Periodic burst short message-oriented quasi-static backward resource allocation method

Abstract

The invention belongs to the technical field of reverse periodic short burst service transmission, and particularly relates to a quasi-static reverse resource allocation method for periodic burst short messages, which comprises the following steps of: providing a time reference for a reverse access channel by using a downlink physical channel of a central station, and receiving a forward time base station signal and finishing time delay compensation by a user; the central station pre-allocates time and frequency resources to the user station with periodic burst when the user accesses the network, and the user sends periodic short burst service on the allocated time and frequency resources; and when the user stops sending the periodic service, a pre-allocated channel release signaling is sent to the center, and the central station recovers the pre-allocated channel. A quasi-static pre-allocation method is used, the problem that the access failure probability is increased due to load increase when a competition channel is adopted is avoided, meanwhile, signaling overhead is reduced, the use efficiency of return resources is improved, center star type satellite networking is involved, and the method is suitable for a periodic burst short message application scene.

Description

Technical Field

[0001] This invention belongs to the field of return periodic short burst service transmission technology, specifically involving a quasi-static return resource allocation method for periodic burst short messages. Background Technology

[0002] In a centralized satellite network, the central station acts as the central node, responsible for broadcasting forward signals and receiving and managing return signals from user stations. User stations recover data by demodulating forward signals and maintain network-wide clock synchronization. Return time-frequency resources are shared by all users, and their allocation method directly affects resource utilization efficiency and service timeliness. Return resource access primarily employs two methods: random contention access and dynamic allocation. Random contention access is for bursty short message services; users do not require allocation from the central station and can autonomously send messages on shared resources via ALOHA, reducing signaling interaction and offering higher efficiency in low-load, short-burst applications. Dynamic allocation, on the other hand, is for long-connection, high-volume applications; users must first apply for channels, and the central station centrally allocates and reclaims resources, achieving dynamic management, but involving greater signaling overhead.

[0003] However, both methods have significant limitations for applications with periodic and bursty return traffic. Random contention access, due to the periodic increase in service load, leads to a significant increase in the probability of user collisions and the risk of access failure; even expanding the access channel does not significantly improve performance. Dynamic allocation, on the other hand, generates substantial overhead due to frequent signaling interactions and the immediate release of the channel after short message transmission, resulting in decreased return resource utilization efficiency and difficulty in guaranteeing service timeliness.

[0004] Therefore, in centralized satellite networks, although random contention and dynamic allocation methods are suitable for low-load bursts and long-connection services, respectively, neither can achieve a balance between access success rate and efficient resource utilization for periodic burst scenarios. More optimized access strategies need to be explored to meet the needs of such applications. Summary of the Invention

[0005] In view of this, the present invention provides a quasi-static return resource allocation method for periodic burst short messages, which can avoid the low access problem caused by random access under high load business, and at the same time, the quasi-static method reduces the interaction signaling with the center, effectively improving the timeliness of short bursts and the utilization efficiency of return resources.

[0006] To achieve the objectives of this invention, the following technical solutions are provided.

[0007] A quasi-static return resource allocation method for periodic bursty short messages, applied to a centralized star-shaped satellite network, includes: The central station broadcasts a forward signal containing the time reference for the entire network to the user stations; When a user joins the network, they report their periodic short bursts of service transmission needs to the central station. According to the service requirements, the central station pre-allocates one or more dedicated time slots and corresponding carrier frequency resources to the user station from the predefined return resource pool; The central station notifies the user station of the resource allocation results via forward signaling; Based on the allocation results, the user station periodically sends short burst messages on the dedicated time slot; When a service is terminated, the user station requests the central station to release resources, and the central station reclaims the resources for reallocation.

[0008] In the pre-allocation step, the central station prioritizes allocating time slot resources on already activated carriers, and only activates new carrier frequency resources when the time slot resources of that carrier are insufficient.

[0009] For service requests where a user station needs to send multiple short messages within a period, the central station prioritizes allocating multiple time slots with adjacent times on the same carrier.

[0010] The forward signal is a TDM signal, and its frame structure is divided into superframe units to provide a synchronization clock reference to the entire network; the return resource pool is divided based on the clock reference to form basic TDMA time slot units.

[0011] When a user station joins the network, it reports its service requirements through a contention access channel. The service requirement information includes at least the service cycle and the number of burst messages.

[0012] The central station manages return resources in three ways: contention for access carriers, periodic burst service carriers, and dynamic service carriers.

[0013] Beneficial effects 1. This invention is based on a pre-allocation method for forward physical layer signals. It utilizes the downlink physical channel of the central station to provide a time reference for the return access channel. Users receive the forward time base station signal and complete delay compensation. When a user joins the network, the central station pre-allocates time and frequency resources for user stations with periodic bursts. Users send periodic short burst services on the allocated time and frequency resources. When a user stops sending periodic services, it sends a release signaling message to the central station to reclaim the pre-allocated channel. Using a quasi-static pre-allocation method avoids the problem of increased access failure probability due to increased load when using contention channels, while reducing signaling overhead and improving the efficiency of return resource utilization. It involves centrally located star-shaped satellite networks and is suitable for application scenarios with periodic burst short messages.

[0014] 2. This invention relates to the allocation of return channel resources for satellites in a centrally located star-shaped network, applicable to return periodic short burst service transmission. Addressing the issues of access success rate, access efficiency, and timeliness faced by traditional access schemes in applications involving return periodic short burst service transmission, this invention, through a larger-scale division of return time by the central station, allocates such services to users in a pre-allocated, quasi-static manner. This avoids the low access problem caused by random access under high-load services. Simultaneously, the quasi-static approach reduces signaling interaction with the central station, effectively improving the timeliness of short bursts and the utilization efficiency of return resources.

[0015] 3. In this invention, the central station adopts a "time slot priority, carrier replenishment" strategy, which optimizes the order of use of limited time and frequency resources. It prioritizes filling the time slots of a single carrier, improving the utilization rate of a single carrier and reducing unnecessary multi-carrier activation, thereby improving the overall spectrum efficiency. Allocating adjacent time slots to services reduces the complexity of frequency switching or time adjustment when user stations transmit, which is beneficial to terminal implementation and reduces power consumption.

[0016] 4. The method of this invention is based on high-precision time synchronization across the entire network. User stations utilize forward signals to complete delay compensation and synchronization, ensuring that all users send signals on pre-allocated precise time slots. This is the technological cornerstone for achieving quasi-static allocation and avoiding mutual interference between users. The entire scheme concentrates resource allocation signaling interaction primarily at two moments: user network access and network exit (or service termination). No scheduling signaling is required during long service transmission periods, greatly reducing the control channel burden. This allows for an excellent balance between high access success rate, low signaling overhead, and high resource utilization efficiency in scenarios involving periodic bursts of short messages. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of a centralized satellite communication network as described in the present invention.

[0018] Figure 2 This is a schematic diagram of the modulation time information (TDM) signal in an embodiment of the present invention.

[0019] Figure 3 This is a schematic diagram of burst short message allocation for periodic signals in an embodiment of the present invention. Detailed Implementation

[0020] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0021] In a centralized star-shaped satellite network, satellites use transparent forwarding, and the central station is responsible for the organization and management of the entire network. The central station sends forward TDM signals and receives return TDMA burst signals sent by user stations, and data exchange takes place at the central station. This invention provides a quasi-static return resource allocation method for periodic burst short messages, applicable to return access resource allocation in centralized star-shaped satellite networks for application scenarios involving periodic burst return services. The centralized satellite communication network involved in this invention includes... Figure 1 As shown. The method of the present invention specifically includes the following steps: Step (1): The satellite network is a centralized network. The central station sends downlink broadcast signals to all user stations, and the signals are modulated with the network-wide time information. User stations receive the downlink signals from the central station and send return signals back to the central station, thus realizing star network communication. All return signals sent by user stations are received and processed by the central station, which is responsible for the management of return access resources for user stations.

[0022] In a centralized satellite network, the central station is the core of the entire network, responsible for managing all user stations. The central station broadcasts TDM forward signals to all users, while the return signal uses TDMA access. The forward signal uses only one TDM carrier, but the central station supports multiple TDMA carriers to carry different service types, such as contention carriers, periodic burst carriers, and service carriers. The central station manages and allocates carriers based on the number of users and service load. Figure 2 This is a schematic diagram of the modulation time information (TDM) signal in this embodiment.

[0023] Step (2): The user station’s return service includes periodic short burst services. During the transmission time of such services, short burst services are sent at a fixed time period. The unit of sending a short burst is one return transmission time slot.

[0024] In step (3), the user station, based on the network-wide time information sent by the central station in step (1), performs ranging through the central station and completes satellite delay compensation to achieve network-wide clock synchronization with the central station. In this embodiment, the basic unit of the forward TDM signal is a TDM superframe, which consists of a superframe header and a data frame. The superframe time period is 100ms, and 10 TDM superframes together form a period of 1s, providing a synchronization clock reference to the entire network.

[0025] Step (4) requires the transmission of the periodic short burst service user stations in step (2), and marking such services and burst demands when entering the network from the central station.

[0026] In this embodiment, the header fields of the 10 TDM superframes are each modulated with an m-stage sequence of length 10, which is used as a time reference for the user station. After synchronizing the TDM signal, the user station simultaneously parses the m-time sequence.

[0027] In this system, the return access uses TDMA (Time-Digital Memory Access), where the basic signal unit is a time slot. Each time slot occupies 10ms, and 10 return time slots form a return data frame. In contention-based and dynamic access, users occupy time slots within the return data frame for transmission. For example, in contention-based burst access, one of the 10 time slots is selected for transmission; in dynamic access, the central station allocates different time slots for users. When time slot resources are insufficient, the central station adds new carriers and allocates them to users. Periodic short message services are uniformly allocated over a longer time scale; a single carrier has 100 time slots within 1 second to support periodic burst short message services for user stations.

[0028] When a user station joins the network, it sends information such as the network entry time and periodic service details to the central station via a contention-based access channel. The central station calculates the satellite-to-ground delay compensation based on the information carried in the user station's entry packet and pre-allocates time slots according to the periodic service transmission requirements. If a user station sends one short message burst per second, the central station selects one time slot from 100 time slots for pre-allocation to the user. If two short message bursts occur within one second, the central station selects two adjacent time slots from the 100 time slots for pre-allocation to the user. If time slot resources are insufficient, a new carrier is selected for allocation. This information is then transmitted to the user via the forward TDM signaling channel.

[0029] In step (5), the central station parses the periodic short burst service transmission requirements in step (4) from the incoming packet. Based on the time slot information divided in the forward signal, the central station allocates time slots and frequency resources to the user station.

[0030] Step (6): In step (5), the central station first allocates time slot resources, and when the time slot resources of each carrier are exhausted, it selects new frequency resources for allocation. For users who have requests to send short messages at double rate within a period, the central station selects adjacent time slot units on the same carrier for allocation.

[0031] in, Figure 3 This is a schematic diagram illustrating the allocation of burst short messages for periodic signals in an embodiment of the present invention. The user parses the network access response information returned by the central station, compensates for the transmission time of the satellite-to-ground distance, and sends burst short messages on the pre-allocated periodic short burst time slots.

[0032] Step (7): The user station sends SMS messages at certain time intervals on the allocated time slots and frequency bands. When the user station leaves the network or stops sending SMS messages, it sends a resource release request to the central station to release the occupied time slots and frequency bands. The central station then re-allocates the reclaimed resources.

[0033] Specifically, when a user station leaves the network or stops sending periodic short messages, it sends a request to the central station to release the pre-allocated channel. The central station receives the channel release request from the user station and reclaims the time slot and frequency resources for the next periodic short burst service allocation.

[0034] This invention includes, but is not limited to, the above embodiments. Any equivalent substitutions or partial improvements made under the spirit and principles of this invention shall be considered within the scope of protection of this invention.

Claims

1. A quasi-static return resource allocation method for periodic bursty short messages, applied to a centralized star-shaped satellite network, characterized in that, include: The central station broadcasts a forward signal containing the time reference for the entire network to the user stations; When a user joins the network, they report their periodic short bursts of service transmission needs to the central station. According to the service requirements, the central station pre-allocates one or more dedicated time slots and corresponding carrier frequency resources to the user station from the predefined return resource pool; The central station notifies the user station of the resource allocation results via forward signaling; Based on the allocation results, the user station periodically sends short burst messages on the dedicated time slot; When a service is terminated, the user station requests the central station to release resources, and the central station reclaims the resources for reallocation.

2. The method according to claim 1, characterized in that, In the pre-allocation step, the central station prioritizes allocating time slot resources on already activated carriers, and only activates new carrier frequency resources when the time slot resources of that carrier are insufficient.

3. The method according to claim 2, characterized in that, For a user station that needs to send multiple short messages within a period, the central station prioritizes allocating multiple time slots with adjacent times on the same carrier.

4. The method according to any one of claims 1-3, characterized in that, The forward signal is a TDM signal, and its frame structure is divided into superframe units to provide a synchronization clock reference to the entire network; the return resource pool is divided based on the clock reference to form basic TDMA time slot units.

5. The method according to claim 4, characterized in that, When a user station joins the network, it reports its service requirements through a contention access channel. The service requirement information includes at least the service cycle and the number of burst messages.

6. The method according to claim 1, characterized in that, The central station manages return resources in three ways: contention for access carriers, periodic burst service carriers, and dynamic service carriers.

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