SUMMARY: Wireless LAN Connectivity

From: David Burwell (
Date: Wed Jul 13 1994 - 02:30:35 CDT

  I have received some leads for manufactures.

Laser Communication..717-394-8634

  I have not called Motorola or Xircom direct, but in a conversation with
a local rep who carries Soletec, Mot. & Xircom, he said Mot. & Xircom were
geared to the "In Office" wireless connections, not building-to-building.

  Laser Communications has a series of products for Building-to-Building. They
are all limited to 1km distance, direct line of sight without trees, poles or
other "obstructions". They will start to degrade in fog (if YOU can't see the
other building, then it will just be starting to have trouble), rain (greater
than 3" per hour), smog, etc. They also will not support A,B & C connections.
If you have 3 buildings to connect, you need 2 pairs of boxes (one pair for
building A to B and one pair for Building A to C). They have 2 products of
interest. One is a LAN bridge for EtherNet, the other is a 24 channel T-1
bridge. The LAN Bridge is 10Mbs and has limited protocal filtering. It
appearently transports any protocal running on the ethernet. It has Ethernet
connections on one side, and the Laser Transceiver connection on the other;
very simple. I don't know about how it is managed through the network, but
there is an RS-232 port for local management. The T-1 Bridge needs a T-1
connection on each end, so the possibilities are endless. Fractional T-1 &
Voice, etc. If you wanted to use the whole T-1 for data, you would need a
DSU/CSU into a router or WAN interface. If you wanted to use VF/DATA, you
would need a D4 channel bank (for VF) and some sort of drop and insert box
for your data. The cost of the LAN bridge is $15,000 per pair and the cost
of the T-1 bridge is $13,750 per pair (plus the extra cost of the D4 banks,
DSU/CSU, etc.). There is no discount.

  Soletec makes only one product for connecting Building to Building. They
use an RF interface (almost microwave) that requires line-of-sight, but it
can have limited "obstructions", trees, poles, towers, etc. The distance limit
is 3 to 5 miles. There are no whether related limits (rain, fog, etc.). They
WILL support A,B & C (and D,E,F,etc.) connections, with only one Transceiver
in each building. The difference is in the antenia. The "hub" building has
an omni-directional antenia and the remote buildings have hi-gain directional
antenia pointed back to the "hub" building. They are limited to 2Mbs through-
put, but they explain that as being "only 7% less that actual ethernet through-
put" (their quote). Their box is manageable from the network and there is a
local RS-232 managment port. It has limited protocol filtering and will trans-
port any protocol running on the Ethernet. It has a security option that will
encript the data between the Tranceivers. It has an Ethernet interface on one
side, and an antenia connection on the other. The MSRP is $4,995 per Transceiver,
$395 for an antenia, and $100 for the mast. The security option is $300 per
box. My local Manufactures Rep. quoted $9,075 for 2 tranceivers, 2 antenia and
2 mast kits.

  When we buy, we will buy the Soletec AirLAN. It appears to be cost effective
and easy to install. The antenia go on the roof and then a log coax back to the
tranceiver with an RJ-45 connection into the hub. The antenia are aligned using
the built-in program for signal stength.

  Thanks to all who replied.

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