NASA space station team pilots voice over IP system

NASA space station team pilots voice over IP system

NASA is readying a voice over IP teleconferencing system to link operations personnel for the International Space Station with research scientists around the world.

The Internet Voice Distribution System, developed by AZ Technology Inc. of Huntsville, Ala., is an alternative to an aging conference system used by the Marshall Space Flight Center, also in Huntsville. The Huntsville Operations Support Center Voice Distribution System, or HVODS, uses dedicated lines.

IVODS has been undergoing tests since June and should be ready for general use by midyear.

One more step

'We are at the last phase of testing before we deploy it in parallel to HVODS,' said Bob Bradford, customer commitment manager at Marshall's Space Communications and Data Systems Office. 'We're hoping we can turn down' the number of dedicated connections.

IVODS started as a two-year contract under the Small Business Innovation Research Program. AZ Technology received a second two-year contract worth $600,000 to make a prototype of a more advanced version.

'To integrate IVODS into a collaboration suite would go a long way toward giving the scientific and operations people good tools,' Bradford said.

'We built the first version to mimic HVODS,' said Jim Chamberlain, AZ Technology's systems and software development manager. 'Now that we're in the PC software world there are a lot of possibilities.' They include adding video and application sharing, improving audio quality and strengthening security.

The Flight Projects Directorate uses voice conferencing to link space station personnel on the ground with scientists who are conducting experiments in space.

Up to 100 conferences, or voice loops, can run concurrently.

HVODS lets users monitor up to eight conferences while actively participating in one of them. The dedicated system uses proprietary handsets, leased lines and a voice switch from Raytheon Co.

The space agency's videoconferences blend old and new equipment

'The switch is old, and it's hard to get parts' for it and the handsets, Bradford said. 'As far as I know, there is no collaborative software package that met NASA's needs.'

AZ Technology's task was to commercialize a system to mix multiple conferences over public networks with adequate security. 'You can run IVODS anywhere you have the proper bandwidth and authentication,' Chamberlain said.

The core of IVODS is CUseeMe Conference Server software from First Virtual Communications Inc. of Santa Clara, Calif. The conference server establishes H.323 industry-standard audiovisual connections and mixes and transmits the audio streams. The VComX Internet Telephony Gateway from VoIP Group Inc. of Miami links the server to NASA's voice switch.

Virtual private network servers from Check Point Software Technologies Ltd. of Redwood City, Calif., secure the Internet connections.

Marshall personnel use HVODS equipment to hold conferences; outside users must have VPN and IVODS client software on their PCs. To run the IVODS client, a remote user needs at least a 500-MHz Pentium system running Microsoft Windows NT or Win 2000 with Internet Explorer 5.0. It must have Sound Blaster-compatible, full-duplex audio and fast Internet access.

High bandwidth is necessary because of the voice encryption. 'That about doubles the bandwidth requirement,' Chamberlain said.

Too much of a good thing

Unencrypted voice requires 16 Kbps per channel, whereas each encrypted channel uses 32 Kbps. Although IVODS users could choose from up to 100 conferences, 'we decided that eight times 32 Kbps was the most bandwidth we wanted anyone using at one time,' Chamberlain said.

Many of the researchers using IVODS have access to the superfast Internet2 backbone. But public Internet connections also work, Chamberlain said.

'Our company is on the public Internet, and we have been testing IVODS back to NASA. It works quite well,' he said.

Through HVODS, the IP system also can connect the space station crew. 'But right now it is turned off' because of security concerns, Chamberlain said.

Better security is something AZ Technology wants to add to the next-generation IVODS, although there is no guarantee NASA will adopt the new version.

About the Author

William Jackson is freelance writer and the author of the CyberEye blog.

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