Page 188 - ITU-T Focus Group IMT-2020 Deliverables

3 ITU-T Focus Group IMT-2020 Deliverables

Appendix I

LTE in Slice for Softwarization

I.1 Overview

As part of the terms of reference for the focus group we are looking at various open source collaboration
efforts to help understand and advance the 5G wireline work being done by the focus group. This is a request
for a short time slot in Beijing to show a little bit of progress with the OpenAirInterface open source
collaboration. This contribution outlines the main points of what will be described in this timeslot.
As part of our proof of concept/open source work we are hoping to use OpenAirInterface together with an
open orchestration system to show some of the concepts of end to end orchestration of a slice where
OpenAirInterface and off the shelf smart phones are examples of a real RAT within a slice.

Obviously we would like to use 5G RAT’s and UE’s/Cores (but they don’t exist yet) however it is reasonable
to expect that any architecture for 5G wireline must be able to support any RAT/CORE/MEC including 4.*G
LTE flavours so this is a useful starting point. We have tried two different open 4G implementations so far
(OpenLTE and OpenAirInterface) and the latter is much better suited and more complete.

I.2 Discussion

Using openAirInterface.org software combined with a software defined radio board (ETTUS B200 accepts I/Q
over USB-3) we have been able to bring up a complete end to end smartphone -> eNB -> vEPC -> Internet
connection including web browsing, software downloads and other normal IP functions end to end. We have
so far had most success with an unlocked brand new Huawei Mate 7 phone. We have also had some success
with an ACER Z630 (still debugging EPC compatibility issues). We had no luck with a used unlocked Samsung
Galaxy S4 due to low level operator locks (Boot Rom) or various Apple products which seem not to want to
connect to any test networks for unknown reasons. The OpenAirInteface wiki lists other devices they have
had success with.

The OpenAirInterface eNB and vEPC are currently run on an i5 quad core with Ubuntu server 14.04 and a
Linux 3.19 low latency kernel and with a USB-3 fronthaul interface to the ETTUS B200. Splitting up the vEPC
is supported (but not yet tried) and an Ethernet fronthaul is apparently possible (but not tried yet). We expect
to try both of these shortly with the goal of being able to script or orchestrate where each piece runs and
how it interconnects in our lab DC / transport network environment.

We have found the OpenAirInterface software quite impressive but it is non-trivial to get everything working,
mostly because the phones themselves have many different permutations and combinations of options all
of which together with custom SIM cards have to be configured perfectly for everything to work. Debugging,
especially the phones is challenging and Android seems to offer the best success so far although other teams
indicate success with IOS based devices.
The goal of this work is to use LTE as an example within a slice and now that we are able to use
OpenAirInterface and various smart phones the next step is to work on multiple instances in different slices
and to explore the requirements of end to end orchestration.

182