Wireless Access

situation:

• event w/ 200 folks playing a smartphone based game
• room has two IAP-105 APs
• bandwidth = 10Mbps up/down

things i (think) i know:

• 105s can support 64 clients each (32 on 2.5G, 32 on 5G bands)
• = 128 clients (phones) supported with current APs
• need a third & fourth AP to take up the ~ 72 other clients
• each 105 is rated at 300Mbps

the questions aka things i do not know and i need help:

• 200 client devices on 10/10 bw = 50Kbps per device (10,000/200)
• is it a bad idea to max out the first 2 APs?
• should i have 5 toal APs to be safe?
• the game (app) needs at least 100Kbps per device, i can upgrade the bandwidth (whoa it is expensive)...how much should i upgrade given people likely doing other things (text, social media, search) during the game.

i know i am forgetting something as it relates to the  IAP-105s 300Mbps ratings.

any help would be much appreciated.  thank you.

It appears that you have a few separate problems. First is the uplink bandwidth. If you see a specified bandwidth, it most times is a peak. So you can be with 50kbps on average, or you can be in trouble. I can't tell, but in many cases having more devices the peak spreads out over time over the devices. In this case, as all users will be using the same application, it may be an issue, but unless you have better data or experience, you can't answer this one.

Then the wifi part. I would say if you have 200 concurrent users in a single room, it makes sense to get a wifi engineer to do a proper design. The numbers you provide for 300 Mbps bandwidth are maximum values that you won't reach in practice. For 2.4 GHz it assumes you have enabled 40MHz channels which is not possible with multiple APs in the same room, and the 300 becomes 150. Then that is a raw value and under good conditions, you may get half of that as radio capacity. So if you are lucky you can achieve 75Mbps on 2.4GHz and 150Mbps on 5GHz. For your game that is enough with one AP as your bandwidth is only 10Mbps.

Then, while the AP can have 255 concurrent sessions per radio, which in software in the default setting is limited to 64 per radio (128 per AP), you should avoid getting to those numbers for proper performance. This is where the design comes in, as putting 8 APs in a single room might result in lots of interference and poor performance as a result of that. For the 105, I would try to stay below 30 (max 40) concurrent clients, which would bring you to 7 APs. You can't, however, have 7 APs on unique channels on 2.4 as there are only 3 (or 4 depending on where you are in the world). If you have better APs, the client count per AP without performance drop may be higher.

I would expect poor performance with just the 2 APs based on the number of concurrent clients. A local wifi engineer should based on the right question be able to give you better advice.

If the game supplier can provide you with better numbers on required bandwidth, or if you try to use the game and measure it yourself, that could give you some better guidance. There are too many unknowns at the moment.

herman, thank you for that.  very helpful.  i appreciate your taking the time to decipher and reply to my situation.

i have some updated news that changes my situation dramatically.  i will have 100Mbps up/down. that ostensibly increases my bw tenfold but doesnt do much for my AP load issue as you point out.

the game needs ~ 100Kbps (mainly occasional server calls - to update the scoreboard etc - as most of the data is cached on the device) for smooth play so i would peg being comfortable at 200Kbps (people will invariably be doing other stuff from time to time as they play).

question:  30 (max 40) concurrent clients on 7 APs..ok...does the AP naturally distribute the load (let's assume the same SSID of 'gameplay')?  or do i have to name each AP differently and divide the 200 players among gameplay1...gameplay7 (via password)?

question:  vs separate AP hardware, would +5 (say netgear) wifi extenders do the same job as 7 APs?

herman this is so helpful and much appreciated!!!

If you have the most recent firmware, ClientMatch should be in the APs that spread clients around over the available. Just make sure that you don't put too many APs on the same radio channel as in a single room that bandwidth will be shared. 

Wifi extenders will make things worse, as they repeat all traffic in the same area and it effectively reduces the 'airtime' by half. That equipment may be nice in a home environment where performance requirement and client density are low. I would avoid them whenever possible if you are concerned about performance and high density.