The key word in wireless is “mobility”. Broadband wire line, WiFi, WiMax and even dial-up are technology enablers that provide a solutions for the increasing need to be “connected”. There are issues with each one: broadband service can be expensive, depending on the provider, and it certainly isn’t available in many rural areas; WiFi has very limited range, again limiting coverage, and dial-up is simply slow and can’t come close to meeting requirements for today’s applications. WiMax has gone through a number of changes and with the introduction of WiMax 4G promises to be a viable solution for PBX connectivity independent of location. Ultimately, a network of connected WiMAX towers will drive the deployment of an 802.20-based Global Area Network (GAN), closely resembling cellular networks, but with far fewer towers required to provide the same coverage. This will allow true ubiquitous access across the country or region, providing bandwidth comparable to cable Internet service, at the very least. The concept of “fixed mobile convergence” moves form concept to reality with WiMax. The ability to move freely from your office PBX extension to your cellular phone number, completely transparently and seamlessly brings the “mobility” functionality into high relief. Companies like ShoreTel already have location based services that enable a PBX telephone extension user to have calls manipulated based on location. Simply stated, when I am in the office my cell phone is a PBX extension, when I am out of the office my PBX extension is a cell phone number. This is completely transparent and requires no change in the users call handling methods. The network sorts it all out for your you. In today's market, dual mode phones are already available. I my self use an Apple IPhone (seach “ShoreTel iPhone” on YouTube.com) for video presentation which is a dual mode phone. In the office the iPhone links automatically with our in-house network using an 802.11g WAP. I can retrieve my email, for example, through the wireless access point. When I am outside the office, I can sync with my email using the AT&T cellular network. In the office I have a SIP softphone running on my iPhone and it becomes my PBX extension. When leaving the office, using the ShoreTel “office anywhere” functionality, my iPhone cellular number becomes my PBX extension. This technology will mature with the growing acceptance and availability of WiFI in general and WiMax in particular. As a result, PBX applications will become hardware independent and provide feature functionality that is geographically and device independent.