Hi Mahler,
I think you may be slightly confused.
WiFi is simply a marketing term coined by the WiFi Alliance (
www.wifialliance.org).
WiFi is used to show interoperability in 802.11b (and 802.11a and 802.11g) networks. In other words, it is most likely that your existing 802.11b access point is
already WiFi compliant. Of course, if it is an old model that was manufactured before the WiFi standard was defined, there is a slight possibility it is not.
Specifically, what make and model of wireless access point do you have?
Remember, WiFi is simply a term used to designate interoperability between 802.11a/b/g networks. so you don't need to "upgrade" to WiFi.
Feel free to ask more questions and I'll see how I can help.
Mr Mephisto