He began by giving a brief overview of the services provided by Stanford Telecom. The company has over 25 years experience providing digital telecommunications. They provide the data links for almost satellites, both military and commercial. They provide high speed wireless data services such as ATM and MMDS and support traditional telephone lines. He showed several view graphs illustrating Stanford Telecom products and services. Most of his discussion will be on LMDS and MMDS wireless.
LMDS and MMDS are similar to cellular radio, and cover limited areas. They take advantage of the users being fixed, with the community subdivided into sectors so that traffic can be allocated as needed. LMDS at 28 ghz is also known as "wireless fiber" with about 1 ghz bandwidth, but limited to receivers within about 2 - 5 km. Farther away than that there is severe signal fade. MMDS at 2.5ghz has a 25 km range, but MMDS has narrower bandwidth, about 10 of LMDS. It offers 2-way high speed service.
Why go wireless instead of fiber? If you can afford fiber, it is better for high speed data, but wireless is cheaper and easy to install.
MMDS antennas can cover all of the area, but at a lower bandwidth. Must be within line of sight of the user, with 2.5ghz MMDS signals being less sensitive than 28ghz LMDS signals. The user has an antenna pointed at the source to get the signal.
Challenge in the technology was developing software to manage many individual 2-way signals. Tracking data, storing it, and sending it to the proper address is the challenge. They provide the boxes to decode the signals, but they are not billing for data by bit rates. Everything in the system is IP compliant. Rates for data over MMDS are 15 mps down, 1.8 mps up.
Hank Magnewski asked about the cost of FTTH and wireless systems, considering the figures that City staff quotes it seems that FTTH is shown as higher than it really is.
David said FTTH is more expensive, but he doesnāt have exact costs. If you can afford FTTH thatās the best and fastest approach.
He showed a chart plotting data rates, comparing ISDN, LMDS, MMDS, etc. Fiber would be way off the chart since it is far and away the fastest. LMDS and MMDS are faster than ISDN, but much slower than fiber.
An overview chart of the broadband central office system was shown. Stanford Telecom provides the firmware in the central office.
The residential gateway for LMDS is being beta tested in the northwest. Cost of the gateway box is unclear at this time, but an affordable box is anything under $1000. The box plugs into a TV, computer, and a phone. Users can have up to 4 phone lines with 10baseT connections. The subscriber terminal will accommodate multiple PCs, each of which shares the Ethernet. Each PC gets its own IP address. There is just 1 IP address/box. Hank noted this can be a problem since many homes have multiple IP addresses. Cable Co-op supports up to 8 IP addresses at present for the most expensive type of service.
Hubs can be placed anywhere, even on a vehicle like a HumVee. The hub contains a web server, NMS processor, AIU server, IP switch router, fans, power supply, and power controller. Trees can give some signal shadowing, but the shadowing doesn't prevent the service from working, it just may not be as high quality in all directions if it is shaded by trees or buildings. There will be some users who are blocked from line-of-sight, and will not be able to get the signals, but most people can be served adequately from the hub. It is not a replacement for fiber, but it's an inexpensive alternate and readily deployable. It has real advantages in 3rd world countries.
The LMDS system tied to the fiber loop would provide real cost savings and competitive advantages.
Dave showed a chart which compared LMDS/MMDS, FTH, TTC, HFC, ASDL, and satellite service. Highest cost is for FTTH, then FTC, HFC, and ASDL. Satellite has limited bandwidth capacity, it is hard to integrate voice, data & video from satellites, and satellite service has an expensive infrastructure. It is designed for use with phones costing $3000, and 70,000 of them were sold before the system was turned on. There is a big demand for the services in poor countries. FTTC handles 12 -24 homes/node, and offers high bandwidth, installs fast, is low cost with no cabling runs to curbs, sectoring allows tailoring to businesses and residential users. Overall costs are very high. Fiber to the curb (FTTC) is less expensive than FTTH, serving 12-14 homes/node with coax distribution and less bandwidth. ASDL is cheaper to install but more expensive to maintain and has distance restrictions. Capacity is limited and bit rates depend on distance from the switch. LMDS/MMDS has the lowest per subscriber cost, has bandwidth similar to fiber, with up to 2000 users/hub.
Hubs cost about $100,000. It's expensive to get into the business. After spending $17 million for development Stanford Telecom now is in the beta test phase.
Hank asked "Can we install LMDS systems?" Dave said yes, but you first need to get a 28ghz license, but it has limited range, and is more sensitive to the line-of-sight transmission limits. LMDS can be provided if people want it.
Satellite TDMA has been expanded since 1985 to where at present it is linking huge areas at lower data rates via GEO satellite at 22,300 miles up. Home receiving antennas are 10 to 18" in diameter. There's a half-second delay for voice due to the time the signal travels to and from the satellite, but data has no noticeable delay.
Currently all orders for the gateway unit are from Palo Alto type areas. The biggest market longer term will be 3rd world countries. The provider and beta test location have been asked not to be identified (several people guessed Seattle).
What is the deployment cost for LMDS and MMDS? How does it compare to other types of connections?
Dave said he will have to get back with real figures, since he's more in the satellite technical area, not costs.
It is more of a problem getting the system to work in cities where there are many tall buildings with rooftop equipment, limits on where antennas can be mounted, line-of-sight interferences, etc.?
David said "There must be 1 antenna and converter per apartment."
Keith Cooley: Are there any other kinds of interference - electrical, interference, etc.?
David replied: Not normally, but there can be problems if someone transmits on the frequency incorrectly and jams the transmission inadvertently.
Is there a conflict with someone like TCI services?
Stanford Technology helps them, not hurts them, because they don't compete with a TCI or similar entity over services or content, they just offer a cheaper way to transmit signals.
There is a significant wireless market, and Stanford Telecom expects to get a good return on their investment. In some parts of the world they can sell as many units as they can deliver. Data on satellites is compressed because costs are high for satellite channels.
Adjourned at 8:35 AM. Next meeting will be Wed. Jan. 6, 7:30 AM.
Nanospace will take over our web service next month, so we have to move our address. Everyone will be resubscribed to Nanospace automatically. PAMF will move to Nanospace for service from the new campus.
Submitted by Bob Moss. For decoding all the TLAs (three-letter acronyms) in the minutes, refer to him. He works at Cable Co-op, and is a member of the Barron Park Association.
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