The present invention relates to mobile communications devices and networks, particularly
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 communication
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 control
channels, the so-called physical downlink control channel (PDCCH) and/or the socalled
evolved PDCCH (EPDCCH) in Rel-13, carries the scheduling assignments and
other control information. The (E)PDCCH serves a variety of purposes. Primarily, it is
used to convey the scheduling decisions to individual communication devices, i.e.
scheduling assignments for uplink and downlink communication.
[0004] The information carried on the (E)PDCCH is referred to as downlink control in-
[0005]
formation (DCI). Physical control channels, such as the (E)PDCCH, are transmitted on
an aggregation of one or several consecutive control channel elements (CCEs), where a
control channel element corresponds to nine resource element groups (REGs). Each
REG has four resource elements (REs).
A paging channel is provided over (mapped to) the physical downlink shared channel
(PDSCH) for notifying communication devices about a system information change
and/or incoming communications for one or more communication devices (such as
mobile terminated calls, short text messages, downlink data, and/or the like). Paging
messages (although they are transmitted over the PDSCH) are scheduled via the
(E)PDCCH. Specifically, in each radio frame transmitted by the base station there is at
least one predetermined paging occasion (PO) (a maximum of four POs per radio
frame), each PO being a subframe in which the base station may transmit control data
over the PDCCH in order to schedule an associated paging message. Each paging
2
wo 2016/163127 PCT/JP2016/001951
[0006]
[0007]
message can identify one or more communication devices for which the paging
message is sent. Whenever a PO includes a so-called paging identifier, i.e. a paging
radio network temporary identifier (P-RNTI), which is the same for all LTE devices in
the cell, each communication device processes the control data, and proceeds to
decoding the paging message broadcast over the paging channel (at the time-frequency
resource identified by the control data).
In more detail, whenever there is downlink data (or incoming call) for a particular
communication device, the network notifies the base station(s) that may be serving that
communication device about the data (or call). In response to this, the base station
generates a radio resource control (RRC) paging message and transmits the generated
paging message for the communication device (by broadcasting via the PDSCH). The
paging message is scheduled using one of the predetermined POs, the location of
which is known to the communication devices (e.g. from the base station's system Information
broadcast). The paging message includes one or more paging records
identifying each communication device being paged and the reason for paging that
communication device.
If a communication device finds the (E)PDCCH addressed by P-RNTI in (the control
data sent via) the PO, then it proceeds to receiving and decoding the RRC paging
message from the PDSCH resource block (RB) identified by the associated control
data transmitted via the PDCCH PO. If a paging record is found for a particular communication
device in the decoded RRC paging message, then that communication
device proceeds to respond to the paging message (whilst other, non-paged, communication
devices continue monitoring for the next PO). If appropriate, the paged communication
device performs a random access procedure with the base station in order
to establish a connection with the network and to be able to respond to the incoming
communication that the paging message (i.e. the communication device's paging
record) relates to.
[0008] Recent developments in telecommunications have seen a large increase in the use of
[0009]
machine-type communications (MTC) devices 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. Machinetype
communication devices are also known as machine-to-machine (M2M) communication
devices.
MTC devices connect to the network (after performing an appropriate random access
procedure, if necessary) 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.
3
wo 2016/163127 PCT/JP2016/001951
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 technical specification (TS) 22.368 V13.1.0 the contents of which are Incorporated
herein by reference.
[0010] For the Release 13 (Rel-13) version of the standards relating to MTC devices,
[0011]
[0012]
support for a reduced bandwidth of 1.4 MHz in downlink and uplink is envisaged.
Thus, some 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. Beneficially, the EPDCCH is transmitted over a
relatively narrow frequency spectrum (1.4 Mhz) that makes it compatible with Rel-13
reduced bandwidth MTC devices.
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, such as the
EPDCCH, not being received by an MTC device. In order to mitigate this risk, it has
been proposed to increase the coverage of transmissions to support such MTC devices
(e.g. corresponding to 20dB for frequency division duplex (FDD) transmissions).
One approach proposed for the enhancement of coverage, for so-called 'coverage
enhanced MTC devices', is the repetition of the same information (e.g. a DCI sent over
the EPDCCH) across multiple subframes (e.g. two, three, or four subframes). In other
words, for coverage enhanced (CE) MTC devices, the base station duplicates the
transmitted information in the time domain (the base station re-transmits the same Information
in one or more subframes subsequent to the subframe in which that information
is first sent). Such a coverage enhanced MTC device can be configured to
combine the multiple copies of the (same) information received in the multiple
subframes, and after combining the received information, the coverage enhanced MTC
device is more likely to be able to decode the received information successfully than
based on a single copy of the transmitted information. Similarly to the repetition of the
same information by the base station, coverage enhanced MTC devices are also
configured to duplicate (in the time domain) information transmitted to the base station
to facilitate successful reception of that information at the base station.
[0013] In practice, MTC devices may be deployed in different locations and they may experience
different channel conditions. Therefore, the number of repetitions may need
to be tailored for each device's situation or coverage level, and each MTC device
4
wo 2016/163127 PCT/JP2016/001951
[0014]
[0015]
informs 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.
Paging messages are transmitted separately for MTC devices (e.g. low-complexity
and/or coverage enhanced MTC devices) and for other (non-MTC) communication
devices, such as conventional mobile telephones. Furthermore, 3GPP envisaged that
paging messages for MTC devices may be transmitted in different subbands in dependence
on the MTC device's mode of operation (e.g. whether it is operating in
normal coverage mode (OdB CE level), at 5dB CE level, at 10dB CE level, or at 15dB
CE level).
Summary of Invention
Technical Problem
It can be seen, therefore, that where the paging is intended for aCE MTC device
repetition of transmissions will need to be supported. However, current paging
procedures do not support such repetition.
[0016] Moreover, even if repetition were supported, there can be uncertainty, at the base
station, regarding the type of MTC device being paged and/or its required coverage enhancement
level which can result in an incorrect number of repetitions being used and/
or paging messages being sent in the wrong time-frequency resource, and/or with
wrong format. For example, if the CE level is linked to the specific 1.4MHz sub-band
(the paging location) in which paging communications are broadcast (as currently
proposed by some 3GPP participants), then this uncertainty regarding the CE level can
result in some low-complexity MTC devices being tuned to a 1.4 MHz bandwidth that
is outside the subband over which the paging message (and/or the associated control
data) is transmitted for these MTC devices. However, there is no trivial way of
ensuring that the CE level employed by the communication device is the same as the
CE level employed by the base station (for that communication device).
[0017] Accordingly, the present invention seeks to provide systems, devices and methods
which at least partially address the above issues.
Solution to Problem
[0018] In one aspect, the invention provides a base station for a communication system in
which machine type communication 'MTC' devices communicate via said base
station, the base station comprising: means for determining that there is a requirement
to notify said MTC devices that there has been a system information update; means for
notifying any idle mode MTC devices about the system information update by sending
a notification using a paging message; and means for providing any radio resource
control 'RRC' connected mode MTC devices with the system information using MTC
5
wo 2016/163127 PCT/JP2016/001951
[0019]
[0020]
[0021]
[0022]
[0023]
[0024]
device dedicated signalling.
In one aspect, the invention provides a machine type communication 'MTC' device
for communicating with a base station, the MTC device comprising: means for
forming a radio resource control 'RRC' connection with said base station to enter an
RRC connected mode; a transceiver configured to obtain, using dedicated signalling,
system information associated with a cell of the base station, when in said RRC
connected mode.
In one aspect, the invention provides a method performed by a base station for a
communication system in which machine type communication 'MTC' devices communicate
via said base station, the method comprising: determining that there is a requirement
to notify said MTC devices that there has been a system information update;
notifying any idle mode MTC devices about the system information update by sending
a notification using a paging message; and providing any radio resource control 'RRC'
connected mode MTC devices with the system information using MTC device
dedicated signalling.
In one aspect, the invention provides a method performed by a machine type communication
'MTC' device in a communication system in which MTC devices communicate
via a base station, the method comprising: forming a radio resource control
'RRC' connection with said base station to enter an RRC connected mode; and
obtaining, using dedicated signalling, system information associated with a cell of the
base station, when in said RRC connected mode.
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.
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 combination
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 individually.
Embodiments of the invention will now be described by way of example only with
reference to the attached figures in which:
Brief Description of Drawings
[0025] [fig.1]Figure 1 schematically illustrates a telecommunication system to which em6
wo 2016/163127 PCT/JP2016/001951
[0026]
[0027]
bodiments of the invention may be applied;
[fig.2]Figure 2 is a block diagram illustrating the main components of the communication
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 paging can be realised in the
system shown in Figure 1;
[fig.5]Figure 5 illustrates an exemplary paging configuration option that can be
employed in the system shown in Figure 1;
[fig.6]Figure 6 illustrates another exemplary paging configuration option that can be
employed in the system shown in Figure 1;
[fig.7]Figure 7 illustrates another exemplary paging configuration option that can be
employed in the system shown in Figure 1;
[fig.8]Figure 8 illustrates another exemplary paging configuration option that can be
employed in the system shown in Figure 1;
[fig.9]Figure 9 illustrates an exemplary way in which a required coverage enhancement
level (to be employed in a particular cell) can be determined for a communication
device in the system shown in Figure 1; and
[fig.10]Figure 10 illustrates another exemplary way in which a required coverage enhancement
level (to be employed in a particular cell) can be determined for a communication
device in the system shown in Figure 1.
Description of Embodiments

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 implemented,
will typically include other base stations and communication devices.
Each communication device 3 may fall into one or more 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 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). It will be appreciated
that some communication devices that belong to this category may not
support the EPDCCH (only PDCCH). A second category of UEs include commu7
wo 2016/163127 PCT/JP2016/001951
nication devices that support the current release of the LTE standard (e.g. Rel-13 and/
or later). A third 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 fourth
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).
[0028] In this example, the mobile telephone 3-1 comprises a Rel-13 UE, and the MTC
[0029]
device 3-2 comprises a reduced bandwidth MTC device (which may also be configured
for an appropriate level of coverage enhancement). Although not shown in Figure 1, it
is assumed that a number of other MTC devices are also present within the cell of the
base station 5.
The base station 5 is connected to the core network 7 via an S 1 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 information
(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.
[0030] The base station 5 is configured to transmit a physical downlink control channel
(PDCCH) and an evolved PDCCH (EPDCCH) for reception by the communication
devices 3 located within the base station's 5 cell. The (E)PDCCH allocates uplink and
downlink resources to the communication devices 3. One difference between the
PDCCH and the EPDCCH is that the EPDCCH uses a relatively narrow frequency
spectrum (1.4 Mhz) that makes it compatible with Rel-13 reduced bandwidth MTC
devices, whilst PDCCH uses a wider frequency spectrum in order to provide backward
compatibility with legacy communication devices.
[0031] The so-called common search space (CSS) is a search space for all/multiple UEs in a
[0032]
cell to blindly decode the PDCCH(s) carrying downlink control information (DCI)
which is common to all/multiple communication devices 3. For example, the CSS may
carry downlink control information (DCI) for: system information blocks (SIBs) which
contain information related to cell access parameters; random access channel (RACH)
messages; and/or the paging channel (PCH). In LTE Rel-13, the CSS (also referred to
as 'eCSS') forms part of the search space of the EPDCCH.
Due to the reduced bandwidth of 1.4 MHz in downlink and uplink, the MTC device
3-2 cannot receive the PDCCH which is densely spread across the entire cell
8
wo 2016/163127 PCT/JP2016/001951
bandwidth (i.e. it may be transmitted over frequencies falling outside the 1.4 MHz
supported by the MTC device 3-2). However, the MTC device 3-2 can receive the
EPDCCH CSS (eCSS) which is transmitted over 6 RBs, i.e. within the 1.4 MHz band
supported by the MTC device 3-2.
[0033] In order to support MTC devices, the base station's 5 cell bandwidth includes a
number of subbands (e.g. non-overlapping subbands), each subband comprising 6 RBs
(or less). Beneficially, since bandwidth reduced MTC devices are able to communicate
over a maximum of 1.4MHz bandwidth (which roughly corresponds to 6 RBs), the
communication device 3-2 is able to send and receive (eCSS and other) data over the
particular subband that its transceiver is currently tuned to.
[0034] Paging messages are transmitted separately for MTC devices (e.g. low-complexity
and/or coverage enhanced MTC devices) and for other communication devices. Paging
messages for MTC devices support PDSCH subframe bundling/repetition with
multiple bundle sizes/repetition levels (in accordance with the required level of
coverage enhancement). Beneficially, the base station 5 paging the communication
device 3-2 is provided with information that allows it to determine that the communication
device 3-2 comprises a low-complexity (bandwidth reduced) MTC device
and/or an MTC device configured for coverage enhancement. The base station 5 is
provided with information that allows it to determine the amount of coverage enhancement
(repetitions) required during paging message transmission.
[0035] Advantageously, the base station 5 and the MTC device 3-2 are configured to employ
[0036]
the same CE level for paging (and indeed other communications) in the base station's 5
cell. The appropriate CE level may be determined (e.g. based on signal strength or
quality) by either the base station 5 or the MTC device 3-2 (and notified to the other
one). The appropriate CE level is kept synchronised between the base station 5 and the
MTC device 3-2 (either directly or via the core network 7). Beneficially, the appropriate
CE level for a communication device is notified to the core network (e.g. the
MME), and thus when initiating paging the MME is able to instruct the respective
paging base station for each cell of a particular tracking area (TA) to employ an appropriate
CE level in that cell for the MTC device that is being paged.
It will be appreciated that when a communication device to be paged is operating in
the so-called idle state, its location is known to MME on a tracking area (TA) basis
only (rather than on a cell level). Therefore, the MME instructs all base stations within
that TA (including e.g. base station 5 in Figure 1) to transmit an appropriately
formatted RRC paging message (including a paging record for that communication
device in the RRC paging message) by employing the required CE level for their cell
with respect of the paged communication device. The term idle state as used herein
refers to an operational mode in which the communication device is currently not
9
wo 2016/163127 PCT/JP2016/001951
sending/receiving user data over its dedicated radio bearer(s), although its transceiver
may be active (e.g. it may still receive broadcast data, perform signal measurements,
and/or the like).
[0037] As with conventional paging a paging occasion (PO) is configured for paging the
MTC devices. Beneficially, however, the PO defines a plurality ('bundle') of
subframes in a certain subband (e.g. by defining the start point- or index of the first
subframe- of that bundle of subframes).
[0038] In the examples described in more detail below, the system may employ scheduling
(e.g. Layer 1 (L1) scheduling) of the paging transmissions via the ePDCCH. However,
in a particularly beneficial example control-less paging is used, i.e. paging without
requiring associated resources being scheduled in the ePDCCH. Instead, paging
messages are transmitted over a transmission block of predetermined size (and over a
predetermined subband), which can be received by each communication device 3
within the cell of the base station 5.
[0039] The bundle of subframes defined by the PO are subframes in which the MTC device
is to monitor the repetitions of the ePDCCH for paging message scheduling in the case
where the ePDCCH is used to schedule paging transmission. The bundle of subframes
defined by the PO are subframes in which the MTC device is to monitor the repetitions
of the PDSCH for a paging message in the case where the ePDCCH is not used for
scheduling paging transmission.
[0040] The base station 5 may configure different resources and/or paging regions per CE
[0041]
[0042]
level to effectively separate the paging for MTC devices having different CE levels
between different respective resources and/or paging regions. However, in a particularly
beneficial example, paging message transmissions are not separated for
different coverage enhancement levels (allowing all MTC devices, regardless of CE
level, to benefit from scheduled or control-less paging in the same subband). In this
case, paging message transmissions may be realised using either with or without
ePDCCH.
In summary, the above described communication system supports various beneficial
options for paging communication devices within the cell of the base station, with
particular focus on the limitations of MTC devices. Paging messages can be scheduled
dynamically and (if applicable) in dependence on the required CE level for each MTC
device without (significantly) affecting legacy and/or conventional communication
devices in the cell.

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.
10
wo 2016/163127 PCT/JP2016/001951
[0043]
[0044]
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.
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 communications control module 43, a scheduling determination
module 44, an MTC module 45, and a paging module 47.
The communications 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).
[0045] The scheduling determination module 44 monitors transmissions by the base station
5 in predetermined POs (if applicable) and determines whether or not the monitored
POs include control data for scheduling a paging transmission. If a monitored PO does
include such control data, then the scheduling determination module 44 determines the
communication resources (e.g. subframe/subband) associated with the paging
transmission. In case a control-less is being used, the scheduling determination module
44 maintains information identifying the resources over which control-less paging
messages can be transmitted and instructs the paging module 47 to decode paging
messages transmitted therein.
[0046] The MTC module 45 is operable to carry out machine-type communication tasks. For
example, the MTC module 45 may collect data for sending (e.g. periodically and/or
upon detecting a trigger) to a remote server (via the transceiver circuit 31). The MTC
module 45 is also responsible for obtaining (determining and/or obtaining from the
base station 5) an appropriate CE level to be used in the cell of the base station 5
serving the communication device 3.
[0047] The paging module 47 receives (over appropriate communication resources de-
[0048]
termined by the scheduling module 44) and processes paging messages addressed to
the communication device 3.

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 S1 interface). The
operation of the transceiver circuit 51 is controlled by a controller 57 in accordance
11
wo 2016/163127 PCT/JP2016/001951
[0049]
[0050]
[0051]
[0052]
with software stored in memory 59.
The software includes, among other things, an operating system 61, a communications
control module 63, a paging module 65, a system information module 67,
and an MTC support module 69.
The communications control module 53 controls communications with the communication
devices 3.
The paging module 65 generates and transmits paging messages (via the communications
control module 63) for communication devices 3 located within the cell of
the base station 5.
The system information module 67 is responsible for broadcasting system Information
(such as configuration of the cell of the base station 5) and/or other
broadcast transmissions for receipt by the communication devices 3 located within the
cell of the base station 5. For example, the broadcast portion transmits, over appropriate
PO(s), paging messages (generated by the paging module 65).
[0053] The MTC support module 69 handles (generates, sends, and receives) messages for
[0054]
MTC devices in the cell of the base station 5. The MTC support module 69 is responsible
for ensuring that each such message is transmitted using the required number
of repetitions (in dependence on the CE level, if configured) and using the appropriate
time and frequency resources (in a given subframe I within the 1.4 MHz band
supported by the MTC devices). The MTC support module 69 is also responsible for
obtaining (determining and/or obtaining from the core network 7) an appropriate CE
level to be employed in the cell of the base station 5 when communicating with the
communication device 3.
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.
[0055]
Figure 4 illustrates an exemplary way in which paging can be realised in the communication
system 1 shown in Figure 1. Specifically, in this example, paging messages
are transmitted over the PDSCH without any associated control data (DCI) being
transmitted over the (E)PDCCH for scheduling the paging transmissions. Beneficially,
the location (e.g. time/frequency resource) and the size of the paging message (e.g. determined
by an associated transport block size (TBS)) are configured via system Information
broadcast.
12
wo 2016/163127 PCT/JP2016/001951
[0056] Moreover, the location and/or the size of the paging message may also be updated
via system information broadcast, if necessary. For example, the base station 5 is able
to indicate/adjust the TBS for paging message via the system information based on at
least one of:
-the (current) average MTC paging load in the cell;
- the number of connected UEs in the cell; and
-the (measured/determined/estimated) resource usage for the base station (not
limited to MTC paging).
[0057] In addition, other paging related information may also be indicated via the system In-
[0058]
[0059]
[0060]
[0061]
formation, such as the PO(s) (e.g. a start point thereof in the ePDCCH/PDSCH)
currently configured for the base station's 5 cell. It will be appreciated that a different
PO(s) may be configured (and broadcast via the system information) for each category
of communication devices and/or for each CE level.

In order to inform the communication devices 3 located within the cell of the base
station 5 about a change of the system information (e.g. PO configuration, paging TBS,
channel configuration, and/or the like), the base station 5 is configured to generate and
send an appropriately formatted paging message to the communication devices 3. The
system information change paging is carried out using a one bit indicator (known as
'systeminfoModification' bit) which is transmitted together with other regular (UE
specific) paging records, if any. When it is about to change any system information
element, the base station 5 transmits this indicator bit on all POs for all communication
devices in its cell in order to ensure that each communication device 3 has an opportunity
to receive the updated system information without delay. Each communication
device receiving (via any PO) a paging message that includes the system information
change indicator bit proceeds to obtaining the updated system information
by listening to the next system information broadcast (e.g. at the boundary of the
'BCCH modification period').
It will be appreciated, however, that a system information change may be notified in
a different way for communication devices (at least for MTC devices) operating in the
'RRC_IDLE' and in the 'RRC_CONNECTED' state.
System information change for UEs in RRC IDLE
It will be appreciated that for communication devices in idle mode, the system Information
modification indicator is transmitted together with normal paging record(s).
In this case, the base station 5 needs to send the system information change indicator
bit on all POs thereby addressing all types of communication devices (including MTC
devices and legacy UEs as well).
Optionally, e.g. if system information changes are relatively frequent, paging for
13
wo 2016/163127 PCT/JP2016/001951
system information modification may be separated from normal paging. In this case,
preferably, paging for system information is transmitted in a predetermined common
subband (e.g. the central subband), and all communication devices need to be
configured to work on this common subband (at least during the PO) and monitor for
the system information modification bit in one or more POs of this subband. Consequently,
MTC devices cannot be scheduled in other subbands during the paging
occasions for system modification in the common subband. However, in this case there
is no need to include the 'systeminfoModification' bit in every PO in every subband,
albeit requiring some additional paging monitoring by the MTC devices, which might
slightly increase their power consumption.
[0062] System information change for UEs in RRC CONNECTED
It is likely that communication devices in RRC_CONNECTED mode are scheduled
on a subband that is different from the subband for monitoring paging. In any case, it
will be appreciated that the system information modification indicator may be
transmitted together with normal paging record(s), as above, i.e. the base station 5
needs to send the system information change indicator bit on all POs in every subband
in order to reach all types of communication devices. However, this option may require
communication devices in RRC_CONNECTED mode to re-tune to their associated
paging subband in order to obtain the system information change notification.
[0063] Therefore, in this system, dedicated signalling is used for informing
RRC_CONNECTED communication devices (at least MTC devices) about a change in
system information. For example, if there is on-going data transmission for a particular
communication device, it is possible to multiplex the updated system information (at
least the changed part thereof) and other data being transmitted to that communication
device. Consequently, RRC-CONNECTED communication devices are not required to
monitor their associated PO for system information modification because the updated
system information is sent via unicast transmission. This may result in improved
operation of communication devices, especially MTC devices that operate over a
limited bandwidth.
[0064] In another option, it may be possible to force a communication device operating in
the RRC_CONNECTED to obtain the system information by releasing the communication
device's RRC connection. This may be beneficial if, for example, there is no
ongoing data transmission to this communication device (thus the risk of data loss is
kept minimal). Once its RRC connection is released, the communication device
proceeds to read the system information transmitted via the broadcast channel (as per
default procedure).
[0065] It will be appreciated that the unicast based option and the RRC release based option
may be employed together by the base station 5 (depending on implementation).
14
wo 2016/163127 PCT/JP2016/001951
[0066]
[0067]

In the current LTE standards, a paging occasion (PO) is defined as a subframe where
there may be a P-RNTI transmitted on the PDCCH for scheduling a paging message. A
radio frame may contain one to four POs. When DRX is used the UE needs to monitor
only one PO per DRX cycle.
In the present system, however, the POs are defined such that repetitions for MTC
devices are also supported (when appropriate). Specifically, a PO in this system is
defined as (the start point of) a bundle of subframes in a certain subband where:
- the UE monitors repetitions of ePDCCH for paging message scheduling in
case ePDCCH is needed for paging transmission; or
- the UE monitors repetitions of PDSCH for paging message in case ePDCCH is
not needed for paging transmission.
[0068] Furthermore, there may be different POs for different sub-bands (e.g. to support
MTC devices with different CE levels).
[0069] Figures 5 to 8 illustrate further details of various PO configuration options and the
resulting paging transmissions in this system.
[0070] Specifically, the examples shown in Figures 5 and 6 illustrate scenarios when paging
message transmissions are separated for different coverage enhancement levels.
[0071] Figure 5 illustrates paging message transmissions using ePDCCH (eCSS). In this
[0072]
example, the scheduling information (e.g. time-frequency resource, MCS/TBS) that
allows the MTC device to acquire a paging message on the PDSCH is dynamically
indicated by in ePDCCH. In this case, a different P-RNTI and/or a different eCSS may
be used for each CE level.
Figure 6 illustrates paging message transmissions without using ePDSCH. This
solution may also be referred to a 'control-less' paging, i.e. the scheduling information
(e.g. time-frequency resource, MCS/TBS) that allows the MTC device to acquire a
paging message on the PDSCH is not indicated dynamically by in ePDCCH, but it is
predefined or it is indicated in (or forms part of) the system information). In this case,
different time and/or frequency resources (within the PDSCH) may be allocated for
different CE levels. It will be appreciated that in the PDSCH based scenario shown in
Figure 6, effectively, a control-less paging may be realised for each CE level, e.g. as
described above with reference to Figure 4.
[0073] In the examples shown in Figures 7 and 8, paging message transmissions are not
separated for different coverage enhancement levels. Specifically, Figure 7 illustrates
paging message transmissions with ePDCCH, and Figure 8 illustrates paging message
transmissions without ePDCCH (e.g. when ePDCCH is not or cannot be used for
paging transmissions). It will be appreciated that in the scenario shown in Figure 8, effectively,
a control-less paging may be realised, e.g. as described above with reference
15
wo 2016/163127 PCT/JP2016/001951
[0074]
[0075]
to Figure 4.

In the following, a number of options are described for determining an appropriate
CE level for a particular MTC device 3-2 in the base station's 5 cell, and to ensure that
the same CE level is employed by both the MTC device 3-2 and its serving base station
5 in their communications with each other.
Figure 9 illustrates an option in which the serving base station 5 (denoted 'eNB') is
responsible for the decision on which CE level a particular MTC device (denoted
'UE') should employ in a given cell.
[0076] As illustrated in step S92, the base station 5 is configured to determine (using its
MTC support module 69) an appropriate CE level for the MTC device 3-2 based on the
random access procedure (denoted 'PRACH' in Figure 9) performed between the base
station 5 and the MTC device 3-2 in the cell of the base station 5 (as generally shown
in step S91).
[0077] Once the base station 5 has determined the appropriate CE level for the MTC device
[0078]
3-2, it informs (in step S93) the core network 7 (e.g. the MME/HSS) which stores this
information for later use (e.g. for paging the MTC device 3-2 via this base station 5).
As generally shown in step S94, the base station 5 may also inform the MTC device
3-2 about the determined CE level for its cell, either in a separate message or as part of
the random access procedure (e.g. step S94 may form part of step S91). It will be appreciated
that the base station 5 may be configured to inform the MTC device about
the CE level implicitly, for example, by employing a given number of repetitions
(during and/or after the random access procedure) corresponding to the determined CE
level.
[0079] It will be appreciated that there are a number of ways in which the base station 5 can
derive the appropriate CE/repetition level for an MTC device, based on the RACH
procedure, including for example:
1) MTC devices with different CE level may use different preamble resources
(with corresponding different repetition times) in accordance with an appropriate predetermined
relationship mapping between preamble resources and corresponding CE
levels. In this case, the base station can determine the appropriate CE level based on
which preamble resources (and/or based on the repetition times) used by the MTC
device 3-2. In this case however, optionally, the base station may also be configured to
use a different CE level than the CE level indicated by the relationship mapping
between preamble resources and corresponding CE levels (e.g. if the base station 5 is
able to successfully decode the MTC device's preamble transmission by combing
fewer repetitions than required for that CE level).
2) Otherwise, if there is no associated preamble resource set configured for each
16
wo 2016/163127 PCT/JP2016/001951
[0080]
different CE level, then the base station 5 may be configured to determine the coverage
level based on a number of repetitions required for successful decoding of the
preamble transmitted by the MTC device 3-2.
Furthermore, e.g. if the MTC device 3-2 has never been connected to this cell I or it
has not connected to this cell within a predetermined time window, then one or more of
the following options may also be used:
3) The base station 5 may be configured to assume the maximum and/or a
default CE/repetition level for the MTC device 3-2 in a cell in which the MTC device
3-2 has never been connected (or it has not connected within a predetermined time
window).
4) If the MTC device 3-2 reselected to a new cell (of the base station 5), then an
appropriate RACH procedure may be triggered (by the MTC module 45) in order to let
the base station 5 detect the associated CE level of that MTC device 3-2 in the new
cell, otherwise the MTC device 3-2 may not be paged in the new cell until it has
performed a RACH procedure via that cell (although the MTC device 3-2 is still being
paged in other cells) or the MTC device 3-2 will be paged by assuming the maximum
and/or a default CE/repetition in this new cell.
[0081] It will be appreciated that if the required CE level of an MTC device changes in a cell
[0082]
[0083]
(e.g. based on its own estimation), particularly in the current cell in which the MTC
device is currently camping, then an appropriate RACH procedure may be triggered
(by the MTC module 45) in order to let the base station 5 update the associated CE
level stored for the MTC device (for that cell).
Beneficially, therefore, this option allows more control for the base station 5 in the
determination of an appropriate CE level. In this case the same MTC device may have
different CE/repetition levels in different cells. However, such cell specific CE level
can be stored in the core network 7 (MME/HSS), for each MTC device, so that each
MTC device can be paged in any cell using the appropriate CE level (and repetitions)
required in that cell. Thus, when the MME initiates paging of the MTC device 3-2, in
step S95, it includes in its paging request the cell ID(s) and the respective associated
CE/repetition level for each cell in which the MTC device 3-2 is to be paged.
As generally shown in step S96, since both the base station 5 and the MTC device
3-2 employ the same CE level, the base station 5 is operable to transmit (and the MTC
device 3-2 is operable to monitor) on the correct PO resource corresponding to that CE
level. Thus, when in step S97 the base station 5 transmits a paging message (scheduled
via the PO in S96) for the MTC device 3-2, it can apply the correct CE level for that
MTC device 3-2 (and employ the required number of repetitions, if any).
[0084] Figure 10 illustrates an option in which the MTC device 3-2 is responsible for the
decision on which CE level that MTC device 3-2 employs in a given cell.
17
wo 2016/163127 PCT/JP2016/001951
[0085]
[0086]
[0087]
[0088]
Specifically, in this case the MTC device's 3-2 determination (in step S102) is based
on measurements of the (downlink) radio conditions of a number of cells (e.g. all
detected cells) in the vicinity of the MTC device 3-2. It will be appreciated that the
MTC device 3-2 may measure the radio conditions for at least its current serving cell,
e.g. the cell of the base station 5.
Once the MTC device 3-2 has determined, in step S102, its appropriate CE level for
a particular cell (or a set of respective CE levels for a plurality of cells), it informs the
core network 7 (e.g. the MME/HSS) about the applicable CE level(s) and (optionally)
the corresponding cell ID(s). It will be appreciated that the MTC device 3-2 may report
to the applicable CE level(s) (corresponding cell ID(s), if any) as part of a capability
report (and/or the like).
It will be appreciated that if the MTC device 3-2 determines (e.g. based on its own
estimation I signal quality measurements) that the required CE level (in at least one
cell) has changed, particularly in the current cell in which the MTC device 3-2 is
currently camping, then the MTC device 3-2 may notify the core network 7 and update
the associated CE level stored for the MTC device (for the at least one cell in which
the CE level has changed).
It will be appreciated that the MTC device 3-2 may be configured to report/update
the CE level when one or more of the following conditions are met: i) the MTC device
performs an attach procedure; ii) the MTC device has found a new neighbour cell as
paging cell; and iii) the MTC device determines a change in the required CE level and/
or a change in radio conditions in a cell.
[0089] The core network 7 stores this information for later use (e.g. for paging the MTC
device 3-2 in step S105). Steps S105 to S107 correspond to steps S95 to S97 described
above, thus their description is omitted herein for simplicity.
[0090] A benefit associated with this option is that the required CE levels for a plurality of
[0091]
cells (including e.g. potential paging cells for the MTC device 3-2) can be measured
and reported to core network 7 at once.

Detailed exemplary embodiments have been described above. As those skilled in the
art will appreciate, a number of modifications and alternatives can be made to the
above exemplary embodiments whilst still benefiting from the inventions embodied
therein.
[0092] In the above description, repetition in time domain is assumed for all transmissions.
However, such repetitions are omitted in Figures 4 to 10 for simplicity.
[0093] A number of options have been described above, with reference to Figures 5 to 8. It
will be appreciated that these options are not mutually exclusive and any of the options
may be combined within the same system, either within a single cell and/or in
18
wo 2016/163127 PCT/JP2016/001951
neighbouring cells. For example, the base station may be configured to change from
one operation mode to another, e.g. periodically, in dependence on the number/type of
MTC devices in its cell, in dependence on the overall load in the cell, in dependence on
the type of communication (e.g. broadcast/unicast), and/or the like.
[0094] 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.
[0095] In the above exemplary embodiments, an LTE telecommunications system was
[0096]
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.
In the exemplary embodiments described above, the base station and the communication
device each include transceiver circuit. Typically, this circuitry will be formed
by dedicated hardware circuits. However, in some exemplary embodiments, part of the
transceiver circuitry may be implemented as software run by the corresponding
controller.
[0097] In the above exemplary 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.
[0098] It will be appreciated that the base station may comprise: means for receiving, from a
core network entity, a paging request for paging at least one MTC device; means for
determining a paging occasion when said at least one MTC device will be sent paging
related information, wherein said paging occasion identifies a plurality of subframes in
which said paging related information will be first sent and then repeated; and means
for sending, and then repeating, said paging related information in said plurality of
subframes identified by said paging occasion.
[0099] The paging related information may comprise scheduling information identifying
time and/or frequency resources to be used for sending a paging message to said at
least one MTC device, and said plurality of subframes identified by said paging
occasion may be subframes in which a control channel carrying said paging related Information
will be sent.
19
wo 2016/163127 PCT/JP2016/001951
[0100] The at least one MTC device may comprise at least one coverage enhanced MTC
device having a first coverage enhancement level and at least one coverage enhanced
MTC device having a second coverage enhancement level that is different to said first
coverage enhancement level.
[0101] In this case, the paging related information may comprise a first paging identifier
(e.g. a radio network temporary identifier) for identifying paging related information
for said at least one coverage enhanced MTC device having a first coverage enhancement
level, and a second paging identifier (e.g. a different radio network
temporary identifier) for identifying paging related information for said at least one
coverage enhanced MTC device having a second coverage enhancement level.
[0102] The paging related information for said at least one coverage enhanced MTC device
[0103]
having a first coverage enhancement level may be first sent in a control channel in a
first subframe, and paging related information for said at least one coverage enhanced
MTC device having a second coverage enhancement level may be first sent in a control
channel in a second sub-frame that is different to said first subframe.
The paging related information for said at least one coverage enhanced MTC device
having a first coverage enhancement level may be sent in a control channel in at least
one subframe in which paging related information for said at least one coverage
enhanced MTC device having a second coverage enhancement level is also sent using
the same control channel.
[0104] The paging related information may comprise at least one paging message for said at
[0105]
least one MTC device, and said plurality of subframes identified by said paging
occasion may be subframes in which said at least one paging message will be sent and
then repeated. In this case, the base station may further comprise means for sending, to
said at least one MTC device, scheduling information for identifying resources to be
used for sending said at least one paging message, in a system information block. For
example, the scheduling information may comprise information identifying a transport
block size 'TBS' for said requested paging.
The at least one MTC device may comprise at least one coverage enhanced MTC
device having a first coverage enhancement level and at least one coverage enhanced
MTC device having a second coverage enhancement level that is different to said first
coverage enhancement level.
[0106] In this case, the paging message for said at least one coverage enhanced MTC device
having a first coverage enhancement level may be sent using a first predetermined
frequency resource, and a paging message for said at least one coverage enhanced
MTC device having a second coverage enhancement level may be sent using a second
predetermined frequency resource that is different to said first predetermined
frequency resource.
20
wo 2016/163127 PCT/JP2016/001951
[0107]
[0108]
The paging message for said at least one coverage enhanced MTC device having a
first coverage enhancement level may be first sent in a data channel in a first subframe,
and a paging message for said at least one coverage enhanced MTC device having a
second coverage enhancement level may be first sent in a data channel in a second
subframe that is different to said first subframe.
The paging message for said at least one coverage enhanced MTC device having a
first coverage enhancement level may be sent in a data channel in at least one subframe
in which a paging message for said at least one coverage enhanced MTC device having
a second coverage enhancement level is also sent in the same data channel.
[0109] If the at least one MTC device comprises at least one coverage enhanced MTC
[0110]
[0 111]
[0112]
device, then said base station may further comprise means for identifying a coverage
enhancement level associated with said at least one coverage enhanced MTC device,
and said means for sending, and then repeating, said paging related information may be
configured to repeat sending said paging related information for a number of repetitions
defined by said coverage enhancement level.
The paging request may comprise information identifying said coverage enhancement
level and wherein said means for identifying a coverage enhancement level
associated with said at least one coverage enhanced MTC device is configured to
identify said coverage enhancement level based on said information identifying said
coverage enhancement level in said paging request.
The means for identifying a coverage enhancement level associated with said at least
one coverage enhanced MTC device may be configured to identify said coverage enhancement
level based on information (e.g. a random access preamble sequence index)
obtained during a procedure to set up a random access channel (RACH) with said at
least one coverage enhanced MTC device.
If a respective coverage enhancement level cannot be determined for said at least one
coverage enhanced MTC device, then said means for sending, and then repeating, said
paging related information may be configured to repeat sending said paging related information
for a number of repetitions defined in accordance with a predetermined (e.g.
a maximum and/or default) coverage enhancement level.
[0113] In the above exemplary embodiments, machine-type communication devices and
[0114]
mobile telephones are described. However, it will be appreciated that mobile
telephones (and similar user equipment) may also be configured to operate as machinetype
communication devices. For example, the mobile telephone 3-1 may include
(and/or provide the functionality of) the MTC module 45.
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
21
wo 2016/163127 PCT/JP2016/001951
table (source: 3GPP TS22.368 V13.1.0, Annex B). This list is not exhaustive and is
intended to be indicative of the scope of machine-type communication applications.
[0115] [Table 1]
Service Area MTC applications
Surveillance systems
Security
Backup for landline
Control of physical access (e.g. to buildings)
Car/driver security
Fleet Management
Order M::jflagement
Pay as you drive
Tracking & Tracing
Asset Tracking
Navigation
Traffic information
Road tolling
Road traffic optimisation/steering
Point of sales
Payment Vending machines
Gaming machines
Monitoring vital signs
Health
Supporting the aged or handicapped
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
[0 116] Various other modifications will be apparent to those skilled in the art and will not be
described in further detail here.
22
wo 2016/163127 PCT/JP2016/001951
[0117]
[0118]
[0119]
[0120]
[0121]
The following is a detailed description of the way in which the present inventions
may be implemented in the currently proposed 3GPP standard. Whilst various features
are described as being essential or necessary, this may only be the case for the
proposed 3GPP standard, for example due to other requirements imposed by the
standard. These statements should not, therefore, be construed as limiting the present
invention in any way.
Title: Paging for Rel-13 MTC UE
1. Introduction
The repetition is widely needed for both broadcast and unicast channels which
address to MTCe UE including low complexity UE in normal coverage and in
coverage enhancement, so paging transmission procedure needs to be re-designed for
Rel-13 MTCe UE.
In this contribution, we share our views on the following issues:
1. Whether dynamic L1 scheduling i.e. ePDCCH is needed for paging
transmission?
2. How to do the paging for system information change?
3. Are the paging messages transmissions separated or not for different types of
Rel13 MTC UEs?
4. How to determine the CE/repetition level of a UE for paging transmission?
2. Discussion
In current specification TS 36.304, one Paging Occasion (PO) is a subframe where
there may be P-RNTI transmitted on PDCCH addressing the paging message. One
Radio Frame contains one or more Paging Occasion(s). When DRX is used the UE
needs only to monitor one PO per DRX cycle.
[0122] In the context of Rel-13 MTC, since repetition will be needed, PO is not one
subframe anymore. We propose to adopt following definition of PO:
[0123] Proposal1: Paging Occasion (PO) is the (start point of) a bundle of subframes in a
certain sub-band where:
- The UE monitors the repetitions of ePDCCH for paging message scheduling in
case ePDCCH is needed for paging transmission, or
- The UE monitors the repetitions of PDSCH for paging message in case
ePDCCH is not needed for paging transmission.
[0124] We may have different PO on different sub-bands.
[0125] 2.1 paging for system information change
As we know, the paging message is also used to inform UEs in RRC_IDLE and UEs
in RRC_CONNECTED about a system information change. The system information
change paging is one bit indicator and transmitted together with other normal paging
records if any. When it is about to change any system information element, eNB has to
23
wo 2016/163127 PCT/JP2016/001951
transmit this indicator on all POs for all UEs to guarantee all UEs will be informed in
time.
[0 126] In the context of Rel-13 MTC, let's discuss system information modification for UEs
in RRC-IDLE and RRC-CONNECTED mode separately:
System information change for UEs in RRC_IDLE
[0127] Option1: Paging for system information modification is transmitted together with
normal paging records (As legacy)
[0128] With this option, eNB has to send the paging on all POs addressing to all types of
[0129]
[0130]
Rel-13 MTC UEs as legacy. The effort to send on all POs is much bigger than legacy
due to hundreds of repetitions.
Option 2: paging for system information modification is separated from normal
pagmg
With this option, the paging for system information has to be transmitted in a
common sub-band, and all UEs shall work on this common sub-band and try to
monitor the paging occasions for system information modification. This means all Rel-
13 MTC UEs cannot be scheduled in other sub-band during the paging occasions for
system modification. Moreover this would be additional paging monitoring work from
UE perspective, and lead to more power consumption.
[0131] Considering the system information change will be very rare, we slightly prefer
option 1:
[0132] Proposal: System information modification indicator is transmitted together with
normal paging record(s).
[0133] System information change for UEs in RRC CONNECTED
[0134] Option1: Notification of the system information change via Paging (as legacy)
[0135]
[0136]
It is likely that UE in RRC_CONNECTED mode is scheduled on a sub-band
different from the sub-band for monitoring paging. This will require UE to re-tune to
the sub-band for paging and for the system information reading.
Option2: send the new system information via dedicated signalling:
UE can keep working on the sub-band for unicast channels. If there is a large amount
of rel13 UE in RRC-CONNECTED, it will be very costly to send the changed system
information one UE by one UE. However if there is on-going data transmission to the
target UE, by multiplexing the system information and the data, it will be less costly
provided only changed part of SI will be sent to UE.
Option3: Release RRC connection
If there is no ongoing data transmission to a UE, then another possible choice is to
release this UE, hence the UE will read the system information via broadcast channel.
[0137] Option 2 and option 3 can work together by eNB implementation. Considering the
UE in coverage enhancement will be kept in RRC-CONNECTED mode only if there is
24
wo 2016/163127 PCT/JP2016/001951
on-going data, it is propose:
[0138] Proposal: Dedicated signalling will be used for system information change for RRCCONNECTED
REL13 MTC UEs, i.e. RRC-CONNECTED REL13 MTC UEs are not
required to monitoring paging for system information modification.
[0139] 2.2 With or without ePDCCH
Similar to system information transmission, one key question regarding paging
transmission is whether dynamic Ll scheduling information in ePDCCH is needed or
not, we have pros and cons analysis as below:
[0140] Without ePDCCH (i.e. without dynamic Ll scheduling information):
[0141]
[0142]
- Lack of scheduling flexibility: the radio resource for paging transmissions,
modulation order, coding rate cannot be changed dynamically.
-Fixed TBS/MCS and Radio Resource: fixed number (e.g. only 1) of UE can be
paged in one PO.
- Extra paging delay if there is no space to accommodate all paging requests:
when more UE needs to be paged, eNB could delay the paging to next PO, this will
cause scheduling delay.
- Paging capacity limit due to the fixed TBS. on the other hand, more POs can
be configured to increase the paging capacity, however it will cause more UE power
consumption to monitor more POs.
- Save the resource use for ePDCCH transmission.
With ePDCCH (i.e. with dynamic Ll scheduling information)
- More scheduling flexibility: the radio resource for paging transmissions,
modulation order, coding rate can be changed dynamically
- Changeable TBS/MCS and Radio Resource: number of UEs paged in one PO
is flexible.
-Paging capacity is adaptive to the paging request.
- More radio resource used for ePDCCH transmission.
- Double power consumption: for each PO, UE has to monitor ePDCCH bundle
first and then the PDSCH bundle if ePDCCH with P-RNTI detected (this is very
likely). This means double power consumption in maximum due to the ePDCCHPDSCH
two-step paging monitoring
Comparing "without ePDCCH" option, "with ePDCCH" option has obvious
flexibility in term of scheduling, paging capacity and is more adaptive. However it is
not clear it will be more resource efficient thinking extra resource required for
ePDCCH repetitions. Also it will result in much more awake time and increased power
consumption from UE point of view. A compromised way is to allow limited
flexibility on top of the option "without ePDCCH", e.g. to indicate/adjust the TB size
of paging message in system information based on e.g. MTC paging load of the cell.
25
wo 2016/163127 PCT/JP2016/001951
[0143] Proposal: RAN2 consider to not have dynamic L1 scheduling information in
[0144]
ePDCCH but indicate limited scheduling information e.g. TBS in SI for paging
transmission.
2.3 Separated or not
RAN1 agreed that the paging messages for Rel-13 low-complexity UEs and/or UEs
operating in coverage enhancements (CE) are transmitted separately from paging
messages for other UEs. It has not been confirmed whether paging messages for Rel-
13 low-complexity UEs operating in normal coverage and operating in different
coverage enhancements (CE) are transmitted separately or not.
[0145] In the following discussion, we do not particularly mention LC Rel-13 MTC UE in
normal coverage. Low complexity UE in normal coverage can be considered as one
special repetition/CE level e.g. CE levelO, since UE position is unknown for NW, so
cell edge coverage is assumed when calculating the repartition times.
[0 146] If they are separated: For each CE level, separated ePDCCH/PDSCH transmission is
[0147]
needed. When there is one paging targeting a UE in CE level 1 and another paging
targeting a UE in CE level2, two ePDCCH is needed if ePDCCH is there, or two
PDSCHs are needed if ePDCCH is not there. There may be more PDSCH load due to
separate padding for different TBs. Regarding system information modification, eNB
has to send paging/paging scheduling on all POs corresponding to all repetition levels,
and this also means more resource consumption. UE and network side shall strictly
have the same assumption on the repetition level in all situations, otherwise, it will
result in misalignment between transmission and monitoring resource, and then paging
will always fail.
If they are not separated: As shown in figure, repetition times should be the
maximum value required by all paged UEs. When there is one paging targeting a UE in
CE level 1 requiring N times of repetitions and another paging targeting a UE in CE
level4 requiring M times of repetitions, wherein M>N, eNB will transmit the paging
message including both paging records of these two UEs with M times of repetitions.
In the control of eNB implementation, when the repetition times between paged UEs
are too much different, and there are many paging requests, UE can group the similar
CE level UEs' pagings together and page different groups in different time at the cost
of extra paging delay. From UE point of view, Different CE level UEs try to combine
ePDCCH/PDSCH on enough number of sub frames. Follow the same example, UE in
CE level 1 try to decode the combination of N subframes ePDCCH/PDSCH, but UE in
CE level 4 try to decode the combination of M subframes ePDCCH/PDSCH to check if
it is paged. If there is only small amount of paging requests, it might be more resource
efficient by multiplexing paging records even though they have very different
repetition times. There will be less resource consumption for paging of system m26
wo 2016/163127 PCT/JP2016/001951
[0148]
[0149]
[0150]
[0151]
[0152]
formation modification.
If ePDCCH is there, for the "separated option", even though different ePDCCH is
needed for different CE levels, it is still possible to multiplex paging records addressing
to different CE level into one PDSCH/TB, in a way that all ePDCCHs point to
the same PDSCH.
We slightly prefer not to separate the paging transmission for different type of Rel-13
MTC UEs based on above analysis:
Proposal: not to separate the paging transmissions for different type of Rel-13 MTC
UEs, i.e. Network may transmit paging records addressing to different type/CE level
Rel-13 MTC UEs in one paging message.
2.4 CE level determination
To determine the CE level of UE in a certain cell, there are two options:
Option 1: eNB-based [as shown in Figure 9]
eNB makes the final decision on which CE level the UE is in a given cell, and then
inform CN and also maybe inform UE to align the understanding. This option allows
more control in eNB side. The same UE possibly has different CE/repetition level in
different cell, and in order to allow to page a UE in more than one cells as we have
today, the CE levels in all cells have to be collected one by one based on RACH
procedure.
[0153] Option 2: UE-based [as shown in Figure 10]
UE measures the DL radio condition of all detected cells, and determine the CE
levels in each cells, and then report to CN e.g. as part of capability report. eNB has less
control with this option, we have to make sure the UE will not abuse this and report
higher CE level than it needs. The CE levels in all paging cells can be measured and
reported in one shot to network.
[0154] Proposal: RAN2 discuss whether the CE level determination is UE based or eNB
[0155]
[0156]
based.
The whole or part of the exemplary embodiments disclosed above can be described
as, but not limited to, the following supplementary note.
(Supplementary note 1) A base station for a communication system in which
machine type communication 'MTC' devices communicate via said base station, the
base station comprising:
means for receiving, from a core network entity, a paging request for paging at least
one MTC device;
means for determining a paging occasion when said at least one MTC device will be
sent paging related information, wherein said paging occasion identifies a plurality of
subframes in which said paging related information will be first sent and then repeated;
and
27
wo 2016/163127 PCT/JP2016/001951
means for sending, and then repeating, said paging related information in said plurality
of subframes identified by said paging occasion.
[0157] (Supplementary note 2) The base station according to Supplementary note 1, wherein
[0158]
said paging related information comprises scheduling information identifying time
and/or frequency resources to be used for sending a paging message to said at least one
MTC device, and wherein said plurality of subframes identified by said paging
occasion are subframes in which a control channel carrying said paging related Information
will be sent.
(Supplementary note 3) The base station according to Supplementary note 2, wherein
said at least one MTC device comprises at least one coverage enhanced MTC device
having a first coverage enhancement level and at least one coverage enhanced MTC
device having a second coverage enhancement level that is different to said first
coverage enhancement level.
[0159] (Supplementary note 4) The base station according to Supplementary note 3, wherein
said paging related information comprises a first paging identifier (e.g. a radio network
temporary identifier) for identifying paging related information for said at least one
coverage enhanced MTC device having a first coverage enhancement level, and a
second paging identifier (e.g. a different radio network temporary identifier) for
identifying paging related information for said at least one coverage enhanced MTC
device having a second coverage enhancement level.
[0160] (Supplementary note 5) The base station according to Supplementary note 3, wherein
paging related information for said at least one coverage enhanced MTC device having
a first coverage enhancement level is first sent in a control channel in a first subframe,
and paging related information for said at least one coverage enhanced MTC device
having a second coverage enhancement level is first sent in a control channel in a
second sub-frame that is different to said first subframe.
[0161] (Supplementary note 6) The base station according to Supplementary note 3, wherein
paging related information for said at least one coverage enhanced MTC device having
a first coverage enhancement level is sent in a control channel in at least one subframe
in which paging related information for said at least one coverage enhanced MTC
device having a second coverage enhancement level is also sent using the same control
channel.
[0162] (Supplementary note 7) The base station according to Supplementary note 1, wherein
said paging related information comprises at least one paging message for said at least
one MTC device, and wherein said plurality of subframes identified by said paging
occasion are subframes in which said at least one paging message will be sent and then
repeated.
[0163] (Supplementary note 8) The base station according to Supplementary note 7, wherein
28
wo 2016/163127 PCT/JP2016/001951
said base station further comprises means for sending, to said at least one MTC device,
scheduling information for identifying resources to be used for sending said at least
one paging message, in a system information block.
[0164] (Supplementary note 9) The base station according to Supplementary note 8, wherein
[0165]
said scheduling information comprises information identifying a transport block size
'TBS' for said requested paging.
(Supplementary note 10) The base station according to any of Supplementary notes 7
to 9, wherein said at least one MTC device comprises at least one coverage enhanced
MTC device having a first coverage enhancement level and at least one coverage
enhanced MTC device having a second coverage enhancement level that is different to
said first coverage enhancement level.
[0166] (Supplementary note 11) The base station according to Supplementary note 10,
wherein a paging message for said at least one coverage enhanced MTC device having
a first coverage enhancement level is sent using a first predetermined frequency
resource, and a paging message for said at least one coverage enhanced MTC device
having a second coverage enhancement level is sent using a second predetermined
frequency resource that is different to said first predetermined frequency resource.
[0167] (Supplementary note 12) The base station according to Supplementary note 10,
wherein a paging message for said at least one coverage enhanced MTC device having
a first coverage enhancement level is first sent in a data channel in a first subframe,
and a paging message for said at least one coverage enhanced MTC device having a
second coverage enhancement level is first sent in a data channel in a second subframe
that is different to said first subframe.
[0168] (Supplementary note 13) The base station according to Supplementary note 10,
wherein a paging message for said at least one coverage enhanced MTC device having
a first coverage enhancement level is sent in a data channel in at least one subframe in
which a paging message for said at least one coverage enhanced MTC device having a
second coverage enhancement level is also sent in the same data channel.
[0169] (Supplementary note 14) The base station according to any of Supplementary notes 1
to 9, wherein said at least one MTC device comprises at least one coverage enhanced
MTC device, wherein said base station further comprises means for identifying a
coverage enhancement level associated with said at least one coverage enhanced MTC
device, and wherein said means for sending, and then repeating, said paging related information
is configured to repeat sending said paging related information for a number
of repetitions defined by said coverage enhancement level.
[0170] (Supplementary note 15) The base station according to Supplementary note 14,
wherein said paging request comprises information identifying said coverage enhancement
level and wherein said means for identifying a coverage enhancement level
29
wo 2016/163127 PCT/JP2016/001951
associated with said at least one coverage enhanced MTC device is configured to
identify said coverage enhancement level based on said information identifying said
coverage enhancement level in said paging request.
[0 171] (Supplementary note 16) The base station according to Supplementary note 14,
wherein said means for identifying a coverage enhancement level associated with said
at least one coverage enhanced MTC device is configured to identify said coverage enhancement
level based on information (e.g. a random access preamble sequence index)
obtained during a procedure to set up a random access channel (RACH) with said at
least one coverage enhanced MTC device.
[0172] (Supplementary note 17) The base station according to Supplementary note 14,
wherein if a respective coverage enhancement level cannot be determined for said at
least one coverage enhanced MTC device, then said means for sending, and then
repeating, said paging related information is configured to repeat sending said paging
related information for a number of repetitions defined in accordance with a predetermined
(e.g. a maximum and/or default) coverage enhancement level.
[0173] (Supplementary note 18) A base station for a communication system in which
machine type communication 'MTC' devices communicate via said base station, the
base station comprising:
means for receiving, from a core network entity, a paging request for paging at least
one MTC device;
means for determining a paging occasion when said at least one MTC device will be
sent a paging message;
means for sending, to said at least one MTC device, scheduling information for
identifying resources to be used for sending said paging message, in a system Information
block;
means for sending, to said at least one MTC device, said paging message using said
resources in accordance with said paging occasion.
[0174] (Supplementary note 19) A base station for a communication system in which
machine type communication 'MTC' devices communicate via said base station, the
base station comprising:
means for receiving, from a core network entity, a paging request for paging at least
one coverage enhanced MTC device;
means for identifying a coverage enhancement level associated with said at least one
coverage enhanced MTC device; and
means for sending paging related information and then repeating sending said paging
related information for a number of repetitions defined by coverage enhancement level.
[0175] (Supplementary note 20) A base station for a communication system in which
machine type communication 'MTC' devices communicate via said base station, the
30
wo 2016/163127 PCT/JP2016/001951
[0176]
[0177]
base station comprising:
means for determining that there is a requirement to notify said MTC devices that there
has been a change in system information resulting in modified system information;
means for notifying any idle mode MTC devices that there has been a change in
system information by sending a notification together with any paging records for said
MTC devices using a paging message; and
means for providing any radio resource control 'RRC' connected mode MTC devices
with at least a modified part of the modified system information using MTC device
dedicated signalling (e.g. unicast I dedicated RRC signalling).
(Supplementary note 21) A machine type communication 'MTC' device for communicating
with a base station, the MTC device comprising:
means for determining a paging occasion when said base station may send paging
related information, wherein said paging occasion identifies a plurality of subframes in
which said paging related information will be first sent and then repeated by said base
station; and
means for receiving said paging related information in said plurality of subframes
identified by said paging occasion.
(Supplementary note 22) A machine type communication 'MTC' device for a communication
system in which machine type communication 'MTC' devices communicate
via a base station, the MTC device comprising:
means for obtaining, from a system information block broadcast by said base station,
scheduling information for identifying resources to be used for sending at least one
pagmg message;
means for determining a paging occasion when said base station may send a paging
message for said MTC device;
means for determining, from said scheduling information said resources to be used
for sending at least one paging message; and
means for receiving said paging message using said resources in accordance with
said paging occasion.
[0178] (Supplementary note 23) A machine type communication 'MTC' device for a communication
system in which MTC devices communicate via a base station, the MTC
device comprising:
means for performing measurements for establishing a measure of a signal quality associated
with at least one cell;
means for determining, based on said measure of a signal quality associated with at
least one cell, a respective coverage enhancement level associated with said at least
one cell; and
means for sending said respective coverage enhancement level associated with said at
31
wo 2016/163127 PCT/JP2016/001951
[0179]
least one cell to said base station.
(Supplementary note 24) A machine type communication 'MTC' device for a communication
system in which MTC devices communicate via a base station, the MTC
device comprising:
means for forming a radio resource control 'RRC' connection with said base station
to enter an RRC connected mode;
a transceiver configured to obtain, using dedicated signalling (e.g. unicast I dedicated
RRC signalling), (at least a modified part of) modified system information associated
with a cell of the base station, when in said RRC connected mode.
[0180] (Supplementary note 25) A core network node (e.g. a mobility management entity)
for a communication system, the core network node comprising:
means for obtaining information identifying a coverage enhancement level required
in a cell of a base station for at least one coverage enhanced MTC device;
means for generating a paging request for paging said at least one coverage enhanced
MTC device via said base station, wherein said paging request includes said information
identifying said coverage enhancement level required in said cell of a base
station for said at least one coverage enhanced MTC device; and
means for sending said paging request to said base station for paging said at least one
coverage enhanced MTC device in said cell in accordance with said coverage enhancement
level required in said cell.
[0181] (Supplementary note 26) A system comprising the base station according to any of
[0182]
[0183]
Supplementary notes 1 to 20, the MTC device according to any of Supplementary
notes 21 to 24, and the core network node according to Supplementary note 25.
(Supplementary note 27) A method performed by a base station in a communication
system in which machine type communication 'MTC' devices communicate via said
base station, the method comprising:
receiving, from a core network entity, a paging request for paging at least one MTC
device;
determining a paging occasion when said at least one MTC device will be sent
paging related information, wherein said paging occasion identifies a plurality of
subframes in which said paging related information will be first sent and then repeated;
and
sending, and then repeating, said paging related information in said plurality of
subframes identified by said paging occasion.
(Supplementary note 28) A method performed by a base station for a communication
system in which machine type communication 'MTC' devices communicate via said
base station, the method comprising:
receiving, from a core network entity, a paging request for paging at least one MTC
32
wo 2016/163127 PCT/JP2016/001951
device;
determining a paging occasion when said at least one MTC device will be sent a
pagmg message;
sending, to said at least one MTC device, scheduling information for identifying
resources to be used for sending said paging message, in a system information block;
sending, to said at least one MTC device, said paging message using said resources in
accordance with said paging occasion.
[0184] (Supplementary note 29) A method performed by a base station for a communication
system in which machine type communication 'MTC' devices communicate via said
base station, the method comprising:
receiving, from a core network entity, a paging request for paging at least one
coverage enhanced MTC device;
identifying a coverage enhancement level associated with said at least one coverage
enhanced MTC device; and
sending paging related information and then repeating sending said paging related Information
for a number of repetitions defined by coverage enhancement level.
[0185] (Supplementary note 30) A method performed by a base station for a communication
[0186]
system in which machine type communication 'MTC' devices communicate via said
base station, the method comprising:
determining that there is a requirement to notify said MTC devices that there has
been a change in system information resulting in modified system information;
notifying any idle mode MTC devices that there has been a change in system information
by sending a notification together with any paging records for said MTC
devices using a paging message; and
providing any radio resource control 'RRC' connected mode MTC devices with at
least a modified part of the modified system information using MTC device dedicated
signalling (e.g. unicast I dedicated RRC signalling).
(Supplementary note 31) A method performed by a machine type communication
'MTC' device for communicating with a base station, the method comprising:
determining a paging occasion when said base station may send paging related Information,
wherein said paging occasion identifies a plurality of subframes in which
said paging related information will be first sent and then repeated by said base station;
and
receiving said paging related information in said plurality of subframes identified by
said paging occasion.
[0187] (Supplementary note 32) A method performed by a machine type communication
'MTC' device in a communication system in which machine type communication
'MTC' devices communicate via a base station, the method comprising:
33
wo 2016/163127 PCT/JP2016/001951
[0188]
[0189]
obtaining, from a system information block broadcast by said base station, scheduling
information for identifying resources to be used for sending at least one paging
message;
determining a paging occasion when said base station may send a paging message for
said MTC device;
determining, from said scheduling information said resources to be used for sending at
least one paging message; and
receiving said paging message using said resources in accordance with said paging
occasiOn.
(Supplementary note 33) A method performed by a machine type communication
'MTC' device in a communication system in which MTC devices communicate via a
base station, the method comprising:
performing measurements for establishing a measure of a signal quality associated
with at least one cell;
determining, based on said measure of a signal quality associated with at least one
cell, a respective coverage enhancement level associated with said at least one cell; and
sending said respective coverage enhancement level associated with said at least one
cell to said base station.
(Supplementary note 34) A method performed by a machine type communication
'MTC' device in a communication system in which MTC devices communicate via a
base station, the method comprising:
forming a radio resource control 'RRC' connection with said base station to enter an
RRC connected mode; and
obtaining, using dedicated signalling (e.g. unicast I dedicated RRC signalling), (at
least a modified part of) modified system information associated with a cell of the base
station, when in said RRC connected mode.
[0190] (Supplementary note 35) A method performed by a core network node (e.g. a
[0191]
mobility management entity) for a communication system, the method comprising:
obtaining information identifying a coverage enhancement level required in a cell of
a base station for at least one coverage enhanced MTC device;
generating a paging request for paging said at least one coverage enhanced MTC
device via said base station, wherein said paging request includes said information
identifying said coverage enhancement level required in said cell of a base station for
said at least one coverage enhanced MTC device; and
sending said paging request to said base station for paging said at least one coverage
enhanced MTC device in said cell in accordance with said coverage enhancement level
required in said cell.
(Supplementary note 36) A computer implementable instructions product comprising
34
wo 2016/163127 PCT/JP2016/001951
computer implementable instructions for causing a programmable communications
device to perform the method of any of Supplementary notes 27 to 35.
[0192] This application is based upon and claims the benefit of priority from United
Kingdom Patent Application No. 1506156.7, filed on AprillO, 2015, the disclosure of
which is incorporated herein in its entirety by reference.
wo 2016/163127
[Claim 1]
[Claim 2]
[Claim 3]
[Claim 4]
[Claim 5]
[Claim 6]
[Claim 7]
[Claim 8]
[Claim 9]
35
PCT/JP2016/001951

Claims
A base station for a communication system in which machine type
communication 'MTC' devices communicate via said base station, the
base station comprising:
means for determining that there is a requirement to notify said MTC
devices that there has been a system information update;
means for notifying any idle mode MTC devices about the system Information
update by sending a notification using a paging message; and
means for providing any radio resource control 'RRC' connected mode
MTC devices with the system information using MTC device dedicated
signalling.
The base station according to claim 1, wherein said MTC device is a
bandwidth reduced user equipment (UE).
The base station according to claim 1 or 2, wherein said MTC device is
a low complexity user equipment (UE).
The base station according to claim 1, 2 or 3, wherein said MTC device
is a coverage enhanced (CE) user equipment (UE).
The base station according to any preceding claim further comprising
means for determining a paging occasion when at least one MTC
device will be sent paging related information on an associated physical
downlink control channel, wherein said paging occasion is a starting
subframe of a number of repetitions of said physical downlink control
channel.
The base station according to claim 5, further comprising means for
sending said paging related information on said physical downlink
control channel in said starting subframe and then repeating said paging
related information in said repetitions of said physical downlink control
channel.
The base station according to claim 5 or 6, wherein said paging related
information comprises a paging radio network temporary identifier
(P-RNTI).
The base station according to claim 7, wherein said paging related Information
comprises a first P-RNTI for at least one coverage enhanced
MTC device having a first coverage enhancement level, and a different
P-RNTI for at least one coverage enhanced MTC device having a
second coverage enhancement level.
The base station according to any of claims 5 to 8, wherein paging
wo 2016/163127
[Claim 10]
[Claim 11]
[Claim 12]
[Claim 13]
[Claim 14]
36
PCT/JP2016/001951
related information for at least one coverage enhanced MTC device
having a first coverage enhancement level is first sent in a control
channel in a first subframe, and paging related information for at least
one coverage enhanced MTC device having a second coverage enhancement
level is first sent in a control channel in a second sub-frame
that is different to said first subframe.
The base station according to any of claims 5 to 8, wherein paging
related information for at least one coverage enhanced MTC device
having a first coverage enhancement level is sent in a control channel
in at least one subframe in which paging related information for at least
one coverage enhanced MTC device having a second coverage enhancement
level is also sent using the same control channel.
The base station according to any preceding claim wherein said base
station is configured for sending, to at least one MTC device,
scheduling information for identifying resources to be used for sending
at least one paging message, in a system information block.
The base station according to any preceding claim wherein said base
station is configured for sending a paging message for at least one
coverage enhanced MTC device having a first coverage enhancement
level using a first predetermined frequency resource, and for sending a
paging message for at least one coverage enhanced MTC device having
a second coverage enhancement level using a second predetermined
frequency resource that is different to said first predetermined
frequency resource.
A machine type communication 'MTC' device for a communication
system in which MTC devices communicate via a base station, the
MTC device comprising:
means for forming a radio resource control 'RRC' connection with said
base station to enter an RRC connected mode; and
a transceiver configured to obtain, using dedicated signalling, system
information associated with a cell of the base station, when in said RRC
connected mode.
A method performed by a base station for a communication system in
which machine type communication 'MTC' devices communicate via
said base station, the method comprising:
determining that there is a requirement to notify said MTC devices that
there has been a system information update;
notifying any idle mode MTC devices about the system information
wo 2016/163127
[Claim 15]
[Claim 16]
[Claim 17]
37
PCT/JP2016/001951
update by sending a notification using a paging message; and
providing any radio resource control 'RRC' connected mode MTC
devices with the system information using MTC device dedicated
signalling.
A method performed by a machine type communication 'MTC' device
in a communication system in which MTC devices communicate via a
base station, the method comprising:
forming a radio resource control 'RRC' connection with said base
station to enter an RRC connected mode; and
obtaining, using dedicated signalling, system information associated
with a cell of the base station, when in said RRC connected mode.
A base station for a communication system in which machine type
communication 'MTC' devices communicate via said base station, the
base station comprising:
a controller configured to determine that there is a requirement to notify
said MTC devices that there has been a system information update; and
a transmitter configured to notify any idle mode MTC devices about the
system information update by sending a notification using a paging
message,
wherein the transmitter is further configured to provide any radio
resource control 'RRC' connected mode MTC devices with the system
information using MTC device dedicated signalling.
A machine type communication 'MTC' device for a communication
system in which MTC devices communicate via a base station, the
MTC device comprising:
a controller configured to form a radio resource control 'RRC'
connection with said base station to enter an RRC connected mode; and
a transceiver configured to obtain, using dedicated signalling, system
information associated with a cell of the base station, when in said RRC
connected mode.