On Sat, 6 Jul 2002, Ken Chang wrote:
> I happen to be one who don't like PHS so much, though there're
> a lot of clever designs and it's playing a good role as "poor
> man's WLAN".
Far from it. There are a lot of issues that PHS deals with that
WLAN systems, such as 802.11, don't.
1. Spectrum allocation: PHS has spectrum. So does WLAN. Maybe. If
nobody nearby isn't already trying to use it for something else. Or
someone half a kilometer away hasn't installed the wrong type of
light bulb. If someone is screwing with PHS spectrum, the government
will step in an stop them. If someone is screwing with 802.11
spectrum, well, tough luck.
There's probably even a nice little Yakuza protection racket
in this. You want the 802.11 hub in your restaurant to keep
working? Pay 'em to make sure that the bandwidth stays clear.
Otherwise you'll suddenly find huge amounts of RF energy suddenly
appearing in that part of the spectrum....
2. "Vendor attachment," for lack of a better term. I can turn
on my Air-H" card anywhere, and I get connected to DDI pocket.
With 802.11, when there's five access points within 100 m of
me, God knows who I connect to. If anyone.
3. Billing. PHS has established billing systems. 802.11 doesn't.
There are various proposals and whatnot, but I don't see us having a
real standard any time soon.
> ...for voice and light data we have GSM already and for
> heavier data we have Wi-Fi, where is the room left for PHS?
I'm not sure what you mean by "light data" versus "heavy data." GSM's
9600 bps is good for text messages, not much more. You certainly don't
want to be downloading your e-mail over it, much less browsing the web.
PHS's 128K, while it's not going to do streaming video of any quality,
is certainly fine for basic e-mail and web browsing. Maybe you forgot
"mid-range data."
I carry an 802.11 card with me everywhere, but I'm not about to
give up my PHS card yet. When 802.11 works, it's nice enough. But
far too often, it doesn't work well, or doesn't work at all.
> PHS is more expensive than PDC if one tries to provide similar
> coverage, and its last stronghold, the 64 kb/s data, will be
> eliminated by WLAN in half to one year's time (you can have
> unlimited voice/video phone calls with WLAN).
If you really think so, I'd like to make a substantial bet with you on
this. How does 100,000 yen sound? Why don't you write up under what
terms you'll consider PHS to be "eliminated," and we'll set something up.
cjs
--
Curt Sampson <cjs_at_cynic.net> +81 90 7737 2974 http://www.netbsd.org
Don't you know, in this new Dark Age, we're all light. --XTC
Received on Mon Jul 8 05:05:17 2002