KR20030035680A - method for selecting a codec mode of the internet-phone - Google Patents

Abstract

PURPOSE: A method for selecting a CODEC mode of an Internet phone is provided to control the CODEC mode according to a network state without an additional circuit, thereby enhancing the function of the Internet phone. CONSTITUTION: In an Internet phone, a DSP(Digital Signal Processing) loading is performed by using a previous set profile and then a telephone number is transmitted(S2). Thereafter, a testing signal is transmitted to an opponent's Internet phone and then a network state is checked by using a returned signal by reflecting from the corresponding network path(S3). Thereafter, an adaptive code type to the present network state is selected and then the profile is reconstructed by the selected code type(S4). A communication signal is coded by the newly set code type and then transmitted to the opponent's telephone(S5).

Description

Method for selecting a codec mode of the internet-phone}

The present invention relates to a method of selecting a codec mode of an internet phone, and more particularly, to a method of selecting a codec mode of an internet phone for transmitting a communication signal by testing a network state before a call and selecting a codec mode according to the test result.

In general, an Internet phone refers to a system or service used as a normal phone by transmitting and receiving voice via the Internet. These phones became popular since 1995, when US venture company vocal tech developed a system for making calls through microphones and speakers that connect to personal computers (PCs). And PC, PC and phone or between phone and phone. In addition, the Internet phone as described above refers to a communication that converts the relay network portion of the telephone network to the Internet by connecting in the form of a telephone network-internet-telephone network. There may be delays, poor sound quality, or limited coverage areas.

Then, referring to the conventional Internet phone network as described above with reference to Figure 1, the Internet phone (71, 72) for converting and transmitting the voice or video signal to the IP signal through the Internet 70, and the Internet phone (71, 72) Gateways (73, 74) for analyzing the communication signal transmitted from the) converted to a signal suitable for the other landline telephone.

Here, the Internet phones 71 and 72 may select G.711, G.723, G.729, etc., which are international standards of codecs for compressing communication signals. In addition, the Internet phones 71 and 72 can communicate only during the telephone period of the same codec method.

On the other hand, looking at the call method of the conventional Internet phone as described above, first, to take a profile (profile) set on the internal memory to set the codec method. For example, when the codec method is set to G.711, the Internet phone 71 converts the other party's phone number and voice signal set by the user into a digital signal and codes the G.711 codec method. Send via At this time, if the set other party's telephone number is an Internet phone 72 having an IP address, the communication signal is input to the receiving Internet phone 72 through the Internet 70. Then, the receiving Internet phone 72 decodes the inputted communication signal using a set codec method, for example, G.711 method, converts the received communication signal into an analog signal and outputs the same through a handset. On the other hand, if the destination of the Internet phone 71 is a landline telephone, the gateway 74 located near the landline telephone analyzes a communication signal through an auto-negotiation process and checks the corresponding codec method. In addition, the gateway 74 codes the communication signal using the identified codec method, for example, G.711, and transmits the communication signal to the landline to make a normal call.

However, in the Internet phone as described above, since the codec setting itself is set irrespective of the network state, for example, when the network is very busy, the codec method should be set accordingly. As a result, not only the call quality deteriorates, but also a significant burden on the network.

Accordingly, the present invention has been invented to solve the above-mentioned conventional problems, and by actively testing the state of the network before a call and selecting a codec mode according to the test result, the present invention can actively cope with the network situation. Accordingly, an object of the present invention is to provide a method of selecting a codec mode of an Internet phone capable of optimizing communication quality of a communication signal.

Another object of the present invention is to provide a method of selecting a codec mode of an Internet phone, which controls the codec mode according to the network state without any additional circuit configuration, thereby significantly improving the functionality of the Internet phone.

In order to achieve the above object, the present invention provides an Internet phone access step of loading a DSP and transmitting a telephone number signal by using a profile set in an Internet phone, and a test signal after the Internet phone access step. A network state detection step of detecting a network state by using a signal recovered by reflecting the corresponding network path, and selecting a codec method suitable for the current network state after the network state detection step, and reconfiguring a profile using the selected codec method. A codec mode selection method of an internet phone is provided, which comprises an optimal codec method setting step and an internet call step of coding a communication signal with a newly set codec method after the optimal codec method setting step.

1 is an explanatory diagram illustrating a conventional internet phone.

2 is an explanatory diagram illustrating an internet phone to which the present invention is applied.

3 is a flowchart of the present invention.

<Detailed Description of Codes>

1: Internet Phone 2: Handset

3: A / D converter 4: DSP

5: internet 6: CPU

7: D / A converter 8: Key panel part

9: Internet Phone 10: Gateway

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

The Internet phone 1 to which the present invention is applied includes an A / D converter 3 for converting an analog voice signal of a user input through the handset 2 into a digital signal, as shown in FIG. DSP (4) for coding or decoding the audio signal input from the converter (3) by the set codec method, and the CPU (4) including the DSP (4) for controlling the transmission function of the audio signal transmitted via the Internet (5). (6) and D / D, which converts the digital communication signal input via the Internet 5 coded by the DSP 4 according to the control signal of the CPU 6 into an analog signal and outputs it through the handset 2; A converter 7 is included.

The CPU 6 is connected with a key panel unit 8 for inputting a telephone number set by the user.

Here, the gateway 10 may be provided between the Internet phone 1 and the Internet 5 to analyze and transmit a communication signal transmitted from the Internet phone 1 to a signal suitable for the other landline phone 9. .

Next, the method of the present invention applied to the Internet phone as described above will be described.

As shown in FIG. 3, the method of the present invention proceeds from the initial state S1 to the Internet phone connection step S2, and loads the DSP using a preset profile and transmits a telephone number signal. After the internet phone access step (S2), the network state detection step (S3) is performed to send a test signal to the other party's Internet phone, and reflect the network path to detect the network state using the recovered signal. In addition, after the network state detection step S3, the process proceeds to the optimal codec method setting step S4 to select a codec method suitable for the current network state and reconstructs the profile with the selected codec method. After the optimal codec setting step (S4), the process proceeds to the internet call step (S5), whereby a communication signal is coded by the newly set codec method and transmitted to the other party's phone.

That is, when a telephone call is made to the Internet phone 1 to which the method of the present invention is applied, first, when the user inputs the other party's telephone number signal through the key panel unit 8, the CPU 6 recognizes this and sets a preset PROFILE. Is read from a memory (not shown) and the predetermined codec method is loaded into the DSP 4 using this information. Then, the CPU 6 uses the telephone number input from the key panel unit 8 as a network path to the counterpart phone 9 via the Internet 5 for a test signal for testing the state of the network. The test signal is retrieved after transmission, and this testing is performed several times (N times). For example, the CPU 6 loads a signal for a ping test to the counterpart phone number and adds it N times on the Internet transmission path formed between the counterpart phone to obtain an average network traffic as shown in Equation (1).

Average network traffic = (A1 + A2 + ... + AN) / N

A: Response Speed

Here, the network state testing can be used as long as it can measure the network state without relying only on the ping test.

Then, the CPU 6 obtains the average network traffic through the above process and uses it to grasp the network state. For example, it is determined whether the current network is busy or desired. At this time, the CPU 6 selects an appropriate codec method using the average network traffic calculated as described above. For example, if the average network traffic is smaller than the first reference value R1, that is, the response speed is the first. Codec 1, for example, G.711 is selected if the response speed is lower than the reference value R1. If the average network traffic is larger than the first reference value R2 and smaller than the first reference value R1, that is, the response speed is the first. If it is between the reference value R1 and the second reference value, codec 2, for example, G.729 is selected, and if the average network traffic is larger than the second reference value R2, that is, the response speed is set to the second reference value R2. If greater, select Codec 3, for example G. 723.

That is, the CPU 6 selects an optimal codec method according to the response state of the network and creates a new profile using the selected codec method. The CPU 6 resets the DSP 4 by the newly selected codec method using the newly created PROFILE. The CPU 6 codes the voice signal converted into a digital signal through the A / D converter 3 through the DSP 4 having a codec method that is optimally matched to the network state, to the counterpart phone 9. send. Therefore, through the above-described method, the user can make an optimal call in accordance with the network condition.

On the other hand, the communication signal input through the Internet 5 is decoded by the codec method set by the DSP 4 under the control of the CPU 6 and output to the D / A converter 7. Then, the D / A converter 7 converts the communication signal input from the DSP 4 into an analog signal and emits it to the outside through the handset 2 to execute a normal call.

In this process, if the destination of the Internet phone 1 is a landline phone, the gateway 10 located near the landline phone analyzes a communication signal through an auto-negotiation process to determine a corresponding codec method. . In addition, the gateway 10 codes a communication signal using the identified codec method and transmits the communication signal to the landline to make a normal call.

As described above, the present invention can actively cope with the network situation by testing the state of the network before the call and selecting the codec mode according to the test result, thereby optimizing the call quality of the communication signal accordingly. It has advantages.

In addition, according to the present invention, since the codec mode is controlled according to the network state without additional circuit configuration, there is also an effect of significantly improving the functionality of the Internet phone.

Claims (2)

Internet phone accessing step of loading DSP and transmitting telephone number signal using preset profile in internet phone, and sending out test signal to other internet phone after reflecting internet network and reflecting the network path. A network state detection step of detecting a network state using a signal, an optimal codec method setting step of selecting a codec method suitable for a current network state after the network state detection step and reconstructing a profile with the selected codec method, and the optimum codec A method of selecting a codec mode of an internet phone, characterized by comprising: an internet call step of coding a communication signal using a newly set codec method after the method setting step and transmitting the same to a counterpart phone. 2. The method according to claim 1, wherein the testing signaling method during the network state detecting step is a ping testing method.