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Only Wireless, No Wires

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cschock

IS-IT--Management
Sep 30, 2002
22
US
I have been tasked to build a complete wireless network and run no wires! I know this will be impossible because there will have to be either cat5/6 or fiber between the access points. I also know that the bandwidth will degrade with the ammount of users per access point. I am looking at 5GHz equipment because of interference and better bandwidth.

The building is around 70,000 square feet with an office area and the rest being open manufacturing. We are in the initial phases of this and no set-in-stone blue-prints are done yet. I am looking for any advise to the craziness of this project and any direction to follow. I know a site survey will have to be done, but we are not there yet. This is still conceptual and I need some base-line input.

Thanks!!!!!!
cs.
 
You're gonna have to run cat-5 wires to the access points regardless.

802.11a is nice, but I've found the power requirements to drive such devices to be more costly in the long run. 802.11a will automatically require more power to get the same distance as 802.11b or 802.11g.

With the release of 802.11g devices (which can be used with either 802.11b or 802.11g), I would seriously look into that option. 802.11b/802.11g are more proven technologies and require less power to work. Also, the range is as good or better than 802.11a.

Also, to blanket an area with wireless so users don't see any degradation in performance when moving throughout, you'll need more access points than you think. I'd say at least one every hundred feet in each direction. So, to blanket a 200-400 square foot area with no signal loss, you'll need 4 access points. We were in a similar situation and that's what we found to work with no service interruption.

Hope this helps.
 
Well to add to his post.. You're also gonna need some kind of cat5 to run between your bridges that run your access points to some kind of central router.

We have a central cisco router, running to 3 bridges, which each then carry the signal for 3 APs citywide.

And our 3 Cisco 350 APs blanket the city of Hillsdale, Michigan... each AP is capable of 22 miles if you up the output on the AP..

Hope this helps..
 
I can offer you a solution but not at 5 GHz. I will ensure that there is no interference at 2.4GHz using a Vivato indoor WiFi switch. I can show you a demo if you are available to come to NYC. Check out my site at
 
Without knowing a lot more about the layout of the building including the materials used in construction I don't believe anyone can accurately predict what it will take. If the building was wide open and was constructed so as to minimize multipath, it could be possible to cover the area with 2.4 Ghz and the proper antennas.

On the other hand, a metal building with all kinds of manufacturing equipment in an area of high interference or perhaps industrial microwave equipment would be another situation.

If aggregate bandwidth is the major concern, use Cat5 cable and low power antennas to create many micro cells as opposed to fewer "long range" cells.

I suppose the network could be designed without wires but that would be risky. Whatever equipment you choose (I am not bashing manufacturers here) will eventually break. Since you have to run power to each access point anyway, pull Cat5 at the same time.

If this is a matter of life and death, use the Powerline equipment and backhaul from it. Somehow it seems like a waste though.

Regarding 5 gHz stuff, Proxim makes a Harmony line with has a connectorized access point and FCC certified antennas. This access point requires an access point controller (and I believe some Cat5 wiring) but this could be a manageable solution for you also.
Until the building is built and a site survey is done, quote this project for the very worst scenario. Of course, I'm a pessimist.
 
Newisp has given a correct prognosis for 802.11b contemporary devices. My suggestion is based on a new paradigm for 802.11b. It is WiFi switching. Vivato is the first 802.11b switch on the market. It changes the landscape on how we view WiFi site surveys.

One Vivato indoor switch will cover the 70,000 square feet in your open manufacturing area.

Newisp mentioned that the 5 GHz Harmony unit need a controller. This was true for the earlier model of access points however Proxim has since removed that requirement from their 5GHz access points. The controller is now only used for management of all their 802.11 products.

You can contact me if you want to see a live Vivato demo or you can look at the clip on the below link.




A.K.Pollard
 
That does look like an exciting product. This only issue I can see is the aggregate bandwidth issue. If several "micro cells" are created with the channels reused every few hundred feet, more cumulative bandwidth can be delivered to the overall facility.

As an illustration, let's assume the building is 200 X 350 and is completely open. If we were to place very tightly aligned 802.11g access points every hundred feet we would effectively be sharing the bandwidth in 100 X 200 areas. If there were only 10 connections in that area they would be sharing the entire throughput of that one access point. If we use one access point to light up the entire building, based on the same user density we would share the total amount of bandwidth throughout 350 users.

I believe the issue is one of how much bandwidth is needed where. In an organization needs several hundred people to have large chunks of bandwidth one access point will not be able to support the demand. On the other hand if there are fewer low usage (like some types of data collection and text only email in low quantities) one access could certainly handle the operation.

As to the completely wireless solution, there are several different approaches. If you have a completely clean area with no 2.4 or 5 gHz interference you could consider using 802.11g access points for distribution with the 5 gHz handling the backhaul.

Again, I would like to emphasize all of this is speculation without a lot more information. In the worst case scenario (or Murphy's most likely outcome) the building could be a nightmare of multipath, blind spots and right in the middle of someone else's WMUX backhaul shot. Or maybe I'm the only one with that luck.
 
Thank you all for your responses and advice.

I have a long way to go before the site survey is even ready to be done. I am just utilizing the time to look at all possible scenerios to make this happen.

When I get more information I will post it.

Thanks Again!
CS.
 
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