Wireless link through AP (POINT <--> AP <--> POINT) question.

Hi.

I need to link two points without visibility. Distance is abount 400
meters and there is a high building beetween them.

Each of those two computers have Dlink's DWL-520+ PCI adapters inside
connected to yagi-type antena (16dBi).

Can you recommend me an access point that will be placed on this
building that stands in the way ? I've heard that only D-Link access
points would work as a bridge beetween Dlink client adapters.

Would you be so kind and give me 100% working solution for making such a
link between two DWL-520+ cards ? It should be as fast and stable as
only can be

We can connect external antenas to this AP by the way (we have two Yagi
16dBi antenas that can be used).

Tkank you very much in advance.

Best regards

You want 100% you better phone dlink and get someone to do a site survey -
theres no 100% !!

Dlink sells an extender bridge that SHOULD do what you require, but you do
need to make sure the hardware is compatible with dlink and bridging.

"Beerman" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> Hi.
>
> I need to link two points without visibility. Distance is abount 400
> meters and there is a high building beetween them.
>
> Each of those two computers have Dlink's DWL-520+ PCI adapters inside
> connected to yagi-type antena (16dBi).
>
> Can you recommend me an access point that will be placed on this
> building that stands in the way ? I've heard that only D-Link access
> points would work as a bridge beetween Dlink client adapters.
>
> Would you be so kind and give me 100% working solution for making such a
> link between two DWL-520+ cards ? It should be as fast and stable as
> only can be
>
> We can connect external antenas to this AP by the way (we have two Yagi
> 16dBi antenas that can be used).
>
> Tkank you very much in advance.
>
> Best regards
>

Well the visibility issue is your main problem. Considering that it is 400m
there is no way your signal will go through a building unless it's made of
pure glass. You could try bouncing the signal of another building that both
can see, but you need to be extremely accurate even if it will work.

Ignoring the visibility issue, if let's say you could connect. If you don't
need the functionality of the cards being wireless client you could setup a
bridge just between them. You could connect them in ad-hoc mode and MAC
bridge the card to an ethernet card at each point (if you want to connect
two networks) although you need windows xp to do that. By the way, ad-hoc is
not very reliable but it works ok most of the time. Make sure to use wep
though.
"Beerman" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> Hi.
>
> I need to link two points without visibility. Distance is abount 400
> meters and there is a high building beetween them.
>
> Each of those two computers have Dlink's DWL-520+ PCI adapters inside
> connected to yagi-type antena (16dBi).
>
> Can you recommend me an access point that will be placed on this
> building that stands in the way ? I've heard that only D-Link access
> points would work as a bridge beetween Dlink client adapters.
>
> Would you be so kind and give me 100% working solution for making such a
> link between two DWL-520+ cards ? It should be as fast and stable as
> only can be
>
> We can connect external antenas to this AP by the way (we have two Yagi
> 16dBi antenas that can be used).
>
> Tkank you very much in advance.
>
> Best regards
>

In article <7h%Wb.20458$yE5.96018@attbi_s54>, (E-Mail Removed)
says...
> Well the visibility issue is your main problem. Considering that it is 400m
> there is no way your signal will go through a building unless it's made of
> pure glass. You could try bouncing the signal of another building that both
> can see, but you need to be extremely accurate even if it will work.

No way There is no any building except this one. We were trying to
make a passive repeater (with two back-ended yagi antenas) but it didn't
work at all. The building is an insurmountable obstruction.
>
> Ignoring the visibility issue, if let's say you could connect.

We could not. We need a fully working signal repeater between aour two
DWL-520+. Probably DWL-800+ (recommended by dlink) should work but it is
very hard to get it in Poland, so i wonder which other specific D-Link
AP can handle this (DWL-900+ meaby) ?

"Beerman" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> In article <7h%Wb.20458$yE5.96018@attbi_s54>, (E-Mail Removed)
> says...
> > Well the visibility issue is your main problem. Considering that it is
400m
> > there is no way your signal will go through a building unless it's made
of
> > pure glass. You could try bouncing the signal of another building that
both
> > can see, but you need to be extremely accurate even if it will work.
>
> No way There is no any building except this one. We were trying to
> make a passive repeater (with two back-ended yagi antenas) but it didn't
> work at all. The building is an insurmountable obstruction.
> >
> > Ignoring the visibility issue, if let's say you could connect.
>
> We could not. We need a fully working signal repeater between aour two
> DWL-520+. Probably DWL-800+ (recommended by dlink) should work but it is
> very hard to get it in Poland, so i wonder which other specific D-Link
> AP can handle this (DWL-900+ meaby) ?

I appreciate that you feel a need for 100% reliability, however as has been
pointed out already, over 400m, there are no guarantees it will work. The
best you could get would be to have an on-site inspection and test. If you
can then make a good connection with a GOOD degree of spare signal strength
left over, it might be close enough to your 100% to keep you happy. I do not
know your application but I am guessing that you would not lose the business
overnight if the link went down for 3 minutes at 05:25. If it WOULD be that
dramatic then don't even THINK about Wifi. You'll be an unhappy bunny sooner
than you planned.

You also need to remember that we are talking about an unlicenced part of
the band - so you have no rights over, say channel 7 any more than Mr smith
does opposite you. You may get interference from other Ap's / bridges /
Ad-hocs, or you may not, no guarantees here I'm afraid. Old Bill's 2.4ghz
cordless next door might also reduce reliability and range when he is on the
blower - as might Maud's slightly leaky microwave oven - or the paranoid who
lives in the building with all four channels of his 2.4Ghz wireless camera
system monitoring the outside world for him.

I'm not trying to spoil your interest in 802.11 WiFi - it's a brilliant
product that does a great job. BUT when things become "mission critical" as
you are hinting at, it has no place for consideration and CERTAINLY not at
the sort of distances we are talking about.

You might find someone who can make it work for you, but please understand
that no amount of sales-patter can take away the fact that interference from
other sources is there - and growing every day as more and more people fight
for the same channels. If he tells you he can guarantee 100% uptime then
remember this message.

If you want 100% guaranteed, look elsewhere than wireless lan. If you can
get hold of a 900Mhz system and speed is not important (1 Mb max) then
900Mhz tends to be a bit more hardy and may even try going through the rogue
building "as-is". Problem is cost seems to be higher, they are few and far
between, bandwidth is lower and I'm not sure if they can be used legally in
all Countries. Lastly, you still have to accept all and any interference
from other users. - Reminds me, I must post a question on 900Mhz AP next.

Depending on your needs, you might find it worth "biting the bullet" and
having a leased line of some kind - you might get 99.99% uptime on that. I
woiuld suggest using Internet to link but I do not know if you have
broadband, and of course, many BB isp's struggle to avoid donwtimes of an
hour or so here and there, especially when upgrading the network.

If "a few short blips a week" is acceptable then post a follow up and
perhaps give us a hint as to the type of use the network is going to be
used, not because we are nosey, but when you understand the traffic (video
stream, online database, real time EPOS etc, security system etc) it becomes
easier to understand the issues involved and make constructive comments.

Mark