RU2283545C2 - Method and device for permitting discrepancy in communication networks umts - Google Patents

Abstract

FIELD: radio communication systems engineering, possible use in communication networks compliant with universal mobile telecommunication system (UMTS) standard.

SUBSTANCE: method and device are meant for permitting discrepancy between speech data, transferred in speech codec mode with first distribution symbol for speech codec mode on first network portion, and speech data, transferred in speech codec mode with second distribution symbol for speech codec mode on second network portion, while speech data, bypassing encoding and decoding devices and commutation field for temporal packing are diverted to output of transcoder.

EFFECT: possible realization of roaming and transfer between technologically different networks practically without delay of qualitatively improved transformed speech data.

2 cl, 2 dwg

Description

EP-A-1158823 describes a method for resolving a mismatch of speech data transmitted in a speech codec mode.

The invention relates to a method and apparatus for resolving a mismatch between voice data transmitted in a speech codec mode with a first distribution symbol for a speech codec mode in a first network portion of a communication network based on speech compression, for example, according to the UMTS (Universal Mobile Telecommunication System) standard, and voice data transmitted in the speech codec mode with a second distribution symbol for the speech codec mode in the second network section according to the generic term s 1 and 8 of the claims.

Universal Mobile Telecommunications System (UMTS) is one of many mobile radio communication systems that provide a user of a mobile terminal with a variety of services.

The UMTS system operates in the ranges 1885-2025 MHz and 2110-2200 MHz and provides, in addition to the previously known functional capabilities of narrow-band mobile communication systems, as well as data transfer rates of up to 2 Mbps.

The goal of the UMTS mobile communication system is to make available to the user on a global scale a unified third-generation mobile communication system and to provide for the first time the possibility of roaming and handoff between technically different networks, such as, for example, GSM (Global System for Mobile Communication), using dual-band dual-mode terminals.

Communication networks that are based on the UMTS standard require, due to incompatible versions of the user plane protocols, or the choice of different codec modes for user A and user B, use of UMTS mobile service switching centers (UMSCs), which, as switches or transcoders, provide transcoding of existing voice connections from one adaptive multi-rate (AMR) codec mode to another AMR codec mode.

Such transcoding is carried out in the usual way by decoding the speech data transmitted in the first mode of the speech codec into 160 linear samples with 13 bits and then encoding the speech data transmitted in the second mode of the speech codec. To this end, voice data that is transmitted to the switch in a speech frame sent by the UTRAN radio network over an interval of 20 ms is decoded by a decoding device, and the speech data is previously encoded in the first adaptive multi-rate (AMR) codec mode. After decoding, the speech data contained in the speech frame is converted into words with linear pulse-code modulation (PCM), for example, 13 bits long. Then they are compressed in accordance with the law of A / μ-conversion to obtain words with an information content of 8 bits and are time-multiplexed (multiplexed) by means of a switching field of temporary compaction. Time-compacted data is decompressed to obtain linear PCM words with information content, for example, of 13 bits, and then encoded in the new AMR codec mode.

Due to the use of a synchronously functioning switching field of temporary compaction, a transmission is made from the UTRAN radio network to this network with a delay of 20 ms. In addition, when encoding and decoding, as well as during compression in accordance with the A / μ-conversion law, the quality of speech data to be encoded or decoded and words to be compressed with linear PCM is deteriorated.

Depending on the different network sections of a UMTS-based communication network, different versions of the UMTS standard can be used during a voice connection, and distribution symbols are used to determine what type of codec mode is used for voice data transmitted on a particular network section. (identification). Such symbols are called pointers (RFCIs) of a combination of sub-streams of a radio access network carrier channel (RAB).

The voice data to be transmitted can be transmitted depending on the network segment either in different codec modes with different RFCIs assigned to them, or in the same codec modes and different RFCIs, or in the same codec modes and the same RFCIs. If different RFCIs are used, this can lead to inconsistencies in the RFCIs despite using the same codec modes. Such a mismatch in RFCI pointers is avoided due to the transcoding described above, which results in high delay times and a decrease in the quality of the speech signal.

Thus, it is an object of the present invention to improve a method and apparatus for resolving and / or eliminating a mismatch in RFCI pointers, which are distributed among codec modes for encoded speech data in a speech compression-based communication network, such that the conversion of speech data in a communication network performed almost without delay and provides improved speech quality.

This problem is solved in the claimed method by the signs of paragraph 1 of the claims, and in the claimed device by the signs of paragraph 8 of the claims.

An essential feature of the invention is that, inside one transcoder, the speech data transmitted with the first distribution symbol included in the transcoder bypassing the encoding and decoding devices and the time division switching field is allocated to the transcoder output if the voice data transmitted with the first distribution symbol and transmitted from the second character of the distribution of speech data is encoded in the same codec mode. Preferably, incoming speech data directly from the output of the input device for matching distribution symbols by the UP protocol is allocated to the input of the output device for matching distribution symbols.

A consequence of bypassing the switching field of the temporary compaction is that it becomes possible almost without delay to match the RFCI pointers (distribution symbols) of the speech data with the first and second RFCI pointers. Bypassing the encoding and decoding devices causes that there is no quality degradation during the encoding and decoding steps. In addition, after conducting an initial check to see if the directly applicable codec modes are the same or if they differ, transcoding occurs when different RFCI indicators associated with the speech data must be converted using the UP protocol. Thus, the speech data passes through the entire transcoder without encoding or decoding, if only the speech data is encoded by the same encoding mode. Thus, transcoding is excluded.

As possible modes of the speech codec for voice data received from the UTRAN radio network or transmitted to this network as part of a voice connection, such speech codec modes as adaptive multi-speed codecs, codecs for compressing speech data, codecs for adaptive differential pulse code can be used modulations and codecs to improve transmission speed and transmission quality. Moreover, voice data, which is incoming and outgoing for the switch, within one speech frame can differ from each other in the same mode of the speech codec or in several modes of the speech codec.

The bypass device, which is preferably directly connected to the RFCI pointer matching devices, can preferably be implemented as software in a digital signal processor (DSP), user programmable gate array (FPGA) oriented to a specialized integrated circuit (ASIC) or network processor, the digital signal processor may include additional devices to avoid mismatch. The digital signal processor may, for example, further comprise a switching device implemented in the bypass device or associated with the bypass device for turning the bypass device on or off. In this way, it is possible, by disabling the bypass device, to transmit voice data in the usual way, namely by means of encoding and decoding devices and compression and decompression devices and by connecting the switching field of the temporary seal.

The device for allowing or eliminating the mismatch of RFCI indicators of encoded speech data, in particular, encoded speech AMR codec, contains, along with the bypass device, also a verification device designed to determine whether speech data is encoded with the first RFCI indicator and speech data with the second RFCI indicator in the identical mode of the speech codec or identical modes of the speech codec. If the verification device determines that there are consistent modes of the speech codec, then the bypass device is turned on by the switching device. In this way, it is possible to quickly switch the transcoder from its transcoding state to the direct transmission state in order to eliminate time delays.

Other preferred embodiments are reflected in the dependent claims.

Other advantages and expedient options also arise from the following description, illustrated by the drawings, which show the following:

Figure 1 is a schematic representation of a conventional method for resolving or eliminating a mismatch of RFCIs using features of a device and

FIG. 2 is a schematic representation of a method according to the invention for resolving or eliminating a mismatch of RFCI pointers according to an embodiment using device features.

The conventional method for allowing or eliminating RFCI pointer mismatch using device features, shown in FIG. 1, illustrates a method that can be implemented in a transcoder located on a UMTS-based communication network.

Voice data is transferred from the UTRAN 1 radio communication network to the asynchronous transmission mode level (ATM level) 2a, 2b and, through adaptation layer 2 of the ATM (AAL2) 3a, 3b, are segmented into ATM elements with variable bit rates with real-time connection-oriented transmission .

Then, using the devices 4a, 4b for matching RFCIs (UP termination), which represent a reference point between the UTRAN and the core network (CN) or between UTRAN and UTRAN, or between CN and CN in the user plane, the adjustment is made (correction) RFCI pointers. By means of an encoding and decoding device 5a and 5b (adaptive multi-rate codec), incoming speech data encoded in the AMR codec mode is decoded and converted to linear pulse code modulation (PCM) words with an information content of 13 bits.

These PCM words are then compressed using the compression and decompression devices 6a and 6b in accordance with the A / μ conversion law and compressed into words with 8-bit content and are returned back through the switching field 8 of the temporary compression via the E1 interfaces 7a and 7b for decompression using the compression and decompression apparatus 6a and 6b, and for encoding in a new mode the AMR codec by the encoding apparatus 5a and 5b. Reference numerals 9a and 9b, 10a and 10b indicate directions of incoming and outgoing encoded speech data.

Figure 2 shows a schematic representation of an example embodiment of a method of the invention with device elements. Elements or process steps identical to those shown in FIG. 1 are denoted by the same reference numerals.

The process of the method described with reference to FIG. 1 coincides with the method according to the invention shown in FIG. 2 prior to the step of matching or converting RFCI pointers using the device 4a and 4b for matching distribution symbols (RFCI pointers). Unlike the traditional method shown in FIG. 1, in this embodiment, a bypass device 11 is located directly behind the devices 4a and 4b for matching RFCI pointers, which, through loop connections 16 and 17, provides the ability to directly extract coded speech data coming from the outputs of devices 4a and 4b for matching RFCI pointers to inputs, respectively other devices 4b, 4a for matching RFCI pointers.

The correction of the mismatch of the RFCI pointers is done by processing through the UP protocol in the output device 4a and 4b to match the RFCI pointers. By means of a switching device, which includes switches 12-15, it is possible to turn on the bypass device, as shown for the current situation shown in figure 2. Alternatively, turning off the bypass device can be ensured by the fact that the switches 12-15 switch to the terminals 18-21, which can be reconnected with the encoding and decoding devices, as well as with the compression and decompression devices and with the switching switching field 8 of the temporary seal, like this shown for example in figure 1.

In this way, it is possible to quickly switch the device for implementing the method according to the invention into a transcoding state according to the conventional method.

The totality of the features disclosed in the application materials is claimed as the essence of the invention, since these features, both individually and in combination, are novel in comparison with the prior art.

List of Reference Items

one UTRAN Radio Network 2a, 2b ATM level 3a, 3b AAL 2 (ATM Adaptation Level 2) 4a, 4b RFCI pointer matching devices via UP protocol 5a, 5b AMR decoding and encoding devices 6a, 6b compression and decompression devices 7a, 7b E1 interface 8 temporary compaction switch 9a, 9b incoming and outgoing voice data connections 10a, 10b incoming and outgoing voice data connections eleven bypass device 12-15 switches 16, 17 bypass connections 18-21 pins of switching devices

Claims (8)

1. A method for resolving a mismatch between speech data transmitted in a speech codec mode with a first distribution symbol for a speech codec mode in a first network portion of a communication network based on speech compression and speech data transmitted in a speech codec mode with a second distribution symbol for a speech mode codec on the second network section, inside the transcoder, and the speech data included in the transcoder with the first distribution symbol bypassing the encoding and decoding and switching devices (6a, 6b) of the temporary compression field (8) by the bypass device (11) is allocated to the output of the transcoder if the speech data transmitted with the first distribution symbol and the speech data transmitted with the second distribution symbol are encoded in the same speech codec mode, characterized in that the speech data with the first distribution symbol directly from the output of the input device (4a, 4b), for matching the distribution symbols by the UP protocol, are allocated to the input of the output device (4b, 4a) for matching the symbol in distribution, and the output device (4b, 4a) for harmonizing the distribution of symbol matches the first symbol distribution to a second symbol distribution. 2. The method according to claim 1, characterized in that the first and second distribution symbols are indicators of the combination of protocols of the carrier channel of the radio access network. 3. The method according to claim 1 or 2, characterized in that the speech codecs underlying the modes of speech codecs include adaptive multi-speed codecs, codecs for compressing speech data, codecs for adaptive differential pulse code modulation and codecs for improving speed transmission and transmission quality. 4. The method according to claim 1, characterized in that the bypass device (11) is implemented on the basis of software in a digital signal processor, a user-programmable gate array, application-oriented specialized integrated circuit or network processor. 5. The method according to claim 1, characterized in that the speech data transmitted in the speech codec mode is transmitted in a speech frame from or to the UTRAN radio communication network or the core network. 6. A device for resolving the mismatch between speech data transmitted in a speech codec mode with a first distribution symbol for a speech codec mode in a first network portion of a communication network based on speech compression and speech data transmitted in a speech codec mode with a second distribution symbol for a mode speech codec in the second network section, inside the transcoder, according to the method of the preceding paragraphs, characterized in that it contains a bypass device (11) for direct input voice data with the first distribution symbol from the output of the input device (4a, 4b) for matching distribution symbols by means of the UP protocol directly to the input of the output device (4b, 4a) for matching the distribution symbol. 7. The device according to claim 6, characterized in that it comprises a switching device (12-15, 18-21) located in the bypass device for turning the bypass device (11) on and / or off. 8. The device according to claim 6 or 7, characterized in that the bypass device (11) is located in the digital signal processor, a user-programmable gate array, oriented to the application of a specialized integrated circuit or network processor.

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