Does the S3 have wifi?

no it does not. you need a work around. they are quite a few ways to work around it. A switch like this

http://www.newegg.com/Product/Product.aspx?Item=N82E16833156251&cm_re=trendnet_teg-s80g-_-33-156-251-_-Product

and this item

http://www.newegg.com/Product/Product.aspx?Item=N82E16833109056

this will allow up to 7 s-3's

I happen to have the switch and cables for it . I do not have the tp-link

My listing for the switch is here

https://bitcointalk.org/index.php?topic=683435.msg7751340#msg7751340

I charge the same and toss in free cables. my switch is new and sealed