Wireless systems, central equipment, and mobile station equipment
The central device in wireless train communication systems predicts communication failures and adapts transmission methods to ensure effective communication quality and capacity by dynamically switching between capacity and quality priority methods during train passages or adverse weather.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- Filing Date
- 2023-03-09
- Publication Date
- 2026-03-13
AI Technical Summary
Existing wireless communication systems in trains struggle to dynamically adapt communication methods to ensure both communication quality and capacity, particularly during train passages where communication failures are likely due to overlapping or adverse weather conditions.
A central device predicts communication failure sections and determines optimal communication times using transmission capacity or quality priority methods based on remaining passage time and required communication times, dynamically switching between these methods to maintain effective communication.
Ensures optimal communication quality and capacity by dynamically selecting between transmission capacity and quality priority methods, minimizing communication deterioration during train passages or adverse weather conditions.
Smart Images
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Abstract
Description
Technical Field
[0001] The present disclosure relates to a wireless system, Central equipment and mobile station equipment and pertains to
Background Art
[0002] In a wireless system used in trains, conventionally, a technique has been proposed in which a mobile station predicts the timing of passing by another mobile station and selects a quality - priority communication method in a communication section where a passing - by of a mobile station with weak radio wave reception intensity occurs, and a transmission - capacity - priority communication method outside that communication section.
Prior Art Documents
[0008] A central device according to one aspect of the present disclosure is a central device that communicates with a mobile station device mounted on a train via a base station device that wirelessly communicates communication information, comprising: a communication failure section prediction unit that predicts a section of the section on which the train travels that is likely to experience communication failures; a communication time determination unit that determines a transmission capacity priority communication time, which is the time interval required when communicating the communication information using a transmission capacity priority communication method, and a quality priority communication time, which is the time interval required when communicating the communication information using a quality priority communication method that is slower in communication speed than the transmission capacity priority method but has higher communication quality; and when the train communicates the communication information while passing through the communication failure section, if the value obtained by adding the transmission capacity priority communication time to the remaining time interval for the train to pass through the communication failure section is shorter than the quality priority communication time, the unit determines to adopt the transmission capacity priority method to communicate the communication information after the remaining time for passing through the communication failure section has elapsed, and if the value is greater than or equal to the quality priority communication time, Without waiting for the remaining communication failure section to pass, immediately, The system is characterized by comprising: a control unit that decides to communicate the communication information using the aforementioned quality-prioritizing method; and a communication unit that notifies the base station equipment of the communication method decided by the control unit.
[0009] A mobile station device according to one aspect of the present disclosure is a mobile station device that communicates communication information with a central device via a base station device, comprising: a wireless communication unit that receives the communication information from the central device via the base station device, the communication information including passing time, a transmission capacity priority communication time which is the time interval required when communicating the communication information using a transmission capacity priority communication method, and a quality priority communication time which is the time interval required when communicating using a quality priority communication method which is slower in communication speed than the transmission capacity priority method but has higher communication quality; and the mobile station device is mounted on Ta rowWhen a vehicle transmits the communication information while passing through a section of poor communication where communication failures are likely to occur, if the value obtained by adding the transmission capacity priority communication time to the remaining time interval until the train passes through the section of poor communication is shorter than the quality priority communication time, it is decided to transmit the communication information using the transmission capacity priority method after the remaining time interval until the train passes through the section of poor communication has elapsed. If the value is equal to or greater than the quality priority communication time, Without waiting for the remaining communication failure section to pass, immediately, The wireless communication unit comprises a control unit that decides to communicate the communication information using the aforementioned quality-prioritizing method, and the wireless communication unit communicates with the base station device using the communication method determined by the control unit. [Effects of the Invention]
[0011] According to one or more aspects of this disclosure, the optimal wireless communication method can be selected depending on the timing of initiating communication. [Brief explanation of the drawing]
[0012] [Figure 1] This is a block diagram that schematically shows the configuration of the wireless system according to Embodiment 1. [Figure 2] This is a block diagram schematically showing the configuration of the central device in Embodiment 1. [Figure 3] (A) and (B) are block diagrams showing hardware configuration examples. [Figure 4] This is a block diagram schematically showing the configuration of the mobile station equipment in Embodiments 1 to 3. [Figure 5] This is a sequence diagram showing the operation of the wireless system according to Embodiment 1. [Figure 6] This is a block diagram schematically showing the configuration of the wireless system according to Embodiment 2. [Figure 7] This is a block diagram schematically showing the configuration of the central device in Embodiment 2. [Figure 8] This is a sequence diagram showing the operation of the wireless system according to Embodiment 2. [Figure 9]It is a block diagram schematically showing the configuration of the wireless system according to Embodiment 3. [Figure 10] It is a block diagram schematically showing the configuration of the central device in Embodiment 3. [Figure 11] It is a sequence diagram showing the operation of the wireless system according to Embodiment 3.
Mode for Carrying Out the Invention
[0013] Embodiment 1. FIG. 1 is a block diagram schematically showing the configuration of the wireless system 100 according to Embodiment 1. The wireless system 100 includes mobile station devices 110A, 110B, 110C, base station devices 120A, 120B, and a central device 130. In Embodiment 1, a case where a communication poor section, which is a section where communication failure is likely to occur, is an overtaking section where two trains pass each other will be described as an example.
[0014] In the example shown in FIG. 1, trains 102A and 102B are running on the up line 101A, and train 102C is running on the down line 101B. Each of trains 102A to 102C may be composed of one vehicle or a plurality of vehicles.
[0015] Hereinafter, when trains 102A to 102C are not particularly distinguished, the capital letter at the end of the reference numeral will be omitted and they will be denoted as train 102. Such a notation method will also be adopted for other reference numerals.
[0016] Mobile station device 110A is mounted on train 102A, mobile station device 110B is mounted on train 102B, and mobile station device 110C is mounted on train 102C. Base station device 120 and central device 130 are included in wireless communication equipment 103. Here, base station device 120 and central device 130 are also referred to as wireless communication devices.
[0017] In the wireless system 100, the mobile station equipment 110 mounted on the train 102 communicates wirelessly with the central unit 130 via the base station equipment 120 included in the wireless communication equipment 103. In other words, the wireless system 100 is a system that wirelessly communicates communication information between a mobile station device 110 mounted on train 102 and a wireless communication device not mounted on train 102. Here, the base station device 120 communicates with the mobile station device 110 using the communication method determined by the central device 130.
[0018] The base station device 120A has transceiver units 121A and 121B, and the transceiver units 121A and 121B are connected to leaky coaxial cables (hereinafter referred to as LCX) 122A and 122B, respectively.
[0019] The base station device 120B has transceiver units 121C and 121D, which are connected to LCX 122C and 122D, respectively.
[0020] The transmitting / receiving unit 121 uses the LCX 122 connected to it as an antenna and communicates radio waves via the LCX 122.
[0021] Although simplified in Figure 1, each of the LCX122A, 122B, 122C, and 122D consists of a set of LCX units installed on both the up and down sides. LCX122A, 122B, 122C, and 122D are installed along tracks 101A and 101B in communication sections 104A, 104B, 104C, and 104D, respectively, and are used for communication in the communication sections 104A, 104B, 104C, and 104D in which they are installed. These communication sections 104 will be managed by the wireless communication equipment 103.
[0022] In the example shown in Figure 1, trains 102A and 102B pass each other in communication section 104B. However, the communication section 104 that includes the location where train 102 passes each other, which is communication section 104B in Figure 1, is also called the passing section 105. Conversely, the communication sections 104 where train 102 does not pass each other, which are communication sections 104A, 104C, and 104D in Figure 1, are also called the non-passing section 106.
[0023] The central unit 130 identifies the passing section 105 by predicting when trains 102 will pass each other, and controls the communication method with the mobile station unit 110. Figure 2 is a block diagram that schematically shows the configuration of the central device 130. The central device 130 includes a train schedule acquisition unit 131, an information acquisition unit 132, a storage unit 133, a passing section prediction unit 134, a communication time specification unit 135, a communication method control unit 136, and a communication unit 137.
[0024] The train schedule acquisition unit 131 acquires train schedule information, which is information regarding the operation schedule of each train 102, from a predetermined information provider (for example, a train control center). For example, the train schedule acquisition unit 131 acquires train schedule information from the information provider via the communication unit 137.
[0025] Furthermore, if the train schedule information is updated as appropriate by the information provider, the train schedule acquisition unit 131 monitors the update or obtains the latest train schedule information when the information provider transmits the updated train schedule information. The train schedule acquisition unit 131 supplies the acquired train schedule information to the storage unit 133 and the passing section prediction unit 134.
[0026] The scheduled operation information includes, for example, information that associates train identification information, which is information used to identify each train 102, with the scheduled operation details, which are the planned movements of the train. In other words, the scheduled operation information shows the planned movements of each train.
[0027] Train identification information includes, for example, the train set number. The planned route includes, for example, the route location, route time, and route speed. The information contained in the train schedule information is linked. Therefore, for example, by setting the train set number as the search key and searching the train schedule information, it is possible to extract the planned running details of the desired train 102. Also, for example, by setting the running time as the search key, it is possible to extract the running position of each train 102 at the desired time.
[0028] The information acquisition unit 132 acquires various information from each mobile station device 110 and each base station device 120, and supplies the acquired information to the storage unit 133, the passing section prediction unit 134, the communication time specification unit 135, and the communication method control unit 136. For example, the information acquisition unit 132 acquires mobile station information from the mobile station equipment 110. The information acquisition unit 132 also acquires base station information from the base station equipment 120. The information exchanged between the central unit 130 and the mobile station equipment 110, including the mobile station information, is also referred to as communication information.
[0029] The mobile station information includes, for example, the train set number of train 102, the actual running details of train 102, and the mobile station communication status, which is the communication status of the mobile station equipment 110 installed on train 102.
[0030] The actual driving details include, for example, the position, speed, and detection time of the train 102 as it was operating. The actual driving details may also include, for example, passing detection information, which indicates that a passing encounter was actually detected. The mobile station communication status includes, for example, the reception level, line quality, and the time of detection. The information contained in the mobile station information is correlated. Therefore, by setting the detection time as the search key, for example, it is possible to extract information detected at a desired time.
[0031] Base station information is, for example, information that associates base station identification information, which is information for identifying each base station device 120, base station internal identification information, which is information for identifying each transceiver 121 within the base station device 120, and base station communication status, which is information regarding the communication status of the base station device 120. The base station communication status includes, for example, the reception level, line quality, and the time of detection. The information contained in base station data is interconnected. Therefore, for example, by setting the detection time as the search key, it is possible to extract information detected at a desired time.
[0032] The memory unit 133 stores the operation schedule information supplied from the operation schedule acquisition unit 131, and the mobile station information and base station information supplied from the information acquisition unit 132. Here, it is assumed that a database is constructed by associating the information stored in the memory unit 133. This allows, for example, the planned and actual running details of a desired train 102 to be extracted by setting the train formation number as the search key. At the same time, it is possible to extract either or both of the mobile station communication status and base station communication information associated with the actual running details.
[0033] The passing section prediction unit 134 functions as a communication failure section prediction unit that predicts communication failure sections, which are sections within the section on which train 102 is traveling, where communication failures are likely to occur. In Embodiment 1, the passing section prediction unit 134 predicts, using a predetermined passing section prediction method, which communication section 104 and when the passing of trains 102 will occur, and supplies the prediction result to the communication system control unit 136. The passing section prediction unit 134 also sends the prediction result to each base station device 120 via the communication unit 137.
[0034] Specifically, the passing section prediction unit 134 predicts the train 102 that will pass each other. Furthermore, the passing section prediction unit 134 predicts the passing locations where passing will occur, and thereby identifies the communication section 104 that includes the passing locations, and predicts the passing section 105. For example, by pre-storing information on the setting range of each communication section 104, in other words, information on the installation range of each LCX 12, in the storage unit 133, the passing section prediction unit 134 can associate the predicted passing location with the communication section 104B that includes that passing location.
[0035] Furthermore, the passing section prediction unit 134 predicts the passing time, which is the time when the trains will pass each other. The passing time may be defined, for example, as the period from the time the passing begins to the time the passing ends, or the passing period may be defined as the period from the time when both trains 102 predicted to pass each other are in the passing section 105 until that state ends. Other definitions may also be used for the passing time.
[0036] As a method for predicting passing situations, it is possible to predict the occurrence of passing situations by using at least one of the planned driving content and the actual driving content. For example, the passing section prediction unit 134 can predict the occurrence of passing sections by comparing the planned running details of each train 102 supplied by the operation schedule acquisition unit 131. Furthermore, the passing section prediction unit 134 may correct the planned driving content based on the actual driving content supplied in real time from the information acquisition unit 132, and predict the occurrence of passing sections from the corrected planned driving content. Furthermore, the passing section prediction unit 134 may predict the occurrence of passing sections by referring to past actual driving data of the same schedule stored in the memory unit 133, in addition to, or instead of, real-time actual driving data. By considering various types of information in this way, the prediction accuracy can be improved.
[0037] Alternatively, for example, the passing section prediction unit 134 may predict the occurrence of passing sections by comparing them with the actual driving content supplied in real time from the information acquisition unit 132, rather than using the planned driving content supplied from the operation schedule acquisition unit 131. In this case as well, the passing section prediction unit 134 may refer to past actual driving data stored in the memory unit 133. For example, if the reliability of the planned driving data decreases due to disruptions in the operating schedule, the passing section prediction unit 134 can ensure prediction accuracy by not using the planned driving data.
[0038] The passing interval prediction unit 134 may employ passing methods other than those exemplified above. Furthermore, while the passing interval prediction unit 134 may be equipped with only one type of passing prediction method, it may also be equipped with multiple types of passing prediction methods, and the passing interval prediction unit 134 may switch between them as appropriate.
[0039] Furthermore, the passing section prediction unit 134 can predict the communication environment level in the passing section 105 by, for example, referring to past mobile station communication status and base station communication status stored in the memory unit 133. In addition, the passing section prediction unit 134 may use information other than communication status, such as the boundary of the communication section 104, handover, equipment malfunction, or weather (snow, snowfall, or rainfall), to predict the communication environment level by acquiring such information in real time or by storing such information in the memory unit 133, etc.
[0040] Such predictions of communication environment levels can also be made for non-passing sections 106. For example, the passing section prediction unit 134 may be configured to predict deterioration of the communication environment in non-passing sections 106 due to factors other than passing.
[0041] The communication time determination unit 135 determines the communication time, which is the time interval required when transmitting communication information using each communication method, and provides the determined communication time to the communication method control unit 136. Specifically, the communication time determination unit 135 determines the transmission capacity priority communication time, which is the time interval required when transmitting communication information using the transmission capacity priority method, and the quality priority communication time, which is the time interval required when transmitting communication information using the quality priority method, which has a slower communication speed than the transmission capacity priority method but offers higher communication quality. Furthermore, the communication time identification unit 135 sends the identified communication time to each base station device 120 via the communication unit 137.
[0042] The communication time determination unit 135 may, for example, calculate in real time the communication time when the transmission size of the communication information is transmitted using each communication method available to the central device 130. Alternatively, the communication time identification unit 135 may maintain a table for each communication method that records the communication time relative to the transmission size, and retrieve the communication time from that table according to the transmission size of the communication information.
[0043] The communication time determination unit 135 may employ communication time determination methods other than those exemplified above. Furthermore, while the communication time determination unit 135 may be equipped with only one type of communication time determination method, it may also be equipped with multiple types of communication time determination methods and switch between them as appropriate.
[0044] The communication method control unit 136 determines the communication method to be used in each communication section 104 based on the passing time predicted by the passing section prediction unit 134 and the communication time calculated by the communication time specification unit 135.
[0045] Specifically, when transmitting communication information, if the train 102 transmitting the communication information is located in a passing section predicted by the passing section prediction unit 134, the communication control unit 136 uses the remaining passing time, which is the remaining time from the start of transmission of the communication information until passing the passing section 105, and the communication time of the communication information determined by the communication time determination unit 135 to determine the communication method in that passing section using the following conditions.
[0046] If "remaining delay time + communication time under transmission capacity priority method < communication time under communication quality priority method", the communication control unit 136 applies the transmission capacity priority method, waits for the remaining delay time, and then starts communication under the transmission capacity priority method.
[0047] If "remaining time for passing each other + communication time for transmission capacity priority method ≥ communication time for communication quality priority method", the communication method control unit 136 applies the communication quality priority method and immediately starts communication. Here, the remaining passing time is the remaining time interval during which the trains will pass through the section where communication is poor.
[0048] Furthermore, when the communication control unit 136 transmits communication information, if the train 102 to which the communication information is to be transmitted is located in the non-passing section 106 predicted by the passing section prediction unit 134, it applies the transmission capacity priority method and immediately starts communication. The communication method determined as described above is notified to the base station device 120 via the communication unit 137, and the base station device 120 communicates with the mobile station device 110 using the determined communication method.
[0049] Communication quality and transmission capacity can be controlled by selecting modulation schemes and other parameters. For example, schemes that operate at a low C / N ratio can improve communication quality, while schemes that require a high C / N ratio can increase transmission capacity.
[0050] As described above, whether each communication section 104 becomes a passing section 105 or a non-passing section 106 changes dynamically as the train 102 moves. Therefore, the prediction results by the passing section prediction unit 134 also change dynamically, and the switching of the communication method for each communication section 104 is performed dynamically by the communication method control unit 136.
[0051] As described above, the communication control unit 136 functions as a control unit that, when train 102 is passing through a passing section which is a communication failure section and is attempting to transmit communication information, decides to adopt the transmission capacity priority method and transmit the communication information after the remaining time to pass through the communication failure section has elapsed, if the value obtained by adding the transmission capacity priority communication time to the remaining time to pass through the communication failure section is shorter than the quality priority communication time, and decides to adopt the quality priority method and transmit the communication information if the added value is equal to or greater than the quality priority communication time.
[0052] The communication unit 137 communicates with the base station equipment 120. The communication unit 137 can also communicate with devices other than the base station equipment 120.
[0053] Some or all of the operation schedule acquisition unit 131, information acquisition unit 132, passing section prediction unit 134, communication time specification unit 135, and communication method control unit 136 described above can be configured, for example, with a memory 10 and a processor 11 such as a CPU (Central Processing Unit) that executes the program stored in the memory 10, as shown in Figure 3(A). In other words, the central device 130 can be implemented by a so-called computer. Such a program may be provided via a network, or it may be provided by being recorded on a recording medium. That is, such a program may be provided, for example, as a program product.
[0054] Furthermore, some or all of the operation schedule acquisition unit 131, information acquisition unit 132, passing section prediction unit 134, communication time specification unit 135, and communication method control unit 136 can be composed of processing circuits 12 such as a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, an ASIC (Application Specific Integrated Circuit), or an FPGA (Field Programmable Gate Array), as shown in Figure 3(B). As described above, the operation schedule acquisition unit 131, information acquisition unit 132, passing section prediction unit 134, communication time specification unit 135, and communication method control unit 136 can be configured as a processing circuit network.
[0055] The storage unit 133 can be composed of storage devices such as an HDD (Hard Disk Drive), an SSD (Solid State Drive), volatile memory, and non-volatile memory. The communication unit 137 can be configured using a communication interface (I / F) such as a network interface card (NIC).
[0056] Figure 4 is a block diagram that schematically shows the configuration of the mobile station equipment 110. The mobile station device 110 comprises a wireless communication unit 111, a communication control unit 112, and a storage unit 113. The wireless communication unit 111 communicates wirelessly with the base station device 120. Here, the wireless communication unit 111 transmits and receives communication information using the communication method determined by the communication control unit 112.
[0057] The communication control unit 112 controls the processing in the mobile station device 110. For example, the communication control unit 112 generates mobile station information and transmits it to the base station device 120 via the radio communication unit 111. The mobile station information is then sent from the base station device 120 to the central device 130.
[0058] Furthermore, the communication control unit 112 receives information from the central device 130 via the wireless communication unit 111 and switches the communication method used when the wireless communication unit 111 communicates between the transmission capacity priority method and the communication quality priority method. For example, if the remaining delay time + the communication time in the transmission capacity priority method < the communication time in the communication quality priority method is found in the received information, the communication control unit 112 applies the transmission capacity priority method, waits for the remaining delay time, and then starts communication in the transmission capacity priority method.
[0059] On the other hand, if "remaining time for passing each other + communication time for transmission capacity priority method ≥ communication time for communication quality priority method", the communication control unit 112 applies the communication quality priority method and immediately starts transmitting communication information.
[0060] Furthermore, when the communication control unit 112 transmits communication information, if its own train 102 is present in the non-passing section 106, it applies the transmission capacity priority method and immediately starts transmitting the communication information.
[0061] As described above, when train 102 is passing through a passing section which is a communication failure section and is attempting to transmit communication information, the communication control unit 112, when the value obtained by adding the transmission capacity priority communication time to the remaining time interval for passing through the communication failure section is shorter than the quality priority communication time, decides to adopt the transmission capacity priority method and transmit the communication information after the remaining time for passing through the communication failure section has elapsed. If the added value is equal to or greater than the quality priority communication time, the control unit decides to adopt the quality priority method and transmit the communication information.
[0062] The memory unit 113 stores information necessary for processing in the mobile station device 110.
[0063] Some or all of the communication control unit 112 described above can be configured, for example, as shown in Figure 4(A), with a memory 10 and a processor 11 that executes the program stored in the memory 10. Furthermore, part or all of the communication control unit 112 can be composed of a processing circuit 12, for example, as shown in Figure 4(B). As described above, the communication control unit 112 can be configured with a processing circuit network.
[0064] The storage unit 113 can be composed of storage devices such as HDDs, SSDs, volatile memory, and non-volatile memory. The wireless communication unit 111 can be configured using a wireless communication interface.
[0065] Next, I will explain how it works. Figure 5 is a sequence diagram showing the operation of the wireless system 100 according to Embodiment 1. First, the operation schedule acquisition unit 131 of the central device 130 acquires operation schedule information, and the information acquisition unit 132 acquires base station information and mobile station information (S10).
[0066] Next, the passing section prediction unit 134 of the central device 130 predicts the passing section for train 102 (S11). The processes in steps S10 and S11 are executed periodically, for example.
[0067] Next, the passing section prediction unit 134 of the central device 130 predicts the passing time from the predicted passing section (S12).
[0068] Next, the communication time determination unit 135 of the central device 130 calculates the communication time required when transmitting communication information using each communication method (S13). The resulting communication time is then provided to the communication method control unit 136. The passing time, communication time under the transmission capacity priority method, and communication time under the communication quality priority method, calculated as described above, are transmitted to the mobile station device 110 via the communication unit 137 (S14, S15). The predicted passing time is then provided to the communication method control unit 136 of the central device 130.
[0069] Next, when transmitting communication information, the communication method control unit 136 of the central unit 130, if the train 102 on which the mobile station device 110 transmitting the communication information is installed is traveling in a passing section, decides to apply the transmission capacity priority method if the condition "remaining passing time + communication time for the transmission capacity priority method < communication time for the communication quality priority method" is met (S16). Here, we will explain assuming that the application of the transmission capacity priority method has been decided. In this case, the communication method control unit 136 waits for the remaining passing time to elapse and then executes the communication.
[0070] Furthermore, the mobile station device 110 selects a communication method by determining whether the above conditions are met based on the received passing time, the communication time under the transmission capacity priority method, and the communication time under the communication quality priority method (S17). Here, we will explain assuming that the application of the transmission capacity priority method has been decided. In this case, the mobile station device 110 waits for the remaining passing time to elapse and then performs communication.
[0071] In the above sequence, as shown in steps S14 and S15, the passing time, the communication time in the transmission capacity priority method, and the communication time in the communication quality priority method are transmitted to the mobile station device 110. However, Embodiment 1 is not limited to such examples. For example, the communication method control unit 136 of the central device 130 may transmit the communication method selection result to the mobile station device 110. The mobile station device 110 may control its own communication method based on the received selection result.
[0072] Although the above example illustrates the case where two opposing trains 102 pass each other, the wireless system 100 described in Embodiment 1 can also be applied to cases where two trains are traveling in the same direction and passing each other occurs due to overtaking.
[0073] According to the above, if the condition "remaining passing time + communication time using the transmission capacity priority method < communication time using the communication quality priority method" is met, then communication using the transmission capacity communication method will be performed after traveling through a communication section with poor radio wave conditions. This minimizes the deterioration of communication quality when the communication environment worsens due to the passing of moving objects. Therefore, it is possible to ensure both communication quality and transmission capacity compared to a configuration with a fixed communication method.
[0074] Embodiment 2. In Embodiment 1 described above, a configuration for predicting communication failure due to trains 102 passing each other was illustrated. Embodiment 2 illustrates a configuration for predicting communication failure due to worsening weather. In other words, Embodiment 2 describes an example where the communication failure section is a section where the weather is deteriorating.
[0075] Figure 6 is a block diagram schematically showing the configuration of the wireless system 200 according to Embodiment 2. The wireless system 200 comprises mobile station equipment 210A and 210B, base station equipment 120A and 120B, and a central unit 230. The base station device 120 of the wireless system 200 according to Embodiment 2 is the same as the base station device 120 of the wireless system 100 according to Embodiment 1. However, in the example shown in Figure 5, it is assumed that trains 102A and 102B are running on the up track 101A. Furthermore, train 102A is equipped with mobile station equipment 210A, and train 102B is equipped with mobile station equipment 210B.
[0076] In the wireless system 200, the mobile station equipment 210 mounted on the train 102 communicates wirelessly with the central equipment 230 via the base station equipment 120 included in the wireless communication equipment 103.
[0077] In Embodiment 2, it is assumed that the weather is deteriorating in the area included in communication section 104B. The communication section 104 that includes the area with deteriorating weather, or communication section 104B in Figure 6, is also referred to as the bad weather section 205. The communication section 104 that does not include the area with deteriorating weather is also referred to as the good weather section 206.
[0078] The central unit 230 identifies the bad weather section 205 by predicting the deterioration of the weather and controls the communication method with the mobile station unit 210. Figure 7 is a block diagram schematically showing the configuration of the central device 230. The central unit 230 includes a route schedule acquisition unit 131, an information acquisition unit 132, a storage unit 233, a communication time specification unit 135, a communication method control unit 236, a communication unit 137, a weather information acquisition unit 238, and a bad weather section travel prediction unit 239.
[0079] In Embodiment 2, the operation schedule acquisition unit 131, information acquisition unit 132, communication time specification unit 135, and communication unit 137 of the central device 230 are the same as those of the operation schedule acquisition unit 131, information acquisition unit 132, communication time specification unit 135, and communication unit 137 of the central device 130 in Embodiment 1. However, the train schedule acquisition unit 131 also supplies the acquired train schedule information to the weather information acquisition unit 238.
[0080] The weather information acquisition unit 238, by referring to the operation schedule information acquired from the operation schedule acquisition unit 131, acquires weather information such as precipitation and snowfall information (for example, weather data published by the Japan Meteorological Agency) for the communication section 104 on which each train 102 travels, from predetermined information providers via the communication unit 137. When the weather information is updated by the information provider as appropriate, the weather information acquisition unit 238 monitors the update or acquires the latest weather information when the information provider transmits the updated weather information. The weather information acquisition unit 238 then supplies the acquired weather information to the storage unit 233 and the bad weather section travel prediction unit 239.
[0081] The memory unit 233 stores the operation schedule information supplied from the operation schedule acquisition unit 131, the mobile station information and base station information supplied from the information acquisition unit 132, and the weather information supplied from the weather information acquisition unit 238.
[0082] The bad weather section travel prediction unit 239 identifies which communication section 104 will become a bad weather section 205 and identifies the train 102 that will travel through the bad weather section 205. The bad weather section travel prediction unit 239 then predicts the bad weather section travel time, which is the amount of time that train 102 will travel through the bad weather section.
[0083] Specifically, the bad weather section travel prediction unit 239 predicts which train 102 will travel in which communication section 104 during bad weather using a predetermined bad weather section travel prediction method, and supplies the prediction result to the communication system control unit 236. The bad weather section travel prediction unit 239 also sends the prediction result to the mobile station device 210 via the communication unit 137.
[0084] One method for predicting travel in bad weather sections is to predict the occurrence of travel in bad weather sections based on the planned travel details of each train 102 supplied by the operation schedule acquisition unit 131 and the weather information supplied by the weather information acquisition unit 238. Alternatively, the bad weather section travel prediction unit 239 may correct the bad weather sections in accordance with the weather information supplied in real time from the weather information acquisition unit 238 and make a prediction based on the corrected content. Or, in addition to real-time weather information, the bad weather section travel prediction unit 239 may refer to weather information for actual travel sections of the same operation schedule from past weather information stored in the storage unit 233. By considering various types of information in this way, the prediction accuracy can be improved.
[0085] The communication method control unit 236 determines the communication method to be used in each communication section 104 based on the bad weather section travel time predicted by the bad weather section travel prediction unit 239 and the communication time calculated by the communication time specification unit 135.
[0086] Specifically, when transmitting communication information, if the train 102 transmitting the communication information is in a bad weather section 205 predicted by the bad weather section travel prediction unit 239, the communication control unit 236 uses the remaining bad weather section travel time, which is the remaining travel time from the start of transmission of the communication information until passing through the bad weather section 205, and the communication time of the communication information determined by the communication time determination unit 135, to determine the communication method in that bad weather section 205 using the following conditions.
[0087] If "remaining time spent traveling in the bad weather section + communication time using the transmission capacity priority method < communication time using the communication quality priority method", the communication control unit 236 applies the transmission capacity priority method, waits for the remaining time spent traveling in the bad weather section, and then starts communication using the transmission capacity priority method. Here, the remaining time spent traveling in the bad weather section is the remaining time interval during which train 102 will pass through the bad weather section as a communication failure section.
[0088] If "remaining time spent driving in bad weather + communication time under the transmission capacity priority method ≥ communication time under the communication quality priority method", the communication control unit 236 applies the communication quality priority method and immediately starts communication.
[0089] Furthermore, when the communication control unit 236 transmits communication information, if the train 102 to which the communication information is to be transmitted is located in the good weather section 206 predicted by the bad weather section travel prediction unit 239, it applies the transmission capacity priority method and immediately starts communication.
[0090] Some or all of the weather information acquisition unit 238 and the bad weather section travel prediction unit 239 described above can also be configured, for example, as shown in Figure 4(A), with a memory 10 and a processor 11 that executes the program stored in the memory 10. Furthermore, some or all of the weather information acquisition unit 238 and the bad weather section travel prediction unit 239 can be configured in the processing circuit 12, for example, as shown in Figure 4(B). As described above, the weather information acquisition unit 238 and the bad weather section travel prediction unit 239 can be configured as a processing circuit network.
[0091] As shown in Figure 4, the mobile station device 210 in Embodiment 2 comprises a wireless communication unit 111, a communication control unit 212, and a storage unit 113. The wireless communication unit 111 and the storage unit 113 of the mobile station device 210 in Embodiment 2 are the same as the wireless communication unit 111 and the storage unit 113 of the mobile station device 110 in Embodiment 1.
[0092] The communication control unit 212 controls the processing performed by the mobile station device 210. For example, the communication control unit 212 generates mobile station information and transmits that mobile station information to the base station device 120 via the radio communication unit 111. The mobile station information is then sent from the base station device 120 to the central device 230.
[0093] Furthermore, the communication control unit 212 receives information from the central device 130 via the wireless communication unit 111 and switches the communication method used when the wireless communication unit 111 communicates between the transmission capacity priority method and the communication quality priority method. For example, the communication control unit 212, based on the received information including the time spent traveling in the bad weather section, the communication time using the transmission capacity priority method, and the communication time using the communication quality priority method, applies the transmission capacity priority method if "remaining time spent traveling in the bad weather section + communication time using the transmission capacity priority method < communication time using the communication quality priority method," waits for the remaining time spent traveling in the bad weather section, and then starts communication using the transmission capacity priority method.
[0094] If "remaining time spent traveling in bad weather + communication time using the transmission capacity priority method ≥ communication time using the communication quality priority method", the communication control unit 212 applies the communication quality priority method and immediately starts communication.
[0095] Furthermore, when the communication control unit 212 transmits communication information, if its own train 102 is in the good weather section 206, it applies the transmission capacity priority method and immediately starts communication.
[0096] Next, I will explain how it works. Figure 8 is a sequence diagram showing the operation of the wireless system 200 according to Embodiment 2. First, the operation schedule acquisition unit 131 of the central device 230 acquires operation schedule information, the information acquisition unit 132 acquires base station information and mobile station information, and the weather information acquisition unit 238 acquires weather information (S20).
[0097] Next, the bad weather section travel prediction unit 239 of the central device 230 predicts the bad weather section (S21). The processing in steps S20 and S21 is performed periodically, for example.
[0098] Next, the bad weather section travel prediction unit 239 of the central device 230 predicts the travel time in the bad weather section from the predicted bad weather section (S22). The travel time in the bad weather section is provided to the communication system control unit 236.
[0099] Next, the communication time determination unit 135 of the central device 230 calculates the communication time required when transmitting communication information using each communication method (S23). The resulting communication time is then provided to the communication method control unit 236. The travel time in the bad weather section, the communication time using the transmission capacity priority method, and the communication time using the communication quality priority method, calculated as described above, are transmitted to the mobile station device 210 via the communication unit 137 (S24, S25).
[0100] Next, when transmitting communication information, the communication method control unit 236 of the central unit 230 decides to apply the transmission capacity priority method if the train 102, on which the mobile station device 210 transmitting the communication information is installed, is traveling through a bad weather section, and the condition "remaining travel time in the bad weather section + communication time for the transmission capacity priority method < communication time for the communication quality priority method" is met (S26). Here, we will explain assuming that the application of the transmission capacity priority method has been decided. In this case, the communication method control unit 236 waits for the remaining travel time in the bad weather section to elapse before executing the communication.
[0101] Furthermore, the mobile station device 210 selects a communication method by determining whether the above conditions are met based on the received time spent traveling in the bad weather section, the communication time using the transmission capacity priority method, and the communication time using the communication quality priority method (S27). Here, we will explain assuming that the application of the transmission capacity priority method has been decided. In this case, the mobile station device 210 waits for the remaining passing time to elapse and then performs communication.
[0102] According to the above, if the condition "remaining travel time in bad weather section + communication time using the transmission capacity priority method < communication time using the communication quality priority method" is met, then communication using the transmission capacity communication method will be performed after traveling through the communication section with poor radio wave conditions. This minimizes the deterioration of communication quality when the communication environment deteriorates due to bad weather. Therefore, compared to a configuration with a fixed communication method, both communication quality and transmission capacity can be ensured.
[0103] Embodiment 3. Embodiment 3 illustrates a configuration that predicts the deterioration of radio wave conditions at a fixed location, such as in a tunnel section. In other words, Embodiment 3 describes an example where the communication failure section is a radio wave failure section, which is a section where factors that worsen radio waves exist.
[0104] Figure 9 is a block diagram schematically showing the configuration of the wireless system 300 according to Embodiment 3. The wireless system 300 comprises mobile station equipment 310A and 310B, base station equipment 120A and 120B, and a central unit 330. The base station device 120 of the wireless system 300 according to Embodiment 3 is the same as the base station device 120 of the wireless system 100 according to Embodiment 1. However, in the example shown in Figure 9, it is assumed that trains 102A and 102B are running on the up track 101A. Furthermore, train 102A is equipped with mobile station equipment 310A, and train 102B is equipped with mobile station equipment 310B.
[0105] In the wireless system 300, the mobile station equipment 310 mounted on the train 102 communicates wirelessly with the central unit 330 via the base station equipment 120 included in the wireless communication equipment 103.
[0106] In Embodiment 3, a tunnel is provided in the communication section 104B. The communication section 104 that includes locations where factors that degrade radio waves exist, such as tunnels, is also referred to as the poor radio wave section 305 in Figure 9. The communication section 104 that does not include locations where factors that degrade radio waves exist is also referred to as the good radio wave section 306.
[0107] The central unit 330 identifies the radio wave interference section 305 based on the conditions around the line 101A and controls the communication method with the mobile station unit 310. Figure 10 is a block diagram schematically showing the configuration of the central device 330. The central unit 330 includes a route schedule acquisition unit 131, an information acquisition unit 132, a storage unit 333, a communication time specification unit 135, a communication method control unit 336, a communication unit 137, and a radio wave poor section travel prediction unit 340.
[0108] In Embodiment 3, the operation schedule acquisition unit 131, information acquisition unit 132, communication time specification unit 135, and communication unit 137 of the central device 330 are the same as those of the operation schedule acquisition unit 131, information acquisition unit 132, communication time specification unit 135, and communication unit 137 of the central device 130 in Embodiment 1. However, the operation schedule acquisition unit 131 also supplies the acquired operation schedule information to the radio wave poor section travel prediction unit 340.
[0109] The memory unit 333 stores the operation schedule information supplied from the operation schedule acquisition unit 131, and the mobile station information and base station information supplied from the information acquisition unit 132. Furthermore, the memory unit 333 also stores radio wave degradation information, which is information indicating locations where factors that worsen radio waves exist, such as tunnels. The memory unit 333 then constructs a database by associating the acquired information. This allows, for example, the association of the tunnel length and location of tunnel sections through which trains have passed in the past with the communication location and time of each communication and the radio wave strength data at the time of communication.
[0110] The radio wave poor section travel prediction unit 340 identifies which communication section 104 will become the radio wave poor section 305 and identifies the train 102 that will travel through the radio wave poor section 305. The radio wave poor section travel prediction unit 340 then predicts the radio wave poor section travel time, which is the amount of time the train 102 will travel through the radio wave poor section 305.
[0111] Specifically, the radio wave poor section travel prediction unit 340 predicts which train 102 will travel through which communication section 104 in a radio wave poor area using a predetermined radio wave poor section travel prediction method, and supplies the prediction result to the communication system control unit 336. The radio wave poor section travel prediction unit 340 also sends the prediction result to the mobile station device 310 via the communication unit 137.
[0112] One method for predicting travel through sections with poor radio signal reception is to refer to information stored in the memory unit 333 to predict travel through tunnel sections where poor radio signal reception is likely to occur. Alternatively, the radio signal reception section travel prediction unit 340 may predict the time when radio signal strength will decrease by obtaining the radio signal strength at different times of communication from the information stored in the memory unit 333. In this way, the radio signal reception section travel prediction unit 340 can improve its prediction accuracy by considering various types of information stored in the memory unit 333.
[0113] The communication method control unit 336 determines the communication method to be used in each communication section 104 based on the radio wave poor section travel time predicted by the radio wave poor section travel prediction unit 340 and the communication time calculated by the communication time specification unit 135.
[0114] Specifically, when transmitting communication information, if the train 102 transmitting the communication information is in a radio wave-poor section 305 predicted by the radio wave-poor section travel prediction unit 340, the communication control unit 336 uses the remaining travel time in the radio wave-poor section, which is the remaining travel time from the start of transmission of the communication information until passing through the radio wave-poor section 305, and the communication time of the communication information determined by the communication time determination unit 135, to determine the communication method in the radio wave-poor section 305 using the following conditions.
[0115] If "remaining time spent traveling in the section with poor radio signal + communication time using the transmission capacity priority method < communication time using the communication quality priority method", the communication control unit 336 applies the transmission capacity priority method, waits for the remaining time spent traveling in the section with poor radio signal, and then starts communication using the transmission capacity priority method. Here, the remaining time spent traveling through the radio wave-deprived section is the remaining time interval during which train 102 will pass through the radio wave-deprived section, which is a communication-deprived section.
[0116] If "remaining time spent in the section with poor radio signal + communication time using the transmission capacity priority method ≥ communication time using the communication quality priority method", the communication control unit 336 applies the communication quality priority method and immediately starts communication.
[0117] Furthermore, when the communication control unit 336 transmits communication information, if the train 102 to which the communication information is to be transmitted is located in the radio wave-good section 306 predicted by the radio wave-poor section travel prediction unit 340, it applies the transmission capacity priority method and immediately starts communication.
[0118] Some or all of the radio wave poor section travel prediction unit 340 described above can also be configured, for example, as shown in Figure 4(A), with a memory 10 and a processor 11 that executes the program stored in the memory 10. Furthermore, part or all of the radio wave poor section travel prediction unit 340 can be configured with a processing circuit 12, for example, as shown in Figure 4(B). As described above, the radio wave poor section travel prediction unit 340 can be configured with a processing circuit network.
[0119] As shown in Figure 4, the mobile station device 310 in Embodiment 3 comprises a wireless communication unit 111, a communication control unit 312, and a storage unit 113. The wireless communication unit 111 and the storage unit 113 of the mobile station device 310 in Embodiment 3 are the same as the wireless communication unit 111 and the storage unit 113 of the mobile station device 110 in Embodiment 1.
[0120] The communication control unit 312 controls the processing performed by the mobile station device 310. For example, the communication control unit 312 generates mobile station information and transmits it to the base station device 120 via the radio communication unit 111. The mobile station information is then sent from the base station device 120 to the central device 330.
[0121] Furthermore, the communication control unit 312 receives information from the central device 330 via the wireless communication unit 111 and switches the communication method used when the wireless communication unit 111 communicates between the transmission capacity priority method and the communication quality priority method. For example, the communication control unit 312, based on the received information including the time spent traveling in the radio wave poor section, the communication time using the transmission capacity priority method, and the communication time using the communication quality priority method, applies the transmission capacity priority method if "remaining time spent traveling in the radio wave poor section + communication time using the transmission capacity priority method < communication time using the communication quality priority method," waits for the remaining time spent traveling in the radio wave poor section, and then starts communication using the transmission capacity priority method.
[0122] If "remaining time spent in the section with poor radio signal + communication time using the transmission capacity priority method ≥ communication time using the communication quality priority method", the communication control unit 312 applies the communication quality priority method and immediately starts communication.
[0123] Furthermore, when the communication control unit 312 transmits communication information, if its own train 102 is in a radio wave-good section 306, it applies the transmission capacity priority method and immediately starts communication.
[0124] Next, I will explain how it works. Figure 11 is a sequence diagram showing the operation of the wireless system 300 according to Embodiment 3. First, the operation schedule acquisition unit 131 of the central device 330 acquires operation schedule information, and the information acquisition unit 132 acquires base station information and mobile station information (S30).
[0125] Next, the radio wave poor section travel prediction unit 340 of the central device 330 predicts the radio wave poor section (S31). The processing in steps S30 and S31 is performed periodically, for example.
[0126] Next, the communication control unit 336 of the central device 330 predicts the travel time in the radio wave poor section from the predicted radio wave poor section (S32). The travel time in the radio wave poor section is provided to the communication control unit 336.
[0127] Next, the radio wave poor section travel prediction unit 340 of the central device 330 calculates the communication time required when transmitting communication information using each communication method (S33). The resulting communication time is provided to the communication method control unit 336. The travel time in the radio wave poor section, the communication time using the transmission capacity priority method, and the communication time using the communication quality priority method, calculated as described above, are transmitted to the mobile station device 310 via the communication unit 137 (S34, S35).
[0128] Next, when transmitting communication information, the communication method control unit 336 of the central unit 330, if the train 102 on which the mobile station device 310 transmitting the communication information is installed is traveling through a bad weather section, decides to apply the transmission capacity priority method if the condition "remaining travel time in the radio wave poor section + communication time for the transmission capacity priority method < communication time for the communication quality priority method" is met (S36). Here, we will explain assuming that the application of the transmission capacity priority method has been decided. In this case, the communication method control unit 336 waits for the remaining travel time in the radio wave poor section to elapse and then executes the communication.
[0129] Furthermore, the mobile station device 310 selects a communication method by determining whether the above conditions are met based on the received time spent traveling through the radio wave-poor section, the communication time using the transmission capacity priority method, and the communication time using the communication quality priority method (S37). Here, we will explain assuming that the application of the transmission capacity priority method has been decided. In this case, the mobile station device 310 waits for the remaining time spent traveling through the radio wave-poor section to elapse before performing communication.
[0130] According to the above, if the condition "remaining travel time in the section with poor radio signal + communication time using the transmission capacity priority method < communication time using the communication quality priority method" is met, then communication using the transmission capacity communication method will be performed after traveling through the section with poor radio signal conditions. This minimizes the deterioration of communication quality when the communication environment deteriorates due to tunnels or surrounding buildings, etc. Therefore, compared to a configuration with a fixed communication method, both communication quality and transmission capacity can be ensured. [Explanation of symbols]
[0131] 100,200,300 Wireless system, 110,210,310 Mobile station equipment, 111 Wireless communication unit, 112,212,312 Communication control unit, 113 Memory unit, 120 Base station equipment, 130,230,330 Central unit, 131 Operation schedule acquisition unit, 132 Information acquisition unit, 133,233,333 Memory unit, 134 Passing section prediction unit, 135 Communication time specification unit, 136,236,336 Communication method control unit, 137 Communication unit, 238 Weather information acquisition unit, 239 Bad weather section travel prediction unit, 340 Radio wave poor section travel prediction unit.
Claims
1. A wireless system comprising a mobile station device mounted on a train, a base station device that communicates wirelessly with the mobile station device, and a central device that communicates with the base station device, The aforementioned central device is A communication failure section prediction unit predicts communication failure sections within the section on which the aforementioned train travels, which are sections where communication failures are likely to occur. A communication time identification unit that identifies the transmission capacity priority communication time, which is the time interval required when transmitting communication information using a transmission capacity priority communication method, and the quality priority communication time, which is the time interval required when transmitting the communication information using a quality priority communication method, which has a slower communication speed but higher communication quality than the transmission capacity priority method. When the train transmits the communication information while passing through the communication failure section, if the value obtained by adding the transmission capacity priority communication time to the remaining time interval for the train to pass through the communication failure section is shorter than the quality priority communication time, the control unit decides to adopt the transmission capacity priority method and transmit the communication information after the remaining time for passing through the communication failure section has elapsed, and if the value is equal to or greater than the quality priority communication time, the control unit decides to adopt the quality priority method and transmit the communication information immediately without waiting for the remaining time for passing through the communication failure section to elapse. The system includes a communication unit that notifies the base station device of the communication method determined by the control unit, The base station device communicates with the mobile station device using the notified communication method. A wireless system characterized by the following features.
2. The section with the communication failure is a passing section, which is a section where two trains, including the aforementioned train, pass each other. The wireless system according to claim 1, characterized by the following:
3. The aforementioned communication failure section is a section where the weather is deteriorating. The wireless system according to claim 1, characterized by the following:
4. The aforementioned communication failure section is a radio wave failure section in which factors that worsen the radio waves used by the mobile station equipment exist. The wireless system according to claim 1, characterized by the following:
5. A central device that communicates with mobile station equipment mounted on a train via a base station device that wirelessly transmits communication information, A communication failure section prediction unit predicts communication failure sections within the section on which the aforementioned train travels, which are sections where communication failures are likely to occur. A communication time identification unit that identifies the transmission capacity priority communication time, which is the time interval required when transmitting the aforementioned communication information using a transmission capacity priority communication method, and the quality priority communication time, which is the time interval required when transmitting the aforementioned communication information using a quality priority communication method, which has a slower communication speed than the transmission capacity priority method but higher communication quality, When the train transmits the communication information while passing through the communication failure section, if the value obtained by adding the transmission capacity priority communication time to the remaining time interval for the train to pass through the communication failure section is shorter than the quality priority communication time, the control unit decides to adopt the transmission capacity priority method and transmit the communication information after the remaining time for passing through the communication failure section has elapsed, and if the value is equal to or greater than the quality priority communication time, the control unit decides to adopt the quality priority method and transmit the communication information immediately without waiting for the remaining time for passing through the communication failure section to elapse. The system includes a communication unit that notifies the base station equipment of the communication method determined by the control unit. A central device characterized by the following:
6. The section with the communication failure is a passing section, which is a section where two trains, including the aforementioned train, pass each other. The central apparatus according to claim 5, characterized by the following:
7. The aforementioned communication failure section is a section where the weather is deteriorating. The central apparatus according to claim 5, characterized by the following:
8. The aforementioned communication failure section is a radio wave failure section in which factors that worsen the radio waves used by the mobile station equipment exist. The central apparatus according to claim 5, characterized by the following:
9. A mobile station device that communicates communication information with a central device via a base station device, A wireless communication unit receives the communication information, including the passing time, the transmission capacity priority communication time which is the time interval required when transmitting the communication information using a transmission capacity priority communication method, and the quality priority communication time which is the time interval required when communicating using a quality priority communication method which is slower in communication speed than the transmission capacity priority method but has higher communication quality, from the central device via the base station device. The control unit comprises the following: When a train equipped with the mobile station device transmits communication information while passing through a communication failure section, which is a section where communication failures are likely to occur, if the value obtained by adding the transmission capacity priority communication time to the remaining time interval for the train to pass through the communication failure section is shorter than the quality priority communication time, the control unit decides to adopt the transmission capacity priority method to transmit the communication information after the remaining time for passing through the communication failure section has elapsed; if the value is equal to or greater than the quality priority communication time, the control unit decides to adopt the quality priority method to transmit the communication information immediately without waiting for the remaining time for passing through the communication failure section to elapse. The wireless communication unit communicates with the base station device using the communication method determined by the control unit. A mobile station device characterized by the following:
Citation Information
Patent Citations
Connection of circuit element
JP1984055027A
JPP6975010B
JPP7018735B