Re: Channel Capacity [ was: Re: [tlug] NTT Hikari Fiber - Does it "Just Work" with Linux (Kubuntu)?

["Keith Bawden" <keith@example.com>]

On 9/6/07, Nguyen Vu Hung <vu-hung@example.com> wrote:
> 1. Why Walsh Codes, CDMA make channel capacity large?
> 2. Why Walsh Codes help switching antennas better ( newly forked by you
> :D )?

No they do not allow you to switch antennas any better. We are still
on topic here. They allow frequency reuse in an antenna closer than
than previous systems did thereby increasing the capacity of the
system. The more readily you can reuse a channel the more channels you
can fit in a smaller geographic area.

For example; looking at this image:

http://www.telecomabc.nl/c/plaatjes/cel-cluster.gif

You can see that to reuse frequency number two you need to be at least
two cells away. Any closer and there will be cross talk. Older systems
may have required a distance of 3,4 or more cells to allow a channel
to be reused[1].

Regards, Keith

[1] http://www.soi.wide.ad.jp/class/20000002/slides/06/15.html