JP3001560B1 - TDMA mobile communication system - Google Patents

Abstract

Abstract: PROBLEM TO BE SOLVED: To average transmission time of a signal in a transmission buffer by transmitting the signal in order of arrival, thereby improving transmission efficiency. SOLUTION: A schedule table 34 is prepared to manage the slot use status from the current frame to several frames ahead. Signals that can be transmitted on an empty schedule when a signal arrives are scheduled, and signals that cannot be scheduled are accumulated in the transmission buffers 0 to n together with the signal transmission start conditions in the order of arrival. The head data of the schedule table 34 is transmitted to the terminal 40 for each frame,
The schedule table 34 is updated one frame ahead,
The transmission conditions of the signals in the transmission buffers 0 to n are determined in the order of arrival with respect to the last one frame that is the new schedule table, and signals that can start transmission are assigned.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a TDMA mobile communication system in which a base station performs bidirectional communication with a plurality of terminals in a service area using time-division multiplexed time slots, and more particularly to a TDMA mobile communication system. The present invention relates to a transmission method of a base station in a system.

[0002]

2. Description of the Related Art FIG. 12 shows a configuration of a transmission system in a conventional TDMA mobile communication system. The transmission signal transmitted from the base station to the terminal is stored in the transmission buffer in the transmission device together with the transmission start condition in the order of request. The transmitting device determines the use state of the slot for each time slot, determines the transmission conditions of the signals in the transmission buffer in the order of request for unused slots, selects a signal that can start transmission, and Assign to slots. The signals stored in the transmission buffer are selected in the order in which unused slots occur. Therefore, there is a case where the timing of starting transmission of the first-arriving signal is lost due to the start of transmission of the later-arriving signal in the unused slot.

[0003]

As described above, in the conventional transmission system in the TDMA mobile communication system, the timing of starting transmission of the first-arriving signal is lost due to overtaking by the late-arrival signal, and the transmission is performed forever. It is highly likely that unlucky signals that cannot be started and remain stored in the transmission buffer are likely to occur, and if many signals with a small transmission start timing arrive, the occupancy of the transmission buffer increases. There is a problem.

An object of the present invention is to provide a TDMA type mobile communication system capable of improving transmission efficiency by averaging the time during which a signal stays in a transmission buffer.

[0005]

SUMMARY OF THE INVENTION The present invention relates to a TDMA mobile communication system in which a base station performs two-way communication using time-division multiplexed time slots with a plurality of terminals in a service area. The apparatus has a schedule table that manages the slot usage status from the current frame to a few frames ahead. A signal that can be transmitted by an empty schedule when a signal arrives is scheduled, and a signal that cannot be scheduled is a signal transmission start condition. Together with the arrival data in the transmission buffer, and transmits the data at the head of the schedule table to the terminal for each frame, updates the schedule table one frame ahead, and updates the schedule table for the last one frame which is a new schedule table. The transmission conditions of the signals in the transmission buffer in the order of arrival, and A a signal and assigns to the schedule.

[0006]

Next, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of a TDMA mobile communication system according to the present invention. The TDMA mobile communication system shown in FIG.
It comprises a base station controller 20, a transmitter 30 in a packet base station modem, and a terminal 40.

The transmitting device 30 in the packet base station modem includes a transmission data storage memory 3 used as a transmission buffer for storing transmission signals and signal transmission start conditions.
1 and a schedule table 34 for managing the slot usage status from the current frame to several frames ahead, and an arrival order management table 35 for managing the signal transmission start conditions and the arrival order of unschedulable signals.

FIG. 2 is a diagram showing the internal configuration of the transmission buffer. The transmission buffer is an area for storing a transmission signal transmitted to the terminal together with a transmission start condition. The transmission buffer includes a transmission start condition “transmission start frame #”,
There are "used channel #", "used time slot number", "transmission data" which is an area for storing transmission data, and "previous link buffer number" and "rear link buffer number" which are information for chain link management. .

FIG. 3 shows empty buffer management information and transmission waiting buffer management information. Free buffer management information is
This is information for chain link management of unused transmission buffers. The transmission-waiting buffer management information is information for managing transmission links in the order of request in a chain link. Each information includes a start buffer number, an end buffer number, and the number of buffers.

FIG. 4 shows a transmission schedule. The transmission schedule is information for managing a channel state. This information has time slot information for several frames for each channel unit. The time slot information includes the presence / absence of transmission data, the number of continuously available frames, the number of the buffer being transmitted,
There is a transmission unit number (a pointer indicating what number is to be transmitted by dividing the transmission data by the time slot size).

Next, the operation of the embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 5 is a flowchart for explaining the operation in the TDMA mobile communication system of this embodiment. To manage the transmission signal, a schedule table is prepared to manage the slot usage status from the current frame to several frames ahead. Signals that can be transmitted on an empty schedule when a signal arrives are scheduled, and signals that cannot be scheduled are stored in the transmission buffer in the order of arrival together with signal transmission start conditions. The head data of the schedule table is transmitted to the terminal for each frame, the schedule table is updated one frame ahead, and the last one frame, which is a new schedule table, of the signal in the transmission buffer in the order of arrival. The transmission condition is determined, and a signal that can start transmission is assigned to the schedule.

FIGS. 6 and 7 show the outline of transition of each information when a signal arrives from the communication network. In this embodiment,
It is assumed that the number of buffers MAX is 4, the number of time slots is 3, and the number of frames in the schedule table is 6.

In the initial state, as shown in FIG. 6, all buffers are linked to free buffer management information.
The initial values of the time slot information in the schedule table are as follows: transmission data presence / absence = no transmission buffer number = unset transmission unit number = unset for all time slots. With respect to the initial state, (transmission start frame #, used channel #, used time slot number) is (5, 0, 1),
It is assumed that transmission signals (2, 0, 4), (6, 0, 1), and (3, 0, 3) are sequentially requested. At this time, (5, 0,
1) is set in the schedule table because the schedule is vacant. (2, 0, 4) is linked to the transmission wait buffer management information because scheduling is impossible because the first signal is scheduled. (6,0,1)
Is outside the schedule table range and is linked to the transmission waiting buffer management information. (3, 0, 3) is linked to the transmission-waiting buffer management information because the previous signal is scheduled, so that scheduling is impossible.

The link state of the buffer changes as shown in FIG. 7, and the schedule table becomes the state of FIG.

In the conventional method, when all the time slots are vacant, the frames to be visited are transmitted in the order of earliest. Therefore, the transmission of the subsequent (2, 0, 4) is started first, and the transmission of the preceding (5, 0) is started. , 1) cannot be transmitted and is sent to the next transmission timing, but at the next transmission timing, the subsequent (3, 0, 3) starts transmission first and cannot be transmitted. If a similar subsequent signal arrives while waiting for the next transmission timing, the transmission will wait again and occupy the buffer. No occupancy.

The stored signal is selected according to the flowchart of FIG. After obtaining the head from the head buffer number of the transmission waiting buffer management information, the processing is performed in the order of request by following the chain link. When the data at the beginning of the schedule table is transmitted, the schedule table is updated one frame ahead.

At this time, since the signals stored in the area indicated by area (1) in FIG. 10 have already been determined to be unschedulable at the time of arrival, the final signals in the new schedule table shown in area (2) in FIG. Only the frame needs to be determined. Therefore, the processing load is equal to the conventional one.

In this embodiment, the signals that can be set in the schedule table at the time of arrival of the signals are scheduled, so that the transmission of the first-arrival signal is not interrupted by the transmission of the late-arrival signal in the schedule table. Is guaranteed.

In the schedule processing, the degree of load varies depending on the size of the schedule table to be set and the number of accumulated signals to be determined, but it is determined whether or not all the schedule tables can be scheduled when a signal arrives. Thus, the schedule determination of the stored signals is performed only for the last frame for each frame, and the schedule table determined at the time of arrival is not included in the schedule. Is only one, and only one frame is the target schedule table in the schedule for determining all the stored signals, and the load is distributed. At this time, the load of the schedule processing performed for each frame is equal to that of the conventional method regardless of the size of the schedule table.

[0022]

As described above, according to the present invention, the schedule table is prepared to manage the slot use status up to several frames ahead, and when the signal arrives at the base station, the signal that can be transmitted on an empty schedule can be started. Realizes transmission in the order of arrival by scheduling, and averages the time spent in a transmission buffer for a signal, thereby improving transmission efficiency.

The schedule determination for all schedule tables is performed every time a signal arrives, and the schedule determination for signals that could not be scheduled at the time of arrival stored in the transmission buffer is updated every frame. By performing the process only for the last frame of the schedule table, it is possible to distribute the load increased by the schedule processing.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an embodiment of a TDMA mobile communication system of the present invention.

FIG. 2 is a diagram illustrating an internal configuration of a transmission buffer.

FIG. 3 is a diagram showing empty buffer management information and transmission waiting buffer management information used for buffer management.

FIG. 4 is a diagram showing a schedule table used for time slot state management.

FIG. 5 is a flowchart for explaining the operation of this embodiment.

FIG. 6 is a diagram illustrating a state of empty / transmission waiting buffer management information and information of a transmission buffer in an initial state.

FIG. 7 is a diagram showing the states of empty / transmission waiting buffer management information and information of transmission buffers when a signal arrives.

FIG. 8 is a diagram showing a state of a schedule table when a signal arrives.

FIG. 9 is a flowchart showing an outline of an operation of selecting a stored signal.

FIG. 10 is a diagram showing a schedule target area of a schedule table.

FIG. 11 is a diagram showing a schedule target area of a schedule table.

FIG. 12 is a diagram illustrating a configuration of a transmission system in a conventional TDMA mobile communication system.

[Explanation of symbols]

 REFERENCE SIGNS LIST 10 communication network 20 base station control device 30 transmission device 31 transmission data storage memory 32 memory for terminal transmission data setting 33 frame trigger generator 34 schedule table 35 arrival order management table 40 terminal

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification code FI H04Q 7/38

Claims (6)

(57) [Claims] 1. A TDMA mobile communication system in which a base station performs bidirectional communication with time-division multiplexed time slots with a plurality of terminals in a service area, wherein a transmission signal transmitted from the base station to the terminal is transmitted to the base station. Means for scheduling upon arrival at the station, means for storing a plurality of signals that cannot be scheduled upon arrival at the base station, means for selecting and scheduling a signal that satisfies the vacant schedule from the signals stored for each frame, A TDMA type mobile communication system, characterized in that a base station includes a transmission device having means for transmitting a signal to a terminal. 2. A TDMA mobile communication system in which a base station performs two-way communication using time-division multiplexed time slots with a plurality of terminals in a service area, wherein a transmission signal transmitted from the base station to the terminal is transmitted. Means for scheduling upon arrival at the base station in accordance with the start condition; means for storing a plurality of signals which cannot be scheduled upon arrival at the base station together with the transmission start condition in the order of request; Means for selecting and scheduling signals that meet the conditions of
A TDMA mobile communication system, comprising: a base station having a transmission device having means for transmitting to a terminal when a selected signal is present. 3. A TDMA mobile communication system in which a base station performs two-way communication with time-division multiplexed time slots with a plurality of terminals in a service area. It has a schedule table that manages the slot usage status up to the destination. Signals that can start transmission on an empty schedule when a signal arrives are scheduled, and signals that cannot be scheduled are stored in the transmission buffer along with signal transmission start conditions in the order of arrival. The data at the beginning of the schedule table is transmitted to the terminal for each frame, the schedule table is updated one frame ahead, and the last one frame, which is a new schedule table, is stored in the transmission buffer in the order of arrival. Judgment of signal transmission conditions, and set signals that can start transmission to the schedule A TDMA mobile communication system, wherein the mobile communication system is assigned. 4. A transmission method of a base station in a TDMA type mobile communication system in which a base station performs bidirectional communication using time-division multiplexed time slots with a plurality of terminals in a service area. A transmission signal to be transmitted is scheduled at the time of arrival at the base station, a plurality of signals that cannot be scheduled at the time of arrival at the base station are stored, a signal that satisfies the condition for the vacant schedule is selected from the signals stored for each frame, and the scheduled signal is scheduled. A transmission method for a base station in a TDMA mobile communication system, comprising transmitting a signal to a terminal. 5. A transmission method of a base station in a TDMA mobile communication system in which a base station performs two-way communication using time-division multiplexed time slots with a plurality of terminals in a service area. The transmission signal to be transmitted is scheduled at the time of arrival at the base station according to the transmission start condition, a plurality of signals that cannot be scheduled at the time of arrival at the base station are stored together with the transmission start condition in the order of request, and the condition of the signal stored in the order of request is determined for each frame. TDM characterized by selecting and scheduling a signal that matches a condition of a vacant schedule and transmitting the selected signal to a terminal when the selected signal exists.
A transmission method of a base station in an A-type mobile communication system. 6. A transmission method of a base station in a TDMA mobile communication system in which a base station performs bidirectional communication using time slots multiplexed with a plurality of terminals in a service area, wherein a schedule table is prepared. It manages the slot usage status from the current frame to a few frames ahead, schedules signals that can start transmission on an empty schedule when a signal arrives, and stores unschedulable signals in the transmission buffer along with signal transmission start conditions in the order of arrival. Then, the head data of the schedule table is transmitted to the terminal for each frame, the schedule table is updated one frame ahead, and the last one frame which is a new schedule table is stored in the transmission buffer in the order of arrival. Signal transmission conditions are determined, and signals that can start transmission are Transmission method for a base station in a TDMA mobile communication system, wherein