"Stephen Shaffer" wrote in message
...
All,

I have a friend that is an advid adventure racer. He is getting ready
to outfit a small RV for a race later this year, and told me that he
is getting XM installed because "they are going to offer a data
channel so you can get Internet Access."

Sounds fishy to me...

Can anyone verify or deny?

I cannot verify nor deny, but I smell the fish as well.

It doesn't seem technically possible. They do not any significant bandwidth
to dedicate to non-broadcast uses. What about 100 "digital" customers who
wanted 56 kilobits at the same time - that's 5.6 megabits per second - about
equal their whole program bandwidth, I suspect.

And XM/Sirius are one-way services. You'd still need to use the phone for
the you-to-them direction.

The rumor is probably based on XM's announcement that they will be sending
digital weather forecasts. But that would be only one low-speed channel.

"R J Carpenter" wrote in message
...

"Stephen Shaffer" wrote in message
...
All,

I have a friend that is an advid adventure racer. He is getting ready
to outfit a small RV for a race later this year, and told me that he
is getting XM installed because "they are going to offer a data
channel so you can get Internet Access."

Sounds fishy to me...

Can anyone verify or deny?

I cannot verify nor deny, but I smell the fish as well.

It doesn't seem technically possible. They do not any significant
bandwidth
to dedicate to non-broadcast uses. What about 100 "digital" customers who
wanted 56 kilobits at the same time - that's 5.6 megabits per second -
about
equal their whole program bandwidth, I suspect.

Are you saying each channel is only 56kbit? I thought both XM & Sirius were
64kbit?

Yea, they don't have enough bandwidth for decent stereo, much less
datacasting.

Is that why XM sounds worse than FM?

"Drewdawg" wrote in message ...

"R J Carpenter" wrote in message
...

to dedicate to non-broadcast uses. What about 100 "digital" customers
who
wanted 56 kilobits at the same time - that's 5.6 megabits per second -
about
equal their whole program bandwidth, I suspect.

Are you saying each channel is only 56kbit? I thought both XM & Sirius
were
64kbit?

I said no such thing. I postulated the load from a digital service, and
then estimated that it might be ABOUT the same as the program load.

I have no idea how many bits per baud (or hertz RF bandwidth) XM or Sirius
achieve.

I bet real money that the talk channels are allocated fewer bits than the
music channels. I'll also wager that some music channels are "more equal"
than others when the bits are passed out.
========
As I've also said, XM and Sirius are using advanced processing to "make a
linen purse of quality from a sow's ear of bits". They have no expectation
of making a silk purse. They are aiming for good enough for most people,
and are selling primarily on content.
========
If you want to see complaints about digital quality, subscribe to
alt.radio.digital, which is largely devoted to digital broadcasting in the
UK.

Bob C.