3gpp workshop on lte in unlicensed spectrum, june 13, 2014: chairman summary

© 3GPP 2009 Mobile World Congress, Barcelona, 19th February 2009© 3GPP 2013 RWS-140029 Chairman Summary 1

Chairman Summary

3GPP workshop on LTE in unlicensed spectrumSophia Antipolis, France, June 13, 2014

Dino FloreTSG-RAN Chairman


DISCLAIMER

This document is my synthesis of the workshop contributions and discussion, hoping that it can help companies achieve convergence in follow-up discussions on this subject

The document discusses the main deployment options and requirements emerging from the discussion• The point here is not to note every single variant that was

mentioned! Options or requirements that did not receive enough attention can be discussed offline among interested companies, and if consensus emerges around them, they can be later captured in future SI proposals


Motivation

Licensed spectrum remains 3GPP operators’ top priority to deliver advanced services and better user experience

Opportunistic use of unlicensed spectrum will be an important complement to meet future traffic demand

The new feature can be an attractive option for operators to utilize unlicensed spectrum with a unified network•Offering potential operational cost saving, improved spectral efficiency and better user experience


Target Frequencies

Most of the companies indicated that we should first focus on unlicensed operation in 5 GHz

Other frequencies were mentioned in few contributions, but unless consensus emerges around those in follow up discussions, these can be addressed at later time

In any case, the core technology should be as much as possible frequency agnostic so that, if needed, it can be later ported to other frequencies


Regulatory Landscape

Many companies provided an overview of the regulatory requirements for unlicensed operation in 5 GHz

Different regional requirements emerged, in terms of power levels, channel sensing etc.

Most of the companies prefer 3GPP to focus on the standardization of a global solution that can work across regions


Deployment scenarios & modes of operation

Strong interest to study both indoor and outdoor deployments

Debate on deployment models and corresponding modes of operation to be studied (see next slide):

Deployment model Mode of operation

Co-located cells

Licensed-AssistedCarrier Aggregation

Non co-located cells w/ ideal backhaul

Non co-located cells w/out ideal backhaul Dual Connectivity

Standalone cells Standalone


Debate on modes of operation

Strong interest to start first with Licensed-Assisted Carrier Aggregation operation leveraging on the existing LTE Carrier Aggregation framework• Two available options:

(1) Cells on unlicensed spectrum used for downlink only(2) Cells on unlicensed spectrum used for both downlink and uplink

• Many companies propose to start working on (1) then follow with (2)

Most of the companies see the value to study Licensed-Assisted Dual Connectivity operation as well, but prefer to do so at later time• The feature will hopefully leverage on the Dual Connectivity feature currently

being developed in Rel-12

Diverging opinions on Standalone operation• Some companies proposed to study also this mode; some companies explicitly

requested not to study it.• It seems hard to start this option at this time. But it can be re-assessed in the

future.


Main emerging requirements

Need for a global solution• Addressing the regulatory requirements of different regions• Trying to harmonize as much as possible band definition(s)

Coexistence requirements• Coexistence with Wifi• Coexistence among cells from the same or different operators

RAN should also look at possible in-device coexistence issues


Performance Results

Multiple contributions provided promising initial simulation results

Initial results show that, when augmented with the appropriate coexistence mechanisms to operate in unlicensed spectrum, e.g. Listen-Before-Talk, LTE can effectively coexist with Wifi and outperform it in terms of spectral efficiency


Workplan considerations

Interested companies should converge offline on a SI proposal clearly defining the scope of the technical work

• No need of further RAN plenary discussions simply to document all options and requirements that have been mentioned, nor to start technical discussions in RAN

• On the other hand, it is highly recommended to focus the technical work by carefully selecting (or phasing) among the main options and requirements

• Technical work should start in RAN1 with the definition of the exact evaluation methodology, the study of the necessary enablers and coexistence scenarios

• Once RAN1 has sufficiently progressed with the study, work can then follow in other WGs, including RAN4 work on the exact new band(s) specification

SI proposal to be discussed in the regular approval process in Sept


Others

Naming conventions• Some criticality emerged on the naming convention to be

used in future 3GPP discussions• The current SI proposal focuses on carrier aggregation

operations and uses the acronym LAA (Licensed Assisted Access)

3gpp workshop on lte in unlicensed spectrum, june 13, 2014: chairman summary

Technology

gpp workshop

gpp operators

chairman summary

mobile world congress

unlicensed operation

carrier aggregation

regulatory requirements

interested companies