CA2162284A1 - Multimedia network system with high speed data bus for transfers between network interface board and video board - Google Patents

Abstract

A multimedia network system (10) for connection to a computer (12) and a computer network (28). Asynchronous transmission mode cells on the network (28) are processed by a network interface board (22) with synchronous signals routed to an ISOBUS (26) and asynchronous signals routed through a packet memory (54) to the computer (12). Asynchronous signals are routed through the ISOBUS
(26) to a video board (24) and converted for output to one or more audio/video output devices (36). Signals originating at one or more audio/video input devices (34) are processed through the video board (24) and the network interface board (22) to the network (28).

Description

~094l27296 2 1 6 2 2 8 4 PCT~S94/051~

2 MuLTh~n ~NErWORKSYSr~MunrH ~GHSPEEDDATABUSFORTRANS~ Wk~

3 NETWORK~RFACEBOARDANDVIDEDBOARD

7 The present invention relates generally to the field of 8 electronic data communication and more particularly to a 9 system for local and wide area transmission of video and text information. The predominant current usage of the multimedia 11 network system is as a means for the exchange of information 12 between a great variety of types of computerized devices such 13 that information exchange is not limited by the type of 14 computerized sending device or receiving device, nor by the nature of format of the digitized information to be exchanged.

17 The advent of the "information age" and the accompanying 18 proliferation of computerized devices for generating and using 19 digitized information has resulted a number of different machines and methods for the sharing of such information 21 between users of such devices. This digitized information 22 takes many different forms, including but not limited to 23 digitized voice and other sound, digitized pictures (both 24 moving and still) and data in many different formats. Given the great variety of types of digital data being generated, it 26 is not surprising that quite a few methods for sharing such 27 data have been devised, it being quite natural that different 28 types of data might optimally be transmitted by different 29 means. The most obvious, although certainly not the only, differences between the transmission requirements of disparate 31 data types are the relative complexity of the data and the 32 rapidity with which a quantity of data must be transmitted.
33 Simple data transmission may be accomplished at relatively low 34 rates while, at the other end of the spectrum, digital moving pictures require a wide bandwidth and high transmission 36 frequency to update an image sufficiently quickly (even with 37 the use of sophisticated data compression techniques).
38 In fulfillment of these various needs, local area network 39 systems ("LANs") of various types have been developed for SUBSTITUTE SH~E~ (RULE 26) wo 94/27296 2 1 622 8 4 ~CT~S94/051~

1 communication over short distances, and a further variety of 2 wide area network systems ("WANs"), such as ARPANET, INTERNET, 3 and USENET, have been developed for communication over longer 4 distances. Fiber optic transmission systems, such as the Fiber Distributed Data Interface ("FDDI") and Distributed 6 Queue Dual Bus ("DQDB") have been developed more recently.
7 Even networks that operate at gigabit (billion bits per 8 second) speeds and which consist of parallel connections 9 between computers, such as a network marketed by Ultra Network Technologies, are available for linking supercomputers. At 11 the present time, special networks have also been implemented 12 for different services such as voice, data and video. While 13 some of these networks have been adaptable to more than one 14 data format, each has been restricted to only a limited spectrum of data types and the various networks in common 16 usage are generally mutually incompatible.
17 While many single purpose data transmission means and 18 methods were well adapted for their intended purpose, it 19 became evident some time ago that it would be desirable to transmit more than one type of data by the same means. One of 21 the first instances of this occurred in LAN type settings 22 wherein it was found to be desirable to be able to transmit 23 both voice and data over the same switched communications 24 lines. In response to the need to communicate a variety of types of digital information, Integrated Services Digital 26 Networks ("ISDN") have been developed for communicating 27 integrated voice and data messages. However, early versions 28 of ISDN methods have been limited in bandwidth such that 29 moving pictures and other such time compacted information are not amendable to transmission thereby. A standard for a 31 Broadband Integrated Services Digital Network ("BISDN") which 32 will have the necessary transmission capabilities is being 33 considered, and the International Telegraph and Telephone 34 Consultive Committee ("CCITT") has published a Study Group XVIII Report R 34 with recommendations concerning BISDN.
36 Asynchronous Transfer Mode ("ATM") is the transfer mode for 37 implementing BISDN, and ATM is independent of the physical 38 means of transport of BISDN signaling. The essence of BISDN
39 is versatility, and so the proposals for its implementation SUBSTITUTE SH~T (RULE 26) W094/27296 2 1 6 2 2 8 4 PCT~S94/051~

1 leave it up to independent inventors to devise means for 2 implementing communications in accordance with the proposed 3 functional criteria. According to paragraph 2.3 of the above 4 mentioned CCITT report, "The BISDN architecture is detailed in functional terms and is, therefore, technology and 6 implementation independent".
7 Clearly, it would be advantageous to create a "technology 8 and implementation" which would implement digital 9 communications according to the BISDN defined functions. In some small degree, such means are indirectly assumed by the 11 defined application. By specific intent, the detailed nature 12 of such means is not defined by the functions themselves.
13 Indeed, it is contemplated that a variety of such means may be 14 developed to accomplish various aspects of the defined functions. While it may be relatively easy to implement 16 specific functions of BISDN, prior to the present invention a 17 means for more general implementation of these functions has 18 not been defined. Furthermore, while it might be a more 19 straightforward (although still quite complicated) engineering task to bring about universal implementation of BISDN
21 functions through the use of very expensive high speed 22 computers which could provide the necessary processing power 23 to handle several broad bandwidth signals in parallel, prior 24 to the present invention there has been no general means of implementation of BISDN which could be accomplished using 26 commonly available and relatively inexpensive small computing 27 devices such as personal computers and the like.
28 To the inventors' knowledge, no means for implementing the 29 range of BISDN functional capabilities has been developed.
All concepts for such means which have been advanced have been 31 either limited in functional capability or else have been too 32 expensive to implement for broad based consumer level 33 acceptance.

Accordingly, it is an object of the present invention to 36 provide means for communicating digitized information which is 37 relatively independent of the form or content of such 38 information.
39 It is another object of the present invention to provide a SUBST~TUTE SHEET (RULE 261 2~ 62284 WO94/272sG PCT~S94/051 1 means for communicating a variety of types of digitized 2 information which means is compatible with many existing data 3 communications means and methods.
4 It is still another object of the present invention to provide a means for communicating digital information which 6 can transmit and receive communications having text, graphics, 7 data, image and moving picture information therein in 8 combination.
9 It is yet another object of the present invention to provide a means for communicating digital information which is 11 adaptable for use with commonly available computers.
12 It is still another object of the present invention to 13 provide a means for communicating digital information which is 14 inexpensive to produce.
It is yet another object of the present invention to 16 provide a means for communicating digital information which is 17 adaptable to essentially any function contemplated by proposed 18 BISDN functional criteria.
19 Briefly, the preferred embodiment of the present invention is a multimedia network system having a plurality of interface 21 units communicating with each other, with user computer input 22 and output devices, and with the network through three 23 distinct physical channels. Communication with the network is 24 through a Synchronous Optical Network ("SONET") Interface.
Communication with a host computer/controller is through a 26 host bus interface, and communications with other interface 27 units is through a unique Iso-Channel Bus ("ISOBUS"). In 28 addition, communication with input and output devices may be 29 made directly to the interface units thus, avoiding the necessity of requiring such communications to be directed 31 through a host computer/controller. In the best presently 32 known embodiment of the invention, a network card communicates 33 directly with the network and a video card communicates with 34 video and audio input and output devices. Both the network card and the video card communicate with and are controlled by 36 the host computer/controller through the host bus interface, 37 and communication between the video card and the network card 38 is via the ISOBUS.
39 An advantage of the present invention is that a great SU~S~ITUT~ S~EEl (RULE 26) ~o 94,272g6 2 1 6 228 4 PCT~S94/051~

1 variety of types of digital information may be communicated 2 thereby.
3 A further advantage of the present invention is that it 4 may be used in conjunction with commonly available personal computers and other inexpensive computer devices.
6 Yet another advantage of the present invention is that 7 existing data communications means and methods may be 8 integrated to communicate through a single data terminal.
9 Still another advantage of the present invention is that it is inherently relatively inexpensive to produce.
ll Yet another advantage of the present invention is that it 12 uses inexpensive peripheral devices.
13 Still another -advantage of the present invention is that 14 the universality of application will improve economies of scale, thus further reducing cost to the consumer.
16 Yet another advantage of the present invention is that it 17 can provide high quality moving picture video communications 18 while also communicating voice and/or other data.
19 These and other objects and advantages of the present invention will become clear to those skilled in the art in 21 view of the description of the best presently known mode of 22 carrying out the invention and the industrial applicability of 23 the preferred embodiment as described herein and as 24 illustrated in the several figures of the drawing.
BRIEF DESCRIPTION OF THE DRAWING
26 Fig. 1 is a block diagram of a multimedia network system 27 according to the present invention;
28 Fig. 2 is a block diagram of the network interface board 29 of Fig. 1;
Fig. 3 is a block diagram of the video board of Fig. 1;
31 Fig. 4 is an example network configuration employing the 32 inventive multimedia network system;
33 Fig. 5 is a block diagram of an example of the broadband 34 information server of Fig. 4; and Fig. 6 is a more detailed block diagram of the SONET
36 interface of Fig. 2.

38 The best presently known mode for carrying out the 39 invention is multimedia network system for interfacing a BISDN

SUBSTITUTE SHEET (RULE 26) W094t272~ 2 1 6 2 2 8 4 PCT~S94/05112 1 network to a network terminal. The predominant expected usage 2 of the inventive multimedia network system is in the data 3 processing and communications industry, particularly in end 4 user terminals wherein the ability to process a digital information in a great variety of formats is desirable.
6 The multimedia network system of the presently preferred 7 embodiment of the present invention is illustrated in a block 8 diagram in Fig. 1 and is designated therein by the general 9 reference character 10. The multimedia network system 10 has a computer 12 with a computer bus 14 therein. As will be 11 discussed in more detail hereinafter, it is intended that the 12 inventive multimedia network system 10 be adapted for usage 13 with a variety of computers 12 and computer buses 14. By way 14 of example, in the best presently known embodiment 10 of the present invention, the computer bus 14 is a microchannel bus.
16 As will be evident to one skilled in the art, the computer 12 17 has a central processing unit ("CPU) 16 connected to the 18 computer bus 14 for processing data provided from the computer 19 bus 14 and returning processed data to the computer bus 14.
Other conventional peripheral devices in the best presently 21 known embodiment 10 of the present invention include a 22 keyboard 18 and a printer 20 for input and output, 23 respectively, of data to and from the computer 12. Additional 24 data input and output means such as scanners, pen type input devices, and the like (not shown) may also optionally be 26 provided as required by the application.
27 At the heart of the best presently known embodiment 10 of 28 the present invention is a network interface subsystem 21 29 having a network interface board 22 and a video board 24. As can be seen in the view of Fig. 1, the network interface board 31 22 and the video board 24 are each connected directly to the 32 computer bus 14. The video board 24 and the network interface 33 board 22 are further connected to each other through an ISOBUS
34 26. The ISOBUS 26 is a slotted time domain multiplexed data bus for transport of constant bit rate services (such as ATM).
36 In the best presently known embodiment 10 of the present 37 invention, the ISOBUS 26 is a 16 bit wide bus operating at a 38 basic clock rate of 38.88 MHz. Transmission on the ISOBUS 26 39 is time divided into 8848 slots (plus a spare 11 clocks SUBSTITUTE SHEET (RULE 26~

wog4/272s6 PCT~S94/~1 1 between frames). The signals on the ISOBUS 26 are the 16 data 2 lines, the 38.88 MHz clock, a frame clock, and a payload 3 signal. For the sake of versatility in application, in the 4 best presently known embodiment O of the present invention it is required that any device connected to the ISOBUS 26 (the 6 network interface board 22 and the video board 24 in the 7 example of Fig. 1) be capable of providing the clock signals, 8 however only one is chosen to do so at any given time. The 9 payload signal is driven by whichever device is assigned the transmit function.
11 The network interface board 22 is connected to a BISDN
12 network through one or more network interface connections 30.
13 In the best presently known embodiment 10 of the present 14 invention, the network interface connection 30 is a fiber optic cable, although it is envisioned that other physical 16 carriers having sufficient bandwidth might be employed for 17 this purpose in the future.
18 Optionally connected to the video board 24 are a plurality 19 of audio/video input devices 34 and/or an additional plurality of audio/video output devices 36. As can be seen in the view 21 of Fig. 1, the best presently known embodiment 10 of the 22 present invention has a video camera 34a and a microphone 34b 23 as audio/video input devices 34, and a video monitor 36a and a 24 speaker 36b as audio/video output devices 36.
Fig. 2 is a more detailed block diagram of the network 26 interface board 22. As can be seen in the view of Fig. 2, a 27 Synchronous Optical Network ("SONET") interface 38 converts 28 fiber optic signals carried on the network interface 29 connection 30 to electrical signals employed within the network interface board 22, and vice versa (data flow is 31 bidirectional in the network interface connection 30. The 32 SONET interface 38 will be discussed in more detail 33 hereinafter. Data flow on the network interface connection 30 34 is in the form of ATM cells. Alternative ATM cell structures are defined beginning at page 90 of the aforementioned CCITT
36 report. Incoming data (now embodied as electrical signal ATM
37 cells) is sent to an input buffer 40 which, in the best 38 presently known embodiment 10 of the present invention is a 39 512 X 16 bit FIFO buffer. From the input buffer 40 incoming SUBSTITUT~ SHEET (RULE 26) W094/27296 2 1 62 ~ 84 PCT~S94/Q5112 1 data is provided to a segmentation and reassembly - receive 2 unit ("SARA-R") 42. The SARA-R 42 is an ATM reassembly 3 processor for reassembling incoming ATM cells (received from 4 the input buffer 40) into their original signal format(s) and separates constant bit rate streams for the ISOBUS 26, and is 6 a unit commercially available from TranSwitch Corporation. In 7 accordance with the normal operation of the SARA-R, a 8 reassembly control memory 44 is provided.
9 Reassembled signals from the SARA-R 42 are provided onto a receive bus 46. Constant Bit Rate signals on the receive bus 11 46 are recognized and buffered at a plurality (16 in the best 12 presently known embodiment 10 of the present invention, of 13 which 5 are depicted in the simplified view of Fig. 2) of CBR
14 receive buffers 48. From the CBR receive buffers 48 the CBR
signals are converted from 32 bit to 16 bit format at a 32/16 16 bit convertor 50, and are then provided (now in 16 bit form) 17 to an IsoChannel interface 52 (since there are multiple 18 instances of an IsoChannel interface 52 in the best presently 19 known embodiment 10 of the present invention, the present instance is designated herein as a network board IsoChannel 21 interface 52a). The network board IsoChannel interface 52a 22 interfaces the CBR signals to the ISOBUS 26.
23 One skilled in the art will recognize that CBR signals 24 (otherwise known as synchronous signals) include most forms of video signaling wherein data flow can be defined in units of 26 fixed length. Asynchronous signals, on the other hand, are 27 defined as being provided in "packets" of relatively 28 indeterminate length. As one example, LAN signaling (as in 29 the ETHERNET protocol) is generally accomplished using packet signals. In the best presently known embodiment 10 of the 31 present invention, packet signals are picked up from the 32 receive bus 46 by a packet memory 54. The packet memory 54 is 33 a 256 x 36 bit DRAM with a receive port 56, a send port 58 and 34 a host bus port 60.
From the packet memory 54, asynchronous signals are 36 communicated through the host bus port 60 to a host bus 62.
37 The host bus communicates through a host bus interface 64 of 38 the network interface board 22 to the computer bus 14 of the 39 computer 12 (Fig. 1) which, as previously discussed, is a SUBSTITUTE SHEET (RULE 26) ~1 ~22~4 ~094/27296 PCT~S94/051~

1 microchannel bus in the best presently known embodiment 10 of 2 the present invention. Since there are multiple instances of 3 a host bus interface 64 in the best presently known embodiment 4 10 of the present invention, the present instance is designated herein as a network board host bus interface 64a).
6 Asynchronous signals from the packet memory 54 are routed and 7 processed by the computer 12 in conventional manner according 8 to the specific type of asynchronous signal involved. In 9 general, the fact that the asynchronous signals are introduced to the computer bus 14 via the network board 22 (as opposed to 11 a board specifically adapted for interface of just one 12 specific type of asynchronous signal) will not be of relevance 13 to the manner in which the computer 12 processes such 14 asynchronous signal(s). Asynchronous signals generated by the computer 12 will be returned through the computer bus 14 and 16 the network board host bus interface 64a to the packet memory 17 54 (through the host bus port 60 thereof).
18 From the packet memory 54 outgoing asynchronous signals 19 are output through the send port 58 to a send bus 66.
Synchronous signals coming from the ISOBUS 26 are returned 21 through the network board IsoChannel interface 52a and then 22 through a 16/32 bit convertor 68 to a CBR send buffer 70 From 23 the CBR send buffer 70 the outgoing synchronous signals are 24 provided to the send bus 66. Signals on the send bus 66 which, as previously discussed include both synchronous 26 signals from the IsoChannel bus 26 and asynchronous signals 27 from the packet memory 54 are provided to a SARA-S 72.
28 The SARA-S 72 is a processor, available from the same 29 source as is the SARA-R 42, for assembling digital signals into ATM cells. As is customary for the functioning of the 31 SARA-S 72, a segmentation control memory 74 is provided.
32 Outgoing ATM cells (signals) are buffered at an output buffer 33 76 on their way to the SONET interface 38 for conversion to 34 fiber optic signals for output to the network interface connection 30.
36 CBR data and packet data are kept from clashing on the 37 send bus 66 because, when CBR data is present the SARA-S 72 is 38 interrupted (CBR data being given higher priority that packet 39 data). If there is no CBR data on the send bus 66 or in the SUBSTITUTE SHEET (RU~E 26) W094/27296 PCT~S94/0~112 1 output buffer 76 then the SARA-S 72 sends packet data from the 2 send port 58 of the packet memory S4 if there is any to send.
3 otherwise, the SARA-S 72 sends empty ATM cells.
4 As can be seen in the view of Fig. 2., and as can be appreciated by one skilled in the art, the host bus 62 6 communicates with the packet memory 54, the network board 7 IsoChannel interface 52a, the network board host bus interface 8 64a, the input buffer 40, the output buffer 76, the SARA-R 42, 9 the SARA-S 72, the reassembly control memory 44 and the segmentation control memory 74 for operation under control of 11 the CPU 16 (Fig. 1) of the computer 12.
12 Fig. 3 is a more detailed block diagram of the video board 13 24 of Fig. 1 according to the best presently known embodiment 14 10 of the present invention. It should be noted that, in some limited applications where video and/or audio input and/or 16 output is not required, it will not be necessary to include a 17 video board 24. However, where video or audio input or output 18 is required the video board 24 according to the best presently 19 known embodiment 10 of the present invention will be used in the multimedia network system 10. Since it is a primary 21 purpose of the present invention to enable video and audio 22 input and output, it is anticipated that in most applications 23 the video board 24 will be included, as illustrated herein.
24 As has been previously discussed, the video board 24 is connected both to the computer bus 14 and to the ISOBUS 26.
26 The video board 24 according to the best presently known 27 embodiment 10 of the present invention is conceptually divided 28 into three functional subsystems: an input subsystem 78, an 29 interface subsystem 80 and an output subsystem 82.
A plurality (two, in the example of Fig. 3) of audio 31 inputs 84 are provided to an audio input processor 86 and then 32 to an input audio control unit 88. In the best presently 33 known embodiment 10 of the present invention, the audio input 34 processor 86 is adapted for accepting Audio Engineering Society ("AES") stereo standard inputs and ALaw or ULaw audio 36 inputs (ALaw and ULaw audio are the designations of the data 37 formats used in conventional digital telephony). The audio 38 input processor 86 converts analog audio signals to digital.
39 An additional plurality (two, in the example of Fig. 3) of SUBSTITUTE SHEET (RULE 26) 2~ 62284 ~094/27296 PCT~S94/051 1 video inputs 90 are provided to a video A/D convertor 92, a 2 color decoder 94 and a pixel decimation unit 96. The color 3 decoder 94 converts raw digitized video into conventional 4 Y W4,1,1 format.
The pixel decimation unit 96 removes data from the digital 6 video image (as by eliminating every other line and every 7 other pixel from the remaining lines of the image) to reduce 8 the amount of digital information that must be transmitted.
9 This process, of course, reduces the image quality somewhat, but this is a desirable trade off in many applications. As 11 indicated in the view of Fig. 3, a bypass 97 is provided for 12 selectively (under control of the computer 12) bypassing the 13 pixel decimation unit 96. In many instances of application, 14 high quality video is not required and the data additional data compression provided by the pixel decimation unit 96 is 16 most desirable. However, in some applications (such as video 17 product brochures and negotiation conferences wherein it is 18 desirable to closely view the party with whom one is 19 communicating) it will be desirable to bypass the pixel decimation unit 96 to allow full quality video.
21 Processed audio and video signals are provided to a video 22 board IsoChannel interface 52b in the interface subsystem 80 23 of the video board 24. Also, as can be seen in the view of 24 Fig. 3, the audio input processor 86, input audio control unit 88, color decoder 94 and pixel decimation unit 96 operate 26 under control data (generated by the CPU 16 (Fig. 1) of the 27 computer 12) and provided through the computer bus 14 and a 28 video board host bus interface 64b of the interface subsystem 29 80.
Video and audio signals (in digital format, as previously 31 discussed in relation to the network interface board 22) are 32 also received over the ISOBUS 26 and forwarded to the output 33 subsystem 82. In the best presently known embodiment ~0 of 34 the present invention, since only two components, namely the network interface board 22 and the video board 24 are 36 connected to the ISOBUS 26, signals arriving at the video 37 board 24 on the ISOBUS 26 must necessarily have been produced 38 to the ISOBUS 26 from the network interface board 22.
39 However, it is contemplated by the inventors that, in at least SUBSTiTUT~ SHEET (RULE 26) W094/Z7~96 2 1 6 2 2 8 4 1~ PCTn~05l~

1 some applications, there may be additional devices 2 contributing to or receiving signals to and from the ISOBUS
3 26, and the present invention is not restricted to this 4 specific limitation of the best presently known embodiment 10.
Also, as can be seen in the view of Fig. 3, the output 6 subsystem 82 operates according to control data received from 7 the computer bus 14 and forwarded through the video board host 8 bus interface 64b.
9 The output subsystem 82 of the video board 24 has an output audio control unit 98 and an audio output processor 100 11 for converting the digitized audio arriving at the video board 12 24 on the ISOBUS 26 into a conventional analog audio output 13 102. In the best presently known embodiment 10 of the present 14 invention, the audio input processor 86 and the audio output lS processor 100 are actually physically embodied together in the 16 same mechanical package, although this is not a necessary 17 aspect of the invention.
18 Also in the output subsystem 82 are a pixel expansion unit 19 104 for restoring missing data from images that have been pixel decimated (discussed previously herein in relation to 21 the pixel decimation unit 96). As indicated in the block 22 diagram of Fig. 3, a second bypass 97 is provided for 23 bypassing the pixel expansion unit for those applications 24 wherein it is not necessary to reconstitute a pixel compressed image. The output subsystem 82 further has a color space 26 convertor 106, a video ram 108, a video D/A and multiplexer 27 110 and a windowing engine 112.
28 As discussed in part above, the pixel expansion unit 104 29 adjusts incoming decimated video signals to simulated PAL/NTSC
and Y W4,1,1 signals. The color space convertor 106 converts 31 Y W4,1,1 to conventional RGB. The resulting RGB encoded data 32 is temporarily stored in the video ram 08 to be acted upon, as 33 requested by the operator via software drivers, by the 34 windowing engine 112 to provide a video output to the video monitor 36a (Fig. 1). The video D/A and multiplexer 110 36 converts the RGB into conventional VGA analog format and 37 further mixes data incoming from the BISDN network 28 (Fig. 1) 38 with additional video signals incoming from video inputs 90 39 and/or video supplied by the computer 12 (Fig. 1).

SlJBSTITUT~ SHEET (RULE 26) 1 A video output 114 is provided from the video D/A and 2 multiplexer 110 to the video monitor 36a (Fig. 1). In the 3 best presently known embodiment 10 of the present invention, 4 the video output 114 is a conventional Super Video Graphics Array ("SVGA") compatible signal.
6 Fig. 4 is an example network 116 configuration employing a 7 the multimedia network systems 10. The quantity and 8 arrangement of each of the components in the illustration of 9 Fig. 4 is for the purpose of example only, and is not intended to be limiting. The network 116 in the example of Fig. 4 has 11 a plurality (two in the example of Fig. 4) of Local Area 12 Networks ("LANs") 118, a conventional (non-multimedia) work 13 group LAN 120, and a media resource center 122 connected to an 14 Asynchronous Transfer Mode ("AT~") switch 124 by a plurality (four in the example of Fig. 4) of BISDN busses. The ATM
16 switch 124 is further connected to a public switched network 17 130 by an additional BISDN bus 128, an ISDN bus 132 and a 18 switched multi-megabit data service ("SMDS") bus 134 to 19 provide flexibility in communications with the public switched network.
21 In the multimedia work group LANs 118, computers 20 (the 22 term computers 20 is used generally here, as one skilled in 23 the art will recognize that workstations on a LAN can consist 24 of computerized devices, point of sale terminals and related devices being examples, which are generally not specifically 26 referred to as computers) are connected within in the 27 multimedia LANs 118 through a matching plurality of the 28 network interface subsystems 21 by isochronous, high 29 bandwidth, busses which meet IEEE 802.6 standards ("IEEE 802.6 busses") 138. As used herein, the term "isochronous" refers 31 to a transmission mode which pre-allocates regular, periodic 32 transfer slots on a link. Fixed length ATM cells are used as 33 the common transport mode throughout the multimedia LANs 118.
34 To provide backward compatibility, the conventional non-multimedia LAN 120 is connected to the ATM switch 124 (through 36 the associated BISDN bus 128) by a router 40. The computers 37 20 of the non-multimedia LAN 120 are connected to one another 38 and to the router 140 by a bus conforming to IEEE 802.3 39 standards ("IEEE 802.3 bus") 142.

Su~sTlTlJTF SHEET (RULE 26) W094/27296 PCT~S94/Q51 1 The media resource center 140 in the example of Fig. 4 has 2 therein a broadband information server ("BIS") 144.
3 The multimedia LANS 118 support the capture, storage, 4 transfer and display of audio and video digital data streams (as well other types of digitally encoded information) in a 6 networked environment. The network 116 including the 7 multimedia LANs 118 enables networked video conferencing, 8 audio video databases, and the like, within the network 116.
9 An example of the BIS 144 of Fig. 4 is illustrated in block schematic form in Fig. 5. As can be appreciated in 11 light of the above discussion, the BIS is intended to provide 12 video information, upon demand, to other devices connected to 13 the network 16 (Fig. 4). In the example of Fig. 5, the BIS
14 144 is equipped with a plurality (four in the example of Fig.

5) of audio/video input devices 34 (examples of which have 16 been discussed previously herein in relation to Fig. 1) 17 providing input through an analog crossbar switching matrix 18 146 to a plurality (four in the example of Fig. 5) of the 19 network interface subsystems 21 previously discussed in relation to Fig. 1. As described, each of the network 21 interface subsystems 21 is equipped with a video board 24 and 22 a network interface board 22. As previously discussed herein 23 in relation to Fig. 4, output from the BIS 144 is provided to 24 the ATM switch 124 for distribution to the network 116 (not shown in the view of Fig. 5). A control unit 50 is provided 26 for controlling the analog crossbar switching matrix 146 and 27 the network interface subsystems 21, as previously discussed 28 herein. A mass storage unit 150 is provided for storing the 29 audio/video information acquired from the audio/video input devices 34 such that it can be sent out to the network 116 31 upon demand.
32 Fig. 6 is a block diagram showing the makeup of the SONET
33 interface 38 of Fig. 2 as it is constructed in the best 34 presently known embodiment 10 of the present invention. As can be seen in the view of Fig. 2. The SONET interface 38 has 36 an optical transceiver 152 for receiving and transmitting 37 optical signals. Although it was not originally intended for 38 this sort of application, a transceiver commonly available 39 from Sumitomo has been adapted as the optical transceiver 152 SUBSTITUTE SHEET (P~ULE 26) wo 94,272g6 2 1 6 2 2 8 4 PCT~S94/051~

1 in the best presently known embodiment 10 of the present 2 invention. A receiver 154 is provided for accepting signals 3 from the optical transceiver 152 and forwarding them to a 4 field programmable gate array ("FPGA") 156 and a SONET
termination unit 158. The receiver 154 is part number S3006 6 supplied by AMCC and is designed specifically for operation in 7 accordance to SONET OC-3 specifications. As can be discerned 8 in more detail in the specifications available from the 9 manufacturer, the receiver 154 provides clock separation, serial to parallel conversion, frame synchronization, loss of 11 signal sensing, frame loss alarming ECL to TTL level 12 translation and both line and terminal loop back capability.
13 The SONET termination unit 158 is a part number SOT-3 14 available from TransSwitch. SONET functions are provided by the SONET termination unit 58 in accordance with the design 16 intent of the manufacturer. The FPGA is a type 1224 field 17 programmable gate array available from ACTEL.
18 Also provided in the BIS 144 is a transmitter 160 for 19 receiving signal from the FPGA 156 and forwarding it to the optical transceiver 152. The transmitter 160 is part number 21 S3005 available from the same source as previously cited for 22 the receiver 154. The transmitter, 154 provides parallel to 23 serial conversion, clock generation, terminal and line 24 loopback, TTL to ECL translation and line encoding functions.
A crystal oscillator 162 is provides a reference clock for the 26 SONET interface 144 and the master clock for CBR functions on 27 the network interface board 22 (Fig. 1). (As previously 28 discussed herein, each board connected to the ISOBUS 26 29 should, according to the best presently known embodiment 10 of the present invention, be capable of providing system clock.
31 In order to completely discose the present invention for 32 the benefit of those skilled in the art who wish to understand 33 the exact manner in which the best presently known embodiment 34 10 of the present invention carries out the inventive method and means, a detailed description of the communication 36 protocol for the ISOBUS 26 is included herewith as appendix A
37 hereto. A detailed description of the remainder of the data 38 communications protocols operating within the network 39 interface subsystem 21 is included as appendix B hereto.

SUB~TITUTE ~EET (RULE 263 W094/27296 2 1 6 2 2 8 4 PCT~S94/~51~

1 As is shown above, in great part, the multimedia network 2 system 10 according to the present invention provides a means 3 for implementing communications within and between a great 4 variety of computer devices, and both within and between a variety of computer networks and other computer 6 interconnection means. Among the substantial differences 7 between the present inventive multimedia network system 10 and 8 the prior art are the inclusion in the network interface board 9 22 of the enabling means described herein for communicating both synchronous and asynchronous data in a manner such that 11 the differentiation between data types is essentially 12 transparent to the user. Furthermore, the unique division of 13 functions between the network interface boards 22 and the 14 video boards 24, and the unique ISOBUS 26 for transmitting high speed CBR data therebetween provide a level of 16 versatility of data communications unknown in the prior art, 17 particularly since the video boards 24 and the network 18 interface boards 22 can be used in various combinations and 19 quantities according to the needs of a particular application, as previously discussed herein in relation to the BIS 144.
21 Circuitry details of the present invention are conventional 22 given the functional descriptions and interrelationship of the 23 various components described herein, and no significant 24 changes of materials are envisioned nor are any special constructions required.
26 Various modifications may be made to the invention without 27 altering its value or scope. As just one example, as 28 increasing production quantities of the inventive multimedia 29 network systems 10 permit, it should be possible to combine functions described herein as being embodied in separate 31 subunits into integrated circuit packages.
32 All of the above are only some of the examples of 33 available embodiments of the present invention. Those skilled 34 in the art will readily observe that numerous other modifications and alterations may be made without departing 36 from the spirit and scope of the invention. Accordingly, the 37 above disclosure is not intended as limiting and the appended 38 claims are to be interpreted as encompassing the entire scope 39 of the invention.

SUBSTITUTE SHEET (RULE 26) W094/27296 PCT~S94/05112 2 The multimedia network system 10 is intended to be widely 3 used in a great variety of digital data communications.
4 Indeed, it is difficult to point to one specific intended usage that would be more likely to predominate over others.
6 As just an example, the inventors are developing an 7 application wherein department store point of sales terminals 8 could be connected to a central data base by means of the 9 inventive multimedia network system 10. In such an application, not only could the purchaser's credit data be 11 made available in real time, and the purchaser's account 12 updated as the sale is made, it would even be possible to 13 display the user's picture at the point of sale (to verify 14 identification) and/or to transmit an image of the user's fingerprint from the point of sale for computerized comparison 16 to data base fingerprints. As the science of retinal laser 17 identification is perfected, this means of identification 18 could also be added to the system.
19 Additional prospective applications range from the communication of weather radar images to interested weather 21 observers (in which case, a radar unit (not shown) would be 22 added as an additional audio/video input device 34) to the 23 accomplishment of more mundane tasks such as computerized 24 "shop at home" services, and the like.
The present inventive multimedia network system 10 has 26 application for both "on line" type services such as bulletin 27 boards (wherein the user is charged for time on the system) 28 and "on demand" services wherein the user is charged a fixed 29 fee for a transaction (or a fixed purchase price, or the like).
31 In summary, it is the very purpose of the present 32 invention not to be restricted by the type of data which it is 33 desired to communicate. Therefore, the industrial 34 applicability should be limited only by the imagination of the users of the invention. A more detailed discussion of how the 36 present invention might interface with the several emerging 37 related technologies is included her as appendix C hereto.
38 The multimedia network system 10 of the present invention 39 may be utilized in any application wherein a conventional SUBSTlTUrE SHEE~ (RU~E 26) 2~ 62284 W094/27296 PCT~S94/05112 1 computer data communications means are used. Furthermore, the 2 inventive multimedia network system 10 is expected to create 3 new applications wherein the communication of digital 4 information might be useful.
Since the multimedia network system lo of the present 6 invention may be readily constructed and may be adapted for 7 use with existing computer equipment and other existing 8 peripheral devices it is expected that it will be acceptable 9 in the industry as a substitutes for existing data communications means. For these and other reasons, it is 11 expected that the utility and industrial applicability of the 12 invention will be both significant in scope and long-lasting 13 in duration.

~UBSTITUTE SHEET (RULE 26) wog4n7296 PCT~S94/05112 1 APPENDI~ A
2IsoChannel Timing 5Basic Clock Rate: 38.88 MHz or 25.720164 nS
7 Isoch~nnel Time Zones = 169 per second 9 Tcl = IsoChannel Cell Period = 26 clocks Q 25.720164 ns = 668.724 nS
11 Ttz = IsoCh~nn~l Time Zone Period = l/169 = 5.917159 ms 13 Ncz = Number of Cell Periods per Time Zone = Ttz/Tcl Ncz = 5.917159 ms/668.724 ns = 8848.432238 17 Ncz = 8848 + (.432238 * 26 clocks / Cell Period) 18 = 8848 + 11 Clocks 19 Ttz = 5.917159 ms 21 1 8848 x 26 clocks 11 22 Clks ¦ ¦ 5.916876 ms 23 283 ns 24 1~ >1~ >

27 ZCLK = Zone Clock _¦

30 For an overview of IsoChannel sequencing see Dwg. #CBM-B102 33 ICSRAM: Isochannel Scheduling IsoChannel traffic is governed by the schedule of 36 isochronous cell traffic at the IsoChannel. One cell period 37 at the IsoChannel consists of 26 clocks. 24 clock times are 38 used to transfer cell data two bytes wide and two clock times 39 are used for overhead. Each cell time is associated with one SUB~ lt SHEE~ (RUlE 26) W0 94/272g6 ~ 84 PCT~S94/051~

1 of 64 IsoChannel users, identified by a six bit IsoChannel 2 User ID field (IUID).
3 Each circuit board residing on the IsoChannel is 4 controlled by three enable signals, the 38.8 MHz bus clock and a special control RAM called the IsoChannel Scheduling RAM
6 (ICSRAM). The ICSRAM are individually written and maintained 7 by the host as new CBR virtual circuits are established and 8 torn down. Each RAM uses 8848 locations, coinciding with the 9 8848 IsoChannel cell periods and cycles through all locations in one IsoChannel Time Zone Period.
11 Each IsoChannel board is assigned one (or several) IUIDs 12 and looks for that ID at the output of the ICSRAM to determine 13 when to talk, listen or idle. The RAM is byte wide, 6 bits 14 for the IUID and 2 control bits encode the expected activity.
The two control bits are encoded as follows:
16 Bit 7 Bit 6 17 0 o Idle 18 0 1 Talk: Write data to the bus 19 1 0 Listen: Read data from the bus 1 1 Talk and listen (used for testing) 21 The ICSRAM address counter is updated two clocks prior to the 22 start of a cell period, to allow time for the logic to prepare 23 for the upcoming cycle. The address counter is reset during 24 the low time of ZCLK.
l l l 26 Clock edge 0 ^ 1 ^ 2 ^ 3 ^ 22 ^ 23 ^ 24 ^ 25 ^ 0 ^ 1 IUID = IsoChannel IUID Valid Cell 0 ¦ IUID Valid 31 Cell 1 User ID Valid 33 ¦<----- One Cell Period ----~¦

IsoChannel Data Path 37 The IsoChannel data path is implemented as the three deep 38 pipeline: an edge triggered latch is used at the entrance and 39 exit from the IsoChannel itself, resulting in three pipeline SUbSlllult SHEr (RULE 26) wo 94/27296 2 1 6 2 2 8 4 PCT~S94/05112 1 phases.
2 Talker Listener 3 Isochannel 4 > REG T ¦ ~¦ REG L ¦ --~
.

7 Within a Cell Period, three enable signals are used to 8 sequence the pipelined data transfer over IsoChannel. TENA is 9 used the IsoChannel :Talker: to enable 24 waves of two-byte-wide data at each clock edge, which are latched at REG T. The 11 zeroeth data wave is valid on the input to the IsoChannel 12 latch at the onset of the enable signal and changes with the 13 first clock edge.

IENA is used to enable latching at the listener board, REG L, 16 one clock later. Finally LENA is used by the listener to 17 provide 24 timeframes to write REG L data to the onboard 18 destination.

Clock edge 0 1 2 3 22 23 24 25 0 23 TENA = Talk Enable _¦ 1 2 22 23 24 l_l _ 26 ¦ ¦ _Data wave number 28 IENA = Iso Enable I _l 1 2 22 23 29 1 _l _ 31 ___ 32 LENA = Listen Enable ~ ¦ 0 1 2 22 33 23 1 _l_ 36 QBUS Interface to Host 38 ICS~M~ are individually loaded by the host. The RAMs are 39 memory mapped to the host address space and located at offset SUBSI~Iult SHttl (RULE 26) W094/27296 ~l 6 ~ 2 8 4 22 PCT~S94/05112 1 0x40000 from the base address of the board (addresses 40000 to 2 4228f). Q8US is a local bus used to distribute host bus 3 signals to the IsoChannel control block as well as other board 4 resources. QBUS timing is shown on Dwg. CBM-T-101; QBUS
signals are described below.

7 QD00..7 I/O A bidirectional eight bit local data bus.
8 QA00..15 I Sixteen bit local address bus.

QMEMRD* I Active low signal used to gate the read data 11 onto the data bus.

13 QMEMWRT* I Active low write enable signal.

QALE I Active high pulse used to latch an incoming 16 address 18 QCHWAIT* O Open collector signal driven by IsoChannel logic 19 (and other board logic) to extend the cycle time.

22 ISOCS* I A decode of the high order QAnn address bits.
23 Directs the memory operation to the IsoChannel 24 devices.

26 ISOINTR* I IsoChannel interrupt request for service. Use 27 an open collector driver. If there is more 28 than one reason to interrupt, provide a status 29 register which can be read and written by the host using ISOCS2*

32 ISOCS2* I A second decode of the high order QAnn address 33 bits. If other control pulses or status 34 registers need to be implemented they are mapped to address space 48000 thru 4800f.

SUBSIl~Ult SHEEI (RULE 26) APPBNDIX B
2 l. SCOPE
3 l . l Introduction 4 The recent introduction of suitable opera~ionql standards, sophisticated application of S specific h~ d circuits, and the potential of C4~ carrier in~rl~ of long dictqnce 6 high speed con~ n( bit services in accolda~ce with the s~da~ds has enabled an oppollunily for 7 high quality video l;elwo~ g. One of the neceC~q~y co"l~o~ellts to exploit this o~l,o,lu~ y is a 8 DATA-FLOW (MediaNet(tm)) arc~ e to enable end to end (tçrminql to terminql) and server 9 to terTnin-q-l corS~ 1 bit rate services. CBM Inc. has a family of products to imrlPmPnt this a~ e. One of the primary L.. rl;onc l~f~e;:C5 y for proper filncti~ ning of a data-flow system 11 is a method for geneldil~g and le-.~ -g audio and video ;-~r.,.,.. -~;.. n This fi~n~innqlity is 12 embodied in the CBM Inc. MNAVlmc audio/video board.

14 1.2 MNAVlmc The CBM Inc. MNAVlmc is a Micro-Channel c~ ;I,le audiohideo display/capture 16 board with an iso~L~onous bus connp~ion to allow constant bit rate services to be used for the 17 purpose of c ~llt~ ;.. g and ~ -g real time audio and video as well as r~c~ h.g the audio and 18 video.
19 The MNAVlmc S~l~pO,~ capture of PAL or NTSC video and cu.,~ ion to YUV 4,4,1 for tral~"lis~ion over the IsoChannel(tm) to the ~lwol~ board for ~I~l~P~l;O-~ to the outside world.
21 IsoChannel is part of CBM's data flow a~h;l~--e allowing for data to flow ~.. ~ ly and 22 smoothly to or from l~ ",;,-ql~, servers, switches, or bridges.
23 The MNAVlmc s.lppolls capture of audio in two forns. One is tPle~hone quality digital 24 audio in nT ~w or Alaw standards. The other form is AES (Audio ~g;~ Society) digital stereo.
26 The MNAVlmc s~po,ls the display of real time video from the ~Plwull- or from local 27 sources.
28 The MNAVlmc s~po-~ the reg~ -- of digital audio from the n~WO11~ in both forms.
29 The MNAVlmc opel~tes in concert with Windows 3.1 and plOpliPt~ CBM sofl-.~e to implement a smoothly functioning operator interfi~e for con~P~ n to video co~f~ ;iLg, video 31 data bases, security systems, retail sale or other i.. r.,.. ~ ;O~- kiosks, as well as iy~plir~vq~ions 32 enlo~ q~ .g mutual doclllnP~nt editing, and Vmail.

34 2. Functional description The CBM Inc. MNAVlmc is a PCB assembly that ~ -ri~c~V IsoChannel (tm) to analog 36 video and audio I/Q The data present on the IsoChannel is co.~ ;sed of time slots. The slots are 37 C~lyillg video, audio, or other col.. C~ bandwidth signals. In control terms, the MNAVlmc is a 38 device that is setup by external signiqli~ from the host bus. After ;~;I;q~ n and setup, the 39 MNAVlmc accepts the slots and COn~le~lS them to the dtlp~o~ le analog form and accepts analog SUBSmUrE SHEEr (RULE 26) WO 94/272% PCT/US94/05112 input and formats them into slots cells and l-~mils them on the IsoChannel bus.
2 The analog side of the board interf~rpc to video and audio connPrtinn~. The video is PALINTSC
3 composite analog video and the audio intPrf~e is single channel voice grade analog or AES stereo.
4 The Micro Channel host bus intPrfare provides power and a data path for setting and reading board parameters as well as still frame capture ;~ ri~e 6 The IsoChannel intafq.~re is l~onsihle for ~.. ~;.. 1~i.. ;~g s~u-~ fi-n with the bus, 7 receivi~ g control i.. rO.. ~ n from the host bus, receiving data on its qC~igr Pd slots, and sending 8 data on its qccigned ~ n.;l slots. The MNAVlmc uses BTL l,~sc~ for the line electrical g i.. 1~ri~e. All 1~ 3~ir)nc are as qcsig~Pd by the controlling software. Local display of c~luled data can be done by setting slot acc;~ on the IsoChannel to ~c~il and receive on the same 11 time slots.

13 2.1 IsoChannel intprfare 14 The IsoChannel intPrf:~e is a slotted time domain mllltirl~P.~Pd data bus deci~pd srerifirqlly for ILans~o,l of cQn~ 1 bit rate services to and from nelwo,k and audio/video sut,~ -,s. The 16 IsoChannel is implpmpnted using FPGA terhn~'ogy to CBM's r.~ rperifir~irm The 17 IsoChannel is a 16 bit wide bus at a basic clock rate of 38.88 MHz. The IsoChannel is divided 18 into 169 frames or zones per second. Each frame is further divided into 8848 slots (plus a spare 19 11 clocks at frame time). The signals on the bus are the 16 data lines, the 38.88 MHz clock, and a frame clock, and a payload signal. It is ,c~uir~ that any IsoChannel device be capable of 21 providing the clock, h~,~.c.a only one is chosen in an IsoChannel e~ ped system to do so. The 22 payload signal is driven by whichever device is q~cignPd the ll~s--lil r.l~- L;on in a given slot.
2 3 The host c~ ul~r has the r~o~ ility of controlling the operation of the Isot'hqnnel The 24 control of the IsoChannel is acc~lichPd by loading a ram whose Ol ~.a~iOn iS s~"~h,u--i4~ and mapped to the IsoChannel slots. IsoChannel traffic is go.~,.ued by the s~hPdllle of isGeh.ùnu~ cell 26 traffic at the Iso~l~qnnPl One slot period at the IsoChannel consists of 26 clocks. 24 docks are 27 used to transfer cell data two bytes wide and two clock times are used for overhead. Each cell 2 8 time is associated with one of 64 isocl.~o~ous users, i-lPntifiPd by a si~c bit wide user ID field in the 29 control ram. In addition two bits in each byte of the control ram are devoted to read or write co~ dc to/from the bus in conjull~lioll with each usa ID field. The ram uses 8848 loC~-~innC
31 for co"~ dence to the slots on ISorhqnnpl. The IsoChannel is fle~cible by virtue of the ability 32 to be programmed on a slot by slot basis and places data onto the bus by plO~A~ hle data 3 3 density instructions from the host. Instructions are static in nature, that is i~Luclions are held and 34 e~ernt~P~ cQntinll~usly until changed by the host. In addition the IsoChannel provides FIFO
3 5 burr~ g for output data stre ms.

SUBSll~U~E SNEEI (RUIE 26) ~o 94/27296 PCT/US94/05112 2.2 Video fimrtion 2The video rU~ nc on the MNAVlmc are display of video from the IsoChannel or from a 3 local source, and capture of video data from a camera or other analog video source in PAL or -4 NTSC format.

6 2.2.1 Input video processing (From IsoChannel bus) 7 The video flow from the IsoChannel is first processed in an FPGA to put it in a form 8 accc~table to con~,el-~ional and proven video Ci~.,ui~l~. The balance of the video data stream going 9 to the display is processed by a Chips & Technologies windowing engine and overlay buffer control chip set (69003/69004) o~,c,ding in conjunction with Philips color space CO~ el 11 (SAA7182). The balance of the ci~.;uil.~ is video ram for buff~ g pul~osei and a Brooktree 12 ramdac (BT121). The input video processing ci~;uil-~ has the following plul~el~ies: F-pqnrlc video 13 data stream (adds non displayed samples); provides e~p~q,rlcion of CIF data; marries an incoll~ing 14 video stream to the graphics subsystem of a co.. -~ule~ by interlq~ing with the graphics controller;
provides scan rate cûL.~e.~ion and windowing control for display of a live video image on a 16 co.-.~.ltel grarhics Llonilol, accepts YUV 4,1,1 PAL or NTSC digital video data; RGB 16, 24, 32 17 bit output; controls window position by X-Y coo~i.. ~t~; in~lepen~lpnt X-Y scaling of video Image 18 to as small as 1/8 original Image size; int~lac~l or non-;~t~-lr~i video; output r~sol,Jtiol-c up to 19 1024x768; still frame capture suppOllèd; COll~ the bufre ~d RGB data to analog data; ~wil~hes 2 0 data streams from video to graphics per the input video p~ocessol, provides frame llulre~ ii-g for the 21 ;~cu~ video data stream which is coordin~led with the gr~?hics subs~ elll via the video 2 2 processor wu.~i-.g in conjunclion D/A Cû~ . and analog switch.

2 4 2.2.2 Output video ru~ ;on Clo IsoChannel bus) The Capture video ru~ is i.. l~le ~ ed using Philips A/D chroma and luminance AID
26 coll~ .s ~DA8709/l~DA8708) in ~ccoc:~';ûn with a video multi ~ -J decoder (SAA7151).
27 This co.. l~màlion ~a~lur~ and COIl~ PAL or NTSC analog data to and l---.. ;---n-e data to YUV
28 4,1,1. Further processing is inlrle.. r.-led in FPGA tPrhn~logy for the pul~OS~S of con~ ~r~t;ne 29 data, (le.llo~s non displayed samples) and de~ E data for CIF r~solution if nr~ess~y.
31 2.3 Audio ~uI,s~i,t~ms (CODEC) 3 2 With the e~certi~m of Pnr~su1~ion of data and the ~ lo~ e of data from IsoCh~ ~n~l, the 3 3 audio ~ul,~ ,.l- is primarily the r~ onc:l.ility a single IC (Analog Devices AD1849). This device 34 contains e,.~ ing needed for both AES stereo and monaulal cv~ g of audio ii~rU-.~ ;t)n The features imrlrm~nt~ on the MNAVlmc are as follows: frame ~yllcLuni~lion of AES data 36 stream, data field decode for host e~ ;on, sigma/delta D/A con~el~-oll, proP.;~ le mute 37 fimrtion stereo and mono audio line outputs, line and miclophûne inputs, progl~ ~""~1 le gain, 38 sigma/delta A/D convtl~ion, monitor function, coll~e.~ analog audio data to an ALAW or uLAW
39 PaIS digital data streams; cûll~e~ ParS digital data stream to analog audio.
SU~ UltSHEE~ ~RUlE26~

wo 94/27296 2 1 6 2 2 8 4 PCT~S94/05112 Some support for the AD1849 is built into the FPGA for en/~o~ the data for transport by 2 the ISot'h~nn~pl. These are frame s~ l~o~ ion of AES data stream for proper decoding and data 3 field Pnc~rsul~ion and framing for IsoChannel l~,o,l.
2.4 Hostbus interface 6 The MNAVlmc host bus is a MicroChannel (tm) ~ ible illl~Çace which provides the 7 i.~1~ . ri~re to the host CPU for control and status data "~Ic~cl.ange for each of the features available 8 on the board.

2.5 ~e~1.s~ d~pcc~irti~n 11 The MNAVlmc co--fo~ s with the .--o- h~ standards for Microt'h~nnPl The 12 connP~tinnc for audio and video are a 26 pin "D" and have the pin PCsi~ .p.~l~ as follows:
13 ~ Pin#
14 video in (signal) 8 video in (return) 17 16 audio line out left (signal) 4 17 audio line out left (return) 13 18 audio line out right (signal) 5 19 audio line out right (return) 14 audio line in left (signal) 2 21 audio line in left (return) 11 22 audio line in right (signal) 3 23 audio line in right (return) 12 24 audio mono out (signal) 6 audio mono out (return) 15 2 6 audio mic in left (signal) 2 7 audio mic in left (return) 10 2 8 audio mic in right (signal) 7 29 audio mic in right (return) 17 chassis gnd 24 31 NC 9,16,18-23,25,26 32 The co~ ionc for VGA are in~ple---~ d in a 15 pin ~D" co~ ~tor and has the following pin 33 ~c~
34 Si~nal Red video 36 Gre_n video 2 3 7 Blue video 3 38 NC 4,9,11,12,15 39 Digital return S

SUBSlllll~E SHEE~ (RU~E 26) ~o 94/27296 2 1 6 2 2 8 4 PCT~S94/05112 red return 6 2 Greenreturn 7 3 Blue return 8 4 Digital return 10 Hffync 13 6 V-sync 14 8 3.0 NetworkVideo format Overview 9 The low speed (155.52 Mbs) MPVd;~nPt COnnf'`,~ n is limited to 149.56 Mbs for data 1 ~o-~ and any video format must be less than or equal to this value jn~ly~ljn~ ATM cell 11 overhead. By USiDg YUV 4:1:1 the network bandwidth re~u,.. ".lcnLs for ~ 4~ ressed video 12 L~ oll will be as follows*:
13 720X590X25 ~PAL) 127.44 Mbs 14 720X483X30 (NTSC) 12~.1936 Mbs 352X28 (CIF) 36.49536 Mbs 16 *note: these values do not include the ATM cell o~,e~head and are stripped of non displayed pixels.

18 The video data is stripped of samples that are not in~ d~pd in actual display of data and sync 19 i~rO~ iOn is encod~P~ by value. A byte that is equal to zero is a ho~ ;~v~ sync, two bytes of zero is a vertical sync, and three bytes is vertical sync/frame tag. Immediately after dete~i~ a 21 frame tag, the following four bytes of the video data are the frame number which is used for 22 gene.dLil. an h~ t on value or else the count can be acc~ d at any time by the host bus. In 23 "~f~lifinn, the frame number can be initi~li7e~ to any value, be set to h crell,en or dccr~;,-.e~, and 24 the in~ lup~ can have di~er~l~l logical rel-~;r~r h;l)5 (< =, ~ =, =). The front and baclc porch timing is not l~C.. ~;ft,~ and is ~eco~5l~uct~d locally. The number of ATM cells that are sent per 26 video frame are adjusted so they can ~ . ilJu~e in a regular manner onto the Iso~-~nPI . It is the 27 function of an FPGA on the MNAVlmc to l.~lale MediaNet data formats to and from 2 8 con~er,lional data forms.

SUBSlllult SHE~ (RUlE 26) APPENDIX C
2l. The El~ F ~ A;~ C~
3 A few years ago, Alan Kay provided the author a tour of Xerox's Palo Alto Research 4 Center. The things being done there were with con~l~ulef~ were a revelation. The intPracti9n of S ll-year olds with the c~ u~ was being studied by a psychologist; the children had ~leci~np~d 6 their own icons for the graphics-oriented system they were wvlkillg with. While Kay played Bach 7 on an organ console, his program cdplur~ the music on a monitor screen. Kay edited his with a 8 mouse, and the system played the new version back, c~mplete with organ-pipe turnon tr~n~iPnt~.
9 This CO1~ U~e~ and the others were tied together with shared cable system, but almost as an afterthought; how people i.lt~ ed with col~ ulc~ was more ilpol~l than how C4111~U
11 i,l~e-~.~led with each other.
12 By now the use of graphical int-erfacPs with icons has become cv.~ L~ e, as has 13 hlercon.. e~ g systems with FthPrrPt The i~1p~r~re between the user and the c~ u~e~ has 14 progressed from a one~ n~l folded ~llala~ler stream to a two~ on~l page or desktop metarh--r. The use of local area networks has made it possible for small, cheap, co.ll~uler~ to take 16 over much of the work of l.lai~l~lcs. these innovations arising from PARC and similar places 17 have now been ~csimil~p~l into the .--ai~lled,.. ; Microsoft's Windows has moved from a clumsy 18 imit~ti-)n of the Macintssh to a must have item for serious PC users. Where will our next 19 revelation come from.
2 0 In a~ ,in that ~ n cQncidp~ that we live in a 4 dimPn~ional world, with time as the 21 fourth ~limPnCiQn and thus far only two spatial ~ "enCi~ have been luul---ely used in cv---l-ul- -22 ;~r~ r;-- e~s. It now appears clear that the next major step forward is to make use of the time 23 d;.. ~ncion This means going from still frames to video an other moving images, and from simple 24 beeps to audio ca~,abililies rivaling Kay's work of the s_.eu~ies.
The third space d;~ cicn will be honored mainly by being simulated in two ~1;.. n~ r c for 26 arp~ ionc such as - h~ ~' design. CV ~yu~liOn may be done in three d;~ but the 27 human i l~t;la. ~ivn will still assume a flat canvas. True three~;~ cn~l output media, such as 28 hologl~, are still a large ~lict~nce on the h~ri7l~n 29 In going to a cvlll~uli~g e~vilolllll~l that takes advantage of the time domain, the best 3 0 description is mllltimPAiq The ~lPmqnAs of video and audio are substantially dirr~e"l from current 31 data transfer appli~qti~m~ and will require new hardware in three major areas:
3 2 On the desktop 3 3 The reh~vl~
34 The mvltim~PAiq server A cu~ that intends to work in mllltimPAiq ~-l-~uling must make sure that all three of these 3 6 bases are covered, either itself of by partners it works with.

3 8 This ~ ;. n is similar to the one that existed in the early fifties with color television. No 3 9 one would want to buy a color set if there were no programs being broadcast in color, and no SUBSlT~E SHEE~ ~RULE 26) wo 94/272g6 2 1 6228 4 PCT/US94/05112 station would invest in color ~Ji~ without and a~ ipnr~e to justify it. Fo,lullattil~ RCA both 2 m~m~f~red sets and owned broadc~ting st~tion~; it s~lbsi~ ~ both sides until the market 3 reached a self-suyyolling size, at which point it had a s_b~ -' lead over its coluy~ ul~.
4 Timing is also a critical e1PmPnt There is little room for a startup if major firms already do.. ;.. i1e the market, but success is equally elusive if one is too early. The fate of the early work 6 is well known.

8 1.1 CBM in the E.,,~;n Market 9 CBM is addlessil,g the three hardware areas ",~ n~ above: the desktop, the n~,~WO1k~
and the server. It is positionp~ to achieve the nr~ critical mass: in each of them it will have 11 products that will work together well and also provide an open system in which users can attach 12 other eq~ 1 and applir~irm~. Users now demand s~dards-based systems that will allow 13 other vendors' .. A~k;.,r5 to attach the nelW(~ and will permit a wide variety of appli~ ~ion~ to 14 access the illro""A1ion coming in over the n~twolL
The timing is right. Video-cu,l,ylesi~ion terhn~ 'cgy is making rapid strides, leading edge 16 applic ~ nc are in sight, and multiservice nelWul~ are ~ hlg from s~dards CU ~ ~S~ with 17 serious plans being made to i.. l l~ 1 them as public r~ ;Ps In order to get the users a little be 18 p~ Apple is now in~'h]~ sun-.~orlly video deco~ ssion plOgl~ called Qlli~`lrtimP in 19 the Mac opelati"g system, and is ~sou~agii~g the dt~ oy---~ ~ of h~.l. ord C .k ~ for it.
2 0 Video co",yl~ssion until now has largely been a pluyl;~ y field, with users requ,ldd to buy 21 mAtl~hed pairs of col"~lession/deco- ~ ession boxes from the same vendor. Now ~d.uds are 22 c~rhing up with the terhnology from several directions, and it is hllyûl~t to be able to claim 23 standards comrliqnre although which standard is still a matter of choice. JPEG aoint Picture 24 Editing Group), CCll'r, or the de-facto Intel/lBM DVI (Digital Video I~lel~eliVe) s~da~d developed for games. A system that ;~u~pOltS whatever the ~ -~J~ needs, or thinks he needs, is 2 6 the right answer.

2 8 1.2 CBM Experience: the Berkom c ~ n 29 The country that has been most aOOl~;~ive in pushing for high-speed public n~woll hlg has been Ge ",~. A number of trial nelwol~ ol)eldlillg up to 155 Mbs have been set up over the 31 last few years. One such project, Berkom (for Berliner ~tmmllni~ c~ t~u)~ provided 32 e~perience in high-speed ~elwull~inO for CBM's original parent, Con~P~. This te~l ~o~cO~ is 3 3 nûw available to CBM.
34 For Rerlr m, con~lAt~p~ developed ~IllyOne,l~:i of a mllltimPdiq nelWO1l~. audio, video, and graphics boards for PCs, as well as ne,lWcll~ ;"lr,~r.-~C ~uypGllhlg early versions of B~adl)al~d 36 ISDN at 139 and 153 Mbs. The e pP,riPn~e gained by the RUn~iP~rost in o~ g a variety of 3 7 app~ qtil~n~ and services over the trial .. ~1WU1I~ has provided CBM with insight into the potentiql of 38 such system. This insight goes well beyond that shown by most nelwo~h~g c~ y~-~;Ps, small or 39 large, and should be conc;~lP~red one of the firm's greatest ~ "ollls.
SUBSllrUltSHE1 (RUlE26) 2 13 ~d~.. l areas 3 This section will cover specific CBM products, with lere.ence to the overall needs of the 4 mnltimPdi~ systems.

6 13.1 n ~topinterfac~
7 Since there are several desktop families in co~on use, cove~ g the market ~eqll~tPly 8 involves providing boards for all of them. The PC, the M-~intosh and the Unix-based systems 9 such æ Sun will all have to be covered in order to provide for existing desktops. There are tens of millions of PC's and other desktop CO~ r-~ inQt~llPA. in this country. It would be totally 11 impractical to require users to discard them in order to phæe in new rmlltimPAi~ applir~ti~)nQ-.
12 CBM has boards with co----- on f~nrtion~lity dPQig~P~ for the most popular c~ e~ buses:
13 AT bus and MCA bus for IBM c~ 1P-Q
14 Nubus for M~intoQ-h II
S-bus for the Sun SPARC family.
16 These boards differ in their ~ e- ri-~e to the co~ Ju~r's system bus but otherwise provide co~ o 17 filnrtion~lity and cO.. ---~ types of crmn-p-ction to the n~wulL Data pæsing from board to board, 18 for example from the n~wulL board to the video board, b~l,asses the system bus and uses CBM's 19 own Iso('h^~nPl This appl~,acll makes a great deal of sense. It offloads the CU~ UIC~'S system bus, which 21 might otherwise be totally clogged by the data volume ~equi,cd by full-motion video. It also 22 provides -dd;l;o~l cG,~ ol-ality between the board designs used in the various har.l-.~e 23 pl ~ rO.. ~, which otherwise differ in the way they transfer data over the system bus.
24 Software is a very tricky issue for networks whose operation affects all parts of the 2 5 co~ ul~ ., with file tnan~fP., audio, and video being routed to the Tnonitor- Particularly in the PC
2 6 with DOS, the normal rigid bû! ~d~- ;es between applic~ti~nc~ O~e.dting system, and device drivers 27 were never developed. As a result, 3rplic~tion~ have had to know far too much about the devices 28 on the system. If one is to introduce a new device, it must su~c;hu~ take ad~tage of st~d~
29 APIs (~Mlir~tion Program T.~r ri-~s), since old programs have no way of acc~ o~h.g new 3 0 drivers.
31 Other ùpc-~ systems, such æ Uni~ of the M~ ntlsh op~ld"lg system, have more 32 sophi~tirSted fi~;liti~ but n~ .e~ cless have quirks that are not easy to work around.
33 These problems have lcc~;-/ed a great deal of ~ttPntion at CBM. Without the benefit of 34 eYh~ctive e~p~pripnce~ it would be difficult to say if all the po~nlial problems have been solved, 3 5 but it is clear that there is an aliP~qu~te level of t-~c.lise to deal with any problems that could come 36 up.

3 8 13.2 The server 39 Most CQ-~ Ps ~t~e~ted in developing rnn1timPAi~ systems æsume that the source of the SuB~ it SHEE~ (~U~E ~6) WO 94/27296 2 1 6 2 2 8 4 PCT/US94/051i2 i~".,~ion is so--l~.. L~ e else. G~ne.alil,g the video, pe~ rO.. ,-g the c~lc~ n for v~Cuqli7?ti~n~
2 and sou,c~ug cQmrlPY audio signals are all so---eo~-e else s problem. This is a bit like the sound of 3 one hand clapping: in~ ing to co~ P-- ~ te, but difficult to find an applic ~iQn for. CBM, in 4 - contrast, has tackled the server problem and made it central to its strategy.
s The ;.-rO.. ~ion volume that can be abso,l,ed by video workstations is ~"o",-ùus. There is 6 little likelihood that it will be possible to generate everything on the fly; data, video egmentC and 7 an e.,o,.,ld-ls variety of mqt~riql will need to be ~ nP~ up from storage media and sent via the 8 netwo,k to the mnltimediq wu.~ ;on 9 The server needs a great deal of versatility in its arc~ re since the applications are quite varied and subject to change as more appli~ionc are conc~;ved fro mllltimPY~ systems.
11 F-~m~lPs of the storage media that users may need include:
12 laser video disc 13 music CD

digital audio tape 16 video tape (in a large variety of formats) 17 co~ ~nal col"~,ule, disc 18 optical read/write disc 19 paper ~ocllmP~nt plus scanner 2 0 as well as other high-volume sources such as 21 video camera 22 radar ,~G;ver 2 3 i~l,~"hll output 24 CBM has r co~"i~d this issue in making the server central to the a~C~ ;t. Its MDBS/1 p~vides a variety of inputs s~ ble to the networlc output. This system should be able to retain 2 6 its fle.~il,ilil~ and be able to handle new media as they come along.

28 133 Source Switching 29 With a wide variety of source media and mnltirle dp~ ;onc~ some sort of switching is ,~qui,ed to get the data to the proper end point. CBM allows for this in having a central ATM
31 switch at the heart of the netwo~k~ in fact as an integral part of the mllltimP~iq server.
32 An ATM switch can in fact be a number of dirr~.e~ things. The basic idea is simply that 33 the unit of data switched is a fixed-length packet or ~cell" in the ~ r world. The ~
34 capability of such ~wild,es follows from the fact that the small cells can be interleaved easily on any co.. -----~ n line ranging from voice-grade up to gigabits per second. This allows fi~ced-3 6 and variable-balldwidll, services to coexists col~o-~bly on the same r.~wo,L
37 Any shared m~ lm network or shared.l"t -ld-y can act as a switch. Units of data (in this 38 case cells) are brought into ~ from one port and are read out to another. The shared 39 rnPAi~lm nctwu~ (which can include a"~ i.,g from a ~ ti~up wide are ne~wul~ down to the SUBSlml~E~HEE~ (RUI 26) 2~ 62~84 backplane of a cou.yulcr) accepts data from one node, addressP~d to another. Of these tw-o 2 mPth~ , the shared ~ h~l~ is probably the easiest and ~l-P~ to implement, ~ltht)ugh when the 3 number of ports on the ~ uo,~ becouues high, access logic for the memory beings to looks like a 4 shared bus.

6 13.4 ~ ses di~lrib~dio~-7 The c~ ol- de~ ol of all the options used by CBM in swilclPing and di~ibulion 8 (both on the ple~l~ises and off) is the use of ATM cells. Differing switch terhn~ logies can be used, 9 and dirr~,.clll cQlle~tion and dis~lil,ulion n(,lwo,~ can be installed, but ;--ru~ l;on source and destin^~ir~n can be jnC~ Pd from the dirr~ences.
11 For example, the distribution of ATM cells on the p~.llises can be either point-to-point or 12 via an 8û2.6 network.
13 The cell formats for these two nelwulks are very similar. For public networks, 802.6-based 14 feeder networks will hand over their cells to ATM switches, which will be capable of h~nrlling very large volumes totaling hundreds of gigabits per second in the a~ alc. In premises 16 ri~,lwu,~, this cQmp~tibility means that CBM will be able to make use of both te~hn- logies.
17 The point-to-point network is relatively simple: for each fiber, one end ~ cells at 18 will, and the other end receives them. The ultimate d~ ;on of each cell may actually de 19 dirr~le lt, but the link has only two nodes and avoids the need for a mp~il)m-access protocol 2 0 r~uilod with shared media such as F.thP~Pt 21 CBM has provided a cost crr~tivc point-to-point network adapter in its BFA/l, which uses 22 the cell formats e~lle.ging from the Bro~ 1 ISDN i~ku~ddldiL~tion effort. when B-ISDN is 2 3 installed in a public n~lwo~k, the B~A/1 will be usable for off-p~ s_s .lwu~ g as well as on-24 pl~.uises.
The otha ~ s, the IEEE 802.6 protocol, was dFCi~,J~fd to support multimedia 2 6 applications over ~l;C~ ec of tens of miles,but it sill work -very well for plC Sf~ ~rplir ~ nS~ It 27 is a shared-medium network with a medium-access protocol that is d;~ re ;~ ;live colllya~od 28 to LANs. It also is cell-bæed, with a cell size and structure dp-cign~pd to be ~ya~ible with wide-29 area nelwu,ks based on ATM ~will~hing.
The use of a shared n~,lwulk has its pros and cons relative to the ATM switch and d~PAir^~Pd 31 links. The positive side is that a switch is not needed at all since the cells can be addr~sed 32 directly to any dr~ n on the nCIWOIL Further, no single point ûf failure e~ists; if any node 33 fails, the ne~w("k a~-lullldically ~W~r~g~e itself.
34 The limit^~ion iS in the total ll~uugllyul available. Chips will short~y appear on the market 3 5 capable of running the protocol at a speed of 45 Mbps, but higher SONET speeds such as 155 and 3 6 622 Mbps are still a couple of years away. Since the 802.6 nctwollL is bidire~tinn~l, the 45 Mbps 3 7 speed gives a total of 90 Mbps for all the users on the system, but that is not suffi~iPnt to support 38 ~ co--~ esso~ video.
39 A ~ulylolllise solution prol,osed by CBM makes sense. It involves using 802.6 as a SUBSlITU~ SHE~ ~RUL~

2 1 6228~

mllltimPAi~ rcLwu,L for modest size wo~ uul~s, with the groups "l~rcQ-~nP~l~Pd via a point-to-2 point links from a bridges to an ATM switch. The BFA/l-based link can run at high speed to 3 retrieve data from the server or from the outside world, with ~ .il.ulion to the desktop via the 4 shared-mPAillm 802.6 nclwulL This solution will work so long as the bandwidth dem~n~lc are moderate; it has the advantage of sharing the medium among a number of w~.L~I ~ions. Any 6 wo.l~ ion which requires continuously high rates, as for example, in unco~ lcssed or lightly 7 col,l~lessPd video, can be co~ ed directly to the switch.

9 1.3.5 Off p~- es l,~h.(~ i.. g Premises r,clwolkillg is of course only part of the r~uir~"e.lt. High-speed netwo,Lil.g 11 f~ilitiP~5 are now being planned by the tplephnnp co~-y~ ~iP-c~ with actual service begi~ g in 12 1992. The service is SMDS, which is based on the IEEE 802.6 standard with some cimrlifi~ati-nn 13 and some additions. While the 802.6 terhnology is not eff~ Pnt for users distributed .. ,.iru~ y 14 over l,."~dreds of rniles, as employed by SMDS it will work very well.
SMDS will use 802.6 as the protocol between the ~Ilc~ cr pre",ises and the central office.
16 In order to provide privacy, the connPction for particular ~ubs~ ;her will not pass through anyone 17 else's ple.",ses; m-lltiple C~ r~liQnc to the bus are pe .~ A but they will all be within the same 18 ~;u~Lullle~'s f~ilitips. Connections between central offices may or may not u e the 802.6 protocol 19 (eventually they will be l~loadl.~ ~ ISDN with large ATM s.. il~,Lcs) but the users will not be 2 0 aware of the dirr~l~.,ce.
21 The a~lrlitionc made to the 802.6 s~,d~d include the scl~ni-~g of source and destin^~ion 2 2 addresses and the inc~l~,o,dion of billing f~ilitiPs The capability of ml~hirle pre~ses 23 conmPctinnc at the T1 speed is not lequi~ed, making the link in effect point-to-point. In this case 24 the di~ ted queue protocol need not really be implemented, but the format of the fields in the cells sent down the line must be the same as when Inultirle co~ P~l;nnc share the bus.
26 SMDS e~ provides only for data tranQ~niQsiQn with a c~ ~l;n~lf ~c service 27 co~ 1 with that provided by LANs. This is not ideal for multiservice f~ itiPs~ but the 802.6 2 8 protocol will ~cco.~ -od~e the other services (drafts are being written now in the IEEE u~
29 and SMDS can be upgraded to handle them. There is a natural rPluct~nce on the part of the telephone i"lusL,~ to c~",~e with existing PaIS for voice, but the eCo~n~;cc indicate that 3 1 carrying voice from pltll~ises to CO on the 802.6 link make a lot of sense. If the RBOCs don't do 3 2 it, the ~ " ~ ;ve carriers will.
33 Variable-bit-rate services, on the other hand are new and not cross-elastic with existing 34 revenue sources. As a result, there should belittle reh,~ ce on the part of the carriers to adopt 3 5 such features, provided existing e lui~l"enl can be upgraded eco~o~ y to support it.
3 6 The keys to the adoption of SMDS are the provision of cost-effecnve tariffs, the av~q~ bi71~y 3 7 of CPE facilines, an~7 the fr~rn770~ion of switches in a suff cient set of centra,7 offices.
38 Present e,~ c are that Bell Atlantic will offer service late in l99l to selected .-~ u~
39 on a special~uote basis, with the tariffed service coming on-stream in the spring of 1992.

SU~IIIU~E S~EE~ (RU~E 26~

WO 94/27296 2 t 6 2 2 8 4 PCT/US94105112 Pacific Bell will probably the second of the RBOCs to offer the service; their field trial 2 started with Stanford Uni~ y and wound up with a number of name Silicon Valley firms such as 3 Apple and Hewlett-Packard.
13.5.1 Until SMDS arrives 6 With the t~lçFh~nç i~u~ ramps up SMDS, other qlle~ es are available for the short 7 run. These include the old standby of leased lines, an expensive solution if there are many sites to 8 be h~Lerco~ ~ but rea30nable if there are only a few. The jump in Cdl)aCily between T1 at 9 1.544 Mbps and T3 at 44.7 Mbps is a very large one; however, Çl~elional T3 may become available in some cases.
11 Another short-term solvtinn is frame relay. Frame relay service is r~ g up faster than 12 SMDS, but it is limited to T1 speed. The ~.sage se~ilive feature of frame relay is a big relay is a 13 big benefit for slower applications, but multiservice applic^~ion~ will be at the high end of the Tl 14 range, not the low end. l::l,e.l~.. ally frame relay will migrate to T3, but SMDS may well arrive first and provide the general co~ ;vily that frame relay, with its pe-.~ ( virtual circuits, 16 cannot match.
17 A dark horse for inle.~l-n~ g multiservice sites is primary-rate ISDN. The ~cc~1~-~re of 18 ISDN in the US has been so slow that it would be risky to count on basic-rate ISDN, let alone 19 primary rate ISDN, in most parts of the country in the next few years. The market failures of ISDN have col~ lced most of the players to wait for a new roll of the dice--some looking at 21 frame relay and some at SMDS.

2 3 2. Gating t~ o!ogies 24 The advent of ~llticervice r.~,twu-l~ will be the result of a number of technical factors, all 2 5 of which seem to be at the right point either now or in the ;-~ e future.

27 2.1 Video ~ r-28 The video Co~ l~SiOn buC;~ '~c has arc~l~ra~d rapidly in the last few years. Having lived 29 for perhaps a decade on the long-distance video ~.. l~encing applirq~i~n this ~d~lsh~ has 3 0 r~ceived a shot in the arm from the appl~ ach of HI~TV. The desirability of having a digital TV
31 system, coupled with the 30 MHz baudwidlll of HD~rV, has made col~ ,ssion a must i 32 co~ ~nal 6 MHz ~ 1c are to be used. Also, the d;~ of video e.lt.,.l~ over 3 3 digital fiber lines also depends on the use of cOll-~llf ~ssion.
34 The result is that a variety of s~ld~ds and approatl~es are rea~llin fruition in dirr~,.e.
areas. The JPEG aOint Picture Editing Group) started from the point of en~odine still frames, 36 while the DVI consolliulll (plin.;i~ally Intel IBM) started from video game technology. CCll~, 37 lcl~i~e~illg the telephnne il~duslly~ of course is doing its own thing.
38 Whichever ~I,loach bccollles the most popular, the result is that the .. --~............ r.-- ~u ;~ e volumes 3 9 and integration in silicon will force prices down to a few hundred dollars per ~f ~.. ;n.'il within a few SU~SllIU~E Sl~E~ ILE ~

wo 94/272g6 2 1 6 2 2 8 4 PCT~Sg4/05ll2 years. This will make it possible to run the deslctop CO~ u~ with video capability at a price that 2 Lundr~s of thousands of users will sign up for over the decade 4 2.2 High speed m:~.u~ rs The hol~u.. ~ race in microprocessors in no more than a year away from the lO0 MIPS
6 level, an i~clJ~n;-h;ug level of power when co.llparod with the original VAX at 1 MIPS, which was 7 capable of su~ol~ing t-wo dozen time sharing users.
8 If a 1 MIPS can do a l~sye~ ')le job of word processing or running a s~re~lchPet what can 9 be done with lO0 MIPS? M^nirul^~irn of pixels, video and audio synthesis, conlrle~
c4~ tion protocols, all can be done in the processor's spare time. Certainly atti~r~ 1 to a 11 multiservice n~lwolk will not result in the processor being sw~ul,~ed.
12 Concull~ tly, the speeds as well as the sizes of lUt~-Ol,~ chips have been increasillg.
13 DRAMs, the main lllelllol~ element in most desktop m~hinps~ are widely available under 60 14 n~noseronrl~ cycle time, with 4 megabit capacity-. Likewise, the SR~M chips used in the fastest memories or caches, have dropped ~ .k;,l~.n;~lly in price for a give speed. The result is that the 16 cost of building "~ s for visually~ri~Pnt~Pd data is not an il~ibilil.g factor.

18 23 Multisen~ice n~h.~
19 The final en^l~1ing terhn~l~gy is in the nclw(J~killg area. The last decade has seen a strong march toward ~d&.ls on the part of the user cQ------~--;~, with the result that a r-r.~ lard 21 relwulk is a very difficult sell. Users would prefer to wait for so---l ll.;.. g that is at least plausibly 2 2 a s~uldaLd~ even it if means delaying their inlrl~ n plans.
23 The l~ey to providing netwoll~ that worlc well with dirr~re.-l kinds of traffic is to divide the 24 data streams into small s~grnPnt~ or cells that can be readily ;~t~ P~ This has been the main con~ ;nA that has led 802.6 I.. ~opolitan n~.Jll~g standard to the use of cells. For this 26 reason and also because of the po~";~l cost and speed a~v~ges of ATM s~.itch~s, the wide area 2 7 ~elwo~ ,g world is also headed toward a cell ~
28 Taking the cell ~proach to the desktop then brings the lu-lllisl.vice aJv~g~ to the LAN
29 user. In adrlitinn~ it provides a CQ~C;~ a~ach to II~WUl~illg, with PSs~ ly s~ ss bo.~ ;es between local, metropolitan/campus, and wide area n~lwul~. This latter advantage 31 will make the cell-to-the-desktop dpproacll adv~g~us even to the c~u~ lional data L~wulLug ~2 user, whose major application is simply the transfer of data files.
33 The result can be simrl;r~r ~ n of the mlwoll~i-.g process, where the ;~ f'4 ~ ~;bilities of the 34 various nclwol~h.g layers CTCP/IP, ISQ SNA, DECnet, etc.) can be cir~;uuu~e.ll~d. The use of a global E.l64 address with geographic si~ifirqll~e (it is esc~ ly a tel~rhone number) will bring 3 6 to co.ll~ulel n~wul~ g the a~ ~ges that the telerhnn~ iu.lusll~ has had in country codes, area 37 codes, etc." and the post office has had in zip codes. No switch will have to know much more 3 8 than its immediate ~ l to be able to route data worldwide.
39 The 802.6protocol has been d~igr~ to handle ~nn~l;nnless data, i~hl~l~ous traffic SUBSrIT-UTE SHEET (Rll~ 2~

wo 94/272g6 2 1 6 2 2 8 4 PCT/US94/05112 (fixed bit rate), and variable bit rate traffic C4'~5;C~ 1 with the needs of coul~lesscd video. In 2 order to meet the time COl~llahl~S of the SMDS introduction, the 802.6 standard was issued with 3 cove~ge only for connectionless data. All other items were left for future; work is now under 4 way on them.
The le ~ .g two ser-vices are now being finiclleA Most of the ~ignifir~nt de~i~;onc in the 6 isocLo~ous case have been made: the cells will be d~PAir~r~d to a single c~rmf~- lion rather than 7 being shared between many Cf~ r~;OI~c, as origin~lly envisioned. Such cells will be directly 8 co~ ;ble with ATM sWil hillg. The ",~ .. for s~ ollillg the generation of cells at a 9 variety of fiuced bit rates has been largely defined: the only comrlir~ ~ion is the ll~poll of l .544 Mbps Tl traffic, which does not fit the pattern of N x 64 kilobits per second.
11 The mPrh~ni~m for sl~yu,ling variable bit rate service has been proposed and refined 12 several times. It is likely that all the ci nifir~nt dericinnc will be made within the next four 13 months.
14 The result of this schedule is that it will be possible to start ;.. ~~ c 1y on the developmr~nt of ha~dw~e that implements all the 802.6 services. If some changes are made as the s~lda~d goes 16 through the a~r vvdl process, the designs can be updated before final c~.. -;l.. -r-.~ to pror1~rtion 17 silicon.
18 In the short run, the lack of high-speed 802.6 or ATM-oriented silicon can present a 19 problem. At Tl speed, there is no need to go to VLSI imrll ,-r~ ;o.. FPGA chips p~og~ cd in-house are the solution being adopted in most places. The key to cost~rr~li~.e jmple .. ~ n 21 at high speeds is the availability of co ~ .cial chips. Small 802.6 netwu~l~ have been built 22 without VLSI, but the costs will deter wides~lead imp1~.n~ ~t~;OI- Chips running at 45 Mbps will 2 3 be available in 1992, but it is not clear whether s~fficiPnt features will be available. Custom 2 4 ASICs are plob~ly the best answer; new tools make this an increasi~ly viable option for modest 2 5 pror1uction runs.

27 3. C~ E t~ gJi~
28 The idea of a ~ ;b.l1~ video-oriented c~ u'~ system is a new one in the market, but 29 one that appears inevitable due to the collvel e.ce of the various terhnir~l and market forces 3 o mPntionP~ earlier.
31 The three coll,l onc lb, source, nclw~kil~g~ and desktop, must all be handled skillfully and 32 cost-t;rr~ ively for the cùlllpa~y to succe~PA. If any one is p~.ce;~od as h~ad~uate~ the other two 3 3 will fail to sell also. Therefore we need to review tbe other all~ s, the roads not taken, to be 34 assured that the m~-lretpl~^e will not go in another di~liom Or if it might do so, we should be 3 5 assured that product changes are feasible.
36 The coll~ i-lg scene in all respects is s~lffi~ipntly comrlic ~PA that there is a great benefit 37 for people to do the same thing as their r,c;gLbGl~ are doing, even if they are not netwoll~ed 38 together. I"ne comfort level ~coci~PA with being able to col"~ale notes with so --P~ne else drives 3 9 ~;--c~o- -P- ~ to opt for the same thing that is already in col~ n use, if it will serve their needs. For SU~ SHEE~ (RUlE 26~

~VO 94t27296 2 1 6 2 2 8 4 PCTIUS94/05112 this reason it is very hard for a new product, even if full of new features, to achieve dc.~ --re if 2 an existing product is most people's default choice. The success of Microsoft DOS, Lotus 1-2-3, 3 or the HP laser printers are cases in point.
4 In new areas, h~ er, there is no default choice, and the filed is open to new players.
Skill in picking the right technical choices, and enough elbow room to do midcou~e corrections, 6 make the dirrer~ce between the startup that sUcce~C and the one that fails.

8 3.1 n^^~topall~-~ati~s 9 The variables at this point on the product sl,e~ are mainly the pl~formc ~ppo,led and the type of video co~ r~sion used. By s.l~,2o,li-.g most of the co ~--o~ desktop ~ in~$
11 in-luding the AT bus and the MCA bus for the PC, the Nubus for the Mac, and Sbus for Sun 12 SPARC, most of the illlpoll~ln~ C are covered.
13 Adding support for another make of c~ u~ would not be a ~liffl~.lt operation; simply 14 ~l~ting the existing logic to a dirr~e~ll system bus, but keeping the IsoChannel and the external co--~f~;~-n the same.
16 The evolution of the video colJl~essioll te~hnn'ogy is likely to cQnti~lP for some time. The 17 various s~d~ds may co~lPsce in time, but the tP~hnn'ogy is s~ffi~ipntly ;~ that new 18 tn~th~dc may arrive on the scene at any time. The only way to handle this will be to redesign to 19 video co~ ion/d~ r~ ,ion section of the board, but preserving tbe e~ternal connections to 2 0 the LllwOll~, the system bus, and the Iso~ nPh 22 3.2 Ser~eralt~.-ali~
23 This situation is perhaps the easiest of the three in terms of the ~;lade or l~lil~lion issues 24 c~n~ d. Once the al.h;~b-~e of the server is est~ i~pA~ addr~i lg new media is a matter of d~ new boards to accommDdate the hardware. The physical drive hardware to support new 26 media will come from outside sources, and the development requ~ is to adapt the data format 27 native to that mPAhlm to the nlwoll~g r~,lh~ of the CBM system. For e~ ple, a 28 read/write laser disc player might require a new adapter board utili7i~ C~ from a read-29 only laser disc board. P~l-le.~hil. relations with companies p-~---olh~e new media will clearly be a 3 0 possibility.

32 33 Networking slt_rnst;~es 33 This is the most critical area. Users will not install a multirlirity of L~.Ol~ to serve 34 dirrele.~t applic~i~nc They need to feel confi~lPnt that they will be able to attach the e~ nl from a variety of vendors to their LelwOIhi, and hence insist on st~dards-based nets. The 36 n~WUII~ techn~-'ogy of choice must both meet the needs defined by the applir^fion (which a 37 proprietary design could do also) and also have broad ~c~t~ e in the field.
38 High speed net~ ~,ll~ are relatively new, but ~here do e~cist a number of ~lt~ s to be 3 9 e~ Pd as possible paths.

SU~ SN~ UlE 26~

2 33.1 FDDI
3 FDDI has been ~ecign~ as a data n~tWOll~, srerifi~ y as a primary n~.o,l~ rather than as 4 a ba~ Qn~. It provides packet transport at 100 .. e~d~ib per second with a yrolocol talcen from the IEEE 802.5 token-passing ring. It has made a few changes; one for the better is relo~lri~ at 6 each node, which avoids the jitter problems ~UI~ly pl~line large token ring inst~ innc. As a 7 b7~ 0~ rather than primary li~two~ FDDI has problems with llal~/&C.l~ bri~lgi~ because of 8 ring slliyyin and achlowl~g~n~nt bit issued. Some vendors (such as Motorola and N~ional) 9 have di~.g~d from the s~d~-l in these areas.
However, FDDI has not been ~igned to handle any traffic other than paclcet data from y~t~ , For large netwol~ the latency problem is an issue; even if the load is light, one must 12 wait until the token arrives before initiating li ~r~ 0l~ Sending video over FDDI would subject 13 it to ul.celLaill delays, very lilcely e~ceeAing the l~ui~ b of ~eq~ e picture quality. The 14 same issue also affects voice and high-quality audio, which is in fact less tolerant of tran- ~ ;
glitches than video.
16 On the positive side, FDDI has been csyolsed fully by the COIIIy.lt~l indu~ , and there is 17 no sho-~e of Letwu~ products that use it.

2 0 FDDI-II is the FDDI world's attempt at a ~ .vice L~. ~1}, one that has shown no signs 21 of success yet. It has the fatal flaw of being c--r_ ~lc with FDDI; the two ~ io.~s cannot 22 share the same fiber. As a result, FDDI's success mitigates against the ~ 1Oy~ n of FDDI-II.
23 The .. lllib&~ice capability of FDDI-II is limited. It plùvides iso~Lo lous channels of 6 24 Mbps (up to 16 of them), which must be s.lWivided e~nally for applications such as voice that 2S worlc in terms of small chaonels. No vanable bit rate capability other than the connectionless 26 paclcets is available.
27 While the c~ may eventually change, the a' ptinn Of FDDI-II is currently close to 28 nil. Some silicon vendors are leaving hooks for it in their newer chips, but the market demand has 29 not yet to ~t~ 7e an fact, the FDDI demand has not reached e~cpectations, as the problems of vendors like In-Net AC .. ,r~ e ) 32 333 Frame rela~
33 Frame relay has achie.ed a great success within the past year, at least as far as publicity is 34 c4~ d In a sense it is ISDN in Aicguice, with the LAP-D paclcet format slightly ,--~;I:PA. It has the a.lv~t~ge in the i t~ twul~hlg field of l~.-;-;~ no ha~.l.. ~e changes, unlilce SMDS.
36 This makes it an e~p~llp~nt target for op~llu~ for private network ~-~ppl;l.~ aod vendors lilce 37 Northern Telecom, whose SL-100 switches can support it.
38 Like FDDI, frame relay is designed to support data only. C~ it is limited to 2 39 l-,e~ils per second by the standards, and to permanent virtual circuits by all the current SUBSl~ultSHttl (RULE26) impl~ ;o~s> but it is possible that these factors may change.
2 The major weakness long-term is that frame relay is not s~a~Pgi~ for trhe carriers. They 3 seem to be unanimous in the view that a cell-based strategy holds trhe best long~erm plo*,e~ for 4 them. Despite the recent publicity for frame relay, they do not have the money to support two new gene.ations of swiL~Liug e~ If they support frame relay, most of them will do it by 6 C~n~e.luloF to cells transmitted over SMDS or I~o~l~ ~d ISDN.

8 33.4 Circuit switclhing 9 Like neo-Victorian a~ u~e, somPthing we had bid goodbye to is back. For gigabit streams, it makes some sense. The limit to LCh.oll~ speeds in such cases is tihe protocol 11 proce-cci~ and with circuit s-.h~iu there isles protocol proces~;ug per l-.e~ e of data 12 ~-A--~---;lled than there is with packet swil-Liu (such as frame relay) or cell s. i~ (such as 13 802.6 or ATM). Therefore for the very highest rates, cell s-.il~ hhlg may be the method of choice, 14 as in doing a brain dump of a Cray.
But the playing field is leveled sr-- . Lal by the brea~ ,ughs r~r~ ted by banyan 16 switches. When they come into widespread use, they will be able to handle lm~ltiple gigabit 17 streams, ~lthough the costs will be prohi~ e for most p,~.. "ises inct?~ iOnc.

19 33.5 IEEE802.9 2 0 The 802.9 ~.. --~ ~ is the PBX manura~ lu~ ' toehold in the 802 standards s~u.. ~ ,~e. Its 21 charter is tro provide integrated voice and data access to a LAN. The cc--~ l~ started by 22 elu~e.~tiug ISDN at 4 megabit instead of l.S; the results in the market place will be predictable.
2 3 As an encore, they are wol~in on a ~high-speed~ version that will run over twisted pair 24 from a desktop to a coAr~ -ator at 20 megabits per second. This repraents the upper speed boundary of IEEE Project 802's charter (the 802.6 MAN O~roup got an e~emption), but in the face 26 of 100-megabit FDDI over twisted pair, it is not lilcely to turn may heads.
2 7 For several years, the 802.6 co------;l l~ e has been pLOp<jSil~ that 802.9 worlc on a compatible 2 8 system, with the cells from an 802.6 bae~ going over twisted pair to the deslctop, but so far to 29 no avail.
31 3.36 E~ ls~tems 32 Often t~ ~ sleO~ is de.elo~ed and y~b~ ed in research lab~ but is never actively 3 3 pushed as a CC.ul".~C l offering. A recent case in point is the H-bus d~ . ~lopod at Bellcore for the 34 ~ c~---~ p~c,luses end of a B~o~ tl ISDN link.
This design, like a large number of others done in Bellcore and Bell Laboratories, is a 36 ~ .alion item. Bellcore in fact feeds t~P~hnolcgy to the tPl-eph~nP i~d~l,~ through standa-~ds 37 O~ nc; its work in SMDS/IEEE 802.6 and I3~o~1----A ISDN are cases in point. Other 38 items of p.up~;~ry ~ O~ could presumably be lic~n~Pd by third par~es alld manuL~, 39 but there is no history of this having happened in t-he n~.c.. l~ field.
SUBSlllult SNEE~ (RULE 26) WO 94n7296 2 1 6 2 2 8 4 PCT/US94/05112 24.0 Summary 3The c~ y ~e~ hl~lu~ is now on the verge of a major change in the human~
4ihl~c~a.,~n; the h-cc.~ ;r~ of moving images into the desktop ~ hh~e This --u.~.. ,c~l is far enough along that we can say with c~nfid~Pn( e that it is oc~ p, but 6new enough to be wide open in terms of marlcet oy~ ul~ . The critical t~ ~gies are 7s~ffl~ Pntly well developed to support viable appli~ ~tirmc 8CBM is addr~mg the three key e1P~ . in video-based d;~ ul~A c~ ~yu~;u~, the 9desktop, the n~lwu.k, and the server. Its current plans show it has the vision to understand the 10opyo~lullily that cu--~,nll~ e~cists for a cu.ll~-~Ch~ set of prudu~,b.
11The u~dt; lyhlg t~hn~logies that are l~uh`ed for the implementation of ~ Ai~
12nelwo.~ are well un~P~t~od co ~on~ c are available now, with the e~cception of high-speed 13 imple .. c~ ;Qn of 802.6 and perhaps the more advanced video conl~r~ssion algo-i~s. However 14these items are not requi.~ 1y, they should be available in ample time for CBM's plans.
15From a terhnol~gy ;~ JOhI~ CBM's uCl ;~ re and implementation d~ :~;c~c have been 16 both forward-looking and well thought out. They should have a very s~lcc~C~r.. l future.

SUBSmU~E Sh~l (RU~E ~63

Claims (14)

In the claims:

1. A multimedia network system for operation in conjunction with a computer and a data network, comprising:
a high speed data bus;
a network interface board connected to the high speed data bus and further connected to a system bus of the computer and further connected to the data network; wherein a video board connected to the high speed data bus and further connected to the system bus of the computer and further connected to an audio video device; wherein said network interface board receives a plurality of data cells from the data network, routes asynchronous signals within the data cells to the computer and further routes synchronous signals to the high speed data bus.

2. The multimedia network system of claim 1, and further including:
a video board connected to the high speed data bus and further connected to the system bus of the computer and further connected to an audio video device; wherein the video board converts information received on said high speed data bus into conventional video signals and outputs the conventional audio/video signals to an audio/video output device.

3. The multimedia network system of claim 2, wherein:
the video board further accepts signals from an audio/video input device, converts the signals from the audio/video input device into a form acceptable by said high speed data bus, and puts those signals on the high speed data bus.

4. The multimedia network system of claim 3, wherein:
said network interface board formats signals received from said high speed data bus into asynchronous transfer mode (ATM) cells and further transmits those ATM cells onto the data network.

5. The multimedia network system of claim 4, wherein:
said network interface board further formats asynchronous signals received from the computer into ATM cells and further transmits those ATM cells onto the data network.

6. The multimedia network system of claim 1, wherein:
the data network is a broadband integrated signal and data (BISDN) network.

7. A data communications device, comprising:
a network interface unit for receiving data cells from a network and for transmitting data cells to the network, the network interface unit being connected to a computer such that data cells containing asynchronous data are transmitted to the computer for use therein and for distribution to a local area network to which the computer is further connected.

8. The data communications device of claim 7, wherein:
signals are received at the data communications device as optical signals and are converted therein into electrical signals; and signals to be transmitted from the data communications device are converted from electrical signals into optical signals for transmission via a fiber optic transmission means.

9. The data communications device of claim 7, wherein:
data arrives at the data communications device in the form of asynchronous transfer mode (ATM) cells;
the ATM cells are reformatted, as appropriate, within the data communications device into synchronous and asynchronous signals and both the synchronous and asynchronous signals are provided to receive data bus such that asynchronous signals can be retrieved from the data bus into a packet memory for use in the manner conventional to the particular type of asynchronous signals.

10. The data communications device of claim 9, and further including:
an audio/video unit for receiving synchronous data from said network interface unit and converting the synchronous data into audio and video outputs.

11. The data communications device of claim 10, wherein:
the audio/video unit further receives audio and video inputs and converts the audio and video inputs in form for transmission to said network interface unit.

12. The data communications device of claim 10, and further including:
a high speed data bus interconnecting said network interface unit and the audio/video unit for transmitting synchronous signals between said network interface unit and the audio/video unit.

13. A method for processing data contained in asynchronous transfer mode (ATM) cell format, comprising:
receiving the ATM cells are converting them into electrical signals;
reformatting the data into synchronous and asynchronous formats as is appropriate to the particular data;

providing asynchronous data to data bus; and transmitting synchronous data via a high speed link to a video processing means for converting the synchronous data into video and audio outputs.

14. The method of claim 13, wherein:
asynchronous data is provided from the data bus to a packet memory for processing as appropriate to the particular packet format of the asynchronous data.