An emergency intercom method with the ability to simultaneously access voice in both wide and narrow bands

Abstract

The present invention discloses an emergency intercom method with the ability to simultaneously access voice in both wideband and narrowband. In an emergency communication scenario, a multi-mode emergency intercom with both wideband and narrowband systems is used to establish communication, and voice packets carrying sequence tags are sent on two networks according to a voice frame length of 60 ms; the core network aligns the voice frames through the sequence tags, and within a buffer time of 300 ms, compares the integrity of the voice packets transmitted from the narrowband and wideband networks, regenerates a complete piece of voice, transforms it into wideband and narrowband formats, and distributes it to the wideband and narrowband networks. Since voice interruption only occurs when transmission is impossible on both networks, otherwise voice playback is continuous. By adopting this method, seamless switching occurs and the voice of the other network is distributed when a single mode is disturbed, and the voice is without missing or repeating words, and there is no need for the user to manually switch.

Description

Technical Field

[0001] The present invention relates to the field of emergency communication, and more particularly, to an emergency intercom method with the ability to simultaneously access voice in both wideband and narrowband Background Art

[0002] Emergency communication refers to the communication means and methods that comprehensively utilize various communication resources to ensure rescue, emergency assistance, and necessary communication when natural or man-made sudden emergencies occur. It is a temporary special communication mechanism provided for dealing with emergencies. A multi-mode emergency intercom with both broadband and narrowband systems is an important emergency guarantee means.

[0003] In emergency tasks, communication conditions are often extremely poor. For example, in the case of "three breaks" communication, power outages, line breaks, and network outages may occur, and public network communication cannot be guaranteed, so narrowband is required as the main force; while in some cases, narrowband intercom may have insufficient coverage or serious interference, and broadband communication is needed as a supplement and guarantee. In existing systems, voice can often only be uploaded through one channel, resulting in continuous interruptions of voice during emergency rescue operations as the environment changes or rapid movement occurs. When the coverage areas overlap and are both poor, missing words, broken words, and repeated words are obvious.

[0004] In summary, the existing technology lacks an emergency intercom method with the ability to simultaneously access voice in both wideband and narrowband. Summary of the Invention

[0005] In view of the defects and problems existing in the prior art, the purpose of the present invention is to provide an emergency intercom method with the ability to simultaneously access voice in both wideband and narrowband.

[0006] The technical solution adopted by the present invention is as follows: An emergency intercom method with the ability to simultaneously access voice in both wideband and narrowband has the following steps:

[0007] A1. In an emergency communication scenario, establish communication using a multi-mode emergency intercom with both broadband and narrowband systems, and send voice packets carrying sequence flags on both networks at a voice frame length of 60 ms.

[0008] A2. The broadband and narrowband networks send the received voice packets to the core network for subsequent processing.

[0009] 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 a buffer time of 300 ms, it compares the integrity of the voice packets transmitted by the narrowband and broadband networks, selects the packet with better integrity through checksum and error correction, and regenerates a complete segment of voice in units of 60 ms, transforms it into broadband and narrowband formats, and distributes it to the broadband and narrowband networks.

[0010] After the A4, broadband and narrowband networks receive the voice sent by the core network, they send the voice to the walkie-talkies corresponding to the corresponding frequency points and corresponding groups; if the receiving walkie-talkie is a multi-mode emergency walkie-talkie with both broadband and narrowband systems, the receiving walkie-talkie will receive two voice frames of broadband and narrowband, and then use the vocoder FEC to check the integrity of the voice frames, select the voice frame with the most complete serial number within the same time period, preferentially select the narrowband network voice, and then convert the voice frame into an audio signal and broadcast it through the speaker.

[0011] In step A1, the multi-mode emergency walkie-talkie with both broadband and narrowband systems contains an NVOC vocoder with a 60ms packetization and two compression rate bandwidths, and the NVOC vocoder has the ability to freely switch from one rate to another at 60ms intervals.

[0012] Regarding the characteristic that the ordinary narrowband network uses 2.4Kbps voice compression and cannot carry timestamps, the multi-mode emergency walkie-talkie with both broadband and narrowband systems selects a 2.15Kbps voice compression algorithm, carries continuous frame serial numbers without affecting voice intelligibility, and carries the same frame serial numbers in 12.2Kbps voice.

[0013] In step A2, the broadband and narrowband networks continuously receive two-way voice, and transmit the voice frames with check information and frame serial numbers to the core network. The core network's subsequent processing is to compare the voice integrity received by the broadband and narrowband networks simultaneously and regenerate a voice with the highest integrity.

[0014] The beneficial effects of the present invention are: Since the voice will only be interrupted when both networks are unable to transmit, otherwise the voice playback is continuous. By using this method, when a single mode is disturbed, it seamlessly switches and issues the voice of the other network, and the voice does not miss words or repeat words, and does not require the user to manually switch. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of emergency service interaction in an embodiment of the present invention;

[0016] Figure 2 is Figure 1 a schematic diagram of the internal processing flow interaction of the transmitting walkie-talkie in DETAILED DESCRIPTION OF THE INVENTION

[0017] The present invention will be further described below with reference to the drawings and embodiments.

[0018] Refer to Figure 1 、 Figure 2 , an emergency intercom method with the ability to simultaneously access voice in both wide and narrow bands has the following steps:

[0019] A1. In an emergency communication scenario, establish communication using a multi-mode emergency walkie-talkie with both broadband and narrowband modes, and send voice packets with sequence flags on two networks according to a 60 ms voice frame length.

[0020] The multi-mode emergency walkie-talkie with both broadband and narrowband modes contains an NVOC vocoder that divides packets according to 60 ms and has two compression rate bandwidths. The NVOC vocoder has the ability to freely switch from one rate to another in units of 60 ms.

[0021] Regarding the characteristic that the ordinary narrowband network cannot carry timestamps with 2.4 Kbps voice compression, the multi-mode emergency walkie-talkie with both broadband and narrowband modes selects a 2.15 Kbps voice compression algorithm. Without affecting voice intelligibility, it carries continuous frame numbers and also carries the same frame numbers in 12.2 Kbps voice.

[0022] A2. The broadband and narrowband networks send the received voice packets to the core network for subsequent processing.

[0023] The broadband and narrowband networks continuously receive two-way voice and transmit the voice frames with check information and frame numbers to the core network. The subsequent processing by the core network is to simultaneously compare the integrity of the voice received by the broadband and narrowband networks and regenerate a voice with the highest integrity.

[0024] After receiving the voice data sent by the broadband and narrowband networks, the core network first aligns the voice frames through the sequence flag. Within a 300 ms buffer time, it compares the integrity of the voice packets transmitted by the narrowband and broadband networks, selects the packet with better integrity between the two through checksum and error correction, and regenerates a complete voice in units of 60 ms, transforms it into broadband and narrowband formats, and distributes it to the broadband and narrowband networks.

[0025] After receiving the voice sent by the core network, the broadband and narrowband networks send the voice to the walkie-talkies corresponding to the corresponding frequency points and corresponding groups; if the receiving walkie-talkie is a multi-mode emergency walkie-talkie with both broadband and narrowband modes, the receiving walkie-talkie will receive two voice frames of broadband and narrowband. Then, it checks the integrity of the voice frames through the vocoder FEC, selects the voice frame with the most complete serial number within the same time period, gives priority to the narrowband network voice, and then transforms the voice frame into an audio signal and broadcasts it through the speaker.

[0026] Giving priority to the narrowband network voice means that if the received narrowband voice is complete and continuous, there is no need to wait for the broadband voice packet, and the voice can be directly played.

[0027] The core network has the ability to buffer and verify voice frames, can judge the sequence number and integrity of voice frames, select the most complete one among two-rate voice frames with the same voice frame sequence number, and convert it into another rate through a vocoder.

[0028] Embodiment: In an emergency communication scenario, emergency personnel use a multi-mode emergency walkie-talkie with both broadband and narrowband systems. The multi-mode emergency walkie-talkie has a narrowband channel and a broadband channel. The narrowband channel can access a narrowband network, such as a PDT trunking network or a PDT ad-hoc network. The broadband channel can access a broadband network, such as a 4G / 5G public network. It is equipped with a narrowband and broadband integrated vocoder (model NVOC). The vocoder has the ability to load narrowband and broadband vocoders simultaneously and can compress the same voice stream into a narrowband voice stream (2.15 Kbps) and a broadband voice stream (12.2 Kbps).

[0029] If there is only one network at the emergency incident site, the multi-mode emergency walkie-talkie works in a 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 Specification for Emergency Special Digital Trunking (ePDT) Communication System". If the multi-mode emergency walkie-talkie detects the simultaneous presence of broadband and narrowband networks at the emergency site, it will camp on both the broadband and narrowband networks simultaneously.

[0030] When an emergency occurs, the user presses the PTT button to initiate an emergency voice call. The subsequent process is as Figure 2 shown. The user's voice is first collected by the microphone on the transmitting walkie-talkie, converted through AD (analog-to-digital conversion), and then enters the vocoder. The vocoder can compress the voice into a narrowband voice stream and a broadband voice stream, form voice frames of 60 ms per packet, attach a 12-bit sequence flag to the voice frames, add FEC and error correction codes according to the rules, and finally send the voice packets with sequence flags on the broadband and narrowband networks respectively, as shown in A and B in Figure 1 .

[0031] The broadband network and the narrowband network will receive the voice packets with sequence flags corresponding to their respective networks sent by the transmitting walkie-talkie and forward them to the core network for subsequent processing, as shown in C and D in Figure 1 .

[0032] After receiving the voice packets with sequence flags received by the broadband and narrowband networks, the core network first aligns them through the sequence flags, buffers them for no more than 300 ms, compares the voice packets sent by the narrowband and broadband networks, selects the packet with better integrity through verification and error correction, regenerates the voice in units of 60 ms. If the regenerated voice is in broadband mode, a narrowband voice packet needs to be converted again. If the regenerated voice is in narrowband mode, a broadband voice packet needs to be converted. According to the target address of the voice, it is sent to the corresponding broadband and narrowband networks according to the trunking communication rules, as shown in Figure 1As shown in E and F.

[0033] After receiving the voice sent by the core network, the broadband and narrowband networks forward the voice to the receiving walkie-talkie at the target address according to the trunking communication rules, as Figure 1 shown in G and H.

[0034] If the receiving walkie-talkie is a multi-mode emergency walkie-talkie with both broadband and narrowband modes, it will receive two voice frames sent by the broadband and narrowband networks. The receiving walkie-talkie also needs to align according to the serial number and verify the integrity of the voice frame through the vocoder FEC, and select the most complete one of the voice frames for playback. Since the narrowband network has a low transmission rate but strong anti-interference ability, while the broadband network is the opposite, so when the integrity is the same, the narrowband network voice is preferred; if the receiving walkie-talkie is a single-mode walkie-talkie, it can only receive the voice frame sent by a single network in the corresponding mode. The receiving walkie-talkie converts the voice frame into an audio signal and broadcasts it through the speaker.

Claims

1. An emergency intercom method with the ability to simultaneously access voice in both wide and narrow bands, characterized in that, The method has the following steps: A1. Establish communication using a multi-mode emergency walkie-talkie with both broadband and narrowband modes in an emergency communication scenario, and send voice packets with sequence flags on both networks according to a voice frame length of 60 ms; A2. The broadband and narrowband networks send the received voice packets to the core network for subsequent processing; A3. After the core network receives the voice data sent by the broadband and narrowband networks, first align the voice frames through the sequence flags. Within a buffer time of 300 ms, compare the integrity of the voice packets transmitted by the narrowband and broadband networks, select the packet with better integrity through checksum and error correction, and regenerate a complete segment of voice in units of 60 ms, transform it into broadband and narrowband formats, and send it to the broadband and narrowband networks; A4. After the broadband and narrowband networks receive the voice sent by the core network, send the voice to the walkie-talkies corresponding to the corresponding frequency points and corresponding groups; if the receiving walkie-talkie is a multi-mode emergency walkie-talkie with both broadband and narrowband modes, the receiving walkie-talkie will receive two copies of voice frames in broadband and narrowband. Then, check the integrity of the voice frames through the vocoder FEC, and select the voice frame with the most complete sequence number within the same time period. If the voice received from the narrowband network is complete and continuous, there is no need to wait for the voice packet from the broadband network, and directly transform the voice frame of the narrowband network into an audio signal and play it through the speaker; after the core network receives the voice packets with sequence flags received by the broadband and narrowband networks, first align them through the sequence flags, and within a buffer of no more than 300 ms, compare the voice packets sent by the narrowband and broadband networks, and select the voice packet with better integrity through checksum and error correction.

2. The emergency intercom method with the ability to simultaneously access voice in wide and narrow bands according to claim 1, wherein, In step A1, the multi-mode emergency walkie-talkie with both broadband and narrowband modes contains a vocoder with two compression rate bandwidths that are packetized according to 60 ms, and the vocoder has the ability to freely switch from one rate to another in units of 60 ms.

3. The emergency intercom method with the ability to simultaneously access voice in wide and narrow bands according to claim 2, characterized in that The multi-mode emergency walkie-talkie with both broadband and narrowband modes selects a voice compression algorithm of 2.15 Kbps for the narrowband voice stream and 12.2 Kbps for the broadband voice stream for the characteristic that the 2.4 Kbps voice compression of the ordinary narrowband network cannot carry timestamps, and carries the same frame sequence number continuously without affecting the voice intelligibility.

4. The emergency intercom method with the ability to simultaneously access voice in both wide and narrow bands according to claim 3, characterized in that, In step A2, the broadband and narrowband networks continuously receive two-way voice, and transmit the voice frames with check information and frame sequence numbers to the core network. The subsequent processing by the core network is to compare the integrity of the voice received by the broadband and narrowband networks simultaneously and regenerate a voice with the highest integrity.

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