MXPA98007919A - Format of communications adaptat - Google Patents

Abstract

The present invention relates to a method for improving data transfer performance over communication networks that connect data networks and users using adaptive communication formatting. Adaptive communication formatting includes encoding (or compressing) the data and applying error control schemes, to reduce the amount of data that is transmitted and to correct and / or hide errors that occur during data transmission. In one embodiment, the present invention uses a set of transcoding techniques to encode (or compress) the data and a set of error control schemes to correct and / or hide errors that occur during data transmission. The particular sets of transcoding techniques and error control schemes selected to format the data are adaptive to factors, such as the nature of the communications network that connects a user to an access server in the data network, the user preferences and the data type of the data that is transmitted to the user (or access server)

Description

FORMAT OF ADAPTIVE COMMUNICATIONS BACKGROUND OF THE INVENTION The subscribers of wireless communication systems are increasing in phenomenal numbers with more than 45 million subscribers in the U.S.A. and 120 million subscribers worldwide. As new service providers enter the wireless communications market, the level of competition for old service providers increases to retain the existing customer base while attracting new subscribers. To maintain continuous growth of subscriber numbers and income levels, service providers are offering value-added services to their subscribers. The explosion of the Internet has provided service providers with wired and wireless communications systems, with an address to develop value-added services. Currently, there are more than 50 million Internet users. Internet access is typically through a wired communications network. However, wired access to the Internet requires some kind of physical connection between the users and the wired communications network. In this way, the mobility of users who access the Internet through a wired or wired connection is severely limited. ref. 28215 In contrast, access to the Internet through a wireless communication system offers a large amount of mobility to users / subscribers. However, wireless Internet access can be prohibitively expensive to most users / subscribers. Specifically, wireless communication systems such as those based on the GSM and IS-95 CDMA standards are limited in daily interface access speeds (ie narrow bandwidth) and are subject to an error-prone transmission environment. For example, data transmitted over wireless communication systems based on IS-95 CDMA may be subject to a speed of 3% or more bit error. These limitations increase the amount of time required for successful data transfers between the Internet and the user / subscriber, which in turn increases the cost of a wireless telephone call to the user / subscriber. Accordingly, there is a need to improve the performance of data transfer (ie reduced transmission time) over communication networks that connect the Internet or other data networks to the user / subscriber. SUMMARY OF THE INVENTION The present invention relates to a method for improving data transfer performance over communication networks that connect data networks and users using an adaptive communications format. Adaptive communication formatting includes encoding (or compressing) the data and applying error control schemes to reduce the amount of data that is transmitted and to correct and / or hide errors that occur during data transmission. In one embodiment, the present invention uses a set of transcoding techniques to encode (or compress) the data and a set of error control schemes to correct and / or hide errors that occur during data transmission. The particular sets of transcoding techniques and error control schemes selected to format the data are adaptive to factors, such as the nature of the communications network that connects a user to an access server in the data network, the preferences of the user. user, and the data types of the data that is transmitted to the user (or the access server). BRIEF DESCRIPTION OF THE DRAWINGS The features and advantages of the present invention will be better understood with respect to the following description, appended claims and accompanying drawings wherein: Figure 1 illustrates an architecture for a system for accessing a data network according to the present invention; Figure 2 illustrates a stream of bits entering and leaving the access server; Figure 3 illustrates a functional block diagram of the access server according to an embodiment of the present invention; Figure 4 illustrates a table for selecting transcoding techniques and error control schemes for use in formatting data; and Figure 5 illustrates a diagram showing examples of transcoding techniques and error control schemes that can be used for transmission of particular data type in wireless connections. DETAILED DESCRIPTION Figure 1 illustrates an architecture for a system 10 for accessing a data network according to the present invention. The system 10 comprises a data network 12 (for example Internet), a user 14, and a communication network 16. The communication network 16 comprises a plurality of wired and / or wireless communications systems, to provide a wired connection and / or wireless between the data network 12 and the user 14. The wired communication systems include public switched telephone networks (PSTN = Public Switching Telep one Networks), integrated digital switching networks (ISDN), lines IT and lines El. Wireless communication systems include those based on multiple access with frequency division (FDMA Frequency Division Multiple Access), multiple access with time division (TDMA = Time Division Multiple Access) and multiple access with division of code ( CDMA = Code Multiple Division Access). The data network 12 comprises a plurality of interconnected computers that include at least one access server 20 and at least one host 22. The access server 20 is a computer associated with a service provider to which the user subscribes to access the data network 12. The guest 22 is a computer with data that is searched by the user 14. The access server 20 and the guest 22 can also be the same computer. The user 14 comprises a communications device 24 (for example telephone, mobile telephone and / or modem) for receiving and transmitting data to and from the access server 20 via the communications network 14, and a remote computer 26 having software ( software) for processing data for transmission to the access server 20, or for displaying on an output device associated with the remote computer 26, such as a video display, an audio display, a printer, memory, etc. The user 14 gains access to the data network 12 through the access server 20. Specifically, the user 14 dials a number associated with the access server 20. The communication network 16 connects the user 14 to the access server 20 using the dialed number. By connecting to the access server 20, the user 14 can retrieve data from the host 22. In general, the data (which is retrieved by the user) may be in the form of a file or a recording device output in real time, such as a video camera, microphone, digitizer, fax, transducers or measuring devices. In all cases, the data will have associated information indicating a type for the data. For purposes of discussion, the present invention will be described herein as retrieving data in the form of a file from host 22. However, it is not to be construed as limiting the present invention to retrieving data in the form of a file. The data (or file) is retrieved by a bitstream from the host 22 to the access server 20 to the user 14. The bitstream includes the control and data information. The data has a file name associated with a file extension indicating a type (and / or sub-type) of data. The control information includes a user indicator to identify the user for whom the data is intended, error control information to correct and / or hide errors that occur during data transmission, and / or data type indicator to identify the data types of the associated data. Data types include, but are not limited to, speech / voice, video / image and text. Each type of data has one or more sub-types. Examples of speech / voice sub-types (and file extensions) include audio (.au), wave (.wav), and speech (.sp). Examples of video / image sub-types include tagged image format (.tif) files, graphic image format (.gif) files, the Moving Images Expert Group (.mpg and .mp2) file. Examples of text sub-types include MS Word (.doc) and ASCII (.txt). Formatting Adaptive Communications In the access server 20, the data is formatted using a mixture of transcoding techniques and error control schemes to facilitate data transmission within the acceptable quality level, as will be described herein. Figure 2 illustrates an input bit stream 23 and a bit stream 25 exiting from the access server 20. When the bitstream 23 arrives at the access server, the bit stream 23 includes the control information and indicator user and data to identify the user to whom the data is intended. The data is formatted by access server 20 and transmitted to user 14 by bit stream 25, which includes encoded data, error control information to control and / or hide errors resulting from data transmission, and control information -indicator of data type, to identify the data types of the associated (coded) data as will be described here. Transcoding techniques include coding algorithms to encode or compress (the data). Coding (or compressing) the data facilitates the transmission of data by reducing the amount of data to be transmitted, which in turn decreases the time required to transmit the data (i.e. transmission time) from the user access server on a channel of transmission with limited bandwidth (ie slower access speeds). Some coding algorithms however have associated loss that may adversely affect the data quality. Linear prediction excited by algebraic code (ACELP = Algebraic Code Excited Linear Prediction), linear prediction excited by vector sum (VSELP = Vector Sum Excited Linear Prediction), improved variable speed encoder (EVRC = Enhanced Variable Rate Coder), h.263 ( which is a set of guidelines considered by the International Telecommunication Union for implementation in standards) pkzip (by PKWare, Inc.), MPEG and MPEG2 (group of moving image experts) and JPEG (expert group of joint images) are some example of coding algorithm that are well known in the art. Each of the aforementioned coding algorithms has different associated levels or compression percentages. Error control schemes include techniques for correcting and / or hiding errors that occur during data transmission from access server 20 to user 14. Error control schemes provide means to ensure data integrity have not been compromised beyond levels acceptable Some error control schemes however increase the data transmission time by adding control information to the data and / or require re-transmission of the data when data error is detected. Progress error correction (FEC = Forward Error Correction), cyclic redundancy check (CRC = Cyclical Redundancy Check), interrogation in the automatic transmission (ARQ = Automatic Retransmission Query), hybrid ARQ (ie a combination of ARQ and FEC) ) and error concealment (eg silenced, extrapolation of good previous frames and interpolation of previous and succeeding good frames) are some examples of error control schemes that are well known in the art. Each of the aforementioned error control schemes have different associated levels of concealment and / or error correction. The particular transcoding techniques and error control schemes used to format the data should be adaptive to factors such as the nature in the communications network 16 that connects the user 14 to the access server 20, user preferences 14, and data types as will be discussed here. It should be noted that the present invention will not be limited to being adaptive only in the aforementioned factors. Other factors, such as interactivity, bit rate and transmission delay may also be applicable. First Factor The first factor involves the nature of the communication network 16 that connects the user 14 to the access server 20. The nature of the communication systems, in general (regardless of whether the communication system is wired or wireless) varies from one to the other. The nature of the communication system depends on sub-factors such as whether the communication system is wired or wireless, whether the communication system is analog or digital, the available bandwidth, the bit rate, the signal-to-signal ratio -interference, the bit error rate and the transmission delay, as will be described here. As previously mentioned, the communication network 16 comprises a plurality of wired and / or wireless communication systems to provide the user 14 with a wired or wireless connection to the access server 20. For discussion purposes, a wireless connection involves using the less a wireless communication system for connecting the user 14 to the access server 20. In contrast, a wired or wired connection involves not using wired communication system to connect the user 14 to the access server 20. The wireless connections have several different disadvantages over wired connections. First, the transmission times for data over wireless connections are typically greater than the transmission times for the same data in wired connections. The reasons for this are because wireless connections generally have less available bandwidth with lower bit rates and longer transmission delays than wired connections. Therefore, it may be convenient to use a transcoding technique that will encode (or compress) the data as much as possible to reduce the transmission time over the wireless connections (and probably some wired connections). The benefits made in facilitating data transmission however must be balanced against losses associated with compression (or coding). Second, data transmitted over a wired connection is more susceptible to data errors than the data admitted over wired connections. The reasons for this are because wireless connections generally have lower signal-to-interference ratios and higher bit error rates than wired connections. Therefore, it may be convenient to increase the amount of error control applied to data transmissions over wireless connections. The benefits of increasing error control (ie, increased quality), however, must be balanced against increased data transmission time. Second Factor The second factor involves the preferences of the user 14. The preferences of the user 14 should reflect the physical equipment and software capabilities of the user 14 and the access server 20, and balance between facilitating data transfer and acceptable data quality. The service provider and the subscribers should agree on the form in which the data is formatted, that is, agree on which transcoding techniques and error control schemes to use. Any form that is used by the access server 20 to format the data, the user 14 should be able to deform the formatted data. In other words, the access server 20 should agree to use transcoding techniques and compatible error control schemes with the transcoding techniques and error control schemes available to the user 14. Failure to use compatible transcoding techniques and error control schemes will result in the user 14 receiving a bitstream that can not be deformed. This agreement can be negotiated between the service provider and the subscriber before or at the time the user connects to the access server 20. The user's preferences 14 should also reflect a balance by the user between facilitating data transfer and acceptable data quality . For example, if user 14 requires high quality data, user 14 may have to compensate by facilitating data transfer by increased data quality.

In this way, the user 14 can choose a transcoding technique with less compression and minimal loss (for example, pkzip) and an error control scheme with higher error correction (for example, ARQ) to format the data on the access server. Third Factor The third factor is the type of data. Certain transcoding techniques and error control schemes are most effective when used to format particular data types. In this way, the transcoding techniques and error control schemes selected to format the data should be adaptive to the data type, as described here. Transcoding techniques include coding algorithms to encode or compress particular data types; gzip and pkzip for text data; VCELP, ASELP and EVRC for speech / voice data; and h.263 for video / image data. Using a text transcoding technique (for example, a transcoding technique with gzip) to compress speech / speech data may not be as effective as using a speech transcoding technique (for example, a transcoding technique with VCELP) to compress the same data, this is the amount of data compression may not be the same.

Error control schemes include techniques for different levels of correction and / or error concealment. The level of concealment and / or error correction applied to data should depend on the amount of error tolerable by the user, which, in turn, depends on the type of data. For example, errors in audio / speech and video / image data types may be tolerable in a certain proportion. In these cases, errors in audio / speech data types may be better hidden by mute and errors in video / image data types may be better hidden by interpolating from previous good frames. By contrast, errors in text data types can be intolerable. In this case, the errors are corrected (not hidden) when requesting data retransmission asking, that is, ARQ. Figure 3 is a functional block diagram of the access server 20 according to an embodiment of the present invention. The access server 20 comprises a data selector 30, a plurality of text, speech / voice and video / image 32-n transcoding techniques (i.e., transcoding techniques for text types, speech / voice and video / image ), a plurality of text, speech / voice and video / image control schemes 34-n (i.e., error control schemes for text, speech / voice and video / image data types) and a combiner 38 for multiply formatted data. The data selector 30 is a device, such as a microprocessor with software, for selecting a transcoding technique 32 -n and an error control scheme 34-? A for formatting the data. The transcoding technique 32 and the error control scheme 34 -n are chosen using the data type, the identity of the user and / or a user table 40 that specifies user preferences (i.e. transcoding techniques and transmission schemes). error control transferred by each user for each type and / or sub-data type The data selector 30 can determine the type of data using the file extension, other information contained within the bit stream, predefined data types and / or a combination of those mentioned above For example, the data selector 30 can determine which data with .wav file extensions are speech / voice data types The data selector 30 can determine the identity of the user using the user indicator control information (in the bit stream) .There is that Figure 3 shows a 1-in-1 correlation between transcoding techniques and error control schemes. However, this should not be considered as limiting the present invention to modalities with this correlation. A one-to-many correlation between transcoding techniques and error control schemes, or vice versa are also possible. Figure 4 illustrates an example of a user table 40. The transcoding techniques and error control schemes in table 40 specified by each user and type (and / or sub-type) of data should reflect the aforementioned factors, that is, the nature of the communications network that connects users to the access server, the software and equipment capabilities and / or preferences of the user and the access server, and the types of data. For example, suppose that user number 000001 connects to the access server using a wireless connection. Table 40 specifies for user number 000001 a set of transcoding techniques and error control schemes for each type (and / or sub-type) of data that is available to both user number 000001 and the access server and which they will facilitate data transmission within acceptable quality levels over a wireless connection. In contrast, user number 000222 is connected to access server 20 by the wired connection. For users connected by a wired connection (for example, user number 000222), table 40 specifies without formatting (ie, without transcoding techniques or error control schemes) because wired connections (with wider bandwidths) are less prone to error than wired connections with narrower bandwidth. It should be noted that the present invention will not be limited to using table 40 illustrated in Figure 4. Other types of tables or collections of information such as databases can also be used to specify transcoding techniques and error control schemes to format data intended for particular users. Other information may also be stored in the table, such as an indication if the user connects via a wired or wireless connection, or separate sets of transcoding techniques and error control schemes for wired and wireless connections. It should be noted that if the data selector requires a determination regarding the way in which the user connects to the access server, this determination can be made using a flag indicative of the connection, or a predefined value, the telephone number marked by the user to connect to the access server, etc. The access server 20 can create or obtain the table 40 in a variety of ways. The subscriber can submit a competing form to the service provider, indicating the transcoding techniques and error control schemes available to the user and the manner in which the user will connect to the access server. The service provider will use the information in the complete form to select transcoding techniques and error control schemes available to both the user and the access server and optimal for the form of connection. Said selections are then added or used to construct the table 40. Alternatively, the user can provide this information electronically when accessing the access server 20 or the table can be constructed using pre-defined sets of transcoding techniques and control schemes of mistake. After the data selector 30 chooses a transcoding technique and an error control scheme, the selected 32-n transcoding technique is used to encode (or compress) the data and the error-select control scheme 32 -n is used to add error control information to the encoded data, as illustrated by the bit stream 25 in Figure 2. Data type indicator-control information is then added to the formatted data (i.e. data encoded with associated error control information) when the formatted data is multiplied by the combiner 38. Subsequently the multiplexed data is made to be transmitted by the access server 20 to the user 14 on the communication network 16. In the user 14, the data The multiples are demultiplied and deformed using the appropriate sets of transcoding techniques and error control schemes. Specifically, the user 14 looks up the data type indicator control information, to select the appropriate transcoding techniques and error control schemes to deform (or reciprocate the operations of the transcoding techniques and error control schemes on the server of access) of the formatted data. The deformed data is subsequently output to a video display, audio display, printer and / or computer memory associated with the remote computer 26. Figure 5 is a diagram 50 illustrating examples of transcoding techniques and control schemes of error that can be used for transmission of particular data type over wireless connections. The diagram 50 shows sub-data type and its associated bit rates, coding algorithms and data rate coding bit rate after encoding (or compression) and error control schemes. For example data with an audio sub-type have a bit rate of 256 kbps. If a transcoding technique with VCLP coding algorithm is used to encode the audio data, the bit rate can be played at 8 kbps. Subsequently, hybrid and muted ARQ (a form of error concealment to the encoded data) (or tablets) is applied in the error control scheme before being transmitted over a wireless connection. Although the present invention has been described in considerable detail with reference to certain embodiments, other actions are possible. Therefore, the spirit and scope of the present invention will not be limited to the description of the modalities contained herein. It is noted that in relation to this date, the best method known to the applicant to carry out the aforementioned invention, is that which is clear from the present description of the invention. Having described the invention as above, property is claimed as contained in the following:

Claims (28)

1. CLAIMS 1. - A method for transmitting data over a communications network, the method is characterized by the steps of: determining a data type for the data; select a transcoding technique and an error control scheme to format the data based on the types of data; encode the data using the selected transcoding technique; and apply the error control scheme select to the data.
2. 2. - The method according to claim 1, characterized in that the additional step of: multiplying the data for transmission over the communications network.
3. 3. The method according to claim 2, characterized in that the step of multiplying includes adding a data type indicator to the data.
4. 4. - The method according to claim 1, characterized in that the select error control scheme adds error control information to the data.
5. 5. - The method according to claim 1, characterized in that the data type is determined using an extension of the file associated with the data.
6. 6. - The method according to claim 1, characterized in that the type of data is determined using a type of pre-defined data.
7. 7. - The method according to claim 1, characterized in that the transcoding technique and error control schemes are also chosen based on the nature of the communication network.
8. 8. - The method according to claim 1, characterized in that the transcoding technique and error control schemes are also chosen based on user preferences.
9. 9. - The method according to claim 1, characterized in that the transcoding techniques and error control schemes are chosen using information that specifies a set of transcoding techniques and error control schemes for each type of data.
10. 10. - The method according to claim 1, characterized in that the transcoding technique and error control schemes are chosen using information that specifies a set of transcoding techniques and error control schemes for each user.
11. 11. - The method according to claim 1, characterized in that the transcoding techniques and error control schemes are chosen using information that specifies a set of transcoding techniques and error control schemes for a wireless connection between an access server and an user.
12. 12. - The method according to claim 1, characterized in that the transcoding techniques and error control schemes are chosen using pre-defined transcoding techniques and error control schemes.
13. 13. - The method according to claim 1, characterized in that a transcoding technique using a pkzip coding algorithm is chosen for text data types.
14. 14. - The method according to claim 1, characterized in that a transcoding technique using an ACELP coding algorithm is chosen for speech data types.
15. 15. - The method according to claim 1, characterized in that a transcoding technique using a VSELP coding algorithm is chosen for speech data types.
16. 16. - The method according to claim 1, characterized in that a transcoding technique using an EVRC coding algorithm is chosen for speech data types.
17. 17. - The method according to claim 1, characterized in that an error control scheme using a hybrid ARQ error control scheme is chosen for speech data types.
18. 18. The method according to claim 1, characterized in that an error control scheme using a hybrid ARQ error control scheme is chosen for video data types.
19. 19. - The method according to claim 1, characterized in that an error control scheme using an ARQ error control scheme is chosen for speech data types.
20. 20. The method according to claim 1, characterized in that an error control scheme using an ARQ error control scheme is chosen for video data types.
21. 21. The method according to claim 1, characterized in that an error control scheme that uses a mute technique is chosen for speech data types.
22. 22. - The method according to claim 1, characterized in that an error control scheme that uses interpolation techniques based on previous and successive good frames is chosen for speech data types.
23. 23. - The method according to claim 1, characterized in that an error control scheme that uses extrapolation techniques based on previous good frames is chosen for speech data types.
24. 24. - The method according to claim 1, characterized in that an error control scheme that uses interpolation techniques based on previous and successive good frames, is chosen for video data types.
25. 25. The method according to claim 1, characterized in that an error control scheme that uses extrapolation techniques based on previous good frames, is chosen for video data types.
26. 26. The method according to claim 1, characterized in that an error control scheme using ARQ technique is chosen for text data types. «» 27
27. 27.- A method for transmitting data over a communications network, the method is characterized by the steps of: selecting a transcoding technique and an error control scheme to format the data based on whether the communication network includes a wireless communication system, - encoding the data using the transcoding technique if the communication network is a wireless communication system; and apply the error control scheme select to the data if the communications network is a wireless communication system.
28. 28.- A method for transmitting data over a communications network, the method is characterized by the steps of: selecting a transcoding technique and an error control scheme to format the data based on user preferences; encode the data using the selected transcoding technique; and apply the error control scheme select to the data.