JPH01204543A - Radio packet transmission system - Google Patents

Abstract

PURPOSE:To attain accurate data transmission service by setting a bit representing the reception of an odd or even number frame in case of acknowledging the reception and controlling the system so that no data missing (block missing) takes place at the communication with a terminal equipment. CONSTITUTION:The system is provided additionally with an odd/even block bit (BLOCK bit) distinguishing whether good/bad reception of an even number BLOCK or good/bad reception of an odd number BLOCK is supplied to good/ bad reception of a normal block from a terminal equipment side. Thus, missing block in a data is not caused even when the terminal equipment cannot receive a P#lRvi representing the inverted transmission right by the addition of the odd/even block bit. Thus, accurate data transmission service is attained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a wireless packet transmission system, and particularly to a wireless packet transmission system that prevents data from being dropped.

[Conventional technology]

A polling method in a conventional wireless packet transmission method is shown in FIG. 2(a). In the figure, P#0 is a call invitation polling signal, and P#1 and P#2 are polling numbers given to specific terminals currently communicating. In this figure, two terminals are communicating. This figure is the first P#0,
A terminal with number i (this i is unrelated to the polling number) makes a call request, and the polling number #l is sent by P-tFl.
Indicates that the terminal given the above has transmitted uplink data.

FIG. 2(b) shows the signal structure of the downlink slot in the above system, which is divided into a polling section and a data section.

Normally, a terminal station is in receive mode or transmit mode, and when in receive mode it monitors the data section to determine whether it is its own data, and when in transmit mode it monitors the polling section and issues the packet itself. Judging the timing.

Furthermore, when the terminal station is in the data reception mode, it shows a flow as shown in FIG. 3(a). In the figure, D(0) to D(n) are units (packets) of wireless packet transmission, and here, n times is defined as one block (BLOCK). Also, P#I
l indicates the polling number for terminal α, and P#IIRvi indicates the process by which the system side obtains the transmission right from the terminal. When the system side sends the m-th block to the terminal α, the system sends an invitation to the terminal α using P#p to detect whether the mm block has been successfully received. When terminal α receives the mth block normally, it sends a block confirmation signal (BL
OCK ACK) is sent to the system side, and if there is an error in the data, a block unconfirmed signal (BLOCK NAC) is sent to the system side. ACK is sent to terminal α when the system side receives NAK.
Polling P#ff1Rvi is sent to invert the transmission right, and the next data or retransmission data is sent. In this way, data is sent sequentially in packet format.

Now, as shown in FIG. 3(b), the terminal α that has received the m-th block
returns ACK indicating normal reception P#ρRv
Suppose we are waiting for i. The P sent by the system at this time
# When an error occurs in ρRvi or it cannot be received,
Terminal α continues to determine that it has the right to transmit, and monitors the polling section. The system side transmits P#pRvi indicating transmission right reversal, and then starts transmitting the data of the (m+1)th block.
1) After sending the block, the terminal side correctly (m+1)
To confirm whether the block has been received, the terminal is invited to send and waits for the reception length/failure from the terminal. If the terminal is unable to receive the previous P#4Rvi indicating transmission right reversal and is waiting for transmission right reversal, it will receive P#4Rvi again indicating transmission right reversal.
When receiving l, the system determines that the previously sent BLOCKACK indicating the reception length/non-reception of m blocks has not arrived at the system side, and sends BLOCK A (, K again. At this time, the system side ( Since the BLOC-K ACK indicating good reception was received after transmitting block m+1), block (m+2) is transmitted next.

[Problem to be solved by the invention]

In the conventional method described above, when the system side is sending data, the reception length/non-reception on the terminal side is checked for each block, and when the terminal side cannot receive a signal that takes the transmission right to the system side, the terminal side and the system A difference in transmission rights occurs between the two sides.

For this reason, the terminal side cannot receive the block transmitted by the system side during that time, and one block of data is omitted from the data transmitted by the system side. However, at this time, both the system and the two terminals do not recognize that the data is missing, so they proceed to the next step. This method has the drawback that data dropouts occur and accurate data transmission services cannot be provided.

[Means to solve the problem]

According to the present invention, a base station uses polling to communicate with a terminal, and the base station uses a wireless communication system in which several data packets are sent in units of blocks and the base station obtains reception confirmation in units of blocks from the receiving terminal side. In a data packet transmission method, a wireless device is characterized in that control is performed to prevent data dropout (block dropout) from occurring in communication with a terminal by setting a bit indicating reception of an odd or even frame when confirming reception. A packet transmission method is obtained.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a flowchart during downlink data transmission in the wireless packet transmission system of the present invention. The odd/even block bit (BLOCKb it) is used to distinguish whether the reception length of an even BLOCK or the reception length of an odd BLOCK is output in the normal block reception length/non-reception from the terminal side. This is added to the conventional example.

By adding these odd/even block bits, even if the terminal cannot receive P#ARvi indicating the transmission right reversal shown above, data blocks will not be missed.

This is shown below.

In FIG. 1(b), the system side transmits the data of the m-th block, receives BLOCK ACK (odd) from the terminal side indicating the successful completion of reception of odd-numbered blocks, and then (m+1).
P#j7R indicating transmit right reversal to transmit block
Indicates a case where vi was sent but could not be received on the terminal side.

At this time, the terminal side determines that it still has the right to transmit and monitors the polling section. Since the system side issued P#ARvi indicating transmission right reversal, it started transmitting the next (m+1) block, and after transmitting the nth packet, that is, the last packet of the (m+1) block, the terminal side To check whether it was received correctly,
Invite the terminal to send the message. The terminal that was unable to receive the transmission right reversal earlier and is waiting for the transmission right reversal now returns to P#β.
When receiving a BLOCK ACK (odd) indicating the reception length/product of the previously sent m blocks. The system side that receives this detects that the terminal has received only up to m blocks of data, and retransmits (m+1) blocks.

〔Effect of the invention〕

As explained above, the present invention adds a bit indicating the reception of an (odd/even number) frame to the reception length/rejection signal of each block issued from the terminal side, thereby preventing data loss during data transmission/reception. In other words, block omissions are eliminated and accurate data transmission service can be performed.

[Brief explanation of the drawing]

FIGS. 1(a) and 1(b) are diagrams showing the flow on the system side and the terminal side of the wireless packet transmission method of the present invention.
FIG. 1(a) is a diagram showing a normal state, FIG. 1(b) is a diagram showing a state when transmission right reversal cannot be received on the terminal side, and FIG. 2 is a diagram showing a polling method in wireless packet transmission. Second
Figure (a) is a diagram showing the relationship between polling and response signals;
Figure (b) is an explanatory diagram of slots, and Figure 3 is a diagram showing the flow of terminal α on the system side in a conventional example, where Figure 3 (a) is normal and Figure 3 (b) is transmission right reversal. Indicates the status when the terminal cannot receive the message. D(0) to D(n)...Data packet, P
#n...Send invitation polling, P#ARvi・
...Polling for transmission right reversal, BLOCK AC
K (odd/even) (b) Figure 1 (b) Figure 7 (a) (b) Figure 3

Claims (1)

[Claims] In a wireless data packet transmission method in which a base station communicates with a terminal using polling, several data packets are made into one block, and the base station obtains reception confirmation for each block from the receiving terminal side, A wireless packet transmission system characterized in that control is performed so that data dropout (block dropout) does not occur in communication with the terminal by setting a bit indicating reception of an odd or even frame during the reception confirmation.