LTE - What Is It Really?
LTE is 4G, the fourth generation of mobile systems and we at Ericsson Research have been part of making all mobile generations happen.
As LTE continues to evolve, we would like to share and discuss with you some of the details making up LTE and what is coming next.
The first generation of systems was analogue mobile and the second generation of systems was dominated by GSM. Both provided mainly voice calls. With 3G came mobile data, but it is with 4G that we have true mobile broadband. 4G LTE is now being rolled out globally and we are counting 175 million LTE subscribers today.
LTE is specified for a range of different frequency bands. This makes it possible to deploy LTE across the world in the bands made available for mobile broadband in different regions of the world. With multiple bands supported in LTE devices, roaming across the world is also made possible.
LTE is the first mobile system that is designed for mobile broadband from the start. Traditional voice services are not a main focus and will be provided as Voice-over-IP instead of the traditional circuit switched mode. The effort of developing LTE was very much based on the lessons learnt from 3G, where “true” mobile broadband really came with the introduction of HSPA in what was called 3.5G.
Some of the major technology components in LTE that enable mobile broadband are:
- High frequency bandwidths give room for wideband transmissions that enable the high end-user data rates that are an essential part of 4G. Today we see up to 100 Mbps and even more in LTE systems in operation.
- High flexibility in the radio access to allow for many simultaneous users that have a variable need for the radio resources over time.
- Intelligent use of multiple antennas to give high peak data rates and at the same time efficient use of the radio resources.
If you want to read up more on the details of the LTE radio access, the book “4G: LTE/LTE-Advanced for mobile broadband” written by fellow researchers from Ericsson, including myself, gives both an overview of key technologies used and detailed descriptions of how they are applied for LTE.
At Ericsson Research, we continue with the evolution of LTE for mobile broadband. Features will be added for new use cases in the next release of LTE specifications. Examples of such new use cases are:
- Enhanced local-area access through network densification.
- Machine-type communications, providing efficient connections for non-human centric such as burglar alarms, power meters etc.
- Device-to-device communications, where direct communication between wireless devices is enabled in a peer-to-peer mode.
We’ll be coming back with more on the components needed for the new use cases in the ongoing evolution of LTE.
Johan Sköld, Principal Researcher, Ericsson Research