User guide

Canopy
®
OFDM Backhaul Solutions
Backhaul Solutions for the Most Challenging Locations and Applications
FAQ
1. What interference mitigation techniques are used on the OFDM Backhaul Radios?
The Canopy OFDM Backhaul Radios deliver optimal network performance in challenging environments
by uniquely combining five mitigation techniques including: dual polarized antennas, Transmit Diversity,
orthogonal frequency division multiplexing (OFDM), adaptive modulation and dynamic frequency
selection (DFS). In addition, the radios use less channel width, minimizing the risk for RF interference
and boosting performance in noisy environments.
2. What throughput do I get at maximum range?
The unique design of the Canopy OFDM Backhaul Radios, combats interference (leading to higher
throughput) while maximizing signal range (through high system gain). Operating range and data
throughput of wireless communication is dependent on conditions. The 30/60 and 150/300 Mbps modules
can support up to 6 miles (10Km) Non Line-of-Sight, up to 25 miles (40km) near Line-of-Sight and up to
124 miles (200Km) Line-of-Sight . The data rate is variable based on modulation scheme, and ranges
from 1.5 to 21 Mbps for the Canopy 30 Mbps BH, from 3.0 to 43 Mbps for the Canopy 60 Mbps BH, from
7.2 to 150 Mbps for the Canopy 150 Mbps BH and from 14.4 to 300 Mbps for the Canopy 300 Mbps BH.
To best estimate throughput incorporating topographic variances and obstructions, we developed a
Backhaul Link Estimator Tool which will provide case specific link performance estimates.
http://motorola.canopywireless.com/support/software/
3. How does the OFDM Backhaul provide security for data traffic?
In order to ensure secure transmission, the Canopy OFDM Backhaul Radios are pre-programmed to
communicate only with a matched radio. At installation time each link must be programmed with the MAC
& IP address of its partner. The two ends of the link will only communicate with one another, eliminating
any chance of “man in the middle” attacks. Over the air security is achieved through a proprietary
scrambling mechanism that cannot be disabled or spoofed by commercial tools. The pre-pairing also
allows fast deployment as all that is needed is power for the modules to start searching for each other.
4. What comprises the built-in proprietary security over the air features?
The unique combination of security techniques (scrambling & matched radios) provides excellent over the
air security for the network. Each matched pair employs a built in complex proprietary signal with
scrambling applied to give an added security layer which protects the data being transmitted. On the
transmission, the signal passes through the following processes;
1) Reed Solomon forward error correction where added bits are applied
2) Scrambling with a code that repeats every eight Reed Solomon code words (about 1ms).
3) Interleaver where the signal is then changed in order.
4) Convolutional Encoding where the signal is scrambled into two streams and then sent serially
with some bits unsent.
5) Then the signal is coded onto one of BPSK, QPSK, 16QAM, 64QAM or 256QAM waveforms.
6) Then the signal is interleaved across a 1024 carrier OFDM waveform.
5. What security measures should be used along with the built-in over the air security?
Motorola encourages encryption of data before it’s transmitted by using the security measures built in to
routers, network devices and web sites in order to ensure end-to-end protection of data.
6. Are the OFDM Backhaul radios an 802.11a device?
No. The 30/60 and 150/300 Mbps Backhaul use different encoding and radio transmission systems than
802.11a. In areas where 802.11a systems are operating, the backhaul will detect the 802.11a radio
signals and choose a clear channel away from any interference.
Issue 4, March 2005 Page 18 of 30