UMA

UMA is an interesting new development in the mobile world. UMA stands for "Unlicensed Mobile Access", i.e. VoIP over WiFi. Well, not really - read on.

Actually, already some companies are working on seamless data roaming between cellular (GPRS, EDGE and UMTS) and WiFi (or Bluetooth) networks. The obvious next step is to extend that to voice using VoIP over WIFI. WiFi is of course much cheaper, allowing cost savings for corporate users; possibly also savings for telcos (data is less expensive than voice), but at the same time reduced revenue due to a reduced amount of traditional cellular voice calls.

In a way UMA isn´t VoIP, it rather just tunnels the entire GSM or CDMA session over WiFi and the internet. So it´s not seamless roaming between SIP or H.323 and cellular networks, but seamless - roaming and handover - and GSM voice and data service between the Unlicensed Mobile Access Network (UMAN) and the cellular radio access network (RAN). More about this at phonescoop, UMA Technology and Kineto Wireless (PDF).

Essentially I think UMA enables mobile carriers to further run around the telcos (in the private consumers space) and offer one-stop solutions for the corporate customer (see also this article about VoIP wireless).