(keitai-l) Re: Camera phones - USB & WPAN

From: Ken Chang <kench_at_hotmail.com>
Date: 07/26/02
Message-ID: <F118hVNj9PDCgvQwzBP000178be@hotmail.com>
hi guys, Benjamin and Petri,

(1)
what bandwidth do you think is required for video?

while MP3 needs about 100 kb/s, the "quality" video on the 'net
is only about 200 kb/s with peak rate 150% to 200% the average.

if MPEG4 codec is built in the display device, the Bluetooth
432-721 kb/s raw bandwidth is about enough for half rate CIF
which will be quite good for a small bedroom TV and more than
enough for handheld devices.

(2)
I see two issues for a mass market radio interface important:
- capacity/interference, and
- security

for Bluetooth, the capacity for audio appliances in public may
be enough for now, but I doubt there is room left if you want
to use Bluetooth in a wide range of digital devices (it won't
useful if not).

security is a terrible problem.  if wired is like naked eyes,
then wireless is X-ray which make everyone exposed naked: you
cannot even build a fence to protect yourself using a firewall.
my understanding why the wireless protocols have to be complex.

is Bluetooth really secure so that we don't have to worry?
http://www.niksula.cs.hut.fi/~jiitv/bluesec.html

WPAN is not a piece of cake, it's a nut.  maybe we should wait
for more studies within 802.15, the Americans often get things
rights with security (the IS-41 AC is way better than GSM AuC).

cheers,

Ken


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Received on Fri Jul 26 20:36:51 2002