MXPA00000258A - Enhanced interworking function for interfacing digital cellular voice and fax protocols and internet protocols - Google Patents

Abstract

An enhanced interworking function (E-IWF) (14) supports a method of direct digital interworking between a radio telecommunications network (15-18) and standard Internet Protocol (IP) routers (12-13). A general purpose interworking function performs speech transcoding and data interworking. A specific translation interworking function translates directly between mobile-specific voice incoding (24) and Voice-over-IP protocols (23), and between mobile-specific fax encoding (62) and Fax-on-IP protocols (71). The method provides interworking between cellular protocols in a time division multiple access (TDMA) cellular telecommunications network, and Internet protocols being utilized by an Internet End-System (ES) (31) or fax gateway (49).

Description

"ENHANCED INTERLACEMENT FUNCTION TO INTERCONTINUE DIGITAL CELLULAR VOICE AND FAX PROTOCOLS AND PROTOCOLS OF INTERNET" BACKGROUND OF THE INVENTION TECHNICAL FIELD OF THE INVENTION This invention relates to radio telecommunication systems and, more particularly, to a system and method for interconnecting digital mobile radio and fax protocols with Internet Protocols.

DESCRIPTION OF THE RELATED TECHNIQUE Recently, Internet telephone products and services (based on Internet Protocol (IP)) have been introduced that promise improved speech quality and connectivity with other Internet subscribers and with regular (non-IP) telephone subscribers. With increases in Internet bandwidth and the deployment of enhanced IP-based real-time protocols (RTP) and reservation protocols (RSVP), the Internet is balanced to eventually offer the type of speech quality of subscribers to the Internet. Normal landline have come to wait. These developments are not limited to the public Internet, but apply to private Internet and Local Area Networks (LANs) as well. The Internet already offers diffusion and multiple broadcasting capabilities (through MBONE routers) that have the potential to emulate conference call services. Other peculiarities of computer telephony using the Internet are now finding their introduction of commercially available software applications. The existing radio telecommunication systems such as the Global System for Mobile Communications (GSM), Multiple Time Division Access Systems (TDMA) such as the Advanced Digital Mobile Phone System (D-AMPS) (IS-136), Code Division Multiple Access Systems (CDMA) (IS-95), and Personal Communication Services (PCS) systems all use digital speech codes for the transmission of speech information, and all have specified support for a service of digital asynchronous circuit mode data using an Interlace Function (IWF). The standards for these systems are incorporated herein by reference herein. The role of the IWF is to provide a transfer function between the specialized data protocols used by the radio telecommunication systems and the normal terrestrial data protocols. More specifically, the IWF provides transfer functions between digital radio link (RLP) protocols and analogue landline modems, Integrated Services Digital Network (ISDN) terminals, terminal adapters, and packet data networks . The functions executed in the IWF include adaptation of the regime between the transmission regime through the air interface and the transmission regime through the terrestrial lines. Therefore, the IWF executes flow control, error control, sequence control, data damping, encryption, compression, etc. The existing IWF, however, does not perform entanglement functions between the mobile-specific voice coding protocols and the mobile radio side of a connection and the Voice-over-Internet Protocol (Voice over IP) encoding protocols. ) (which is sometimes referred to as Voice-on-Net or VON) on the Internet side of the connection. Also, the existing IWF does not perform interleaving functions between the specific mobile fax coding protocols on the mobile radio side of a connection and Internet Fax-on-Internet Protocol (Fax-on-IP) encoding protocols on the side Internet connection.

Although the teachings of the prior art of a solution for the aforementioned deficiency and inconvenience such as that disclosed herein are not known, several references discuss the subject matter that bears some relation to matters discussed herein. European Patent Application Number EPO 740 445 A2 discloses a method and system for establishing voice communications using a computer network. Nevertheless, this reference discusses communications with the Internet only from landline phone networks. There is no teaching or suggestion of an improved IWF to interconnect mobile terminals directly with the Internet. PCT Patent Application Number WO 96/20553 discloses a unified message and communication system that uses the global Internet to link multiple local landline telephone networks. This reference discusses communications with the Internet only from landline phone networks. There is no teaching or suggestion of an improved IWF to interconnect mobile terminals directly with the Internet. PCT Patent Application Number WO 96/29808 discloses a system and method for simultaneously transmitting voice and data on shared voice telephone lines. The system allows a single computer or a plurality of computers to connect to a central computer network using existing telephone wires that continue to provide normal voice access to the Public Switched Telephone Network (PSTN). This reference discusses communications with the Internet only from landline telephone networks. There is no teaching or suggestion of an improved IWF to interconnect mobile terminals directly with the Internet. PCT Patent Application Number WO 96/34341 discloses a message storage and delivery system that connects to a plurality of direct dial-in (DID) telephone lines and receives facsimile messages, voice messages and data messages. The messages are stored in the memory and become a hyper-text constitution language (HTML) for transmission over the Internet. Users can access the storage and delivery system of messages either through the telephone network or the Internet. However, this reference discusses communications with the Internet only from landline telephone networks. There is no teaching or suggestion of an improved IWF to interconnect mobile terminals directly with the Internet.

The review of each of the aforementioned references reveals that there is no disclosure or suggestion of a system or method such as that described and claimed herein. In order to overcome the disadvantage of existing solutions, it would be advantageous if there were an improved IWF (E-IWF) to perform interleaving functions between specific, mobile voice coding protocols and Voice-over-IP coding protocols as well as to perform interlacing functions between the specific mobile fax coding protocols and Fax-in-IP coding protocols. This E-IWF would provide a means for a mobile station to interconnect voice and fax with the Internet, directly or indirectly, through an E-IWF that may be associated with a mobile switching center (MSC). The present invention provides this improved IWF.

COMPENDIUM OF THE INVENTION In one aspect, the present invention is an improved IWF that supports direct digital linkage between a radio telecommunications network and normal IP networks comprising routers through, for example, an Ethernet interface (CSMA / CD IEEE 802.3) . The present invention supports speech transcoding and data interleaving within an IWF for general purposes and provides specific transfer from specialized air interface coding methods (eg Linear Predictive Vector Sum Excitation vocoders (VSELP), Predictive Linear Excitatory Vocoders of the Adaptive Codebook (ACELP) such as the Full Alternative Regime Code (AFR) standardized in IS-641, Enhanced Full Regime of GSM (GSM-EFR), etc.) directly to the Voice protocols -over-IP. In different modes, this is achieved with or without an intermediate pulse code (PCM) or analog modulation conversion. In another aspect, the present invention is a method for supporting direct digital interleaving between a radio telecommunications network and normal Internet Protocol (IP) routers. The method comprises the steps of performing speech transcoding and data interleaving with an interlacing function for general purposes, and the transfer between specialized air interface coding methods and Voice-over-IP protocols with an interlacing function of specific transfer. In yet another aspect, the present invention is a method for the interweaving between the cellular voice protocols in a time division multiple access cellular telecommunications network (TDMA), and Internet protocols that are used by a Final Internet System. (IS) . The method begins by encoding a voice signal from a mobile station into one of the cellular voice protocols, creating a voice box of the coded voice signal, interleaving in voice box in one or more bursts of TDMA, and transmitting the bursts of TDMA through a radio link to a base station. The voice box is multiplexed at the base station and transmitted to the E-IWF. This is followed by transcoding the speech frame in a first code to an isochronous stream of digitized speech samples, transcoding the stream of digitized speech samples into a second code in a Voice-over-IP service data unit (SDU). ), and framing the SDU with a transport layer protocol. The step of transcoding the speech frame in a first code to an isochronous stream of digitized speech samples such as PCM or adaptive differential pulse code modulation (ADPCM). The framed SDU is then carried by a data link layer network interface and a physical layer transmission medium. The method is then interconnected with an Internet Service Provider (ISP).

In still another aspect, the present invention is a method for the interconnection between the cellular fax protocols and Internet protocols, the cellular fax protocols being used by a mobile station in a time division multiple access cellular telecommunications network ( TDMA) to transmit an image to a fax machine at the remote end via the Internet, and the Internet protocols are used for a fax access. The method begins by originating a mobile fax call, establishing a Radio Link Protocol (RLP) to communicate between the mobile station and the cellular telecommunications network, and by scanning, coding and compressing the image into a stream of fax data.

This is followed by sending a sequence of digitized call set-up signals between an enhanced interleaving function (E-IWF) in a cellular telecommunications network and the far end fax machine, preparing a format of the fax data stream in the tables of the User's Data Protocol (UDP) and separating the tables in Internet Protocol (IP) datagrams, and transmitting the UDP / IP datagrams through the Internet to the fax access. The method then executes the steps of converting, in the fax access, the UDP / IP datagrams into fax modem voice band information, by sending the fax modem voice band information to the fax machine in the remote end and recreating the image on the far-end fax machine.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be better understood and its numerous objects and advantages will become more apparent to those skilled in the art by reference to the following drawing, together with the accompanying specification, in which: Figure 1 is a simplified functional diagram of a connection of a mobile terminal with a terminal on the Internet using voice protocols and the enhanced interleaving function (E-IWF) of the present invention; Figure 2 is a communications protocol stack illustrating the communications protocols used, and the protocol transfers executed while making the connection of Figure 1 for a mobile terminal operating in a TDMA radio telecommunication system; Figure 3 is a process diagram illustrating the steps of the method of the present invention when entanglement is carried out between cellular voice protocols and Internet protocols; Figure 4 is a communications protocol stack illustrating a connection between the E-IWF of the present invention and an Internet End System when using Internet transport protocols that provide improved real-time transport of time-sensitive information; Figure 5 is a simplified functional diagram of a connection of a terminal of the mobile computer via the Internet to a fax terminal in the PSTN using fax protocols and the enhanced interleaving function (E-IWF) of the present invention; Figure 6 is a flow chart illustrating the steps of two alternative methods of interlacing fax protocols with the Fax-in-IP protocols used over the Internet; Figure 7 is a communications protocol stack illustrating a connection of a terminal of the mobile computer / fax machine with a fax machine via fax protocols using the Internet and the E-IWF of the present invention; and Figure 8 is a flow chart of the steps used to support a mobile IP-Fax-in-call.

DETAILED DESCRIPTION OF THE MODALITIES The preferred embodiment is described herein in terms of an implementation in a TDMA IS-136 radio telecommunications network such as the Advanced Digital Mobile Phone System (D-AMPS). However, the enhanced entanglement function (E-IWF) of the present invention is also applicable to other cellular and personal communication service (PCS) systems such as for example GSM, CDMA, Digital Pacific Cellular (PDC), Manageable System Personal (PHS), Digital Enhanced Cordless Exempt (DECT) telephony, third generation wide band systems and several satellite systems such as Globalstar, Iridium, etc. In addition, the functions performed by the present invention not only connect to the Internet, but also support the intertwining with intra-networks of the corporation. Figure 1 is a simplified functional diagram of a connection of a mobile terminal 11 with a terminal (host or end system) 12 on the Internet 13 using the E-IWF 14 of the present invention. The E-IWF 14 allows a mobile subscriber to make an IS-136 (digital) voice call to another Internet subscriber or to a landline terminal through an IP-based network (e.g., the Internet) without having to go through the PSTN and an extra analog conversion. The connection involves the entanglement between two different voice codes and the protocol layers below the voice layer. In Figure 1, a mobile station (MS) 15 communicates through radio frequency transmissions 16 with a radio base station (RBS) 17. The data is encoded and transmitted in the radio frequency transmissions 16 in accordance with the different air interface standards. The RBS 17 is connected to a mobile switching center (MSC) 18 via cables, microwave links or other suitable means known in the art. The MSC is associated with the E-IWF 14 which provides the necessary entanglement to move from the specialized air interface coding methods directly to the Voice-over-IP encoding used for data transmissions over the Internet 13. Still when Figure 1 shows the EI F 14 implemented with the MSC 18, it can also be implemented as a node alone or connected to the RBS 17. Figure 2 is a communications protocol stack illustrating the telecommunications protocols used, and the transfers protocols executed while the connection of Figure 1 is made to a mobile terminal operating in a TDMA radio telecommunication system. Several protocol stacks, which are loosely related to layers 1-7 of Open Systems Interconnection (OSI) are shown for MS-15, E-IWF 14 and Internet 13. Within MS 15, tables 21 of Air interface voices are prepared in format according to layer 22 of IS-136 which relates to the lower layers of OSI (i.e., the physical layer and part of the link layer). The voice frames are formed by a mobile digital voice code using techniques such as for example Adaptive Codebook Excitation Linear Predictive (ACELP) or other digital voice codes. In Figure 2, the voice boxes are shown as Alternate Complete System (AFR) tables. The AFR code is an ACELP code used in the IS-136 TDMA systems as an alternative to the Vector Summation Excitation Line Predictive (VSELP). The voice frames 21 are transmitted via the radio link to the RBS 17 and then to the MSC 18 without changing the protocol stack. The E-IWF 14 includes certain functionality of the Radio Base Station (RBS) and can be partially implemented in the RBS 17. In the E-IWF 14, the voice frames 21 are prepared directly to a Voice-over protocol 23 - corresponding IP, a layer 24 of the User's Data Protocol (UDP) and an Internet Protocol (IP) layer 25. The UDP layer 24 and the IP layer 25 are loosely related to the OSI layers 4 and 3, respectively. If the direct preparation of the voice frames 21 in the Voice-over-IP protocol 23 may not be possible due to the complexity of the transfer, then alternatively an intermediate PCM or ADPCM conversion can be used. This is discussed in more detail below. The E-IWF 14 then moves the layer 22 of IS-136 to the lower layers 26 that are related to the OSI layers 1-2. The formats in each level are determined from the industry standards for the respective protocols that constitute that level. For example, the AFR Voice protocol is specified in IS-641, and the VSELP protocol is specified in IS-54 and IS-136. Currently, Voice-over-IP is typically a speech coding algorithm even though some coding techniques are based on the G.728 standard (e.g. MICOM). There are two or three commonly used algorithms and the E-IWF 14 is moved between the mobile digital voice boxes such as the AFR 21 voice and these commonly used logarithms. The UDP and IP protocols are like the AFR Voice, also specified in the industry standards. While the IS-136 protocols are shown, AFR and UDP, these are only exemplary and other similar protocols can be used. In addition, the terrestrial multiple media standards related to the present invention include H.323, H.324 and T.120. These standards describe the control and discipline of multi-media conferences, but can apply to voice calls over the Internet. These standards, together with IS-54, IS-641 and G.728 are incorporated herein by reference. There are several alternative methods to move between the AFR Voice and the three commonly used Voice-over-IP algorithms. The simplest method is to use an intermediate PCM conversion so that there are conversions from AFR to PCM and from PCM to Voice-over-IP within the E-IWF 14. Another method is to use voice coding preparation directly between the algorithm Voice AFR voice coding and voice-over-IP voice coding algorithm. This works well when the two codes are derived from the same code family. Another method is for the E-IWF 14 to retain the contents of the Voice AFR box and place it on top of the UDP and IP 24 and 25 layers. A code identical to that used to encode the Voice AFR box it is then used to decode on the Internet side of the connection. In this method there is no transfer of the required voice frames; the pictures are taken in a transparent way. The entanglement occurs mainly in the layers below.

Table 1 below provides examples of protocols in each OSI layer, including Internet Protocol (IP) and other associated protocols.

Table 1 Request Transfer Emulation of Electronic Terminal File Presentation Protocol of Transfer Protocol Transfer Telnet File Session (FTP) of Simple Mail (SMTP) Transport Protocol of Transmission Data Protocol Control (TCP) User (UDP) Network Internet Protocol Resolution Protocol (IP) Internet Control Address Message (ARP) (ICMP) Network Interface Card Link CSMA / CD Data (Ethernet), garment ring, Frame Relay, Fiber Distributed Data Interface (FDDI), ATM Physical Transmission Media Wire pair, fiber optics, coaxial cable, radio Figure 3 is a flow chart illustrating the steps of the method of the present invention when there is an entanglement between cellular voice protocols and Internet protocols. The method is illustrated for transmissions from mobile station 15 to Internet 13, but also works for transmissions for another direction. In step (a), the mobile station 15 encodes the user's voice according to an industry standard. In this example, IS-641 (AFR) is used. A voice box of 20 milliseconds is created and interspersed with other frames in two bursts of TDMA according to IS-136. The TDMA bursts are transmitted over radio link 16 to the RBS 17. The radio link is terminated in the RBS, and the voice box is multiplexed and transported through the MSC 18 to the E-IWF 14. This transport can be carried out using proprietary methods or one of several known transport technologies of physical RBS-to-MSC / link, t such as frame relay or Asynchronous Transfer Mode (ATM) in Tl. In step (b), the E-IWF 14 receives the voice AFR frames and supports the frames in a first code that transcodes the frames according to the speech coding algorithm specified in IS-641. At this point, the output of the transcoding function is PCM or Adaptive Differential PCM Voice (ADPCM) characterized by a current of 64 to 32 kbps isochronous digitized speech samples. In step (c), the PCM or ADPCM stream is admitted to a second voice code in the E-IWF that transcodes the stream to the Voice-over-IP format 23 using a commonly used speech coding algorithm found in products such as Vocaltec, MICOM V / IP (and other products based on the G.728 standard), Netspeak Webphone, and NetPhone NETphone products. The output of the second code is a service data unit (SDU) which is a block of data to be handled by a lower layer. In step (d), the SDU is framed using, for example, a transport layer of UDP or Transmission Control Protocol (TCP) in accordance with the Internet Task Force (IETF) RFC standards, which are incorporated in the present by reference. UDP is preferred since TCP retransmits received errors, which is undesirable for real-time speech. The transport level box is separated into IPv4 or IPv6 datagrams also in accordance with the IETF RFC standards. The IP datagram stream is then carried by one of a plurality of lower layer protocols, such as, for example, CSMA / CD (Ethernet), Frame Relay, Garment Ring, Distributed Fiber Data Interface (FDDI) or ATM , etc) . The E-I F 14 is then interconnected in the network layer (and lower layers) with an Internet Service Provider (ISP). The ISP access network provides widespread access to the Internet database and also supports the construction of tunnels indirectly with the intra-networks of the corporation. The ISP network may comprise a plurality of Network Access Servers (ÑAS) and routers that provide routing of IP datagrams, authentication and firewall functions. Also, if cellular / PCS operators wish to integrate the ISP access network functionality completely within a cellular network, the E-IWF of the present invention can directly support routing, authentication and firewall functions. Most Internet codes are variable rate codes. However, some cellular voice codes such as ACELP and VSELP are constant rate codes. Therefore, the E-IWF 14 must handle the speech spaces from the Internet 13 and detect silently from the mobile station 15. In the present invention, the same speech coding algorithm can be used on both the cellular terminal / PCS side of the connection and on the side of the Internet Final System (ES). In this case, the E-IWF deinterleaves the speech frames and sends the frames through the appropriate transport layer (e.g. UDP), IP and the appropriate physical / link layers for interleaving with the Internet. In this way, the E-IWF 14 must handle the latent variability inherent in the Internet. This is especially critical when constant rate codes are used. In one embodiment, the E-IWF 14 maintains a small IWF buffer and generates comfortable, confident noise speech frames that are transmitted to the mobile station when speech frames are not available in the buffer or when they have not been received speech boxes within the next interval of the mobile speech box (every 20 milliseconds for full-regime voice in IS-136). The E-IWF 14 also detects frames of the silent period from the mobile station. This can be achieved by generating in the mobile station, a voice activity field that is added to each user's TDMA frame. Alternatively, the E-IWF can analyze the frames received from the mobile station for certain amplitude and speech activity related to the code parameters. The E-IWF can also have comprehensive support for its echo pressure or echo cancellation, speech activity detection and comfortable noise insertion. Figure 4 is a communications protocol stack illustrating a connection between the E-IWF 14 of the present invention and the Internet End System 31 when using Internet transport protocols that provide enhanced real-time transport of information sensitive to the weather. A Real Transport Protocol (RTP) 32 is a real-time protocol that is currently being standardized. The RTP protocol operates independently of the network infrastructure and provides payload identification, sequence numbering, time stamping, and supply supervision. In this way, the RTP protocol 32 makes a direct connection between the E-IWF 14 and the Internet ES 31 in the session and presentation layers of the OSI protocol stack. A Reservation Protocol (RSVP) 33 is also being standardized at present. The RSVP protocol can partially take the place of UDP or TCP protocols. When a guest such as E-IWF 14 or Internet ES 31 requests a specific Quality of Service (QoS) from the network, the QoS request is made to all routers 34 that remain in a specific ES-to-ES path. The RSVP protocol allows the network to adapt nicely to certain network conditions.

The present invention also supports the entanglement between the mobile specific fax coding protocols on the mobile radio side of a connection and Internet Fax-on-Internet Protocol (Fax-on-IP) coding protocols on the Internet side of the connection. In existing TDMA systems, instead of sustaining fax modulation tones (eg V.29) directly through the air interface voice codes, such as ACELP (which would be subject to serious degradation), the TDMA support fax applications using a specialized radio link protocol (RLP1) that connects the mobile terminal (MT2) and the Function of Interlacing (IWF) associated with MSC. The radio link protocol is defined in IS-130 with the support AT data piece fax commands defined in IS-135. These standards are incorporated herein by reference herein. The normal mobile fax calls, the IWF feeds, the fax information carried in the RLP boxes to an integrated fax modem that communicates with another fax machine connected to the PSTN / ISDN. On the Internet side of the connection, there are a number of fax IP access products in the market that connect the Internet with PSTN or PBX networks to allow a normal fax machine to use the Fax-in-POTS (Simple Old Telephone Service) to use the public Internet or a private intranet to transmit the fax information to another fax machine or application. The present invention encompasses the space between these fax IP access products and the RLP protocol specified in IS-130 and in IS-135 for Fax-in-TDMA. Figure 5 is a simplified functional diagram of a connection of a terminal 41 of the mobile computer over the Internet 42 to a fax terminal 43 in the PSTN 44 using fax protocols and the enhanced interleaving function (E-IWF) 14 of the present invention. The mobile terminal 41 is connected to a mobile station (MS) 45. The MS 45 communicates through the radio frequency transmissions 46 with a radio-based station (RBS) 47. The data is encoded and transmitted in the transmissions 46 of radio frequency in accordance with the different air interface standards. The RBS 47 is connected to a mobile switching center (MSC) 48 through cables, microwave links or other suitable means known in the art. The MSC is associated with the E-IWF 14 which provides the necessary entanglement to move from the specialized air interface coding methods directly to the Fax-in-IP coding used for data transmissions over the Internet 42. An access 49 IP fax allows a normal fax machine to use the public Internet or a private intranet to transmit the fax information to another fax machine or application. Figure 6 is a flow chart illustrating the steps of two alternative methods for interweaving mobile fax protocols to Fax-on-IP protocols used over the Internet. The first method digitizes and encodes the fax information through a voiceband encoder, and frames the fax information in UDP frames in IP. The first method treats the output signal of the fax machine as another voiceband signal and digitizes and encodes the signal using a code which for example can be a G.729 code. The benefits of this approach is that the existing network and the infrastructure of the fax machine can be reused. The second method digitally derives the face information before the modulation and directly frames it in the IP UDP frames without having to go through an intermediate analog step. The second method is more robust from a transmission point of view, but requires that the fax signal be derived digitally before modulation. Both methods start when the image of a document 51 is scanned at 52 and coded at 53. Note that both methods can read and process an economized normal image file (e.g., TIFF, PCX, TCX) instead of scanning an image in real time. Method 1 then proceeds to step 54 where the fax signal is modulated. At 55, the modulated signal is digitized and encoded as a speech band signal. At 56, the encoded speech band signal is framed in UDP frames in IP. Method 2 goes directly from step 53 to step 57 where the encoded image is digitally derived and falls squarely in the IP UDP frames. Both methods then send the IP datagrams through the Internet to the destination. The E-IWF 14 of the present invention then provides an additional IWF functionality for interleaving the specialized RLP (eg, Fax-in-TDMA) with the output of any of the Fax-in-IP methods of Figure 6. This allows a mobile user to initiate a fax call to another fax machine or an application using the Internet or a private intranet. The three benefits of this approach are: - reduced long distance fax transmission costs; shorter transmission and connection times (especially using private intranet links of higher bandwidth); and - potentially better transmission image quality.

Figure 7 is a communications protocol stack illustrating a connection of a terminal of the mobile computer / fax machine with a fax machine via the Internet using fax protocols and the E-IWF of the present invention. The fwing definitions apply to Figure 7: PC-Fax This standard (EIA-592) specifies the protocols for use between the terminal (DTE) and the fax modem (DCE). The terminal can control and configure the DCE. In the mobile scenario the DCE is largely included in the IWF. T.30 This protocol defines the procedures necessary for the transmission of documents between two fax stations in the PSTN. It supports the establishment of the call, release, compatibility check and supervision of line conditions. T.4 / T.6 These protocols specify the image compression method and the resulting data format. Several different encoding / compression formats are specified. V.x These are fax modulation standards that specify the physical layer modulation constellation (based, e.g., QAM), which generates a resulting speech band signal.

These standards and protocols are incorporated herein by reference. Figure 7 shows a Mobile Station / Terminal 61 with fax capability. The MS / Terminal 61 uses a protocol stack comprising PC-Fax (EIA-592) 62, a layer 63 of IS 130/135, and a layer 64 of IS-136. The MS / Terminal communicates through a radio link 65 with a Radio Base Station (RBS) which, for reasons of simplicity, is shown combined with an MSC and the E-IWF 14 of the present invention as a single entity 66. This link 65 uses the PC-Fax protocol in TDMA (EIA-592) and IS-136 and IS-130. The E-IWF processes the output of the layers 63 of IS-130/135 according to the methods of Figure 6 and places the output in the UDP frames 67 carried by the IP datagrams in the IP layer 68. UDP frames in IP are sent over the Internet to Fax-in-IP Access 71. The Fax-in-IP Access 71 allows a normal fax machine 72 to use the public Internet or private intranet to transmit the fax information to another fax machine or application. Access 71 can be connected to the fax machine 72 through, for example, PSTN using Fax-in-POTS protocols, through a PBX network, or directly through a cable. Figure 8 is a flow chart of the steps used to support a mobile Fax-in-IP call.

Referring to Figures 6, 7 and 8, the normal mobile fax call is initiated in accordance with IS-135 in step 81. This may include the PC terminal sending the mobile terminal (MT2) 61 a command that specifies a fax service that triggers a call originating in step 82 and subsequently the installation of the radio link protocol (RLP1 described in IS-130) to 83. Together, the MT2 61 scans, encodes and compresses the image (if is required) according to either T.4 or T.6 in steps 84. The source image may already be binary, or the PC terminal may already execute the scanning and encoding functions. In step 85, the E-IWF initiates the call setup sequence T.30 with the far end fax machine 72. The sequence includes sending the GNG tone, the flags and a facility setup message. These T.30 tones and commands / responses are sent as voiceband tones modulated by a lower layer modem. At 86, the E-IWF modulates the RLP radio side output and T.30 signals using one of the normal fax modems (e.g., V.17, V.29). The result is a speech band signal (e.g., QAM). At 87, the E-IWF re-encodes the voiceband fax modem signal using any normal Voice-over-IP code (e.g., G.729 used by Micron). The additional silence detection logic can also be used. The frames of the voice coder resulting from frames using UDP and then separated into IP datagrams in step 88 for transmission on the Internet. In step 89, before, or once the initial handshake of step 85 is completed, the E-IWF transmits the original T.4 / T.6 coded information according to the method in step 88. At the far end of Fax transmission, Fax-in-IP access 71 receives the IP datagrams at 90 and converts them back into the original fax modem voiceband information. At 91, the voicemail information of the fax modem can be distributed directly to an existing G3Fax machine (off the shelf) to recreate the image of the document. In addition, a special-purpose fax application or device can be interwoven directly in the Fax-in-IP transmission, essentially covering the fax access functionality. The method steps related to method 2 in Figure 6 do not require steps 86 and 87. Method 2 simply retains the digital coding and transmits transparently to the other side carried over UDP / IP. The special fax call / reply tones (GNG, CED), however, are replaced by new digital messages equivalent to analog set tones. Therefore, it is believed that the operation and construction of the present invention will become apparent from the foregoing description. Even though the method, apparatus and system shown and described have been characterized as being preferred, it will be readily apparent that various changes and modifications could be made therein without deviating from the spirit and scope of the invention, such as it is defined in the following claims.

Claims (21)

R E I V I N D I C A C I O N S

1. An improved interlacing function (E-IWF) that supports direct digital entanglement between a radio telecommunications network and the normal Internet Protocol (IP) routers, the E-IWF comprises: a general-purpose entanglement function that performs speech transcoding and data interleaving; and a specific transfer entanglement function that moves between specialized air interface voice coding methods and Voice-over-IP protocols.

2. The enhanced entanglement function of claim 1, wherein the specific transfer interleaving function is transferred to and from specialized air interface voice coding methods, which are selected from the group consisting of: Linear Predictive Vocoders Vector Sum Excitement (VSELP); Linear Predictive Codebook Exciting Vocoders (CELP); CELP Adaptive Vocoders (ACELP); and Vocoders of the Global System for Mobile Communications - Complete Improved Regime (GSM-EFR).

3. The enhanced interleaving function of claim 1, wherein the specific transfer interleaving function translates to and from the Voice-over-IP protocols used in products that are selected from the group consisting of: Vocaltec; MICOM'S V / IP; products based on G.728; and Netspeak Webphone.

The improved interleaving function of claim 1, wherein the specific transfer interleaving function shifts between specialized air interface voice coding methods and impulse code modulated voice and pulse modulated pulse speech and voice-over-IP protocols.

5. An enhanced entanglement function (E-IWF) that supports direct digital entanglement between a network of radio telecommunication networks and standard Internet Protocol (IP) routers, the E-IWF comprises: an interlacing function for general purposes that executes speech transcoding and data interleaving; and a specific transfer intertwining function that moves directly between Predictive Linear Adaptive Code Book Excitation speech (ACELP) and Voice-over-IP protocols.

6. A method to support direct digital entanglement between a radio telecommunications network and normal Internet Protocol (IP) routers, the method comprises the steps of: executing speech transcoding and data interleaving with an interlacing function for general purposes; and transfer between the air interface voice coding methods specialized the protocols of Voice-over-IP with a specific transfer intertwining function.

7. The method for supporting direct digital interleaving of claim 6, wherein the transfer step between the specialized air interface voice coding methods and the Voice-over-IP protocols includes moving to and from the methods of Specialized air interface voice coding selected from the group consisting of: Linear Predictive Vocators of Vector Sum Excitation (VSELP); Linear Predictive Codebook Exciting Vocoders (CELP); CELP Adaptive Vocoders (ACELP); and Vocofificadores of the Global System for Mobile Communications-Fully Improved Regime (GSM-EFR).

8. The method for supporting direct digital interleaving of claim 6, wherein the transfer step between the specialized air interface voice coding methods and the Voice-over-IP protocols includes moving to and from the protocols of Voice-over-IP used in products that are selected from the group consisting of: Vocaltec; MICOM's V / IP; products based on G.728; and Netspeak Webp one.

The method for supporting the direct digital interleaving of claim 6, wherein the steps of operation and movement are carried out in an enhanced interleaving function (E-IWF), and the method further comprises the step of directly connecting the E-IWF with the Internet Final System (ES) using a real-time protocol (RTP).

10. A method to interweave between cellular voice protocols and Internet protocols, cellular voice protocols being used by a mobile station in a time division multiple access cellular telecommunications network (TDMA) and internet protocols being used by Internet End System (ES), the method comprises the steps of: encoding a voice signal from the mobile station in one of the cellular voice protocols; create a voice box of the encoded voice signal; intersperse the voice box in at least one pop of TDMA; transmit at least one burst of TDMA through a radio link to a base station; multiplex the voice box in the base station; transmit the multiplexed voice frame to an enhanced interleaving function (E-IWF); transcoding the speech frame in a first code to an isochronous stream of digitized speech samples; transcoding the digitized speech sample stream in a second code to a Voice-over-IP (SDU) service data unit; frame the SDU in frames with a transport layer protocol; segment the tables into Internet Protocol (IP) datagrams; carry the IP datagrams with a data link layer network interface and physical layer transmission media; and interconnect with an Internet Service Provider (ISP).

11. The method of interleaving between the cellular voice protocols and the Internet protocols of claim 10, which further comprises sustaining the cancellation and suppression of the echo.

The method of interweaving between cellular voice protocols and Internet protocols of claim 10, further comprising supporting the detection of voice activity.

13. The method of entanglement between the cellular voice protocols and the Internet protocols of claim 10, further comprising supporting the insertion of comfortable noise.

14. A method for interweaving between cellular voice protocols and Internet protocols, cellular voice protocols being used by a mobile station in a time division multiple access cellular telecommunications network (TDMA) and internet protocols being used by a private intra-network, the method comprising the steps of: encoding a voice signal from the mobile station into one of the cellular voice protocols; create a voice box from the encoded voice signal; intersperse the voice box in at least one pop of TDMA; transmit at least one burst of TDMA through a radio link to a base station; multiplex the voice box in the base station; transmit the multiplexed voice frame to an enhanced interleaving function (E-IWF); transcoding the speech frame in a first code to the isochronous current of the digitized speech samples; transcoding the stream of digitized speech samples in a second code to the Voice-over-IP service data unit (SDU); Frame SDU in frames with a transport layer protocol; segment the tables into Internet Protocol (IP) datagrams; carry the IP datagrams with a data link layer network interface and physical layer transmission media; and interface with the private intra-network.

15. An enhanced entanglement function (E-IWF) that supports direct digital entanglement between a radio telecommunications network and normal internet protocol (IP) routers, the E-IWF comprises: an interlacing function for purposes general that executes speech transcoding and data interleaving; and a specific transfer interleaving function that moves between specialized air interface fax coding methods and fax-in-IP protocols.

16. A method for interweaving between cellular fax protocols and Internet protocols, cellular fax protocols being used by a mobile station in a time division multiple access (TDMA) cellular telecommunications network to transmit an image to a Far-end fax machine via the Internet, Internet protocols being used by a fax access, the method comprises the steps of: originating a mobile fax call; establish a Radio Link Protocol (RLP) for communication between the mobile station and the cellular telecommunication network; explore, encode and compress the image in a stream of fax data; sending a sequence of digitized call setup signals between an enhanced interleaving function (E-IWF) in the cellular telecommunications network and the far-end fax machine; prepare a format of the fax data stream in the User Data Protocol (UDP) tables and segment the tables into Internet Protocol (IP) datagrams; transmit the UDP / IP datograms through the Internet to fax access; converting UDP / IP datagrams into fax modem voiceband information into fax access; send the fax modem voice band information to the far end fax machine; and re-create the image on the far-end fax machine.

17. The method of interleaving between the cellular fax protocols and the internet protocols of claim 16, which further comprises, after the step of scanning, encoding and compressing the image into a fax data stream, the steps of: sending a sequence of call set-up signals between an enhanced interleaving function (E-IWF) in the cellular telecommunications network and the far-end fax machine, the signals being sent as voiceband tones modulated by a modem; modulating the information carried by RLP from the mobile station with a fax modem to form a voice band fax modem signal; and re-encoding the voiceband fax modem signal using a Voice-over-IP code.

18. A system for training a mobile fax terminal in a radio telecommunications network to communicate with a second fax machine through Internet, the system comprises: an enhanced entanglement function (E-IWF), the E-IWF comprises: a general purpose entanglement function that executes speech transcoding and data interleaving; and a specific transfer interleaving function that moves between the specialized air interface fax coding methods and the Fax-in-IP protocols; and a Fax-in-IP Access connected with the E-IWF, the Fax-in-IP Access allowing the second fax machine to communicate with other fax machines over the Internet. The system of claim 18, wherein the specific transfer interleaving function that it moves between the specialized air interface fax coding methods and the Fax-in-IP protocols includes a means to process the data of the IS-130/135 layers towards User Data Protocol (UDP) tables carried by the IP datagrams. The system of claim 18, wherein the Fax-in-IP Access connects to the second fax machine through a Public Switched Telephone Network (PSTN) using Fax-in-POTS protocols (service of Simple Old Telephone). The system of claim 18, wherein the Fax-in-IP Access connects to the second fax machine through a Private Branch Exchange (PBX) network.