Patent Publication Number: US-10333675-B2

Title: System and method for heterogeneous carrier aggregation

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a continuation of U.S. patent application Ser. No. 13/773,020 (now U.S. Pat. No. 9,629,028), filed Feb. 21, 2013, which claims priority from U.S. Provisional Patent Application No. 61/612,127, filed Mar. 16, 2012, the disclosures of which are incorporated by reference herein. 
    
    
     BACKGROUND 
     Field 
     Aspects of the present disclosure relate generally to wireless communication systems, and more particularly, to aggregation of heterogeneous carriers below an internet protocol (IP) layer of operation. 
     Background 
     Wireless communication networks are widely deployed to provide various communication services such as voice, video, packet data, messaging, broadcast, etc. These wireless networks may be multiple-access networks capable of supporting multiple users by sharing the available network resources. Examples of such multiple-access networks include Code Division Multiple Access (CDMA) networks, Time Division Multiple Access (TDMA) networks, Frequency Division Multiple Access (FDMA) networks, Orthogonal FDMA (OFDMA) networks, and Single-Carrier FDMA (SC-FDMA) networks. 
     A wireless communication network may include a number of network entities, such as base stations, that can support communication for a number of mobile entities/devices, such as, for example, user equipments (UEs) or access terminals (ATs). A mobile device may communicate with a base station via a downlink and uplink. The downlink (or forward link) refers to the communication link from the base station to the UE, and the uplink (or reverse link) refers to the communication link from the UE to the base station. 
     The 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) represents a major advance in cellular technology as an evolution of Global System for Mobile communications (GSM) and Universal Mobile Telecommunications System (UMTS). The LTE physical layer (PHY) provides a highly efficient way to convey both data and control information between a base station, such as an evolved Node B (eNB), and a mobile device, such as a UE. 
     With increased consumer demand for mobile broadband and Internet access, wireless service providers have implemented cellular carrier aggregation to increase the available bandwidth of WWANs. Such approaches may involve aggregating one or more homogenous cellular carriers as contemplated for LTE networks. However, such carrier aggregation techniques do not address the distinct challenges of aggregating heterogeneous carriers in a wireless communication system. 
     SUMMARY 
     Illustrative embodiments of the present invention that are shown in the drawings are summarized below. These and other embodiments are more fully described in the detailed description section. It is to be understood, however, that the invention is not limited to the forms described in this Summary of the Invention or in the detailed description. 
     In accordance with one or more aspects of the embodiments described herein, there is provided a method for aggregating heterogeneous component carriers, such as, for example, wireless wide area network (e.g., cellular) and wireless local area network (WLAN) carriers. The method may be operable by a mobile device (e.g., a dual WWAN-WLAN capable UE) in wireless communication system. The method may involve receiving a configuration for aggregating a plurality of component carriers comprising at least one WWAN carrier and at least one WLAN carrier, wherein the aggregation is performed at a layer of the mobile device below an internet protocol (IP) layer. Aggregation of the heterogeneous carriers may be performed by MAC-layer or RLC-layer protocol entities. The method may involve determining a mapping of uplink traffic in relation to the at least one cellular carrier and the at least one WLAN carrier. The method may involve sending the uplink traffic based at least in part on the mapping. 
     In related aspects, the mapping is based on a traffic flow identifier. The traffic flow identifier may be a logical channel identifier (LCID) when the given protocol layer comprises a media access control (MAC) protocol layer. The traffic flow identifier may be a bearer identifier when the given protocol layer comprises a protocol layer above the MAC protocol layer. In further related aspects, an electronic device (e.g., a UE or component(s) thereof) may be configured to execute the above described methodology. 
     In accordance with one or more aspects of the embodiments described herein, there is provided another method operable by a mobile device. The method may involve receiving a configuration for aggregating a plurality of component carriers comprising at least one cellular carrier and at least one WLAN carrier, wherein the aggregation is performed at a layer of the mobile device below an IP layer. The method may involve determining an association of traffic types with cellular or WLAN carrier types for downlink traffic. The method may involve mirroring the association when sending the uplink traffic in response to the grant. In related aspects, an electronic device (e.g., a UE or component(s) thereof) may be configured to execute the above described methodology. 
     In accordance with one or more aspects of the embodiments described herein, there is provided a method operable by a network entity. The method may involve sending a configuration to a mobile device for aggregating a plurality of component carriers comprising at least one cellular carrier and at least one WLAN carrier, wherein the aggregation is performed at a layer of the mobile device below an IP layer. The method may involve determining a downlink mapping of downlink traffic in relation to the at least one cellular carrier and the at least one WLAN carrier. The method may involve sending the downlink traffic based at least in part on the downlink mapping. 
     In related aspects, the method may further involve: determining a mapping of uplink traffic in relation to the at least one cellular carrier and the at least one WLAN carrier; sending to the mobile device, on a configured cellular carrier, a grant for uplink transmission on one of the plurality of component carriers; and receiving the uplink traffic in response to the grant in accordance with the uplink mapping. In yet further related aspects, an electronic device (e.g., an eNB or component(s) thereof) may be configured to execute the above-described methodology. 
     To the accomplishment of the foregoing and related ends, the one or more embodiments include the features hereinafter fully described and particularly pointed out in the claims. The following description and the annexed drawings set forth in detail certain illustrative aspects of the one or more embodiments. These aspects are indicative, however, of but a few of the various ways in which the principles of various embodiments may be employed and the described embodiments are intended to include all such aspects and their equivalents. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a block diagram illustrating an exemplary telecommunications system that includes both a wireless wide area network (WWAN) and wireless local area network (WLAN). 
         FIG. 2  is a block diagram illustrating an example of a downlink frame structure in a telecommunications system. 
         FIG. 3  is a block diagram illustrating a design of a base station and a UE configured according to one aspect of the present disclosure. 
         FIG. 4  shows carrier aggregation for uplink in accordance with aspects of the embodiments described herein. 
         FIG. 5  illustrates an exemplary base station that includes a cellular/WWAN radio module and a WLAN radio module. 
         FIG. 6  illustrates an exemplary mobile device that includes a cellular/WWAN radio module and a WLAN radio module. 
         FIGS. 7A-E  and  8  show examples of a carrier aggregation methodology operable by a network entity. 
         FIG. 9  illustrates another example carrier aggregation methodology operable by a WLAN AP. 
         FIGS. 10A-B  illustrate another carrier aggregation methodology operable by a mobile device. 
         FIGS. 11A-E  illustrate an example carrier aggregation methodology, operable by a mobile device, involving determining a mapping of traffic in relation to heterogeneous component carriers. 
         FIGS. 12A-B  illustrate further aspects of the example carrier aggregation methodology of  FIG. 11A . 
         FIGS. 13A-D  illustrate an example carrier aggregation methodology, operable by a network entity, involving determining a mapping of traffic in relation to heterogeneous component carriers. 
     
    
    
     DETAILED DESCRIPTION 
     The detailed description set forth below, in connection with the appended drawings, is intended as a description of various configurations and is not intended to represent the only configurations in which the concepts described herein may be practiced. The detailed description includes specific details for the purpose of providing a thorough understanding of the various concepts. However, it will be apparent to those skilled in the art that these concepts may be practiced without these specific details. In some instances, well-known structures and components are shown in block diagram form in order to avoid obscuring such concepts. 
     The techniques described herein may be used for various wireless communication networks such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA and other networks. The terms “network” and “system” are often used interchangeably. A CDMA network may implement a radio technology such as Universal Terrestrial Radio Access (UTRA), CDMA2000, etc. UTRA includes Wideband CDMA (WCDMA) and other variants of CDMA. CDMA2000 covers IS-2000, IS-95 and IS-856 standards. A TDMA network may implement a radio technology such as Global System for Mobile Communications (GSM). An OFDMA network may implement a radio technology such as Evolved UTRA (E-UTRA), Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDMA, etc. UTRA and E-UTRA are part of Universal Mobile Telecommunication System (UMTS). 3GPP Long Term Evolution (LTE) and LTE-Advanced (LTE-A) are new releases of UMTS that use E-UTRA. UTRA, E-UTRA, UMTS, LTE, LTE-A and GSM are described in documents from an organization named “3rd Generation Partnership Project” (3GPP). CDMA2000 and UMB are described in documents from an organization named “3rd Generation Partnership Project 2” (3GPP2). The techniques described herein may be used for the wireless networks and radio technologies mentioned above as well as other wireless networks and radio technologies. For clarity, certain aspects of the techniques are described below for LTE, and LTE terminology is used in much of the description below. 
     The present disclosure provides techniques for aggregating a plurality of heterogeneous component carriers at a sub-IP protocol layer of operation. The plurality of component carriers may include both cellular and WLAN carriers and various methodologies are provided for addressing dissimilarities between the carrier types. To this end, protocol entities at a MAC-layer and/or RLC-layer of operation may be modified in a wireless communication device to accommodate different capabilities of the aggregated carriers and to support a sub-IP layer mapping of traffic. In various aspects, the mapping may be based on traffic flow identifiers, may reflect policy-based restrictions, may mirror downlink transmissions, may facilitate carrier selection, may be static or dynamic in nature, and/or may change in response to activation/deactivation of the aggregated carriers.  FIG. 1  shows a wireless communication network  100 , which may be an LTE network, a UMTS network, or the like. It is noted that the wireless network  100  generally includes or refers to a cellular network or wireless wide area network (WWAN), but may also optionally include or otherwise communicate with one or more wireless local area networks (WLANs). The wireless network  100  may include a number of base stations  110  and other network entities. A base station may be a station that communicates with the mobile devices and may also be referred to as an evolved Node B (eNB), a Node B, an access point (AP), or other term. Each base station  110   a ,  110   b ,  110   c  may provide communication coverage for a particular geographic area. In 3GPP, the term “cell” can refer to a coverage area of base station and/or a base station subsystem serving this coverage area, depending on the context in which the term is used. 
     The wireless network  100  may include relay stations  110   r  and a network controller  130 . A relay station is a station that receives a transmission of data and/or other information from an upstream station (e.g., an base station or a mobile device) and sends a transmission of the data and/or other information to a downstream station (e.g., a mobile device or an base station). A relay station may also be a mobile device that relays transmissions for other mobile devices. As shown in  FIG. 1 , a relay station  110   r  may communicate with the base station  110   a  and mobile device  120   r  in order to facilitate communication. A network controller  130  may couple to a set of base stations and provide coordination and control and/or access to a core network. In this example, network controller  130  communicate with the base stations  110 ,  150  via a backhaul. Base stations  110  may also communicate with one another, e.g., directly or indirectly via wireless or wireline backhaul. It is noted that the wireless network  100  may support synchronous or asynchronous operation. For synchronous operation, the base stations may have similar frame timing, and transmissions from different base stations may be approximately aligned in time. For asynchronous operation, the base stations may have different frame timing, and transmissions from different base stations may not be aligned in time. The techniques described herein may be used for both synchronous and asynchronous operation. 
     The wireless network  100  may include different types of cells. A macro cell may cover a relatively large geographic area (e.g., several kilometers in radius) and may allow unrestricted access by mobile devices with service subscription. A pico cell may cover a relatively small geographic area and may allow unrestricted access by mobile devices with service subscription. A femto cell may cover a relatively small geographic area (e.g., a home) and may allow restricted access by mobile devices having association with the femto cell (e.g., mobile devices in a Closed Subscriber Group (CSG), UEs for users in the home, etc.). In the example shown in  FIG. 1 , the base stations  110   a ,  110   b  and  110   c  may be macro eNBs for the macro cells  102   a ,  102   b  and  102   c , respectively. The base station  110   x  may be a pico eNB for a pico cell  102   x , serving a mobile device  120   x . The base stations  110   y  and  110   z  may be femto eNBs for the femto cells  102   y  and  102   z , respectively. A base station may support one or multiple (e.g., three) cells. 
     It is noted that the mobile devices  120 ,  155  may be dispersed throughout the wireless network  100 . A mobile device may also be referred to as a user equipment (UE), a wireless device, a terminal, a mobile station, a subscriber unit, etc. A mobile device may be a cellular 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, or other mobile entities. A mobile device may communicate with macro eNBs, pico eNBs, femto eNBs, relays, or other network entities which form part of wireless network  100 . 
     In related aspects, a mobile device may also communicate with a WLAN AP according to one or more standards, such as the IEEE 802.11 standard, including, for example these amendments: 802.11a-1999 (commonly called “802.11a”), 802.11b-1999 (commonly called “802.11b”), 802.11g-2003 (commonly called “802.11g”), and so on. For instance, in wireless network  100 , a dual-capability mobile device  155  and a dual-capability base station  150  are shown within the coverage area of macro cell  110   c . The base station  150  may be coupled with elements of the core WWAN network over a backhaul or similar connection. As discussed herein, each dual-capability device  150 ,  155  may include two or more radios supporting concurrent communication on WWAN and WLAN carriers. 
     Within the wireless network  100 , each mobile device may utilize a single carrier or multiple carriers for downlink and uplink communications. A carrier may refer to a range of frequencies used for communication and may have certain associated characteristics, such as the type of radio and protocols in use at that frequency. When a mobile device  120 ,  155  communicates on multiple carriers, the downlink and uplink carriers may be referred to as component carriers. Operation on multiple component carriers may be referred to as multi-carrier operation or carrier aggregation. Carrier aggregation configurations may be symmetric (a same number of DL component carriers as UL component carriers), or asymmetric (a different number of DL and UL component carriers). Also, a set of the frequency division duplexing (FDD) carrier may be aggregated with a set of the time-division duplexing (TDD) carrier, for instance LTE-FDD+WLAN-TDD. 
     As discussed herein, carrier aggregation may be performed for heterogeneous carriers. For example, depending upon their respective capabilities, a base station  150  and a mobile device  155  may communicate on two or more WWAN carriers and at least one WLAN carrier. Wireless devices which support concurrent communication on both cellular and WLAN carriers will be referred to herein as a “dual-capability” devices. Aggregation may increase available spectrum while also preserving the ability of the WWAN network to control communications on each carrier that is configured for the mobile device. In one example, an E-UTRA network controls various communication operations for the aggregated WLAN carrier. Control of the WLAN carrier may include, for example, determining which traffic will be conveyed on the WLAN carrier, carrier activation and deactivation, managing association and authentication to the WLAN AP, controlling the modulation and coding rate used on the WLAN up and downlinks, and addressing other issues associated with the aggregation of the WLAN and non-WLAN carriers. 
     The aggregation of heterogeneous carriers may be performed below the internet protocol (IP) layer such as at the media access control (MAC), radio link control (RLC), or packet data convergence (PDCP) layer of the E-UTRA protocol architecture. In one case, aggregation of the WLAN carrier is performed at the MAC layer and adapted for use with LTE systems. 
     It is noted that LTE utilizes orthogonal frequency division multiplexing (OFDM) on the downlink and single-carrier frequency division multiplexing (SC-FDM) on the uplink. OFDM and SC-FDM partition the system bandwidth into multiple (K) orthogonal subcarriers, which are also commonly referred to as tones, bins, etc. Each subcarrier may be modulated with data. In general, modulation symbols are sent in the frequency domain with OFDM and in the time domain with SC-FDM. The spacing between adjacent subcarriers may be fixed, and the total number of subcarriers (K) may be dependent on the system bandwidth. For example, K may be equal to 128, 256, 512, 1024 or 2048 for system bandwidth of 1.25, 2.5, 5, 10 or 20 megahertz (MHz), respectively. The system bandwidth may also be partitioned into subbands. For example, a subband may cover 1.08 MHz, and there may be 1, 2, 4, 8 or 16 subbands for system bandwidth of 1.25, 2.5, 5, 10 or 20 MHz, respectively. 
       FIG. 2  shows a downlink frame structure used in LTE. The transmission timeline for the downlink 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., 7 symbol periods for a normal cyclic prefix (CP), as shown in  FIG. 2 , or 14 symbol periods for an extended cyclic prefix. The normal CP and extended CP may be referred to herein as different CP types. The 2L symbol periods in each subframe may be assigned indices of 0 through 2L−1. The available time frequency resources may be partitioned into resource blocks. Each resource block may cover N subcarriers (e.g., 12 subcarriers) in one slot. 
     In LTE, an eNB may send a primary synchronization signal (PSS) and a secondary synchronization signal (SSS) for each cell in the eNB. The primary and secondary synchronization signals may be sent in symbol periods  6  and  5 , respectively, in each of subframes  0  and  5  of each radio frame with the normal cyclic prefix, as shown in  FIG. 2 . The synchronization signals may be used by UEs for cell detection and acquisition. The eNB may send a Physical Broadcast Channel (PBCH) in symbol periods  0  to  3  in slot  1  of subframe  0 . The PBCH may carry certain system information. 
     The eNB may send a Physical Control Format Indicator Channel (PCFICH) in only a portion of the first symbol period of each subframe, although depicted in the entire first symbol period in  FIG. 2 . The PCFICH may convey the number of symbol periods (M) used for control channels, where M may be equal to 1, 2 or 3 and may change from subframe to subframe. M may also be equal to 4 for a small system bandwidth, e.g., with less than 10 resource blocks. In the example shown in  FIG. 2 , M=3. Hybrid Automatic Repeat reQuest (HARQ) provides a combination of high-rate forward error-correcting coding and Automatic Repeat reQuest (ARQ) error-control. The eNB may send a Physical HARQ Indicator Channel (PHICH) and a Physical Downlink Control Channel (PDCCH) in the first M symbol periods of each subframe (M=3 in  FIG. 2 ). As such, the PHICH may carry information to support HARQ or the like. The PDCCH may carry information on resource allocation for UEs and control information for downlink channels. Although not shown in the first symbol period in  FIG. 2 , it is understood that the PDCCH and PHICH are also included in the first symbol period. Similarly, the PHICH and PDCCH are also both in the second and third symbol periods, although not shown that way in  FIG. 2 . The eNB may send a Physical Downlink Shared Channel (PDSCH) in the remaining symbol periods of each subframe. The PDSCH may carry data for UEs scheduled for data transmission on the downlink. The various signals and channels 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 eNB may send the PSS, SSS and PBCH in the center 1.08 MHz of the system bandwidth used by the eNB. The eNB may send the PCFICH and PHICH across the entire system bandwidth in each symbol period in which these channels are sent. The eNB may send the PDCCH to groups of UEs in certain portions of the system bandwidth. The eNB may send the PDSCH to specific UEs in specific portions of the system bandwidth. The eNB may send the PSS, SSS, PBCH, PCFICH and PHICH in a broadcast manner to all UEs, may send the PDCCH in a unicast manner to specific UEs, and may also send the PDSCH in a unicast manner to specific UEs. 
     A number of resource elements may be available in each symbol period. 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. Resource elements not used for a reference signal in each symbol period may be arranged into resource element groups (REGs). Each REG may include four resource elements in one symbol period. The PCFICH may occupy four REGs, which may be spaced approximately equally across frequency, in symbol period  0 . The PHICH may occupy three REGs, which may be spread across frequency, in one or more configurable symbol periods. For example, the three REGs for the PHICH may all belong in symbol period  0  or may be spread in symbol periods  0 ,  1  and  2 . The PDCCH may occupy 9, 18, 32 or 64 REGs, which may be selected from the available REGs, in the first M symbol periods. Only certain combinations of REGs may be allowed for the PDCCH. 
     A UE may know the specific REGs used for the PHICH and the PCFICH. The UE may search different combinations of REGs for the PDCCH. The number of combinations to search is typically less than the number of allowed combinations for the PDCCH. An eNB may send the PDCCH to the UE in any of the combinations that the UE will search. It is noted that a UE may be 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 power, path loss, signal-to-noise ratio (SNR), etc. 
       FIG. 3  shows a block diagram of a design of a base station/eNB  110  and a UE  120 , which may be dual-capability devices that operate generally as discussed in connection with  FIG. 1 . The base station  110  may be equipped with antennas  334   a  through  334   t , and the UE  120  may be equipped with antennas  352   a  through  352   r.    
     At the base station  110 , a transmit processor  320  may receive data from a data source  312  and control information from a controller/processor  340 . The control information may be for the PBCH, PCFICH, PHICH, PDCCH, etc. The data may be for the PDSCH, etc. The processor  320  may process (e.g., encode and symbol map) the data and control information to obtain data symbols and control symbols, respectively. A transmit (TX) multiple-input multiple-output (MIMO) processor  330  may perform spatial processing (e.g., precoding) on the data symbols, the control symbols, and/or the reference symbols, if applicable, and may provide output symbol streams to the modulators (MODs)  332   a  through  332   t . Each modulator  332  may process a respective output symbol stream (e.g., for OFDM, etc.) to obtain an output sample stream. Each modulator  332  may further process (e.g., convert to analog, amplify, filter, and upconvert) the output sample stream to obtain a downlink signal. Downlink signals from modulators  332   a  through  332   t  may be transmitted via the antennas  334   a  through  334   t , respectively. 
     At the UE  120 , the antennas  352   a  through  352   r  may receive the downlink signals from the base station  110  and may provide received signals to the demodulators (DEMODs)  354   a  through  354   r , respectively. Each demodulator  354  may condition (e.g., filter, amplify, downconvert, and digitize) a respective received signal to obtain input samples. Each demodulator  354  may further process the input samples (e.g., for OFDM, etc.) to obtain received symbols. A MIMO detector  356  may obtain received symbols from all the demodulators  354   a  through  354   r , perform MIMO detection on the received symbols if applicable, and provide detected symbols. A receive processor  358  may process (e.g., demodulate, deinterleave, and decode) the detected symbols, provide decoded data for the UE  120  to a data sink  360 , and provide decoded control information to a controller/processor  380 . 
     On the uplink, at the UE  120 , a transmit processor  364  may receive and process data (e.g., for the PUSCH) from a data source  362  and control information (e.g., for the PUCCH) from the controller/processor  380 . The processor  364  may also generate reference symbols for a reference signal. The symbols from the transmit processor  364  may be precoded by a TX MIMO processor  366  if applicable, further processed by the modulators  354   a  through  354   r  (e.g., for SC-FDM, etc.), and transmitted to the base station  110 . At the base station  110 , the uplink signals from the UE  120  may be received by the antennas  334 , processed by the demodulators  332 , detected by a MIMO detector  336  if applicable, and further processed by a receive processor  338  to obtain decoded data and control information sent by the UE  120 . The processor  338  may provide the decoded data to a data sink  339  and the decoded control information to the controller/processor  340 . 
     As noted above, the base station  110  and the UE  120  may be dual-capability devices that support concurrent communication on both cellular and WLAN carriers. The base station  110  and the UE  120 , and components thereof, may be configured for carrier aggregation of heterogeneous carriers. In one aspect, there is provided a carrier aggregation technique that leverages LTE architecture. The technique generally involves performing the aggregation with a WLAN at the HARQ entity level (in the MAC layer), as illustrated in the  FIG. 4 . As one example,  FIG. 4  shows an exemplary arrangement in which, at the MAC layer, a dual-capability device includes protocol entities for a first and second LTE/UMTS carrier (i.e., HARQ entities for component carriers (CCs), such as CC 1 , CC 2 ) as well as a protocol entity for WLAN carrier (802.11 SAL). These protocol entities are shown as coupled with a multiplexer and a scheduling element for aggregating protocol data units (PDUs) associated with the dissimilar carriers. Aspects of this protocol architecture may be incorporated in a controller, processor, scheduler, and/or other elements as described herein. In related aspects, the aggregation of the WWAN carrier and the WLAN carrier may be performed at other layers below the IP layer, such as, for example, a Radio Link Control (RLC) layer, a Packet Data Convergence Protocol (PDCP) layer, or the like. 
     The controllers/processors  340  and  380  may direct the operation at the base station  110  and the UE  120 , respectively. The processor  340  and/or other processors and modules at the base station  110  may perform or direct the execution of the functional blocks illustrated in  FIGS. 4 and 5 , and/or other processes for the techniques described herein. The processor  380  and/or other processors and modules at the UE  120  may also perform or direct the execution of the functional blocks illustrated in  FIGS. 4 and 6 , and/or other processes for the techniques described herein. In related aspects, the processor(s)  340  and/or  380  may generate a carrier aggregation configuration. A scheduler  344  may schedule UEs for data transmission on the downlink and/or uplink, and may also schedule transmissions on the cellular or WLAN carriers. The memories  342  and  382  may store data and program codes for the base station  110  and the UE  120 , respectively, including data/code for executing aggregation of the cellular or WLAN carriers. For example, the controller/processor  380  may implement a protocol stack that supports a traffic mapping function with respect to heterogeneous carrier aggregation.  FIG. 4  provides an example of such a protocol stack in which the MAC layer protocol entity multiplexes the cellular/WLAN traffic and includes a scheduling/priority handling block or entity that handles MAC layer mapping operations. In another example, the controller/processor  380  may implement a protocol stack in which an RLC layer entity handles mapping operations and scheduling/priority operations. While  FIG. 4  illustrates aspects of uplink operation, the same principles hold for the downlink operation. 
     More specifically, at the UE  120 , the receive processor  358  and/or the MIMO detector  356  may be configured to receiving a configuration for aggregating a plurality of component carriers comprising at least one cellular carrier and a WLAN carrier, wherein the aggregation is performed at a given protocol layer of the UE  120  below an IP layer. The controller or processor  380 , in conjunction with the memory  382 , may be configured to determine, at the given protocol layer, a mapping of uplink traffic in relation to the at least one cellular carrier and the WLAN carrier. The transmit processor  364  and/or the TX MIMO processor  366  may be configured to sending an uplink transmission based at least in part on the mapping. 
     The mapping may be based on a traffic flow identifier, which may be: a logical channel identifier (LCID) if the given protocol layer is a media access control (MAC) protocol layer; or a bearer identifier if the given protocol layer is above the MAC protocol layer. In one example, the processor  380  may be configured to: determine the LCID associated with data for the uplink transmission; determine, based on the mapping, one or more traffic restrictions associated with the LCID; and select a carrier from the plurality of component carriers in accordance with the one or more traffic restrictions. In another example, the processor  380  may be configured to: determine the bearer identifier associated with data for the uplink transmission; determine the bearer identifier associated with data for the uplink transmission; and select a carrier from the plurality of component carriers in accordance with the one or more traffic restrictions. The transmit processor  364  and/or the TX MIMO processor  366  may be configured to send the data in the uplink transmission on the selected carrier. 
     The processor  380  may be configured to determine an association of traffic types with respective ones of the plurality of component carriers based on downlink traffic received by the UE  120 , wherein the mapping of uplink traffic mirrors the association of traffic types determined based on the downlink traffic. 
     A first traffic type may be associated with the at least one cellular carrier and a second traffic type may be associated with the WLAN carrier, wherein given layer comprises a MAC protocol layer. The processor  380  may be configured to performing carrier selection at the MAC protocol layer based on the association and a type of the uplink traffic. 
     The processor  380 , the receive processor  358 , and/or the transmit processor  364  may be configured to: receive an uplink grant indicating an allocation of uplink resources on a first cellular carrier in the plurality of component carriers; identify data for the uplink transmission on the first cellular carrier based on the mapping; and send the data on the first cellular carrier in accordance with the uplink grant. 
     The processor  380  and/or the transmit processor  364  may be configured to: determine the availability of data for uplink transmission; determine, based on the mapping, a carrier in the plurality of component carriers for sending the data; and send the data in the uplink transmission absent an uplink grant, in response to determining that the data maps to the WLAN carrier. 
     The processor  380  and/or the transmit processor  364  may be configured to: select a given one of the plurality of component carriers at the media access control (MAC) layer; and multiplex the uplink traffic onto each carrier based at least in part on the mapping, wherein the mapping is based at least in part on Quality of Service (QoS) information. The processor  380  and/or the transmit processor  364  may be configured to: form MAC protocol data units (PDUs) based on the mapping; and send the MAC PDUs based on an uplink grant or a MAC PDU size. 
     The mapping may indicate that the uplink traffic may use either the at least one cellular carrier or the WLAN carrier, and the aggregation may be performed at the MAC layer. The processor  380  may be configured to: form PDUs at the RLC layer; and transport the PDUs via the at least one cellular carrier or the WLAN carrier. 
     The processor  380  may be configured to cease applying the mapping in response to deactivation of at least one carrier in the plurality of component carriers. The processor  380  may be configured to: disable a Dynamic Host Configuration Protocol (DHCP) above the IP layer for the WLAN carrier in connection with the configuration for aggregating the plurality of component carriers; determine an IP address for a cellular radio module of the UE  120 ; and assign the IP address to the WLAN radio module of the UE  120 . The processor  380  may be configured to instruct the transmit processor  364  to signal a cellular-WLAN carrier aggregation capability of the UE  120  to at least one network entity (e.g., the eNB  110 ). 
     The receive processor  358  and/or the MIMO detector  356  may be configured to receive a beacon or probe response from a WLAN access point (AP), the beacon or probe response advertising support for cellular-WLAN carrier aggregation by the WLAN AP. The receive processor  358 , MIMO detector  356 , and/or the processor  380  may be configured to: obtain security credentials from a cellular base station; and provide the security credentials to a WLAN AP. 
     The receive processor  358  and/or the MIMO detector  356  may be configured to receive dynamic signaling from a network entity indicating which bearers are sent over which carriers. For example, the signaling may indicate, for each LCID in a plurality of LCIDs, which carrier in the plurality of component carriers to use for corresponding uplink traffic. 
     At the base station  110 , the transmit processor  320 , the TX MIMO processor  330 , and/or the controller/processor  340  may be configured to send a configuration to a mobile device for aggregating a plurality of component carriers comprising at least one cellular carrier and at least one WLAN carrier, wherein the aggregation is performed at a layer of the mobile device below an IP layer. The processor  340  and/or the scheduler  344  may be configured to determine a downlink mapping of downlink uplink traffic in relation to the at least one cellular carrier and the at least one WLAN carrier. The receive processor  338  and/or the MIMO detector  336  may be configured to receive the uplink traffic based at least in part on the downlink mapping. 
     In one example, the processor  340  and/or the scheduler  344  may be configured to: determine the LCID associated with data for the uplink transmission; determine, based on the mapping, one or more traffic restrictions associated with the LCID; and select a carrier from the plurality of component carriers in accordance with the one or more traffic restrictions. In another example, the processor  340  and/or the scheduler  344  may be configured to: determine the bearer identifier associated with data for the uplink transmission; determine, based on the mapping, one or more traffic restrictions associated with the bearer identifier; and select a carrier from the plurality of component carriers in accordance with the one or more traffic restrictions. The receive processor  338  and/or the MIMO detector  336  may be configured to receive the data in the uplink transmission on the selected carrier. 
     The transmit processor  320  may be configured to send an uplink grant indicating an allocation of uplink resources on a first cellular carrier in the plurality of component carriers. The receive processor  338  may be configured to receive data on the first cellular carrier in accordance with the uplink grant. 
     Carrier aggregation may performed at the MAC layer, and the receive processor  338  may be configured to receive MAC PDUs based on an uplink grant or a MAC PDU size. The transmit processor  320  may be configured to, at the RLC layer, transport PDUs via the at least one cellular carrier or the WLAN carrier. 
     In one example, the transmit processor  320  may be configured to send dynamic signaling indicating which bearers are sent over which carriers, wherein the signaling indicates a packet size threshold, a default carrier, and which carrier to use in response to the packet size exceeding the threshold. In another example, the mapping may include a static policy, wherein the static policy includes an access network discovery and selection function (ANDSF) or the like. 
     With respect to dual-capability devices (e.g., the mobile device  155  and the base station  150  of  FIG. 1 ), such devices include at least two radios, in addition to the elements shown for the base station  110  and UE  120  of  FIG. 3 . In the example of  FIG. 1 , the mobile device  155  and the base station  150  each include a WWAN radio (e.g., the WWAN radio of  FIG. 3 , or the like), but each additionally include a WLAN radio, thereby allowing for concurrent operation of a WLAN carrier with a non-WLAN carrier. With LTE Rel-10, the aggregation of homogenous LTE carriers is performed by the MAC. However, the LTE Rel-10 MAC layer does not support QoS at a component carrier level, does not recognize different capabilities associated with aggregated carriers, and does not enable a sub-IP layer mapping of traffic. 
     In accordance with aspects of the present disclosure, there are provided a dual-capability base station (e.g., the eNB  110 ) and a dual-capability mobile device (e.g., the UE  120 ) which are configured for aggregation of a WLAN carrier with a non-WLAN carrier, below the IP layer (e.g., at the MAC layer). In one embodiment, the WWAN base station and the WLAN AP  150  may be co-located. With reference to the embodiment of  FIG. 5 , there is shown a network entity or base station  500  that includes a cellular/WWAN base station co-located with a WLAN AP. The network entity  500 , for example, may include aspects of the dual-capability base station  150  ( FIG. 1 ) and/or base stations  110  ( FIG. 1 ,  FIG. 3 ) with their respective functionality. 
     In the present example, the network entity  500  includes a cellular/WWAN radio module  510  and a WLAN radio module  520 . The network entity  500  may optionally include a controller module  530  in operative communication with the cellular/WWAN radio module  510  and the WLAN radio module  520  to coordinate the activity of the modules  510 ,  520  and/or components thereof. 
     In related aspects, the cellular/WWAN radio module  510  may include a transmitter (TX) component  512 , a receiver (RX) component  514 , a processor component  516 , and a HARQ component  518 , wherein each of the components are in operative communication with each other. The cellular/WWAN radio module  510  may include one or more of the components of base station  110  shown on the left hand side of  FIG. 3 . The WLAN radio module  520  may include a TX component  522 , a RX component  524 , and a processor component  526 , wherein each of the components are in operative communication with each other. In further related aspects, one or more of the components  512 - 518  and/or  522 - 526  may be configured to perform the carrier aggregation operations described herein, such as, for example, the exemplary methodologies shown in  FIGS. 7A-E ,  8 - 9 , and  13 A-D, and described in further detail below. 
     With reference to  FIG. 6 , there is shown an exemplary dual-capability mobile device  600  that includes a cellular/WWAN radio module  610  and a WLAN radio module  620 , and is basically analogous to the dual-capability base station  500  of  FIG. 5 . The cellular/WWAN radio module  610  may include one or more of the components of mobile device  120  shown on the right hand side of  FIG. 3  and/or the functionality of mobile device  155 . For the sake of conciseness, the rest of the details regarding the mobile device  600  are not further elaborated on; however, it is to be understood that the remaining features and aspects of the mobile device  600  are substantially similar to those described above with respect to the base station  500  of  FIG. 5 . In related aspects, one or more of the components  612 - 618  and/or  622 - 626  may be configured to perform the carrier aggregation operations described herein, such as, for example, the exemplary methodologies shown in  FIGS. 8, 10A -B,  11 A-E, and  12 A-B, and described in further detail below. 
     In accordance with aspects of the subject of this disclosure, there is provided a wireless network (e.g., an LTE or UMTS network) configured to include and control one or more WLANs. The wireless network may include one or more dual-capability network entities with features for cellular-WLAN carrier aggregation, such as, for example, WWAN-WLAN carrier aggregation. For illustrative purposes, described herein are techniques to perform aggregation of LTE and WLAN carriers below the IP layer, and fully integrated with the E-UTRA. 
     Configuration of a WLAN secondary cell (Scell): With reference once again to  FIG. 4-6 , in one aspect of WLAN carrier aggregation, the WLAN carrier is under control of the E-UTRA network (E-UTRAN) and may be configured by signaling from the LTE/UMTS carrier. E-UTRAN, for example, may use Radio Resource Control (RRC) to control the association and authentication of the WLAN station to a given AP, also referred to as adding or removing a WLAN Scell. For example, the base station&#39;s RRC (re)configuration message may specify one or more parameters used for communication on the WLAN carrier: (a) WLAN channel number that uniquely identifies the carrier; and/or (b) the service set identification (SSID) of the target WLAN, such as service provided by dual-capability base station  500 . As described herein, base station  500  may control configuration as well as activation and deactivation of the WLAN carrier. In some aspects, the UMTS/LTE carrier may serve a primary component carrier (PCC) over which configuration and control information is received for the secondary WLAN carrier. 
     In related aspects, with reference to  FIGS. 5-6 , component(s) of the base station&#39;s cellular radio module  510  (e.g., the processor component  516 ) may generate the RRC (re)configuration message or the like, which may be sent by the TX component  512  to the RX component  614  in the mobile device&#39;s cellular radio module  610 . 
     Authentication to a WLAN Scell: 3GPP, IEEE, and other standard bodies have standardized methods that allow a mobile device to seamlessly authenticate onto a WLAN network under the control of the operator. While such methods may be implemented, they may involve having the mobile device contact servers, such as, for example, authentication, authorization, and accounting (AAA) servers laying outside of the local area network. This adds latency to the WLAN authentication, as well as traffic on the E-UTRAN. Advantageously, base station  500  avoids this latency and added complexity by collocating the WWAN eNB with the WLAN AP (e.g., when the cellular/WWAN radio module is co-located with the WLAN radio module). 
     As one example of direct access and authentication, base station  500  may provide a temporal key to the UE in order to let it authenticate with the WLAN. Such a key can be included in the RRC (re)configuration message carried by the UMTS/LTE carrier. When the eNB and AP are co-located, they may be configured with or exchange a set of the keys, and may burn a new key for each new authentication of a WLAN station (e.g., the WLAN radio module  620  of the mobile device  600 ) on the AP. The key may be transported securely due to RRC/PDCP operation on the LTE carrier. The WLAN authentication performed by the mobile device  600  towards the base station  500  (AP) may use that shared key. 
     In related aspects, with reference to  FIGS. 5-6 , the base station&#39;s processor  516  in its cellular radio module  510  may generate and provide the key that is included in the RRC (re)configuration message sent by the TX component  512  to the RX component  614  in the mobile device&#39;s cellular radio module  610 . In further related aspects, the base station&#39;s cellular radio module  510  may provide the key to the co-located WLAN radio module  520 . 
     Controlling the WLAN carrier—Downlink: The eNB/AP (e.g., the base station  500  with radio modules  510 ,  520 ) may decide when to schedule on the LTE carrier or the WLAN carrier. The eNB/AP (e.g., the radio modules  510 ,  520 ) may inform the WLAN station (e.g., WLAN radio module  620 ) when it does not plan to use the WLAN carrier for some future time via the activation/deactivation command. In one aspect, activation or deactivation commands for the WLAN CC may be sent on the LTE/UMTS CC. The WLAN station may use the activation/deactivation information to enable a suitable sleep mode on the WLAN interface. The eNB/AP may use flow classification or packet inspection techniques to select whether a packet should be transmitted over LTE or WLAN CC. It is noted that such activation or deactivation commands affect the configured carriers, and therefore affects mapping, carrier selection, QoS, etc. 
     Controlling the WLAN carrier—Uplink: While the WLAN CC is activated, it may continue to pull data for transmission from the transmit buffers. In some situations (e.g., voice over LTE) the eNB/AP may desire to steer some transmissions over LTE and others over WLAN. However, the LTE MAC may be agnostic to Quality of Service (QoS) and may have been designed with the assumption that all carriers provide similar quality of service. To alleviate this, a new parameter may be associated with each logical channel ID (LCID) in order to indicate if that LCID can/cannot be transported over a WLAN carrier. As the MAC/HARQ entity builds a MAC PDU and obeys the uplink logical channel prioritization and multiplexing rules it also ensures the LCID selected is allowed on the target carrier. 
     In related aspects, with reference to  FIGS. 5-6 , the processors  516 ,  616  of the cellular radio modules  510 ,  610  may control and handle decisions regarding whether transmissions will be over LTE or WLAN. The HARQ components  518  and/or  618  may (alone or in conjunction with the processors  516  and/or  616 ) build the MAC PDU and handle compliance with the uplink logical channel prioritization and multiplexing rules. In further related aspects, additional details and approaches to steering certain types of uplink traffic toward WWAN or WLAN carrier types are provided below in the context of mapping/associating certain types of traffic to/with certain carriers. 
     Discovery and association with the WLAN: As specified in the 802.11 standard, the discovery and association procedure is generally initiated by the WLAN station (e.g., the WLAN radio module  620  of the mobile device  600 ). The WLAN station may however need to know if this particular WLAN is a WLAN which is managed by the E-UTRAN. For example, the WLAN station should not trigger the upper layers to perform Dynamic Host Configuration Protocol (DHCP) on a carrier managed by the E-UTRAN. It is noted that a dual-capability mobile device (e.g., the mobile device  600 ) may announce (e.g., via TX components  612  and/or  622 ) that it is capable of cellular-WLAN carrier aggregation, and may additionally send information regarding the frequencies it can support. In another example, the secondary WLAN carrier uses the same IP address as cellular carriers, which follows from carrier configuration. A practical consequence is that the WLAN avoids initiating DHCP to get is own IP address. 
     In one approach, the WLAN AP (e.g., the WLAN radio module  520  of the base station  500 ) may indicate this capability in the Beacon, Probe Response or via the Access Network Query Protocol or the Generic Advertisement Service. In another approach, the eNB (e.g., the cellular radio module  510  of the base station  500 ) may broadcast information about the availability of a WLAN carrier in a specified system information block (SIB). This has the advantage that the mobile device could use this information to connect to WLAN even if it had switched off the WLAN for power consumption purposes. In this case the eNB (e.g., the TX component  512  of the cellular radio module  510 ) may broadcast some details about the WLAN (e.g., basic SSID (BSSID), SSID, frequency, channel, or the like). In yet another approach, the RRC reconfiguration message mentioned above may be used for this purpose. 
     It is noted that the dual scenario is also important—i.e., making sure that STAs (e.g., the WLAN radio module  620  in the mobile device  600 ) which do not support this capability either not connect to the WLAN or get a normal WLAN behavior. For this purpose the WLAN station which supports the WLAN carrier aggregation feature could provide this indication in the Association Request message. 
     Mapping of traffic to specific carrier: With the aggregation of homogeneous carriers in LTE, it may be assumed that the carriers have the same capabilities and provide the same QoS; however, this is not the case when heterogeneous carriers, such as when LTE and WLAN are aggregated together. Some traffic, e.g., voice over IP (VoIP), may be preferred over LTE rather than WLAN. The eNB/AP (e.g., the cellular and WLAN radio modules  510 ,  520  of the base station  500 ) is in control of which carrier to use for downlink packets. However for the uplink the multiplexing and carrier selection is done at the UE&#39;s MAC which does not have any QoS knowledge. To provide the MAC with QoS knowledge, the following approaches may be used. 
     A static mapping between logical channels (i.e., bearers) and carrier could be defined by the standard or configured by the operator. For example, the eNB/AP (e.g., the cellular and WLAN radio modules  510 ,  520  of the base station  500 ) may be configured to refrain from using the WLAN carrier when QoS class identifier (QCI)=1 is used. In related aspects, the static mapping may include a static policy, which in turn may include an access network discovery and selection function (ANDSF) or the like. 
     The network entity knowing about a traffic requirement (e.g., the Packet Data Network Gateway (PDN GW)) may indicate dynamically via explicit signaling (e.g., a flag in a GPRS tunneling protocol (GTP) message) to the eNB (e.g., the cellular radio module  510 ) if a given bearer/logical channel can be sent over a given carrier or not. 
     Packets could be marked by a network entity which has knowledge about traffic requirements. This may be the PDN GW (or TDF) but could be also the eNB above or at PDCP layer (since below that layer packets are ciphered). The marking and the respective meaning need however to be communicated in some form to the MAC layer. As explained above, the LTE MAC may be agnostic to QoS and may have been designed with the assumption that all carriers provide similar quality of service. To alleviate this, a new parameter or marking may be associated with each LCID, resulting in an extended LCID, to indicate whether that LCID can be transported over a WLAN carrier. 
     For uplink, current LTE carrier aggregation assumes that the grants provided to the UE (e.g., cellular radio module  610  or component(s) thereof) are specific for a given carrier. However the grants are agnostic of the actual type of data traffic sent to the carrier. If there is a need to send some traffic to specific carriers an approach may be implemented wherein the UE may have policies about which traffic can be sent over which carrier. Therefore when the UE receives a grant from the network for a specific carrier, the UE is responsible to send the correct traffic to the given carrier based on policies. In a related fifth approach, the MAC layer may indicate that the grants are traffic-specific. 
     The UE (e.g., cellular radio module  610  or component(s) thereof) may mirror the traffic to carrier mapping performed by the network, i.e., if the network sent a specific traffic flow over a given carrier, the respective uplink traffic will be sent to the same carrier. With this approach, when the UE initiates the connection it may initially use the wrong carrier, but may correct itself by determining an association of traffic types with WWAN or WLAN carrier types for downlink traffic, and mirroring the association when sending further uplink traffic. 
     In view of exemplary systems shown and described herein, methodologies that may be implemented in accordance with the disclosed subject matter, will be better appreciated with reference to various flow charts. While, for purposes of simplicity of explanation, methodologies are shown and described as a series of acts/blocks, it is to be understood and appreciated that the claimed subject matter is not limited by the number or order of blocks, as some blocks may occur in different orders and/or at substantially the same time with other blocks from what is depicted and described herein. Moreover, not all illustrated blocks may be required to implement methodologies described herein. It is to be appreciated that functionality associated with blocks may be implemented by software, hardware, a combination thereof or any other suitable means (e.g., device, system, process, or component). Additionally, it should be further appreciated that methodologies disclosed throughout this specification are capable of being stored on an article of manufacture to facilitate transporting and transferring such methodologies to various devices. Those skilled in the art will understand and appreciate that a methodology could alternatively be represented as a series of interrelated states or events, such as in a state diagram. 
     With reference to  FIG. 7A , illustrated is a methodology  700  that may be performed at a network entity, such as, for example, the cellular radio module  510  of the base station  500  in  FIG. 5 . The method  700  may involve, at  710 , at a given layer located below an IP layer, receiving information about a cellular network carrier and a WLAN carrier. Block  710  may be performed by the RX component  514  of the cellular radio module  510  and/or the RX component  524  of the WLAN radio module  520 . The method  700  may involve, at  720 , performing carrier aggregation of the cellular network carrier and the WLAN carrier based on the received information. Block  720  may be performed by the processor  516  and the HARQ component  518  of the cellular radio module  510 . 
     With reference to  FIGS. 7B-E  and  8 , there are shown further operations or aspects of method  700  that are optional are not required to perform the method  700 . If the method  700  includes at least one block of  FIGS. 7B-E  and  8 , then the method  700  may terminate after the at least one block, without necessarily having to include any subsequent downstream block(s) that may be illustrated. With reference to  FIG. 7B , the given layer may be a MAC, an RLC or a PDCP layer (block  730 ). The MAC layer may include a HARQ entity layer (block  732 ). The method  700  may further involve sending an activation/deactivation status of the WLAN carrier to a WLAN station (block  736 ). The method  700  may involve selecting data to include in a PDU based on at least one of (a) a target carrier for transporting the PDU and (b) allowed carriers for a logical channel (block  740 ). 
     With reference to  FIG. 7C , the cellular network may be an LTE network, and the cellular network carrier may be an LTE carrier (block  742 ). The cellular network may be a UMTS network, and the cellular network carrier may be a UMTS carrier (block  744 ). The received information may include an RRC configuration message that includes at least one of: a WLAN channel number for identifying the WLAN carrier; an SSID; and credentials for authentication on the SSID (block  746 ). The method  700  may further involve authenticating a WLAN station based on the credentials provided in the RRC configuration message (block  748 ). The method  700  may further involve providing in the RRC configuration message keying material for WLAN link layer encryption (block  750 ). The method  700  may further involve providing in the RRC configuration message information to succeed WLAN admission control mechanisms (block  750 ). The RRC configuration message may include routing instructions indicating which carrier a data flow should be transmitted on (block  752 ). The network entity may be or include an eNB or a Node B. 
     With reference to  FIG. 7D , the method  700  may further involve: receiving QoS information (block  760 ); and mapping data traffic to a given carrier selected from among the cellular network carrier and the WLAN carrier based at least in part on the received QoS information (block  762 ). Block  762  may include a static mapping between logical channels, and wherein the given carrier is configured by a network operator (block  764 ). The given carrier may be the WLAN carrier, in response to the QCI being a defined value (e.g., QCI=1) (block  766 ). The method  700  may further involve, in response to receiving traffic requirement information, notifying at least one cellular base station whether a given bearer or logical channel can be sent over the given carrier (block  768 ). The traffic requirement information may include a PDN GW (block  770 ); and block  768  may include sending a GTP message to the at least one cellular base station, wherein GPRS means General Packet Radio Service (block  772 ). 
     With reference to  FIG. 7E , block  762  may include considering a grant for a specific carrier from the network to a given mobile entity (block  774 ). Block  720  may include aggregating PDUs at the given layer (block  776 ). The given layer may be a MAC layer, wherein the method  700  further involves performing a HARQ process with respect to the cellular network carrier and disabling HARQ operation with respect to the WLAN carrier at the MAC layer (block  778 ). Block  782  may include setting a new data indicator for PDUs corresponding to the WLAN carrier (block  780 ). The given layer may be a MAC layer, 
     With reference to  FIG. 8 , the cellular network may be an LTE network or a UMTS network, and the method  700  may involve configuring the WLAN carrier as a Scell of a mobile station (block  786 ). Block  786  may include sending an RRC reconfiguration message having at least one of a WLAN channel number, an SSID, or authentication credentials for the WLAN carrier (block  788 ). The RRC reconfiguration message may be sent after the mobile station associates with the network entity for WLAN communication (block  790 ). The method  700  may further involve transmitting activation/deactivation commands for the WLAN carrier on the cellular carrier to the mobile station (block  792 ). The method  700  may further involve transmitting a WLAN beacon indicating the network entity supports communication on both the cellular carrier and the WLAN carrier (block  794 ). The method  700  may further involve transmitting information about the WLAN carrier in system broadcast information of the cellular network (block  796 ). 
     With reference to  FIG. 9 , illustrated is a methodology  900  that may be performed by a WLAN AP or a WLAN AP module of a network entity (e.g., the WLAN radio module  520  of the base station  500  in  FIG. 5 ). The method  900  may involve, at  910 , receiving information regarding at least one of a MTU, an RTS threshold, uplink radio link conditions, and whether frame aggregation is configured. Block  910  may be performed by the RX component  524  of the WLAN radio module  520 . The method  900  may involve, at  920 , selecting a payload size to transmit based at least in part on the received information. Block  920  may be performed by the processor  526  of the WLAN radio module  520 . 
     With reference to  FIG. 10A , illustrated is a methodology  1000  that may be performed by a mobile entity, such as, for example, the cellular radio module  610  of the mobile device  600  in  FIG. 6 . The method  1000  may involve, at  1010 , detecting a WLAN AP. Block  1010  may be performed by the RX component  624  of the WLAN radio module  620 . The method  1000  may involve, at  1020 , transmitting, to at least one of the WLAN AP and a network entity (e.g., eNB), information regarding whether the mobile entity is capable of cellular-WLAN carrier aggregation. Block  1020  may be performed by the TX component  622  of the WLAN radio module  620  and the TX component  612  of the cellular radio module  610 . 
     With reference to  FIG. 10B , there are shown further operations or aspects of method  1000  that are optional are not required to perform the method  1000 . If the method  1000  includes at least one block of  FIG. 10B , then the method  1000  may terminate after the at least one block, without necessarily having to include any subsequent downstream block(s) that may be illustrated. For example, the method  1000  may further involve receiving, from the WLAN station, a cellular-WLAN carrier aggregation capability indicator in a beacon or probe response (block  1030 ). 
     The method  1000  may further involve providing an LTE identifier and a WLAN identifier to at least one of an eNB and the WLAN station (block  1032 ). The LTE identifier may include a radio network temporary identifier (RNTI) or the like, and the WLAN identifier may include a MAC address or the like (block  1034 ). The method  1000  may involve: receiving, from at least one network entity (e.g. an eNB), availability information about a WLAN carrier in a specified SIB (block  1036 ); and connecting to a WLAN based on the received availability information (block  1038 ). The method  1000  may further involve mirroring a traffic-carrier assignment done by the at least one network entity (block  1040 ). Block  1040  may include, in response to the at least one network entity sending a specific traffic over a given carrier, sending respective uplink traffic on the given carrier (block  1042 ). 
     With reference to  FIG. 11A , illustrated is an example methodology  1100 , performed by the mobile device  600 , involving determining a mapping of uplink traffic in relation to heterogeneous component carriers. The method  1100  may involve, at  1110 , receiving a configuration for aggregating a plurality of component carriers comprising at least one cellular carrier and a WLAN carrier, wherein the aggregation is performed at a given protocol layer of the mobile device below an IP layer. Block  1110  may be performed by the RX component  614  of the cellular radio module  610 . The method  1100  may involve, at  1120 , determining, at the given protocol layer, a mapping of uplink traffic in relation to the at least one cellular carrier and the WLAN carrier. Block  1120  may be performed by the processor  616  of the cellular radio module  610  and/or the controller  630 . The method  1100  may involve, at  1130 , sending an uplink transmission based at least in part on the mapping. If the mapping indicates that the uplink traffic is be sent on the at least one WLAN carrier, the block  1030  may be performed by the TX component  622  of the WLAN radio module  620 . In addition, the HARQ component  618  of the cellular radio module  610  may disable the HARQ operation, thereby facilitating WWAN-WLAN aggregation in view of the differences in how the WWAN and WLAN handle data traffic. If the mapping indicates that the uplink traffic is be sent on the at least one WWAN carrier, the block  1030  may be performed by the TX component  612  of the cellular radio module  610 . In addition, the HARQ component  618  of the cellular radio module  610  may enable or verify proper functioning of the HARQ operation. 
     With reference to  FIGS. 11B-E  and  12 A-B, there are shown further operations or aspects of method  1100  that are optional are not required to perform the method  1100 . If the method  1100  includes at least one block of  FIGS. 11B-E  and  12 A-B, then the method  1100  may terminate after the at least one block, without necessarily having to include any subsequent downstream block(s) that may be illustrated. For example, the mapping may be based on a traffic flow identifier (block  1140 ). The traffic flow identifier may include a LCID, in response to the given protocol layer comprising a MAC protocol layer, or a bearer identifier, in response to the given protocol layer being above the MAC protocol layer (block  1142 ). 
     The method  1100  may further involve: determining the LCID associated with data for the uplink transmission (block  1144 ); determining, based on the mapping, one or more traffic restrictions associated with the LCID (block  1146 ); selecting a carrier from the plurality of component carriers in accordance with the one or more traffic restrictions (block  1148 ); and sending the data in the uplink transmission on the selected carrier (block  1150 ). 
     With reference to  FIG. 11C , the method  1100  may involve: determining the bearer identifier associated with data for the uplink transmission (block  1152 ); determining, based on the mapping, one or more traffic restrictions associated with the bearer identifier (block  1154 ); selecting a carrier from the plurality of component carriers in accordance with the one or more traffic restrictions (block  1156 ); and sending the data in the uplink transmission on the selected carrier (block  1158 ). 
     The method  1100  may involve: determining an association of traffic types with respective ones of the plurality of component carriers based on downlink traffic received by the mobile device, wherein the mapping of uplink traffic mirrors the association of traffic types determined based on the downlink traffic (block  1160 ). Block  1160  may be performed by the processor  616  of the cellular radio module  610 , the processor  626  of the WLAN radio module  620 , and/or the controller  630 . A first traffic type may be associated with the at least one cellular carrier and a second traffic type is associated with the WLAN carrier (block  1162 ). The given layer may include a MAC protocol layer, wherein determining the mapping (block  1120 ) may involve performing carrier selection at the MAC protocol layer based on the association and a type of the uplink traffic (block  1164 ). 
     With reference to  FIG. 11D , the method  1100  may involve: receiving an uplink grant indicating an allocation of uplink resources on a first cellular carrier in the plurality of component carriers (block  1166 ); identifying data for the uplink transmission on the first cellular carrier based on the mapping (block  1168 ); and sending the data on the first cellular carrier in accordance with the uplink grant (block  1170 ). 
     The method  1100  may involve: determining the availability of data for uplink transmission (block  1172 ); determining, based on the mapping, a carrier in the plurality of component carriers for sending the data (block  1174 ); and sending the data in the uplink transmission absent an uplink grant, in response to determining that the data maps to the WLAN carrier (block  1176 ). The mapping may exclude predetermined types of uplink traffic from transmission on the WLAN carrier (block  1178 ). 
     With reference to  FIG. 11E , sending the uplink transmission (block  1130 ) may involve, at the MAC layer, selecting a given one of the plurality of component carriers and multiplexing the uplink traffic onto each carrier based at least in part on the mapping (block  1180 ). The mapping may be based at least in part on QoS information, wherein at least one of the selecting and the multiplexing is based at least in part on the QoS information (block  1182 ). 
     The aggregation may be performed at the MAC layer, and the method  1100  may involve: forming MAC PDUs based on the mapping (block  1184 ), and sending the MAC PDUs based on an uplink grant or a MAC PDU size (block  1186 ). 
     The mapping may indicate that the uplink traffic may use either the at least one cellular carrier or the WLAN carrier (block  1188 ). The aggregation may be performed at the MAC layer, and the method  1100  may involve: forming PDUs at the RLC layer (block  1190 ); and transporting the PDUs via the at least one cellular carrier or the WLAN carrier (block  1192 ). The method  1100  may further involve ceasing to apply the mapping, in response to a given one of the component carriers being deactivated (block  1194 ). 
     With reference to  FIG. 12A , the method  1100  may further involve: preventing DHCP above the IP layer for a given carrier managed by a cellular network (block  1198 ); determining an IP address for a cellular radio module of the mobile device (block  1199 ); and assigning the IP address to the WLAN radio module of the mobile device (block  1200 ). 
     The method  1100  may further involve announcing cellular-WLAN carrier aggregation capability of the mobile device to at least one network entity (block  1202 ). The method  1100  may further involve receiving a beacon or probe response from a WLAN AP, the beacon or probe response advertising support for cellular-WLAN carrier aggregation by the WLAN AP (block  1204 ). The method  1100  may further involve obtaining security credentials from a cellular base station, and providing the security credentials to a WLAN AP (block  1206 ). 
     Determining the mapping (block  1120 ) may involve receiving dynamic signaling from a network entity indicating which bearers are sent over which carriers (block  1208 ). The signaling may indicate, for each LCID in a plurality of LCIDs, which carrier in the plurality of component carriers to use for corresponding uplink traffic, wherein the indication may be per bearer and per direction, wherein a given LCID maps to the WLAN carrier for downlink traffic and to the at least one cellular carrier for the uplink traffic (block  1210 ). 
     With reference to  FIG. 12B , the signaling may indicate a packet size threshold, a default carrier, and which carrier to use in response to the packet size exceeding the threshold (block  1212 ). The signaling may include, for each LCID, a parameter indicating whether data traffic may be transmitted on the WLAN carrier in addition to the at least one cellular carrier (block  1214 ). 
     A QoS associated with the at least one cellular carrier may differ from a QoS associated with the WLAN carrier (block  1216 ). The mapping may include a static policy, wherein the static policy comprises an ANDSF or the like (block  1218 ). The mapping may be based on a QoS indicator for one or more of the plurality of component carriers (block  1220 ). 
     With reference to  FIG. 13A , illustrated is an example methodology  1300 , performed by a network entity (e.g., the base station  500 ), involving determining a mapping of downlink and/or uplink traffic in relation to heterogeneous component carriers. The method  1300  may involve, at  1310 , sending a configuration to a mobile device for aggregating a plurality of component carriers comprising at least one cellular carrier and at least one WLAN carrier, wherein the aggregation is performed at a layer of the mobile device below an IP layer. Block  1310  may be performed by the TX component  512  of the cellular radio module  510 . The method  1300  may involve, at  1320 , determining a mapping of uplink traffic in relation to the at least one cellular carrier and the at least one WLAN carrier. Block  1320  may be performed by the processor  516  of the cellular radio module  510  and/or the controller  530 . The method  1300  may involve, at  1330 , receiving the uplink traffic based at least in part on the mapping. If the mapping indicates that the uplink traffic is be sent on the at least one WLAN carrier, then the block  1330  may be performed by the RX component  524  of the WLAN radio module  520 . In addition, the HARQ component  518  of the cellular radio module  510  may disable the HARQ operation, thereby facilitating WWAN-WLAN aggregation in view of the differences in how the WWAN and WLAN handle data traffic. If the mapping indicates that the uplink traffic is be sent on the cellular carrier, then the block  1330  may be performed by the RX component  514  of the cellular radio module  510 . In addition, the HARQ component  518  of the cellular radio module  510  may enable or verify proper functioning of the HARQ operation. 
     With reference to  FIGS. 13B-D , there are shown further operations or aspects of method  1300  that are optional are not required to perform the method  1300 . If the method  1300  includes at least one block of  FIGS. 13B-D , then the method  1300  may terminate after the at least one block, without necessarily having to include any subsequent downstream block(s) that may be illustrated. For example, the mapping may be based on a traffic flow identifier (block  1340 ). The traffic flow identifier may be a LCID, in response to the given protocol layer comprising a MAC protocol layer (block  1342 ). The traffic flow identifier may be a bearer identifier, in response to the given protocol layer being above the MAC protocol layer (block  1344 ). 
     The method  1300  may involve: determining the LCID associated with data for the uplink transmission (block  1346 ); determining, based on the mapping, one or more traffic restrictions associated with the LCID (block  1348 ); selecting a carrier from the plurality of component carriers in accordance with the one or more traffic restrictions (block  1350 ); and receiving the data in the uplink transmission on the selected carrier (block  1352 ). Blocks  1346 - 1350  may be performed by the processor  516  of the cellular radio module  510 , the processor  526  of the WLAN radio module  520 , and/or the controller  530 . Block  1352  may be performed by the RX component  514  of the cellular radio module  510 , and/or the RX component  524  of the WLAN radio module  520 . 
     With reference to  FIG. 13C , the method  1300  may involve: determining the bearer identifier associated with data for the uplink transmission (block  1354 ); determining, based on the mapping, one or more traffic restrictions associated with the bearer identifier (block  1356 ); selecting a carrier from the plurality of component carriers in accordance with the one or more traffic restrictions (block  1358 ); and receiving the data in the uplink transmission on the selected carrier (block  1360 ). Blocks  1354 - 1358  may be performed by the processor  516  of the cellular radio module  510 , the processor  526  of the WLAN radio module  520 , and/or the controller  530 . Block  1360  may be performed by the RX component  514  of the cellular radio module  510 , and/or the RX component  524  of the WLAN radio module  520 . 
     The method  1300  may involve: sending an uplink grant indicating an allocation of uplink resources on a first cellular carrier in the plurality of component carriers (block  1362 ); and receiving data on the first cellular carrier in accordance with the uplink grant (block  1364 ). The aggregation may be performed at the MAC layer, and the method  1300  may involve receiving MAC PDUs based on an uplink grant or a MAC PDU size (block  1366 ). 
     With reference to  FIG. 13D , the mapping may indicate that the uplink traffic may use either the at least one cellular carrier or the WLAN carrier (block  1368 ). The aggregation is performed at the MAC layer, the method  1300  may involve, at RLC layer, transporting PDUs via the at least one cellular carrier or the WLAN carrier (block  1370 ). 
     The method  1300  may involve sending dynamic signaling indicating which bearers are sent over which carriers, wherein the signaling indicates a packet size threshold, a default carrier, and which carrier to use in response to the packet size exceeding the threshold (block  1372 ). The mapping may include a static policy, wherein the static policy comprises an ANDSF or the like (block  1374 ). 
     Those of skill in the art would understand that information and signals may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof. 
     Those of skill would further appreciate that the various illustrative logical blocks, modules, circuits, and algorithm steps described in connection with the disclosure herein may be implemented as electronic hardware, computer software, or combinations of both. To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present disclosure. 
     The various illustrative logical blocks, modules, and circuits described in connection with the disclosure herein may be implemented or performed with a general-purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general-purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration. 
     The steps of a method or algorithm described in connection with the disclosure herein may be embodied directly in hardware, in a software module executed by a processor, or in a combination of the two. A software module may reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor such that the processor can read information from, and write information to, the storage medium. In the alternative, the storage medium may be integral to the processor. The processor and the storage medium may reside in an ASIC. The ASIC may reside in a user terminal. In the alternative, the processor and the storage medium may reside as discrete components in a user terminal. 
     In one or more exemplary designs, the functions described may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Computer-readable media includes both computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A storage media may be any available media that can be accessed by a general purpose or special purpose computer. By way of example, and not limitation, such computer-readable media can include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code means in the form of instructions or data structures and that can be accessed by a general-purpose or special-purpose computer, or a general-purpose or special-purpose processor. Also, any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or non-transitory wireless technologies, then the coaxial cable, fiber optic cable, twisted pair, DSL, or the non-transitory wireless technologies are included in the definition of medium. Disk and disc, as used herein, includes compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk and blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above should also be included within the scope of computer-readable media. 
     The previous description of the disclosure is provided to enable any person skilled in the art to make or use the disclosure. Various modifications to the disclosure will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other variations without departing from the spirit or scope of the disclosure. Thus, the disclosure is not intended to be limited to the examples and designs described herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.