EP3281439A1 - Discontinuous reception (drx) for licensed assisted access (laa) - Google Patents

Abstract

Systems, methods, apparatuses, and computer program products for DRX for LAA are provided. One method includes monitoring, by a UE, the licensed assisted access (LAA) cell while a primary cell (Pcell) is not actively being monitored. Additionally, another method may include, when the UE is scheduled on the LAA cell, the user equipment actively monitoring a primary cell (Pcell).

Description

DISCONTINUOUS RECEPTION (DRX) FOR LICENSED ASSISTED ACCESS (LAA)

CROSS-REFERENCE TO RELATED APPLICATIONS:

This application claims priority from United States Provisional Application No. 62/145,296, filed on April 9, 2015. The entire contents of this earlier filed application are hereby incorporated by reference in their entirety.

BACKGROUND:

Field:

Embodiments of the invention generally relate to wireless communications networks, such as, but not limited to, the Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (UTRAN), Long Term Evolution (LTE) Evolved UTRAN (E-UTRAN), LTE-Advanced (LTE-A), future 5G radio access technology, and/or High Speed Packet Access (HSPA).

Description of the Related Art:

Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (UTRAN) refers to a communications network including base stations, or Node Bs, and for example radio network controllers (RNC). UTRAN allows for connectivity between the user equipment (UE) and the core network. The RNC provides control functionalities for one or more Node Bs. The RNC and its corresponding Node Bs are called the Radio Network Subsystem (RNS). In case of E- UTRAN (enhanced UTRAN), no RNC exists and most of the RNC functionalities are contained in the enhanced Node B (eNodeB or eNB).

Long Term Evolution (LTE) or E-UTRAN refers to improvements of the UMTS through improved efficiency and services, lower costs, and use of new spectrum opportunities. In particular, LTE is a 3GPP standard that provides for uplink peak rates of at least, for example, 75 megabits per second (Mbps) per carrier and downlink peak rates of at least, for example, 300 Mbps per carrier. LTE supports scalable carrier bandwidths from 20 MHz down to 1.4 MHz and supports both Frequency Division Duplex (FDD) and Time Division Duplex (TDD).

As mentioned above, LTE may also improve spectral efficiency in networks, allowing carriers to provide more data and voice services over a given bandwidth. Therefore, LTE is designed to fulfill the needs for high-speed data and media transport in addition to high-capacity voice support. Advantages of LTE include, for example, high throughput, low latency, FDD and TDD support in the same platform, an improved end-user experience, and a simple architecture resulting in low operating costs.

Certain releases of 3 GPP LTE (e.g., LTE Rel-10, LTE Rel-1 1 , LTE Rel-12, LTE Rel- 13) are targeted towards international mobile telecommunications advanced (IMT-A) systems, referred to herein for convenience simply as LTE-Advanced (LTE-A).

LTE-A is directed toward extending and optimizing the 3GPP LTE radio access technologies. A goal of LTE-A is to provide significantly enhanced services by means of higher data rates and lower latency with reduced cost. LTE-A is a more optimized radio system fulfilling the international telecommunication union-radio (ITU-R) requirements for IMT-Advanced while keeping the backward compatibility. One the key features of LTE-A, introduced in LTE Rel-10, is carrier aggregation (CA), which allows for increasing the data rates through aggregation of two or more LTE carriers.

SUMMARY:

One embodiment is directed to a method including monitoring, by a UE, the LAA cell while the PCell is not actively being monitored.

In an embodiment, the method may include, when the UE is scheduled on the LAA cell, the user equipment actively monitoring the PCell. Another embodiment is directed to an apparatus which may include at least one processor and at least one memory including computer program code. The at least one memory and the computer program code are configured, with the at least one processor, to cause the apparatus at least to monitor the LAA cell while the PCell is not actively being monitored.

In another embodiment, the at least one memory and the computer program code are configured, with the at least one processor, to cause the apparatus at least to, when the apparatus is scheduled on the LAA cell, to actively monitor the PCell.

Another embodiment is directed to an apparatus that may include monitoring means for monitoring the LAA cell while the PCell is not actively being monitored.

In an embodiment, an apparatus may include, when the UE is scheduled on the LAA cell, activating means for actively monitoring the PCell.

Another embodiment is directed to a computer program embodied on a non-transitory computer readable medium. The computer program may be configured to control a processor to perform a process, which may include monitoring the LAA cell while the PCell is not actively being monitored.

In an embodiment, the computer program may be configured to control a processor to perform a process, which may include, when the UE is scheduled on the LAA cell, actively monitoring the PCell.

BRIEF DESCRIPTION OF THE DRAWINGS:

For proper understanding of the invention, reference should be made to the accompanying drawings, wherein:

Fig. 1 illustrates a block diagram of an apparatus, according to one embodiment; and Fig. 2 illustrates a flow diagram of a method, according to one embodiment. DETAILED DESCRIPTION:

It will be readily understood that the components of the invention, as generally described and illustrated in the figures herein, may be arranged and designed in a wide variety of different configurations. Thus, the following detailed description of embodiments of systems, methods, apparatuses, and computer program products for discontinuous reception (DRX) for licensed-assisted access (LAA), as represented in the attached figures, is not intended to limit the scope of the invention, but is merely representative of some selected embodiments of the invention.

The features, structures, or characteristics of the invention described throughout this specification may be combined in any suitable manner in one or more embodiments. For example, the usage of the phrases "certain embodiments," "some embodiments," or other similar language, throughout this specification refers to the fact that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the present invention. Thus, appearances of the phrases "in certain embodiments," "in some embodiments," "in other embodiments," or other similar language, throughout this specification do not necessarily all refer to the same group of embodiments, and the described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

Additionally, if desired, the different functions discussed below may be performed in a different order and/or concurrently with each other. Furthermore, if desired, one or more of the described functions may be optional or may be combined. As such, the following description should be considered as merely illustrative of the principles, teachings and embodiments of this invention, and not in limitation thereof.

Embodiments of the invention relate to LTE licensed-assisted access (LAA). A goal of LAA, which is also referred to as LTE on unlicensed band (LTE-U), is that LTE in one example may be deployed as a component carrier (CC) on the unlicensed bands, in addition to its licensed band carriers. The aim is for LTE carriers to co-exist with Wi-Fi on the unlicensed band and create a constructive communication environment. Some benefits that LAA brings include that LTE provides quality of service (QoS) and seems to be strong where Wi-Fi is known to suffer, e.g., Wi-Fi may not perform well in system throughput when heavily loaded which happens for example in dense, data intense deployments.

The LTE operation could, for example, be in an unlicensed band in the 5GHz band (which potentially has up to 500 MHz of available spectrum), while for licensed it is in the 2GHz band. A key aspect is that the licensed band may be used, e.g., for control (mobility, signaling) and at least initially also for providing uplink, while the unlicensed band is used for data rate boost. Licensed-assisted access is, for example, a 2 downlink - 1 uplink (2DL-1UL) scheme, where the primary cell (Pcell) is in the licensed band, and one or more secondary cells (Scells) are in the unlicensed bands. Therefore, LAA may be used as a supplemental downlink carrier (SDL) scheme or it may contain uplink (UL) and downlink (DL) in a LTE CA configuration. Alternatively, the LAA cell may be deployed as stand-alone operation LTE in unlicensed providing both DL and UL including control signaling.

In CA, the same DRX operation applies to all configured and activated serving cells (i.e., identical active time for physical downlink control channel (PDCCH) monitoring). In other words, there is a common DRX applied to all the component carriers (CCs). In dual connectivity (DC), separate DRX configurations can be applied to master cell group (MCG) and secondary cell group (SCG), and the cell group (CG) specific DRX operation applies to all configured and activated serving cells in the same CG (i.e., identical active time for PDCCH monitoring). LAA is in first step CA based, i.e., licensed band CCs and un-licensed band CCs are served by the same eNB. Thus, the common DRX currently used in CA could be seen as the baseline here, as it is already specified for CA. In later phases LAA could also be deployed as stand-alone LTE or similar in unlicensed. In the following basic LAA deployed as CA will be used as example.

In LAA, which is CA based, the eNB has to perform clear channel assessment (CCA). Due to this, the difference to licensed LTE band and CA is that before the eNB is allowed to transmit something to the UE on the cell in un-licensed band it should perform listen before talk (LBT) on the un-licensed band (LBT can be frame based equipment (FBE) or load based equipment (LBE)). Afterwards, if and once the eNB acquires the channel, the eNB can use the channel - e.g., PDCCHs, PDSCHs, etc., could be transmitted.

However, one major difference to CA having SCell in licensed band is that, due to LBT, there is no guarantee that the channel is obtained for scheduling the UE exactly when desired by the eNB. In addition, even if CCA succeeds (and the eNB can use it for scheduling) the channel most likely can only be kept occupied by the eNB for a limited time due to regulations (regulatory requirements). Thus, the DRX configuration should probably not be very strict for the LAA cells.

In the long run, a goal is to enable the network to offload the UEs to the LAA cell(s) - e.g., the user is offloaded to LAA cell for best effort. Of course, currently, where there is not UL in LAA, the PCell is needed in order to enable, e.g., hybrid automatic repeat request (HA Q) feedback and also other signaling, such as control signaling (e.g., medium access control (MAC), radio resource control (RRC)) will go through the PCell. Likely, in the future, a LAA cell will also support UL and also support more stand-alone operation.

Also, in the future and for LAA, one important point is UE power consumption and consideration on how to reduce and/or minimize UE power consumption, for example by looking at the PCell and LAA cell monitoring requirements. As described, the scheduling in the LAA cell cannot be guaranteed on the same level as is known from the licensed band LTE cell/Scell due to CCA/LBT (i.e., eNB has to capture the channel before it is allowed transmitting). Based on this, there would likely need to be some sort of longer monitoring time in the LAA cell in the unlicensed band for enabling the network to reach the UE and ensure that the UE does not go to sleep (stop monitoring for possible network schedulings) too early. What is needed in LAA is to enable the UE additional power saving opportunities by not always requiring the UE to monitor the PCell; although the UE would be monitoring the LAA cell (or in general cell(s) in the unlicensed band).

One embodiment is directed to allow for the LAA cell monitoring to be not strictly linked to the PCell monitoring. In other words, embodiments allow LAA cell monitoring only enabling PCell DRX (power saving). As PCell is needed for supporting LAA cell feedback (e.g., HA Q feedback), the PCell may be activated when LAA cell (cell in unlicensed band) is then scheduled. The PCell wake up would be triggered by the LAA cell scheduling, for example in order to enable UL transmissions or transmissions of other signaling messages.

This means that LAA cell may be in active mode (e.g., monitored for potential scheduling(s)), while not necessarily requiring that the PCell is active (e.g., UE actively monitoring the PCell for scheduling). Whenever the UE detects that a LAA scheduling by the network intended for the UE occurs, this leads to PCell wake up. More specifically, when the network schedules the first LAA scheduling for the UE, the UE starts the PCell InactivityTimer. Additionally, the network may start the network counterpart of the inactivity timer. It should be noted that embodiments are not limited to DL scheduling in LAA cell, but could also apply to UL scheduling in LAA cell.

An embodiment of the invention may be implemented, for example, in 3GPP TS 36.321 LTE Rel-13 specification, section 5.7. For instance, when DRX is configured, the MAC entity may, for each sub frame:

• during the Active Time, for a PDCCH-subframe, if the subframe is not required for uplink transmission for half-duplex FDD UE operation, if the subframe is not a half-duplex guard subframe and if the subframe is not part of a configured measurement gap; or

• during the Active Time, for a subframe other than a PDCCH-subframe and for a UE capable of simultaneous reception and transmission in the aggregated cells, if the subframe is a downlink subframe indicated by a valid elMTA LI signalling for at least one serving cell not configured with schedulingCellld [8] and if the subframe is not part of a configured measurement gap; or

• during the Active Time, for a subframe other than a PDCCH-subframe and for a UE not capable of simultaneous reception and transmission in the aggregated cells, if the subframe is a downlink subframe indicated by a valid elMTA LI signalling for the SpCell and if the subframe is not part of a configured measurement gap:

o monitor the PDCCH;

o if the PDCCH indicates a DL transmission or if a DL assignment has been configured for this subframe, it may start the HA Q RTT Timer for the corresponding HARQ process and stop the drx- RetransmissionTimer for the corresponding HARQ process;

o if the PDCCH indicates a new transmission (DL or UL), it may start or restart drx-InactivityTimer and, if the new transmission is in LAA cell, it may start or restart drx-InactivityTimer of the PCell or the corresponding cell group.

Even if DRX is not applied in the LAA cell, the UE may be configured still to start the drx-InactivityTimer of the PCell or corresponding cell group, if scheduled in LAA cell (i.e., the PDCCH indicates a new transmission UL or DL).

Therefore, one embodiment is directed to reducing the PCell monitoring requirements by allowing the UE to not always be required to monitor the PCell (the cell in the licensed band), although it will monitor the LAA cell (the cell(s) in the unlicensed band). As the scheduling in the LAA cell cannot be guaranteed due to LBT, there may be a need for having extended cell monitoring, i.e., longer monitoring time in the LAA cell for enabling the network to reach the UE and ensure that the UE does not go to sleep too early. Longer monitoring times will negatively impact the UE power consumption which is not desirable and should be avoided. LAA cell is monitored according to DRX if configured. The UE monitoring of the LAA cell and DRX may be different or same (parameter-wise) as the PCell. For example, the PCell DRX and LAA cell DRX parameters may be common (as known from CA), but the timers may function in an independent way. PCell can sleep and can be woken up by the UE being scheduled on LAA cell. Therefore, since the PCell can be awakened (re-activated) by scheduling the UE in LAA cell, the PCell monitoring is not necessarily needed all the time; while monitoring the LAA cell and power savings due to turning off PCell monitoring can be gained.

One example approach may implement continuous monitoring on LAA cell using existing methods: to keep the common DRX and keep the UE monitoring the LAA cell by either continuous dummy scheduling on PCell, as known from CA to keep SCell activated. This approach may have drawbacks, such as wasting of both UL and DL resources.

In another example alternative, the UE is not allowed to monitor the PCell although it has to monitor the LAA cell. If the UE is subsequently scheduled on the LAA cell, then the UE would 'resume' (or activate) the PCell, e.g., for additional monitoring and/or UL feedback.

In yet another embodiment, the network (e.g., network node or eNB) may activate the PCell. For example, the network may consider the PCell for the UE as activated when the UE is scheduled in a LAA cell. In this embodiment, the network may configure the LAA cell specific (some or all) DRX parameters.

In some embodiments, it may be that the UE has no DRX opportunity in LAA cell, but power saving (due to LAA cell) is accomplished by deactivating the LAA cell.

From a mobility robustness point of view, however, it may be beneficial that when the UE is scheduled in LAA cell (and not just monitoring), the UE would also resume monitoring the PCell on licensed carrier - if it is not doing so already. From the point of view of the 3 GPP specification, this would mean that the UE would start the DRX inactivity timer of the PCell whenever the UE would be scheduled in LAA cell (e.g., SCell).

It is noted that the DRX inactivity timer may specify the number of consecutive PDCCH-subframe(s) for which the UE should be active after successfully decoding a PDCCH indicating a new transmission (UL or DL). The DRX inactivity timer may be restarted upon receiving PDCCH for a new transmission (UL or DL). Upon the expiry of the timer the UE moves to DRX mode.

Another approach includes configuring the UE with rather relaxed LAA cell specific DRX parameters (long on-duration, inactivity timer, etc.) or no DRX parameters. However, this approach may not result in optimum UE power consumption and/or user experience.

Another embodiment includes ensuring that the LAA cell monitoring is not strictly linked to the PCell monitoring. In other words, in this embodiment, the PCell DRX and LAA cell DRX parameters may be common, but the timers may function in a more independent way. For example, the on-duration timer and/or the inactivity timer on LAA cell may be longer than on PCell; while the actual on-duration timer could be synchronized, but some additional LAA cell monitoring may be added in order to enable PCell power off while keeping more flexibility on LAA cell in order to enable the network to reach the UE even when LBT is used.

In this embodiment, the UE is then allowed to not monitor the PCell as strictly as the LAA cell allowing for better power saving. When the UE is then potentially scheduled on the LAA cell, the UE will re-activate the PCell and start monitoring (and perform/allow UL scheduling and transmission of, for example, control data). This approach will also allow UE PCell power savings by not having, for instance, the periodic UL transmissions on PCell while monitoring the LAA cell.

Thus, embodiments provide that the UE does not necessarily need to monitor the PCell while the LAA cell is monitored. When the UE is scheduled in the LAA cell, the PCell may then be activated (but the UE has 3/4ms for ensuring transmit timing accuracy on PCell).

The UE may use this information such that it may follow the LBT rule in monitoring. In case the UE is not scheduled, it can seize monitoring until the next LBT occasion. The network may use this for intelligent offloading and PCell physical uplink control channel (PUCCH) sharing though LAA cell scheduling (UE would not use the PUCCH in PCell unless scheduled in LAA cell).

In other example embodiments, more flexible monitoring schemes for LAA cell could be used: for example, the network would not need to consider LAA scheduling and LBT when configuring DRX (e.g., no need for longer onDuration, inactivity timer and such). Therefore, the UE could turn off the PCell while awaiting scheduling on LAA cell (e.g., in case of having PUCCH on LAA cell this becomes very useful).

In another example embodiment, it could be considered how LBT rules may be used in the LAA cell, as input to improved LAA cell monitoring rules. The LBT rules may differ from region to region (for example 4 and 10 ms) and this could be informed (signaled) to the UE. Also, the network intent of primarily scheduling the UE on the LAA cell could be informed (signaled) to UE.

Fig. 1 illustrates an example of an apparatus 10 according to an embodiment. In an embodiment, apparatus 10 may be a node or element in a communications network or associated with such a network, such as a UE, mobile device, mobile unit, a machine type UE or other device. However, in other embodiments, apparatus 10 may be other components within a radio access network. It should be noted that one of ordinary skill in the art would understand that apparatus 10 may include components or features not shown in Fig. 1.

As illustrated in Fig. 1, apparatus 10 includes a processor 22 for processing information and executing instructions or operations. Processor 22 may be any type of general or specific purpose processor. While a single processor 22 is shown in Fig. 1, multiple processors may be utilized according to other embodiments. In fact, processor 22 may include one or more of general-purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs), field-programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), and processors based on a multi-core processor architecture, as examples.

Apparatus 10 may further include or be coupled to a memory 14 (internal or external), which may be coupled to processor 22, for storing information and instructions that may be executed by processor 22. Memory 14 may be one or more memories and of any type suitable to the local application environment, and may be implemented using any suitable volatile or nonvolatile data storage technology such as a semiconductor- based memory device, a magnetic memory device and system, an optical memory device and system, fixed memory, and removable memory. For example, memory 14 can be comprised of any combination of random access memory (RAM), read only memory (ROM), static storage such as a magnetic or optical disk, or any other type of non-transitory machine or computer readable media. The instructions stored in memory 14 may include program instructions or computer program code that, when executed by processor 22, enable the apparatus 10 to perform tasks as described herein.

In some embodiments, apparatus 10 may also include or be coupled to one or more antennas 25 for transmitting and receiving signals and/or data to and from apparatus 10. Apparatus 10 may further include or be coupled to a transceiver 28 configured to transmit and receive information. For instance, transceiver 28 may be configured to modulate information on to a carrier waveform for transmission by the antenna(s) 25 and demodulate information received via the antenna(s) 25 for further processing by other elements of apparatus 10. In other embodiments, transceiver 28 may be capable of transmitting and receiving signals or data directly.

Processor 22 may perform functions associated with the operation of apparatus 10 which may include, for example, precoding of antenna gain/phase parameters, encoding and decoding of individual bits forming a communication message, formatting of information, and overall control of the apparatus 10, including processes related to management of communication resources.

In an embodiment, memory 14 may store software modules that provide functionality when executed by processor 22. The modules may include, for example, an operating system that provides operating system functionality for apparatus 10. The memory may also store one or more functional modules, such as an application or program, to provide additional functionality for apparatus 10. The components of apparatus 10 may be implemented in hardware, or as any suitable combination of hardware and software.

In one embodiment, apparatus 10 may be a node or element in a communications network or associated with such a network, such as a UE, mobile device, mobile unit, a machine type UE or other device. According to one embodiment, apparatus 10 may be controlled by memory 14 and processor 22 to monitor the LAA cell while the PCell is not in an active state (i.e., apparatus 10 monitors the LAA cell while not monitoring the PCell). In one example, the LAA cell is a SCell. In an embodiment, when apparatus 10 is scheduled on the LAA cell, apparatus 10 may be controlled by memory 14 and processor 22 to activate/monitor the PCell, for example, in order to enable UL feedback to the network. In certain embodiments, apparatus 10 may be controlled to activate/monitor the PCell by starting the DRX inactivity timer of the PCell or corresponding cell group.

In another embodiment, the network (e.g., network node or eNB) may activate the PCell. For example, the network may consider the PCell for the UE as activated when the UE is scheduled in a LAA cell. In this embodiment, the network may configure the LAA cell specific (some or all) DRX parameters.

According to some embodiments, the PCell DRX and LAA cell DRX parameters are different. For example, in an embodiment, the On Duration timer on LAA cell may be longer than the On Duration timer on the PCell. It is noted that the On Duration timer may specify the number of consecutive PDCCH- subframe(s) at the beginning of each DRX Cycle (DRX ON). In other words, it is the number of subframes over which the UE shall read PDCCH during every DRX cycle before entering the power saving mode (DRX OFF).

Fig. 2 illustrates an example flow diagram of a method of DRX for LAA, according to an embodiment of the invention. In one example, the method of Fig. 2 may be performed by a UE. As illustrated in Fig. 2, the method may include, at 200, monitoring the LAA cell while the PCell is not in an active state (i.e., monitoring the LAA cell while not monitoring the PCell). In one example, the LAA cell is a SCell. In an embodiment, when the UE is scheduled on the LAA cell, the method may include, at 210, activating/monitoring the PCell, for example, in order to enable UL feedback to the network. In certain embodiments, the activating/monitoring of the PCell may include starting the DRX inactivity timer of the PCell or corresponding cell group.

Embodiments of the invention provide several advantages, benefits, and technical improvements. One benefit is that certain embodiments enable more flexible monitoring schemes for LAA cell. For example, as discussed above, the network would not need to consider LAA scheduling and LBT when configuring DRX (no need for longer onDuration, inactivity timer, etc.), the UE could turn off the PCell while waiting for scheduling on LAA cell. Another benefit includes the possibility of using the LBT rule in the LAA cell as input to improved LAA cell monitoring rules. The LBT rules differ a bit from region to region (4 and 10 ms) and this may also be informed to the UE. Also, the network intent of primarily scheduling the UE on the LAA cell could be informed, etc.

In some embodiments, the functionality of any of the methods described herein, such as those illustrated in Fig. 2 discussed above, may be implemented by software and/or computer program code or portions of it stored in memory or other computer readable or tangible media, and executed by a processor. In some embodiments, the apparatuses described herein may be, included or be associated with at least one software application, module, unit or entity configured as arithmetic operation(s), or as a program or portions of it (including an added or updated software routine), executed by at least one operation processor.

Programs, also called program products or computer programs, including software routines, applets and macros, may be stored in any apparatus-readable data storage medium and they include program instructions to perform particular tasks. A computer program product may comprise one or more computer-executable components which, when the program is run, are configured to carry out embodiments. The one or more computer-executable components may be at least one software code or portions of it. Modifications and configurations required for implementing functionality of an embodiment may be performed as routine(s), which may be implemented as added or updated software routine(s). Software routine(s) may be downloaded into the apparatus.

Software or a computer program code or portions of it may be in a source code form, object code form, or in some intermediate form, and it may be stored in some sort of carrier, distribution medium, or computer readable medium, which may be any entity or device capable of carrying the program. Such carriers include a record medium, computer memory, read-only memory, photoelectrical and/or electrical carrier signal, telecommunications signal, and software distribution package, for example. Depending on the processing power needed, the computer program may be executed in a single electronic digital computer or it may be distributed amongst a number of computers. The computer readable medium or computer readable storage medium may be a non-transitory medium.

In other embodiments, the functionality of any method or apparatus described herein may be performed by hardware, for example through the use of an application specific integrated circuit (ASIC), a programmable gate array (PGA), a field programmable gate array (FPGA), or any other combination of hardware and software. In yet another embodiment, the functionality may be implemented as a signal, a non-tangible means that can be carried by an electromagnetic signal downloaded from the Internet or other network. According to an embodiment, an apparatus, such as a node, device, or a corresponding component, may be configured as a computer or a microprocessor, such as single-chip computer element, or as a chipset, including at least a memory for providing storage capacity used for arithmetic operation and an operation processor for executing the arithmetic operation.

One having ordinary skill in the art will readily understand that the invention as discussed above may be practiced with steps in a different order, and/or with hardware elements in configurations which are different than those which are disclosed. Therefore, although the invention has been described based upon these preferred embodiments, it would be apparent to those of skill in the art that certain modifications, variations, and alternative constructions would be apparent, while remaining within the spirit and scope of the invention.

Claims

Claims:

1. A method, comprising:

monitoring, by a user equipment, a licensed assisted access (LAA) cell while a primary cell (Pcell) is not actively being monitored.

2. The method according to claim 1, wherein the monitoring of the licensed assisted access (LAA) cell comprises monitoring the licensed assisted access (LAA) cell continuously or according to discontinuous reception (DRX).

3. The method according to claims 1 or 2, wherein the licensed assisted access (LAA) cell comprises at least one of a secondary cell (SCell) or standalone operation.

4. An apparatus, comprising:

at least one processor; and

at least one memory including computer program code, wherein the at least one memory and the computer program code are configured, with the at least one processor, to cause the apparatus at least to

monitor a licensed assisted access (LAA) cell while a primary cell (Pcell) is not actively being monitored.

5. An apparatus, comprising:

monitoring means for monitoring a licensed assisted access (LAA) cell while a primary cell (Pcell) is not actively being monitored.

6. The apparatus according to claim 5, wherein the monitoring means comprises means for monitoring the licensed assisted access (LAA) cell continuously or according to discontinuous reception (DRX).

7. The apparatus according to claims 5 or 6, wherein the licensed assisted access (LAA) cell comprises at least one of a secondary cell (SCell) or standalone operation.

8. A method, comprising:

when a user equipment is scheduled on a licensed assisted access (LAA) cell, the user equipment actively monitoring a primary cell (Pcell).

9. The method according to claim 8, wherein the actively monitoring of the primary cell (PCell) further comprises at least one of:

starting an inactivity timer of the primary cell (PCell); or

monitoring according to a predefined rule.

10. The method according to claims 8 or 9, wherein the actively monitoring of the primary cell (Pcell) is performed in order to enable downlink or uplink (UL) feedback to the network.

1 1. The method according to claim 8, wherein the licensed assisted access (LAA) cell comprises a secondary cell (SCell).

12. An apparatus, comprising:

at least one processor; and

at least one memory including computer program code, wherein the at least one memory and the computer program code are configured, with the at least one processor, to cause the apparatus at least to, when the apparatus is scheduled on a licensed assisted access (LAA) cell, actively monitor a primary cell (Pcell).

13. An apparatus, comprising:

when the apparatus is scheduled on a licensed assisted access (LAA) cell, monitoring means for actively monitoring a primary cell (Pcell).

14. The apparatus according to claim 13, wherein the monitoring means further comprises at least one of:

means for starting an inactivity timer of the primary cell (PCell); or means for monitoring according to a predefined rule.

15. The apparatus according to claims 13 or 14, wherein the actively monitoring of the primary cell (Pcell) is performed in order to enable downlink or uplink (UL) feedback to the network.

16. The apparatus according to claim 13, wherein the licensed assisted access (LAA) cell comprises a secondary cell (SCell).

17. A computer program, embodied on a non-transitory computer readable medium, the computer program configured to control a processor to perform a method according to any one of claims 1-3 or 8-11.