Emergency talkback method with wide-band and narrow-band simultaneous voice access capability

Abstract

The invention discloses an emergency talkback method with a wide-band and narrow-band simultaneous voice access capability. The method comprises the following steps: establishing communication by using a multimode emergency interphone with a broadband system and a narrowband system in an emergency communication scene, and sending a voice packet carrying a sequence mark on two networks according to a voice frame length of 60ms; the core network carries out voice frame alignment through a sequence mark, carries out completeness comparison on voice packets transmitted by the narrowband network and the broadband network within a buffer time of 300ms, regenerates a section of complete voice, converts the voice into a broadband format and a narrowband format, and issues the voice to the broadband network and the narrowband network; the voice is interrupted only under the condition that the transmission cannot be carried out by the two networks, otherwise, the voice playing is continuous. By the adoption of the method, when a single mode is disturbed, seamless switching is conducted, voice of another network is issued, the voice is not lost or duplicated, and manual switching of a user is not needed.

Description

Technical Field

[0001] The present invention relates to the field of emergency communications, and in particular to an emergency intercom method with broadband and narrowband simultaneous voice access capabilities. Background Art

[0002] Emergency communication refers to the communication means and methods required for rescue, emergency assistance and necessary communications by comprehensively utilizing various communication resources when natural or man-made emergencies occur. It is a temporary special communication mechanism provided to deal with emergencies. Multi-mode emergency intercoms with both broadband and narrowband formats are important emergency support means.

[0003] In emergency tasks, communication conditions are often very poor. For example, in the three-break communication, there will be power outages, circuit breakages, and network disconnections. Public network communication cannot be guaranteed, and narrowband is needed as the main force; and sometimes, narrowband intercom may have insufficient coverage or serious interference, and broadband communication is needed as a supplement and guarantee. Existing systems often can only upload voice through one channel, resulting in continuous interruption of voice during emergency rescue as the environment changes or rapid movement. When the coverage areas overlap and are all poor, missing words, broken words, and repeated words are obvious.

[0004] In summary, the prior art lacks an emergency intercom method with broadband and narrowband simultaneous voice access capabilities. Summary of the invention

[0005] In view of the defects and problems existing in the prior art, the object of the present invention is to provide an emergency intercom method with wide-band and narrow-band simultaneous voice access capabilities.

[0006] The technical solution adopted by the present invention is: an emergency intercom method with broadband and narrowband simultaneous voice access capability has the following steps: A1. In emergency communication scenarios, use a multi-mode emergency intercom with both broadband and narrowband standards to establish communication, and send voice packets carrying sequence markers on two networks according to the 60ms voice frame length.

[0007] A2. The broadband and narrowband networks send the received voice packets to the core network for subsequent processing.

[0008] A3. After the core network receives the voice data sent by the broadband and narrowband networks, it first aligns the voice frames through the sequence markers. Within the 300ms buffer time, it compares the integrity of the voice packets sent from the narrowband and broadband networks. Through verification and error correction, it selects the packet with better integrity. In units of 60ms, it regenerates a complete voice segment, converts it into broadband and narrowband formats, and sends it to the broadband and narrowband networks.

[0009] A4. After receiving the voice from the core network, the broadband and narrowband networks will send the voice to the intercoms of the corresponding frequency and group. If the receiving intercom is a multi-mode emergency intercom with both broadband and narrowband standards, the receiving intercom will receive two voice frames, broadband and narrowband, and then verify the integrity of the voice frame through the vocoder FEC, select the voice frame with the most complete sequence number in the same time period, give priority to narrowband network voice, and then convert the voice frame into an audio signal and broadcast it through the speaker.

[0010] In step A1, the multi-mode emergency intercom with both broadband and narrowband standards contains an NVOC vocoder with two compression rate bandwidths according to 60ms packetization. The NVOC vocoder has the ability to freely switch from one rate to another in units of 60ms.

[0011] The multi-mode emergency intercom with both broadband and narrowband standards uses a 2.15Kbps voice compression algorithm to address the fact that 2.4Kbps voice compression used in ordinary narrowband networks cannot carry timestamps. It carries continuous frame numbers without affecting voice intelligibility and carries the same frame numbers in 12.2Kbps voice.

[0012] In step A2, the broadband and narrowband networks continuously receive two voice channels and transmit the voice frames with verification information and frame numbers to the core network. The core network then performs subsequent processing by comparing the integrity of the voices received by the broadband and narrowband networks at the same time and regenerating a voice with the highest integrity.

[0013] The beneficial effect of the present invention is that the voice will be interrupted only when both networks cannot transmit, otherwise the voice playback is continuous. With this method, when a single mode is disturbed, the voice of another network is seamlessly switched and sent, and the voice does not lose words or repeat words, and the user does not need to switch manually. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a schematic diagram of emergency service interaction in an embodiment of the present invention; Figure 2 for Figure 1 Schematic diagram of the internal processing flow interaction of the transmitting walkie-talkie. DETAILED DESCRIPTION

[0015] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0016] Reference Figure 1 , Figure 2 , an emergency intercom method with broadband and narrowband simultaneous voice access capability has the following steps: A1. In emergency communication scenarios, use a multi-mode emergency intercom with both broadband and narrowband standards to establish communication, and send voice packets carrying sequence markers on two networks according to the 60ms voice frame length.

[0017] The multi-mode emergency intercom with both broadband and narrowband standards contains an NVOC vocoder with two compression rate bandwidths according to 60ms packetization. The NVOC vocoder has the ability to freely switch from one rate to another in units of 60ms.

[0018] The multi-mode emergency intercom with both broadband and narrowband standards uses a 2.15Kbps voice compression algorithm to address the fact that 2.4Kbps voice compression used in ordinary narrowband networks cannot carry timestamps. It carries continuous frame numbers without affecting voice intelligibility and carries the same frame numbers in 12.2Kbps voice.

[0019] A2. The broadband and narrowband networks send the received voice packets to the core network for subsequent processing.

[0020] The broadband and narrowband networks continuously receive two voice channels and transmit the voice frames with verification information and frame numbers to the core network. The core network then performs subsequent processing by comparing the integrity of the voices received by the broadband and narrowband networks at the same time and regenerating a voice with the highest integrity.

[0021] A3. After the core network receives the voice data sent by the broadband and narrowband networks, it first aligns the voice frames through the sequence markers. Within the 300ms buffer time, it compares the integrity of the voice packets sent from the narrowband and broadband networks. Through verification and error correction, it selects the packet with better integrity. In units of 60ms, it regenerates a complete voice segment, converts it into broadband and narrowband formats, and sends it to the broadband and narrowband networks.

[0022] A4. After receiving the voice from the core network, the broadband and narrowband networks will send the voice to the intercoms of the corresponding frequency and group. If the receiving intercom is a multi-mode emergency intercom with both broadband and narrowband standards, the receiving intercom will receive two voice frames, broadband and narrowband, and then verify the integrity of the voice frame through the vocoder FEC, select the voice frame with the most complete sequence number in the same time period, give priority to narrowband network voice, and then convert the voice frame into an audio signal and broadcast it through the speaker.

[0023] Giving priority to narrowband network voice means that if the narrowband voice is received completely and continuously, the voice is played directly without waiting for the broadband voice packet.

[0024] The core network has the ability to buffer and verify voice frames, and can determine the voice frame sequence number and integrity, select the most complete one among the two voice frames at the same rate with the same voice frame sequence number, and convert it into another rate through the vocoder.

[0025] Example: In emergency communication scenarios, emergency personnel use multi-mode emergency intercoms with both broadband and narrowband formats. Multi-mode emergency intercoms have narrowband channels and broadband channels. Narrowband channels can access narrowband networks. For example, PDT clusters and PDT self-organizing networks; broadband channels can access broadband networks, such as 4G / 5G public networks; and have a broadband and narrowband fusion vocoder (model NVOC). The vocoder has the ability to load broadband and narrowband vocoders at the same time, and can compress the same voice stream into a narrowband voice stream (2.15Kbps) and a broadband voice stream (12.2Kbps).

[0026] If there is only one network at the emergency site, the multi-mode emergency intercom will work in single mode. The working mode can be found in the industry standard of the Ministry of Emergency Management of the People's Republic of China "Technical Specifications for Emergency Dedicated Digital Trunking (ePDT) Communication System"; if the multi-mode emergency intercom detects the existence of both broadband and narrowband networks at the emergency site, it will reside in both broadband and narrowband networks at the same time.

[0027] When an emergency occurs, the user presses the PTT button to initiate an emergency voice call. The subsequent process is as follows Figure 2 The user's voice is first collected by the microphone on the transmitting intercom, and then enters the vocoder after AD (analog-to-digital conversion). The vocoder can compress the voice into narrowband voice streams and broadband voice streams, forming voice frames of 60ms per packet, attaching 12-bit sequence marks to the voice frames, adding FEC and error correction codes according to the rules, and finally sending the voice packets carrying sequence marks on the broadband and narrowband networks respectively, as shown in Figure 1 As shown in A and B.

[0028] The broadband network and narrowband network will receive the voice packets carrying sequence marks from the corresponding network sent by the transmitting intercom and forward them to the core network for subsequent processing, such as Figure 1 As shown in C and D.

[0029] After the core network receives the voice packets with sequence marks received by the broadband and narrowband networks, it first aligns them through the sequence marks, compares the voice packets sent by the narrowband and broadband networks through a buffer of no more than 300ms, selects the packet with better integrity through verification and error correction, and regenerates the voice in units of 60ms. If the regenerated voice is in broadband mode, it needs to convert another narrowband voice packet. If the regenerated voice is in narrowband mode, it needs to convert another broadband voice packet. According to the target address of the voice and the cluster communication rules, it is sent to the corresponding broadband and narrowband networks, such as Figure 1As shown in E and F.

[0030] After receiving the voice from the core network, the broadband and narrowband networks forward the voice to the receiving intercom at the target address according to the trunking communication rules, such as Figure 1 As shown in G and H.

[0031] If the receiving intercom is a multi-mode emergency intercom with both broadband and narrowband standards, it will receive two voice frames sent by the broadband and narrowband networks. The receiving intercom also needs to align the sequence numbers and verify the integrity of the voice frames through the vocoder FEC, and select the most complete voice frame for playback. Since the narrowband network has a low transmission rate but strong anti-interference ability, while the broadband network is the opposite, narrowband network voice is preferred when the integrity is consistent; if the receiving intercom is a single-mode intercom, it can only receive voice frames sent by a single network in the corresponding mode. The receiving intercom converts the voice frames into audio signals and broadcasts them through the speaker.

Claims

1. An emergency intercom method with broadband and narrowband simultaneous voice access capability, characterized in that: The method has the following steps: A1. In the emergency communication scenario, a multi-mode emergency intercom with both broadband and narrowband standards is used to establish communication, and voice packets carrying sequence markers are sent on two networks according to the 60ms voice frame length; A2, broadband and narrowband networks send received voice packets to the core network for subsequent processing; A3. After receiving the voice data sent by the broadband and narrowband networks, the core network first aligns the voice frames through the sequence flags. Within the 300ms buffer time, the voice packets sent by the narrowband and broadband networks are compared for completeness. The packet with better integrity is selected through verification and error correction. A complete voice segment is regenerated in units of 60ms, converted into broadband and narrowband formats, and sent to the broadband and narrowband networks. A4. After receiving the voice from the core network, the broadband and narrowband networks will send the voice to the intercoms of the corresponding frequency and group. If the receiving intercom is a multi-mode emergency intercom with both broadband and narrowband standards, the receiving intercom will receive two voice frames, broadband and narrowband, and then verify the integrity of the voice frame through the vocoder FEC, select the voice frame with the most complete sequence number in the same time period, give priority to narrowband network voice, and then convert the voice frame into an audio signal and broadcast it through the speaker.

2. According to claim 1, an emergency intercom method with broadband and narrowband simultaneous voice access capability is characterized in that: In step A1, the multi-mode emergency intercom with both broadband and narrowband standards contains a vocoder with two compression rate bandwidths according to 60ms packetization, and the vocoder has the ability to freely switch from one rate to another in units of 60ms.

3. The emergency intercom method with broadband and narrowband simultaneous voice access capability according to claim 2 is characterized in that: The multi-mode emergency intercom with both broadband and narrowband standards uses a 2.15Kbps voice compression algorithm to address the fact that 2.4Kbps voice compression used in ordinary narrowband networks cannot carry timestamps. It carries continuous frame numbers without affecting voice intelligibility and carries the same frame numbers in 12.2Kbps voice.

4. The emergency intercom method with broadband and narrowband simultaneous voice access capability according to claim 3 is characterized in that: In step A2, the broadband and narrowband networks continuously receive two voice channels and transmit the voice frames with verification information and frame numbers to the core network. The core network then performs subsequent processing by comparing the integrity of the voices received by the broadband and narrowband networks at the same time and regenerating a voice with the highest integrity.

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