LTE and Wi-Fi are finally bridging the gap between cellular and wireless LANs, enabling UC for the smartphone era
Mobile IP telephony is nothing new, however the innovation has come from app developers, not carriers. Over the top messaging (OTT) services like WhatsApp, Facebook Messenger, WeChat, Google Hangouts and iMessages/Facetime have displaced traditional carrier SMS for text messaging and now provide voice and video calling and conferencing. Pair this with the fact that smartphones have turned office landline numbers into a liability for employees that now live on their mobile devices and what once seemed like a shiny, new IP PBX with UC features like private messaging, presence and email integration is more like a burning platform. Carriers and telephony equipment vendors recognize the problem and are countering with emergent technologies like voice over LTE (VoLTE) and voice over Wi-Fi (VoWiFi) that offer tantalizing features marrying the best of traditional telephone networks with mobile IP OTT services.
In this report (registration required), I examine the confluence of carrier and Wi-Fi networks using next-gen LTE that finally delivers on the promise of Rich Communication Services (RCS) built on IP Multimedia Subsystem (IMS). With carriers now supporting voice over LTE (VoLTE) and voice over Wi-Fi (VoWiFi), the gap between voice and SMS on the PSTN and rich communications on Internet OTT is closing. The report explains each technology, how they are related, the benefits to carriers, businesses and users and some service opportunities for IT service partners.
The foundation for improvement is VoLTE which treats voice as just another data stream. Aside from allowing simultaneous voice calls and data transmission (something Verizon customers have longed for), it provides faster call setup time, better voice quality, more efficient use of RF spectrum and support for call handoff from Wi-Fi to LTE. VoWiFi, which T-Mobile pioneered in the US, one ups services like Skype, Facetime or Hangouts by using a phone’s native dialer app with the same number whether the device is connected over WiFi or LTE. Although made popular was a way to bypass carrier charges, particularly for oversea calls, in the era of unlimited domestic voice minutes and pennies-per-minute international rates, VoWiFi should be seen as supplementing cellular networks, not bypassing them.
There are still challenges left to be solved including the verifying the quality and reliability of public hotspots for Wi-Fi calling and problems with location services and 911 calls over Wi-Fi which the report details.
Offloading increasingly crowded licensed spectrum thereby improving performance and reliability. For businesses hybrid LTE-Wi-Fi networks enable compelling fixed mobile convergence services that smooth the transition PBXs and landlines to smartphones, while retaining existing, well-known fixed extensions and avoiding expensive carrier data plans. Convergence also enables the use of video calling and text messaging using a common number on a device employees actually want to use.