macro diversity communications. For example, wireless communications system 100 may use a transmission scheme between a transmitting device (e.g., a base station 105) and a receiving device (e.g., a UE 115) , where the transmitting device is equipped with multiple antennas and the receiving devices are equipped with one or more antennas. MIMO communications may employ multipath signal propagation to increase the spectral efficiency by transmitting or receiving multiple signals via different spatial layers, which may be referred to as spatial multiplexing. The multiple signals may, for example, be transmitted by the transmitting device via different antennas or different combinations of antennas. Likewise, the multiple signals may be received by the receiving device via different antennas or different combinations of antennas. Each of the multiple signals may be referred to as a separate spatial stream, and may carry bits associated with the same data stream (e.g., the same codeword) or different data streams. Different spatial layers may be associated with different antenna ports used for channel measurement and reporting. MIMO techniques include single-user MIMO (SU-MIMO) where multiple spatial layers are transmitted to the same receiving device, and multiple-user MIMO (MU-MIMO) where multiple spatial layers are transmitted to multiple devices.

Beamforming, which may also be referred to as spatial filtering, directional transmission, or directional reception, is a signal processing technique that may be used at a transmitting device or a receiving device (e.g., a base station 105 or a UE 115) to shape or steer an antenna beam (e.g., a transmit beam or receive beam) along a spatial path between the transmitting device and the receiving device. Beamforming may be achieved by combining the signals communicated via antenna elements of an antenna array such that signals propagating at particular orientations with respect to an antenna array experience constructive interference while others experience destructive interference. The adjustment of signals communicated via the antenna elements may include a transmitting device or a receiving device applying certain amplitude and phase offsets to signals carried via each of the antenna elements associated with the device. The adjustments associated with each of the antenna elements may be defined by a beamforming weight set associated with a particular orientation (e.g., with respect to the antenna array of the transmitting device or receiving device, or with respect to some other orientation) .

In one example, a base station 105 may use multiple antennas or antenna arrays to conduct beamforming operations for directional communications with a UE 115. For instance, some signals (e.g. synchronization signals, reference signals, beam selection signals, or other control signals) may be transmitted by a base station 105 multiple times in different directions, which may include a signal being transmitted according to different beamforming weight sets associated with different directions of transmission. Transmissions in different beam directions may be used to identify (e.g., by the base station 105 or a receiving device, such as a UE 115) a beam direction for subsequent transmission and/or reception by the base station 105. Some signals, such as data signals associated with a particular receiving device, may be transmitted by a base station 105 in a single beam direction (e.g., a direction associated with the receiving device, such as a UE 115) . In some examples, the beam direction associated with transmissions along a single beam direction may be determined based at least in in part on a signal that was transmitted in different beam directions. For example, a UE 115 may receive one or more of the signals transmitted by the base station 105 in different directions, and the UE 115 may report to the base station 105 an indication of the signal it received with a highest signal quality, or an otherwise acceptable signal quality. Although these techniques are described with reference to signals transmitted in one or more directions by a base station 105, a UE 115 may employ similar techniques for transmitting signals multiple times in different directions (e.g., for identifying a beam direction for subsequent transmission or reception by the UE 115) , or transmitting a signal in a single direction (e.g., for transmitting data to a receiving device) .

A receiving device (e.g., a UE 115, which may be an example of a mmW receiving device) may try multiple receive beams when receiving various signals from the base station 105, such as synchronization signals, reference signals, beam selection signals, or other control signals. For example, a receiving device may try multiple receive directions by receiving via different antenna subarrays, by processing received signals according to different antenna subarrays, by receiving according to different receive beamforming weight sets applied to signals received at a plurality of antenna elements of an antenna array, or by processing received signals according to different receive beamforming weight sets applied to signals received at a plurality of antenna elements of an antenna array, any of which may be referred to as “listening” according to different receive beams or receive directions. In some examples a receiving device may use a single receive beam to receive along a single beam direction (e.g., when receiving a data signal) . The single receive beam may be aligned in a beam direction determined based at least in part on listening according to different receive beam directions (e.g., a beam direction determined to have a highest signal strength, highest signal-to-noise ratio, or otherwise acceptable signal quality based at least in part on listening according to multiple beam directions) .

In some cases, the antennas of a base station 105 or UE 115 may be located within one or more antenna arrays, which may support MIMO operations, or transmit or receive beamforming. For example, one or more base station antennas or antenna arrays may be co-located at an antenna assembly, such as an antenna tower. In some cases, antennas or antenna arrays associated with a base station 105 may be located in diverse geographic locations. A base station 105 may have an antenna array with a number of rows and columns of antenna ports that the base station 105 may use to support beamforming of communications with a UE 115. Likewise, a UE 115 may have one or more antenna arrays that may support various MIMO, beamforming, or macro diversity operations.

In some cases, wireless communications system 100 may be a packet-based network that operate according to a layered protocol stack. In the user plane, communications at the bearer or Packet Data Convergence Protocol (PDCP) layer may be IP-based. A Radio Link Control (RLC) layer may in some cases perform packet segmentation and reassembly to communicate over logical channels. The RLC layer may also include a retransmission mechanism, such as automatic repeat request (ARQ) , to provide retransmission at the RLC layer. A Medium Access Control (MAC) layer may perform priority handling and multiplexing of logical channels into transport channels. The MAC layer may also include a retransmission mechanism, such as hybrid automatic repeat request (HARQ) , to provide retransmission at the MAC layer to improve link efficiency. In the control plane, the Radio Resource Control (RRC) protocol layer may provide establishment, configuration, and maintenance of an RRC connection between a UE 115 and a base station 105 or core network 130 supporting radio bearers for user plane data. At the Physical (PHY) layer, transport channels may be mapped to physical channels.

In some cases, UEs 115 and base stations 105 may support retransmissions of data to increase the likelihood that data is received successfully. HARQ feedback is one technique of increasing the likelihood that data is received correctly over a communication link 125. HARQ may include a combination of error detection (e.g., using a cyclic redundancy check (CRC) ) , forward error correction (FEC) , and retransmission. HARQ may improve throughput at the MAC layer in poor radio conditions (e.g., signal-to-noise conditions) . In some cases, a wireless device may support same-slot HARQ feedback, where the device may provide HARQ feedback in a specific slot for data received in a previous symbol in the slot. In other cases, the device may provide HARQ feedback in a subsequent slot, or according to some other time interval.

Time intervals in LTE or NR may be expressed in multiples of a basic time unit, which may, for example, refer to a sampling period of T_s = 1/30, 720,000 seconds. Time intervals of a communications resource may be organized according to radio frames each having a duration of 10 milliseconds (ms) , where the frame period may be expressed as T_f = 307, 200 T_s. The radio frames may be identified by a system frame number (SFN) ranging from 0 to 1023. Each frame may include 10 subframes numbered from 0 to 9, and each subframe may have a duration of 1 ms. A subframe may be further divided into 2 slots each having a duration of 0.5 ms, and each slot may contain 6 or 7 modulation symbol periods (e.g., depending on the length of the cyclic prefix prepended to each symbol period) . Excluding the cyclic prefix, each symbol period may contain 2048 sampling periods. In some cases a subframe may be the smallest scheduling unit of the wireless communications system 100, and may be referred to as a transmission time interval (TTI) . In other cases, a smallest scheduling unit of the wireless communications system 100 may be shorter than a subframe or may be dynamically selected (e.g., in bursts of shortened TTIs (sTTIs) or in selected component carriers using sTTIs) .

In some wireless communications systems, a slot may further be divided into multiple mini-slots containing one or more symbols. In some instances, a symbol of a mini-slot or a mini-slot may be the smallest unit of scheduling. Each symbol may vary in duration depending on the subcarrier spacing or frequency band of operation, for example. Further, some wireless communications systems may implement slot aggregation in which multiple slots or mini-slots are aggregated together and used for communication between a UE 115 and a base station 105.

The term “carrier” refers to a set of radio frequency spectrum resources having a defined physical layer structure for supporting communications over a communication link 125. For example, a carrier of a communication link 125 may include a portion of a radio frequency spectrum band that is operated according to physical layer channels for a given RAT. Each physical layer channel may carry user data, control information, or other signaling. A carrier may be associated with a pre-defined frequency channel (e.g., an E-UTRA absolute radio frequency channel number (EARFCN) ) , and may be positioned according to a channel raster for discovery by UEs 115. Carriers may be downlink or uplink (e.g., in an FDD mode) , or be configured to carry downlink and uplink communications (e.g., in a TDD mode) . In some examples, signal waveforms transmitted over a carrier may be made up of multiple sub-carriers (e.g., using multi-carrier modulation (MCM) techniques such as OFDM or DFT-s-OFDM) .

The organizational structure of the carriers may be different for different RATs (e.g., LTE, LTE-A, NR, etc. ) . For example, communications over a carrier may be organized according to TTIs or slots, each of which may include user data as well as control information or signaling to support decoding the user data. A carrier may also include dedicated acquisition signaling (e.g., synchronization signals or system information, etc. ) and control signaling that coordinates operation for the carrier. In some examples (e.g., in a carrier aggregation configuration) , a carrier may also have acquisition signaling or control signaling that coordinates operations for other carriers.

Physical channels may be multiplexed on a carrier according to various techniques. A physical control channel and a physical data channel may be multiplexed on a downlink carrier, for example, using time division multiplexing (TDM) techniques, frequency division multiplexing (FDM) techniques, or hybrid TDM-FDM techniques. In some examples, control information transmitted in a physical control channel may be distributed between different control regions in a cascaded manner (e.g., between a common control region or common search space and one or more UE-specific control regions or UE-specific search spaces) .

A carrier may be associated with a particular bandwidth of the radio frequency spectrum, and in some examples the carrier bandwidth may be referred to as a “system bandwidth” of the carrier or the wireless communications system 100. For example, the carrier bandwidth may be one of a number of predetermined bandwidths for carriers of a particular RAT (e.g., 1.4, 3, 5, 10, 15, 20, 40, or 80 MHz) . In some examples, each served UE 115 may be configured for operating over portions or all of the carrier bandwidth. In other examples, some UEs 115 may be configured for operation using a narrowband protocol type that is associated with a predefined portion or range (e.g., set of subcarriers or RBs) within a carrier (e.g., “in-band” deployment of a narrowband protocol type) .

In a system employing MCM techniques, a resource element may consist of one symbol period (e.g., a duration of one modulation symbol) and one subcarrier, where the symbol period and subcarrier spacing are inversely related. The number of bits carried by each resource element may depend on the modulation scheme (e.g., the order of the modulation scheme) . Thus, the more resource elements that a UE 115 receives and the higher the order of the modulation scheme, the higher the data rate may be for the UE 115. In MIMO systems, a wireless communications resource may refer to a combination of a radio frequency spectrum resource, a time resource, and a spatial resource (e.g., spatial layers) , and the use of multiple spatial layers may further increase the data rate for communications with a UE 115.

Devices of the wireless communications system 100 (e.g., base stations 105 or UEs 115) may have a hardware configuration that supports communications over a particular carrier bandwidth, or may be configurable to support communications over one of a set of carrier bandwidths. In some examples, the wireless communications system 100 may include base stations 105 and/or UEs that can support simultaneous communications via carriers associated with more than one different carrier bandwidth or more than one different RATs.

Wireless communications system 100 may support communication with a UE 115 on multiple cells or carriers, a feature which may be referred to as carrier aggregation (CA) or multi-carrier operation. A UE 115 may be configured with multiple downlink CCs and one or more uplink CCs according to a carrier aggregation configuration. Carrier aggregation may be used with both FDD and TDD component carriers.

In some cases, wireless communications system 100 may utilize enhanced component carriers (eCCs) . An eCC may be characterized by one or more features including wider carrier or frequency channel bandwidth, shorter symbol duration, shorter TTI duration, or modified control channel configuration. In some cases, an eCC may be associated with a carrier aggregation configuration or a dual connectivity configuration (e.g., when multiple serving cells have a suboptimal or non-ideal backhaul link) . An eCC may also be configured for use in unlicensed spectrum or shared spectrum (e.g., where more than one operator is allowed to use the spectrum) . An eCC characterized by wide carrier bandwidth may include one or more segments that may be utilized by UEs 115 that are not capable of monitoring the whole carrier bandwidth or are otherwise configured to use a limited carrier bandwidth (e.g., to conserve power) .

In some cases, an eCC may utilize a different symbol duration than other CCs, which may include use of a reduced symbol duration as compared with symbol durations of the other CCs. A shorter symbol duration may be associated with increased spacing between adjacent subcarriers. A device, such as a UE 115 or base station 105, utilizing eCCs may transmit wideband signals (e.g., according to frequency channel or carrier bandwidths of 20, 40, 60, 80 MHz, etc. ) at reduced symbol durations (e.g., 16.67 microseconds) . A TTI in eCC may consist of one or multiple symbol periods. In some cases, the TTI duration (that is, the number of symbol periods in a TTI) may be variable.

Wireless communications systems such as an NR system may utilize any combination of licensed, shared, and unlicensed spectrum bands, among others. The flexibility of eCC symbol duration and subcarrier spacing may allow for the use of eCC across multiple spectrums. In some examples, NR shared spectrum may increase spectrum utilization and spectral efficiency, specifically through dynamic vertical (e.g., across frequency) and horizontal (e.g., across time) sharing of resources.

FIG. 2 illustrates an example of a wireless communications system 200 that supports macro diversity communication in accordance with various aspects of the present disclosure. In some examples, wireless communications system 200 may comprise aspects of wireless communication system 100. In the example of FIG. 2, the wireless communications system 200 may include a core network 130-a, an MeNB 105-a, an SgNB 105-b, and a UE 115-a, which may respectively be examples of a core network 130, base stations 105, and a UE 115 as described in reference to FIG. 1.

The core network 130-a may be an EPC and be an example of an EPC as described above. The core network 130-a may comprise an MME 210, an SGW 215, and a PGW 220, which may respectively be examples of an MME, SGW, and PGW as described above.

The MeNB 105-a may be an example of base station 105 as described above. For example, the MeNB 105-a may be an eNB that supports an LTE RAT. The MeNB 105-a may be part of an NSA deployment in which the MeNB 105-a is configured to act as a master base station. The MeNB may be communicatively coupled with the core network 130-a via a first backhaul link 132-a and a second backhaul link 132-b. The first backhaul link 132-a may comprise a control plane interface between the MeNB 105-a and the MME 210, which may be referred to as an S1-C or S1-MME interface. The second backhaul link 132-b may comprise a user plane interface between the MeNB 105-a and the SGW 215, which may be referred to as an S1-U interface. The MeNB 105-a may be part of an NSA deployment in which the MeNB 105-a is configured to act as a master base station for the SgNB 105-b.

The SgNB 105-b may also be an example of base station 105 as described above. For example, the SgNB 105-b may be a gNB that supports a 5G RAT, which may also be referred to as an NR RAT. The SgNB 105-b may be part of the same NSA deployment as the MeNB 105-a, and the SgNB 105-b may be configured to act as a secondary base station to the MeNB 105-a. For example, the SgNB 105-b may lack any direct connection to the core network 130-a but may be communicatively coupled with the MeNB 105-a via link inter-base station link 134-a. The inter-base station link 134-a may comprise an inter-base station interface, which may be referred to as an Xx interface.

The UE 115-a may be an example of a UE 115 as described above and may support multiple RATs. For example, the UE 115-a may support the LTE RAT supported by the MeNB 105-a and the 5G RAT supported by the SgNB 105-b. The MeNB 105-a, SgNB 105-b, and UE 115-a may be physically located such that the UE 115-a may be capable of simultaneously communicating with the MeNB 105-a using the LTE RAT via an LTE wireless communication link 125-a and communicating with the SgNB 105-b using the 5G RAT via a 5G wireless communication link 125-b.

The MeNB 105-a and the SgNB may be physically collocated (e.g., share a same physical structure) or not. Likewise, the MeNB 105-a and the SgNB may be considered to be a single base station 105 that supports both the LTE RAT and the 5G RAT or may be considered to be two separate base stations 105 that each support a distinct RAT. Regardless of whether the MeNB 105-a and the SgNB are physically collocated or considered a single base station 105, the MeNB 105-a and the SgNB may in some cases share processing resources, such as hardware, software, or firmware resources. For example, the RAN protocol stack for the LTE RAT and the RAN protocol stack for 5G RAT may have one or more common logical layers, and the MeNB 105-a may in some cases perform processing associated with such common logical layers for data transmitted or received by either or both of the MeNB 105-a or the SgNB 105-b. A logical layer common to RAN protocol stacks for multiple RATs may be referred to as a shared processing layer.

In some cases, the MeNB 105-a may use a single-RAT transmission mode and transmit one copy of a packet to the UE 115-a using the LTE RAT (e.g., barring invocation of an LTE retransmission mechanism, such as a HARQ request by the UE 115-a, the MeNB 105-a sends only one copy of the packet to the UE 115-a) . As another example of a single-RAT transmission mode, the MeNB 105-a may transmit one copy of a packet to the UE 115-a using the 5G RAT (e.g., barring invocation of a 5G retransmission mechanism, such as a HARQ request by the UE 115-a, the MeNB 105-a sends only one copy of the packet to the UE 115-a) by transmitting the one copy of the packet to the SgNB 105-b via inter-base station link 134-a, such that the SgNB 105-b may transmit the one copy of the packet to the UE 115-a via the 5G wireless communication link 125-b.

In other cases, the MeNB 105-a may use a macro diversity transmission mode and transmit two copies of the packet to the UE 115-a, using the LTE RAT for a first copy of the packet and the 5G RAT for the second copy of the packet. The MeNB 105-a may transmit the second copy of the packet to the UE 115-a using the 5G RAT by transmitting the second copy of the packet to the SgNB 105-b via inter-base station link 134-a, such that the SgNB 105-b may transmit the second copy of the packet to the UE 115-a via the 5G wireless communication link 125-b. When the MeNB 105-a uses a macro diversity transmission mode, the UE 115-a may determine a successful receipt of the packet if the UE 115-a is able to decode at least one copy of the packet.

The MeNB 105-a may determine whether to use a single-RAT transmission mode (and which RAT to use for the single transmission mode) or a macro diversity transmission mode based on one or more factors, alone or in combination. For example, the MeNB 105-a may determine the transmission mode based at least in part on a data type of the packet. For example, certain types of data may be subject to strict latency requirements such that one or more retransmission mechanisms may not be viable, and the MeNB 105-a may determine to use a macro diversity transmission mode based at least in part on the packet comprising latency-sensitive data.

Examples of latency-sensitive data for which a macro diversity transmission mode may be suitable include real-time data such as voice data or videoconference data. For example, retransmission mechanisms at certain logical layers (e.g., ARQ mechanisms at an RLC layer) may not be utilized for voice data (or other types of real-time data) , which may result in packet drops and poor perceived voice quality (e.g., if a HARQ mechanism at a MAC layer is unsuccessful) . In some cases, excessive packet drops may result in handovers to different generations of networks depending on the extent of coverage (e.g., handover from an LTE network to a 3G or 2G network) , which may cause perceived interruptions in voice calls and further deterioration of perceived voice quality. Another example of latency-sensitive data may be broadcast data for which reception by multiple UEs 115 on a synchronized basis is desirable. Yet another example of latency-sensitive data may be mission critical data or any other type of data subject to relatively strict low latency requirements, such as ultra-reliable low latency communications (URLLCs) .

As another example, the MeNB 105-a may determine the transmission mode based at least in part on a channel quality associated with either the LTE RAT (e.g., the channel quality of the LTE wireless communication link 125-a) or the 5G RAT (e.g., the channel quality of the 5G wireless communication link 125-b or, if wireless, the inter-base station communication link 134-a) . For example, if a channel quality associated with the LTE RAT is poor relative to a channel quality associated with the 5G RAT, or vice versa, the MeNB 105-a may determine to use a macro diversity transmission mode to compensate for the poor quality RAT. Alternatively, if the channel quality associated with one RAT is below a threshold quality while the channel quality associated with the other RAT is above a threshold quality, the MeNB 105-a may determine to use a single-RAT transmission mode using only the RAT having the higher associated channel quality. As yet another example, if the channel quality associated with both RATs is below a threshold quality, the MeNB 105-a may determine to use a macro diversity transmission mode to compensate for the low channel quality associated with each RAT. As yet another example, if the channel quality associated with one RAT is above a threshold quality, the MeNB 105-a may determine to use a single-RAT transmission mode using only the RAT having the high associated channel quality, thus conserving resources.

The MeNB 105-a may determine the quality of different channels associated with different RATs by monitoring channel quality direction or by obtaining channel quality reports from the SgNB 105-b or the UE 115-a. Associated channel quality may differ between different RATs for a variety of factors, such as, for example, different frequency bands that may be used by different RATs (e.g., a higher frequency band may have greater attenuation over distance than a lower frequency band) , different modulation or coding schemes that may be used by different RATs, or geographic factors (e.g., one of the LTE wireless communication link 125-a and the 5G wireless communication link 125-b may have greater line-of-sight to the UE 115-a than the other) .

The UE 115-a may also use either a single-RAT transmission mode or a macro diversity transmission mode. For example, the UE 115-a may use a single-RAT transmission mode to transmit one copy of a packet to the MeNB 105-a using an LTE RAT (e.g., via the LTE wireless communication link 125-a) , may use a single-RAT transmission mode to transmit one copy of the packet to the SgNB 105-b using a 5G RAT (e.g., via the 5G wireless communication link 125-b) , or may use a macro diversity transmission mode to transmit two copies of the packet, with the first copy of the packet transmitted to the MeNB 105-a using the LTE RAT (e.g., via the LTE wireless communication link 125-a) and the second copy of the packet transmitted to the SgNB 105-b using the 5G RAT (e.g., via the 5G wireless communication link 125-b) . When the UE 115-a uses a macro diversity transmission mode, the MeNB 105-a or the SgNB 105-b may determine a successful receipt of the packet if either the MeNB 105-a or the SgNB 105-b is able to decode at least one copy of the packet. For example, the MeNB 105-a and the SgNB 105-b may have a shared processing layer, and if the shared processing layer determines that at least one copy of the packet has been successfully decoded, it may determine a successful receipt of the packet on behalf of both the MeNB 105-a and the SgNB 105-b.

The UE 115-a may determine which transmission mode to use for a packet based at least in part on a data type of the packet or channel quality associated with a relevant RAT as described above for the MeNB 105-a. Also, the UE 115-a may determine which transmission mode to use for a packet based at least in part on a permissible transmit power for the packet. For example, the UE 115-a may have a maximum transmit power (e.g., due to standardized transmit power limitations, which may in some cases reflect maximum permissible exposure limitations, or battery limitations) , and the UE 115-a may determine to use a single-RAT transmission mode for the packet if the permissible transmit power is below a threshold transmit power level and may determine to use a macro diversity transmission mode for the packet if the permissible transmit power is above the threshold transmit power level.

Although the example of wireless communications system 200 has been described in terms of LTE and 5G, one of ordinary skill will recognize that the teachings herein may be extended to other RATs, other numbers of RATs, and other types of core networks. One of ordinary skill will likewise recognize that a 5G base station may act as a master base station (e.g, an MgNB) while an LTE base station may act as secondary base station (e.g., an SeNB) .

FIG. 3 illustrates an example of a process 300 that supports macro diversity communication in accordance with various aspects of the present disclosure. In some examples, process 300 maybe implement by aspects of wireless communication system 100 or wireless communications system 200. In the example of FIG. 3, process 300 may be implemented by a core network 130-b, an MeNB 105-c, an SgNB 105-d, and a UE 115-b, which may be examples of the core networks 130, base stations 105, and UEs 115 of FIG. 1 or FIG. 2.

The MeNB 105-c may receive a packet 305 from the core network 130-b. The packet 305 may be either a control plane packet or a user plane packet. For example, the packet 305 may be a user plane packet and may comprise one or more types of real-time data subject to strict latency requirements, such as voice data or videoconferencing data.

The MeNB 105-c may process the packet 305 such that it is received by shared processing layer 310. The shared processing layer 310 may be a logical layer that is common to a first RAN protocol stack for a first RAT (e.g., an LTE RAT) supported by the MeNB 105-c and a second RAN protocol stack for a second RAT (e.g., a 5G RAT) supported by the SgNB 105-d. In some cases, the shared processing layer 310 may at least in part comprise a PDCP layer that is common to the LTE RAN protocol stack at the MeNB 105-c and the 5G RAN protocol stack at the SgNB 105-b. In other cases, the shared processing layer 310 may be a layer that is relatively higher than a PDCP layer.

The MeNB 105-c may identify one or more single-RAT transmission modes (e.g., a first single-RAT transmission mode using LTE or a second single-RAT transmission mode using 5G) as well as a macro diversity transmission mode using more than one RAT (e.g., a macro diversity transmission mode using both LTE and 5G) as candidate transmission modes for the packet 305. The MeNB 105-c may select a transmission mode for the packet 305 based on one or more factors, alone or in combination, according to the techniques described herein. For example, the MeNB 105-c may determine that a data type for the packet 305 is a real-time data type (e.g., voice data) and may determine the transmission mode for the packet 305 as a macro diversity transmission mode (e.g., the macro diversity transmission mode using both LTE and 5G) . In some cases, the MeNB 105-c may identify transmission modes and select a transmission mode for the packet 305 at the shared processing layer 310.

Having selected the transmission mode for the packet 305 as the macro diversity transmission mode, the MeNB 105-c may create two copies of the packet 305. For example, the MeNB 105-c may create two copies of the packet 305 at the shared processing layer 310.

The MeNB 105-c may pass a first copy 335 of the packet 305 from the shared processing layer 310 to a relatively lower RAT 1 processing layer 315, which may pass the first copy 335 of the packet 305 to a RAT 1 physical layer 320, which may result in transmission of the first copy 335 of the packet 305 to the UE 115-b. In some cases, RAT 1 processing layer 315 may comprise an RLC or MAC layer associated with the first RAT. In this way, the MeNB 105-c may transmit the first copy 335 of the packet 305 to the UE 115-b via a first RAT (e.g., an LTE RAT) .

The MeNB 105-c may pass a second copy 340 of the packet 305 from the shared processing layer 310 to a relatively lower RAT 2 processing layer 325, which may pass the second copy 340 of the packet 305 to a RAT 2 physical layer 330, which may result in transmission of the second copy 340 of the packet 305 to the UE 115-b. In some cases, RAT 2 processing layer 325 may comprise an RLC or MAC layer associated with the second RAT. In this way, the MeNB 105-c may transmit the second copy 340 of the packet 305 to the UE 115-b via a second RAT (e.g., a 5G RAT) , substantially simultaneously with transmitting the first copy 335 of the packet 305 to the UE 115-b via the first RAT (e.g., the LTE RAT) . In some cases, passing the second copy 340 of the packet 305 from the shared processing layer 310 to the lower RAT 2 processing layer 325 may involve use of an internal or external communication link and interface, such as the inter-base station communication link 134-a and the Xx interface described above in reference to wireless communications system 200.

The UE 115-b may receive the first copy 335 and the second copy 340 of the packet 305 via the first RAT and the second RAT respectively and may determine a successful receipt of the packet 305 if the UE 115-b is able to successfully decode either the first copy 335 or the second copy 340. For example, the UE 115-b may receive the first copy 335 of the packet 305 at a RAT 1 physical layer 345, which may pass the first copy 335 to a relatively higher RAT 1 processing layer 350, which may pass the first copy 335 to a shared processing layer 365. Likewise, the UE 115-b may receive the second copy 340 of the packet 305 at a RAT 2 physical layer 355, which may pass the second copy 340 to a relatively higher RAT 2 processing layer 360, which may pass the second copy 340 to the shared processing layer 365. In some cases, the shared processing layer 365 may at least in part comprise a PDCP layer that is common to the LTE RAN protocol stack and the 5G RAN protocol stack at the UE 115-a. In other cases, the shared processing layer 365 may be a layer that is relatively higher than a PDCP layer. RAT 1 processing layer 350 and RAT 2 processing layer 360 may each comprise an RLC or MAC layer associated with the corresponding RAT.

In some cases, either the RAT 1 physical layer 345 and RAT 2 physical layer 355 or the RAT 1 processing layer 350 and RAT 2 processing layer 360 may attempt to decode the first copy 335 and second copy 340 of the packet 305 and pass an indication of a successful or unsuccessful decode to the shared processing layer 365. In other cases, the shared processing layer 365 may attempt to decode the first copy 335 and second copy 340 of the packet 305.

If the UE 115-b determines a successful decode of at least one copy of the packet 305, the UE 115-b may discard any other copy of the packet 305. For example, if the UE 115-b determines a successful decode of the first copy 335 of the packet 305, the UE 115-b may discard the second copy 340, or vice versa. In some cases, the shared processing layer 365 may implement the determination of whether at least one copy of the packet 305 has been successfully decoded and the discard of any other copy of the packet 305.

Although the example of process 300 has been described in terms of LTE and 5G, one of ordinary skill will recognize that the teachings herein may be extended to other RATs, other numbers of RATs, and other types of core networks. One of ordinary skill will likewise recognize that a 5G base station may act as a master base station (e.g, an MgNB) while an LTE base station may act as secondary base station (e.g., an SeNB) . One of ordinary skill will also recognize that other processing steps or logical layers may be added to or interposed between the processing steps and logical layers shown in example process 300.

FIG. 4 illustrates an example of a process 400 that supports macro diversity communication in accordance with various aspects of the present disclosure. In some examples, process 400 may be implemented by aspects of wireless communication system 100 or wireless communications system 200. In the example of FIG. 3, process 300 may be implemented by an MeNB 105-c, an SgNB 105-d, and a UE 115-b, which may be the same as the MeNB 105-c, SgNB 105-d, and UE 115-b of FIG. 3.

The UE 115-b may determine to transmit a packet to one or both of the MeNB 105-c and the SgNB 105-d. The packet may be either a control plane packet or a user plane packet. For example, the packet may be a user plane packet and may comprise one or more types of real-time data subject to strict latency requirements, such as voice data or videoconferencing data.

The UE 115-b may process the packet such that it is received by shared processing layer 365. The shared processing layer 365 may be a logical layer that is common to a first RAN protocol stack for a first RAT (e.g., an LTE RAT) supported by the UE 115-b and a second RAN protocol stack for a second RAT (e.g., a 5G RAT) supported by the UE 115-b. In some cases, the shared processing layer 365 may at least in part comprise a PDCP layer that is common to the LTE RAN protocol stack and the 5G RAN protocol stack at the UE 115-b. In other cases, the shared processing layer 365 may be a layer that is relatively higher than a PDCP layer.

The UE 115-b may identify one or more single-RAT transmission modes (e.g., a first single-RAT transmission mode using LTE or a second single-RAT transmission mode using 5G) as well as a macro diversity transmission mode using more than one RAT (e.g., a macro diversity transmission mode using both LTE and 5G) as candidate transmission modes for the packet. The UE 115-b may select a transmission mode for the packet based on one or more factors, alone or in combination, according to the techniques described herein. For example, the UE 115-b may determine that a data type for the packet is a real-time data type (e.g., voice data) and may determine the transmission mode for the packet as a macro diversity transmission mode (e.g., the macro diversity transmission mode using both LTE and 5G) . In some cases, the UE 115-b may identify transmission modes and select a transmission mode for the packet at the shared processing layer 365.

Having selected the transmission mode for the packet as the macro diversity transmission mode, the UE 115-b may create two copies of the packet. For example, the UE 115-b may create two copies of the packet at the shared processing layer 365.

The UE 115-b may pass a first copy 370 of the packet from the shared processing layer 365 to a relatively lower RAT 1 processing layer 350, which may pass the first copy 370 of the packet to a RAT 1 physical layer 345, which may result in transmission of the first copy 370 of the packet to the MeNB 105-c. In some cases, RAT 1 processing layer 350 may comprise an RLC or MAC layer associated with the first RAT. In this way, the UE 115-b may transmit the first copy 370 of the packet to the MeNB 105-c via a first RAT (e.g., an LTE RAT) .

The UE 115-b may pass a second copy 375 of the packet from the shared processing layer 365 to a relatively lower RAT 2 processing layer 360, which may pass the second copy 375 of the packet to a RAT 2 physical layer 355, which may result in transmission of the second copy 375 of the packet to the SgNB 105-d. In some cases, RAT 2 processing layer 360 may comprise an RLC or MAC layer associated with the second RAT. In this way, the UE 115-b may transmit the second copy 375 of the packet to the SgNB 105-d via a second RAT (e.g., a 5G RAT) , substantially simultaneously with transmitting the first copy 370 of the packet to the MeNB 105-c via the first RAT (e.g., the LTE RAT) .

The MeNB 105-c may receive the first copy 370 of the packet via the first RAT, and the SgNB 105-d may receive the second copy 375 of the packet via the second RAT. The MeNB 105-c may determine a successful receipt of the packet if the MeNB 105-c is able to successfully decode the first copy 370 of the packet or if the SgNB 105-d is able to successfully decode the second copy 375 of the packet. For example, the MeNB 105-c may receive the first copy 370 of the packet at a RAT 1 physical layer 320, which may pass the first copy 335 to a relatively higher RAT 1 processing layer 315, which may pass the first copy 370 to a shared processing layer 310. Likewise, the SgNB 105-d may receive the second copy 375 of the packet 305 at a RAT 2 physical layer 330, which may pass the second copy 375 to a relatively higher RAT 2 processing layer 325, which may pass the second copy 375 to the shared processing layer 310. In some cases, the shared processing layer 310 may at least in part comprise a PDCP layer that is common to the LTE RAN protocol stack at the MeNB 105-c and the 5G RAN protocol stack at the SgNB 105-b. In other cases, the shared processing layer 310 may be a layer that is relatively higher than a PDCP layer. RAT 1 processing layer 315 and RAT 2 processing layer 325 may each comprise an RLC or MAC layer associated with the corresponding RAT.

In some cases, either the RAT 1 physical layer 320 and RAT 2 physical layer 330 or the RAT 1 processing layer 315 and RAT 2 processing layer 325 may attempt to decode the first copy 370 and second copy 375 of the packet and pass an indication of a successful or unsuccessful decode to the shared processing layer 310. In other cases, the shared processing layer 310 may attempt to decode the first copy 370 and second copy 375 of the packet.

If the MeNB 105-c determines a successful decode of at least one copy of the packet, the MeNB 105-c may discard any other copy of the packet. For example, if the MeNB 105-c determines a successful decode of the first copy 370 of the packet, the MeNB 105-c may discard the second copy 375, or vice versa. In some cases, the shared processing layer 310 may implement the determination of whether at least one copy of the packet has been successfully decoded and the discard of any other copy of the packet.

Although the example of process 400 has been described in terms of LTE and 5G, one of ordinary skill will recognize that the teachings herein may be extended to other RATs, other numbers of RATs, and other types of core networks. One of ordinary skill will likewise recognize that a 5G base station may act as a master base station (e.g, an MgNB) while an LTE base station may act as secondary base station (e.g., an SeNB) . One of ordinary skill will also recognize that other processing steps or logical layers may be added to or interposed between the processing steps and logical layers shown in example process 400.

FIG. 5 shows a block diagram 500 of a wireless device 505 that supports macro diversity communication in accordance with aspects of the present disclosure. Wireless device 505 may be an example of aspects of a UE 115 or base station 105 as described herein. Wireless device 505 may include receiver 510, communications manager 515, and transmitter 520. Wireless device 505 may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses) .

Receiver 510 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to macro diversity communication, etc. ) . Information may be passed on to other components of the device. The receiver 510 may be an example of aspects of the transceiver 835 described with reference to FIG. 8 or the transceiver 935 described with reference to FIG. 9. The receiver 510 may utilize a single antenna or a set of antennas.

Communications manager 515 may be an example of aspects of the communications manager 815 described with reference to FIG. 8 or the communications manager 915 described with reference to FIG. 9.

Communications manager 515 and/or at least some of its various sub-components may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions of the communications manager 515 and/or at least some of its various sub-components may be executed by a general-purpose processor, a digital signal processor (DSP) , an application-specific integrated circuit (ASIC) , an field-programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described in the present disclosure. The communications manager 515 and/or at least some of its various sub-components may be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations by one or more physical devices. In some examples, communications manager 515 and/or at least some of its various sub-components may be a separate and distinct component in accordance with various aspects of the present disclosure. In other examples, communications manager 515 and/or at least some of its various sub-components may be combined with one or more other hardware components, including but not limited to an I/O component, a transceiver, a network server, another computing device, one or more other components described in the present disclosure, or a combination thereof in accordance with various aspects of the present disclosure.

Communications manager 515 may identify a first transmission mode that includes wireless transmission of one copy of a packet using a first RAT, identify a second transmission mode that includes wireless transmission of a first copy of the packet using the first RAT and a second copy of the packet using a second RAT, select, from the first transmission mode or the second transmission mode, a transmission mode for wireless transmission of the packet, and transmit the packet in accordance with the transmission mode. The communications manager 515 may also receive a first copy of a packet via a first RAT, receive a second copy of the packet via a second RAT, and determine a successful receipt of the packet based on a successful decode of at least one copy of the packet.

Transmitter 520 may transmit signals generated by other components of the device. In some examples, the transmitter 520 may be collocated with a receiver 510 in a transceiver module. For example, the transmitter 520 may be an example of aspects of the transceiver 835 described with reference to FIG. 8. The transmitter 520 may utilize a single antenna or a set of antennas.

FIG. 6 shows a block diagram 600 of a wireless device 605 that supports macro diversity communication in accordance with aspects of the present disclosure. Wireless device 605 may be an example of aspects of a wireless device 505 or a UE 115 or base station 105 as described with reference to FIG. 5. Wireless device 605 may include receiver 610, communications manager 615, and transmitter 620. Wireless device 605 may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses) .

Receiver 610 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to macro diversity communication, etc. ) . Information may be passed on to other components of the device. The receiver 610 may be an example of aspects of the transceiver 835 described with reference to FIG. 8 or the transceiver 935 described with reference to FIG. 9. The receiver 610 may utilize a single antenna or a set of antennas.

Communications manager 615 may be an example of aspects of the communications manager 815 described with reference to FIG. 8 or the communications manager 915 described with reference to FIG. 9.

Communications manager 615 may also include first transmission mode manager 625, second transmission mode manager 630, transmission manager 635, first RAT reception manager 640, second RAT reception manager 645, and reception manager 650.

When wireless device 605 acts as a transmitting node, first transmission mode manager 625 may identify a first transmission mode that includes wireless transmission of one copy of a packet using a first RAT. In some cases, transmitting the packet in accordance with the first transmission mode includes transmitting the one copy of the packet using a permissible transmit power, which may be a maximum transmit power. Second transmission mode manager 630 may identify a second transmission mode that includes wireless transmission of a first copy of the packet using the first RAT and a second copy of the packet using a second RAT. In some cases, one of the first RAT and second RAT includes an LTE RAT and another of the first RAT and the second RAT includes a 5G RAT.

Transmission manager 635 may select, from the first transmission mode or the second transmission mode, a transmission mode for wireless transmission of the packet, and transmit the packet in accordance with the transmission mode. Transmission manager 635 may select the transmission mode based on a data type of the packet, a permissible transmit power for the packet, a channel quality for at least one of the first RAT and the second RAT, any combination thereof, or based on some other factor. For example, transmission manager 635 may determine the transmission mode as the second transmission mode based at least in part on determining that the data type of the packet is a real-time data type. As another example, transmission manager 635 may determine the transmission mode as the second transmission mode, and thus determine to transmit the second copy of the packet using the second RAT, based at least in part on the channel quality for at least one of the first RAT and the second RAT.

When wireless device 605 acts as a receiving node, first RAT reception manager 640 may receive a first copy of a packet via a first RAT, and second RAT reception manager 645 may receive a second copy of the packet via a second RAT. Reception manager 650 may determine a successful receipt of the packet based on a successful decode of at least one copy of the packet. For example, reception manager 650 may receive, at a shared processing layer common to at least the first RAT and the second RAT, the first copy of the packet from a first lower processing layer specific to the first RAT and the second copy of the packet from a second lower processing layer specific to the second RAT, determine the successful decode of at least one copy of the packet, and discard at least one other copy of the packet.

Transmitter 620 may transmit signals generated by other components of the device. In some examples, the transmitter 620 may be collocated with a receiver 610 in a transceiver module. For example, the transmitter 620 may be an example of aspects of the transceiver 835 described with reference to FIG. 8. The transmitter 620 may utilize a single antenna or a set of antennas.

FIG. 7 shows a block diagram 700 of a communications manager 715 that supports macro diversity communication in accordance with aspects of the present disclosure. The communications manager 715 may be an example of aspects of a communications manager 515, a communications manager 615, a communications manager 815, or a communications manager 915 as described with reference to FIGs. 5, 6, 8, and 9. The communications manager 715 may include first transmission mode manager 720, second transmission mode manager 725, transmission manager 730, first RAT reception manager 735, second RAT reception manager 740, reception manager 745, shared processing layer 750, first lower processing layer 755, second lower processing layer 760, data type component 765, transmission power manager 770, and channel quality manager 775. Each of these modules may communicate, directly or indirectly, with one another (e.g., via one or more buses) .

When the node that includes communications manager 715 acts as a transmitting node, first transmission mode manager 720 may identify a first transmission mode that includes wireless transmission of one copy of a packet using a first RAT. In some cases, transmitting the packet in accordance with the first transmission mode includes transmitting the one copy of the packet using a permissible transmit power, which may be a maximum transmit power. Second transmission mode manager 725 may identify a second transmission mode that includes wireless transmission of a first copy of the packet using the first RAT and a second copy of the packet using a second RAT. In some cases, one of the first RAT and second RAT includes an LTE RAT and another of the first RAT and the second RAT includes a 5G RAT.

Transmission manager 730 may select, from the first transmission mode or the second transmission mode, a transmission mode for wireless transmission of the packet and transmit the packet in accordance with the transmission mode. Transmission manager 730 may select the transmission mode based on a data type of the packet, based on a permissible transmit power for the packet, based on a channel quality for at least one of the first RAT and the second RAT, any combination thereof, or based on some other factor. For example, transmission manager 730 may determine the transmission mode as the second transmission mode based at least in part on determining that the data type of the packet is a real-time data type. As another example, transmission manager 730 may determine the transmission mode as the second transmission mode, and thus determine to transmit the second copy of the packet using the second RAT, based at least in part on the channel quality for at least one of the first RAT and the second RAT.

In some cases, transmitting the packet in accordance with the second transmission mode includes creating the first copy of the packet and the second copy of the packet at a shared processing layer 750 common to at least the first RAT and the second RAT. Shared processing layer 750 may pass the first copy of the packet to a first lower processing layer 755, the first lower processing layer specific to the first RAT and pass the second copy of the packet to a second lower processing layer 760, the second lower processing layer specific to the second RAT. In some cases, the shared processing layer 750 common to at least the first RAT and the second RAT is common to at least a first base station that supports the first RAT and a second base station that supports the second RAT. In some cases, the first lower processing layer 755 is specific to a first base station, and the second lower processing layer 760 is specific to a second base station-the first base station and the second base station may be part of a same physical structure, as illustrated in the example FIG. 7, or may be part of distinct physical structures linked by a communication interface, in which case the communications manager 715 of an individual base station may include only one of the first lower processing layer and the second lower processing layer 760. In some cases, the shared processing layer 750 common to at least the first RAT and the second RAT is common to a UE that supports the first RAT and the second RAT, and first lower processing layer 755 and the second lower processing layer 760 may be included in the UE. In some cases, the shared processing layer 750 includes a PDCP layer.

Data type component 765 may determine a data type of the packet. In some cases, selecting the transmission mode further includes determining that the data type for the packet is a real-time data type. In some cases, the real-time data type includes voice data, videoconferencing data, or any combination thereof.

Transmission power manager 770 may determine a permissible transmit power for the packet. In some cases, selecting the transmission mode includes determining the transmission mode as the first transmission mode based on the permissible transmit power being less than a transmission mode power threshold.

Channel quality manager 775 may determine a channel quality associated with at least one of the first RAT and the second RAT.

When the node that includes communications manager 715 acts as a receiving node, first RAT reception manager 735 may receive a first copy of a packet via a first RAT, and second RAT reception manager 740 may receive a second copy of the packet via a second RAT. Reception manager 745 may determine a successful receipt of the packet based on a successful decode of at least one copy of the packet. For example, reception manager 745 may receive, at a shared processing layer common to at least the first RAT and the second RAT, the first copy of the packet from a first lower processing layer specific to the first RAT and the second copy of the packet from a second lower processing layer specific to the second RAT, determine the successful decode of at least one copy of the packet, and discard at least one other copy of the packet.

FIG. 8 shows a diagram of a system 800 including a device 805 that supports macro diversity communication in accordance with aspects of the present disclosure. Device 805 may be an example of or include the components of wireless device 505, wireless device 605, or a UE 115 as described above, e.g., with reference to FIGs. 5 and 6. Device 805 may include components for bi-directional voice and data communications including components for transmitting and receiving communications, including UE communications manager 815, processor 820, memory 825, software 830, transceiver 835, antenna 840, and I/O controller 845. These components may be in electronic communication via one or more buses (e.g., bus 810) . Device 805 may communicate wirelessly with one or more base stations 105.

Processor 820 may include an intelligent hardware device, (e.g., a general-purpose processor, a DSP, a central processing unit (CPU) , a microcontroller, an ASIC, an FPGA, a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof) . In some cases, processor 820 may be configured to operate a memory array using a memory controller. In other cases, a memory controller may be integrated into processor 820. Processor 820 may be configured to execute computer-readable instructions stored in a memory to perform various functions (e.g., functions or tasks supporting macro diversity communication) .

Memory 825 may include random access memory (RAM) and read only memory (ROM) . The memory 825 may store computer-readable, computer-executable software 830 including instructions that, when executed, cause the processor to perform various functions described herein. In some cases, the memory 825 may contain, among other things, a basic input/output system (BIOS) which may control basic hardware or software operation such as the interaction with peripheral components or devices.

Software 830 may include code to implement aspects of the present disclosure, including code to support macro diversity communication. Software 830 may be stored in a non-transitory computer-readable medium such as system memory or other memory. In some cases, the software 830 may not be directly executable by the processor but may cause a computer (e.g., when compiled and executed) to perform functions described herein.

Transceiver 835 may communicate bi-directionally, via one or more antennas, wired, or wireless links as described above. For example, the transceiver 835 may represent a wireless transceiver and may communicate bi-directionally with another wireless transceiver. The transceiver 835 may also include a modem to modulate the packets and provide the modulated packets to the antennas for transmission, and to demodulate packets received from the antennas.

In some cases, the wireless device may include a single antenna 840. However, in some cases the device may have more than one antenna 840, which may be capable of concurrently transmitting or receiving multiple wireless transmissions.

I/O controller 845 may manage input and output signals for device 805. I/O controller 845 may also manage peripherals not integrated into device 805. In some cases, I/O controller 845 may represent a physical connection or port to an external peripheral. In some cases, I/O controller 845 may utilize an operating system such as

or another known operating system. In other cases, I/O controller 845 may represent or interact with a modem, a keyboard, a mouse, a touchscreen, or a similar device. In some cases, I/O controller 845 may be implemented as part of a processor. In some cases, a user may interact with device 805 via I/O controller 845 or via hardware components controlled by I/O controller 845.

FIG. 9 shows a diagram of a system 900 including a device 905 that supports macro diversity communication in accordance with aspects of the present disclosure. Device 905 may be an example of or include the components of wireless device 505, wireless device 605, or a UE 115 as described above, e.g., with reference to FIGs. 5 and 6. Device 905 may include components for bi-directional voice and data communications including components for transmitting and receiving communications, including base station communications manager 915, processor 920, memory 925, software 930, transceiver 935, antenna 940, and network communications manager 945, and inter-station communications manager 950. These components may be in electronic communication via one or more buses (e.g., bus 910) . Device 905 may communicate wirelessly with one or more UEs 115.

Processor 920 may include an intelligent hardware device, (e.g., a general-purpose processor, a DSP, a CPU, a microcontroller, an ASIC, an FPGA, a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof) . In some cases, processor 920 may be configured to operate a memory array using a memory controller. In other cases, a memory controller may be integrated into processor 920. Processor 920 may be configured to execute computer-readable instructions stored in a memory to perform various functions (e.g., functions or tasks supporting macro diversity communication) .

Memory 925 may include RAM and ROM. The memory 925 may store computer-readable, computer-executable software 930 including instructions that, when executed, cause the processor to perform various functions described herein. In some cases, the memory 925 may contain, among other things, a BIOS which may control basic hardware or software operation such as the interaction with peripheral components or devices.

Software 930 may include code to implement aspects of the present disclosure, including code to support macro diversity communication. Software 930 may be stored in a non-transitory computer-readable medium such as system memory or other memory. In some cases, the software 930 may not be directly executable by the processor but may cause a computer (e.g., when compiled and executed) to perform functions described herein.

Transceiver 935 may communicate bi-directionally, via one or more antennas, wired, or wireless links as described above. For example, the transceiver 935 may represent a wireless transceiver and may communicate bi-directionally with another wireless transceiver. The transceiver 935 may also include a modem to modulate the packets and provide the modulated packets to the antennas for transmission, and to demodulate packets received from the antennas.

In some cases, the wireless device may include a single antenna 940. However, in some cases the device may have more than one antenna 940, which may be capable of concurrently transmitting or receiving multiple wireless transmissions.

Network communications manager 945 may manage communications with the core network (e.g., via one or more wired backhaul links) . For example, the network communications manager 945 may manage the transfer of data communications for client devices, such as one or more UEs 115.

Inter-station communications manager 950 may manage communications with other base station 105, and may include a controller or scheduler for controlling communications with UEs 115 in cooperation with other base stations 105. For example, the inter-station communications manager 950 may coordinate scheduling for transmissions to UEs 115 for various interference mitigation techniques such as beamforming or joint transmission or for macro diversity communications as described herein. In some examples, inter-station communications manager 950 may provide an X2 interface within an LTE/LTE-A wireless communication network technology or an Xx or other inter-base station interface as described herein in order to provide communication between base stations 105.

FIG. 10 shows a flowchart illustrating a method 1000 for macro diversity communication in accordance with aspects of the present disclosure. The operations of method 1000 may be implemented by a UE 115 or base station 105 or its components as described herein. For example, the operations of method 1000 may be performed by a communications manager as described with reference to FIGs. 5 through 7. In some examples, a UE 115 or base station 105 may execute a set of codes to control the functional elements of the device to perform the functions described below. Additionally or alternatively, the UE 115 or base station 105 may perform aspects of the functions described below using special-purpose hardware.

At 1005 the UE 115 or base station 105 may identify a first transmission mode that comprises wireless transmission of one copy of a packet using a first RAT. The operations of 1005 may be performed according to the methods described herein. In certain examples, aspects of the operations of 1005 may be performed by a first transmission mode manager as described with reference to FIGs. 5 through 7.

At 1010 the UE 115 or base station 105 may identify a second transmission mode that comprises wireless transmission of a first copy of the packet using the first RAT and a second copy of the packet using a second RAT. The operations of 1010 may be performed according to the methods described herein. In certain examples, aspects of the operations of 1010 may be performed by a second transmission mode manager as described with reference to FIGs. 5 through 7.

At 1015 the UE 115 or base station 105 may select, from the first transmission mode or the second transmission mode, a transmission mode for wireless transmission of the packet. The operations of 1015 may be performed according to the methods described herein. In certain examples, aspects of the operations of 1015 may be performed by a transmission manager as described with reference to FIGs. 5 through 7.

At 1020 the UE 115 or base station 105 may transmit the packet in accordance with the transmission mode. The operations of 1020 may be performed according to the methods described herein. In certain examples, aspects of the operations of 1020 may be performed by a transmission manager as described with reference to FIGs. 5 through 7.

FIG. 11 shows a flowchart illustrating a method 1100 for macro diversity communication in accordance with aspects of the present disclosure. The operations of method 1100 may be implemented by a UE 115 or base station 105 or its components as described herein. For example, the operations of method 1100 may be performed by a communications manager as described with reference to FIGs. 5 through 7. In some examples, a UE 115 or base station 105 may execute a set of codes to control the functional elements of the device to perform the functions described below. Additionally or alternatively, the UE 115 or base station 105 may perform aspects of the functions described below using special-purpose hardware.

At 1105 the UE 115 or base station 105 may receive a first copy of a packet via a first RAT. The operations of 1105 may be performed according to the methods described herein. In certain examples, aspects of the operations of 1105 may be performed by a first RAT reception manager as described with reference to FIGs. 5 through 7.

At 1110 the UE 115 or base station 105 may receive a second copy of the packet via a second RAT. The operations of 1110 may be performed according to the methods described herein. In certain examples, aspects of the operations of 1110 may be performed by a second RAT reception manager as described with reference to FIGs. 5 through 7.

At 1115 the UE 115 or base station 105 may determine a successful receipt of the packet based at least in part on a successful decode of at least one copy of the packet. The operations of 1115 may be performed according to the methods described herein. In certain examples, aspects of the operations of 1115 may be performed by a reception manager as described with reference to FIGs. 5 through 7.

It should be noted that the methods described above describe possible implementations, and that the operations and the steps may be rearranged or otherwise modified and that other implementations are possible. Further, aspects from two or more of the methods may be combined.

Techniques described herein may be used for various wireless communications systems such as code division multiple access (CDMA) , time division multiple access (TDMA) , frequency division multiple access (FDMA) , orthogonal frequency division multiple access (OFDMA) , single carrier frequency division multiple access (SC-FDMA) , and other systems. A CDMA system may implement a radio technology such as CDMA2000, Universal Terrestrial Radio Access (UTRA) , etc. CDMA2000 covers IS-2000, IS-95, and IS-856 standards. IS-2000 Releases may be commonly referred to as CDMA2000 1X, 1X, etc. IS-856 (TIA-856) is commonly referred to as CDMA2000 1xEV-DO, High Rate Packet Data (HRPD) , etc. UTRA includes Wideband CDMA (WCDMA) and other variants of CDMA. A TDMA system may implement a radio technology such as Global System for Mobile Communications (GSM) .

An OFDMA system may implement a radio technology such as Ultra Mobile Broadband (UMB) , Evolved UTRA (E-UTRA) , Institute of Electrical and Electronics Engineers (IEEE) 802.11 (Wi-Fi) , IEEE 802.16 (WiMAX) , IEEE 802.20, Flash-OFDM, etc. UTRA and E-UTRA are part of Universal Mobile Telecommunications System (UMTS) . LTE and LTE-Aare releases of UMTS that use E-UTRA. UTRA, E-UTRA, UMTS, LTE, LTE-A, NR, and GSM are described in documents from the organization named “3rd Generation Partnership Project” (3GPP) . CDMA2000 and UMB are described in documents from an organization named “3rd Generation Partnership Project 2” (3GPP2) . The techniques described herein may be used for the systems and radio technologies mentioned above as well as other systems and radio technologies. While aspects of an LTE or an NR system may be described for purposes of example, and LTE or NR terminology may be used in much of the description, the techniques described herein are applicable beyond LTE or NR applications.

A macro cell generally covers a relatively large geographic area (e.g., several kilometers in radius) and may allow unrestricted access by UEs 115 with service subscriptions with the network provider. A small cell may be associated with a lower-powered base station 105, as compared with a macro cell, and a small cell may operate in the same or different (e.g., licensed, unlicensed, etc. ) frequency bands as macro cells. Small cells may include pico cells, femto cells, and micro cells according to various examples. A pico cell, for example, may cover a small geographic area and may allow unrestricted access by UEs 115 with service subscriptions with the network provider. A femto cell may also cover a small geographic area (e.g., a home) and may provide restricted access by UEs 115 having an association with the femto cell (e.g., UEs 115 in a closed subscriber group (CSG) , UEs 115 for users in the home, and the like) . An eNB for a macro cell may be referred to as a macro eNB. An eNB for a small cell may be referred to as a small cell eNB, a pico eNB, a femto eNB, or a home eNB. An eNB may support one or multiple (e.g., two, three, four, and the like) cells, and may also support communications using one or multiple component carriers.

The wireless communications system 100 or systems described herein may support synchronous or asynchronous operation. For synchronous operation, the base stations 105 may have similar frame timing, and transmissions from different base stations 105 may be approximately aligned in time. For asynchronous operation, the base stations 105 may have different frame timing, and transmissions from different base stations 105 may not be aligned in time. The techniques described herein may be used for either synchronous or asynchronous operations.

Information and signals described herein may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

The various illustrative blocks and modules described in connection with the disclosure herein may be implemented or performed with a general-purpose processor, a digital signal processor (DSP) , an application-specific integrated circuit (ASIC) , a field-programmable gate array (FPGA) or other programmable logic device (PLD) , discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general-purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices (e.g., a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration) .

The functions described herein may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Other examples and implementations are within the scope of the disclosure and appended claims. For example, due to the nature of software, functions described above can be implemented using software executed by a processor, hardware, firmware, hardwiring, or combinations of any of these. Features implementing functions may also be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations or by separate physical devices.

Computer-readable media includes both non-transitory computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A non-transitory storage medium may be any available medium that can be accessed by a general purpose or special purpose computer. By way of example, and not limitation, non-transitory computer-readable media may comprise random-access memory (RAM) , read-only memory (ROM) , electrically erasable programmable read only memory (EEPROM) , flash memory, compact disk (CD) ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other non-transitory medium that can be used to carry or store desired program code means in the form of instructions or data structures and that can be accessed by a general-purpose or special-purpose computer, or a general-purpose or special-purpose processor. Also, any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL) , or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of medium. Disk and disc, as used herein, include CD, laser disc, optical disc, digital versatile disc (DVD) , floppy disk and Blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above are also included within the scope of computer-readable media.

As used herein, including in the claims, “or” as used in a list of items (e.g., a list of items prefaced by a phrase such as “at least one of” or “one or more of” ) indicates an inclusive list such that, for example, a list of at least one of A, B, or C means A or B or C or AB or AC or BC or ABC (i.e., A and B and C) . Also, as used herein, the phrase “based on” shall not be construed as a reference to a closed set of conditions. For example, an exemplary step that is described as “based on condition A” may be based on both a condition A and a condition B without departing from the scope of the present disclosure. In other words, as used herein, the phrase “based on” shall be construed in the same manner as the phrase “based at least in part on. ”

In the appended figures, similar components or features may have the same reference label. Further, various components of the same type may be distinguished by following the reference label by a dash and a second label that distinguishes among the similar components. If just the first reference label is used in the specification, the description is applicable to any one of the similar components having the same first reference label irrespective of the second reference label, or other subsequent reference label.

The description set forth herein, in connection with the appended drawings, describes example configurations and does not represent all the examples that may be implemented or that are within the scope of the claims. The term “exemplary” used herein means “serving as an example, instance, or illustration, ” and not “preferred” or “advantageous over other examples. ” The detailed description includes specific details for the purpose of providing an understanding of the described techniques. These techniques, however, may be practiced without these specific details. In some instances, well-known structures and devices are shown in block diagram form in order to avoid obscuring the concepts of the described examples.

The description herein is provided to enable a person skilled in the art to make or use the disclosure. Various modifications to the disclosure will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other variations without departing from the scope of the disclosure. Thus, the disclosure is not limited to the examples and designs described herein, but is to be accorded the broadest scope consistent with the principles and novel features disclosed herein.

Claims

A method for wireless communication, comprising:

identifying a first transmission mode that comprises wireless transmission of one copy of a packet using a first radio access technology (RAT) ;

identifying a second transmission mode that comprises wireless transmission of a first copy of the packet using the first RAT and a second copy of the packet using a second RAT;

selecting, from the first transmission mode or the second transmission mode, a transmission mode for wireless transmission of the packet; and

transmitting the packet in accordance with the transmission mode.
The method of claim 1, wherein transmitting the packet in accordance with the second transmission mode comprises:

creating the first copy of the packet and the second copy of the packet at a shared processing layer common to at least the first RAT and the second RAT;

passing the first copy of the packet to a first lower processing layer, the first lower processing layer specific to the first RAT; and

passing the second copy of the packet to a second lower processing layer, the second lower processing layer specific to the second RAT.
The method of claim 2, wherein:

the shared processing layer common to at least the first RAT and the second RAT is common to at least a first base station that supports the first RAT and a second base station that supports the second RAT;

the first lower processing layer is specific to the first base station; and

the second lower processing layer is specific to the second base station.
The method of claim 2, wherein the shared processing layer common to at least the first RAT and the second RAT is common to a user equipment (UE) that supports the first RAT and the second RAT.
The method of claim 2, wherein the shared processing layer comprises a packet data convergence protocol (PDCP) layer.
The method of claim 1, wherein selecting the transmission mode is based at least in part on a data type of the packet.
The method of claim 6, wherein selecting the transmission mode further comprises:

determining that the data type for the packet is a real-time data type; and

determining the transmission mode as the second transmission mode.
The method of claim 7, wherein the real-time data type comprises voice data, videoconferencing data, or any combination thereof.
The method of claim 1, wherein selecting the transmission mode is based at least in part on a permissible transmit power for the packet.
The method of claim 9, wherein selecting the transmission mode comprises:

determining the transmission mode as the first transmission mode based at least in part on the permissible transmit power being less than a transmission mode power threshold.
The method of claim 9, wherein transmitting the packet in accordance with the first transmission mode comprises:

transmitting the one copy of the packet using the permissible transmit power.
The method of claim 1, wherein selecting the transmission mode is based at least in part on a channel quality for at least one of the first RAT and the second RAT.
The method of claim 12, further comprising:

determining a channel quality associated with at least one of the first RAT and the second RAT; and

determining to transmit the second copy of the packet using the second RAT based at least in part on the channel quality.
The method of claim 1, wherein one of the first RAT and the second RAT comprises a long-term evolution (LTE) RAT and another of the first RAT and the second RAT comprises a fifth generation (5G) RAT.
A method for wireless communication, comprising:

receiving a first copy of a packet via a first radio access technology (RAT) ;

receiving a second copy of the packet via a second RAT; and

determining a successful receipt of the packet based at least in part on a successful decode of at least one copy of the packet.
The method of claim 15, further comprising:

receiving, at a shared processing layer common to at least the first RAT and the second RAT, the first copy of the packet from a first lower processing layer specific to the first RAT and the second copy of the packet from a second lower processing layer specific to the second RAT;

determining the successful decode of at least one copy of the packet; and

discarding at least one other copy of the packet.
An apparatus for wireless communication, comprising:

means for identifying a first transmission mode that comprises wireless transmission of one copy of a packet using a first radio access technology (RAT) ;

means for identifying a second transmission mode that comprises wireless transmission of a first copy of the packet using the first RAT and a second copy of the packet using a second RAT;

means for selecting, from the first transmission mode or the second transmission mode, a transmission mode for wireless transmission of the packet; and

means for transmitting the packet in accordance with the transmission mode.
An apparatus for wireless communication, comprising:

means for receiving a first copy of a packet via a first radio access technology (RAT) ;

means for receiving a second copy of the packet via a second RAT; and

means for determining a successful receipt of the packet based at least in part on a successful decode of at least one copy of the packet.
An apparatus for wireless communication, comprising:

a processor;

memory in electronic communication with the processor; and

instructions stored in the memory and executable by the processor to cause the apparatus to:

identify a first transmission mode that comprises wireless transmission of one copy of a packet using a first radio access technology (RAT) ;

identify a second transmission mode that comprises wireless transmission of a first copy of the packet using the first RAT and a second copy of the packet using a second RAT;

select, from the first transmission mode or the second transmission mode, a transmission mode for wireless transmission of the packet; and

transmit the packet in accordance with the transmission mode.
An apparatus for wireless communication, comprising:

a processor;

memory in electronic communication with the processor; and

instructions stored in the memory and executable by the processor to cause the apparatus to:

receive a first copy of a packet via a first radio access technology (RAT) ;

receive a second copy of the packet via a second RAT; and

determine a successful receipt of the packet based at least in part on a successful decode of at least one copy of the packet.
A non-transitory computer-readable medium storing code for wireless communication, the code comprising instructions executable by a processor to:

identify a first transmission mode that comprises wireless transmission of one copy of a packet using a first radio access technology (RAT) ;

identify a second transmission mode that comprises wireless transmission of a first copy of the packet using the first RAT and a second copy of the packet using a second RAT;

select, from the first transmission mode or the second transmission mode, a transmission mode for wireless transmission of the packet; and

transmit the packet in accordance with the transmission mode.
A non-transitory computer-readable medium storing code for wireless communication, the code comprising instructions executable by a processor to:

receive a first copy of a packet via a first radio access technology (RAT) ;

receive a second copy of the packet via a second RAT; and

determine a successful receipt of the packet based at least in part on a successful decode of at least one copy of the packet.