CN110999383B

CN110999383B - Hybrid autonomous and network activation for carrier aggregation

Info

Publication number: CN110999383B
Application number: CN201780094107.9A
Authority: CN
Inventors: 于�玲; 李海涛; J·斯坦科扎克; V·V·潘
Original assignee: Nokia Shanghai Bell Co Ltd; Nokia Solutions and Networks Oy
Current assignee: Nokia Shanghai Bell Co Ltd; Nokia Solutions and Networks Oy
Priority date: 2017-08-21
Filing date: 2017-08-21
Publication date: 2023-03-10
Anticipated expiration: 2037-08-21
Also published as: CN110999383A; WO2019036863A1

Abstract

Example embodiments of the present disclosure relate to hybrid autonomous and network activation of carrier aggregation. According to some embodiments, a user equipment estimates one or more traffic loads associated with one or more of a plurality of resource pools for a plurality of carriers available for carrier aggregation. The user equipment is then selectively enabled for autonomous activation of carrier aggregation based on the one or more traffic loads. The network controller provides information indicative of the one or more thresholds. The network controller may then receive signaling indicating whether the user equipment is enabled for autonomous activation of carrier aggregation based on a comparison of the one or more thresholds with one or more traffic loads estimated by the user equipment. In some cases, the traffic load is indicated by a Channel Busy Ratio (CBR) that represents a fraction of time that one or more of the plurality of resource pools is busy.

Description

Hybrid autonomous and network activation for carrier aggregation

Background

Vehicle-to-vehicle (V2V) and vehicle-to-all (V2X) communications are a form of device-to-device (D2D) communications that take into account the characteristics of vehicles such as cars and trucks. For example, V2V or V2X communications may be performed on an interface that is enhanced for vehicular use cases and supports communications between nodes traveling at high relative speeds (up to 250 km/h) and high density vehicles (e.g., thousands of nodes). This interface may be referred to as a PC5 or a side chain (SL) interface. Services provided using V2V or V2X communication include: a fleet of vehicles that enables the vehicles to dynamically form a fleet of vehicles that travel together; an extended sensor that enables the exchange of raw or processed data between a vehicle, roadside unit, pedestrian device and V2X application server; advanced driving for realizing semi-automatic or fully automatic driving; and remote driving, which enables a remote driver or a V2X application to operate a remote vehicle.

Disclosure of Invention

The following presents a simplified summary of the disclosed subject matter in order to provide a basic understanding of some aspects of the disclosed subject matter. This summary is not an extensive overview of the disclosed subject matter. It is not intended to identify key or critical elements of the disclosed subject matter or to delineate the scope of the disclosed subject matter. Its sole purpose is to present some concepts in a simplified form as a prelude to the more detailed description that is discussed later.

In some embodiments, a method for hybrid autonomous and network activation for carrier aggregation is provided. The method comprises the following steps: at least one traffic load is estimated at a user equipment, the at least one traffic load being associated with at least one resource pool of a plurality of resource pools for a plurality of carriers available for carrier aggregation. The method further comprises the following steps: the user equipment is selectively enabled for autonomous activation of carrier aggregation based on at least one traffic load.

In some embodiments, selectively enabling autonomous activation of carrier aggregation by a user equipment comprises: the at least one traffic load is compared with at least one first threshold.

In some embodiments, selectively enabling autonomous activation of carrier aggregation by a user equipment comprises: enabling autonomous activation of carrier aggregation by the user equipment in response to the at least one traffic load being less than the at least one first threshold.

In some embodiments, the method further comprises: information indicative of the at least one first threshold is received from the network controller via broadcast signaling or signaling specific to the user equipment.

In some embodiments, the method further comprises: transmitting a request for network activation for carrier aggregation from a user equipment in response to at least one traffic load being greater than at least one first threshold.

In some embodiments, the method further comprises: information indicative of at least one second threshold value is received at the user equipment, the at least one second threshold value being used for comparison with at least one traffic load.

In some embodiments, receiving information comprises receiving information indicating: whether the user equipment is allowed to enter an idle mode and selectively enable autonomous activation of carrier aggregation using at least one second threshold.

In some embodiments, the method further comprises: providing, from a user equipment in response to enabling autonomous activation of carrier aggregation, an indication of: whether the at least one first threshold or the at least one second threshold is used to enable autonomous activation of carrier aggregation.

In some embodiments, estimating the at least one traffic load comprises: at least one Channel Busy Ratio (CBR) is determined, the at least one CBR representing a fraction of time at least one resource pool of a plurality of resource pools is busy.

In some embodiments, a method for hybrid autonomous and network activation for carrier aggregation is provided. The method comprises the following steps: information is provided from a network controller to a user equipment indicating at least one first threshold for comparing with at least one traffic load associated with at least one of a plurality of resource pools for a plurality of carriers available for carrier aggregation. The method further comprises the following steps: a request for network activation for carrier aggregation is received at a network controller and from a user equipment in response to at least one traffic load being greater than at least one first threshold.

In some embodiments, providing information indicative of the at least one first threshold comprises: information is provided indicating at least one first threshold for comparison with at least one Channel Busy Ratio (CBR), the at least one CBR representing a fraction of time at which at least one of a plurality of resource pools is busy.

In some embodiments, providing information indicative of the at least one first threshold comprises at least one of: broadcasting information indicative of the at least one first threshold value and transmitting a dedicated signal to the user equipment, the dedicated signal comprising the information indicative of the at least one first threshold value.

In some embodiments, the method further comprises: signaling is received at the network controller indicating whether the user equipment is enabled for autonomous activation of carrier aggregation based on the comparison.

In some embodiments, the method further comprises: information is provided from the network controller to the user equipment indicating at least one second threshold value for comparison with at least one traffic load.

In some embodiments, providing information comprises providing information indicative of: whether the user equipment is allowed to enter an idle mode and selectively enable autonomous activation of carrier aggregation using at least one second threshold.

In some embodiments, the method further comprises: receiving, at a network controller from a user equipment in response to enabling autonomous activation of carrier aggregation, an indication of: whether the at least one first threshold or the at least one second threshold is used to enable autonomous activation of carrier aggregation.

In some embodiments, the method further comprises: providing, from the network controller, a reconfiguration message to configure the user equipment for network resource allocation or to configure the user equipment for carrier aggregation with at least one other resource pool having a capacity that allows carrier aggregation by the user equipment.

In some embodiments, there is provided a user equipment comprising: a transceiver configured to estimate at least one traffic load associated with at least one resource pool of a plurality of resource pools for a plurality of carriers available for carrier aggregation. The user equipment further comprises: a processor configured to selectively enable autonomous activation of carrier aggregation by a user equipment based on at least one traffic load.

In some embodiments, the processor is configured to: the at least one traffic load is compared with at least one first threshold.

In some embodiments, the processor is configured to: enabling autonomous activation of carrier aggregation by the user equipment in response to the at least one traffic load being less than the at least one first threshold.

In some embodiments, the transceiver is configured to: information indicative of the at least one first threshold is received from the network controller via broadcast signaling or signaling specific to the user equipment.

In some embodiments, the transceiver is configured to: transmitting a request for network activation for carrier aggregation in response to at least one traffic load being greater than at least one first threshold.

In some embodiments, the transceiver is configured to: information is received indicating at least one second threshold value for comparison with at least one traffic load.

In some embodiments, the transceiver is configured to: receiving information indicating whether the user equipment is allowed to enter an idle mode, and the processor is configured to: the autonomous activation of carrier aggregation is selectively enabled using at least one second threshold.

In some embodiments, the transceiver is configured to: providing, in response to enabling autonomous activation of carrier aggregation, an indication of: whether the at least one first threshold or the at least one second threshold is used to enable autonomous activation of carrier aggregation.

In some embodiments, the transceiver is configured to: at least one Channel Busy Ratio (CBR) is determined, the at least one CBR representing a fraction of time at which at least one of the plurality of resource pools is busy.

In some embodiments, there is provided an apparatus comprising: a processor configured to generate information indicative of at least one first threshold for comparison with at least one traffic load associated with at least one of a plurality of resource pools for a plurality of carriers available for carrier aggregation. The processor further comprises: a transceiver configured to transmit the information to a user equipment and receive a request for network activation for carrier aggregation from the user equipment in response to at least one traffic load being greater than at least one first threshold.

In some embodiments, the transceiver is configured to: information is provided indicating at least one first threshold for comparison with at least one Channel Busy Ratio (CBR), the at least one CBR representing a fraction of time at which at least one of a plurality of resource pools is busy.

In some embodiments, the transceiver is configured to perform at least one of: broadcasting information indicative of the at least one first threshold value and transmitting a dedicated signal to the user equipment, the dedicated signal comprising the information indicative of the at least one first threshold value.

In some embodiments, the transceiver is configured to: signaling is received indicating whether the user equipment is enabled for autonomous activation of carrier aggregation based on the comparison.

In some embodiments, the transceiver is configured to: information is provided to the user equipment indicating at least one second threshold value for comparison with at least one traffic load.

In some embodiments, the transceiver is configured to provide information indicating: whether the user equipment is allowed to enter an idle mode and selectively enable autonomous activation of carrier aggregation using at least one second threshold.

In some embodiments, the transceiver is configured to: receiving, from a user equipment in response to enabling autonomous activation of carrier aggregation, an indication of: whether the at least one first threshold or the at least one second threshold is used to enable autonomous activation of carrier aggregation.

In some embodiments, the transceiver is configured to: providing a reconfiguration message to configure the user equipment for network resource allocation or to configure the user equipment for carrier aggregation utilizing at least one other resource pool having a capacity to accommodate carrier aggregation by the user equipment.

Drawings

The present disclosure may be better understood, and its numerous features and advantages made apparent to those skilled in the art by referencing the accompanying drawings. The use of the same reference symbols in different drawings indicates similar or identical items.

Fig. 1 is a block diagram of a first example of a wireless communication system in accordance with some embodiments.

Fig. 2 is a block diagram of a second example of a wireless communication system supporting autonomous activation of selectively enabled carrier aggregation, in accordance with some embodiments.

Fig. 3 illustrates a first part of a message flow for supporting hybrid autonomous and network activation of carrier aggregation, in accordance with some embodiments.

Fig. 4 illustrates a second part of a message flow for supporting hybrid autonomous and network activation of carrier aggregation, in accordance with some embodiments.

Detailed Description

Carrier aggregation is used to combine the resources of multiple carriers to support communication between two nodes. For example, multiple carriers of different frequencies may be aggregated to support communication between two vehicles in V2V communication or a vehicle in V2X communication and another node. Carrier aggregation may be used for parallel transmission of Medium Access Control (MAC) Packet Data Units (PDUs), where carriers are used to transmit MAC PDUs with different payloads on different carriers at the same or different transmission times. Carrier aggregation may also be used to transmit duplicate copies of the same packet in parallel on different carriers at the same or different transmission times. From the receiver perspective, carrier aggregation may also be used to increase capacity by combining the available capacity of multiple carriers for simultaneous or concurrent reception by the receiver. Thus, carrier aggregation may be used to improve the available data rate and/or reliability of transmissions over an interface, such as a PC5 interface.

The user equipment may perform autonomous activation of carrier aggregation, which results in allocating resources of the resource pool for each aggregated carrier. Autonomous activation does not require approval or confirmation by any network entity. Thus, if a large number of user equipments concurrently activate carrier aggregation, the complete autonomous activation of carrier aggregation by the user equipments may result in resource pool congestion on one or more carriers. The fully autonomous activation of carrier aggregation may also lead to unreasonable overuse by some user equipments. Conventional congestion control mechanisms on the PC5 interface place restrictions on the resources and modulation/coding schemes (MCS) available to user equipments communicating on congested carriers, which may undermine the purpose of carrier aggregation, e.g. by making it difficult or impossible for the user equipments to achieve the high data rates or high reliability provided by carrier aggregation.

The activation of network-controlled carrier aggregation may be used to coordinate carrier aggregation among multiple user equipments, which may reduce the likelihood of resource pool congestion. For example, the network may receive requests to activate carrier aggregation from multiple user equipment and then selectively activate carrier aggregation for one or more requesting user equipment, e.g., on an available resource per carrier basis. However, network control of carrier aggregation introduces additional signaling overhead between the user equipment and the network.

The lower overhead of autonomous activation of carrier aggregation is combined with superior congestion control of network activation by selectively enabling user equipment for autonomous activation of carrier aggregation based on traffic load associated with carriers available for aggregation. In some embodiments, a user equipment determines a Channel Busy Ratio (CBR) that represents a fraction of time that one or more channels of a resource pool associated with a carrier are busy. For example, the user equipment may measure signal strength on one or more channels and determine the CBR as a fraction of time that the measured signal strength is above a value indicating that the channel is occupied by one or more other transmitters. The user equipment autonomously activates carrier aggregation if the traffic load (e.g., as represented by CBR) is below a first threshold, which may be configured using broadcast signaling or dedicated signaling. The first threshold may have a value common to the resource pools or different resource pools for different carriers may have different values. The user equipment requests network activation of carrier aggregation if the traffic load is above a first threshold. In response to receiving the request, some embodiments of the network configure one or more base stations to schedule resource allocations for the user equipment on the carrier. The base station may then activate carrier aggregation for the user equipment. The network may also increase the first threshold for autonomous activation in response to receiving the request.

Fig. 1 is a block diagram of a first example of a wireless communication system 100 according to some embodiments. The wireless communication system 100 operates in accordance with one or more standards, such as the Long Term Evolution (LTE), LTE-advanced (LTE-a), or fifth generation (5G) standards defined by the third generation partnership project (3 GPP). The wireless communication system 100 includes one or more base stations 105, the one or more base stations 105 providing wireless connectivity within a geographic area or cell. The base stations 105 may also be referred to as node bs, enodebs, radio access networks, macrocells, base station routers, access points, metropolitan cells, macrocells, picocells, femtocells, or other similar terms. The

user devices

110, 111, 112 (collectively referred to herein as "user devices 110-112") are capable of accessing the wireless communication system 100 using

wireless connections

115, 116, 117 (collectively referred to herein as "wireless connections 115-117"). User devices 110-112 include

personal devices

110, 111, such as cellular phones, smart phones, tablets, laptops, or other wireless-enabled devices. The user devices 110-112 also include a vehicle, such as vehicle 112.

The wireless communication system 100 supports device-to-device (D2D) communication including vehicle-to-vehicle (V2V) and vehicle-to-all (V2X) communication. For example, the user device 110 may establish a direct D2D wireless connection 120 with the user device 111. For another example, user device 111 may establish a direct V2V wireless connection 125 with vehicle 112. As discussed herein, the

wireless connections

120, 125 may be implemented as PC5 connections or side chain (SL) connections. The base station 105 is not in the communication path used by the

wireless connections

120, 125. Some embodiments of the D2D, V2V, or V2X communication protocols support voice or data transmission on a one-to-one basis (unicast), on a one-to-many basis (multicast) for applications such as push-to-talk (PTT), or on a one-to-all basis (multicast). The user equipment 110-112 may also act as a relay station for D2D communication between other user equipment.

The wireless connections 115-117, 120, 125 support multiple carriers that may be aggregated, e.g., to increase the available data rate and/or reliability of transmissions over the wireless connections 115-117, 120, 125. The carrier aggregation includes a primary carrier responsible for conveying control plane signaling and user plane signaling, and one or more secondary carriers for conveying control plane signaling. Carrier aggregation may be activated by user equipment 110-112 or network controller 130. As used herein, the term "activation" refers to the allocation of resources from a resource pool associated with an aggregated carrier, as well as the configuration of user equipment 110-112 and corresponding wireless connections 115-117, 120, 125. The user equipment 110-112 may autonomously activate carrier aggregation, which means that the user equipment 110-112 may activate carrier aggregation without input or authorization from the network controller 130. Alternatively, the network controller 130 may activate carrier aggregation, for example, by configuring the base station 105 to allocate resources from a resource pool of aggregated carriers to corresponding user equipments 110-112 and then schedule communications on the aggregated carriers. In some embodiments of the wireless communication system 100, the network controller 130 and the base stations 105 may be implemented in one network entity.

The wireless communication system 100 implements a hybrid carrier aggregation activation technique that permits user equipment 110-112 to autonomously activate carrier aggregation in some cases, and relies on a network controller 130 (which may be implemented in the same physical entity as the base station 105) to activate carrier aggregation in other cases. The user equipments 110-112 are configured to autonomously activate carrier aggregation when the traffic load on one or more of the wireless connections 115-117, 120, 125 is relatively low. The network controller 130 is configured to activate carrier aggregation when the traffic load on one or more of the wireless connections 115-117, 120, 125 is relatively high. The network controller 130 may thus effectively control the number of user equipments which activate carrier aggregation in configured carriers in high traffic load situations. The high traffic load condition and the low traffic load condition may be determined by comparing the traffic load to one or more thresholds, e.g., thresholds of a Channel Busy Ratio (CBR) representing a fraction of time that a corresponding resource pool of the carrier is busy. In some embodiments, a common threshold is provided to the user equipments 110-112 and is used to trigger autonomous activation of carrier aggregation by the user equipments 110-112. The network controller 130 may configure a dedicated threshold for a subset of the user equipment 110-112 to control the number of user equipment 110-112 that are permitted to autonomously activate carrier aggregation on one or more carriers. The method also supports prioritizing user equipments 110-112 of the resource pool of the shared carrier.

Some embodiments of the network controller 130 provide information indicating one or more thresholds for comparison with traffic load associated with a pool of resources available for carriers of the carrier aggregation. The threshold information may be broadcast by the base station 105 or the threshold information may be transmitted to the respective user equipment 110-112 using dedicated signaling, e.g., over the wireless connections 115-117. The threshold may be common (i.e., the same) to the resource pools of the different carriers, or the values may be set to different values for different resource pools in different carriers. The user equipment 110-112 may estimate traffic load associated with one or more resource pools that may be used for carriers of carrier aggregation. The estimated traffic load may then be compared to a corresponding threshold to determine whether the traffic load is low or high. The user equipment 110-112 selectively enables autonomous activation of carrier aggregation based on the comparison. The user equipment 110-112 may optionally transmit signaling to the network controller 130 to indicate whether the user equipment 110-112 is enabled for autonomous activation of carrier aggregation. The signaling may include a signal transmitted on the aggregated carrier (if carrier aggregation is autonomously activated) or may include a request for network control of carrier aggregation, as discussed herein.

Fig. 2 is a block diagram of a second example of a wireless communication system 200 that supports autonomous activation of selectively enabled carrier aggregation, in accordance with some embodiments. The wireless communication system 200 includes a user equipment 205, a base station 210, and a network controller 215. Thus, the communication system 200 may be implemented in some embodiments of the communication system 100 shown in fig. 1. In some embodiments of the wireless communication system 200, the base station 210 and the network controller 215 are implemented in the same physical entity.

The user equipment 205 and the base station 210 comprise

transceivers

220, 225, the

transceivers

220, 225 being used for transmitting and receiving signals on one or more of a set of carriers 230 implemented by a wireless connection between the user equipment 205 and the base station 210. For clarity, although a wireless connection between the user equipment 205 and the base station 210 is shown in fig. 2, the transceiver 220 may also support similar wireless connections with other user equipment, e.g., for D2D, V2V, or V2X communications, as discussed herein. The carriers within the group 230 may be available for aggregation by the user equipment 205. For example, the subset of carriers 235 may be aggregated. One of the carriers in the subset 235 may be configured as a primary carrier and the other carriers in the subset 235 may be configured as secondary carriers.

The user equipment 205 and the base station 210 further

comprise corresponding processors

240, 245 and

memories

250, 255. The

processors

240, 245 may be used to execute instructions stored in the

respective memories

250, 255 and to store information in the

respective memories

250, 255, such as the results of the executed instructions.

The network controller 215 includes a transceiver 260, the transceiver 260 being used to transmit and receive signals over an interface with the base station 210. The network controller also includes a processor 265 and a memory 270. Processor 265 may be used to execute instructions stored in memory 270 and to store information in memory 270, such as the results of executed instructions.

The network controller 215 is configured to provide thresholds and other information to configure the user equipment 205 to selectively enable autonomous activation of carrier aggregation. Some embodiments of the network controller 215 provide signaling to configure the threshold value of CBR (Th _ ca _ low) for the resource pools of the different carriers in the group 230. The user equipment 205 autonomously activates carrier aggregation using the threshold if the measured value of CBR is below Th ca low. The value of Th _ ca _ low may be configured using broadcast or dedicated signaling from the base station 210. The value of Th _ ca _ low may be configured commonly for all resource pools of carriers in group 230, or different values of Th _ ca _ low may be assigned to different resource pools in different carriers of group 230. Some embodiments of the network controller 215 may provide information indicating: whether the value of Th _ ca _ low is applied to all carriers available for aggregation or the value of Th _ ca _ low is applied only to the secondary carrier. The information may also be predefined such that the network controller 215 is not required to provide the information. Some embodiments of the network controller 215 provide configuration information to indicate whether network controlled activation of carrier aggregation is supported. For example, when no resource pool with a CBR value below Th _ ca _ low can be found for autonomous activation of carrier aggregation, the network controller 215 may provide configuration information to indicate to the user equipment 205 whether an activation request for carrier aggregation should be sent to the network controller 215.

In relatively high load scenarios, some embodiments of the network controller 215 are configured to enable fully network controlled activation of carrier aggregation by allocating resources of a dedicated resource pool (e.g., subset 235) of aggregated carriers. The network controller 215 or the base station 210 may also schedule communications on the aggregated carriers. This may be referred to as "mode 3" operation. The network controller 215 may also modify the threshold in response to the user equipment 205 being unable to autonomously activate carrier aggregation. Some embodiments of the network controller 215 configure the user equipment 205 to continue autonomous activation of carrier aggregation, but utilize a modified CBR threshold Th _ ca _ high (which is greater than Th _ ca _ low). The network controller 215 may also perform network controlled activation of carrier aggregation by configuring the user equipment 205 to aggregate carriers using a particular resource pool in different carriers.

The activation of the network controlled carrier aggregation may be triggered by a request for activation of carrier aggregation transmitted by the user equipment 205 and received by the network controller 215. In some embodiments, the response of the network controller 215 to the request for activation of carrier aggregation is determined based on: whether the network controller 215 previously configured the user equipment 205 to selectively enable autonomous activation of carrier aggregation based on the modified threshold Th _ ca _ high. For example, if the network controller 215 receives a subsequent request for activation of carrier aggregation after the network controller 215 configures the modified threshold Th _ ca _ high for the user equipment 205, the network controller 215 may enable the base station 210 to perform mode 3 resource allocation for the user equipment 205 to permit the base station 210 to control activation of carrier aggregation. Alternatively, the network controller 215 may configure certain resource pools for carrier aggregation for the user equipment 205 if there is still capacity in these resource pools for carrier aggregation that allows the user equipment 205 to do carrier aggregation.

In the event that the network controller 215 decides to configure the user equipment 205 to continue autonomous activation of carrier activation, the network controller 215 may configure the modified CBR threshold Th ca high for the user equipment 205 via dedicated signalling. The value of Th _ ca _ high may be common for all carriers or the value of Th _ ca _ high may be different for different carriers. The value of Th _ ca _ high may be configured to be applied to all carriers (e.g., primary and secondary carriers) or to the secondary carrier only. The network controller 215 may also indicate to the user equipment 205 whether an activation request for carrier aggregation may be sent to the network controller 215 if no resource pool with CBR below Th _ ca _ high can be found. In addition to Th _ ca _ high, the network controller 215 is also able to configure the user equipment 205 to enter an idle mode while still using Th _ ca _ high for autonomous activation of carrier aggregation.

Some embodiments of the user equipment 205 determine whether to autonomously activate carrier aggregation or network control requesting activation of carrier aggregation based on a threshold configured by the network controller 215. The threshold values may be stored in memory 250 along with other configuration information. For example, the user equipment 205 may determine to autonomously activate carrier aggregation in response to a measured value of CBR in a resource pool of the carrier of interest (either in the primary carrier and the secondary carrier or only in the secondary carrier based on configuration information received from the network controller 215) being below Th _ ca _ low or Th _ ca _ high (if Th _ ca _ high has been configured, as discussed herein). If the user equipment 205 cannot identify any resource pool with a measured value of CBR below the configured value of Th _ ca _ low or Th _ ca _ high, the user equipment 205 provides a request to the network controller 215 to provide control of activation of carrier aggregation. The request for network control may be provided if the network controller 215 has previously provided information indicating activation of carrier aggregation to support network control when Th _ ca _ low or Th _ ca _ high is configured. Some embodiments of the user equipment 205 are able to enter an idle state (or idle mode) after Th _ ca _ high is configured, and the user equipment 205 may continue to use Th _ ca _ high for autonomous activation of carrier aggregation while in the idle state. The network controller 215 may provide configuration information that configures the user equipment 205 to continue performing autonomous activation of carrier aggregation while in the idle state.

Handing over the user equipment 205 to another base station may cause the reconfiguration of the user equipment 205 to be autonomous activation of carrier aggregation. For example, after the user equipment 205 reselects to a new cell, the value of the threshold Th _ ca _ high previously configured in the user equipment 205 may be invalid. In this case, if the user equipment 205 cannot locate any resource pool having a CBR value below the threshold configured by the new reselected cell Th _ ca _ low, the user equipment 205 may transmit a request to the network controller 215 to request network control of activation of carrier aggregation.

Some embodiments of the user equipment 205 transmit an activation request for carrier aggregation to the network controller 215 in order to request network control of the activation of carrier aggregation. The activation request is triggered by comparing the traffic load (e.g. a measured value of CBR), and the activation request may indicate whether the user equipment 205 is configured to compare the traffic load with a threshold Th _ ca _ low or a modified threshold Th _ ca _ high. If the user equipment 205 is operating in an idle state, the user equipment 205 may transmit information indicating which threshold value was used because the network controller 215 has no access to the context of the user equipment 205 and therefore cannot determine whether Th ca high has been configured to the user equipment 205.

Some embodiments of the user equipment 205 provide scheduling assignments for SL transmissions to other user equipments to indicate whether the user equipment 205 is configured to selectively enable autonomous activation of carrier aggregation using the threshold Th _ ca _ low or a modified threshold Th _ ca _ high. Based on the indication in the scheduling assignment, in case of SL transmission resource collision between two user equipments, SL transmissions of other user equipments configured to use the threshold Th _ ca _ low may be preempted in favor of user equipments configured to use the modified threshold Th _ ca _ high.

Fig. 3 illustrates a first portion 300 of a message flow for supporting hybrid autonomous and network activation of carrier aggregation in accordance with some embodiments. The first part 300 of the message flow shows messages exchanged between the Network (NW) and the User Equipment (UE). For example, the first portion 300 may represent messages exchanged between the network controller 130 and one or more of the user equipment 110-112 shown in fig. 1 or messages exchanged between the network controller 215 and the user equipment 205 shown in fig. 2.

The network provides configuration information including a first threshold value, such as threshold value Th _ ca _ low, in message 305. Some embodiments of message 305 are a sidelink carrier aggregation (SL CA) configuration message. The message 305 may be embedded in a System Information Block (SIB), such as a V2X-related SIB, or the message 305 may be incorporated in an RRC reconfiguration message for performing V2X-related configuration of the user equipment.

The user equipment uses the first threshold to configure monitoring of traffic load on a configured set of carriers available for carrier aggregation. The user equipment determines at decision block 310 whether the traffic load exceeds a first threshold. For example, the user equipment may compare a measured value of CBR associated with one or more carriers with a value of a threshold Th _ ca _ low. If the traffic load is less than the first threshold, indicating that allocation of resources to carrier aggregation is unlikely to cause congestion in the network, the user equipment may, at block 315, autonomously activate carrier aggregation for one or more of the set of configured carriers. If the traffic load is greater than the first threshold, indicating that autonomous allocation of resources to carrier aggregation may cause congestion and thus network coordination may be needed to avoid congestion, at block 320, the user equipment may generate a request for network control of activation of carrier aggregation. In some embodiments, while the user equipment is in the RRC idle state, the user equipment may perform a comparison with a configured threshold, such as a SIB configured CBR threshold. If the comparison triggers transmission of a request for active network control, the user equipment may transition to the RRC connected state to transmit the request in message 325.

The user equipment transmits a network controlled activation request for activation of carrier aggregation to the network in message 325. Some embodiments of message 325 are embedded in an RRC message, such as an RRC sildelinkueinformation message. Message 325 may also include an indication of: message 325 has been generated and transmitted in response to a comparison of the traffic load to a first threshold (e.g., a comparison of a measured value of CBR to a value of threshold Th _ ca _ low). In response to receiving the message 325 including an indication of the first threshold, the network may configure (at block 330) a second threshold for transmission to the user device. For example, the network may generate a modified threshold Th _ ca _ high that is greater than the value of the threshold Th _ ca _ low. The network provides the second threshold to the user equipment in message 335. For example, the message 335 may be embedded in an RRC SL CA configuration message that includes a modified threshold Th CA high.

Fig. 4 illustrates a second part 400 of a message flow for supporting hybrid autonomous and network activation of carrier aggregation, in accordance with some embodiments. The second part 400 of the message flow shows messages exchanged between the Network (NW) and the User Equipment (UE). For example, the second portion 400 may represent messages exchanged between the network controller 130 and one or more of the user devices 110-112 shown in fig. 1 or messages exchanged between the network controller 215 and the user device 205 shown in fig. 2. In some embodiments, the second portion 400 of the message flow is performed after the first portion 300 of the message flow shown in fig. 3.

The network provides the second threshold to the user equipment in message 405. For example, the message 405 may be embedded in an RRC SL CA configuration message that includes a modified threshold Th CA high. Thus, message 405 may correspond to message 335 in first portion 300 of the message flow shown in FIG. 3.

The user equipment uses the second threshold to configure monitoring of traffic load on a set of carriers configured to be available for carrier aggregation. The user equipment determines at decision block 410 whether the traffic load exceeds a second threshold. For example, the user equipment may compare the measured value of CBR associated with one or more carriers with the value of the modified threshold Th _ ca _ high. If the traffic load is less than the second threshold, indicating that allocating resources to carrier aggregation is unlikely to cause congestion in the network, the user equipment may autonomously activate carrier aggregation for one or more of the set of configured carriers at block 415. If the traffic load is greater than the second threshold, indicating that autonomous allocation of resources to carrier aggregation may cause congestion and thus network coordination may be required to avoid congestion, the user equipment may generate a request for network control of activation of carrier aggregation at block 420.

The user equipment transmits a network-controlled activation request for activation of carrier aggregation to the network in message 425. Some embodiments of message 425 are embedded in an RRC message, such as an RRC SidelinkUEInformation message. Message 425 may also include an indication of: message 425 has been generated and transmitted in response to a comparison of the traffic load to a second threshold (e.g., a comparison of the measured value of CBR to the value of threshold Th _ ca _ high). In some embodiments, while the user equipment is in the RRC idle state, the user equipment may perform a comparison with a configured threshold, such as a SIB configured CBR threshold. If the comparison triggers transmission of a request for active network control, the user equipment may transition to the RRC connected state to transmit the request in message 425.

In response to receiving the message 425 including an indication of the second threshold, the network may configure (at block 430) mode 3 operation or allocate a particular resource pool to the user equipment for carrier aggregation. For example, if the network configures mode 3 operation, the network may transmit instructions to configure one or more base stations to schedule resource allocations for user equipment on carriers. The base station may then activate carrier aggregation for the user equipment. For another example, the network may identify particular resource pools that may be used for carrier aggregation because these resource pools have available capacity to allow the user equipment to perform carrier aggregation. The network provides the configuration information to the user equipment in message 435. For example, the message 435 may be embedded in an RRC reconfiguration message that includes parameters for configuring the user equipment for mode 3 operation or carrier aggregation using an available resource pool identified by the network.

In some embodiments, certain aspects of the techniques described above may be implemented by one or more processors of a processing system executing software. The software includes one or more sets of executable instructions stored or tangibly embodied on a non-transitory computer-readable storage medium. The software may include instructions and certain data that, when executed by one or more processors, manipulate the one or more processors to perform one or more aspects of the techniques described above. A non-volatile computer-readable storage medium may include, for example, a magnetic or optical disk storage device, a solid-state storage device such as a flash memory, a cache, a Random Access Memory (RAM), or other non-volatile memory device or devices, and so forth. Executable instructions stored on a non-transitory computer-readable storage medium may be source code, assembly language code, object code, or other instruction formats that are interpreted or otherwise executable by one or more processors.

A computer-readable storage medium may include any storage medium, or combination of storage media, that is accessible by a computer system during use to provide instructions and/or data to the computer system. Such storage media may include, but is not limited to, optical media (e.g., compact Discs (CDs), digital Versatile Discs (DVDs), blu-ray discs), magnetic media (e.g., floppy disks, tape, or magnetic hard drives), volatile memory (e.g., random Access Memory (RAM) or cache), non-volatile memory (e.g., read Only Memory (ROM) or flash memory), or micro-electromechanical systems (MEMS) -based storage media. The computer-readable storage medium can be embedded in a computing system (e.g., system RAM or ROM), fixedly attached to a computing system (e.g., a magnetic hard drive), removably attached to a computing system (e.g., an optical disk or Universal Serial Bus (USB) based flash memory), or coupled to a computer system via a wired or wireless network (e.g., network Accessible Storage (NAS)).

Note that not all of the activities or elements described above in the general description are required, that a portion of a particular activity or device may not be required, and that one or more other activities may be performed or other elements included in addition to those described. Still further, the order in which activities are listed is not necessarily the order in which the activities are performed. In addition, the concepts have been described with reference to specific embodiments. However, one of ordinary skill in the art appreciates that various modifications and changes can be made without departing from the scope of the present disclosure as set forth in the claims below. Accordingly, the specification and figures are to be regarded in an illustrative rather than a restrictive sense, and all such modifications are intended to be included within the scope of the present disclosure.

Benefits, other advantages, and solutions to problems have been described above with regard to specific embodiments. However, the benefits, advantages, solutions to problems, and any feature(s) that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as a critical, required, or essential feature or element of any or all the claims. Moreover, the particular embodiments disclosed above are illustrative only, as the disclosed subject matter may be modified and practiced in different but equivalent manners apparent to those skilled in the art having the benefit of the teachings herein. No limitations are intended to the details of construction or design herein shown, other than as described in the claims below. It is therefore evident that the particular embodiments disclosed above may be altered or modified and all such variations are considered within the scope of the disclosed subject matter. Accordingly, the protection sought herein is as set forth in the claims below.

Claims

1. A method for communication, comprising:

estimating, at a user equipment, at least one traffic load associated with at least one resource pool of a plurality of resource pools for a plurality of carriers available for carrier aggregation; and

selectively enabling autonomous activation of carrier aggregation by the user equipment based on the at least one traffic load.

2. The method of claim 1, wherein selectively enabling the user equipment for autonomous activation of carrier aggregation comprises: comparing the at least one traffic load to at least one first threshold.

3. The method of claim 2, wherein selectively enabling the user equipment for autonomous activation of carrier aggregation comprises: enabling autonomous activation of carrier aggregation by the user equipment in response to the at least one traffic load being less than the at least one first threshold.

4. The method of claim 2, further comprising:

receiving information indicative of the at least one first threshold from a network controller via broadcast signaling or signaling specific to the user equipment.

5. The method of claim 2, further comprising:

transmitting a request for network activation for carrier aggregation from the user equipment in response to the at least one traffic load being greater than the at least one first threshold.

6. The method of claim 5, further comprising:

receiving, at the user equipment, information indicative of at least one second threshold value for comparison with the at least one traffic load.

7. The method of claim 6, wherein receiving the information comprises receiving information indicating: whether the user equipment is allowed to enter an idle mode and selectively enable autonomous activation of carrier aggregation using the at least one second threshold.

8. The method of claim 6, further comprising:

providing, from the user equipment in response to enabling autonomous activation of carrier aggregation, an indication of: whether the at least one first threshold or the at least one second threshold is used to enable autonomous activation of carrier aggregation.

9. The method of claim 1, wherein estimating the at least one traffic load comprises: determining at least one channel busy ratio, CBR, the at least one CBR representing a fraction of time the at least one of the plurality of resource pools is busy.

10. A method for communication, comprising:

providing, from a network controller to a user equipment, information indicative of at least one first threshold for comparison with at least one traffic load associated with at least one resource pool of a plurality of resource pools for a plurality of carriers available for carrier aggregation; and

receiving, at the network controller and from the user equipment, a request for network activation for carrier aggregation in response to the at least one traffic load being greater than the at least one first threshold.

11. The method of claim 10, providing the information indicative of the at least one first threshold value comprises: providing information indicative of at least one first threshold for comparison with at least one channel busy ratio, CBR, the at least one CBR representing a fraction of time that the at least one of the plurality of resource pools is busy.

12. The method of claim 10, wherein providing the information indicative of the at least one first threshold comprises at least one of:

broadcasting the information indicative of the at least one first threshold; and

transmitting a dedicated signal to the user equipment, the dedicated signal comprising the information indicative of the at least one first threshold.

13. The method of claim 10, further comprising:

receiving, at the network controller, signaling indicating whether the user equipment is enabled for autonomous activation of carrier aggregation based on the comparison.

14. The method of claim 10, further comprising:

providing, from the network controller to the user equipment, information indicative of at least one second threshold for comparison with the at least one traffic load.

15. The method of claim 14, wherein providing the information comprises providing information indicating: whether the user equipment is allowed to enter an idle mode and selectively enable autonomous activation of carrier aggregation using the at least one second threshold.

16. The method of claim 10, further comprising:

receiving, at the network controller from the user equipment in response to enabling autonomous activation of carrier aggregation, an indication of: whether the at least one first threshold or the at least one second threshold is used to enable autonomous activation of carrier aggregation.

17. The method of claim 14, further comprising:

providing, from the network controller, a reconfiguration message to configure the user equipment for network resource allocation or to configure the user equipment for carrier aggregation with at least one other resource pool having a capacity that allows carrier aggregation by the user equipment.

18. A user equipment, comprising:

a transceiver configured to estimate at least one traffic load associated with at least one resource pool of a plurality of resource pools for a plurality of carriers available for carrier aggregation; and

a processor configured to selectively enable autonomous activation of carrier aggregation by the user equipment based on the at least one traffic load.

19. The user equipment of claim 18, wherein the processor is configured to: comparing the at least one traffic load with at least one first threshold.

20. The user equipment of claim 19, wherein the processor is configured to: enabling autonomous activation of carrier aggregation by the user equipment in response to the at least one traffic load being less than the at least one first threshold.

21. The user equipment of claim 19, wherein the transceiver is configured to: receiving information indicative of the at least one first threshold from a network controller via broadcast signaling or signaling specific to the user equipment.

22. The user equipment of claim 19, wherein the transceiver is configured to: transmitting a request for network activation for carrier aggregation in response to the at least one traffic load being greater than the at least one first threshold.

23. The user equipment of claim 22, wherein the transceiver is configured to: receiving information indicative of at least one second threshold value for comparison with the at least one traffic load.

24. The user equipment of claim 23, wherein the transceiver is configured to: receiving information indicating whether the user equipment is allowed to enter an idle mode, and wherein the processor is configured to: selectively enabling autonomous activation of carrier aggregation using the at least one second threshold.

25. The user equipment of claim 23, wherein the transceiver is configured to provide, in response to enabling autonomous activation of carrier aggregation, an indication of: whether the at least one first threshold or the at least one second threshold is used to enable autonomous activation of carrier aggregation.

26. The user equipment of claim 18, wherein the transceiver is configured to: determining at least one channel busy ratio CBR, the at least one CBR representing a fraction of time that the at least one of the plurality of resource pools is busy.

27. An apparatus for communication, comprising:

a processor configured to generate information indicative of at least one first threshold for comparison with at least one traffic load associated with at least one resource pool of a plurality of resource pools for a plurality of carriers available for carrier aggregation, and

a transceiver configured to receive a request for network activation for carrier aggregation from a user equipment in response to the at least one traffic load being greater than the at least one first threshold.

28. The apparatus of claim 27, wherein the transceiver is configured to: providing information indicative of at least one first threshold for comparison with at least one channel busy ratio, CBR, the at least one CBR representing a fraction of time that the at least one of the plurality of resource pools is busy.

29. The apparatus of claim 27, wherein the transceiver is configured to perform at least one of:

30. The apparatus of claim 27, wherein the transceiver is configured to: transmitting the information to a user equipment and receiving signaling indicating whether the user equipment is enabled for autonomous activation of carrier aggregation based on the comparison.

31. The apparatus of claim 27, wherein the transceiver is configured to: providing information indicative of at least one second threshold to the user equipment, the at least one second threshold being used for comparison with the at least one traffic load.

32. The apparatus of claim 31, wherein the transceiver is configured to provide information indicating: whether the user equipment is allowed to enter an idle mode and selectively enable autonomous activation of carrier aggregation using the at least one second threshold.

33. The apparatus of claim 31, wherein the transceiver is configured to: providing a reconfiguration message to configure the user equipment for network resource allocation or to configure the user equipment for carrier aggregation with at least one other resource pool having a capacity that allows carrier aggregation by the user equipment.

34. The apparatus of claim 27, wherein the transceiver is configured to: receiving, from the user equipment in response to enabling autonomous activation of carrier aggregation, an indication of: whether the at least one first threshold or the at least one second threshold is used to enable autonomous activation of carrier aggregation.