Patent Application
20240388881
The present disclosure relates to communication control technology in wireless communication system.
The number, types, and applications of wireless communication devices, represented by smartphones and Internet of Things (IoT) devices, continue to increase, and wireless communication standards continue to be expanded and improved. For example, the commercial service of the fifth generation mobile communication system known as “5G” started in 2018, and the standards are still being developed by the 3GPP (Third Generation Partnership Project). Efforts are also underway to develop standards for “6G” or the sixth generation mobile communication system, which would be the next generation of wireless communication standards following 5G.
Mobile communication networks for portable communication devices such as smartphones and cell phones (hereinafter collectively referred to as communication device(s)) are usually constructed by communication cells (hereinafter referred to as terrestrial communication cell(s) or fixed communication cell(s)) provided by base stations statically installed on the ground (hereinafter referred to as terrestrial base station(s) or fixed base station(s)). However, mobile communication cannot be performed outside fixed communication cells, and the quality of mobile communications might be low depending on time and/or place even within fixed communication cells.
To solve these problems, moving stations are being considered to supplement the fixed communication cells provided by the fixed base stations. Possible moving stations are assumed to be something like a communication satellite that itself functions as a base station (hereinafter referred to as a moving base station) or something like a repeater that communicates with an existing fixed base station to expand an existing fixed communication cell (hereinafter referred to as a relay station).
The inventor recognized the issue that moving stations can move between different emergency information distribution areas, while fixed base stations, which are stationarily installed on the ground, statically belong to specific emergency information distribution areas. In conventional wireless communication standards represented by 5G, emergency information distribution cannot be appropriately performed by such moving stations.
The present disclosure was made in consideration of this situation, and its purpose is to provide a communication control apparatus etc. that can appropriately perform emergency information distribution by a moving station.
In order to solve the above problem, a communication control apparatus in a certain aspect of the present disclosure comprises at least one processor that performs: by an emergency information distribution area estimation unit, estimating an emergency information distribution area where a moving station capable of communicating with a communication device is located; and by an emergency information distribution control unit, having the moving station distribute emergency information for the estimated emergency information distribution area.
According to this aspect, emergency information distribution by the moving station can be appropriately performed based on the estimation result of the emergency information distribution area where the moving station is located.
Another aspect of the present disclosure is a communication control method. The method comprises: estimating an emergency information distribution area where a moving station capable of communicating with a communication device is located; and having the moving station distribute emergency information for the estimated emergency information distribution area.
Further another aspect of the present disclosure is a computer-readable medium. The computer-readable medium stores a communication control program causing a computer to perform: estimating an emergency information distribution area where a moving station capable of communicating with a communication device is located; and having the moving station distribute emergency information for the estimated emergency information distribution area.
In addition, any combination of the above components, and any conversion of the expression of the present disclosure among methods, devices, systems, recording media, computer programs and the like are also encompassed within this disclosure.
According to the present disclosure, emergency information distribution by a moving station can be appropriately performed.
The 5G wireless communication system 11 may include a plurality of 5G base stations 111A, 111B, and 111C (hereinafter collectively referred to as 5G base station 111) installed on the ground capable of communicating by 5G NR with communication devices or communication devices 2A, 2B, 2C, and 2D (hereinafter collectively referred to as communication device(s) 2) such as smartphones, which are also referred to as UE (User Equipment). 5G base station 111 is also referred to as gNodeB (gNB). The coverage or support range of each 5G base station 111A, 111B and 111C is referred to as a cell 112A, 112B and 112C (hereinafter collectively referred to as 5G cell 112).
The size of the 5G cell 112 of each 5G base station 111 is arbitrary, but typically ranges from a few meters to several tens of kilometers in radius. Although there is no established definition, cells with a radius of a few meters to ten meters are called femtocells, cells with a radius of ten meters to several tens of meters are called picocells, cells with a radius of several tens of meters to several hundred meters are called microcells, and cells with a radius of more than several hundreds of meters are called macrocells. In 5G, high frequency radio waves such as millimeter waves are often used, and their high tendency to propagate in a straight-line causes radio waves to be blocked by obstacles, shortening the communication distance. For this reason, 5G tends to use more small cells than 4G and earlier generations.
The communication device 2 can conduct 5G communication when it is located within at least one of a plurality of 5G cells 112A, 112B and 112C. In the example shown in the figure, communication device 2B in 5G cells 112A and 112B can communicate with both 5G base stations 111A and 111B by 5G NR. In addition, the communication device 2C in the 5G cell 112C can communicate with the 5G base station 111C by 5G NR. Communication device 2A and 2D are outside of all 5G cells 112A, 112B and 112C, so they are not able to communicate by 5G NR. The 5G NR-based 5G communication between each communication device 2 and each 5G base station 111 is managed by the 5GC, which is the core network. For example, the 5GC transfers data to and from each 5G base station 111, transfers data to and from external networks such as the EPC, the satellite communication system 13 and the Internet, and manages the movement of the communication device 2.
The 4G wireless communication system 12 comprises a plurality of 4G base stations 121 (only one of them is shown in
The communication device 2 can conduct 4G communication when it is located within 4G cell 122. In the example shown in the figure, the communication devices 2A and 2B in the 4G cell 122 can communicate with the 4G base station 121 by LTE or LTE-Advanced. Communication device 2C and 2D are outside the 4G cell 122 and are not able to communicate by LTE or LTE-Advanced. The 4G communication by LTE and LTE-Advanced between each communication device 2 and each 4G base station 121 is managed by the EPC, which is the core network. For example, the EPC manages the transfer of data to and from each 4G base station 121, the transfer of data to and from external networks such as 5GC, the satellite communication system 13 and the Internet, and the movement management of the communication device 2.
If we take a look at each communication device 2A, 2B, 2C and 2D in the example shown in the figure, the communication device 2A is in a state that enables 4G communication with 4G base station 121, and communication device 2B is in a state that enables 5G communication with 5G base stations 111A and 111B and 4G communication with 4G base station 121, and communication device 2C is in a state that enables 5G communication with 5G base station 111C. When there are multiple base stations (111A, 111B and 121) as in the case of communication device 2B, one base station is selected as the most suitable for the communication device 2B in terms of communication quality etc., under the control of the 5GC and/or the EPC, which is the core network. For the communication device 2D that is not in a state that enables 5G communication with any 5G base station 111 or 4G communication with any 4G base station 121, the communication is conducted using the satellite communication system 13 described below.
The satellite communication system 13 is the wireless communication system using communication satellites 131 as non-terrestrial base stations. The communication satellites 131 are low-earth-orbit satellites flying in low-earth-orbit outer space of 500 to 700 km above the ground. Similar to 5G base station 111 and 4G base station 121, the communication range or support range of each communication satellite 131 is also called a cell and is shown as 132. Thus, a communication satellite 131 as a non-terrestrial base station provides a satellite communication cell 132 as a non-terrestrial communication cell onto the ground. Communication device 2 on the ground can conduct satellite communication when it is inside the satellite communication cell 132. Similar to 5G base station 111 in the 5G wireless communication system 11 and 4G base station 121 in the 4G wireless communication system 12, communication satellite 131 as the base station in the satellite communication system 13 is capable of wireless communication directly or indirectly via aircraft etc. with the communication device 2 within the satellite communication cell 132. The radio access technology used by the communication satellite 131 for wireless communication with the communication device 2 in the satellite communication cell 132 may be 5G NR, the same as the 5G base station 111, or LTE or LTE-Advanced, the same as the 4G base station 121, or any other radio access technology that the communication device 2 can use. Therefore, there is no need for the communication device 2 to have any special functions or components for satellite communication.
The satellite communication system 13 is equipped with a gateway 133 as a ground station that is installed on the ground and can communicate with the communication satellite 131. The gateway 133 is equipped with a satellite antenna to communicate with the communication satellite 131, and is connected to the 5G base station 111 and the 4G base station 121 as terrestrial base stations that constitute the terrestrial network (TN). In this way, the gateway 133 connects the non-terrestrial network (NTN), which is comprising communication satellites 131 as a non-terrestrial base station or a satellite base station, and the terrestrial network TN, which is comprising terrestrial base stations 111 and 121, for mutual communication. When the communication satellite 131 conducts 5G communication with the communication device 2 in the satellite communication cell 132 by 5G NR, the 5GC connected via the gateway 133 and the 5G base station 111 in the TN (or the 5G radio access network) is used as the core network. When the communication satellite 131 conducts 4G communication with the communication device 2 in the satellite communication cell 132 by LTE or LTE-Advanced, the EPC connected via the gateway 133 and the 4G base station 121 in the TN (or the 4G radio access network) is used as the core network. In this way, appropriate coordination is made between different wireless communication systems such as 5G wireless communication system 11, 4G wireless communication system 12, satellite communication system 13 etc. through the gateway 133.
Satellite communication by communication satellites 131 is mainly used for covering areas with no or few terrestrial base stations such as 5G base stations 111 and 4G base stations 121 etc. In the example shown in the figure, a communication device 2D that is outside the communication cells of all the terrestrial base stations communicates with the communication satellite 131. On the other hand, communication devices 2A, 2B and 2C that are in good communication with either of the terrestrial base stations, are also in the satellite communication cell 132 and can communicate with the communication satellite 131. However, by communicating with the terrestrial base stations instead of the communication satellite 131 as the satellite base station in principle, the limited communication resources (including power) of the communication satellite 131 are saved for the communication device 2D etc. The communication satellite 131 uses beamforming to direct the communication radio wave to the communication device 2D in the satellite communication cell 132, thereby the communication quality with the communication device 2D is improved.
The size of the satellite communication cell 132 of the communication satellite 131 as a satellite base station depends on the number of beams emitted by the communication satellite 131. For example, a satellite communication cell 132 with a diameter of about 24 km can be formed by combining up to 2, 800 beams. As illustrated, a satellite communication cell 132 is typically larger than a terrestrial communication cell such as a 5G cell 112 or a 4G cell 122, and could contain one or more 5G cells 112 and/or 4G cells 122 inside it. The above example shows a communication satellite 131 flying in low-earth-orbit outer space at a height of about 500 km to 700 km above the ground as a flying non-terrestrial base station. However, a communication satellite flying in geostationary orbit or other higher orbit in outer space, or an unmanned or manned aircraft flying in stratosphere or other lower (e.g. about 20 km above the ground) atmosphere may be used as a non-terrestrial base station in addition to or instead of the communication satellite 131.
As shown in
To solve these problems, as schematically shown in
IAB is a technology specified in 5G to expand a communication cell of a parent node, utilizing wireless backhaul between a base station that serves as an IAB donor (parent node) and an IAB node (child node) and/or between parent and child IAB nodes (where an IAB node closer to the IAB donor is the parent node, and an IAB node far from the IAB donor is the child node). Here, “expansion of a communication cell” includes not only expanding the area covered by an existing communication cell, but also improving the communication quality of at least part of an existing communication cell. Furthermore, “expansion of the area covered by a communication cell” includes not only expanding the area in the horizontal plane of an existing communication cell, but also expanding an existing communication cell vertically, e.g. underground or to the upper and/or lower floors of a building.
In
Two fixed base stations FS1 and FS2 are illustrated in
The communication-device functional unit 34 (IAB-MT) of the moving station MS, depending on the position of the moving station MS, can connect wirelessly with the distributed unit DU of either fixed base station FS. In the example in
The moving station MS is attached to a movable object, except when it can move (or fly) autonomously like the communications satellite 131. A movable object is any movable thing or person and includes, for example, automobiles, trains, motorcycles, bicycles, airplanes, ships, and any other vehicles. The moving station MS may be a communication device 2 used by a moving person, for example, a communication device 2 equipped with a tethering function and/or personal hotspot function. Since such a communication device 2 (moving station MS) usually functions as a wireless LAN access point, the RAT (e.g. 5G NR) used by the base station to be expanded (e.g. the second fixed base station FS2) and the RAT used by the expanding moving station MS may be different.
The inventor recognized the issue that moving stations MS can move between different emergency information distribution areas (EA1, EA2 described below), while fixed base stations FS1, FS2, which are stationarily installed on the ground, statically belong to specific emergency information distribution areas. As described below, in conventional wireless communication standards represented by 5G, emergency information distribution cannot be appropriately performed by such moving stations MS.
An emergency information distribution area is an area where emergency information concerning earthquake, tsunami and other disasters etc. is distributed simultaneously or broadcasted. A system that distributes emergency information is called a public warning system (PWS), and also an earthquake and tsunami warning system (ETWS) especially if it distributes warnings about disasters such as earthquakes and tsunamis. Emergency information distribution areas are generally set up in units of administrative divisions such as cities, wards, towns and villages. Each fixed base station FS1, FS2 stationarily installed on the ground belongs to the emergency information distribution area set up in the administrative division of the place where it is installed. In the example in
The emergency information distribution system simultaneously distributes emergency information to all communication devices UE in the emergency information distribution area where disasters or other emergencies have occurred. Specifically, when a disaster etc. occurs in the first emergency information distribution area EA1, the first fixed base station FS1 belonging to the first emergency information distribution area EA1 simultaneously distributes emergency information to all communication devices UE in the first fixed communication cell FC1. Similarly, when a disaster etc. occurs in the second emergency information distribution area EA2, the second fixed base station FS2 belonging to the second emergency information distribution area EA2 simultaneously distributes emergency information to all communication devices UE in the second fixed communication cell FC2.
As such, the fixed base stations FS1, FS2 fixedly installed on the ground are fixedly associated with the specific emergency information distribution areas EA1, EA2, can appropriately perform emergency information distribution in each of the emergency information distribution areas EA1, EA2. On the other hand, the moving station MS can move among different emergency information distribution areas EA1 and EA2. Therefore, it is necessary to appropriately switch the emergency information distribution areas EA1 and EA2 for distributing emergency information depending on the location and/or the situation of the moving station MS. Thus, the main purpose of this embodiment is to provide a communication control apparatus 3 that can properly perform emergency information distribution by the moving station MS.
The communication control apparatus 3 comprises an emergency information distribution area estimation unit 31, an emergency information distribution control unit 32, an area placement information acquisition unit 33, a communication-device functional unit 34, a base-station functional unit 35, positioning unit 36, and a communication quality comparison unit 37. Some of these functional blocks can be omitted as long as the communication control apparatus 3 realizes at least some of the operations and/or effects described below. These functional blocks are realized by the cooperation of hardware resources, such as the central processing unit, memory, input devices, output devices, and peripheral devices connected to the computer, and software that is executed using them. Regardless of the type of computer or its installation location, each of the above functional blocks may be realized with the hardware resources of a single computer, or by combining hardware resources distributed across multiple computers. Especially in this embodiment, some or all of functional blocks of the communication control apparatus 3 may be realized in a centralized or distributed manner by computer and/or processor provided in the communication device UE, the moving station MS (including the movable object), the distributed unit DU1, DU2, the central unit CU, and the core network CN. In the example in
The emergency information distribution area estimation unit 31 provided in the central unit CU estimates an emergency information distribution area where the moving station MS is located. The emergency information distribution control unit 32 provided in the central unit CU has the moving station MS distribute emergency information for the emergency information distribution area estimated by the emergency information distribution area estimation unit 31. If the emergency information distribution area estimation unit 31 estimates that the moving station MS is located in the first emergency information distribution area EA1, the emergency information distribution control unit 32 has the moving station MS distribute emergency information for the first emergency information distribution area EA1. If the emergency information distribution area estimation unit 31 estimates that the moving station MS is located in the second emergency information distribution area EA2, the emergency information distribution control unit 32 has the moving station MS distribute emergency information for the second emergency information distribution area EA2.
The method by which the emergency information distribution area estimation unit 31 estimates the emergency information distribution area in which the moving station MS is located is arbitrary, but some specific examples are shown below.
In the first example, the emergency information distribution area estimation unit 31 estimates that the moving station MS is located in the emergency information distribution area EA to which the fixed base station FS to which the moving station MS is connected belongs. In the example shown in
In the example in
In the second example, the emergency information distribution area estimation unit 31 estimates the emergency information distribution area EA where the moving station MS is located, based on the placement information of the emergency information distribution area EA acquired by the area placement information acquisition unit 33, and the position of the moving station MS measured by the positioning unit 36. The area placement information acquisition unit 33 acquires placement information, such as the coverage area and/or boundaries of each emergency information distribution area EA, from the core network CN side. The positioning unit 36 measures the position of the moving station MS based on, for example, a satellite positioning system such as GPS (Global Positioning System) and GNSS (Global Navigation Satellite System). The positioning unit 36 may be mounted on the moving station MS, on the movable object to which the moving station MS is attached, or on a communication device 2 or other devices carried by a person boarding the moving station MS. Furthermore, the positioning unit 36 may estimate or measure the position of the moving station MS, utilizing information collection and/or information analysis functions such as an NWDAF (Network Data Analytics Function) and/or an LMF (Location Management Function) of the core network CN, and/or various information that can be referenced in the application layer. By comparing the placement information of the emergency information distribution area EA obtained by the area placement information acquisition unit 33 and the position of the moving station MS measured by the positioning unit 36, the emergency information distribution area estimation unit 31 can estimate the emergency information distribution area EA in which the moving station MS is located.
In this example, it is assumed that the emergency information distribution area estimation unit 31 estimates that the moving station MS is located in the first emergency information distribution area EA1. Then, the emergency information distribution control unit 32 has the base-station functional unit 35 of the moving station MS distribute emergency information for the first emergency information distribution area EA1. At this time, as mentioned above, since the communication-device functional unit 34 of the moving station MS is connected to the second distributed unit DU2 of the second fixed base station FS2, the emergency information for the first emergency information distribution area EA1 generated on the core network CN side is distributed from the fixed base station (FS2) belonging to the different emergency information distribution area (EA2) to the moving station MS. In this way, the second fixed base station FS2 forwards the emergency information for the first emergency information distribution area EA1 to the moving station MS. However, since the second fixed base station FS2 itself belongs to the second emergency information distribution area EA2 different from the first emergency information distribution area EA1, it does not distribute this emergency information to communication devices UE. It should be noted that the first fixed base station FS1 belonging to the first emergency information distribution area EA1 distributes the emergency information to communication devices UE in the same manner as moving station MS. As described above, according to this example, the emergency information distribution control unit 32 can have the moving station MS distribute the emergency information acquired from the fixed station (FS2) to which the moving station MS is connected, for the emergency information distribution area (EA1) different from the emergency information distribution area (EA2) to which the fixed station (FS2) belongs.
In the third example, the emergency information distribution area estimation unit 31 estimates that the moving station MS is located in the emergency information distribution area EA to which the fixed base station FS with the highest communication quality for the moving station MS among the plurality of fixed base stations FS belongs. The communication quality of the plurality of fixed base stations FS around the moving station MS is measured and compared by the communication quality comparison unit 37 provided in the moving station MS and/or the movable object. Here, it is assumed that the communication quality comparison unit 37 determines that the communication quality for the moving station MS is the highest by the second fixed base stations FS2 among the shown two fixed base stations FS1 and FS2, and the emergency information distribution area estimation unit 31 estimates that the moving station MS is located in the second emergency information distribution area EA2 to which the second fixed base station FS2 belongs. Then, the emergency information distribution control unit 32 has the base-station functional unit 35 of the moving station MS distribute emergency information for the second emergency information distribution area EA2. The emergency information distributed by the base-station functional unit 35 of the moving station MS is generated on the core network CN side, and distributed to the second distributed unit DU2 of the second fixed base station FS2. The emergency information is then distributed from the second distributed unit DU2 to the communication-device functional unit 34 of the moving station MS, and distributed to the communication device UE by the base-station functional unit 35 of the moving station MS. In this way, the moving station MS redistributes the emergency information obtained from the fixed base station FS by the communication-device functional unit 34 through the base-station functional unit 35.
It should be noted that, when the emergency information distribution area estimation unit 31 estimates that the moving station MS is located in the second emergency information distribution area EA2 to which the second fixed base station FS2 belongs, the communication-device functional unit 34 of the moving station MS may be connected to the first distributed unit DU1 of the first fixed base station FS1. In this case, the emergency information for the second emergency information distribution area EA2 generated on the core network CN side is distributed from the fixed base station (FS1) belonging to the different emergency information distribution area (EA1) to the moving station MS. In this way, the first fixed base station FS1 forwards the emergency information for the second emergency information distribution area EA2 to the moving station MS. However, since the first fixed base station FS1 itself belongs to the first emergency information distribution area EA1 different from the second emergency information distribution area EA2, it does not distribute this emergency information to communication devices UE. It should be noted that the second fixed base station FS2 belonging to the second emergency information distribution area EA2 distributes the emergency information to communication devices UE in the same manner as moving station MS. As described above, according to this example, the emergency information distribution control unit 32 can have the moving station MS distribute the emergency information acquired from the fixed station (FS1) to which the moving station MS is connected, for the emergency information distribution area (EA2) different from the emergency information distribution area (EA1) to which the fixed station (FS1) belongs.
The moving base station MS, which can communicate directly with the core network CN and the communication device UE, can be equipped with all the functional blocks of the communication control apparatus 3. Note that the communication-device functional unit 34 (IAB-MT) and the base-station functional unit 35 (IAB-DU), which were provided in
The emergency information distribution area estimation unit 31 may estimate the emergency information distribution area EA where the moving base station MS is located, based on the placement information of the emergency information distribution area EA acquired by the area placement information acquisition unit 33, and the position of the moving base station MS measured by the positioning unit 36. Besides, the emergency information distribution area estimation unit 31 may estimate that the moving base station MS is located in the emergency information distribution area EA to which the fixed base station FS with the highest communication quality measured by the communication quality comparison unit 37 among the plurality of fixed base stations FS belongs. The emergency information distribution control unit 32 has the moving base station MS distribute emergency information (generated by the core network CN and/or the moving base station MS) for the emergency information distribution area EA estimated by the emergency information distribution area estimation unit 31.
However, the emergency information distribution control unit 32 may determine whether or not to allow the relay station RN, which has received the emergency information for the second emergency information distribution area EA2 from the second fixed base station FS2, to redistribute this emergency information, according to the estimation result of the emergency information distribution area estimation unit 31. For example, if the emergency information distribution area estimation unit 31 estimates that the relay station RN is located in the first emergency information distribution area EA1, the emergency information distribution control unit 32 does not allow the relay station RN, which has received the emergency information for the second emergency information distribution area EA2 from the second fixed base station FS2, to redistribute this emergency information. It should be noted that some or all of the functional blocks such as the emergency information distribution area estimation unit 31, the emergency information distribution control unit 32, the area placement information acquisition unit 33 to control the emergency information distribution by the relay station RN, may be provided in the fixed base station (FS2) and/or the distributed unit (DU2) to which the relay station RN is connected, or in the relay station RN itself.
The present disclosure has been described above based on embodiments. It is understood by those skilled in the art that the embodiments are exemplary and that various variations are possible in the combination of each component and each process thereof, and that such variations are also within the scope of the present disclosure.
The functional configuration of each device described in the embodiment can be realized by hardware resources or software resources, or by the cooperation of hardware resources and software resources. As hardware resources, processors, ROM, RAM, and other LSIs can be used. Operating systems, applications, and other programs can be used as software resources.
The present disclosure may be expressed as the following items.
1. A communication control apparatus comprising at least one processor that performs:
This application claims priority of Japanese patent application 2022-015791, filed on Feb. 3, 2022, which is hereby incorporated by reference in its entirety.
The present disclosure relates to communication control technology in wireless communication system.
1 wireless communication system, 2 communication device, 3 communication control apparatus, 11 5G wireless communication system, 12 4G wireless communication system, 13 satellite communication system, 31 emergency information distribution area estimation unit, 32 emergency information distribution control unit, 33 area placement information acquisition unit, 34 communication-device functional unit, 35 base-station functional unit, 36 positioning unit, 37 communication quality comparison unit.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2022-015791 | Feb 2022 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2022/012047 | 3/16/2022 | WO |
