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EP-4398657-B1 - COMMUNICATION CONTROL DEVICE, COMMUNICATION CONTROL METHOD, AND COMMUNICATION CONTROL PROGRAM

EP4398657B1EP 4398657 B1EP4398657 B1EP 4398657B1EP-4398657-B1

Inventors

  • MUHAMMAD Awn
  • SHETE Pankaj

Dates

Publication Date
20260513
Application Date
20211111

Claims (12)

  1. A communication control apparatus configured to control a terrestrial network, TN, comprising a terrestrial base station (111) installed on the ground and capable of communicating with a communication device (2B, 2C, 2D) in a terrestrial communication cell provided by the terrestrial base station (111) on the ground by means of time-continuous TN data, and, a non-terrestrial network, NTN, comprising a flying base station (131) and capable of communicating with a communication device in a flying communication cell (132) provided by the flying base station on the ground by means of time-continuous NTN data, comprising: a signal strength reduction unit (31) configured to reduce signal strength of at least portion of at least one of the TN data and the NTN data at least in an overlapping area of the terrestrial communication cell and the flying communication cell; a communication delay acquisition unit (33) configured to acquire communication delay between the flying base station and the flying communication cell; and a synchronization unit (34) configured to synchronize the TN data and the NTN data based on the communication delay acquired by the communication delay acquisition unit, said apparatus further comprising an ephemeris information acquisition unit (32) configured to acquire ephemeris information of the flying base station, and a flying communication cell position acquisition unit that acquires representative position information of the flying communication cell, wherein the communication delay acquisition unit is configured to calculate the communication delay between the flying base station and the flying communication cell, based on the representative position information of the flying communication cell acquired by the flying communication cell position acquisition unit and the ephemeris information of the flying base station acquired by the ephemeris information acquisition unit, and the synchronization unit is configured to cause the flying base station to transmit the NTN data earlier than the TN data transmitted by the terrestrial base station by the communication delay calculated by the communication delay acquisition unit, wherein the representative position information of the satellite communication cell is the position information of the center of the satellite communication cell.
  2. The communication control apparatus according to claim 1, wherein the signal strength reduction unit (31) is configured to prohibit transmission of signal by a portion of at least one of the TN data and the NTN data at least in the overlapping area of the terrestrial communication cell and the flying communication cell.
  3. The communication control apparatus according to claim 1 or 2, wherein the signal strength reduction unit (31) is configured to reduce signal strength of at least portion of the TN data at least in the overlapping area of the terrestrial communication cell and the flying communication cell.
  4. The communication control apparatus according to claim 3, wherein the flying base station communicates with communication device in the overlapping area of the terrestrial communication cell and the flying communication cell by means of the NTN data while the signal strength reduction unit (31) is configured to reduce signal strength of the TN data.
  5. The communication control apparatus according to any of claims 1 to 4, wherein the signal strength reduction unit (31) is configured to reduce signal strength of the data according to a predetermined pattern that specifies a portion of data included in a data group.
  6. The communication control apparatus according to any of claims 1 to 5, further comprising an ephemeris information acquisition unit (32) configured to acquire ephemeris information of the flying base station, wherein in case the communication delay acquisition unit is provided in a communication device comprising a positioning sensor that can measure its own position information, the communication delay acquisition unit is configured to calculate the communication delay between the flying base station and the communication device in the flying communication cell, based on the position information of the communication device measured by the positioning sensor and the ephemeris information of the flying base station acquired by the ephemeris information acquisition unit, and the synchronization unit (34) is configured to cause the flying base station to transmit the NTN data earlier than the TN data transmitted by the terrestrial base station by the communication delay calculated by the communication delay acquisition unit.
  7. The communication control apparatus according to any of claims 1 to 6, wherein the synchronization unit is provided in the terrestrial base station, and configured to cause terrestrial base station to delay the start of transmission of the TN data by the communication delay acquired by the communication delay acquisition unit, after the flying base station starts transmission of the NTN data.
  8. The communication control apparatus according to any of claims 1 to 7, wherein a gateway capable (133) of communicating with both the flying base station and the terrestrial base station is installed on the ground, and the communication delay acquisition unit is configured too acquire the delay of the gateway's communication with the flying communication cell via the flying base station.
  9. The communication control apparatus according to claim 8, wherein the communication delay acquisition unit is provided in the terrestrial base station connected to the gateway.
  10. The communication control apparatus according to claim 9, further comprising an ephemeris information acquisition unit configured to acquire ephemeris information of the flying base station, wherein the communication delay acquisition unit is configured to calculate the communication delay between the gateway and the flying base station, based on the ephemeris information of the flying base station acquired by the ephemeris information acquisition unit.
  11. A communication control method that controls a terrestrial network, TN, comprising a terrestrial base station installed on the ground and capable of communicating with a communication device in a terrestrial communication cell provided by the terrestrial base station on the ground by means of time-continuous TN data, and, a non-terrestrial network, NTN, comprising a flying base station and capable of communicating with a communication device in a flying communication cell provided by the flying base station on the ground by means of time-continuous NTN data, comprising: reducing signal strength of at least portion of at least one of the TN data and the NTN data at least in an overlapping area of the terrestrial communication cell and the flying communication cell; acquiring communication delay between the flying base station and the flying communication cell; and synchronizing the TN data and the NTN data based on the acquired communication delay, said method further comprising acquiring, by an ephemeris information acquisition unit, ephemeris information of the flying base station, and acquiring, by a flying communication cell position acquisition unit, representative position information of the flying communication cell, calculating, by a communication delay acquisition unit, communication delay between the flying base station and the flying communication cell, based on the representative position information of the flying communication cell acquired by the flying communication cell position acquisition unit and the ephemeris information of the flying base station acquired by the ephemeris information acquisition unit, and causing, by a synchronization unit, the flying base station to transmit the NTN data earlier than the TN data transmitted by the terrestrial base station by the communication delay calculated by the communication delay acquisition unit, wherein the representative position information of the satellite communication cell is the position information of the center of the satellite communication cell.
  12. A communication control program that controls a terrestrial network, TN, comprising a terrestrial base station installed on the ground and capable of communicating with a communication device in a terrestrial communication cell provided by the terrestrial base station on the ground by means of time-continuous TN data, and, a non-terrestrial network, NTN, comprising a flying base station and capable of communicating with a communication device in a flying communication cell provided by the flying base station on the ground by means of time-continuous NTN data, causing a computer to perform the method according to claim 11.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present disclosure relates to communication control technology in communication system. 2. Description of the Related Art 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 mobile or 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)") provided by base stations installed on the ground (hereinafter referred to as "terrestrial base station(s)"). However, in some areas, it was difficult to install a sufficient number of terrestrial base stations for various reasons, resulting in a relatively low quality of mobile communications. JP6704438B2 discloses a communication system in which a large NTN cell overlaps a smaller TN cell. By using almost blank subframes (ABS) the interference between the NTN BS and the TN BS is controlled. In order to solve the issue of the disparity in mobile communication quality among different regions and the so-called "out-of-range" issue, where mobile communication devices cannot communicate in some regions, non-terrestrial networks (NTN) have been considered. In NTN, communication satellites or unmanned aircrafts flying in outer space or the atmosphere, such as the stratosphere, are used as base stations (hereinafter referred to as flying base station(s), and especially communication satellites are referred to as satellite base station(s)). The flying base station provides a communication cell on the ground (hereinafter referred to as flying communication cell(s), and especially communication cells provided by communication satellites are referred to as satellite communication cell(s)). A communication device in a flying communication cell communicates with a flying base station directly or indirectly via other communication devices. By providing flying communication cells in areas where terrestrial communication cells are not sufficient, the quality of mobile communication in such areas can be improved. Patent Literature 1: JP-A-2010-278886 SUMMARY OF THE INVENTION The invention is set out in the appended independent claims, with further embodiments provided in the dependent claims. Terrestrial communication cell and flying communication cell provided on the ground by terrestrial base station and flying base station may overlap each other. When such terrestrial communication cell and flying communication cell use overlapping or adjacent frequency bands, if terrestrial communication radio waves from a terrestrial base station and flying communication radio waves from a flying base station interfere with each other in the overlapping area of the communication cells, a communication device in the overlapping area may not be able to communicate with one or both of the terrestrial base station and the flying base station. In addition, flying base stations such as communication satellites and unmanned aircrafts cause significant communication delays or propagation delays because of the greater distance from communication device compared to terrestrial base stations installed on the ground. Thus, the inventor recognized that interference and delay between the TN and the NTN must be considered in a communication system where a terrestrial network (TN) and a non-terrestrial network coexist. The present disclosure was made in view of the circumstances, and its purpose is to provide a communication control apparatus and the like which consider interference and delay between TN and NTN. In order to solve the above issue, a communication control apparatus in a certain aspect of the present disclosure that controls a terrestrial network including a terrestrial base station installed on the ground and capable of communicating with a communication device in a terrestrial communication cell provided by the terrestrial base station on the ground by means of time-continuous TN data, and, a non-terrestrial network including a flying base station and capable of communicating with a communication device in a flying communication cell provided by the flying base station on the ground by means of time-continuous NTN data, includes: a signal strength reduction unit that reduces signal strength of at least portion of at least one of the TN data an