Outcomes, Insights and Best Practices from IIC Testbeds: LTE for Metro Testbed
use anti-interference technology to avoid
interference with Wi-Fi and Bluetooth via
licensed, dedicated spectrums.
is not degraded under various conditions
and find a working profile. The second use
case addresses multi-service support, CBTC
testing, trunking communication and
network function in various scenarios such
as emergency calls, priority calls, area
broadcasts, call transfers and system
recordings. The testbed also tests PIS and
video surveillance uses under the new
network.
The testbed is deployed in Huawei’s
OpenLab in Suzhou, Jiangsu province in
eastern China. This lab was established by
Huawei in 2017 to promote the
development of the industrial internet
ecosystem through in-depth cooperation.
The testbed’s field test is performed on
Ningbo Rail Transit’s metro line in the city of
Ningbo in eastern China. An LTE network is
deployed along the test rail track of about
one kilometer, covering 500 meters above
ground and 500 meters underground—
accounting for two typical scenarios in a
metro environment.
In phase one of the testbed, connectivity
issues were fixed by using one network to
support multiple services, including critical
services. In phase two, the testbed team will
continue working for a scenario of moving
the large amount of data collected from all
metro service systems to a cloud platform.
Looking ahead, the team hopes to
implement more possible technologies such
as big data analysis, artificial intelligence (AI)
and knowledge maps in the metro rail
industry.
The testbed team plans to produce four
deliverables, starting with a technical report.
The technical report is a summary of the lab
test and field test results. The lab test report
is finished, and the field test report will be
produced upon the completion of the test in
the near future.
There are four key technology areas found in
the rail industry that apply to the LTE for
Metro Testbed. The first is Quality of Service
(QoS) enhancement, aiming to guarantee
the reliable transmission of CBTC signals.
CBTC is the highest priority because it
prevents preempting resources needed for
other services.
The second deliverable is an experience
report comprising the challenges and
lessons learned in the field test. This report
will also provide feedback to the IIC
Networking Task Group on network
architecture, challenges in mission critical
systems and other considerations in a metro
environment.
The second key technology is wide coverage.
One remote radio unit (RRU) can cover 1.2
kilometers, a greater range than that of most
network coverage methods—such as Wi-Fi.
An RRU can therefore reduce the number of
signal handovers.
The next deliverable will be a consolidated
profile providing best practices for train-
track control and management in the metro
rail industry, as well as an input for
discussions
around
possible
future
standardization in the rail industry.
Next, a fast handover algorithm can support
high train speeds—more than 400
kilometers per hour. Finally, metro systems
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March 2020