STEINHAUSER KARL (DE)
BISCONTINI BRUNO (DE)
BARRERA ALEJANDRO MURILLO (DE)
US20190074854A1 | 2019-03-07 | |||
US10461421B1 | 2019-10-29 | |||
EP3518587A1 | 2019-07-31 |
Claims 1. A method for avoiding radiation from a network (1) at a location (2), wherein the network (1) is a radio communication network that comprises a node (3) and a user equipment, UE, (4) and wherein the method comprises: operating (S100, S100a, S700, S1100, S1700) a terminal (5) at the location (2); and operating (S400, S400a, S600, S1600, S800, S1400, S1800) the node (3) to produce a high signal quality at the UE (4) and a low signal strength at the terminal (5). 2. The method of claim 1 , wherein operating (S100, S100a, S1100) the terminal (5) at the location (2) comprises: transmitting (S 110 , S 110a , S 1110), by the terminal (5), a pilot signal; and wherein said operating (S400, S400a, S1400) the node (3) to produce a high signal quality at the UE (4) and a low signal strength at the terminal (5) is done in response to receiving the pilot signal. 3. The method of claim 2, wherein the pilot signal is transmitted (S 110 , S110a, S1110) continuously, periodically or repeatedly. 4. The method of claim 3, wherein the pilot signal is transmitted (S 110 , S110a, S1110) in a time-frequency resource allocated to the terminal (5) by the network (1). 5. The method of any one of the preceding claims, wherein the network (1 ) comprises one or more nodes (3) and multiple UEs (4), and the method comprises: operating (S400a) the one or more nodes (3) using multiple frequency resources at a same time, to produce high signal qualities at the multiple UEs (4) and low signal strengths at the terminal (5). 6. The method of claim 5, wherein operating (S100a) the terminal (5) at the location (2) comprises: signaling (S105a) the multiple frequency resources to the network (1) by the terminal (5). 7. The method of claim 6, wherein signaling (S105a) the multiple frequency resources to the network (1) by the terminal (5) comprises: transmitting multiple pilot signals (S110a), corresponding one-to-one to the multiple frequency resources, each pilot signal being transmitted in its corresponding frequency resource. 8. The method of any one of the preceding claims, comprising: identifying (S300, S300a S1300) the terminal (5) as a radiation protection terminal to the network (1); wherein said operating (S400, S400a, S600, S1600, S800, S1400, S1800) the node (3) to produce a high signal quality at the UE (4) and a low signal strength at the terminal (5) is done in response to identifying (S300, S300a, S1300) the terminal (5) as a radiation protection terminal to the network (1). 9. The method of any one of the preceding claims, wherein operating (S400, S400a, S800, S1400, S1800) the node (3) to produce a high signal quality at the UE (4) and a low signal strength at the terminal (5) comprises: transmitting (S450, S450a, S850, S1450, S1850), by the node (3), a radio frequency, RF, signal based on a UE CSI and a terminal CSI, wherein the UE CSI is channel state information, CSI, about RF propagation from the node (3) to the UE (4) and the terminal CSI is CSI about RF propagation from the node (3) to the terminal (5). 10. The method of claim 9, wherein transmitting (S450, S450a, S850, S1450, S1850) the RF signal by the node (3) comprises beam shaping (S451 , S451 a, S851 , S1451 , S1851) based on the UE CSI and the terminal CSI. 11. The method of claim 9 or 10, comprising: receiving (S420, S420a, S1420; S720, S1720), by the node (3) or by the terminal (5), a pilot signal from the terminal (5) or from the node (3), respectively; and determining (S430, S430a, S1430; S730, S1730) the terminal CSI based on the pilot signal received from the terminal (5) or from the node (3), respectively. 12. The method of any one of the preceding claims, comprising: receiving (S1420; S1720), by the node (3) or by the UE (4), a pilot signal from the UE (4) or from the node (3), respectively; and determining (S1430; S1730) the UE CSI based on the pilot signal received from the UE (4) or from the node (3), respectively. 13. A terminal device operable as a terminal (5) in a network (1 ), for avoiding radiation from the network (1 ) at a current location (2) of the terminal device, wherein the network (1) is a radio communication network that comprises a node (3) and a user equipment, UE, (4) and the terminal device is configured to enable the node (3) to produce a high signal quality at the UE (4) and a low signal strength at the terminal device. 14. The terminal device of claim 13, wherein said enabling of the node (3) to produce a high signal quality at the UE (4) and a low signal strength at the terminal device comprises transmitting, by the terminal device, a pilot signal. 15. The terminal device of claim 14, configured to transmit the pilot signal continuously, periodically or repeatedly. 16. The terminal device of claim 14 or 15, configured to transmit the pilot signal in a time- frequency resource allocated to the terminal device by the network (1). 17. The terminal device of any one of the claims 13 to 16, configured to signal multiple frequency resources to the network (1 ). 18. The terminal device of claim 17, wherein the signaling of the multiple frequency resources to the network (1) comprises transmitting multiple pilot signals, corresponding one-to-one to the multiple frequency resources, wherein each pilot signal is transmitted in its corresponding frequency resource. 19. The terminal device of the claim 18, configured to provide information to the node (3) for being identified as a radiation protection terminal to the network (1). 20. The terminal device of any one of the claims 13 to 19, configured to receive a pilot signal from the node (3); and determine a terminal CSI based on the pilot signal received from the node (3). 21. A node device operable as a node (3) in a network (1 ), wherein the network (1 ) is a radio communication network that comprises a node (3) and a user equipment, UE, (4) and wherein the node (3) is configured to produce a high signal quality at the UE (4) and a low signal strength at the terminal (5) in response to operation of the terminal (5). 22. The node device of claim 21 , configured to produce a high signal quality at the UE (4) and a low signal strength at the terminal (5) in response to receiving a pilot signal from the terminal (5). 23. The node device of claim 21 or 22, configured to produce a high signal quality at the UE (4) and a low signal strength at the terminal (5) in response to identifying the terminal (5) as a radiation protection terminal to the network (1). 24. The node device of any one of claims 21 to 23, wherein said producing of a high signal quality at the UE (4) and a low signal strength at the terminal (5) comprises transmitting, by the node (3), a radio frequency, RF, signal based on a UE CSI and a terminal CSI, wherein the UE CSI is channel state information, CSI, about RF propagation from the node (3) to the UE (4) and the terminal CSI is CSI about RF propagation from the node (3) to the terminal (5). 25. The node device of claim 24, wherein said transmitting the RF signal by the node (3) comprises beam shaping based on the UE CSI and the terminal CSI. 26. The node device of claim 24 or 25, configured to receive a pilot signal from the terminal (5); and determine the terminal CSI based on the pilot signal received from the terminal (5). 27. The node device of any one of claims 21 to 26, configured to receive a pilot signal from the UE (4); and determine the terminal CSI based on the pilot signal received from the UE (4). 28. A computer program for a terminal device operable as a terminal (5) in a network (1 ), for avoiding radiation from the network (1 ) at a current location (2) of the terminal device, wherein the network (1) is a radio communication network that comprises a node (3) and a user equipment, UE, (4), the computer program comprising instructions which, when the program is executed by a computer, cause the computer to operate the terminal device to enable the node (3) to produce a high signal quality at the UE (4) and a low signal strength at the terminal device. 29. A computer program for a node device operable as a node (3) in a network (1 ), wherein the network (1) is a radio communication network that comprises a node (3) and a user equipment, UE, (4) the computer program comprising instructions which, when the program is executed by a computer, cause the computer to operate the node (3) to produce a high signal quality at the UE (4) and a low signal strength at the terminal (5) in response to an operation of the terminal (5). 30. The computer program of claim 28 or 29, comprising instructions which, when the program is executed by the computer, cause the computer to operate the steps of the method of any one of claims 2 to 12. |
The present invention relates to techniques for radiation avoidance in a wireless radiofrequency communication network.
The invention more specifically relates to a method, a terminal device, a node device, a computer program for the terminal device and a computer program for the node.
Wireless communication systems can generate, as an unwanted side effect, levels of radiation that may be too high at sensitive spots. Sensitive spots may, for example, be places with medical equipment (e.g. at hospitals), test equipment in laboratories, or communication transceivers, or any other place at which high levels of radio frequency (RF) radiation may have a negative impact.
Unwanted radiation at a spot can be reduced by suppressing or cancelling radiation or filtering waves that radiate into a place from identified directions. Beamforming techniques may be used for this purpose.
It is an object of the present invention to provide improved radiation avoidance at a selected location.
This object is achieved by the subject matter of the independent claims. Advantageous embodiments are given in the dependent claims.
According to an aspect of the invention, a method for avoiding radiation from a radio communication network at a location is provided. The radio communication network (also referred to herein briefly as the network) comprises a node and a user equipment (UE). The network may comprise multiple nodes and multiple UEs. For example, the network may be a 4G or a 5G radio communication network. The method comprises operating a terminal at the location and operating the node to produce a high signal quality at the UE and a low signal strength at the terminal.
According to another aspect of the invention, a terminal device operable as a terminal in a network is provided. The terminal device is suitable for avoiding radiation from the network at a current location of the terminal device. The network is a radio communication network that comprises a node and a UE. The terminal device is configured to enable the node to produce a high signal quality at the UE and a low signal strength at the terminal device.
According to another aspect of the invention, a node device operable as a node in a network is provided. The network is a radio communication network that comprises a node and a user UE. The node is configured to produce a high signal quality at the UE and a low signal strength at the terminal in response to operation of the terminal.
Another aspect of the invention relates to a computer program for a terminal device operable as a terminal in a network, for avoiding radiation from the network at a current location of the terminal device. The network is a radio communication network that comprises a node and a UE. The computer program comprises instructions which, when the program is executed by a computer, cause the computer to operate the terminal device to enable the node to produce a high signal quality at the UE and a low signal strength at the terminal device.
Another aspect of the invention relates to a computer program for a node device operable as a node in a network. The network is a radio communication network that comprises the node and a UE. The computer program comprises instructions which, when the program is executed by a computer, cause the computer to operate the node device to produce a high signal quality at the UE and a low signal strength at the terminal in response to operation of the terminal.
According to the invention, the node, in response to receiving pilot signals from the terminal, strives to avoid transmitting powerful signals toward the terminal location, thereby avoiding radiation at the terminal location. Preferably, avoiding radiation is realized simultaneously in multiple frequency bands. In other words, the invention provides a high signal quality at the location of a UE but not at the place, at which the terminal is located. This concept may be extended to multiple nodes and multiple terminals in the network.
The terminal may notably be placed at a sensitive spot. This is a place with a requirement to receive low radiation - for example, a school, a hospital or a laboratory. For example, the level of radiation must not exceed a certain level so as not to affect measurements of medical or laboratory equipment.
Preferably, the node device and the terminal device are configured to communicate with each other as per a protocol. The present disclosure provides a proactive, flexible and dynamic method for controlling network nodes to transmit less power to specific spots and areas, e.g. by forming suitable radiation patterns. The network node(s) may be a base station, for example.
Mitigation of power transmittance is controlled by the system of one or more nodes. The power mitigation may involve reducing or cancelling the power transmittance at the sensitive spot. Thereby, equipment, which is located at the sensitive spot, is not impaired by radiation from the network node(s).
The one or more terminals are operated to provide avoiding radiation from the network at the respective location of the terminal. Utilizing the terminals allows acquiring channel knowledge in multi-path environments. The invention is applicable within the framework of 5G networks, in which smart antennas with dynamic very-narrow-beam radiation patterns are used, which increases the risk of surpassing safety electromagnetic field (EMF) levels on sensitive spots.
In a static or slowly changing environment, the terminals can be operated in a training mode, in which the respective terminal and the respective node interact with each other to provide channel information. Channel information may be channel state information (CSI) or may include channel state information. Channel state information describes how a signal propagates from a transmitter to a receiver and represents how the signal evolves during its propagation. After channel information has been obtained, the one or more terminals are switched off. The channel information enables the one or more nodes to produce a high signal quality at the UE and a low signal strength at the terminal. A static environment comprises, for example, UEs and/or terminal devices, which do not move.
The terminal devices may be in groups in order to broaden a region, in which the node provides signals with a low signal strength. The terminal devices may be movable. This allows flexible and dynamic control of the radiation of a node, which may be the main node at the respective location of the terminal device. Furthermore, any number of areas, which are provided with low signal intensities, may be possible, up to the system limit.
Each of the terminal devices may comprise a computer program which is locally or remotely controlled. Preferably, the terminal is registered as a device with special rights in the network. The terminal device may identify itself to the network, e.g. by transmitting an identifier to the network. The identifier identifies the terminal as a radiation protection terminal. The identification may be carried out separately or the identifier may be included in a pilot signal transmitted by the terminal device. In this case the pilot signal is used for generating the terminal CSI and for identifying the terminal as a radiation protection device toward the network. Thus, the network is enabled to avoid generating high signal strengths at the terminal. The terminal does not consume service resources, i.e. it is not a system user and does not receive any data. The method cost is only related to the spatial filtering at the physical layer.
Optionally, operating the terminal at the location comprises transmitting, by the terminal, a pilot signal; and wherein said operating the node to produce a high signal quality at the UE and a low signal strength at the terminal is done in response to receiving the pilot signal. The pilot signals are uplink pilots or downlink pilots, for example for providing feedback. Optionally, a configuration of the terminal device to enable the node to produce a high signal quality at the UE and a low signal strength at the terminal device comprises a configuration to transmit, by the terminal device, a pilot signal. Optionally, the node device is configured to produce a high signal quality at the UE and a low signal strength at the terminal in response to receiving a pilot signal from the terminal.
Such a configuration relates to an operation of the terminal to transmit uplink pilot signals. Thereby, the terminal provides channel information to the node. By receiving a pilot signal from the terminal, the node is made aware of the terminal. Only in this case does the node transmit radio frequency signals. Unnecessary emission of radio signals is reduced.
Optionally, the pilot signal is transmitted continuously, periodically or repeatedly. Optionally, the terminal device is configured to transmit the pilot signal continuously, periodically or repeatedly.
Thereby, the terminal can transmit cycles of pilot signals to the node for providing channel information to the node. The signals may be transmitted over a whole period of operation of the terminal device. For example, periodically or repeatedly transmitting pilot signals may be advantageous in case of movements of the terminal so that radiofrequency radiation of the node can be adapted in accordance with the location of the terminal device.
Optionally, the pilot signal is transmitted in a time-frequency resource allocated to the terminal by the network. Optionally, the terminal device is configured to transmit the pilot signal in a time-frequency resource allocated to the terminal device by the network.
A frequency resource may be a frequency band, for example, or may include multiple frequency bands. In other words, the latter pilot signals are frequency-distributed pilot signals. The configuration of the terminal device to transmit cycles of pilot signals may be beneficial in case that the sensitive spot comprises laboratory equipment which is sensitive to certain frequencies. The one or more terminal devices may be configured to transmit and/or receive frequency-distributed pilot signals. Alternatively, or additionally, one or more node devices may be configured to transmit and/or receive frequency-distributed pilot signals.
Optionally, the one or more terminal devices are configured to transmit signals by time- division-duplexing (TDD) and by frequency-division-duplexing (FDD) in uplink and downlink transmissions. Optionally, the one or more node devices are configured to transmit signals by time-division-duplexing (TDD) and by frequency-division-duplexing (FDD) in uplink and downlink transmissions.
Optionally, the network comprises one or more nodes and multiple UEs, and the method comprises operating the one or more nodes using multiple frequency resources at a same time, to produce high signal qualities at the multiple UEs and low signal strengths at the terminal. Optionally, the terminal device is configured to signal the multiple frequency resources to the network. Optionally, the network comprises multiple UEs, and the node device is configured to use multiple frequency resources at a same time, to produce high signal qualities at the multiple UEs and low signal strengths at the terminal.
Using sets of pilot signals at different frequencies allows providing broader bands, in which a low signal strength at the location of the terminal can be provided.
Optionally, operating the terminal at the location comprises signaling the multiple frequency resources to the network by the terminal. Alternatively, one or more UEs may operate as a terminal and signal the multiple frequency resources to the network.
Optionally, signaling the multiple frequency resources to the network by the terminal comprises transmitting multiple pilot signals, corresponding one-to-one to the multiple frequency resources, each pilot signal being transmitted in its corresponding frequency resource. Alternatively, the one or more UEs may transmit multiple pilot signals, corresponding one-to-one to the multiple frequency resources, each pilot signal being transmitted in its corresponding frequency resource.
Thereby, radiation mitigation is allowed in several frequency resources and not only one frequency resource. In other words, a terminal may be protected from radiation of multiple frequencies. Such a configuration of the terminal to signal multiple frequency resources may be beneficial in case of a hospital comprising a lot of laboratory equipment and possibly patients being sensitive to radiation signals. The signaling may be also carried out by a UE being configured to operate as a terminal.
Optionally, the method comprises identifying the terminal as a radiation protection terminal to the network; wherein said operating the node to produce a high signal quality at the UE and a low signal strength at the terminal is done in response to identifying the terminal as a radiation protection terminal to the network. Optionally, the terminal device is configured to identify itself as a radiation protection terminal to the network. Optionally, the node device is configured to produce a high signal quality at the UE and a low signal strength at the terminal in response to identifying the terminal as a radiation protection terminal to the network.
Such identification may be carried out when installing the terminal at the network. Identification may be, alternatively, or additionally, carried out after having moved the terminal. The terminal may be configured to provide its identification to the node via the pilot signal which the terminal transmits to the node. For example, the terminal identifies itself to the network, e.g. by transmitting an identifier to the network, wherein the identifier identifies the terminal as a radiation protection terminal. In one embodiment, the identifier is included in a pilot signal transmitted by the terminal. In this case the pilot signal is used for generating the terminal CSI and for identifying the terminal as a radiation protection device toward the network. Thus, network is enabled to avoid generating high signal strengths at the terminal.
Optionally, operating the node to produce a high signal quality at the UE and a low signal strength at the terminal comprises transmitting, by the node, a radio frequency (RF) signal based on a UE CSI and a terminal CSI, wherein the UE CSI is channel state information (CSI) about RF propagation from the node to the UE and the terminal CSI is CSI about RF propagation from the node to the terminal. Beam steering may be carried out in one or more frequencies. Optionally, transmitting the RF signal, by the node, comprises beam shaping based on the UE CSI and the terminal CSI. Optionally, the terminal device is configured to receive a pilot signal from the node and to determine a terminal CSI based on the pilot signal received from the node. The pilot signal may be transmitted continuously, periodically or repeatedly. Thereby, the node device can transmit cycles of pilot signals to the terminal for providing channel information to the node. Controlling the node may comprise or consist in beam steering. Beam shaping and beam steering may be realized by Singular Value Decomposition (SVD) applied to a channel matrix which includes the radiation patterns.
Optionally, the method comprises receiving, by the node or by the terminal, a pilot signal from the terminal or from the node, respectively; and determining the terminal CSI based on the pilot signal received from the terminal or from the node, respectively. Optionally, the node device is configured to receive a pilot signal from the terminal; and to determine the terminal CSI based on the pilot signal received from the terminal. Optionally, the terminal device is configured to receive a pilot signal from the node; and to determine the terminal CSI based on the pilot signal received from the node.
In other words, the method may be applied either by receiving uplink pilot signals, by the node, which have been transmitted by the terminal, or by receiving downlink pilot signals, by the terminal, which have been transmitted by the node. Preferably, the terminal device is configured to transmit uplink-pilot signals in an open-loop mode. In the open-loop mode, the terminal only provides the pilot signal to the node, which determines channel information based on the pilot signal. Preferably, in a closed-loop mode, the node transmits downlink- pilot signal and the terminal acquires channel information from the pilot signal received from the node. After having acquired the channel information, the terminal provides a feedback to the node.
Optionally, the method comprises receiving, by the node or by the UE, a pilot signal from the UE or from the node, respectively; and determining the UE CSI based on the pilot signal received from the UE or from the node, respectively.
In other words, the UE may operate in the same way as a terminal. Such UE is called UE- terminal. Another UE not being located near the UE operating as a terminal may receive a signal with a high signal quality of the node, as a result of the operation of node and UE- terminal to acquire channel information. The method may be applied either by receiving uplink pilot signals, by the node, which are transmitted by the UE, or by receiving downlink pilot signals, by the UE, which have been transmitted by the node.
These and other aspects of the invention will be apparent from and elucidated with reference to the embodiments described hereinafter. Individual features disclosed in the embodiments can constitute alone or in combination an aspect of the present invention. Features of the different embodiments can be carried over from one embodiment to another embodiment. In the drawings:
Fig. 1 shows a schematic drawing of a network according to a first embodiment of the invention,
Fig. 2 shows a flow diagram of a method according to a first embodiment of the invention,
Fig. 3 shows a schematic drawing of a network according to a second embodiment of the invention,
Fig. 4 shows a flow diagram of a method according to a second embodiment of the invention,
Fig. 5 shows a flow diagram of a method according to a third embodiment of the invention,
Fig. 6 shows a schematic drawing of a network according to a third embodiment of the invention,
Fig. 7 shows a flow diagram of a method according to a fourth embodiment of the invention, and
Fig. 8 shows a flow diagram of a method according to a fifth embodiment of the invention.
Fig. 1 schematically shows a radio communication network 1. The network 1 comprises one or more nodes for serving a plurality of user equipments. The network 1 is configured to keep radiation levels at a location 2 of a terminal 5 minimal.
The network 1 comprises a node 3 (e.g. a base station or an eNodeB), a user equipment (UE) 4 (e.g. a mobile device such as a mobile phone, a smartphone or a tablet) and one or several terminals 5. The network 1 may comprise further nodes (not shown) and further UEs 4. Each terminal 5 is located at a respective location 2. The terminals 5 and the UE 4 can exchange signals with the node 3, or with each other. Thus, the UE 4 communicates with the node 3. The node 3 may generate a transmission beam that corresponds to a lobe 10 as schematically shown in Fig. 1. When the node 3 adapts its transmission characteristics, an adapted lobe 11 may be provided as schematically shown in Fig. 1. The node 3 can avoid high signal power at the locations 2 by suitably configuring its signal emission characteristics. The adapted signal emission characteristics provides that the UEs 4 can exchange signals. Furthermore, high radiation intensity at terminals 5 is avoided by the adapted signal emission characteristics. The beam lobes 10, 11 are shown for the sake of explanation. In practice, a node may have an emission characteristic that comprises multiple lobes and side lobes.
An embodiment of a method for avoiding radiation from the network 1 at the location 2 of the terminal 5 is shown in a flow diagram in Fig. 2. The terminal 5 and the node 3 cooperate to obtain channel state information (CSI) for RF signal propagation from the node 3 to the terminal 5. The node 3 uses the CSI to generate radio frequency signals with a high signal quality at the UE 4 and a low signal strength at the terminal 5. In a step “S100”, the terminal 5 is operated at the location 2.
In a step “S300”, the terminal 5 is identified as a radiation protection terminal to the network 1. The terminal 5 may be registered as a terminal with special rights in the network 1. Identifying the terminal 5 is carried out based on a pilot signal sent by the terminal 5 when operating the terminal 5 in step “S100”. Alternatively, the terminal 5 may be identified before operating the terminal 5 in step “S100”.
Generally, in any of the embodiments of the Figures, the terminal 5 identifies itself to the network 1 , e.g. by transmitting an identifier to the network 1. The identifier identifies the terminal 5 as a radiation protection terminal. The identification may be done separately, or (as described with reference to the embodiment shown in Fig. 2) the identifier is included in a pilot signal transmitted by the terminal 5. In this case, the pilot signal is used for generating the terminal CSI and for identifying the terminal 5 as a radiation protection device toward the network 1. Thus, network 1 is enabled to avoid generating high signal strengths at the terminal 5.
According to a step “S400”, the node 3 is operated to produce a high signal quality at the UE 4 and a low signal strength at the respective terminal 5. Operating (S400) the node 3 to produce a high signal quality at the UE 4 and a low signal strength at the terminal 5 is done in response to receiving the pilot signal of the terminal 5. More specifically, operating (S400) of the node 3 to produce a high signal quality at the UE 4 and a low signal strength at the terminal 5 is done in response to identifying (S300) the terminal 5 as a radiation protection terminal to the network 1.
By operating (S400) the node 3 to produce a high signal quality at the UE 4 and a low signal strength at the respective terminal 5 a reduced level of radiation from the network 1 at the location 2 of the terminal 5 can be achieved. In other words, a signal transmitted to one of the UEs 4 will have a low level at the locations 2 of the terminals 5 (see Fig. 1 ). Operating (S100) the terminal 5 at the location 2 comprises, according to a step “S110”, transmitting, by the terminal 5, the pilot signal. Step “S110” of transmitting the pilot signal may be carried out continuously, periodically or repeatedly. The pilot signal is transmitted (S110) in a time-frequency resource allocated to the terminal 5 by the network 1. A frequency resource may be a frequency band, for example, or may include multiple frequency bands.
Operating (S400) the node 3 to produce a high signal quality at the UE 4 and a low signal strength at the respective terminal 5 involves steps “S420”, “S430” and “S450”. According to step “S420”, the node 3 receives the pilot signal from the terminal 5. Such a pilot signal is also called “uplink pilot” or “uplink pilot signal”. According to step “S430”, the node 3 determines terminal CSI based on the pilot signal received from the terminal 5. The terminal CSI is channel state information (CSI) about radio frequency (RF) propagation from the node 3 to the terminal 5. According to a step “S450”, the node 3 transmits a radio frequency (RF) signal based on a UE CSI and a terminal CSI. The step “S450” comprises a step “S451” of beam shaping based on the UE CSI and the terminal CSI. The UE CSI is channel state information (CSI) about RF propagation from the node 3 to the UE 4 and the terminal CSI is CSI about RF propagation from the node 3 to the terminal 5.
Avoiding radiation from the network 1 at the respective location 2 of the terminal 5 is provided by beamforming radiation patterns of the node 3. The underlying mathematical tool is Singular Value Decomposition (SVD), applied to a channel matrix which includes transmitter or receiver multiple radiation patterns and the propagation effects towards the locations 2 of the terminals 5. By applying SVD to channels provided by the terminals 5, a set of orthogonal transmit patterns which are projected to their null space, i.e. which present nulls at the locations 2 of the terminals 5, is obtained. A set of orthogonal transmit patterns which present nulls at the locations 2 of the terminals 5 is provided.
Fig. 3 schematically shows a first network 1a and a second network 1b. The first network 1a comprises one or more terminals 5 and the second network 1b comprises one or more terminals 5. The UEs 4 of the networks 1a, 1b are not depicted. However, there are one or more UEs 4 present in each of the networks 1a, 1b.
Fig. 4 shows a flow diagram of a method according to a second embodiment of the invention. According to a step “S100a”, the respective terminal 5 is operated at the location 2. This comprises, according to a step “S105a”, signaling multiple frequency resources to the network 1 by the terminal 5. Signaling (S105a) comprises a step “S110a” of transmitting multiple pilot signals, corresponding one-to-one to the multiple frequency resources. Each pilot signal is transmitted in its corresponding frequency resource.
According to a step “S300a” the respective terminal 5 is identified a radiation protection terminal to the network 1. Further, according to step “S400a”, the method comprises operating the one or more nodes 3 to produce a high signal quality at the UE 4 and a low signal strength at the terminal 5. Operating (S400a) each of the nodes 3 comprises the steps “S420a”, “S430a” and “S450a”. According to step “S420a” each of the nodes 3 receives pilot signals from the terminal 5. According to step “S430a”, the terminal CSI is determined based on the pilot signals received from the respective terminal 5. According to step “S450a”, each of the nodes 3 transmits a radio frequency (RF) signal based on a UE CSI and a terminal CSI. The step of transmitting RF signals comprises a step “S451a” of beam shaping based on the UE CSI and the terminal CSI.
Fig. 5 shows a flow diagram of a method according to a third embodiment of the invention. According to a step “S300”, the terminal 5 is identified as a radiation protection terminal to the network 1. According to a step “S600”, the node 3 is operated to produce a high signal quality at the UE 4 and a low signal strength at the terminal 5. This involves, according to a step “S610”, transmitting, by the node 3, of a pilot signal. According to a step “S700”, a terminal 5 is operated at the location 2. This involves, according to a step “S720”, receiving, by the terminal 5, the pilot signal from the node 3 and, according to a step “S730”, determining the terminal CSI based on the pilot signal received from the node 3. According to a step “S800”, the node 3 is operated to produce a high signal quality at the UE 4 and a low signal strength at the terminal 5. Step “S800” includes step “S850”. According to step “S850”, the node 3 transmits a radio frequency (RF) signal based on a UE CSI and a terminal CSI. This includes a step “S851” of beam shaping based on the UE CSI and the terminal CSI.
Fig. 6 shows a schematic drawing of a network 1 according to a third embodiment of the invention. The network 1 comprises a node 3 and multiple terminals 5. The UEs 4 comprised by the network 1 are not depicted. The network 1 may also comprise more than one node 3.
The network 1 is configured in a similar way as the previously described networks 1 , although the terminals 5 are not shown in this embodiment. However, the terminals 5 are arranged in the same manner as in the embodiment of Figure 1 , or they are arranged at different locations 2. Additionally, the network 1 comprises means 9 configured to monitor electromagnetic fields (EMF) at the location 2 of the terminal 5 which is near a hospital 7. In addition, two terminals 5 are provided at the location 2 near laboratory equipment 8. The node 3 receives pilot signals from both terminals 5 and accordingly adapts the transmission characteristics to reduce signal power toward the terminals 5. Using the two terminals 5 allows enlarging an area in which the signal power is reduced, which is schematically shown by the smaller second adapted beam lobe 11 b compared to the first adapted beam lobe 11 a, which is near the medical equipment of the hospital 7.
The methods according to Figures 7 and 8 are carried out by a network 1 which comprises one or more UEs 4 operating as a terminal 5. It is indicated to such UEs 4 by “UE-terminals”. Other UEs 4 may benefit from the operation of the UE-terminals.
Fig. 7 shows a flow diagram of a method according to a fourth embodiment of the invention. According to step “S1100“, a UE 4 is operated as a terminal (UE-terminal) at the location 2. Step “S1100” comprises a step “S1110”. In step “S1110”, the UE-terminal transmits a pilot signal. In a step “S1300”, the UE-terminal is identified as a radiation protection terminal to the network 1. In a step “S1400”, the node 3 is operated to produce a high signal quality at another UE 4 and a low signal strength at the terminal, which is the UE-terminal. Step “S1400” comprises steps “S1420”, “S1430” and “S1450”. In a step “S1420”, the node 3 receives a pilot signal from the UE-terminal. In a step “S1430”, the node 3 determines the terminal CSI based on the pilot signal received from the UE-terminal. In a step “S1450”, the node 3 transmits a radio frequency (RF) signal based on a UE CSI and a terminal CSI. The step “S1450” comprises a step “S1451” of beam shaping based on the UE CSI and the terminal CSI.
Fig. 8 shows a flow diagram of a method according to a fifth embodiment of the invention. In a step “S1300”, the UE 4, which is the terminal (in the following indicated by “UE-terminal”), is identified as a radiation protection terminal to the network 1. In a step “S1600”, the node 3 is operated to produce a high signal quality at another UE 4 and a low signal strength at the terminal, which is the UE-terminal. Step “S1600” comprises step “S1610”. In step “S1610”, the node 3 transmits a pilot signal. In a step “S1700”, the UE 4 is operated as a terminal (UE- terminal) at the location 2. This involves, in a step “S1720”, receiving, by the UE-terminal, a pilot signal from the node 3 and, in a step “S1730”, determining the terminal CSI based on the pilot signal received from the node 3. In a step “S1800”, the node 3 is operated to produce a high signal quality at another UE 4 and a low signal strength at the terminal, which is the UE-terminal. This involves, in a step “S1850”, transmitting, by the node 3, a radio frequency (RF) signal based on a UE CSI and a terminal CSI. The step “S1850” involves, in a step “S1851”, beam shaping based on the UE CSI and the terminal CSI. The invention comprises a network 1 having all functional units of the network 1 according to the previous embodiments, whereas no terminals 5 are provided (not shown). Such a network 1 can be used in those cases in which a previous training mode is viable. In a training mode, system training is possible, for example, if an environment was static or stationary enough. In such a case, the network 1 operates in a training mode using one or more terminals 5, and in a normal operation mode, the network 1 operates in absence of the terminals 5. In other words, in normal operation mode, the node 3 is aware of sensitive spots and accordingly adapts transmitted radio frequency signals, which have a high signal quality at locations of UEs 4 and a low signal strength at locations 2, at which sensitive spots are located. The terminals 5 may be switched off or moved away in the normal mode.
The method makes use of a protocol involving one or more nodes 3 and one or more terminals 5.
The terminals 5 may be installed, e.g. attached or mounted, at a selected location 2. Alternatively, the terminal 5 can be attached onto a mobile station. Each of the terminals 5 comprises a computer program (SW application) and can be locally or remotely controlled. It can be programmed to be switched on only during specified periods of time.
The terminal 5 does not consume service resources, i.e. it is not a system user and does not receive any data. The method cost is only related to the spatial filtering at the physical layer.
In virtual applications, e.g. theoretical models or 3D model simulations of the network 1 , the existence of the terminal 5 is equivalent to acquiring channel information. Then, the channel is a radio frequency (RF) path from the node 3 and to the target point.
The invention has been described in conjunction with various embodiments.
Variations of the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims. In the claims, the word “comprising” does not exclude other elements or steps, and the indefinite article “a” or “an” does not exclude a plurality. A single processor or other unit may fulfill the functions of several items recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims do not indicate that a combination of these measured cannot be used to advantage. A computer program may be stored/distributed on a suitable medium, such as an optical storage medium or a solid-state medium, or it may be provided via a wired or wireless telecommunication system, e.g. using the Internet or some other communications protocol.
Reference signs:
1 network
1a first network
1 b second network
2 location
3 node
4 user equipment
5 terminal
7 medical equipment of a hospital
8 laboratory equipment
9 means for monitoring electromagnetic fields
10 beam lobe
11 adapted beam lobe
11 a first adapted beam lobe 11 b second adapted beam lobe
S100 operating a terminal at the location S100a operating a terminal at the location
S105a signaling multiple frequency resources to the network by the terminal S110 transmitting, by the terminal, a pilot signal
S110a transmitting multiple pilot signals, corresponding one-to-one to the multiple frequency resources, each pilot signal being transmitted in its corresponding frequency resource S300 identifying the terminal as a radiation protection terminal to the network S300a identifying the terminal as a radiation protection terminal to the network S400 operating the node to produce a high signal quality at the UE and a low signal strength at the terminal
S400a operating the one or more nodes to produce a high signal quality at the UE and a low signal strength at the terminal
S420 receiving, by the node, a pilot signal from the terminal S420a receiving, by the node, pilot signals from the terminal
S430 determining the terminal CSI based on the pilot signal received from the terminal S430a determining the terminal CSI based on pilot signals received from the terminal S450 transmitting, by the node, a radio frequency, RF, signal based on a UE CSI and a terminal CSI S450a transmitting, by the node, a radio frequency, RF, signal based on a UE CSI and a terminal CSI
S451 beam shaping based on the UE CSI and the terminal CSI S451a beam shaping based on the UE CSI and the terminal CSI S600 operating the node to produce a high signal quality at the UE and a low signal strength at the terminal S610 transmitting, by the node, a pilot signal S700 operating a terminal at the location S720 receiving, by the terminal, a pilot signal from the node S730 determining the terminal CSI based on the pilot signal received from the node S800 operating the node to produce a high signal quality at the UE and a low signal strength at the terminal
5850 transmitting, by the node, a radio frequency, RF, signal based on a UE CSI and a terminal CSI
5851 beam shaping based on the UE CSI and the terminal CSI S1100 operating a UE as a terminal (UE-terminal) at the location S1110 transmitting, by the UE-terminal, a pilot signal
S1300 identifying the UE-terminal as a radiation protection terminal to the network S1400 operating the node to produce a high signal quality at another UE and a low signal strength at the terminal, which is the UE-terminal S1420 receiving, by the node, a pilot signal from the UE-terminal
S1430 determining the terminal CSI based on the pilot signal received from the UE-terminal
51450 transmitting, by the node, a radio frequency, RF, signal based on a UE CSI and a terminal CSI
51451 beam shaping based on the UE CSI and the terminal CSI
S1600 operating a node to produce a high signal quality at the UE and a low signal strength at the terminal, which is a UE-terminal S1610 transmitting, by the node, a pilot signal S1700 operating a UE as a terminal (UE-terminal) at the location S1720 receiving, by the UE-terminal, a pilot signal from the node S1730 determining the terminal CSI based on the pilot signal received from the node S1800 operating the node to produce a high signal quality at another UE and a low signal strength at the terminal, which is the UE-terminal
51850 transmitting, by the node, a radio frequency, RF, signal based on a UE CSI and a terminal CSI
51851 beam shaping based on the UE CSI and the terminal CSI