Operating a terminal device in a wireless communication system
FIELD OF THE INVENTION
The present invention relates to a method for operating a terminal device of a wire¬
less communication system, especially to a method for improving a coverage in the
wireless communication system. The present invention relates furthermore to a
method for operating a base station of a wireless communication system, and the
present invention relates to a terminal device, for example a cellular phone, and a
base station implementing the methods.
BACKGROUND OF THE INVENTION
A wireless communication system, for example a cellular-based wireless telecom¬
munication network, which is also called mobile communication system, may con¬
sist of different communication units, so-called network nodes. An exemplary wire¬
less communication system 100 is shown in Fig. 1. The network nodes may comprise
for example a base station 101 acting as an interface between an operator
core network 03 and the access network. The base station 101 may provide a
coverage within a radio cell 102. Further network nodes may comprise for example
terminal devices 105 and 106 acting as the end devices providing radio access
communication capabilities. The terminal devices 105 and 106 may be used for
example as a machine type communication device or a consumer oriented device,
such as a mobile phone or a smart phone. As shown in Fig. 1, a terminal device
107 outside the radio cell 102 is not covered by the base station 101 and therefore
cannot participate in communication of the wireless communication system 100.
For increasing or improving the coverage of the wireless communication system
100, further base stations may be installed providing additional radio cells. As an
alternative, repeaters may be installed at specific locations. With a repeater, the
signals transmitted between base station 101 and the terminal 107 may be repeat¬
ed or sent again, in order to improve network coverage.
Beside the general coverage extension functionality achievable by a stationary deployed
repeater, there may be other reasons for using a repeater. One specific use
case may be for example that the wireless communication system shall be able to
dynamically increase its network coverage to support emergency services required
for public safety requirements. Therefore, in such a network or communication sys¬
tem it may be required to quickly expand network coverage and capacity at specific
locations, even if these locations are at the border or outside the ordinary network
coverage area. In another scenario it may be required that the coverage of a radio
cell should be able to dynamically increase due to a failure of a neighboring base
station. However, repeaters and additional base stations cause cost and mainte¬
nance.
Therefore, it is an object of the present invention to provide an improved method to
dynamically increase the coverage of a radio cell of a wireless communication sys¬
tem as needed and at low cost.
SUMMARY OF THE INVENTION
According to the present invention, this object is achieved by a method for operat¬
ing a terminal device of a wireless communication system as defined in claim 1, a
method for operating a base station of a wireless communication system as defined
in claim 8, a terminal device for a wireless communication system as defined
in claim 11 and a base station for a wireless communication system as defined in
claim 14. The dependent claims define preferred and advantageous embodiments
of the invention.
According to an aspect of the present invention, a method for operating a terminal
device of a wireless communication system is provided. The terminal device is
connected to a base station of the wireless communication system. According to
the method, the terminal device provides an intermediate node functionality. The
intermediate node functionality enables the terminal device to forward communica¬
tion data received from the base station to a further terminal device and to forward
communication data received from the further terminal device to the base station.
Furthermore, according to the method, the terminal device receives a permission to
activate the intermediate node functionality from the base station and upon recep¬
tion of the permission from the base station, the terminal device activates the in¬
termediate node functionality. With the intermediate node functionality of the termi¬
nal device, the terminal device enables the further terminal device to communicate
with the base station although the further terminal device may be outside the cov¬
erage of the base station. Thus, the coverage of the base station may be extended.
However, the terminal device needs the permission from the base station to acti¬
vate the intermediate node functionality which enables the base station to control
the coverage extension. For example, the coverage extension may be allowed only
in case of an emergency or for specific services or in case a neighboring base sta¬
tion fails.
According to an embodiment, forwarding the communication data received from the
base station to the further terminal comprises receiving a radio signal from the
base station which comprises digital data and transmitting a radio signal which
comprises the digital data in an unchanged form as the digital data has been re¬
ceived from the base station. Furthermore, forwarding the communication data re¬
ceived from the further terminal device to the base station comprises receiving a
radio signal from the further terminal device which comprises digital data and
transmitting a radio signal which comprises the digital data in an unchanged form
as the digital data has been received from the further terminal device. In other
words, the digital data forwarded by the intermediate node functionality from the
base station to the further terminal device and vice versa, is not modified, and thus
the terminal device acts as a repeater. The received radio signal and the transmitted
radio signal may use the same frequency band or may use different frequency
bands. However, from the point of view of the base station, the digital data are
transparently passed through the terminal device to the further terminal device and
vice versa. After activating the intermediate node functionality in the terminal de¬
vice, the data communication between the base station and the further terminal
device can be performed as if the further terminal device would be within the origi¬
nal coverage of the base station.
According to another embodiment, the wireless communication network comprises
a cellular communication network, for example a cellular-based wireless telecom¬
munication network like for example 3GPP (3rd Generation Partnership Project)
LTE (Long Term Evolution) systems. The terminal device is registered at a radio
cell provided by the base station. The intermediate node functionality comprises a
base station functionality. The base station functionality is configured to establish a
further radio cell and to provide a cell identifier for the further radio cell. The cell
identifier of the further radio cell is different from a cell identifier of the radio cell of
the base station. The further terminal device which is located inside a radio range
of the terminal device, registers at the further radio cell. Thus, the terminal device
acts as a small base station providing the further small radio cell, a so-called femtocell,
causing an improved coverage to the wireless communication system. Data
communication between the base station functionality of the terminal device and
the further terminal device is performed as usual in cellular communication networks.
The communication between the base station functionality of the terminal
device and the base station of the wireless communication system is also per¬
formed as usual in a cellular communication network. However, the base station
functionality of the terminal device may have a reduced functionality, for example
the base station functionality of the terminal device may not provide billing information
and may provide communication data to an emergency service in the wire¬
less communication system only. However, the base station functionality provided
by the terminal device may comprise a full functionality without any restrictions.
According to a further embodiment, the method comprises detecting the further
terminal device via a direct radio communication between the terminal device and
the further terminal device. The further terminal device is located within a radio
range of the terminal device. Upon detection of the further terminal device, the terminal
device requests at the base station the permission to activate the intermedi¬
ate node functionality. The direct radio communication between the terminal device
and the further terminal device may comprise a message from the further terminal
device indicating that the further terminal device is not within a radio range of the
base station or is not in contact with any base station. Thus, based on a direct de¬
vice-to-device communication between the terminal device and the further terminal
device, the further terminal device may indicate that it does not have contact to the
base station and/or wants to have contact to a base station, and based on this in¬
formation, the terminal device requests at the base station the permission to extend
the coverage of the radio cell provided by the base station by activating the inter¬
mediate node functionality. In other words, the device-to-device communication is
used to discover and determine a suitable terminal device to become an intermedi¬
ate node such as a repeater or a base station. By adding a protocol element to the
communication between the base station and the terminal device, the terminal device
can request activating the intermediate node functionality and the base station
can acknowledge or refuse the request. When the request is granted, the terminal
device activates the intermediate node functionality and may work as a repeater or
a base station thus including the further terminal device into the wireless communi¬
cation system via the base station.
According to a further embodiment of the method, configuration data is transmitted
from the base station to the terminal device. The configuration data configures the
intermediate node functionality of the terminal device. The configuration data may
comprise a maximum output power of a radio signal for forwarding communication
data received from the base station to the further terminal device. By configuring
the maximum output power, the base station may control the coverage extension
provided by the terminal device. As an alternative or additionally, the configuration
data comprises a cell identifier to be used by the intermediate node functionality
when the intermediate node functionality comprises the base station functionality.
In other words, when the terminal device acts as a further base station, the base
station controls the cell identifier used by the further base station. As an alternative
or additionally, the configuration data may comprise a neighbor cell identifier of a
neighbor base station. The neighbor base station is a base station located in the
neighborhood of the sending base station. Information about base stations in the
neighborhood of a base station are communicated between the base stations and
distributed to terminal devices to improve a transition of a terminal device from one
radio cell to another radio cell. Therefore, providing the neighbor cell identifier as
configuration data to the terminal device acting as a further base station, the termi¬
nal device can provide this information to the further terminal device for improving a
cell change of the further terminal device. Furthermore, additionally or as an alter¬
native, the configuration data may comprise a frequency band for a radio signal for
forwarding communication data received from the base station to the further termi¬
nal device. By configuring the frequency band to be used by the terminal device for
forwarding communication data, for example when the terminal device is acting as
a repeater, frequency interference may be avoided.
In another embodiment, the method further comprises receiving from the base sta¬
tion a message to deactivate the intermediate node functionality. Upon receiving
the message from the base station, the terminal device deactivates the intermedi¬
ate node functionality. Thus, the base station maintains control of the coverage
provided by the base station.
According to another aspect of the present invention, the method for operating a
base station of a wireless communication system is provided. According to the
method, the base station sends to a terminal device a permission to activate an
intermediate node functionality provided at the terminal device. The intermediate
node functionality enables the terminal device to forward communication data re¬
ceived from the base station to a further terminal device and, in vice versa, to for¬
ward communication data received from the further terminal device to the base sta¬
tion. Thus, the base station can request the terminal device to act as a repeater or
a base station of a femto-cell to extend coverage of the wireless communication
system.
According to an embodiment, the base station receives from the terminal device a
request for the permission to activate the intermediate node functionality, and the
base station sends the permission to activate the intermediate node functionality to
the terminal device upon receiving this request from the terminal device. For example,
when the terminal device has detected a further terminal device which is out
of reach of the base station, the terminal device may request at the base station to
get an allowance to activate the intermediate node functionality to include the fur¬
ther terminal device into the coverage of the base station. Upon receiving the re¬
quest from the terminal device, the base station may decide if it wants to extend
the coverage, for example based on a current load of the base station or a state of
the wireless communication system, for example if the wireless communication
system is in an emergency state in which emergency calls also from terminal de
vices outside the regular coverage shall be served.
According to a further embodiment, the base station sends configuration data to
the terminal device for configuring the intermediate node functionality. The configu¬
ration data comprises at least one of the following group:
- a maximum output power of a radio signal for forwarding communication data re¬
ceived from the base station to the further terminal device,
- a cell identifier to be used by the intermediate node functionality in case the ter¬
minal device acts as a base station,
- a neighbor cell identifier of a neighbor base station which is located in the neigh¬
borhood of the base station, and
- a frequency band for a radio signal to be used by the terminal device for forwarding
communication data to the further terminal device.
According to another embodiment, the base station sends a message to deactivate
the intermediate node functionality to the terminal device. Thus, the base station
may keep control of the coverage provided by the base station in combination with
the terminal device. For example, the base station may enable coverage extension
as described above for specific services or in specific states only. For example, the
coverage extension may be provided for communication data relating to a voice
communication between the further terminal device and an emergency service pro¬
vided by the wireless communication system. Thus, emergency calls from the fur¬
ther terminal device may be handled via the intermediate node functionality of the
terminal device and by the base station. As described above, the wireless communication
system may comprise a cellular-based wireless telecommunication net¬
work. In emergency situations, especially when for example a part of the telecom¬
munication network fails, emergency calls should be nevertheless be served. This
may be accomplished by the above-described methods enabling the wireless
communication system to dynamically extend the coverage of a base station in
combination with terminal devices registered at the base station.
According to another aspect of the present invention, a terminal device for a wire¬
less communication system is provided. The terminal device comprises a trans¬
ceiver unit for establishing a data communication between the terminal device and
a base station of the wireless communication system and for establishing a data
communication between the terminal device and a further terminal device. The
communication between the terminal device and the further terminal device is also
called a device-to-device communication. Such a device-to-device communication
(D2D communication) is already proposed for 3GPP standards. The terminal device
comprises furthermore a processing unit configured to receive from the base
station a permission to activate an intermediate node functionality provided at the
terminal device. The intermediate node functionality is configured to forward com¬
munication data received from the base station to the further terminal device and to
forward communication data received from the further terminal device to the base
station. The processing unit is furthermore configured to activate the intermediate
node functionality upon receiving the permission from the base station.
According to an embodiment, the terminal device is configured to perform the
above-described methods and embodiments. Therefore, the terminal device may
comprise also the above-described advantages.
Furthermore, the terminal device may comprise a mobile phone, a personal digital
assistant, a tablet computer, a laptop computer or a notebook computer.
According to another aspect, a base station for a wireless communication system is
provided. The base station comprises a transceiver unit for establishing a data
communication between the terminal device and the base station, and a pro¬
cessing unit. The processing unit is configured to send to the terminal device a
permission to activate an intermediate node functionality provided at the terminal
device. The intermediate node functionality enables the terminal device to forward
communication data received from the base station to a further terminal device and
to forward communication data received from the further terminal device to the
base station. The base station may be configured to perform the above-described
methods and embodiments and comprises therefore the above-described ad¬
vantages.
Although specific features described in the above summary and the following de¬
tailed description are described in connection with specific embodiments and as¬
pects of the present invention, it should be understood that the features of the em¬
bodiments and aspects may be combined with each other unless specifically noted
otherwise.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will now be described in more detail with reference to the
accompanying drawings.
Fig. 1 shows a wireless communication system and a terminal device outside a
coverage of the wireless communication system.
Fig. 2 shows the wireless communication system of Fig. 1, in which a terminal de¬
vice acts as a repeater for extending a coverage of the wireless communication
system according to an embodiment of the present invention.
Fig. 3 shows the wireless communication system of Fig. 1, in which a terminal de¬
vice acts as a base station for extending a coverage of the wireless communication
system according to an embodiment of the present invention.
Fig. 4 shows a terminal device and a base station according to embodiments of the
present invention.
Fig. 5 shows a flow chart comprising method steps according to an embodiment of
the present invention.
Fig. 6 shows a structure of a communication between a base station and terminal
devices according to an embodiment of the present invention.
Fig. 7 shows a structure of a communication between a base station and terminal
devices according to a further embodiment of the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
In the following, exemplary embodiments of the invention will be described in more
detail. It has to be understood that the features of the various exemplary embodi¬
ments described herein may be combined with each other unless specifically noted
otherwise. Same reference signs in the various drawings refer to similar or identical
components.
Fig. 1 shows a wireless communication system 100, for example a cellular-based
wireless telecommunication network. The communication system 100 may com¬
prise a plurality of base stations. One of these base stations is shown as base sta¬
tion 101 in Fig. . The base stations may communicate with each other via wireless
radio communications or via an operator core network 103 which comprise wireless
and wired connection. The operator core network 103 may be connected a wired
communication system, for example the internet. The operator core network 103
may comprise several services, for example an emergency service 104 directing
emergency calls to a fire service or a police service. The base station 101 provides
a radio cell 02 in which terminal devices 105 and 106 may communicate directly
with the base station 101 via a radio frequency communication as indicated by the
dashed arrows. A terminal device outside the radio cell 02, for example the termi¬
nal device 107, cannot communicate with the base station 101 due to insufficient
radio frequency range.
Fig. 2 shows schematically how to extend the coverage provided by the base station
101 in such a way that the terminal device 107 can communicate in the wire¬
less communication system 100. In one or more areas within or outside existing
network coverage 102 the terminal devices 105-107 are using a so-called deviceto-
device (D2D) communication to discover that they are within a radio frequency
range of each other. In Fig. 2 the terminal devices 06 and 107 may discover that
they are within range of each other (dashed arrow). The concept of device-todevice
discovery is currently being discussed and standardized within the 3rd Gen¬
eration Partnership Project (3GPP). One example is the requirement document for
device-to-device communication being defined in 3GPP TS22.278. These terminal
devices 106 and 107 may be terminal devices used for public safety, for example
police, fire department and so on, but they are not limited to the public safety usage,
and may comprise private use devices, like mobile phones or smart phones. How¬
ever, when limiting the service to public safety, the required mechanisms for charg¬
ing, billing and so on will be significantly relaxed.
In the device-to-device communication one or more terminal devices may signal to
other terminal devices whether it has access to the existing cellular communication
network. One of these terminal devices, for example terminal device 106, is identi¬
fied to potentially be used as a repeater to provide communication capabilities for
other terminal devices in the device-to-device communicating group, for example
terminal device 107. This terminal device 107 now can be served by the repeated
signal from terminal device 106 and needs not to be served directly by the base
station 101 .
Another way to extend the coverage of the wireless communication system 100 is
shown in Fig. 3. Instead of acting as a repeater, the terminal device 106 may act as
a further base station with its own closed subscriber group. Thus, the terminal device
106 provides a radio cell 108 within the direct reach of the radio frequency
range of the terminal device 106. Such a small radio cell 08 may be called femtocell.
Hence, instead of acting as a repeater, the terminal device 106 will have its
own cell identifier and its own authentication and authorization functionality. The
terminal device 106 uses its existing radio link to the base station 101 as a backhaul
for access to the operator core network 06. All communication in the link be¬
tween the base station 101 and the terminal device 106 looks from the point of
view of the base station 101 like communication from the terminal device 106 only.
Fig. 4 shows the base station 101 and the terminal device 106 in more detail. The
base station 101 comprises a radio frequency unit 402 coupled to an antenna 401
of the base station 101 for establishing a data communication between the base
station 101 and a terminal device, for example the terminal device 106. The radio
frequency unit 402 is configured to receive and send communication data from and
to the terminal devices within the radio cell 102 and is therefore also called transceiver
unit. The base station 101 comprises furthermore a processing unit 403 for
handling the communication data, registering terminal devices and so on. The ter¬
minal device 106 comprises an antenna 404, a radio frequency unit 405 coupled to
the antenna 404, and a processing unit 406. The radio frequency unit 405 is con¬
figured to establish a data communication between the terminal device 106 and the
base station 101 and is furthermore configured to establish a data communication
between the terminal device 106 and another terminal device, for example the ter¬
minal device 107, when the terminal device 107 is within a radio frequency range of
the terminal device 106. In the following, the terminal device 106 which is located
within the radio cell 102 of the base station 101 will be called terminal device A and
the terminal device 107 which is located outside the radio cell 102 will be called
terminal device B.
Extending the coverage of the wireless communication system 100 as described
above in connection with Figs. 2 and 3 will now be described in more detail in con¬
nection with Fig. 5. Fig. 5 shows a method 500 comprising method steps 501-507.
In step 501 a device-to-device communication is established between terminal devices.
Via the device-to-device communication terminal device A 106 is discovered
to be used as a potential repeater or base station to provide a data communication
with the base station 101 for other devices within a radio frequency range of the
terminal device A which are out of coverage of the wireless communication system.
For example, if terminal device B 107 is detected to be out of coverage of the wireless
communication system 100 in step 501 , this is communicated in step 502 via
the device-to-device communication between terminal device B 107 and terminal
device A 106, which is inside the radio cell 102. Then, in step 503, terminal device
A 106 sends a request to the base station 101 to get a permission for activating an
intermediate node functionality of the terminal device A 106. The intermediate node
functionality may comprise for example the repeater functionality described in con¬
nection with Fig. 2 or the base station functionality described in connection with Fig.
3. In step 504 the terminal device A 106 receives an answer from the base station
101 on the request. If the base station 101 does not give the permission and there¬
fore does not acknowledge to activate the intermediate node functionality, the
method 500 is continued in step 501 . If an acknowledgment is received from the
base station 101 in step 504, the method 500 is continued in step 505 in which the
terminal device A 106 receives parameters for configuring the intermediate node
functionality from the base station 101 . The parameters may comprise for example
a parameter instructing the terminal device A 106 to act as a repeater or to act as a
base station. Furthermore, the parameters may define a maximum output power of
a radio signal for forwarding communication data from the base station 101 to the
terminal device B 107, a cell identifier to be used by the terminal device A 106 in
case it is acting as a base station, a neighbor cell identifier of a neighbor base sta¬
tion located in the neighborhood of the base station 101 , and a frequency band for
a radio signal for forwarding communication data from the base station 101 to the
terminal device B 107. In step 506 the intermediate node functionality is activated
in the terminal device A 106. The intermediate node functionality may be performed
for example in the processing unit 406 of the terminal device A 106. When the ter¬
minal device A 106 is acting as a repeater, the terminal device A 106 may receive
a radio signal comprising digital data from the base station 101 and forward the
digital data in an unchanged form as received from the base station 101 to the terminal
device B 107. Therefore, from the point of view of the terminal device B 107,
there is a transparent communication between the base station 101 and the termi¬
nal device B 107. When the terminal device A 106 acts as a base station, the ter¬
minal device B 107 may register at the base station functionality of terminal device
A 106 and may communicate with the terminal device A 106 like with any other
base station.
As long as the intermediate node functionality is active in terminal A 106, the cov¬
erage of the wireless communication system 00 is extended such that it covers
the terminal device B 107. At any time, the base station 101 may send a message
to the terminal device A 106 indicating to deactivate the intermediate node func¬
tionality and thus cancelling the permission to act as a repeater or a base station
(step 507). If such a message is received, terminal device A 106 deactivates the
intermediate node functionality and the method 500 is continued in step 501 .
A communication structure for the above-described method is illustrated in Figs. 6
and 7. In Fig. 6 the terminal device A 106 acts as a repeater, and in Fig. 7 the ter¬
minal device A 106 acts as a base station. First, the terminal devices A and B dis¬
cover each other when they are within a radio frequency reach of each other (D2D
discovery). Via the device-to-device communication, terminal device B may indicate
that it does not have a connection to a wireless communication system (D2D
communication). Therefore, terminal device A sends a permission request to the
base station and receives a permission acknowledge (ACK) from the base station
to activate its intermediate node functionality. Furthermore, the terminal device A
receives parameters from the base station to configure the intermediate node functionality.
In the example shown in Fig. 6 , the intermediate node functionality comprises a
repeater functionality. Therefore, terminal device A transparently forwards commu¬
nication data between the base station and the terminal device B. Hence, terminal
device B registers via the terminal device A at the base station and a data communication
between the base station and the terminal device B can be performed.
When the base station sends a message to the terminal device A for cancelling the
permission for acting as a repeater, terminal device A deactivates the repeater
functionality and the data communication between the base station and the termi¬
nal device B is interrupted.
In the example shown in Fig. 7, the terminal device A acts as a base station.
Therefore, the terminal device B registers at the base station functionality of the
terminal device A and a communication between the terminal device A and the
terminal device B is established. Furthermore, the base station functionality of the
terminal device A uses the communication link between the terminal device A and
the base station for transmitting communication data from the terminal device B to
the operator core network and vice versa. The base station functionality of the ter¬
minal device A may be deactivated at any time upon receiving a corresponding
request from the base station.
The above-described methods require modifications to for example 3GPP stand¬
ards for example for the signaling between the base station and the terminal device
for transitioning the terminal device from a pure terminal device to a repeater or a
base station. This may require modifications for example in the radio resource control
(RRC) signaling, where this type of request could be a new RRC configuration
request. Furthermore, the device-to-device discovery and device-to-device com¬
munication needs to be included into the corresponding standards, for example the
3GPP standards.
To sum up, this method covers the possibility to use parts of already proposed
functionality in 3GPP systems in a new way by means of adding communication
protocol possibilities for converting a terminal device into a repeater. The main pur-
1S
pose may be handling coverage situations in public safety use cases. As an alter¬
native, as described above, a terminal device may be converted into a small cell
(femto-cell) base station with its own access rights.
While exemplary embodiments have been described above, various modifications
may be implemented in other embodiments. For example, the coverage of the wire¬
less communication system 100 may be extended even further, when the abovedescribed
terminal devices are cascaded or put in a chain repeating the repeated
signal once more or forming a chain of femto-cells. Furthermore, the abovedescribed
repeater and base station functionalities may be combined with each
other such that for example terminal device 06 acts as a repeater and terminal
device 107 acts additionally as a base station to extend the coverage of the wire¬
less communication system 100 for further terminal devices within the radio fre¬
quency range of the terminal device 107.

CLAIMS
1. A method for operating a terminal device of a wireless communication system,
the terminal device (106) being connected to a base station (101) of the wireless
communication system ( 00), wherein the method comprises:
providing an intermediate node functionality at the terminal device (106), the
intermediate node functionality being configured to forward communication data
received from the base station (101) to a further terminal device (107) and to for¬
ward communication data received from the further terminal device (107) to the
base station (101),
receiving from the base station (101) a permission to activate the intermedi¬
ate node functionality, and
upon receiving the permission from the base station (101), activating the
intermediate node functionality.
2. The method according to claim 1,
wherein forwarding the communication data received from the base station (101) to
the further terminal device (107) comprises receiving from the base station ( 01) a
radio signal comprising digital data and transmitting a radio signal comprising the
digital data in unchanged form as received from the base station (101), and
wherein forwarding the communication data received from the further terminal de¬
vice (107) to the base station (101) comprises receiving from the further terminal
device (107) a radio signal comprising digital data and transmitting a radio signal
comprising the digital data in unchanged form as received from the further terminal
device (107).
3. The method according to claim 1 or 2 , wherein the wireless communication net¬
work (100) comprises a cellular communication network and the terminal device
(106) is registered at a radio cell (102) provided by the base station (101), wherein
the intermediate node functionality comprises a base station functionality compris¬
ing:
establishing a further radio cell (108),
providing a cell identifier for the further radio cell (108), the cell identifier be¬
ing different from a cell identifier of the radio cell (102) of the base station (101),
and
registering the further terminal device ( 107) at the further radio cell ( 08).
4 . The method according to any one of the preceding claims, further comprising:
detecting the further terminal device (107) via a direct radio communication
between the terminal device (106) and the further terminal device (107), wherein
the further terminal device ( 07) is located within a radio range of the terminal device
(106), and
upon detecting the further terminal device (107), requesting at the base sta¬
tion (101) the permission to activate the intermediate node functionality.
5. The method according to claim 4, wherein detecting the further terminal device
( 107) comprises receiving a message from the further terminal device ( 107) indicat¬
ing that the further terminal device (107) is not within a radio range of the base sta¬
tion (101).
6 . The method according to any one of the preceding claims, further comprising
receiving configuration data from the base station (101) for configuring the inter¬
mediate node functionality, the configuration data comprising at least one of a
group consisting of:
a maximum output power of a radio signal for forwarding communication
data received from the base station (101) to the further terminal device (107),
- a cell identifier to be used by the intermediate node functionality in case the
intermediate node functionality comprises a base station functionality,
a neighbor cell identifier of a neighbor base station, the neighbor base sta¬
tion being located in the neighborhood of the base station (101), and
a frequency band for a radio signal for forwarding communication data received
from the base station (101) to the further terminal device (107).
7. The method according to any one of the preceding claims, further comprising:
receiving from the base station (101) a message to de-activate the interme¬
diate node functionality, and
de-activating the intermediate node functionality upon receiving the mes¬
sage from the base station (101).
8. A method for operating a base station of a wireless communication system, the
method comprising:
sending to a terminal device (106) a permission to activate an intermediate
node functionality provided at the terminal device (106), the intermediate node
functionality enabling the terminal device (106) to forward communication data re¬
ceived from the base station (101) to a further terminal device (107) and to forward
communication data received from the further terminal device (107) to the base
station (101).
9. The method according to claim 8, further comprising:
receiving from the terminal device (106) a request for the permission to acti¬
vate the intermediate node functionality, and
upon receiving the request from the terminal device (106), sending to the
terminal device (106) the permission to activate the intermediate node functionality.
0. The method according to claim 8 or 9, further comprising sending configuration
data to the terminal device (106) for configuring the intermediate node functionality,
the configuration data comprising at least one of a group consisting of:
a maximum output power of a radio signal for forwarding communication
data received from the base station (101) to the further terminal device (107),
a cell identifier to be used by the intermediate node functionality in case the
intermediate node functionality comprises a base station functionality,
a neighbor cell identifier of a neighbor base station, the neighbor base sta¬
tion being located in the neighborhood of the base station (101), and
- a frequency band for a radio signal for forwarding communication data re¬
ceived from the base station (101) to the further terminal device (107).
1. A terminal device for a wireless communication system, comprising:
a transceiver unit (405) for establishing a data communication between the
terminal device (106) and a base station (101) of the wireless communication sys¬
tem (100) and for establishing a data communication between the terminal device
(106) and a further terminal device (107), and
a processing unit (406) configured
to receive from the base station (101) a permission to activate an intermediate
node functionality provided at the terminal device (106), wherein the intermediate
node functionality is configured to forward communication data received from the
base station (101) to the further terminal device (107) and to forward communica¬
tion data received from the further terminal device (107) to the base station (101),
and
to activate the intermediate node functionality upon receiving the permission from
the base station (101).
12. The terminal device according to claim 11, wherein the terminal device (106) is
configured to perform the method according to any one of claims 1-7.
13. The terminal device according to claim 11 or 12, wherein the terminal device
(106) comprises at least one device of a group consisting of a mobile phone, a per¬
sonal digital assistant, a tablet computer, a laptop computer, and a notebook com¬
puter.
14. A base station for a wireless communication system, comprising:
- a transceiver unit (402) for establishing a data communication between a
terminal device (106) and the base station (101), and
a processing unit (403) configured to send to the terminal device (106) a
permission to activate an intermediate node functionality provided at the terminal
device (106), wherein the intermediate node functionality enables the terminal device
(106) to forward communication data received from the base station (101) to a
further terminal device (107) and to forward communication data received from the
further terminal device (107) to the base station (101).
15. The base station according to claim 14, wherein the base station (101) is con¬
figured to perform the method according to any one of claims 8-10.