Once again you dodged the details.ANYONE can take a SIP phone connect it to a small wireless to ethernet bridge and connect it to a “publicc” wireless network. I run a similar configuration here (grandstream SIP phone on an SMC 2670, and it works well! There is nothing new in that . In fact I have seen several companies now promoting SIP or Skinny portable phones that connect with Wi Fi. I use my grandstream with the 8kbps compression codec and have excellent results, except on one call to rural Mexico. That is more likely a call routing issue.
What is different about your technology that sets it apart? That users are connected to your server?