An organization with ADSL Internet access and a Wi-Fi router. The IP-PBX is connected to the LAN. Cellular phones in the organization register to the IP-PBX.
At a hotel that has a wired LAN connection. Extension is now forwarded to the laptop.
At a cafe. Phone call received via Wi-Fi to cell phone (the call was forwarded by the secretary to the office extension). Calls to the office are free calls and land-line calls to other phone numbers charged as if from the office.
Out on the street. A call dialed to an office extension is routed by the IP-PBX, which determines that the cell phone is not currently registered as a SIP phone, to the cell phone using the cellular network.
Reduce Communication Costs While Increasing Accessibility Fixed Mobile Convergence with an IP-PBX