RE: XM Satellite Radio

["Peter Murray" <pete@partnercomm.com>]

Sven (and the group)-

It's the FM band's lower frequencies that make it's excellent local coverage
possible. Because those waves will bend and reflect, they can be received
behind mountains, inside tunnels (to a certain distance). They can only bend
and reflect so much, though - that's why you can get Pittsburgh radio about
750 feet into any of the tunnels here, but the middle 1500 is silence.

XM and Sirius are using frequencies that behave much more like light - very
line of sight. I would bet that a hand could knock out reception of their
signals, just as they can my DirecTV. Buffers in the mobile head unit should
take care of short interruptions in signal, just as a RealPlayer client
buffers the inbound UDP stream from the network audio/video server.

-Peter Murray (N3IXY+internet geek)
Pittsburgh, PA

-----Original Message-----
From: owner-boston-radio-interest@bostonradio.org
[mailto:owner-boston-radio-interest@bostonradio.org]On Behalf Of Sven
Franklyn Weil
Sent: Thursday, November 29, 2001 10:51 PM
To: Cooper Fox
Cc: bri@bostonradio.org
Subject: Re: XM Satellite Radio


On Thu, 29 Nov 2001, Cooper Fox wrote:

> No signal drop outs?  I guess i was wrong in what i

Both XM and SIRIUS are also installing terrestial repeaters to supplement
the bird droppings in urban areas with lots of skyscrapers.

However, this still doesn't prevent signal dropouts when you're going
underneath a wide overpass, unlike local FM radio which for some reason
you don't lose anywhere, except when you're going through a deep, long
tunnel (at least that's been my experience -- immaculate reception of
local FM stations in a car).

--
Sven Franklyn Weil            "The needs of the many outweigh
<sven@gordsven.com>                      the needs of the few
<http://www.gordsven.com/sven>                   or the one."
                                                     -- Surak