WO2012100627A1

WO2012100627A1 - Method for updating clock offset, method and apparatus for announcing clock offset message

Info

Publication number: WO2012100627A1
Application number: PCT/CN2011/084939
Authority: WO
Inventors: 梁剑耀
Original assignee: 华为技术有限公司
Priority date: 2011-01-26
Filing date: 2011-12-29
Publication date: 2012-08-02
Also published as: CN102098144A

Abstract

The invention discloses a method for updating clock offset, method and apparatus for announcing the clock offset message. The method includes: receiving the message from the corresponding communication terminal; acquiring the message type according to the message type field of said message; updating local clock offset according to the type of said message and said message. The apparatus includes: receiving module, acquiring module and update module. The invention enables the accurate judgement of the message type when receiving 0 length application data, by acquiring the message type according to the message type field of the message, When the message is received from the corresponding communication terminal, and processing local clock offset accordingly in accordance with the message type, thus, the dead circulation of the message is avoided and the communication error rate is reduced.

Description

Method for updating clock offset, method and device for notifying clock offset message. The present application claims to be filed on January 26, 2011, the Chinese Patent Office, the application number is 201110028100.1, the invention name is "clock offset update method, clock offset The priority of the Chinese Patent Application, the disclosure of which is incorporated herein by reference. Technical field

The present invention relates to the field of communications technologies, and in particular, to a clock offset update method, a clock offset message notification method and apparatus. Background technique

The CTCS-3 (China Train Control System, China Train Control System Level 3) train operation control system standard is the main technical standard for the Chinese railway speed 300-350km passenger line. RSSP-IK Railway Signal Safety Protocol II, Railway Signal Security Protocol II X Corresponding to the ETCS (European Train Control System) standard Subset098 protocol is one of the important communication and interface protocols for RBC-RBC (Radio Block Center), RBC-IL (Interlocking, Interlocking) ), communication between RBC-TSRS (Temporary Speed Restriction Server). The RSSP-II protocol is mainly used to protect against threats such as out-of-order, delay, error, forgery, and insertion of messages in an open network.

The RSSP-II protocol defense message delay is TTS (Triple Time Stamp) technology. The TTS technology needs to periodically update the local clock offset between the two communicating parties. It periodically sends a clock offset update request message to the other party, and updates the clock offset of both parties after receiving the update clock offset response message.

After analyzing the prior art, the inventors have found that the prior art has at least the following disadvantages: In the prior art, the clock offset update request message and the response message format are exactly the same, and the only difference between the two and the normal application data message is that The first two have no application data. Therefore, only The message length and the Last receiver time stamp are used to distinguish the three. When the network sends an error of 0 length application data, the receiver (A) determines the clock offset update request message from the peer, and sends a response message to the receiver. The opposite end (B), the opposite end (B) receives the response message, and also determines the clock offset update request message, and returns the clock offset update response message, and repeats, resulting in an infinite loop of the message and a high communication error rate. Summary of the invention

Embodiments of the present invention provide a method for updating a clock offset, an announcement method and a device for a clock offset message. The technical solution is as follows:

In one aspect, an embodiment of the present invention provides a method for updating a clock offset, including: receiving a message from a communication peer, where the message includes a message type field;

Obtaining, according to a message type field of the message, a type of the message, when the message type field is a first value, the message is a clock offset update request message from the communication peer; when the message type field When the value is the second value, the message is a clock offset update response message from the communication peer; and

And if the message type field is the first value or the second value, updating the local clock offset according to the type of the message and the message.

On the other hand, an embodiment of the present invention provides a method for advertising a clock offset message, including: sending a message to a communication peer, where the message includes a message type field;

When the message type field is the first value, the message is a clock offset update request message; and

When the message type field is the second value, the message is a clock offset update response message. In one aspect, an embodiment of the present invention provides an apparatus for updating a clock offset, including: a receiving module, configured to receive a message from a communication peer, where the message includes a message type field; and an acquiring module, configured to be used according to the message The message type field acquires the type of the message, and the update module is configured to: when the message type field is the first value, the message is from the a clock offset update request message of the communication peer; when the message type field is the second value, the message is a clock offset update response message from the communication peer; and

On the other hand, an embodiment of the present invention provides an apparatus for advertising a clock offset message, including: a sending module, configured to send a message to a communication peer, where the message includes a message type field; when the message type field is a value, the message is a clock offset update request message; and

When the message type field is the second value, the message is a clock offset update response message. In another aspect, an embodiment of the present invention provides a clock offset update system, including: a device for updating a clock offset, configured to receive a message from a communication peer, where the message includes a message type field; a message according to the message The type field obtains the type of the message; when the message type field is the first value, the message is a clock offset update request message from the communication peer; when the message type field is the second value, The message is a clock offset update response message from the communication peer; and if the message type field is the first value or the second value, updating the local according to the type of the message and the message Clock offset

a notification device of the clock offset message, configured to send a message to the communication peer, where the message includes a message type field; when the message type field is the first value, the message is a clock offset update request message; When the message type field is the second value, the message is a clock offset update response message.

The beneficial effects of the technical solutions provided by the embodiments of the present invention are:

When receiving the message from the communication peer, the message type is obtained according to the message type field of the message, and the local clock offset is processed according to the message type, so that when the 0-length application data is received, the message type can be accurately identified. The occurrence of an infinite loop of messages is avoided, and the communication error rate is reduced. DRAWINGS

1 is a flowchart of a method for updating a clock offset according to an embodiment of the present invention; FIG. 2 is a flowchart of a method for updating a clock offset according to an embodiment of the present invention; FIG. 4 is a schematic structural diagram of an apparatus for updating a clock offset according to an embodiment of the present invention; FIG. 5 is a schematic diagram of a clock offset message according to an embodiment of the present invention; Schematic diagram of the notification device;

FIG. 6 is a schematic structural diagram of a clock offset update system according to an embodiment of the present invention. detailed description

The embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

Example 1

In order to avoid the occurrence of a message infinite loop and reduce the communication error rate, the embodiment of the present invention provides a method for clock offset update. Referring to FIG. 1, the method includes:

101 : receiving a message from a communication peer, where the message includes a message type field;

102: Obtain a type of the message according to a message type field of the message;

103: When the message type field is the first value, the message is a clock offset update request message from the communication peer; when the message type field is the second value, the message is a clock offset from the communication peer Update response message; and

If the message type field is the first value or the second value, the local clock offset is updated according to the type of the message and the message.

In another embodiment of the present invention, updating the local clock offset according to the type of the message and the message includes:

When the message is a clock offset update request message from the communication peer, the clock offset update response message is sent to the communication peer end, and the clock offset update response message carries the clock offset received. a local timestamp of the new request message and a local timestamp of the clock offset update response message; when the message is a clock offset update response message from the communication peer, the clock offset is updated according to the receipt from the communication peer The local timestamp when replying to the message and the clock offset update response message from the correspondent end of the communication update the local clock offset.

In another embodiment provided by the present invention, the method further includes:

When the message type field is a third value, the message is an application data message; and if the message type field is the third value, performing the application data according to the type of the message and the message Processing of the message.

The method provided by the embodiment of the present invention obtains a message type according to a message type field of a message when receiving a message from a communication peer end, and processes a local clock offset according to the message type, so that when the 0-length application data is received, , can accurately identify the message type, avoid the appearance of the message infinite loop, and reduce the communication error rate.

Referring to FIG. 2, FIG. 2 is a further embodiment of the present invention. The interaction between the initiator A and the responder B is taken as an example. The method includes:

201: The initiator A sends a clock offset update request message to the responder B, where the message type field of the clock offset update request message is equal to the first value;

In the embodiment of the present invention, the message type field of the clock offset update request message is equal to the first value, and the message type field of the clock offset update response message is equal to the second value, and the message type of the application data message is used. The field is equal to the third value, and the three types of messages are defined as different values on the message type field to distinguish their types, avoiding confusion of messages. Preferably, the message type field is a header field of the three types of messages.

Those skilled in the art can know that the clock offset update request message carries the local transmission time stamp TA(x). In addition, the first value, the second value, and the third value are set by the developer according to the computing power of the system or other factors, and the invention is not specifically limited.

202: Responder B receives the message from initiator A and obtains a message type field of the message; In the embodiment of the present invention, the message received by the responder B may be a clock offset update response message, a clock offset update request message, or an application data message. By obtaining its message type field, the message type of the message may be obtained.

It should be noted that the message format of the clock offset update request message and the clock offset update response message is exactly the same, except that the value of the message type field is different from the application data message in that the first two are not applied. data.

203: Determine a value of the message type field, where the message type field is a first value, and the learned message is a clock offset update request message from the communication peer end;

In the embodiment of the present invention, the initiator A sends a clock offset update request message as an example. If the message sent by the initiator A is a clock offset update response message, the message type field is known as the second. The value, if the message sent by the initiator A is an application data message, it can be known that the message type field is the third value. Preferably, the third value is 6.

204: Responder B sends a clock offset update response message to initiator A, where the clock offset update response message carries a local timestamp of the received clock offset update request message and a local timestamp of the transmit clock offset update response message;

In the embodiment of the present invention, when receiving the clock offset update request message, the responder B needs to construct a clock offset update response message (Clock offset update Answer), and sends the message to the initiator A, where the message carries TA ( x ), the local timestamp TB ( m ) when the clock offset update request message is received, and the local time stamp TB(n) when the clock offset update response message is sent. In addition, when the received message is determined to be an application data message, processing of the application data message is performed.

205: Initiator A receives the message from responder B and obtains the message type field of the message;

206: Determine a value of the message type field, where the message type field is a second value, then The message is a clock offset update response message from the communication peer;

In the embodiment of the present invention, since the type of the message has been determined according to the message type field, the step of checking whether the clock offset update request message is sent by the prior art may be omitted, which simplifies the communication process and further improves. Communication efficiency.

207: Initiator A updates the local clock offset based on the local timestamp when receiving the clock offset update response message from Responder B and the clock offset update response message from Responder B.

Specifically, the initiator A receives the clock offset update response message, records the local timestamp TA ( y ) of the received clock offset update response message, and checks whether the Last receiver time stam field carried by the clock offset update response message is equal to the present The local timestamp when the transmit clock offset update request message is saved. If yes, the local clock offset needs to be calculated. If not, the local clock offset does not need to be updated. The local clock offset maximum value of initiator A TA_offset_max and local clock offset minimum TA_offset-min is calculated as follows:

TA—offset—max = TA(y) - TB(n);

TA—offset—min = TA(x) - TB(m).

Example 3

In order to avoid the occurrence of a message infinite loop and reduce the communication error rate, the embodiment of the present invention provides a method for advertising a clock offset message. Referring to FIG. 3, the method includes:

301: Send a message to the communication peer, where the message includes a message type field;

When the message type field is the first value, the message is a clock offset update request message; and when the message type field is the second value, the message is a clock offset update response message. The method further includes: when the message type field is a third value, the message is an application data cancellation Interest.

In this embodiment, before step 301, the method may further include: locally receiving a message sent by the communication peer, where the message sent by the communication peer includes a message type field, and when the message type field is the first value, the communication peer The sent message is a clock offset update request message, and the step 301 specifically includes: sending a message to the communication peer end, where the message is a clock offset update response message. Need to explain,

In this embodiment, the step 301 may be: when the clock offset update needs to be performed locally, the message is sent to the communication peer, and the message is a clock offset update request message.

The method provided by the present invention is similar to the message type field setting in the method provided in Embodiment 2, and is not mentioned again.

The method provided by the embodiment of the present invention, by sending a message to the communication peer, causes the communication peer to process the local clock offset according to the message type, so that when the 0-length application data is received, the message type can be accurately identified, and the message type is avoided. The appearance of an infinite loop of messages reduces the communication error rate.

Example 4

In order to avoid the occurrence of a message infinite loop and reduce the communication error rate, an embodiment of the present invention provides a device for clock offset update. Referring to FIG. 4, the device includes:

a receiving module 401, configured to receive a message from a communication peer, where the message includes a message type field;

The obtaining module 402 is configured to obtain a type of the message according to a message type field of the message, and an update module 403, configured to: when the message type field is the first value, the message is a clock offset update request message from the communication peer end When the message type field is the second value, the message is a clock offset update response message from the communication peer; and

The update module 403 is specifically configured to: when the message is a clock offset update request message from the communication peer, send a clock offset update response message to the communication peer, where the clock offset update response is cancelled. The information carries the local timestamp of the clock offset update request message and the local timestamp of the clock offset update response message.

The update module 403 is further configured to: when the message is a clock offset update response message from the communication peer end, according to the local timestamp when the response message is received from the clock offset of the communication peer end, and the local timestamp from the communication peer end The clock offset update response message updates the local clock offset.

The method further includes: when the message type field is a third value, the message is an application data message; and

If the message type field is the third value, processing the application data message according to the type of the message and the message.

The message type field is the header field of the message.

The device provided by the embodiment of the present invention obtains the message type according to the message type field of the message when receiving the message from the communication peer, and processes the local clock offset according to the message type, so that when the 0-length application data is received, , can accurately identify the message type, avoid the appearance of the message infinite loop, and reduce the communication error rate.

An embodiment of the present invention provides a notification device for a clock offset message. Referring to FIG. 5, the device includes:

The sending module 501 is configured to send a message to the communication peer, where the message includes a message type field; when the message type field is the first value, the message is a clock offset update request message; and when the message type field is the second When the value is, the message is a clock offset update response message. When the message type field is the third value, the message is an application data message.

The device provided by the embodiment of the present invention, by sending a message to the communication peer, causes the communication peer to process the local clock offset according to the message type, so that when the 0-length application data is received, the message type can be accurately identified, and the message type is avoided. The appearance of an infinite loop of messages reduces the communication error rate.

The embodiment of the present invention provides a clock offset update system. Referring to FIG. 6, the system includes: a clock offset update device 601, configured to receive a message from a communication peer, where the message includes a message type field; The message type field gets the type of the message; when the message class When the type field is the first value, the message is a clock offset update request message from the communication peer; when the message type field is the second value, the message is a clock offset update response message from the communication peer; and If the message type field is the first value or the second value, updating the local clock offset according to the type of the message and the message;

The notification device 602 of the clock offset message is configured to send a message to the communication peer, where the message includes a message type field; when the message type field is the first value, the message is a clock offset update request message; and when the message When the type field is the second value, the message is a clock offset update response message.

The system provided by the embodiment of the present invention obtains the message type according to the message type field of the message when receiving the message from the communication peer, and processes the local clock offset according to the message type, so that when the 0-length application data is received, , can accurately identify the message type, avoid the appearance of the message infinite loop, and reduce the communication error rate.

The device and the system provided by the embodiment of the present invention are the same as the method embodiment, and the specific implementation process is described in the method embodiment, and details are not described herein again.

All or part of the above technical solutions provided by the embodiments of the present invention may be completed by hardware related to program instructions, and the program may be stored in a readable storage medium, and the storage medium includes: ROM, RAM, disk or CD. And other media that can store program code.

The above is only the preferred embodiment of the present invention, and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., which are within the spirit and scope of the present invention, should be included in the protection of the present invention. Within the scope.

Claims

Claim

A method for updating a clock offset, comprising:

Receiving a message from a communication peer, the message including a message type field;

The method according to claim 1, wherein the updating the local clock offset according to the type of the message and the message comprises:

When the message is a clock offset update request message from the communication peer, sending a clock offset update response message to the communication peer, where the clock offset update response message carries the clock offset update request a local timestamp of the message and a local timestamp of sending the clock offset update response message;

When the message is a clock offset update response message from the communication peer, the local timestamp when the response message is received from the clock offset of the communication peer and the clock from the communication peer The offset update response message updates the local clock offset.

3. The method according to claim 1, further comprising: when the message type field is a third value, the message is an application data message; and

The method according to any one of claims 1 to 3, wherein the message type word The segment is the header field of the message.

5. A method for advertising a clock offset message, comprising:

Sending a message to the communication peer, where the message includes a message type field;

When the message type field is the second value, the message is a clock offset update response message.

The method according to claim 5, wherein when the message type field is a third value, the message is an application data message.

7. A device for updating a clock offset, comprising:

a receiving module, configured to receive a message from a communication peer, where the message includes a message type field, an acquiring module, configured to acquire a type of the message according to a message type field of the message, and an update module, configured to: when the message type When the field is the first value, the message is a clock offset update request message from the communication peer; when the message type field is the second value, the message is a clock offset update from the communication peer Reply message; and

The device according to claim 7, wherein the update module is configured to send a clock offset to the communication peer when the message is a clock offset update request message from the communication peer end. Updating a response message, where the clock offset update response message carries a local timestamp of receiving the clock offset update request message and a local timestamp of sending the clock offset update response message;

The update module is further configured to: the message is a clock offset update response from the communication peer In the message, the local clock offset is updated according to the local timestamp when the clock offset update response message from the communication peer is received and the clock offset update response message from the communication peer.

9. The apparatus according to claim 7, further comprising: when the message type field is a third value, the message is an application data message; and

The apparatus according to any one of claims 7-9, wherein the message type field is a header field of the message.

11. A device for notifying a clock offset message, comprising:

a sending module, configured to send a message to the communication peer, where the message includes a message type field; when the message type field is the first value, the message is a clock offset update request message; when the message type field is The second value is the clock offset update response message.

12. The apparatus according to claim 11, wherein when the message type field is a third value, the message is an application data message.

13. A clock offset update system, comprising:

And a device for receiving a clock offset, configured to receive a message from a communication peer, where the message includes a message type field; obtaining a type of the message according to a message type field of the message; and when the message type field is a first value The message is a clock offset update request message from the communication peer; when the message type field is a second value, the message is a clock offset update response message from the communication peer; The message type field is the first value or the first a second value, updating a local clock offset according to the type of the message and the message; a notification device of the clock offset message, configured to send a message to the communication peer, the message includes a message type field; when the message type When the field is the first value, the message is a clock offset update request message; and when the message type field is the second value, the message is a clock offset update response message.