WO2013063780A1

WO2013063780A1 - Method and apparatus for transmitting machine type communication data via a packet downlink control channel

Info

Publication number: WO2013063780A1
Application number: PCT/CN2011/081720
Authority: WO
Inventors: Jing HAN; Wei Bai; Haiming Wang
Original assignee: Renesas Mobile Corporation
Priority date: 2011-11-03
Filing date: 2011-11-03
Publication date: 2013-05-10

Abstract

A method and apparatus are provided to increase the efficiency with which machine type communication (MTC) data, such as relatively small amounts of MTC data, is transmitted. In the context of a method, MTC downlink data may be included within a payload to be transmitted via a packet downlink control channel (PDCCH). The method may also include causing an indication that the PDCCH will carry MTC downlink data to be provided to an MTC device. The method may also cause the MTC downlink data to be provided to the MTC device via the PDCCH, A corresponding apparatus and computer program product are also provided.

Description

METHOD AND APPARATUS FOR TRANSMITTING

MACHINE TYPE COMMUNICATION DATA VIA A PACKET DOWNLINK CONTROL CHANNEL

TECHNOLOGICAL FIELD

A method and apparatus are provided according to an example embodiment of the present invention to transmit machine type communication (MTC) downlink data and, more particular, to transmit MTC downlink data via a packet downlink control channel (PDCCH).

BACKGROUND

Machine type communication (MTC) provides for machine-to-machine communication, thereby facilitating the automated data exchange between machines. Although systems that employ MTC are already in use, new and additional systems that utilize MTC are being designed and standardized in an effort to develop an internet of things (IOT). As such, the prevalence of MTC is anticipated to increase in the future. In this regard, it is expected that a relatively large number of MTC devices will regularly require network access so as to support the transmission of MTC data. For example, 30,000 or more MTC devices may require access a network within a relatively short period of time, such as ten seconds, in order to transmit MTC data.

[0001] MTC data transmissions may require some signaling overhead, such as PHY signaling overhead, to effect the transmissions. For example, MTC data transmissions that are supported by a packet downlink shared channel (PDSCH) may require resource allocations and control signaling to be conducted via the packet downlink control channel (PDCCH). MTC may routinely require the transmission of relatively small amounts of data from, for example, a network entity, such as a base station or the like, to a mobile terminal. In one instance, a data packet having less than 1024 bytes may be considered to be small. In other instances, a data packet may be divided into smaller pieces, each of which may have only tens of bits and may be considered small. For relatively small MTC data transmissions, the data packet may be relatively small compared to the resources that is utilized for the control signaling, such as for PHY control signaling. By way of example in which the PDSCH carries the MTC data and the PDCCH is utilized for control signaling, the minimum resource within the PDSCH that may be allocated to each MTC device for transmission of the data may be one physical resource block (PR.B). In this example in which the MTC data is to be transmitted via one PRB, the PDCCH overhead may be relatively large and, in one example in which the PDCCH utilizes four control channel elements (CCEs), may consume 36 resource element groups (REGs),

[0002] Not only is the control channel overhead relatively large, but the data packet, such as the PRB, that includes the data to be transmitted may be oversized and, in some instances, substantially oversized relative to the MTC data to be transmitted. In this regard, a PRB may carry up to 712 bits if one layer is configured, up to 1480 bits if two layers are configured and up to 2984 bits if four layers are configured. However, the relatively small MTC data transmissions are frequently much smaller than the PRB such that the PRB must include a number of padding bits and, in some instances, may include more padding bits than the bits that are utilized for the MTC data.

[0003] In order to utilize MTC in an efficient manner, particularly as the transmission of MTC data increases, it would therefore be desirable to improve the efficiency with which MTC data is transmitted and, in particular, the efficiency with which relatively small MTC data transmissions are made, such as relatively small MTC data transmissions from a network entity, such as a base station or the like to an MTC device.

BRIEF SUMMARY

[0004] A method and apparatus are therefore provided according to an example embodiment in order to increase the efficiency with which MTC data, such as relatively small amounts of MTC data, is transmitted. In this regard, the method and apparatus of an example embodiment facilitates the transmission of MTC downlink data from a network entity, such as a base station or the like, to an MTC device by reducing the signaling overhead and/or the number of padding bits relative to the size of the MTC data being transmitted. For example, the method and apparatus of an example embodiment may utilize the packet downlink control channel (PDCCH) to not only provide control signaling, but also to carry the MTC data, such as in a payload that need not be much larger than the MTC data itself. By improving the efficiency with which relatively small amounts of MTC data is transmitted across a network, the overall efficiency of MTC may be improved.

[0005] In one embodiment, a method is provided that comprises including machine type communication (MTC) downlink data within a payload to be transmitted via a packet downlink control channel (PDCCH). The method of this embodiment may also include causing an indication that the PDCCH will carry MTC downlink data to be provided to an MTC device. The method may also cause the MTC downlink data to be provided to the MTC device via the PDCCH. By utilizing the PDCCH to carry the MTC downlink data, the method of an example embodiment of the present invention may more efficiently transmit the MTC downlink data.

[0006] In another embodiment, an apparatus is provided that includes at least one processor and at least one memory including computer program code with the at least one memory and the computer program code being configured, with the at least one processor, to cause the apparatus to at least include machine type communication (MTC) downlink data within a payload to be transmitted via a packet downlink control channel (PDCCH). The at least one memory and the computer program code of one embodiment are also configured to, with the at least one processor, cause the apparatus to cause an indication that the PDCCH will carry MTC downlink data to be provided to an MTC device. The at least one memory and computer program code may also be configured to, with the at least one processor, cause the apparatus to cause the MTC downlink data to be provided to the MTC device via the PDCCH.

[0007] In the further embodiment, a computer program product may be provided that includes at least one non-transitory computer-readable storage medium having computer- readable program instruction stored therein with the computer-readable program instructions including program instructions configured to include machine type communication (MTC) downlink data within a payload to be transmitted via a packet downlink control channel (PDCCH). The computer-readable program instructions may also include program instructions configured to cause an indication that the PDCCH will carry MTC downlink data to be provided to an MTC device. The computer-readable program instructions of this embodiment may also include program instructions configured to cause the MTC downlink data to be provided to the MTC device via the PDCCH.

[0008] In yet another embodiment, an apparatus is provided that includes means for including machine type communication (MTC) downlink data within a payload to be transmitted via a packet downlink control channel (PDCCH). The apparatus of this embodiment may also include means for causing an indication that the PDCCH will carry MTC downlink data to be provided to an MTC device. The apparatus of this embodiment may also include means for causing the MTC downlink data to be provided to the MTC device via the PDCCH. [0009] In one embodiment, a method is provided that includes receiving an indication that a packet downlink control channel (PDCCH) will carry machine type communication (MTC) downlink data. The method of this embodiment may also include receiving the MTC downlink data via the PDCCH and extracting the MTC downlink data from a payload transmitted via the PDCCH.

[0010] In another embodiment, an apparatus is provided that includes at least one processor and at least one memory including computer program code with the at least one memory and the computer program code being configured to, with the at least one processor, cause the apparatus to at least receive an indication that a packet downlink control channel (PDCCH) will carry machine type communication (MTC) downlink data. The at last least one memory and the computer program code of this embodiment may also be configured to, with the at least one processor, cause the apparatus to receive the MTC downlink data from the PDCCH and to extract the MTC downlink data from the payload transmitted via the PDCCH.

[0011] In a further embodiment, a computer program product is provided that includes at least one non-transitory computer-readable storage medium having computer-readable program instructions stored therein with the computer-readable program instructions including program instructions configured to receive an indication that a packet downlink control channel (PDCCH) will carry machine type communication (MTC) downlink data. The computer-readable program instructions of this embodiment may also include program instructions configured to receive the MTC downlink data via the PDCCH and program instructions configured to extract the MTC downlink data from the payload transmitted via the PDCCH.

[0012] In yet another embodiment, an apparatus is provided that includes means for receiving an indication that a packet downlink control channel (PDCCH) will carry machine type communication (MTC) downlink data. The apparatus of this embodiment may also include means for receiving the MTC downlink data via the PDCCH and means for extracting the MTC downlink data from a payload transmitted via the PDCCH.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0013] Having best described example embodiments of the invention in general terms, reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, and wherein: [0014] Figure 1 illustrates a system including an MTC device and a network entity, such as a base station, configured to support MTC data transmissions in accordance with one embodiment of the present invention;

[0015] Figure 2 is a block diagram of an apparatus embodied by a network entity, such as a base station, in accordance with one embodiment of the present invention;

[0016] Figure 3 is a block diagram of an apparatus embodied by an MTC device in accordance with one embodiment of the present invention;

[0017] Figure 4 is a flow chart illustrating the operations performed from the perspective of a network entity in accordance with one embodiment of the present invention;

[0018] Figure 5 illustrates a media access control (MAC) packet data unit (PDU) as configured in accordance with one embodiment of the present invention;

[0019] Figure 6 illustrates downlink data mapping to the packet downlink control channel (PDCCH) in accordance with one embodiment of the present invention;

[0020] Figure 7 illustrates a MAC architecture for supporting the logical channel mapping according to one embodiment of the present invention; and

[0021] Figure 8 is a flow chart illustrating operations performed from the perspective of an MTC device in accordance with one embodiment of the present invention.

DETAILED DESCRIPTION

[0022] The present invention now will be described more fully hereinafter with reference to the accompanying drawings, in which some, but not all embodiments of the inventions are shown. Indeed, these inventions may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements. Like numbers refer to like elements throughout.

[0023] The term 'circuitry' refers to all of the following: (a) hardware-only circuit implementations (such as implementations in only analog and/or digital circuitry) and (b) to combinations of circuits and software (and/or firmware), such as (as applicable): (i) to a combination of processor(s) or (ii) to portions of processor(s)/software (including digital signal processor(s)), software, and memory(ies) that work together to cause an apparatus, such as a mobile phone or server, to perform the various functions) and (c) to circuits, such as microprocessor(s) or a portion of microprocessor(s), that require software or firmware for operation, even if the software or firmware is not present.

[0024] This definition of 'circuitry' applies to all uses of this term in this application, including any claims. As a further example, as used in this application, the term "circuitry" would also cover an implementation of merely a processor (or multiple processors) or portion of a processor and its (or their) accompanying software and/or firmware. The term "circuitry" would also cover, for example and if applicable to the particular claim element, sensor circuitry to provide one or more sensing functions, a subscriber identity module (SIM) memory device or SIM card, a baseband integrated circuit or applications processor integrated circuit for a mobile phone or similar integrated circuit in a server, a cellular network device, or other network device.

[0025J In accordance with an example embodiment of the present invention, a communication system is provided in which a network entity, such as a base station 12, e.g., an access point, a Node B, an evolved Node B (eNB) or the like, may communicate with one or more machine type communication (MTC) devices, such as a mobile terminal 14 or other user equipment (UE), via a network 10, such as a cellular or other wireless network. While the network may be configured in accordance with the Long Term Evolution (LTE) specifications, the network may employ other mobile access mechanisms such as wideband code division multiple access (W-CDMA), CDMA2000, global system for mobile communications (GSM), general packet radio service (GPRS), LTE-Advanced (LTE-A) and/or the like.

[0026] The network 10 may include a collection of various different nodes, network entities, members, devices or functions that may be in communication with each other via corresponding wired and/or wireless interfaces. As such, the illustration of Figure 1 should be understood to be an example of a broad view of certain elements of the system and not an all inclusive or detailed view of the system or the network. The base station 12 could be, for example, part of one or more cellular or mobile networks or public land mobile networks (PLMNs). In turn, other devices such as processing devices (e.g., personal computers, server computers or the like) may be coupled to the terminals via the network.

[0027] The system may include various types of MTC devices. In some example embodiments, the MTC device is a mobile terminal 14 which may, in turn, be any of a number of devices, including without limitation, a mobile telephone, portable digital assistant (PDA), pager, laptop computer, or any of numerous other hand held or portable communication devices, computation devices, content generation devices, content consumption devices, or combinations thereof. In other embodiments, however, the MTC device may be a fixed or stationary device, such as a personal computer, a computer workstation and any other type of machine that is configured to communicate via MTC.

[0028] A network entity, such as the base station 12, may be embodied as or otherwise include an apparatus 20 as generically represented by the block diagram of Figure 2. While one embodiment of the apparatus is illustrated and described below, it should be noted that the components, devices or elements described below may not be mandatory and thus some may be omitted in certain embodiments. Additionally, some embodiments may include further or different components, devices or elements beyond those shown and described herein.

[0029] As shown in Figure 2, the apparatus 20 may include or otherwise be in communication with a processor 22 that is configurable to perform functions in accordance with example embodiments described herein. In some embodiments, the apparatus or the processor 22 may be embodied as a chip or chip set. In other words, the apparatus or the processor 22 may comprise one or more physical packages (e.g., chips) including materials, components and/or wires on a structural assembly (e.g., a baseboard). The structural assembly may provide physical strength, conservation of size, and/or limitation of electrical interaction for component circuitry included thereon. The apparatus or the processor 22 may therefore, in some cases, be configured to implement an embodiment of the present invention on a single chip or as a single "system on a chip." As such, in some cases, a chip or chipset may constitute means for performing one or more operations for providing the functionalities described herein.

(0030] The processor 22 may be embodied in a number of different ways. For example, the processor may be embodied as various processing means such as one or more of a microprocessor or other processing element, a coprocessor, a controller or various other computing or processing devices including integrated circuits such as, for example, an ASIC (application specific integrated circuit), an FPGA (field programmable gate array), or the like. In an example embodiment, the processor may be configured to execute instructions stored in memory 24 or otherwise accessible to the processor. As such, whether configured by hardware or by a combination of hardware and software, the processor may represent an entity capable of performing operations according to embodiments of the present invention while configured accordingly. Thus, for example, when the processor is embodied as an ASIC, FPGA or the like, the processor may be specifically configured hardware for conducting the operations described herein. Alternatively, as another example, when the processor is embodied as an executor of software instructions, the instructions may specifically configure the processor to perform the operations described herein.

[0031] The apparatus 20 of the illustrated embodiment also includes a communication interface 26. The communication interface may include one or more interface mechanisms for enabling communication with other devices, such as the mobile terminal 12 and/or networks, such as network 10. In some cases, the communication interface may be any means such as a device or circuitry embodied in either hardware, or a combination of hardware and software that is configured to receive and/or transmit data from/to a network and/or any other device or module in communication with the processor 22. In this regard, the communication interface may include, for example, an antenna (or multiple antennas) and supporting hardware and/or software for enabling communications with a wireless communication network and/or a communication modem, such as a cellular modem, for enabling communications with the mobile terminals and/or the networks.

[0032] The apparatus 20 of the illustrated embodiment also includes a memory 24. In an example embodiment, the memory 24 may include one or more non-transitory memory devices such as, for example, volatile and/or non-volatile memory that may be either fixed or removable (including without limitation flash EEPROM memory). The memory may be configured to store information, data, applications, instructions or the like for enabling the apparatus 20 to carry out various functions in accordance with example embodiments of the present invention. For example, the memory could be configured to buffer input data for processing by the processor 22. Additionally or alternatively, the memory could be configured to store instructions for execution by the processor. Among the contents of the memory, applications may be stored for execution by the processor in order to carry out the functionality associated with each respective application. In some cases, the memory may be in communication with the processor via a bus for passing information among components of the apparatus.

[0033] In one embodiment, the MTC device, such as a mobile terminal 14, may be embodied as or otherwise include an apparatus 30 as generically represented by the block diagram of Figure 3. In this regard, the apparatus may be configured to provide for communications with the network 10, such as cellular communications with the network via the base station 12. While the apparatus may be employed, for example, by a mobile terminal, it should be noted that the components, devices or elements described below may not be mandatory and thus some may be omitted in certain embodiments. Additionally, some embodiments may include further or different components, devices or elements beyond those shown and described herein. Moreover, the apparatus may be embodied by other types of MTC devices, including fixed or stationary devices.

[0034] As shown in Figure 3, the apparatus 30 may include or otherwise be in communication with a processor 32 that is configurable to perform actions in accordance with example embodiments described herein. In some embodiments, the apparatus or the processor 32 may be embodied as a chip or chip set. In other words, the apparatus or the processor 32 may comprise one or more physical packages (e.g., chips) including materials, components and/or wires on a structural assembly (e.g., a baseboard). The structural assembly may provide physical strength, conservation of size, and/or limitation of electrical interaction for component circuitry included thereon. The apparatus or the processor 32 may therefore, in some cases, be configured to implement an embodiment of the present invention on a single chip or as a single "system on a chip." As such, in some cases, a chip or chipset may constitute means for performing one or more operations for providing the functionalities described herein.

[0035] The processor 32 may be embodied in a number of different ways. For example, the processor may be embodied as various processing means such as one or more of a microprocessor or other processing element, a coprocessor, a controller or various other computing or processing devices including integrated circuits such as, for example, an ASIC, an FPGA or the like. In an example embodiment, the processor may be configured to execute instructions stored in the memory 34 or otherwise accessible to the processor. As such, whether configured by hardware or by a combination of hardware and software, the processor may represent an entity capable of performing operations according to embodiments of the present invention while configured accordingly. Thus, for example, when the processor is embodied as an ASIC, FPGA or the like, the processor may be specifically configured hardware for conducting the operations described herein. Alternatively, as another example, when the processor is embodied as an executor of software instructions, the instructions may specifically configure the processor to perform the operations described herein. [0036] The apparatus 30 may also include a user interface 38. The user interface may be in communication with the processor 32 to receive an indication of a user input at the user interface and/or to provide an audible, visual, mechanical or other output to the user. As such, the user interface may include, for example, a keyboard, a mouse, a joystick, a display, a touch screen, a microphone, a speaker, and/or other input/output mechanisms.

[0037] The apparatus 30 may also include a communication interface 36. The communication interface may include one or more interface mechanisms for enabling communication with other devices, such as other MTC devices, e.g., mobile terminals, fixed or stationary computing devices, etc., and/or networks, such as network 10 via base station 12. In some cases, the communication interface may be any means such as a device or circuitry embodied in either hardware, or a combination of hardware and software that is configured to receive and/or transmit data from/to a network and/or any other device or module in communication with the processor 32. In this regard, the communication interface may include, for example, an antenna (or multiple antennas) and supporting hardware and/or software for enabling communications with a wireless communication network and/or a communication modem or other hardware/software for supporting communication via cable, digital subscriber line (DSL), universal serial bus (USB), Ethernet or other methods.

[0038] As shown in Figure 3, the apparatus 30 may also include memory 34. The memory may include one or more non-transitory memory devices such as, for example, volatile and/or non-volatile memory that may be either fixed or removable. The memory may be configured to store information, data, applications, instructions or the like for enabling the apparatus to carry out various functions in accordance with example embodiments of the present invention. For example, the memory could be configured to buffer input data for processing by the processor 32. Additionally or alternatively, the memory could be configured to store instructions for execution by the processor. Among the contents of the memory, applications may be stored for execution by the processor in order to carry out the functionality associated with each respective application. In some cases, the memory may be in communication with the processor via a bus for passing information among components of the apparatus.

[0039] Referring now to Figure 4, the operations undertaken by a network entity of one embodiment of the present invention, such as the network entity, e.g., base station 12 that includes the apparatus 20 of Figure 2, are illustrated. As shown in block 40, the apparatus 20 embodied by a network entity may include means, such as the processor 22, the communication interface 26 or the like, for including machine type communication (MTC) downlink data within a payload to be transmitted via an LI control channel, such as a packet data control channel (PDCCH). Although the PDCCH may directly carry the MTC downlink data in various manners, the MTC downlink data is included in accordance with one embodiment within the payload of a media access control (MAC) packet data unit (PDU) which, in turn, is carried by the PDCCH.

[0040] As shown in Figure 5, a MAC PDU 50 may include a MAC subheader 52 and a payload consisting of a MAC service data unit (SDU) 54 and optionally one or more padding bits 56. The payload of a MAC PDU may have different sizes. By way of example, in an LTE system, there may be a plurality of different PDCCH formats, that is, downlink control information (DCI) formats, that have different payload sizes. For the 20 mHz bandwidth, DCI formats 0, 1, 1A, IB, 1C, 2 and 2A may have payload sizes in bits of 27, 39, 28, 30, 15, 51 and 48, respectively. As such, for the 20 mHz bandwidth, the payload size provided by the PDCCH may vary from 15 bits to 51 bits. Thus, the maximum payload size carried by the PDCCH for a 20 mHz bandwidth may be 51 bits. As a result of the limited payload size, the MAC PDU that is carried by the PDCCH may be reconfigured in accordance with one embodiment in order to reduce the size of the MAC subheader and to accordingly allow for an increase in the size of the payload, that is, the MAC SDU, which may, in turn, include additional MTC downlink data. The reduction in the size of the MAC subheader may also reduce the signaling overhead associated with the transmission of a MAC PDU so as to further increase the efficiency with which MTC downlink data may be carried by the payload of a MAC PDU and provided to an MTC device.

[0041] In one example embodiment, the MAC subheader 52 is reconfigured so as to have a length of one byte. In order to limit the length of the MAC subheader to one byte, the MAC subheader may include only the R, the logical channel index (LCID) and the MAC SDU length (L) fields. The R field represents reserved bits and has been reserved for future use. In this regard, the E and F fields of the MAC subheader representing an extension field that indicates if there is a subsequent MAC control element (CE) or MAC SDU and the size of the length field, respectively, may be eliminated since the MAC PDU 50 includes only a single MAC SDU 54.

[0042] The LCID may serve to identify various MTC services. In one embodiment, however, the length of the LCID may be reduced to four or fewer bits so as to indicate a maximum of 16 different logical channels since the MTC device, such as a mobile terminal 14, to which the MTC downlink data is provided is not anticipated to provide a large number of MTC services. In one embodiment, the length of the L field that defines the maximum length of the MAC SDU 54 may be three bits such that the maximum length of the MAC SDU that may be indicated by the L field is 8 bytes. By reducing the size of the MAC subheader 52, the MAC PDU 50 may still provide the information that is required by an MTC device, but may do so with less signaling overhead. Within the payload of the MAC PDU, such as within the MAC SDU, the MTC downlink data may be included so as to be directly carried by the PDCCH, thereby further increasing the efficiency with which the MTC downlink data may be provided to an MTC device, such as a mobile terminal 14.

[0043] In order to map the MTC downlink data to the PDCCH in an LTE system, one or more new mappings may be provided. As shown in Figure 6, for example, downlink logical channels, such as the dedicated control channel (DCCH) and the dedicated traffic channel (DTCH), may be directly mapped to the PDCCH as shown by the dashed lines. In order to support this new mapping between the downlink logical channels, such as the DCCH and the DTCH, and the PDCCH, the MAC architecture may be correspondingly reconfigured as shown in Figure 7. In this regard, the MAC layer for the PDCCH may be simplified so as to include automatic repeat request (ARQ) functionality, but not multiplexing and some of the other functionality provided by a MAC layer that is associated with the packet data shared channel (PDSCH) and that is utilized in an instance in which the MTC downlink data is transmitted via the PDSCH. Since only the DCCH and the DTCH are mapped to the PDCCH in one

embodiment, it is not anticipated that a substantial number of services will be provided by the MTC device to which the MTC downlink data is provided, thereby permitting the length of the LCID field to be reduced as described above.

[0044] As shown in block 42 of Figure 4, the apparatus 20 embodied by the network entity, such as a base station 12, may also include means, such as the processor 22, the communication interface 26 or the like, for causing an indication that the PDCCH will carry the MTC downlink data to be provided to an MTC device, such as a mobile terminal 14. The indication may be provided in various manners in accordance with embodiments of the present invention. In one embodiment, an indication that a PDCCH will carry MTC downlink data may be provided to an MTC device by applying a predefined mask to the cyclic redundancy check (CRC) of the MAC PDU that includes the payload to be transmitted via the PDCCH. [0045] In this embodiment, the predefined mask may be different than other masks that may be applied to the CRC and, as such, is indicative of the PDCCH carrying the MTC downlink data. In this regard, one or more other masks, such as the mask associated with the radio network temporary identifier (RNTI), e.g., the cell radio network temporary identifier (C-RNTI), of the MTC device to which the MTC downlink data is directed, may be applied to the CRC in addition to the predefined mask that is indicative of the PDCCH carrying the MTC downlink data. Thus, upon detecting that the predefined mask has been applied to the CRC, an MTC device may determine that the PDCCH will carry the MTC downlink data.

[0046] Additionally or alternatively, the apparatus 20 embodied by the network entity, such as the processor 22, the communication interface 26 or the like, may cause the indication that the PDCCH will carry MTC downlink data to be provided by higher layer signaling, such as radio resource control (RRC) signaling, that is provided to the MTC device and that is indicative of the PDCCH carrying MTC downlink data. Once an MTC device receives the RRC signaling that is indicative of the PDCCH carrying MTC download data, the MTC device may regard the subsequent PDCCH communications to be carrying MTC downlink data, After the MTC downlink data has been provided to the MTC device, the apparatus embodied by the network entity may cause an indication to be provided to the MTC device that subsequent PDCCH communications will not carry MTC downlink data, but will, instead, have a more conventional form. In this embodiment, a predefined DCI format, different than that utilized for the provision of the MAC PDU(s) 50 that carry the MTC downlink data, may be identified and may serve as the indication. In this embodiment, the apparatus embodied by the network entity, such as a processor, the communication interface or the like, may be configured to utilize the predefined DCI format with PDCCH communications in an instance in which the apparatus embodied by the network entity desires to revert from the provision of MAC PDUs that include MTC downlink data to the more conventional operation in which the PDCCH carries scheduling grants and/or other scheduling information. In this instance, an MTC device may recognize the predefined DCI format and may thereafter consider subsequent PDCCH communication to be carrying scheduling information, such as scheduling grants, as opposed to MTC downlink data until such time that RRC signaling is again provided so as to indicate that subsequent PDCCH communications will include MTC downlink data. [0047] As another alternative, the apparatus 20 embodied by the network entity, such as the processor 22, the communication interface 26 or the like, may be configured to address the payload to be transmitted via the PDCCH with a predefined address, e.g., RNTI, that is indicative of the PDCCH carrying MTC downlink data. While a PDCCH communication may be addressed in various manners, the predefined address may be utilized to scramble the payload, such as by scrambling the CRC of the MAC PDU. In this embodiment, upon detecting that the payload that is transmitted via the PDCCH is addressed with the predefined address, such as by being scrambled with the predefined address, the MTC device may determine that the payload transmitted via the PDCCH includes MTC downlink data.

[0048] As shown in block 44 of Figure 4, the apparatus 20 embodied by the network entity may also include means, such as the processor 22, the communication interface 26 or the like, for causing the MTC downlink data to be provided to the MTC device via the PDCCH. As described above, the MTC downlink data may be included in the payload of a MAC PDU 50, such as within a MAC SDU 54, that is then transmitted via the PDCCH to the MTC device. As noted above, the method and apparatus of an example embodiment are configured to provide MTC downlink data via an LI control channel. While the legacy PDCCH is one example of an LI control channel, other examples of an LI control channel may be utilized including the E- PDCCH, that is, an enhanced PDCCH. The E-PDCCH may be transmitted in symbols 3-14, where were originally utilized for the PDSCH domain. The E-PDCCH may be utilized to provide additional capacity relative to the PDCCH so that additional MTC downlink data may be transmitted to the MTC device. As used herein, reference to PDCCH shall include the various examples of the PDCCH including the legacy PDCCH and the E-PDCCH. In this embodiment, the network entity and the MTC device may be preconfigured to be able to provide E-PDCCH symbols instead of PDSCH symbols. The provision of E-PDCCH symbols which include MTC downlink data may be selectively enabled and disabled by signaling between the network entity and the MTC device, such as by broadcast or groupcast signaling.

[0049] In some embodiments, certain ones of the operations above may be modified or further amplified as described below. Moreover, in some embodiments additional optional operations may also be included (an example of which is shown in dashed lines in Figures 4 and 8). It should be appreciated that each of the modifications, optional additions or amplifications below may be included with the operations above either alone or in combination with any others among the features described herein.

[0050] In one embodiment, the apparatus 20 embodied by the network entity may be optionally configured to determine whether the MTC device successfully received and decoded the MTC downlink data. As shown in block 46 of Figure 4, the apparatus embodied by the network entity may include means, such as the processor 22, the communication interface 26 or the like, for receiving an acknowledgement (ACK) in an instance in which the MTC device has received and decoded the payload including the MTC downlink data transmitted via the PDCCH. In this embodiment, the apparatus embodied by the network entity may also include means, such as the processor, the communication interface or the like, for causing the MTC downlink data to be retransmitted to the MTC device via the PDCCH in an instance in which the ACK was not received. See block 44 of Figure 4. In order to provide for the acknowledgement of successful receipt of the MTC downlink data via the PDCCH, the MAC layer may include ARQ

functionality as noted above in conjunction with Figure 7, but need not include other

functionality that may otherwise be included in the MAC architecture of the PDSCH that otherwise may carry the MTC downlink data. In this embodiment, the network entity does not rely upon the receipt of a NACK signal to determine that the MTC downlink data was not properly received by the MTC device since the MTC device may not even be aware that MTC downlink data was included in a PDCCH communication in instances in which the PDCCH communication was never received by the MTC device. By determining whether an

acknowledgement from the MTC device was received in response to the transmission of MTC downlink data carried by the PDCCH, the apparatus embodied by the network entity can be either assured of the successful receipt of the MTC downlink data by the MTC device or may repeat the transmission of the MTC downlink data to the MTC device.

[0051] Referring now to Figure 8, the operations performed by an apparatus 30 embodied by an MTC device, such as a mobile terminal 14, are illustrated. As shown in block 70 of Figure 8, the apparatus embodied by the MTC device may include means, such as the processor 32, the communication interface 36 or the like, for receiving an indication that the PDCCH will carry MTC downlink data. The indication that the PDCCH will carry MTC downlink data may be provided in various manners. For example, the apparatus embodied by the MTC device may include means, such as the processor, the communication interface or the like, for determining that a predefined mask was applied to the CRC associated with the payload transmitted via the PDCCH. As described above, the predefined mask may be different than other masks and may be indicative of the PDCCH carrying MTC downlink data. In an instance in which the apparatus embodied by the MTC device determines that a predefined mask has been applied to the CRC, the MTC device may then consider the payload transmitted via the PDCCH to be carrying MTC downlink data.

10052] Alternatively, the indication received by the MTC device that the PDCCH will carry MTC downlink data may be provided by higher layer signaling, such as RRC signaling, in another alternative, the indication that the PDCCH will carry MTC downlink data may be based upon a determination by the apparatus 30 embodied by the MTC device, such as the processor 32, the communication interface 36 or the like, that the payload transmitted via the PDCCH has or is otherwise associated with a predefined address, such as a predefined RJMTI, indicative of the PDCCH carrying MTC downlink data. For example, the apparatus embodied by the MTC device, such as the processor, the communication interface or the like, may determine that the payload transmitted via the PDCCH is scrambled with the predefined address that is indicative of the PDCCH carrying MTC downlink data. In this instance, the apparatus embodied by the MTC device may then consider the payload transmitted via the subsequent PDCCH communications to include MTC downlink data. As described above, the MTC device may revert to conventional operations with the PDCCH no longer including MTC downlink data and, instead, including scheduling information, such as scheduling grants, upon receipt of symbols transmitted via the PDCCH that have a predefined format, such as a predefined DCI format.

[00531 As shown in block 72 of Figure 8, the apparatus 30 embodied by the MTC device may also include means, such as the processor 32, the communication interface 36 or the like, for receiving the MTC downlink data via the PDCCH. In one embodiment, the MTC downlink data is provided in a payload transmitted via the PDCCH, such that the payload of a MAC PDU 50, such as the MAC SDU 54. In another embodiment, however, the apparatus embodied by the MTC device, such as the processor, the communication interface or the like, may receive the MTC downlink data via the E-PDCCH, which is transmitted in symbols that were originally used for the PDSCH. By repurposing the symbols that were previously used for PDSCH to be used for E-PDDCH symbols that include MTC downlink data, additional MTC downlink data may be provided to the MTC device while still utilizing the payload of the PDCCH, such as the E- PDCCH, to carry the MTC downlink data so as to avoid excessive signaling overhead.

[0054] With reference to block 74 of Figure 8, the apparatus 30 embodied by the MTC device may also include means, such as the processor 32 or the like, for extracting the MTC downlink data from the payload transmitted via the PDCCH. As described above, the apparatus embodied by the MTC device, such as the processor, may extract the MTC downlink data from the payload of a MAC PDU 50, such as a MAC SDU 54, transmitted via the PDCCH.

[0055] In one embodiment, the apparatus 30 embodied by the MTC device may optionally also include means, such as the processor 32, the communication interface 36 or the like, for determining whether the MTC device has received and successfully decoded the payload transmitted via the PDCCH that includes the MTC downlink data. See block 76. In an instance in which the MTC device has received and successfully decoded the MTC downlink data included in the payload transmitted via the PDCCH, the apparatus embodied by the MTC device of this embodiment may also include means, such as the processor, the communication interface or the like, for causing an ACK to be provided. However, in an instance in which the MTC device has not received and/or has not successfully decoded MTC downlink data from a payload transmitted via the PDCCH, the apparatus embodied by the MTC device may not provide any signaling got the network entity.

[0056] As described above, Figures 4 and 8 are flowcharts of the operations performed from the perspective of a network entity, such as the base station 12, and from the perspective of an MTC device, such as a mobile terminal 14. It will be understood that each block of the flowcharts, and combinations of blocks in the flowcharts, may be implemented by various means, such as hardware, firmware, processor, circuitry, and/or other device associated with execution of software including one or more computer program instructions. For example, one or more of the procedures shown by the flowcharts may be embodied by computer program instructions. In this regard, the computer program instructions which embody the procedures depicted by the flowcharts may be stored by a memory device of an apparatus employing an embodiment of the present invention and executed by a processor in the apparatus.

]0057] As will be appreciated, any such computer program instructions may be loaded onto a computer or other programmable apparatus (e.g., hardware) to produce a machine, such that the resulting computer or other programmable apparatus provides for implementation of the functions specified in the flowchart block(s). These computer program instructions may also be stored in a non-transitory computer-readable storage memory that may direct a computer or other programmable apparatus to function in a particular manner, such that the instructions stored in the computer-readable storage memory produce an article of manufacture, the execution of which implements the function specified in the flowchart block(s). The computer program instructions may also be loaded onto a computer or other programmable apparatus to cause a series of operations to be performed on the computer or other programmable apparatus to produce a computer-implemented process such that the instructions which execute on the computer or other programmable apparatus provide operations for implementing the functions specified in the flowchart blocks.

[0058] Accordingly, blocks of the flowcharts support combinations of means for performing the specified functions and combinations of operations for performing the specified functions. It will also be understood that one or more blocks of the flowcharts, and combinations of blocks in the flowcharts, can be implemented by special-purpose hardware-based computer systems which perform the specified functions, or combinations of special purpose hardware and computer instructions.

[0059] By including the MTC downlink data within the payload transmitted via the

PDCCH, the overhead that is otherwise associated with the transmission of MTC downlink data via the PDSCH may be reduced such that MTC downlink data may be provided to MTC devices more efficiently. In this regard, the control signaling provided by the PDCCH in association with the MTC downlink data within the payload of the PDCCH may be reduced since the MTC downlink data will be directly detected, but not scheduled by control signaling. In this regard, in prior approaches that included the data in the PDSCH, the PDCCH was required to provide control signaling for scheduling purposes. In accordance with an example embodiment, however, the PDCCH may now carry the downlink data, but without the control signaling that was previously required to schedule the data in the PDSCH. Additionally or alternatively, the number of padding bits may be reduced in accordance with an embodiment of the present invention relative to the inclusion of MTC downlink data in one or more PRBs since the size of the payload within which the MTC downlink data is disposed may be sized in a manner that more closely approximates the size of the MTC downlink data, particularly in instances in which relatively small amounts of data are transmitted. These increases in efficiency may become particularly advantageous as MTC devices proliferate and as even more MTC downlink data is transmitted from various network entities to MTC devices.

[0060] Many modifications and other embodiments of the inventions set forth herein will come to mind to one skilled in the art to which these inventions pertain having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the inventions are not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.

Claims

WHAT IS CLAIMED IS:

1. A method comprising:

including machine type communication (MTC) downlink data within a payload to be transmitted via a packet downlink control channel (PDCCH);

causing an indication that the PDCCH will carry MTC downlink data to be provided to an MTC device; and

causing the MTC downlink data to be provided to the MTC device via the PDCCH.

2. A method according to Claim 1 wherein including the MTC downlink data within a payload comprises including the MTC downlink data within a media access control (MAC) payload to be transmitted via the PDCCH.

3. A method according to any one of Claims 1 or 2 wherein causing an indication comprises applying a predefined mask to a cyclic redundancy check associated with the payload to be transmitted via the PDCCH, wherein the predefined mask is indicative of the PDCCH carrying MTC downlink data.

4. A method according to any one of Claims 1 or 2 wherein causing an indication comprises causing radio resource control (RRC) signaling to be provided to the MTC device that is indicative of the PDCCH carrying MTC downlink data.

5. A method according to any one of Claims 1 or 2 wherein causing an indication comprises addressing the payload to be transmitted via the PDCCH with a predefined address indicative of the PDCCH carrying MTC downlink data.

6. A method according to any one of Claims 1 or 2 further comprising receiving an acknowledgement (ACK) in an instance in which the MTC device has received and decoded the payload transmitted via the PDCCH and causing the MTC downlink data to be retransmitted to the MTC device via the PDCCH in an instance in which the ACK was not received.

7. A method according to any one of Claims 1 or 2 wherein including the TC downlink data within the payload to be transmitted via the PDCCH comprises including the MTC downlink data within the payload to be transmitted via an enhanced PDCCH.

8. An apparatus comprising:

at least one processor; and

at least one memory including computer program code, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus to at least:

include machine type communication (MTC) downlink data within a payload to be transmitted via a packet downlink control channel (PDCCH);

cause an indication that the PDCCH will carry MTC downlink data to be provided to an MTC device; and

cause the MTC downlink data to be provided to the MTC device via the PDCCH.

9. An apparatus according to Claim 8 wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus to include the MTC downlink data within a payload by including the MTC downlink data within a media access control (MAC) payload to be transmitted via the PDCCH.

10. An apparatus according to any one of Claims 8 or 9 wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus to cause an indication by applying a predefined mask to a cyclic redundancy check associated with the payload to be transmitted via the PDCCH, wherein the predefined mask is indicative of the PDCCH carrying MTC downlink data.

11. An apparatus according to any one of Claims 8 or 9 wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus to cause an indication by causing radio resource control (RRC) signaling to be provided to the MTC device that is indicative of the PDCCH carrying MTC downlink data.

12. An apparatus according to any one of Claims 8 or 9 wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus to cause an indication by addressing the payload to be transmitted via the PDCCH with a predefined address indicative of the PDCCH carrying MTC downlink data.

13. An apparatus according to any one of Claims 8 or 9 wherein the at least one memory and the computer program code are further configured, with the at least one processor, to cause the apparatus to receive an acknowledgement (ACK) in an instance in which the MTC device has received and decoded the payload transmitted via the PDCCH and to cause the MTC downlink data to be retransmitted to the MTC device via the PDCCH in an instance in which the ACK was not received.

14. An apparatus according to any one of Claims 8 or 9 wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus to include the MTC downlink data within the payload to be transmitted via the PDCH by including the MTC downlink data within the payload to be transmitted via an enhanced PDCCH.

15. A method comprising:

receiving an indication that a packet downlink control channel (PDCCH) will carry machine type communication (MTC) downlink data;

receiving the MTC downlink data via the PDCCH; and

extracting the MTC downlink data from a payload transmitted via the PDCCH.

16. A method according to Claim 8 wherein extracting the MTC downlink data from the payload comprises extracting the MTC downlink data from a media access control (MAC) payload transmitted via the PDCCH.

17. A method according to any one of Claims 8 or 9 wherein receiving an indication comprises determining that a predefined mask was applied to a cyclic redundancy check associated with the payload transmitted via the PDCCH, wherein the predefined mask is indicative of the PDCCH carrying MTC downlink data.

18. A method according to any one of Claims 8 or 9 wherein receiving an indication 5 comprises receiving radio resource control (RRC) signaling that is indicative of the PDCCH carrying MTC downlink data.

19. A method according to any one of Claims 8 or 9 wherein receiving an indication comprises determining that the payload transmitted via the PDCCH has a predefined address ] 0 indicative of the PDCCH carrying MTC downlink data.

20. A method according to any one of Claims 8 or 9 further comprising causing an acknowledgement (ACK) to be provided only in an instance in which the MTC device has received and decoded the payload transmitted via the PDCCH.

15

21. A method according to any one of Claims 8 or 9 wherein the PDCCH comprises an enhanced PDCCH.

22. An apparatus comprising:

0 at least one processor; and

receive an indication that a packet downlink control channel (PDCCH) will carry 5 machine type communication (MTC) downlink data;

receive the MTC downlink data via the PDCCH; and

extract the MTC downlink data from a payload transmitted via the PDCCH,

23. An apparatus according to Claim 22 wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus to extract the MTC downlink data from the payload by extracting the MTC downlink data from a media access control (MAC) payload transmitted via the PDCCH.

24. An apparatus according to any one of Claims 22 or 23 wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus to receive an indication by determining that a predefined mask was applied to a cyclic redundancy check associated with the payload transmitted via the PDCCH, wherein the predefined mask is indicative of the PDCCH carrying MTC downlink data. 25, An apparatus according to any one of Claims 22 or 23 wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus to receive an indication by receiving radio resource control (RRC) signaling that is indicative of the PDCCH carrying MTC downlink data. 26. An apparatus according to any one of Claims 22 or 23 wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus to receive an indication by determining that the payload transmitted via the

PDCCH has a predefined address indicative of the PDCCH carrying MTC downlink data. 27. An apparatus according to any one of Claims 22 or 23 wherein the at least one memory and the computer program code are further configured to, with the at least one processor, cause the apparatus to cause an acknowledgement (ACK) to be provided only in an instance in which the MTC device has received and decoded the payload transmitted via the PDCCH. 28. An apparatus according to any one of Claims 22 or 23 wherein the PDCCH comprises an enhanced PDCCH.