Wireless Ethernet Bridge User Manual

Overview OFDM
Trango Broadband Wireless — Atlas5010 page 6
Chapter 1 Overview
The Atlas5010 is a point-to-point (PtP) wireless Ethernet transmission system which provides network connectivity at
speeds up to 45 Mbps depending on th e transmission distance and noise floor. The Atlas5 010 utilizes OFDM technology
and is designed for use in long range backhaul and wide area data networking applications.
Users are required to simply specify one P5010M (INT or EXT) unit type as master unit (MU) and on e unit as remote
unit (RU). Each unit utilizes power-over-Ethernet (PoE) and is designed for outdoor environments. The cable entry
point can accommodate both Shielded twisted pair Cat5 (STP) and unshielded twisted pair Cat5 (UTP), with the addition
of conduit for tower mounting.
OFDM
The Atlas platform utilizes Orthogonal Frequency Division Duplex (OFDM) processing which offers link stab ility and
performance in the presence of multipath interference.
Adaptive Modulation
One of the key advantages of the Atlas series radio platform is utilization of multiple modulation schemes including the
following:
• Binary Phase Shift Keying (BPSK)
• Quadrature Phase Shift Keying (QPSK)
• 16 Quadratu re Amplitude Modulation (16QAM)
• 64 Quadrature Amplitude Modulation (64QAM)
The Atlas system allows individual selection of the upstream and downstream modulation schemes. The modulation
schemes can be adjusted manually or automatically (automatic rate shifting ) fo r changing propagation and interference
conditions. The higher order modulation schemes (64QAM) are typically deployed at reduced ranges while lowe r order
modulation schemes (BPSK) are implemented at long distances.
ARQ
Another key advantage of the Atlas platform is its Automatic Repeat Request (ARQ) transmission correction scheme.
The ARQ algorithm detects packet loss due to fading and interference cond itions and requests the remote radio to re-
transmit specific packets.
Dual Polarity Antenna
Atlas radios feature built-in dual polarity antenn a functio nality. Users may select either horizontal or vertical antenna
polarity through th e unit’s software. Switchable antenna polarity provides greater spectral flex ib ility.