Satellite system random access method for ground differentiated terminals

Abstract

The invention discloses a satellite system random access method for ground differentiated terminals, and belongs to the technical field of wireless communication access. A public access channel is set through a wide-area-oriented full-coverage access beam, a local-coverage enhanced access beam supporting small terminal access and a service beam, so that any type of terminal ensures that at least one public access channel can provide access service in a system, and the terminal is supported to quickly access a satellite system based on a simplified access process. The satellite random access method disclosed by the invention is simple to implement and can be flexibly configured according to system design requirements, the design complexity and implementation cost of satellite system access processing are greatly reduced, and the system access efficiency is improved.

Description

Technical Field

[0001] The present invention relates to a satellite system random access method for ground differentiated terminals, belonging to the technical field of wireless communication access. Background Art

[0002] As the scale of space satellite networks continues to expand, user demand for satellite communication resources is also increasing. The types of services requested by various types of end users are becoming more diverse, and end users hope to be able to access satellite systems anytime, anywhere.

[0003] In existing satellite systems based on the DVB-S2 protocol and other satellite communication systems, ground terminal access is usually based on a pre-planning mechanism. Access channel and time slot information is known in advance, and access and business communications are carried out on designated channels. This makes it difficult to meet the on-demand access needs of various terminals, and the flexibility of business applications is limited. Summary of the Invention

[0004] The technical problem solved by the present invention is to overcome the deficiencies of the prior art and propose a satellite system random access method for ground differentiated terminals.

[0005] The technical solution of the present invention is:

[0006] A satellite system random access method for ground-based differentiated terminals, comprising:

[0007] The satellite system establishes a public access channel for terminals with different access capabilities by configuring different types of beams, including configuring at least one omnidirectional signaling beam to cover the satellite's service range; configuring at least one phased array enhanced signaling beam to scan and cover the satellite's service range; each service beam of the satellite system is equipped with a public access time slot to support direct access by terminals under the service beam;

[0008] Each signaling beam and service beam is designed with a downlink broadcast channel and a signaling / service multiplexing channel;

[0009] After the satellite's on-orbit control channel is opened, the satellite periodically broadcasts each beam announcement through the downlink broadcast channel. The beam announcement includes relevant beam parameter information and public access channel information, and also carries time information;

[0010] User terminals on the ground select public access channels to complete random access.

[0011] Preferably, the omnidirectional signaling beam supports access by large ground terminals or medium-sized user terminals.

[0012] Preferably, the phased array enhanced signaling beam supports access by small ground user terminals.

[0013] Preferably, both the omnidirectional signaling beam and the phased array enhanced signaling beam are equipped with several carriers and channels for public access, and different rate levels are set according to different terminal capability characteristics and can be flexibly adjusted.

[0014] Preferably, the broadcast channel is configured as a low-speed channel that can be received by all terminals, and the signaling / service multiplexing channel adopts a TDM system.

[0015] Preferably, the ground user terminal can achieve satellite-ground time synchronization and obtain public access information by receiving the beam announcement of any beam.

[0016] Preferably, each ground user terminal selects a public access channel to complete random access, and the specific steps are as follows:

[0017] Step 1: After receiving the beam announcement, the ground user terminal sends an access request from the selected public access channel. The request carries the ground user terminal's own information and other necessary reporting information.

[0018] Step 2: After receiving the access request, the satellite system network control unit compares it with the terminal configuration information. If the authentication is successful, a success message is returned in the access response; otherwise, a failure message is returned.

[0019] Step 3: After receiving the access response success signaling, the ground user terminal sends an access confirmation signaling;

[0020] Step 4: After receiving the access confirmation signaling, the satellite system network control unit sends the working parameters to the ground user terminal, and the access process is completed.

[0021] Preferably, the satellite system random access method supports any access communication protocol.

[0022] Compared with the existing satellite system access method, the present invention has the following advantages:

[0023] (1) Existing system access mostly adopts a pre-planning mechanism. The random access method designed in this invention first configures a multi-signaling beam + service beam public access channel from the perspective of system and satellite payload design, ensuring that different types of ground user terminals can complete access on the physical channel. It is simple to implement and can be flexibly configured according to system design requirements, greatly reducing the design complexity and implementation cost of satellite system access processing.

[0024] (2) The present invention designs a beam broadcast notification mechanism and a public access channel synchronization mechanism, which can support access communication protocols such as S-Aloha and effectively improve the terminal access efficiency in the system.

[0025] (3) The present invention designs a four-way handshake access process to support user terminals to quickly access the satellite system. In actual system tests, the terminal access time is much less than 1s in the absence of collisions, and the terminal access time does not exceed 2s under a 1 / 4 collision probability. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 A schematic diagram of the process of a terminal rapid access system provided by the present invention. DETAILED DESCRIPTION

[0027] The present invention proposes a satellite system random access method for ground-based differentiated terminals. By setting different types of access beams and public access channels and simplifying the access process, it can support various terminals with differentiated station types and communication capabilities to achieve random access under the satellite system.

[0028] Specifically, the present invention includes the following contents:

[0029] 1) System public access channel settings

[0030] Satellites are equipped with at least one omnidirectional signaling beam, covering the service range of all their service beams. Omnidirectional signaling beams have low gain and can usually only support access from large ground terminals (e.g., antennas with an aperture of 2.0m or more) or medium-sized user terminals (e.g., antennas with an aperture of 0.9-1.5m).

[0031] The satellite is equipped with at least one phased array enhanced signaling beam, which scans and covers the service range of all service beams. The enhanced signaling beam is narrow and has relatively high beam gain, which can support access from small ground user terminals (such as those with an antenna diameter of less than 0.7m).

[0032] A public access time slot is reserved in each satellite service beam to support direct access by terminals under the service beam.

[0033] Both the omnidirectional signaling beam and the phased array enhanced signaling beam use multiple carriers and channels for public access. Different rate levels are set to accommodate the capabilities of various terminals, large, medium, and small, and support flexible adjustment. The rate, time slot, and modulation and coding schemes for the uplink public access channels of the signaling and service beams are calculated and flexibly configured based on the number of terminals supported by the system.

[0034] 2) Public access channel synchronization

[0035] To improve satellite system access efficiency, uplink access protocols such as S-Aloha or other protocols can be considered. Generally, the more efficient the access communication protocol, the better the system's access performance. Slot-based access protocols require time slot synchronization between the ground and satellite.

[0036] A downlink broadcast channel and a signaling / service multiplexing channel are designed in each signaling beam and service beam. The broadcast channel is configured as a low-speed channel that can be received by all terminals. The signaling / service multiplexing channel is recommended to adopt the TDM system, and the rate can be considered adaptive to support large, medium and small terminals.

[0037] The network control unit periodically broadcasts the relevant beam parameter information and public access channel information of each beam through the downlink broadcast channel, and carries time information at the same time, so that the ground user terminal can achieve satellite-ground time synchronization and obtain public access information when receiving the beam announcement of any beam, thereby realizing random access at the channel level.

[0038] 3) Terminal Quick Access Process

[0039] After the satellite is in orbit and network control and opening are completed, the network construction operation requires configuring the access authentication information of each ground user terminal to the satellite network control unit.

[0040] The specific access process is as follows Figure 1 shown.

[0041] Step 1: After receiving the beam announcement, the user terminal sends an access request through the selected public access channel. The request carries the terminal's own information and other necessary reporting information.

[0042] Step 2: After receiving the access request, the satellite network control unit compares it with the terminal configuration information. If authentication is successful, the access response returns a success message; otherwise, it returns a failure message. Access response failures are usually caused by inconsistencies between the information carried in the terminal access request and the configuration information, requiring a terminal or backend modification. Another possible cause is a link error, where the access request message contains an error, resulting in an access response failure. In this case, re-accessing the connection is sufficient.

[0043] Step 3: After receiving the access response success signaling, the user terminal sends an access confirmation signaling.

[0044] Step 4: The satellite network control unit receives the access confirmation and sends the working parameters to the user terminal, and the access process is completed.

[0045] To address the need for on-demand access for multiple types of ground-based terminals in satellite communication systems, this invention proposes an on-demand access method based on system-level access channel configuration. This method utilizes a wide-area, full-coverage access beam, a localized, enhanced-coverage access beam supporting access by small terminals, and a service beam to establish a public access channel. This ensures that any type of terminal in the system has access services provided by at least one public access channel. This simplified access process supports rapid terminal access to the satellite system. The satellite system on-demand access method designed in this invention improves system access efficiency and supports on-demand terminal access.

[0046] The random access method of the present invention is simple to implement and can be flexibly configured according to system design requirements, greatly reducing the design complexity and implementation cost of satellite system access processing, improving user access efficiency and system application effectiveness, and is applicable to all wireless communication systems based on the MF-TDMA system, especially satellite communication systems.

[0047] Parts of the present invention that are not described in detail belong to common knowledge among those skilled in the art.

Claims

1. A satellite system random access method for ground-based differentiated terminals, characterized in that: include: The satellite system establishes a public access channel for terminals with different access capabilities by configuring different types of beams, including configuring at least one omnidirectional signaling beam to cover the satellite's service range; configuring at least one phased array enhanced signaling beam to scan and cover the satellite's service range; each service beam of the satellite system is equipped with a public access time slot to support direct access by terminals under the service beam; Each signaling beam and service beam is designed with a downlink broadcast channel and a signaling / service multiplexing channel; After the satellite's on-orbit control channel is opened, the satellite periodically broadcasts each beam announcement through the downlink broadcast channel. The beam announcement includes relevant beam parameter information and public access channel information, and also carries time information; User terminals on the ground select public access channels to complete random access.

2. The method for random access to a satellite system for terrestrial differentiated terminals according to claim 1, wherein: Omnidirectional signaling beams support access by large ground terminals or medium-sized user terminals.

3. The satellite system random access method for terrestrial differentiated terminals according to claim 1, characterized in that: Phased array enhanced signaling beam supports access by small ground user terminals.

4. The satellite system random access method for terrestrial differentiated terminals according to claim 1, characterized in that: Both the omnidirectional signaling beam and the phased array enhanced signaling beam set up several carriers and channels for public access. Different rate levels are set according to the different terminal capabilities and can be flexibly adjusted.

5. The satellite system random access method for terrestrial differentiated terminals according to claim 1, characterized in that: The broadcast channel is configured as a low-speed channel that can be received by all terminals, and the signaling / service multiplexing channel adopts the TDM system.

6. The satellite system random access method for terrestrial differentiated terminals according to claim 1, characterized in that: When the ground user terminal receives the beam notification of any beam, it can achieve satellite-ground time synchronization and obtain public access information.

7. The satellite system random access method for terrestrial differentiated terminals according to claim 1, characterized in that: Each ground user terminal selects a public access channel to complete random access. The specific steps are as follows: Step 1: After receiving the beam announcement, the ground user terminal sends an access request from the selected public access channel. The request carries the ground user terminal's own information and other necessary reporting information. Step 2: After receiving the access request, the satellite system network control unit compares it with the terminal configuration information. If the authentication is successful, a success message is returned in the access response; otherwise, a failure message is returned. Step 3: After receiving the access response success signaling, the ground user terminal sends an access confirmation signaling; Step 4: After receiving the access confirmation signaling, the satellite system network control unit sends the working parameters to the ground user terminal, and the access process is completed.

8. The satellite system random access method for terrestrial differentiated terminals according to claim 1, characterized in that: The satellite system random access method supports any access communication protocol.

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