MXPA98001338A - Set of fttc interface circuits as an unit of fis layer - Google Patents

Abstract

In a communications network of Azincrona Transfer Mode (ATM) (159) operating through a shared communications medium, a method of address and access control is required between a central receiver-transmitter (120) and multiple transmitters and receivers (130). A device identifier is placed in the Generic Flow Control (GFC) field (400) of the ATM cells (320) to indicate that the cells (320) are designated for a particular transmitter-receiver or for particular transmitters and receivers in the residence. In the reverse direction, the transceivers (130) in the residence use the GFC field to indicate that they are trying to subscribe to the network. The bits of the GFC return to zero before passing the ATM cells to the processing layer A

Description

CONJECT OF INTERFACE CIRCUITS FTTC AS AN ENTITY OF PHYSICAL LAYER Inventors Kenneth M. Buckland, 7466 Mercedes Way, Rhonert Park, California Thomas R. Ea is, 5206 Pressley Road, Santa Rosa, California Lac X. Trinh, 1255 Marlene Court, Rohnert park, California Steven D. Armick, 4471 Mount Taylor Road, Santa Rosa, California Cross-references This application claims the benefit of United States Provisional Application No. 60/003, 464 filed September 8, 1995, entitled "FTTC Interface Circuit Assembly as a Physical Capability Entity" of which the inventors are, , Kenneth M.Buckland, Thomas R. Eames, Lac X. Trinh and Steven D. War ick, with an attorney's file number NP2007.

Field of the Invention The field of the invention is telecommunications, and more specifically, the use of Asynchronous Transfer Mode (ATM) technology to transport cell-based information by a physical means (layer) in which a single panto of the network connect to multiple devices in a multiple point-to-point configuration.

Background of the Invention In ATM distribution systems, the physical layer is defined as a functional group composed of hard disk (hardware) communication means, soft disk (software) and transmission that converts an ATM cell stream into bits that are to be transported by means of transmission communication and supports the transmission and reception of these bits. Examples of the transmission medium are fiber optic, coaxial cable, free space and twisted copper pairs. Once the information is transported through the physical layer, it is presented to the next layer, the layer of the Asynchronous Transmission Modality.

(ATM). At the output of the device, the information can be presented through a number of interfaces, one of which is the Universal Test & PHY Operations Interface for ATM (UTOPIA) as described by the ATM Foru.

Simultaneously with the development of ATM technology, there have been advances in Fiber of Restriction (FTTC) technology in which devices connect to simple points in the network called Broadband Network Units (BNUs) that in turn they are connected to the subscriber's residence through a coaxial cable and to the devices in the residence through a passive separator and an internal coaxial wiring. In these FTTC networks, the signals can be sent to the residence through a simple coaxial cable that connects the residence to the NBU, but the passive network in the house results in information that reaches multiple devices; everyone must have the ability to determine what signals are for that particular device. Similarly, when the devices transmit from the residence to the NBU, the NBU must have a mechanism to determine from which device the information was transmitted.

When the ATM transmission techniques are used, the information is in the form of cells containing an address that is known as the Virtual Path Identifier (VPI) and the Virtual Channel Identifier (VCI). The field of the VPI and the VCI can be read to determine the destination of a particular cell, but when a multiple point-to-point network that does not contain switching or route capacity is part of the cells of the physical layer destined for a particular device It will reach multiple devices. Having the receiving devices read all the cells to determine which cells are actually intended for that device from their VPI / VCI values results in an inefficient means of cell discrimination and will require an additional cell processing capacity in each device. An additional problem arises when in the reverse direction over the multiple point-to-point network the devices will transmit cells to a single receiving point and that the receiving point will not be able to determine from which source device the cells were transmitted, without the inspection of the values VE'I / VCI.

One of the goals of the present invention is to provide one or more modalities that allow the transport of ATM cells to a multiple point-to-point network, or those found in the FTTC.

Another goal of the present invention is to provide one or more modalities that result in a physical layer in which transmitters and receivers can be implemented in monolithic integrated circuits at low cost that provide cell discrimination, so that the physical layer supports the cells that are transmitted to a multiple point-to-point network without the revision of the VPI / VCI field within the cells.

Compendium of the Invention In an ATM distribution system in which the cells are received from an ATM network at a single network point with directed information contained within the VPI / VCI field of the cell; The bits within a specific field within the cell called the Generic Flow Control (GFC) field are set to correspond to the target device for that particular cell. Cells can be transmitted to the other side of the multiple point-to-point network, such as the coaxial network that exists in an FTTC system, where multiple devices within a residence receive all the information transmitted to that residence. In the devices in the residence the GFCV field is used to determine which cells are destined for that device, without having to check the VPI / VCI fields inside the cells. The GFC bits are reset to zero before the cells pass from the device to the terminal user, and thus the details of the physical layer do not pass to the ATM layer.

For cells transmitted in the reverse direction, from the devices to a single point in the network by the multi-point coaxial network, the GFC bits are encoded with the information corresponding to the device number of the originating device. When received at the single point of the network, the originating device can be determined by checking the GFC bits. This information is useful in the verification of traffic from the devices and determining which devices should have permission to transmit over the coaxial network. As for the tracking direction, the GFC bits can be reset to zero when the information passes back to the ATM layer, so that the details of the physical layer are hidden from that layer (ATM).

Brief Description of the Drawings Figure 1 shows a network of a Restriction Fiber with a multiple point-to-point coaxial network connecting the Broadband Network Unit (NBU) with devices in the residence.

Figure 2 shows an FTTC network connected to the ATM network with devices at the end of the FTTC network.

Figure 3 shows an ATM cell and the fields within the cell.

Figure 4 illustrates a table of GFC field designations.

Figure 5 shows a hybrid fiber coaxial network with a multiple point-to-point coaxial network connecting a Coaxial Termination Unit (CTU) with devices in the residence.

Description of the Modality or Preferred Modalities Figure 1 illustrates a Fiber of Restriction (FTTC) network that sends telecommunications services to a residence (250). The services are provided in the FTTC network shown in Figure 1 through a Broadband Digital Terminal (100) that is connected to a Broadband Network Unit (110) through an optical fiber (200) . The connection to the residence (250) is made with a physical layer receiver BNU (120) that is connected by means of a coaxial tension wire (210) with a separator (220) that is connected to one or more devices (140) through an inner coaxial cable (230) Each device contains a physical layer device receiver (130). The relevant interfaces of this network are illustrated in Figure 1 and are the interface UNI (300) on the coaxial cable and the interface UTOPIA (310) on the output of the device. The Inferid from the User Network (UNI) is a specification that covers the parameters of the interface from the physical layer to the ATM layer.

Figure 2 illustrates an FTTC network and is identical to the one shown in Figure 1 with the additional representation of the status of the ATM cells (320) the ATM pre-learning cells (380) and the Generic Flow Control fields (499) ) inside the cells as the cells pass through the network. The cells enter the FTTC system in Figure 2 from an external ATM network (159 through an optical fiber (220) that interconnects the ATM network with the Broadband Digital Terminal, BDT (100). Broad Band Digital Terminal BDT (100) with the Wide Band Network Unit (110) which is connected to a separator (220) through a coaxial tension wire (210) The separator is connected to a device (140) ) through an internal coaxial cable (230) The FTTC network shown in Figure 2, and the UNI interfaces (300) and the UTOPIA interface (310) shown in Figure 2 are the same as those show in Figure 1.

The contents of an ATM cell (320) as shown in Figure 2, is one further illustrated in Figure 3 wherein an ATM byte cell 53 is displayed and the fields defined: the Generic Flow Control field (400), the Identifier field of the Virtual Trajectory (410), the Virtual Channel Identifier (420), the Load Type field (430), the Clelula Loss Priority field (440), the Error Head Verification field (450) and the cell payload (460).

A first embodiment of the invention is the FTTF network shown in Figures 1 and 2 in which the ATM cells (320) shown in Figure 3 enter the Terminal Broadband Digital BDT (100) and the Control field of Generic Flow (400) of ATM cells (320) is undefined.

These real bits can be set to zero, but the field content is not relevant to this mode at this stage. In the Broadband Digital Terminal (100) the bits in the Genetic Flow Control field (400 are set to the device number corresponding to the device number of the destination device (140).) In addition, a prepended field (401) ) is added to the ATM cell to form an ATM prependent cell (38) The prepended field (401) is used to lead the cell from the BDT to the appropriate physical layer transmitter BNU (120). the information of the Generic Flow Control field can be determined from the address information contained within the field of the Virtual Path Identifier (410) and the field of the Virtual Channel Identifier (420) in the ATM cell (320) As shown in Figure 2, the cells that leave the Broad Band Digital Terminal, BDT (100) established the Generic Flow Control field (400) to correspond with the number of the device. vo of the destination device. The cells are received by the Broadband Network Unit, NBU (110) and are transmitted by the multiple point-to-point coaxial network comprising the coaxial cable (210), a separator (220) and an internal coaxial cable (230). ). Cells passing from the Wide Band Network Unit BNU (110) through the UNI interface (300) have established the Generic Flow Control field (400) to indicate the device number of the destination device. Because multiple devices can be connected to the coaxial network, the Generic Flow Control field (44) is used by the device to determine which cells are intended for that particular device. An important advantage of this modality is that it is not necessary to check the field of the Virtual Channel Identifier (420) or the field of the Virtual Path Identifier (410) to determine if the cells are destined for that device. Using the Generic Flow Control field to address a multiple point-to-point means results in a physical layer discrimination of the cells as opposed to discrimination of the ATM layer of the cells. The specification of the UNI interface adheres to both the output of the Broad Band Network Unit, BNU (300) as to the input of the device (140), since there are no fields added to the ATM cell. At the output of the device - (140) the cells can be presented to the subscriber's equipment using a UTOPIA interface (310) with the Generic Flow Control field (400) bits set to zero, since the cells have reached the point terminal of the FTTC network. It should be further noted that the UTOPIA interface may exist within the Broadband Network Unit BNU (300) or the Broadband Digital Terminal (100).

In this first mode the cells are transmitted in the reverse direction (from the devices to a NBU) using a similar address scheme as that used in the forward direction (NBU to the device) in which the device number of the device it was coded in the Generic Flow Control field of the ATM cell. Although all cells reach the NBU, it is useful to determine from which device the cells originated. The information regarding the origin of the cells can also be used by the BDT, but it can be extracted before the transmission of the cells of the ATM network. An alternative method in which the NBU retains the trace of which device has been granted the authorization of the transmission and correlates the arrival of each cell with the concession is possible but very complex. If the ATM layer is not requested by the source device number, the bits in the Generic Flow Control field can be returned to zero for the transmission of that layer.

Figure 4 shows a possible address scheme that can be used in the first mode and that gives the sense of each of the possible values for all combinations of the four bits in the Generic Flow Control field. From this table it can be seen that both in the downstream and upstream directions the decimal values of 2-14 in the Generic Flow Control field correspond to the device numbers of the devices. In the downstream direction, a designation of all zeros (zero decimal in the Generic Flow Control field) in the Generic Flow Control field indicates that the cell is intended to be broadcast to all devices, whereas in upstream the designation of all zeros indicates that a device is trying to subscribe to the network and still does not receive a device number. The decimal value of 15 is reserved for special purposes.

A second embodiment is to use a hybrid coaxial fiber network such as that shown in Figure 5, in which the signals are transmitted in a multiplexed sub-carrier division form from a final cable treatment to and from a node (203 ) through an optical fiber. The signals from the node (203) are transported to the residence (250) through a network of coaxial power cable (213), amplifiers (233), dumb streams (243) and coaxial cable tensioner (210) that is connects to a coaxial termination unit (233) on the side of the house that contains the modems to receive and transmit the information to and from the final treatment. The coaxial termination unit also contains a physical layer transmitter and receiver of the coaxial termination unit (247) for transmission and reception to and from the devices (140) within the residence through a separator (220) and an internal coaxial cable (230). There exists an interface UNI (300) in the output of the coaxial termination unit (223) and in the input of the device (130). An UTOPIA interface (310) exists at the output of the devices.

In the second modality shown in Figure 5, the multiple point-to-point network exists between the coaxial termination unit and the devices in a manner similar to that of the multiple point-to-point network that existed between the NBU and the devices. dispositives. As in the first embodiment, the Generic Flow Control field is used to indicate the device number of the device for transmission to that device, and the reception from that device over the coaxial network from multiple point to point. The direction scheme shown in Figure 4 can be used in the second mode.

A means for effecting the first mode on an FTTC network like the one shown in Figure 1 is to use a BDT that receives signals of the SONET type containing ATM cells from cells of the AT network.; on an optical fiber that use a transmission ratio 0C-3c to 1552.52 Mb / s. Within the BDT information in the field of the Virtual Path Identifier and the field of the Virtual Channel Identifier of the cells are verified to determine the destination device for that cell. The information for the prependent field is calculated from the VPI / VCI fields and the prependent is added to the ATM cell to lead the cell to the appropriate physical layer receiver and transmitter of BNU and which corresponds to the coaxial tensor cable. The bits in the Generic Flow Control field are set to the appropriate device number to correspond to the destination device. The table shown in Figure 4 can be used to perform this mode.

In this mode the cells are sent from the BDT to the NBU on an optical fiber using a data rate of 155.52 Mb / s having a format that is similar but not identical to the SONET. Cells are transmitted to the residence from the NBU by the coaxial network using a Quadrature Phase Change Transmission (QPSK) modulation technique that carries information at 51.84 Mb / s on a 622.08 MHz carrier. In the devices, the Generic Flow Control field is used to determine if that device should process a particular cell and pass it to the UTOPIA interface or if it should be discarded. All devices process the diffusion cells that the GFC field of all zeros recognizes. Traditional digital logic can be used to carry out the discrimination function. When it passes to the UTOPIA interface, the Generic Flow Control field is set to zero. This function can also be achieved using digital logic.

In the reverse direction, the cells are transmitted upstream from the devices to the NBU via the coaxial network at an aggregate information rate of 19.44 Mb / s on a 29.16 MHz carrier. The QPSK modulation is also used in the upstream direction , and the Time Division Multiple Access (TDMA) technique is used to multiply the cells of several devices. The Generic Flow Control field is used to identify from which device the cell is transmitted.

An application for a better embodiment of this invention is to transport digital viae switched by an FTTC network to one or more devices in a residence. The devices (140) can be part of a television "set-top" that provides digital to analog conversion and allows the user to send signals back to the network to request different channels or services. In this application the field of Generic Flow Control is used in the downstream to facilitate that the devices easily discriminate the cells that contain the video for the "set-top" of the television In the reverse direction of the field of Flow Control Generic is used to identify from which "set-top" television the residence originated the signal.

A first advantage of the present invention is that the physical layer circuitry can be implemented in a monolithic silicon integrated circuit. The physical layer circuitry in the BNU physical layer transmitter-receiver may be different from that in the physical layer transmitter-receiver device, but it is possible to develop two integrated circuits, one of which is used in all transmitters- BNU physical layer receivers and another that is equal to all physical layer transmitter-receiver devices.

A second advantage is that standard ATM integrated circuits can be used for ATM layer processing, since no additional fields are added to the ATM cells to drive them to the devices.

A third advantage is that the FTTC network can be seen as a physical layer that presents UNI and UTOPIA layer layers ATM. Transfers from the ATM layer to a special or proprietary physical layer are not necessary, since the use of the Generic Flow Control field for the device address is contained within the FTTC physical layer.

Although the present invention has been described in great detail with reference to certain preferred versions thereof, other versions are possible. The goal of the invention is a method and apparatus for effecting a set of interface circuits as a physical layer that uses the HFC bits in an ATM cell to distinguish the devices and the function of the cell with different functions so that the currents towards down and up remain the same. Therefore, the spirit and scope of the appended claims should not be limited to the description of the preferred versions contained herein.

Claims (20)

1. In an asynchronous transfer mode communication network using asynchronous transfer mode cells as a structure for containing information and containing information path where this asynchronous transfer mode communication network has a physical layer and where this physical layer has at least one cell transmitter-receiver of a first type connected to multiple cell-receiver-transmitters of a second type by a shared communications means, a method for driving the cells from a cell-type transmitter-receiver of a first type at least one of the cell transmitter-receivers of a second type and controlling the access by means of the transceivers of a second type to the shared communication means; this method is characterized by; set at least one bit within a generic flow control field of the cells of the asynchronous transfer mode to indicate that the cells of the asynchronous transfer mode are intended for at least one of the one-second cell transmitter-receivers kind, transmit the asynchronous transfer cells from the cell receiver-transmitter of a first type, receiving the cells of asynchronous transfer mode at least cell receptor-transmitter of a second type, and determining whether the cells of asynchronous transfer mode are intended for at least one of the cell receivers-transmitters of a second type based on a generic flow control field.

2. an asincrone transfer mode communication network using asynchronous transfer mode cells as a structure for containing data and for containing information path where the asynchronous transfer mode communication network has a physical layer and where the physical layer it has at least one cell receiver-transmitter of a first type connected to multiple cell receiver-transmitters of a second type by a shared communications means; a method for driving cells from the cell transmitter-receiver of a first type to at least one cell transmitter-receiver of a second type and controlling access by means of those cell transmitters-receivers of a second type of means of shared communications; the method is characterized by setting at least one bit within a generic flow control field of the asynchronous transfer mode cell to indicate that the asynchronous transfer mode cell is being used to subscribe one of the cell transmitter-receivers of a second type in a communications network of asynchronous transfer mode.

3. The method described in claim 1 is further characterized in that those bits within the generic flow control field are set to zero before passing the cells from the asynchronous transfer mode to an asynchronous transfer mode processing layer.

. The method described in claim 2 further characterized in that those bits within the generic flow control field are set to zero before passing the asynchronous transfer mode cells to an asynchronous transfer mode processing layer.

5. In an asynchronous transfer mode communication network using asynchronous transfer mode cells as a structure for containing information and containing information path where this asynchronous transfer mode communication network has a physical layer and where this physical layer has at least one cell transmitter-receiver of a first type connected to multiple cell receiver-transmitters of a second type by a shared communications means, a method for driving the cells from a cell transmitter-receiver of a first type at least one of the cell transmitter-receivers of a second type and controlling the access by means of the transceivers of a second type to the shared communication means; this method is characterized by; set all the bits within a four-bit generic flow control champion of the cells of the asynchronous transfer mode to zero to indicate that the cells of the asynchronous transfer mode are intended for all the cell transmitter-receivers of a second type, transmitting the cells of the asynchronous transfer mode from the cell recretor-transmitter of a first type, receiving the cells of the asynchronous transfer mode in all cell transmitter-receivers of a second type. determine whether the cells of the asynchronous transfer mode are intended for at least one cell transmitter-receiver of a second type based on the generic flow control field.

6. In an asynchronous transfer mode communication network using asynchronous transfer mode cells or a structure for containing information and containing information path where this asynchronous transfer mode communication network has a physical layer and where this layer The physical device has at least one cell transmitter-receiver of a first type connected to multiple cell receiver-transmitters of a second tipc by a shared communications means, a method for driving the cells from a cell transmitter-receiver of a first type to at least one of the cell transmitter-receivers of a second type and controlling the access by means of the transceivers of a second type to the shared communication medium; this method is characterized by; set at least one bit within a four-bit generic flow control field of the cells of the asynchronous transfer mode to represent a binary value for a device identifier in the decimal field corresponding to 2-14, so that the cells of the asynchronous transfer mode are destined for one of the transmitters-cell receptors of a second type with a device identifier, transmitting the cells of asynchronous transfer mode from the cell transmitter-receiver of a first type, receiving the cells of the asynchronous transfer mode in at least one of the cell transmitters-receivers of a second type, and determining whether the cells of the asynchronous transfer mode are intended for at least one of the cell transmitter-receivers of a second type based on the generic flow control field.

7. In an asynchronous transfer mode communication network using asynchronous transfer mode cells as a structure for containing information and containing information path where this asynchronous transfer mode communication network has a physical layer and where this physical layer has at least one cell transmitter-receiver of a first type connected to multiple cell receiver-transmitters of a second type by a shared communications means, a method for driving the cells from a cell transmitter-receiver of a first type at least one of the cell transmitter-receivers of a second type and controlling the access by means of the transceivers of a second type to the shared communication means; this method is characterized by setting all the bits within a four-bit generic flow center field of the zero transfer mode cell to indicate that the cell of the asynchronous transfer mode is being used to subscribe to one of the transmitters-receivers of a second type in the communications network of asynchronous transfer mode.

8. The method described in claim 5 further is characterized in that those bits within the generic flow control field are set to zero before passing the cells from the asynchronous transfer mode to a processing layer of asynchronous transmission mode. .

9. The method described in claim 6 is further characterized in that those bits within the generic flow control field are set to zero before passing the cells from the asynchronous transfer mode to an asynchronous transfer mode processing layer.

10. The method described in claim 7 further is characterized in that those bits within the generic flow control field are set to zero before passing the cells from the asynchronous transfer mode to an asynchronous transfer mode processing layer.

11. In an asynchronous transfer mode communication network using asynchronous transfer mode cells as a structure for containing information and containing information path where this asynchronous transfer mode communication network has a physical layer and where this physical layer has at least one cell transmitter-receiver of a first type connected to multiple cell-receiver-transmitters of a second type by a shared communications means, a method for driving the cells from a cell-type transmitter-receiver of a first type at least one of the cell transmitter-receivers of a second type and controlling the access by means of the transceivers of a second type to the shared communication means; this method is characterized by; means for establishing at least one bit within a generic flow control field of the cells of the asynchronous transfer mode to indicate that the cells of the asynchronous transfer mode are intended for at least one of the cell transmitting receptors of a second type, means for transmitting the cells of the asynchronous transfer mode from the receiving transmitter of a second type, means for determining whether the cells of the asynchronous transfer mode are intended for at least one of the transmitters receiving a second type based on the generic flow control field.

12. In an asynchronous transfer mode communication network using asynchronous transfer mode cells as a structure for containing information and containing information path where this asynchronous transfer mode communication network has a physical layer and where this physical layer has at least one cell transmitter-receiver of a first type connected to multiple cell receiver-transmitters of a second type by a shared communications means, a method for driving the cells from a cell transmitter-receiver of a first type at least one of the cell transmitter-receivers of a second type and controlling the access by means of the transceivers of a second type to the shared communication means; this method is characterized by a means to establish at least one bit within a generic flow control card of the asynchronous transfer mode cell to indicate that the asynchronous transfer mode cell is being used to subscribe to the receiving transmitters of a second type in the communications network of asynchronous transfer mode.

13. The method described in claim 11 further is characterized in that those bits within the generic flow control field are set to zero before passing the cells from the asynchronous transfer mode to an asynchronous transfer mode processing layer.

14. The method described in claim 12 further is characterized in that those bits within the generic flow control field are set to zero before passing the cells from the asynchronous transfer mode to an asynchronous transfer mode processing layer.

15. In a network of asynchronous transfer mode communications that uses asynchronous transfer mode cells as a structure to contain information and contain information path where this asynchronous transfer mode communication network has a physical layer and where this physical layer has when less a cell-type transmitter-receiver of a first type connected to multiple-cell receiver-transmitters of a second type by a shared communications means, a method for driving cells from a cell-type transmitter-receiver of a first type to at least one of the cell-type transmitters-receivers of a second type and controlling access by means of transmitters-receivers of a second type up to the shared media; this method is characterized by; means for setting all the bits within a four-bit generic flow control field of the cells of the transfer mode asynchronously to zero to indicate that the cells of the asynchronous transfer mode are intended for all cell-transmitter-receivers of a second type, means for transmitting the cells of the asynchronous transfer mode from the cell recretor-transmitter of a first type, receiving the cells of the asynchronous transfer mode in all the cell transmitter-receivers of a second type, means for determining whether the cells of the asynchronous transfer mode are intended for at least one cell transmitter-receiver of a second type based on the generic flow control field.

16. In an asynchronous transfer mode communication network using asynchronous transfer mode cells as a structure for containing information and containing information path where this asynchronous transfer mode communication network has a physical layer and where this physical layer has at least one cell transmitter-receiver of a first type connected to multiple cell-receiver-transmitters of a second type by a shared communications means, a method for driving the cells from a cell-type transmitter-receiver of a first type at least one of the cell transmitter-receivers of a second type and controlling the access by means of the transceivers of a second type to the shared communication means; this method is characterized by; means for establishing at least one bit within a four-bit generic flow control field of the cells of the asynchronous transfer mode to represent a binary valence for a device identifier in the decimal field corresponding to 2-14, so that the cells of the asynchronous transfer mode are destined for one of the cell transmitter-receptors of a second type with a device identifier, means for transmitting the cells of asynchronous transfer mode from the cell transceiver of a first type, receiving the cells of the asynchronous transfer mode in at least one of the cell transceivers of a second type, and means for determining whether the cells of the asynchronous transfer mode are intended for at least one of the cell transmitter-receivers of a second type based on the generic flow control field.

17. In an asynchronous transfer mode communication network using asynchronous transfer mode cells as a structure for containing information and containing information path where this asynchronous transfer mode communication network has a physical layer and where this physical layer has at least one cell transmitter-receiver of a first type connected to multiple cell-receiver-transmitters of a second type by a shared communications means, a method for driving the cells from a cell-type transmitter-receiver of a first type at least one of the cell transmitter-receivers of a second type and controlling the access by means of the transceivers of a second type to the shared communication means; this method is characterized by a means to set all the bits within a four-bit generic flow center field of the zero transfer mode cell to indicate that the cell of the asynchronous transfer mode is being used for subscribing to one of the transceivers of a second type in the communications network of asynchronous transfer mode.

18. The method described in claim 15, further characterized in that those bits within the generic flow control field are set to zero before passing the cells from the asynchronous transfer mode to an asynchronous transfer mode processing layer.

19. The method described in claim 16 further is characterized in that those bits within the generic flow control field are set to zero before passing the cells from the asynchronous transfer mode to an asynchronous transfer mode processing layer.

20. The method described in claim 16 further is characterized in that those bits within the generic flow control field are set to zero before passing the cells from the asynchronous transfer mode to an asynchronous transfer mode processing layer.