Technical Field
[0001] The present invention relates to mobile communications devices and networks, p ar
ticularly but not exclusively those operating according to the 3rd Generation
Partnership Project (3GPP) standards or equivalents or derivatives thereof. The
invention has particular although not exclusive relevance to the Long Term Evolution
(LTE) of UTRAN (called Evolved Universal Terrestrial Radio Access Network
(E-UTRAN)), including LTE- Advanced.
Background Art
[0002] In a mobile (cellular) communications network, (user) communication devices (also
known as user equipment (UE), for example mobile telephones) communicate with
remote servers or with other communication devices via base stations. In their commu
nication with each other, communication devices and base stations use licensed radio
frequencies, which are typically divided into frequency bands and/or time blocks.
[0003] In order to be able to communicate via the base stations, communication devices
need to monitor control channels operated by the base stations. One of these physical
control channels, the so-called physical downlink control channel (PDCCH) carries
control information for scheduling of downlink and uplink resources to individual
communication devices. Physical downlink control (PDCCH) channels are transmitted
on an aggregation of one or several consecutive control channel elements (CCEs).
Scheduling is realised by the serving base station transmitting, over the PDCCH, a
Downlink Control Information (DCI) to each communication device that has been
scheduled resources in the current scheduling round. Downlink data that has been
scheduled this way is transmitted over the so-called Physical Downlink Shared
Channel (PDSCH) using the resources allocated by the DCI. The PDSCH resources a s
sociated with the PDCCH control information (DCI) are normally provided within the
same subframe, albeit using different frequencies.
[0004] The so-called physical uplink control channel (PUCCH) carries, in the uplink from
the communication device to the serving base station, information referred to as Uplink
Control Information (UCI). The UCI includes, amongst others, the so-called Hybrid
Automatic Repeat Request (HARQ) feedback which is generated by the commu
nication device and sent to the serving base station in response to downlink data trans
missions received over the resources specified by the DCI. The UCI may also include
channel quality indication (CQI), although this is optional. Normally, PUCCH
resources are allocated to each communication device such that each communication
device has time for processing the received downlink data before sending an ap
propriate (HARQ) Ack/Nack. Typically, PUCCH resources are allocated in the fourth
subframe following transmission of the corresponding downlink data over the PDSCH,
leaving a total of three subframes for processing the received data and generating an
Ack/Nack.
[0005] The more communication devices there are in a cell and the more data is com
municated for these communication devices, the more control signalling and HARQ
feedback needs to be transmitted. Therefore, the amount of resources allocated for the
PUCCH may change in dependence on the number of communication devices served
by the base station.
[0006] In the Rel-13 version of the LTE standards, it is envisioned that the PUCCH will be
provided in accordance with the current (Rel-8 based) design. In particular, the current
PUCCH design specifies, amongst others, that:
- the PUCCH is located at an edge of the total available cell bandwidth and that
PUCCH slot hopping can also be applied (slot hopping is a technique for improving
frequency diversity by frequently alternating the location of the PUCCH physical
resources between opposite edges of the cell bandwidth); and
- the number of physical resource blocks (PRBs) in a slot that is available for
potential PUCCH transmission is configured by higher layer signalling using the
'push-HoppingOffset' parameter.
[0007] However, recent developments in telecommunications have seen a large increase in
the use of machine-type communications (MTC) UEs which are networked devices
arranged to communicate and perform actions without human assistance. Examples of
such devices include smart meters, which can be configured to perform measurements
and relay these measurements to other devices via a telecommunication network.
Machine-type communication devices are also known as machine-to-machine (M2M)
communication devices.
[0008] MTC devices connect to the network whenever they have data to send to or receive
from a remote 'machine' (e.g. a server) or user. MTC devices use communication
protocols and standards that are optimised for mobile telephones or similar user
equipment. However, MTC devices, once deployed, typically operate without
requiring human supervision or interaction, and follow software instructions stored in
an internal memory. MTC devices might also remain stationary and/or inactive for a
long period of time. The specific network requirements to support MTC devices have
been dealt with in the 3GPP TS 22.368 standard, the contents of which are in
corporated herein by reference.
Summary of Invention
Technical Problem
[0009] For the Release 13 (Rel-13) version of the standards relating to MTC devices,
support for a reduced bandwidth of 1.4 MHz in downlink and uplink is envisaged.
Thus, some MTC devices (referred to as 'reduced bandwidth MTC devices') will
support only a limited bandwidth (typically 1.4 MHz) compared to the total LTE
bandwidth and/or they may have fewer/simplified components. This allows such
'reduced bandwidth' MTC devices to be made more economically compared to MTC
devices supporting a larger bandwidth and/or having more complicated components.
[0010] However, the inventors have realised that, since reduced bandwidth MTC devices
cannot communicate over the entire cell bandwidth, it may not always be possible to
schedule such reduced bandwidth MTC devices in Rel-13 using the current (Rel-8
based) PDCCH/PUCCH channel design, especially when PUCCH slot hopping is also
employed in the cell.
[001 1] Further, the lack of network coverage (e.g. when deployed indoors), in combination
with the often limited functionality of MTC devices, can result in such MTC devices
having a low data rate and therefore there is a risk of some messages or channels not
being received by an MTC device. In order to mitigate this risk, it has been proposed to
increase the coverage of the PDCCH (or enhanced PDCCH ('EPDCCH') in Rel-13) to
support such MTC devices (e.g. corresponding to 20dB for frequency division duplex
(FDD) transmissions). To facilitate such enhanced 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 enhancement) to allow the base station to adjust its
control signalling appropriately.
[0012] Ideally, physical layer control signalling (such as (E)PDCCH, PUCCH, and/or the
like) and higher layer common control information (e.g. SIB, random access response
(RAR), paging messages, and/or the like) exhibit a high level of commonality between
solutions for reduced bandwidth communication devices and solutions for coverage
enhanced communication devices.
[0013] However, it is presently not known how to support reduced bandwidth MTC devices
whilst also ensuring that an appropriate coverage enhancement can be provided when
scheduling coverage enhanced MTC devices.
Solution of Problem
[0014] The present invention seeks to provide systems, devices and methods which at least
partially address the above issues.
[0015] In an exemplary aspect of the invention, there is provided a communication
apparatus which is operable to communicate with at least one of a first type mobile
station and a second type mobile station, the communication apparatus including: a
means for assigning a first frequency resource for a first uplink control channel of the
first type mobile station per slot; and a means for assigning a second frequency
resource for a second uplink control channel of the second type mobile station per a set
of subframe.
[0016] In another exemplary aspect of the invention, there is provided a mobile station
which is operable to communicate with a communication apparatus, the mobile station
including: a means for determining first frequency resource which is assigned for a
first uplink control channel per a set of subframe; and a means for transmitting the
uplink control channel based on the first frequency resource.
[0017] In another exemplary aspect of the invention, there is provided a method performed
by a communication apparatus which is operable to communicate with at least one of a
first type mobile station and a second type mobile station, the method including:
assigning a first frequency resource for a first uplink control channel of the first type
mobile station per slot; and assigning a second frequency resource for a second uplink
control channel of the second type mobile station per a set of subframe.
[0018] In another exemplary aspect of the invention, there is provided a method performed
by a mobile station which is operable to communicate with a communication
apparatus, the method including: determining first frequency resource which is
assigned for a first uplink control channel per a set of subframe; and transmitting the
uplink control channel based on the first frequency resource.
[0019] Aspects of the invention extend to corresponding systems, methods, and computer
program products such as computer readable storage media having instructions stored
thereon which are operable to program a programmable processor to carry out a
method as described in the aspects and possibilities set out above or recited in the
claims and/or to program a suitably adapted computer to provide the apparatus recited
in any of the claims.
[0020] Each feature disclosed in this specification (which term includes the claims) and/or
shown in the drawings may be incorporated in the invention independently (or in com
bination with) any other disclosed and/or illustrated features. In particular but without
limitation the features of any of the claims dependent from a particular independent
claim may be introduced into that independent claim in any combination or indi
vidually.
Brief Description of Drawings
[0021] Embodiments of the invention will now be described by way of example only with
reference to the attached figures in which:
[fig.l]Figure 1 schematically illustrates a telecommunication system to which em
bodiments of the invention may be applied;
[fig.2]Figure 2 is a block diagram illustrating the main components of the commu
nication device shown in Figure 1;
[fig.3]Figure 3 is a block diagram illustrating the main components of the base station
shown in Figure 1;
[fig.4]Figure 4 illustrates an exemplary way in which an MTC specific physical uplink
control channel can be provided in the system shown in Figure 1;
[fig.5]Figure 5 illustrates an exemplary way in which an MTC specific physical uplink
control channel can be provided in the system shown in Figure 1;
[fig.6]Figure 6 illustrates an exemplary way in which an MTC specific physical uplink
control channel can be provided in the system shown in Figure 1;
[fig.7]Figure 7 illustrates an exemplary way in which an MTC specific physical uplink
control channel can be provided in the system shown in Figure 1;
[fig.8]Figure 8 illustrates an exemplary way in which an MTC specific physical uplink
control channel can be provided in the system shown in Figure 1;
[fig.9]Figure 9 illustrates an exemplary way in which an MTC specific physical uplink
control channel can be provided in the system shown in Figure 1;
[fig. 10]Figure 10 illustrates an exemplary way in which an MTC specific physical
uplink control channel can be provided in the system shown in Figure 1; and
[fig.ll]Figure 1 1 illustrates an exemplary way in which an MTC specific physical
uplink control channel can be provided in the system shown in Figure 1.
Description of Embodiments
[0022]
Figure 1 schematically illustrates a mobile (cellular) telecommunication system 1 in
which communication devices 3 (such as mobile telephone 3-1 and MTC device 3-2)
can communicate with each other and/or with other communication nodes via an EUTRAN
base station 5 (denoted 'eNB') and a core network 7. As those skilled in the
art will appreciate, whilst one mobile telephone 3-1, one MTC device 3-2, and one
base station 5 are shown in Figure 1 for illustration purposes, the system, when im
plemented, will typically include other base stations and communication devices.
[0023] The base station 5 is connected to the core network 7 via an SI interface. The core
network 7 includes, amongst others: a gateway for connecting to other networks, such
as the Internet and/or to servers hosted outside the core network 7; a mobility
management entity (MME) for keeping track of the locations of the communication
devices 3 (e.g. the mobile telephone and the MTC device) within the communication
network 1; and a home subscriber server (HSS) for storing subscription related in
formation (e.g. information identifying which communication device 3 is configured as
a machine-type communication device) and for storing control parameters specific for
each communication device 3.
[0024] The base station 5 is configured to provide a number of control channels, including,
for example, a physical downlink control channel (PDCCH) and a physical uplink
control channel (PUCCH). The PDCCH is used by the base station 5 for allocating
resources to the communication devices 3 (typically by sending a UE-specific DCI to
each communication device that has been scheduled in the current scheduling round).
The PUCCH is used by the communication devices 3 for sending a UE-specific UCI to
the base station (e.g. an appropriate HARQ Ack/Nack corresponding to downlink data
received using the resources allocated by the DCI).
[0025] Each communication device 3 may fall into one or more of categories of UEs. A first
category of UEs include communication devices that support only an earlier release of
the LTE standard (e.g. Rel-8, Rel-9, Rel-10, Rel-11, and/or Rel-12). Such group of
communication devices are commonly referred to as legacy UEs (assuming that the
base station 5 is operating in accordance with Rel-13 of the LTE standards). A second
category of UEs include reduced bandwidth UEs (e.g. Rel-13 MTC devices capable of
using a 1.4 Mhz bandwidth only), which are not able to communicate over the entire
bandwidth available in the cell of the base station 5. A third category of UEs includes
coverage enhanced UEs (e.g. some MTC devices), which require certain base station
functionalities to be simplified and/or relaxed (although such coverage enhanced UEs
may support other functionalities as normal).
[0026] Beneficially, in order to support reduced bandwidth MTC devices, respective
reduced bandwidth MTC specific PUCCH resources are configured for each MTC
device in such a way that the PUCCH resources used in a first slot in the time domain
(e.g. the first slot of a subframe) and the PUCCH resources used in a second slot in the
time domain (e.g. the second slot of the subframe) are limited to being transmitted
within the reduced bandwidth (typically 1.4MHz) supported by the reduced bandwidth
MTC device even where slot-to-slot hopping is employed, in which the frequency
position of the PUCCH resources in the second slot effectively mirrors the frequency
position of the PUCCH resources in the first slot, around the centre of the cell
bandwidth.
[0027] A number of specific embodiments are described in which this is achieved.
In one embodiment, for example, this is achieved by Over-provisioning' the PUCCH
such that the PUCCH resources available for scheduling to MTC devices include
resources that extend from the upper and lower frequencies of the cell bandwidth into a
central portion of the cell bandwidth that is smaller than the bandwidth of the reduced
bandwidth MTC device. For example the central portion may have a bandwidth no
greater than six adjacent resource blocks (~1.08MHz) which is less than the typical
1.4MHz bandwidth of a reduced bandwidth MTC device. Beneficially, in this embodiment
each category of communication devices can be allocated PUCCH resources
within the same PUCCH and in the same manner (i.e. with an appropriate slot
hopping).
[0028] In another embodiment, for example, this is achieved by allocating resources (a
maximum of six adjacent resource blocks) for the MTC devices to transmit PUCCH
control information in a shared channel that does not employ slot hopping. For
example, 'PUCCH' control information may be transmitted using the resources of the
physical uplink shared channel (PUSCH). Therefore, effectively, the MTC devices
may be configured to transmit their PUCCH signalling using shared resources (e.g.
PUSCH), rather than dedicated resources (e.g. conventional, or legacy, PUCCH). Ben
eficially, in this embodiment there is no need to Over-provision' the conventional
PUCCH to account for the MTC devices (which typically communicate less
frequently, and hence they need to send fewer PUCCH signalling, than other types of
communication devices).
[0029] In yet another embodiment, for example, this is achieved by providing a separate,
MTC specific, PUCCH channel near a central portion of the cell bandwidth that is
smaller than the bandwidth of the reduced bandwidth MTC device (and that is
separated from the legacy PUCCH that extends from the edges of the cell bandwidth).
For example, such a separate, MTC specific, PUCCH channel may be provided over
the central portion having a bandwidth no greater than six adjacent resource blocks
(~1.08MHz). One benefit of this embodiment is that there is no need to share the MTC
PUCCH resources with the resources normally used for the uplink shared channel
communications.
[0030] In yet another embodiment, for example, this is achieved by allocating a set of
resources forming part of a convention (legacy) PUCCH region to MTC devices and
disabling slot hopping in that set of resources. One benefit of this embodiment is that
PUCCH resources may be provided near the edges of the cell bandwidth for each
category of communication devices.
[0031] In yet another embodiment, for example, this is achieved by configuring the MTC
devices to transmit, in a first slot, their PUCCH signalling using part of the legacy
PUCCH resources, at the upper or lower edges of the cell bandwidth, that is smaller
than the bandwidth of the reduced bandwidth MTC device. In this case, rather than
performing conventional slot hopping in which the PUCCH resources used in the
second slot are at a frequency position that mirrors the frequency position of the
PUCCH resources in the first slot, the MTC devices are configured to apply time
division multiplexing techniques in order to maintain the benefit of frequency diversity
otherwise provided by slot hopping. Specifically, after completing its PUCCH
transmission in the first slot, but prior to transmitting in the second slot, the MTC
device is configured to switch/re-tune its (reduced bandwidth) transceiver to move its
operational frequency band to a position that mirrors, around the centre of the cell
bandwidth, the position of the operational frequency band used in the first slot. Once
the MTC device has completed switching/re-tuning its transceiver, it continues its
PUCCH transmission in the second slot at a frequency position (within the entire cell
bandwidth) that may (but doesn't have to) mirror, around the centre of the cell
bandwidth, the frequency position (within the entire cell bandwidth) used in the first
slot.
[0032] Advantageously, the provision of such MTC specific PUCCH resources in ac
cordance with any of the above embodiment does not affect the provision of PUCCH
resources for legacy communication devices, because there is no need for the base
station to change the way its legacy PUCCH is provided.
[0033] In summary, the PUCCH is beneficially configured in the cell of the base station 5 in
such a way that different categories of communication devices are allocated different
types of PUCCH resources. Therefore, legacy communication devices may be
allocated resources in a conventional (Rel-8 based) PUCCH, whilst MTC devices may
be allocated resources in the MTC specific PUCCH (in a portion of the cell bandwidth
that is smaller than the bandwidth of the reduced bandwidth MTC device).
[0034] Therefore, it is possible to support MTC devices (especially reduces bandwidth MTC
devices) without sacrificing the backward compatibility and/or without having to limit
the PUCCH bandwidth to 1.4 MHz. Further, it is also possible to support PUCCH slot
hopping for compatible communication devices and thereby benefit from frequency
diversity.
[0035] Beneficially, in order to provide the required commonality between solutions for
reduced bandwidth MTC devices and the solutions for coverage enhanced MTC
devices, in each of the embodiments summarised above, the reduced bandwidth MTC
PUCCH techniques can also be applied for coverage enhanced MTC devices. Unlike
the reduced bandwidth MTC device, however, in the case of coverage enhanced MTC
devices every relevant channel (e.g. comprising the PDSCH, PUCCH and the PRACH
as well as the EPDCCH) is repeated in multiple subframes where the number of rep
etitions depends on the level of coverage enhancement.
[0036]
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
mobile (or 'cellular') telephone configured as a machine-type communication device.
The communication device 3 comprises a transceiver circuit 31 which is operable to
transmit signals to, and to receive signals from, the base station 5 via at least one
antenna 33. Typically, the communication device 3 also includes a user interface 35
which allows a user to interact with the communication device 3, however this user
interface 35 may be omitted for some MTC devices.
[0037] The operation of the transceiver circuit 3 1 is controlled by a controller 37 in ac
cordance with software stored in memory 39. The software includes, among other
things, an operating system 41, a communication control module 43, and an MTC
module 45.
[0038] The communication control module 43 controls communications between the com
munication device 3 and the base station 5 and/or other communication nodes (via the
base station 5). As shown in Figure 2, the communication control module 43 includes,
amongst others, an EPDCCH module portion (for managing communications over the
enhanced physical downlink control channel), a PDSCH module portion (for managing
communications over the physical downlink shared channel), and a PUCCH module
portion (for managing communications over the physical uplink control channel).
[0039] The MTC module 45 is operable to carry out machine-type communication tasks. For
example, the MTC module 45 may (e.g. periodically) receive data from a remote
server (via the transceiver circuit 31) over resources allocated to the MTC device 3 by
the base station 5. The MTC module 45 may also collect data for sending (e.g. peri
odically and/or upon detecting a trigger) to a remote server (via the transceiver circuit
31).
[0040]
Figure 3 is a block diagram illustrating the main components 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, and to
receive signals from, the communication devices 3 via one or more antennas 53. The
base station 5 is also operable to transmit signals to and to receive signals from a core
network 7 via an appropriate core network interface 55 (such as an SI interface). The
operation of the transceiver circuit 51 is controlled by a controller 57 in accordance
with software stored in memory 59.
[0041] The software includes, among other things, an operating system 61, a communication
control module 63, and a UE category determination module 65.
[0042] The communication control module 53 controls communications with the commu
nication devices 3 (including any MTC devices). The communication control module
53 is also responsible for scheduling the resources to be used by the communication
devices 3 served by this base station 5. As shown in Figure 3, the communication
control module 63 includes, amongst others, an EPDCCH module portion (for
managing communications over the enhanced physical downlink control channel), a
PDSCH module portion (for managing communications over the physical downlink
shared channel), and a PUCCH module portion (for managing communications over
the physical uplink control channel).
[0043] The UE category determination module 65 determines the category of the commu
nication devices 3 served by the base station 5, based on, for example, information
obtained from the communication devices 3 and/or from another network node (e.g.
the HSS). When appropriate, the UE category determination module 65 provides in
formation identifying the category of each served communication devices to the other
modules, e.g. the communication control module 53, so that the other modules can
adjust their operation accordingly.
[0044] In the above description, the communication device 3 and the base station 5 are
described for ease of understanding as having a number of discrete modules. Whilst
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 built into the overall operating system or code and so these
modules may not be discernible as discrete entities.
[0045] The following is a description of various ways in which the physical uplink control
channel may be provided in LTE systems.
[0046]
Figure 4 illustrates an exemplary way in which PUCCH mapping to PRBs and
PUCCH slot hopping may be performed in accordance with the PUCCH design for
Rel-8 of LTE. It will be appreciated that this PUCCH design (which is also referred to
as 'legacy PUCCH') is not limited to Rel-8 LTE systems and it is also used in later
versions of the LTE standards (e.g. Rel-9 to Rel-12) for backward compatibility with
user equipment supporting only the Rel-8 version of LTE.
[0047] The bandwidth of the cell comprises a number ('N_RB') of physical resource blocks
(i.e. cell resource blocks #0 through #N_RB shown in Figure 4, where 'N_RB' denotes
the total number of physical resource blocks per slot). As explained above, the PUCCH
is typically located at (or near) the edges of the available cell bandwidth. The number
of physical resource blocks in a slot for potential PUCCH transmission is configured
by higher layer signalling using the 'push-HoppingOffset' parameter (denoted
'N_HO_RB' in Figure 4). It will be appreciated that the value of the
'push-HoppingOffset' parameter depends on the number of communication devices
served by the base station in its cell. In the example shown in Figure 4, N_HO_RB =
12, i.e. the PUCCH in this example includes a total of twelve resource blocks (six at
each edge of each slot). Therefore, a total of twelve resource blocks are allocated for
the PUCCH (although not all of these resource blocks are necessarily used in every
slot, since in each subframe the actual number of resource blocks used depends on the
number of communication devices scheduled in that particular subframe). The
'push-HoppingOffset' parameter may be signalled to the UEs using RRC configuration
signalling.
[0048] It will be appreciated that such a legacy PUCCH area may be provided near an edge
of the slots such that it does not exceed the 1.4 MHz bandwidth limit supported by
some of the MTC devices. For example, in the scenario shown in Figure 4, the six
neighbouring resource blocks near either edge of the cell bandwidth correspond to such
a 1.4 MHz bandwidth (or less). Therefore, a limited bandwidth MTC device would be
able to transmit signals over either the top 'legacy PUCCH' area or the bottom 'legacy
PUCCH' area (but not both areas) and even if the value of N_HO_RB does exceed '6',
the MTC device will only transmit maximum 6 RBs that contains it PUCCH part in
any given subframe.
[0049] However, in accordance with Rel-8 PUCCH design, PUCCH slot hopping is also
applied in order to improve frequency diversity in the cell. Therefore, as indicated in
Figure 4 by a diagonal arrow for PUCCH resource block #1, the location of each
PUCCH resource block is alternating between the two opposite edges of the cell
bandwidth between two slots (i.e. PUCCH resource block # 1 is provided via cell
resource block #N_RB in slot 1 and via cell resource block #0 in slot 2).
[0050] Consequently, a reduced bandwidth MTC device (such as the MTC device 3-2 of
Figure 1) having a typical bandwidth of 1.4 MHz may not be able to communicate (e.g.
transmit signals) at both ends of the cell bandwidth in a particular subframe. Therefore,
in case of the scenario shown in Figure 4, such an MTC device transmits its scheduled
PUCCH control information at both resource blocks #0 (in slot 1) and #N_RB (in slot
2) - although the MTC device may be able to switch from one 1.4 MHz portion to a
different 1.4 MHz portion of the cell bandwidth from one subframe to another.
[0051] This issue may be overcome by employing one or more of the following PUCCH
design options A to G (described with reference to Figures 5 to 10 below), whilst also
maintaining backward compatibility with communication devices supporting the
legacy (Rel-8 based) PUCCH.
[0052] It will be appreciated that these options are not mutually exclusive and any of the
options A to G may be combined within the same system, either within a single cell
and/or in neighbouring cells. For example, the base station 5 may be configured to
change from one PUCCH configuration to another, e.g. periodically, in dependence on
the number of MTC devices 2 in its cell, in dependence on the overall load in the cell,
and/or the like.
[0053]
Figure 5 illustrates an exemplary way in which an MTC specific physical uplink
control channel can be provided in the system shown in Figure 1.
[0054] This embodiment is based on the concept of over-provisioning the PUCCH. Such
over-provisioning can be realised by the base station 5 selecting (using its PUCCH
module portion) the value of the 'push-HoppingOffset' parameter (denoted
'N_HO_RB' in Figure 5) such that it is large enough to include (at least some of) the
physical resource blocks located near the centre six cell resource blocks. Advan
tageously, in this case an MTC specific PUCCH area may be provided over (some of)
the centre six physical resource blocks from among the cell resource blocks #0 to
#N_RB (i.e. over a bandwidth not exceeding 1.4 MHz). Therefore, even if PUCCH slot
hopping is enabled in the cell, the PUCCH resources allocated to MTC device alternate
between physical resource blocks that are located within a 1.4 MHz bandwidth.
[0055] Advantageously, the provision of an MTC specific PUCCH area in this manner does
not affect the provision of a legacy (Rel-8 based) PUCCH since the range of physical
resource blocks used for the PUCCH are defined, starting from the edges of each slot,
by the 'N_HO_RB' parameter. Therefore, a sufficient level of frequency diversity may
be maintained for compatible communication devices by allocating resource blocks
from within such an over-provisioned PUCCH area but closer to the edges of the slots
(e.g. outside the centre six physical resource blocks).
[0056] It will be appreciated that the base station 5 may be configured to obtain (using its
UE category determination module 65) information identifying whether a particular
communication device (e.g. the MTC device 3-2) comprises a machine-type commu
nication device and/or functionality. The base station 5 may obtain such information,
for example, from the HSS and/or from the communication device itself. The base
station 5 may also be configured to obtain information identifying whether a particular
MTC device comprises a reduced bandwidth MTC device or a coverage enhanced
MTC device. Therefore, based on the obtained information, the base station 5 can
allocate (using its PUCCH module portion) appropriate PUCCH resources: i) to MTC
devices (at least reduced bandwidth MTC devices or, optionally, to all MTC devices)
in the MTC specific PUCCH area comprising the centre six physical resource blocks;
and to other communication devices (e.g. regular mobile telephones and/or coverage
enhanced MTC devices) outside the centre six physical resource blocks (preferably
near the edges of the slots if frequency diversity is required).
[0057] It will be appreciated that since Rel-13 MTC devices are expected to support ap
plications with very small data rates (i.e. small pay loads), there is no need for such
MTC devices to support the so-called Multiple Input Multiple Output (MIMO)
technique (and/or to have multiple antennas). This may in turn reduce the processing
complexity and power consumption of such MTC devices. Further, for Rel-13 MTC
devices it is sufficient for the base station 5 to transmit a single transport block in the
downlink which will only require a single Ack/Nack (in a single UCI) to be conveyed
in the uplink PUCCH channel, further reducing the complexity of the required MTC
specific PUCCH.
[0058] In addition, there is also no need to obtain CQI feedback from the MTC devices
because of their narrow (1.4 MHz) supported bandwidth. Therefore, it will be ap
preciated that only PUCCH Format 1 and l a would be needed for MTC devices in Rel-
13 (i.e. PUCCH Formats lb/2/2a/2b/3 may not be needed).
[0059]
Figure 6 illustrates another exemplary way in which an MTC specific physical uplink
control channel can be provided in the system shown in Figure 1.
[0060] This embodiment is based on the concept of carrying the PUCCH control signalling
(for MTC devices) over the PUSCH channel. Specifically, the PUSCH in this example
is provided near the centre portion of the physical resource blocks used in the cell of
the base station 5 (e.g. near the centre six (or fewer) cell resource blocks). However,
rather than carrying only shared uplink signalling, the PUSCH in this embodiment is
adapted to carry the PUCCH control signalling for MTC devices. Therefore, in this
example, there is no need for over-provisioning the PUCCH (i.e. a legacy PUCCH,
preferably with slot hopping enabled, can be provided for non-MTC communication
devices without the base station 5 having to select a large 'N_HO_RB' value).
[0061] Beneficially, even if PUCCH slot hopping is enabled in the cell for legacy
(non-MTC) communication devices, the PUCCH resources allocated to MTC device
remain unaffected and/or can alternate between physical resource blocks of the
PUSCH that are located within a 1.4 MHz bandwidth (around the centre of the cell
bandwidth).
[0062] In practice, this option means that either the control information (e.g. UCI) sent by
the MTC devices needs to be multiplexed with the data normally transmitted over the
PUSCH or the PUSCH resource blocks allocated to MTC devices only carry the
control information (UCI). It will be appreciated that it is possible to send information
on the PUSCH without any scheduled uplink data (UL-SCH), for example, as specified
in section 5.2.4 of 3GPP TS 36.212, and in sections 8.6. 1 and 8.6.2 of TS 36.213, the
contents of which are incorporated herein by reference. This technique may be
extended to enable MTC devices to send the control information (e.g. UCI) without
multiplexing it with other PUSCH data.
[0063] If the control information sent by a particular MTC device is being multiplexed with
PUSCH data, then the base station 5 may be configured to allocate (using its commu
nication control module 63) the uplink physical resource block for a given MTC device
using the uplink grant control data that schedules the PUSCH data (that is to be mul
tiplexed with that MTC device's control information).
[0064] If the control information by a particular MTC device is transmitted on the PUSCH
without scheduling any PUSCH data (i.e. without multiplexing), then the number of
the uplink physical resource blocks for a given MTC device that will carry the a s
sociated control information can be given in a number of ways, for example, including:
- indicated dynamically by the uplink grant mechanism (e.g. using an appropriate
DCI format) that is normally used for scheduling PUSCH data;
- configured by RRC signalling (e.g. semi-statically); and/or
- based on a semi-persistent scheduling (SPS) allocation (i.e. the physical resource
block to be used by a given MTC device may be configured for the MTC device by an
appropriate SPS configuration).
[0065]
Figure 7 illustrates another exemplary way in which an MTC specific physical uplink
control channel can be provided in the system shown in Figure 1.
[0066] In this example, the base station 5 provides an MTC specific PUCCH. It will be ap
preciated that, for backward compatibility, such an MTC specific PUCCH may be
provided in addition to a regular, legacy PUCCH (defined by 'N_HO_RB') provided at
the edges of the slots.
[0067] As shown in Figure 7, the MTC specific PUCCH is provided over a maximum of six
physical resource blocks (i.e. over a bandwidth not exceeding 1.4 MHz) near the centre
of the range of physical resource blocks #0 to #N_RB of the cell. The MTC specific
PUCCH area includes MTC resources #0 to 5, which may be used by a maximum of
six MTC devices per scheduling round. However, since the MTC devices are typically
transmitting small bursts of data, each MTC resource #0 to 5 may be re-allocated to a
different MTC device in a subsequent scheduling round.
[0068] It will be appreciated that, if appropriate, such an MTC specific PUCCH may be
provided solely for the use of MTC devices (e.g. Rel-13 reduced bandwidth MTC
devices) even without slot hopping enabled (i.e. without backward compatibility). In
this case, it will be appreciated that each MTC device may be scheduled to transmit, in
both slots, using the same six resource blocks that contain the PUCCH information for
that MTC device.
[0069] If appropriate (e.g. when slot hopping is not used), it will also be appreciated that the
MTC specific PUCCH may also be provided closer to (or even adjacent to) the legacy
PUCCH rather than at the centre area (as shown in Figure 7).
[0070]
Figure 8 illustrates yet another exemplary way in which an MTC specific physical
uplink control channel can be provided in the system shown in Figure 1.
[0071] Effectively, option D can be seen as a modification of option C. However, in this
case the MTC specific PUCCH is provided as part of the legacy PUCCH rather than
adjacent to it.
[0072] Therefore, when the base station 5 configures (using its PUCCH module portion) the
value of the 'push-HoppingOffset' parameter (denoted 'N_HO_RB' in Figure 8), the
base station selects the value such that it also includes (a maximum of) six physical
resource blocks located immediately after the legacy PUCCH area (provided at the
edges) towards the centre of the slots. In the example shown in Figure 8 there are
three-three MTC specific PUCCH resource blocks allocated next to both portions of
the legacy PUCCH provided at the lower and upper edges of the slots (although it is
possible to provide up to six MTC specific PUCCH resource blocks next to each
portion of the legacy PUCCH, i.e. not exceeding 1.4 MHz).
[0073] It will be appreciated that whilst in the legacy PUCCH area slot hopping may be
supported (for frequency diversity), the MTC specific PUCCH is provided without slot
hopping enabled in order to ensure compatibility with Rel-13 reduced bandwidth MTC
devices (and/or similar). Therefore, regardless whether or not PUCCH slot hopping is
enabled in the cell for legacy devices, the PUCCH resources allocated to MTC devices
remain within the same resource block (and/or alternate only within the same 1.4 MHz
bandwidth) in both slots.
[0074]
Figure 9 illustrates yet another exemplary way in which an MTC specific physical
uplink control channel can be provided in the system shown in Figure 1.
[0075] In this example, only a legacy PUCCH is configured by the 'push-HoppingOffset'
parameter (denoted 'N_HO_RB' in Figure 9). However, in this case the MTC device is
configured to transmit over its allocated PUCCH resource block in a time division
multiplexing (TDM) manner. In other words, as illustrated in Figure 9, the base station
5 allocates (using its PUCCH module portion) a PUCCH resource (e.g. PUCCH
resource block # 1 forming part of a legacy PUCCH) to the MTC device (denoted 'UE'
in Figure 9). However, rather than performing slot hopping between slot 1 and slot 2
(which would require a transceiver that is capable of simultaneously operating over the
entire cell bandwidth), the MTC device transmits only a first part of its scheduled
uplink data for the duration of slot 1. Then, after slot 1, the MTC device performs an
appropriate switching and/or tuning if its transmitter (Tx) 3 1 to a frequency band
covering the physical resource block in slot 2 corresponding to the PUCCH resource
block # 1 after slot hopping. After Tx switchin/tuning, the MTC device transmits the
remaining part of its scheduled uplink data for the duration of slot 2.
[0076] It means that a reduced bandwidth MTC device (e.g. a Rel-13 MTC device) may be
scheduled to transmit (using its transceiver circuit 31) over a maximum of six
neighbouring resource blocks in the first slot (that contains the MTC device's corre
sponding PUCCH information) and then switch/tune its transceiver circuit 31 to the
corresponding resource block(s) of the second slot.
[0077] As a modification of this embodiment, each physical resource block may be shared
between two MTC devices. In other words, the base station 5 may allocate a PUCCH
resource (e.g. PUCCH resource block #1) to a first MTC device for the duration of slot
1, and allocate the same PUCCH resource to a second MTC device for the duration of
slot 2. In this case, there is no need for either MTC device to perform any Tx
switching/tuning between slots 1 and 2 (although the MTC devices may need to
suspend transmission for the duration of the slot in which the physical resource block
is allocated to a different MTC device). However, since MTC devices normally
transmit a relatively low amount of data, this modification may not have any sig
nificant drawback (and may even improve the MTC device's overall power con
sumption).
[0078]
In accordance with the LTE FDD specifications for Rel-8, a communication device 3
needs to time its Ack/Nack transmissions (confirming successful/unsuccessful receipt
of a downlink packet) as follows:
i) in subframe n-4, the communication device 3 receives (E)PDCCH control
signalling (which indicates that downlink resources have been allocated to the commu
nication device 3 for receiving downlink data) and detects associated PDSCH
signalling (i.e. downlink data for the communication device 3);
ii) in subframe n-4, the communication device 3 receives the scheduled downlink
data from the base station 5 via the PDSCH;
iii) in subframes n-3 to n-1, the communication device 3 processes the received
downlink data; and
iv) in subframe n, the communication device 3 transmits to the base station 5: an
acknowledgement (HARQ-ACK) upon successful receipt of the PDSCH control
signalling; or a negative acknowledgement (HARQ-NACK) upon unsuccessful receipt
of the PDSCH control signalling.
[0079] In accordance with this timing method, the communication device 3 receives both the
(E)PDCCH and the PDSCH in the same subframe (i.e. in subframe n-4) and the com
munication device 3 has a maximum of three subframes (i.e. from subframe n-3 to
subframe n-1) to process the PDSCH control signalling before sending an appropriate
HARQ Ack/Nack response to the base station 5.
[0080] However, in LTE Rel-13, MTC devices are not expected to be able to receive their
EPDCCH and PDSCH signalling within the same subframe. This is because the
EPDCCH and the PDSCH are not necessarily transmitted within the same 1.4 MHz
bandwidth that the (reduced bandwidth) MTC devices are capable of using in that
subframe. Therefore, in LTE Rel-13 the following options are envisaged for the timing
the Ack/Nack transmissions by MTC devices for their PDSCH signalling:
1) No EPDCCH control signalling is transmitted in subframe n-4:
In this case the MTC device detects its PDSCH control signalling in subframe n-4; and
transmits a corresponding (HARQ) ACK/NACK in subframe n. Therefore, in this case
the EPDCCH and the PDSCH signalling for the MTC device are not transmitted in the
same subframe (as they would be in accordance with legacy, e.g. Rel-8 practices).
It will be appreciated therefore that uplink (PUCCH) resources for transmitting the
Ack/Nack may be allocated to the MTC devices semi- statically (e.g. using higher layer
signalling similar to the (Rel-8) SPS PUCCH resource allocation technique, which is
illustrated in Table 9.2-2 of 3GPP TS 36.213). Alternatively, the EPDCCH control
signalling may be transmitted in subframe n-5.
2) No PDSCH control signalling transmitted in subframe n-4:
In this case (which is illustrated in Figure 10) the MTC device detects its EPDCCH
control signalling in subframe n-4; detects its PDSCH control signalling in subframe n-
3; and transmits a corresponding (HARQ) ACK/NACK in subframe n. Beneficially,
the base station 5 is not restricted in this case to transmit both the EPDCCH and the
PDSCH over the same 1.4 MHz bandwidth that (reduced bandwidth) MTC devices are
capable of using in a given subframe (although the MTC devices may need to switch
from the EPDCCH frequency band to the PDSCH frequency band, if different,
between subframes n-4 and n-3).
In this case therefore the time duration available for the MTC device to process the
received PDSCH signalling is reduced to approximately two subframes (from three
subframes in accordance with the above Rel-8 Ack/Nack transmission method).
However, since a typical MTC device is not receiving large blocks of data, such a
shortened processing time is expected to be sufficient.
[0081]
Since in Rel-13 there expected to be a high level of commonality between the
solutions for bandwidth reduced communication devices and coverage enhanced com
munication devices, it will be appreciated that the above described options may be
applied for coverage enhanced MTC devices as well.
[0082] However, as illustrated in Figure 11, in this case each relevant channel (for example,
the EPDCCH, the PDSCH, the PUCCH, and/or the PRACH) is repeated in multiple
subframes (i.e. in the time domain) and the information transmitted in each channel is
combined by the MTC device in order to increase detectability of that channel.
[0083] Figure 11 illustrates a modification of the embodiment shown in Figure 10 (i.e.
option F/2) in order to support (coverage enhanced) MTC devices when repetition of
the relevant channels is enabled.
[0084] Specifically, in this case both the EPDCCH and the PDSCH are repeated by the base
station 5. Similarly, the MTC device is configured to transmit an Ack/Nack for each
repetition of the PDSCH signalling. However, there are only three subframes allocated
for processing the received (repeated) PDSCH signalling and the MTC device is
configured to send the corresponding Ack/Nack transmissions in successive subframes
(i.e. without any additional subframes allocated for processing between two subsequent
acknowledgements) .
[0085] Therefore, as illustrated in Figure 11 for a coverage enhancement requiring three rep
etitions (i.e. a total of four transmissions of the same information), the base station 5
transmits the same EPDCCH signalling in each of subframes n-4 to n-1 (a total of four
subframes). Next, the base station 5 transmits the (same) PDSCH signalling in each of
subframes n to n+3 (a total of four subframes). Subframes n+4 to n+6 (i.e. a total of
three subframes) are allocated for the MTC device 3 for processing the received
PDSCH signalling (i.e. to determine whether or not the downlink data was received
successfully). Finally, in subframes n+7 to n+10 (a total of four subframes), the MTC
device transmits the appropriate Ack/Nack to the base station in dependence on the
result of the processing.
[0086] It will be appreciated that in this case the PUCCH resources (for transmitting the
Ack/Nack) may be allocated to the MTC device semi- statically (e.g. using higher layer
signalling similar to the (Rel-8) SPS PUCCH resource allocation technique shown in
Table 9.2-2 of 3GPP TS 36.213).
[0087]
Detailed embodiments have been described above. As those skilled in the art will ap
preciate, a number of modifications and alternatives can be made to the above em
bodiments whilst still benefiting from the inventions embodied therein.
[0088] In some of the above embodiments, information relating to the PUCCH allocations
may be signalled to the MTC device via higher layers (e.g. by configuring semipersistent
scheduling for the MTC device). Alternatively or additionally, some or all of
this information can be obtained by the MTC device in a different manner. Fur
thermore, the applicable PUCCH configuration may not be explicitly signalled by the
base station and may instead be determined based upon other information, such as a
cell ID associated with the base station and/or a device ID associated with the MTC
device. This has the benefit of reducing the amount of data that has to be signalled to
the communication devices.
[0089] It will be appreciated that although the communication system is described in terms
of the base station operating as a E-UTRAN base station (eNB), the same principles
may be applied to base stations operating as macro or pico base stations, femto base
stations, relay nodes providing elements of base station functionality, home base
stations (HeNB), or other such communication nodes.
[0090] In the above embodiments, an LTE telecommunications system was described. As
those skilled in the art will appreciate, the techniques described in the present application
can be employed in other communications systems, including earlier 3GPP
type systems. Other communications nodes or devices may include user devices such
as, for example, personal digital assistants, laptop computers, web browsers, etc.
[0091] In the embodiments described above, the base station and the communication device
each include transceiver circuitry. Typically, this circuitry will be formed by dedicated
hardware circuits. However, in some embodiments, part of the transceiver circuitry
may be implemented as software run by the corresponding controller.
[0092] In the above embodiments, a number of software modules were described. As those
skilled in the art will appreciate, the software modules may be provided in compiled or
un-compiled form and may be supplied to the base station or the user device as a signal
over a computer network, or on a recording medium. Further, the functionality
performed by part or all of this software may be performed using one or more
dedicated hardware circuits.
[0093] In the above embodiments, machine-type communication devices and mobile
telephones are described. However, it will be appreciated that mobile telephones (and
similar user equipment) may also be configured to operate as machine-type commu
nication devices. For example, the mobile telephone 3-1 may include (and/or provide
the functionality of) the MTC module 45.
[0094] Examples of MTC applications
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.
[0095]
[Table 1]
Service Area MTC applications
Surveillance systems
Backup for landline
Security
Control of physical access (e.g. to buildings)
Car/driver security
Fleet Management
Order Management
Pay as you drive
Asset Tracking
Tracking & Tracing
Navigation
Traffic information
Road tolling
Road traffic optimisation/steering
Point of sales
Payment Vending machines
Gaming machines
Monitoring vital signs
Supporting the aged or handicapped
Health
Web Access Telemedicine points
Remote diagnostics
Sensors
Lighting
Pumps
Remote Maintenance/Control Valves
Elevator control
Vending machine control
Vehicle diagnostics
Power
Gas
Water
Metering
Heating
Grid control
Industrial metering
Digital photo frame
Consumer Devices Digital camera
eBook
[0096] Various other modifications will be apparent to those skilled in the art and will not be
described in further detail here.
[0097] This invention has been described by way of embodiments above, but this invention
is not limited to the embodiments. A part or the entirety of the above-mentioned em
bodiments may be described by way of the following supplementary notes, but this
invention is not limited to the following supplementary notes.
[0098] (Supplementary Note 1)
A communication node for a communication system, wherein the communication
node comprises:
means for operating a cell having a cell bandwidth;
means for communicating, with a plurality of different types of communication
devices within said cell, wherein said plurality of different types of communication
devices include a reduced bandwidth machine-type communication, 'MTC, device
having a bandwidth that is small compared to the cell bandwidth; and
means for allocating frequency resources respectively to each communication device
operating within said cell, for use in transmitting uplink control data, in dependence on
whether or not that communication device is an MTC device;
wherein said allocating means is operable to allocate said frequency resources such
that:
when the communication device is a reduced bandwidth MTC device, said MTC
device communicates uplink control data using a first frequency resource in a first slot
of a subframe and a second frequency resource in a second slot of that subframe
wherein said first frequency resource and said second frequency resource share the
same frequency or are separated in frequency by no more than the bandwidth of the
reduced bandwidth MTC device; and when the communication device is not a reduced
bandwidth MTC device, said communication device that is not a reduced bandwidth
MTC device communicates uplink control data using a first non-MTC frequency
resource in the first slot of a subframe and a second non-MTC frequency resource in
the second slot of that subframe wherein said first non-MTC frequency resource and
said second non-MTC frequency resource are separated in frequency by more than the
bandwidth of the reduced bandwidth MTC device; and
wherein said communicating means is operable to receive uplink control information
from each communication device operating within said cell using the respective
frequency resources allocated to each communication device operating within said cell
in dependence on whether or not that communication device is an MTC device.
[0099] (Supplementary Note 2)
A communication node of the supplementary note 1 wherein said first frequency
resource and said second frequency resource are separated in frequency by no more
than the bandwidth of the reduced bandwidth MTC device and are respectively above
and below a centre frequency of said cell bandwidth.
[0100] (Supplementary Note 3)
A communication node of the supplementary note 1 wherein said first frequency
resource and said second frequency resource share the same frequency.
[0101] (Supplementary Note 4)
A communication node of any one of the supplementary notes 1 of 3 wherein said
first frequency resource, said second frequency resource, said first non-MTC resource
and said second non-MTC resource all form part of a common uplink control channel
region (e.g. a physical uplink control channel, 'PUCCH').
[0102] (Supplementary Note 5)
A communication node of any one of the supplementary notes lof 3 wherein said
first non-MTC resource and said second non-MTC resource form part of an uplink
control channel region (e.g. a physical uplink control channel, 'PUCCH') that does not
extend across a centre of the cell bandwidth, and said first frequency resource and said
second frequency resource form part of another separate region.
[0103] (Supplementary Note 6)
A communication node of the supplementary note 5 wherein said separate region
extends across the centre of the cell bandwidth.
[0104] (Supplementary Note 7)
A communication node of the supplementary note 5 or 6 wherein said first frequency
resource and said second frequency resource form part of a further MTC dedicated
uplink control channel region (e.g. an MTC physical uplink control channel,
'PUCCH') that is separate from said uplink control channel region comprising said
first non-MTC resource and said second non-MTC resource.
[0105] (Supplementary Note 8)
A communication node of the supplementary note 5 or 6 wherein said first frequency
resource and said second frequency resource form part of an uplink shared channel
region (e.g. a shared data channel / physical uplink shared channel, 'PUSCH').
[0106] (Supplementary Note 9)
A communication node of any one of the supplementary notes 1 to 8 wherein said
communicating means is further operable to communicate, with an enhanced coverage
MTC device having enhanced coverage compared to other MTC devices and wherein
said allocating means is operable to allocate said frequency resources such that: when
the communication device is an enhanced coverage MTC device, said MTC device
communicates uplink control data using a further first frequency resource in a first slot
of a subframe and a further second frequency resource in a second slot of that
subframe wherein said further first frequency resource and said further second
frequency resource share the same frequency or are separated in frequency by no more
than the bandwidth of a reduced bandwidth MTC device.
[0107] (Supplementary Note 10)
A machine-type communication, 'MTC, device for a communication system in
which a plurality of different types of communication devices can communicate with a
communication node that operates a cell having a cell bandwidth, wherein the plurality
of different types of communication devices include a reduced bandwidth machinetype
communication, 'MTC, device having a bandwidth that is small compared to the
cell bandwidth, wherein the MTC device comprises:
means for communicating with the communication node within the cell operated by
that communication node; and
means for obtaining an allocation of frequency resources, for use in transmitting
uplink control data to the communication node, wherein said allocation is such that
said communicating means communicates uplink control data using a first frequency
resource in a first slot of a subframe and a second frequency resource in a second slot
of that subframe wherein said first frequency resource and said second frequency
resource share the same frequency or are separated in frequency by no more than the
bandwidth of a reduced bandwidth MTC device; and
wherein said communicating means is operable to transmit uplink control in
formation using the allocation of frequency resources.
[0108] (Supplementary Note 11)
A machine-type communication, 'MTC, device for a communication system in
which a plurality of different types of communication devices can communicate with a
communication node that operates a cell having a cell bandwidth, wherein the plurality
of different types of communication devices include a reduced bandwidth machinetype
communication, 'MTC, device having a bandwidth that is small compared to the
cell bandwidth, wherein the MTC device comprises:
means for communicating with the communication node within the cell operated by
that communication node and using frequency resources within a frequency of an MTC
frequency band;
means for moving a carrier frequency of said MTC frequency band; and
means for obtaining an allocation of frequency resources, for use in transmitting
uplink control data to the communication node wherein said allocation is such that said
communicating means communicates uplink control data using a first frequency
resource in a first slot of a subframe and a second frequency resource in a second slot
of that subframe wherein said first frequency resource and said second frequency
resource share the same frequency or are separated in frequency by more than the
bandwidth of a reduced bandwidth MTC device;
wherein said carrier frequency moving means is operable to move said carrier
frequency between said first slot and said second slot such that said MTC frequency
band includes the first frequency resource in the first slot of the subframe and includes
the second frequency resource in the second slot of said subframe; and
whereby said communicating means is operable to transmit uplink control information
using the first frequency resource in the first slot of the subframe and to transmit
uplink control information using the second frequency resource in the second slot of
said subframe.
[0109] (Supplementary Note 12)
An MTC device of the supplementary note 10 or 11 wherein said MTC device is an
enhanced coverage MTC device.
[01 10] (Supplementary Note 13)
An MTC device of the supplementary note 10 or 11 wherein said MTC device is a
reduced bandwidth MTC device.
[01 11] (Supplementary Note 14)
A communication node for a communication system, wherein the communication
node comprises:
means for operating a cell; and
means for communicating with a plurality of different types of communication
devices within said cell using radio frames, each radio frame comprising a sequence of
subframes, wherein said plurality of different types of communication devices include
a machine-type communication, 'MTC, device;
wherein said communicating means is operable:
to provide downlink control channel signalling for at least one MTC device in a first
of said subframes, and to repeat said downlink control channel signalling in at least
one subsequent subframe;
to provide downlink shared channel signalling for said at least one MTC device in a
subframe subsequent to said subframes in which said downlink control channel
signalling is provided and to repeat said downlink shared channel signalling in at least
one subsequent subframe; and
to receive, from the at least one MTC device, uplink control information relating to
said downlink shared channel signalling in a subframe subsequent to said subframes in
which said downlink shared channel signalling is provided and to receive a repetition
of said uplink control information in at least one subsequent subframe.
[0112] (Supplementary Note 15)
A communication node of the supplementary note 14 further comprising means for
semi-statically allocating resources to said at least one MTC device for use in
transmitting said uplink control information relating to said downlink shared channel
signalling.
[0113] (Supplementary Note 16)
A communication node of the supplementary note 14 or 15 wherein said commu
nicating means is operable to: first receive, from the at least one MTC device, said
uplink control information relating to said downlink shared channel signalling in a
subframe that is a fourth subframe subsequent to a last of said subframes in which said
downlink shared channel signalling is provided.
[0114] (Supplementary Note 17)
A machine-type communication, 'MTC, device for a communication system,
wherein the MTC device comprises:
means for communicating, with a communication node within a cell operated by that
communication node, using radio frames, each radio frame comprising a sequence of
subframes;
wherein said communicating means is operable:
to receive downlink control channel signalling for said MTC device in a first of said
subframes, and a repetition of said downlink control channel signalling in at least one
subsequent subframe;
to receive downlink shared channel signalling for said MTC device in a subframe
subsequent to said subframes in which said downlink control channel signalling is
received and a repetition of said downlink shared channel signalling in at least one
subsequent subframe; and
to provide, to said communication node, uplink control information relating to said
downlink shared channel signalling in a subframe subsequent to said subframes in
which said downlink shared channel signalling is received and to repeat said uplink
control information in at least one subsequent subframe.
[0115] (Supplementary Note 18)
A communication node for a communication system, wherein the communication
node comprises:
means for operating a cell;
means for communicating with a plurality of different types of communication
devices within said cell using radio frames, each radio frame comprising a sequence of
subframes, wherein said plurality of different types of communication devices include
a machine-type communication, 'MTC, device; and
means for semi-statically allocating resources to at least one MTC device for use in
transmitting uplink control information relating to downlink shared channel signalling;
wherein said communicating means is operable:
to provide downlink shared channel signalling for said at least one MTC device in a
subframe; and
to receive from the at least one MTC device, using said semi-statically allocated
resources, uplink control information relating to said downlink shared channel
signalling in a subframe subsequent to said subframe in which said downlink shared
channel signalling is provided, wherein the subframe in which said uplink control in
formation is received is a fourth of a plurality of subframes subsequent to said
subframe in which said downlink shared channel signalling is provided.
[0116] (Supplementary Note 19)
A machine-type communication, 'MTC, device for a communication system,
wherein the MTC device comprises:
means for communicating, with a communication node within a cell operated by that
communication node, using radio frames, each radio frame comprising a sequence of
subframes;
means for receiving, semi-statically, an allocation of resources for said MTC device
for use in transmitting uplink control information relating to downlink shared channel
signalling;
wherein said communicating means is operable:
to receive downlink shared channel signalling for said MTC device in a subframe;
and
to provide, to said communication node, using said semi-statically allocated
resources, uplink control information relating to said downlink shared channel
signalling in a subframe subsequent to said subframe in which said downlink shared
channel signalling is received, wherein the subframe in which said uplink control in
formation is provided is a fourth of a plurality of subframes subsequent to said
subframe in which said downlink shared channel signalling is received.
[01 17] (Supplementary Note 20)
A communication node for a communication system, wherein the communication
node comprises:
means for operating a cell; and
means for communicating with a plurality of different types of communication
devices within said cell using radio frames, each radio frame comprising a sequence of
subframes, wherein said plurality of different types of communication devices include
a machine-type communication, 'MTC, device; and
wherein said communicating means is operable:
to provide downlink shared channel signalling for at least one MTC device in a
subframe; and
to receive, from the at least one MTC device, uplink control information relating to
said downlink shared channel signalling in a subframe subsequent to said subframe in
which said downlink shared channel signalling is provided, wherein the subframe in
which said uplink control information is received is a third of a plurality of subframes
subsequent to said subframe in which said downlink shared channel signalling is
provided.
[0118] (Supplementary Note 2 1)
A machine-type communication, 'MTC, device for a communication system,
wherein the MTC device comprises:
means for communicating, with a communication node within a cell operated by that
communication node, using radio frames, each radio frame comprising a sequence of
subframes;
wherein said communicating means is operable:
to receive downlink shared channel signalling for an MTC device in a subframe; and
to provide, to said communication node, uplink control information relating to said
downlink shared channel signalling in a subframe subsequent to said subframe in
which said downlink shared channel signalling is received, wherein the subframe in
which said uplink control information is provided is a third of a plurality of subframes
subsequent to said subframe in which said downlink shared channel signalling is
received.
[01 19] (Supplementary Note 22)
A method performed by a communication node of a communication system, wherein
the method comprises:
operating a cell having a cell bandwidth;
communicating, with a plurality of different types of communication devices within
said cell, wherein said plurality of different types of communication devices include a
reduced bandwidth machine-type communication, 'MTC, device having a bandwidth
that is small compared to the cell bandwidth; and
allocating frequency resources respectively to each communication device operating
within said cell, for use in transmitting uplink control data, in dependence on whether
or not that communication device is an MTC device;
wherein said allocating comprises allocating said frequency resources such that:
when the communication device is a reduced bandwidth MTC device, said MTC
device communicates uplink control data using a first frequency resource in a first slot
of a subframe and a second frequency resource in a second slot of that subframe
wherein said first frequency resource and said second frequency resource share the
same frequency or are separated in frequency by no more than the bandwidth of the
reduced bandwidth MTC device; and
when the communication device is not a reduced bandwidth MTC device, said com
munication device that is not a reduced bandwidth MTC device communicates uplink
control data using a first non-MTC frequency resource in the first slot of a subframe
and a second non-MTC frequency resource in the second slot of that subframe wherein
said first non-MTC frequency resource and said second non-MTC frequency resource
are separated in frequency by more than the bandwidth of the reduced bandwidth MTC
device; and
wherein said communicating comprises receiving uplink control information from each
communication device operating within said cell using the respective frequency
resources allocated to each communication device operating within said cell in de
pendence on whether or not that communication device is an MTC device.
[0120] (Supplementary Note 23)
A method performed by a machine-type communication, 'MTC, device of a com
munication system in which a plurality of different types of communication devices
can communicate with a communication node that operates a cell having a cell
bandwidth, wherein the plurality of different types of communication devices include a
reduced bandwidth MTC device having a bandwidth that is small compared to the cell
bandwidth, wherein the method comprises:
communicating with the communication node within the cell operated by that com
munication node; and
obtaining an allocation of frequency resources, for use in transmitting uplink control
data to the communication node, wherein said allocation is such that said commu
nicating communicates uplink control data using a first frequency resource in a first
slot of a subframe and a second frequency resource in a second slot of that subframe
wherein said first frequency resource and said second frequency resource share the
same frequency or are separated in frequency by no more than the bandwidth of a
reduced bandwidth MTC device; and
wherein said communicating comprises transmitting uplink control information using
the allocation of frequency resources.
[0121] (Supplementary Note 24)
A method performed by a machine-type communication, 'MTC, device of a com
munication system in which a plurality of different types of communication devices
can communicate with a communication node that operates a cell having a cell
bandwidth, wherein the plurality of different types of communication devices include a
reduced bandwidth MTC device having a bandwidth that is small compared to the cell
bandwidth, wherein the method comprises:
communicating with the communication node within the cell operated by that com
munication node and using frequency resources within a frequency of an MTC
frequency band;
obtaining an allocation of frequency resources, for use in transmitting uplink control
data to the communication node wherein said allocation is such that said communicating
communicates uplink control data using a first frequency resource in a first
slot of a subframe and a second frequency resource in a second slot of that subframe
wherein said first frequency resource and said second frequency resource share the
same frequency or are separated in frequency by more than the bandwidth of a reduced
bandwidth MTC device;
moving a carrier frequency of said MTC frequency band between said first slot and
said second slot such that said MTC frequency band includes the first frequency
resource in the first slot of the subframe and includes the second frequency resource in
the second slot of said subframe; and
whereby said communicating comprises transmitting uplink control information using
the first frequency resource in the first slot of the subframe and transmitting uplink
control information using the second frequency resource in the second slot of said
subframe.
[0122] (Supplementary Note 25)
A method performed by a communication node of a communication system, wherein
the method comprises:
operating a cell; and
communicating with a plurality of different types of communication devices within
said cell using radio frames, each radio frame comprising a sequence of subframes,
wherein said plurality of different types of communication devices include a machinetype
communication, 'MTC, device;
wherein said communicating comprises:
providing downlink control channel signalling for at least one MTC device in a first
of said subframes, and repeating said downlink control channel signalling in at least
one subsequent subframe;
providing downlink shared channel signalling for said at least one MTC device in a
subframe subsequent to said subframes in which said downlink control channel
signalling is provided and repeating said downlink shared channel signalling in at least
one subsequent subframe; and
receiving, from the at least one MTC device, uplink control information relating to
said downlink shared channel signalling in a subframe subsequent to said subframes in
which said downlink shared channel signalling is provided and receiving a repetition of
said uplink control information in at least one subsequent subframe.
[0123] (Supplementary Note 26)
A method performed by a machine-type communication, 'MTC, device of a com
munication system, wherein the method comprises:
communicating, with a communication node within a cell operated by that commu
nication node, using radio frames, each radio frame comprising a sequence of
subframes;
wherein said communicating comprises:
receiving downlink control channel signalling for said MTC device in a first of said
subframes, and receiving a repetition of said downlink control channel signalling in at
least one subsequent subframe;
receiving downlink shared channel signalling for said MTC device in a subframe
subsequent to said subframes in which said downlink control channel signalling is
received and a receiving repetition of said downlink shared channel signalling in at
least one subsequent subframe; and
providing, to said communication node, uplink control information relating to said
downlink shared channel signalling in a subframe subsequent to said subframes in
which said downlink shared channel signalling is received and repeating said uplink
control information in at least one subsequent subframe.
[0124] (Supplementary Note 27)
A method performed by a communication node of a communication system, wherein
the method comprises:
operating a cell;
communicating with a plurality of different types of communication devices within
said cell using radio frames, each radio frame comprising a sequence of subframes,
wherein said plurality of different types of communication devices include a machinetype
communication, 'MTC, device; and
semi- statically allocating resources to at least one MTC device for use in transmitting
uplink control information relating to downlink shared channel signalling;
wherein said communicating comprises:
providing downlink shared channel signalling for said at least one MTC device in a
subframe; and
receiving from the at least one MTC device, using said semi- statically allocated
resources, uplink control information relating to said downlink shared channel
signalling in a subframe subsequent to said subframe in which said downlink shared
channel signalling is provided, wherein the subframe in which said uplink control in
formation is received is a fourth of a plurality of subframes subsequent to said
subframe in which said downlink shared channel signalling is provided.
[0125] (Supplementary Note 28)
A method performed by a machine-type communication, 'MTC, device of a com
munication system, wherein the method comprises:
communicating, with a communication node within a cell operated by that commu
nication node, using radio frames, each radio frame comprising a sequence of
subframes;
receiving, semi-statically, an allocation of resources for said MTC device for use in
transmitting uplink control information relating to downlink shared channel signalling;
wherein said communicating comprises:
receiving downlink shared channel signalling for said MTC device in a subframe; and
to providing, to said communication node, using said semi-statically allocated
resources, uplink control information relating to said downlink shared channel
signalling in a subframe subsequent to said subframe in which said downlink shared
channel signalling is received, wherein the subframe in which said uplink control in
formation is provided is a fourth of a plurality of subframes subsequent to said
subframe in which said downlink shared channel signalling is received.
[0126] (Supplementary Note 29)
A method performed by a communication node of a communication system, wherein
the method comprises:
operating a cell; and
communicating with a plurality of different types of communication devices within
said cell using radio frames, each radio frame comprising a sequence of subframes,
wherein said plurality of different types of communication devices include a machinetype
communication, 'MTC, device; and
wherein said communicating comprises:
providing downlink shared channel signalling for at least one MTC device in a
subframe; and
receiving, from the at least one MTC device, uplink control information relating to
said downlink shared channel signalling in a subframe subsequent to said subframe in
which said downlink shared channel signalling is provided, wherein the subframe in
which said uplink control information is received is a third of a plurality of subframes
subsequent to said subframe in which said downlink shared channel signalling is
provided.
[0127] (Supplementary Note 30)
A method performed by a machine-type communication, 'MTC, device of a com
munication system, wherein the method comprises:
communicating, with a communication node within a cell operated by that commu
nication node, using radio frames, each radio frame comprising a sequence of
subframes;
wherein said communicating comprises:
receiving downlink shared channel signalling for an MTC device in a subframe; and
providing, to said communication node, uplink control information relating to said
downlink shared channel signalling in a subframe subsequent to said subframe in
which said downlink shared channel signalling is received, wherein the subframe in
which said uplink control information is provided is a third of a plurality of subframes
subsequent to said subframe in which said downlink shared channel signalling is
received.
[0128] (Supplementary Note 31)
A communication system comprising at least one communication node according to
any of the supplementary notes 1 to 9, 14 to 16, 18 or 20 and at least one machine-type
communication, 'MTC, device according to any of the supplementary notes 10 to 13,
17, 19 or 21.
[0129] (Supplementary Note 32)
A computer program product comprising computer implementable instructions for
causing processing apparatus to perform the method of any of the supplementary notes
22 to 30.
[0130] This application is based upon and claims the benefit of priority from United
Kingdom patent application No. 1416796.9, filed on September 23, 2014, the
disclosure of which is incorporated herein in its entirety by reference.
PCT7JP2015/004690

Claims
1.A communication apparatus which is operable to communicate with at
least one of a first type mobile station and a second type mobile station,
the communication apparatus comprising:
means for assigning a first frequency resource for a first uplink control
channel of the first type mobile station per slot; and
means for assigning a second frequency resource for a second uplink
control channel of the second type mobile station per a set of subframe.
2.A communication apparatus according to claim 1, wherein the commu
nication apparatus further comprises means for multiplexing the first
frequency resource and the second frequency resource.
3.A communication apparatus according to claim 1 or 2, wherein the first
frequency resource is based on slot hopping.
A communication apparatus according to any of claim 1 to 3, wherein
the communication apparatus further comprises means for applying a
starting offset based on level of coverage enhancement.
A communication apparatus according to claim 4, wherein the starting
offset is signalled to the second type mobile station.
A communication apparatus according to claim 4, wherein the starting
offset is signalled by RRC configuration.
A communication apparatus according to any of claim 1 to 6, wherein
the second type mobile station is machine-type communication (MTC)
device.
A communication apparatus according to any of claim 1 to 7, wherein
the set of subframe comprises plural subframes.
A mobile station which is operable to communicate with a commu
nication apparatus, the mobile station comprising:
means for determining first frequency resource which is assigned for a
first uplink control channel per a set of subframe; and
means for transmitting the uplink control channel based on the first
frequency resource.
A mobile station according to claim 9, wherein the first frequency
resource is multiplexed with a second frequency resource that is for a
second uplink control channel of another type mobile station.
A mobile station according to claim 9 or 10, wherein the mobile station
further comprises means for receiving a starting offset which is de
termined based on level of coverage enhancement.
PCT7JP2015/004690
A mobile station according to claim 11, wherein the starting offset is
signalled by RRC configuration.
A mobile station according to any of claim 9 to 12, wherein the mobile
station is machine-type communication(MTC) device.
A mobile station according to any of claim 9 to 13, wherein the set of
subframe comprises plural subframes.
15.A method performed by a communication apparatus which is operable
to communicate with at least one of a first type mobile station and a
second type mobile station, the method comprising:
assigning a first frequency resource for a first uplink control channel of
the first type mobile station per slot; and
assigning a second frequency resource for a second uplink control
channel of the second type mobile station per a set of subframe.
16.A method performed by a mobile station which is operable to com
municate with a communication apparatus, the method comprising:
determining first frequency resource which is assigned for a first uplink
control channel per a set of subframe; and
transmitting the uplink control channel based on the first frequency
resource.
17.A computer implementable instructions product comprising computer
implementable instructions for causing a programmable commu
nications device to perform the method of claim 15 or 16.