User's Manual

March 1, 2002 Page B3
require six ARCi Hub Antennas arranged pointing outward spaced every 60 degrees. A
system only looking up a narrow canyon from one end might require only one ARCi Hub
Antenna. Cables are run from the antenna(s) into the building to the hub equipment
room.
The ARCi Subscriber Antenna is mounted outdoors at the subscriber location with line
of sight to the hub antenna. A single cable is run to the modem and computer inside the
subscriber location.
The electronic equipment associated with the ARCi Hub Antenna and the ARCi Subscriber
Antenna is housed in weatherproof enclosures inside each antenna housing.
The
Wireless Hub (also known as the Wireless Modem Termination System, or WMTS ),
controls the flow of data between the Gateway to the Internet and each subscriber
wireless modem. It transmits a continuous downstream of user data interspersed with
modem commands to each Wireless Modem in the system. When a user has data to
transmit upstream to the Internet, the modem awaits its time slot (as assigned by the
wireless hub), turns on its transmitter, sends its data to the hub, and then turns off its
transmitter. The
WMTS , working in conjunction with the Network Manager , provides
the system with TCP/IP-related services such as DHCP server, TFTP server, time server,
etc.
The Gateway provides certain TCP/IP and ISP functions such as routing, address
translation, caching, security, etc.
The Hub Antenna and Subscriber Antenna are ARCi products. The WMTS and Wireless
Modem are components of the Vyyo Broadband Wireless Access System.
The Network Manager is an IBM-compatible PC with the Windows 2000 operating
system, Network Manager software provided by Vyyo, and a commercial SNMPc package.
The Gateway consists of a PC running ISP-provided software (probably a form of Unix)
and may also include external hardware such as a router, CSU/DSU. etc.
The protocols that govern the operation of the
ARCi Internet system and the Vyyo
Broadband Wireless Access System generally conform to the cable TV industry
DOCSIS standard, as enhanced for wireless operation.