Power allocation for uplink transmissions

Aspects of the present disclosure relate to wireless communications and, more particularly, to how to allocate transmission power for uplink transmissions on different component carriers.

This application claims priority to International Application No. PCT/CN2016/101439 filed Oct. 7, 2016, which is assigned to the assignee of the present application and is expressly incorporated by reference herein in its entirety.

FIELD OF THE DISCLOSURE

Aspects of the present disclosure generally relate to wireless communication and, more particularly, to allocate power for uplink transmissions.

DESCRIPTION OF RELATED ART

Wireless communication systems are widely deployed to provide various types of communication content such as voice, data, and so on. These systems may be multiple-access systems capable of supporting communication with multiple users by sharing the available system resources (e.g., bandwidth and transmit power). Examples of such multiple-access systems include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE)/LTE-Advanced systems and orthogonal frequency division multiple access (OFDMA) systems.

Generally, a wireless multiple-access communication system can simultaneously support communication for multiple wireless terminals. Each terminal communicates with one or more base stations via transmissions on the forward and reverse links. The forward link (or downlink) refers to the communication link from the base stations (e.g., Node B, evolved Node B (eNB), Access Point (AP), Base Station Transceiver (BST), Transmit/Receive Point (TRP)) to the terminals, and the reverse link (or uplink) refers to the communication link from the terminals to the base stations. This communication link may be established via a single-input single-output, multiple-input single-output or a multiple-input multiple-output (MIMO) system.

SUMMARY

Certain aspects of the present disclosure generally relate to power allocation for uplink transmissions.

Certain aspects of the present disclosure provide a method of wireless communications. The method generally includes satisfying a first transmission power threshold (PLIMIT) to limit transmission power (Ppcc) for an uplink transmission on a first or primary component carrier (PCC), determining a transmission power (Pscc) for an uplink transmission on a second component carrier (SCC) when the transmission power for the uplink transmission on the first component carrier is limited, and transmitting the uplink transmission on the SCC with the Pscc. The transmission power for the uplink transmission on the second component carrier may be determined as a minimum of a transmission power adjusted by transmit power control (TPC) and the first limit value reduced by a threshold adjustment value.

Certain aspects of the present disclosure provide an apparatus for wireless communications. The apparatus generally includes means for satisfying a first transmission power threshold (PLIMIT) to limit transmission power (Ppcc) for an uplink transmission on a first component carrier (PCC), means for determining a transmission power (Pscc) for an uplink transmission on a second component carrier (SCC) when the transmission power for the uplink transmission on the first component carrier is limited, and means for transmitting the uplink transmission on the SCC with the Pscc. The transmission power for the uplink transmission on the second component carrier may be determined as a minimum of a transmission power adjusted by transmit power control (TPC) and the first limit value reduced by a threshold adjustment value.

Certain aspects of the present disclosure provide a computer readable medium having instructions stored thereon for wireless communications. The instructions generally include instructions for satisfying a first transmission power threshold (PLIMIT) to limit transmission power (Ppcc) for an uplink transmission on a first component carrier (PCC), determining a transmission power (Pscc) for an uplink transmission on a second component carrier (SCC) when the transmission power for the uplink transmission on the first component carrier is limited, and transmitting the uplink transmission on the SCC with the Pscc. The transmission power for the uplink transmission on the second component carrier may be determined as a minimum of a transmission power adjusted by transmit power control (TPC) and the first limit value reduced by a threshold adjustment value.

Certain aspects of the present disclosure provide an apparatus for wireless communications. The apparatus generally includes at least one processor configured to satisfy a first transmission power threshold (PLIMIT) to limit transmission power (Ppcc) for an uplink transmission on a first component carrier (PCC) and determine a transmission power (Pscc) for an uplink transmission on a second component carrier (SCC) when the transmission power for the uplink transmission on the first component carrier is limited, and a transmitter configured to transmit the uplink transmission on the SCC with the Pscc. The transmission power for the uplink transmission on the second component carrier may be determined as a minimum of a transmission power adjusted by transmit power control (TPC) and the first limit value reduced by a threshold adjustment value.

Aspects generally include methods, apparatus, systems, computer program products, and processing systems, as substantially described herein with reference to and as illustrated by the accompanying drawings.

Other aspects, features, and embodiments of the present invention will become apparent to those of ordinary skill in the art, upon reviewing the following description of specific, exemplary aspects of the present invention in conjunction with the accompanying figures. While features of the present disclosure may be discussed relative to certain aspects and figures below, all embodiments of the present disclosure can include one or more of the advantageous features discussed herein. In other words, while one or more aspects may be discussed as having certain advantageous features, one or more of such features may also be used in accordance with the various aspects of the disclosure discussed herein. In similar fashion, while exemplary aspects may be discussed below as device, system, or method aspects it should be understood that such exemplary aspects can be implemented in various devices, systems, and methods.

DETAILED DESCRIPTION

Aspects of the present disclosure relate to transmission power control. According to certain aspects, a user equipment (UE) can allocate transmit power (e.g., between or among different component carriers in a manner that, for example, limits transmission power for an uplink transmission on one component carrier, while maintaining at least some usable transmission power for an uplink transmission power on another component carrier.

Some examples of UEs may include cellular phones, smart phones, personal digital assistants (PDAs), wireless modems, handheld devices, tablets, laptop computers, netbooks, smartbooks, ultrabooks, medical device or equipment, biometric sensors/devices, wearable devices (smart watches, smart clothing, smart glasses, smart wrist bands, smart jewelry (e.g., smart ring, smart bracelet)), an entertainment device (e.g., a music or video device, or a satellite radio), a vehicular component or sensor, smart meters/sensors, industrial manufacturing equipment, a global positioning system device, or any other suitable device that is configured to communicate via a wireless or wired medium. Some UEs may be considered evolved or enhanced machine-type communication (eMTC) UEs. MTC and eMTC UEs include, for example, robots, drones, remote devices, such as sensors, meters, monitors, location tags, etc., that may communicate with a base station, another device (e.g., remote device), or some other entity. A wireless node may provide, for example, connectivity for or to a network (e.g., a wide area network such as Internet or a cellular network) via a wired or wireless communication link.

Example Wireless Communications Network

FIG. 1illustrates an example wireless communication network100, in which aspects of the present disclosure may be practiced. For example, one or more UEs120may be configured to allocate transmission power between different component carriers when sending uplink transmissions in accordance with aspects of the present disclosure.

The network100may be an LTE network or some other wireless network. Wireless network100may include a number of evolved Node Bs (eNBs)110and other network entities. An eNB is an entity that communicates with user equipments (UEs) and may also be referred to as a base station, a Node B, an access point, etc. Each eNB may provide communication coverage for a particular geographic area. In 3GPP, the term “cell” can refer to a coverage area of an eNB and/or an eNB subsystem serving this coverage area, depending on the context in which the term is used.

An eNB may provide communication coverage for a macro cell, a pico cell, a femto cell, and/or other types of cell. A macro cell may cover a relatively large geographic area (e.g., several kilometers in radius) and may allow unrestricted access by UEs with service subscription. A pico cell may cover a relatively small geographic area and may allow unrestricted access by UEs with service subscription. A femto cell may cover a relatively small geographic area (e.g., a home) and may allow restricted access by UEs having association with the femto cell (e.g., UEs in a closed subscriber group (CSG)). An eNB for a macro cell may be referred to as a macro eNB. An eNB for a pico cell may be referred to as a pico eNB. An eNB for a femto cell may be referred to as a femto eNB or a home eNB (HeNB). In the example shown inFIG. 1, an eNB110amay be a macro eNB for a macro cell102a, an eNB110bmay be a pico eNB for a pico cell102b, and an eNB110cmay be a femto eNB for a femto cell102c. An eNB may support one or multiple (e.g., three) cells. The terms “eNB”, “base station” and “cell” may be used interchangeably herein.

Wireless network100may also include relay stations. A relay station is an entity that can receive a transmission of data from an upstream station (e.g., an eNB or a UE) and send a transmission of the data to a downstream station (e.g., a UE or an eNB). A relay station may also be a UE that can relay transmissions for other UEs. In the example shown inFIG. 1, a relay station110dmay communicate with macro eNB110aand a UE120din order to facilitate communication between eNB110aand UE120d. A relay station may also be referred to as a relay eNB, a relay base station, a relay, etc.

Wireless network100may be a heterogeneous network that includes eNBs of different types, e.g., macro eNBs, pico eNBs, femto eNBs, relay eNBs, etc. These different types of eNBs may have different transmit power levels, different coverage areas, and different impact on interference in wireless network100. For example, macro eNBs may have a high transmit power level (e.g., 5 to 40 Watts) whereas pico eNBs, femto eNBs, and relay eNBs may have lower transmit power levels (e.g., 0.1 to 2 Watts).

A network controller130may couple to a set of eNBs and may provide coordination and control for these eNBs. Network controller130may communicate with the eNBs via a backhaul. The eNBs may also communicate with one another, e.g., directly or indirectly via a wireless or wireline backhaul.

UEs120(e.g.,120a,120b,120c) may be dispersed throughout wireless network100, and each UE may be stationary or mobile. A UE may also be referred to as an access terminal, a terminal, a mobile station, a subscriber unit, a station, etc. A UE may be a cellular phone (e.g., a smart phone), a personal digital assistant (PDA), a wireless modem, a wireless communication device, a handheld device, a laptop computer, a cordless phone, a wireless local loop (WLL) station, a tablet, a camera, a gaming device, a netbook, a smartbook, an ultrabook, etc. InFIG. 1, a solid line with double arrows indicates desired transmissions between a UE and a serving eNB, which is an eNB designated to serve the UE on the downlink and/or uplink. A dashed line with double arrows indicates potentially interfering transmissions between a UE and an eNB.

Controller/processor280may direct the operation UE120to perform techniques presented herein for transmission power control for uplink transmissions, for example, sent using carrier aggregation (e.g., in accordance with the operations shown inFIG. 6).

Memories242and282may store data and program codes for base station110and UE120, respectively. A scheduler246may schedule UEs for data transmission on the downlink and/or uplink.

FIG. 3shows an exemplary frame structure300for FDD in LTE. The transmission timeline for each of the downlink and uplink may be partitioned into units of radio frames. Each radio frame may have a predetermined duration (e.g., 10 milliseconds (ms)) and may be partitioned into 10 subframes with indices of 0 through 9. Each subframe may include two slots. Each radio frame may thus include 20 slots with indices of 0 through 19. Each slot may include L symbol periods, e.g., seven symbol periods for a normal cyclic prefix (as shown inFIG. 3) or six symbol periods for an extended cyclic prefix. The 2L symbol periods in each subframe may be assigned indices of 0 through 2L−1.

In LTE, an eNB may transmit a primary synchronization signal (PSS) and a secondary synchronization signal (SSS) on the downlink in the center of the system bandwidth for each cell supported by the eNB. The PSS and SSS may be transmitted in symbol periods 6 and 5, respectively, in subframes 0 and 5 of each radio frame with the normal cyclic prefix, as shown inFIG. 3. The PSS and SSS may be used by UEs for cell search and acquisition. The eNB may transmit a cell-specific reference signal (CRS) across the system bandwidth for each cell supported by the eNB. The CRS may be transmitted in certain symbol periods of each subframe and may be used by the UEs to perform channel estimation, channel quality measurement, and/or other functions. The eNB may also transmit a physical broadcast channel (PBCH) in symbol periods 0 to 3 in slot 1 of certain radio frames. The PBCH may carry some system information. The eNB may transmit other system information such as system information blocks (SIBs) on a physical downlink shared channel (PDSCH) in certain subframes. The eNB may transmit control information/data on a physical downlink control channel (PDCCH) in the first B symbol periods of a subframe, where B may be configurable for each subframe. The eNB may transmit traffic data and/or other data on the PDSCH in the remaining symbol periods of each subframe. In aspects, a serving cell and one or more neighbor cells are synchronous, such that SSS for the serving and the one or more neighbor cells may interfere.

FIG. 4shows two exemplary subframe formats410and420with the normal cyclic prefix. The available time frequency resources may be partitioned into resource blocks. Each resource block may cover12subcarriers in one slot and may include a number of resource elements. Each resource element may cover one subcarrier in one symbol period and may be used to send one modulation symbol, which may be a real or complex value.

Subframe format410may be used for two antennas. A CRS may be transmitted from antennas 0 and 1 in symbol periods 0, 4, 7 and 11. A reference signal is a signal that is known a priori by a transmitter and a receiver and may also be referred to as pilot. A CRS is a reference signal that is specific for a cell, e.g., generated based on a cell identity (ID). InFIG. 4, for a given resource element with label Ra, a modulation symbol may be transmitted on that resource element from antenna a, and no modulation symbols may be transmitted on that resource element from other antennas. Subframe format420may be used with four antennas. A CRS may be transmitted from antennas 0 and 1 in symbol periods 0, 4, 7 and 11 and from antennas 2 and 3 in symbol periods 1 and 8. For both subframe formats410and420, a CRS may be transmitted on evenly spaced subcarriers, which may be determined based on cell ID. CRSs may be transmitted on the same or different subcarriers, depending on their cell IDs. For both subframe formats410and420, resource elements not used for the CRS may be used to transmit data (e.g., traffic data, control data, and/or other data).

The PSS, SSS, CRS and PBCH in LTE are described in 3GPP TS 36.211, entitled “Evolved Universal Terrestrial Radio Access (E-UTRA); Physical Channels and Modulation,” which is publicly available.

The wireless network may support hybrid automatic retransmission request (HARQ) for data transmission on the downlink and uplink. For HARQ, a transmitter (e.g., an eNB) may send one or more transmissions of a packet until the packet is decoded correctly by a receiver (e.g., a UE) or some other termination condition is encountered. For synchronous HARQ, all transmissions of the packet may be sent in subframes of a single interlace. For asynchronous HARQ, each transmission of the packet may be sent in any subframe.

A UE may be located within the coverage of multiple eNBs. One of these eNBs may be selected to serve the UE. The serving eNB may be selected based on various criteria such as received signal strength, received signal quality, pathloss, etc. Received signal quality may be quantified by a signal-to-noise-and-interference ratio (SINR), or a reference signal received quality (RSRQ), or some other metric. The UE may operate in a dominant interference scenario in which the UE may observe high interference from one or more interfering eNBs.

FIG. 5illustrates various components that may be utilized in a wireless device502that may be employed within the wireless communication system100illustrated inFIG. 1. The wireless device502is an example of a device that may be configured to implement the various methods described herein. The wireless device502may be any of the wireless nodes (e.g., UEs120). For example, the wireless device502may be configured to perform operations and techniques illustrated inFIG. 6as well as other operations described herein.

The wireless device502may include a processor504that controls operation of the wireless device502. The processor504may also be referred to as a central processing unit (CPU). Memory506, which may include both read-only memory (ROM) and random access memory (RAM), provides instructions and data to the processor504. A portion of the memory506may also include non-volatile random access memory (NVRAM). The processor504typically performs logical and arithmetic operations based on program instructions stored within the memory506. The instructions in the memory506may be executable to implement the methods described herein. Some non-limiting examples of the processor504may include Snapdragon processor, application specific integrated circuits (ASICs), programmable logic, etc.

The wireless device502may also include a housing508that may include a transmitter510and a receiver512to allow transmission and reception of data between the wireless device502and a remote location. The transmitter510and receiver512may be combined into a transceiver514. A single transmit antenna or a plurality of transmit antennas516may be attached to the housing508and electrically coupled to the transceiver514. The wireless device502may also include (not shown) multiple transmitters, multiple receivers, and multiple transceivers. The wireless device502can also include wireless battery charging equipment.

The wireless device502may also include a signal detector518that may be used in an effort to detect and quantify the level of signals received by the transceiver514. The signal detector518may detect such signals as total energy, energy per subcarrier per symbol, power spectral density and other signals. The wireless device302may also include a digital signal processor (DSP)520for use in processing signals.

The various components of the wireless device502may be coupled together by a bus system522, which may include a power bus, a control signal bus, and a status signal bus in addition to a data bus. The processor504may be configured to access instructions stored in the memory506to perform beam refinement with aspects of the present disclosure discussed below.

Example Transmit Power Control (e.g., for Uplink Carrier Aggregation)

For uplink (UL) carrier aggregation (CA) the UE is allowed to set its configured maximum output transmit (TX) power PCMAX,cfor serving cell c and its total configured maximum output TX power PCMAX. Current UL CA TX power control implementations typically limit both the per serving cell and the total TX power to a same parameter PCMAX, which generally refers to an allowable maximum TX power, for UL intra-band contiguous and non-contiguous CA. The value of PCMAXis generally calculated by applying a maximum power reduction (MPR) to a maximum power limit corresponding to a UE power class.

If the UE has PUSCH transmissions with UCI (UL control information) on serving cell j and PUSCH without UCI in any of the remaining serving cells, and the TX power for the PUSCH transmissions with UCI after being adjusted via transmit power control (TPC) would exceed PCMAX, PUSCH transmissions without UCI will be discarded according to a priority scheme:

∑c≠j⁢w⁡(i)·P^PUSCH,c⁡(i)≤(P^CMAX⁡(i)-P^PUSCH,j⁡(i))
where {circumflex over (P)}PUSCH,j(i) is the PUSCH TX power for the cell with UCI in subframe i, w(i) is a scaling factor of the PUSCH TX power {circumflex over (P)}PUSCH,c(i) for serving cell c without UCI and {circumflex over (P)}CMAX(i) is the linear value of PCMAXin subframe i. Since {circumflex over (P)}PUSCH,j(i) will be {circumflex over (P)}CMAX(i) in this case, w(i) need to be zero, eliminating the TX power for serving cell c without UCI.

This scenario may occur for various reasons, for example, as the result of heavy UL traffic demand (e.g., large resource block allocation, large modulator order) in addition to the cell edge scenario. Therefore, the percentage of end users who get affected may be significant. When this happens, the UE suffers from (i) loss in throughput as the serving cell without UCI is effectively disabled and/or (ii) unnecessary extra current consumption for intra-band UL CA as the circuit is configured for the aggregated transmission bandwidth, regardless of discarded serving cell without UCI or not.

As more operators deploy Uplink Carrier Aggregation (ULCA), especially in the case where the operator wants to use ULCA to make up for the limited UL resource (e.g., 2 or 4 subframes out of every 10 subframes for TDD LTE uplink-downlink configuration2and1), it is desirable to address this issue, which could provide a competitive advantage.

Aspects of the present disclosure provide techniques for allocating transmission power for uplink transmissions among different component carriers, that may help address the issues described above. The techniques may be used to allocate transmission power, for example, between or among a component carrier with UCI and at least one component carrier without UCI.

FIG. 6illustrates example operations that may be performed by a user equipment to allocate transmission power, in accordance with certain aspects of the present disclosure.

As illustrated, operations600start at602, by satisfying a first transmission power limit value (e.g., PCMAX) to limit transmission power ({circumflex over (P)}PUSCH,j(i)) for an uplink transmission on a first component carrier with UCI which is typically the primary component carrier (PCC).

At604, the UE determines a transmission power ({circumflex over (P)}PUSCH,c(i)) for an uplink transmission on a secondary component carrier (SCC) without UCI when the transmission power for the uplink transmission on the first component carrier is limited. As illustrated, in some cases, the transmission power for the uplink transmission on the second component carrier is determined as a minimum of: a transmission power adjusted by transmit power control (TPC) and the first limit value reduced by a threshold adjustment value. At606, the UE transmits the uplink transmission on the first and second component carriers.

According to certain aspects, the transmission power for the uplink transmission on the SCC is determined as a minimum of a previous transmission power adjusted by transmit power control (TPC), and the PLIMITis reduced by a threshold adjustment value. In such aspects, the threshold adjustment value is selected to allow detection of the uplink transmission on the second component carrier.

According to certain aspects, PLIMITis determined by applying a power reduction (PR) to a network configured maximum transmission power. In such aspects, the transmission power for the uplink transmission on the second component carrier is determined such that a total uplink transmission power of the uplink transmissions on the first and second component carriers does not exceed the network configured maximum transmission power.

Additionally or alternatively, in such aspects, the threshold adjustment value is determined such that a total uplink transmission power of the uplink transmissions on the first and second component carriers exceeds Plimitbut does not exceed the network configured maximum transmission power.

In aspects, the uplink transmission on a first component carrier carries uplink control information (UCI). In aspects, the UCI is associated with a hybrid automatic repeat request (HARQ) procedure.

According to certain aspects, the operations600further includes determining a transmission power threshold for limiting transmission power for an uplink transmission on the SCC. In such aspects, the operations600further includes determining the Psccfor the uplink transmission on the SCC when the transmission power for the uplink transmission on the first component carrier is limited includes determining the Psccfor the uplink transmission on the SCC based on the transmission power threshold for limiting transmission power for an uplink transmission on the SCC. In aspects, transmitting includes transmitting pursuant to an UL carrier aggregation configuration

The following is an example algorithm that may be used to determine the transmission power (e.g. {circumflex over (P)}PUSCH,j(i)) for an uplink transmission on the second component carrier (e.g., SCC) when the transmission power for the uplink transmission with UCI on the first component carrier is limited (e.g., if the power on PCC ({circumflex over (P)}PUSCH,j(i)) satisfies a threshold and/or is limited to Pmax:

This approach may be explained with reference to an example. The example assumes that a maximum allowable transmission power for a UE (e.g., configured by the network or according to the UE power class), for example, is 23 dBm. The example also assumes that MPR (e.g., from a table in a specification) according to PUSCH scheduling on both a PCC and a SCC is 3 dB.

Applying this value to the maximum transmission power (23 dBm), yields PCMAX=20 dBm (e.g., first transmission power limit value=20 dBm). Further, assuming at the moment that TPC (TX power control) for PCC requires 22 dBm for PCC that has UCI. Two scenarios are examined:(i) 10 dBm for SCC. In this example, then, PPUSCH,PCC=20 dBm and PPUSCH,SCC=10 dBm (and UL transmission on SCC is not limited).(ii) 19 dBm for SCC. In this example, then PPUSCH,PCC=20 dBm. Therefore, the equation above yields: PPUSCH,SCC=PCMAX−Threshold=20 dBm−7 dB=13 dBm—assuming 7 dB threshold (e.g, which serves as a threshold adjustment value). This allows SCC to still be used to deliver data. In aspects, the threshold adjustment value is determined such that a total (e.g., linear addition) uplink transmission power of the uplink transmissions on the first and second component carriers exceeds first transmission power limit value but does not exceed the network configured maximum transmission

The net effect of this algorithm is that it essentially applies different limits on per serving cell and on the total power. This approach may exploit that MPR is essentially an allowance, but not a requirement and that there is NO requirement to apply the same MPR on each CC and on the total.

The proposed techniques brings in two benefits. The first benefit may be an enhanced UL throughput by means of either one of the following—in either case SCC now delivers throughput versus none without the proposal. First of all, SCCa. SCC power capping to (PCMAX−Threshold) is compensated for by re-transmissions; (e.g., in the eventuality the uplink transmission on the SCC with the Psccis not successfully received)b. Network lowers MCS rate on SCC in response to re-transmissions when they becomes excessive due to continued power capping
By means of either a or b, SCC may now be able to deliver throughput.

Aspects of the present disclosure may also help achieve power efficiency. For intraband contiguous ULCA, the Tx chain is always configured for the aggregated transmission bandwidth regardless of TX activities on SCC. Thus, not transmitting PUSCH on SCC when there is a PUSCH grant is a waste of current consumption. Furthermore, given relatively low PA efficiency, transmitting SCC at a fraction of a dB higher than total TX power (e.g., Pmax) advantageously increases efficiency in terms of bits/sec/joule while overhead of turning on the PA virtually does not change.

As used herein, the term “identifying” encompasses a wide variety of actions. For example, “identifying” may include calculating, computing, processing, deriving, investigating, looking up (e.g., looking up in a table, a database or another data structure), ascertaining and the like. Also, “identifying” may include receiving (e.g., receiving information), accessing (e.g., accessing data in a memory) and the like. Also, “identifying” may include resolving, selecting, choosing, establishing and the like.

In some cases, rather than actually communicating a frame, a device may have an interface to communicate a frame for transmission or reception. For example, a processor may output a frame, via a bus interface, to an RF front end for transmission. Similarly, rather than actually receiving a frame, a device may have an interface to obtain a frame received from another device. For example, a processor may obtain (or receive) a frame, via a bus interface, from an RF front end for transmission.

The various operations of methods described above may be performed by any suitable means capable of performing the corresponding functions. The means may include various hardware and/or software/firmware component(s) and/or module(s), including, but not limited to a circuit, an application specific integrated circuit (ASIC), or processor. Generally, where there are operations illustrated in figures, those operations may have corresponding counterpart means-plus-function components.

The various operations of methods described above may be performed by any suitable means capable of performing the corresponding functions. The means may include various hardware and/or software/firmware component(s) and/or module(s), including, but not limited to a circuit, an application specific integrated circuit (ASIC), or processor. Generally, where there are operations illustrated in Figures, those operations may be performed by any suitable corresponding counterpart means-plus-function components.