The method of automatic off-grid under the DMR transfer pattern
Technical field
The present invention discloses a kind of DMR communication means, the method for automatic off-grid under particularly a kind of DMR transfer pattern.
Background technology
DMR is the abbreviation of Digital Mobile Radio, is the consensus standard that European digital handset uses.Stipulate in the DMR agreement, under the transfer pattern, if in the channel access procedure of DMR terminal after the Active Frame of repeaters transmit maximum times, if travelling carriage (being the DMR terminal) is not also received the valid frame of repeater downlink, then this emission of DMR terminal will be rejected, and be considered as once invalid conversation.In this case, cause the conversation failure.
Summary of the invention
At the shortcoming that can cause the conversation failure under the above-mentioned DMR transfer pattern of mentioning of the prior art, the invention provides the method for automatic off-grid under a kind of DMR transfer pattern, if the DMR terminal is behind the Active Frame of repeaters transmit set point number, the DMR terminal is not also received valid frame at the down link of repeater, the DMR terminal switches to tranmitting frequency the direct mode operation frequency automatically, carry out message transmission with direct mode operation, improved the success rate of conversation greatly.
The technical scheme that the present invention solves its technical problem employing is: the method for automatic off-grid under a kind of DMR transfer pattern, this method is for being under the transfer pattern when communication system, if the DMR terminal is behind the Active Frame of repeaters transmit set point number, the DMR terminal is not also received valid frame at the down link of repeater, the DMR terminal switches to tranmitting frequency the repeaters transmit frequency automatically, carries out message transmission with direct mode operation.
The technical scheme that the present invention solves its technical problem employing further comprises:
Behind described this end of conversation, the automatic switchback transfer of DMR terminal pattern.
The invention has the beneficial effects as follows: the present invention can't receive at down link under the situation of base station valid frame can significantly improve the success rate of communication, does not need user intervention, takes over seamlessly, and is more suitable for the application of emergent aspect.
The present invention will be further described below in conjunction with the drawings and specific embodiments.
Description of drawings
Fig. 1 is communication scheme under the transfer pattern of the present invention.
Fig. 2 is communication scheme under the direct mode operation of the present invention.
Fig. 3 is a workflow diagram of the present invention.
Embodiment
Present embodiment is the preferred embodiment for the present invention, and other all its principles are identical with present embodiment or approximate with basic structure, all within protection range of the present invention.
Please referring to accompanying drawing 1, the present invention communicating terminal A(under the transfer pattern is the DMR terminal) and communicating terminal B(be the DMR terminal) with tranmitting frequency f
1, receive frequency f
2Carry out communication with trunk desk, communicating terminal A is earlier with f
1Frequency sends to repeater with information, and repeater converts thereof into f again
2Frequency sends to communicating terminal B, finishes communication.
Please referring to accompanying drawing 3, communication system among the present invention is operated in transfer pattern following time, when DMR terminal (in the present embodiment, it is intercom, perhaps can be referred to as communicating terminal A or communicating terminal B) if behind the Active Frame of repeaters transmit set point number, the DMR terminal also not in the down link of repeater (being the feedback information of repeater) to the DMR terminal receive valid frame (valid frame in the present embodiment is meant the information that affirmation repeater that repeater sends is connected with the DMR terminal), the tranmitting frequency that the DMR terminal switches to tranmitting frequency repeater automatically is f
2, carry out message transmission with direct mode operation.Behind this end of conversation, the automatic switchback transfer of DMR terminal pattern.
When the present invention specifically implements, for activating the flow process of base station under the transfer pattern, as can be known when N=N_Wakeup(wherein N be the Active Frame number of times that the DMR terminal sends, N_Wakeup is the activation number of times of the maximum of DMR agreement regulation) time emission be rejected or be suspended, (this moment is for terminal tranmitting frequency f will to cause this Communications failure
1, receive frequency f
2).And the theory among employing the present invention, for a DMR terminal to carry out the emission of Active Frame under the transfer pattern, if equal the IDLE frame (being the valid frame that the repeater affirmation is communicated with the DMR terminal) that N_Wakeup does not also receive repeater downlink at N, then this terminal automatically switches to direct mode operation, please referring to accompanying drawing 2.Direct mode operation when communication, detect busy spare time of channel earlier, if idle then directly carry out the emission of voice head and voice superframes thereof (its tranmitting frequency is f
2).When initiate to operate with the transfer pattern again when calling out after this end of conversation next time.And, carry out the reception of corresponding modes according to the pattern of frame synchronization for receiving terminal.In the present embodiment, for receiving terminal is by the synchronous pattern of judgment frame, enter the reception of corresponding modes, if physical layer is detected to be transfer model frame sync pattern then to notify the upper strata to switch to transfer pattern accepting state, if detectedly be direct mode operation frame synchronization pattern then notify the upper strata to switch to the direct mode operation accepting state.When this receiving terminal will be launched according to the transfer pattern launch when with the intermediate station connection failure after invent proposition according to this paper automatic off-grid technology carry out communication.
The present invention can't receive at down link under the situation of base station valid frame can significantly improve the success rate of communication, does not need user intervention, takes over seamlessly, and is more suitable for the application of emergent aspect.