Method of operating a base station of a cellular
communications network
Specification
Field of the invention
The present invention relates to a method of operating a
base station of a cellular communications network, wherein
said base station is configured to receive signalling
information from at least one terminal served by said base
station and/or from a further network element of said
cellular communications network.
The present invention further relates to a base station of
a cellular communications network.
Moreover, the present invention relates to a method of
operating a terminal of a cellular communications network
and a terminal of a cellular communications network.
It is an object of the present invention to provide an
improved method of operating a base station of a cellular
communications network and an improved base station of a
cellular communications network as well as an improved
terminal of a cellular communications network and a method
of operating such a terminal which enable an increased
degree of flexibility regarding the signalling of timecritical
information such as emergency information
characterising emergencies such as traffic accidents and
the like.
Summary
According to the present invention, regarding the abovementioned
method of operating a base station of a cellular
communications network, this object is achieved in that
said base station determines whether received signalling
information comprises an emergency indication which
indicates an existing or impending emergency situation, and
in that said base station notifies at least one further
terminal served by said base station and/or a further
network element of said emergency situation.
The notification of further terminals served by said base
station or even further network elements of the
communications network advantageously enables to instantly
propagate information on emergency situations throughout
the whole communications network. Preferably, according to
an embodiment, the base station notifies terminals of users
that are comprised in a specific cell served by said base
station or terminals of a plurality of different cells
served by said base station.
According to a preferred embodiment, which enables to
propagate emergency information with particularly low
latencies, said step of notifying said at least one further
terminal served by said base station is performed
independently of a core network and/or further components
of the communications network. I.e., the base station
according to the embodiment advantageously instantly
forwards information related to said emergency indication
it has received from the terminal to further terminals
which might profit from receiving and evaluating said
emergency indication. Particularly, according to the
present embodiment, the base station does not rely on any
further communication with a core network and/or other
components of the communications network such as a radio
network controller or the like prior to deciding whether to
notify further terminals of the emergency situation,
whereby latency may be reduced.
According to an embodiment, upon receiving an emergency
indication, said base station may instantly forward
information related to said emergency indication to other
terminals. Thus, a specific resource allocation for said
terminal sending the emergency notification need not
necessarily be established. This embodiment is advantageous
in such cases where a complete emergency indication may be
integrated into the signalling information sent from the
terminal detecting the emergency to the base station.
However, according to a further embodiment, in such cases,
where a higher amount of data is related to an emergency
indication, the base station may, upon receiving said
emergency indication, instantly reserve and grant further
uplink resources to said terminal that has sent the
emergency indication, which enables the terminal to rapidly
send further emergency- related information to the base
station thus completing the emergency signalling process in
an uplink direction.
A combination of the above listed embodiments is also
possible. I.e., upon receiving an emergency indication,
said base station may, in a first step, instantly forward
information related to said emergency indication to other
terminals. In a second step, said base station may
reserve and grant further uplink resources to said terminal
that has sent the emergency indication thus enabling the
completion of the emergency signaling from the terminal to
the base station.
According to a further embodiment, said step of notifying
comprises broadcasting an emergency signalling message to a
predetermined group of terminals and/or a predetermined
group of further network elements such as further base
stations or gateways to other networks or the like. By
broadcasting an emergency signalling message, a
particularly efficient propagation of emergency information
is enabled.
According to a further embodiment, said step of notifying
comprises notifying at least one neighbouring base station
of said emergency situation, which is particularly
advantageous in such cases, wherein the emergency situation
affects a specific geographical region or location related
to the neighbouring base stations.
According to another preferred embodiment, said step of
notifying comprises forwarding information related to said
emergency indication to a collector node that is configured
to collect emergency indications, which may be received
from one or more base stations according to the
embodiments. Additionally, the collector node may be
configured to forward information related to said collected
emergency indications to other network elements or
terminals. Additionally, the collector node may correlate a
plurality of incoming emergency indications and perform
statistical analysis on said incoming emergency indications
to influence the information forwarded to other network
elements .
According to yet another embodiment of the present
invention, said communications network is compatible with
the third generation partnership project, 3GPP, long-term
evolution, LTE, standard, particularly LTE rel. 8 , wherein
said base station uses a portion of downlink control
information, DCI, to notify one or more terminals of a
safety message comprising information relating to said
emergency situation, and wherein said base station uses at
least one physical resource block, PRB, of a physical
downlink shared channel, PDSCH, to transfer said safety
message to said one or more terminals.
According to a further embodiment, said base station uses a
radio network temporary identifier, RNTI, to define a group
of terminals that are to be supplied with said safety
message, which facilitates the simultaneous signalling of
emergency information to a plurality of selected terminals
served by the base station. By using the RNTI mechanism, an
efficient control which terminal is to be provided with an
emergency signalling by the base station is enabled.
A further solution to the object of the present invention
is given by a base station according to claim 10. Said base
station is configured to determine whether received
signalling information comprises an emergency indication
which indicates an existing or impending emergency
situation, and to notify at least one further terminal
served by said base station and/or a further network
element of said emergency situation.
Further advantageous embodiments of the base station are
given by dependent claims 11 to 13.
A further solution to the object of the present invention
is given by a method of operating a terminal of a cellular
communications network according to claim 8 . Said method
proposes said terminal to determine whether an emergency
situation exists or is likely to come up in future,
wherein, if an emergency situation exists or is likely to
come up in future, said terminal integrates an emergency
indication which indicates said existing or impending
emergency situation into said signalling information.
According to a further embodiment, said step of determining
whether an emergency situation exists or is likely to come
up in future comprises at least one of:
- receiving corresponding information from an
external system by means of an interface,
- analyzing at least one physical parameter of the
terminal for determining whether an emergency
situation exists or is likely to come up in
future.
According to a preferred embodiment, the terminal may be
integrated into a vehicle such as a car and may be
connected to a control unit of an engine of said car or the
like. The terminal may e.g. offer the functionality of an
LTE modem to the electronic devices of the car. The
terminal according to the embodiments may receive
information related to a possible emergency situation from
the car systems. For instance, car systems may already
provide for an evaluation of physical parameters of the car
such as parameters of a break system characterizing an
acceleration and/or deceleration of the car and the like.
This information may be provided to the terminal according
to the embodiments by means of the terminal's interface to
the car system, which may e.g. comprise a CAN (controller
area network) interface or an interface of the PlexRay type
or the like. Thus, the terminal according to the
embodiments can use information processed by the vehicle's
systems that possibly indicate an emergency situation.
Alternatively or in addition to receiving said emergency
information from a system external to the terminal, the
terminal may also determine a possible emergency situation
on its own. For instance, the terminal may be configured to
analyse at least one physical parameter of the terminal
such as e.g. a position and/or speed of the terminal, which
may be determined via a position detection system (global
positioning system, GPS) . From analysing such parameters of
the terminal, the terminal may independently conclude
whether an emergency situation exists or is likely to come
up in future.
A further solution to the object of the present invention
is given by a terminal of a cellular communications network
according to claim 14. Said terminal is configured to
determine whether an emergency situation exists or is
likely to come up in future, wherein said terminal is
further configured to, if an emergency situation exists or
is likely to come up in future, integrate an emergency
indication which indicates said existing or impending
emergency situation into said signalling information.
Further advantageous embodiments are given by the dependent
claims .
Brief description of the figures
Further features, aspects and advantages of the present
invention are given in the following detailed description
with reference to the drawings in which:
Figure 1 depicts a simplified block diagram of a
communications network comprising a base station
according to the embodiments,
Figure 2 depicts a simplified flow chart of a method of
operating a base station according to an
embodiment , and
Figure 3 depicts combined time- frequency- resources
employed by a base station according to the
embodiments for signalling emergency information
to one or more terminals according to the
embodiments .
Description of the embodiments
Figure 1 depicts a block diagram of a cellular
communications network 100 which comprises a base station
110 and a plurality of terminals 10a, 10b, 10c, lOd that
are currently served by said base station 110 in a per se
known manner. According to a particularly preferred
embodiment, said communications network 100 is compatible
with the third generation partnership project, 3GPP, longterm
evolution, LTE, standard release 8 .
Apart from the base station 110 and the terminals 10a, ~ ,
lOd, the communications network 100 also comprises at least
one further base station 110 1 and further network elements
120, 130, which may e.g. represent radio network
controllers or further network elements related to an
operation of a core network the communications network 100
is based on.
The terminals 10a, lOd may communicate with the base
station 110 in a per se known manner to exchange data such
as voice and/or further data. To enable an efficient
signalling of an emergency situation one of said terminals
10a, 10b, 10c, lOd becomes aware of, the base station 110
is configured to determine whether signalling information
sil that is received from a terminal 10a comprises an
emergency indication which indicates an existing or
impending emergency situation as determined by the sending
terminal 10a.
For instance, the terminal 10a may be configured as an LTE
modem and may be comprised within a vehicle such as a car
(not shown) , and the terminal 10a may be connected to one
or more control units of further systems 12 of the car such
as an engine or a breaking system or the like. Such
connection may be established via a suitable interface 11
to the car systems 12.
From these car systems 12, the terminal 10a may determine
indicia that an emergency situation such as a car accident
has happened or is likely to happen in future. This may
e.g. be derived from excessive acceleration and/or
deceleration values or variations in time of said
parameters as retrieved from the car systems 12.
According to a preferred embodiment, such emergency
information is signalled by the terminal 10a to the base
station 110 for further propagation to other entities in
order to warn a plurality of people that may also be
affected by the emergency situation. For this purpose, the
terminal 10a integrates an emergency indication which
corresponds with the emergency situation as determined by
the mobile terminal 10a into the signalling information sil
that is sent to the base station 110 in an uplink data
transfer direction.
After receiving said signalling information sil from the
terminal 10a, the base station 110 determines whether said
received signalling information sil comprises an emergency
indication that indicates an existing or impending
emergency situation as determined by said terminal 10a.
If said determination made by the base station 110 yields
that said signalling information sil in fact comprises an
emergency indication, said base station 110 notifies at
least one further terminal 10b, 10c served by said base
station 110 of said emergency situation. Thereby, further
terminals 10b, 10c may instantly be warned of the emergency
situation detected by the terminal 10a.
For instance, a group 6 of terminals may be defined, which
are to receive emergency information whenever the base
station 110 receives corresponding signalling information
from a terminal or from another source of emergency
information.
According to a preferred embodiment, the base station 110
may determine whether to include a new terminal detected in
its radio cell into said group 6 depending on contracting
parameters of the respective terminal or further properties
of the terminal such as the terminal being integrated into
a vehicle or being part of a conventional mobile phone or
personal digital assistant or the like.
For example, only such terminals 10a, 10b, 10c, which are
part of a vehicle system, may be associated with the
emergency notification group G . A further terminal lOd,
which represents a mobile phone of a pedestrian, may not be
included into the emergency notification group G by the
base station 110, according to warning policies of the
network's operator.
Other criteria whether to integrate terminals into the
notification group G may be a service plan to which users
of the terminals may subscribe and the like.
According to an embodiment, upon receiving an emergency
indication from the terminal 10a, said base station 110 may
instantly forward information related to said emergency
indication to other terminals 10b, 10c. Thus, a specific
resource allocation for said terminal 10a sending the
emergency notification need not necessarily be established
subsequent to its initial emergency notification to the
base station 110 via the message sil. This embodiment is
advantageous in such cases where a complete emergency
indication may be integrated into the signalling
information sent from the terminal 10a detecting the
emergency to the base station 110.
However, according to a further embodiment, in such cases,
where a higher amount of data is related to an emergency
indication, the base station 110 may, upon receiving said
emergency indication from the terminal 10a, instantly
reserve and grant further uplink resources to said terminal
10a that has sent the emergency indication, which enables
the terminal 10a to rapidly send further emergency- related
information to the base station 110 thus completing the
emergency signalling process in an uplink direction. This
way, substantial amounts of emergency-related data such as
comprehensive time series of parameters such as vehicle
speed, position details, audio and/or video data captured
by a car system 12 and the like may be forwarded to the
base station 110.
In contrast to conventional scheduling algorithms, after
receiving an emergency indication from a terminal 10a, the
base station 110 performs a specific resource scheduling
which takes into account the "real -time" requirements
related to an efficient emergency signalling. Said specific
resource scheduling may e.g. give priority for reserving
further uplink resources for the terminal 10a that has
already recently indicated an emergency condition, whereas
other terminals 10b, 10c, lOd currently not having
signalled an emergency indication are served with a lower
priority by the base station 110.
A combination of the above listed embodiments is also
possible. I.e., upon receiving an emergency indication,
said base station 110 may, in a first step, instantly
forward information related to said emergency indication to
other terminals 10b, 10c. In a second step, said base
station 110 may reserve and grant further uplink resources
to said terminal 10a that has sent the emergency indication
thus enabling the completion of the emergency signaling
from the terminal 10a to the base station 110.
A particularly preferred embodiment provides that said step
of notifying at least one further terminal 10b, 10c served
by said base station 110 is performed independently of a
core network and/or further components of the
communications network 100. Thus, once the base station 110
receives signalling information sil which comprises an
emergency indication, the base station 110 may
independently decide whether to forward said emergency
information to further terminals 10b, 10c or further
network elements such as the network element 130 without
being required to contact a core network or other network
elements for the process of deciding whether to forward
said emergency information. Thus, particularly low latency
times may be achieved in propagating received emergency
information from the base station 110 to further terminals
10b, 10c.
According to a particularly preferred embodiment, even in
such cases, where further uplink resources are to be
reserved for the terminal 10a that reports an emergency
condition, the base station 110 can decide on its own, i.e.
independently of the core network, how to schedule such
further uplink resources to the terminal 10a, whereby a
particularly quick resource scheduling can be achieved that
improves instant propagation of emergency- related
information throughout the network 100.
According to a further preferred embodiment, said step of
notifying comprises broadcasting an emergency signalling
message esl to the predetermined group G of terminals 10a,
10b, 10c, whereby a particularly efficient, simultaneous
notification of a plurality of terminals may be achieved,
as compared to a plurality of subsequent single
notifications, which may, however, also be employed
according to a further embodiment.
According to a further particularly preferred embodiment,
said step of notifying comprises notifying at least one
neighbouring base station 110' of said emergency situation,
cf . the emergency signalling message es3, whereby further
terminals and/or vehicles comprising terminals that are colocated
with a vehicle associated with the terminal 10a may
be notified of the emergency situation.
It is also possible to provide further network elements 130
of the communications network 100 or groups G ' thereof with
emergency notifications es2. The further network elements
130 may e.g. represent gateways which transform received
emergency messages es2 to further message formats and/or
communications systems such as a plain old telephony system
POTS (not depicted) and/or a world wide web interface and
the like.
According to a further embodiment, the base station 110 may
also be configured to forward information related to said
emergency indication to a collector node 140 (Figure 1 )
that is configured to collect emergency indications,
preferably from a plurality of different base stations 110,
110 ', said collector node 140 further being configured to
forward information related to collected emergency
indications to other network elements.
For example, the collector node 140 may perform statistical
analysis and/or further analysis of incoming emergency
information and may perform further processing of said
emergency information to improve the quality and
reliability of said emergency information. After such
processing, the collector node 140 may forward related
information to network elements such as the base stations
110, 110•.
According to a further embodiment, the base station 110 mayreceive
signalling information si2 that might contain an
emergency indication from a further network element 120 of
the network 120. In this case, the base station may also
forward said emergency indication or information derived
therefrom to suitable recipients 10a, 10b, 10c, 110', 130.
Figure 2 shows a simplified flow chart of a method
according to an embodiment. In a first step 200, the base
station 110 (Figure 1 ) determines whether received
signalling information sil comprises an emergency
indication which indicates an existing or impending
emergency situation.
In a second step 210, said base station 110 notifies at
least one further terminal 10b, 10c served by said base
station 110 and/or a further network element 130, 140 of
said emergency situation.
According to a particularly preferred embodiment, the base
station 110 is not required to communicate with a core
network connected to said communications network 100 and/or
further network elements between performing the steps 200,
210 according to Figure 2 . This results in particularly low
latency times for propagating emergency information from
the terminal 10a via said base station 110 to further
terminals 10b, 10c. Generally, the base station 110 may be
configured to forward received emergency information to a
single terminal 10b served by one of its own radio cells, a
plurality G of terminals served by one of its own radio
cells, to all terminals served by its own radio cells or to
other network elements such as a neighbouring base station
110' or a further network element such as a gateway 130. It
is also possible for the base station 110 to define a
further group G ' of further network elements 130, .. which
are supposed to be supplied with the emergency information
as received by the base station 110.
According to a further preferred embodiment, a per se known
downlink control information, DCI, mechanism of the LTE
system may be employed to notify one or more terminals 10a,
10b, 10c (Figure 1 ) of a safety message SM which comprises
information related to said emergency situation and which
is to be forwarded by the base station 110 to the terminals
10a, 10b, 10c. As such, the safety message SM corresponds
with the message es1 already explained above.
Figure 3 depicts a block designating a time-bandwidth
resource as known from the LTE standard. The depicted timebandwidth
resource corresponds to a sub frame comprising a
length of 1 ms which is subdivided into e.g. 14 symbols as
also defined by the LTE standard.
Correspondingly, one or more symbols of said subframe form
a physical downlink control channel PDCCH as depicted by
Figure 3 , and the remaining symbols of said subframe
constitute a physical downlink shared channel PDSCH.
According to an embodiment, the base station 110 (Figure 1 )
uses a portion DCI_1 of said downlink control information
DCI comprised within the PDCCH to notify the terminals 10a,
10b, 10c of a safety message SM which comprises information
related to said emergency information and which will be
forwarded to the terminals 10a, 10b, 10c as described
below.
As can be seen from Figure 3 , the safety message SM is
integrated into the physical downlink shared channel PDSCH
portion of the time-bandwidth- resource block depicted by
Figure 3 , wherein one or more bandwidth subcarriers are
reserved by the base station 110 for the safety message SM
comprising the emergency information. Other subcarriers of
the PDSCH may - in a per se known manner - be reserved by
the base station 110 for user data UD_1, UD_2 that is to be
transmitted to a terminal served by the base station 110.
According to a further advantageous embodiment, the base
station 110 uses a radio network temporary identifier,
RNTI, to define the group G (Figure 1 ) of terminals 10a,
10b, 10c that are to be supplied with said safety message
SM.
For instance, whenever a terminal 10a joins a radio cell
provided by said base station 110, the base station 110
decides whether to add said joining terminal 10a to the
group G . If the terminal 10a is admitted to said group G ,
it is assigned a specific value of the RNTI that designates
said terminal 10a as a recipient for the safety message SM
as propagated by the base station 110 upon receiving
corresponding signalling information sil from a terminal
that has detected an emergency situation.
By employing a specific RNTI for distributing the safety
message SM to the group G of terminals, a particularly
efficient data transmission conveying the emergency- related
information to the terminals is enabled.
In other words, the group G can be considered as a special
user equipment capability class which comprises only such
terminals that are compatible with a base station 110
according to the embodiments regarding the forwarding
and/or receiving of emergency information. Generally, any
kind of signalling information sil that is sent from a
terminal 10a to the base station 110 may be employed to
provide an emergency notification to the base station 110.
For example, if resources are already allocated to a
terminal 10a, the terminal 10a can use a buffer status
report (BSR) or a scheduling request (SR) to indicate that
new data should be sent. The BSR or SR may also be employed
to indicate to the base station 110 that an emergency
situation does exist. A further possibility for signalling
to the base station 110 is carrying out a per se known
random access channel (RACH) procedure. In all of the afore
mentioned cases, a special configuration can be selected
for the signalling sil to the base station 110 to indicate
the emergency situation.
According to a particularly preferred embodiment, the base
station 110, upon receiving signalling information sil that
comprises an emergency notification, will allocate as fast
as possible an uplink grant to the terminal 10a which
enables the terminal 10a to send further information
related to the emergency information in an uplink direction
to the base station 110.
Generally, according to an embodiment, it is possible to
convey an emergency notification in an existing signalling
mechanism (BSR, SR, RACH) as already mentioned above.
However, to enable the terminal 10a to forward a
substantial amount of data exceeding an amount of data that
may be conveyed by using mere signalling mechanisms sil,
the base station 110 can allocate dedicated uplink
resources so that the terminal 10a can send further
information related to the emergency situation to the base
station 110. Particularly, this uplink grant is processed
by the base station 110 independently of a core network or
further network elements, whereby additional signalling
processes can be saved and low latencies may be achieved.
A further possibility to notify the base station 110 of an
emergency situation may be to provide a specific portion of
a media access control (MAC) layer header. For instance, in
the MAC header of data sent from the terminal 10a to the
base station 110, an information and/or a flag can be
included which is used to notify the base station 110 about
the type of emergency- related information that is sent,
e.g. denoting an accident, an expected accident or an
unusually high acceleration or deceleration of a car
comprising the terminal 10a.
According to a preferred embodiment, the base station 110,
as already explained above, sends an emergency situation
message esl, es2, es3 to selected recipients such as the
group 6 of terminals or the further network elements 130 or
a neighbouring base station 110 '.
The method according to the embodiments may advantageously
be used for operating terminals 10a, 10b, 10c, which are
related to vehicles such as cars, said terminals e.g.
representing LTE modems, and to propagate emergency- related
information from one terminal 10a to further terminals 10b,
10c that may possibly also be involved in such emergency
situation detected by the first terminal 10a.
Advantageously, the embodiments according to the present
invention eliminate the necessity to provide proprietary
car-to-car communication systems which might also serve to
exchange emergency- related information between the cars or
terminals integrated into said cars, respectively. By
providing the method according to the present invention, an
existing communications infrastructure of a cellular
communications network such as e.g. according to the LTE
standard may advantageously be used for propagating timecritical
information.
By providing the method according to the present invention,
the extending LTE rel. 8 standard may advantageously be
extended to support time- and/or safety-critical
applications which have stringent delay requirements.
The methods according the embodiments may advantageously be
used by a car-based terminal 10a (Figure 1 ) to forward
safety warnings to other, co-located terminals 10b, 10c
which may be involved in the same traffic situation.
Corresponding delay requirements of 50 milliseconds and
less may be met by the principle of the present invention.
When using an LTE -type RNTI, this RNTI may be employed to
indicate an information about a transport format and
resource allocation that is used by the base station 110 to
send the safety message SM (Figure 3 ) and/or the emergency
signalling message esl (Figure 1 ) .
According to a preferred embodiment, the messages SM, esl,
es2, es3 comprise information on a type and severeness of
emergency and/or information on a position of the detected
emergency situation. A vehicle's on board unit that is
connected to an LTE modem 10b according to an embodiment
may, after receiving corresponding information SM, esl from
the base station 110, take into account said information
and may trigger further actions of a vehicle system such as
notifying its driver of the received information or even
automatically starting a braking maneuver of the vehicle.
The description and drawings merely illustrate the
principles of the invention. It will thus be appreciated
that those skilled in the art will be able to devise
various arrangements that, although not explicitly
described or shown herein, embody the principles of the
invention and are included within its spirit and scope.
Furthermore, all examples recited herein are principally
intended expressly to be only for pedagogical purposes to
aid the reader in understanding the principles of the
invention and the concepts contributed by the inventor (s)
to furthering the art, and are to be construed as being
without limitation to such specifically recited examples
and conditions. Moreover, all statements herein reciting
principles, aspects, and embodiments of the invention, as
well as specific examples thereof, are intended to
encompass equivalents thereof.
The functions of the various elements shown in the FIGs.,
including any functional blocks labeled as 'processors',
may be provided through the use of dedicated hardware as
well as hardware capable of executing software in
association with appropriate software. When provided by a
processor, the functions may be provided by a single
dedicated processor, by a single shared processor, or by a
plurality of individual processors, some of which may be
shared. Moreover, explicit use of the term 'processor' or
'controller' should not be construed to refer exclusively
to hardware capable of executing software, and may
implicitly include, without limitation, digital signal
processor (DSP) hardware, network processor, application
specific integrated circuit (ASIC) , field programmable gate
array (FPGA) , read only memory (ROM) for storing software,
random access memory (RAM), and non volatile storage. Other
hardware, conventional and/or custom, may also be included.
Similarly, any switches shown in the FIGS, are conceptual
only. Their function may be carried out through the
operation of program logic, through dedicated logic,
through the interaction of program control and dedicated
logic, or even manually, the particular technique being
selectable by the implementer as more specifically
understood from the context.
It should be appreciated by those skilled in the art that
any block diagrams herein represent conceptual views of
illustrative circuitry embodying the principles of the
invention. Similarly, it will be appreciated that any flow
charts, flow diagrams, state transition diagrams, pseudo
code, and the like represent various processes which may be
substantially represented in computer readable medium and
so executed by a computer or processor, whether or not such
computer or processor is explicitly shown.
Claims
1 . Method of operating a base station (110) of a cellular
communications network (100) , wherein said base
station (110) is configured to receive signaling
information (sil, si2) from at least one terminal
(10a) served by said base station (110) and/or from a
further network element (120) of said cellular
communications network (100) , wherein said base
station (110) determines (200) whether received
signaling information (sil, si2) comprises an
emergency indication which indicates an existing or
impending emergency situation, and wherein said base
station (110) notifies (210) at least one further
terminal (10b, 10c) served by said base station (110)
and/or a further network element (130) of said
emergency situation, characterized in that said step
of notifying (210) said at least one further terminal
(10b, 10c) served by said base station (110) is
performed independently of a core network, and/or
further components of the communications network
(100) .
2 . Method according to one of the preceding claims,
wherein said step of notifying (210) comprises
broadcasting an emergency signalling message (esl,
es2) to a predetermined group (G) of terminals (10a,
10b, 10c) and/or a predetermined group (G' ) of further
network elements (130) .
3 . Method according to one of the preceding claims,
wherein said step of notifying (210) comprises
notifying at least one neighbouring base station
(110') of said emergency situation.
4 . Method according to one of the preceding claims,
wherein said step of notifying (210) comprises
forwarding information related to said emergency
indication to a collector node (140) that is
configured to collect emergency indications and to
forward information related to collected emergency
indications to other network elements (110 / 110', 120,
130) or terminals (10a, 10b, 10c) .
5 . Method according to one of the preceding claims,
wherein said communications network (100) is
compatible with the 3GPP LTE standard, wherein said
base station (110) uses a portion (DCI_1) of downlink
control information, DCI, to notify one or more
terminals (10a, 10b, 10c) of a safety message (SM)
comprising information related to said emergency
situation, and wherein said base station (110) uses at
least one physical resource block of a physical
downlink shared channel, PDSCH, to transfer said
safety message (SM) to said one or more terminals
(10a, 10b, 10c) .
6 . Method according to claim 5 , wherein said base station
(110) uses a radio network temporary identifier, RNTI,
to define a group (G) of terminals (10a, 10b, 10c)
that are to be supplied with said safety message (SM) .
7 . Base station (110) of a cellular communications
network (100), wherein said base station (110) is
configured to receive signaling information (sil, si2)
from at least one terminal (10a) served by said base
station (110) and/or from a further network element
25
wherein said base station (110) is configured to
determine (200) whether received signaling information
(sil, si2) comprises an emergency indication which
indicates an existing or impending emergency
situation, and wherein said base station (110) is
configured to notify (210) at least one further
terminal (10b, 10c) served by said base station (110)
and/or a further network element (130) of said
emergency situation, characterized in that said base
station (110) is configured to perform said step of
notifying (210) said at least one further terminal
(10b, 10c) served by said base station (110)
independently of a core network and/or further
components of the communications network (100) .
8 . Base station according to claim 7 , wherein said base
station (110) is configured to broadcast an emergency
signalling message (esl, es2) to a predetermined group
(G) of terminals (10a, 10b, 10c) and/or a
predetermined group (G' ) of further network elements
(130) .
9 . Base station according to one of the claims 7 to 8 ,
wherein said communications network (100) is
compatible with the 3GPP LTE standard, wherein said
base station (110) is configured to use a portion
(DCI_1) of downlink control information, DCI, to
notify one or more terminals (10a, 10b, 10c) of a
safety message (SM) comprising information related to
said emergency situation, and wherein said base
station (110) is configured to use at least one
physical resource block of a physical downlink shared
channel, PDSCH, to transfer said safety message (SM)
to said one or more terminals (10a, 10b, 10c) .