JP3506899B2 - ATM cell radio transmission equipment - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an ATM (Asynchr)
onous Transfer Mode: Used for communication. The present invention relates to a technique for transmitting ATM cells via a wireless TDMA line. The present invention relates to a technique for improving the efficiency of wireless line use by using TDMA bursts of different lengths in an ATM cell wireless transmission system. INDUSTRIAL APPLICABILITY The present invention can also be used in an ATM cell wireless transmission system capable of reducing power consumption of a wireless mobile terminal.

[0002]

2. Description of the Related Art FIG. 5 shows an example of an ATM cell wireless transmission system. In this ATM cell wireless transmission system, the master station 1 and the slave stations 11 ₁ and 11 ₂ are connected by a wireless TDMA line,
The cell is transmitted by TDMA burst, and the master station 1 uses the communication line 1
2 is connected to another network via the slave stations 11 ₁ and 11
Reference numeral ₂ similarly shows an example of a TDMA wireless communication system connected to another network via the communication lines 13 and 14.

FIG. 6 shows an operation flow in the case of transmitting an ATM cell of a high-speed communication line from a child station to a parent station in a conventional ATM cell radio transmission system (reference: Aikawa et al., "ATM Wireless"). Access / Prototype Device-TDMA
-", The Institute of Electronics, Information and Communication Engineers, 1997 Communication Society Conference, B-5-110). In FIG. 6, the transmission speed of the communication line to which the master station or the slave station is connected is 5 ATM cells / T.
The DMA frame and TDMA burst are examples of accommodating 4 ATM cells.

In FIG. 6, the slave station accommodates ATM cells input in TDMA frame units into two TDMA bursts and transmits them to the master station through a wireless TDMA line. The master station is TD
ATM cells are separated and output from two TDMA bursts received in units of MA frames.

FIG. 7 shows an operation flow when an ATM cell of a low speed communication line is transmitted from a slave station to a master station in this conventional ATM cell wireless transmission system. FIG. 7 shows an example in which the transmission rate of the communication line is 1 ATM cell / 2 TDMA frame.

[0006] In FIG. 7, the slave station has one TDMA frame unit regardless of the presence or absence of an ATM cell to be transmitted.
Send the DMA burst to the wireless TDMA line. The master station sends A to the TDMA burst received in TDMA frame units.
If the TM cell is accommodated, the ATM cell is separated and output.

In the example shown in FIGS. 6 and 7, TDM is used.
The number of TDMA bursts in A frame units is calculated by the following equation 1.

[0008]

[Equation 1] Here, N_bst is TDMA in TDMA frame units.
The burst number, CR_pk, is the transmission speed of the communication line (cell /
Sec), L_tfrm is the TDMA frame length (sec), L_
bst is the number of cells accommodated in one TDMA burst,
[X] is the smallest integer greater than or equal to x.

As described above, in the conventional ATM wireless transmission system, the TDMA burst is transmitted only at the TDMA frame intervals, and the number of cells accommodated in the TDMA burst is only one.

[0010]

In wireless communication,
Since the effective use of frequency resources is one of the important issues, it is necessary to improve the line use efficiency by improving the use efficiency of TDMA burst in wireless TDMA communication. Further, in mobile radio systems and the like, lowering the power consumption of wireless mobile terminals is one of the important issues. Therefore, in the wireless TDMA communication, it is also necessary to suppress the power consumption of the wireless mobile terminal by not transmitting the TDMA burst that does not accommodate the ATM cell having the information.

However, according to the conventional method, first, as shown in FIG.
The second TD in the TDMA frame is used because only one type of TDMA burst is used as shown in FIG.
There is a problem that the use efficiency of the MA burst becomes low and the line use efficiency deteriorates. Also, as shown in FIG.
If the TDMA burst is transmitted only at the DMA frame interval, the TDMA burst that does not accommodate the ATM cell having the information to be transmitted is also transmitted, which causes a problem that extra transmission power is consumed. In particular, if the slave station is a wireless mobile terminal, there is a great demand for reducing the transmission power, and therefore a slave station device with even lower power consumption is required.

The present invention solves the problems of the prior art as described above. When the ATM cells of communication lines of various transmission speeds are transmitted by the wireless TDMA line, the line use efficiency and power consumption are improved. An object of the present invention is to provide an ATM cell wireless transmission system that realizes suppression.

[0013]

According to the present invention, a master station and a slave station are connected via a wireless TDMA line, and the master station or the slave station accommodates an input ATM cell in a TDMA burst. In an ATM cell wireless transmission device comprising means for transmitting by a wireless TDMA line and means for outputting an ATM cell separated from a TDMA burst transmitted by the wireless TDMA line, the slave station or the master station is a containing cell. including means for transmitting the ATM cell to generate at least two types of TDMA bursts different numbers.

According to the present invention, ATM cells can be transmitted by properly using TDMA bursts having different lengths according to the transmission rate of ATM cells input from a terrestrial network or a terminal device. As a result, the usage efficiency of the TDMA burst is increased, so that the wireless line usage efficiency is increased and the wireless resources can be effectively used. Also, an ATM having transmission information
Since a TDMA burst that does not accommodate cells is not transmitted, the TDMA burst transmission time can be shortened and power consumption can be reduced.

Further, the slave station or the master station has means for calculating the required number of TDMA bursts corresponding to the transmission rate of ATM cells input in order from the TDMA burst having a large number of cells accommodated, and the calculated result as a partner. It may be configured to include means for notifying the station.

The slave station or the master station calculates the required number of TDMA bursts according to the transmission rate of the input ATM cells. This is done by an algorithm for accommodating ATM cells in order from the TDMA burst with the largest number of accommodated cells. This is done by calculating the number of required TDMA bursts. The calculated result is notified to the partner station, and necessary TDMA bursts are allocated. The master station can also calculate the number of TDMA bursts required by the slave station based on the transmission speed of the slave station.

Further, the slave station or the master station calculates a threshold value in which the use efficiency of the radio channel is higher when one TDMA burst having a large number of cells is used than when a plurality of TDMA bursts having a small number of cells are used. Means and means for selecting a TDMA burst having a large number of accommodated cells when the transmission rate of an ATM cell input when calculating the number of TDMA bursts exceeds this threshold value can be adopted.

In this case, the T which has a higher wireless line use efficiency
Since it is possible to communicate using DMA burst,
Furthermore, the wireless line use efficiency can be improved.

The slave station or the master station is provided with the TDMA.
A means for generating at least one kind of superframe in which a predetermined number of TDMA frames which are transmission intervals of bursts are collected, a means for generating at least one kind of TDMA burst having this superframe as a transmission interval, and the number of TDMA bursts It may be configured to include a calculating unit.

By transmitting the TDMA bursts at the superframe intervals, it is possible to improve the wireless line use efficiency and reduce the power consumption of the transmitter even when transmitting the ATM cells of the low speed communication line. it can.

Both the slave station and the master station can be provided with means for calculating the number of TDMA bursts required to transmit ATM cells, and the calculation result is notified to the partner station. The master station may be configured to calculate the number of TDMA bursts required for the slave station according to the transmission speed of the slave station and notify the slave station of the calculation result. In either method, allocation of TDMA bursts is performed by the master station upon allocation request.

The present invention is a wireless communication system in which one master station and a plurality of slave stations are connected by a wireless TDMA line, or a wireless communication system in which a plurality of master stations and one slave station are connected by a wireless TDMA line. It is particularly useful when applied to a mobile radio system in which a child station is a wireless mobile terminal.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below.

According to the present invention, a master station 10 and a slave station 11 as shown in FIG. 5 are connected to each other via a wireless TDMA line.
In the DMA communication system, the master station 10 or the slave station 11 is
The ATM cell input from the terrestrial network or terminal equipment is TD
Means for accommodating in MA burst and transmitting through the wireless TDMA line, and TDMA transmitted through the wireless TDMA line
In an ATM cell wireless transmission device having means for outputting an ATM cell separated from a burst to a terrestrial network or a terminal device, a feature of the present invention is that the slave station 11 or the master station 1
0 is at least two types of TDMAs that accommodate different numbers of cells.
It is characterized in that it includes means for generating bursts and transmitting ATM cells. Further, the slave station 11 or the master station 10 inputs ATs in order from the TDMA burst with the largest number of cells accommodated.
It includes means for calculating the required number of TDMA bursts according to the transmission rate of M cells, and means for notifying the partner station of the calculated result.

FIG. 1 shows an operation flow in the case of transmitting an ATM cell of a high speed communication line from a slave station to a master station in this ATM cell wireless transmission system. This Figure 1
Is a transmission rate of a communication line connected to a terrestrial network or a terminal device for a slave station is 5 ATM cells per 1 TDMA frame, and TDMA burst is a short TDMA burst containing 1 ATM cell and a long TDMA burst containing 4 ATM cells. In this example, two types are used and the length of the superframe is twice that of the TDMA frame.

In FIG. 1, since the transmission rate of the communication line is 5 ATM cells / TDMA frame, TD
One short TDMA burst and one long TDMA burst are used per MA frame. The slave station accommodates the input ATM cells in short TDMA bursts and long TDMA bursts in units of TDMA frames, and transmits them to the master station via the wireless TDMA line. The master station receives each TDM in TDMA frame units.
ATM cells are separated from the A burst and output.

FIG. 2 shows an embodiment A of another invention.
In the TM cell wireless transmission system, an operation flow when an ATM cell of a low speed communication line is transmitted from a child station to a parent station is shown. FIG. 2 uses two types of transmission speed of the communication line on the slave station side: a 1ATM cell / 2TDMA frame, a TDMA burst uses a short TDMA burst accommodating 1ATM cell, and a long TDMA burst accommodating 4ATM cell. In this example, the length is twice that of the TDMA frame.

As shown in FIG. 2, the slave station transmits one short TDMA burst to the wireless TDMA line in superframe units, and the master station is accommodated in the short TDMA burst received in superframe units. Separates and outputs ATM cells. In this case, when the communication line is slow, ATM cells are transmitted by short TDMA burst, so that the occupied time of the wireless line can be shortened and the wireless line can be used more efficiently. Further, the transmitter can also reduce the transmission time of the TDMA burst, so that power consumption can be suppressed. Particularly in a mode in which a plurality of slave stations communicate with one master station by sharing a TDMA wireless line, the effect of improving the use efficiency of the wireless line is great.

Next, FIG. 3 shows, as another embodiment of the present invention, an operation flow when ATM cells are transmitted by combining a TDMA frame and a superframe from a child station to a parent station. In the example shown in FIG. 3, the transmission rate of the communication line is 11 ATM cells / 2 TDMA frames, and the TDMA burst uses two types of a short TDMA burst containing 1 ATM cell and a long TDMA burst containing 4 ATM cells. The frame is an example in which the length is the case of two TDMA frames.

In FIG. 3, the slave station has a short TDMA burst and a long TDM in TDMA frame units.
One A burst is used and one short TDMA burst is used for each superframe, and the short TDMA burst is transmitted to the master station. The master station separates and outputs the ATM cells contained in each received TDMA burst. In this example, even in the case of a high-speed communication line, TDM with different lengths
Since ATM cells can be transmitted by combining A bursts, it is possible to improve the use efficiency of the wireless TDMA line.

FIG. 4 shows a flowchart for calculating the number of TDMA bursts used in the wireless TDMA line from the transmission speed of the communication line in the ATM cell wireless transmission system. In FIG. 4, N_1b is a long T
DMA burst number, N_sb1 is short TDMA burst number in TDMA frame unit, N_sb2 is short TDMA burst number in super frame unit, CR_p
k is the transmission speed (cells / second) of the communication line, L_1b is the number of cells accommodated in the long TDMA burst, and L_sb1 is TDM.
Number of cells accommodated in short TDMA burst in A frame unit, L_sb2 is short TD in super frame unit
Number of cells accommodated in MA burst, L_tfrm is TD
MA frame length (seconds), L_sfrm is a superframe length.

TD used in the wireless TDMA line in FIG.
The operation of calculating the MA burst number will be described. First, TD
To calculate the number of MA bursts, N_1b, N_s
reset b1 and N_sb2 (step 11),
Number of ATM cells N_p in communication line in TDMA frame unit
k is calculated (step 12). Next, if N_pk is greater than or equal to the threshold value N_th given by the equation (2), (N_p
k ≧ N_th), N_1b is incremented by 1, and the number N_pk of ATM cells that cannot be transmitted is calculated (step 1
3 → step 14). If this N_pk is N_th or more, the same procedure is repeated (step 13 → step 1).
4).

[0033]

[Equation 2] Here, in Expression (2), B_lb is long TDMA.
Burst length (bits), B_sb1 is short TDMA
Burst length (bits). That is, N_th is the number of ATM cells in which the total length of the long TDMA burst length and the total length of the short TDMA burst are equal, and if the number of ATM cells to be transmitted is N_th or more, the long TDMA burst will improve the line use efficiency. . next,
N_pk is less than N_th (N_pk <N_th), and
If N_sb1 or more (N_pk ≧ N_sb1), N_
sb1 is incremented by 1 to calculate the number of ATM cells N_pk that cannot be transmitted (step 13 → step 15 → step 16), and if this N_pk is N_sb1 or more, the same procedure is repeated (step 15 → step 16).
Finally, N_sb2 is calculated and the process ends (step 17 →
Step 18). However, [x] is the smallest integer greater than or equal to x.

The calculation of the required number of TDMA bursts is
It can be either a slave station or a master station. When transmitting from the slave station, the slave station calculates the number of TDMA bursts to be used in the wireless TDMA line based on the transmission speed of the communication line, notifies the master station of this, and receives the allocation of the TDMA burst to receive the ATM cell. Can be transmitted. Also calculate the TDMA bursts required number based on the transmission rate of the communication line of the slave station is the master station, which may be a notice child to the child station. When transmitting from the master station, the master station notifies the slave station of the number of TDMA bursts required.

In the present invention, a plurality of slave stations communicate with one master station by sharing a wireless TDMA line, or a plurality of master stations communicate with one slave station by wireless TD.
It can be used in any case where communication is performed by sharing the MA line.

As described above, TDMA bursts having different numbers of accommodated cells are selectively used according to the transmission speed of the communication line, and TDMA bursts are transmitted in units of TDMA frames and superframes so that the lines can be transmitted at various transmission speeds. It is possible to improve usage efficiency and suppress power consumption.

[0037]

As described above, according to the present invention,
By transmitting an effective cell in combination with TDMA bursts having different lengths, it is possible to use the optimum radio line by using the extra radio resources to the minimum, so that it is possible to improve the line use efficiency.

Further, since the transmitters of the master station and the slave stations rarely transmit TDMA bursts including cells without transmission information, their power consumption can be reduced. This reduction in power consumption is particularly useful when the mobile station is used in a mobile communication system such as a mobile station or a wireless mobile terminal.

[Brief description of drawings]

FIG. 1 is an operation flow diagram illustrating ATM cell transmission in TDMA frame units according to the present invention.

FIG. 2 is an operation flow diagram for explaining ATM cell transmission in superframe units according to the present invention.

FIG. 3 is a diagram for explaining ATM cell transmission in which a TDMA frame unit and a super frame unit of the present invention are combined.

FIG. 4 is a flowchart illustrating TDMA burst number calculation according to the present invention.

FIG. 5 is a diagram showing an example of an ATM cell wireless system.

FIG. 6 is an operation flow diagram illustrating conventional ATM cell transmission.

FIG. 7 is an operation flow diagram illustrating conventional ATM cell transmission.

[Explanation of symbols]

10 Master station 11 ₁ , 11 ₂ Slave station 12, 13, 14 Communication line

─────────────────────────────────────────────────── --Continued from the front page (56) References JP 10-56468 (JP, A) JP 9-298545 (JP, A) JP 6-244862 (JP, A) JP 61- 129931 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) H04L 12/28 H04B 7/24 H04J 3/00

Claims (8)

(57) [Claims] 1. A master station and a slave station are connected via a wireless TDMA line, and the master station or the slave station inputs an AT.
The wireless TDMA by accommodating M cells in a TDMA burst
In an ATM cell wireless transmission device comprising means for transmitting on a line and means for outputting an ATM cell separated from a TDMA burst transmitted on the wireless TDMA line, the slave station or the master station is at least two different generates TDMA burst seen including means for transmitting the ATM cells of the child station or the master station, a large number containing cell of TDMA
Depending on the transmission speed of ATM cells input sequentially from burst
And a means for calculating the required number of TDMA bursts.
And a means for notifying the partner station of the result obtained . 2. A master station and a slave station are connected via a wireless TDMA line.
Connected to each other, and the master station or the slave station inputs the AT
The wireless TDMA by accommodating M cells in a TDMA burst
Means for transmitting over the line, and a means for transmitting over the wireless TDMA line.
Output ATM cells separated from the generated TDMA burst
In the ATM cell wireless transmission device, the slave station or the master station has a different number of cells.
Both types of TDMA bursts are generated and ATM cells are
Including transmission means, multiple slave stations and one master station are wireless
An ATM cell wireless transmission device characterized by being connected by a TDMA line . 3. A master station and a slave station via a wireless TDMA line
ATM connected to and input to the master station or the slave station
The cell is accommodated in a TDMA burst and the wireless TDMA
And a means for transmitting over the line,
The ATM cell separated from the TDMA burst
In the ATM cell wireless transmission device including a means, the slave station or the master station has a small number of accommodated cells.
Both types of TDMA bursts are generated and ATM cells are
A plurality of master stations and one slave station are connected by a wireless TDMA line, including means for transmitting.
An ATM wireless transmission device characterized by the above . 4. A plurality of slave stations and one master station are wireless TDM.
ATM cell radio transmission apparatus according to claim 1 Symbol placement connected with A line. 5. A wireless TDM system comprising a plurality of master stations and one slave station.
The ATM cell wireless transmission device according to claim 1 , wherein the ATM cell wireless transmission device is connected by an A line. 6. The number of cells accommodated in the slave station or the master station
With less TDMA bursts than using multiple
It is better to use one TDMA burst, which has many
Means for calculating a threshold value for increasing the usage efficiency, and the TDMA
ATM cell transmission speed input when calculating the number of bursts
When the degree exceeds this threshold, the number of accommodated cells is large
ATM cell wireless transmission device according to any one of claims 1 and means for selecting the A burst 5. 7. The slave station or the master station is the TDM.
A certain number of TDMA frames, which is the transmission interval of A burst
Generate at least one type of superframe
Means and a few
Means for generating at least one type of TDMA burst;
Claim 1 comprising means for calculating the number of TDMA bursts
7. The ATM cell wireless transmission device according to any one of items 1 to 6. 8. The plurality of slave stations include a master station and a TDM.
7. A wireless mobile terminal connected by a wireless connection A.
In addition, the ATM cell wireless transmission device described in item 7.