Abstract:
Methods and apparatus, including computer program products, are provided for reporting blindly configured carrier aggregation secondary cells. In one aspect there is provided a method. The method may include detecting, by the user equipment, a secondary cell configured for the user equipment to allow access for carrier aggregation, wherein the secondary cell is blindly configured by a network before the detecting by the user equipment; and sending, by the user equipment, a report representative of the detected secondary cell to notify the network of the detecting by the user equipment. Related apparatus, systems, methods, and articles are also described.

Description:
FIELD 
       [0001]    The subject matter described herein relates to wireless communications and, in particular, carrier aggregation and the configuration and activation of one or more secondary cells (SCells). 
       BACKGROUND 
       [0002]    Carrier aggregation allows increased bandwidth and, as such, increased data rates to a user equipment by aggregating carriers. For example, a user equipment may be allocated a primary carrier serving a primary cell (PCell) and one or more secondary carriers serving corresponding secondary cells (SCells). These carriers may be continuous within the same frequency band, non-contiguous within a given frequency band, or non-contiguous among frequency bands. 
         [0003]    Blind SCell configuration refers to a network configuring one or more SCells for a user equipment, without the user equipment first detecting and/or reporting the SCells to the network. As such, before the user equipment detects and/or reports a cell to the network, the network has blindly configured the cell as a SCell for the user equipment, so the SCell is available for the user equipment when the user equipment subsequently detects SCell and SCell is activated. Although the network knows when configuring a given SCell blindly that the user equipment has not yet detected the SCell, the network presumes the user equipment (given its current location based on for example a current serving PCell) will at some point detect the SCell and activate the SCell to enable data transmission through the SCell. 
       SUMMARY 
       [0004]    Methods and apparatus, including computer program products, are provided for reporting blindly configured carrier aggregation secondary cells. In one aspect there is provided a method. The method may include detecting, by the user equipment, a secondary cell configured for the user equipment to allow access for carrier aggregation, wherein the secondary cell is blindly configured by a network before the detecting by the user equipment; and sending, by the user equipment, a report representative of the detected secondary cell to notify the network of the detecting by the user equipment. 
         [0005]    In some variations, one or more of the features disclosed herein including the following features may optionally be included in any feasible combination. The report may include an identity of the secondary cell. The sending may be performed before the secondary cell is activated for the carrier aggregation. The report may include a measurement report including one or more measurements of the detected secondary cell. The one or more measurements may include at least one of a reference signal received power measurement or a reference signal received quality measurement. The one or more measurements may be at least predefined in a standard or configured in a measurement configuration provided by the network. An event reporting criteria may be triggered, when the secondary cell is detected. The event reporting criteria may be predefined in a standard. The user equipment may access a primary cell including a primary carrier for a first data transmission and may further access the detected secondary cell including a secondary carrier for a second data transmission. The secondary cell may include a plurality of secondary cells. 
         [0006]    The above-noted aspects and features may be implemented in systems, apparatus, methods, and/or articles depending on the desired configuration. The details of one or more variations of the subject matter described herein are set forth in the accompanying drawings and the description below. Features and advantages of the subject matter described herein will be apparent from the description and drawings, and from the claims. 
     
    
     
       DESCRIPTION OF DRAWINGS 
         [0007]    In the drawings, 
           [0008]      FIG. 1  depicts an example of a system configured for carrier aggregation including a primary cell and a secondary cell, in accordance with some exemplary embodiments; 
           [0009]      FIG. 2  depicts an example processes for user equipment reporting of a blindly configured secondary cell, in accordance with some exemplary embodiments; 
           [0010]      FIG. 3  depicts an example of a user equipment, in accordance with some exemplary embodiments; and 
           [0011]      FIG. 4  depicts an example of a base station, in accordance with some exemplary embodiments. 
       
    
    
       [0012]    Like labels are used to refer to same or similar items in the drawings. 
       DETAILED DESCRIPTION 
       [0013]    The subject matter disclosed herein provides a way for the network to know when the user equipment has actually detected a blindly configured SCell(s). Specifically, there is provided a way of reporting to the network when the user equipment has detected one or more preconfigured (for example, blindly configured) SCells—allowing the network to command activation or use, if it so chooses, the detected SCell for data transmission by a subsequent activation of the detected SCell. Moreover, the detected SCell may be reported rather than requiring the user equipment to for example periodically report non-detected secondary cells. Furthermore, the user equipment reporting of the blindly configured SCell may, in some example embodiments, prevent unnecessary activation of blindly configured SCells (for example, sending an activation command for the SCell before the user equipment is within range of the SCell may be considered at the very least a waste of network resources). 
         [0014]    In some example embodiments, there is provided a reporting rule (for example one or more criteria) and a measurement report defined and applied for blindly configured SCell, such as SCells preconfigured by the network for use by a user equipment in carrier aggregation before the user equipment has had a chance to detect the SCell. For example, when the user equipment detects a blindly configured SCell, the user equipment may, in some example embodiments, report to the network that it has now detected a blindly configured SCell. In some example embodiments, this reporting may include an identification of the detected blindly configured SCell, such as an identifier of the SCell, a physical cell identity (PCI) of the SCell, and the like. Because the network knows beforehand that it has configured the given SCell blindly for use by the given user equipment, when this user equipment sends to the network a report indicating a detection of the given SCell, the network may thus detect (for example, presume, recognize, detect, understand, and the like) that the given SCell is being reported to the network as a blindly configured SCell now being detected by the given user equipment. Accordingly, no further measurement control signaling is required to notify the network why it is receiving the SCell identifier sent by the given user equipment. 
         [0015]    In some example embodiments, the report sent by the user equipment to the network may, as noted, indicate that the user equipment has detected a blindly configured SCell. Moreover, the report may be defined, so that when the user equipment successfully detects the blindly configured SCell and performs a measurement (for example, an initial reference signal received power (RSRP) measurement and/or a reference signal received quality (RSRQ) measurement) of the SCell, the user equipment reports the measurement(s) including an identifier of the detected SCell. 
         [0016]    Although some of the examples described herein refer to detecting and reporting a single blindly configured SCell, the user equipment may detect and report a plurality of blindly configured SCells as well. Moreover, this reporting may use normal SCell measurement reporting used for detected SCells. 
         [0017]    In some example embodiments, the reporting of the detected blindly configured SCell may be based on one or more criteria defined at the user equipment, so that when the criteria are satisfied a report is sent to the network. For example, an event reporting criterion may specify that the user equipment should send a measurement report when a blindly configured SCell is detected, and this reporting criterion may specify the type of measurements (for example, RSRP, RSRQ, and/or any other power/quality metrics) to be sent to the network when the event reporting criteria is triggered at the user equipment. 
         [0018]    Event reporting criteria may be provided to the user equipment by the network and/or specified in a standard. For example, the event reporting criteria may be defined as an event that triggers reporting in a manner similar to Events A1, A2, and the like described in 3rd Generation Partnership Project, Technical Specification Group Radio Access Network, Evolved Universal Terrestrial Radio Access (E-UTRA) Radio Resource Control (RRC), Protocol specification (Release 8) TS 36.331 (herein after TS 36.331); 3rd Generation Partnership Project, Technical Specification Group Radio Access Network, Evolved Universal Terrestrial Radio Access (E-UTRA), Requirements for support of radio resource management (Release 8) 3GPP TS 36.133 (hereinafter TS 36.133), and/or any other standards as well. For example, an event may be defined so that the user equipment triggers a report when a blindly configured SCell is detected. Moreover, the event trigger may define one or more measurements, such as RSRP and/or RSRQ, to be performed by the user equipment, and these measurements may be configurable or selectable by the network (for example, the network may request in a measurement configuration what types of measurements the user equipment should perform on the detected SCell). For example, the event may specify that the measurement report should be sent to the network when (for example, as soon as) the user equipment detects the SCell (which may be based on the identity of the Scell, such as physical cell identity (PCI)) and performs an initial RSRP or RSRQ SCell measurement (which would be included in the measurement report). 
         [0019]    The criteria that trigger the user equipment to send a report to the network may be that the user equipment has detected the blindly configured SCell (for example, the user equipment has be able find the identity, PCI, and the like of that SCell using a cell search procedure). In addition to the identity of the detected SCell, this report may include a measurement, such as the RSRP level and/or RSRQ level, for the detected SCell. However, the measured RSRP or RSRQ in the report may, in some example embodiments, not need to satisfy a certain predefined threshold (for example, above or below a given threshold for a certain measurement). 
         [0020]    In some example embodiments, the measurements of the blindly configured SCell(s) may be performed in accordance with SCell measurement configuration or control information. In some example embodiments, the types of measurements made by the user equipment of a blindly detected SCell (which are subsequently reported to the network) may be statically defined in a standard or defined in accordance with an explicit request from the network. In addition, the measurements may, in some example embodiments, be defined as dedicated measurement control information, although such dedicated definition may not be used as well. 
         [0021]      FIG. 1  depicts an example of a system  100  including a user equipment (UE)  114  detecting a blindly configured SCell  112 B. The phrase blindly configured refers to the network (for example, a node therein, such as base station  110 A serving PCell  112 A) preconfiguring SCell  112 B and serving access point/base station  110 B to provide a carrier aggregation SCell for user equipment  114  before user equipment  114  detects SCell  112 B and/or reports the Scell. The inter-site carrier aggregation depicted at  FIG. 1  includes a macrocell  112 A acting as a PCell served by a macrocell base station  110 A (for example, an evolved Node B base station and the like) on a first carrier, such as frequency F 1 , and a small cell  112 B acting as a SCell, which is served by a base station  110 B on a second carrier, such as frequency F 2 . Although  FIG. 1  depicts inter-site carrier aggregation, other types of carrier aggregation may be used as well. 
         [0022]    Furthermore,  FIG. 1  depicts the path  166  traveled by the user equipment. At point A  190 A, the user equipment  114  has not yet detected the small cell  112  B blindly configured by the network including base station  110 A since the user equipment  114  is not sufficiently close to SCell  112 B including base station  110 B. At point B  190 B however, user equipment  114  is sufficiently close to detect the blindly configured SCell  112 B including base station  110 B. As such, user equipment  114  may, in some example embodiments, send a report indicating the detection of SCell  112 B, and this report may include information, such as the identity of the SCell  112 B, measurement information, and/or the like. Furthermore, this report may, as noted above, be trigger by an event reporting criteria. 
         [0023]    Although  FIG. 1  depicts a certain quantity of user equipment, base stations, and cells including SCells and PCells, other quantities and configurations may be used as well. 
         [0024]      FIG. 2  depicts an example process  200  for user equipment reporting of a blindly detected SCell, in accordance with some example embodiments. The description of  FIG. 2  also refers to  FIG. 1 . 
         [0025]    At  202 , a network, such as a cellular radio access network including base station  110 A and/or another base station/node, may configure user equipment  114  with carrier aggregation and may configure small cell  112 B to provide a SCell for user equipment  114 , in accordance with some example embodiments. Moreover, the network may configure the SCell  112 B blindly before user equipment detects SCell  112 B, in accordance with some example embodiments. 
         [0026]    At  204 , user equipment  114  may detect blindly configured SCell  112 B, in accordance with some example embodiments. For example, user equipment  114  may detect at point B  190 B, the blindly configured SCell  112 B, and this detection may be based on the identity of the Scell (for example, the user equipment may detect the PCI of the SCell  112 B as that of a secondary cell which should be accessed for carrier aggregation). In some example embodiments, the user equipment  114  may include event reporting criteria. This event reporting criteria may specify that user equipment  114  should send a measurement report when a blindly configured SCell is detected, and this reporting criteria may specify the type of measurements (for example, RSRP, RSRQ, and/or any other power/quality metrics) to be sent to the network when the event reporting criteria is triggered at the user equipment. 
         [0027]    At  206 , user equipment  114  may, in accordance with some example embodiments, perform one or more measurements, such as RSRQ measurements and RSRP measurements, of the SCell  112 B, which has been blindly configured by the network for carrier aggregation. The types of measurements may be requested in a measurement configuration sent by the network, statically defined in for example a standard, and the like. 
         [0028]    At  208 , user equipment  114  may report the detection of the blindly configured SCell  112 B and/or the measurements made at  206 , in accordance with some example embodiments. For example, user equipment  114  may send a report to the network, such as base station  110 A. The report may include the identity of the blindly configured SCell  112 B, one or more measurements of the SCell  112 B, and the like. Once the network receives the report sent at  208 , the network may activate the SCell  112 B for use when communication with user equipment  114 , if user equipment  114  has not activated the SCell  112 B. 
         [0029]      FIG. 3  illustrates a block diagram of an apparatus  10 , which can be configured as user equipment in accordance with some example embodiments. 
         [0030]    The apparatus  10  may include at least one antenna  12  in communication with a transmitter  14  and a receiver  16 . Alternatively transmit and receive antennas may be separate. 
         [0031]    The apparatus  10  may also include a processor  20  configured to provide signals to and receive signals from the transmitter and receiver, respectively, and to control the functioning of the apparatus. Processor  20  may be configured to control the functioning of the transmitter and receiver by effecting control signaling via electrical leads to the transmitter and receiver. Likewise processor  20  may be configured to control other elements of apparatus  10  by effecting control signaling via electrical leads connecting processor  20  to the other elements, such as for example, a display or a memory. The processor  20  may, for example, be embodied in a variety of ways including circuitry, at least one processing core, one or more microprocessors with accompanying digital signal processor(s), one or more processor(s) without an accompanying digital signal processor, one or more coprocessors, one or more multi-core processors, one or more controllers, processing circuitry, one or more computers, various other processing elements including integrated circuits (for example, an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), and/or the like), or some combination thereof. Accordingly, although illustrated in  FIG. 3  as a single processor, in some example embodiments the processor  20  may comprise a plurality of processors or processing cores. 
         [0032]    Signals sent and received by the processor  20  may include signaling information in accordance with an air interface standard of an applicable cellular system, and/or any number of different wireline or wireless networking techniques, comprising but not limited to Wi-Fi, wireless local access network (WLAN) techniques, such as for example, Institute of Electrical and Electronics Engineers (IEEE) 802.11, 802.16, and/or the like. In addition, these signals may include speech data, user generated data, user requested data, and/or the like. 
         [0033]    The apparatus  10  may be capable of operating with one or more air interface standards, communication protocols, modulation types, access types, and/or the like. For example, the apparatus  10  and/or a cellular modem therein may be capable of operating in accordance with various first generation (1G) communication protocols, second generation (2G or 2.5G) communication protocols, third-generation (3G) communication protocols, fourth-generation (4G) communication protocols, Internet Protocol Multimedia Subsystem (IMS) communication protocols (for example, session initiation protocol (SIP) and/or the like. For example, the apparatus  10  may be capable of operating in accordance with 2G wireless communication protocols IS-136, Time Division Multiple Access TDMA, Global System for Mobile communications, GSM, IS-95, Code Division Multiple Access, CDMA, and/or the like. In addition, for example, the apparatus  10  may be capable of operating in accordance with 2.5G wireless communication protocols General Packet Radio Service (GPRS), Enhanced Data GSM Environment (EDGE), and/or the like. Further, for example, the apparatus  10  may be capable of operating in accordance with 3G wireless communication protocols, such as for example, Universal Mobile Telecommunications System (UMTS), Code Division Multiple Access 2000 (CDMA2000), Wideband Code Division Multiple Access (WCDMA), Time Division-Synchronous Code Division Multiple Access (TD-SCDMA), and/or the like. The apparatus  10  may be additionally capable of operating in accordance with 3.9G wireless communication protocols, such as for example, Long Term Evolution (LTE), Evolved Universal Terrestrial Radio Access Network (E-UTRAN), and/or the like. Additionally, for example, the apparatus  10  may be capable of operating in accordance with 4G wireless communication protocols, such as for example, LTE Advanced and/or the like as well as similar wireless communication protocols that may be subsequently developed. 
         [0034]    It is understood that the processor  20  may include circuitry for implementing audio/video and logic functions of apparatus  10 . For example, the processor  20  may comprise a digital signal processor device, a microprocessor device, an analog-to-digital converter, a digital-to-analog converter, and/or the like. Control and signal processing functions of the apparatus  10  may be allocated between these devices according to their respective capabilities. The processor  20  may additionally comprise an internal voice coder (VC)  20   a , an internal data modem (DM)  20   b , and/or the like. Further, the processor  20  may include functionality to operate one or more software programs, which may be stored in memory. In general, processor  20  and stored software instructions may be configured to cause apparatus  10  to perform actions. For example, processor  20  may be capable of operating a connectivity program, such as for example, a web browser. The connectivity program may allow the apparatus  10  to transmit and receive web content, such as for example, location-based content, according to a protocol, such as for example, wireless application protocol, WAP, hypertext transfer protocol, HTTP, and/or the like. 
         [0035]    Apparatus  10  may also comprise a user interface including, for example, an earphone or speaker  24 , a ringer  22 , a microphone  26 , a display  28 , a user input interface, and/or the like, which may be operationally coupled to the processor  20 . The display  28  may, as noted above, include a touch sensitive display, where a user may touch and/or gesture to make selections, enter values, and/or the like. The processor  20  may also include user interface circuitry configured to control at least some functions of one or more elements of the user interface, such as for example, the speaker  24 , the ringer  22 , the microphone  26 , the display  28 , and/or the like. The processor  20  and/or user interface circuitry comprising the processor  20  may be configured to control one or more functions of one or more elements of the user interface through computer program instructions, for example, software and/or firmware, stored on a memory accessible to the processor  20 , for example, volatile memory  40 , non-volatile memory  42 , and/or the like. The apparatus  10  may include a battery for powering various circuits related to the mobile terminal, for example, a circuit to provide mechanical vibration as a detectable output. The user input interface may comprise devices allowing the apparatus  20  to receive data, such as for example, a keypad  30  (which can be a virtual keyboard presented on display  28  or an externally coupled keyboard) and/or other input devices. 
         [0036]    As shown in  FIG. 3 , apparatus  10  may also include one or more mechanisms for sharing and/or obtaining data. For example, the apparatus  10  may include a short-range radio frequency (RF) transceiver and/or interrogator  64 , so data may be shared with and/or obtained from electronic devices in accordance with RF techniques. The apparatus  10  may include other short-range transceivers, such as for example, an infrared (IR) transceiver  66 , a Bluetooth (BT) transceiver  68  operating using Bluetooth wireless technology, a wireless universal serial bus (USB) transceiver  70 , and/or the like. The Bluetooth transceiver  68  may be capable of operating according to low power or ultra-low power Bluetooth technology, for example, Wibree, radio standards. In this regard, the apparatus  10  and, in particular, the short-range transceiver may be capable of transmitting data to and/or receiving data from electronic devices within a proximity of the apparatus, such as for example, within 10 meters, for example. The apparatus  10  including the WiFi or wireless local area networking modem may also be capable of transmitting and/or receiving data from electronic devices according to various wireless networking techniques, including 6LoWpan, Wi-Fi, Wi-Fi low power, WLAN techniques such as for example, IEEE 802.11 techniques, IEEE 802.15 techniques, IEEE 802.16 techniques, and/or the like. 
         [0037]    The apparatus  10  may comprise memory, such as for example, a subscriber identity module (SIM)  38 , a removable user identity module (R-UIM), and/or the like, which may store information elements related to a mobile subscriber. In addition to the SIM, the apparatus  10  may include other removable and/or fixed memory. The apparatus  10  may include volatile memory  40  and/or non-volatile memory  42 . For example, volatile memory  40  may include Random Access Memory (RAM) including dynamic and/or static RAM, on-chip or off-chip cache memory, and/or the like. Non-volatile memory  42 , which may be embedded and/or removable, may include, for example, read-only memory, flash memory, magnetic storage devices, for example, hard disks, floppy disk drives, magnetic tape, optical disc drives and/or media, non-volatile random access memory (NVRAM), and/or the like. Like volatile memory  40 , non-volatile memory  42  may include a cache area for temporary storage of data. At least part of the volatile and/or non-volatile memory may be embedded in processor  20 . The memories may store one or more software programs, instructions, pieces of information, data, and/or the like which may be used by the apparatus for performing functions of the user equipment/mobile terminal. The memories may comprise an identifier, such as for example, an international mobile equipment identification (IMEI) code, capable of uniquely identifying apparatus  10 . The functions may include one or more of the operations disclosed herein with respect to the user equipment, such as for example, the functions disclosed at process  200  (for example, detect the SCell, trigger a measurement report indicating the detection of the SCell, and/or the like). The memories may comprise an identifier, such as for example, an international mobile equipment identification (IMEI) code, capable of uniquely identifying apparatus  10 . In the example embodiment, the processor  20  may be configured using computer code stored at memory  40  and/or  42  to enable the user equipment to detect and/or measure SCells, trigger reporting events, and/or any other function associated with the user equipment or apparatus disclosed herein. 
         [0038]      FIG. 4  depicts an example implementation of a network node, such as a base station, access point, and/or any other type of node. The network node may include one or more antennas  720  configured to transmit via a downlink and configured to receive uplinks via the antenna(s)  720 . The network node may further include a plurality of radio interfaces  740  coupled to the antenna  720 . The radio interfaces may correspond one or more of the following: Long Term Evolution (LTE, or E-UTRAN), Third Generation (3G, UTRAN, or high speed packet access (HSPA)), Global System for Mobile communications (GSM), wireless local area network (WLAN) technology, such as for example 802.11 WiFi and/or the like, Bluetooth, Bluetooth low energy (BT-LE), near field communications (NFC), and any other radio technologies. The radio interface  740  may further include other components, such as filters, converters (for example, digital-to-analog converters and/or the like), mappers, a Fast Fourier Transform (FFT) module, and/or the like, to generate symbols for a transmission via one or more downlinks and to receive symbols (for example, via an uplink). The network node may further include one or more processors, such as processor  730 , for controlling the network node and for accessing and executing program code stored in memory  735 . In some example embodiments, memory  735  includes code, which when executed by at least one processor causes one or more of the operations described herein with respect to a base station and/or a wireless access point. For example, the network node may configure the SCell, receive the report regarding the detection of the SCell, activate the SCell when detected, and/or the like. 
         [0039]    Some of the embodiments disclosed herein may be implemented in software, hardware, application logic, or a combination of software, hardware, and application logic. The software, application logic, and/or hardware may reside on memory  40 , the control apparatus  20 , or electronic components, for example. In some example embodiment, the application logic, software or an instruction set is maintained on any one of various conventional computer-readable media. In the context of this document, a “computer-readable medium” may be any non-transitory media that can contain, store, communicate, propagate or transport the instructions for use by or in connection with an instruction execution system, apparatus, or device, such as for example, a computer or data processor, with examples depicted at  FIGS. 3 and 4 . A computer-readable medium may comprise a non-transitory computer-readable storage medium that may be any media that can contain or store the instructions for use by or in connection with an instruction execution system, apparatus, or device, such as for example, a computer. Moreover, some of the embodiments disclosed herein include computer programs configured to cause methods as disclosed herein (see, for example, process  200  and/or the like). 
         [0040]    Without in any way limiting the scope, interpretation, or application of the claims appearing below, a technical effect of one or more of the example embodiments disclosed herein may include increased predictability of blind cell activation and/or the like. 
         [0041]    If desired, the different functions discussed herein may be performed in a different order and/or concurrently with each other. Furthermore, if desired, one or more of the above-described functions may be optional or may be combined. Although various aspects of the invention are set out in the independent claims, other aspects of the invention comprise other combinations of features from the described embodiments and/or the dependent claims with the features of the independent claims, and not solely the combinations explicitly set out in the claims. It is also noted herein that while the above describes example embodiments, these descriptions should not be viewed in a limiting sense. Rather, there are several variations and modifications that may be made without departing from the scope of the present invention as defined in the appended claims. Other embodiments may be within the scope of the following claims. The term “based on” includes “based on at least.”