JPH06350501A - Radio data communication system - Google Patents

Abstract

PURPOSE:To provide a radio data communication system for improving throughput inside a service area. CONSTITUTION:This system is composed of a base station 1 composed of plural base units 1-1 to 1-N and plural slave stations 1-1 to 1-M connected through radio lines to this base station 1 and transmits data between the base station 1 and the slave stations with a ping-pong system. The base station 1 is provided with a code dividing and multiplexing means for multiplexing the data, polling means as a multiaccess system for transmitting the data, means for synchronizing timing for all the transmission/reception slots of the base units 1-1 to 1-N, and means for assigning channels from the channel with highest data transmission speed ability by unitarily managing the channel assign inside the radio data communication system.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to wireless communication between one base station and a plurality of slave stations, and more particularly to a wireless data communication system for transmitting data between the base station and slave stations by a ping-pong method (TDD). Regarding

[0002]

2. Description of the Related Art In a data transmission method such as an ISM band wireless LAN system, usable frequency band is limited, and communication (uplink / downlink) between a base station composed of a plurality of base stations and a plurality of slave stations. Is a ping-pong method (TDD). In addition, a large number of terminals (slave stations) are generally accommodated in the service area, and in order to increase the throughput of the entire service area, it is required to increase the number of channels capable of simultaneous communication. In order to meet this requirement, should the code division multiplexing (CDMA) be used as the multiplexing method (ISM)?
In a band wireless LAN, a spread spectrum method is obligatory) or frequency division multiplexing (FDMA) within a designated frequency band can be considered.

On the other hand, as a multi-access method for controlling the transmission timing when a plurality of terminals share the same channel, CSMA, which is a contention method, or a non-collision type, which has a relatively large amount of information of each terminal. The polling method used in some cases is effective.

FIG. 7 shows an example of channel assignment on the base station side in the case of the conventional CDMA / polling / TDD system.

This example is a system in which the number of channels in the service area is three-channel multiplexed by CDMA and polling is performed in each channel. The base stations are three master units # 1 to # 3. Each master unit polls the five slave stations it manages in the transmission slot and receives the data of the corresponding slave station in the reception slot.
In this case, as a polling method, a method of sequentially polling regardless of the presence / absence of transmission data of the slave station in order to perform fair access to all slave stations, or a child having a transmission request (or a new registration request) There is a method of polling only stations.

[0006]

In the former sequential polling, the service speed received by each slave station for polling regardless of the presence / absence of transmission data of the slave station will decrease in accordance with the number of polling devices. . Now, when the number of polling devices is one, and the data transmission rate of the master station and the slave station is K (b / s), the data transmission rate is reduced to about K / 5 by sequential polling in this example.

In the latter case, as shown in FIG. 8, each master issues a P0 command in transmission slot 3 to a slave station which is predetermined to be managed by itself. The P0 command is a command for inquiring the slave station about the presence or absence of a new registration request. Each master unit polls the slave station, which has made a new registration request for this P0 command, in the transmission slot 4. As shown by the ↓ mark in FIG. 7, even if a new registration request is accepted, the service speed corresponding to each parent device is about K / 4 on the # 1 side and about K / 2 on the # 3 side. This is because the entire service area has a data transmission rate of about K / 4, although the # 1 side has a free channel having a data transmission rate of K, but the # 1 side has a data transmission rate of about K / 4. It means that the throughput of is decreasing.

As described above, in the conventional CDMA / polling system, since the master station does not unify the channel assignment in the service area, there is a drawback that the throughput in the service area is reduced as described above.

The above description is for CDMA / polling / T.
Although it is the case of the DD system, the same problem occurs in the FDMA / polling / TDD system according to the conventional technique.

Further, as a conventional radio data communication system, as disclosed in, for example, Japanese Patent Laid-Open No. 01-276935, it responds to each mobile station that has sent a resend request, information indicating the length of surplus data. By transmitting data sequentially at time intervals, the data collection efficiency of the entire system can be improved, and in Japanese Patent Laid-Open No. 01-232838, communication channels can be time-divided according to the transmission data length of a mobile station. There are such things as efficient use of channels to transmit data. In addition, as a conventional wireless data communication system, for example, Japanese Patent Laid-Open No. 63-250
237, JP-A-60-077549, JP-A-59-158150 and the like.

An object of the present invention is to provide a wireless data communication system capable of increasing throughput in a service area.

[0012]

According to the present invention, there is provided a base station including a plurality of base stations and a plurality of slave stations connected to the base station via a wireless line. In a wireless data communication system in which data is transmitted between slave stations by a ping-pong method, the base station uses a code division multiplexing means for multiplexing the data and a multi-access method for transmitting the data. Polling means, means for synchronizing the timings of all transmission / reception slots of the master unit, and means for centrally managing channel assignment in the wireless data communication system to assign from a channel having a high data transmission rate capability. There is provided a wireless data communication system including:

Further, according to the present invention, a base station including a plurality of base stations and a plurality of slave stations connected to the base station via a wireless line are provided, and between the base station and the slave stations. In a wireless data communication system adapted to transmit data by a ping-pong method, the base station, a frequency multiplexing means for multiplexing the data, a polling means as a multi-access method for transmitting the data, A means for synchronizing the timings of all the transmission / reception slots of the master unit and a means for centrally managing the channel assignment in the wireless data communication system and assigning from a channel having a high data transmission rate capability are provided. A featured wireless data communication system is obtained.

[0014]

Embodiments of the present invention will now be described with reference to the drawings.

As shown in FIG. 1, according to the present invention, a base station 1 composed of a plurality of parent devices 1-1, ..., 1-N, and this base station 1
, A plurality of slave stations 2-1 ...
2-M, the base station 1 and the slave stations 2-1 and
.., 2-M are transmitted by the ping-pong method.

FIG. 2 is a diagram showing channel assignments corresponding to CDMA / polling / TDD among the channel assignments within the service area of the present invention. The example shown in FIG.
This is a case in which the master unit that serves as the master uses the code C1 and the master unit that serves as the slave uses the codes C2 to CN, and polls a maximum of m units for each code. According to the present invention, as indicated by the mark → in FIG. 2, in the case of performing new polling registration within the service area, the channel having the highest data transmission speed among the idle channels is assigned. This channel assignment management is performed by the master master unit among the master units 1-1, ..., 1-N of the base station 1.

FIG. 3 shows the master and slave master units 1-1,
..., 1-N transmission / reception slot timing examples are shown. As shown in FIG. 3, the master, which is the master, issues a P0 command in transmission slot 3 to all slave stations in the service area. This P0 command includes the channel information to be newly registered in the service area.

In the example of FIG. 3, (reference numeral: C2, polling #
3) is the channel information to be newly registered. By monitoring this P0 command, all slave stations in the service area know the channel used when newly registering.

FIG. 4 is a block diagram showing a first embodiment of the present invention. The embodiment shown in FIG. 4 is an example corresponding to the CDMA / polling / TDD system. The base station 1 includes a master device 1-1 that serves as a master and master devices 1-2 to 1-N that serve as a slave. The master device 1-1 serving as a master has a TDD control unit 11, a polling control unit 12, a spread spectrum modulation / demodulation unit 13, a spread encoder 14, a radio unit 15, an antenna 16, a timing control unit 17, and a channel. And an assign unit 18.

The TDD controller 11 is the timing controller 1
Transmission and reception slots are cut out according to the timing from 7. The polling controller 12 includes a channel assigner 18
Receives the identification information of the slave station to be polled from the slave station, issues a poll command to the corresponding slave station in the transmission slot, and performs a handshake with the slave station to receive data from the slave station in the reception slot.

At the time of transmission, the spread spectrum modulator / demodulator 13 spreads the data from the polling controller 12 with the code Ci given from the spread encoder 14 and outputs it to the radio unit 15. On the other hand, at the time of reception, the received signal from the wireless unit 15 is despread with the code ci from the spreading encoder 14.
The spreading encoder 14 generates a predetermined assigned code among N sets of codes ci (i = 1 to N) used in the entire system. Here, it is assumed that the code ci is a code set that satisfies orthogonality in the synchronization state. At the time of transmission, the wireless unit 15 converts the spread signal from the spread modulator / demodulator 13 into a predetermined wireless frequency band and outputs it to the antenna 16. At the time of reception, the radio unit 15 conversely frequency-converts the received signal from the antenna 16 and outputs it to the spread modulator / demodulator 13.

The timing controller 17 controls the master base unit 2
1 generates a timing signal for synchronizing the transmission / reception slots of the master devices 22 to 2N which are slaves. The channel assigning unit 18 centrally manages the channels in the service area and allocates the slave stations to be polled to each master unit so that the maximum throughput can be obtained at that time.
On the other hand, the slave master unit has the same structure as the master master unit 21 except for the timing control unit 17 and the channel assign unit 18.
It becomes the composition which deleted and.

On the other hand, FIG. 5 shows FDMA / Polling / TD among channel assignments in the service area of the present invention.
It is a figure which shows the channel assignment corresponding to D.

FIG. 6 is a block diagram showing the second embodiment of the present invention. The embodiment shown in FIG. 6 is an example corresponding to the FDMA / polling / TDD system. In the second embodiment, the master device 1-1 serving as a master has a TDD control unit 11 and
The polling controller 12, the wireless unit 15, the local oscillator 19, the antenna 16, the timing controller 17, and the channel assigner 18 are included. In the second embodiment, the local oscillator 19 generates a carrier for frequency-multiplexing N waves within a designated frequency range and applies the carrier to the radio unit 15. Other than that, the same as in the first embodiment. Is.

[0025]

As described above, according to the present invention, the channel assignment in the service area is centrally managed by the master unit, and when a new channel is assigned, it has the highest speed capability among the idle channels. By assigning from the channel, the throughput in the service area can be increased.

[Brief description of drawings]

FIG. 1 is a block diagram showing a first embodiment of the present invention.

FIG. 2 is a diagram showing an example of channel assignment according to the present invention.

FIG. 3 is a diagram showing an example of a transmission slot of a base unit of the base station of the present invention.

FIG. 4 is a block diagram showing a configuration of a master unit according to the first embodiment of the present invention.

FIG. 5 is a diagram showing another example of channel assignment according to the present invention.

FIG. 6 is a block diagram showing a configuration of a parent device according to a second embodiment of the present invention.

FIG. 7 is a diagram showing channel assignment in a conventional example.

FIG. 8 is a diagram showing a transmission slot of a base unit of a conventional example.

[Explanation of symbols]

 1 Base station 1-1, ..., 1-N Master unit 2-1, ..., 2-M Slave station 3,4 Transmission slot of master unit 11 TDD control unit 12 Polling control unit 13 Spread spectrum modulator / demodulator 14 Spreading encoder 15 radio unit 16 antenna 17 timing control unit 18 channel assign unit 19 local oscillator

Claims (2)

[Claims] 1. A ping-pong method for transmitting data between the base station and the slave stations, which comprises a base station including a plurality of master stations and a plurality of slave stations connected to the base station via a wireless line. In the wireless data communication system configured to be performed by the base station, the base station includes a code division multiplexing unit that multiplexes the data, a polling unit as a multi-access method for transmitting the data, and all of the master units. Radio data comprising means for synchronizing the timing of transmission / reception slots, and means for unifying channel assignment in the radio data communication system to assign from a channel having a high data transmission rate capability. Communications system. 2. A ping-pong system for transmitting data between the base station and the slave stations, the base station including a plurality of base stations and a plurality of slave stations connected to the base station via a wireless line. In the wireless data communication system, the base station has a frequency multiplexing means for multiplexing the data, a polling means as a multi-access method for transmitting the data, and all transmissions of the master unit. Wireless data communication characterized by means for synchronizing the timing of receiving slots and means for unifying channel assignment in the wireless data communication system and assigning from a channel having a high data transmission rate capability system.