Some additional critique on TeraBeam from Stephen Saunders, Editor of Light Reading, who takes a more granular look at the upstream and downstream bit rates in the p-mp scheme, which he is suggesting will prevail during normal operation. I would agree with his assessments here, i.e. both the pros and the cons which he cites. The data rate (speed, throughput) anomalies which he cites are additive to the other inhibiting factors to overall end-to-end gigabit operation which I outlined yesterday in the post to which this one is linked. And these realities stand in stark contrast to the message that was strongly implied during yesterday's conference call, and that message was that end users would enjoy Gigabit speeds. Sometimes it's better to be prudent and tell it like it really is right out of the gate, rather than having to be corrected later on by those who would appear to be sharp-shooting. Don't you agree?
FAC
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lightreading.com
"The Truth About TeraBeam"
Service providers that buy into TeraBeam's fiberless optical technology with
hopes of living a gigabit dream could wake up to a megabit reality.
That?s the real story to emerge from a press conference held yesterday by
TeraBeam Networks terabeam.com and Lucent Networks
lucent.com to announce a joint venture to sell Terabeam?s
?breakthrough fiberless optical technology.?
Essentially, the conference lacked in detail what it missed in clarity. No price
was announced, and neither vendor would give specifics on throughput, range or,
indeed, how Terabeam?s laser-based wireless technology works.
However, some digging by Light Reading later turned up one reason why both
vendors may have been unwilling to provide more granular information.
TeraBeam says its product supports ?gigabits per second speeds.? However, on
closer examination it turns out that the capacity of the network is shared between
subscribers -- a fact confirmed later by TeraBeam. That means that service
providers that deploy services based on TeraBeam technology, and businesses
that buy into those services, are more likely to see megabit speeds than gigabit
throughput.
Here?s why. Terabeam?s products deliver 1-Gbit/s point-to-multipoint connectivity
between a base station, which is installed on a service provider building, and
multiple subscriber terminals (actually, small dishes that sit in the window of
users' offices).
Despite the company?s name, the base station acts more like an arc light than a
beam ? dividing each metro area into 90-degree sectors, or cells, and ?sweeping?
them.
A typical 90 degree cell might contain between 15 and 40 user terminals ? up to
a maximum of 96, according to Greg Amadon, chairman and CTO of TeraBeam.
And the data capacity of each cell is shared between the terminals. Thus, if the
cell is being used to carry gigabit Ethernet traffic, and there are 40 terminals in
the cell, each customer will receive an average of 25 Mbit/s of capacity (1,000
Mbit/s, divided by 40) -- not the ?gigabit? throughput that TeraBeam and Rich
McGinn, chairman and CEO of Lucent, vouchsafed in today?s conference.
This limitation of TeraBeam's architecture is worst for downstream traffic -- being
sent from the base station to the subscriber terminal. According to TeraBeam's
Amadon, upstream traffic, sent from subscribers to the base station, travels at "a
minimum of 100 Mbit/s."
So does this mean that TeraBeam's solution is without merit? No -- for two
reasons. First, multi-megabit speeds are still a huge improvement over the 1.5
Mbit/s T1 connections that many businesses are still using for Internet
connectivity.
Second, TeraBeam's point-to-multipoint architecture lowers the overall cost of the
network by allowing service providers to install cheaper subscriber-side
equipment. Other laser-based fiberless optical products -- from companies like
AstroTerra Corp., Canon Inc., FsONA Communications Corp., and Jolt Ltd. -- can
only be installed in point-to-point configurations, with expensive equipment at
each end of the network connection.
More serious competition for TeraBeam could come from AirFiber Inc.
airfiber.com, a new startup that is due to announce its first products in
the next few weeks.
--Stephen Saunders, US editor Light Reading lightreading.com |
