Background

Today, connectivity is becoming more and more important for marine applications. Getting and keeping connected at ocean so that the ships can move safely is a big challenge.

IFLY 4G LTE private network solution can solve this problem by supplying the ship a stable, high speed and secure network. Let's learn how the system can help.

1.Testing Duration: 2018.03.26 to 2018.04.05

2.Purpose of Testing is to:

① Test the performance of TD-LTE Wireless Private Network Technology in the marine environment

② Verify the wireless coverage of the integrated base station (Patron-A10) in the ocean

③ Relationship between wireless coverage distance and installation height of private network base station(PATRON-A10)

④ What is the download rate of the mobile terminals on board when the base station is deployed in the air with the helium balloon?

⑤ How about the network speed of the mobile terminals on the ship with the base station deployed in the air by the helium balloon.

⑥ Verify the impact of the base station antenna on the wireless coverage as it swings with the balloon in the sky.

3.Equipment Involved In The Testing:

Equipment on helium balloon

① TD-LTE wireless private network integration system (PATRON-A10) * 1

② High gain dual polarized directional antenna * 1 (including feeder cable)

③ Optical Transceiver * 2

④ 500meters multimode fiber

⑤ Network Cable

⑥ Notebook*1

⑦ Wireless Router*1

Equipment on Ship

⑧ High-power Vehicle-mount CPE (KNIGHT-V10) * 1

⑨ High gain 1.8meters omnidirectional fiberglass antenna * 2 (including feeder cable)

⑩ Network cable

⑪ Notebook

⑫ Wireless Router

Built Up the Entire Testing System

Install the base station

The LTE private network all in one base station is deployed on a helium balloon 4km far away from the shoreline. The maximum height of the helium balloon is 500 meters. But in this test its actual height is about 150m. 

The installation of the directional antenna on the balloon is shown in Figure 1. The vertical angle is fixed (1° perpendicular to the ground) and the horizontal angle of the main lobe faces the sea. The horizontal angle of the antenna can be quickly adjusted by the Pan-Tilt to ensure the signal coverage direction and area.

Network construction

The wireless all-in-one LTE base station(Patron-A10) on the balloon connects to the ground fiber network through the Ethernet cable, fiber cable, fiber transceiver and router A. At same time it connects to the FTP server (notebook) through the wireless router B.

Deploy 10watts CPE (Knight-V10) on board

Install the CPE (Knight-V10) on the fishing boat and the antennas are mounted on the top of the cab. The main antenna is mounted at a distance of 4.5 meters from sea level and the secondary antenna is 3.5 meters from sea level. The distance between the two antennas is about 1.8 meters.

The notebook on the ship connects to the CPE through a network cable and connects to the remote FTP server through the CPE. The notebook’s FPT software and the remote FTP server are together to used to do the FTP download testing. At the same time, the traffic statistics tool running on the notebook can record the internet flow and rate in real time. The other testers use mobile phone or and a pad to connect to the WLAN covered by CPE for surfing the Internet in the cabin, such as watching an online movie or making a video call to test the Internet speed.

The Base Station's Configuration

Centre Frequency: 575Mhz

Bandwidth: 10Mhz

Wireless Power: 2 * 39.8dbm

Special Sub-frame Ratio: 2:5

NC: is configured as 8

Antenna SWR: main antenna 1.17, auxiliary antenna 1.20

The Entire Testing Process

Test Start

At 15:33 on 3rd April, the fishing boat sailed out, and at 17:26, the balloon was lifted to a height of 150meters and hovered. Then the CPE wirelessly connected with the base station normally, and at this time the fishing boat is 33km far away from the station.

Testing Content

The notebook on the ship did FTP-download, and the target file size is 30G. The pre-installed BWM software recorded the real-time internet flow and recorded the GPS information in real time through the mobile phone. 

Other staff members on the fishing boat accessed the Internet via WIFI to watch online video and made video calls. The online video is smooth and video calls voice is clear. The whole testing is 33km-57.5km.

Test Recording Table

During the test, the stuff members on ship recorded the GPS coordinates, CPE signal strength, FTP average download rate and other information in real time. The data recording tables are as below (the distance value is the distance between ship and the shore, and the download rate value is download rate recorded by BWM software)

Distance(km)	32.4	34.2	36	37.8	39.6	41.4	43.2	45	46.8	48.6	50.4	52.2	54	55.8
Signal Strength(dbm)	-85	-83	-83	-84	-85	-83	-83	-90	-86	-85	-86	-87	-88	-89
Download Rate(Mbps)	10.7	15.3	16.7	16.7	2.54	5.77	1.22	11.1	11.0	4.68	5.07	6.98	11.4	1.89

Signal Interruption

At 19:33 3rd April, the signal was suddenly interrupted. When the signal is interrupted, the fishing boat is about 63km away from the base station on shore (check the figure below). When the signal is interrupted, the CPE signal strength is -90dbm. The Base station GPS information: 120.23388888, 34.286944. And the last FTP normal point GPS information: 120.9143155, 34.2194236

Test Finished

On 5th April, all the stuff members on ship returned back to shore and finished the testing.

Analysis of The Testing Result

The horizontal coverage angle of antenna and the fishing boat navigation direction

The coverage angle of the antenna is basically the same as the ship's route. From the CPE signal strength, it can be concluded that the signal jitter is relatively small. In this way, the directional pan-tilt antenna can basically meet the signal coverage requirements in Ocean. During the test, the directional antenna has a maximum off angle of 10°.

The Record Of FTP

The right figure shows the FTP real-time download rate and the corresponding GPS location information are reflected in the map. During the test, there were several data traffic jitters, and the signal in most areas was good. The average download rate was above 2Mbps, and the last lost connection location(63km away from the shore) was 1.4 Mbps.

Mobile Terminal Test Results

From the CPE access to the wireless private network to it lost the connection, the online video watched by the staff members is very smooth and no stuck.

Signal Interruption

According to the base station and CPE parameter settings, when the signal is interrupted, the CPE signal strength should be around -110dbm. However, in the test results, the signal strength is -90dbm. 

After the technical team's analysis, it was concluded that the NCS value was not set to the farthest parameter configuration is the main reason. Before test begins, the staff member didn’t set the NCS value to the farthest settings because the farthest settings will affect the download rate. 

Refer to the following figure:

NCS Configuration	Single Antenna's Theoretical Band ( 20Mhz base station)	Dual Antenna's Theoretical Bandwidth (20Mhz base station )
Settings in This Test	52Mbps	110Mbps
The Farthest Settings	25Mbps	50Mbps

Suggestion: Set NCS to the farthest setting in next time testing and pay attention to the system’s throughput and the number of connected users when NCS is set to different configuration.

Conclusion

IFLY technical team gained valuable test data and experience through this testing. This test verified the network coverage ability of the TD-LTE wireless private network system in the marine environment and the signal coverage capability in the ocean. At same they also obtained the download rate of the high-power CPE at different sailing distances and the user experience after the mobile terminals access to the Internet.