CN101764680A

Movatterモバイル変換

Info

Publication number: CN101764680A
Application number: CN200810189266A
Authority: CN
Inventors: 王继宏; 孙佳
Original assignee: ZTE Corp
Current assignee: ZTE Corp
Priority date: 2008-12-26
Filing date: 2008-12-26
Publication date: 2010-06-30

Abstract

The invention provides a method for increasing the transmission efficiency of data services. The method comprises the following step: when a lost data block is detected by a receiving party, an answer message containing the receiving bitmap of the receiving window of the receiving party is sent to a sending party by the receiving party. Consequently, when the loss of data blocks is continuously caused at the receiving party, the method of the invention is capable of making the adjustment in a timely manner and sending an answer to the sending partying which sends the Nacked (negative acknowledgement) data blocks using the V(A)-based index and undergoing the earliest transmission in the data array V(B) after receiving the answer, thereby effectively preventing a window from being delayed.

Description

Method for improving data service transmission efficiency of mobile communication system

Technical Field

The invention relates to the field of mobile communication, in particular to a method for improving the transmission efficiency of a data service of a mobile communication system.

Background

In the mobile communication system, in the confirmation mode, both sides of the data service adopt a sliding window mechanism, and the both sides of the data service respectively have a transmitting and receiving window, and after receiving a certain amount of data, the receiving side sends a confirmation message to the sending side to inform the sending side of the condition of receiving the bitmap in the current receiving window. The sender confirms whether the receiver correctly receives the previously sent data block or not according to the confirmation message, and retransmits the data block which is not received and the forward sliding window according to the confirmation message. The windows at the two ends of the transceiver continuously slide forwards according to the rule. When the distance between the earliest unacknowledged received data block and the next data block to be received in the window of the receiving party reaches the size of the window, the data block cannot slide forwards, so that the receiving window is stopped; the distance between the earliest unacknowledged data block and the next data block to be sent in the sending window reaches the window size and cannot slide forward, and the sending window is stopped. The sliding window mechanism is widely used in the existing communication system, and can effectively improve the transmission efficiency. However, the time interval between the sending and receiving sides is long, and once the window is stopped, the efficiency is greatly affected or the service fails because of the failure of recovery. Due to the mixed network structure and the complex wireless environment, the mobile communication system has the disadvantages that the time delay exists, the data is easy to lose, the window stagnation chance is large, and the business abnormal release chance is large. When the wireless environment does not meet the requirement of high-speed transmission, the increase of uplink lost blocks may cause the stalling of a sliding window, so that an uplink TBF (Temporary Block Flow) is abnormally released, and the downlink TBF also has the problem, which may affect the transmission rate and stability of data services to a great extent.

In a GSM (Global System for Mobile Communications) System, both sides maintaining a transmission/reception window are an MS (Mobile terminal) and a Packet Control Unit (PCU) on the network side, respectively. When uploading data service, the mobile terminal side mainly maintains a sending window, and the network side mainly maintains a receiving window; when downloading data service, the mobile terminal side mainly maintains the receiving window, and the network side mainly maintains the sending window. The two sides keep the window sliding by adopting a response mechanism, and if one side of the window reaches the maximum and does not move, the window is in an abnormal flow of window stagnation. If the window is stuck frequently for a long period of time, transmission performance is greatly affected.

With the development of mobile communication technology and the diversification of services, data services are applied more and more, and the requirements are higher and higher. In uplink data service, since the mobile terminal as the sender has more restrictions (power, modem and transmission) than the network equipment, and most of the current mobile terminals have weaker uplink multi-slot capability than downlink. For example, when an ms with basic multi-slot capability of 8(CLASS8) performs uplink and downlink transmission simultaneously, it generally uses 4-slot reception and 1-slot transmission. The uplink service often cannot have too large a window, and the chances of both sides answering are less than those of downlink.

The wireless network itself is a complex and variable environment, and in this environment, even if a dynamic adaptation algorithm is adopted, the wireless environment at that time cannot be completely reflected. Data loss is inevitable in a wireless environment and the impact on data transmission often affects window sliding, causing window stalling and more serious consequences. When a mobile terminal receives and transmits data in a poor wireless environment, a phenomenon that a data block is lost often occurs. Thus, the data block in the send window is not acknowledged and the window cannot slide. If the data block with key mark and the data block with confirmation mark are lost, the two parties can not know the window position and data receiving condition of the other party, even the windows of the two parties can not be recovered due to long-term stagnation. The mobile terminal, even under a better wireless environment, will have the above-mentioned problems due to wireless interference. At present, no good processing method exists for data loss, and the data block with the key mark and the data block with the confirmation mark are lost without judgment means and consideration.

Chinese patent No. CN200510089858 provides a method for reducing downlink radio link control sliding window stagnation and improving downlink transmission efficiency, but it does not provide a solution for window stagnation in uplink traffic. Meanwhile, the patent focuses on ensuring the timeliness and accuracy of the packet downlink response.

In the protocol, only the most basic method for maintaining the window is given, and a specific algorithm for solving and preventing window stagnation in special cases is not given. For example, in the prior art, if a data block sent by a mobile terminal to a network side is in a lost state all the time, the network side does not send an uplink response message to the mobile terminal, a bitmap of the mobile terminal is not updated when the mobile terminal does not receive the uplink response message, v (a) does not move, thereby causing window stalling, v (a) is a data block array which is not confirmed at first in a window specified by a protocol, v (b) is a confirmation state array, and v (a) stays at a data block which is not sent at the earliest and is in a non-confirmation (Nacked) state when there is a non-confirmation data block in v (b), and if v (a) does not move all the time, the window stalling is caused. Similar problems exist when the network side sends data blocks to the mobile terminal.

Disclosure of Invention

The technical problem to be solved by the invention is to provide a method for improving the packet transmission efficiency of a mobile communication system, so that window stagnation is prevented, and the data transmission utilization rate of a packet channel is effectively improved.

In order to solve the above technical problem, the present invention provides a method for improving data service transmission efficiency, comprising:

when the receiver detects the lost data block, the receiver sends a response message to the sender, wherein the message carries a receiving bitmap of a receiving window of the receiver.

Further, the method may further have a characteristic that the sender retransmits the data block whose state is not confirmed to the receiver according to the reception bitmap after receiving the response message.

Further, the method may further have a feature that the receiver sends the response message to the sender only when detecting that the data block that is continuously lost is not less than a given threshold N.

Further, the method may further have the following characteristic that the sender is a mobile terminal, the receiver is a network side, and the response message is an uplink response message.

Furthermore, the method may further have the following characteristic that the receiver detecting the lost data block means that when the network side receives the data block sent by the mobile terminal, it detects that the data block is not sent on the uplink data block allocated to the mobile terminal by the network side; or, the network side does not receive the data block sent by the mobile terminal on the uplink data block allocated to the mobile terminal.

Further, the method may further have the following characteristic that the sender is a network side, the receiver is a mobile terminal, and the response message is a packet downlink response message.

Furthermore, the method may further have the following characteristic that the receiver detecting the lost data block means that the mobile terminal detects that the data block is not sent on the downlink data block allocated to the mobile terminal by the network side when receiving the data block sent by the network side; or, the mobile terminal does not receive the data block sent by the network side on the downlink data block allocated to the mobile terminal.

According to the method, when the data block is continuously lost, the receiver can make timely adjustment to send a response to the sender, and the sender sends the data block which is sent earliest and has the state of 'unacknowledged' (Nacked) in the V (B) array by taking V (A) as an index after receiving the response, so that window stagnation is effectively prevented.

Drawings

Fig. 1 is a flow chart of a method for improving data transmission efficiency according to the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

In the prior art, if a data block sent to a network side by a mobile terminal is always in a lost state, the network side does not send an uplink response message to the mobile terminal, thereby causing window stagnation. In the invention, when the network side does not receive the uplink data block sent by the mobile terminal, that is, the network side detects that the data block is lost, when the number of the lost data block is not less than the preset threshold value N (the value background of N is configurable, for example, 5), the network side sends the uplink response message to the mobile terminal, and the mobile terminal updates V (A) and V (B) according to the bitmap carried in the message after receiving the uplink response message, so that the mobile terminal can timely resend the data block which is sent earliest and does not receive the confirmation message, thereby preventing the window at the mobile terminal from being stagnated. V (A) is the array of the first unacknowledged data blocks in the window specified by the protocol, and V (B) is the array of the validation states. Similarly, when the mobile terminal is a receiving end, and the mobile terminal detects that the data block is lost, when the number of the lost data blocks is not less than a preset threshold value N (the value of N is available in the background), the mobile terminal sends a packet downlink response message to the network side, and the network side updates a local bitmap according to a receiving bitmap of a receiving window of the mobile terminal carried in the message after receiving the packet downlink response message, so that the network side resends the data block which is sent earliest and does not receive the confirmation message in time, and the window stagnation of the network side can be prevented.

Referring to fig. 1, the flow of improving the data service transmission efficiency according to the present invention is as follows:

step 101, a mobile terminal sends a data block to a network side;

102, when detecting that data block loss occurs, a network side sends a block loss message to an uplink state machine; the network side detects that the data block loss occurs means that the network side receives the data block sent by the mobile terminal, judges whether the data block is sent on the uplink data block allocated to the mobile terminal by the network, if the data block is not sent on the uplink data block allocated to the mobile terminal, the network side considers that the data block loss occurs, or the network side does not receive the data block on the uplink data block allocated to the mobile terminal, the network side considers that the uplink data block loss occurs, if the data block is not lost, the network side executes the subsequent steps according to the protocol specification and carries out periodic packet uplink response;

103, when the uplink state machine receives the block loss message in the transmission state, judging whether no less than N uplink data blocks are lost, for example, N is 5, and VR is not equal to oldVR, if the condition is satisfied, entering 104, otherwise, returning tostep 101; wherein,

VR is the first data block expected to be received in the receiving window specified by the protocol, oldVR is VR before the receiving window moves (last window), VR is not equal to oldVR and is used for judging whether N uplink data blocks are continuously lost;

104, the network side sends an uplink response message to the mobile terminal, wherein the message carries a receiving bitmap of a network side receiving window;

and 105, after receiving the uplink response message, the mobile terminal retransmits the data block which is transmitted earliest and has the state of 'unacknowledged' (Nacked) in the array of V (B) by taking V (A) as an index to the network side according to the receiving bitmap in the message.

The network side maintains a packet control unit of the receive window.

According to the method, when the data block is continuously lost, the receiver can make timely adjustment to send a response message to the sender, and the sender sends the data block which is sent earliest and is in a state of 'unacknowledged' (Nacked) in the V (B) array by taking V (A) as an index to the receiver after receiving the response message, so that window stagnation is effectively prevented.

The present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof, and it should be understood that various changes and modifications can be effected therein by one skilled in the art without departing from the spirit and scope of the invention as defined in the appended claims.

Claims

1. A method for improving data traffic transmission efficiency, comprising:

2. The method of claim 1, wherein the sender retransmits the data block whose status is unconfirmed to the receiver according to the reception bitmap after receiving the response message.

3. The method according to claim 1 or 2, characterized in that the receiver sends the reply message to the sender only when it detects that the continuously lost data block is not less than a given threshold N.

4. The method according to claim 1 or 2, wherein the sender is a mobile terminal, the receiver is a network side, and the response message is an uplink response message.

5. The method of claim 4, wherein the receiver detecting the missing data block means that when the network side receives the data block sent by the mobile terminal, it detects that the data block is not sent on the uplink data block allocated to the mobile terminal by the network side; or, the network side does not receive the data block sent by the mobile terminal on the uplink data block allocated to the mobile terminal.

6. The method according to claim 1 or 2, wherein the sender is a network side, the receiver is a mobile terminal, and the response message is a packet downlink response message.

7. The method of claim 6, wherein the receiver detecting the missing data block means that when the mobile terminal receives the data block sent by the network side, it detects that the data block is not sent on the downlink data block allocated to the mobile terminal by the network side; or, the mobile terminal does not receive the data block sent by the network side on the downlink data block allocated to the mobile terminal.