Basic Guidelines
Tropos 3310 and 3320 Router Installation Guide
6
Antenna Options
Tropos 3310/3320 routers are equipped with omni-directional antennas mounted on the router.
Tropos recommends the use of these antennas and discourages use of remote mounted antennas.
Note
Only use antennas supplied by Tropos. Operating a router with a non-qualified antenna may be in
violation of FCC Rules Part 15.203(c), Code of Federal Regulations, Title 47.
Site Surveys
Because of differences in component configuration, placement, and physical environment, every
network application is a unique installation. Before installing multiple routers, perform a site
survey to determine the optimal use of networking components and to maximize range,
coverage, and network performance. Consider the following operating and environmental
conditions when performing a site survey:
Data rates
—Sensitivity and range are inversely proportional to data bit rates. The
maximum radio range is achieved at the lowest workable data rate. A decrease in receiver
threshold sensitivity occurs as the radio data increases.
Antenna type and placement
—Proper antenna configuration is a critical factor in
maximizing radio range. As a general rule, range increases in proportion to antenna height
and gain.
Physical environment
—Clear or open areas provide better radio range than closed or filled
areas. Also, the less cluttered the operating environment, the greater the range.
Obstructions
—A physical obstruction, such as a building or tree, can block or hinder
communication between Tropos routers. Avoid locating the antennas in a location where
there is an obstruction between the sending and receiving antennas.
Building materials
—Radio penetration is greatly influenced by the building material used
in construction. For example, drywall construction allows greater range than concrete
blocks. Metal or steel construction is a barrier to radio signals.
For additional planning information, refer to the
Tropos Networks System Design Guidelines
.
Wireless Coverage and Range
Tropos wireless network operation depends upon multi-hop data transfers across nodes to
provide connectivity to a Tropos gateway. These gateways need to be placed close enough to
each other so that one device can communicate with other routers over the RF wireless interface.
However, clustering too many routers together within a small geographic area may create a
situation in which the routers are subject to excessive interference. This can adversely affect
network performance and throughput.
Each Tropos router should have a partial overlapping coverage area with at least one other
router. As a general rule, placing a router so that it has partial overlapping coverage area with
two other routers provides adequate network redundancy while also mitigating interference.
