Implementing method and apparatus for shielding DTMF sound of outer telephone

Abstract

The invention provides a realization method and a device for shielding DTMF (dual-tone multifrequency) voice, namely, out-of-band multi-tone multi-frequency voice of an external phone; wherein, the method comprises the following steps: step A: key events of the external phone is detected in a real time manner; step B. whether a current phone is in a connected state is judged, and if the answer is yes, the analog voice signals collected by the telephone are modulated into voice pulses modulated PCM data flows, intercepted and pressed in a cache; after delaying a preset time, relevant PCM data flow is sent; step C. after the key events of the phone are detected, a non-key tone data frame is adopted to replace the data frame of the cache of the delaying preset time; a protocol stack is triggered, and a DTMF signaling is generated by the protocol stack and is sent to a network side; an out-of-band DTMF event transmission can be realized by sending the DTMF signaling. On the basis of not increasing a processing chip, a device and cost, the method and the device of the invention can effectively remove the second dialing sound of DTMF of the external telephone.

Description

technical field [0001] The invention relates to the technical field of wireless communication, in particular to a method and device for shielding DTMF (DualTone Multi-Frequency out-of-band Multi-Tone Multi-Frequency) tones of an external phone. Background technique [0002] With the gradual popularization of mobile communications and the decline of tariffs in recent years, especially high-speed mobile data communications such as GPRS, UMTS, HSDPA, and CDMA provide more and more services to wireless terminal users, and the convenience and flexibility of mobile communications It is also more and more attractive to fixed-line users. Wireless access box products are mobile system solutions for fixed-type users in remote and new markets, and have entered a stage of rapid development around the world. Because this product needs to be compatible with different operation modes and business types of fixed and mobile users, the technology related to this product is also developing rap...

AI Technical Summary

Problems solved by technology

However, since the DTMF tone is directly generated by the phone, and in order to be compatible with ordinary phones for easy marketing, it is impossible to remove the DTMF tone from the source phone.

In addition, the corresponding DTMF frequency can also be filtered out or biased through the corresponding hardware circuit, so that the network side cannot recognize the in-band DTMF tone, but this solution requires additional processing chips, devices and costs

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