Web-TV Demo Truck with Satellite Link

ver 0.1 - 2000.06.19 - dkzh

Project Summary

The concept is to provide a mobile demo platform that can be driven to venues, to show off Web-TV products. The satellite link is suggested to free us from the problem of scheduling appearances far enough in advance as to allow the temporary installation (and testing, etc.) of high-capacity network links to connect the demo units with the Web-TV Service Network.

(This paper is put together from conversations and thoughts based on those conversations. It should not be interpreted as a project plan, although the contents may be used as a straw man for future discussions.)

Trailer Remote Operations

In the case that the truck is ordered, and the equipment is deployed, I can see a need for the capability to remotely configure the equipment in the truck. In the 'normal' configuration, the satellite link would be the primary network path, and with the judicious use of some network gear, we can add a great deal of remote configuration support to the trailer.

Presumptions:

  1. Transport staff may only have junior-level system/network skills.
  2. The trailer will have GPS and electronic compass (for satellite pointing).
  3. Demo staff would travel to meet the trailer separately.
  4. Technical staff would be on-call to help support the trailer activities.
  5. Being related to the ISP service, SOC/NSG could possibly monitor the trailer gear.

Electronic Program Guides

The truck will appear in different time zones, from time to time. Do we want to consider using a ZIP code from a low-population-density area from each of the time zones, so that the hour-to-hour programming maps correctly?

Using a small, RV-style TV antenna, it's possible that we could pick up one or more 'local' off-air channels wherever the trailer is, and use Channel Processors to put them onto specific channels.

Some canned content could come from DVD players on-board the trailer.

Once the satellites are acquired, we might be able to derive channels and turn them into analog channels on the trailer, to highlight partner networks (MSNBC, etc.)

Network and Head End

It is likely that the network equipment (including satellite modems) will need to share the operations area with the video head-end equipment. Advantages to this arrangement include;

  • Connecting serial consoles of video gear to the terminal server.
  • Operator has access to diagnostics PC and can watch LEDs to see changes take affect.
  • Leverage the cooling system for the trailer.

Bench Demo Network

The Network portion is provided by the WNI network connections at Silicon Valley Campus, where a 10 Mbps connection is made to the "Network" router (router 2 in this diagram).

The EIA-530 serial cable link connects the router to the "Network" satellite modem, an SPL/ACT SkyLane SL-512 modem. The output of the modem is a 70 MHz IF stream. The input is adjustable, in the 950-1200 MHz ("L-Band") range.

On the test bench, the 70 MHz IF goes into a Cross Technologies model 2005 Test Upconverter, which allows us to set the frequency for the carrier that will be sent to the receiver on the "Trailer" modem.

These Test Upconverters limit our test link bandwidth to 64 Kbps, which is marginally more than a 56 Kbps modem call, with no delay on the link. In actual use, the modem would be fed into a high-speed uplink, providing 500 Mbps bandwidth for the link, with 1/2-3/4 second link latency.

The "Trailer" end of the link has a matching modem, connected to another router. On the test bench, this is connected directly to the Ascend NAS via a CAT-5 crossover ethernet cable.

The connection between the Ascend NAS and the Gordon Kapes System 930 Telephony Simulator is a standard CAT-5 ethernet cable, but the signaling is actually an ISDN PRI (1.5 Mbps) link. The G.K. box is basically a very small Central Office in this configuration.

We will attach up to four set-top boxes directly to the G.K., using RJ-11 phone cables. The device can support 48 lines, but the additional lines would need to come from 24-port patch panels (connected via 50-pin AMP/Cinch connectors).

Satellite Truck Considerations

Much of the network equipment in the network diagram (shown at left) has asynchronous serial console ports to aid in configuration. (In the case of network gear, the serial port might be the only way to configure the equipment if the network interface is misconfigured.)

One suggestion is to use a router with multiple async serial ports, which are capable of supporting Reverse Telnet access. (A Cisco 2511 provides 16 async ports, in addition to the high-speed serial link for the satellite modem.) You could also consider a stand-alone terminal server, instead of a router-and-terminal server combination.

There should be a PC on-board, configured to perform diagnostics on the network and equipment. This device should have a scriptable application environment, so that custom scripting can be built to perform high- and low-level diagnostics of the equipment. This could include a built-in modem, that could test-dial in through the telephony simulator, and test connections to the Ascend NAS.

If the link back to the network fails, there are a number of tests that could be performed. Do you want a human to do that testing, or do you want a computer to do the testing, and report the results (maybe even suggesting possible resolutions to the problems)?

The serial data output from the GPS receiver can be split, so that it goes to both the device controlling the pointing of the satellite dish(es), as well as to a terminal server port. This way, once the link is up, the network operations center can get access to the Lat./Long. data, if that information would be useful for plotting the location of the trailer in a mapping application. (It's conceivable that the same GPS could be used for computer-aided navigation for the truck driver.)

If any of the set-top boxes have diagnostic ports on them, it's possible that they can be connected to the terminal server, allowing on-site developers to use the diagnostics machine to monitor the output. (Developers back at SVC might also be able to watch the output of those ports.)

The diagnostics PC could also be the documentation repository (HTML pages for text and images), using Front Page to remotely update the documentation as needed, or simply bringing a floppy and/or CD media for physically updating the machine.

What about adding a web-cam capability, so we can see the lights on the equipment?

On-board Diagnostics PC

This is just some brainstorming...what could we do, hypothetically speaking, with the diagnostics PC on the trailer.

  • GPS-based navigation software, so the driver can locate his next stop, print route maps, etc.
    • Requires an ink-jet printer, and consumables...taps into GPS used for satellite targeting.
    • An alternative would be to browse the web for mapping/navigation sites, but this would only work while the satellite antennas were up, during transponder windows. This would require a bunch of power, and would be hard to access when on the road for sudden venue changes.
    • Another option would be to have a cab-mounted laptop, tied to the GPS, but that might be distracting to the driver, or get in the way.
  • Serial Console access, using Telnet application (for many windows at once).
    • Logging console application on-board?
  • Web-based system documentation;
    • Links Page (URLs for vendor's pages related to equipment on-board)
    • Contacts Page (How to reach "the Right People" when you need them)
    • Troubleshooting Page(s)
      • How to tell what's wrong; How to fix it.
      • Who to call if you can't fix it.
    • Instruction (Process) Pages
      • Deploying steps, awnings, satellite dishes, etc.
      • Pre-trip checklist (check generator fuel, kick tires, etc.)
      • On-site Set-Up checklist.
  • Web-based reports and logging (web forms), and demo support.
    • Logging who showed up to present demos that day.
    • Demo statistics (how many visitors, referrals, sales?)
  • Network/Systems management.
    • Scripted utility to try to touch each network device.
    • SNMP management applet?
    • Computer setup/control for decoders, etc.
  • Web-cam capability.
    • Remotely triggerable, so SOC can trigger the snapshot.
    • View of the front panel lights on gear?
    • Second camera to look at the demo area(s) to see guests?