Method and apparatus for supporting uplink transmission and MBMS for a WTRU with reduced bandwidth

Embodiments described herein may include methods, systems, and apparatuses that support transmissions in wireless transmit and receive units (WTRUs) having reduced capabilities. Uplink transmissions and multimedia broadcast multicast service (MBMS) may be supported in WTRUs operating on a reduced bandwidth within an overall system bandwidth by receiving an uplink (UL) resource allocation within the reduced bandwidth, and sending a transmission over the UL resource allocation. The reduced bandwidth may include a small number of physical resource blocks (PRBs) that do not overlap with PRBs located on the band edge of the overall system bandwidth containing a system PUCCH. The UL resource may be located in both band edges of the reduced bandwidth, may be a PRB-pair in the same frequency of the reduced bandwidth, or may be a PRB-pair in a first slot in a first subframe and second slot in a second subframe of the reduced bandwidth.

BACKGROUND

Due to cost and complexity issues, a low-cost wireless transmit and receive unit (WTRU) may have one more reduced capabilities as compared to regular (i.e., more complex) WTRUs. Low-cost WTRUs may be restricted by, for example, a reduced bandwidth, a single receiver mode (Rx), or a transport block size (TBS) restriction. Hence, methods and procedures may be needed to enable communication and proper operation to support the coexistence of low-cost WTRUs and regular WTRUs.

SUMMARY

In an embodiment, a method of for supporting uplink transmissions in a wireless transmit and receive unit (WTRU) operating on a reduced bandwidth of a system bandwidth is disclosed. The method may include: determining a frequency location of the reduced bandwidth within the system bandwidth for an uplink (UL) transmission; determining an UL resource for a physical uplink control channel (PUCCH) transmission within the determined frequency location of the reduced bandwidth; and sending a PUCCH in the determined reduced bandwidth and UL resource.

In an embodiment, wireless transmit/receive unit (WTRU) supporting uplink transmissions and multimedia broadcast multicast service (MBMS) while operating on a reduced bandwidth of a system bandwidth, is disclosed. The WTRU may include: circuitry configured to determine a frequency location of the reduced bandwidth within the system bandwidth for an uplink (UL) transmission; circuitry configured to determine an UL resource for a physical uplink control channel (PUCCH) transmission within the determined frequency location of the reduced bandwidth; and circuitry configured to send a PUCCH in the determined reduced bandwidth and UL resource.

DETAILED DESCRIPTION

Embodiments described herein may include methods, systems, and apparatuses that support transmissions in wireless transmit and receive units (WTRUs) having reduced capabilities. It should be noted that hereinafter, the terms low-cost WTRU, LC-MTC, reduced capability WTRU, low-cost WTRU with reduced capability, limited capability WTRU, and low-cost WTRU with limited capability may be interchangeably used and are not intended to be limiting. Also, WTRU, regular Long Term Evolution (LTE) WTRU, LTE WTRU, legacy WTRU, WTRU without reduced capability, and WTRU without limited capability may be used interchangeably and are not intended to be limiting.

Referring now toFIG. 1B, a system diagram of an example WTRU102is shown. The WTRU102may include a processor118, a transceiver120, a transmit/receive element122, a speaker/microphone124, a keypad126, a display/touchpad128, non-removable memory130, removable memory132, a power source134, a global positioning system (GPS) chipset136, and other peripherals138. It will be appreciated that the WTRU102may include any sub-combination of the foregoing elements while remaining consistent with an embodiment.

Referring now toFIG. 1C, a system diagram of the RAN104and the core network106according to an embodiment is shown. As noted above, the RAN104may employ an E-UTRA radio technology to communicate with the WTRUs102a,102b,102cover the air interface116. The RAN104may also be in communication with the core network106.

The serving gateway144may also be connected to the PDN gateway146, which may provide the WTRUs102a,102b,102cwith access to packet-switched networks, such as the Internet110, to facilitate communications between the WTRUs102a,102b,102cand IP-enabled devices.

In LTE communication, an uplink control channel, such as a Physical Uplink Control Channel (PUCCH), may transmit, may be used to transmit, may carry, and/or may include control signaling that may be independent of traffic data. The control signaling may include one or more of hybrid automatic repeat request (HARQ) acknowledge/negative acknowledgements (ACK/NACK), channel quality indicators (CQI), multiple input multiple output (MIMO) feedback, and/or scheduling requests for uplink transmission.

The physical resources used for PUCCH may depend on two parameters, NRB(2)and Ncs(1), that may be given by higher layers. The variable NRB(2)≤0 may denote the bandwidth in terms of resource blocks that are available for use by PUCCH formats 2/2a/2b transmission in each slot. The variable Ncs(1)may denote the number of cyclic shifts used for PUCCH formats 1/1a/1b in a resource block used for a mix of formats 1/1a/1b and 2/2a/2b. The value of Ncs(1)may be an integer multiple of ΔshiftPUCCHwithin the range of {0, 1, . . . , 7}, where ΔshiftPUCCHmay be provided by higher layers. No mixed resource block is present if Ncs(1)=0. At most one resource block in each slot may support a mix of formats 1/1a/1b and 2/2a/2b. Resources used for transmission of PUCCH formats 1/1a/1b, 2/2a/2b and 3 may be represented by the non-negative indices

Referring now toFIG. 2, a mapping of modulation symbols for the PUCCH is shown. The physical resource blocks to be used for transmission of PUCCH in slot nsmay be given by

In case of simultaneous transmission of sounding reference signal and PUCCH format 1, 1a, 1b or 3 when there is one serving cell configured, a shortened PUCCH format may be used where the last SC-FDMA symbol in the second slot of a subframe may be left empty.

A Frequency-division duplexing (FDD) HARQ-ACK procedure for a configured serving cell may include a HARQ-ACK transmission on two antenna ports (pϵ[p0,p1]) that is supported for PUCCH format 1a/1b. For FDD and one configured serving cell, the WTRU102may use PUCCH resource nPUCCH(1,{tilde over (p)})for transmission of HARQ-ACK in subframe n for {tilde over (p)} mapped to antenna port p for PUCCH format 1a/1b as follows.

For a Physical Downlink Shared Channel (PDSCH) transmission indicated by the detection of a corresponding Physical Downlink Control Channel (PDCCH) in subframe n−4, or for a PDCCH indicating downlink semi-persistent scheduling (SPS) release in subframe n−4, the WTRU102may use) nPUCCH(1,{tilde over (p)}0)=nCCE+NPUCCH(1)for antenna port p0, where nCCEis the number of the first Control Channel Element (CCE) (i.e., the lowest CCE index used to construct the PDCCH) used for transmission of the corresponding Downlink Control Information (DCI) assignment and NPUCCH(1)is configured by higher layers. For two antenna port transmissions, the PUCCH resource for antenna port p1is given by nPUCCH(1,{tilde over (p)}1)=nCCE+1+NPUCCH(1).

For a PDSCH transmission on the primary cell where there is not a corresponding PDCCH detected in subframe n−4, the value of nPUCCH(1,{tilde over (p)})may be determined according to higher layer configuration and pre-configured table of PUCCH resource values. For a WTRU102configured for two antenna port transmission, a PUCCH resource value in a pre-configured table of PUCCH resource values may map to two PUCCH resources. The first PUCCH resource nPUCCH(1,{tilde over (p)}0)may be for antenna port p0and the second PUCCH resource nPUCCH(1,{tilde over (p)}1)may be for antenna port p1. Otherwise, the PUCCH resource value may map to a single PUCCH resource nPUCCH(1,{tilde over (p)}0)for antenna port p0.

Referring now toFIG. 3, a logical network architecture for an Evolved Multimedia Broadcast/Multicast Service (eMBMS) is shown. The Multi-cell/multicast Coordination Entity (MCE) may provide the admission control and radio resources used by the base stations114a,114bin a multicast-broadcast single-frequency network (MBSFN) area for MBMS transmissions. The establishment and allocation of radio bearers as well as physical radio resources for MBMS may be coordinated by this entity. The MBMS GW may provide IP multicast functionality to forward MBMS user data to the base stations114a,114bin a coordinated manner. The M1, M2, and M3 may provide the control plane interface for MBMS between the entities involved in MBMS.

Regarding access stratum aspects, a MBSFN area may define a set of cells which coordinate the transmission of MBMS related data for one or more MBMS services. In an embodiment, a base station114a,114bmay belong to up to 8 MBSFN areas.

MBMS control information, such as and as such Multicast Control Channel (MCCH), and data, such as Multicast Traffic Channel (MTCH), may be transmitted in a MBSFN subframe as defined in SIB2 of the cell. In each MBSFN subframe, a single Physical Multicast Channel (PMCH) may be transmitted that carries one MBMS related transport channel (MCH), which in turn multiplexes1MCCH and multiple MTCH logical channels. The multiplexing information of MCCH/MTCH may be provided in the MAC header of the MCH.

A single MCH transport channel may be transmitted onto a single PMCH in one MBSFN subframe. The transport format for the MCH is fixed and specified in broadcast information from the base station114a,114b.

The WTRU102may configure for reception of a specific MBMS service with the following steps. The WTRU102may receive SIB2 for MBSFN subframe configuration. The WTRU102may then receive SIB13 to obtain knowledge on how to receive the MCCH for this particular MBSFN area. Next, the WTRU102may receive the MCCH to obtain knowledge about the CSA period, CSA pattern, and MSP for the service of interest. Then, the WTRU102may receive the MSI at the beginning of each MSP. This may provide the terminal with information on which subframes the service of interest can be found in.

The MCCH which carries MBMS configuration information may be transmitted periodically in a MBSFN subframe, as defined for the MBSFN area in SIB13. The information included in MCCH may be changed from time to time by the base station114a,114b. In order to indicate the changes of MCCH to MBMS a receiving WTRU102, it may transmit an 8-bit bitmask via PDCCH masked M-RNTI using DCI format 1C. The 8-bit bitmask may indicate the MBSFN area for which the MCCH has been changed. The changes to MCCH may take place at the beginning of the next MCCH modification period, as configured in SIB13.

Hereafter, the reduced uplink bandwidth may be referred to as an uplink bandwidth in which a low-cost WTRU may transmit uplink signals. In an embodiment, the uplink reduced bandwidth may be consecutive 6 PRBs located within a system bandwidth. The 6 PRBs may be replaced with any numbers such as NrPRBs where Nr<100. The uplink reduced bandwidth may be interchangeably used as frequency location of the uplink reduced bandwidth, uplink frequency location of the low-cost WTRU, and a set of uplink PRBs for a low-cost WTRU with reduced bandwidth.

A PUCCH resource may be provided and/or used in a reduced bandwidth. A PUCCH for some legacy WTRUs may be located in at both of the band edges of the full system bandwidth in a subframe. For example, the PUCCH resource may be located at physical resource block (PRB) #0and PRB #49for a 10 MHz system bandwidth, which may contain a total of 50 PRBs.

In contrast, a low-cost WTRU may have limited capabilities, such as a reduced bandwidth, and may not be able to access or transmit the PUCCH resource at the edges of a larger bandwidth (e.g., 10 MHz). For example, a low-cost WTRU may operate only within a small number of PRBs (e.g., 6 PRBs) out of the total number of PRBs in a subframe (e.g., 50 PRBs). The small number of PRBs may not overlap with the PUCCH resource at the band edges of the legacy WTRUs.

In an embodiment, a PUCCH resource for low-cost WTRUs (LC-PUCCH resource) may be located in one or both band edges of a reduced bandwidth that is supported by the low-cost WTRUs. It should be noted that the LC-PUCCH resource may be intended and provided for use by another WTRU and still be consistent with this disclosure. The terms reduced and limited (e.g., reduced bandwidth and limited bandwidth) may be used interchangeably. Reduced bandwidth may refer to a reduced bandwidth in the uplink (and/or downlink). Reduced bandwidth may be with respect to the uplink (and/or downlink) bandwidth of a cell (e.g., a serving cell of a reduced bandwidth WTRU). A WTRU which may behave in a manner consistent with a reduced bandwidth WTRU may be considered a reduced bandwidth WTRU. System bandwidth may be used to represent the system uplink and/or downlink bandwidth. The terms system, cell, base station, and eNB may be used interchangeably.

Referring now toFIG. 4, an example of a LC-PUCCH resource allocation in a reduced bandwidth404is shown. The reduced bandwidth may correspond to the bandwidth supported by a low-cost WTRU. For exemplary purposes, the example LC-PUCCH resource is referred to as a Type-A LC-PUCCH resource402. In an embodiment, the Type-A LC-PUCCH resource402may be located in both band edges of the reduced bandwidth404. The reduced bandwidth404may be defined or predefined as a certain subset of PRBs (e.g., the center 6 PRBs) of a total system bandwidth406. The total system bandwidth may be the uplink bandwidth (e.g., full uplink bandwidth) supported by or used by the cell providing the LC-PUCCH resource. The Type-A LC-PUCCH resource402may be located in both band edges of the certain subset of PRBs and may use slot hopping. A Type-A LC-PUCCH resource402allocation may be the same as a legacy PUCCH resource (e.g., for legacy WTRUs) when the reduced bandwidth404and the total system bandwidth406are the same.

It should be noted that hereinafter the term PRB-pair may refer to two PRBs paired within a subframe, wherein a first PRB may be located in a first slot of a subframe and a second PRB may be located in a second slot of the subframe. If a slot hopping is used, the two PRBs paired may be located in a different frequency. If a slot hopping is not used for a PRB-pair, the two PRBs may be located in a same frequency in the subframe.

InFIG. 4, the nPRB′ denotes a physical resource block number within the reduced bandwidth404and the NRB,reULdenotes an uplink reduced bandwidth configuration. As an example, if the reduced bandwidth404is defined as 6 PRBs, then NRB,reUL=6 and NPRB′ϵ{0, 1, 2, 3, 4, 5}. In an embodiment, the location of the reduced bandwidth404within the system bandwidth406may be predefined. In another embodiment, the location of the reduced bandwidth404within the system bandwidth406may be defined as a function of one or more of following parameters: subframe number; slot number; system frame number (SFN); WTRU-ID, such as Cell Radio Network Temporary Identifier (C-RNTI); frequency location of an Enhanced Physical Downlink Control Channel (EPDCCH); starting Control Channel Element (CCE) number of associated PDCCH; starting Enhanced CCE (ECCE) number of associated EPDCCH; and physical Cell ID. It should be noted that the terms downlink control channel, physical downlink control channel (PDCCH) enhanced physical downlink control channel (EPDCCH), and MTC physical downlink control channel (M-PDCCH) may be interchangeably used. In addition, the terms CCE, enhanced CCE (ECCE), and MTC CCE (MCCE) may be used interchangeably.

In another embodiment, the location of the reduced bandwidth404within the system bandwidth406may be defined with a predefined hopping pattern. The reduced bandwidth404may be configured via higher layer signaling, such as via a Master Information Block (MIB) or a System Information Block (SIB).

Referring now toFIG. 5, another example of a LC-PUCCH resource allocation in a reduced bandwidth504is shown. The reduced bandwidth504may correspond to the bandwidth supported by a low-cost WTRU. For exemplary purposes, the example LC-PUCCH resource is referred to as a Type-B LC-PUCCH resource. In an embodiment, the Type-B LC-PUCCH502resource may be defined without slot hopping within the reduced bandwidth504. The Type-B LC-PUCCH resource502may be or include a PRB-pair508located in the same frequency within the reduced bandwidth504. The reduced bandwidth504may be defined or predefined as a certain subset of PRBs (e.g., center 6 PRBs) of a total system bandwidth506. The Type-B LC-PUCCH resource502may be located in a band edge of the certain subset of PRBs.

InFIG. 5, the nPRB′ denotes a physical resource block number within the reduced bandwidth504and the NRB,reULdenotes an uplink reduced bandwidth configuration. As an example, if the reduced bandwidth504is defined as 6 PRBs, then NRB,reUL=6 and nPRB′ϵ{0, 1, 2, 3, 4, 5}. In an embodiment, the location of the reduced bandwidth504within the system bandwidth506may be predefined. In another embodiment, the location of the reduced bandwidth504within the system bandwidth506may be defined as a function of one or more of following parameters: subframe number; slot number; system frame number (SFN); WTRU-ID, such as C-RNTI; frequency location of a PDCCH or EPDCCH; starting CCE number of associated PDCCH; starting ECCE number of associated EPDCCH; and physical Cell ID. In another embodiment, the location of the reduced bandwidth504within the system bandwidth506may be defined with a predefined hopping pattern. The reduced bandwidth504may be configured via higher layer signaling, such as via a MIB or a SIB.

Referring to the Type-B LC-PUCCH504, the PRB-pair508located in the same frequency may be used as, or for, a LC-PUCCH resource. Although the PRB-pair508is shown at one edge of the reduced bandwidth504, embodiments are considered in which the PRB-pair508is located at an opposite edge of the reduced bandwidth504. In an embodiment, one edge of the reduced bandwidth504may correspond to the first PRB of the PRB-pair and the other edge of the reduced bandwidth504may correspond to the second PRB of the PRB-pair. In an embodiment, the PRB-pair508may be located at any location within the reduced bandwidth504. The location of the PRB-pair508may be defined or configured by higher layer signaling, an indicator in the Downlink Control Information (DCI) associated with the PUCCH (e.g., LC-PUCCH) transmission, or as a function of the starting CCE (or ECCE) number for the PDCCH (or EPDCCH) associated with the LC-PUCCH transmission.

Referring now toFIG. 6, another example of a LC-PUCCH resource allocation in a reduced bandwidth604is shown. The reduced bandwidth604may correspond to the bandwidth supported by a low-cost WTRU. For exemplary purposes, the example LC-PUCCH resource is referred to as a Type-C LC-PUCCH resource602.

Referring to the Type-C LC-PUCCH602, a PRB-pair may be located over two or more subframes of the transmission. Here, a first PRB606(denoted m=0) in the first slot of the subframe610(denoted subframe n) and a second PRB608(denoted m=0)608in the first slot of the subframe612(denoted subframe n+1) may be used as a PRB-pair for the Type-C LC-PUCCH602. In another example, a first PRB606in the first slot of the subframe610and a second PRB608in the second slot of the subframe612may be used as a PRB-pair for the Type-C LC-PUCCH602. In another example, the first PRB606may be in the second slot of the subframe610and the second PRB608may be in the second slot of the subframe612, and together may be used as a PRB-pair for the Type-C LC PUCCH602.

In an embodiment, the PRB-pair in the Type-C LC-PUCCH602may be located in both band edges of the system bandwidth. For example, the first PRB606may be located in the first PRB (nPRB=0) of the system bandwidth in the first subframe610and the second PRB may be located in the last PRB (nPRB=NRBUL−1) of the system bandwidth in the second subframe612.

In an embodiment, an offset may be used, for example to avoid PUCCH resource collision between legacy-PUCCH and the Type-C LC-PUCCH602. For example, the first PRB606may be located in the first PRB of the system bandwidth (e.g., NRBULPRBs) with an offset (e.g., nPRB=ΔRB) in the first subframe610and the second PRB608may be located in the last PRB of the system bandwidth (e.g., NRBULPRBs) with an offset (e.g., nPRB=NRBUL−1−ΔRB) in the second subframe612. The offset ΔRBmay be configured via higher layer signaling (e.g., via MIB, SIB, and/or RRC signaling). The offset ΔRBmay be defined as a function of a higher layer parameter for legacy-PUCCH resource configuration. The offset ΔRBmay be defined as a function of at least one of following parameters: bandwidth available for use by PUCCH formats 2/2a/2b for legacy WTRUs (e.g., NRB(2)); number of cyclic shifts used for mixed format (e.g. NCS(1)); and NPUCCH(1). In an embodiment, the PUCCH resources may be shared between legacy-PUCCH and Type-C LC-PUCCH602.

In an embodiment, two or more LC-PUCCH resource allocation types may be defined and/or configured and/or used. The LC-PUCCH resource type may be selected and/or used based on or according one or more of a LC-PUCCH transmission mode, an uplink transmission mode, a Physical Uplink Shared Channel (PUSCH) resource allocation type, higher layer configuration and/or dynamic indication.

A localized LC-PUCCH transmission mode and a distributed LC-PUCCH transmission mode may be defined. One of the LC-PUCCH transmission modes may be configured, selected, and/or indicated via higher layer signaling or dynamic signaling. A low-cost WTRU may select and/or use a LC-PUCCH resource type according to or at least based on the LC-PUCCH transmission mode.

A localized uplink transmission mode and a distributed uplink transmission mode may be defined. One of the uplink transmission modes may be configured via higher layer signaling or dynamic signaling. A WTRU may select and/or use a LC-PUCCH resource type according to, or at least based on, the uplink transmission mode.

For LC-PUSCH allocation, hopping may or may not be activated. A low-cost WTRU may select and/or use a LC-PUCCH resource type according to or at least based on whether LC-PUSCH hopping is activated. For example, if LC-PUSCH hopping is activated, the Type-A LC-PUCCH resource may be used. If PUSCH hopping is not activated, the Type-B LC-PUCCH resource may be used for LC-PUCCH resource allocation.

The LC-PUCCH resource type may be used according to, or at least based on, a higher layer configuration. A broadcast signal or system information (e.g., SIB) may configure or indicate the LC-PUCCH resource allocation type to be used. Higher layer RRC signaling (e.g., broadcast or dedicated) may be used to configure or indicate the LC-PUCCH resource type for a low-cost WTRU and/or for the cell. A low-cost WTRU may select and/or use a LC-PUCCH resource type according to, or at least based, on received broadcast and/or higher layer signaling.

The LC-PUCCH resource type may be used according to, or at least based on, a dynamic indication. The indicator may be provided or included in a DCI associated with the LC-PUCCH transmission. A low-cost WTRU may select and/or use a LC-PUCCH resource type according to or at least based on the indicator.

In an embodiment, a subset of PUCCH formats may be supported in, by, or for the LC-PUCCH. For example, PUCCH formats 1/1a/1b may be supported in the LC-PUCCH. The PRB resource allocation for PUCCH formats 1/1a/1b in the LC-PUCCH may be defined without the resource allocation for PUCCH format 2/2a/2b as follows:

The PUCCH index in the single component carrier case may be defined as follows:
nPUCCH(1,{tilde over (p)}0)=nCCE(Equation 6)

A WTRU102may transmit a PUCCH (or a PUCCH format) in a LC-PUCCH resource. A WTRU102may determine a LC-PUCCH resource and/or type, for example based on definition, configuration, and/or indication, and may transmit a PUCCH in the determined LC-PUCCH resource using the determined LC-PUCCH type.

Referring now toFIG. 7, multiple LC-PUCCH resource configurations are shown. In an embodiment, two or more LC-PUCCH resources702may be configured in a cell-specific manner. A low-cost WTRU may transmit PUCCH in one of the configured LC-PUCCH resources702in a subframe706.

A LC-PUCCH resource702may be defined as a set of uplink PRBs which may correspond to the reduced bandwidth704of a low-cost WTRU. For example, if the reduced bandwidth704supported by a low-cost WTRU is a certain number of PRBs (e.g., 6 PRBs), then a LC-PUCCH resource702may be defined as the certain number of PRBs (e.g., 6 PRBs).

In an embodiment, two or more LC-PUCCH resources702may be defined in different sets of uplink PRBs which may be non-overlapped in the subframe706. In an example, a primary LC-PUCCH resource702may be defined in a center frequency band. The set of PRBs for a LC-PUCCH resource702may be defined with a small number PRBs (e.g., 6 PRBs). The primary LC-PUCCH resource702may be defined in the center PRBs (e.g., center 6 PRBs) within the system bandwidth708. A secondary LC-PUCCH resource702may be configured via higher layer signaling. In an example, an offset value (e.g., a frequency offset in PRBs from the PRBs for primary LC-PUCCH resource) may be signaled to indicate the location of the secondary LC-PUCCH resource702. In an embodiment, one or more secondary LC-PUCCH resources702may be configured. The offset may be defined as a number of PRBs.

In an embodiment, two or more LC-PUCCH resources702may be configured via higher layer signaling. If the higher layer signaling (or configuration) is not available or not provided, a default LC-PUCCH resource702may be used. The default LC-PUCCH resource702may be predefined in a fixed location or defined as a function of at least one of physical cell-ID, WTRU-ID, subframe number, and slot number. Two or more LC-PUCCH resources702may be defined in a different set of uplink PRBs which may be fully or partially overlapped in the subframe.

In an embodiment, a low-cost WTRU may be configured with at least one of the LC-PUCCH resources702(e.g., cell-specific LC-PUCCH resources) for PUCCH transmission. The configured LC-PUCCH resource702may be considered as a WTRU-specific LC-PUCCH resource702.

If a LC-PUCCH resource702is defined as the cell-specific low-cost PUCCH resource702, the WTRU-specific LC-PUCCH resource702may be the same as the cell-specific LC-PUCCH resource702. Additional configuration may not be needed or used to identify the WTRU-specific LC-PUCCH resource702.

The WTRU-specific LC-PUCCH resource702may be configured or indicated via higher layer signaling, for example, if two or more LC-PUCCH resources702are defined as cell-specific LC-PUCCH resources702. The WTRU-specific LC-PUCCH resource702may be indicated dynamically. An indicator may be carried in the DCI associated with the PUCCH transmission. The WTRU-specific LC-PUCCH resource702may be determined as a function of at least one of: WTRU-ID (e.g. C-RNTI); subframe number; SFN; frequency location of EPDCCH; and starting ECCE number of the associated EPDCCH.

In an embodiment, the LC-PUCCH resource702may be configured in a subset of uplink subframes, for example, within the reduced bandwidth704.

One or more cell-specific LC-PUCCH resources702may be configured in some or all of the uplink subframes within the reduced bandwidth704. A subset of the cell-specific LC-PUCCH resources702may be used for WTRU-specific LC-PUCCH resources702. A low-cost WTRU may be configured with and/or use the subset of LC-PUCCH resources, which may be WTRU-specific702. A low-cost WTRU may be may be configured to transmit PUCCH in only a WTRU-specific LC-PUCCH resource702. If a WTRU-specific LC-PUCCH resource702is only available in a subset of the uplink subframes, HARQ bundling and/or multiplexing may be used. One or more downlink subframes may be associated (e.g., for DL HARQ process feedback) with an uplink subframe that contains a WTRU-specific LC-PUCCH resource. One or more HARQ-ACK information that corresponds to the associated downlink subframes (and/or HARQ processes) may be bundled and/or multiplexed for transmission (e.g., PUCCH transmission in a LC-PUCCH resource) in the uplink subframe containing the WTRU-specific LC-PUCCH resource702.

The WTRU-specific LC-PUCCH resource702may be configured by an eNB or cell, and/or may be determined by the low-cost WTRU. One or more WTRU-specific LC-PUCCH resources702may be configured via higher layer signaling. One or more WTRU-specific LC-PUCCH resources702may be determined as a function of at least one of WTRU-ID (e.g. C-RNTI), subframe number, SFN, frequency location of EPDCCH, and starting ECCE number of the associated EPDCCH. The WTRU-specific LC-PUCCH resource702may be indicated dynamically via associated EPDCCH (e.g., via a DCI).

A WTRU, such as a low-cost WTRU or a WTRU supporting or using coverage enhancement, may transmit LC-PUCCH with repetitions. The repetition number may be determined based on the coverage enhancement (CE) level. It should be noted that the terms CE level and repetition number may be substituted for each other and still be consistent with this disclosure. The first transmission in a transmission with subsequent repetitions may be included or counted as one of the repetitions.

One or more CE levels may be used in a system. Number of repetitions or repeated transmissions may be represented by Nrep. For example, a CE level such as CE level-0may be used for normal coverage. For normal coverage, Nrepmay be 1 to correspond to a single transmission with no additional repetitions. There be one or more CE levels with repetition, for example CE level-1(e.g., Nrep=x1), CE level-2(e.g., Nrep=x2), and CE level-3(e.g., Nrep=x3) that may be used for coverage enhancement. Three levels are provided as an exemplary and non-limiting example. The variables x1, x2, and x3 may be positive integer numbers where x3>x2>x1. The number of CE levels supported in the system is not limited to a certain number. The numbering and ordering of the CE levels is also for example and not intended to be limiting.

In an embodiment, a LC-PUCCH type may be determined based on a CE level. For example, Type-A LC-PUCCH may be used for a lower CE level (e.g., one or more of CE level-0, CE level-1, and/or CE level-2). Type-B LC-PUCCH may be used for a higher CE level than the Type-A LC-PUCCH may be used for. For a LC-PUCCH transmission, a low-cost WTRU may determine the LC-PUCCH type based at least on CE level and transmit the LC-PUCCH in the LC-PUCCH resource of the determined type.

The WTRU-specific LC-PUCCH resource may be determined by, for example, the low-cost WTRU, as a function of at least one of: a CE-level, number of repetitions, a repetition number in Nrep(e.g. n-th repetition out of Nrep repetitions), WTRU-ID (e.g. C-RNTI), subframe number, SFN, frequency location of EPDCCH, and a starting ECCE number of the associated EPDCCH. A low-cost WTRU may transmit a LC-PUCCH (e.g., a LC-PUCCH repetition) in the LC-PUCCH resource of the determined type.

In an example, a low-cost WTRU may use one LC-PUCCH type for repetition numbers in Nrepbeginning with1and ending with n (e.g., for repetitions 1 through 10 for Nrep=20) and another LC-PUCCH type for repetition numbers in Nrepbeginning with n+1 through the last repetition (e.g., for repetitions 11-20 for Nrep=20).

The frequency location of the WTRU-specific LC-PUCCH resource may be same during Nxsubframes when repetition is used with a repetition number Nrep. The WTRU-specific LC-PUCCH resource may be determined based on one or more parameters described herein for the first subframe of every Nxsubframes. In an example, Nxmay be a predefined value or may be configured via higher layer signaling. In another example, the Nx may be determined as a function of Nrepor CE level. The Nxmay be a number smaller than Nrepor the Nxmay be a number determined irrespective of the Nrepused.

Although legacy-PUCCH resources may not collide with sounding reference signals (SRSs) since they are typically located on the band edges of the system bandwidth, the LC-PUCCH resource702may collide with SRS since it may be located in the reduced bandwidth704. In order to avoid collisions, a low-cost WTRU may use a shortened PUCCH format in the cell-specific SRS subframes irrespective of the simultaneous ACK/NACK and SRS transmissions. For example, the last LC-PUCCH symbol in a subframe may not be transmitted if a low-cost WTRU may use a shortened LC-PUCCH format.

For example, the low-cost WTRU may receive SoundingRS-UL-Config which may include SoundingRS-UL-ConfigCommon and SoundingRS-UL-ConfigDedicated. The SoundingRS-UL-ConfigCommon may include the cell-specific SRS configuration related information. The SoundingRS-UL-ConfigDedicated may include the WTRU-specific SRS configuration related information. The low-cost WTRU may receive the SoundingRS-UL-ConfigCommon and read the cell-specific SRS configuration information while the low-cost WTRU may not follow ackNackSRS-simultaneousTransmission field in the SoundingRS-UL-ConfigCommon and assume that ackNackSRS-simultaneousTransmission is always activated. In this case, one or more of following parameters may apply.

A low-cost WTRU may use shortened PUCCH format always in the cell-specific SRS subframe irrespective of the simultaneous A/N and SRS transmission configuration if the uplink system bandwidth is larger than a certain bandwidth (e.g., 6 PRBs). If the uplink system bandwidth is equal to the certain bandwidth (e.g., 6 PRBs), the low-cost WTRU may follow the simultaneous ACK/NACK and SRS transmission configuration indicated by ackNackSRS-SimultaneousTransmission. The certain bandwidth may be predefined as the bandwidth supported by a certain WTRU category or a certain WTRU with limited capability. The certain bandwidth may be dependent on WTRU capability.

A low-cost WTRU may use shortened PUCCH format always in the cell-specific SRS subframe irrespective of the simultaneous ACK/NACK and SRS transmission configuration if the uplink system bandwidth is larger than reduced bandwidth704for the low-cost WTRU. If the uplink system bandwidth is the same as the reduced bandwidth704for the low-cost WTRU, the low-cost WTRU may follow the simultaneous ACK/NACK and SRS transmission configuration indicated by ackNackSRS-SimultaneousTransmission.

A low-cost WTRU may use shortened PUCCH format in the cell-specific SRS subframe irrespective of the simultaneous ACK/NACK and SRS transmission configuration according to the PUCCH format. For example, a low-cost WTRU may use shortened PUCCH format for the PUCCH format 1/1a/1b while the low-cost WTRU may drop the PUCCH in the cell-specific SRS subframe for the PUCCH format 2/2a/2b/3.

In an embodiment, a low-cost WTRU specific ackNackSRS-SimultaneousTransmission may be transmitted, which may be independently transmitted from the legacy WTRU ackNackSRS-SimultaneousTransmission. For example, a low-cost WTRU specific sounding RS configuration (e.g., SoundingRS-UL-ConfigMTC) may be introduced in the SoundingRS-UL-Config so that the low-cost WTRU may read the low-cost WTRU specific sounding RS configuration which may include the simultaneous ACK/NACK and SRS transmission in the reduced bandwidth704. In this case, one or more of following parameters may apply.

The low-cost WTRU specific sounding RS configuration (e.g. SoundingRS-UL-ConfigMTC) may include at least one of the followings: cell-specific SRS bandwidth within the reduced bandwidth704(e.g. srs-BandwidthConfigMTC); cell-specific SRS subframe configuration within the reduced bandwidth704(e.g. srs-SubframeConfigMTC); and simultaneous ACK/NACK and SRS transmission in the reduced bandwidth704(e.g. ackNackSRS-SimultaneousTransmissionMTC).

The low-cost WTRU specific sounding RS configuration may be transmitted in the broadcasting channel transmitted in the downlink reduced bandwidth704.

In an embodiment, a LC-PUCCH resource702may not be configured in the cell-specific SRS subframe. In an example, the LC-PUCCH resource702may be located in the subframe without SRS. Therefore, a low-cost WTRU may assume that LC-PUCCH702resource is not available in the cell-specific SRS subframes. In this case, one or more of following parameters may apply.

ACK/NACK bundling or multiplexing may be used if the multiple ACK/NACK need to be transmitted in an uplink subframe due to the limited LC-PUCCH resources702. For example, if a low-cost WTRU received a PDSCH in the subframe n and the subframe n+4 in the uplink is configured as cell-specific SRS subframe, then the ACK/NACK may be bundled or multiplexed with other PDSCH and transmitted in uplink subframe other than subframe n+4.

A low-cost WTRU may be configured to either transmit shortened PUCCH format in cell-specific SRS subframe always or drop/bundle/multiplex ACK/NACK in the cell-specific SRS subframe.

In another embodiment, a low-cost WTRU may drop/bundle/multiplex PUCCH transmission in the cell-specific SRS subframe if simultaneous ACK/NACK and SRS transmission is not activated. In an example, a low-cost WTRU may assume that LC-PUCCH resource702may not be available in the cell-specific SRS subframe if simultaneous ACK/NACK and SRS transmission is not activated which may be indicated from ackNackSRS-SimultaneousTransmission.

The use of shortened LC-PUCCH format in the cell-specific SRS subframe may be determined based on the CE level used by the low-cost WTRU. The low-cost WTRU may use a shortened LC-PUCCH format in the cell-specific SRS subframe if the low-cost WTRU is operating in a certain coverage enhancement level for LC-PUCCH transmission. For example, the shortened LC-PUCCH format may be used in the cell-specific SRS subframe if a low-cost WTRU is operating a lower CE level which may require a smaller repetition number (e.g. Nrep=x1). In contrast, a shortened LC-PUCCH format may not be used in the cell specific SRS subframe if a low-cost WTRU is operating a higher CE level which may require a larger repetition number (e.g. Nrep=x2, wherein x2>x1).

Due to the reduced bandwidth704, the fixed uplink resource (e.g., center 6 RBs) may result in scheduling restriction for the low-cost WTRUs since all low-cost WTRUs may need to share the reduced bandwidth704resource.

In an embodiment, the uplink reduced bandwidth704may be defined in a WTRU-specific manner within the system bandwidth708. Therefore, two or more low-cost WTRUs may have different reduced bandwidth704location in the same network. For example, a low-cost WTRU may be configured or assigned with the first set of 6 PRBs as a reduced bandwidth704while another low-cost WTRU may be configured or assigned with another 6 PRBs non-overlapped with the first set of 6 PRBs.

In an example, the uplink band for low-cost WTRU may be configured or assigned with following procedures.

A low-cost WTRU may first receive the uplink band information from SIB-1 (e.g. freqBandIndicator) and SIB-2 (e.g. ul-Bandwidth, ul-CarrierFreq).

The low-cost WTRU may receive reduced bandwidth704related information via higher layer signaling. For example, the low-cost WTRU specific uplink carrier frequency information (e.g. ul-CarrierFreqMTC) may be carried via a broadcasting signaling (e.g. SIB-x, where the x may be but not limited to 1 or 2). Alternatively, the starting PRB index for the reduced bandwidth704may be indicated via the broadcasting signaling. If the uplink reduced bandwidth704information is not provided, a low-cost WTRU may assume that the uplink reduced bandwidth704is the center 6 PRBs of the system bandwidth.

If the uplink reduced bandwidth704is the same as the center 6 PRBs, the Physical Random Access Channel (PRACH) resource configuration may be commonly used for a legacy WTRU and a low-cost WTRU. Therefore, the low-cost WTRU may use the same PRACH resource configuration for legacy WTRUs. If partitioned PRACH resource information, which may be a subset of the PRACH resources for legacy WTRUs, is provided for low-cost WTRU, the low-cost WTRU may only use the partitioned PRACH resources.

If the uplink reduced bandwidth704is different from the center 6 PRBs and the PRACH resource configuration is provided for the uplink reduced bandwidth704, the low-cost WTRU may use the PRACH resource configuration within the uplink reduced bandwidth704for PRACH preamble transmission in the contention based random access. If there is no uplink reduced bandwidth704specific PRACH resource configuration, the low-cost WTRU may assume that the same PRACH resource configuration for legacy WTRUs may be used for the uplink reduced bandwidth704.

During or after RACH procedures, a low-cost WTRU may be configured with another uplink reduced bandwidth704. This reduced bandwidth704may be different from the uplink reduced bandwidth704configured from the broadcasting signaling (e.g. SIB-x, where the x could be but is not limited to 1 or 2). In an example, the WTRU-specific uplink reduced bandwidth704configuration message may be carried via RACH msg2 or msg4. Alternatively, the WTRU-specific uplink reduced bandwidth704configuration message may be carried via dedicated RRC message or medium access control (MAC) control element (CE) after RACH procedure. If no WTRU-specific uplink reduced bandwidth704is configured for a low-cost UE, the UE may assume that the UE-specific uplink reduced bandwidth704is the same as the uplink reduced bandwidth704configured via broadcasting signaling.

In another example, two or more uplink reduced bandwidths704may be defined via broadcasting signaling and a low-cost WTRU may determine which uplink reduced bandwidth704the low-cost WTRU will camp on. For example, a low-cost WTRU may receive information about the two or more uplink reduced bandwidth704, and the low-cost WTRU may transmit a PRACH preamble on the one of the configured uplink reduced bandwidth704. If the low-cost WTRU finishes the RACH procedures in the uplink reduced bandwidth704on which the WTRU transmitted a corresponding PRACH preamble, the low-cost WTRU may assume that the uplink reduced bandwidth704is the WTRU-specific uplink reduced bandwidth.

In an embodiment, the low-cost WTRU may receive the uplink reduced bandwidth704information from SIB-1 and SIB-2. In another embodiment, the low-cost WTRU may receive the uplink reduced bandwidth704related information via higher layer signaling. The higher layer signaling may include at least two or more uplink reduced bandwidths704. In an example, two or more uplink carrier frequency information (e.g. ul-CarrierFreqMTC-1 and ul-CarrierFreqMTC-2) may be carried via broadcasting signaling. In another example, two or more starting PRB index (e.g. ul-rbStartRB-1 and ul-rbStartRB-2) for the uplink reduced bandwidths704may be informed via broadcasting signaling. If one of the uplink reduced bandwidths704is located in the center 6 PRBs, the associated information may not be provided via broadcasting signaling and the low-cost WTRU may assume that the center 6 PRBs may be used as default uplink reduced bandwidth.

The PRACH configuration information may be provided for the configured uplink reduced bandwidths704. In an example, the PRACH configuration information for the legacy WTRU102may be reused for the configured uplink reduced bandwidths704. In another example, a separate PRACH configuration information for each uplink reduced bandwidth704may be provided. Alternatively, a common PRACH configuration for each of the uplink reduced bandwidths704may be provided. In an embodiment, this common PRACH configuration may be different from the PRACH configuration for the legacy WTRU102.

The low-cost WTRU may transmit a PRACH preamble in an uplink reduced bandwidth704based on the corresponding PRACH configuration. The low-cost WTRU may try to transmit a PRACH preamble in an uplink reduced bandwidth704at a time. If the low-cost WTRU does not receive the corresponding Random Access Response (RAR), the low-cost WTRU may try to transmit a PRACH preamble with higher power in the same uplink reduced bandwidth704until it reaches to the maximum transmit power. In an embodiment, the power increment level may be predefined. If the low-cost WTRU still doesn't receive the RAR for the PRACH preamble transmission with maximum transmit power, the low-cost WTRU may try to transmit a PRACH preamble in another reduced bandwidth704. The low-cost WTRU may try to transmit a PRACH preamble in an uplink reduced bandwidth704at a time and the low-cost WTRU may attempt to transmit a PRACH preamble on two or more uplink reduced bandwidths704.

If the low-cost WTRU receives an RAR corresponding to a specific uplink reduced bandwidth704, the WTRU may transmit RACH msg3 in the corresponding uplink reduced bandwidth704. Alternatively, the RAR may include the WTRU-specific uplink reduced bandwidth704the low-cost WTRU may use for RACH msg3 transmission.

In another embodiment, two or more reduced bandwidths704may be configured according to the uplink channel. For example, a set of PRBs may be defined or configured for PRACH transmission while another set of PRBs may be defined or configured as PUSCH/PUCCH transmission. In this case, one or more of following may apply.

The PRACH resource for low-cost WTRU may be defined in the center 6 PRBs in the subframe configured for PRACH transmission while another 6 PRBs located in other location which may be not overlapped with the center 6 PRBs may be used for PUSCH/PUCCH transmission.

The frequency location of the PRACH resource for low-cost WTRU may be predefined. As similar with the PRACH resources for the legacy WTRU, the frequency location of the PRACH resource for the low-cost WTRU may be the center 6 PRBs in the FDD system and up to six frequency locations of PRACH resource may be configurable in TDD system.

In an example in the TDD, the frequency location of PRACH resource may be fixed to one for the low-cost WTRU irrespective of the number of frequency locations configured for the PRACH resources. Alternatively, the frequency location of the PRACH resource for the low-cost WTRU may be non-overlapped frequency location for the PRACH resources for the legacy WTRU. If the system bandwidth is the same as the uplink reduced bandwidth704, the PRACH resources may be commonly used for both legacy WTRUs and low-cost WTRUs.

The uplink reduced bandwidth704for the PUSCH/PUCCH may be indicated via a broadcasting signaling. If there is no signaling for the uplink reduced bandwidth704for the PUSCH/PUCCH, a low-cost WTRU may assume that the uplink reduced bandwidth704for PUSCH/PUCCH may be the center 6 PRBs.

The uplink reduced bandwidth704for the PUSCH/PUCCH may be defined as a function of the system bandwidth. In an example, if the system bandwidth is smaller than or equal to Nthresh, which may be a predetermined value, a low-cost WTRU may assume that the uplink reduced bandwidth704is located in the center 6 PRBs. In another example, if the system bandwidth is larger than Nthresh, a low-cost WTRU may assume that the uplink reduced bandwidth704is located in the set of 6 PRBs which as an offset from the center 6 PRBs, where the offset may be predefined or configured via higher layer signaling. Also, the offset may be cell common or WTRU-specific.

In an embodiment, the uplink reduced bandwidth704for the PRACH resource and PUSCH/PUCCH resources for low-cost WTRU may be configured. In another embodiment, the PRACH resource may be fixed to a center 6 PRBs while the set of PRBs for PUSCH/PUCCH may be configured in a WTRU-specific manner. The PRACH resource may be common for all low-cost WTRUs while the PUSCH/PUCCH resource (i.e., WTRU-specific reduced bandwidth location) may be configured in a WTRU-specific manner. The WTRU-specific PUSCH/PUCCH resource may be indicated in the RAR. For example, two or more set of PUSCH/PUCCH reduced bandwidth704resources may be configured as a cell-specific PUSCH/PUCCH reduced bandwidth704resources and one of them may be indicated in the RAR for msg3 transmission.

In another embodiment, different sets of PRBs may be defined or configured for PRACH, PUSCH, and PUCCH, respectively. Therefore, a low-cost WTRU may need to transmit PRACH preamble, PUSCH, and PUCCH in the different set of PRBs. A low-cost WTRU may need to transmit PUSCH and PUCCH in a different set of uplink PRBs. If a low-cost WTRU may need to transmit a PUSCH containing UCI, the uplink reduced bandwidth for PUSCH may be used.

Another issue with the use of reduced bandwidths704on low-cost WTRUs is that a base station114a,114bmay have no knowledge about whether a Physical Multicast Channel (PMCH) or a Multimedia Broadcast Multicast Service (MBMS) is being received by the low-cost WTRU. A base station114a,114bmay not know whether a MBMS service is specifically used by a low-cost WTRU. This may impact the ability of the low-cost WTRU to properly receive PMCH (and as such Multicast Control Channel (MCCH) and/or Multicast Traffic Channel (MTCH)) if the resources used for PMCH exceed the reduced bandwidth capability of the WTRU.

A base station114a,114bmay be indicated by MBMS network entities such as the Multi-cell/multicast Coordination Entity (MCE) that a particular MBMS service and/or Multicast-broadcast single-frequency network (MBSFN) service area may be received by the low-cost WTRU. A low-cost WTRU may be indicated during MBMS service discovery and/or by a base station114a,114bthat a MBMS service and/or MBSFN area may support reception by a low-cost WTRU. The following provides solutions for indicating such information to a base station114a,114band/or a low-cost WTRU, and may be used in combination or individually.

For the following solutions, in support of the reduced capability WTRUs for a particular MBMS service, the MCE and base station114a,114bmay allocate resources for MBMS data transmission on those resources that may be received by the reduced capability WTRUs. For example, in MBSFN subframes, an base station114a,114bmay transmit PMCH which may carry MCCH and MTCH in resources that may be received by a reduced bandwidth WTRU, e.g., in the center 6 PRBs.

In an embodiment, the low-cost WTRU may receive a MBMS service level indicator. A low-cost WTRU may be indicated that a MBMS service may specifically for low-cost WTRUs. For example, the MBMS service may specifically be designated for reduced bandwidth WTRUs. A normal WTRU102may not be restricted to receive such MBMS service and may be rejected when trying to subscribe to the service. A low-cost WTRU may be indicated that a particular MBMS service may be accessed by a reduced capability WTRU, however, the service may not be exclusively consumed by reduced capability WTRUs. Alternatively, a low-cost WTRU may be indicated that a particular MBMS service may not be allowed reception by a low-cost WTRU. The low-cost WTRU may be denied reception upon attempting to subscribe to this type of MBMS service.

A low-cost WTRU may receive reduced capability support indication as part of the MBMS announcement and/or discovery process. For example, a low-cost WTRU may be indicated of this information as part of the User Service Description (USD) information. As part of the USD information, a low-cost WTRU may be indicated of MBMS service support for reduced capability WTRUs as part of the MBMS Feature Requirement List which is part of the USD. For example, a low-cost WTRU may subscribe to a MBMS service if the requirements indicate that reduced capability and/or reduced bandwidth feature is supported by that low-cost WTRU.

A base station114a,114bmay indicate to a low-cost WTRU that a MBSFN area may support reception of MBMS by a reduced capability WTRU. For example, a base station114a,114bmay transmit such indication in SIB13 along with other information regarding the MBSFN area. The support of reduced capability may be dynamic and changed by the MCE and base station114a,114bbased on MBMS service that is transmitted in the MBSFN area or based on the capabilities of the low-cost WTRU that is subscribed to the MBMS service. Possibly, a base station114a,114bmay change the indication of reduced capability WTRU support to support of normal WTRUs102when a particular MBSFN area no longer provides MBMS services targeted for reduced capability WTRUs. The change of such indication may be provided by the normal SIB modification procedure.

The base station114a,114band/or the MCE may allocate one or more MBSFN subframes as indicated in SIB2 to support MBMS services to reduced capability WTRUs. A low-cost WTRU may be indicated one or more MBSFN subframes, for example in SIB2, available for reduced capability WTRUs along with the MBSFN subframe configuration. The reduced capability supporting MBSFN subframes may be allocated to one or more MBSFN areas as defined by the base station114a,114band/or MCE, which may transmit control information and data for MBMS services supporting reduced capability WTRUs.

For example, a MCE and a base station114a,114bmay allocate a set of MBMS services specific to reduced capability WTRUs to a MBSFN area defined by a certain group of cells that have a high density of such devices. The MCE may then schedule the transmission of control information and data for these MBMS services on pre-allocated subset of available MBSFN subframes, and additionally schedule the MBMS service transmissions based on a specific periodicity. During the MBSFN subframes allocated for reduced capability WTRUs, a base station114a,114bmay then transmit PMCH, and optionally PDCCH, with MBMS Radio Network Temporary Identifier (M-RNTI) in a manner which may be received by the low-cost WTRU.

A base station114a,114bmay receive an indication from the MCE to support (or not support) reduced capability WTRUs for a particular MBMS session, service and/or MBSFN area. For example, the base station114a,114b, based on this indication may transmit MCCH and MTCH on PMCH, for a particular MBSFN area or possibly for a particular PMCH or MBMS session. The base station114a,114bmay determine, based on the scheduling information, which MBSFN subframes may be used to transmit a reduced bandwidth PMCH such that a reduced capability WTRU may be able to receive the PMCH properly.

The base station114a,114bmay receive an indication from the MCE to support (or not support) for MBMS scheduling information. For example, a base station114a,114bmay receive the indication to support reduced capability WTRUs as an additional information element in the M2-AP MBMS Scheduling Information message. Based on the received MCCH Update Time IE and the additional IE, the base station114a,114bmay transmit the PDCCH with M-RNTI to indicate upcoming change to the MCCH in a reduced bandwidth PDCCH or possible EPDCCH. This may enable a low-cost WTRU that has subscribed to the particular MBMS service to properly receive the updated MCCH.

A low-cost WTRU may receive PMCH in one or more of MBSFN subframe associated with the MBSFN area targeted for the low-cost WTRU within the smaller bandwidth. In an example, the low-cost WTRU may receive PMCH in the subset of PRBs in the system bandwidth. In this embodiment, one or more of following parameters may apply.

When the low-cost WTRU decodes the PMCH, the IMCS, which may be an indicator of modulation and coding scheme, for the PMCH may be configured by higher layer. The low-cost WTRU may use IMCSfor the PMCH and a transport block size (TBS) table to determine the modulation order and TBS index. The TBS may be determined with the assumption that NPRBis equal to NPRB,rewhere NPRB,remay be the number of physical resource blocks (PRBs) for the reduced bandwidth, and NPRB,remay be smaller than NPRB.

The frequency location of the PMCH in the MBSFN subframe may be predefined to a fixed location (e.g. center 6 PRBs), signaled via higher layer, or configured as a function of MBSFN area index.

When the low-cost WTRU monitors the MCCH change notification, if the system bandwidth is the same as the reduced bandwidth704, the low-cost WTRU may monitor the PDCCH with the cyclic redundancy check (CRC) scrambled by the M-RNTI within the PDCCH common search space in an MBSFN subframe.

When the low-cost WTRU monitors the MCCH change notification, if the system bandwidth is larger than the reduced bandwidth704, the low-cost WTRU may monitor PDCCH with the CRC scrambled by the M-RNTI within EPDCCH common search space.

When the low-cost WTRU monitors the MCCH change notification, the EPDCCH common search space for MCCH change notification may be located in the non-MBSFN region. Alternatively, the EPDCCH common search space for MCCH change notification may be located in the MBSFN region. Here, the EPDCCH common search space in the MBSFN region may be defined as an extended cyclic prefix irrespective of the CP length in the non-MBSFN region.