[Boki]

Hi All,

In communication, the BER is the lower the better, right?

Best regards,
Boki.

 

[Joel Kolstad]

In communication, the BER is the lower the better, right?

Generally, yes -- BER = Bit Error Rate, and fewer errors are better.

Most real systems are designed to operate with a given BER or better, so
from a certain point of view achieving a BER well in excess of what's
necessary is most likely a waste of resources, but no one's ever going to
complain if you can deliver a better BER without spending more money.

 

[Boki]

Joel Kolstad 寫�：

Generally, yes -- BER = Bit Error Rate, and fewer errors are better.

Most real systems are designed to operate with a given BER or better, so
from a certain point of view achieving a BER well in excess of what's
necessary is most likely a waste of resources, but no one's ever going to
complain if you can deliver a better BER without spending more money.

How about Bluetooth?

When I get BER = 0.01% ,so I reduce my power to make BER close to 0.1%

so I can get less power consumption, does this make sense? ( I don't
know answer )

Best regards,
Boki.

 

[Mike]

Hi All,

In communication, the BER is the lower the better, right?

Nope. The optimum is best, and the system designers have to decide how to
define optimum.

-- Mike --

 

[Joel Kolstad]

Hi Boki,

"How about Bluetooth?

When I get BER = 0.01% ,so I reduce my power to make BER close to 0.1%

so I can get less power consumption, does this make sense?"

I don't know the particulars of Bluetooth, but from Googling around it looks
like the spec says that you are supposed to achieve a BER of 0.1%. Hence,
*so long as you can achieve that BER at the distance required*, saving power
looks like a win.

If you build your hardware such that it has this "power-save" mode
available, you can always make this issue their problem by telling them you
want them to drop into power-save mode whenever the BER is 0.1% or lower,
and otherwise run at the higher power -- this is a very common technique.

---Joel

 

[PeteS]

Thanks : )

Best regards,
Boki.

What BER you can live with (and I deal with Bluetooth every day in my
products) depends on what the link is being used for.

For voice data which can not be retransmitted (well, it could but there
would be no point) you want as low a BER as possible. I am talking here
about links that do not operate at much higher speed than necessary but
a typical bluetooth synchronous (SCO) link which provides a 8K frame
rate where the frames are to be pushed / pulled directly to / from a
codec.

For the asynchronous data (ACL) channels, if your datarate is low and
you embed CRC/checksum in the data you can simply retransmit the data
if you can't live with errors in the serial datastream.

Voice links are rated at 1E-6 BER for 'carrier grade' status,
incidentally.

You will start to notice significant degradation in a bluetooth voice
link at 1E-2 BER. 1E-3 (0.1%) gives understandable and fairly clear
voice links, at least in my experience.

Cheers

PeteS