lte-handover on high speed trains - winst.com.t · pdf fileprisma telecom testing srl ......
TRANSCRIPT
![Page 1: LTE-Handover on High Speed Trains - winst.com.t · PDF filePRISMA Telecom Testing Srl ... PE-Wireshark AirMosaic GUI eLSU GbE Test Manager Workstation eNodeB cell 2 eNodeB ... 1 1](https://reader033.vdocument.in/reader033/viewer/2022051508/5aaa00eb7f8b9a9a188da9d6/html5/thumbnails/1.jpg)
PRISMA Telecom Testing Srl | Private & Confidential | Vers. 1.6
LTE-Handover on High Speed Trains: In-lab experimental study on the current
and future solutions
A.Parichehreh, P.Marini, Luca Dell’Anna, Umberto Spagnolini
2016.10.19
IWPC Workshop
Evolving the Internet of Things
Turin, October 18-20, 2016
![Page 2: LTE-Handover on High Speed Trains - winst.com.t · PDF filePRISMA Telecom Testing Srl ... PE-Wireshark AirMosaic GUI eLSU GbE Test Manager Workstation eNodeB cell 2 eNodeB ... 1 1](https://reader033.vdocument.in/reader033/viewer/2022051508/5aaa00eb7f8b9a9a188da9d6/html5/thumbnails/2.jpg)
Confidential – Version 1.6
Agenda
Massive handovers in HST scenario
Introduction to HST onboard Connectivity
Page 2
UeSIM (User Equipment Simulator)
Two-tier Architecture for on-board wreless connectivity
Experimental Result
In-Lab Exerimental Setup
Conclusion
![Page 3: LTE-Handover on High Speed Trains - winst.com.t · PDF filePRISMA Telecom Testing Srl ... PE-Wireshark AirMosaic GUI eLSU GbE Test Manager Workstation eNodeB cell 2 eNodeB ... 1 1](https://reader033.vdocument.in/reader033/viewer/2022051508/5aaa00eb7f8b9a9a188da9d6/html5/thumbnails/3.jpg)
Confidential – Version 1.6
Introduction to HST On-board Internet Service
Page 3
• Satellite Communication • Low bandwidth and high latency • Disconnections across tunnels • Cost of communication
• GSM-R • signaling of train and
ground station • 114 kbit/second for GPRS
• HSPA/HSPA+ • 3G technology based on CDMA • 14 Mbps in DL and 5.76 Mbps in UL.
• LTE/LTE-A • 4G technology based on TDMA/FDMA • 100Mbps peak data rate in high mobility scenario (>350km/h).
HST with speed up to 500 km/h
• Challenges • Varying channel and Doppler Shift • Penetration loss • Frequent handovers • Resource limitations
High speed train (HST) is becoming one of the preferred mid-range
transportation and the on-board Internet service is a must for train operators.
![Page 4: LTE-Handover on High Speed Trains - winst.com.t · PDF filePRISMA Telecom Testing Srl ... PE-Wireshark AirMosaic GUI eLSU GbE Test Manager Workstation eNodeB cell 2 eNodeB ... 1 1](https://reader033.vdocument.in/reader033/viewer/2022051508/5aaa00eb7f8b9a9a188da9d6/html5/thumbnails/4.jpg)
Confidential – Version 1.6
Problem definition of Handover (HO) in mobility system
Low mobility scenario train setting (e.g., v=70km/h = 20m/s, carriage length=25m) • Arrival time of carriage i+1 is larger than the HO time of carriage i • All HO related to one carriage is concluded before the next carriage
Page 4
Cell border
HO latency
RS
RP
[dB
m]
Ms
Mn
H
Os
On
TTT
A3 E
vent
Meas. R
eport
![Page 5: LTE-Handover on High Speed Trains - winst.com.t · PDF filePRISMA Telecom Testing Srl ... PE-Wireshark AirMosaic GUI eLSU GbE Test Manager Workstation eNodeB cell 2 eNodeB ... 1 1](https://reader033.vdocument.in/reader033/viewer/2022051508/5aaa00eb7f8b9a9a188da9d6/html5/thumbnails/5.jpg)
Confidential – Version 1.6
Problem definition of Handover (HO) in mobility system
High mobility scenario train setting (e.g., v = 350km/h = 97m/s, carriage length=25m) • Arrival time of carriage i+1 is smaller than the HO time of carriage i
Page 5
Handovers (HOs) of multiple UEs (20-60UE/carriage) and carriages (8-10carriage/train) must be done within a short time to guarantee QoE over the RACH signaling with heavy signaling overload. Basic idea and motivation:
• To study and verify the performance of different manufacturer for this special challenging scenario
Cell border
HO latency Depend on the HST speed/load
RS
RP
[dB
m]
Ms
Mn
H
Os
On
TTT
A3 E
vent
Meas. R
eport
![Page 6: LTE-Handover on High Speed Trains - winst.com.t · PDF filePRISMA Telecom Testing Srl ... PE-Wireshark AirMosaic GUI eLSU GbE Test Manager Workstation eNodeB cell 2 eNodeB ... 1 1](https://reader033.vdocument.in/reader033/viewer/2022051508/5aaa00eb7f8b9a9a188da9d6/html5/thumbnails/6.jpg)
Confidential – Version 1.6
Amplify and Forward (AF)-LTE Relaying
Page 6
Radio Relay
Technology General Description Advantages/Disadvantages
Type-1
Layer-1 relay
(analog repeater)
AF relay
AF of on-board UEs (transparent relay)
with full-duplex capability.
+
• Simple and inexpensive
• Minimum impact on the LTE standard
(already defined in LTE Rel.8)
• Suitable solution when carriage are shielded
-
• Noise and inter-cell interference amplification
• Frequent HOs, the same as baseline scenario (with direct link between UEs and
ground eNB)
LTE Relay LTE Relay
HO region L
TE
serv
ice
rate
Moving direction
![Page 7: LTE-Handover on High Speed Trains - winst.com.t · PDF filePRISMA Telecom Testing Srl ... PE-Wireshark AirMosaic GUI eLSU GbE Test Manager Workstation eNodeB cell 2 eNodeB ... 1 1](https://reader033.vdocument.in/reader033/viewer/2022051508/5aaa00eb7f8b9a9a188da9d6/html5/thumbnails/7.jpg)
Confidential – Version 1.6
Decode and Forward (DF)-LTE Relaying
Page 7
Radio Relay
Technology General Description Advantages/Disadvantages
Type-2:
Moving Relay Node
(MRN)
Acting with the same functionalities of a
base station, non-transparent for on-
board UEs.
DF half-duplex relay.
+
• Noise and inter-cell interference mitigation capability
• Group HOs and Tracking Area Updates (TAU)
-
• Requires its own PCID and non-transparent to UEs
• UEs need mobility management for joining to MRN
• Extra resource allocation overhead for LTE backhaul link between Donner evolved
NodeB (DeNB) and MRN (Un), and MRN and UEs (Uu).
• Needs further modifications on LTE specification (LTE Rel.12)
MRN MRN
HO region L
TE
serv
ice
rate
Moving direction
Uu
Un
Uu
![Page 8: LTE-Handover on High Speed Trains - winst.com.t · PDF filePRISMA Telecom Testing Srl ... PE-Wireshark AirMosaic GUI eLSU GbE Test Manager Workstation eNodeB cell 2 eNodeB ... 1 1](https://reader033.vdocument.in/reader033/viewer/2022051508/5aaa00eb7f8b9a9a188da9d6/html5/thumbnails/8.jpg)
Confidential – Version 1.6
UeSIM Architecture
Page 8
• Protocol processor and IP traffic generator. Processes the lower protocol layers for LTE/WCDMA/GSM (MAC, RLC, PDCP)
• Simulation control and Control Plane processing
• Optimized implementation of RRC/NAS
• SDR Unit provides multi-standard baseband processing and includes the RF interface • The same SDR Unit can be configured to work with any 3GPP radio access technology and any frequency band: GSM, UMTS, LTE/FDD, LTE/TDD
SDR Units S1 eNodeB
cell 1
GbE
PE-Wireshark AirMosaic
GUI
eLSU
GbE Test Manager
Workstation
eNodeB
cell 2
eNodeB
cell 3
S1
S1
ePC
Core Network
Logging workstation
tracing from Radio to
Application Layer
User Workstation controlling
test scenario, mobility,
application, radio conditions
![Page 9: LTE-Handover on High Speed Trains - winst.com.t · PDF filePRISMA Telecom Testing Srl ... PE-Wireshark AirMosaic GUI eLSU GbE Test Manager Workstation eNodeB cell 2 eNodeB ... 1 1](https://reader033.vdocument.in/reader033/viewer/2022051508/5aaa00eb7f8b9a9a188da9d6/html5/thumbnails/9.jpg)
Confidential – Version 1.6
TCP measurement of the ensemble of on-board UEs
Page 9
UE 1
UE N
eN
B
Core
ne
two
rk
UE N
UE 1
UE 2 UE 2
Onboard
UE
s
Internet
Services
D=1km
0
0
0
0
0
Moving direction v=300kmph
a)
b)
c)
d)
e)
UE 1
UE 2
UE N
eNB1→ eNB2
eNB2→ eNB3
eNBK-1→ eNBK
eNB1 eNB2 eNB3 eNBK
PHY
UE N
PHY
MAC
MAC
MAC
MAC
MAC
MAC
UE 1
UE 2
UE N
UE 1
UE 2
PHY level
settings
BB Interf eNodeB
cable
Mu
ltiu
ser
traff
ic
gen
era
tor
(vid
eo,
HT
TP
, F
TP
)
eNodeB
Cell k
Cell k+1
Simulated group of UEs via UeSIM LTE eNB & core network
LTE HO procedure
On-board UEs
UE1 –CH2 UE1-CH1
UE2 –CH2 UE2-CH1
UE2 –CH2 UEN-CH1
UE1 (TCP
connection)
UE2 (TCP
connection)
UEN TCP
connection) Tra
ffic
an
aly
sis
(QoS
, th
roughput)
eNB
port 1
port 2
cable
eNB
UE1 (TCP
connection)
UE2 (TCP
connection)
UEN (TCP
connection)
PD
CP
RLC
MA
C
PD
CP
RLC
MA
C
PD
CP
RLC
MA
C
(L1-L3) PHY
![Page 10: LTE-Handover on High Speed Trains - winst.com.t · PDF filePRISMA Telecom Testing Srl ... PE-Wireshark AirMosaic GUI eLSU GbE Test Manager Workstation eNodeB cell 2 eNodeB ... 1 1](https://reader033.vdocument.in/reader033/viewer/2022051508/5aaa00eb7f8b9a9a188da9d6/html5/thumbnails/10.jpg)
Confidential – Version 1.6
Network Configuration
Page 10
Network Configuration
eNB
LTE (Rel-11) band 7
downlink uplink bandwidt
h
2620MHz 2500MHz 10MHz
Cell size 1km
Off-track distance 50m [10]
UE Category Cat 4, 2×2 MIMO, 150Mbps (with 64QAM MCS)
Mobility scenario 300Km/h
Number of UEs {8,10,15,18,22,30} per carriage
HO Configuration
Hysteresis value 0dB
A3-offset 2dB
Time-To-Triger value 40ms
RACH Configuration
PRACH Configuration Index 3
Total number of dedicated preamble 56
Maximum preamble transmission 10
RA response window size 8ms
![Page 11: LTE-Handover on High Speed Trains - winst.com.t · PDF filePRISMA Telecom Testing Srl ... PE-Wireshark AirMosaic GUI eLSU GbE Test Manager Workstation eNodeB cell 2 eNodeB ... 1 1](https://reader033.vdocument.in/reader033/viewer/2022051508/5aaa00eb7f8b9a9a188da9d6/html5/thumbnails/11.jpg)
Confidential – Version 1.6
Throughput of the AF-LTE HST
Page 11
,HN
)t,h,i(TThroughputAverage
t
N
1i
H
1hPDSCH
t
where N is the total UEs on-board and Ht is the non-zero hits in the throughput measured at time t.
100
Avera
ge T
hro
ughput
[Mbps] 15x4 UEs (L1 relay)
0
c)
HO transition
100
Avera
ge T
hro
ughput
[Mbps]
30x4 UEs (L1 relay)
0
f)
HO transition
8x4 UEs (L1 relay)
-5 0 +5 Time (s)
-10 +10
D=1km
0
a)
HO transition
100
Avera
ge T
hro
ughput
[Mbps]
10x4 UEs (L1 relay)
0
b)
HO transition
100
Avera
ge T
hro
ughput
[Mbps] 22x4 UEs (L1 relay)
0
e)
HO transition
100
Avera
ge T
hro
ughput
[Mbps] 18x4 UEs (L1 relay)
0
d)
HO transition
100
Avera
ge T
hro
ughput
[Mbps]
a)
-5 0 +5 Time (s)
-10 +10
D=1km
-5 0 +5 Time (s)
-10 +10
D=1km
8x4 UEs (L1 relay)
By increasing the number of UEs, not only throughput reduces, but also the HO transient time increases (due to the HO signaling
of massive UEs)
![Page 12: LTE-Handover on High Speed Trains - winst.com.t · PDF filePRISMA Telecom Testing Srl ... PE-Wireshark AirMosaic GUI eLSU GbE Test Manager Workstation eNodeB cell 2 eNodeB ... 1 1](https://reader033.vdocument.in/reader033/viewer/2022051508/5aaa00eb7f8b9a9a188da9d6/html5/thumbnails/12.jpg)
Confidential – Version 1.6
Service Time of the AF-LTE HST
Page 12
0 0.01 0.02 0.03 0.04 0.05 0
0.2
0.4
0.6
0.8
1
Service Time [ms]
cdf
8x4 in cell
l cell = -5770
l HO =-848
8x4 in HO
5 10 15 20 0
0.2
0.4
0.6
0.8
1
Service Time [ms]
cdf
10x4 in cell
l cell = -5.302
l HO = -0.6992
10x4 in HO
0 5 10 15 20 0
0.2
0.4
0.6
0.8
1
Service Time [ms]
cdf
15x4 in cell
l cell = -4.378
l HO = -0.7443
15x4 in HO
0 5 10 15 20 0
0.2
0.4
0.6
0.8
1
Service Time [ms] cdf
18x4 in cell
l cell = -1.847
l HO = -0.5897
18x4 in HO
0 5 10 15 20 0
0.2
0.4
0.6
0.8
1
Service Time [ms]
cdf
22x4 in cell
l cell = -1.133
l HO = -0.5309
22x4 in HO
0 5 10 15 20 0
0.2
0.4
0.6
0.8
1
Service Time [ms]
cdf
30x4 in cell
l cell = -0.7582
l HO = -0.4583
30x4 in HO
a) b)
c) d)
e) f)
![Page 13: LTE-Handover on High Speed Trains - winst.com.t · PDF filePRISMA Telecom Testing Srl ... PE-Wireshark AirMosaic GUI eLSU GbE Test Manager Workstation eNodeB cell 2 eNodeB ... 1 1](https://reader033.vdocument.in/reader033/viewer/2022051508/5aaa00eb7f8b9a9a188da9d6/html5/thumbnails/13.jpg)
Confidential – Version 1.6
CDF of Handover Latency of the AF-LTE HST
Page 13
HO latency shows an exponential behaviour with the rate parameter depending on the cell load
10 0
10 1
10 2
10 3
0
0.2
0.4
0.6
0.8
1
t= RRC complete
- RRC config
(ms)
EC
DF
Experimental 4X4 UEs
F(t; t ° )=1-e
-0.275t
Experimental 30x4 UEs
F(t; t ° )=1-e
-0.002t
0 200 400 600 800 1000 1200 0
0.2
0.4
0.6
0.8
1
t= RRC complete
-RRC config
(ms)
EC
DF
4x4 UEs
8x4 UEs
15x4 UEs
18x4 UEs
22x4 UEs
30x4 UEs
1 2 3 4 5 6
0.5
1
1 2 3 4 5 60
500
𝜏°
HO
ave
rag
e la
ten
cy
8x4 10x4 15x4 18x4 22x4 30x4
![Page 14: LTE-Handover on High Speed Trains - winst.com.t · PDF filePRISMA Telecom Testing Srl ... PE-Wireshark AirMosaic GUI eLSU GbE Test Manager Workstation eNodeB cell 2 eNodeB ... 1 1](https://reader033.vdocument.in/reader033/viewer/2022051508/5aaa00eb7f8b9a9a188da9d6/html5/thumbnails/14.jpg)
Confidential – Version 1.6
Multicell Access Scheme
Page 14
HST with relay nodes (Layer-1 relay or MRN) equipped with directional antenna
Basic idea: • Manipulating the HO decisions of on-board relays with spatial adaptation of the signal.
a)
Moving direction
mobile relay (L1 or MRN)
forward
omni-directional
backward
dispatcher
b)
eNBk+1 eNBk eNBk-1
![Page 15: LTE-Handover on High Speed Trains - winst.com.t · PDF filePRISMA Telecom Testing Srl ... PE-Wireshark AirMosaic GUI eLSU GbE Test Manager Workstation eNodeB cell 2 eNodeB ... 1 1](https://reader033.vdocument.in/reader033/viewer/2022051508/5aaa00eb7f8b9a9a188da9d6/html5/thumbnails/15.jpg)
Confidential – Version 1.6
HST Outage Probability: Theoretical Analytics
Page 15
HST Outage Probability Analysis:
where
so that
where
and
Note that
1
2
)()()1(N
i
N
out
i
outout
HST
out PPPP
)()),(1(),( )()()()(
th
i
k
iii
out PHHPkk
kj
k
))H(P1(1)H,( )i(
k
)i(
j
)i(
2
k
2
j
kk
jj
10
)i(
k
)i(
j /x))t(,(g
x))t(,(glog10HQ)H(P
.2
1)( 2
2
x
x
dxexQ
(1)
(2)
(3)
(4)
(5) kkk10thk
)i(
k /x))t(,(glog10Q1)(P
![Page 16: LTE-Handover on High Speed Trains - winst.com.t · PDF filePRISMA Telecom Testing Srl ... PE-Wireshark AirMosaic GUI eLSU GbE Test Manager Workstation eNodeB cell 2 eNodeB ... 1 1](https://reader033.vdocument.in/reader033/viewer/2022051508/5aaa00eb7f8b9a9a188da9d6/html5/thumbnails/16.jpg)
Confidential – Version 1.6
Computer Simulation Results: Train Outage Analysis
Page 16
Outage probability anaylsis [1]
[1] A. Parichehreh, S. Savazzi, L. Goratti, U. Spagnolini: Seamless LTE connectivity in high-speed trains. Wireless Commu.and Mobile Computing
16(12): 1478-1494 (2016)
![Page 17: LTE-Handover on High Speed Trains - winst.com.t · PDF filePRISMA Telecom Testing Srl ... PE-Wireshark AirMosaic GUI eLSU GbE Test Manager Workstation eNodeB cell 2 eNodeB ... 1 1](https://reader033.vdocument.in/reader033/viewer/2022051508/5aaa00eb7f8b9a9a188da9d6/html5/thumbnails/17.jpg)
Confidential – Version 1.6
Computer Simulation Results: Train Outage Analysis
Page 17
Overlapped HOs can happen due to mispositioning of eNBs along the track.
Before the HO of directional antenna
Subject to:
Directional antenna postpones its HO affirmatively in favor of omni-directional antennas to prevent HO overlapping.
(1)
(2a)
(2b)
},{minarg],[ )()1(
},{
)()1(
)()1(
N
HOHO
N PPN
max0 PPout
max
)()1(
min },{ N
directional antenna HO
Geometrical position [km]
0.5 1 1.5 2 2.5 3 3.5 25
30
35
40
45
50
Beam
wid
th (∆𝜃
)
Time
𝑇𝑜𝑓𝑓 On service eNB #2
𝑇𝑜𝑓𝑓 On service period eNB #2 On service eNB #1
On service eNB #3 Direct.
Omni.
10 -4
10 -2
10 0
Outa
ge p
robabili
ty
P out direct
P out omni
Delay in HO
#1 #2
#3
![Page 18: LTE-Handover on High Speed Trains - winst.com.t · PDF filePRISMA Telecom Testing Srl ... PE-Wireshark AirMosaic GUI eLSU GbE Test Manager Workstation eNodeB cell 2 eNodeB ... 1 1](https://reader033.vdocument.in/reader033/viewer/2022051508/5aaa00eb7f8b9a9a188da9d6/html5/thumbnails/18.jpg)
Confidential – Version 1.6
Multicell Access Scheme Experimental results: PRISMA MRN and layer-1 relay with Directional Antennas versus
Omni Antennas
Page 18
0 0.5 1 1.5 20
0.2
0.4
0.6
0.8
1
Average Throughput [Mbps]
CC
DF
L1
MRM
L1+MA
MRN+MA
0 200 400 600 800 10000
0.2
0.4
0.6
0.8
1
RRCCompleted
-RRCConf ig
time (ms)E
CD
F
MRN+MA
L1 + MA
L1
(a) (b)
![Page 19: LTE-Handover on High Speed Trains - winst.com.t · PDF filePRISMA Telecom Testing Srl ... PE-Wireshark AirMosaic GUI eLSU GbE Test Manager Workstation eNodeB cell 2 eNodeB ... 1 1](https://reader033.vdocument.in/reader033/viewer/2022051508/5aaa00eb7f8b9a9a188da9d6/html5/thumbnails/19.jpg)
Confidential – Version 1.6
Conclusion
• In-Lab test has been set to validate the performance with “actual” eNB from major
manufacturers.
• In-Lab experimental results proves the QoS/QoE impairments of HO in HST
• Fixed-beam directional antenna is compatible with all the existing on-board relay
solutions and it is a promising solution to provide multi-cell access.
• Advantages:
Further reduction of the HO signaling and interruption time
Better QoS provisioning via multi-cell access mechanism
Distributing/balancing the on-board load among multiple LTE cells
No change in the current LTE specification.
Further tests for higher speeds (400-450kmph) are planned with more eNBs (from other
manufacturers), mixed UMTS/LTE technologies (inter-RAT HO)
More info on In-Lab setup: http://www.prismatelecomtesting.com/
Page 19
![Page 20: LTE-Handover on High Speed Trains - winst.com.t · PDF filePRISMA Telecom Testing Srl ... PE-Wireshark AirMosaic GUI eLSU GbE Test Manager Workstation eNodeB cell 2 eNodeB ... 1 1](https://reader033.vdocument.in/reader033/viewer/2022051508/5aaa00eb7f8b9a9a188da9d6/html5/thumbnails/20.jpg)
Confidential – Version 1.6
Via Petrocchi 4 I 20127 Milano
T+39.02.26113507 F+39.02.26113597
www.prismatelecomtesting.com
C.F. e P.IVA IT 08876610968
Thank You! Page 20