On 2016-11-21 02:53, Mikael Abrahamsson wrote:
Typically it travels on another "bearer" compared to Internet traffic.
http://blog.3g4g.co.uk/2013/08/volte-bearers.html
Think of bearers as "tunnels" between the mobile core network and the device.
Many thanks for the pointer. The fact that VoLTE has its own dedicated APN explains things. I am however a bit confused on the "bearer" term. Say a carrier has spectrum in 700Mhz bands A and B each 5mhz in each direction, bonded together as a single 10mhz (each way) channel. The docunment states: "R.92 requires the use of a particular set of radio bearers" Does this mean that a bearer is given specific spectrum within a block (such as a dedicated colour on a fibre) or that it is just given dedicated capacity on the single data channel formed by LTE compressing all of the spectrum into one big channel ? I though I understood the concept when the name "tunnel" had been mentioned because I understand that a handset estabishes a "hopping" tunnel with local IP which changes as you move from tower to tower, but the tunnel itself maintains a permanent IP connection that remains unchanged as you move from tower to tower. In such a concept, I could understand each tunnel (one to the data APN, one to the IMS/VoLTE APN) having bandwidth allocations. But when the text brought up "radio bearer", I got confused again sicne radio implies breaking the spectrum apart, which would reduce LTE compression efficiency.