(keitai-l) Re: Privacy concerns contra usability?

From: Juergen Specht <js_at_anima.de>
Date: 08/21/00
Message-ID: <39A1553F.611DA79F@anima.de>
Juergen Specht wrote:
> punnamas vichitkulwongsa wrote:
> > Currently, network operators know which cell you are in. Cell size varies
> > depending on the network technology (PHS has much smaller cell size, average
> > 50 meters radius, PDC and other cellular technologies usually have larger
> > cell size), and the location of the cells (an indoor cell like Subway
> > station can tell extremely accurate position info; out in the middle of
> > nowhere, cell size could be up to 20-30 km wide).
> Sorry, but this is outdated information...with actual
> technology you can include some more information than only the
> next cell which you are 'pinging' too. You can use run time lengths
> of signals also and combine this to come close to 1 meter now.
Uh, and for the people who don't know how it works, here is
a small scheme. There is not only one cell involved, you need
at least 2 to really know a position. Simple spoken the * is the
phone and can be detected by 3 cells here (use a non proportional
font like courier):

                        [cell]
                           |
                           |     /
                           |    /
                           |   /
                           |  / 
                           | /
                           |/
[cell]---------------------*---------------
                          /|
                         / |
                        /  |
                       /   |
                      /    |
                     /     |
                    /      |
                   /       |
                [cell]

J.
Received on Mon Aug 21 19:08:15 2000