BR112016020301B1 - TIMER CONFIGURATION FOR SECONDARY CELLS IN LTE/LTE-A NETWORKS USING UNLICENSED SPECTRUM - Google Patents

Abstract

TIMER CONFIGURATION FOR SECONDARY CELLS IN LTE/LTE-A NETWORKS THAT USE UNLICENSED SPECTRUM Secondary cell timer configuration is revealed for Long Term Evolution (LTE)/LTE-Advanced (LTE-A) that has unlicensed spectrum. licensed. To save power in a user equipment (UE), secondary cells can be deactivated by setting a secondary cell deactivation timer. Because of transmission uncertainties in operation in LTE/LTE-A systems having unlicensed spectrum, deactivation timers for unlicensed spectrum may be provided in a free channel assessment (CCA) dependent configuration, a CCA independent configuration or an alternative threshold-driven configuration of both CCA-dependent and CCA-independent configurations.

Description

[0001] This application claims the benefit of US Provisional Patent Application No. 61/948,440, titled, “TIMER CONFIGURATION FOR SECONDARY CELLS IN LTE/LTE-A NETWORKS USING UNLICENSED SPECTRUM” filed March 5, 2014, and Utility Patent Application No. 14/618,606, titled, “TIMER CONFIGURATION FOR SECONDARY CELLS IN LTE/LTE-A NETWORKS USING UNLICENSED SPECTRUM”, deposited on February 10, 2015, which are expressly incorporated herein in full, by way of reference.

BACKGROUND Field

[0002] Aspects of the present disclosure relate generally to wireless communication systems, and more particularly, to timer configuration for secondary cells in Long Term Evolution (LTE) and LTE Advanced (LTE-A) networks using spectrum unlicensed.

Fundamentals

[0003] Wireless communication systems are widely used to provide various telecommunications services, such as voice, video, packet data, messages, broadcasts and the like. These wireless networks can be multiple access networks capable of supporting multiple users by sharing available network resources. These networks, which are multiple access networks, support communications for multiple users by sharing available network resources. An example of such a network is the Universal Terrestrial Radio Access Network (UTRAN). UTRAN is the radio access network (RAN) defined as a part of the Universal Mobile Telecommunications System (UMTS), a third generation (3G) mobile telephone technology supported by the 3rd Generation Partnership Project (3GPP). Examples of multiple access network formats include Code Division Multiple Access (CDMA) networks, Time Division Multiple Access (TDMA) networks, Frequency Division Multiple Access (FDMA) networks, Orthogonal FDMA networks (OFDMA ) and Single Carrier FDMA (SC-FDMA) networks.

[0004] A wireless communication network may include multiple base stations or B nodes that can support communication to multiple user equipment (UEs). A UE can communicate with a base station via downlink and uplink. The downlink (or forward link) refers to the communication link from the base station to the UE, and uplink (or reverse link) refers to the communication link from the UE to the base station.

[0005] A base station may transmit data and control information in a downlink to a UE and/or may receive data and control information in the uplink from the UE. In downlink, a transmission from the base station may encounter interference due to transmissions from neighboring base stations or transmitters of another wireless radio frequency (RF). In the uplink, a transmission from the UE may encounter interference from uplink transmissions from other UEs communicating with neighboring base stations or from other wireless RF transmitters. This interference can degrade performance in both the downlink and uplink.

[0006] As demand for mobile broadband access continues to increase, the possibilities for interference and congested networks grow with more UEs accessing long-range wireless communications networks and more short-range wireless systems being deployed in communities Research and development continue to advance UMTS technologies, not only to meet the growing demand for mobile broadband access, but to advance and improve the user experience with mobile communications.

SUMMARY

[0007] In one aspect of the disclosure, a wireless communication method includes receiving the setting of a duration of a deactivation timer for a secondary cell associated with a UE, detecting a channel reservation signal about the secondary cell from a serving base station, and start the deactivation timer in response to the channel reservation signal.

[0008] In a further aspect of the disclosure, a wireless communication method includes transmitting the setting of a duration of a deactivation timer to a secondary cell associated with a UE, detecting a successful free channel assessment (CCA) check from the secondary cell for transmission to the UE, and start the deactivation timer for the secondary cell, in response to the detection of successful CCA check.

[0009] In a further aspect of the disclosure, a method of wireless communication includes receiving the configuration of a duration of a deactivation timer for a secondary cell associated with a UE, determining that the secondary cell is in the unlicensed spectrum, reconfiguring the deactivation timer for the secondary cell for a duration of unlicensed spectrum, and starting the deactivation timer after reconfiguration.

[0010] In a further aspect of the disclosure, a wireless communication method includes transmitting the setting of a duration of a deactivation timer to a secondary cell associated with a UE, determining that the secondary cell is in the unlicensed spectrum, reconfiguring the deactivation timer for the secondary cell for a duration of unlicensed spectrum, and starting the deactivation timer after reconfiguration.

[0011] In a further aspect of the disclosure, a wireless communication method includes receiving the setting of a duration of a deactivation timer for a secondary cell associated with a UE, selecting a CCA-dependent deactivation timer configuration in response to the duration that is below a threshold, select a CCA-independent sleep timer setting in response to the duration that is above the threshold, and start a sleep timer in accordance with the selected sleep timer setting.

[0012] In a further aspect of the disclosure, a wireless communication method includes transmitting the configuration of a duration of a deactivation timer to a secondary cell associated with a UE, identifying a CCA-dependent deactivation timer configuration for the UE in response to the duration that is below a threshold, identify a CCA-independent deactivation timer configuration for the UE in response to the duration that is above the threshold and start a deactivation timer in accordance with the identified deactivation timer configuration.

[0013] In a further aspect of the disclosure, a wireless communication method includes receiving an indication from a serving base station that identifies a deactivation timer scheme to apply to a UE, the deactivation timer scheme including or a CCA-dependent sleep timer configuration, a CCA-independent sleep timer configuration, or a hybrid CCA-dependent/CCA-independent sleep timer configuration. The method further includes receiving the configuration of a duration of a deactivation timer for a secondary cell associated with the UE and starting a deactivation timer in accordance with the identified deactivation timer scheme.

[0014] In a further aspect of the disclosure, a wireless communication method includes transmitting an indication to a UE that identifies a deactivation timer scheme to apply to the UE, wherein the deactivation timer scheme includes or a timer configuration dependent off timer configuration, a CCA independent off timer configuration, or a hybrid CCA dependent/CCA independent off timer configuration. The method further includes transmitting the configuration of a duration of a deactivation timer to a secondary cell associated with the UE and starting a deactivation timer in accordance with the identified deactivation timer scheme.

[0015] In a further aspect of the disclosure, a wireless communication method includes receiving an uplink grant to an unlicensed secondary cell, performing a CCA check on the unlicensed secondary cell in preparation for uplink transmission, disabling the unlicensed secondary cell, licensed in response to any failure to detect a free CCA check to access the unlicensed secondary cell for a radio frame duration, when the uplink grant is received in each radio frame duration through inter-carrier scheduling, failure to detect the free CCA check to access the unlicensed secondary cell for the duration of radio frames, when the uplink lease is received through the unlicensed secondary cell and downlink transmissions are detected by a UE in the unlicensed secondary cell, or failure to detect downlink transmissions over the unlicensed secondary cell.

[0016] In a further aspect of the disclosure, a wireless communication method includes periodically receiving a CCA-exempt transmission (CET) from a transmitter over an unlicensed carrier, and in response to decoding failure of an unlicensed carrier, and in response to failure to decode the CET a predetermined number of consecutive times, transmit a message to the transmitter over an accessible carrier other than the unlicensed carrier, and disable the unlicensed carrier.

[0017] In a further aspect of the disclosure, an equipment configured for wireless communication includes means for receiving the configuration of a duration of a deactivation timer for a secondary cell associated with a UE, means for detecting a channel reservation signal over the secondary cell from a serving base station, and means for starting the deactivation timer in response to the channel reservation signal.

[0018] In a further aspect of the disclosure, an equipment configured for wireless communication includes means for transmitting the setting of a duration of a deactivation timer to a secondary cell associated with a UE, means for detecting a successful CCA of the secondary cell for transmission to the UE, and means for starting the deactivation timer for the secondary cell, in response to detection of successful CCA verification.

[0019] In a further aspect of the disclosure, an equipment configured for wireless communication includes means for receiving the setting of a duration of a deactivation timer for a secondary cell associated with the UE, means for determining that the secondary cell is in the spectrum unlicensed, means for resetting the deactivation timer for the secondary cell to a duration of the unlicensed spectrum, and means for starting the deactivation timer after reconfiguration.

[0020] In a further aspect of the disclosure, an equipment configured for wireless communication includes means for transmitting the setting of a duration of a deactivation timer to a secondary cell associated with a UE, means for determining that the secondary cell is in the spectrum unlicensed, means for resetting the deactivation timer for the secondary cell to a duration of the unlicensed spectrum, and means for starting the deactivation timer after reconfiguration.

[0021] In a further aspect of the disclosure, an equipment configured for wireless communication includes means for receiving the setting of a duration of a deactivation timer for a secondary cell associated with the UE, means for selecting a dependent deactivation timer configuration of CCA in response to duration that is below a threshold, means for selecting an off timer setting independent of CCA in response to duration that is above the threshold, and means for starting an off timer in accordance with the off timer setting. deactivation selected.

[0022] In a further aspect of the disclosure, an equipment configured for wireless communication includes means for transmitting the setting of a duration of a deactivation timer to a secondary cell associated with a UE, means for identifying a dependent deactivation timer configuration of CCA to the UE in response to duration that is below a threshold, means for identifying an independent deactivation timer configuration of CCA to the UE in response to duration that is above the threshold, and means for starting a deactivation timer accordingly with the deactivation timer setting identified.

[0023] In a further aspect of the disclosure, an equipment configured for wireless communication includes means for receiving an indication from a serving base station that identifies a deactivation timer scheme to apply to a UE, the deactivation timer scheme being deactivation includes either a CCA-dependent deactivation timer configuration, a CCA-independent deactivation timer configuration, or a hybrid CCA-dependent/CCA-independent deactivation timer configuration. The equipment further includes means for receiving the setting of a duration of a deactivation timer for a secondary cell associated with the UE and means for starting a deactivation timer in accordance with the identified deactivation timer scheme.

[0024] In a further aspect of the disclosure, equipment configured for wireless communication includes means for transmitting an indication to a UE that identifies a deactivation timer scheme to apply to the UE, the deactivation timer scheme including or a CCA dependent off timer configuration, a CCA independent off timer configuration, or a hybrid CCA dependent/CCA independent off timer configuration. The equipment further includes means for transmitting the setting of a duration of a deactivation timer to a secondary cell associated with the UE and means for starting a deactivation timer in accordance with the identified deactivation timer scheme.

[0025] In a further aspect of the disclosure, an equipment configured for wireless communication includes means for receiving an uplink grant to an unlicensed secondary cell, means for performing a CCA check on the unlicensed secondary cell in preparation for the uplink transmission, means for disabling the unlicensed secondary cell in response to any failure to detect a free CCA check to access the unlicensed secondary cell for a radio frame duration, when the uplink grant is received in each of the radio frame duration through inter-carrier scheduling, failure to detect the free CCA check to access the unlicensed secondary cell for the duration of radio frames, when the uplink grant is received through the unlicensed secondary cell and downlink transmissions are detected by the UE in the unlicensed secondary cell, or failure to detect downlink transmissions over the unlicensed secondary cell.

[0026] In a further aspect of the disclosure, an equipment configured for wireless communication includes means for periodically receiving a CET from a transmitter over an unlicensed carrier, and means executable in response to failure to decode the CET a predetermined number of consecutive times. , for transmission by the receiver of a message to the transmitter over an accessible carrier other than the unlicensed carrier, and for deactivation of the unlicensed carrier.

[0027] In a further aspect of the disclosure, a non-transitory computer readable medium has program code stored thereon. This program code includes code for receiving the setting of a duration of a deactivation timer for a secondary cell associated with a UE, code for detecting a channel reservation signal over the secondary cell from a serving base station, and code to start the deactivation timer in response to the channel reservation signal.

[0028] In a further aspect of the disclosure, a non-transitory computer readable medium has program code stored thereon. This program code includes code for transmitting the setting of a duration of a deactivation timer to a secondary cell associated with a UE, code for detecting a successful CCA from the secondary cell for transmission to the UE, and code for starting the deactivation timer. deactivation to the secondary cell, in response to detection of successful CCA check.

[0029] In a further aspect of the disclosure, a non-transitory computer readable medium has program code stored thereon. This program code includes code to receive setting a duration of a deactivation timer for a secondary cell associated with a UE, code to determine that the secondary cell is in the unlicensed spectrum, code to reset the deactivation timer for the cell secondary for a duration of unlicensed spectrum, and code to start the deactivation timer after reconfiguration.

[0030] In a further aspect of the disclosure, a non-transitory computer readable medium has program code stored thereon. This program code includes code for transmitting the setting of a duration of a deactivation timer to a secondary cell associated with a UE, code for determining that the secondary cell is in the unlicensed spectrum, code for resetting the deactivation timer for the cell secondary for a duration of unlicensed spectrum, and code to start the deactivation timer after reconfiguration.

[0031] In a further aspect of the disclosure, a non-transitory computer readable medium has program code stored thereon. This program code includes code for receiving the setting of a deactivation timer duration for a secondary cell associated with a UE, code for selecting a CCA-dependent deactivation timer setting in response to the duration being below a threshold, code for selecting a CCA-independent off timer setting in response to the duration that is above the threshold and code for starting a turn off timer in accordance with the selected off timer setting.

[0032] In a further aspect of the disclosure, a non-transitory computer readable medium has program code stored thereon. This program code includes code for transmitting the setting of a deactivation timer duration to a secondary cell associated with a UE, code for identifying a CCA-dependent deactivation timer setting for the UE in response to the duration that is below a threshold, code for identifying a CCA-independent deactivation timer configuration for the UE in response to duration that is above the threshold, and code for starting a deactivation timer in accordance with the identified deactivation timer configuration.

[0033] In a further aspect of the disclosure, a non-transitory computer readable medium has program code stored thereon. This program code includes code for receiving an indication from a serving base station that identifies a deactivation timer scheme to apply to a UE, wherein the deactivation timer scheme includes either a CCA-dependent deactivation timer configuration, a CCA-independent off-timer configuration, or a hybrid CCA-dependent/CCA-independent off-timer configuration. The computer program product further includes code for receiving the setting of a duration of a deactivation timer for a secondary cell associated with the UE and code for starting a deactivation timer in accordance with the identified deactivation timer scheme.

[0034] In a further aspect of the disclosure, a non-transitory computer readable medium has program code stored thereon. This program code includes code for transmitting an indication to a UE that identifies a deactivation timer scheme to apply to the UE, wherein the deactivation timer scheme includes either a CCA-dependent deactivation timer configuration, a deactivation timer configuration CCA-independent off timer configuration, or a hybrid CCA-dependent/CCA-independent off timer configuration. The computer program product further includes code for transmitting the setting of a duration of a deactivation timer to a secondary cell associated with the UE and code for starting a deactivation timer in accordance with the identified deactivation timer scheme.

[0035] In a further aspect of the disclosure, a non-transitory computer readable medium has program code stored therein. The program code includes code for receiving an uplink grant to an unlicensed secondary cell, code for performing a CCA check on the unlicensed secondary cell in preparation for uplink transmission, code for disabling the unlicensed secondary cell in response to any failure in detecting a free CCA check to access the unlicensed secondary cell for a radio frame duration, when the uplink grant is received in each of the radio frame duration through inter-carrier scheduling, failure to detect the free CCA check CCA free to access the unlicensed secondary cell for the duration of radio frames when the uplink lease is received through the unlicensed secondary cell and downlink transmissions are detected by a UE in the unlicensed secondary cell, or fails to detect the downlink transmissions over the unlicensed secondary cell.

[0036] In a further aspect of the disclosure, a non-transitory computer readable medium has program code stored thereon. The program code includes code for periodically receiving a CET from a transmitter over an unlicensed carrier, and executable in response to failure to decode the CET a predetermined number of consecutive times, code for transmitting a message to the transmitter over an accessible carrier different from the unlicensed carrier, and code to disable the unlicensed carrier.

[0037] In a further aspect of the disclosure, an equipment includes at least one processor and a memory coupled to the processor. The processor is configured to receive the setting of a duration of a deactivation timer for a secondary cell associated with a UE, to detect a channel reservation signal over the secondary cell from a serving base station, and to initiate the off timer in response to the channel reservation signal.

[0038] In a further aspect of the disclosure, an equipment includes at least one processor and a memory coupled to the processor. The processor is configured to transmit the configuration of a duration of a deactivation timer to a secondary cell associated with a UE, to detect a successful CCA of the secondary cell for transmission to the UE, and to start the deactivation timer for the cell. secondary, in response to the detection of successful CCA verification.

[0039] In a further aspect of the disclosure, an equipment includes at least one processor and a memory coupled to the processor. The processor is configured to receive the setting of a duration of a deactivation timer for a secondary cell associated with a UE, to determine that the secondary cell is in the unlicensed spectrum, to reset the deactivation timer for the secondary cell to a duration of unlicensed spectrum, and to start the deactivation timer after reconfiguration.

[0040] In a further aspect of the disclosure, an equipment includes at least one processor and a memory coupled to the processor. The processor is configured to transmit the setting of a duration of a deactivation timer to a secondary cell associated with a UE, to determine that the secondary cell is in the unlicensed spectrum, to reset the deactivation timer for the secondary cell to a duration of unlicensed spectrum, and to start the deactivation timer after reconfiguration.

[0041] In a further aspect of the disclosure, an equipment includes at least one processor and a memory coupled to the processor. The processor is configured to receive the configuration of a duration of a deactivation timer for a secondary cell associated with a UE, to select a CCA-dependent deactivation timer configuration in response to the duration that is below a threshold, to select a setting the CCA-independent off timer in response to the duration that is above the threshold and to start a off timer in accordance with the selected off timer setting.

[0042] In a further aspect of the disclosure, an equipment includes at least one processor and a memory coupled to the processor. The processor is configured to transmit the configuration of a duration of a deactivation timer to a secondary cell associated with a UE, to identify a CCA-dependent deactivation timer configuration for the UE in response to the duration that is below a threshold, to identify a CCA-independent deactivation timer configuration for the UE in response to the duration that is above the threshold and to start a deactivation timer in accordance with the identified deactivation timer configuration.

[0043] In a further aspect of the disclosure, an equipment includes at least one processor and a memory coupled to the processor. The processor is configured to receive an indication from a serving base station that identifies a deactivation timer scheme to apply to a UE, wherein the deactivation timer scheme includes either a CCA-dependent deactivation timer configuration, a CCA-independent off timer configuration, or a hybrid CCA-dependent/CCA-independent off timer configuration. The configuration of the at least one processor further includes the configuration for receiving the configuration of a duration of a deactivation timer for a secondary cell associated with the UE and for starting a deactivation timer in accordance with the identified deactivation timer scheme.

[0044] In a further aspect of the disclosure, an equipment includes at least one processor and a memory coupled to the processor. The processor is configured to transmit an indication to a UE that identifies a deactivation timer scheme to apply to the UE, wherein the deactivation timer scheme includes either a CCA-dependent deactivation timer configuration, a deactivation timer configuration CCA-independent, or a hybrid CCA-dependent/CCA-independent off timer configuration. The configuration of the at least one processor further includes the configuration for transmitting the configuration of a duration of a deactivation timer to a secondary cell associated with the UE and for starting a deactivation timer in accordance with the identified deactivation timer scheme.

[0045] In a further aspect of the disclosure, an equipment includes at least one processor and a memory coupled to the processor. The processor is configured to receive an uplink grant for an unlicensed secondary cell, to perform a CCA check on the unlicensed secondary cell in preparation for uplink transmission, to disable the unlicensed secondary cell in response to any failure to detect a check of CCA free to access unlicensed secondary cell for a duration of radio frames, when the uplink grant is received in each of the duration of radio frames through inter-carrier scheduling, failure to detect the CCA free to access check the unlicensed secondary cell for the duration of radio frames, when the uplink lease is received over the unlicensed secondary cell and downlink transmissions are detected by a UE in the unlicensed secondary cell, or fails to detect downlink transmissions over the secondary cell unlicensed.

[0046] In a further aspect of the disclosure, an equipment includes at least one processor and a memory coupled to the processor. The processor is configured to periodically receive a CET from a transmitter over an unlicensed carrier, and in response to failure to decode the CET a predetermined number of consecutive times, to transmit a message to the transmitter over an accessible carrier other than the unlicensed carrier. licensed carrier, and to deactivate the unlicensed carrier.

BRIEF DESCRIPTION OF THE DRAWINGS

[0047] FIG. 1 shows a diagram illustrating an example of a wireless communication system according to various embodiments.

[0048] FIG. 2A shows a diagram illustrating example deployment scenarios for using LTE in an unlicensed spectrum according to various embodiments.

[0049] FIG. 2B shows a diagram illustrating another example of a deployment scenario for using LTE in an unlicensed spectrum according to various embodiments.

[0050] FIG. 3 shows a diagram illustrating an example of carrier aggregation when using LTE simultaneously in licensed and unlicensed spectrum according to various embodiments.

[0051] FIG. 4 is a block diagram conceptually illustrating a design of a base station/eNB and a UE configured in accordance with an aspect of the present disclosure.

[0052] FIGS. 5A and 5B are transmission streams illustrating a series of radio transmission frames in communication systems configured in accordance with aspects of the present disclosure.

[0053] FIGS. 6A and 6B are functional block diagrams illustrating exemplary blocks executed in a UE and base station to implement aspects of the present disclosure.

[0054] FIGS. 7A and 7B are functional block diagrams illustrating exemplary blocks executed in a UE and base station to implement aspects of the present disclosure.

[0055] FIGS. 8A and 8B are functional block diagrams illustrating exemplary blocks executed in a UE and base station to implement aspects of the present disclosure.

[0056] FIGS. 9A and 9B are functional block diagrams illustrating exemplary blocks executed in a UE and base station to implement aspects of the present disclosure.

[0057] FIG. 10 is a functional block diagram illustrating exemplary blocks executed to implement an aspect of the present disclosure.

[0058] FIG. 11 is a functional block diagram illustrating exemplary blocks executed to implement an aspect of the present disclosure.

[0059] FIG. 12 is a block diagram illustrating components of a UE configured in accordance with an aspect of the present disclosure.

[0060] FIG. 13 is a block diagram illustrating components of an eNB configured in accordance with an aspect of the present disclosure.

DETAILED DESCRIPTION

[0061] The detailed description presented below in connection with the accompanying drawings is intended to be a description of various configurations and is not intended to limit the scope of the disclosure. Instead, the detailed description includes specific details for the purpose of providing a complete understanding of the revealed implementations. It will be apparent to those skilled in the art that these specific details are not necessary in each case and that, in some cases, well-known structures and components are shown in block diagram form for clarity of presentation.

[0062] Carriers have thus far looked to WiFi as the primary mechanism for using unlicensed spectrum to alleviate increasing levels of congestion on cellular networks. However, a new carrier type (NCT) based on LTE/LTE-A that extends into the unlicensed spectrum may be compatible with carrier-grade WiFi, making LTE/LTE-A with the unlicensed spectrum an alternative. to Wi-Fi. LTE/LTE-A with unlicensed spectrum can leverage LTE concepts and can introduce some modifications to the physical layer (PHY) and media access control (MAC) aspects of the network or network devices to provide efficient operation of unlicensed spectrum and to meet regulatory requirements. Unlicensed spectrum can range from 600 Megahertz (MHz) to 6 Gigahertz (GHz), for example. In some scenarios, LTE/LTE-A with unlicensed spectrum can perform significantly better than WiFi. For example, a full LTE/LTE-A with unlicensed spectrum deployment (for single or multiple operators) compared to In all Wi-Fi deployments, or when there are dense small cell deployments, LTE/LTE-A with unlicensed spectrum can perform significantly better than Wi-Fi. LTE/LTE-A with unlicensed spectrum can work better than WiFi in other scenarios, such as when LTE/LTE-A with the unlicensed spectrum is mixed with WiFi (by single or multiple carriers).

[0063] For a single service provider (SP), an LTE/LTE-A network with the unlicensed spectrum can be configured to be synchronous with an LTE network on the licensed spectrum. However, LTE/LTE-A networks with unlicensed spectrum deployed on a given channel by multiple SPs can be configured to be synchronous between the multiple SPs. One approach to incorporating both of the above characteristics may involve utilizing a constant timing offset between LTE/LTE-A networks without the unlicensed spectrum and LTE/LTE-A networks with the unlicensed spectrum for a given SP. An LTE/LTE-A network with unlicensed spectrum can provide unicast and/or multicast services according to the needs of the SP. Additionally, an LTE/LTE-A network with unlicensed spectrum can operate in a bootstrap mode in which LTE cells act as an anchor and provide relevant cell information (e.g., radio frame timing, common channel configuration, system frame number or SFN, etc.) for LTE/LTE-A cells with unlicensed spectrum. In this mode, there can be close interoperability between LTE/LTE-A without the unlicensed spectrum and LTE/LTE-A with the unlicensed spectrum. For example, bootstrap mode can support the supplemental downlink and carrier aggregation modes described above. The PHY-MAC layers of the LTE/LTE-A network with unlicensed spectrum can operate in a standalone mode, in which the LTE/LTE-A network with unlicensed spectrum operates independently from an LTE network without spectrum unlicensed. In this case, there may be poor interoperability between LTE without unlicensed spectrum and LTE/LTE-A, with unlicensed spectrum based on RLC-level aggregation with LTE/LTE-A co-located with/without unlicensed spectrum cells , or multiflow between multiple cells and/or base stations, for example.

[0064] The techniques described here can be used for various wireless communication systems such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA and other systems. The terms “system” and “network” are often used interchangeably. A CDMA system can implement a radio technology such as CDMA2000, Universal Terrestrial Radio Access (UTRA), etc. CDMA2000 covers the IS-2000, IS-95, and IS-856 standards. IS-2000 Versions 0 and A are commonly referred to as CDMA2000 1X, 1X, etc. IS-856 (TIA-856) is commonly referred to as CDMA2000 1xEV-DO, High Rate Packet Data (HRPD), etc. UTRA includes Broadband CDMA (WCDMA) and other CDMA variants. A TDMA system can implement a radio technology such as Global System for Mobile Communications (GSM). An OFDMA system can implement a radio technology such as Ultra Mobile Broadband (UMB), Evolved UTRA (E-UTRA), IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDM, etc. UTRA and E-UTRA are part of the Universal Mobile Telecommunications System (UMTS). LTE and LTE-Advanced (LTE-A) are new versions of UMTS that use E-UTRA. UTRA, E-UTRA, UMTS, LTE, LTE-A, and GSM are described in documents from an organization called the “3rd Generation Partnership Project” (3GPP). CDMA2000 and UMB are described in documents from an organization called “3rd Generation Partnership Project 2” (3GPP2). The techniques described herein can be used for the radio systems and technologies mentioned above as well as other radio systems and technologies. The description below, however, describes an LTE system for example purposes, and LTE terminology is used throughout much of the description below, although the techniques are applicable beyond LTE applications.

[0065] Therefore, the following description provides examples and is not limiting of the scope, applicability or configuration presented in the claims. Changes can be made to the function and arrangement of the elements discussed, without departing from the spirit and scope of the revelation. Various embodiments may omit, replace, or add various procedures or components, as appropriate. For example, the described methods may be performed in a different order than described, and various steps may be added, omitted, or combined. Furthermore, features described in connection with certain embodiments may be combined in other embodiments.

[0066] Referring first to FIG. 1, a diagram illustrates an example of a wireless communication system or network 100. The system 100 includes base stations (or cells) 105, communication devices 115, and a core network 130. The base stations 105 can communicate with the devices communication network 115 under the control of a base station controller (not shown), which may be part of the core network 130 or the base stations 105 in various embodiments. The base stations 105 may communicate control information and/or user data to the core network 130 via backhaul links 132. In embodiments, the base stations 105 may communicate, either directly or indirectly, with each other. others through backhaul links 134, which may be wired or wireless communication links. System 100 may support operation on multiple carriers (waveform signals of different frequencies). Multi-carrier transmitters can simultaneously transmit modulated signals over multiple carriers. For example, each communication link 125 may be a multi-carrier signal modulated in accordance with the various radio technologies described above. Each modulated signal can be sent on a different carrier and can carry control information (e.g. reference signals, control channels, etc.), overhead information, data, etc.

[0067] Base stations 105 may communicate remotely with devices 115 via one or more base station antennas. Each of the base station locations 105 may provide communications coverage for a respective geographic area 110. In some embodiments, the base stations 105 may be referred to as a base transceiver station, a radio base station, an access point, a transceiver radio station, a basic service set (BSS), an extended service set (ESS), a Node B, eNode B (eNB), Homemade NodeB, a Homemade eNode B, or some other suitable terminology. The coverage area 110 for a base station can be divided into sectors that constitute only a part of the coverage area (not shown). The system 100 may include base stations 105 of different types (e.g., macro, micro, and/or pico base stations). There may be overlapping coverage areas for different technologies.

[0068] In some embodiments, system 100 is an LTE/LTE-A network that supports one or more unlicensed spectrum operating modes or deployment scenarios. In other embodiments, the system 100 may support wireless communications using an unlicensed spectrum and an access technology other than LTE/LTE-A, with the unlicensed spectrum, or a licensed spectrum and an access technology other than LTE/LTE -A. The terms Evolved Node B (eNB) and user equipment (UE) may generally be used to describe base stations 105 and devices 115, respectively. System 100 may be a Heterogeneous LTE/LTE-A network in which different types of eNB provide coverage for different geographic regions. For example, each eNB 105 may provide communications coverage for a macro cell, a pico cell, a femto cell, and/or other cell types. Small cells such as pico cells, femto cells, and/or other cell types may include low-power nodes or LPNs. A macro cell typically covers a relatively large geographic area (e.g., several kilometers in radius) and can allow unrestricted access by UEs with service subscriptions with the network provider. A pico cell generally covers a relatively smaller geographic area and can allow unrestricted access by UEs with service subscriptions with the network provider. A femto cell could also generally cover a relatively small geographic area (e.g., a house) and, in addition to unrestricted access, could also provide restricted access by UEs that have an association with the femto cell (e.g., UEs from a closed subscriber group (CSG), UEs for users in the home, and so on). An eNB for a macro cell can be referred to as a macro eNB. An eNB for a peak cell can be referred to as a peak eNB. And an eNB for a femto cell can be referred to as a femto eNB or homemade eNB. An eNB may support one or several (e.g., two, three, four, and the like) cells.

[0069] The core network 130 may communicate with the eNBs 105 via a backhaul channel 132 (e.g., SI, etc.) The eNBs 105 may also communicate with each other, e.g., directly or indirectly via backhaul links (e.g., X2, etc.) and/or via backhaul links 132 (e.g., via core network 130). The system 100 may support synchronous or asynchronous operation. For synchronous operation, eNBs can have similar frame and/or propagation timing and transmissions from different eNBs can be approximately aligned in time. For asynchronous operation, eNBs may have different frame and/or propagation timing and transmissions from different eNBs may not be approximately aligned in time. The techniques described here can be used for either synchronous or asynchronous operations.

[0070] The UEs 115 may be dispersed throughout the system 100, and each UE may be stationary or mobile. A UE 115 may also be referred to by those skilled in the art as a mobile station, a subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a mobile device, a wireless device, a wireless communications device, a remote device, a mobile subscriber station, an access terminal, a mobile terminal, a wireless terminal, a remote terminal, an apparatus, a user agent, a mobile client, a client, or some other appropriate terminology. A UE 115 may be a cellular telephone, a personal digital assistant (PDA), a wireless modem, a wireless communication device, a handheld device, a tablet computer, a portable computer, a cordless telephone, a circuit station wireless location (WLL), or similar. A UE may be able to communicate with macro eNBs, pico eNBs, femto eNBs, relays, and the like.

[0071] Communications links 125 shown in system 100 may include uplink (UL) transmissions from a mobile device 115 to a base station 105, and/or downlink (DL) transmissions from a base station 105 to a device mobile 115. Downlink transmissions can also be called forward link transmissions while uplink transmissions can also be called reverse link transmissions. Downlink transmissions can be made using licensed spectrum (e.g. LTE), unlicensed spectrum (e.g. LTE/LTE-A, with unlicensed spectrum), or both (LTE/LTE-A with/without the unlicensed spectrum). Similarly, uplink transmissions can be made using licensed spectrum (e.g., LTE), unlicensed spectrum (e.g., LTE/LTE-A, with the unlicensed spectrum), or both (LTE/LTE-A with/without unlicensed spectrum).

[0072] In some embodiments of system 100, various deployment scenarios for LTE/LTE-A, with unlicensed spectrum may be supported, including a supplemental downlink (SDL) mode in which LTE downlink capability, in a spectrum licensed spectrum can be offloaded to an unlicensed spectrum, a carrier aggregation mode in which both LTE downlink and uplink capacity can be offloaded from a licensed spectrum to an unlicensed spectrum, and an independent mode, in which the LTE downlink and uplink communications between a base station (e.g. eNB) and a UE may occur in an unlicensed spectrum. The base stations 105 as well as the UEs 115 may support one or more of these or similar modes of operation. OFDMA communications signals may be used in communications links 125 for LTE downlink transmissions in an unlicensed spectrum, while SC-FDMA communications signals may be used in communications links 125 for LTE uplink transmissions in an unlicensed spectrum. Additional details on implementing LTE/LTE-A with unlicensed spectrum deployment scenarios or modes of operation on a system such as system 100, as well as other features and functions related to operating LTE/LTE-A with the spectrum unlicensed, are provided below with reference to FIGs. 2A - 13.

[0073] Going next to FIG. 2A, a diagram 200 shows examples of a supplemental downlink mode and a carrier aggregation mode for an LTE network that supports LTE/LTE-A with unlicensed spectrum. Diagram 200 may be an example of portions of system 100 of FIG. 1. Furthermore, the base station 105-a may be an example of the base stations 105 of FIG. 1, while the UEs 115-a may be the UEs 115 of FIG. 1.

[0074] In the example of a supplemental downlink mode in diagram 200, the base station 105-a may transmit OFDMA communication signals to a UE 115-a using a downlink 205. The downlink 205 is associated with a frequency F1 in a spectrum unlicensed. The base station 105-a may transmit OFDMA communication signals to the same UE 115-a using a bidirectional link 210 and may receive SC-FDMA communication signals from the UE 115-a via the bidirectional link 210. The bidirectional link 210 is associated with an F4 frequency in an unlicensed spectrum. The downlink 205 in the unlicensed spectrum and the bidirectional link 210 in the licensed spectrum may operate simultaneously. The downlink 205 may provide an offload of downlink capacity to the base station 105-a. In some embodiments, the downlink 205 may be used for unicast services (e.g., directed to one UE) or for multicast services (e.g., having multiple UEs). This scenario can occur with any service provider (e.g. traditional mobile network operator or MNO) that uses licensed spectrum and needs to alleviate some traffic and/or signaling congestion.

[0075] In an example of a carrier aggregation mode in diagram 200, the base station 105-A may transmit OFDMA communication signals to a UE 115-a using a bidirectional link 215 and may receive SC-FDMA communication signals to from the same UE 115-a through the bidirectional link 215. The bidirectional link 215 is associated with a frequency F1 in an unlicensed spectrum. The base station 105-a may also transmit OFDMA communication signals to the same UE 115-a using a bidirectional link 220 and may receive SC-FDMA communication signals from the same UE 115-a via the bidirectional link 220. The link bidirectional 220 is associated with an F2 frequency in an unlicensed spectrum. The bidirectional link 215 may provide an offload of uplink and downlink capacity to the base station 105-a. Like the supplemental downlink described above, this scenario can occur with any service provider (e.g. MNO) that uses licensed spectrum and needs to alleviate some traffic and/or signaling congestion.

[0076] In another example of a carrier aggregation mode in diagram 200, base station 105-A may transmit OFDMA communication signals to a UE 115-a using a bidirectional link 225 and may receive SC-FDMA communication signals to from the same UE 115-a through the bidirectional link 225. The bidirectional link 225 is associated with a frequency F3 in an unlicensed spectrum. The base station 105-a may also transmit OFDMA communication signals to the same UE 115-a using a bidirectional link 230 and may receive SC-FDMA communication signals from the same UE 115-a via the bidirectional link 230. The link bidirectional 230 is associated with an F2 frequency in the licensed spectrum. The bidirectional link 225 may provide an offload of uplink and downlink capacity to the base station 105-a. This example and those provided above are presented for illustrative purposes and there may be other similar modes of operation or deployment scenarios that combine LTE/LTE-A with or without unlicensed spectrum for capacity offloading.

[0077] As described above, the typical service provider that can benefit from the capacity offload offered using LTE/LTE-A, with unlicensed spectrum is a traditional MNO with LTE spectrum. For these service providers, an exemplary configuration might include a bootstrap mode (e.g., supplemental downlink, carrier aggregation) that utilizes the LTE Primary Component Carrier (PCC) in the licensed spectrum and the Secondary Component Carrier (SCC) in the unlicensed spectrum.

[0078] In supplemental downlink mode, control for LTE/LTE-A with unlicensed spectrum may be carried to the LTE uplink (e.g., the uplink portion of bidirectional link 210). One of the reasons for providing downlink capacity offloading is because data demand is largely driven by downlink consumption. Furthermore, in this mode, there may not be a regulatory impact as the UE is not transmitting in the unlicensed spectrum. There is no need to implement listen-before-talk (LVT) or carrier sense multiple access (CSMA) requirements on the UE. However, LBT can be implemented at the base station (e.g., eNB), for example, using a periodic (e.g., every 10 milliseconds) free channel assessment (CCA) and/or a hold-and-hold mechanism. release aligned to a radio frame boundary.

[0079] In carrier aggregation mode, data and control can be communicated over LTE (e.g. bidirectional links 210, 220 and 230), while data can be communicated over LTE/LTE-A with unlicensed spectrum (e.g. example, bidirectional links 215 and 225). The carrier aggregation mechanisms supported by the use of LTE/LTE-A with the unlicensed spectrum may fall under a frequency division duplexing - hybrid time division duplexing (FDD-TDD) carrier aggregation or a carrier aggregation TDD-TDD with different symmetry between component carriers.

[0080] FIG. 2B shows a diagram 200-a illustrating an example of a standalone mode for LTE/LTE-A with unlicensed spectrum. Diagram 200-a may be an example of portions of system 100 of FIG. 1. Furthermore, base station 105-b may be an example of base stations 105 of FIG. 1, and base station 105-a of FIG. 2A, while UE 115-b may be an example of the UEs 115 of FIG. 1, and the UEs 115-a of FIG. 2A.

[0081] In the example of a standalone mode in diagram 200-a, the base station 105-a may transmit OFDMA communication signals to the UE 115-a using a bidirectional link 240 and may receive SC-FDMA communication signals from the UE 115-b via bidirectional link 240. Bidirectional link 240 is associated with an F3 frequency in an unlicensed spectrum described above with reference to FIG. 2A. Standalone mode can be used in non-traditional wireless access scenarios, such as in-stadium access (e.g., unicast, multicast). The typical service provider for this mode of operation might be a stadium owner, cable company, event hosts, hotels, businesses, and large corporations that do not have licensed spectrum. For these service providers, an operational configuration for standalone mode can use PCC in unlicensed spectrum. Furthermore, LBT can be implemented at both the base station and the UE.

[0082] Going next to FIG. 3, a diagram 300 illustrates an example of carrier aggregation when using LTE simultaneously in licensed and unlicensed spectrum according to various embodiments. The carrier aggregation scheme in diagram 300 may correspond to the hybrid FDD-TDD carrier aggregation described above with reference to FIG. 2A. The carrier aggregation type may be used in at least the portions of system 100 of FIG. 1. Furthermore, this type of carrier aggregation can be used in base stations 105 and 105-a of FIG. 1 and FIG. 2A, respectively, and/or in UEs 115 and 115-a, of FIG. 1 and FIG. 2A, respectively.

[0083] In this example, an FDD (LTE FDD) can be performed in connection with LTE in the downlink, a first TDD (TDD1) can be performed in connection with LTE/LTE-A with unlicensed spectrum, a second TDD (TDD2) can be performed in connection with LTE with licensed spectrum and another FDD (LTE FDD) can be performed in connection with LTE in the uplink with licensed spectrum. TDD1 results in a DL:UL ratio of 6:4, while the ratio for TDD2 is 7:3. On the time scale, the different effective DL:UL ratios are 3:1, 1:3, 2:2, 3:1, 2:2, and 3:1. This example is presented for illustrative purposes and there may be other schemes carrier aggregation systems that combine LTE/LTE-A operations with or without unlicensed spectrum.

[0084] FIG. 4 shows a block diagram of a design of a base station/eNB 105 and a UE 115, which may be one of the base stations/eNBs and one of the UEs in FIG. 1. The eNB 105 can be equipped with antennas 434a to 434t, and the UE 115 can be equipped with antennas 452a to 452r. In the eNB 105, a transmission processor 420 may receive data from a data source 412 and control information from a controller/processor 440. The control information may be for the physical transmission channel (PBCH), channel physical control format indicator (PCFICH), physical hybrid automatic repeat request indicator channel (PHICH), physical downlink control channel (PDCCH), etc. Data can be for physical downlink shared channel (PDSCH), etc. The transmission processor 420 may process (e.g., encode and symbol map) the data and control information to obtain data symbols and control symbols, respectively. The transmission processor 420 may also generate reference symbols, for example, for the primary synchronization signal (PSS), secondary synchronization signal (SSS), and cell-specific reference signal. A multiple-input multiple-output (MIMO) transmission (Tx) processor 430 may perform spatial processing (e.g., precoding) on data symbols, control symbols, and/or reference symbols, if applicable, and may provide output symbol streams for modulators (MODs) 432a through 432t. Each modulator 432 may process a respective output symbol stream (e.g., for OFDM, etc.) to obtain an output sample stream. Each modulator 432 may further process (e.g., convert to analog, amplify, filter, and overconvert) the output sample stream to obtain a downlink signal. Downlink signals from modulators 432a to 432t can be transmitted through antennas 434a to 434t, respectively.

[0085] In the UE 115, the antennas 452a to 452r can receive the downlink signals from the eNB 105 and can provide the received signals to the demodulators (DEMODs) 454a to 454r, respectively. Each demodulator 454 may condition (e.g., filter, amplify, subconvert, and digitize) a respective received signal to obtain input samples. Each demodulator 454 may further process the input samples (e.g., for OFDM, etc.) to obtain received symbols. A MIMO detector 456 can obtain received symbols from all demodulators 454a to 454r, perform MIMO detection on the received symbols if applicable, and output the detected symbols. A receiving processor 458 may process (e.g., demodulate, deinterleave, and decode) the detected symbols, provide decoded data to the UE 115 for a data store 460, and provide the decoded control information to a processor/controller 480.

[0086] In the uplink, at UE 115, a transmission processor 464 may receive and process data (e.g., for the physical uplink shared channel (PUSCH) from a data source 462 and control information (e.g., for the physical uplink control channel (PUCCH) from the controller/processor 480. The transmission processor 464 may also generate reference symbols for the reference signal. Symbols from the transmission processor 464 may be preceded by a TX MIMO processor 466 if applicable, further processed by demodulators 454a to 454r (e.g., for SC-FDM, etc.), and transmitted to the eNodeB 105. In the eNB 105, the uplink signals from the UE 115 can be received by the antennas 434, processed by modulators 432, detected by a MIMO detector 436, if applicable, and further processed by a receive processor 438 to obtain decoded data and control information sent by the UE 115. The processor 438 may provide the decoded data to a data store 439 and the control information decoded to the controller/processor 440.

[0087] Controllers/processors 440 and 480 may direct operation on the eNB 105 and the UE 115, respectively. The controller/processor 440 and/or other processors and modules in the eNB 105 may execute or direct the execution of various processes for the techniques described herein. The controllers/processor 480 and/or other processors and modules in the UE 115 may also execute or direct the execution of the fundamental blocks illustrated in FIGs. 6-11 and/or other processes for the techniques described herein. Memories 442 and 482 can store data and program codes for the eNB 105 and the UE 115, respectively. A scheduler 444 may schedule UEs for data transmission in the downlink and/or uplink.

[0088] In the carrier aggregation functionality, secondary cells can be semi-statically configured by the base station via an RRC reconfiguration message. Activation and deactivation of secondary cells can then be performed by a base station on a rapid basis using media access control (MAC) control elements. Furthermore, to save power in the UE, secondary cells can also be disabled using a timer in the UE. By default, the timer can be set to infinity, but can be configured to be various radio frame lengths. For example, the timer can be set to one of 2, 4, 8, 16, 32, 64, or 128 radio frames. The UE will cease monitoring a secondary cell if no downlink grants are received for the secondary cell for the configured number of subframes. Aspects of the present disclosure provide secondary cell deactivation timer configuration for LTE/LTE-A networks with unlicensed spectrum that take into account the uncertainties of unlicensed spectrum transmissions.

[0089] In a first aspect of the disclosure, the setting of a deactivation timer may depend on the success of the CCA. FIG. 5A is a block diagram illustrating a transmission chain 50 with a series of 1-X transmit radio frames in a communication system configured in accordance with an aspect of the present disclosure. The deactivation timer of a UE within the illustrated system may be configured or adjusted to a certain number of consecutive radio frames, N, when CCA success has been detected by a UE. For the purposes of this example, the UE receives deactivation timer configuration 500 in frame 1 which sets the timer for a duration of N radio frames. The success of CCA can be detected by detecting transmission of a channel reservation signal. When a base station or other transmit node detects a successful CCA check, the base station will either immediately begin data transmissions or begin transmitting a signal that reserves the channel for the next radio frame. The channel reservation signal may be data transmissions, a usage beacon (CUBS) signal, or another such base station signature signal that identifies that the base station has been authorized to transmit on the channel (e.g., after of a successful CCA). When the UE detects such a channel reservation signal, after detecting the free CCA check at 501, the deactivation timer is started, at 502, for N consecutive radio frames, so that when no data is scheduled for N consecutive radio frames, after detecting the channel reservation signal, the UE deactivates the secondary cell. As illustrated, N was chosen by the serving base station as 4 radio frames. Thus, if the UE does not receive scheduled data on frames 3-6, then it will deactivate the secondary cell. However, the deactivation timer is dependent on detecting successful CCA results. When the UE receives the timer configuration in frame 1, the timer does not start until the first successful CCA is detected. With such CCA-dependent timer deactivation schemes, the timer duration can be configured for smaller numbers of radio frames (e.g., 2, 4, and 8 radio frames).

[0090] It should be noted that data refers to control channel data when self-scheduling is used for downlink grants, while data refers to data channel data when inter-carrier scheduling is used. used for downlink grants.

[0091] FIGS. 6A and 6B are functional block diagrams illustrating exemplary blocks executed in a UE and a base station to implement an aspect of the present disclosure. In block 603, a serving base station transmits the configuration of a duration of a deactivation timer to a secondary cell associated with a UE. In block 600, the UE receives this deactivation timer configuration and configures its deactivation timer accordingly. In block 601, the UE detects a channel reservation signal (e.g., CUBS, etc.) over the secondary cell from the serving base station, and in block 602, starts the deactivation timer in response to the reservation signal. channel. In block 604, the serving base station also detects a successful CCA in the secondary cell and, in block 605, starts a parallel deactivation timer associated with the secondary cell for the UE. If the UE fails to detect programming or data transmission through the secondary cell within the duration of the deactivation timer, the UE will deactivate the secondary cell. The base station maintains its parallel timer and, if there is no data to be marked to the UE during the duration of the timer, it will identify the secondary cell as being deactivated by the UE upon expiration of the deactivation timer.

[0092] In a second alternative aspect of the present disclosure, the setting of a deactivation timer may be independent of the success of the CCA. Returning to FIG. 5B is a functional block diagram illustrating a transmission chain 51 with a series of 1-X radio frames in a communication system configured in accordance with one aspect of the present disclosure. At 503, the UE receives the deactivation timer configuration from the serving base station. In these CCA-independent configurations, the values of the deactivation timers for the component carriers in the unlicensed spectrum are increased to compensate for channel access uncertainties. For example, a deactivation timer of 2, 4, 8 radio frames may be too short for channels with multiple public land mobile networks (PLMNs) and WiFi nodes. If the deactivation timer was configured for a duration of 4 radio frames , as illustrated in the CCA-dependent deactivation timer configuration schematic of FIG. 5A, the timer would expire and the secondary cell would be deactivated even before the first successful CCA was achieved in frame 18. As such, in the CCA-independent deactivation timer configuration scheme, durations are selected to be longer when the secondary cell is in the unlicensed spectrum.

[0093] For example, when unlicensed spectrum is detected by a specific secondary cell, the deactivation timer is set to an increased timer value (e.g., 16, 32, 64, or 128 radio frames). Thus, when the deactivation timer is set to 503, the UE detects whether the secondary cell associated with the deactivation timer is in the licensed or unlicensed spectrum. If the cell is in the unlicensed spectrum, then the UE will select a timer duration from a set of unlicensed duration values, N. The set of unlicensed deactivation timer durations are longer durations (e.g. 16, 32, 64 radio frames, and the like). Once the unlicensed timer duration is selected, the UE resets and starts the deactivation timer with the longest unlicensed duration. If no downlink transmission is detected within the N radio frames, the UE disables the secondary cell. The UE detects a first free CCA during frame 18, at 505, which is within the duration of radio frame 32 that was reconfigured by the UE. If no data is programmed or transmitted after frame 18 and up to frame 32, the UE will deactivate the second cell.

[0094] FIGS. 7A and 7B are functional block diagrams illustrating exemplary blocks executed in a UE and a base station to implement an aspect of the present disclosure. In block 704, a serving base station transmits the configuration of a deactivation timer to a secondary cell associated with a UE. In block 700, the UE receives the configuration signal that includes the duration of the deactivation timer. In block 701, the UE determines whether the secondary cell is within licensed spectrum or unlicensed spectrum. In block 702, when the secondary cell is determined to be within the unlicensed spectrum, the UE resets the deactivation timer with a duration of the unlicensed spectrum. The duration of unlicensed spectrum may be longer than shorter duration options (e.g., greater than 16 radio frames). In block 705, the serving base station recognizes that the secondary cell is in the unlicensed spectrum and also, in block 706, resets its parallel deactivation timer using the longest unlicensed spectrum duration. In blocks 703 and 707, the UE and serving base station, respectively, then start their deactivation timers after reconfiguring for the unlicensed spectrum duration. If no data is received before the expiration of the deactivation timer, the UE may deactivate the secondary cell. The serving base station, upon expiration of its parallel deactivation timer without any data to schedule for transmission to the UE, will identify the secondary cell as being deactivated by the UE.

[0095] In a third alternative aspect of the present invention, the choice between the CCA-dependent aspect and the CCA-independent aspect is based on a threshold timer value. For example, if the deactivation timer is set to a smaller value (for example, 2,4, or 8 radio frames), the CCA-dependent timer setting is used. Therefore, the deactivation timer is started only upon detection of a successful CCA (e.g. detection of a channel reservation signal). Otherwise, if the deactivation timer is set to a larger value (for example, 16 or more radio frames), the CCA-independent timer setting is used.

[0096] FIGS. 8A and 8B are functional block diagrams illustrating exemplary blocks executed in a UE and a base station to implement an aspect of the present disclosure. In block 804, a serving base station transmits the configuration of a duration of a deactivation timer to a secondary cell associated with a specific UE. In block 800, the UE receives the deactivation timer configuration. In block 802, a determination is made by the UE whether the configured duration meets a predetermined threshold length. If the configuration duration is small or a small number of radio frames, then the UE selects a CCA-dependent deactivation timer configuration in block 802. If the configuration duration is large or a larger number of radio frames, radio, the UE then selects a CCA-independent deactivation timer configuration in block 803. On the base station side, the base station also makes a determination in block 806 of whether the configured duration meets the predetermined threshold. If not, and the duration is shorter, then in block 807, the base station identifies the CCA-dependent timer configuration for its parallel deactivation timer. If the configured duration is longer, then in block 808, the base station identifies the CCA-dependent off timer configuration for its parallel off timer. In blocks 804 and 809, the UE and serving base station, respectively, start their deactivation timers in accordance with the selected or identified deactivation timer configuration.

[0097] Furthermore, it should be noted that in additional alternative aspects, all three alternative aspects may be supported, in which the base station indicates via an RRC reconfiguration message to the UE that the alternative aspects are to be used. FIGS. 9A and 9B are functional block diagrams illustrating exemplary blocks executed in a UE and a base station to implement an aspect of the present disclosure. In block 903, a serving base station transmits an indication to a UE that identifies a deactivation timer scheme to apply to the UE. The indication may identify a CCA-dependent disable timer setting, as illustrated in FIGS. 5A, 6A and 6B, a CCA-independent deactivation timer configuration, as illustrated in FIGS. 5B, 7A and 7B, or a hybrid CCA-dependent/CCA-independent off timer configuration, as illustrated in FIGS. 8A and 8B. At block 900, the UE receives an indication that identifies which deactivation timer scheme to apply. In block 904, the serving base station transmits the configuration of the duration of a deactivation timer to a secondary cell associated with the UE. In block 901, the UE receives the configured duration for the deactivation timer. In blocks 902 and 905, the UE and serving base station, respectively, start their deactivation timers according to the identified deactivation timer scheme, as illustrated in FIGs. 5-8.

[0098] The various aspects described in relation to the three alternatives above may be applicable to supplementary downlink mode and independent mode for LTE/LTE-A networks with unlicensed spectrum. Additional aspects applicable to LTE/LTE-A networks with unlicensed spectrum in carrier aggregation mode may include additional features to deal with uplink transmission uncertainty. For uplink communications over the secondary cells, the secondary cell can be deactivated using an uplink deactivation timer under specific conditions after a number of radio frames. For example, when the UE is programmed for multi-carrier and cannot access the uplink channel for M radio frames after continuously receiving an uplink grant on each radio frame, the UE may disable the secondary cell. Additionally, when the UE is self-programmed and cannot access the uplink channel for M radio frames after detecting a downlink transmission and receiving an uplink grant, the UE may also disable the secondary cell. Furthermore, the UE may disable the secondary cell when no downlink traffic/activity is detected in the secondary cell. It should be noted that, in general, the number of radio frames configured for an uplink deactivation timer, is not equal to the number of radio frames configured for a downlink deactivation timer, N. When there is a greater amount of downlink traffic ,M will typically be small in order to more quickly obtain free resources for downlink transmissions. Otherwise, M may be close to the value of N.

[0099] FIG. 10 is a functional block diagram illustrating exemplary blocks executed to implement an aspect of the present disclosure. In block 1000, the UE receives an uplink grant to an unlicensed secondary cell. In preparation for uplink transmissions, the UE, in block 1001, performs a CCA check on the unlicensed secondary cell. In block 1002, a determination is made whether downlink transmission is detected in the unlicensed secondary cell. If no downlink transmission and thus no activity is detected in the unlicensed secondary cell, then, in block 1006, the UE deactivates the unlicensed secondary cell. If activity is detected in the unlicensed secondary cell, then another determination is made, in block 1003, whether a free CCA has been detected. If so, then the UE can perform its uplink transmissions and return to the beginning of the process in block 1000. Otherwise, if no free CCA has been detected, if, in block 1004, the uplink grant has been auto-programmed on the secondary carrier unlicensed, then, in block 1006, the UE deactivates the unlicensed secondary carrier. Otherwise, if the uplink grant was intercarrier scheduled, then, in block 1005, a determination is made whether an uplink grant was received in each frame within the duration of the deactivation timer. If not, then the UE proceeds from block 1000. Otherwise, if an uplink lease was received in each frame within the disable timer duration, but the UE was unable to access the unlicensed secondary cell within the duration, then, in block 1006, the UE deactivates the unlicensed secondary cell.

[00100] Additional aspects of the present disclosure provide for the handling of CCA-exempt downlink transmissions (CETs). CCA is not required for stand-alone transmissions subject to various regulatory requirements. These transmissions are referred to as CET and can be scheduled regularly, for example every 80 ms, with a duration of a fraction of a subframe. The CET can be present in both uplink and downlink transmission and can carry system information and other relevant information (e.g. group power control, etc.). Aspects of the present disclosure provide for the use of a deactivation timer when a UE fails to correctly decode such a downlink CET. For example, if a UE cannot correctly decode the downlink CET for M consecutive radio frames, the UE may send a message that the CET cannot be decoded in the specific secondary cell for the uplink base station (or licensed or unlicensed uplink). licensed from another cell), and then deactivate the cell.

[00101] Additional aspects of the present disclosure also provide manipulation of the uplink CET in LET/LTE-A networks with unlicensed spectrum in carrier aggregation mode and autonomous mode. Similar to the handling of downlink CETs, aspects of the present disclosure also provide for the use of a deactivation timer when a base station fails to correctly decode such uplink CETs. For example, if a base station cannot correctly decode the uplink CET for M consecutive radio frames, the base station can send a message that the CET cannot be decoded to the UE (or licensed or unlicensed downlink from another cell) and then disable the cell. It should be noted that when operating in standalone mode, a primary cell may not be deactivated.

[00102] FIG. 11 is a functional block diagram illustrating exemplary blocks executed to implement an aspect of the present disclosure in CET manipulation. In block 1100, a receiver, which may be either a UE, such as a receiver, or a base station, such as a receiver of transmissions from the UE, periodically receives the CET from a transmitter over an unlicensed carrier. The transmitter may be either a base station, when transmitting downlink data to a UE, or may be a UE, when transmitting uplink data to the base station. CETs are transmitted at regularly scheduled intervals, for example every 80 ms, if the CET cannot be decoded for a certain number of consecutive transmissions, then the secondary cell over which the CETs are transmitted may not be suitable. Accordingly, in block 1101, a determination is made whether CET transmissions have failed to be adequately decoded for a predetermined number of consecutive transmissions. If not, and some have been successfully decoded, then the receiver returns to the process at block 1100. Otherwise, if the CET has not been successfully decoded for the predetermined number of consecutive transmissions, then at block 1102, the The receiver transmits a message to the transmitter via an accessible carrier that the CETs have not been successfully decoded, and, in block 1103, the receiver disables the unlicensed carrier. In order to successfully send the message to the transmitter, in block 1102, the receiver would transmit the message using either a licensed carrier or another unlicensed carrier that is different from the current unlicensed carrier over which the CETs are being received.

[00103] FIGS. 12 and 13 are block diagrams illustrating components of a UE 1200 and a base station 1300 configured in accordance with an aspect of the present disclosure. The UE 1200 includes controller/processor 480. The controller/processor 480 includes one or more processors that execute logic, stored in memory 482, and control the components and hardware that provide the features and functionality of the UE 1200. Likewise, the base station 1300 includes controller/processor 440. Controller/processor 440 includes one or more processors that execute logic, stored in memory 442, and control the components and hardware that provide the features and functionality of base station 1300. UE 1200 and the base station 1300 can execute the processes and procedures and perform the functions on the various aspects as illustrated in FIGS. 5-11, respectively. For example, CCA check modules 1201 and 1301, in memories 482 and 442, respectively, can be executed by controller/processors 480 and 440 to both perform CCA checks for uplink communications over unlicensed carriers and also to detect Successful CCA from other serving base stations, for CCA dependent off timer configuration. Unlicensed durations 1202 and 1302, in memories 482 and 440, may also be used in CCA-independent timer disable configurations. When the received durations are below a threshold, the UE 1200 may select and the base station 1300 may identify a longer duration from the unlicensed durations 1202 and 1302. Additionally, each of the UE 1200 and base station 1300 may use hybrid CCA-dependent/CCA-independent sleep timer configurations or selectable operations of all of these sleep timer schemes, maintaining the functionality of the various operations in sleep timer schemes 1203 and 1303, in memories 482 and 442. In operation of hybrid CCA-dependent/CCA-independent configuration, the controller/processors 480 and 440 would compare the configured durations against a threshold to determine whether a CCA-dependent configuration scheme is used for shorter durations or a CCA-independent configuration scheme is used for longer periods. Thus, the various aspects of the present invention illustrated in FIGs. 5-11 can be implemented using the resources and components of the UE 1200 and base station 1300.

[00104] One skilled in the art would understand that information and signals can be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referred to throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

[00105] The functional blocks and modules in FIGs. 6-11 may include processors, electronic devices, hardware devices, electronic sub-components, logic circuits, memories, software codes, firmware codes, etc., or any combination thereof.

[00106] Those skilled in the art would further appreciate that the various illustrative logical blocks, modules, circuits and algorithm steps described in connection with the present disclosure can be implemented as electronic hardware, computer software, or combinations of both. To clearly illustrate this interchangeability of hardware and software, various components, blocks, modules, circuits and illustrative steps have been described above, generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends on the specific application and design limitations imposed on the overall system. Persons skilled in the art may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be construed as causing a departure from the scope of the present disclosure. Those skilled in the art will also readily recognize that the order or combination of components, methods, or interactions that are described herein are merely examples and that the components, methods, or interactions of the various aspects of the present disclosure may be combined or carried out in ways other than those illustrated and described here.

[00107] The various logic blocks, modules and illustrative circuits described in connection with the present disclosure can be implemented or executed with a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) signal or other programmable logic device (PLD), discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general-purpose processor may be a microprocessor, but alternatively, the processor may be any conventional processor, controller, microcontroller, or conventional state machine. A processor may also be implemented as a combination of computing devices, for example, a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other type of configuration.

[00108] The steps of a method or algorithm described in relation to the disclosure herein may be incorporated directly into hardware, into a software module executed by a processor, or in a combination of the two. A software module may reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM, registers, hard disk, a removable disk, a CD-ROM, or any other form of storage media known in the art. An exemplary storage medium is coupled to the processor so that the processor can read information from, and write information to, the storage medium. Alternatively, the storage media may be an integral part of the processor. The processor and storage media can reside in an ASIC. The ASIC may reside on a user terminal. Alternatively, the processor and storage media may reside as distinct components in a user terminal.

[00109] In one or more exemplary designs, the described functions can be implemented in hardware, software, firmware or any combination thereof. If implemented in software, functions may be stored in or transmitted through one or more instructions or code on a computer-readable medium. Computer-readable media include computer storage media and communication media, including any medium that facilitates the transfer of a computer program from one place to another. A computer-readable storage medium can be any available medium that can be accessed by a general-purpose or special-purpose computer. By way of example, and not as a limitation, such computer-readable media may comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that may be used to transport or store means of desired program code in the form of instructions or data structures and which can be accessed by a general-purpose computer or special-purpose computer, or a general-purpose processor or special-purpose processor. Also, any connection can properly be called a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source over a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave, then coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of media. Disc and floppy disk, as used herein, include compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk, and Blu-ray disc where floppy disks generally reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above should also be included within the scope of computer-readable media.

[00110] As used herein, including in the claims, the term “and/or”, when used in a list of two or more articles, means that any one of the mentioned items can be employed alone, or any combination of two or more of the Mentioned items can be employed. For example, if a composition is described as containing components A, B and/or C, the composition may contain only A; under; only C; A and B in combination; A and C in combination; B and C in combination; or A, B, and C in combination. Also, as used herein, including in the claims, “or,” as used in a list of items preceded by “at least one of” indicates a disjunctive list such that, for example, a list of “at least one of A , B, or C” means A or B or C or AB or AC or AC or ABC (that is, A and B and C) or any of these in any combination thereof.

[00111] The foregoing description of the disclosure is provided to enable any person skilled in the art to make or use the disclosure. Various modifications to the disclosure will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other variations without departing from the spirit and scope of the disclosure. Accordingly, the description is not intended to be limited to the examples and drawings described herein, but should be in accordance with the broadest scope consistent with the principles and novel features described herein.

Claims (15)

1. Wireless communication method, comprising: receiving (700) setting a duration of a deactivation timer for a secondary cell associated with a user equipment, UE; the method further comprising: determining (701) whether the secondary cell is within the licensed or unlicensed spectrum; when the secondary cell is within unlicensed spectrum, reset (702) the deactivation timer using an unlicensed spectrum duration; and starting (703) the deactivation timer after reconfiguring for the duration of the unlicensed spectrum. 2. Method according to claim 1, characterized in that the duration of the unlicensed spectrum is greater than a set of shorter duration options for licensed spectrum. 3. Method according to claim 2, characterized in that the duration of the unlicensed spectrum is one of: 16 radio frames, 32 radio frames, 64 radio frames, or 128 radio frames; and wherein the set of shorter duration options for licensed spectrum consists of: 2 radio frames, 4 radio frames, and 8 radio frames. 4. Method, according to claim 1, characterized by further including: detection of no programmed data throughout the duration of the deactivation timer; and in response to detecting no data programmed for the duration, disable the secondary cell. 5. The method of claim 4, wherein the data includes one or more of: control channel data when downlink grants are received over the secondary cell; and data channel data, when the downlink grants are cross-carriers received from the secondary cell. 6. A wireless communication method, comprising: transmitting (704) setting a duration of a deactivation timer to a secondary cell associated with a user equipment, UE; the method further comprising: determining (705) whether the secondary cell is within the licensed or unlicensed spectrum; when the secondary cell is within unlicensed spectrum, reset (706) the deactivation timer using an unlicensed spectrum duration; and starting (707) the deactivation timer after reconfiguring for the duration of the unlicensed spectrum. 7. Method according to claim 6, characterized in that the duration of the unlicensed spectrum is greater than a set of shorter duration options for licensed spectrum. 8. Method according to claim 7, characterized in that the duration of the unlicensed spectrum is one of: 16 radio frames, 32 radio frames, 64 radio frames, or 128 radio frames; and wherein the set of shorter duration options for licensed spectrum consists of: 2 radio frames, 4 radio frames, and 8 radio frames. 9. The method of claim 6, further including: determining that there is no data to program to the UE about the secondary cell for the duration of the deactivation timer; and in response to determining that there is no data to program for the duration, disable the secondary cell. 10. The method of claim 9, wherein the data includes one or more of: control channel data when downlink grants are transmitted over the secondary cell; and data channel data, when the downlink leases are cross-carriers transmitted from the secondary cell. 11. Equipment configured for wireless communication, comprising: means for receiving (700) setting a duration of a deactivation timer for a secondary cell associated with a user equipment, UE; the equipment further comprising: means for determining (701) whether the secondary cell is within the licensed or unlicensed spectrum; means for resetting (702) the deactivation timer using an unlicensed spectrum duration when the secondary cell is determined to be within the unlicensed spectrum; and means for starting (703) the deactivation timer after reconfiguring for the duration of the unlicensed spectrum. 12. Equipment according to claim 11, further including: means for detecting that there is no data programmed during the duration of the deactivation timer; and means, executable in response to detecting that there is no data scheduled for the duration, to deactivate the secondary cell. 13. Equipment configured for wireless communication, comprising: means for transmitting (704) the configuration of a duration of a deactivation timer to a secondary cell associated with a user equipment, UE; the equipment further comprising: means for determining (705) whether the secondary cell is within the licensed or unlicensed spectrum; means for resetting (706) the deactivation timer using an unlicensed spectrum duration when the secondary cell is determined to be within the unlicensed spectrum; and means for starting (707) the deactivation timer after reconfiguring for the duration of the unlicensed spectrum. 14. Equipment according to claim 13, further including: means for determining that there is no data to program to the UE about the secondary cell for the duration of the deactivation timer; and means, executable in response to determining that there is no data to program for the duration, to deactivate the secondary cell. 15. Memory characterized by comprising instructions that, when executed, cause a computer to perform a method as defined in any one of claims 1 to 10.