+

WO1999066760A1 - Procede pour corriger des erreurs de transmission dans une liaison de communication - Google Patents

Procede pour corriger des erreurs de transmission dans une liaison de communication Download PDF

Info

Publication number
WO1999066760A1
WO1999066760A1 PCT/DE1999/001609 DE9901609W WO9966760A1 WO 1999066760 A1 WO1999066760 A1 WO 1999066760A1 DE 9901609 W DE9901609 W DE 9901609W WO 9966760 A1 WO9966760 A1 WO 9966760A1
Authority
WO
WIPO (PCT)
Prior art keywords
data
prediction
communication link
received
unit
Prior art date
Application number
PCT/DE1999/001609
Other languages
German (de)
English (en)
Inventor
Klaus Hünlich
Original Assignee
Siemens Aktiengesellschaft
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Siemens Aktiengesellschaft filed Critical Siemens Aktiengesellschaft
Publication of WO1999066760A1 publication Critical patent/WO1999066760A1/fr

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04Q—SELECTING
    • H04Q11/00—Selecting arrangements for multiplex systems
    • H04Q11/04—Selecting arrangements for multiplex systems for time-division multiplexing
    • H04Q11/0428—Integrated services digital network, i.e. systems for transmission of different types of digitised signals, e.g. speech, data, telecentral, television signals
    • H04Q11/0478—Provisions for broadband connections
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L12/00—Data switching networks
    • H04L12/54—Store-and-forward switching systems 
    • H04L12/56—Packet switching systems
    • H04L12/5601—Transfer mode dependent, e.g. ATM
    • H04L2012/5638—Services, e.g. multimedia, GOS, QOS
    • H04L2012/5646—Cell characteristics, e.g. loss, delay, jitter, sequence integrity
    • H04L2012/5647—Cell loss
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L12/00—Data switching networks
    • H04L12/54—Store-and-forward switching systems 
    • H04L12/56—Packet switching systems
    • H04L12/5601—Transfer mode dependent, e.g. ATM
    • H04L2012/5638—Services, e.g. multimedia, GOS, QOS
    • H04L2012/5646—Cell characteristics, e.g. loss, delay, jitter, sequence integrity
    • H04L2012/5652—Cell construction, e.g. including header, packetisation, depacketisation, assembly, reassembly
    • H04L2012/5653—Cell construction, e.g. including header, packetisation, depacketisation, assembly, reassembly using the ATM adaptation layer [AAL]
    • H04L2012/5656—Cell construction, e.g. including header, packetisation, depacketisation, assembly, reassembly using the ATM adaptation layer [AAL] using the AAL2
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L12/00—Data switching networks
    • H04L12/54—Store-and-forward switching systems 
    • H04L12/56—Packet switching systems
    • H04L12/5601—Transfer mode dependent, e.g. ATM
    • H04L2012/5638—Services, e.g. multimedia, GOS, QOS
    • H04L2012/5671—Support of voice

Definitions

  • the invention relates to a method and a device for correcting transmission errors in a communication connection.
  • ATM asynchronous transfer mode
  • data are transmitted in cells of 53 bytes (48 bytes of user data, 5 bytes of control data) regardless of the information they represent (voice communication, data communication, multimedia).
  • the network resources of the communication system are shared between connections with different quality of service and bit rate requirements.
  • connection types are possible in an ATM network, which differ in their bit rate statistics.
  • a connection with a constant bit rate or deterministic bit rate has a fixed transmission bit rate (cell rate) over the entire connection duration. This bit rate must be constantly made available by the network.
  • This type of connection is particularly suitable for real-time applications such as voice communication or video telephony, for which strict requirements are placed on line delay fluctuations, and which has a comparatively constant transmission rate.
  • connection type is the available bit rate, whereby the data is transmitted depending on the network capacity currently available.
  • This type of connection is not suitable for real-time applications, but as inexpensive data transmission such as e-mail.
  • connection type variable bit rate the data to be transmitted of a virtual connection are transmitted at a time-varying transmission rate. Examples of such a connection type are video connections in which the video signals are encoded with a variable bit rate, voice communication with pause suppression and certain data transmission services.
  • Variable bit rate connections where the average bit rate is well below the maximum bit rate are suitable for statistical multiplexing. Many connections with a variable bit rate are routed via a common line or via a common switching matrix, whereby it is not necessary to reserve the maximum bit rate for each individual connection, since many uncorrelated connections with a lower average bit rate compared to the maximum bit rate have the available transmission capacity share on average. It is thus possible to "overbook" the line to a certain extent. The network infrastructure can thus be better used overall.
  • the ATM adaptation layer extends the service offered by the ATM layer so that the special requirements of the protocols can be met.
  • An important task of AAL is also to adapt the different data formats of the higher protocol layers to the ATM cell format.
  • ATM adaptation layers There are different types of ATM adaptation layers (type 0 to type 5) that are specified by international standardization.
  • the ATM adaptation layer type 2 defined by the International Telecommunications Union in Recommendation 1.363.2 is intended for the bandwidth-efficient transmission of services of low bit rate and short data packets of variable length in delay-sensitive applications, ie real-time applications.
  • the data stream of several AAL type 2 users can be be supported.
  • the typical application of the AAL type 2 layer is the simultaneous transmission of several telephone calls with pause suppression.
  • the AAL type 2 sublayer is shown schematically in FIG. It consists of a common sub-layer (CPS) and a service-specific convergence sub-layer (SSCS).
  • the SSCS sublayer is not mandatory and can also be omitted depending on the service used.
  • a header section contains channel identification data (CID), length identification data (LI), user-user assignment data (UUI) and error correction data
  • CID channel identification data
  • LI length identification data
  • UUI user-user assignment data
  • error correction data error correction data
  • the user information field can accommodate, for example, 64 bytes, via which, for example, five voice communication channels of 12 bytes each can be transmitted.
  • a so-called traffic control must ensure that, despite the common transmission of data cells of different origins, different bit rates and different bit rate statistics, the required transmission quality of the ATM layer is ensured. In particular, the likelihood of cell loss occurring should be kept low. Nevertheless, cell losses can never be completely ruled out in an ATM communication connection.
  • the invention is therefore based on the object of proposing a method for correcting transmission errors in a communication connection, in which the impairment of the transmission quality caused by the transmission errors is minimized.
  • the method according to the invention for correcting transmission errors in a communication connection has the following method steps: (a) receiving the data transmitted by the communication connection,
  • Failed cells are replaced by the prediction data, which are continuously derived from the last received data.
  • the prediction data are modeled on the statistical characteristics of the most recently received data, whereby a better intelligibility of voice data, it is sufficient ⁇ . In particular, crackling noises generated by empty cells are avoided.
  • Failed received data can preferably be replaced in m units of AAL2 packets. Other data lengths of the respective prediction data, for example 12 bytes, are also possible.
  • voice information is transmitted in subchannels of the ATM adaptation layer 2 (AAL 2).
  • AAL 2 ATM adaptation layer 2
  • the received data are preferably weighted and a statistical vector S is determined from the weighted values, it being possible for the received data to be weighted in a two-stage method.
  • a linear prediction method is preferably used as the prediction method.
  • An example of this is the low delay code excited linear prediction method.
  • Prediction data can preferably be stored for a period of approximately 3 ms. A shorter or longer period of time is also possible within the scope of the invention, depending on the area of application and the frequency of cell failures.
  • FIG. 1 is a schematic block diagram of the device according to the invention for correcting transmission errors in an ATM communication link
  • Figure 2 is a schematic representation of the structure of the Type 2 ATM adaptation layer
  • Figure 3 is a schematic representation of a CPS packet of the AAL type 2 sublayer.
  • the device according to the invention for correcting transmission errors in an ATM communication connection is explained with reference to FIG. 1.
  • the data cells arrive at the data loss detection unit 1, in which the received data stream is checked. If the information of the previous cell is completely passed on, a new ATM cell must be present each time. If no new cell has arrived within a predefined tolerance time interval, a signal failure message is forwarded to the multiplexer 5.
  • a two-stage statistics unit 2, 3 is connected to the data loss reception unit 1 and receives the received data and determines the statistical weights of the data stream.
  • the statistical vectors V characterizing the respective received data are determined from these weighted values and forwarded to the prediction unit 4.
  • the prediction unit 4 determines from the statistical vectors V a prediction or extrapolation of the data following the last received data, for example over a period of 3 ms.
  • the prediction unit 4 preferably uses a linear prediction method.
  • An example of this is the Low Delay Code Excited Linear Prediction (LD-CELP), which is used in the LD-CELP
  • the prediction data for a fixed time interval are stored in a memory, which can be assigned to the prediction unit 4 or the multiplexer 5, for example. Does the multiplexer 5 receive from the data loss detection Unit 1 a message that a data failure has been detected, the multiplexer 5 replaces the failed cell with a cell of the prediction data.
  • subchannels of ATM adaptation Layer 2 (FIGS. 2 and 3) are used for transmission and the information length of a subchannel element that forms part of the CPS user data (FIG. 3) is limited, then 12 bytes of information are also required in order to contain the content of a Subchannel element to be replaced approximately. If one uses the method mentioned and described in Recommendation G.728 of the International Telecommunication Union, the steps of weighting and formation of the statistical vector V have to be used twice in succession. You then have 5 by 5 bytes of information in order to in this case, according to the procedure in G.728, 25 missing cycles of 125 ⁇ s each, i.e. correct a total of 3.125 ms using the forecast data.
  • the multiplexer 5 preferably contains a buffer memory for the time compensation of the transit times between the received direct data stream and the correction data.
  • the corrections of the failed data carried out by the method according to the invention correspond to the natural course, for example of a voice communication, much better than known methods, in which either empty cells are inserted or previous cells are repeated. As a result, the quality of the communication link is improved and crackling noises or the like can be avoided.
  • the invention is not restricted to use with the AAL 2 layer and also not to the use of the linear prediction method described in ITU recommendation G.728.
  • the invention can of course also use other types of transmission and suitable prediction methods.

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Data Exchanges In Wide-Area Networks (AREA)

Abstract

L'invention concerne un procédé pour corriger des erreurs de transmission dans une liaison de communication, de préférence dans une liaison de communication MTA. Ce procédé comprend les étapes suivantes: (a) réception des données transmises par l'intermédiaire de la liaison de communication; (b) détermination et mémorisation en continu de données extrapolées, déduites des données de réception; (c) détection de données défaillantes dans le flux de données reçu côté réception de la liaison de communication; (d) remplacement des données défaillantes reçues, par les données extrapolées, en cas de détection de données défaillantes. Dans ce dernier cas, les informations perdues sont remplacées par des données extrapolées modélisées de manière statistique, ce qui assure la meilleure compréhension possible lors d'une communication vocale et permet d'empêcher en particulier l'apparition de claquements ou similaires.
PCT/DE1999/001609 1998-06-15 1999-06-01 Procede pour corriger des erreurs de transmission dans une liaison de communication WO1999066760A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE1998126584 DE19826584A1 (de) 1998-06-15 1998-06-15 Verfahren zur Korrektur von Übertragungsfehlern bei einer Kommunikationsverbindung, vorzugsweise einer ATM-Kommunikationsverbindung
DE19826584.0 1998-06-15

Publications (1)

Publication Number Publication Date
WO1999066760A1 true WO1999066760A1 (fr) 1999-12-23

Family

ID=7870919

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/DE1999/001609 WO1999066760A1 (fr) 1998-06-15 1999-06-01 Procede pour corriger des erreurs de transmission dans une liaison de communication

Country Status (2)

Country Link
DE (1) DE19826584A1 (fr)
WO (1) WO1999066760A1 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR101320818B1 (ko) * 2010-09-30 2013-10-29 애플 인크. 이미지 신호 처리를 위한 오버플로우 제어 기술들

Families Citing this family (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8953882B2 (en) 2012-05-31 2015-02-10 Apple Inc. Systems and methods for determining noise statistics of image data
US9142012B2 (en) 2012-05-31 2015-09-22 Apple Inc. Systems and methods for chroma noise reduction
US8817120B2 (en) 2012-05-31 2014-08-26 Apple Inc. Systems and methods for collecting fixed pattern noise statistics of image data
US9332239B2 (en) 2012-05-31 2016-05-03 Apple Inc. Systems and methods for RGB image processing
US11089247B2 (en) 2012-05-31 2021-08-10 Apple Inc. Systems and method for reducing fixed pattern noise in image data
US8917336B2 (en) 2012-05-31 2014-12-23 Apple Inc. Image signal processing involving geometric distortion correction
US9077943B2 (en) 2012-05-31 2015-07-07 Apple Inc. Local image statistics collection
US9105078B2 (en) 2012-05-31 2015-08-11 Apple Inc. Systems and methods for local tone mapping
US8872946B2 (en) 2012-05-31 2014-10-28 Apple Inc. Systems and methods for raw image processing
US9743057B2 (en) 2012-05-31 2017-08-22 Apple Inc. Systems and methods for lens shading correction
US9025867B2 (en) 2012-05-31 2015-05-05 Apple Inc. Systems and methods for YCC image processing
US9031319B2 (en) 2012-05-31 2015-05-12 Apple Inc. Systems and methods for luma sharpening
US9014504B2 (en) 2012-05-31 2015-04-21 Apple Inc. Systems and methods for highlight recovery in an image signal processor

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0673018A2 (fr) * 1994-03-14 1995-09-20 AT&T Corp. Génération des coefficients de prédiction linéaire en cas d'effacement des trames de données ou de perte des paquets de données
EP0820052A2 (fr) * 1996-03-29 1998-01-21 Mitsubishi Denki Kabushiki Kaisha Système de codage et de transmission de parole

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0673018A2 (fr) * 1994-03-14 1995-09-20 AT&T Corp. Génération des coefficients de prédiction linéaire en cas d'effacement des trames de données ou de perte des paquets de données
EP0820052A2 (fr) * 1996-03-29 1998-01-21 Mitsubishi Denki Kabushiki Kaisha Système de codage et de transmission de parole

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
SUBBIAH B ET AL: "ATM adaptation layer 2 (AAL2) for low bit rate speech and data: issues and challenges", IEEE ATM WORKSHOP. PROCEEDINGS, 1998, pages 225 - 233 233, XP002104243 *

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR101320818B1 (ko) * 2010-09-30 2013-10-29 애플 인크. 이미지 신호 처리를 위한 오버플로우 제어 기술들

Also Published As

Publication number Publication date
DE19826584A1 (de) 1999-12-16

Similar Documents

Publication Publication Date Title
DE69735929T2 (de) Anlage zur Zellenzusammensetzung und Multiplexierung, und Anlage zur Demultiplexierung
DE69835130T2 (de) Rufzulassungssteuerung in einem Sprachpaketsystem
DE69434503T2 (de) Mobiles Funk-Übermittlungssystem
DE69128924T2 (de) System zur Unterdrückung der Verzögerungsverzerrung für ein ATM-Kommunikationssystem
EP0365693B1 (fr) Méthode et dispositif pour transmettre des signaux d'information dans un réseau de communication à large bande
DE4317951C1 (de) Verfahren und Schaltungsanordnung zur Übertragung von Nachrichtenpaketen nach dem Asynchronen Transfermodus in einem Kommunikationsnetz
WO1999066760A1 (fr) Procede pour corriger des erreurs de transmission dans une liaison de communication
EP0528085A1 (fr) Réseau de communication avec commutation ATM et STM
DE69903424T2 (de) Verfahren zur beseitigung von falschverkettung von teilpaketen in aal-2 und teilpaketen mit kanalidentifizierung
DE69824549T2 (de) Atm-kommunikationssystem und -verfahren
DE69635944T2 (de) Schnittstelle zur Erkennung von Verlust einer ATM-Verbindungsaufbauzelle
DE69937700T2 (de) Verfahren und Vorrichtung zur Übertragung von komprimierten Sprachpaketen über ATM
DE69925968T2 (de) Verfahren und System zur Übertragung von Schmalbandverbindungen über ein ATM-Netz
DE60207533T2 (de) Verfahren zur Zeitschlitzverwaltung und Struktur eines Aufwärtssignalrahmens
DE69827379T2 (de) Datenunterdrückung und -regenerierung
EP0830800B1 (fr) Procede de detection et de compensation de l'absence ou de l'insertion incorrecte de cellules dans la methode de transfert asynchrone (atm)
WO1998048590A1 (fr) Procede de transmission d'informations cote abonne dans un reseau de branchements locaux
EP1142434B1 (fr) Procede de transmission de donnees pour reseau de communication par paquets
EP1135958B1 (fr) Procede de configuration d'une unite de terminaison de reseau
EP1049280A2 (fr) Glissement régulé dans la transmission d'un flux de données synchrone à travers un réseau de télécommunication asynchrone
EP0924951B1 (fr) Système de transmission pour la transmission des signaux digitaux de nx64-kb/s avec n adaptable aux proprietés de ligne, à travers une ligne d'abonné suivant des valeurs mesurées de transmission de la ligne d'abonné
EP1068765B1 (fr) Procede et dispositif pour le couplage d'une couche de communication mta a plusieurs connexions de communication a multiplexage dans le temps
DE19832997C2 (de) Netzwerkanpassungseinrichtung und zugehöriges Verfahrens
WO2000077976A2 (fr) Procede pour l'etablissement d'une connexion dans un reseau de communication oriente connexion et paquet
EP1157587B1 (fr) Procede de transmission de donnees par l'intermediaire d'un reseau de communication oriente paquets

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): CA US

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LU MC NL PT SE

121 Ep: the epo has been informed by wipo that ep was designated in this application
DFPE Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101)
122 Ep: pct application non-entry in european phase
NENP Non-entry into the national phase

Ref country code: CA

点击 这是indexloc提供的php浏览器服务，不要输入任何密码和下载