User's Manual
Carlson Wireless USA revision 2.12 Page 12
Voice Coding
Signaling
Modem Support
Fax Support
Digital Interface
Idle Channel Noise
End-to-End System Latency
SPECIFICATIONS
BASEBAND PERFORMANCE
Uncompressed 64 kb/s PCM
DTMF is passed through
up to V.34-1996, (33.6 kb/s)
up to G4, unrestricted
Asynchronous, RS-232, DCE
-68 dBm max (20 dBrnCo)
5 ms typical
NETWORK INTERFACE SPECIFICATIONS - FXO or Central Office
Line Impedance
Maximum Loop Length
Ring Equivalent Number
Ring Detect
2 Wire Return Loss (ERL)
900 Ohm +2.16 uF, loop start
1500 Ohms
0.3B
40-110 Vrms, 17-34 Hz
Greater than 20 dB
Line Impedance
Loop Current
Maximum Loop Length
Ringing Voltage
Ringing Frequency
Ringing Load
2 Wire Return Loss (ERL)
NETWORK INTERFACE SPECIFICATIONS - FXS or Subscriber
600 Ohm, loop start
27 mA fixed
600 Ohms including instrument
86 Vrms Modified Sq Wave
20 Hz standard., 16, 25 Hz opt
5 REN-B max (5 Watts)
Greater than 20 dB
POWER REQUIREMENTS & CONSUMPTION
Filtered DC
Absolute Minimum / Maximum
FXS End, On-Hook
FXS End, 2 Lines Off-Hook
FXO End - On or Off-Hook
12 to 48 volts
10 to 55 volts
2 Watts max
4 Watts typ
2 Watts max
Carlson Wireless USA revision 2.12 Page 5
SYSTEM PLANNING
Certain requirements are necessary for the i-WLL-Trailblazer system to
function.
(1) A radio path with losses fitting within the capacity of the system.
What’s an acceptable “Link Margin“? One accepted theory is that 10 dB
of fade margin will deliver a 90% reliability and 20 dB wi ll deliver a 99%
reliability etc.. There are other factors that affect this including multipath
and polarization. At 2.4 GHz there is only a small ground wave compo-
nent involved in the radio propagation. This means that the above num-
bers are presuming clear LOS (line of sight) and first Fresnel zone. Multi-
path occurs when a reflector such as earth’s terrain or man made struc-
tures cause additional delayed signals to be received. If a reflected signal
was delayed 180 degrees out of phase with the line of sight signal, and
the magnitudes are the same, they will cancel out completely! In the real
world, if you do have line of sight path, multi-path degradation is the rea-
son why you need a minimum of 16 to 20 dB of margin. If you don’t have
line of sight, multi-path could easily cause 16 dB of degradation.
Fade Margin Chart
The above chart shows various antenna and distance combinations. The
external antenna option is only available through professionally trained
dealers.
Distance Distance Antenna Gain Frequency Path Loss ERP Link Margin
in miles in km in dBi in GHz in dB in dBm in dB
1.5 2.4 14.0 2.45 108 30 32
2.0 3.2 14.0 2.45 110 30 30
5.0 8.0 14.0 2.45 118 30 22
7.0 11.3 14.0 2.45 121 30 19
8.0 12.9 14.0 2.45 122 30 17
10.0 16.1 14.0 2.45 124 30 16
12.0 19.3 14.0 2.45 126 30 14
14.0 22.5 14.0 2.45 127 30 13
20.0 32.2 14.0 2.45 130 30 10
20.0 32.2 20.0 2.45 130 36 22
30.0 48.3 23.0 2.45 134 39 24
50.0 80.5 27.0 2.45 138 43 28
* Note: external antennas used for 20, 30 and 50 mile paths