On Dec 30, 2011 9:16 AM, "Alexander Harrowell" <a.harrow...@gmail.com> wrote: > > In the DHCP v6 thread, there was some discussion of > mobility and its IP layer consequences. As various people > pointed out, cellular networks basically handle this in the > RAN (Radio Access Network) and therefore at layer 2, > transparently (well, as much as things ever are) for IP > purposes. It therefore shouldn't be a problem. > > However, as one contributor pointed out, more and more > cellular operators are migrating traffic onto WLAN for > various reasons, notably: > > 1) Spectrum - it's unlicensed, i.e. free > 2) Capex - the equipment is cheaper > 3) Capacity - it's a cheap way of providing high speed > 4) Signalling load - it gets rid of the signalling traffic > associated with detaching and attaching devices from the > core network. This is especially important in view of some > smartphones' behaviour. > > Of course much of the signalling is associated with the > Mobility Management features, and getting rid of it by > punting everything to WLAN implies that you lose the > benefits of this. > > That suggests that if you're going to do this on a big > scale you need to implement Mobile IP or else keep > backhauling traffic from the WLAN access points to the > cellular core network (GAN/Iu interface), which has obvious > effects on the economics of the whole idea. > > Alternatively, you can work on the assumption that the WLAN > is solely for nomadic use rather than true mobility, but a > lot of devices will prefer the WLAN whenever possible. > > Thoughts/experiences? > >
The state of the industry is the support of nomadic mobility from cellular to / from Wi-Fi , there is nearly no support of mobile IP that I have seen. It is going more and more in this direction. At T-Mobile USA we have evolved our wifi calling features from fully mobile UMA / GAN to non-mobile IMS wifi calling. Cb > > -- > The only thing worse than e-mail disclaimers...is people > who send e-mail to lists complaining about them On Dec 30, 2011 9:16 AM, "Alexander Harrowell" <a.harrow...@gmail.com> wrote: > In the DHCP v6 thread, there was some discussion of > mobility and its IP layer consequences. As various people > pointed out, cellular networks basically handle this in the > RAN (Radio Access Network) and therefore at layer 2, > transparently (well, as much as things ever are) for IP > purposes. It therefore shouldn't be a problem. > > However, as one contributor pointed out, more and more > cellular operators are migrating traffic onto WLAN for > various reasons, notably: > > 1) Spectrum - it's unlicensed, i.e. free > 2) Capex - the equipment is cheaper > 3) Capacity - it's a cheap way of providing high speed > 4) Signalling load - it gets rid of the signalling traffic > associated with detaching and attaching devices from the > core network. This is especially important in view of some > smartphones' behaviour. > > Of course much of the signalling is associated with the > Mobility Management features, and getting rid of it by > punting everything to WLAN implies that you lose the > benefits of this. > > That suggests that if you're going to do this on a big > scale you need to implement Mobile IP or else keep > backhauling traffic from the WLAN access points to the > cellular core network (GAN/Iu interface), which has obvious > effects on the economics of the whole idea. > > Alternatively, you can work on the assumption that the WLAN > is solely for nomadic use rather than true mobility, but a > lot of devices will prefer the WLAN whenever possible. > > Thoughts/experiences? > > > > -- > The only thing worse than e-mail disclaimers...is people > who send e-mail to lists complaining about them >