CA2227053A1 - Fttc interface circuitry as a physical layer entity - Google Patents
Fttc interface circuitry as a physical layer entity Download PDFInfo
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- CA2227053A1 CA2227053A1 CA002227053A CA2227053A CA2227053A1 CA 2227053 A1 CA2227053 A1 CA 2227053A1 CA 002227053 A CA002227053 A CA 002227053A CA 2227053 A CA2227053 A CA 2227053A CA 2227053 A1 CA2227053 A1 CA 2227053A1
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- transfer mode
- asynchronous transfer
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Classifications
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04J—MULTIPLEX COMMUNICATION
- H04J3/00—Time-division multiplex systems
- H04J3/24—Time-division multiplex systems in which the allocation is indicated by an address the different channels being transmitted sequentially
- H04J3/26—Time-division multiplex systems in which the allocation is indicated by an address the different channels being transmitted sequentially in which the information and the address are simultaneously transmitted
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04Q—SELECTING
- H04Q11/00—Selecting arrangements for multiplex systems
- H04Q11/04—Selecting arrangements for multiplex systems for time-division multiplexing
- H04Q11/0428—Integrated services digital network, i.e. systems for transmission of different types of digitised signals, e.g. speech, data, telecentral, television signals
- H04Q11/0478—Provisions for broadband connections
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L12/00—Data switching networks
- H04L12/54—Store-and-forward switching systems
- H04L12/56—Packet switching systems
- H04L12/5601—Transfer mode dependent, e.g. ATM
- H04L2012/5603—Access techniques
- H04L2012/5604—Medium of transmission, e.g. fibre, cable, radio
- H04L2012/5605—Fibre
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L12/00—Data switching networks
- H04L12/54—Store-and-forward switching systems
- H04L12/56—Packet switching systems
- H04L12/5601—Transfer mode dependent, e.g. ATM
- H04L2012/5603—Access techniques
- H04L2012/5604—Medium of transmission, e.g. fibre, cable, radio
- H04L2012/5606—Metallic
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L12/00—Data switching networks
- H04L12/54—Store-and-forward switching systems
- H04L12/56—Packet switching systems
- H04L12/5601—Transfer mode dependent, e.g. ATM
- H04L2012/5603—Access techniques
- H04L2012/5609—Topology
- H04L2012/561—Star, e.g. cross-connect, concentrator, subscriber group equipment, remote electronics
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L12/00—Data switching networks
- H04L12/54—Store-and-forward switching systems
- H04L12/56—Packet switching systems
- H04L12/5601—Transfer mode dependent, e.g. ATM
- H04L2012/5614—User Network Interface
- H04L2012/5615—Network termination, e.g. NT1, NT2, PBX
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L12/00—Data switching networks
- H04L12/54—Store-and-forward switching systems
- H04L12/56—Packet switching systems
- H04L12/5601—Transfer mode dependent, e.g. ATM
- H04L2012/5614—User Network Interface
- H04L2012/5616—Terminal equipment, e.g. codecs, synch.
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L12/00—Data switching networks
- H04L12/54—Store-and-forward switching systems
- H04L12/56—Packet switching systems
- H04L12/5601—Transfer mode dependent, e.g. ATM
- H04L2012/5619—Network Node Interface, e.g. tandem connections, transit switching
- H04L2012/562—Routing
Abstract
In an Asynchronous Transfer Mode (ATM) communications network (150) which operates over a shared media a method of addressing and access control between a central transceiver (120) and multiple transceivers (130) is required. A
device identifier is placed in the Generic Flow Control (GFC) field (400) of the ATM cells (320) to indicate that cells (320) are designated for a particular transceiver or transceivers in the residence. In the reverse direction, transceivers (130) in the residence use the GFC field to indicate that they are attempting to sign on to the network. The GFC bits are returned to zero prior to passing the ATM cells to the ATM processing layer.
device identifier is placed in the Generic Flow Control (GFC) field (400) of the ATM cells (320) to indicate that cells (320) are designated for a particular transceiver or transceivers in the residence. In the reverse direction, transceivers (130) in the residence use the GFC field to indicate that they are attempting to sign on to the network. The GFC bits are returned to zero prior to passing the ATM cells to the ATM processing layer.
Description
CA 022270~3 1998-01-1~
Title of the in~ Lio FTTC In~lr~ce Circuitry As A Physical Layer Entity lnventors S KPnneth M. Buckland, of 7466 Mercedes Way, Rohnert Park, California Thomas R. Eames, of 5206 Pressley Road, Santa Rosa, California Lac X. Trinh, of 1255 Marlene Court, Rohnert Park, California Steven D. Warwick, of 4471 Mount Taylor Road, Santa Rosa, California Cross-References This application claims the benefit of U.S. Provisional Application No.
60/003,464 filed on September 8, 1995, entitled ~FTTC Inlel~ce Circuitry as a Physical Layer Entity,~ of which Kenn~-th M. Bllrl~l~n~l, Thomas R. Eames, Lac X. Trinh and Steven D. Warwick are the inventors, with attorney docket number NP2007.
Field of the in~ lion The field of the invention is telecommunications, and more specifically, the use of Asynchronous Transfer Mode (ATM) technology to transport cell based information over a physical medium (layer) in which a single network point connects to multiple devices in 20 a point-to-multipoint configuration.
Background of the invention In ATM distribution systems, the physical layer is defined as a functional group comprised of hardware, software and tr~n~mi~ion media which converts an ATM
SUBS l l l U~E SHEET tRU~E 26) CA 022270~3 1998-01-15 cell stream into bits to be transported over the tr~n.cmi.c.cion media and ~ pOlL~ the tr~n.cmi.esion and reception of these bits. Examples of tr~ncmiccion media are optical fiber, coaxial cable, free space, and twisted copper pairs. Once the data is transported over the physical layer it is presented to the next layer, the Asynchronous Tr~n.cmicsion 5 Mode (ATM) layer. At the output of the device, the data can be presented via a number of interfaces, one of which is the Universal Test & Operations PHY Interface for ATM
(UTOPIA) as described by the ATM Forum.
Simult~neously with the development of ATM technology, there have been advances in Fiber-to-the-Curb (~-I-l C) technology in which devices are connPcted to the 10 telephone central office via a network of optical fibers connecting the central office to single network points called Bro~-lh~nd Network Units (BNUs) which in turn connect to the subscriber residence via a coaxial cable, and to the devices in the residence via a passive splitter and in-home coaxial wiring. In these l;TTC networks, signals can be routed to the residence via a single coaxial cable conn~-cting the residence to the BNU, but IS the passive network in the home results in information arriving at multiple devices, each which must have the abi1ity to determine which signals are for that particular device.
Likewise, when devices transmit from the residence to the BNU the BNU must have a me~ ni.cm for deterrnining from which device the inforrnation was transmitted from.
When ATM transmission techniques are used, the information is in the forrn of 20 cells which contain addressing which is known as the Virtual Path Identifier (VPI) and the Virtual Channel Identifier (VCI). The VPI and VCI fields can be read to deterrnine the destin~tion of a particular cell, but when a passive point-to-multipoint network which does not contain s~ilching or routing capabilities is part of the physical layer cells tlestin~d for a particular device will arrive at multiple devices. Having the all receiving devices read S~JE~STITU~E SHEFr ~RULE 26) CA 022270~3 1998-01-l~
wo 97/09799 PcT/USg6/14498 all of the cells to determine which cells are actually ~l~stin~d for that device from their VPI/VCI values results in an inefficient means of cell discrimin~tion and will require additional cell plvces~ capability at each device. An additional problem arises in that in the reverse direction on the point-to-multipoint network the devices will transmit cells 5 to a single receiving point, and that receiving point will not be able to determine from which ori~in~ting device the cells were transmitted, without inspection of the VPI/VCI
values.
One of the goals of the present invention is to provide one or more embodiments which permit the transport of ATM cells over a point-to-multipoint network, such as those 10 encountered in FTTC.
Another goal of the present invention is to provide one or more embodiments which result in a physical layer in which the transceivers can be implemented in low cost monolithic integr~ttod circuits which provide discrimin~ti~n of cells such that the physical layer :iul,p~ cells being tr~n~mitted over a point-to-multipoint network without 15 ~ mining the VPI/VCI fields within the cells.
.c.. ~ of the invention In an ATM distribution system in which cells are received from an ATM network at a single network point with addressing information contained within the VPI/VCI fields 20 of the cell, bits within a specific field within the cell called the Generic Flow Control (GFC) field are set to correspond to the de~ ion device for that particular cell. The cells can be transmitted across a point-to-multipoint network, such as the coaxial network which exists in a FTTC system, where multiple devices within a residence receive all of the information transmitted to that residence. At the devices in the residence the GFC
SUBSTITUTE SHE~ (RU~E 26) CA 022270~3 1998-01-1~
field is used to deterrnine which cells are ~le,stin~d for that device, without having to eY~mine the VPI/VCI fields within the cells. The GFC bits are snbsequently reset to zero before the cells are passed from the device to a user terminal, thus the details of the physical layer are not passed to the ATM layer.
S For cells transmitted in the reverse direction, from devices to a single network point over the multipoint-to-point coaxial network~ the GFC bits are encoded with information col,t;s~onding to the device number of the origin~ting device. When received at the single network point, the origin~ting device can be determined by er~min~tion of the GFC bits. This information is useful in monitoring the traffic from devices and 10 determining which devices should be granted permission to transmit on the coaxial network. As in the forward direction, the GFC bits can be reset to zero when information is passed back to the ATM layer so that the details of the physical layer are hidden from that (ATM) layer.
Br~ef ~ of the drawings Figure 1 shows a Fiber-to-the-Curb network with a point-to-multipoint coaxial network conn~o~ting the Broadband Network Unit (BNU) with devices in the residence.
Figure 2 shows a l~ l l C network co~ e~d to an ATM network with devices at the end of the Fl'rC network.
Figure 3 shows an ATM cell and the fields within the cell.
Figure 4 illustrates a table of GFC field designations.
Figure S shows a hybrid fiber-coaxial network with a point-to-multipoint coaxial network connPcting a Coaxial Terrnination Unit (CTU) with devices in the residence.
SUBSTITUTE S~F~T ~RUI E 26) CA 022270~3 1998-01-1~
Des.;. ;~,lion of the IJl er~ d embodiment or embo~
Figure 1 illustrates a Fiber-to-the-Curb (FTrC) network which delivers telecommunications services to a residence (250). Services are provided in the FTTC
network shown in Figure 1 via a Broadband Digital Terminal (100) which is connected to S a Broadband Network Unit (110) via an optical fiber (200). The conn~ction to the residence (250) is made by a BNU physical layer transceiver (120) which is connect~-d by a coaxial drop cable (210) to a splitter (220) which is corlnected to one or more devices (140) via in-home coaxial cable (230). Each device contains a device physical layer transceiver (130). The relevant interfaces for this network are illustrated in Figure 1 and 10 are the UNI interface (300) on the coaxial cable and the UTOPIA interface (310) at the output of the device. The User Network Interface (UNI) is a specification which covers the pararneters of the interface from the physical layer to the ATM layer.
Figure 2 illustrates an ~-l-l C network and is id.orltic~l to that shown in Figure 1 with additional ltpl5;sel.l;tlion of the status of ATM cells (320), prepended ATM cells, 15 (380) and the Generic Flow Control fields (400) within the cells as the cells pass through the network. Cells enter the FTTC system in Figure 2 from an external ATM network (150) via an optical fiber (200) which ill~,col,nects the ATM network with the Bro~ib~nd Digital Terminal, BDT (100). An optical fiber connects the Broadband Digital Terminal, BDT (100) to the Broadband Network Unit (110) which connects to a splitter (220) via a 20 coaxial drop cable (210). The splitter is connecte~ to a device (140) via an in-home coaxial cable (230). The FTTC network shown in Figure 2, and the UNI interfaces (300) and UTOPIA interface (310) shown in Figure 2 are the same as those shown in Figure 1.
The content of an ATM cell (320) as shown in Figure 2 is further illustrated in Figure 3 where a 53 octet ATM cell is shown and the fields defined: the Generic Flow 5.
SUBSTITUTE S~EE~ tRULE 26) CA 022270~3 1998-01-1~
Control field (400), the Virtual Path Identifier field (410), the Virtual Channel Identifier (420), the Payload Type field (430), the Cell Loss Priority field (440), the Header Error Check field (450) and the cell payload (460).
A first embodiment of the invention is the ~ l C network shown in Figures 1 and 5 2 in which ATM cells (320) shown in Figure 3 enter the Bro~llb~nd Digital Terminal, BDT (100), and the Generic Flow Control field (400) of the ATM cells (320) is undefined. The actual bits may be set to zero but the content of the field is not relevant to this embodiment at this stage. At the Broadband Digital Terminal (100) the bits in the Generic Flow Control field (400) are set to an device number which co,les~ollds to the 10 device number of the ~le~ ion device (140). In addition, a prepend field (401) is added to the ATM cell to form a prepended ATM cell (380). The prepend field (401) is used for routing the cell from the BDT to the al,ylu~ al~ BNU physical layer transceiver (120). This prepend information and Generic Flow Control field information can be determined from the address information contained within the Virtual Path Identifier field 15 (410) and Virtual C~h~nnel Identifier field (420) in the ATM cell (320). As shown in Figure 2, cells leaving the Broadband Digital Terrninal, BDT (100) have the Generic Flow Control field (400) set to correspond to the device number of the fi~stin~tion device.
The cells are received by the Broadband Network Unit, BNU (110) and are transmitted over the point-to-multipoint coaxial network comprised of coaxial drop cable (210), a 20 splitter (220) and in-home coaxial cable (230). The cells passing from the Broadband Network Unit, BNU (110) over the UNI interface (300) have the Generic Flow Control field (400) set to in-iir~te the device number of the destin~tion device. Since multiple devices can be conn~ct~-d to the coaxial networlc, the Generic Flow Control field (400) is used by the device to determine which cells are fi~stin~d for that particular device. An SUBSTITUTE SHEET tRUl.E 26) CA 022270~3 1998-01-1~
WO 97/09799 PCT/US96/1'1498 hllpol~t advantage of this embodiment is that it is not nPces~ry to ~Y~mine the Virtual Channel Identifier field (420) or the Virtual Path Identifier field (410) to determine if the cells are destinPd for that device. Using the Generic Flow Control field for addressing in a point-to-multipoint environment results in physical layer discrimin~tion of the cells as S opposed to ATM layer discrimination of cells. The UNI interface specification is adhered to at both the exit of the Broadband Network Unit, BNU (300) and at the device (140) input, since there are no additional fields added to the ATM cell. At the output of the device (140) cells can be presented to subscriber equipment using a UTOPIA interface (310), with the Generic Flow Control field (400) bits set to zero, since the cells have 10 arrived at the ~-l~l C network termination point. It should be additionally noted than a UTOPIA interface may exist inside the Broadband Network Unit, BNU (300) or the Broadband Digital Terminal (100).
In this first embodiment cells are transmitted in the reverse direction (from devices to a BNU) using a similar addressing scheme to that used in the forward (BNU to device) lS direction in which the device number of the device is encoded in the Generic Flow Control field of the ATM cell. Although all cells arrive at the BNU it is useful to determine from which device the cells ori~in~ted. Information with respect to the origination of the cells can be used by the BDT as well, but is removed before tr~n~mic~jon of the cells to the ATM network. An alternate method, in which the BNU
20 keeps track of which device it has granted tr~nsmis~ion authorization to and correlates the arrival of each cell with the grant is possible but much more complex. If the origination device number is not required at the ATM layer, the Generic Flow Control field bits can be returned to zero for tr~n~mi~cion to that layer.
Figure 4 shows one possible addressing scheme which can be employed in the first SUBST~UTE SHE~ (RU~ E 26) CA 022270~3 1998-01-1~
WO 97/09799 .-- - - PCT/US96/14498 embodiment and which gives meaning to each of the possible values for all of the combinations of the four bits in the Generic Flow Control field. From this table it can be seen that in both 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 5 downstream direction, an all zeros ~lesign~tion (rie~im~l zero in the Generic Flow Control field) in the Generic Flow Control field indicates that the cell is intended for broadcast to all devices, while in the upstream the all zeros designation in~ tes that a device is aLle,l,pti"g to sign onto the network and has not yet received a device number. The decimal value of 15 is reserved for special purposes.
An second embodiment is to use a hybrid fiber-coaxial network such as the one shown in Figure 5, in which signals are transmitted in a sub-carrier division multiplexed form from a cable head-end to and from a node (203) via an optical fiber. Signals from the node (203) are transported to the residence (250) via a network of coaxial feeder cable (213), amplifiers (233), taps (243) and coaxial drop cable (210) which connects to a 15 coaxial termination unit (223) at the side of the home which contains modems for receiving and tr~n~mirting data to and from the head-end. The coaxial terrnination unit also contains a coaxial termination unit physical layer transceiver (247) for transmitting to and receiving from devices (140) within the residence via a splitter (220) and in-home coaxial cable (230). There exists a UNI interface (300) at the exit of the coaxial 20 termination unit (223) and at the entrance to the device (130). A UTOPIA interface (310) exists at the output of the devices.
In the second embodiment shown in Figure S the point-to-multipoint network exists between the coaxial termination unit and the devices in a similar fashion to the point-to-multipoint network which existed between the BNU and the devices. As in the SUBSTI rUTE 5~FE~ tRULE 26) CA 022270~3 l998-Ol-l~
first emboriiment~ the Generic Flow Control field is used to indicate the device number of the device for transmission to that device, and reception from that device on the point-to-multipoint coaxial network. The addressing scheme shown in Figure 4 can be used in the second embodiment.
A means of r~li7ing the first embodiment on a FTTC network such as the one shown in Figure 1 is to utilize a BDT which receives SONET type signals Cont~ining ATM cells from an ATM network cells on an optical fiber using an OC-3c tr~n~mi~sion rate at 155.52 Mb/s. Within the BDT information in the Virtual Path Identifier field and Virtual Channel Identifier field of the cells is eY~minP~I to determine the destin~tion 10 device for that cell. The information for the prepend field is c~lcul~ted from the VPI/VCI
fields and the prepend is added to the ATM cell to route the cell to the appropriate BNU
physical layer transceiver and co.lt;..~onding coaxial drop cable. The bits in the Generic Flow Control field are set to the appr(,~,iate device number to correspond to the d~-s~ ;on device. The table shown in Figure 4 can be utilized to realize this 15 embodiment.
In this embodiment cells are sent from the BDT to the BNU on an optical fiber using a 155.52 Mb/s data rate which has a formatting which is similar but not identical to SONET. The cells are transmitted to the residence from the BNU over the coaxial network using a Ql~dr~hlre Phase Shift Keying (QPSK) modulation technique which 20 carries data at 51.84 Mb/s on a 622.08 MHz carrier. At the devices, the Generic Flow Control field is used to determine if a particular cell should be processed by that device and passed to the UTOPIA interface or if it should be discarded. Broadcast cells, recognized by an all zero GFC field, are processed by all devices. Traditional digital logic can be used to perform the discrimin~tion function. When passed to the UTOPIA
SUBS~I I UTE SHEET (RU~.E 26) CA 022270~3 1998-01-l~
interface the Generic Flow Control field is set to zero. This function can also be accomplished using digital logic.
In the reverse direction, cells are transmitted upstream from the devices to the BNU over the coaxial network at an aggregate data rate of 19.44 Mb/s on a 29.16 MHz 5 carrier. QPSK modulation is also used in the u~tlcalll direction, and a Time Division Multiple Access (TDMA) technique is used to multiplex the cells from the various devices. The Generic Flow Control field is used to identify from which device the cell was transmitted.
An application for the best mode of the invention is the transport of switched 10 digital video over a ~ l-l C network to one or more devices in a residence. The devices (140) can be part of a television set-top which provides digital to analog conversion and allows the user to send signals back up the network to re~uest dirrele-,t ch~nnel.c or services. In this application the Generic Flow Control field is used in the downstream to enable the devices to easily discriminate cells which contain video for that television set-15 top. In the reverse direction the Generic Flow Control field is used to identify fromwhich television set-top in that residence the signal origin~t~A
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 transceiver may be di~r~ from that in the device physical layer 20 transceiver, but it is possible to develop two integrated circuits, one of which is used in all of the BNU physical layer transceivers and another which is the same for all device physical layer transceivers.
A second advantage is that standard ATM integrated circuits can be used for the ATM layer plucec~ g~ since no additional fields are added to the ATM cells to route 10.
SUBSTITUTE SHFE~ (RULE 26 -CA 022270~3 1998-01-1~
WO 97/09799 . - PCT/US96/14498 them to the devices.
A third advantage is that the FTTC network can be viewed as a physical layer which presents standard UNI and UTOPIA interfaces to the ATM layer. No tr~n~l~tions from the ATM layer to a special or proprietary physical layer are nPcç~ry, since the use S of the Generic Flow Control field for device addressing is contained within the ~ l~l C
physical layer.
Although the present invention has been described in considerable detail with referGnce to certain ~lefelled versions thereof, other versions are possible. The goal of the invention as a method and apl~aldl~ls for re~li7ing interface cil~;uiLI~ as a physical layer 10 which utili_es the HFC bits in an ATM cell to ~i~tin~li~h devices and cell function with different functions for the downstream and the U~S~IG~II remains the same. Therefore the spirit and scope of the appended claims should not be limited to the description of the ~rGÇG"Gd versions cont~inP-d herein.
SUBS 111 UTE 5}tEET ~RU~ E 263
Title of the in~ Lio FTTC In~lr~ce Circuitry As A Physical Layer Entity lnventors S KPnneth M. Buckland, of 7466 Mercedes Way, Rohnert Park, California Thomas R. Eames, of 5206 Pressley Road, Santa Rosa, California Lac X. Trinh, of 1255 Marlene Court, Rohnert Park, California Steven D. Warwick, of 4471 Mount Taylor Road, Santa Rosa, California Cross-References This application claims the benefit of U.S. Provisional Application No.
60/003,464 filed on September 8, 1995, entitled ~FTTC Inlel~ce Circuitry as a Physical Layer Entity,~ of which Kenn~-th M. Bllrl~l~n~l, Thomas R. Eames, Lac X. Trinh and Steven D. Warwick are the inventors, with attorney docket number NP2007.
Field of the in~ lion The field of the invention is telecommunications, and more specifically, the use of Asynchronous Transfer Mode (ATM) technology to transport cell based information over a physical medium (layer) in which a single network point connects to multiple devices in 20 a point-to-multipoint configuration.
Background of the invention In ATM distribution systems, the physical layer is defined as a functional group comprised of hardware, software and tr~n~mi~ion media which converts an ATM
SUBS l l l U~E SHEET tRU~E 26) CA 022270~3 1998-01-15 cell stream into bits to be transported over the tr~n.cmi.c.cion media and ~ pOlL~ the tr~n.cmi.esion and reception of these bits. Examples of tr~ncmiccion media are optical fiber, coaxial cable, free space, and twisted copper pairs. Once the data is transported over the physical layer it is presented to the next layer, the Asynchronous Tr~n.cmicsion 5 Mode (ATM) layer. At the output of the device, the data can be presented via a number of interfaces, one of which is the Universal Test & Operations PHY Interface for ATM
(UTOPIA) as described by the ATM Forum.
Simult~neously with the development of ATM technology, there have been advances in Fiber-to-the-Curb (~-I-l C) technology in which devices are connPcted to the 10 telephone central office via a network of optical fibers connecting the central office to single network points called Bro~-lh~nd Network Units (BNUs) which in turn connect to the subscriber residence via a coaxial cable, and to the devices in the residence via a passive splitter and in-home coaxial wiring. In these l;TTC networks, signals can be routed to the residence via a single coaxial cable conn~-cting the residence to the BNU, but IS the passive network in the home results in information arriving at multiple devices, each which must have the abi1ity to determine which signals are for that particular device.
Likewise, when devices transmit from the residence to the BNU the BNU must have a me~ ni.cm for deterrnining from which device the inforrnation was transmitted from.
When ATM transmission techniques are used, the information is in the forrn of 20 cells which contain addressing which is known as the Virtual Path Identifier (VPI) and the Virtual Channel Identifier (VCI). The VPI and VCI fields can be read to deterrnine the destin~tion of a particular cell, but when a passive point-to-multipoint network which does not contain s~ilching or routing capabilities is part of the physical layer cells tlestin~d for a particular device will arrive at multiple devices. Having the all receiving devices read S~JE~STITU~E SHEFr ~RULE 26) CA 022270~3 1998-01-l~
wo 97/09799 PcT/USg6/14498 all of the cells to determine which cells are actually ~l~stin~d for that device from their VPI/VCI values results in an inefficient means of cell discrimin~tion and will require additional cell plvces~ capability at each device. An additional problem arises in that in the reverse direction on the point-to-multipoint network the devices will transmit cells 5 to a single receiving point, and that receiving point will not be able to determine from which ori~in~ting device the cells were transmitted, without inspection of the VPI/VCI
values.
One of the goals of the present invention is to provide one or more embodiments which permit the transport of ATM cells over a point-to-multipoint network, such as those 10 encountered in FTTC.
Another goal of the present invention is to provide one or more embodiments which result in a physical layer in which the transceivers can be implemented in low cost monolithic integr~ttod circuits which provide discrimin~ti~n of cells such that the physical layer :iul,p~ cells being tr~n~mitted over a point-to-multipoint network without 15 ~ mining the VPI/VCI fields within the cells.
.c.. ~ of the invention In an ATM distribution system in which cells are received from an ATM network at a single network point with addressing information contained within the VPI/VCI fields 20 of the cell, bits within a specific field within the cell called the Generic Flow Control (GFC) field are set to correspond to the de~ ion device for that particular cell. The cells can be transmitted across a point-to-multipoint network, such as the coaxial network which exists in a FTTC system, where multiple devices within a residence receive all of the information transmitted to that residence. At the devices in the residence the GFC
SUBSTITUTE SHE~ (RU~E 26) CA 022270~3 1998-01-1~
field is used to deterrnine which cells are ~le,stin~d for that device, without having to eY~mine the VPI/VCI fields within the cells. The GFC bits are snbsequently reset to zero before the cells are passed from the device to a user terminal, thus the details of the physical layer are not passed to the ATM layer.
S For cells transmitted in the reverse direction, from devices to a single network point over the multipoint-to-point coaxial network~ the GFC bits are encoded with information col,t;s~onding to the device number of the origin~ting device. When received at the single network point, the origin~ting device can be determined by er~min~tion of the GFC bits. This information is useful in monitoring the traffic from devices and 10 determining which devices should be granted permission to transmit on the coaxial network. As in the forward direction, the GFC bits can be reset to zero when information is passed back to the ATM layer so that the details of the physical layer are hidden from that (ATM) layer.
Br~ef ~ of the drawings Figure 1 shows a Fiber-to-the-Curb network with a point-to-multipoint coaxial network conn~o~ting the Broadband Network Unit (BNU) with devices in the residence.
Figure 2 shows a l~ l l C network co~ e~d to an ATM network with devices at the end of the Fl'rC network.
Figure 3 shows an ATM cell and the fields within the cell.
Figure 4 illustrates a table of GFC field designations.
Figure S shows a hybrid fiber-coaxial network with a point-to-multipoint coaxial network connPcting a Coaxial Terrnination Unit (CTU) with devices in the residence.
SUBSTITUTE S~F~T ~RUI E 26) CA 022270~3 1998-01-1~
Des.;. ;~,lion of the IJl er~ d embodiment or embo~
Figure 1 illustrates a Fiber-to-the-Curb (FTrC) network which delivers telecommunications services to a residence (250). Services are provided in the FTTC
network shown in Figure 1 via a Broadband Digital Terminal (100) which is connected to S a Broadband Network Unit (110) via an optical fiber (200). The conn~ction to the residence (250) is made by a BNU physical layer transceiver (120) which is connect~-d by a coaxial drop cable (210) to a splitter (220) which is corlnected to one or more devices (140) via in-home coaxial cable (230). Each device contains a device physical layer transceiver (130). The relevant interfaces for this network are illustrated in Figure 1 and 10 are the UNI interface (300) on the coaxial cable and the UTOPIA interface (310) at the output of the device. The User Network Interface (UNI) is a specification which covers the pararneters of the interface from the physical layer to the ATM layer.
Figure 2 illustrates an ~-l-l C network and is id.orltic~l to that shown in Figure 1 with additional ltpl5;sel.l;tlion of the status of ATM cells (320), prepended ATM cells, 15 (380) and the Generic Flow Control fields (400) within the cells as the cells pass through the network. Cells enter the FTTC system in Figure 2 from an external ATM network (150) via an optical fiber (200) which ill~,col,nects the ATM network with the Bro~ib~nd Digital Terminal, BDT (100). An optical fiber connects the Broadband Digital Terminal, BDT (100) to the Broadband Network Unit (110) which connects to a splitter (220) via a 20 coaxial drop cable (210). The splitter is connecte~ to a device (140) via an in-home coaxial cable (230). The FTTC network shown in Figure 2, and the UNI interfaces (300) and UTOPIA interface (310) shown in Figure 2 are the same as those shown in Figure 1.
The content of an ATM cell (320) as shown in Figure 2 is further illustrated in Figure 3 where a 53 octet ATM cell is shown and the fields defined: the Generic Flow 5.
SUBSTITUTE S~EE~ tRULE 26) CA 022270~3 1998-01-1~
Control field (400), the Virtual Path Identifier field (410), the Virtual Channel Identifier (420), the Payload Type field (430), the Cell Loss Priority field (440), the Header Error Check field (450) and the cell payload (460).
A first embodiment of the invention is the ~ l C network shown in Figures 1 and 5 2 in which ATM cells (320) shown in Figure 3 enter the Bro~llb~nd Digital Terminal, BDT (100), and the Generic Flow Control field (400) of the ATM cells (320) is undefined. The actual bits may be set to zero but the content of the field is not relevant to this embodiment at this stage. At the Broadband Digital Terminal (100) the bits in the Generic Flow Control field (400) are set to an device number which co,les~ollds to the 10 device number of the ~le~ ion device (140). In addition, a prepend field (401) is added to the ATM cell to form a prepended ATM cell (380). The prepend field (401) is used for routing the cell from the BDT to the al,ylu~ al~ BNU physical layer transceiver (120). This prepend information and Generic Flow Control field information can be determined from the address information contained within the Virtual Path Identifier field 15 (410) and Virtual C~h~nnel Identifier field (420) in the ATM cell (320). As shown in Figure 2, cells leaving the Broadband Digital Terrninal, BDT (100) have the Generic Flow Control field (400) set to correspond to the device number of the fi~stin~tion device.
The cells are received by the Broadband Network Unit, BNU (110) and are transmitted over the point-to-multipoint coaxial network comprised of coaxial drop cable (210), a 20 splitter (220) and in-home coaxial cable (230). The cells passing from the Broadband Network Unit, BNU (110) over the UNI interface (300) have the Generic Flow Control field (400) set to in-iir~te the device number of the destin~tion device. Since multiple devices can be conn~ct~-d to the coaxial networlc, the Generic Flow Control field (400) is used by the device to determine which cells are fi~stin~d for that particular device. An SUBSTITUTE SHEET tRUl.E 26) CA 022270~3 1998-01-1~
WO 97/09799 PCT/US96/1'1498 hllpol~t advantage of this embodiment is that it is not nPces~ry to ~Y~mine the Virtual Channel Identifier field (420) or the Virtual Path Identifier field (410) to determine if the cells are destinPd for that device. Using the Generic Flow Control field for addressing in a point-to-multipoint environment results in physical layer discrimin~tion of the cells as S opposed to ATM layer discrimination of cells. The UNI interface specification is adhered to at both the exit of the Broadband Network Unit, BNU (300) and at the device (140) input, since there are no additional fields added to the ATM cell. At the output of the device (140) cells can be presented to subscriber equipment using a UTOPIA interface (310), with the Generic Flow Control field (400) bits set to zero, since the cells have 10 arrived at the ~-l~l C network termination point. It should be additionally noted than a UTOPIA interface may exist inside the Broadband Network Unit, BNU (300) or the Broadband Digital Terminal (100).
In this first embodiment cells are transmitted in the reverse direction (from devices to a BNU) using a similar addressing scheme to that used in the forward (BNU to device) lS direction in which the device number of the device is encoded in the Generic Flow Control field of the ATM cell. Although all cells arrive at the BNU it is useful to determine from which device the cells ori~in~ted. Information with respect to the origination of the cells can be used by the BDT as well, but is removed before tr~n~mic~jon of the cells to the ATM network. An alternate method, in which the BNU
20 keeps track of which device it has granted tr~nsmis~ion authorization to and correlates the arrival of each cell with the grant is possible but much more complex. If the origination device number is not required at the ATM layer, the Generic Flow Control field bits can be returned to zero for tr~n~mi~cion to that layer.
Figure 4 shows one possible addressing scheme which can be employed in the first SUBST~UTE SHE~ (RU~ E 26) CA 022270~3 1998-01-1~
WO 97/09799 .-- - - PCT/US96/14498 embodiment and which gives meaning to each of the possible values for all of the combinations of the four bits in the Generic Flow Control field. From this table it can be seen that in both 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 5 downstream direction, an all zeros ~lesign~tion (rie~im~l zero in the Generic Flow Control field) in the Generic Flow Control field indicates that the cell is intended for broadcast to all devices, while in the upstream the all zeros designation in~ tes that a device is aLle,l,pti"g to sign onto the network and has not yet received a device number. The decimal value of 15 is reserved for special purposes.
An second embodiment is to use a hybrid fiber-coaxial network such as the one shown in Figure 5, in which signals are transmitted in a sub-carrier division multiplexed form from a cable head-end to and from a node (203) via an optical fiber. Signals from the node (203) are transported to the residence (250) via a network of coaxial feeder cable (213), amplifiers (233), taps (243) and coaxial drop cable (210) which connects to a 15 coaxial termination unit (223) at the side of the home which contains modems for receiving and tr~n~mirting data to and from the head-end. The coaxial terrnination unit also contains a coaxial termination unit physical layer transceiver (247) for transmitting to and receiving from devices (140) within the residence via a splitter (220) and in-home coaxial cable (230). There exists a UNI interface (300) at the exit of the coaxial 20 termination unit (223) and at the entrance to the device (130). A UTOPIA interface (310) exists at the output of the devices.
In the second embodiment shown in Figure S the point-to-multipoint network exists between the coaxial termination unit and the devices in a similar fashion to the point-to-multipoint network which existed between the BNU and the devices. As in the SUBSTI rUTE 5~FE~ tRULE 26) CA 022270~3 l998-Ol-l~
first emboriiment~ the Generic Flow Control field is used to indicate the device number of the device for transmission to that device, and reception from that device on the point-to-multipoint coaxial network. The addressing scheme shown in Figure 4 can be used in the second embodiment.
A means of r~li7ing the first embodiment on a FTTC network such as the one shown in Figure 1 is to utilize a BDT which receives SONET type signals Cont~ining ATM cells from an ATM network cells on an optical fiber using an OC-3c tr~n~mi~sion rate at 155.52 Mb/s. Within the BDT information in the Virtual Path Identifier field and Virtual Channel Identifier field of the cells is eY~minP~I to determine the destin~tion 10 device for that cell. The information for the prepend field is c~lcul~ted from the VPI/VCI
fields and the prepend is added to the ATM cell to route the cell to the appropriate BNU
physical layer transceiver and co.lt;..~onding coaxial drop cable. The bits in the Generic Flow Control field are set to the appr(,~,iate device number to correspond to the d~-s~ ;on device. The table shown in Figure 4 can be utilized to realize this 15 embodiment.
In this embodiment cells are sent from the BDT to the BNU on an optical fiber using a 155.52 Mb/s data rate which has a formatting which is similar but not identical to SONET. The cells are transmitted to the residence from the BNU over the coaxial network using a Ql~dr~hlre Phase Shift Keying (QPSK) modulation technique which 20 carries data at 51.84 Mb/s on a 622.08 MHz carrier. At the devices, the Generic Flow Control field is used to determine if a particular cell should be processed by that device and passed to the UTOPIA interface or if it should be discarded. Broadcast cells, recognized by an all zero GFC field, are processed by all devices. Traditional digital logic can be used to perform the discrimin~tion function. When passed to the UTOPIA
SUBS~I I UTE SHEET (RU~.E 26) CA 022270~3 1998-01-l~
interface the Generic Flow Control field is set to zero. This function can also be accomplished using digital logic.
In the reverse direction, cells are transmitted upstream from the devices to the BNU over the coaxial network at an aggregate data rate of 19.44 Mb/s on a 29.16 MHz 5 carrier. QPSK modulation is also used in the u~tlcalll direction, and a Time Division Multiple Access (TDMA) technique is used to multiplex the cells from the various devices. The Generic Flow Control field is used to identify from which device the cell was transmitted.
An application for the best mode of the invention is the transport of switched 10 digital video over a ~ l-l C network to one or more devices in a residence. The devices (140) can be part of a television set-top which provides digital to analog conversion and allows the user to send signals back up the network to re~uest dirrele-,t ch~nnel.c or services. In this application the Generic Flow Control field is used in the downstream to enable the devices to easily discriminate cells which contain video for that television set-15 top. In the reverse direction the Generic Flow Control field is used to identify fromwhich television set-top in that residence the signal origin~t~A
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 transceiver may be di~r~ from that in the device physical layer 20 transceiver, but it is possible to develop two integrated circuits, one of which is used in all of the BNU physical layer transceivers and another which is the same for all device physical layer transceivers.
A second advantage is that standard ATM integrated circuits can be used for the ATM layer plucec~ g~ since no additional fields are added to the ATM cells to route 10.
SUBSTITUTE SHFE~ (RULE 26 -CA 022270~3 1998-01-1~
WO 97/09799 . - PCT/US96/14498 them to the devices.
A third advantage is that the FTTC network can be viewed as a physical layer which presents standard UNI and UTOPIA interfaces to the ATM layer. No tr~n~l~tions from the ATM layer to a special or proprietary physical layer are nPcç~ry, since the use S of the Generic Flow Control field for device addressing is contained within the ~ l~l C
physical layer.
Although the present invention has been described in considerable detail with referGnce to certain ~lefelled versions thereof, other versions are possible. The goal of the invention as a method and apl~aldl~ls for re~li7ing interface cil~;uiLI~ as a physical layer 10 which utili_es the HFC bits in an ATM cell to ~i~tin~li~h devices and cell function with different functions for the downstream and the U~S~IG~II remains the same. Therefore the spirit and scope of the appended claims should not be limited to the description of the ~rGÇG"Gd versions cont~inP-d herein.
SUBS 111 UTE 5}tEET ~RU~ E 263
Claims (20)
1. In an asynchronous transfer mode communications network using asynchronous transfer mode cells as a structure for containing data and containing routing information where said asynchronous transfer mode communications network has a physical layer and where said physical layer has at least one cell transceiver of a first type connected to multiple cell transceiver of a second type over a shared communications media, a method of routing cells from said cell transceiver of a first type to at least one of said cell transceivers of a second type and controlling access by said transceivers of a second type to said shared media, said method characterized by setting at least one bit within a generic flow control field of said asynchronous transfer mode cells to indicate that said asynchronous transfer mode cells are destined for at least one of said cell transceivers of a second type, transmitting said asynchronous transfer mode cells from said cell transceiver of a first type, receiving said asynchronous transfer mode cells in at least one cell transceiver of a second type, and determining whether said asynchronous transfer mode cells are destined for at least one of said cell transceivers of a second type based on said generic flow control field.
2. In an asynchronous transfer mode communications network using asynchronous transfer mode cells as a structure for containing data and containing routing information where said asynchronous transfer mode communications network has a physical layer and where said physical layer has at least one cell transceiver of a first type connected to 12.
multiple cell transceivers of a second type over a shared communications media, a method of routing cells from said cell transceiver of a first type to at least one of said cell transceivers of a second type and controlling access by said transceivers of a second type to said shared media, said method characterized by setting at least one bit within a generic flow control field of said asynchronous transfer mode cell to indicate that said asynchronous transfer mode cell is being utilized to sign one of said cell transceivers of a second type onto said asynchronous transfer mode communications network.
multiple cell transceivers of a second type over a shared communications media, a method of routing cells from said cell transceiver of a first type to at least one of said cell transceivers of a second type and controlling access by said transceivers of a second type to said shared media, said method characterized by setting at least one bit within a generic flow control field of said asynchronous transfer mode cell to indicate that said asynchronous transfer mode cell is being utilized to sign one of said cell transceivers of a second type onto said asynchronous transfer mode communications network.
3. The method described in claim 1 further characterized in that said bits within said generic flow control field are set to zero prior to passing said asynchronous transfer mode cells to an asynchronous transfer mode processing layer.
4. The method described in claim 2 further characterized in that said bits within said generic flow control field are set to zero prior to passing said asynchronous transfer mode cells to an asynchronous transfer mode processing layer.
5. In an asynchronous transfer mode communications network using asynchronous transfer mode cells as a structure for containing data and containing routing information where said asynchronous transfer mode communications network has a physical layer and where said physical layer has at least one cell transceiver of a first type connected to multiple cell transceivers of a second type over a shared communications media, a method of routing cells from said cell transceiver of a first type to at least one of said cell transceivers of a second type and controlling access by said transceivers of a second type to said shared media, said method characterized by 13.
setting all bits within a four bit generic flow control field of said asynchronous transfer mode cells to zero to indicate that said asynchronous transfer mode cells are destined for all cell transceivers of a second type, transmitting said asynchronous transfer mode cells from said cell transceiver of a first type, receiving said asynchronous transfer mode cells at all cell transceivers of a second type, and determining whether said asynchronous transfer mode cells are destined for at least one of said cell transceivers of a second type based on said generic flow control field.
setting all bits within a four bit generic flow control field of said asynchronous transfer mode cells to zero to indicate that said asynchronous transfer mode cells are destined for all cell transceivers of a second type, transmitting said asynchronous transfer mode cells from said cell transceiver of a first type, receiving said asynchronous transfer mode cells at all cell transceivers of a second type, and determining whether said asynchronous transfer mode cells are destined for at least one of said cell transceivers of a second type based on said generic flow control field.
6. In an asynchronous transfer mode communications network using asynchronous transfer mode cells as a structure for containing data and containing routing information where said asynchronous transfer mode communications network has a physical layer and where said physical layer has at least one cell transceiver of a first type connected to multiple cell transceivers of a second type over a shared communications media, a method of routing cells from said cell transceiver of a first type to at least one of said cell transceivers of a second type and controlling access by said transceivers of a second type to said shared media, said method characterized by setting at least one bit within a four bit generic flow control field of said asynchronous transfer mode cells to represent a binary value for a device identifier in the corresponding decimal range of 2-14 such that said asynchronous transfer mode cells are destined for one of said cell transceivers of a second type with said device identifier, transmitting said asynchronous transfer mode cells from said cell transceiver of a first type, receiving said asynchronous transfer mode cells in at least one of said cell transceivers of a second type, and 14.
determining whether said asynchronous transfer mode cells are destined for at least one of said cell transceivers of a second type based on said generic flow control field.
determining whether said asynchronous transfer mode cells are destined for at least one of said cell transceivers of a second type based on said generic flow control field.
7. In an asynchronous transfer mode communications network using asynchronous transfer mode cells as a structure for containing data and containing routing information where said asynchronous transfer mode communications network has a physical layer and where said physical layer has at least one cell transceiver of a first type connected to multiple cell transceivers of a second type over a shared communications media, a method of routing cells from said cell transceiver of a first type to at least one of said cell transceivers of a second type and controlling access by said transceivers of a second type to said shared media, said method characterized by setting all bits within a four bit generic flow control field of said asynchronous transfer mode cell to zero to indicate that said asynchronous transfer mode cell is being utilized to sign one of said cell transceivers of a second type onto said asynchronous transfer mode communications network.
8. The method described in claim 5 further characterized in that said bits within said generic flow control field are set to zero prior to passing said asynchronous transfer mode cells to an asynchronous transfer mode processing layer.
9. The method described in claim 6 further characterized in that said bits within said generic flow control field are set to zero prior to passing said asynchronous transfer mode cells to an asynchronous transfer mode processing layer.
10. The method described in claim 7 further characterized in that said bits within said generic flow control field are set to zero prior to passing said asynchronous transfer mode 15.
cells to an asynchronous transfer mode processing layer.
cells to an asynchronous transfer mode processing layer.
11. In an asynchronous transfer mode communications network using asynchronous transfer mode cells as a structure for containing data and containing routing information where said asynchronous transfer mode communications network has a physical layer and where said physical layer has at least one cell transceiver of a first type connected to multiple cell transceivers of a second type over a shared communications media, a system of routing cells from said cell transceiver of a first type to at least one of said cell transceivers of a second type and controlling access by said transceivers of a second type to said shared media, said system characterized by means for setting at least one bit within a generic flow control field of said asynchronous transfer mode cells to indicate that said asynchronous transfer mode cells are destined for at least one of said cell transceivers of a second type, means for transmitting said asynchronous transfer mode cells from said cell transceiver of a first type, means for receiving said asynchronous transfer mode cells in at least one cell transceiver of a second type, and means for determining whether said asynchronous transfer mode cells are destined for at least one of said cell transceivers of a second type based on said generic flow control field.
12. In an asynchronous transfer mode communications network using asynchronous transfer mode cells as a structure for containing data and containing routing information where said asynchronous transfer mode communications network has a physical layer and where said physical layer has at least one cell transceiver of a first type connected to multiple cell transceivers of a second type over a shared communications media, a system 16.
of routing cells from said cell transceiver of a first type to at least one of said cell transceivers of a second type and controlling access by said transceivers of a second type to said shared media, said system characterized by means for setting at least one bit within a generic flow control field of said asynchronous transfer mode cell to indicate that said asynchronous transfer mode cell is being utilized to sign one of said cell transceivers of a second type onto said asynchronous transfer mode communications network.
of routing cells from said cell transceiver of a first type to at least one of said cell transceivers of a second type and controlling access by said transceivers of a second type to said shared media, said system characterized by means for setting at least one bit within a generic flow control field of said asynchronous transfer mode cell to indicate that said asynchronous transfer mode cell is being utilized to sign one of said cell transceivers of a second type onto said asynchronous transfer mode communications network.
13. The system described in claim 11 further characterized in that said bits within said generic flow control field are set to zero prior to passing said asynchronous transfer mode cells to an asynchronous transfer mode processing layer.
14. The system described in claim 12 further characterized in that said bits within said generic flow control field are set to zero prior to passing said asynchronous transfer mode cells to an asynchronous transfer mode processing layer.
15. In an asynchronous transfer mode communications network using asynchronous transfer mode cells as a structure for containing data and containing routing information where said asynchronous transfer mode communications network has a physical layer and where said physical layer has at least one cell transceiver of a first type connected to multiple cell transceivers of a second type over a shared communications media, a system of routing cells from said cell transceiver of a first type to at least one of said cell transceivers of a second type and controlling access by said transceivers of a second type to said shared media, said system characterized by means for setting all bits within a four bit generic flow control field of said asynchronous transfer mode cells to zero to indicate that said asynchronous transfer mode 17.
cells are destined for all cell transceivers of a second type, means for transmitting said asynchronous transfer mode cells from said cell transceiver of a first type, receiving said asynchronous transfer mode cells at all cell transceivers of a second type, and means for determining whether said asynchronous transfer mode cells are destined for at least one of said cell transceivers of a second type based on said generic flow control field.
cells are destined for all cell transceivers of a second type, means for transmitting said asynchronous transfer mode cells from said cell transceiver of a first type, receiving said asynchronous transfer mode cells at all cell transceivers of a second type, and means for determining whether said asynchronous transfer mode cells are destined for at least one of said cell transceivers of a second type based on said generic flow control field.
16. In an asynchronous transfer mode communications network using asynchronous transfer mode cells as a structure for containing data and containing routing information where said asynchronous transfer mode communications network has a physical layer and where said physical layer has at least one cell transceiver of a first type connected to multiple cell transceivers of a second type over a shared communications media, a system of routing cells from said cell transceiver of a first type to at least one of said cell transceivers of a second type and controlling access by said transceivers of a second type to said shared media, said system characterized by means for setting at least one bit within a four bit generic flow control field of said asynchronous transfer mode cells to represent a binary value for a device identifier in the corresponding decimal range of 2-14 such that said asynchronous transfer mode cells are destined for one of said cell transceivers of a second type with said device identifier, means for transmitting said asynchronous transfer mode cells from said cell transceiver of a first type, receiving said asynchronous transfer mode cells in at least one of said cell transceivers of a second type, and means for determining whether said asynchronous transfer mode cells are destined for at least one of said cell transceivers of a second type based on said generic flow 18.
control field.
control field.
17. In an asynchronous transfer mode communications network using asynchronous transfer mode cells as a structure for containing data and containing routing information where said asynchronous transfer mode communications network has a physical layer and where said physical layer has at least one cell transceiver of a first type connected to multiple cell transceivers of a second type over a shared communications media, a system of routing cells from said cell transceiver of a first type to at least one of said cell transceivers of a second type and controlling access by said transceivers of a second type to said shared media, said system characterized by a means for setting all bits within a four bit generic flow control field of said asynchronous transfer mode cell to zero to indicate that said asynchronous transfer mode cell is being utilized to sign one of said cell transceivers of a second type onto said asynchronous transfer mode communications network.
18. The system described in claim 15 further characterized in that said bits within said generic flow control field are set to zero prior to passing said asynchronous transfer mode cells to an asynchronous transfer mode processing layer.
19. The system described in claim 16 further characterized in that said bits within said generic flow control field are set to zero prior to passing said asynchronous transfer mode cells to an asynchronous transfer mode processing layer.
20. The system described in claim 17 further characterized in that said bits within said generic flow control field are set to zero prior to passing said asynchronous transfer mode 19.
cells to an asynchronous transfer mode processing layer.
20.
cells to an asynchronous transfer mode processing layer.
20.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US346495P | 1995-09-08 | 1995-09-08 | |
| US60/003,464 | 1995-09-08 | ||
| PCT/US1996/014498 WO1997009799A1 (en) | 1995-09-08 | 1996-09-05 | Fttc interface circuitry as a physical layer entity |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2227053A1 true CA2227053A1 (en) | 1997-03-13 |
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ID=21705999
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002227053A Abandoned CA2227053A1 (en) | 1995-09-08 | 1996-09-05 | Fttc interface circuitry as a physical layer entity |
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| EP (1) | EP0850519A1 (en) |
| JP (1) | JPH10511251A (en) |
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| AU (1) | AU7017196A (en) |
| CA (1) | CA2227053A1 (en) |
| NO (1) | NO980917L (en) |
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| US6542266B1 (en) * | 1999-06-24 | 2003-04-01 | Qwest Communications International Inc. | System and method for providing broadband data service |
| SI22463A (en) * | 2007-01-17 | 2008-08-31 | Telekom Slovenije D.D. | Device and procedure for reducing the operation attenuation |
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| US4941089A (en) * | 1986-12-12 | 1990-07-10 | Datapoint Corporation | Input/output network for computer system |
| US4994909A (en) * | 1989-05-04 | 1991-02-19 | Northern Telecom Limited | Video signal distribution system |
| JPH04305754A (en) * | 1991-04-02 | 1992-10-28 | Furukawa Electric Co Ltd:The | Multiplex transmission system |
| JPH05122391A (en) * | 1991-05-08 | 1993-05-18 | Fujitsu Ltd | Information collection service system |
| JPH05122238A (en) * | 1991-10-28 | 1993-05-18 | Fujitsu Ltd | Police system in atm exchange |
| JP2700843B2 (en) * | 1991-12-10 | 1998-01-21 | 三菱電機株式会社 | Multiplex communication controller |
| JPH0637797A (en) * | 1992-05-20 | 1994-02-10 | Xerox Corp | Reserved ring mechanism of packet exchange network |
| US5325356A (en) * | 1992-05-20 | 1994-06-28 | Xerox Corporation | Method for aggregating ports on an ATM switch for the purpose of trunk grouping |
| US5299044A (en) * | 1992-08-24 | 1994-03-29 | At&T Bell Laboratories | Ranging method for use in TDMA systems on tree-and-branch optical networks |
| JPH06132972A (en) * | 1992-10-20 | 1994-05-13 | Fujitsu Ltd | Broad band isdn remote multiplexer |
| US5425027A (en) * | 1993-01-04 | 1995-06-13 | Com21, Inc. | Wide area fiber and TV cable fast packet cell network |
| JPH06335079A (en) * | 1993-05-19 | 1994-12-02 | Fujitsu Ltd | Cell multiplexer in atm network |
| JPH0779233A (en) * | 1993-06-29 | 1995-03-20 | Synoptics Commun Inc | Apparatus for establishing topology, method and apparatus for communicating topology information |
| US5430715A (en) * | 1993-09-15 | 1995-07-04 | Stratacom, Inc. | Flexible destination address mapping mechanism in a cell switching communication controller |
| US5519690A (en) * | 1993-11-08 | 1996-05-21 | Hitachi, Ltd. | Communication control apparatus having function for limiting frame reception and switching system with the same |
| US5517617A (en) * | 1994-06-29 | 1996-05-14 | Digital Equipment Corporation | Automatic assignment of addresses in a computer communications network |
| US5619498A (en) * | 1995-08-08 | 1997-04-08 | Broadband Technologies, Inc. | Flag field-based routing mechanism for fiber optic telecommunication system employing STS-based transmission format containing asynchronous transfer mode cells |
-
1996
- 1996-09-05 JP JP9511452A patent/JPH10511251A/en active Pending
- 1996-09-05 EP EP96931510A patent/EP0850519A1/en not_active Withdrawn
- 1996-09-05 WO PCT/US1996/014498 patent/WO1997009799A1/en not_active Application Discontinuation
- 1996-09-05 KR KR1019980701090A patent/KR19990036421A/en not_active Application Discontinuation
- 1996-09-05 AU AU70171/96A patent/AU7017196A/en not_active Abandoned
- 1996-09-05 US US08/706,573 patent/US5907552A/en not_active Expired - Lifetime
- 1996-09-05 CA CA002227053A patent/CA2227053A1/en not_active Abandoned
-
1998
- 1998-03-03 NO NO980917A patent/NO980917L/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| AU7017196A (en) | 1997-03-27 |
| NO980917L (en) | 1998-05-08 |
| NO980917D0 (en) | 1998-03-03 |
| EP0850519A1 (en) | 1998-07-01 |
| US5907552A (en) | 1999-05-25 |
| JPH10511251A (en) | 1998-10-27 |
| KR19990036421A (en) | 1999-05-25 |
| WO1997009799A1 (en) | 1997-03-13 |
| MX9801338A (en) | 1998-07-31 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| FZDE | Discontinued |