Operator Strategy behind LTE deployment is devided in three categories:
a) Data only services on LTE : LTE is wireless data,all IP technology ,which do not intrinsically support voice calls. To simplify their network evolution to LTE ,many operators initially provide data services only on LTE as it allows operators to quickly deploy LTE access w/o voice core solutions.Operators can easily deployed and get operational experience of LTE network w/o going into the complexity of voice and its extensive regulatory requirements. A ‘data only’ access implies that the operator target those customers who want wireless dongles, netbooks, aircards & similar devices.
One important point to consider is either Operator wants mobility with existing 2G/3G network or wants to offer LTE supporting devices only.As intially LTE coverage would be limited from RF point of view, so when you move outside LTE coverage ,customer will loose its service . Therefore it is expected that 2G/3G operators will allow mobility to extend coverage footpint.
b)Data only services on LTE with 2G/3G voice: Voice is always a major revenue generator.To match the appeal,operators deploying LTE network,need to provide voice services with data offerings. This strategy enables quick deployment of LTE access without the need for an entirely new voice core solution.
c)Voice and Data services on LTE: LTE is wireless data all IP access technology.LTE does not specify the core network for voice services but relies on other core network technologies to deploy voice functionality.3GPP provide various mechanism through which LTE can interact with existing voice core networks.
EXAMPLE: A logical progression for an operator might be to initially deploy data-only services for LTE subscribers and then evolve to offer voice using the existing 2G-3G system. Another operator may offer LTE data services with voice services on the 2G-3G network and then later migrate their voice traffic to LTE. Alternatively, yet another operator may decide to jump straight to the third strategy, offering all voice and data services on LTE without ever deploying the first two options.