Trango
Systems,
Inc
TL45
User
Manual
Rev
2.0r3
LT
‐
9037A
August
15,
2011
Page
30
Automatic
Rate
Shifting
Feature
Description
With
autorateshift
feature
enabled,
the
radios
will
automatically
renegotiate
the
modulation
method
and
speed
speed
to
maximize
wireless
link
integrity.
The
link
speed
will
vary
depending
on
two
factors:
1)
the
number
of
ARQ
errors
received,
2)
successful
processing
of
special
link
assessment
packets
sent
in
both
the
current
and
next
higher
speed.
The
radio
will
shift
to
the
next
higher
in
speed
when
no
errors
are
detected.
The
radio
will
shift
down
in
speed
if
error
rate
is
excessive.
Notes
regarding
the
autorateshift
feature:
1.
The
radio
will
begin
initial
speed
test
when
upon
association
to
peer
radio.
There
are
40
steps
and
around
50
seconds
to
complete
this
initial
test.
The
radio
will
send
link
assessment
packets
(3600
byte
packets
at
a
rate
of
100
packets
per
second)
at
the
highest
speed
(54
Mbps).
The
radio
will
deliver
payload
at
the
speed
which
is
specified
before
association.
If
the
assessment
packet
dropping
rate
is
higher
than
10
percent,
the
speed
test
will
decrease
the
speed
for
assessment
packets.
If
the
current
payload
speed
is
higher
than
the
speed
of
assessment
packet,
the
radio
will
set
the
current
payload
speed
to
be
the
same
as
the
assessment
packet’s
speed.
If
the
current
payload
speed
is
lower
than
the
assessment
packet’s
speed
and
more
than
500
assessment
packets
have
been
transmitted,
the
radio
will
set
the
payload
speed
to
be
the
same
as
assessment
packet’s
speed.
2.
After
completion
of
initial
speed
test,
the
radio
will
set
the
payload
speed
to
be
the
same
as
the
final
speed
of
initial
speed
test.
3.
The
radio
will
check
link
quality
and
adjust
payload
speed
periodically.
a.
The
radio
will
increase
payload
speed
every
60
seconds,
if
i.
Speed
test
which
is
running
at
higher
speed
is
successful.
–and
‐
ii.
Payload’s
ARQ
retransmit
rate
is
less
than
10
percent.
b.
Radio
will
decrease
payload
speed
every
10
seconds,
if
i.
Speed
test
which
is
running
at
payload
speed
is
failure.
–and
‐
ii.
Payload’s
ARQ
retransmit
rate
is
higher
than
10
percent.
4.
Payload
speed
can
be
changed
manually
when
auto
rate
shift
is
on.
But
the
speed
setting
will
not
be
sustained.
Example
:
#> autorateshift on
Success.
#>
