BR112017006136B1 - COMMUNICATION SYSTEM - Google Patents

Abstract

COMMUNICATION SYSTEM. The present invention relates to a communications system wherein a communications node allocates resources for potential use by any of a plurality of user communications devices, including user communications devices of the first type (e.g., legacy type ) and user communication devices of the second type (e.g. machine type). Control data is sent to the user communication devices, defining communication resources for potential use by any of the user communication devices. The control data includes information identifying a first PRACH resource configuration for a first type communication device and a second type resource configuration for a second type of device, so that user devices can be distinguished by the PRACH configuration used. .

Description

TECHNICAL FIELD

[001] The present invention relates to mobile communication devices and networks, in particular, but not exclusively those that operate in accordance with 3GPP (3rd GENERATION PARTNERSHIP PROJECT) standards or equivalents or derivatives thereof. The invention has particular, although not exclusive, relevance to UTRAN's Long Term Evolution - LTE (called Evolved Universal Terrestrial Radio Access Network (E-UTRAN), including LTE-Advanced).

PREVIOUS TECHNIQUE

[002] In a mobile (cellular) communications network, (user) communication devices (also known as user equipment (UE), e.g. mobile phones) communicate with remote servers or with other communication devices via stations base. In their communication with each other, communication devices and base stations use licensed radio frequencies, which are typically divided into frequency bands and/or time blocks.

[003] In order to communicate via base stations, communication devices need to monitor control channels operated by the base stations. One of these control channels, the so-called physical downlink control channel (PDCCH), carries programming assignments and other control information. The PDCCH has a variety of purposes. Firstly, it is used to transmit scheduling decisions to individual communication devices, that is, scheduling assignments for uplink and downlink communication.

[004] The information carried in the PDCCH is called downlink control information (DCI). Physical control channels, such as PDCCH, are transmitted in an aggregate of one or multiple control channel elements (CCEs), where one control channel element corresponds to nine groups of resource elements (REGs). Each REG has four resource elements (REs).

[005] Another control channel, the so-called physical random access channel (PRACH) is provided to synchronize transmissions between a communication device and the network (for example, when establishing initial access to the communication device and/or whenever synchronization is required). In the current standard specification (starting from Rel-8), the resource (preamble, time, frequency) allocated to the PRACH is configured in advance and the applicable PRACH parameters are transmitted by the so-called System Information Block 2 (SIB2). One of the parameters specifies the so-called random access preamble, which consists of a cyclic prefix part and a sequence part. The length of the preamble (that is, the overall length of the two parts combined) depends on the frame structure and random access configuration. The preamble format is controlled by the upper layers (via SIB2). Thus, based on the parameters included in SIB2, communication devices are able to initiate access to the network via the current PRACH resource and use the appropriate parameters (e.g., transmit an appropriate preamble). More details of the physical random access preamble can be found in the section (e.g. transmitting an appropriate preamble). Furthermore, details of the physical layer random access preambles can be found in section 5.7.1 of 3GPP Technical Specification (TS) 36.211, the contents of which are incorporated herein by reference.

[006] When a communication device in idle mode needs to communicate with other communication nodes, it needs to be switched to its operating mode for the so-called radio resource control (RRC) connected mode (from idle mode RPC ). To do this, the communication device performs a random access communication procedure with the appropriate base station (e.g., a base station that has the strongest signal and/or a base station that the communication device is authorized to use). . The random access procedure includes the communicating device selecting and transmitting to the base station (by the PRACH advised via the SIB2) an appropriate preamble sequence together with a temporary identifier to identify the communicating device to the base station. If the base station does not receive the communication device's transmission successfully (e.g., because a plurality of devices are transmitting preambles at the same time, resulting in a collision) and/or does not send an appropriate random access response, then the base station communication channel will be configured to send another preamble sequence after a predetermined delay (and possibly repeat this tap until the station responds). If the communication device's transmission is received successfully (e.g., its transmission does not collide with transmissions by others), then the base station will send an appropriate random access response (in which the base station identifies the communication device it is using the received temporary identifier) and will allocate resources to the communication device to communicate with the network.

[007] Thus, once the base station responds to a preamble transmission by the communication device, the communication device is able to request in its text message the establishment of an RRC (and/or similar) connection, using the allocated resources. Once an RRC connection is established between the communication device and the base station, the communication device is able to communicate with other communication nodes via this base station (and via the core network) using the allocated resources. by the base station.

[008] Recent developments in telecommunications have seen a large increase in the use of machine-type communication devices (MTC), which are network-connected devices arranged to communicate and perform actions without human assistance. Examples of such devices include smart meters, which can be configured to take measurements and relay those measurements to other devices via a telecommunications network. Machine-type communication devices are also known as machine-to-machine (M2M) communication devices.

[009] MTC devices connect to the network (after performing an appropriate random access procedure) whenever they have data to send or receive from a remote "machine" (e.g., a server) or user. MTC devices utilize communication protocols and standards that are optimized for mobile phones or similar user equipment. However, MTC devices, once used, typically operate without requiring supervision or human interaction, and follow software instructions stored in internal memory. MTC devices could also remain stationary and/or inactive for a long period of time. Specific network requirements for supporting MTC devices have been discussed in the 3GPP TS 22.368 standard, the contents of which are incorporated herein by reference.

[0010] For Release 13 (Rel-13) of the standards relating to MTC devices, support for reduced bandwidth of 1.4 MHz on downlink and uplink is considered. Therefore, some MTC devices will only support a limited bandwidth (typically 1.4 MHz) compared to the full LTE bandwidth and/or may have fewer simplified components. This allows such "low bandwidth" MTC devices to be made more economically compared to MTC devices that support higher bandwidth and/or have more complicated components.

[0011] Lack of network coverage (e.g. when employed internally), in combination with often limited functionality of MTC devices, may result in such MTC devices having a low data rate and therefore there is a risk of some messages or some channels, such as PDCCH, cannot be received by an MTC device. To mitigate this risk, it has been proposed to increase the coverage of the PDCCH channel (and/or the evolved physical downlink control channel (EPDCCH) in Rel-13) to support such MTC devices (e.g., corresponding to 20dB for duplex transmissions of frequency division (FDD).

[0012] One proposed approach to increasing coverage, for so-called "enhanced coverage MTC devices", is to repeat the same EPDCCH information (e.g., DCI) across multiple subframes (e.g., two, three, four). In other words, for MTC increased coverage devices, the base station duplicates the EPDCCH information in the time domain (the base station retransmits the same EPDCCH information in one or more subframes subsequent to the subframe in which the EP-DCCH information is first sent) . Such an increased coverage MTC device may be configured to combine multiple copies of the (same) EPDCCH information received in the multiple subframes, and after combining the received information, the increased coverage MTC device may be able to decode the EPDCCH more successfully than based on a single copy of the EPDCCH information.

[0013] In practice, MTC devices may be used in different locations and they may experience different channel conditions. Therefore, the number of repetitions (of the EPDCCH information) may need to be created specifically for each device situation or coverage level. Therefore, in order to facilitate such increased coverage, each MTC device will need to inform its serving base station of the amount of coverage required (e.g., 5dB/10dB/15dB/20dB coverage increase) to enable the station to adjust its control signaling appropriately. .

[0014] However, ideally physical layer control signaling (e.g., EPDCCH signaling) and higher layer common control information (e.g., SIB, random access response (RAR), message sending, and /or similar) exhibit a higher level of commonality between situations for reduced bandwidth communication device and solutions for increased coverage communication devices.

[0015] However, the inventors have realized that in order to support increased bandwidth MTC devices in release 13, the provision of PRACH for the increased bandwidth MTC devices needs to address several issues, including, for example: - Due to the reduced bandwidth of 1.4 MHz on downlink and uplink, reduced bandwidth MTC devices cannot receive a PDCCH that is densely spread across an entire cellular bandwidth (i.e., can be transmitted at frequencies which fall outside the 1.4 MHz supported by the MTC device); - consequently, low-bandwidth MTC devices also cannot receive the programming designation included in legacy RAR messages transmitted on the PDCCH (when it is spread across the entire cellular bandwidth); and - the EPDCCH Common Search Space (CSS) can be defined such that the physical transmission channel (PBCH) indicates its location in time frequency resources, in which case a reduced bandwidth MTC device will be unable to receive the CSS if the PBCH or EPDCCH is transmitted outside the 1.4 MHz band supported by the MTC device.

[0016] It appears that there is no need to change the current PRACH design in order to support reduced bandwidth MTC devices on Rel-13, except that DCI for RAR messages will need to be transmitted EPDCCH Common Search Space (CSS), instead from in the PDCCH CSS, for MTC devices (as an MTC device in Rel-13 will only monitor the EPDCCH CSS for potential dynamic programming of common control information). However, it remains to be resolved how a base station can efficiently and securely identify a low-bandwidth MTC device on Rel-13 so that the corresponding DCI (e.g. RAR message) is transmitted on the EPDCCH CSS (for the reduced bandwidth MTC device).

[0017] In addition to the issues associated with reduced bandwidth MTC devices, the PRACH provision for increased coverage MTC devices in Rel-13 will need to support PRACH repetition, across multiple subframes in the time domain, using the PRACH formats. existing LTE Rel-8 preamble in order to increase PRACH channel coverage and for backward compatibility.

[0018] Therefore, the provision of PRACH for increased coverage MTC UEs in Rel-13 also needs to address at least the following issues: - how to identify reduced bandwidth communication devices and increased coverage MTC communication devices (from so that a DCI/RAR can be transmitted on the EP-DCCH CSS to such communication devices; - how to reduce the probability of collision (contention problem) between reduced bandwidth communication devices and increased coverage communication devices (CE ), and also between different CE levels; and - as there are many associated higher CE levels (due to time domain repetitions), it is desirable to avoid PRACH preamble collision with other coverage levels as well as bandwidth communication devices. reduced bandwidth (although collision/containment with the same CE level must be allowed).

SUMMARY OF THE INVENTION

[0019] The present invention seeks to provide systems, devices and methods that address the above issues at least partially.

[0020] According to one aspect, the invention provides a communications node operable to allocate resources to potential users by any plurality of user communications devices, including first-type (e.g., legacy) communications devices and communications devices. of the second type (e.g., machine type), to communicate with the communications node, the communications node comprising: means for sending, to said plurality of user devices, control data defining communications resources for potential use by any of said plurality of user communication devices, controlling data including at least identifying information; i) a first physical random access channel, PRACH, resource configuration for said first type user communication devices; and ii) a second PRACH resource configuration for said second type devices; means for receiving, from a user communication device of said plurality of user communication devices, a random access message coinciding with one of said first and second type resource configurations, by communication resources defined by said control data; and means for determining, based on the PRACH resource configuration with which the received random access message matches, that said user communication device comprises a user communication device of the first type or a device of the second type.

[0021] The means for sending may be operable to send a random access response (RAR) mapped to a physical downlink control channel (PDCCH), when said user communication device is determined to comprise a communication device of the first type and to send a random access response (RAR) mapped to an augmented physical downlink control channel (EPDCCH) when said user communication device is determined to comprise an MTC device.

[0022] Each PRACH resource configuration may define a preamble sequence and wherein said random access message may include a prefix and a preamble sequence coinciding with one of said first and second type PRACH resource configurations, and in that said determining means may be operable to determine whether the first user communication device comprises a first user communication device of the first type or comprises a device of the second type, based on said preamble sequence included in said access message random.

[0023] The first PRACH resource configuration may define a first set of communication resources for potential use by said first-type user communication devices. The second PRACH resource configuration may define a second set of communication resources, different from the first set, for potential use by said second type devices. The determining means may be operable to determine that: i) the first user communication device comprises a first type user communication device when said receiving means receives said random access message by a communication resource belonging to said first set of communication resources. The determining means may be operable to determine that: ii) the first user communication device comprises a device of the second type when said receiving means receives said random access message by a communication resource belonging to said second resource set of communication.

[0024] The determining means may be operable to terminate when said user communication device is a second type device, if said second type device comprises a reduced bandwidth second type device and/or a second type device. of increased coverage.

[0025] The determining means may be operable to determine when said user communication device is a second type of increased coverage device, a level of increased coverage required by said second type of increased coverage device.

[0026] At least one of said first and second PRACH resource may define a set of communication resources comprising no more than six blocks of physical resources.

[0027] The communications node may comprise a base station.

[0028] The communications node may comprise a base station operating in accordance with the long-term evolving standards set, LTE.

[0029] Communication resources may be resources provided in accordance with at least one of time, frequency, and code sequence multiplexing schemes.

[0030] According to one aspect, the invention provides a machine-type communication device (MTC) for a communication system in which a communications node allocates resources for potential use by any of a plurality of communication devices. user, including user communication devices of the first type (e.g., legacy), and MTC communication devices, the communication device of the second type comprising: means for receiving from the communications node, control data defining communication resources for use potential by any of said plurality of user communication devices, the control data including information identifying at least: i) a first physical random access channel, PRACH resource configuration for said primary user communication devices. first type; and ii) a second PRACH resource configuration for said MTC devices; and means for sending, to the communications node, a random access message matching the common PRACH resource configuration by communications resources defined by said control data.

[0031] The receiving means may be operable to receive a random access response (RAR) mapped to an augmented physical downlink control channel (EPDCCH) that responds to said random access message.

[0032] According to one aspect, the invention provides a method performed by a communications node in a communications system wherein the communications allocate resources for potential use by any of a plurality of user communications devices, including communications devices of users of the first type (e.g., user type, and communication devices of the second type (e.g., machine type), to communicate with the communications node, the method comprising: sending, to said plurality of communication devices, users, control data defining communication resources for potential use by any said plurality of user communication devices, the control data including information identifying at least: a first physical random access channel, PRACH resource configuration for said devices, and of user communication of the first type; and ii) a second configuration of PRACH resources for said devices of the second type; receiving, from a user communication device of said plurality of user communication devices, a random access message coinciding with one of said first and second type resource configurations by communication resources defined by said control data; and determining, based on the PRACH resource configuration with which said random access message coincides, whether said user communication device comprises a user communication device of the first type or comprises a device of the second type.

[0033] The method may further comprise: sending a random access response (RAR) mapped to a physical downlink control channel (PDCCH) when said user communication device to comprise a user communication device of the first type ; and sending a random access response (RAR) mapped to an augmented downlink control channel (EPDCCH) when said user communication device is determined to comprise a second type device.

[0034] According to one aspect, the invention provides a method carried out by a machine-type communications device, "MTC", in a communications system in which a communications node allocates resources for potential use by any of a plurality of communication devices, including first type user communication devices and MTC devices, the method comprising: receiving, from the communications node, control data defining communication resources for potential use by any of said plurality of user communication devices, the control data including information identifying at least: i) a first PRACH physical random access channel configuration for said first type user communication devices; and ii) a second PRACH resource configuration for said MTC devices; and means for sending, to the communications node, a random access message coinciding with said second PRACH resource configuration by communications resources defined by said control data.

[0035] The method may further comprise: receiving a random access response (RAR) mapped to an augmented physical downlink control channel (EPDCCH) that responds to said random access message.

[0036] Aspects of the invention extend to corresponding computer program systems, methods and products, such as computer readable storage media, having instructions stored therein, which are operable to program a programmable processor to perform a method as described, in the aspects and possibilities set out above and cited in the claims and/or to program a computer suitably adapted to provide the apparatus cited in any of the claims.

[0037] Each feature disclosed in this specification (which includes the claims) and/or shown in the drawings can be incorporated into the invention independently (or in combination) of any other features disclosed and/or illustrated. In particular, but without limitation, the features of any of the dependent claims of a given independent claim may be introduced into that independent claim in any combination or individually.

BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Embodiments of the invention are now described by way of example with reference to the attached figures, in which:

[0039] Figure 1 schematically illustrates a telecommunications system to which embodiments of the invention can be applied;

[0040] Figure 2 is a block diagram illustrating the main components of the communication device shown in Figure 1;

[0041] Figure 3 is a block diagram illustrating the main components of the base station shown in Figure 1;

[0042] Figure 4 illustrates an example in which UE category-specific PRACH configurations can be employed in the system shown in Figure 1;

[0043] Figure 5 illustrates an example in which UE category-specific PRACH configurations can be employed in the system shown in Figure 1; It is

[0044] Figure 6 illustrates an example in which UE category-specific PRACH configurations can be employed in the system shown in Figure 1.

DESCRIPTION OF MODALITIES <OVERVIEW>

[0045] Figure 1 schematically illustrates a mobile (cellular) telecommunications system 1, in which communication devices 3 (such as a cell phone 3-1 and MTC device 3-2) can communicate with each other and/or with others communication nodes via an E-UTRAN base station 5 (designated 'eNB') and a core network 7. As appreciated by those skilled in the art, although a cellular phone 3-1, an MTC device 3-2, and a base station 5 are shown in Figure 1 for illustration purposes, the system, when implemented, will typically include other base stations and communication devices.

[0046] Base station 5 is connected to the core network 7 via an S1 interface. The core 7 network includes, among others: a port for connection to other networks, such as the Internet and/or to servers hosted outside the core 7 network; a mobility management entity (MME) to maintain the locations of the communication devices 3 (e.g., the mobile phone and the MTC device) within the communication network 1; and a home subscriber server (HSS) for storing subscription-related information (e.g., information identifying which communication device 3 is configured as a machine-type communication device) and for storing control parameters specific to each communication device 3.

[0047] Each communication device 3 may fall into one or more categories of UEs. A first category of UEs includes communication devices that support only one previous release of the LTE standard (e.g., Rel-8, Rel-9, Rel-10, Rel-11, and/or Rel-12). Such a group of communication devices is commonly called legacy UEs (assuming that base station 5 is operating according to Rel-13 of the LTE standards). It will be noted that some communication devices that belong to this group may not support EPDCCH (PDCCH only). A second category of UEs includes low-bandwidth UEs (e.g., MTC Rel-13 devices, capable of utilizing 1.4 MHz bandwidth only), which are not capable of communicating over the entire bandwidth. available in base station cell 5. A third category of UEs includes increased coverage UEs (e.g., MTC devices), which require certain base station functionalities to be simplified and/or relaxed (although such increased coverage UEs may support other features as normal).

[0048] The base station 5 is configured to transmit a physical downlink control channel (PDCCH) and an evolved PDCCH (EPDCCH) for reception by communication devices 3 located within the cell of the base station 5. The (E)PDCCH allocates uplink and downlink resources to communication devices 3. One difference between PDCCH and EPDCCH is that the common search space of EPDCCH uses relatively narrow frequency spectrum (1.4 Mhz) which makes it compatible with wide MTC devices Rel-13 reduced bandwidth, although PDCCH uses a wider frequency spectrum to provide backward compatibility with legacy (pre-Rel-13) communications devices.

[0049] The so-called common search space (CSS) carries downlink control information (DCI) in the cell that is common to all communication devices 3. For example, the CSS may include: System information blocks ( SIBs) that contain information related to cellular access parameters; random access channel (RACH) message (e.g., Random Access Response (RAR) and/or Contention Resolution); and/or the paging channel (PCH). In LTE Rel-13, CSS forms part of EPDCCH. The resources (time-frequency) allocated to the CSS are indicated via the so-called physical transmission channel (PBCH).

[0050] Base station 5 is configured to transmit a 'SIB2' into its cell for reception by communications devices 3. The SIB2 includes the appropriate parameters for configuring PRACH resources currently in use in the cell of base station 5. A configuration typical PRACH resource for a cell and the parameters and values are illustrated in Table 1. Table 1 - PRACH Source Configuration in SIB2

[0051] As explained above, communication devices 3 need to establish an RRC connection with base station 5 in order to be able to communicate with other devices via this base station 5 (and the core network 7). Therefore, each communication device 3 is configured to perform an appropriate random access procedure (via the PRACH), to synchronize its transmissions with the base station 5, and to indicate to the network the reason for establishing the RRC connection.

[0052] However, as also explained above, some communication devices may only support a previous release of the LTE standard (legacy UEs) rather than the release supported by base station 5, some communication devices may comprise bandwidth UEs. reduced bandwidth, and some communication devices may comprise increased coverage UEs.

[0053] Beneficially, the PRACH is configured in the base station cell 5 such that the different categories of communication devices are allocated different PRACH resources and/or different PRACH preambles for use when initiating a random access procedure. with base station 5. In this example, the different categories of communication devices comprise: i) legacy UEs (MTC devices); ii) low bandwidth UEs); and iii) increased coverage UEs (MTC devices). Thus, the PRACH configuration by base station 5 comprises separate PRACH configuration parameters for each category of UEs (specifying respective associated PRACH resources and/or associated PRACH preambles per category of UE).

[0054] Therefore, upon receipt of a random access preamble sequence, the base station 5 is advantageously able to determine (by checking the PRACH resources and/or PRACH preambles used) the category of communication device 3 that sent the random access sequence. preamble. Specifically, the base station 5 is capable of discerning at least legacy UEs (MTC devices), reduced bandwidth UEs (MTC devices), and increased coverage UEs (MTC devices) from each other.

[0055] In the example shown in Figure 1, mobile phone 3-1 comprises a legacy UE and MTC device 3-2 comprises a reduced bandwidth MTC device. By listening to the SIB2 information (transmitted by the base station 5), both the cell phone 3-1 and the MTC device 3-2 are able to derive the applicable PRACH configuration for their category of UEs, and perform random access procedures accordingly. Thus, mobile phone 3-1 selects one of the appropriate PRACH preambles associated with the legacy UEs and transmits the selected preamble to base station 5 by the PRACH resource associated with the legacy UEs. On the other hand, the MTC device 3-2 selects the appropriate PRACH preambles associated with reduced bandwidth UEs and transmits the selected preamble to the base station 5 by the PRACH resource associated with reduced bandwidth UEs.

[0056] Therefore, based on the received preamble and/or PRACH resource used, the base station 5 is able to discern the mobile phone 3-1 from the MTC device 3-2, and send a random access response (RAR) in a manner corresponding. Specifically, the base station 5 is configured to send a RAR including an appropriate DCI: i) in the PDCCH CSS (in response to a preamble sequence sent by a legacy UE); and in the EPDCCH CSS (in response to a preamble sequence sent by a reduced bandwidth UE and/or an increased coverage UE).

[0057] In summary, the base station is advantageously capable of allocating PRACH resources according to the category of the communication device (transmitting appropriate PRACH modalities per category), and responding to preamble transmissions by communication resources (PDCCH/EPDCCH) that the UE category of the sending communication device it is capable of using.

COMMUNICATION DEVICE

[0058] Figure 2 is a block diagram illustrating the main components of the communication device 3 shown in Figure 1. The communication device 3 may be an MTC device or a cell phone (cell phone) configured as a machine-type communication device. The communication device 3 comprises a transmitter-receiver circuit 31, which is operable to transmit signals to the base station 5 and receive signals from the same via at least one antenna 33. Typically, the communication device 3 also includes a user interface 35 that allows the user to interact with the communication device 3, however, this user interface 35 may be omitted for some MTC devices.

[0059] The operation of the transceiver circuit 31 is controlled by a controller 37 in accordance with software stored in memory 39. The software includes, among other things, an operating system 41, a communication control module 43, an MTC module 45, and a random access module 47.

[0060] The communication control module 43 controls communications between the communication device 3 and the base station 5 and/or other communication nodes (via the base station 5).

[0061] The MTC 45 module is operable to perform machine-type communication tasks. For example, the MTC module 45 may collect data to send (e.g., periodically and/or when it detects a trigger) to a server (via the transceiver circuit 31).

[0062] Random access module 47 is responsible for obtaining and maintaining transmitter synchronization with the network. For example, the random access module 47 may send (via the transceiver circuit 31) a random access transmission (including a selected preamble sequence) to the base station 5 when the communication device 3 needs to establish an RRC connection to the network. . When selecting/sending a random access preamble sequence, the random access module 47 takes into consideration the communication device category 3 and the PRACH configuration (transmitted by the base station 5) applicable to that category of communication devices.

BASE STATION

[0063] Figure 3 is a block diagram illustrating the main elements of the base station 5 shown in Figure 1. The base station 5 comprises an E-UTRAN base station (eNB) comprising a transceiver circuit 51, which is operable to transmit signals to communication devices 3 and receive signals therefrom via one or more antennas 53. Base station 5 is also operable to transmit signals to and receive signals from the core network 7 via an appropriate core network interface 55 (such as an S1 interface). ). The operation of the transceiver circuit 51 is controlled by a controller 57 in accordance with software stored in memory 59.

[0064] The software includes, among other things, an operating system 61, a communication control module 63, a broadcast module 65, a PRACH configuration module 67, and a UE category determination module 69. The communication control module 63 controls communications with communication devices 3. The communication control module is also responsible for programming resources to be used by communication devices 3 served by this base station 5.

[0065] The transmission module 65 transmits, via the transmission channel, System information (such as base station cell configuration 5) for reception by communication devices 3 located within the base station cell 5. For example, the transmission module 65 transmits the PRACH configuration employed in the cell.

[0066] The PRACH configuration module 67 is responsible for configuring associated random access parameters for use by each category of communication devices over the PRACH. The PRACH configuration module 67 is responsible for informing (via the transmission module 65) the communication devices 3 located within the base station cell 5 about the applicable random access configuration (PRACH) for each category of communication devices.

[0067] The UE category determination module 69 determines, based on the received preamble sequence (e.g., time/frequency resource, the preamble sequence is sent in preamble and/or selected preamble) the category of the messenger communication device 3.

[0068] In the above description, the communication device 3 and the base station 5 are described for ease of understanding as having a discrete number of modules. Although these modules may be provided in this way for certain applications, for example, where an existing system has been modified to implement the invention, in other applications, for example, in systems designed with the inventive features in mind from the outset, these modules may be embedded in the overall operating system or code, and thus these modules may not be discernible as discrete entities.

[0069] Various embodiments (options A to D) will be described below, with reference to Figures 4 to 6. It will be noted that these embodiments are not mutually exclusive and any of options A to D may be combined within the same system, or within of a single cell and/or neighboring cells. For example, base station 5 may be configured to switch from one mode of operation to another, e.g., periodically, depending on the number of MTC 2 devices in its cell, depending on the number of preamble retransmissions (e.g., due to collision ), and/or similar.

OPERATION - OPTION A

[0070] This configuration is based on the concept of preamble sequence separation (PRACH). In other words, different (sets of) preamble sequences are reserved for different categories of communication devices 3 (e.g., reduced-bandwidth MTC devices, increased-bandwidth MTC devices, LTE standards mobile phones, and/or or communication devices operating in different operating modes such as MTC mode/UE mode). In this example, base station 5 (using its PRACH configuration module 67) allocates a first set of preamble sequences to legacy communication devices, allocates a second set of preamble sequences (different from the first set) to communication devices ( MTC) operating in reduced bandwidth (BW) mode, and allocates a third set of preamble sequences (different from the first and second sets) to communication devices (MTC) operating in increased coverage (CE) mode. One or more sets of preamble sequences may also be divided into other subsets when appropriate. A preamble sequence separation is illustrated by way of example in Table 2 below, in which the first set includes PRACH preambles 0-31, the second set includes PRACH preambles 32-42, and the third set includes PRACH preambles 43-63 (more divided into four subsets for different levels of coverage increase). Table 2 - Preamble Sequence Partition

[0071] Base station 5 is beneficially configured to transmit (using its transmission module 65) in its cellular information regarding the applicable preamble sequence division via higher layer signaling (e.g., SIB2), e.g., using an index appropriate PRACH configuration. In this way, the base station 5 is able to inform communicating devices 3 within its cell which preamble sequence applies to each category of devices, so that the communicating devices 3 are able to select and transmit a preamble sequence that (implicitly) indicates to the base station 5 the category of that communication device 3.

[0072] For example, if the MTC 3-2 device is a reduced bandwidth UE, then it selects (using its MTC module 45) a preamble from preambles Nos. 32 to 42 and transmits (using its transceiver circuit 31) this preamble to base station 5 via PRACH (in any subframe in which PRACH is configured). Based on the received preamble, the base station 5 is able to determine (using its UE category determination module 69) that the messenger communication device 3-2 is a reduced bandwidth MTC device, and allocates corresponding resources (sets DCI to the MTC 3-2 device so that the resources allocated fall within the bandwidth that the MTC 3-2 device is capable of utilizing).

[0073] Advantageously, based on the received preamble sequence and the set to which that preamble sequence belongs, the base station 5 is able to determine whether to transmit a DCI on the PDCCH CSS (i.e., response to a preamble sequence sent by a legacy MTC device) or to transmit a DCI in the EPDCCH CSS (i.e., in response to a preamble sequence sent by a reduced bandwidth MTC device or an increased coverage MTC device). In other words, base station 5 is configured to send Random Access Response (RAR) messages (which include an appropriate DCI) via the EPDCCH Common Search space (EPDCCH CSS) to low-bandwidth MTC devices and to devices Increased coverage MTC.

[0074] It will be noted that option A can be realized regardless of whether the multiplexer scheme illustrated in Table 2 is used or not. However, if preamble sequence separation is used, then the number of preamble sequences available for each separation may be small, which in turn may increase the possibility of collision of MTC devices.

OPERATION - OPTION B

[0075] Figure 4 illustrates one way in which UE category-specific PRACH modalities can be employed in the System shown in Figure 1. In this example, the base station 5 employs, for each communication device category 3, a respective PRACH configuration using different time resources (e.g. in a subframe for each device category).

[0076] The various PRACH configuration indexes (and associated preamble and subframe formats) that can currently be used in LTE systems are shown in Table 5.7 5.7.1-2 of 3GPP TS 36.211. Some of the PRACH indices that can be used in this example are also shown in Table 3 below. However, rather than supporting a single PRACH configuration in its cell (as currently defined for LTE in 3GPP TS 36.211), base station 5 in this example is configured to apply sequence separation to its PRACH configurations, that is, the Base station 5 employs multiple PRACH configurations in the time domain.

[0077] Specifically, in this example, base station 5 is configured to transmit (using its transmit module 65): i) PRACH configuration index no. 9 to be applied in subframes #1, #4, and #7 (e.g., for legacy UEs); ii) PRACH configuration index no. 10 to be applied in subframes #2, #5, and #8 (e.g., for low-bandwidth UEs); and iii) PRACH configuration index no. 11 to be applied in subframes #3, #6, and #9 (e.g., for increased coverage UEs). This information may be transmitted, for example, as part of the SIB2 information. Table 3 - PRACH settings (source: Table 5.7.1-2 of 3GPP TS 36.211

[0078] For example, base station 5 may transmit (e.g., in advance) the applicable PRACH configuration index for each UE category. However, it will be noted that base station 5 may transmit, in each subframe, the currently available PRACH configuration index, and information identifying the associated UE category (e.g., instead of or in addition to any advance indication).

[0079] By listening to information transmitted from base station 5 (e.g., SIB2), each communication device 3 is able to obtain (using its MTC module 45) the PRACH configuration index for its category. Therefore, whenever a communication device (e.g., the MTC device 3-2) needs to perform a random access procedure, it transmits (using its random access module 47 and transceiver circuit 31) a preamble sequence within the subframe allocated to its category of UEs (as specified by the PRACH configuration index for that category).

[0080] Beneficially, based on the resource (subframe) in which the base station 5 receives the random access message (preamble sequence), the base station 5 is able to determine (using its UE category determination module 69) the category of the sending communication device. Therefore, base station 5 may also determine whether to transmit a DCI on the PDCCH CSS (for legacy UEs) or whether to transmit a DCI on the EPDCCH CSS (for reduced bandwidth UEs and/or increased coverage UEs) in response to the message random access system of the communication device.

[0081] Additionally, for increased coverage UEs, base station 5 (using its PRACH configuration module 67) may also perform preamble sequence separation (as per option A above) within the time-associated PRACH configuration index and inform (e.g., via system transmission), the communication devices 3 about which sequence separation applies to which coverage level within the associated PRACH time resources (subframes).

OPERATION - OPTION C

[0082] Figure 5 illustrates another example in which UE category-specific PRACH configurations may be employed in the System shown in Figure 1. In this example, the base station 5 employs, for each category of communication devices 3, a respective associated PRACH configuration , using different associated frequency resources (e.g., PRACH is provided in a different frequency band for each device category) of the same subframe. Effectively, the resulting PRACH configuration comprises a frequency division multiplexing (FDM) based PRACH, wherein each category of communication device 3 is configured to utilize a different frequency band during the random access procedure.

[0083] In this example, the following PRACH configuration is employed: - region '0' FDM is allocated to legacy UEs; - FDM region ‘1’ is allocated to (MTC) low-bandwidth UEs; and - region ‘2’ is allocated to (MTC) increased coverage UEs.

[0084] It will be noted that in FDM region '2' it is also possible to employ additional sequence separation (as in option A) to distinguish between different levels of increased coverage supported by the mobile communications device transmitting in that FDM region.

[0085] For example, base station 5 may transmit (e.g., in advance and/or in each subframe) information identifying the respective PRACH configuration (including information identifying the associated frequency band) for each UE category.

[0086] By listening to the information (e.g., SIB2) transmitted by the base station 5, each communication device 3 is able to obtain (using its MTC module 45) the applicable PRACH configuration (PRACH frequency band) for its category. Therefore, whenever a communication device (e.g., the MTC 3-2 device) needs to perform a random access procedure, its random access module 47 transmits a preamble sequence within the frequency band configured for its category (e.g. , in any of the subframes #1, #4, and #7 shown in Figure 5).

[0087] Then, depending on the frequency (and time) resource at which the base station 5 receives the preamble sequence transmission, the base station 5 is able to determine (using its UE category determination module 69) the category of the communication device that sends. Therefore, base station 5 may determine whether to transmit a DCI on the PDCCH CSS (for legacy UEs) or whether to transmit a DCI on the EPDCCH CSS (for reduced bandwidth UEs and/or increased coverage UEs) in response to the random access of the communication device.

[0088] Additionally, for increased coverage UEs, the base station 5 may also perform preamble sequence separation (as in option A above) within the associated PRACH frequency resource (FDM region) and report (e.g., via broadcast of System) to the communication device 5 which sequence separation applies to which coverage level within the associated frequency resource.

OPERATION - OPTION D

[0089] Figure 6 illustrates another way in which PRACH configurations of specific UE categories can be employed in the System shown in Figure 1. In this example, base station 5 employs a PRACH configuration based on a hybrid time-frequency resource to differentiate between different categories of communication devices 3.

[0090] Effectively, option D is a combination of options B and C (and can also be combined with option A, when appropriate).

[0091] In the example shown in Figure 6, three categories of communication devices are supported in the base station cell 5. The first category of communication devices includes legacy UEs, the second category includes reduced bandwidth UEs, and the third category includes increased coverage UEs.

[0092] The first category is designated with PRACH resources based on an appropriate PRACH configuration index (in subframes #1, #4, and #7 as specified, for example, by the PRACH index 9 shown in Table 3), although second and third category devices are designated with FDM-based PRACH capabilities (in subframes #2, #5, and #8), wherein each of the communication devices is configured to use a different frequency band during the random access procedure.

[0093] In this example, the following frequency division multiplexing is used: - FDM region '0' is allocated MTC UEs of increased coverage; and - FDM region ‘1’ is allocated to low bandwidth MTC UEs.

[0094] It will be noted that in the FDM region '0' it is possible to employ additional frequency separation (as in option A) to distinguish between different levels of increased coverage supported by the mobile communications device transmitting in that FDM region.

[0095] In this example, base station 5 transmits (e.g., in advance and/or at each subframe) information identifying the respective PRACH configuration (including information identifying the associated frequency band and subframe) to each UE.

[0096] By listening to the information (e.g., SIB2) transmitted by the base station 5, each communication device 3 is able to obtain (using its MTC module 45) the applicable PRACH configuration (PRACH frequency band/PRACH configuration index) for each category. Therefore, whenever a communication device (e.g., the MTC 3-2 device) needs to perform a random access procedure, its random access module 47 transmits a preamble sequence within the configured subframe/frequency band for its category. , depending on the frequency band and subframe in which the base station 5 receives the preamble sequence transmission, the base station 5 is able to determine (using its category determination module UE 69) the category of the communication device that sends Therefore, base station 5 may also determine whether to transmit a DCI on the PDCCH CSS (for legacy UEs) or whether to transmit a DCI on the EPDCCH CSS (for reduced bandwidth UEs and/or increased coverage UEs) in response to the random access message from the communication device Modifications and alternatives

[0097] The detailed Modalities were described above. As technicians in the field know, several modifications and alternatives can be made in the above modalities, still taking advantage of the inventions configured here.

[0098] In the above embodiments, described with reference to figures 4 to 6, a radio frame comprises ten subframes (subframes #0 to #9). As those skilled in the art know, a radio frame can include any number of subframes.

[0099] In the description above, information regarding the PRACH configuration is signaled via SIB2. However, it will be noted that the PRACH configuration (at least part of it) may be signaled via a different system information block, for example, via one or more specific SIB for reduced bandwidth UEs and/or increased coverage UEs. Alternatively or additionally, some or all of this information may be obtained by the communicating devices in a different manner - for example, the PRACH configuration may be signaled via system broadcast (e.g. PBCH) and/or via higher layers (e.g. RRC ).

[00100] Additionally, the applicable PRACH configuration may not be explicitly assigned by the base station and instead may be determined based on other information, such as cell ID associated with the base station. This has the benefit of reducing the amount of data that has to be signaled to communication devices.

[00101] It will be noted that although the Communication System is described in terms of the base station operating as an E-UTRAN base station (eNB), the same principles can be applied to base stations operating as macro or peak base stations, base stations femto, relay nodes providing elements of base station functionality, return base stations (HeNB), or other similar communication nodes.

[00102] In the above embodiments, an LTE telecommunications system was described. As appreciated by those skilled in the art, the techniques described in the present application can be employed in other communication systems, including previous 3GPP-type systems. Other communication nodes may include user devices, such as personal digital assistants, laptop computers, web browsers, etc.

[00103] In the embodiments described above, the base station and the communication device each include a set of transceiver circuits. Typically, this set of circuits will be made up of dedicated hardware circuits. However, in some embodiments, part of the circuitry may be implemented as software run by the corresponding controller.

[00104] In the above embodiments, various software modules have been described. As appreciated by those skilled in the art, the software modules may be provided in compiled or uncompiled form and may be provided to the base station or user device as a signal over a computer network, or a recording medium. Furthermore, the functionality performed by part or all of this software may be performed using one or more dedicated circuits.

[00105] In the above embodiments, machine-type communication devices and mobile phones are described. However, it will be noted that mobile telephones (and similar user equipment) can also be configured to operate as machine-type communication devices. For example, mobile telephone 3-1 may include (and/or provide functionality of) MTC module 45.

EXAMPLES OF MTC APPLICATIONS

[00106] It will be appreciated that each communication device may support one or more MTC applications. Some examples of MTC applications are listed in the following table (source: 3GPP TS 22.368, Annex B). This list is not exhaustive and is intended to be indicative of the scope of machine-type communication applications.

[00107] Various other modifications will be obvious to those skilled in the art and will not be described in detail here.

[00108] Some or all of the modalities mentioned above can be described in the following supplementary notes. However, the present invention is not limited to the following supplementary notes in any way. (Supplementary Note 1)

[00109] Communications node operable to allocate resources for potential use by any of a plurality of communications devices, including legacy user communications devices and machine-type communications (MTC) devices, to communicate with the communications node. communications, the communications node comprising:

[00110] means for sending to said plurality of user communication devices control data defining communication resources for potential use by any of said plurality of user devices, the control data including information identifying at least: i) one first PRACH resource configuration of physical random access channel, PRACH, for said legacy user communication devices; and ii) a second PRACH resource configuration for said MTC devices;

[00111] means for receiving, from a user communication device, a random access message coinciding with one of the first and second PRACH resource configurations of communication resources defined by said control data; It is

[00112] means for determining, based on the PRACH resource configuration with which said received random access message matches, whether the user communication device comprises a legacy user communication device or comprises an MTC device; wherein said means for sending is operable to send a random access response (RAR) mapped to a physical downlink control channel (PDCCH) when said user communication device is determined to comprise a user communication device of legacy and to send a random access response (RAR) mapped to an augmented physical downlink control channel when said user communication device is determined to comprise an MTC communication device. (Supplementary Note 2)

[00113] 1. The Communications Node in accordance with Supplementary Note 1, wherein each said PRACH resource configuration defines an associated preamble sequence and wherein said random access message includes a prefix and a preamble sequence of according to one of said first and second PRACH resource configurations, and wherein said determining means is operable to determine whether said user communication device comprises a user communication device or comprises an MTC device based on said sequence preamble included in said random access message. (Supplementary Note 3)

[00114] 2. The communications node in accordance with Supplementary Note 1 or 2, wherein: i) said first PRACH resource configuration defines a first set of communications resources for potential use by said user communications devices of legacy; and ii) said PRACH resource configuration defines a second set of communication resources, different from the first set, for potential use by said MTC devices; It is

[00115] wherein said determining means is operable to determine that: i) said first user communication device comprises a legacy user communication device when said receiving means receives said random access message by a resource of communication that belongs to said first set of communication resources; and ii) said first user communication device comprises an MTC device when said receiving means receives said random access message by a communication resource belonging to said second set of communication resources. (Supplementary Note 4)

[00116] 3. The communications node according to any of Supplementary Notes 1 to 3, wherein said determining means is operable to determine when the user communications device is an MTC device, whether said MTC device comprises a reduced bandwidth MTC device and/or an increased coverage MTC device. (Supplementary Note 5)

[00117] 4. The communications node in accordance with Supplementary Note 4, wherein said determining means is operable to determine when said user communications device is an increased coverage MTC device, an increased level of coverage required by said increased coverage MTC device. (Supplementary Note 6)

[00118] 5. The communications node according to any one of Supplementary Notes 1 to 5, wherein at least one of said first and second PRACH resource configurations defines a set of communications resources comprising no more than six resource blocks physicists. (Supplementary Note 7)

[00119] 6. The communications node according to any one of Supplementary Notes 1 to 6, comprising a base station. (Supplementary Note 8)

[00120] 7. The communications node in accordance with Supplementary Note 6 comprising a base station operating in accordance with the set of long-term evolution standards, LTE. (Supplementary Note 9)

[00121] 8. The communications node according to any one of Supplementary Notes 1 to 8, wherein said communication resources are resources provided in accordance with at least one of time, frequency, and code sequence multiplexing scheme. (Supplementary Note 10)

[00122] 9. The Machine-Type Communications Device, (MTC), for a communications system in which a communications node allocates resources for potential use by any of a plurality of user communications devices, including co- legacy user communications, the MTC communication device comprising:

[00123] means for receiving, from the communications node, control data defining communications resources for potential use by any of said plurality of communications devices, the control data including information identifying at least: i) a first resource configuration random access channel, PRACH, for said legacy user communication devices; and ii) a second PRACH resource configuration for said MTC devices; It is

[00124] means for sending, to the communications node, a random access message coinciding with said second resource configuration by communication resources defined by said control data;

[00125] wherein said receiving means is operable to receive a random access response (RAR) mapped to an augmented downlink control channel (EPDCCH) that reacts to said random access message. (Supplementary Note 11)

[00126] 10. The Method performed by a communications node in a Communications System wherein a communications node allocates resources for potential use by any of a plurality of user communications devices, including legacy user communications devices and machine-type communication devices, (MTC), for communicating with the communications node, the method comprising:

[00127] send, to said plurality of user communication devices, control data defining communication resources for potential use by any of said plurality of user communication devices, the control data including information identifying at least: i) a first physical random access channel resource configuration, PRACH, for said legacy user communication devices; and ii) a second PRACH resource configuration for said MTC devices;

[00128] receiving, from a user communication device, a random access message coinciding with one of said first and second PRACH resource configurations by communication resources defined by said control data;

[00129] determining, based on the PRACH resource configuration with which the received random access message matches, whether said user communication device comprises a legacy user communication device or an MTC device;

[00130] sending a random access response (RAR) mapped to a physical downlink control channel (PDCCH) when said communication device is determined to comprise a legacy user communication device; It is

[00131] send a random access response RAR) mapped to an augmented physical downlink control channel (EPDCCH) when said user communication device is determined to comprise an MTC device. (Supplementary Note 12)

[00132] 11. The Method performed by a machine-type communications device (MTC), in a Communications System wherein a communications node allocates resources for potential use by any of a plurality of user communications devices, including devices of legacy user communications and machine-type communications (MTC) devices, the method comprising:

[00133] receive, from the communications node, control data defining communications resources for potential use by any of said plurality of user communications devices, the control data including information identifying at least: i) first random access configuration physical, PRACH, for said legacy user communication devices; and ii) second configuration of PRACH resources for said MTC devices;

[00134] sending, to the communications node, a random access message coinciding with said second PRACH resource configuration by communication resources defined by said control data; It is

[00135] receive a random access response (RAR) mapped to an augmented physical downlink control channel (EPDCCH) that reacts to said random access message. (Supplementary Note 13)

[00136] Communication system comprising a communications node in accordance with any one of Supplementary Notes 1 to 8 and a machine-type communication device in accordance with Supplementary Note 9. (Supplementary Note 14)

[00137] 12. The Computer Program Product comprising computer-implementable instructions for causing a processing device to perform a method in accordance with Supplementary Note 10 or 11.

[00138] This application is based on UK patent application no. 1417068.2, filed on September 26, 2014 and claims benefit thereof, the description of which is incorporated herein in its entirety by reference.

Claims (14)

1. Communication apparatus (5) characterized by the fact that it is operable to communicate with at least one of a first type of user equipment, UE (3-1), and a second type of enhanced coverage UE (3-2 ) for which transmissions are repeated in the time domain according to one of a plurality of coverage enhancement levels, wherein different coverage enhancement levels are configured with a different respective number of repetitions, the communication apparatus (5 ) comprising: means (67) for transmitting a control signal, wherein the control signal comprises a first resource configuration for a first physical random access channel, PRACH, for the first type of UE (3-1) and a second resource configuration for a second PRACH for the second type of UE (3-2), wherein said second resource configuration comprises a respective PRACH configuration for each coverage increase level; means (67) for transmitting the second resource configuration to a second PRACH via Radio Resource Control, RRC, layer signaling; and means (63) for receiving a random access message based on any of the first resource configuration and the second resource configuration. 2. Communication apparatus (5), according to claim 1, characterized by the fact that the communication apparatus (5) further comprises means (63) for transmitting a random access response, RAR, in which the RAR is mapped to a physical downlink control channel, PDCCH, in case the RAR is transmitted to the first UE type (3-1), where the RAR is mapped to a machine type communication, MTC, downlink control channel specific physical, PDCCH, in case the RAR is transmitted to the second type of UE (3-2); and wherein when the receiving medium receives a random access message based on a particular PRACH configuration, the RAR transmitting medium is configured to transmit a RAR using the coverage increase level corresponding to that PRACH configuration. 3. Communication apparatus (5) according to claim 1 or 2, characterized in that the random access message is based on the configuration of the first resource in case the first type of UE transmits the random access message, and wherein the random access message is based on the second resource configuration in case that second type of UE transmits the random access message. 4. Communication apparatus (5), according to any one of claims 1 to 3, characterized by the fact that the communication apparatus (5) further comprises means for determining a type of UE based on a resource for receiving the message random access. 5. A user equipment, UE, operable to communicate with a communication apparatus (5), employing coverage enhanced signaling by repeating time domain transmissions in accordance with one of a plurality of coverage enhancement levels, in that different levels of coverage enhancement are configured with a different respective number of repetitions, the UE characterized by the fact that it comprises: means for receiving, via Radio Resource Control, RRC, layer signaling, a resource configuration for an access channel physical random, PRACH, for an enhanced coverage type UE, wherein the resource configuration comprises a respective PRACH configuration for each level of coverage enhancement; and means for transmitting a random access message based on the received resource configuration. 6. UE, according to claim 5, characterized by the fact that the resource configuration is determined based on a category of the UE. 7. UE, according to claim 5 or 6, characterized by the fact that it further comprises means for receiving a random access response, RAR, the RAR being mapped to a machine type communication, MTC, physical downlink control channel specifically, PDCCH. 8. UE according to claim 7, characterized by the fact that the transmission medium is configured to transmit the random access message based on a particular PRACH configuration and the receiving means is configured to receive the RAR using the level coverage increase corresponding to this PRACH configuration. 9. UE, according to any one of claims 5 to 8, characterized by the fact that the UE is a machine-type communication device, MTC. 10. UE, according to claim 9, characterized by the fact that it comprises at least one of: a reduced bandwidth MTC device; and an MTC device with enhanced coverage. 11. UE according to any one of claims 5 to 10, characterized by the fact that the resource configuration is mapped to a level of coverage intensification. 12. UE, according to claim 11, characterized by the fact that the level of coverage intensification is mapped to a series of repetitions of a control channel transmission. 13. A method realized by a communication apparatus (5) that is operable to communicate with at least one of a first type user equipment, UE, and a second type of enhanced coverage UE for which transmissions are repeated in the time domain according to one of a plurality of coverage enhancement levels, wherein different coverage enhancement levels are configured with a different respective number of repetitions, the method characterized by the fact that it comprises: transmitting a control signal , wherein the control signal comprises the first resource configuration for a first physical random access channel, PRACH, for the first type of UE and the second resource configuration for a second PRACH for the second type of UE, wherein the said second resource configuration comprises a respective PRACH configuration for each coverage increase level, wherein the second resource configuration for a second PRACH is transmitted via Radio Resource Control, RRC, layer signaling; and receiving a random access message based on any of the first resource configuration and the second resource configuration. 14. A method carried out by user equipment, UE, which is operable to communicate with a communication apparatus (5), employing coverage-enhanced signaling by repeating time-domain transmissions according to one of a plurality of levels of coverage enhancement, in which different coverage intensities levels are configured with a different respective number of repetitions, the method characterized by the fact that it comprises: receiving, via Radio Resource Control, RRC, layer signaling, a resource configuration for a physical random access channel, PRACH, for an enhanced coverage type UE, wherein the resource configuration comprises a respective PRACH configuration for each level of coverage enhancement; and transmitting a random access message based on the received resource configuration.