Originally Posted by
Brandysull
VoLTE is a transformative technology which allows LTE devices to make phone calls without having to undergo Circuit Switched Fallback. Such tech is important/would be important to an operator like Caricel as they have no legacy networks to 'fallback' to. VoLTE really originates from the IMS (IP Multimedia Subsystem), a optional feature introduced into 3G networks back in 3GPP Release 4 or so which is now absolutely necessary in deploying voice services over LTE. The IMS is one of the revolutionary network elements found within the Evolved Packet Core (EPC) of an LTE network. The IMS itself consists of various other subcomponents that handle many things, to include inter-network/inter-IMS communication (or previously inter-MSC in legacy core networks). VoLTE configurations vary from operator to operator and it can happen where one operator may have CS oriented calls have the terminating device switchdown to 2G/3G. VoLTE can also have devices stay on LTE when receiving CS originated calls... there are additional components within the IMS's architecture which would handle the translation of signaling from VoLTE (based on SIP) to the 2G/3G network of another operator (involving a tonne of complicated jargon which makes no sense for me to explain as the overarching principles would be even more complicated to explain). VoLTE also has adaptable bitrates which allow it to be flexible in regards to voice quality, making it able to adapt to various radio conditions much more than say 3G networks. Our Networks already have IMS functionality available wherein we no longer use PSTN to establish calls to say Digicel to FLOW mobiles, we simply communicate via inter-IMS connections. This vastly reduces the network complexities within the core network and reduces the points of failure as well. The network TCO also goes down as a result, making it an incentive even for non-LTE networks. VoLTE most times is deployed over networks with low band spectrum such as Bands 5, 12, 13, 17, 20, 28 and so on... Access to voice serivces is crucial for any operator especially in emergency situations and as such, you are more likely to find Caricel and Digicel deploy VoLTE than FLOW right now, simply because of the spectrum they operate on. Networks with legacy RAT like 2G/3G need not sweat just yet and can test VoLTE quietly as their LTE network matures and deploy it when the time is right. That time for Caricel however, is now.