A method for multiple access of MF-TDMA and FDMA fusion in a satellite communication network

Abstract

The application discloses a kind of MF-TDMA and FDMA fusion multi-address access methods in satellite communication network, it relates to multi-address access technology in satellite communication field.The application divides satellite communication network into MF-TDMA general transmission layer and FDMA special transmission layer, uses integrated network management to carry out centralized management to two kinds of systems, solves the problem of insufficient high-speed transmission efficiency of MF-TDMA system and few user stations of FDMA system access.The application gives full play to the advantages of two kinds of systems, avoids disadvantages, has the characteristics of flexible networking, high resource utilization, and can be applied to satellite communication network based on transparent transponder, especially suitable for satellite networking application with large number of access user stations and large amount of data of backbone transmission node.

Description

Technical Field

[0001] This invention relates to multiple access technology in the field of satellite communication, and is particularly suitable for satellite networking applications with a large number of access user stations and a large amount of data in the backbone transmission nodes. Background Technology

[0002] Currently, satellite communication networks built on transparent transponders of geostationary orbit satellites mainly use two types of multiple access systems: multi-frequency time division multiple access (MF-TDMA) and frequency division multiple access (FDMA / DAMA).

[0003] The MF-TDMA system divides satellite frequency resources into multiple carriers, each carrier into multiple frames, and each frame into multiple time slots. Satellite networks using MF-TDMA can have multiple sites simultaneously communicating on the same carrier using different time slots, resulting in high network capacity and frequency resource savings. Furthermore, MF-TDMA supports various network topologies, including mesh, star, and hybrid star-network structures, offering high networking flexibility. However, because burst signals within each time slot require the addition of synchronization symbols, and because burst signals within time slots need to maintain a certain interval between themselves and the time slot boundaries for protection, MF-TDMA suffers some transmission efficiency loss, especially in high-speed, high-bandwidth, short-time-slot scenarios.

[0004] The FDMA / DAMA system divides satellite frequency resources into multiple carriers, with each satellite station within the network having its own carrier for communication needs. The carrier is reclaimed after communication ends. FDMA carriers are continuous waves with long synchronization symbol insertion periods, eliminating the need for guard time and resulting in high transmission efficiency and low latency jitter, making them suitable for high-speed and real-time services. However, the exclusive carrier nature of FDMA systems limits network capacity and the number of accessible sites. Furthermore, FDMA systems can only form star-shaped networks, making their topology inflexible. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the MF-TDMA and FDMA systems in the background art and provide a multiple access method that integrates MF-TDMA and FDMA suitable for satellite communication networks. This method improves network capacity and frequency resource utilization, and enables flexible network configuration by dividing the satellite communication network into a general MF-TDMA transport layer and a dedicated FDMA transport layer.

[0006] The objective of this invention is achieved as follows:

[0007] A multiple access method integrating MF-TDMA and FDMA in a satellite communication network, wherein the satellite communication network includes a central station and multiple remote stations, collectively referred to as satellite stations. The central station includes network management center equipment, switching equipment, channel equipment, radio frequency equipment, and service equipment, and the remote stations include channel equipment, radio frequency equipment, and service equipment. The method includes the following steps:

[0008] (1) The satellite communication network is divided into a general transmission layer and a dedicated transmission layer. The general transmission layer uses the MF-TDMA multiple access system, and the dedicated transmission layer uses the FDMA multiple access system. Satellite stations in the network are simultaneously connected to the two transmission layers and use the transceiver channels of the two transmission layers for business communication.

[0009] (2) Divide the satellite transponder frequency resources into TDMA resources and FDMA resources, use TDMA resources to build a general transmission layer, and use FDMA resources to build a dedicated transmission layer;

[0010] (3) The dedicated transmission layer uses the general transmission layer as its control channel. The network management center equipment sends the topology, channel parameters and channel mode parameters of the dedicated transmission layer through the general transmission layer. The network management center equipment collects the operating status of the dedicated transmission layer through the general transmission layer.

[0011] (4) The satellite station is configured with multiple transmit channels and multiple receive channels. The multiple transmit and receive channels work simultaneously. At least one transmit channel and one receive channel are configured as MF-TDMA channels for accessing the general transmission layer. The remaining transmit and receive channels are configured as FDMA channels for accessing the dedicated transmission layer.

[0012] (5) The satellite station detects and records the correspondence between the MAC address of the service data source and the satellite station address in the general transmission layer, forming a mapping table between MAC address and station address;

[0013] (6) After the service data enters the satellite station, the characteristics of the service data are detected, and the transmission channel used by the service data is determined according to the characteristics of the service data and the mapping table between MAC address and station address.

[0014] Furthermore, the specific method of step (2) is as follows:

[0015] (201) Configure the terminal types, number of transceiver channels, and transceiver channel types of each satellite station in the network management center's equipment library;

[0016] (202) Configure general transport layer parameters at the network management center equipment, including topology, frame length, number of time slots, guard time, TDMA carrier parameters, and satellite station duty relationship, and construct a general transport layer;

[0017] (203) Configure dedicated transport layer parameters at the network management center equipment, including dedicated transport layer site topology, FDMA carrier parameters, and FDMA channel mode. The channel mode includes on-demand mode and multicast mode. The on-demand mode channel is used to transmit IP on-demand data, and the multicast mode channel is used to transmit specific IP multicast data.

[0018] Furthermore, the method for selecting the business data transmission channel in step (6) is as follows:

[0019] (601) When the service data is in the ARP protocol, the MF-TDMA service channel is used for transmission;

[0020] (602) When business data is not based on the ARP protocol:

[0021] (6021) When the destination MAC address of the service data is a broadcast address, the MF-TDMA service channel is used for transmission;

[0022] (6022) When the destination MAC address of the service data is a multicast address, the FDMA channel shall be used for transmission if the following conditions are met; otherwise, the MF-TDMA service channel shall be used for transmission:

[0023] Condition 1-1: This site has an FDMA channel operating in multicast mode;

[0024] Conditions 1-2: The multicast address of this channel matches the multicast address of the service data;

[0025] (6023) When the destination MAC address of the service data is a video-on-demand address, the FDMA channel shall be used for transmission if the following conditions are met; otherwise, the MF-TDMA service channel shall be used for transmission:

[0026] Condition 2-1: This site has an FDMA channel operating in on-demand mode;

[0027] Condition 2-2: Find the destination station address of the service data through the mapping table of MAC address and station address. This address is in the destination station address list of the FDMA channel determined in Condition 2-1.

[0028] Compared with the prior art, the present invention has the following advantages:

[0029] 1. The multiple access method that integrates MF-TDMA and FDMA can flexibly select the transmission system according to the type of service transmitted at the site. It enables non-real-time services and low-to-medium speed services to use the general transmission layer, while high-speed services and high real-time services use the dedicated transmission layer, giving full play to the transmission advantages of the two systems and improving network flexibility.

[0030] 2. The general transport layer provides a control channel for the dedicated transport layer, simplifying the use of the FDMA system. Attached Figure Description

[0031] Figure 1 This is a network topology diagram of MF-TDMA and FDMA fusion in an embodiment of the present invention.

[0032] Figure 2 This is a schematic diagram illustrating the distribution of dedicated transport layer parameters and status reporting in an embodiment of the present invention.

[0033] Figure 3 This is a flowchart illustrating the service transmission channel selection process in an embodiment of the present invention. Detailed Implementation

[0034] A multiple access method integrating MF-TDMA and FDMA in a satellite communication network. For example... Figure 1 As shown, a satellite communication network based on transparent transponders for geostationary orbit satellites consists of a central station and remote stations. The central station's main functions in the satellite communication network include network link control and resource allocation. The central station houses a network management center, whose main functions are planning network frequencies and site resources, and monitoring network operation.

[0035] MF-TDMA multiple access divides satellite frequency resources into different carriers in terms of frequency, and then divides these carriers into frames in terms of time. Each frame is further divided into time slots with different functions. The main time slot types include forward control time slots, return control time slots, and data time slots. Forward control time slots are sent by the central station, and both the central station and the network management center use them to send network control information. Return control time slots are sent by remote stations. Each remote station is allocated at least one return control time slot within a superframe period, and uses these slots to send time slot resource request information and status reporting information.

[0036] FDMA (Fixed-DMA Multiple Access) divides satellite frequency resources into different carriers, with each transmitting station having its own carrier. Once a transmitting station no longer uses a carrier, the network management center releases that carrier resource.

[0037] Reference Figure 1-3 The specific steps of this method are as follows:

[0038] (1) The satellite communication network is divided into a general transmission layer and a dedicated transmission layer. The general transmission layer uses the MF-TDMA multiple access system, and the dedicated transmission layer uses the FDMA multiple access system. Satellite stations in the network are simultaneously connected to the two transmission layers and use the transceiver channels of the two transmission layers for business communication.

[0039] The relationship between the general transport layer and the special transport layer is as follows: Figure 1 As shown, the general transport layer can use mesh, star, or hybrid star-mesh topology, while the dedicated transport layer can use mesh or star structures, and the topology relationships between the two are independent of each other.

[0040] (2) Divide the satellite transponder frequency resources into TDMA resources and FDMA resources, use TDMA resources to build a general transmission layer, and use FDMA resources to build a dedicated transmission layer;

[0041] (3) The dedicated transport layer uses the general transport layer as its control channel. The network management center sends out parameters such as the topology, channel parameters and channel mode of the dedicated transport layer through the general transport layer. The network management center collects the operating status of the dedicated transport layer through the general transport layer.

[0042] When a satellite station joins the network, it first connects to the general transport layer to obtain the network parameters of the dedicated transport layer, and then connects to the dedicated transport layer. After that, the satellite station connects to both transport layers at the same time. During the operation of the satellite network, the topology and channel parameters of the dedicated transport layer can also be dynamically modified as needed.

[0043] (4) The satellite station is configured with multiple transmit channels and multiple receive channels. The multiple transmit and receive channels work simultaneously. At least one transmit channel and one receive channel are configured as MF-TDMA channels for accessing the general transmission layer. The remaining transmit and receive channels are configured as FDMA channels for accessing the dedicated transmission layer.

[0044] (5) The satellite station detects and records the correspondence between the MAC address of the service data source and the satellite station address in the general transport layer, forming a MAC address / station address mapping table;

[0045] Because network broadcast data is transmitted through the general transport layer, and IP service communication requires finding the destination MAC address via the ARP protocol (which also passes through the general transport layer), the general transport layer maintains a complete mapping relationship between MAC addresses and station addresses across the entire network. If the source MAC address and its corresponding station address of the service data already exist in the mapping table, no operation is performed; otherwise, the mapping table is updated.

[0046] (6) After the service data enters the satellite station, the characteristics of the service data are detected, and the transmission channel used by the service data is determined according to the characteristics of the service data and the MAC address / station address mapping table.

[0047] Step (2) Transport layer construction specifically includes the following steps:

[0048] (201) Configure the terminal types, number of transceiver channels, and transceiver channel types of each satellite station in the network management center equipment library;

[0049] (202) Configure general transport layer parameters at the network management center, including topology, frame length, number of time slots, guard time, TDMA carrier parameters, satellite station duty relationship, etc., and construct a general transport layer;

[0050] (203) Configure dedicated transport layer parameters at the network management center, including dedicated transport layer site topology, FDMA carrier parameters, and FDMA channel mode. The channel mode includes on-demand mode and multicast mode. On-demand mode channel is used to transmit IP on-demand data, and multicast mode channel is used to transmit specific IP multicast data.

[0051] Step (6) Selecting the business data transmission channel specifically includes the following steps:

[0052] (601) When the service data is in the ARP protocol, the MF-TDMA service channel is used for transmission;

[0053] (602) When business data is not based on the ARP protocol:

[0054] (6021) When the destination MAC address of the service data is a broadcast address, the MF-TDMA service channel is used for transmission;

[0055] (6022) When the destination MAC address of the service data is a multicast address, the FDMA channel is used for transmission when the following conditions are met, otherwise the MF-TDMA service channel is used for transmission: (1) There is an FDMA channel working in multicast mode at this station, (2) The multicast address of the channel matches the multicast address of the service data.

[0056] (6023) When the destination MAC address of the service data is the on-demand address, the FDMA channel is used for transmission when the following conditions are met, otherwise the MF-TDMA service channel is used for transmission: (1) There is an FDMA channel working in on-demand mode at this station, (2) The destination station address of the service data is found through the MAC address / station address mapping table, and this address is in the destination station address list of the FDMA channel determined by condition (1).

[0057] This invention divides the satellite communication network into a general-purpose MF-TDMA transmission layer and a dedicated FDMA transmission layer, using an integrated network management system for centralized management of both systems. This solves the problems of insufficient high-speed transmission efficiency in the MF-TDMA system and the limited number of user stations in the FDMA system. This invention fully leverages the advantages of both systems while mitigating their disadvantages, featuring flexible networking and high resource utilization. It can be applied to satellite communication networks based on transparent transponders, and is particularly suitable for satellite networking applications with a large number of user stations and high data volumes in the backbone transmission nodes.

Claims

1. A multiple access method integrating MF-TDMA and FDMA in a satellite communication network, wherein the satellite communication network includes a central station and multiple remote stations, the central station and remote stations are collectively referred to as satellite stations, the central station includes network management center equipment, switching equipment, channel equipment, radio frequency equipment and service equipment, and the remote stations include channel equipment, radio frequency equipment and service equipment; characterized in that, Includes the following steps: (1) The satellite communication network is divided into a general transmission layer and a dedicated transmission layer. The general transmission layer uses the MF-TDMA multiple access system, and the dedicated transmission layer uses the FDMA multiple access system. Satellite stations in the network are connected to both transmission layers at the same time and use the transceiver channels of both transmission layers for business communication. (2) Divide the satellite transponder frequency resources into TDMA resources and FDMA resources, use TDMA resources to build a general transmission layer, and use FDMA resources to build a dedicated transmission layer; (3) The dedicated transmission layer uses the general transmission layer as its control channel. The network management center equipment sends the topology, channel parameters and channel mode parameters of the dedicated transmission layer through the general transmission layer. The network management center equipment collects the operating status of the dedicated transmission layer through the general transmission layer. (4) The satellite station is configured with multiple transmit channels and multiple receive channels. The multiple transmit and receive channels work simultaneously. At least one transmit channel and one receive channel are configured as MF-TDMA channels for accessing the general transmission layer. The remaining transmit and receive channels are configured as FDMA channels for accessing the dedicated transmission layer. (5) The satellite station detects and records the correspondence between the MAC address of the service data source and the satellite station address in the general transport layer, forming a mapping table between MAC address and station address; (6) After the service data enters the satellite station, the characteristics of the service data are detected, and the transmission channel used by the service data is determined according to the characteristics of the service data and the mapping table between MAC address and station address.

2. The multiple access method for integrating MF-TDMA and FDMA in a satellite communication network according to claim 1, characterized in that, The specific method of step (2) is as follows: (201) Configure the terminal type, number of transceiver channels, and transceiver channel type of each satellite station in the network management center equipment library; (202) Configure general transport layer parameters at the network management center equipment, including topology, frame length, number of time slots, guard time, TDMA carrier parameters, and satellite station duty relationship, and construct a general transport layer; (203) Configure dedicated transport layer parameters at the network management center equipment, including dedicated transport layer site topology, FDMA carrier parameters, and FDMA channel mode. The channel mode includes on-demand mode and multicast mode. The on-demand mode channel is used to transmit IP on-demand data, and the multicast mode channel is used to transmit specific IP multicast data.

3. The multiple access method for integrating MF-TDMA and FDMA in a satellite communication network according to claim 1, characterized in that, The method for selecting the business data transmission channel in step (6) is as follows: (601) When the service data is in the ARP protocol, the MF-TDMA channel is used for transmission; (602) When business data is not based on the ARP protocol: (6021) When the destination MAC address of the service data is a broadcast address, the MF-TDMA channel is used for transmission; (6022) When the destination MAC address of the service data is a multicast address, the FDMA channel shall be used for transmission if the following conditions are met; otherwise, the MF-TDMA channel shall be used for transmission: Condition 1-1: This site has an FDMA channel operating in multicast mode; Conditions 1-2: The multicast address of this channel matches the multicast address of the service data; (6023) When the destination MAC address of the service data is a video-on-demand address, the FDMA channel shall be used for transmission if the following conditions are met; otherwise, the MF-TDMA channel shall be used for transmission: Condition 2-1: This site has an FDMA channel operating in on-demand mode; Condition 2-2: Find the destination station address of the service data through the mapping table of MAC address and station address. This address is in the destination station address list of the FDMA channel determined in Condition 2-1.

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