BeiDou long message communication method

Abstract

The present invention relates to a BeiDou long message communication method. A sending terminal segments a long message into a plurality of subpackage data which can be sent by a BeiDou short message protocol, and sends the plurality of segmented subpackage data to a reception terminal via the BeiDou short message protocol. The BeiDou long message communication method is characterized in that the subpackage data comprises a package title and the data text, wherein the package title comprises a subpackage identifier, a last package identifier, a subpackage ID, a long message belonged ID; the reception terminal caches the received subpackage data, after the reception terminal receives the subpackage data containing the last package identifier, the order of the subpackage data is determined according to the subpackage ID of each subpackage data, and then all subpackage data belonging to the same long message is merged. Compared with the prior art, the BeiDou long message communication method of the present invention can accurately determine whether the sending terminal sends all subpackages of the long message, and whether the reception terminal receives all subpackages of the long message completely.

Description

technical field [0001] The invention relates to a Beidou long message communication method. Background technique [0002] The maximum length of the message in the civil short message communication of the Beidou satellite navigation and positioning system is only about 120 bytes, the amount of data transmitted each time is very limited, and there is also a great limit on the sending frequency (sent once a minute) , which greatly limits the application development based on the Beidou communication function (many practical applications often need to transmit data much larger than 120 bytes). Therefore, the realization of the Beidou long message communication method has very important practical significance. [0003] In addition, the Beidou short message communication protocol belongs to the data link layer in the OSI reference model, but it does not implement the link control function, that is, the reliable transmission mechanism of data, which is very important for the long m...

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Problems solved by technology

[0003] In addition, the Beidou short message communication protocol belongs to the data link layer in the OSI reference model, but it does not implement the link control function, that is, the reliable transmission mechanism of data, which is very important for the long message protocol

[0004] The Chinese invention patent with the application number CN201410014552.8 discloses a "Method for Realizing the Communication Function of Beidou Medium and Long Messages by Using Beidou Short Message Communication", but in this method, how does the receiving end judge the reception of a medium and long message? Whether it is complete, that is, all sub-packets have been received, how does the receiving end judge that the sending end has finished sending, does not give a reliable solution; in addition, in the transmission process, how to deal with packet loss, how to realize the sending end and There is no detailed plan for the packet replenishment mechanism between the receiving end and how to avoid the waiting deadlock between the sending end and the receiving end, so it needs to be further improved

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