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Distance Education... Distance Education...
Distance Education... |
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ADEC Net Frequently Asked Questions (FAQs)border="0"> | Acronyms: | ||
|---|---|---|---|
| ATSC | Advanced Television Standards Committee | ||
| CLI | Compression Labs, Inc. | ||
| DVB | Digital Video Broadcast | ||
| IDI | Intelligent Devices, Inc. | ||
| IRD | Integrated Receiver/Decoder | ||
| ISP | Internet Service Provider | ||
| MCPC | Multiple Channel Per Carrier | ||
| MHz | Megahertz | ||
| MPEG | Motion Picture Expert Group | ||
| POP | Point of Presence | ||
| RF | Radio Frequency | ||
| SCPC | Single Channel Per Carrier | ||
| TVRO | TeleVision Receive Only (antenna) | ||
| VSAT | Very Small Aperture Terminal | ||
Technical Questions (TQ)
A -- The ADEC network will include a digital satellite transponder (36 MHz minimum bandwidth) configured with both MCPC and SCPC channels and employing the DigiCipher II MPEG II ATSC standard. A 9 Mb/s Internet delivery capability will be multiplexed over approximately 12 MHz of MCPC bandwidth. (We are using many of the same elements of the FordStar system for our model.)
The Internet will be put on the transponder from uplink facilities located in Fort Collins, Colorado. The original plan called for high bit-rate delivery over the transponder with the low bit-rate return carried by terrestrial service. We are receiving input from some institutions that we should investigate the possibility of creating a hybrid system which would provide for a satellite return using VSAT technology as well as a terrestrial return. The VSAT hybrid is gaining ground.
If VSAT capability is added to the ADEC telecommunications network, a portion of the ADEC transponder would have to be dedicated to transmitting the return RF signal from the VSAT sites. In addition, VSAT transceivers would be required at each of the VSAT sites.
We have seen demonstrations of both one-way and two-way satellite delivery of the internet. The vendor for the IP interface demonstrated one-way satellite delivery of the internet along with the simultaneous delivery of Georgia Public Television while accessing the worldwideweb at about 400 Kbs. A local ISP was used for return communications to the Internet.
A -- The VSAT, or Very Small Aperture Terminal, is a 0.6- to 2.4-meter satellite earth station incorporated into a network that allows for reliable telecommunications via satellite. VSAT technology represents a cost-effective solution for users seeking an independent communications network connecting a central location and a large number of geographically dispersed sites. A VSAT Terminal may provide one-way or two-way satellite communications.
A -- It will depend on the CLI standard which is in use. A lot of the CLI equipment in the field is the old CLI standard which approximates MPEGI. It is unlikely that sufficient demand could be generated for any MPEG I standard to justify engineering a digital channel with about 3.0 MHz of bandwidth to carry MPEG I signals. The new CLI - MPEG II standard has been purchased by General Instruments and is marketed under the Magnitude trademark. As long as all of the encoding/decoding (CODEC) standards which are placed on the same digital channel are completely interoperable and as long as there is sufficient demand, there should not be a problem for a portion of an ADEC transponder (ie one channel) to be dedicated to MPEG II/DVB) transport. "Digital video information which is encoded in a particular standard can not be decoded with equipment employing a different standard. For example, CLI IRDs would not be able to decode a digital signal which was encoded in the DigiCipher standard. (Individual states need to confer with Jeff Poley and Gary Atkins for state specific information.)
A -- Our delivery of the Internet is transparent to the ISPs so we do not need to give them any special instructions. The principal difference between normal Internet service through an ISP and ADEC Internet delivery involves changes in our addressing scheme with IDI. IDI will indicate to the ISP that the connection on the Internet is complete while in actuality, Internet signals are being delivered by satellite.
A -- 1. Good quality fixed off-set feed solid antenna (dish) with minimum diameter of 1.8 meters (six feet) from Scientific Atlanta, DH, Andrews, Miralite, Vertex, etc. -- $300 to $400 (this dish will be fixed on the ADEC satellite)
2. Norsat phase-stable Ku-band LNB; phase noise spec. of -65 dBc -- $110 to $150
3. Cable at about $7/ft (installed) from antenna to the receiver
4. GI DigiCipher II DSR4200v Integrated Receiver/Decoder (IRD) -- $850 to $1250
5. idi CORRidiOR digital interface for Internet -- $850 to $1200 (Items 4 & 5 can be replaced by a DSR5200v -- $1700 to $2400)
6. Installation/integration -- highly variable.
Total -- $2310 to $3500 plus cable (The lower cost is estimated at bulk purchase, the higher estimate would be single unit purchase)
A -- The best way to get signals to the Hub at Ft. Collins will be to uplink a digital signal to the ADEC transponder in DigiCipher II standard because the provider would, (1) have real-time access to all of the ADEC digital fixed as well as steerable receive antenna, (2) have real-time access to DBS retransmission, (3) have option of program being recorded at Ft. Collins for later retransmission, (4) be able to take advantage of very low transmission costs (no additional cost if a contributing partner).
Programming can be uplinked to state network digital transponders and downlinked at the Hub for retransmission on the ADEC transmission services.
Video-taped programming can be sent to the Hub for programmed transmission on the ADEC MCPC video service, ADEC DBS service or both.
Providers with access to high-speed data transmission and video streaming capabilities can send video to the hub over the Internet.
Programming can be uplinked in analog format and downlinked at the Hub for retransmission on ADEC digital transmission services. Since ADEC will not have an analog transponder, the costs of transmission would be at spot market occasional use rates.
A -- The ADEC system would allow a member to add digital capability to the analog uplink at an initial capital expenditure of between $100,000 and $150,000 and then gain access to a network with extremely low costs of transmission. In addition, the digital equipped downlinks could receive all ADEC and ADEC member DigiCipher digital programming. And with the addition of the CORRidiOR module, the downlink sites could have high-speed access to the Internet while simultaneously receiving digital video programming.
A -- A wide variety of computer networks exist within the ADEC membership each with specific requirements for systems integration. Most if not all of these systems should be capable of being adapted to hybrid networks which can accommodate ADEC satellite delivered Internet if a particular system sees advantages to such a configuration. Some clients in a network environment which might have low operating speeds due to remote location may, for example, be better served if they could easily switch to satellite delivery of the Internet.
A -- The percent uptime for digital satellite delivery of video and Internet should be comparable to existing delivery systems. The error rate is 31 in 1 x 10 ex9.
A -- If your receive site is equipped with a standard analog TVRO steerable antenna and receiver and is also equipped with a properly addressed DSR4200 IRD, you will be able to receive almost all domestically uplinked C and Ku-band analog programming as well as all ADEC digital programming. In addition, your site will be capable of receiving digital programming directly from other providers using the DigiCipher II encoding standard including Clemson University, University of Kentucky, University of Florida, University of Nebraska, Louisiana State University, the University of Georgia, the Universities of Nevada-Reno and Las Vegas and Oklahoma State University. Direct reception of programing from universities with other encoding standards such as CLI Spectrum Saver, SA PowerVu, Wegener or GI Magnitude will not be possible. The ADEC telecommunications hub at Colorado State University in Ft. Collins will, however, be turning selected programming from other standards for delivery to DigiCipher II receive sites.
A -- There would be considerable variance in transmitting systems depending upon the type of service desired. A typical minimal digital uplink system would include:
Institution Specific TQ (ISTQ)
Q -- Are there necessary provider-side considerations to providing digital signals to differing downlink site converters? I guess this question is can our uplink provider or CSU get a readable signal to DigiCipher and Compression Labs sites?
A -- The Spectrum Saver (DVB) and DigiCipher (ATSC) digital standards are not interoperable. The ADEC telecommunications hub will be broadcasting in only one digital standard, that being the DigiCipher II/MPEG II/ATSC standard. The telecommunications hub at Ft Collins, will however, be able to downlink other digital standards if there is sufficient traffic to warrant the purchase of the appropriate digital receiver. The hub will, for example, be downlinking selected programming from members using the Magnitude encoding standard and turning those signals for retransmission to the ADEC system DigiCipher II receivers.
Q -- When ADEC has the new transponder how do we, at the University of Idaho, get our programming to the ADEC teleport? It appears to me that we have a few options. However, many of the options could be prohibitively expensive. They are:
A -- Option #1 would be expensive. ADEC won't be able to afford to provide space on the ADEC transponder for analog service initially due to the huge band-width requirements of analog. Maybe later when we have sufficient capacity. Right now, we are paying about $740/hour for occasional use Ku-band space segment and I would guess that those costs will hold for the medium term.
A -- Option #2 will most likely provide the best short term solution for you since you can use WSU and University of Idaho existing infrastructure. Your microwave feed to WSU could be turned to their Magnitude encoder and delivered to the WSU channel(s). If that channel(s) is on the ADEC transponder, the ADEC hub can turn the signal from Magnitude to DigiCipher to be put on the ADEC channels. If the WSU channel is on a different satellite or transponder, the ADEC Hub could acquire that transponder, download the signal and turn it to the DigiCipher ADEC channel. The charges from ADEC would be minimal using this option. I'm sure that charges by WSU would also be low.
A -- Option #3 is OK and will most likely be used by all of the ADEC members where it is cost effective to do this and where time delay is not important or where multiple broadcasts are anticipated (ie. broadcasting the same content at three different times during the day, for example).
A -- Option #4 is also OK although the costs may be a consideration. You may not be satisfied with the quality of the video images. Most people will accept the quality of compressed video when delivered by an appropriate compressed video medium such as desk top teleconferencing equipment or by computer. The picture quality expectations are much higher for video images delivered to a television monitor. I'm sure that a lot of the members will want to experiment with these types of delivery techniques.
A -- Option #5 will probably work but we have no idea how long we will have to wait to get Internet II off of the ground.
Option #6 might be considered. You might consider the purchase of a DigiCipher II single channel encoder which could be integrated into your existing Ku-band uplink. Oklahoma State University and the University of Nevada-Reno will be broadcasting with these encoders by the beginning of July. The Pennsylvania State University will probably install such a unit early next year. These units cost between $110-135K per unit including installation. Normally a phase stable up-converter is required at about $12-13K. Quite a few of the ADEC members have shown an interest in acquiring the DigiCipher II single channel encoder. If there is enough interest, ADEC could submit a grant application to the Doc/NTIA/PTFP for FY-99 funding assistance for these encoders. Once you have the capability to transmit encoded digital signals, the cost of delivery would be significantly reduced compared to analog transmission. You'd save about $500 to $600 for every Ku-band broadcast hour on the ADEC transponder.
Q -- What part of the system are we spoofing? Is the spoofing technology going to be applied to the latency problems that come with using Internet via satellite for one leg only?
A -- The spoofing technology will be applied at the Internet content uplink at Fort Collins and will be responsive to managing requests over both terrestrial and satellite channels. Spoofing will help solve some the latency and packet acknowledgment issues that are inherent to satellite delivery of the Internet. As we found out during ADEC testing of the proposed system without spoofing, even though the system was capable of delivering about 400kb/s, operating rates were much slower. Most of this delay is attributable to slow return rates for packet acknowledgment which had the system window constantly closing down and reopening. Spoofing will help take care of a lot of this cumulative latency.
Q -- True or false: Only folks with PrimeStar or DirectTV (and what other brand?) dishes will be able to receive our university and the ADEC "24/7" broadcasts.
A -- False. Those with a DSR4200c, DSR4200v or DSR5200v Integrated Receiver/Decoder (IRD) will be able to receive at least one ADEC 24/7 Multiple Channel Per Carrier (MCPC) broadcast from Fort Collins plus all of the ADEC generated programming on the Single Channel Per Carrier (SCPC) channels which are uplinked to the ADEC transponder(s) from ADEC members. It may also be possible that the same programming which will be available on DBS (PrimeStar, Dish and DSS) can be received on the IRDs. This will depend on the agreement that ADEC reaches with the DBS provider(s). In order to get free carriage from the DBS provider for ADEC programming, the provider may require that the feed from Ft. Collins to the DBS provider be proprietary.
If your university transmits programming to ADEC on the ADEC transponder, you could authorize anyone with a DSR4200 IRD to receive the programming. If this programming is then retransmitted by ADEC on the DBS service, all persons subscribing to that service would also be able to receive your programming.
Q -- Are we still talking 400 free broadcast hours? I've heard different figures from different people.
A -- Yes...each ADEC Owner-Member would have a little more that 400 broadcast hours available plus access to additional hours at extremely low rates. Also, Owner-Members have the right to acquire, at cost, full-time bandwidth on the ADEC transponder(s) on their own or in partnership with other ADEC members.
Q -- In light of the "educational programming only" clause, can we use a bit of our broadcast time for university student recruitment?
A -- You'll want to discuss these types of issues with Janet and the Board. Your letter of commitment will have a place for you to raise these types of as yet unresolved policy questions. Blatant advertising would be inappropriate but educational programming that might be of use to students or potential students in learning about what's available at your university would most likely be construed as public service/educational programming if not overdone.
Q -- True or False: In Jim Davis's Matrix message of Sept. 22, he said that we have no idea how many streaming video sessions can be carried on simultaneously with the asymmetrical setup.
A -- Jim's right. There is no way that we know of at this time to simulate multiple video streaming real time since there are a number of critical operating variables that will be defined by the way ADEC members actually use the network. Once we get the ground and space segments operational, we'll be doing a sizing exercise to allocate transponder bandwidth based upon anticipated user requirements which the ADEC members will provide.
The network is constantly scalable so that these bandwidth allocations, particularly with respect to the MCPC allocation, can be continually modified. As you know, video streaming is a bandwidth hog... but here's an advantage of a system such as the one that ADEC is proposing. If an ADEC member determines that it would be in its best interest to use video streaming as a significant element of its distance education program, bandwidth on the ADEC transponder can be acquired and configured to service that program. The platform is very flexible.
Q -- If we can't use our hours in year 1, what's the going rate? Is there a ballpark figure for what satellite time costs?
A -- The ADEC Board has suggested a number of ways that ADEC members may transfer unused video broadcast hours or Internet POPs. ADEC will actively assist ADEC members to recover costs for any unused capacity. ADEC can, for example facilitate transferring capacity to other ADEC members in return for consideration being provided or ADEC may assist in marketing capacity to outside mission oriented users. I'm not sure at this time what the hourly rate for an ADEC digital channel would be but would estimate that it would be offered to outside users for between $125 and $200/hour.
Other Questions (OT)
A -- The initiation date of ADEC programming on DBS is uncertain and will depend upon the timing and outcome of rulemaking by the FCC with regard to Section 25(b) of the Cable Act of 1992 and upon the results of negotiations with EchoStar, PrimeStar and DirecTV. When ADEC programming becomes available thru DBS providers, the receive site would acquire programming with the same equipment and would pay the same access charges which would be applicable to all other DBS subscribers.
The principal advantages of DBS include:
Right now, Hughes is the only DBS provider of Internet (DirecPC). Those who subscribe only to DBS service would NOT be able to receive direct programming from ADEC members on ADEC's SCPC multi-channel service, the ADEC programmed MCPC services from the ADEC hub in Ft. Collins or the ADEC Internet Service. These services will only be accessible through the DSR4200/CORRidiOR or DSR5200v equipment.
A -- ADEC will be developing a staged capability to transmit programming to international audiences. During the initial phases of the telecommunications hub operation, all international programming will be delivered from the hub to the ADEC digital transponder which will be located in the domestic arc. ADEC will assist with the purchase of retransmission services from the private sector which will receive the ADEC digital signal from our transponder and retransmit the signal to an international satellite with final delivery to targeted international downlinks. International sites within the "footprint" of ADEC's transponder such as those in northern Mexico, Canada and the Caribbean Basin will be able to receive programming directly from the ADEC hub..
During later stages of the telecommunications hub development, an additional steerable uplink dedicated to international transmission will be constructed which will be able to access Loral/Orion, Intelsat and PanAmSat international satellites. The location of the hub at the 105 degree meridian will allow direct transmission of RF signals to international satellites with a reach as far east as Moscow, the Middle East and East and Southern Africa and as far west as Central China and Australia.
The cost of international space segment will be dependent upon the amount of time purchased from international satellite operators. The base rate/hour for 6 MHz SCPC service on the PanAmSat fleet is $700/hr (the base rate for 27 MHz analog is $1,500/hr). The rate declines to $460/hr for an average of 5 ½ hours or more per day of usage. International unit rates will be less if the time is purchased from the provider of the ADEC transponder.
A -- Following are approximate costs of installed equipment. The low end of the range represents estimates of costs for volume purchases. The high end of the range represents single purchase costs.
| Digital Uplink Facilities: | ||
| Basic Steerable Analog Uplink (Turnkey) Includes a 4.6 meter antenna |
$165K to $230K | |
| Addition of single channel DigiCipher II encoder to existing Analog uplink | $115K to $145K | |
| Upgrade standard analog service upconverter to phase stable upconverter to provide for digital capability | $10K to $18K | |
| Digital Downlink Facilities: | ||
| Steerable 3.7 Meter Downlink Antenna with Analog Receiver and Phase-Stable Ku and C-band LNBs | $6,000 to $8,500 | |
| Fixed 1.8 Meter Off-Set Feed Solid Antenna with Phase-Stable Ku-band LNB | $400 to $550 | |
| DSR4200v IRD and CORRidiOR IP Interface or DSR5200v IRD | $1,800 to $2,400 | |
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E-mail Site Manager: webmaster@adec.edu |
Last Updated: June 20, 2002 | |