This year WiFi calling has come to US cellphones. T-Mobile launched WiFi calling on BlackBerry devices in 2009, only recently have the other carriers followed suit, with Verizon Wireless, the last supporting this, announcing limited availability now on Android devices and iOS next year. The idea is that WiFi coverage can fill in places where cellular isn\u2019t available. But providing better network access is just half the story. Adding handoff to cellular nets without having to disconnect the call or, even better, to private corporate networks increases the usefulness and really starts to tie the networks together.\nThis isn\u2019t a new idea. As a matter of fact, it's quite an old one that never came to be, despite much hype almost 15 years ago.\nI remember getting a call almost 15 years ago, when I was an industry analyst covering the newly emerging WiFi technology and cellular networks. At the time, 3G networks were just rolling out, so digital coverage was sparse, based on first generation digital GSM, TDMA and CDMA technologies. Voice calling was the killer wireless app at the time, since network data speeds averaged well under 50 kbps and pretty much useless (except for that emerging BlackBerry email service which might just catch on). But voice coverage wasn\u2019t predictable, especially in-building.\nSo back to that call. A trio of vendors, Motorola, Proxim and Avaya had teamed up to provide a solution that would take advantage of WiFi coverage in buildings and handoff calls to the cellular network. The concept was brilliant. Imagine starting a phone call at your desk on your desk phone (or cellphone) carried over the wired or WiFi network. If you need to go, press a button, and that call is switched to any device, like your cell phone. Once the WiFi network starts fading, the call would be switched to the cell network seamlessly. Proxim provided the WiFi access points, Motorola the handsets and Avaya the corporate telephony infrastructure. I decided to call it \u201cfixed mobile convergence\u201d (FMC) and thought it would change the world.\nChange is hard\nThe only problem was it never really worked.\u00a0 Running a call over WiFi worked well, but the challenges came when switching the session to the private cell network. Cell carriers at the time felt they provided a pretty good service and didn\u2019t want to possibly lose out on in-building revenue. (Of course, at that time, it was pretty expensive for people to use their cellphones at their desk, but even then, traffic was already migrating off landlines). People liked the convenience of just using their cellphone, and if the carriers didn\u2019t actively participate in the program, it was bound to fail. AT&T actually embraced this program and did some testing but never fully rolled out a product. As cell phone minutes came down in cost and coverage got better, most people drifted to using their cell phones primarily at work, that is when people still talked one-to-one! Today, we use email and IM for those conversations and save the voice mostly for conference calls.\nToday, many companies have gone full over to IP-based systems and many (like my company Accenture) have fully embraced digital calling and are 100 percent on Microsoft Skype for Business. The calling works equally well on any device over landline, WiFi or cell nets, but having the ability to jump from my desk phone, PC or tablet to my smartphone is something I want and I know others do too. It\u2019s great that the carriers are supporting WiFi calling, but the real advantage would be to go in and out of WiFi and cell, public and private networks, seamlessly. Unfortunately, even after all this time, that\u2019s still not available. Hopefully we won\u2019t have to wait another 15 years!