Method and device for improving audio quality in a mobile radio network

Translation of description of equivalent WO 0030277 A2

Method and apparatus for improving audio quality in a mobile network

description

The invention relates to a method and apparatus for improving the

Audio quality in a mobile network according to the preamble of claim 1.

Mobile networks, such as the GSM mobile network, receive - apart from a predetermined bandwidth limit and the voice codec used - klangbild neutral.

The perceived by the mobile subscriber sound is determined primarily by the mobile stations used, each device manufacturer's device, a slightly different sound "imprints". Currently available

Terminal models exhibit some great differences in sound that are perceived by the device users as different pleasant or less pleasant.

In opinion polls as it was determined that GSM1800 networks better

Sound than GSM900 networks. Since this is not technically understandable, it seems likely that this is due to the device properties. That it is not the GSM1800 networks that sound better, but there are the devices used in this network. The object of the invention is now to provide a method and a device with which a terminal-independent improvement of the audio quality can be achieved in mobile networks.

This object is achieved by the characterizing features of claim 1.

The invention is based on that an equalizer is switched to a communication link associated audio path in

Depending on the types of devices involved in the connection makes an influence on the audio quality in the audio path.

This achieves the advantage that, ie unnoticed be possible defects in the audio quality of individual terminals models network side by the participant, compensate.

No longer the terminal manufacturers, but the network operator now defines the characteristics of the sound quality of its network, by defining the characteristics of the sound of the terminals for each terminal model.

This results in an immediate quality projection of a vehicle equipped with the invention network. A in a conventional power inferior sounding terminal gets in a network that uses the invention, a good sound quality. This projected the subscriber directly to the network quality, as have the above mentioned surveys showed.

Depending on the terminal, a switched into the audio path equalizer is configured such that it eg in a particularly dull sounding device raises the peaks.

The mobile switching center (MSC) determined by retrieving the Mobile Equipment Identity (IMEI: International Mobile Equipment Identity) device model. This query of the IMEI is usually always already in the authentication procedure between Mobile station and mobile network performed using the mobile network only accepts devices with certified IMEI.

The mobile switching center is a call associated audio path known so that it can be directly influenced by driving an audio path associated equalizer.

For each type of device the appropriate sound parameters are stored in a data memory of the mobile switching center and at any time. Based on the stored at a particular device type sound parameters of the equalizer of the associated audio path is configured. The sound parameters can also be held advantageously in the equalizer itself.

The control signal for the control of the equalizer is preferably provided by the mobile switching center, but can also be provided by any other instance of the mobile radio network. It is also possible, by means of a separate trace facility to track the signaling at the various interfaces of the mobile radio system and to control it with the guided data the equalizer.

(TRAU: Transcoder / Rate Adaptation Unit) In a preferred embodiment of the invention, the equalizer near the transcoder is arranged and may preferably be set up as part of the transcoder. The transcoder TRAU converts the coming of the base station controller BSC 16 kbit / s subchannel after the PCM-A-law in a 64 kbit / s signal in the mobile switching center (MSC) is further processed.

ACCORDING another embodiment, the equalizer is connected downstream as a separate unit of transcoding before or. The equalizer may also be arranged in the mobile switching center. The important thing is that the equalizer is switched to a low seen from installation effort forth place in the audio path. A preferred location for example, where a plurality of audio channels converge, eg in the TRAU or the MSC. The equalizer advantageously comprises not only an equalizer, but a variety of Entzerrereinheiten that can be each one audio path or audio channel assigned.

In a further development of the invention it is provided to generate the control signal for the equalizer, not only a function of the mobile Equipment Identity (IMEI), but also as a function of subscriber-individual features. The equalizer could for example for private subscribers, business subscribers, roaming, hard of hearing, etc. set differently.

Finally, there is the possibility / the equalizer for voice encryption - use encryption.

The invention of an exemplary embodiment is described with reference to a detail drawing figure. Here emerge from the drawing further features and advantages of the invention.

Figure 1 shows the example of a GSM mobile radio network which essentially involved in a communication link between a mobile subscriber and a subscriber of a public fixed network devices.

The mobile subscriber wants to establish a voice connection to a subscriber of a public fixed network 9 by means of a mobile station 1 and logs in via a base station 2 in the mobile network. The connection is established in a known manner, first through the base station 2, the base station controller 3 to the mobile switching center 5, which takes care of the further connection to the fixed public network. 9 Between the base station controller 3 and the mobile switching center 5, a transcoding device 4 is connected, may be located within the mobile switching center 5, for example.

According to the invention, an equalizer 7 is now in the audio path 10 of the compound turned, which is preferably arranged in the region of the mobile switching center. 5 The equalizer 7 is transferred from the mobile switching center 5, a Control signal 8 driven. The mobile switching center 5 determined during call setup by retrieving the Mobile Equipment Identity (IMEI) of the device model used by the mobile subscriber 1. The query of the IMEI is provided as standard in GSM. For each marketable device type appropriate sound parameters in a data memory 6 of

Mobile switching center is stored and retrieved at any time 5 bar. Based on the stored at a particular device type sound parameter 7 of the connection associated audio path is configured via the control signal 8 of the equalizer. The sound parameters can also be advantageously held in equalizer 7 itself. The equalizer 7 now affects according to the specifications, the sound in the audio path 10 and improved equalized and / or evens out the sound.