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LTE-Maritime: High-Speed Maritime Wireless Communication based on LTE Technology

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The recent advances in wireless communication technologies allow mobile users to access various data services anytime and anywhere on land, while it is one of challenging issues to provide reliable data communications for maritime users due to the geographic features on sea. Considering the increasing demands of maritime digital data services, we need to develop the maritime communications supporting high-speed data rates and extended communication coverage. In this paper, we present the state-of-the-art researches related to the data requirements of maritime services and the technical characteristics of existing maritime networks. Then, we introduce a long term evolution for maritime (LTE-Maritime) which is an ongoing research project in the Republic of Korea. The objective of LTE-Maritime is to develop a maritime communication infrastructure supporting the data rates in the order of megabits per second within the communication coverage of 100 km. In order to confirm the feasibility of LTE-Maritime, we implemented a testbed for LTE-Maritime which consisted of ships equipped with LTE-Maritime routers, base stations (BSs) along the coast, and an operation center. The experimental results show that LTE-Maritime could be a practical solution for ship-to-shore data communication. Further, we discuss a set of open issues related to the development of LTE-Maritime network.
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LTE-Maritime: High-Speed Maritime
Wireless Communication based on LTE
Technology
SUNG-WOONG JO1and WOO-SEONG SHIM1
1Marine Safety and Environmental Research Department, Korea Research Institute of Ships & Ocean Engineering (KRISO), Yuseonggu, Daejeon 34103,
Republic of Korea (e-mail: {cswo02, pianows}@kriso.re.kr)
Corresponding author: Woo-Seong Shim (e-mail: pianows@kriso.re.kr).
This research was supported by a grant from the National R&D project of “SMART-Navigation - Implementation of Korean e-Navigation
Operation System and Maritime Digital Infrastructure” funded by the Ministry of Oceans and Fisheries (PMS4010).
ABSTRACT The recent advances in wireless communication technologies allow mobile users to access
various data services anytime and anywhere on land, while it is one of challenging issues to provide reliable
data communications for maritime users due to the geographic features on sea. Considering the increasing
demands of maritime digital data services, we need to develop the maritime communications supporting
high-speed data rates and extended communication coverage. In this paper, we present the state-of-the-art
researches related to the data requirements of maritime services and the technical characteristics of existing
maritime networks. Then, we introduce a long term evolution for maritime (LTE-Maritime) which is an
ongoing research project in the Republic of Korea. The objective of LTE-Maritime is to develop a maritime
communication infrastructure supporting the data rates in the order of megabits per second within the
communication coverage of 100 km. In order to confirm the feasibility of LTE-Maritime, we implemented
a testbed for LTE-Maritime which consisted of ships equipped with LTE-Maritime routers, base stations
(BSs) along the coast, and an operation center. The experimental results show that LTE-Maritime could be
a practical solution for ship-to-shore data communication. Further, we discuss a set of open issues related to
the development of LTE-Maritime network.
INDEX TERMS Long term evolution (LTE), LTE-Maritime, maritime data service, maritime wireless
communication, testbed implementation.
I. INTRODUCTION
THE increasing demands of emerging data services re-
quiring high data rates such as ultra-high definition
(UHD) video have driven the rapid advances in wireless com-
munication technologies. Recent communication technolo-
gies like long term evolution (LTE) and Wi-Fi can provide
data rates over dozens of megabits per second to mobile
users. In the near future, i.e., beyond 4G, the fifth generation
(5G) will be launched with the objective of 10 to 100 times
improvement in the number of connected devices and their
data rates. It is expected that 5G could support the data rates
up to tens of gigabits per second with the help of emerging
solutions such as massive multiple-input and multiple-output
(MIMO) and millimeter wave (mmWave) [1].
Contrary to these revolutionary improvements of wireless
communications on land, providing reliable and high-speed
data services for maritime users is still a challenging issue. In
general, maritime environments have the geographical limi-
tation for developing communication infrastructures such as
base station (BS) of LTE and access point (AP) of Wi-Fi. This
makes that maritime communications need more extended
communication coverage than terrestrial communications.
Legacy maritime communication systems such as automatic
identification system (AIS) and global maritime distress and
safety system (GMDSS) have the extended communication
coverage based on medium frequency (MF), high frequency
(HF), and very high frequency (VHF). However, due to
the small channel bandwidth allocated for these maritime
systems, they cannot support high data rate services [2], [3].
In addition, although satellite communication systems could
satisfy the communication needs for high data rate and ex-
tended coverage, the cost and size of satellite communication
remain severe obstacles for typical maritime users [4], [5].
By considering these limitations of current maritime systems,
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S.-W. Jo and W.-S. Shim: LTE-Maritime: High-Speed Maritime Wireless Communication based on LTE Technology
FIGURE 1: General communication network architecture for
maritime environment.
there is a strong need by maritime users for reliable, high-
speed, and cost-effective communication system.
In order to meet the communication requirements of mar-
itime users, in the Republic of Korea, an LTE-Maritime
project was recently launched with the objective of providing
the communication coverage of 100 km and high data rates
in the order of megabits per second. The basic idea of LTE-
Maritime is applying LTE technology currently used in the
terrestrial region to the maritime domain. Throughout this
paper, we focus on answering the question “Could LTE
technology satisfy the communication coverage and data
rate requirements in maritime environments?”. This paper
is organized as follows. In section II, as a motivation of
study, we present the maritime service requirements and
maritime communication systems proposed in recent works
of literatures. This survey indicates that there is a consid-
erable gap between the communication needs of maritime
services and the capability of existing maritime networks.
In section III, we introduce the performance objectives and
specific characteristics of LTE-Maritime. In section IV, the
testbed implementation and onboard experiment results are
described in order to validate the feasibility of LTE-Maritime.
The results show that LTE-Maritime can achieve the data
rates over 10 Mbps even at a distance of 100 km from BS and
it can be a practical solution for maritime communication.
Further, some technical research challenges associated with
the development of LTE-Maritime are discussed in section V.
Finally, we conclude this paper with future research direc-
tions.
II. MOTIVATION OF STUDY
Fig. 1 depicts a general communication network architecture
for the maritime environment. A main component of the ar-
chitecture is two-way communication links between ship-to-
shore and ship-to-ship. The other one is various data services
used for maritime users through the communication links. In
this section, we present a comprehensive survey of maritime
data services and maritime communication systems. The
survey focuses on specific use cases of maritime data ser-
vices and their communication requirements, and technical
characteristics of existing maritime networks in terms of data
rate, communication coverage, and cost.
TABLE 1: Service classfication and data rate requirement
Service type Service Data rate
requirement (kbps)
Safety
service
Radar/AIS plot 100
GMDSS data 10
Mechanical sensors 10
HD video 1500
LiDAR 2000
Infrared camera 1000
VTS coordination 100
SAR 100
Special data gathering 1500
Operational
service
Weather data 9.6
Ship reporting 9.6
Notifications to coastal
States 9.6
Port arrival notification 9.6
MIO 100
Load/discharge
coordination 100
PPU/VTS image 100
Tug/mooring coordination 100
Electronic chart updates 100
Korean e-Navigation
services 1560
Commercial
service
Voyage orders 9.6
Commercial port services 9.6
Operational reports 9.6
Cargo telemetry 64
Payments and inventory 64
VoIP 140
Passenger internet access 150
Crew training 9.6
Infotainment 1500
A. MARITIME SERVICE REQUIREMENTS
According to the maritime radio communications plan
(MRCP) developed by the international association of marine
aids to navigation and lighthouse authorities (IALA) [6], the
maritime services can be divided into three types of safety
service, operational service, and commercial service. Based
on this classification, a variety of maritime data services and
their data rate requirements are summarized in Table 1 [7-9].
Typical maritime services such as AIS, GMDSS, search
and rescue (SAR), maritime information overlays (MIO), and
electronic chart updates are used in most of vessels in order
to assure the safety of life and efficient voyage at sea. These
services require relatively low data rates and their maximum
requirement is 100 kbps. However, as maritime equipment
and services are modernized, the data rate requirements of
maritime services have been gradually increasing. For ex-
ample, Korean e-Navigation services are being developed
to support the safety and efficient navigation specialized
in Korean waters. It is estimated that they need the data
rates of 1.56 Mbps based on the simulation test. Further,
in order to prevent marine accidents, vessels are equipped
with a lot of sensors. It is reported that the data transmission
of sensor information collected from LiDAR and infrared
camera requires a couple of megabits per second. Besides the
safety issues, many crews and passengers want to enjoy the
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S.-W. Jo and W.-S. Shim: LTE-Maritime: High-Speed Maritime Wireless Communication based on LTE Technology
TABLE 2: Maritime wireless communication networks
System/Project Communication technology Communication coverage (km) Maximum data rate (kbps) Cost
MF/HF DSC MF/HF > 463 0.1 Low
VHF DSC VHF 120 1.2 Low
AIS VHF 120 9.6 Low
NAVDAT MF 556 18 Low
VDES VDE VHF 120 307 Low
Inmarsat C GEO Satellite Global, except the polar areas 0.6 High
Inmarsat GX GEO Satellite Global, except the polar areas 50,000 High
VSAT GEO Satellite Global, except the polar areas 46,000 High
Iridium LEO Satellite Global 134 High
WISEPORT WiMAX (IEEE 802.16e) 15 5,000 Medium
TRION WiMAX (IEEE 802.16d) 14.2 (ship-to-shore) 6,000 Medium
8.66 (ship-to-ship)
MariComm LTE (ship-to-shore) 10 (LTE) 7,600 (LTE) Medium
WLAN (ship-to-ship) 20 (WLAN) 4,700 (WLAN)
BLUECOM+ LTE (air-to-surface) 30 (LTE) 5,000 (LTE) Medium
IEEE 802.11g (air-to-air) 60 (IEEE 802.11g) 3,200 (IEEE 802.11g)
India Project LR Wi-Fi 52 (ship-to-shore) 3,000 Low
22.6 (ship-to-ship)
daily of life on the voyage. The infotainment (information
and entertainment) service for social communication and
interaction with family and friends requires the data rate of
1.5 Mbps.
It is noted that although the communication requirements
above mentioned could vary depending on user preferences
and service types, various data services for maritime stake-
holders have been developed and their communication re-
quirements have also been increasing in the order of megabits
per second.
B. MARITIME COMMUNICATION NETWORKS
Developing a new maritime network has attracted significant
attention of researchers to keep pace with the increasing
demands of maritime data services as shown in the previous
section. Table 2 summarizes the maritime wireless communi-
cation networks and their technical characteristics including
legacy maritime systems and recent research projects.
The conventional maritime systems such as digital selec-
tive calling (DSC), AIS, navigation data (NAVDAT), and
VHF data exchange system (VDES) communicate with the
shore by using frequency bands of MH, HF, and VHF [5-6].
They are generally used for the safety of ships and provide
the communication coverage of several hundred kilometers
with low cost. However, they are not applicable for transmit-
ting substantial data services like video and LiDAR due to
their limited channel bandwidth. For example, NAVDAT and
VDES systems can support the data rate up to 18 kbps and
307 kbps, respectively. The satellite systems have been used
for global communications, which are classified into low
earth orbit (LEO), medium earth orbit (MEO), geostationary
orbit (GEO), and high elliptical orbit (HEO) according to
satellite orbits [6], [10]. With advanced communication tech-
nologies, recent satellite systems can support high data rates
as well as global communication coverage. For example, the
data rates of Inmarsat and VSAT commonly used in mar-
itime environments are up to 50 and 46 Mbps, respectively.
Nonetheless, the high cost of launching, operation, and com-
munications charge still remains a disadvantage of satellite
systems. For example, FleetBroadband G service provided
by Inmarsat costs 0.420.85 U.S. dollars per megabyte [5].
In order to deal with these limitations of legacy maritime
communications, many studies are trying to apply existing
terrestrial wireless technologies to maritime communication
systems. In Singapore, a wireless broadband access for sea-
port (WISEPORT) provides the data rate up to 5 Mbps with
the coverage range of 15 km based on worldwide interop-
erability for microwave access (WiMAX) technology [11-
12]. In TRION project, a wireless mesh network is proposed
to extend the communication coverage based on the IEEE
802.16d mesh technology [2]. The mesh nodes consist of
ships and buoys, and they can route and relay the packets
for other nodes according to own routing protocol developed
in the project. In [13], maritime broadband communica-
tion (MariComm) project proposes a wireless heterogeneous
multi-hop relay network based on LTE and WLAN. The
experiment results show that the MariComm system can
provide the data rates over 1 Mbps and the transmission
distance of 100 km from the coast with the support of
multi-hop relay functionality. In BLUECOM+ project [14], a
wireless heterogeneous multi-hop relay network is proposed
by using the tethered balloons above the ocean surface, where
the balloons are used as a wireless router for air-to-air links.
The simulation results show that the proposed network can
achieve the data rate of 3 Mbps and the communication
coverage up to 150 km with two hop relays. However, the
practical experiment in maritime environments remains as
future work. In India, a heterogeneous wireless mesh network
is proposed, where long range (LR) Wi-Fi is used to extend
the communication coverage between ship-to-shore and ship-
to-ship and it is connected to the LTE core network [15].
The experiment results show that it can support the coverage
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S.-W. Jo and W.-S. Shim: LTE-Maritime: High-Speed Maritime Wireless Communication based on LTE Technology
FIGURE 2: LTE-Maritime communication architecture.
of 66.3 km with a relay and the data rate of 750 kbps at a
distance of 45 km.
In addition to these projects developing new infrastructures
for maritime communications, research efforts have been
made for enabling the maritime internet of things (IoTs)
using VHF links available on the majority of vessels [16-17].
They integrated VHF communications with IoT technologies
and protocols to extend the communication coverage in the
maritime environment, however, the data rate of proposed
networks is limited to tens of kbps due to the drawbacks
of VHF links. IEEE 802.11p for intelligent transportation
systems (ITS) can be considered for maritime communi-
cation [8], [11]. The scheduling and routing protocols for
maritime communication have been extensively proposed to
improve the network performance [11-12], [18]. On the other
hand, the communication costs of maritime solutions must
be within the affordable range of maritime users. Although
broadband services operated in the licensed spectrum like
LTE and WiMAX charge communication costs for data
access, a recent study showed that mobile users would be
willing to pay 3065 U.S. dollars per month [19].
III. LTE-MARITIME
LTE-Maritime aims at developing a new wireless maritime
network that enables maritime users to access a variety of
data services requiring the high data rates in coastal areas
of 100 km from a shore. The overview of LTE-Maritime
communication architecture in the project is illustrated in
Fig. 2 and the main features of LTE-Maritime are followings.
LTE-Maritime is based on LTE technology that is a
promising solution for wireless maritime network. LTE
is capable of providing increased data rate, capacity,
and spectral efficiency even in dynamic propagation
environments with the support of advanced techniques
such as MIMO and carrier aggregation (CA) [19-20].
Furthermore, it has the potential to provide the com-
munication coverage about 100 km depending on the
cell environments, though LTE for commercial mobile
communication is designed with a relatively short cell
coverage [5], [21-22]. This superiority of LTE makes
us develop a single-hop network enabling ship-to-shore
data communication based on LTE technology. In gen-
eral, the wireless mesh networks are vulnerable to link
failures caused by radio interference and they could
not assure reliability [23]. Contrary to existing mar-
itime networks for extending the communication cover-
age with multi-hop transmission, LTE-Maritime enables
ships to communicate with onshore BSs directly and it
can improve reliability. Therefore, it is more suitable
especially for the safety related maritime services that
require high reliability as well as low latency.
LTE-Maritime consists of base stations (BSs), evolved
packet core (EPC) equipment, and routers. A number
of BSs are located at a high altitude of mountainous
areas along the coastline to assure the line of sight
(LoS). Each BS is composed of multiple radio units
(RUs) and digital units (DUs). The RU and DU are
responsible for radio transmission and reception, and for
data processing, respectively. Every DU is connected to
LTE-Maritime operation center through the wired net-
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S.-W. Jo and W.-S. Shim: LTE-Maritime: High-Speed Maritime Wireless Communication based on LTE Technology
FIGURE 3: LTE-Maritime testbed and experiment environments.
work. An EPC is located in the operation center and its
entities are serving gateway (S-GW) for packet routing
and charging with policy and charging rules functions
(PCRF); packet data network gateway (P-GW) for qual-
ity of service (QoS) management and anchor point of
external networks; mobility management entity (MME)
for mobility control, authentication, and authorization;
and home subscriber server (HSS) for subscriber man-
agement [20], [24]. On ship side, we developed the
LTE-Maritime router suited for maritime environment.
It is equipped to compass deck of ship with high gain
antennas of 6 dBi and the antenna length of 1.2 m. It
could provide better communication performance than
typical mobile devices.
The performance goal of LTE-Maritime is divided into
two cases depending on the distance from the coastline.
The objective of region A is to cover the area from BS
to 30 km with the average data rates of 6 Mbps and 3
Mbps for downlink (DL) and uplink (UL), respectively.
The objective of region B is to cover the area from 30
km to 100 km with the average data rates of 3 Mbps
and 1 Mbps for DL and UL, respectively. The coverage
objective was set based on the fact that 88% of marine
accidents in Korea happen in non-SOLAS ships within
the coverage of 100 km [25].
With the above characteristics, LTE-Maritime will be de-
veloped by 2020 in the Republic of Korea. It is expected
that LTE-Maritime can support various Korean e-Navigation
services for marine accident prevention and effective navi-
gation. The Korean e-Navigation services include navigation
monitoring and assistance, ship-borne system monitoring,
safe and optimal route planning service, real-time electronic
navigational chart distribution and streaming, pilot and tug
assistance, and maritime environment and safety information.
In addition, LTE-maritime network could provide various
data services for maritime users with improved reliability,
high data rate, long enough coverage, and low cost compared
to current maritime networks.
IV. TESTBED IMPLEMENTATION
In order to validate the feasibility of LTE-Maritime, we
implemented an LTE-Maritime testbed and conducted a lot
of onboard experiments in Korean waters. In this section,
the details of experiment environments are explained and the
performance results of LTE-Maritime are analyzed.
A. EXPERIMENT ENVIRONMENTS
As shown in Fig. 3, for an LTE-Maritime testbed, 13 BSs
were developed at a high altitude of mountainous regions
along the coastline and they consist of 22 RUs and 14 DUs.
For example, a BS in Gangneung area is composed of DU
#1, RU #1, and RU #2 and it is located at 350 m high. In
addition, 3 BSs of femto were developed to enhance the
communication performance in the Islands area. Each BS
is connected to an LTE-Maritime testbed center in Busan
through the wired network. The testbed center consists of
an EPC, an entity management system (EMS), and several
servers. The routers developed for LTE-Maritime with high
gain antenna were equipped to compass deck of ships.
In onboard experiments, the LTE-Maritime router commu-
nicates with onshore BSs while a ship sails along the planned
route. The laptops for performance measurement are con-
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S.-W. Jo and W.-S. Shim: LTE-Maritime: High-Speed Maritime Wireless Communication based on LTE Technology
(a)
(b)
(c)
FIGURE 4: Test results of onboard experiments in different regions. (a) East sea. (b) South sea. (c) Yellow sea.
nected to the router and they measure main communication
parameters such as reference signal received power (RSRP),
signal to interference and noise ratio (SINR), throughput,
physical cell identity (PCI), and the number of resource block
(RB) using a diagnostics monitor (DM) software installed on
the laptops. In addition, for data transmission, a file transfer
protocol (FTP) auto-call server was used where DL, UL, and
idle periods were set to 1, 1, and 3 minutes, respectively. The
frequency range of LTE-Maritime network is 728738 MHz
for UL and 778788 MHz for DL.
B. RESULTS OF EXPERIMENT
Fig. 4 shows the measured experimental results in three
regions of the East sea, the South sea, and the Yellow sea.
In each case, the left top picture depicts the ship’s route, the
route’s distance, the location of BSs, and the direction of the
antenna. The left bottom table represents the average values
of RSRP, SINR, and throughput, and the maximum coverage
overall route. The right graph shows the variation of each
parameter value as the ship sails along the route.
For the East sea case, the variation of RSRP and SINR
values has three kinds of patterns. In the red dotted box, as
the ship sails away from the harbor, both values gradually
increase. This is because, when the ship is near the harbor, it
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S.-W. Jo and W.-S. Shim: LTE-Maritime: High-Speed Maritime Wireless Communication based on LTE Technology
can not assure LoS environment due to surroundings such
as buildings and mountains, and it also be interfered with
other radio signals from terrestrial region. In the blue dotted
box, RSRP and SINR decrease as the signal strength of the
neighboring cell becomes much stronger than that of the
serving cell. After PCI number is changed from 420 to 421
(i.e., a handover (HO) occurs at that point), both values start
to increase. In the rest of the route, the values of RSRP and
SINR obviously decrease according to the distance between
the BS and ship. In addition, the average throughput for both
DL and UL is over 11 Mbps with the maximum coverage of
about 100 km.
For the South sea case, onboard experiments were con-
ducted from Busan to Tsushima on an international passenger
ship, in which the antenna tilt and transmission power of
BS were adjusted from 0 to 10 degree and from 46 to 43
dBm considering the impact of propagation interference on a
neighboring country. The orange dotted box shows a similar
trend with the East sea case near the harbor due to the non-
LoS environment and interference. On the other hand, the
values of RSRP and SINR rapidly decrease and the com-
munication link between the BS and ship is intermittently
disconnected near the destination because the radio signal
is blocked by Tsushima Island. The average throughput for
both DL and UL has relatively high values compared with
the East sea case. For example, the average DL throughput
from Tsushima to Busan is 27.8 Mbps. The reason is that the
South sea experiment has a relatively short route of 65 km
resulting in much stronger RSRP values.
The experiments on the Yellow sea have a distinct char-
acteristic different from the other cases. In this area, there
are a lot of Islands and they interrupt the transmission and
reception of the radio signal. Therefore, in order to reduce the
performance degradation caused by Islands, more BSs were
developed in the Yellow sea region. This environment leads
to frequent HOs and wide fluctuation in RSRP and SINR
values as shown in the green dotted box. Nevertheless, LTE-
Maritime can achieve the average throughput over 22 Mbps
for DL and 12 Mbps for UL with the maximum coverage of
about 107 km.
Looking at these results in terms of the maritime network
performance, we can find that the LTE-Maritime testbed sat-
isfies the maritime user’s need for high-speed communication
over Mbps as well as long communication distance of 100
km. Furthermore, when the cell planning optimization that
decides the network deployment such as the number and
location of BSs, antenna tilt, and transmission power level
is applied by 2020, the communication performance of LTE-
Maritime could be more improved.
V. DISCUSSIONS
The maritime networks have unique characteristics differ-
ent from terrestrial networks in terms of communication
requirements and propagation environments. In this section,
several technical research challenges found in the testbed
experiments and related studies are addressed.
FIGURE 5: Communication distance comparison for Hata and
LoS propagation based on various antenna heights.
A. CELL COVERAGE
The coverage requirement of maritime networks is generally
longer than that of terrestrial networks. In order to estimate
the cell coverage, it is essential to use an appropriate path
loss model in the cell planning stage. The signal path loss
indicates the signal strength reduction while the signal propa-
gates from transmitter to receiver. Modelling the path loss for
maritime communications is a challenging issue due to the
unique features such as varying sea state, reflection, scatter-
ing, and ducting effect. In [26-28], research efforts have been
made for applying existing path loss models to the maritime
environment and developing the maritime models. In this
section, as an example, the widely used Hata propagation
model is discussed. It is applicable for various propagation
environments of LTE communications in the frequency range
of 2002,000 MHz and its equation is expressed as follows
[28-30]
L[dB] = (44.96.55 log10 ht) log10 d+ 45.5 + (35.46
1.1hr) log10 fc13.82 log10 hr+ 0.7hr+C
(1)
where dis the distance between transmitter and receiver
(km), fcis the carrier frequency (MHz), htis the height of
transmitter antenna (m), hris the height of receiver antenna
(m), Cis the constant factor depending on propagation
environment. The value of Cis defined as 3 dB for urban
area and 0 dB for rural area, respectively.
LoS propagation is another factor which limits the com-
munication coverage. The radio horizon distance can be
calculated by the height of transmitter and receiver antennas,
which is given by [31]
dLoS [km]=4.1(phr+pht).(2)
Based on the equations of (1) and (2), Fig. 5 shows the
impact of various antenna heights on the communication
coverage for Hata and LoS propagation. When the commu-
nication distance for Hata propagation is calculated, it is
VOLUME xx, 2018 7
2169-3536 (c) 2018 IEEE. Translations and content mining are permitted for academic research only. Personal use is also permitted, but republication/redistribution requires IEEE permission. See
http://www.ieee.org/publications_standards/publications/rights/index.html for more information.
This article has been accepted for publication in a future issue of this journal, but has not been fully edited. Content may change prior to final publication. Citation information: DOI
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S.-W. Jo and W.-S. Shim: LTE-Maritime: High-Speed Maritime Wireless Communication based on LTE Technology
assumed that received power requirement is -110 dBm, the
safety margin due to shadow fading and other interference
is 8 dB, and the other parameter values are applied equally
to the parameter settings of testbed experiment. It is shown
that, for all cases the communication distance becomes con-
siderably longer as the height of transmitter increases. For
example, when the height of receiver antenna is 10 m, the
communication distance by Hata propagation increases up
to threefold. In addition, the Hata and LoS propagation can
provide the communication distance over 100 km with the
transmitter antenna height of 500 m and receiver antenna
height of 10 m.
From the results of Fig. 5, it is observed that the height
of transmitter and receiver antennas is an important factor
determining the communication distance. That is the reason
why we developed the BSs of LTE-Maritime at a high altitude
of mountainous regions near the coastline. To further design
a practical LTE-Maritime communication system, we need
to modify existing path loss models to be suitable for the
maritime environment. The modeling of maritime path loss
is in progress under our research project of LTE-Maritime
and it is outside the range of this paper.
B. ONBOARD TERMINAL
Unlike typical mobile devices for terrestrial communication,
onboard terminals for maritime communication (e.g., LTE-
Maritime router used in our experiments) have several fea-
tures. The antenna of onboard terminal is usually placed
on the top of the ship. It can provide longer LoS distance
and better received signal quality compared with a mobile
terminal in a cabin which receives the radio signal passing
through the windows. Taking the location of the antenna
into consideration, it needs to be durable in the rough sea
conditions such as wave, wind, and rain. In addition, a high
gain antenna is desired to support improved communication
coverage and data rate. The technical characteristics of dif-
ferent kinds of antennas can be found in [22].
C. MOVEMENT MANAGEMENT
In maritime environments, the constant variation of antenna’s
orientation and height caused by sea surface movement has
significant effects on wireless communication performance.
It may lead to the increase of propagation loss and bit error
rate (BER), and communication link failure [2-3]. In practice,
a measurement study reveals that the variation of antenna’s
height caused by sea movement is one meter, which may
result in the path loss change of 16 dB. The measurement
results conducted at same RSRP condition show that BER
performance decreases in the maritime environment, where
the measured BER values of land-to-land, ship-to-shore, and
ship-to-ship communications are 106,105and 4·105,
respectively. In addition, a study on the BER performance
with different sea states shows that the BER performance
rapidly degrades as the sea state becomes worse [2], [32-33].
Besides the sea surface movement, the mobility pattern
of ships needs to be considered to assure continuous com-
munication services. As a ship sails along the route, the
data rate may sharply drop and the communication link may
be disconnected at the cell edges. For terrestrial commu-
nications, mobility management and HO algorithms have
been designed based on decision parameters such as UE
speed, path loss, available bandwidth [20], [34]. However,
these technologies are carefully investigated for maritime
networks. Because the ships have a different mobility pattern
compared to typical mobile devices and the BSs of maritime
networks are sequentially distributed along the coastal areas
rather than a hexagonal structure of terrestrial networks.
D. INTERFERENCE
Interference leads to SINR degradation and increased colli-
sion probability resulting in the reduction of overall network
performance. In general, mobile communication systems suf-
fer from intra-cell interference and inter-cell interference,
which are caused by adjacent channels within the same
cell and the same frequency channels from neighbor cells,
respectively. The effect of interference on the performance
degradation becomes more severe when a mobile user is
in the crowded areas and at cell edges. In order to deal
with these interference issues in maritime domain, the trans-
mission scheduling scheme and the position-power control
scheme of the pilot sequences have been proposed [35-36].
Moreover, maritime networks may suffer from interfer-
ence by the unwanted spurious signal from adjacent coun-
tries. In order to confirm the existence of spurious signal and
its impact on the LTE-Maritime performance, we conducted
lots of measurement on the Yellow sea region depicted in Fig.
4 (c). By comparing Fig. 6 (a) with Fig. 6 (b), it is confirmed
that there exists a spurious signal in the frequency range of
718737 MHz. Fig.6 (c) and (d) show that the interference
by spurious signal considerably degrades the network per-
formance overall the route and causes call drop as shown in
the red dotted box. In order to address interference problems,
the interference mitigation and avoidance techniques such as
interference cancelation, adaptive beamforming, frequency
reuse, cell coordination, and frequency filtering need to be
further considered for maritime communications [37-38].
E. QOS CONTROL
The safety related services such as vessel status monitoring
and collision avoidance are essential for maritime users like
crews and fishers to prevent accidents. These services are
strictly required to guarantee low latency and high reliability.
In order to satisfy delay sensitive QoS requirements, LTE
has the capability to determine QoS class identifier (QCI)
level based on service characteristics and allocates the limited
radio resource based on QCI information for each service.
Together with these functionalities of LTE, QoS management
schemes for LTE-Maritime need to be further developed
by considering the environmental features like a density of
vessels, maritime service characteristics, and channel status
variation. The QoS control schemes include packet schedul-
8VOLUME xx, 2018
2169-3536 (c) 2018 IEEE. Translations and content mining are permitted for academic research only. Personal use is also permitted, but republication/redistribution requires IEEE permission. See
http://www.ieee.org/publications_standards/publications/rights/index.html for more information.
This article has been accepted for publication in a future issue of this journal, but has not been fully edited. Content may change prior to final publication. Citation information: DOI
10.1109/ACCESS.2019.2912392, IEEE Access
S.-W. Jo and W.-S. Shim: LTE-Maritime: High-Speed Maritime Wireless Communication based on LTE Technology
(a) (b)
(c) (d)
FIGURE 6: Performance comparison of LTE-Maritime with and without interference on Yellow sea. (a) RF sniffing with
interference. (b) RF sniffing without interference. (c) Performance parameters with interference. (d) Performance parameters
without interference.
ing, adaptive modulation, channel coding, adaptive power
control, and cross layer optimization.
VI. CONCLUSION
In this paper, we provide a survey on the wireless maritime
networks to confirm how much existing maritime commu-
nication systems can support the emerging service require-
ments. This survey reveals that existing maritime systems
have the limitations of the low data rate of legacy maritime
communications and the high cost of satellite communica-
tions. As a maritime communication solution based on LTE
technology, we introduce LTE-Maritime that is an ongoing
research project in the Republic of Korea. Contrary to re-
cent efforts for extending the communication coverage with
multi-hop and mesh networks, the BSs of LTE-Maritime
located at high altitude directly communicate with ships to
guarantee the communication coverage and reliability. The
onboard experiments conducted on the testbed show that
LTE-Maritime can support high data rate in the order of Mbps
while providing long coverage around 100 km. Furthermore,
we discuss several considerations such as antenna location,
movement management, interference management, and QoS
control that still need to be addressed. Future research direc-
tions are to derive a maritime propagation loss model through
lots of onboard measurements and conduct a cell planning
based on the derived propagation model. HO, interference
management, and QoS scheduling algorithms will also be
developed to optimize the LTE-Maritime performance by
considering maritime characteristics.
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2169-3536 (c) 2018 IEEE. Translations and content mining are permitted for academic research only. Personal use is also permitted, but republication/redistribution requires IEEE permission. See
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10.1109/ACCESS.2019.2912392, IEEE Access
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SUNG-WOONG JO received his B.S. and Ph.D.
degree from the School of Electrical and Elec-
tronic Engineering, Yonsei University, Seoul, Re-
public of Korea, in 2011 and 2018, respectively.
Since 2017, he has participated in LTE-Maritime
project with the Korea Research Institute of Ships
& Ocean Engineering (KRISO), Daejeon, Repub-
lic of Korea. His research interests include real
time systems, QoS scheduling, mobile communi-
cation, and maritime networks.
WOO-SEONG SHIM received his B.S and Ph.D
degree from the School of Electronic Engineer-
ing, Chung-Nam National University, Daejeon,
Republic of Korea, in 1997 and 2017, respectively.
He has studied in Maritime GIS like electronic
navigational chart and its application system in
early stage of his career. Recently, he is involved
in Korean e-Navigation project, especially devel-
oping LTE-Maritime as a novel maritime high rate
data network.
10 VOLUME xx, 2018
... Innymi technologiami możliwymi do implementacji w systemach MASS są WiFi, WiMax i LTE, szczególnie w pasmach częstotliwości 2,4 GHz, 5,2/5,8 GHz i 5G mmWave dla morskich kanałów bezprzewodowych. Korea Południowa pracuje nad projektem LTE-Maritime, aby zapewnić szybkość transmisji danych przekraczającą 10 Mb/s, z zasięgiem 100 km od stacji bazowych, które to są umieszczone na dużych wysokościach w celu zwiększenia zasięgu (Jo & Shim, 2019 Szybki, szerokopasmowy transfer danych jest potrzebny do kontroli i monitorowania MASS z ROC. Co więcej, łączność MASS może być wspierana przez wspólne wykorzystanie satelitów, sieci multi-hop, mobilnych technologii szerokopasmowych i systemów naziemnych dalekiego zasięgu. ...
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This extensively updated second edition of LTE Signaling, Troubleshooting and Performance Measurement describes the LTE signaling protocols and procedures for the third generation of mobile communications and beyond. It is one of the few books available that explain the LTE signaling messages, procedures and measurements down to the bit & byte level, and all trace examples are taken for a real lab and field trial traces. This book covers the crucial key performance indicators (KPI) to be measured during field trials and deployment phase of new LTE networks. It describes how statistic values can be aggregated and evaluated, and how the network can be optimized during the first stages of deployment, using dedicated examples to enhance understanding. Written by experts in the field of mobile communications, this book systematically describes the most recent LTE signaling procedures, explaining how to identify and troubleshoot abnormal network behavior and common failure causes, as well as describing the normal signaling procedures. This is a unique feature of the book, allowing readers to understand the root cause analysis of problems related to signaling procedures. This book will be especially useful for network operators and equipment manufacturers; engineers; technicians; network planners; developers; researchers; designers; testing personnel and project managers; consulting and training companies; standardization bodies.
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