WO2014047914A1

WO2014047914A1 - Method and apparatus for managing secondary cell measurement

Info

Publication number: WO2014047914A1
Application number: PCT/CN2012/082405
Authority: WO
Inventors: Wei Bai; Christopher Callender; Jing HAN; Na WEI; Tero Heikki Matt HENTTONEN; Haiming Wang
Original assignee: Broadcom Corporation
Priority date: 2012-09-28
Filing date: 2012-09-28
Publication date: 2014-04-03

Abstract

A method, apparatus and computer program product are therefore provided in order to provide for management of measurement of deactivated secondary cells (304, 404) by a mobile terminal (504, 506) in an aggregated earner environment. A network node (502) may communicate with the mobile terminal (504, 506) to enable the mobile terminal to communicate with the network node (502) using aggregated carriers. The network node (502) may specify a set of measurement parameters to the mobile terminal (504, 506) when initiating the aggregated carrier communication. The measurement parameters may be used by the mobile terminal (504, 506) to measure deactivated secondary cells to manage radio frequency retuning operations performed during such measurements. Measuring the deactivated secondary cells according to the measurement parameters may ensure that the network node (502) does not detect packet loss during a retuning operation performed by the mobile terminal (504, 506).

Description

METHOD AND APPARATUS FOR MANAGING SECONDARY CELL

MEASUREMENT

TECHNOLOGICAL FIELD

[0001] The various embodiments described herein relate to the field of mobile wireless communications and, in particular, measurement of secondary cells during carrier aggregation.

BACKGROUND

[0002] Carrier aggregation is one of the key technologies used to increase the throughput for mobile terminals in mobile wireless networks to meet the increasing demand of the data rate. Inter-frequency band canier aggregation and intra-frequency band canier aggregation may both be supported by mobile terminals that are configured for carrier aggregation (CA). For carrier aggregation, two types of cells may be provided: a primary cell (PCell) and a secondary cell (SCell). A mobile terminal may first access the PCell, and once a network node (e.g., an enhanced Node B (eNB)) sees the need to extend the throughput for the mobile terminal, the network node can configure one or more SCells for the mobile terminal.

[0003] If sufficient earner availability exists in a single frequency band, then the network node may assign the SCell to the same frequency band as the PCell, resulting in intra-band aggregation. As new cells are allocated to the same frequency band, the mobile terminal may retune the frequency spectrum measured by the mobile terminal in order to communicate with the newly allocated SCell as well as the original PCell. As cells are activated and deactivated in this manner, the mobile terminal may retune the measured radio frequency to optimize communication on that particular frequency. For example, as SCells are allocated to the frequency band, the mobile terminal may retune the measured spectrum to a wider frequency, to account for the additional portions of the spectrum occupied by the newly allocated SCells. As SCells are de-allocated from the frequency band, the mobile terminal may retune the measured frequency to a narrower frequency range to reduce power consumption.

[0004] Retiming operations are typically performed by the mobile terminal in order to access SCells that are not covered by the initial tuning state of a radio frequency receiver. For example, when SCells are activated, deactivated, or configured, the frequency may be retuned in order to allow the mobile terminal to most efficiently access necessary SCells (e.g., the mobile terminal may save power by not monitoring the narrowest frequency band possible to measure the PCells and SCells with which the terminal is in communication). Although the status of particular SCells is generally controlled in conjunction with the network node, the decision to retune the radio receiver of the mobile tenninal may be initiated by the mobile tenninal.

[0005] During the time that the mobile tenninal is retuning the measured RF spectrum, the mobile terminal may be unable to transmit to or receive communications from the network node on the PCell and possibly other activated SCells as well,. As such, retuning operations may cause packet loss on the PCell and/or other SCells for data received from the network node. Since many retuning operations are perfonned in conjunction with the network node (e.g., activation or configuration of a SCell), the network node may predict these events and adjust transmissions accordingly, such as by lengthening certain timer values in response to events that would trigger a retuning by the mobile terminal. However, in the case of measurement of deactivated SCells, the mobile tenninal may perform such actions unilaterally, without input from the network node. The network node may thus register packet loss when communicating with the mobile terminal if the mobile terminal performs such a measurement of a deactivated SCell.

BRIEF SUMMARY

[0006] A method, apparatus and computer program product are therefore provided according to an example embodiment of the present invention in order to provide for management of measurement of a deactivated SCell by a mobile terminal in a carrier aggregation environment. A network node may communicate with a mobile tenninal to enable the mobile tenninal to communicate with the network node using aggregated earners. The network node may specify a set of measurement parameters to the mobile terminal when initiating the aggregated carrier communication. The mobile terminal may store the set of measurement parameters. The measurement parameters may be used by the mobile terminal perform measurement operations of deactivated SCells that might result in retuning of a radio frequency measured by the mobile tenninal. Measuring the deactivated SCell according to the measurement parameters may ensure that the network node does not detect packet loss during a retuning operation performed by the mobile tenninal.

[0007] Embodiments of the invention provide a method for managing measurement of deactivated a SCell. The method may include causing deactivation of at least one first carrier associated with a first carrier frequency among a plurality of earner frequencies existing within a particular frequency band, receiving one or more measurement parameters for measuring the at least one first carrier, and causing measurement of the at least one first carrier according to the one or more measurement parameters.

[0008] Embodiments of the invention may also provide an apparatus for managing measurement of a deactivated SCell. The apparatus may include at least one processor and at least one memory including computer program instructions, the at least one memory and the computer program instructions configured to, with the at least one processor. The instructions may configure the apparatus to cause deactivation of at least one first carrier associated with a first carrier frequency among a plurality of carrier frequencies existing within a particular frequency band, receive one or more measurement parameters for measuring the at least one first earner, to cause measurement of the at least one first carrier according to the one or more measurement parameters.

[0009] Embodiments of the invention may also provide a computer program product for managing measurement of a deactivated SCell. The computer program product may include at least one computer-readable storage medium bearing computer program instructions embodied therein for use with a computer. The computer program instructions may include program instructions configured to cause deactivation of at least one first carrier associated with a first earner frequency among a plurality of earner frequencies existing within a particular frequency band, receive one or more measurement parameters for measuring the at least one first earner, and cause measurement of the at least one first carrier according to the one or more measurement parameters.

[0010] Embodiments of the invention may also provide another method for managing measurement of a deactivated SCell. The method may include causing a set of measurement parameters to be transmitted to a mobile terminal. The measurement parameters may include an indication of at least one first carrier among a plurality of carriers existing within a particular frequency band, the plurality of carriers used to provide communication with the mobile terminal according to a earner aggregation protocol, and an indication of at least one time window for measuring the at least one first carrier. The method may also include determining a

measurement window for a measurement operation performed on the at least one first carrier by the mobile terminal, where the measurement operation is performed when the at least one carrier is deactivated, and adjusting transmission of data on at least a second earner other than the at least one first earner during the measurement window.

[0011] Embodiments of the invention may also provide another apparatus for managing measurement of a deactivated SCell. The apparatus may include at least one processor and at least one memory including computer program instructions, the at least one memory and the computer program instructions configured to, with the at least one processor, cause the apparatus at least to cause a set of measurement parameters to be transmitted to a mobile terminal, determine a measurement window for a measurement operation performed on the at least one first earner by the mobile terminal, where the measurement operation is performed when the at least one earner is deactivated, and adjust transmission of data on at least a second carrier other than the at least one first carrier during the measurement window. The measurement parameters may include an indication of at least one first earner among a plurality of carriers existing within a particular frequency band, the plurality of carriers used to provide communication with the mobile tenninal according to a carrier aggregation protocol, and an indication of at least one time window for measuring the at least one first carrier;

[0012] Embodiments of the invention may also provide another computer program product for managing measurement of a deactivated SCell. The computer program product may include at least one computer-readable storage medium bearing computer program instructions embodied therein for use with a computer. The computer program instructions may include program instructions configured to cause a set of measurement parameters to be transmitted to a mobile terminal, determine a measurement window for a measurement operation performed on the at least one first earner by the mobile tenninal, where the measurement operation is performed when the at least one carrier is deactivated, and adjust transmission of data on at least second carrier other than the at least one first earner during the measurement window. The

measurement parameters may include an indication of at least one first earner among a plurality of earners existing within a particular frequency band, the plurality of earners used to provide communication with the mobile terminal according to a earner aggregation protocol, and an indication of at least one time window for measuring the at least one first carrier.

BRIEF DESCRIPTION OF THE DRAWINGS [0013] Having thus described certain embodiments of the invention in general terms, reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, and wherein:

[0014] Figure 1 is a block diagram of an apparatus that may be specifically configured in accordance with an example embodiment of the present invention;

[0015] Figures 2-4 are block diagrams depicting a frequency spectrum implementing a earner aggregation process in accordance with an example embodiment of the present invention;

[0016] Figure 5 is a block diagram of a communication network 500 implementing carrier aggregation for communication between a mobile terminal and a network node in accordance with an example embodiment of the present invention;

[0017] Figure 6 is a signal diagram depicting messaging between a mobile terminal and a network node during measurement of a secondary cell in accordance with example embodiments of the present invention;

[0018] Figure 7 is a flow diagram depicting a method for measuring a deactivated secondary cell by a mobile terminal in accordance with example embodiments of the present invention;

[0019] Figure 8 is a flow diagram depicting a method for measuring a deactivated secondary cell by a network node in accordance with example embodiments of the present invention.

DETAILED DESCRIPTION

[0020] Some embodiments of the present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which some, but not all, embodiments of the invention are shown. Indeed, various embodiments of the invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements. Like reference numerals refer to like elements throughout. As used herein, the terms "data," "content," "information," and similar terms may be used interchangeably to refer to data capable of being transmitted, received and/or stored in accordance with

embodiments of the present invention. Thus, use of any such terms should not be taken to limit the spirit and scope of embodiments of the present invention.

[0021] Additionally, as used herein, the term 'circuitry' refers to (a) hardware-only circuit implementations (e.g., implementations in analog circuitry and/or digital circuitry); (b) combinations of circuits and computer program product(s) comprising software and/or firmware instructions stored on one or more computer readable memories that work together to cause an apparatus to perform one or more functions described herein; and (c) circuits, such as, for example, a microprocessor(s) or a portion of a microprocessor(s), that require software or firmware for operation even if the software or firmware is not physically present. This definition of 'circuitry' applies to all uses of this term herein, including in any claims. As a further example, as used herein, the term 'circuitry' also includes an im lementation comprising one or more processors and/or portion(s) thereof and accompanying software and/or firmware. As another example, the term 'circuitry' as used herein also includes, for example, a baseband integrated circuit or applications processor integrated circuit for a mobile phone or a similar integrated circuit in a server, a cellular network device, other network device, and/or other computing device.

[0022] As defined herein, a "computer-readable storage medium," which refers to a non- transitory physical storage medium (e.g., volatile or non-volatile memory device), can be differentiated from a "computer-readable transmission medium," which refers to an

electromagnetic signal.

[0023] A method, apparatus and computer program product are provided in accordance with an example embodiment of the present invention in order to perform measurement of a deactivated secondary cell (SCell) in a communications system implementing an aggregated carrier environment. During communications between a mobile terminal (e.g., a user equipment) and a network node (e.g., an enhanced Node B) using aggregated carriers, the mobile terminal may periodically retune the the radio frequency on which the mobile terminal communicates with the network node. For example, if new SCells are allocated to the mobile terminal, the mobile terminal may increase the bandwidth of the measured radio frequency to account for the new allocations. Conversely, if SCells are deactivated, then the mobile terminal may narrow the bandwidth of the measured radio frequency to conserve device power. If a retune operation occurs without the knowledge of the network node, packet loss between the mobile terminal and the network node may occur, since the mobile terminal may not be able to transmit or receive communications via a primary cell (PCell) or other activated SCells. Although in many cases the network node may be aware of such retuning operations (e.g., the network node may control configuration of the SCells, and thus anticipate any retune operations performed in response to activation, deactivation, or reconfiguration of an SCell), in cases where the mobile terminal measures a deactivated SCell, communications may be disrupted between the network node and the mobile terminal. For example, the mobile terminal may measure a deactivated SCell to comply with the requirements enumerated in the Third Generation Partnership Project (3 GPP) Technical Standard 36.133. In order to avoid this problem, the network node may specify a set of measurement parameters to the mobile terminal, so that the mobile terminal measures the deactivated SCell according to parameters known to the network node, thus allowing the network node to predict measurement of deactivated SCells. As such, the network node may use these parameters to identify when the mobile terminal is likely to retune the radio frequency of the mobile terminal for measurement of a deactivated channel, thus minimizing the potential for missed communication between the mobile terminal and the network node during the retuning operations.

[0024] The system of an embodiment of the present invention may include an apparatus 100 as generally described below in conjunction with Figure 1 for performing one or more of the operations set forth by Figures 2-8 and also described below. In this regard, the apparatus 100 may be embodied by a mobile terminal. In this embodiment, the mobile terminal may be in communication with a display and/or a data network, either directly, such as via a wireless or wireline connection, or indirectly via one or more intermediate computing devices. In this regard, the display and the mobile terminal may be parts of the same system in some embodiments.

However, the apparatus 100 may alternatively be embodied by another computing device that is in communication with the display and the mobile terminal, such as via a wireless connection, a wireline connection or the like. For example, the apparatus may be a user equipment (UE), such as a mobile telephone, a personal digital assistant (PDA), a pager, a laptop computer, a tablet computer, or any of numerous other hand held or portable communication devices, computation devices, content generation devices, content consumption devices or combinations thereof.

[0025] It should also be noted that while Figure 1 illustrates one example of a configuration of an apparatus 100 for managing measurement of a deactivated SCell, numerous other configurations may also be used to implement other embodiments of the present invention. As such, in some embodiments, although devices or elements are shown as being in communication with each other, hereinafter such devices or elements should be considered to be capable of being embodied within the same device or element and thus, devices or elements shown in

communication should be understood to alternatively be portions of the same device or element. [0026] Referring now to Figure 1, the apparatus 100 for managing measurement of a deactivated SCell according to an example embodiment may include or otherwise be in communication with one or more of a processor 102, a memory 104, a communication interface 106, a user interface 108, a camera 110 and a sensor 112. In some embodiments, the processor (and/or co-processors or any other processing circuitry assisting or otherwise associated with the processor) may be in communication with the memory device via a bus for passing information among components of the apparatus. The memory device may include, for example, a non- transitory memory, such as one or more volatile and/or non-volatile memories. In other words, for example, the memory device may be an electronic storage device (e.g., a computer readable storage medium) comprising gates configured to store data (e.g., bits) that may be retrievable by a machine (e.g., a computing device like the processor). The memory device may be configured to store information, data, content, applications, instructions, or the like for enabling the apparatus to carry out various functions in accordance with an example embodiment of the present invention. For example, the memory device could be configured to buffer input data for processing by the processor. Additionally or alternatively, the memory device could be configured to store instructions for execution by the processor.

[0027] In some embodiments, the apparatus 100 may be embodied as a chip or chip set. In other words, the apparatus may comprise one or more physical packages (e.g., chips) including materials, components and/or wires on a stmctural assembly (e.g., a baseboard). The stmctural assembly may provide physical strength, conservation of size, and/or limitation of electrical interaction for component circuitry included thereon. The apparatus may therefore, in some cases, be configured to implement an embodiment of the present invention on a single chip or as a single "system on a chip." As such, in some cases, a chip or chipset may constitute means for performing one or more operations for providing the functionalities described herein.

[0028] The processor 102 may be embodied in a number of different ways. For example, the processor may be embodied as one or more of various hardware processing means such as a coprocessor, a microprocessor, a controller, a digital signal processor (DSP), a processing element with or without an accompanying DSP, or various other processing circuitry including integrated circuits such as, for example, an ASIC (application specific integrated circuit), an FPGA (field programmable gate array), a microcontroller unit (MCU), a hardware accelerator, a special-purpose computer chip, or the like. As such, in some embodiments, the processor may include one or more processing cores configured to perform independently. A multi-core processor may enable multiprocessing within a single physical package. Additionally or alternatively, the processor may include one or more processors configured in tandem via the bus to enable independent execution of instructions, pipelining and/or multithreading.

[0029] In an example embodiment, the processor 102 may be configured to execute instructions stored in the memory device 104 or otherwise accessible to the processor.

Alternatively or additionally, the processor may be configured to execute hard coded

functionality. As such, whether configured by hardware or software methods, or by a

combination thereof, the processor may represent an entity (e.g., physically embodied in circuitry) capable of performing operations according to an embodiment of the present invention while configured accordingly. Thus, for example, when the processor is embodied as an ASIC, FPGA or the like, the processor may be specifically configured hardware for conducting the operations described herein. Alternatively, as another example, when the processor is embodied as an executor of software instructions, the instructions may specifically configure the processor to perform the algorithms and/or operations described herein when the instructions are executed. However, in some cases, the processor may be a processor of a specific device configured to employ an embodiment of the present invention by further configuration of the processor by instructions for performing the algorithms and/or operations described herein. The processor may include, among other things, a clock, an arithmetic logic unit (ALU) and logic gates configured to support operation of the processor.

[0030] Meanwhile, the communication interface 106 may be any means such as a device or circuitry embodied in either hardware or a combination of hardware and software that is configured to receive and/or transmit data from/to a network and/or any other device or module in communication with the apparatus 100, such as by supporting communications with a display and/or a mobile temiinal. In this regard, the communication interface may include, for example, an antenna (or multiple antennas) and supporting hardware and/or software for enabling communications with a wireless communication network. For example, the communication interface 106 may enable access to an aggregated earner network as described below with respect to Figure 5. Additionally or alternatively, the communication interface may include the circuitry for interacting with the antenna(s) to cause transmission of signals via the antenna(s) or to handle receipt of signals received via the antenna(s). In some environments, the communication interface may alternatively or also support wired communication. As such, for example, the communication interface may include a communication modem and/or other hardware/software for supporting communication via cable, digital subscriber line (DSL), universal serial bus (USB) or other mechanisms.

[0031] The apparatus 100 may include a user interface 108 that may, in turn, be in communication with the processor 102 to provide output to the user and, in some embodiments, to receive an indication of a user input. For example, the user interface may include a display and, in some embodiments, may also include a keyboard, a mouse, a joystick, a touch screen, touch areas, soft keys, a microphone, a speaker, or other input/output mechanisms. In one embodiment, the display of the apparatus may be embodied by a liquid crystal display (LCD) screen presented on one surface of the mobile terminal. The processor 102 may comprise user interface circuitry configured to control at least some functions of one or more user interface elements such as a display and, in some embodiments, a speaker, ringer, microphone and/or the like. The processor 102 and/or user interface circuitry comprising the processor 102 may be configured to control one or more functions of one or more user interface elements through computer program instmctions (e.g., software and/or firmware) stored on a memory accessible to the processor (e.g., memory 104, and/or the like).

[0032] In some example embodiments, the apparatus 100 may include an image capturing element, such as a camera 110, video and/or audio module, in communication with the processor 102. The image capturing element may be any means for capturing an image, video and/or audio for storage, display or transmission. For example, in an example embodiment in which the image capturing element is a camera, the camera may include a digital camera capable of forming a digital image file from a captured image. As such, the camera may include all hardware (for example, a lens or other optical component(s), image sensor, image signal processor, and/or the like) and software necessary for creating a digital image file from a captured image. The encoder and/or decoder may encode and/or decode according to, for example, a joint photographic experts group (JPEG) standard, a moving picture experts group (MPEG) standard, or other format.

[0033] As shown in Figure 1, the apparatus 100 may also include one or more sensors 112, such as a location information receiver (e.g., a GPS receiver), an accelerometer, a gyroscope, a compass, or the like, that may be in communication with the processor 102 and may be configured to determine the location of the apparatus and to detect changes in motion and/or orientation of the apparatus.

[0034] The method, apparatus 100 and computer program product may now be described in conjunction with the operations illustrated in Figures 2-8. The apparatus 100 may function as a mobile terminal. In this regard, the apparatus 100 may include means, such as the processor 102, or the like, for managing measurement of a deactivated SCell. The processor 102 may receive infonnation from a network node, specifying measurement parameters for measuring deactivated SCells. For example, the network node may specify a particular measurement time window or periodicity for measuring of deactivated SCells. The processor 102 may thus perform

measurement of deactivated SCells according to the measurement parameters to ensure that messages are not lost from the network node during returning operations associated with the measurement of the deactivated cells.

[003S] In alternative or additional embodiments, the apparatus 100 may function as the network node. In this regard, the apparatus 100 may include means, such as the processor 102, or the like, for managing measurement of a deactivated SCell by a mobile terminal. The processor 102 may cause measurement parameters to be transmitted to the mobile terminal. The processor 102 may ensure that measurement of deactivated SCells is predicted such that packet loss does not occur between the network node and the mobile terminal. In some embodiments, the measurement parameters may be caused to be transmitted to the mobile terminal in response to deactivation of the SCell by the mobile terminal or the network node.

[0036] Figures 2-4 are block diagrams depicting a set of radio frequencies implementing a carrier aggregation process in accordance with an example embodiment of the present invention. Figure 2 depicts a set of radio frequencies200 including multiple carriers aggregated into a single intra-frequency allocation. The set of radio frequencies200 includes a PCell 202 and a SCell 204 in adjacent portions of the spectrum. Communications in the aggregated carrier environment may be managed by the PCell 202, and SCells such as the SCell 204 may be allocated as needed based on the throughput needs of the mobile terminal and network node. It is possible for the mobile terminal to use one radio frequency (RF) chain to support this feature, especially when the two aggregated earners are adj cent to one other in the spectrum. For such a mobile terminal, once the network node configures a SCell for adjacent carriers, the mobile terminal may retune the RF receiver for a wider bandwidth to support canier aggregation. In the example set of radio frequencies200, the PCell 202 and the SCell 204 have been allocated in a contiguous frequency band. In order to communicate via this contiguous frequency band, the radio frequency interface (e.g. , the communications interface 106) may be retuned to communicate on the frequency 206 defined by the contiguous frequency block of the PCell 202 and SCell 204, a bandwidth of 40kHz.

[0037] Figure 3 depicts a second set of radio frequencies300 that represents the radio frequency accessed by the mobile terminal in response to deactivation of the SCell 204. In the second set of radio frequencies300, the PCell 302 is still active, but the SCell 304 has been deactivated. As such, the mobile terminal may cease communications on the portions of the spectrum occupied by the deactivated SCell 304. For more efficient power consumption in the earner aggregation case, a SCell activation/de activation mechanism may be provided. During the deactivated state, the mobile terminal may not monitor the physical downlink control channel (PDCCH), nor transmit any uplink (UL) signal. In some embodiments, the mobile terminal may even turn off or retune the RF receiver to save power. Alternatively, if mobile terminal has retuned the RF receiver to a narrower bandwidth, and the mobile terminal needs to perform a measurement for the deactivated SCell (that now lies outside the radio frequencies measured by the RF receiver), then the mobile terminal may also retune the RF receiver to perform the measurement. In the instant example, in order to conserve device power, the mobile terminal may thus retune the portion of the spectrum measured during communications to the narrower frequency 306 defined by the PCell 302. In this example, the retiming operation performed in response to deactivation of the SCell 304 means that the mobile terminal must only measure a the radio frequency 306, with a 20kHz bandwidth, instead of the 40kHz bandwidth described with respect to Figure 2.

[0038] Figure 4 depicts a third set of radio frequencies400 that represents the radio frequencies measured by the mobile terminal during measurement of the deactivated SCell 404. In order to measure the deactivated SCell 404, the frequency measured by the mobile terminal is retuned to the radio frequency 406 occupied by the PCell 402 and the deactivated SCell 404. During the retuning process, the mobile terminal may momentarily be unable to send or receive data via the PCell, due to the reconfiguration of the RF receiver. Thus, the mobile terminal may miss communications performed using the PCell 402. [0039] Figure 5 is a block diagram of a communication network 500 implementing canier aggregation for communication between mobile terminals 504, 506 and a network node 502 in accordance with an example embodiment of the present invention. The communication network 500 may be provided according to any wireless protocol that is configured to allow canier aggregation. For example, the network may be a long tenn evolution network, an long term evolution-advanced network, or the like. In network parlance, the mobile terminal maybe a user equipment (UE) and the network node may function as a node B, in the case of long term evolution networks, an enhanced Node B (eNB), a Radio Network Controller (RNC), or any other remote network node capable of communicating via a protocol that implements carrier aggregation. As described above with respect to Figure 1, the UE may be any computing device capable of wireless communications, including but not limited to a cellular phone, a smartphone, a personal digital assistant, a laptop computer, a desktop computer, a tablet computer, or the like. The network node 502 may implement a multiple carrier system, with each carrier having certain areas of coverage. In areas where coverage overlaps, the network node 502 may provide carrier aggregation services. For example, the mobile terminal 504 lies within the coverage area of both the first carrier range 508 and the second canier range 510, while the mobile tenninal 506 only lies within the second canier range 510. Thus, the network node 502 might implement a carrier aggregation system for the first mobile tenninal 504, with the first canier functioning as a PCel], and the second carrier functioning as a SCell. The mobile terminal 504 may thus communicate across both cells, effectively doubling data throughput. However, as described above, if the second canier is deactivated, retuning operations resulting from measurement of the deactivated SCell may result in packet loss or other communication problems across the PCell.

[0040] Figure 6 is a signal diagram depicting messaging 600 between a mobile terminal and a network node during measurement of a deactivated SCell in accordance with example embodiments of the present invention. In order to ensure that data is not lost during the radio frequency retuning operations described above, the network node may provide measurement parameters to the mobile terminal to ensure that measurement of the deactivated SCell is performed according to a time window or schedule known to the network node. As such, the network node may predict when such measurements are likely to occur and manage data transmissions to avoid or minimize packet loss. [0041] At action 602, the mobile terminal and the network node begin communication according to a carrier aggregation process. For example, the network node may provide additional throughput to the mobile device by activating one or more SCells. The intra-band carrier aggregation process may include a handshake process or other negotiation between the mobile terminal and the network node, such as the mobile terminal measuring a signal on one or more SCells, communicating the SCell signal measurements to the network node, receiving one or more SCell allocations from the network node, or any other steps necessary to initiate communication across multiple carriers in the same frequency band. The initialization process may be performed by a processing means of the mobile terminal or the network node, such as the processor 102.

[0042] At action 604, the network node informs the mobile tenninal of measurement parameters for measuring deactivated SCells. The measurement parameters may be transmitted to the mobile tenninal at the time the intra-band carrier aggregated communication is established, or the measurement parameters may be provided to the mobile terminal in response to an event that requires the deactivation of one or more SCells. The measurement parameters may include a measurement time window for the mobile terminal to perfonn measurements of the deactivated secondary channel, such that the measurements are only performed during periods specified by the measurement time window. In some embodiments, the measurement parameters may indicate that the network node allows the mobile terminal to implement an autonomous gap for measurement of the deactivated SCells. For example, the autonomous gap may be implemented according to the ETSI TS 136 133 VIO.1.0 technical standard.

[0043] In some embodiments, the measurement parameters may be communicated to the mobile tenninal via radio resource control (RRC) signaling, and the measurement parameters may include configurations for both a starting offset and a periodicity for performance of the measurements. The measurement time window may be bundled with a system frame number (SFN) and a subframe number, providing a time reference for the measurement operations. The measurement parameters may also specify a gap on either side of the measurement window, but it may be possible for the mobile tenninal to receive data during the measurement period aside from the gap period. The transmission of measurement parameters may include a negotiation between the network node and the mobile terminal. For example, the mobile tenninal may signal a number of measurements, a periodicity of measurements, or a length of a measurement window to the network node. In some embodiments, the network node may provide the measurement parameters via a medium access control (MAC) control element (CE). The measurement parameters may be caused to be transmitted by a processing means, such as the processor 102. In some embodiments, negotiation of the measurement parameters may be performed by multiple processing means, such as processors coupled to each of the network node and the mobile terminal, in communication with one another via communications means.

[0044] At action 606 one or more SCells are deactivated. As described above, the SCell may be deactivated in response to communications between the mobile terminal and the network node. The SCell may be deactivated for various reasons. For example, the network node may notify the mobile terminal of deactivation of a SCell using a MAC CE sent to the mobile terminal. As such, the network node may be aware of the deactivation of the SCell, and therefore adjust transmissions to the mobile terminal according to the time window established for measurement of the SCell as defined in the measurement parameters. Alternately, the mobile terminal may deactivate the SCell autonomously, such as in the case of a timeout on the SCell (e.g., expiration of the scellDeactivationTimer associated with the SCell). In such cases, the mobile terminal may inform the network node of the autonomous deactivation. The SCell may be deactivated by the SCell employing a processing means, such as the processor 102.

[0045] At action 608, the mobile terminal performs measurement of the deactivated SCell in accordance with the measurement parameters received from the network node. As such, the mobile terminal may retune the measured frequency spectrum without packet loss on

communications from the network node, as the network node is aware of the measurement time window for the deactivated channel, and can thus avoid transmission of data during the retuning process. In some embodiments, the time window may define a period during which only SCells for which measurement is likely to cause an interruption in communication are measured. For example, the mobile terminal may measure all deactivated SCells during the time window, or any SCells for which measurement is indicated and for which retuning of the RF receiver is required for measurement. The measurements may be caused by a processing means, such as the processor 102.

[0046] Figure 7 is a flow diagram depicting a method 700 for measuring a deactivated secondary cell by a mobile terminal in accordance with example embodiments of the present invention. As described above, a mobile terminal may communicate with a network node via a plurality of carriers aggregated across a frequency band. In the event that one of the secondary carriers is deactivated, the mobile terminal may perform measurements of the secondary carrier in accordance with a set of measurement parameters received from or negotiated with the network node. In this manner, the mobile terminal may avoid data loss when retiming radio frequencies to perform measurement of the deactivated secondary carrier. The method 700 may be performed by a processing means of the mobile terminal, such as a processor 102.

[00471 At action 702, communication is caused by the mobile tenninal across intra-band aggregated carriers. As described above, the mobile terminal may communicate with the network node via a PCell and one or more SCells. This communication may be performed by a communications interface, such as the communications interface 106 described with respect to Figure 1. The communication may be caused to be performed by a processing means, such as the processor 102.

[0048] At action 704, the mobile terminal may cause reception of measurement parameters for measuring of a deactivated SCell. The measurement parameters may define a time window for measurement of the deactivated SCell, such as by specifying scheduling information, a periodicity for repeated measurements, or the like. The measurement parameters may be received from the network node, or the mobile terminal may negotiate the network parameters with the network node. In some embodiments, the measurement parameters are received by the mobile terminal in response to a deactivation of the SCell by the network node, such as when an SCell is deactivated due to no longer requiring the throughput offered by the extra carrier. The measurement parameters may be caused to be received by a processing means, such as the processor 102.

[0049] At action 706, the SCell is deactivated. As described above, the SCell may be deactivated simultaneously with the negotiation or reception of the measurement parameters. Deactivation of the SCell may be performed by the network node although, as described above, in some cases the mobile terminal may autonomously initiate deactivation of the SCell, such as due to expiration of a scellDeactivationTimer timer. Since the network node is aware of SCells that are not autonomously deactivated by the mobile terminal, the network node may anticipate retuning operations that may be performed by the mobile tenninal in response to such non- autonomous deactivations. The SCell may be deactivated by a processing means, such as the processor 102. [0050] At action 708, the measurement of the deactivated SCell is caused according to the measurement parameters. In response to deactivation of a SCell the mobile terminal may retune the radio frequencies measured by the mobile terminal to a narrow set of frequencies in order to conserve power. However, the mobile terminal may still measure the deactivated SCell. To measure the deactivated SCell, the mobile terminal may need to retune the radio frequencies to include the deactivated SCell again, resulting in possible interruption in communications with the network node. As such, the mobile terminal may perform measurements of the deactivated SCell according to the measurement parameters received from the network node. In this manner, the mobile terminal may synchronize retuning operations performed during the measurement of the deactivated SCells to avoid communication errors, such as packet loss, between the mobile terminal and the network node. As described above with respect to Figure 6, the measurement parameters may include a measurement time window or other scheduling information to instruct the mobile terminal to perform measurement of the deactivated secondary channel during particular scheduling windows. During this time window, the mobile terminal may only measure SCells for which measurement might cause interruption of other communications (e.g., for which measurement may cause retuning of a RF receiver, thus causing a interruption in

communications using the PCell). In this manner, the network node may be provided with an awareness of windows during which the mobile terminal is likely to experience reception errors caused by the retuning of the measured frequency spectrum associated with measuring the deactivated SCell. The measurement of the deactivated secondary channel may be caused by a processing means, such as the processor 102.

[0051] Figure 8 is a flow diagram depicting a method 800 for measuring a deactivated secondary cell by a network node in accordance with example embodiments of the present invention. The network node may provide measurement parameters to the mobile terminal to instruct the mobile terminal how to perform measurement of a deactivated SCell. By providing the mobile terminal with a schedule for measuring the deactivated SCell, the network node can plan for when such measurements are likely to occur, and thus the network node can take appropriate action. For example, the network node may avoid transmission of data to the mobile terminal during these retuning operations, or the network node may disregard packet loss that occurs during periods in which retuning may occur. [0052] At action 802, the method 800 causes measurement parameters for a deactivated SCell to be transmitted. As described above, the measurement parameters may specify a measurement time window or other parameters for measurement of a deactivated SCell by the mobile terminal. The measurement parameters may be determined and caused to be transmitted during configuration of the SCell.In some embodiments, the measurement parameters may be determined when the SCell is initialized, such that the network node may still avoid

communication errors even when the mobile terminal autonomously deactivates the SCell. The measurement parameters may be caused to be transmitted by a processing means, such as the processor 102.

[0053] At action 804, the method 800 may predict measurement of a deactivated SCell by the mobile terminal, using the measurement parameters. For example, if the SCell is deactivated at a time To, and the measurement parameters indicate that the mobile terminal should perform measurement of the deactivated SCell at T +5, then the method 800 would predict that the mobile terminal will measure the deactivated SCell at 7j. Alternately or additionally, measurement parameters may be determined based on the initialization of the channel.

Prediction of the measurement may be performed by a processing means, such as the processor 102.

[0054] At action 806, appropriate action is taken at the time predicted by action 804. The network node may perform different actions to account for the possibility that the mobile terminal will be performing a retuning operation at a particular time. For example, the network node may limit data transmission to the mobile terminal at such time to avoid a loss of data that would necessitate a retransmission. The appropriate action may be caused by a processing means, such as the processor 102.

[0055] It will be understood that each block of the flowchart, and combinations of blocks in the flowchart, may be implemented by various means, such as hardware, firmware, processor, circuitry, and/or other devices associated with execution of software including one or more computer program instructions. For example, one or more of the procedures described above may be embodied by computer program instructions. In this regard, the computer program instructions which embody the procedures described above may be stored by a memory 104 of an apparatus employing an embodiment of the present invention and executed by a processor 102 of the apparatus. As will be appreciated, any such computer program instructions may be loaded onto a computer or other programmable apparatus (e.g., hardware) to produce a machine, such that the resulting computer or other programmable apparatus implements the functions specified in the flowchart blocks. These computer program instructions may also be stored in a computer- readable memory that may direct a computer or other programmable apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture the execution of which implements the function specified in the flowchart blocks. The computer program instructions may also be loaded onto a computer or other programmable apparatus to cause a series of operations to be performed on the computer or other programmable apparatus to produce a computer-implemented process such that the instructions which execute on the computer or other programmable apparatus provide operations for implementing the functions specified in the flowchart blocks.

[0056] Accordingly, blocks of the flowchart support combinations of means for performing the specified functions and combinations of operations for performing the specified functions for performing the specified functions. It will also be understood that one or more blocks of the flowchart, and combinations of blocks in the flowchart, can be implemented by special purpose hardware-based computer systems which perform the specified functions, or combinations of special purpose hardware and computer instructions.

[0057] In some embodiments, certain ones of the operations above may be modified or further amplified. Furthermore, in some embodiments, additional optional operations may be included. Modifications, additions, or amplifications to the operations above may be performed in any order and in any combination.

[0058] Many modifications and other embodiments of the inventions set forth herein will come to mind to one skilled in the art to which these inventions pertain having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the inventions are not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Moreover, although the foregoing descriptions and the associated drawings describe example embodiments in the context of certain example combinations of elements and/or functions, it should be appreciated that different combinations of elements and/or functions may be provided by alternative embodiments without departing from the scope of the appended claims. In this regard, for example, different combinations of elements and/or functions than those explicitly described above are also contem lated as may be set forth in some of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.

Claims

WHAT IS CLAIMED IS:

1. A method comprising:

causing deactivation of at least one first earner associated with a first carrier frequency among a plurality of carrier frequencies existing within a particular frequency band;

receiving one or more measurement parameters for measuring the at least one first carrier; and

causing measurement of the at least one first carrier according to the one or more measurement parameters in response to the deactivation of the at least one first earner.

2. The method of claim 1, wherein the measurement parameters define a measurement time window, and wherein, when the at least one first carrier is deactivated, the measurement of the at least one first earner is only performed according to the measurement time window.

3. The method of claim 1, wherein the measurement parameters enable an autonomous gap for measurement of the at least one first earner when the first carrier is deactivated.

4. The method of any of any of claims 1 to 3, wherein the measurement parameters are received from a network node in communication with a mobile terminal via at least one of the plurality of frequencies.

5. The method of any of claims 1 to 4, wherein the at least one first carrier is a secondary earner, and a second carrier among the plurality of frequencies is a primary carrier.

6. The method of any of claims 1 to 5, wherein the measurement parameters further comprise an indication that the measurement parameters are associated with the at least one first carrier.

7. The method of any of claims 1 to 6, wherein the at least one first earner is measured according to the measurement parameters only when the at least one first carrier is deactivated.

8. The method of any of claims 1 to 7, wherein the measurement parameters comprise a measurement time window, and wherein only the at least one first carrier is measured during the measurement time window.

9. The method of any of claims 1 to 8, wherein the measurement parameters comprise a measurement time window, and wherein only one or more carriers for which measurement requires a retuning of a radio frequency receiver are measured during the measurement window.

10. The method of any of claims 1 to 9, wherein the method is performed by a user equipment.

11. The method of claim 10, wherein the user equipment is a mobile phone.

12. An apparatus comprising at least one processor and at least one memory including computer program instructions, the at least one memory and the computer program instructions configured to, with the at least one processor, cause the apparatus at least to:

cause deactivation of at least one first carrier associated with a first carrier frequency among a plurality of earner frequencies existing within a particular frequency band;

receive one or more measurement parameters for measuring the at least one first carrier; and

cause measurement of the at least one first carrier according to the one or more measurement parameters in response to the deactivation of the at least one first carrier.

13. The apparatus of claim 12, wherein the measurement parameters define a measurement time window, and wherein, when the at least one first carrier is deactivated, the measurement of the at least one first carrier is only performed according to the measurement time window.

14. The apparatus of any of claims 12 to 13, wherein the measurement parameters enable an autonomous gap for measurement of the at least one first earner when the first carrier is deactivated.

15. The apparatus of any of claims 12 to 14, wherein the measurement parameters are received from a network node in communication with a mobile terminal via at least one of the plurality of frequencies.

16. The apparatus of any of claims 12 to 15, wherein the at least one first carrier is a secondary carrier, and a second carrier among the plurality of frequencies is a primary carrier.

17. The apparatus of any of claims 12 to 16, wherein the measurement parameters further comprise an indication that the measurement parameters are associated with the at least one first carrier.

18. The apparatus of any of claims 12 to 17, wherein the at least one first carrier is measured according to the measurement parameters only when the at least one first earner is deactivated.

19. The apparatus of any of claims 12 to 18, wherein the measurement parameters comprise a measurement time window, and wherein only the at least one first carrier is measured during the measurement time window.

20. The apparatus of any of claims 12-1 , wherein the apparatus is a user equipment.

21. The apparatus of claim 20, wherein the user equipment is a mobile phone.

22. The apparatus of any of claims 12 to 21, wherein the apparatus operates according to a long term evolution communication protocol, or a long term evolution-advanced communication protocol.

23. A computer program product comprising at least one computer-readable storage medium bearing computer program instmctions embodied therein for use with a computer, the computer program instructions comprising program instructions configured to: cause deactivation of at least one first earner associated with a first carrier frequency among a plurality of carrier frequencies existing within a particular frequency band;

cause measurement of the at least one first carrier according to the one or more measurement parameters in response to the deactivation of the at least one first earner.

24. The computer program product of claim 23, wherein the measurement parameters define a measurement time window, and wherein, when the at least one first carrier is deactivated, the measurement of the at least one first carrier is only performed according to the measurement time window.

25. The computer program product of any of claims 23 to 24, wherein the measurement parameters enable an autonomous gap for measurement of the at least one first carrier when the first carrier is deactivated.

26. The computer program product of any of claims 23 to 25, wherein the measurement parameters are received from a network node in communication with a mobile terminal via at least one of the plurality of frequencies.

27. The computer program product of any of claims 23 to 26, wherein the at least one first earlier is a secondary carrier, and a second carrier among the plurality of frequencies is a primary carrier.

28. The computer program product of any of claims 23 to 27, wherein the measurement parameters further comprise an indication that the measurement parameters are associated with the at least one first carrier.

29. The computer program product of any of claims 23 to 28, wherein the at least one first carrier is measured according to the measurement parameters only when the at least one first carrier is deactivated.

30. The computer program product of any of claims 23 to 29, wherein the measurement parameters comprise a measurement time window, and wherein only the at least one first carrier is measured during the measurement time window.

31. A method comprising:

causing a set of measurement parameters to be transmitted to a mobile terminal, the measurement parameters comprising:

an indication of at least one first earner among a plurality of carriers existing within a particular frequency band, the plurality of carriers used to provide

communication with the mobile terminal according to a carrier aggregation protocol; and an indication of at least one time window for measuring the at least one first carrier;

determining a measurement window for a measurement operation performed on the at least one first earner by the mobile terminal, where the measurement operation is performed when the at least one carrier is deactivated; and

adjusting transmission of data on at least a second carrier other than the at least one first carrier during the measurement window.

32. The method of claim 31, wherein the measurement parameters are transmitted to the mobile terminal during configuration of the at least one first carrier.

33. The method of any of claims 31 to 32, wherein the measurement parameters indicate a time window for the mobile terminal to perform the measurement operation.

34. The method of any of claims 31 to 33, wherein the measurement parameters are caused to be transmitted using one of the plurality of carriers.

35. The method of any of claims 31 to 34, wherein the measurement window defines a time period for the mobile terminal to retune a radio frequency receiver.

36. An apparatus comprising at least one processor and at least one memory including computer program instructions, the at least one memory and the computer program instructions configured to, with the at least one processor, cause the apparatus at least to:

cause a set of measurement parameters to be transmitted to a mobile terminal, the measurement parameters comprising:

an indication of at least one first carrier among a plurality of carriers existing within a particular frequency band, the plurality of earners used to provide

determine a measurement window for a measurement operation performed on the at least one first earner by the mobile terminal, where the measurement operation is performed when the at least one carrier is deactivated; and

adjust transmission of data on at least a second carrier other than the at least one first carrier during the measurement window.

37. The apparatus of claim 36, wherein the measurement parameters are transmitted to the mobile terminal during configuration of the at least one first earner.

38. The method of any of claims 36 to 37, wherein the measurement parameters indicate a time window for the mobile terminal to perform the measurement operation.

39. The apparatus of any of claims 36 to38, wherein the measurement parameters are caused to be transmitted using one of the plurality of earners.

40. The apparatus of any of claims 34 to 39, wherein the measurement window defines a time period for the mobile terminal to retune a radio frequency receiver.

41. The apparatus of any of claims 34 to 40, wherein the mobile terminal is a user equipment.

42. The apparatus of claim 41, wherein the user equipment is a mobile phone.

43. The apparatus of any of claims 34 to 40, wherein the ap aratus operates according to a long term evolution communication protocol, or a long term evolution-advanced communication protocol .

44. A computer program product comprising at least one computer-readable storage medium bearing computer program instructions embodied therein for use with a computer, the computer program instructions comprising program instructions configured to:

an indication of at least one first earner among a plurality of earners existing within a particular frequency band, the plurality of carriers used to provide

adjust transmission of data on at least second earner other than the at least one first carrier during the measurement window.

45. The computer program product of claim 44, wherein the measurement parameters are transmitted to the mobile terminal during configuration of the at least one first carrier.

46. The computer program product of any of claims 44 to 45, wherein the measurement parameters indicate a time window for the mobile terminal to perform the measurement operation.

47. The computer program product of any of claims 44 to 46, wherein the measurement parameters are caused to be transmitted using one of the plurality of carriers.

48. The computer program product of any of claims 44 to 47, wherein the measurement window defines a time period for the mobile terminal to retune a radio frequency receiver.