Interview
Release 16,
going on 17
Erik Guttman, chairman of the 3GPP Service and System Aspects Technical
Specication Group (TSG SA), gives Critical Communications Today an update
on the work to standardise mission-critical services
22
www.criticalcomms.com March 2019
CCT: Can you discuss the enhancements and
features that mission-critical users can expect to
see in Releases 16 and 17? Which do you feel will
have the most positive impact?
EG: We can see incremental progress of mission-critical
features in Release 16 and Release 17. A notable and
important feature is the support for group re-grouping and
broadcast group calls for MCPTT, and the support for
conversation history and content server for MCData. A key
consideration will be the support of mission-critical services
over 5G, which is expected to be ready within Release 17.
CCT: What are your thoughts on the potential to
augment ProSe (both in terms of its capabilities
and the size of its potential market) with the work
on V2X that has/is taking place in Releases 14, 15
and 16?
EG: ere is work currently to develop the ‘New Radio (NR)
sidelink’ in the framework of the RAN Study on NR V2X
(Vehicle to Everything). While this study focuses specically
on V2X use-cases at this point, there is a clear overall goal of
developing general Proximity Services for 5G. A system-level
study in SA2 (the architecture) working group will likely bear
fruit in the Release 17 timeframe (that is, the study will likely
begin in the course of 2019).
CCT: Since our previous article on this topic in
early 2018, how has the work to enable LMR/
LTE interworking progressed and are there any
remaining challenges?
EG: e LMR/LTE work has been progressing quite
well. e rst version of the architecture specication
was concluded in early 2018, and the detailed protocol
specications are being worked through, and these are
expected to be completed in June 2019. Work on the second
version of the architecture is ongoing mainly to align with
new features that were introduced in MCPTT, eg, functional
alias, talker location, etc.
e 3GPP specications provide support between missioncritical
systems and the interworking function which acts
as the gateway to TETRA and P25 systems. erefore there
is no dependency for 3GPP and no need to wait for other
organisations to make progress. However, for the complete
interworking solution to be deployed, it is essential that the
interfaces between the interworking function and the LMR
systems are dened. is work would be undertaken by
organisations outside of 3GPP, eg, in the realm of the Alliance
for Telecommunications Industry Solutions (ATIS) and
ETSITCCE.
CCT: In our previous article, you mentioned
that the tight pairing between MC Services and
LTE was removed in Release 15, but “none of
the implications of that decision have been
investigated” – has this changed?
EG: SA6 has begun a study of implications and opportunities
presented by 5G for Mission Critical Services. ere has
not been a lot of rapid progress because there are several
fundamental service enablers that the Enhanced Packet System
(EPS) supports and the 5G system will have to add. Of
primary relevance to Mission Critical Services are Proximity
Services, MBMS (Multimedia Broadcast/Multicast Service)
support and evolution of the IMS architecture to work
optimally in the 5G environment. ese studies will progress
in the Release 17 timeframe, though some enhancement to
IMS might be included in Release 16.
An aside on the importance of enablers: e 3GPP
system oers many functions and components upon which
services can be based. Mission Critical Services in 3GPP
make extensive use of the Internet Protocol Multimedia
Subsystem (IMS), MBMS, Proximity Services and Group
Communication System Enablers for LTE.
ese enablers are tightly coupled to the 4G Enhanced
Packet Core to deliver optimised services. It will take time to
provide these enablers for the 5G core network. is work has
already begun.
For the complete interworking
solution to be deployed, it is
essential that the interfaces between the
interworking function and the LMR
systems are dened
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