bandwidth calculation

Dear forum,

I will design canopy wireless for one ISP (internet service provider) in
indonesia. they ask me about maximum capacity of canopy wireless point to multipoint (let’s say AP and SM) if they install in maximum user.
for example:
i will use 1 AP advantage (14 MB troughput) for 200 user with SM lite (let’s say use maximum bandwidth 384 kbps). in my calculation, 200 user x @384 kbps = 76 Mbps. is it correct? so what must I do if i meet that condition? because we need 76 Mbps bandwidth,
but we don’t have more bandwidth in one AP (14 Mbps). do you have any document related to that case?

To start wth, download and read the Canopy System User Guide. It has a lot of information that will help you understand Canopy better. Also, your calculations assume every radio will be using the 384 kbps continuously :o - I am pretty sure that will not be the case.

What frequency band would be like to use? If you would really like to use these calculations and numbers, install a full cluster (with CMM) and divide the SMs up among the APs.

But read the manual for sure. :smiley:


For starters, understand that the only way the ISP model works is bandwidth overselling. Not every client will be using the max available bandwidth at the same time, so your job as the specifier of what the required bandwidth will be is basically a best guess scenario. Usage patterns of the future users dictate everything here. That is why with a total aggregate throughput of 14Mb, a single AP can support 200(theoretical) users.

We have just over 150 clients on our network at this point and are nowhere near using our 4.5Mbit pipe, and all our clients have between 1Mbit and 3Mbits bandwidth available to them.

Unfortunately, there’s no magic formula for this. Your best bet will be to start with a T1 (or E1??) and buy a router that will easily allow you to add another, and another, etc. as needed. Then you monitor the snot out of it and remember that the telcos providing the bandwidth don’t necessarily move all that fast.

Bottom line is this: If your clients all turn out to be light web browsers, a single T1 will likely do the job. If they are all trying to fileshare the latest handycam version of all the movies released last weekend, there’s not enough bandwidth in the world.

Hope that helps.

its all about contention ratios…

alot will depend on what type of customers you have, young, old, business, residential, traffic patterns, etc…

you are highly unlikely to be able to serve 200users off one SM as an ISP, we hover around 80-100 based on a 256 download.

However if you get a handful of p2p users they can mess everything up for you…