CN113411119B - GMR-1-based low-orbit satellite narrow-band communication system switching method - Google Patents
GMR-1-based low-orbit satellite narrow-band communication system switching method Download PDFInfo
- Publication number
- CN113411119B CN113411119B CN202110715541.2A CN202110715541A CN113411119B CN 113411119 B CN113411119 B CN 113411119B CN 202110715541 A CN202110715541 A CN 202110715541A CN 113411119 B CN113411119 B CN 113411119B
- Authority
- CN
- China
- Prior art keywords
- terminal
- switching
- base station
- channel
- service
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B7/00—Radio transmission systems, i.e. using radiation field
- H04B7/14—Relay systems
- H04B7/15—Active relay systems
- H04B7/185—Space-based or airborne stations; Stations for satellite systems
- H04B7/1851—Systems using a satellite or space-based relay
- H04B7/18519—Operations control, administration or maintenance
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B7/00—Radio transmission systems, i.e. using radiation field
- H04B7/14—Relay systems
- H04B7/15—Active relay systems
- H04B7/185—Space-based or airborne stations; Stations for satellite systems
- H04B7/1853—Satellite systems for providing telephony service to a mobile station, i.e. mobile satellite service
- H04B7/18539—Arrangements for managing radio, resources, i.e. for establishing or releasing a connection
- H04B7/18541—Arrangements for managing radio, resources, i.e. for establishing or releasing a connection for handover of resources
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Astronomy & Astrophysics (AREA)
- Aviation & Aerospace Engineering (AREA)
- General Physics & Mathematics (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Mobile Radio Communication Systems (AREA)
- Radio Relay Systems (AREA)
Abstract
The invention discloses a GMR-1-based switching method for a low-orbit satellite narrow-band communication system, which transmits synchronization, position and switching control signaling on a channel associated channel and specifically comprises the following steps: transmitting synchronous control signaling content along with the channel while transmitting data in a service channel, wherein the synchronous control signaling content is used for adjusting the time frequency offset of an uplink signal of a user in real time; while transmitting data in the service channel, transmitting the terminal position information along with the channel to realize the service switching control based on the user position information; when the service channel transmits data, the channel is used to transmit the switch control command for switching in the service communication. When the terminal is switched between different beams or different channels of the same satellite, a synchronous switching process is realized, and when the terminal is switched between different satellites, an asynchronous switching process is realized. The invention meets the requirement of fast switching of the low-orbit satellite communication system.
Description
Technical Field
The invention relates to the technical field of low-orbit narrow-band communication systems, in particular to a GMR-1-based switching method for a low-orbit satellite narrow-band communication system.
Background
The low-orbit narrow-band satellite communication system is a satellite communication system for forwarding signals through a low-orbit constellation, is different from a broadband satellite communication system, and a user link of the low-orbit narrow-band satellite communication system mainly works in an L, S frequency band and can support a miniaturized portable terminal. Currently, low orbit constellation satellite communication systems built in the world mainly include Iridium, GlobalStar and the like, and China mainly includes systems such as rainbow clouds and swan gooses. Generally, a low orbit constellation satellite communication system is composed of three parts, i.e., a low orbit constellation, a gateway station, and a user terminal, as shown in fig. 1, (1) the low orbit constellation: the low orbit constellation is composed of a plurality of LEO satellites distributed on the same orbit at different heights, each satellite realizes efficient utilization of user link spectrum resources through multi-beam, all satellites in the constellation are interconnected through inter-satellite links, and the satellites are responsible for maintaining inter-satellite links among themselves and feeder links among gateway stations and system control sections, as shown in fig. 2. (2) A gateway station: the gateway station is used as an important component of the low earth orbit constellation satellite communication system, completes the functions of satellite load management, service processing, network management, operation management, service settlement and the like of the low earth orbit constellation satellite communication system, and is responsible for interconnection and intercommunication of the low earth orbit constellation satellite communication system and ground systems such as PSTN, PLMN and the like. (3) The user terminal: the user terminal is composed of various handheld, portable and vehicle-mounted terminals distributed in the coverage range of the low-orbit constellation wave beam, the terminals are portals and application platforms of a user access low-orbit constellation satellite communication system and are used for establishing data transmission links between the user and the satellite, and each terminal has switching capacity among the wave beams, between the satellites and among the gateways and can provide continuous service for the user.
In order to evaluate the dynamic characteristics of the feed link signals, an iridium constellation satellite system simulation scene is constructed by using STK, and the dynamic characteristics of the electrical receiving signals are simulated by taking the place in Beijing as reference electricity. 1) Frequency dynamics of the signal: from simulation fig. 3 and 4, it can be known that the user link signal doppler is up to 50KHz, the signal change rate is 0.45KHz/s, and the signal has high dynamic characteristics relative to the signal bandwidth adopted by the low-track narrow band. 2) Time delay characteristic of signal: since the constellation satellite moves at a high speed relative to the ground, the dynamic characteristic of the user link signal frequency is introduced, and the change of the user link propagation delay is caused at the same time, and fig. 5 shows a simulation diagram of the change of the feed link delay when the satellite and the gateway station are visible. According to the simulation diagram, due to the change of the propagation distance of the feeder link introduced by the motion of the constellation satellite relative to the gateway station, the propagation delay of the user link is regularly changed within the range of 2.6-8.6 ms, and the estimated maximum time change rate is 0.025 ms/s. From the analysis of the time delay and frequency variation of the user link, in the terminal communication process, the uplink timing and frequency of the terminal need to be continuously adjusted to ensure the synchronization with the network side.
GMR-1 is the narrow-band GSO satellite mobile communication standard established by ETSI, and the working frequency band is L/S. The standard is derived from the 3GPP series terrestrial digital cellular standard GSM and supports access to the GSM/UMTS core network. ACeS, skytetrara, TerreStar and Thuraya all use the GMR-1 series of standards. The GMR-1 system consists of elements such as satellite, Earth mobile station mes (mobile Earth station), gateway station gs (gateway station), and satellite operation center soc (satellite operation center), and between mobile subscribers and fixed subscribers, the GMR-1 system provides GSM basic services such as voice, data transmission, fax, point-to-point short message service, and cell broadcast short message service and value added service. The GMR-1 system may implement worldwide interconnections through public and private switched telecommunications networks such as the Public Switched Telephone Network (PSTN), Public Land Mobile Network (PLMN), and a diagram of the components of the GMR-1 system is shown in fig. 6. GMR-1 defines three traffic channels and associated dedicated control channels, as shown in Table 1. The special control channel is not only used for service management and control signaling transmission such as service establishment and release, but also used for signaling transmission such as time frequency offset adjustment, switching and service control in a service process, in the service communication process, FACCH is realized by occupying time slot resources of the service channel, which often has certain influence on service transmission, SACCH is realized by the service channel along the way, the speed is low, and in GMR-1 standard, bits coded by SACCH are transmitted by 20 continuous service channels.
TABLE 1 GMR-1 traffic channel and dedicated control channel definitions
In an actual system, a Gateway Station (GS) continuously measures time-frequency offset information of a user terminal (user terminal) uplink service channel, and when the offset reaches a certain threshold, a time-frequency offset adjustment instruction is immediately sent to a terminal through a channel associated channel FACCH, and the instruction adjustment is gradual, so that the time-frequency offset of terminal uplink sending can be ensured to be in a receiving window of the gateway station through gradual adjustment of a plurality of continuous frames.
In a low-orbit satellite communication system, a terminal is rapidly switched in different beams of the same satellite and among different satellites due to the high-speed movement of a low orbit relative to the ground, and the GMR-1 standard facing the GSO satellite mobile communication cannot meet the requirement of the rapid switching of the low-orbit satellite communication system.
Disclosure of Invention
The invention aims to provide a GMR-1-based low-orbit satellite narrow-band communication system switching method to meet the requirement of quick switching of a low-orbit satellite communication system.
The technical solution for realizing the purpose of the invention is as follows: a GMR-1-based low-orbit satellite narrow-band communication system switching method transmits synchronization, position and switching control signaling on a channel associated channel, and specifically comprises the following steps:
transmitting synchronous control signaling content along with the channel while transmitting data in a service channel, wherein the synchronous control signaling content is used for adjusting time-frequency offset of a user uplink signal in real time;
While transmitting data in the service channel, transmitting the terminal position information along with the channel to realize the service switching control based on the user position information;
when the service channel transmits data, the channel is used to transmit the switch control command for switching in the service communication.
Further, the GMR-1 based switching method for the low earth orbit satellite narrowband communication system includes synchronous switching and asynchronous switching, which specifically includes the following steps:
when the error frame rate of the terminal on the service channel is higher than the threshold value, the network side allocates another service channel to the user to replace the current service channel, at this moment, the switching between different channels of the same wave beam occurs, the switching belongs to synchronous switching, and after the terminal is switched, the terminal does not need to be accessed again and is directly switched to a new channel;
the moving speed between the low orbit satellite and the terminal is higher than the threshold value, the terminal is switched among different wave beams of the same satellite, the switching at the moment also belongs to synchronous switching, and after the terminal is switched, the terminal is directly switched to a new channel without accessing again;
the moving speed between the low-orbit satellite and the terminal is higher than a threshold value, the terminal is switched between different satellites, at the moment, the uplink of the terminal between the two satellites is asynchronous, the terminal needs to be accessed again after being switched, and service transmission is carried out after the uplink synchronization is realized.
Further, in the GMR-1 based switching method for a narrow-band communication system of a low earth orbit satellite, the synchronous switching, when the terminal switches between different beams or different channels of the same satellite, comprises the following steps:
(1.1) the terminal carries out RRM measurement and user position information reporting according to the measurement configuration;
(1.2) the base station makes switching judgment according to the ephemeris and the information reported by the terminal: when the user channel quality does not meet the requirement or needs to be switched, a switching command is sent out;
(1.3) the base station triggers the switching of the air interface and sends a switching command to the terminal;
(1.4) carrying out downlink synchronization on the terminal and a new cell of the base station;
(1.5) the terminal sends the switching completion to the base station;
and (1.6) entering a closed-loop frequency offset adjusting stage to realize uplink data synchronization of the terminal.
Further, the GMR-1 based switching method for the narrow-band communication system of the low-earth orbit satellite is characterized in that the asynchronous switching process when the terminal is switched among different satellites is as follows:
(2.1) the terminal carries out RRM measurement and user position information reporting according to the measurement configuration;
(2.2) the source base station makes switching judgment according to the ephemeris and the information reported by the terminal;
(2.3) - (2.4) the source base station sends a handover request message to the target base station, and transfers necessary related information for handover preparation; the target base station performs switching preparation, allocates resources for the terminal and replies a switching confirmation message, wherein the switching confirmation message contains a switching command for the terminal;
(2.5) the source terminal triggers the switching of the air interface and sends a switching command to the terminal;
(2.6) - (2.7) in the switching process, the source base station also performs data forward transmission and SN state transmission operation to the target base station, forwards the received downlink data of the terminal to the target base station, and when the terminal is accessed in a target beam, the target beam knows where to start to continuously transmit data for the terminal;
(2.8) carrying out downlink synchronization on the terminal and a new cell of the target base station;
(2.9) - (2.10) the user initiates a random access process to the new target base station;
(2.11) after the terminal is successfully accessed into the target cell, the terminal sends a switching completion message and confirms to the target base station that the switching process is completed, and the target base station confirms the success of the switching by receiving the switching completion message;
(2.12) - (2.13) after receiving the handover completion message of the terminal, the target base station initiates a path switching process to the core network;
(2.14) - (2.15) the target base station sends the received forwarding data to the terminal, and meanwhile, the terminal can start the data transmission process at the uplink and downlink terminals at the target base station side;
and (2.16) the target base station sends a terminal context release message to the source base station, and the source base station is instructed to release the relevant context of the terminal.
Further, the closed-loop time-frequency offset adjustment stage is entered in (1.6), which specifically comprises the following steps:
and the base station measures the service burst information uploaded by the user, performs time-frequency offset measurement, simultaneously sends an uplink adjustment time-frequency offset adjustment instruction to the terminal, and after the terminal adjusts the uplink frequency offset, the base station sends the service burst again until the uplink data synchronization of the terminal is realized.
Further, the handover command in (2.5) is generated by the target base station and carries the RRC connection reconfiguration message of the mobility control information, and the source base station sends the handover command to the terminal in a transparent transmission manner.
Further, the processing modes in (2.6) to (2.7) are only effective in non-real-time data transmission, and direct data discarding is selected for real-time services.
Compared with the prior art, the invention has the remarkable advantages that: (1) an enhanced channel associated channel signaling transmission mechanism is adopted, and when a service channel transmits data, channel associated transmission synchronously controls signaling content, so that the real-time adjustment of the time frequency offset of a user uplink signal is realized; (2) the location information of the terminal is transmitted along with the channel, a service switching control strategy based on the location information of the user is realized, a switching control command is transmitted along with the channel, and the problem of frequent switching in service communication is solved.
Drawings
Fig. 1 is a schematic diagram of a low earth orbit constellation satellite communication system.
Fig. 2 is a schematic diagram of a low-orbit constellation.
Fig. 3 is a diagram illustrating doppler shift of a subscriber link signal in beijing.
Fig. 4 is a diagram illustrating the change rate of the doppler shift of the user link signal in beijing.
Fig. 5 is a graph of the variation of the propagation distance of the user link in beijing.
FIG. 6 is a schematic diagram of the composition of a GMR-1 system.
Fig. 7 is a schematic diagram of satellite beam switching, wherein (a) is a schematic diagram of the same satellite beam switching, and (b) is a schematic diagram of different satellite beam switching.
Fig. 8 is a synchronous handover flowchart.
Fig. 9 is an asynchronous handover flow diagram.
Detailed Description
At present, the industry does not make a narrow-band satellite mobile communication protocol standard meeting the LEO link requirements, and the Iridium satellite is adaptively modified to adapt to the link characteristics of low-earth-orbit users on the basis of a ground mobile communication protocol standard GSM, so as to finally form a communication system meeting the Iridium satellite link requirements.
The invention designs a beam switching process meeting the frequent switching characteristic of low-orbit satellite communication based on GMR-1, namely a switching method of a low-orbit satellite narrow-band communication system based on GMR-1, which transmits synchronization, position and switching control signaling on a channel associated channel, and specifically comprises the following steps:
Transmitting synchronous control signaling content along with the channel while transmitting data in a service channel, wherein the synchronous control signaling content is used for adjusting the time frequency offset of an uplink signal of a user in real time;
while transmitting data in the service channel, transmitting the terminal position information along with the channel to realize the service switching control based on the user position information;
when the service channel transmits data, the channel is used to transmit the switch control command for switching in the service communication.
Further, the GMR-1 based switching method for the low earth orbit satellite narrowband communication system includes synchronous switching and asynchronous switching, which specifically includes the following steps:
when the frame error rate of the terminal on the service channel is higher than the threshold value, the network side allocates another service channel to the user to replace the current service channel, at the moment, the switching between different channels of the same beam occurs, the switching belongs to synchronous switching, and after the terminal is switched, the terminal does not need to be accessed again and is directly switched to a new channel;
the moving speed between the low-orbit satellite and the terminal is higher than a threshold value, the terminal is switched among different beams of the same satellite, the switching at the moment also belongs to synchronous switching, and the terminal is directly switched to a new channel without accessing again after switching;
the moving speed between the low-orbit satellite and the terminal is higher than a threshold value, the terminal is switched among different satellites, at the moment, the terminal is out of synchronization in an uplink mode between the two satellites, the terminal needs to be accessed again after being switched, and service transmission is carried out after the uplink synchronization is achieved.
Further, in the GMR-1 based switching method for a narrow-band communication system of a low earth orbit satellite, the synchronous switching, when the terminal switches between different beams or different channels of the same satellite, comprises the following steps:
(1.1) the terminal carries out RRM measurement and user position information reporting according to the measurement configuration;
(1.2) the base station makes switching judgment according to the ephemeris and the information reported by the terminal: when the user channel quality does not meet the requirement or needs to be switched, a switching command is sent out;
(1.3) the base station triggers the switching of the air interface and sends a switching command to the terminal;
(1.4) carrying out downlink synchronization on the terminal and a new cell of the base station;
(1.5) the terminal sends the switching completion to the base station;
and (1.6) entering a closed-loop frequency offset adjusting stage to realize uplink data synchronization of the terminal.
Further, the GMR-1 based switching method for the narrow-band communication system of the low-earth orbit satellite is characterized in that the asynchronous switching process when the terminal is switched among different satellites is as follows:
(2.1) the terminal carries out RRM measurement and user position information reporting according to the measurement configuration;
(2.2) the source base station makes switching judgment according to the ephemeris and the information reported by the terminal;
(2.3) - (2.4) the source base station sends a handover request message to the target base station, and transfers necessary related information for handover preparation; the target base station performs switching preparation, allocates resources for the terminal and replies a switching confirmation message, wherein the switching confirmation message contains a switching command for the terminal;
(2.5) the source terminal triggers the switching of the air interface and sends a switching command to the terminal;
(2.6) - (2.7) in the switching process, the source base station also performs data forward transmission and SN state transmission operation to the target base station, forwards the received downlink data of the terminal to the target base station, and when the terminal is accessed in the target beam, the target beam knows where to start to continuously transmit data for the terminal;
(2.8) carrying out downlink synchronization on the terminal and a new cell of the target base station;
(2.9) - (2.10) the user initiates a random access process to the new target base station;
(2.11) after the terminal is successfully accessed into the target cell, the terminal sends a switching completion message and confirms that the switching process is completed to the target base station, and the target base station confirms that the switching is successful by receiving the switching completion message;
(2.12) - (2.13) the target base station initiates a path switching process to the core network after receiving the switching completion message of the terminal;
(2.14) - (2.15) the target base station sends the received forwarding data to the terminal, and meanwhile, the terminal can start the data transmission process at the uplink and downlink terminals at the target base station side;
and (2.16) the target base station sends a terminal context release message to the source base station, and the source base station is instructed to release the relevant context of the terminal.
Further, the closed-loop time-frequency offset adjustment stage is entered in (1.6), which specifically comprises the following steps:
and the base station measures service burst information uploaded by a user, performs time-frequency offset measurement, simultaneously sends an uplink adjustment time-frequency offset adjustment instruction to the terminal, and after the terminal adjusts the uplink time-frequency offset, sends the service burst again, and the base station measures the service burst until the uplink data synchronization of the terminal is realized.
Further, the handover command in (2.5) is an RRC connection reconfiguration message that is generated by the target base station and carries mobility control information, and the source base station sends the handover command to the terminal in a transparent transmission manner.
Further, the processing methods in (2.6) to (2.7) are only effective in non-real-time data transmission, and direct data discarding is selected for real-time services.
The invention is described in further detail below with reference to the figures and the embodiments.
Examples
In a typical low-earth orbit satellite narrowband communication system, the handover can be divided into three modes, i.e., handover between different channels in the same beam, handover between different beams in the same satellite, and handover between different satellites, as shown in fig. 7. When the frame error rate of the terminal on the service channel is higher due to interference or other factors, the network side can allocate another service channel to the user to replace the current service channel, at this time, switching between different channels of the same beam occurs, the switching belongs to synchronous switching, and after the terminal is switched, the terminal does not need to be accessed again and is directly switched to a new channel; the terminal is rapidly switched in different wave beams of the same satellite due to the high-speed movement between the low-orbit satellite and the terminal, the switching at the moment also belongs to synchronous switching, and the terminal is directly switched to a new channel without accessing again after switching; the terminal is rapidly switched between different satellites due to the high-speed movement between the low-orbit satellite and the terminal, at the moment, the terminal is out of uplink synchronization between the two satellites, and after the terminal is switched, the terminal needs to be accessed again, so that service transmission is performed after uplink synchronization is realized.
(1) Synchronous switching process
When the terminal switches between different beams or different channels of the same satellite, the switching process is as shown in fig. 8:
1. and the terminal carries out RRM measurement and user position information reporting according to the measurement configuration.
2. And the base station makes switching judgment according to the ephemeris and the terminal reported information. When the channel quality of the user is poor or the beam switching is needed, a switching command is sent out.
3. And the base station triggers the switching of the air interface and sends a switching command to the terminal.
4. The terminal and a new cell of the base station carry out downlink synchronization;
5. the terminal sends a handover complete to the base station,
6. and entering a closed-loop time frequency offset adjusting stage, measuring service burst information uploaded by a user by the base station, measuring time frequency offset, simultaneously sending an uplink adjustment time frequency offset adjusting instruction to the terminal, sending the service burst again after the terminal adjusts the uplink time frequency offset, and measuring by the base station until the uplink data synchronization of the terminal is realized.
(2) Asynchronous handover procedure
When the terminal is switched among different satellites, the switching process is as shown in fig. 9:
1. and the terminal performs RRM measurement and user position information reporting according to the measurement configuration.
2. And the source base station makes switching judgment according to the ephemeris and the information reported by the terminal.
And 3-4, the source base station sends a switching request message to the target base station and transmits necessary related information for switching preparation. The target base station performs switching preparation, allocates resources for the terminal and replies a switching confirmation message, wherein the switching confirmation message contains a switching command for the terminal.
5. And the source terminal triggers the switching of the air interface and sends a switching command to the terminal. The handover command (RRC connection reconfiguration message carrying mobility control information) is generated by the target base station, and the source base station sends the handover command to the terminal in a transparent transmission manner (without any modification).
6-7, in the switching process, the source base station also executes data forward transmission and SN state transmission operation to the target base station, so that the received downlink data of the terminal can be forwarded to the target base station, and when the terminal is accessed by the target beam, the target beam knows where to start to continuously transmit data for the terminal. The mode is only effective in the transmission of non-real-time data such as packets, and direct data discarding can be selected for services with high real-time performance such as voice services
8. Carrying out downlink synchronization on the terminal and a new cell of the target base station;
9-10, initiating a random access process to a new target base station by a user;
11. and after the terminal is successfully accessed into the target cell, the terminal sends a switching completion message and confirms that the switching process is completed to the target base station, and the target base station confirms that the switching is successful by receiving the switching completion message.
12-13, after receiving the switching completion message of the terminal, the target base station initiates a path switching process to the core network.
14-15, the target base station sends the received forwarding data (if any) to the terminal, and meanwhile, the uplink and downlink terminal data transmission process of the terminal at the target base station side can also start.
16. The target base station sends a terminal context release message to the source base station, and indicates that the source base station can release the relevant context of the terminal.
In summary, the invention adapts to the transmission requirement of the high dynamic change channel of the low-orbit satellite narrowband communication system by transmitting the signaling of synchronization, position, switching control and the like on the associated channel; by using an enhanced channel associated channel signaling transmission mechanism, when a service channel transmits data, channel associated transmission synchronously controls signaling content, and real-time adjustment of time frequency offset of a user uplink signal is realized; when the service channel transmits data, the terminal position information is transmitted along with the channel, and the service switching control strategy based on the user position information is realized; when the service channel transmits data, the channel is transmitted with the switching control command, so that the problem of frequent switching in service communication is solved.
Claims (7)
1. A GMR-1-based low-orbit satellite narrowband communication system switching method is characterized in that synchronization, position and switching control signaling are transmitted on a channel associated channel, and specifically comprises the following steps:
Transmitting synchronous control signaling content along with the channel while transmitting data in a service channel, wherein the synchronous control signaling content is used for adjusting the time frequency offset of an uplink signal of a user in real time;
while transmitting data in the service channel, transmitting the terminal position information along with the channel to realize the service switching control based on the user position information;
when the service channel transmits data, the channel is used to transmit the switch control command for switching in the service communication.
2. The GMR-1 based switching method for the low-earth-orbit satellite narrow-band communication system according to claim 1, comprising synchronous switching and asynchronous switching, and the method comprises the following steps:
when the frame error rate of the terminal on the service channel is higher than the threshold value, the network side allocates another service channel to the user to replace the current service channel, at the moment, the switching between different channels of the same beam occurs, the switching belongs to synchronous switching, and after the terminal is switched, the terminal does not need to be accessed again and is directly switched to a new channel;
the moving speed between the low-orbit satellite and the terminal is higher than a threshold value, the terminal is switched among different beams of the same satellite, the switching at the moment also belongs to synchronous switching, and the terminal is directly switched to a new channel without accessing again after switching;
the moving speed between the low-orbit satellite and the terminal is higher than a threshold value, the terminal is switched between different satellites, at the moment, the uplink of the terminal between the two satellites is asynchronous, the terminal needs to be accessed again after being switched, and service transmission is carried out after the uplink synchronization is realized.
3. The GMR-1 based switching method for the low-earth-orbit satellite narrow-band communication system according to claim 2, characterized in that the synchronous switching is performed when the terminal switches between different beams or different channels of the same satellite as follows:
(1.1) the terminal carries out RRM measurement and user position information reporting according to the measurement configuration;
(1.2) the base station makes switching judgment according to the ephemeris and the information reported by the terminal: when the user channel quality does not meet the requirement or needs to be switched, a switching command is sent out;
(1.3) the base station triggers the switching of the air interface and sends a switching command to the terminal;
(1.4) carrying out downlink synchronization on the terminal and a new cell of the base station;
(1.5) the terminal sends the switching completion to the base station;
and (1.6) entering a closed-loop frequency offset adjusting stage to realize uplink data synchronization of the terminal.
4. A GMR-1 based narrowband satellite communication system handover method according to claim 2 or 3, wherein said asynchronous handover, when the terminal is handed over between different satellites, comprises the following steps:
(2.1) the terminal carries out RRM measurement and user position information reporting according to the measurement configuration;
(2.2) the source base station makes switching judgment according to the ephemeris and the information reported by the terminal;
(2.3) - (2.4) the source base station sends a switching request message to the target base station, and transfers necessary relevant information for switching preparation; the target base station performs switching preparation, allocates resources for the terminal and replies a switching confirmation message, wherein the switching confirmation message contains a switching command for the terminal;
(2.5) the source terminal triggers the switching of the air interface and sends a switching command to the terminal;
(2.6) - (2.7) in the switching process, the source base station also performs data forward transmission and SN state transmission operation to the target base station, forwards the received downlink data of the terminal to the target base station, and when the terminal is accessed in the target beam, the target beam knows where to start to continuously transmit data for the terminal;
(2.8) carrying out downlink synchronization on the terminal and a new cell of the target base station;
(2.9) - (2.10) the user initiates a random access process to the new target base station;
(2.11) after the terminal is successfully accessed into the target cell, the terminal sends a switching completion message and confirms that the switching process is completed to the target base station, and the target base station confirms that the switching is successful by receiving the switching completion message;
(2.12) - (2.13) the target base station initiates a path switching process to the core network after receiving the switching completion message of the terminal;
(2.14) - (2.15) the target base station sends the received forwarding data to the terminal, and meanwhile, the terminal can start the data transmission process at the uplink and downlink terminals at the target base station side;
And (2.16) the target base station sends a terminal context release message to the source base station, and the source base station is instructed to release the relevant context of the terminal.
5. The GMR-1 based switching method for the narrow-band communication system of the low-earth orbit satellite according to claim 3, wherein the closed-loop time-frequency offset adjustment stage is entered in (1.6), and specifically the following steps are performed:
and the base station measures service burst information uploaded by a user, performs time-frequency offset measurement, simultaneously sends an uplink adjustment time-frequency offset adjustment instruction to the terminal, and after the terminal adjusts the uplink time-frequency offset, sends the service burst again, and the base station measures the service burst until the uplink data synchronization of the terminal is realized.
6. The GMR-1 based switching method for the low-earth-orbit satellite narrow-band communication system according to claim 4, wherein the switching command in (2.5) is an RRC connection reconfiguration message which is generated by the target base station and carries mobility control information, and the source base station transmits the switching command to the terminal in a transparent transmission mode.
7. The GMR-1 based switching method for the low-earth orbit satellite narrow-band communication system according to claim 4, wherein the processing modes in (2.6) to (2.7) are only effective in non-real-time data transmission, and direct data discarding is selected for real-time traffic.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110715541.2A CN113411119B (en) | 2021-06-28 | 2021-06-28 | GMR-1-based low-orbit satellite narrow-band communication system switching method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110715541.2A CN113411119B (en) | 2021-06-28 | 2021-06-28 | GMR-1-based low-orbit satellite narrow-band communication system switching method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN113411119A CN113411119A (en) | 2021-09-17 |
| CN113411119B true CN113411119B (en) | 2022-06-28 |
Family
ID=77679517
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110715541.2A Active CN113411119B (en) | 2021-06-28 | 2021-06-28 | GMR-1-based low-orbit satellite narrow-band communication system switching method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113411119B (en) |
Families Citing this family (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113852407B (en) * | 2021-09-26 | 2023-12-29 | 中国电子科技集团公司第五十四研究所 | Satellite communication system based on 5G lan architecture and terminal switching method |
| CN113853000B (en) * | 2021-09-27 | 2023-12-29 | 中国电子科技集团公司第五十四研究所 | Inter-satellite switching method for low-orbit satellite system |
| CN114039645B (en) * | 2021-10-26 | 2024-04-16 | 中科南京移动通信与计算创新研究院 | Satellite base station switching method and device, electronic equipment and storage medium |
| CN114070383B (en) * | 2021-11-18 | 2023-06-27 | 东方红卫星移动通信有限公司 | Communication method and device for improving spectrum efficiency in low-orbit satellite communication system |
| CN114142910A (en) * | 2021-11-22 | 2022-03-04 | 南京熊猫汉达科技有限公司 | Cluster communication method and device of low-earth-orbit constellation satellite communication system |
| CN116232411A (en) * | 2021-12-02 | 2023-06-06 | 大唐移动通信设备有限公司 | Inter-satellite switching method, satellite-borne base station, core network and storage medium |
| CN114884564B (en) * | 2022-05-20 | 2023-11-07 | 成都中科微信息技术研究院有限公司 | Improved superframe sequence distribution method and communication system based on DVB-RCS2 protocol |
| CN115189757B (en) * | 2022-09-07 | 2023-01-31 | 银河航天(北京)网络技术有限公司 | Route planning method and device of constellation communication system |
| CN116015411A (en) * | 2022-12-16 | 2023-04-25 | 中电防务科技有限公司 | High dynamic terminal and switching method for satellite mobile communication system |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110572856A (en) * | 2019-07-31 | 2019-12-13 | 成都天奥集团有限公司 | Non-ground mobile communication network random access-free fast switching method |
| CN113038618A (en) * | 2021-05-20 | 2021-06-25 | 银河航天(北京)网络技术有限公司 | Satellite communication system and method for accessing satellite communication system |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US10177837B2 (en) * | 2015-06-17 | 2019-01-08 | Hughes Network Systems, Llc | Approaches for high speed global packet data services for LEO/MEO satellite systems |
-
2021
- 2021-06-28 CN CN202110715541.2A patent/CN113411119B/en active Active
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110572856A (en) * | 2019-07-31 | 2019-12-13 | 成都天奥集团有限公司 | Non-ground mobile communication network random access-free fast switching method |
| CN113038618A (en) * | 2021-05-20 | 2021-06-25 | 银河航天(北京)网络技术有限公司 | Satellite communication system and method for accessing satellite communication system |
Non-Patent Citations (6)
| Title |
|---|
| GMR-1 3G 45.010.《TSI TS 101 376-5-7》.2011, * |
| Part 5: Radio interface physical layer specifications * |
| RTS/SES-00315-5-7.Technical Specification GEO-Mobile Radio Interface Specifications (Release 3) * |
| Sub-part 7: Radio Subsystem Synchronization * |
| Third Generation Satellite Packet Radio Service * |
| 基于GMR-1系统下行链路的π/4-CQPSK解调方法;牛慧莹;《无线电工程》;20170331(第03期);全文 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN113411119A (en) | 2021-09-17 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN113411119B (en) | GMR-1-based low-orbit satellite narrow-band communication system switching method | |
| CN111262616B (en) | User data switching device and switching method for low-orbit satellite gateway station | |
| JPH08335902A (en) | Control of satellite communication system | |
| US7792487B2 (en) | Satellite communication system for communicating packet data messages | |
| US7630682B2 (en) | Satellite communication system employing a combination of time slots and orthogonal codes | |
| JPH098719A (en) | Closed loop power control of low earth orbit satellite communication system | |
| JPH0969807A (en) | Satellite communication system provided with function of monitoring and controlling user's exposure to rf | |
| CN101527973A (en) | System and method for private network coverage of railway | |
| WO2021104327A1 (en) | Communication method and device | |
| KR20010034721A (en) | Method for transferring a data signal in a wireless communication system | |
| CA2278375A1 (en) | Satellite communication system providing multi-gateway diversity and improved satellite loading | |
| WO1997040639A9 (en) | Method and apparatus for tdma wireless communication employing collector arrays for range extension | |
| US6298073B1 (en) | Method using elastic buffering for equalizing transmission delays in a non-earth-synchronous multiple satellite data transmission system | |
| US6477355B1 (en) | Transmission quality reporting | |
| CN113489530B (en) | Method for synchronously switching feeder links in low-earth-orbit constellation satellite communication system | |
| EP1442535B1 (en) | Controlling forward link transmission power | |
| AU2002359303A1 (en) | Controlling forward link transmission power | |
| US7711320B2 (en) | Satellite communication system for communicating packet data messages | |
| US7269421B2 (en) | Control of frame timing on handover | |
| WO2009072727A1 (en) | Communication method in mobile communication system | |
| US6731931B1 (en) | Idle mode measurement | |
| CN113489529B (en) | Inter-station synchronization method in low-orbit constellation satellite communication system | |
| CN113381801B (en) | GMR-1-based signaling setting method for narrow-band communication system of low-orbit satellite | |
| US20060046754A1 (en) | Proxy translator for extending the coverage area of a wireless network | |
| Cao et al. | Key competence analysis of non-terrestrial network-based cellular backhaul |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |