sunflash-Distributed to mailing list sun/NC/north-carolina sunflash-Send requests, problems to owner-sunflash@suntri.east.sun.com ---------------------------------------------------------------------------- The Florida SunFlash Sunergy Newsletter #13 - January, 1994 (part 2 of 2) SunFLASH Vol 62 #13 February 1994 ---------------------------------------------------------------------------- 62.13 Sunergy Newsletter #13 - January, 1994 (part 2 of 2) *6* SunWorld Excerpt: "Internet Sextant" *7* SMCC Announcement *8* SunSoft Announcement *9* Sunergy ftp site login instructions *10* Sunergy enrollment and contact info (581 lines) ---------------------------------------------------------------------------- Distributed by Press Relations (PR), Sun Microsystems Computer Corporation, a Sun Microsystems, Inc., business. All rights reserved. Sunergy Manager: Larry Lettieri Sunergy Editor: Vicki Pedretti Contributing Editor: George Paolini Contact the Sunergy editors by email at: sunergy@sun.com. ********************************************* *5* Transmitting Data Within Video Signals * ********************************************* As a follow-up to the introduction of the use of the vertical blanking interval to transmit closed captioning and teletext and graphics, during the Sunergy #8 satellite broadcast, we offer the following excerpt from: TRANSMITTING DATA WITHIN VIDEO SIGNALS New Opportunities to Exploit an Existing Delivery Medium -J. Duane Northcutt, Sun Microsystems -INTRODUCTION Primarily because of the display technology that has been in use for the past 40 years (i.e., the raster-scanned CRT), gaps exist in almost every video stream -- i.e., there exist spans of time in which no video information is being transferred. Since their inception, virtually all of today's video formats (e.g., NTSC, PAL, SECAM, D1, etc.) have included such an "unused" component in their signal definitions. For this reason, the opportunity exists to insert digital information into these gaps in video signals, by essentially "hiding" information within the video signal. Such techniques for "piggy-backing" the transfer of information are not uncommon in the communications area. For example, a great number of different services (e.g., pagers, background music, stock quotations, etc.) are transmitted by embedding additional information in the inter- stices of radio transmission (e.g., via sub-carrier modulation). It is worth noting that there are a number of characteristics of this type of information transport which are unique and may be quite useful. In particular, this approach makes use of existing infrastructure to deliver substantial amounts of data to a potentially large, and widely distributed group of clients. Piggy-backing data onto existing video signals allows the transport of a moderate bandwidth stream of uni- directional information via all of the various means through which video is currently distributed -- e.g., terrestrial broadcast, videotape, and satellite. This approach enables the low-cost delivery, as well as low- cost reception of streams of digital information to any location where video can be viewed today (e.g., the home, remote sites, branch offices, etc.). There are many new business opportunities which are enabled by this information channel, as well as many new approaches to existing ways of doing business which are made possible by this type of information delivery system. The gaps in television's video transmissions have not remained universally unused across time. In particular, standard techniques exist (and to greater or lesser degrees in different parts of the world) have been used to send digital information along with video signals. This additional information can be directly related to the associated video content (in which case it represents "ancillary" information -- such as the audio channels), or completely unrelated to the video program (in which case it can be thought of as "parasitic" data, that only shares the transport medium with the video). Ancillary data might include information such as television program notes, transcripts of the program's audio, etc. Parasitic data can be any generic data that might be transferred over a traditional computer communications network, e.g., email, documents, digital images, and even digital audio and video that is unrelated to the main video stream. TECHNICAL OVERVIEW The data transfer technology described here arises from the fact that gaps exist in video transmissions that provide opportunities for multiplexing data onto video streams. This section describes the origin and nature of these gaps, how data can be inserted and transported through these gaps, and how data can be extracted from the gaps. The Vertical Blanking Interval in Video --------------------------------------- The gaps that arise in almost all video signals stem from the nature of CRT-based display technology. Most CRT displays make use of a technique known as raster scanning. This involves the "painting" of images onto the phosphor screen by modulating (i.e., turning on and off) an electron beam which is moved in a regular (typically left-to-right and top-to- bottom), pattern across the entire active display area. When the electron beam reaches the end of its raster pattern (e.g., the bottom, right corner of the display), it must be brought back to its starting point (e.g., the upper, left corner of the display). This return process cannot happen instantaneously and no painting of the image is done during this period. Therefore, an interval of time exists where no video information is being transmitted -- creating the "gap" in the video signal that can be used for data transfer. In the video standard used in the US (NTSC), the vertical blanking interval is approximately 10% of the video channel (22 of each field's 252 lines comprise the vertical blanking interval). While television sets do not display any video during their blanking intervals, time does not stop at the source and the transmitters are still active. Therefore, it is possible for transmitters to continue to modulate during the video signal's blanking interval, effectively continuing to transmit data that is not displayed by the receivers. It is possible to see this gap in the video stream by (mis-)adjusting the vertical hold adjustment on a consumer television set. This causes the television's raster scan to lose synchronization with the transmitter's vertical synchronization signal, resulting in the familiar "rolling" picture on the screen. The vertical interval is the black band which appears on the screen when a television is mis-adjusted in this way. If one looks closely, it is possible to see information in the vertical interval, which appears as colored "sparkles" in the otherwise black band. According to conventional broadcast practice, various lines in the vertical interval are used to transmit test information (e.g. Vertical Interval Test Signals (VITS) and Vertical Interval Reference Signals (VIRS)). The presence and location (line number) of these test signals varies widely among different video origination sources, and can be used by broadcasters to determine characteristics (quality) of the end-to-end communications path. In addition to various test signals, there are conventions which define (the formats and line numbers of) other signals in the vertical blanking interval, including those which can be used by the broadcasters to control remote transmitter equipment, and those which can be used by the broadcasters to control remote transmitter equipment and those which can be used by television sets to perform local adjustments (e.g. ghost cancellation). There are also a variety of standards for the inclusion in the vertical interval of lines of video-content-related information streams as well as information that is unrelated to the video program. However, it is worth noting that, while there is a variety of different information that is transmitted in the vertical interval, this information is quite sparse -- the vertical interval of the bulk of the terrestrial broad- cast stations in the US is largely unused. Inserting Data Into the Vertical Interval ----------------------------------------- To conform with existing video format standards, the information added to the vertical blanking interval is organized in the same manner as video -- as individual scan lines. In order to multiplex additional data into a video signal, a free line (i.e., one which does not already have information on it) must be chosen and the data addition equipment synchronizes with the video stream and inserts its data into the video stream at the appropriate time. Special care must be taken to ensure that the inserted data signal conforms to the format of the video signal specification being used. In particular, the signal must follow an appropriate modulation scheme and must not exceed the defined amplitude or frequency limits. However, within these encoding constraints, any type of information can be transmitted. Just as standard data formats exist for transmitting adjunct data with video signals, so too are there existing pieces of equipment that can be used to multiplex (appropriately formatted) data streams onto standard broadcast video signals. There are many well known techniques that can be applied to the encoding digital information onto an analog video channel. Depending on the specific coding technique used, varying amounts of digital data can be inserted into lines of the vertical interval, with differing degrees of signal quality (i.e., Signal-to-Noise Ratio -- SNR) and decoding complexity at the receiving end. In general, the amount of data that can be transmitted within the defined channel (i.e., a video line) is a function of the signal quality. However, using simple encoding/decoding schemes and terrestrial broadcast (or high-quality recording/playback) it is reasonable to expect to be able to success- fully achieve transfer rates on the order of 10Kbps per video line. In theory, it is possible to transfer any number of lines of data over a video distribution system (e.g., tape, Radio Frequency (RF), cable, satellite, etc.) Thus, it is possible to transfer around 10 Kbps on each of some 500-600 lines per frame (depending on the video standard used), resulting in a data rate of 5-6Mbps per video channel. In actual broadcast television environments (either RF, cable, or satellite), it is typically the case that some lines are in use, and hence not avail- able, on each video channel. Therefore, if (a conservative) 10 lines per frame on each channel are available to be used for data transfer, the aggregate data rate would be on the order of 100 Kbps (per television channel). In a delivery system with from 1-100 independent channels, it is therefore possible to achieve practical aggregate data rates of from 100Kps to 500 Mbps. While these data rates may be on the low end of expectations for wired networks, it is quite reasonable for RF-based networks that are capable of spanning large numbers of receivers. Transporting Vertical Interval Data ----------------------------------- As noted above, by conforming to video coding standards, it is possible for adjunct data to be associated with video streams and transported along with the video signal. This means that the data can be effectively transmitted through all the usual means by which video is distributed -- e.g, terrestrial (television) broadcast, satellite transmission, video tape, etc. In effect, by making data appear to be video, it is possible to move it through the same distribution channels used for video. While existing video coding standards were designed to optimize various aspects of the delivery of video over the intended physical channels, and may not be ideal for the transport of other forms of (digital) data, it is possible to define encodings for digital information that also perform well in the various video distribution contexts. Regardless of the specific distribution technique used, the general model remains the same. For example, the output of the originator of a source data stream (i.e., a content provider) is transferred (e.g., via wide-area digital network) to the desired video distributor (e.g., a satellite up-link point), at which point the data is multi- plexed into the video stream and transmitted. Potential receivers of the data stream can exist at any point to which the video signal is ultimately distributed (e.g., all viewers who can receive a given television broadcast channel), and computer equipment can act as recipients of the data stream at any point where the associated video signal can be viewed. Extracting Data from Vertical Interval -------------------------------------- There exists a wide range of equipment for the extraction of currently defined adjunct data from video streams. This equipment ranges from dedicated-function units (e.g., consumer television sets with built- in teletext or closed caption decoders), to sub-system/components (e.g., television add-on decoder boxes), to specialized computer peripherals, and to specialized commercial integrated circuits (e.g., components for data extraction, decoding and display). The general approach to extracting data from the vertical interval begins with the reception of the "carrier" video signal. This can be done by way of an antenna and television tuner or satellite dish and satellite receiver -- either pair of equipment performs the same function of: capturing the full set of transmitted signals, selecting the desired channel, and converting the signal from its RF-modulated form to baseband). Once the desired video signal has been captured, selected, and downconverted, the next step is to strip the adjunct data from the video signal and decode it. Just as there can be many television stations in a single area, so too can there be multiple, independent data streams multiplexed into a single television station's video stream. For this reason, the data extraction units must perform a function similar to that of a video tuner -- i.e., the demultiplexing of multiple independent streams, prior to decoding. ### -Duane Northcutt can be reached at duane.northcutt@sun.com or +1-415-336-1088. --------------------------------------------------------------------------- - INDUSTRY OUTLOOK - --------------------------------------------------------------------------- ************************************************* *6* Advanced Systems Excerpt: Internet Sextant * ************************************************* >From Michael McCarthy, Editor-in-Chief mac@advanced.com (415) 267-1727 Copyright Advanced Systems Magazine, February 1994, adapted with permission. Advanced Systems can be reached at editors@advanced.com. (Advanced Systems Magazine was previously SunWorld Magazine) COLUMN: Archives "Internet Sextant" A free electronic publication helps guide you through the Internet. By Sam Kimery Having trouble navigating the Internet? Do you know where you want to go, but have no idea how to get there? This month, *Archives* looks at a free electronic publication service that may help you become more familiar with the Internet and its uses. Where's Larry King when you need him? The Global Network Navigator (GNN) is published electronically by O'Reilly & Associates Inc. (Sebastopol, CA) using a World-Wide Web (WWW) server. Accessing GNN is done via a WWW client, such as xmosaic (see "Internet triptik," September 1993). GNN is comprised of four publications: GNN News, GNN Magazine, the Whole Net Catalog, and the Navigator's Forum. GNN News is a biweekly report on happenings around the Internet and announcements of new information resources, which includes new WWW servers, collections of art on the Internet, and new products. GNN Magazine is published quarterly and contains what you'd expect in a magazine: feature articles, columns, and commentary. The first issue (October 4, 1993; ISSN 1072-0413) contains a wide array of articles, including a discussion of the current state of the Internet ("American Pie: Is There Enough Internet to Go Around?") and an examination of one effort to build the new data superhighway ("Mitch Kapor, Data Highway Guru"). Monthly columns include "Go Find Out," which contains reviews of network resources, and "Net Heads," a column featuring advice and commentary. A rather unique feature of GNN Magazine is the "Off the Wall Gallery," which features the works of various artists. When entering the gallery, a list of the exhibitors and their backgrounds are displayed. Once an artist has been selected, thumbnail sketches of their work are displayed, along with a description of each image. To view the full image, you simply click on the desired thumbnail sketch, and up pops the art. The third GNN publication is the Whole Internet Catalog, which lists and describes a variety of interesting Internet resources and services. What makes this one different from a plain-paper catalog or a simple ASCII list is that once you find the resource or service that you are interested in, you can select it and GNN will try to automatically connect you to resource or service you require. The Whole Internet Catalog is organized in several ways to help you find the services in which you are interested. Initially, you see a list of rather general topics: technology, for example. Clicking technology takes you to a more specific submenu; something like aviation, biomechanics, or engineering, for example. Clicking the subtopic takes you directly to the subtopic entry in the generic topic list. You can also look at subjects by topic, which contains a complete list of all the subtopics. Or, if you would rather start with the specifics, you can look at all entries in the catalog. Clicking items in this list transfers you directly to the resource of service that you selected. Finally, for those who have already browsed through the catalog, you can jump directly to a description of the new resources and services that have been added. This can save considerable time when you are "joy riding" (a.k.a. "surfing") the Internet. A helping hand For those of you who are new to the Internet, the Navigator's Forum is sure to please. It is dedicated to answering basic questions about the Internet, as well as a medium for exchanging tips and ideas. Subsections of Navigator's Forum include "How do I." and "Basic Services" as well as a thorough history of the Internet. The "How do I." section covers topics that range from finding an e-mail address to transferring files and logging on to a remote machine -- simple stuff for established Internet uses, but potentially tough hurdles for newcomers. The Navigator's Forum Basic Services contains descriptions of many of the basic Internet services, such as Archie, ftp, e-mail, and Usenet news. Finally, there is a section devoted to Internet Etiquette, a must read for new users and experienced hands, as well. Subscribing to GNN To secure yourself a free (yes, FREE) subscription to GNN, you must first become a registered user. The process is relatively painless. Send e-mail to info@gnn.com to receive a registration form. When it is completed, (electronically, of course), return the form via e-mail to the address given. Soon thereafter, you will receive your complimentary GNN publications, along with notification of new publications and special promotions. For those who would like to try out GNN and its various features, the Universal Resource Locator (URL) for GNN is http://nearnet.gnn.com/GNNhome. html. If you are using Mosaic, select Open from the Navigate menu, type URL into the dialog box, and click the Open button. Surfs up! Shoot the Internet curl! [Sam Kimery is a systems engineer at Strategic Technologies Inc. and has been involved with Unix for more than 10 years. His e-mail address is kimery@csoc.com.] --------------------------------------------------------------------------- - PRODUCT UPDATES - --------------------------------------------------------------------------- Excerpts from recent Sun press/business releases. *********************** *7* SMCC Announcement * *********************** SUN TO PROVIDE SOLUTIONS FOR NETWORK-INTENSIVE, MULTI-MEDIA APPLICATIONS Unveils breakthrough ATM products and Fast Ethernet MOUNTAIN VIEW, Calif. - January 19, 1994 - While companies and public policy makers discuss the virtues of the National Information Infrastructure, Sun is providing the technology that makes this data super highway a step closer to a reality. Industry-leading networking solutions were introduced (1/19/94) by Sun Microsystems Computer Corporation (SMCC), including the lowest-cost, highest-performance ATM (Asynchronous Transfer Mode) network adapter cards from any vendor and the first 100 Mbps Ethernet ("Fast Ethernet") network adapter card available from any computer systems vendor. These products offer the network capabilities necessary to deliver today's bandwidth-intensive applications, such as graphics and multi-media, across the global network. [As of January 28, 1994... Joining ComNet's New Product Hall of Fame, voted winners by ComNet-94 attendees, in the ComNet-94 New Product Achievement Award Competition: The Best New LAN & Internetworking Product - SunFastEthernet Adapter The Best New Transport Technology Product - SunATM Adapters] For any SunATM product marketing questions, contact Art Edmonds at art.edmonds@sun.com or at +1-415-336-0662 and for SunFastEthernet questions, contact Tony Lee at tony.lee@sun.com or at +1-415-336-0687. ************************** *8* SunSoft Announcement * ************************** SUNSOFT AND NEXT PARTNER TO DRIVE VOLUME OBJECT STANDARD NeXT to Publish Open Specification; SunSoft Licenses Implementation for Use in Solaris SAN FRANCISCO, November 23, 1993 - To accelerate the standardization of object technology, SunSoft, the system software subsidiary of Sun Microsystems, Inc., and NeXT Computer, Inc. today announced a series of agreements where NeXT will publish an open specification, called OpenStep, and SunSoft will license NEXTSTEP's application environment for use in its Solaris enterprise system software. NeXT will "open up" NEXTSTEP by freely licensing the APIs (Application Programming Interfaces) and the OpenStep trademark to all independent implementations which pass an OpenStep test suite. OpenStep is based on the operating system-independent layers of NEXTSTEP 3.2, which NeXT is shipping today. For further information contact: Jim Green at jim.green@sun.com or +1-415-336-3307. # # # SUNSOFT ANNOUNCES DISTRIBUTED OBJECT INTEROPERABILITY WITH MICROSOFT WINDOWS Agreement With IONA Technologies Provides First Standards-Based Solution For Distributed Object Application Development ObjectWorld, Boston, Mass., January 11, 1994 -- SunSoft, the system software subsidiary of Sun Microsystems, Inc., announced that it has signed a development agreement with IONA Technologies of Dublin, Ireland, to deliver distributed object interoperability across SunSoft's Solaris(r) Distributed Object Environment and Microsoft(r) Windows and Microsoft Windows NT-based systems. The agreement signifies the first interoperability between two OMG CORBA-conformant Object Request Broker (ORB) implementations and gives users a standards-based solution for distributed object application development. Project DOE developers will now be able to access objects on Microsoft Windows and Microsoft Windows NT systems running IONA's Orbix product. Similarly, developers creating object-oriented applications for Microsoft Windows and Microsoft Windows NT systems will be able to access objects created on Solaris-based systems with Project DOE. Next-generation applications can be created out of components residing on a combination of Solaris-based and Microsoft Windows systems on the network. For more information contact: Jim Green at jim.green@sun.com or +1-415-336-3307. # # # --------------------------------------------------------------------------- - SUNERGY INFORMATION - --------------------------------------------------------------------------- ****************************************** *9* Sunergy ftp Site Login Instructions * ****************************************** White papers and other information from the broadcasts can be found at the Sunergy ftp site. Back issues of the Sunergy newsletter, as well as miscellaneous white papers referenced by Sunergy are also available. To access, type the following: $ ftp (or Iftp) sunsite.unc.edu username: anonymous password: **FOR WHITE PAPER RETRIEVAL AND SPEAKER INFORMATION FROM THE SUNERGY SATELLITE BROADCASTS**: ftp> cd /pub/sun-info/sunergy/broadcast_docs/jan_94 ftp> get **FOR BACK ISSUES OF THE SUNERGY NEWSLETTER**: ftp> cd /pub/sun-info/sunergy/newsletters ftp> get **FOR MISCELLANEOUS WHITEPAPERS REFERENCED BY SUNERGY**: ftp> cd /pub/sun-info/sunergy/misc_whitepapers ftp> get ************************** *10* Sunergy Enrollment * ************************** If you are not already a member of Sunergy and would like to join, simply fill out and return this form. If you are already enrolled in Sunergy, please feel free to pass this along. --------------------------------cut here---------------------------------- *****SUNERGY SIGN-UP FORM***** NAME:__________________________________________________________ Title:__________________________________________________________ COMPANY:__________________________________________________________ ADDRESS:__________________________________________________________ __________________________________________________________ CITY:__________________ STATE:_______ ZIP/POSTAL CODE__________ COUNTRY:___________________________ PHONE:___________________________ FAX:_________________________ **E-MAIL:___________________________ RETURN COMPLETED FORM TO: sunergy@sun.com 415/336-5847 **An e-mail address is mandatory for enrollment in Sunergy, as Sunergy information is distributed on an electronic basis only. ======================================================================== c 1994 Sun Microsystems, Inc. Sun, Sun Microsystems, SunWorld, SunSoft, SunPro,SunATM, SunFastEthernet, Sun Microsystems Computer Corporation (SMCC) and Solaris are trademarks or registered trademarks of Sun Microsystems, Inc. Sunergy is a service trademark of Sun Microsystems, Inc. SPARCstation is licensed exclusively to Sun Microsystems, Inc. Products bearing SPARC trademarks are based upon an architecture developed by Sun Microsystems, Inc. UNIX and OPEN LOOK are registered trademarks of UNIX System Laboratories, Inc. All other product or service names mentioned herein are trademarks of their respective owners. ********************************************************************** For information about SunFlash send mail to info-sunflash@Sun.COM. Subscription requests should be sent to sunflash-request@Sun.COM. Archives are on draco.nova.edu, ftp.uu.net, sunsite.unc.edu, src.doc.ic.ac.uk and ftp.adelaide.edu.au For last month's digest, send email to flashadm@sun.com with a Subject line of 60.00 For Gopher and WAIS access: sunsite.unc.edu. (Login as 'gopher' for a simple gopher client, 'swais' for a simple WAIS client (over 500 databases). All prices, availability, and other statements relating to Sun or third party products are valid in the U.S. only. Please contact your local Sales Representative for details of pricing and product availability in your region. Descriptions of, or references to products or publications within SunFlash does not imply an endorsement of that product or publication by Sun Microsystems. Send brief articles (e.g. third party announcements) and include contact information (non-800#, fax #, email, etc) to: John McLaughlin, SunFlash editor, flash@Sun.COM. +1 305 351 4909