A Method for Setting the Relay Stage Number of a Digital Walkie-Talkie

Abstract

The present invention discloses a method for setting the relay stage number of a digital interphone, which includes the following steps: deriving a calculation formula for the maximum relay stage number; writing this formula into the execution program and setting the constants and variables therein, where the variables include the air interface rate Bitrate and the channel coding efficiency R; when powering on, reading or setting the variables, automatically calculating the maximum relay stage number, and taking effect immediately. Through the method of the present invention, the maximum relay stage number can be automatically calculated, and the automatic configuration of the relay stage number can be implemented during development debugging or network deployment. By adopting the above relay stage number limit, the problem of air interface communication conflicts caused by air interface flooding during the networking of digital interphones can be avoided to the greatest extent, and the reliability and practicability of the network can be improved.

Description

Technical Field

[0001] The present invention relates to the field of digital walkie - talkies, and particularly to a method for setting the relay level of a digital walkie - talkie. Background Art

[0002] Among various types of public walkie - talkies, digital walkie - talkies are popular in some fields due to their high spectrum utilization rate and low power consumption. However, because the cost of digital walkie - talkies is much higher than that of analog walkie - talkies, from the user's perspective, these advantages of digital walkie - talkies are not sufficient to open up most of the walkie - talkie application markets.

[0003] It can support data forwarding to implement the voice relay function on the walkie - talkie, and even has the ability of dynamic self - organizing network, which can solve the problem of communication failure due to limited communication distance in the actual use of walkie - talkies, such as in buildings, mountains, etc. There must be certain limiting conditions between data packet forwarding, voice data decompression and playback, and wireless communication rate. Meeting these limiting conditions can avoid the problem of air - interface communication conflict caused by air - interface flooding, and improve the reliability and practicality of the network. Summary of the Invention

[0004] In view of the above - mentioned defects of the prior art, the purpose of the present invention is to provide a method for setting the relay level of a digital walkie - talkie, which calculates and sets the relay level of the digital walkie - talkie on the premise of ensuring the continuity of voice playback and on the condition of avoiding air - interface data conflict caused by flooding.

[0005] To achieve the above purpose, the present invention proposes the following technical solutions:

[0006] A method for setting the relay level of a digital walkie - talkie, comprising the following steps:

[0007] (1) Derive the calculation formula for the maximum relay level m, and the calculation formula is:

[0008]

[0009] Wherein, represents rounding down; T Delay represents the random delay time before forwarding the packet; T SLOT represents the time slot; T SYS represents the system processing time; LEN HDR represents the number of frame header bytes of the data packet; LEN PAYLOAD represents the number of payload bytes of the data packet; R represents the channel coding efficiency; the time slot T SLOT is equal to the sampling time of the PCM data corresponding to the data in a data packet;

[0010] (2) Write the calculation formula for the maximum relay level m in the execution program of the digital interphone, and set the constants and variables therein. The variables include the air interface rate Bitrate and the channel coding efficiency R; set the maximum relay level m as a global variable;

[0011] (3) After the digital interphone is powered on, adjust the setting of the channel coding efficiency R according to the system interference level; automatically obtain or manually set the air interface rate Bitrate and the channel coding efficiency R; then automatically calculate the maximum relay level m and take effect immediately;

[0012] (4) When the forwarding times of the in-network interphone are greater than the maximum relay level m, stop forwarding and wait for receiving new messages.

[0013] Further, the air interface rate Bitrate is jointly determined by the farthest communication distance of the system, the transmit power, and the modulation method, and the newly set Bitrate is broadcast to all in-network devices through the broadcast channel in use.

[0014] Further, the channel coding efficiency R is jointly determined by the system interference level and the verification algorithm, and is calculated through the formula

[0015] R = k / n

[0016] where k is the number of information bits and n is the code length.

[0017] The present invention achieves the following technical effects:

[0018] Through the method of the present invention, the maximum relay level can be automatically calculated, and the automatic configuration of the relay level can be implemented during development and debugging or network deployment. By adopting the above relay level limit, the problem of air interface communication conflict caused by air interface flooding during digital interphone networking can be avoided to the greatest extent, and the reliability and practicability of the network can be improved. Description of the Drawings

[0019] Figure 1 is the intercom and data forwarding processing flow chart of the digital interphone;

[0020] Figure 2 is the flow chart for setting the maximum relay level m of the digital interphone of the present invention. Detailed Embodiments

[0021] To further illustrate the embodiments, the present invention provides drawings. These drawings are a part of the disclosure of the present invention, mainly used to illustrate the embodiments, and can be used to explain the operation principle of the embodiments in conjunction with the relevant descriptions in the specification. With reference to these contents, those of ordinary skill in the art should be able to understand other possible implementation manners and the advantages of the present invention.

[0022] The present invention will be further described in conjunction with the accompanying drawings and specific embodiments.

[0023] The communication process of a digital walkie - talkie generally follows Figure 1 the following process.

[0024] When a certain digital walkie - talkie (such as BP1) starts a PTT call, it performs PCM digital sampling on the input voice, vocoder encoding (voice encoding), compresses and packs it to generate a data packet, and then broadcasts the data packet;

[0025] After other on - network digital walkie - talkies (such as BP2, BP3, …, BPn) receive the data packet sent by the data walkie - talkie BP1 or relayed by other digital walkie - talkies, they decode the data packet, then perform vocoder decoding (voice decoding) on the digital audio signal, output the audio signal in PCM format for audio playback, and when the relay level does not exceed the maximum relay level, relay - forward the data packet at the same time.

[0026] As Figure 2 shown, the maximum relay level of the walkie - talkie can be obtained by calculating with the following formula.

[0027] Let:

[0028] T ENC be the vocoder encoding time;

[0029] T DEC be the vocoder decoding time;

[0030] T TX be the data packet sending time;

[0031] T Delay be the random delay time before forwarding the packet;

[0032] T SLOT be the time slot, which is equal to the sampling time of the PCM data corresponding to the data in a data packet;

[0033] T SYS be the system processing time;

[0034] Bitrate is the air interface rate;

[0035] R is the channel coding efficiency, defined as: R = k / n, where k is the number of information bits and n is the code length.

[0036] To avoid air interface communication conflict problems caused by air interface flooding and improve the reliability and practicality of the network, the following constraint relationship is set:

[0037] It is necessary to ensure that within one time slot, the in-network intercom completes the forwarding of all data packets, which is described by the following formula:

[0038] T SLOT = m * (T SYS + T TX + T DEC + T Delay ) ①

[0039] Among them, m is the maximum relay level.

[0040] Among them, the data packet sending time T TX can be calculated by the following formula:

[0041] T TX = (LEN HDR + LEN PAYLOAD ) * 8Bits / (Bitrate * R) ②

[0042] Among them, LEN HDR is the number of frame header bytes in the data packet; LEN PAYLOAD is the number of payload bytes in the data packet.

[0043] Substituting ② into ①, the maximum relay level can be calculated:

[0044]

[0045] Among them, represents rounding down.

[0046] It can be seen from the above formula that:

[0047] The voice decoding time T DEC , the time slot T SLOT , the system processing time T SYS , the number of frame header bytes LEN HDR of the data packet, and the number of payload bytes LEN PAYLOAD of the data packet can be considered as constants for a digital intercom with a fixed hardware circuit.

[0048] During development and debugging, the adjustable parameters are only the air interface rate Bitrate, the random delay time T Delay before forwarding the packet, and the channel coding efficiency R.

[0049] The random delay time T Delay before forwarding the packet is an adjustable parameter. During development and debugging, the maximum relay level m can be obtained through automatic calculation to avoid the mismatch of the maximum relay level caused by adjusting T Delay and resulting in wireless signal interference. During normal use, the random delay time T before forwarding the packetDelay Set constant

[0050] Therefore, in this embodiment, the calculation formula of the maximum relay level m is written into the execution program of the digital interphone, and constants and variables are set, where the variables include: the air interface rate Bitrate and the channel coding efficiency R. At the same time, the maximum relay level m is set as a global variable.

[0051] The channel coding efficiency R is jointly determined by the system interference level and the check algorithm. The air interface rate Bitrate is jointly determined by the farthest communication distance of the system, the transmission power, and the modulation method. The newly set Bitrate is broadcast to all in-network devices through the currently used broadcast channel. After the digital interphone is powered on, the channel coding efficiency R setting can be adjusted according to the system interference level, that is, the value of the information bit number k or the code length n is adjusted according to the system interference level to improve the anti-interference ability of the system. Then, by automatically obtaining or manually setting the air interface rate Bitrate, the maximum relay level m allowed under the current air interface rate Bitrate can be obtained.

[0052] The maximum relay level m takes effect immediately after being obtained and is called during subsequent program operations.

[0053] The present invention has the following beneficial effects:

[0054] Through the method of the present invention, the maximum relay level can be automatically calculated, and the automatic configuration of the relay level can be implemented during development debugging or network deployment. By adopting the above relay level limit, the problem of air interface communication conflict caused by air interface flooding during digital interphone networking can be avoided to the greatest extent, and the reliability and practicability of the network can be improved.

[0055] Although the present invention is specifically shown and described in conjunction with the preferred embodiments, those skilled in the art should understand that various changes can be made to the present invention in terms of form and details without departing from the spirit and scope of the present invention defined by the appended claims, and all of them fall within the protection scope of the present invention.

Claims

1. A method for setting the relay stage number of a digital walkie-talkie, characterized in that, Including the following steps: (1) Derive the calculation formula for the maximum relay level, and the calculation formula is: Among them, represents floor function; T Delay represents the random delay time before forwarding the message; T SLOT represents time slot; T SYS represents the system processing time; LEN HDR represents the number of header bytes of the data message; LEN PAYLOAD represents the number of payload bytes of the data message; R represents the channel coding efficiency; the time slot T SLOT is equal to the sampling time of the PCM data corresponding to the data in a data message; (2) Write the calculation formula for the maximum relay level m into the execution program of the digital walkie-talkie, and set the constants and variables therein. The variables include the air interface rate Bitrate and the channel coding efficiency R; set the maximum relay level m as a global variable; (3) After the digital walkie-talkie is powered on, adjust the setting of the channel coding efficiency R according to the system interference level; automatically obtain or manually set the air interface rate Bitrate and the channel coding efficiency R; then automatically calculate the maximum relay level m and take effect immediately; (4) When the forwarding times of the in-network walkie-talkie are greater than the maximum relay level m, stop forwarding and wait to receive new messages.

2. The method for setting the relay stage number of the digital walkie-talkie according to claim 1, characterized in that, The air interface rate Bitrate is jointly determined by the farthest communication distance, transmit power and modulation mode of the system, and the newly set Bitrate is broadcast to all in-network devices through the broadcast channel in use.

3. The method for setting the relay stage number of the digital walkie-talkie according to claim 1, characterized in that, The channel coding efficiency R is jointly determined by the system interference level and the parity algorithm, and is calculated by the formula R = k / n where k is the number of information bits and n is the code length.

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