WLAN NETWORK PLANNING

What type of WLAN are you building?

Three basic types WLAN design focuses:

• Coverage (as large area as possible) Outside coverage?

• Capacity (high density of user over a given area)

• Location (the possibility to locate clients)

Because the cell size dictates the capacity there’s a tradeoff between high Coverage and high Capacity. Location usually leads to more Aps required.

Can we get rid of older legacy protocols?

Disabling 802.11b will effectively almost double the capacity on 2.4GHz.

Disable at least 1 & 2 Mbps and consider 5,5Mbps if 802.11b is left.

What type of applications should run?

Wireless Voice over IP (VoWLAN) demands certain attention (not covered in this presentation)

What type of clients do you have?

Are you sitting with older client not supporting 802.11n. Make sure all newer clients support 802.11n on 5GHz also. Can we phase out old 802.11b ones?

Also take into account that different clients have different RF-performace and hence you must find the “Vorst” client type and use that one as reference.

How many SSIDs do we need?

There should never be more than 5 SSIDs per AP even though the AP itself may support many more. 802.11u will solve this limitation in the future.

What are the roaming requirements?

Are we just building a single hotspot or do we need continuous coverage Do you have a monopoly on setting up APs?

Finding yourself being the sole master is rare but if possible this definitly is an

WLAN Network Planning

Perform an onsite site pre-survey

Try to get hold of the drawings of the building. But after that it’s very important to visit the location in person to understand if the drawing is still current or if walls have moved or reinforced or something similar.

Really ambitious people classify walls and the manually input that info to their Wlan planning software (very time consuming). Anyway to

know where thick walls and elevator shafts are and maybe also look for modern high insulating windows (can reduce the signal more than 12dB) is very important.

WLAN Network Planning

Spot check design

Rather than setting up all the APs at once simply select an area of you building and set up 3-4 APs according to your design and then verify.

If your calculations seems to be right you can continue. Another method is to bring up the APs one by one (time consuming) but my experience is that you need to have 3-4 APs running and than after the RRM has done it’s magic se what the result became.

WLAN Network Planning

Setting up APs

Make sure you read the instructions so that the accesspoint can work with full performance. To put it short the AP needs “breathing space”

and to be mounted in the way the company manufacturing it intend.

WLAN Network Planning

The AP1130 was designed for the office environment. Easy mount on a 3m ceiling and propagate the signal down and wide.

WLAN Network Planning

Verify coverage Here there are many schools on how to proceed

I personally prefer to use the Aircheck from Fluke (2000 euro) A free alternative is to combine inSSIDer and iperf to both test the channel allocation and throughput.

An interesting alternative is Wi-Fi inspector from Xirrus

http://www.xirrus.com/library/wifitools.php but this one is maybe better for home users.

Don’t forget to read through the document titled .

gn3-na3-t4-wlan-network-planning which can be found at

http://www.terena.org/activities/campus-bp/pdf/gn3-na3-t4-wlan-network-planning.pdf

WLAN Network Planning

Semi professional site survey on a shoestring budget?

Of all the soft ware I found on the Internet I believe the free version of Wavedeploy from Veriwave . www.wavedeploy.com

Ofcourse this product does not have all the bells and whistles as it’s full blown commersial versions but if you want a product where you can put your laptop on a trolley or just carry it around and marking on your map and end up with a god coverage map. I’ve not tested it yet myself but heard good reviews from colleagues in the

WLAN Network Planning

Per-User Application Throughput examples

WLAN Network Planning

If you want really good capacity in your cubicle

landscape you may have to install one AP every 9^th meter but typically my experience is 16-20 meters depending on walls etc.

WLAN Network Planning

Large highly populated auditoriums need a different approach.

WLAN Network Planning

Typical settings on Cisco controller with 802.11b disabled. This will decrease the cell size and increase the performance.

WLAN Network Planning

My own view and recommendation on WLAN

• Stop using 802.11b clients and disable it on you WLAN

• All new 802.11n clients should support 5GHz

• No more than 15 active associated clients per AP

• If possible a 20% overlap of the cells is something to aim for (for good roaming)

• You should never have less than -65dBm signal strength in your coverage zone

• Try to get RF-spectrum analysis tools for better understanding of what’s going on in your environment.

WLAN Network Planning

Yes!!! We made it.

WLAN Network Planning

In document Campus Best Practice (GN3/NA3/T4) WLAN Network Planning (Page 40-66)