Wi-Fi Maritime Communications Using TV White Spaces MsC Dissertation Luciano Jorge Silva Santos ee08251@fe.up.pt Supervisor Manuel Ricardo Co-supervisor Rui Campos

Wi-Fi Maritime Communications Using TV White Spaces Contents Introduction Current Maritime Communications Context Motivation Previous Work Maritime Environment Outdoor long range link TVWS Propagation models On going Work Theoretical Results Hardware Scenario Experiments Wi-Fi Maritime Communications Using TV White Spaces

Current Maritime Communications Most common used Technologies HF and VHF bands Satellite connections Low bandwidth and expensive 2G/3G (near the shore) Motivation A need for low cost communications A need for high bandwidth and speed networks Real time data transfers Live VoIP and video surveillance streaming Data exchange between fishing boats Wi-Fi Maritime Communications Using TV White Spaces

Wi-Fi Maritime Communications Using TV White Spaces Motivation Not viable to install base stations in the high sea Connection range up to 100 Km from the shore Transition to digital television 700 MHz band released by analogic television Longer transmission ranges Better propagation characteristics in comparison with 2.4 GHz and 5.8 GHz No current tests done with this band in maritime environment Wi-Fi Maritime Communications Using TV White Spaces

Wi-Fi Maritime Communications Using TV White Spaces Maritime Environment Completely different from land environment Difficult to predict maritime state Frequency propagation over water Surface multipath reflection Wave occlusion Blockage RF signal by near boats Boat rocking motion Continuous changes in the antenna orientation and height These factors provokes Unstable connection Strongly affects signal strength Long delays Increase PER Wi-Fi Maritime Communications Using TV White Spaces

Propagation model for maritime communications Proposed 2 Ray Path Loss model L = Path Loss dB ht = Transmitter antenna height hr = Receiver antenna Height d= Distance (m) λ = Wavelength Signal reflection on the sea surface (two ray) ht=hr=18m F=2,4 GHz Wi-Fi Maritime Communications Using TV White Spaces

Outdoor long distance link with TVWS band System configuration Equipment Mikrotik RB433 router boards Ubiquiti XR7 700 MHz cards 14 dBi Yagi Directional antennas Configurations Tx power: 28 dBm Channel width 5 Mhz 802.11b 7 m 18 m 50 m Variation of RSSI between node 1 and 2 Node 1 to 2 Node 1 to 3 Node 2 to 1 Node 2 to 3 Node 3 to 1 Node 3 to 2 1.62 Mbps 1.8 Mbps 1.65 Mbps 0.67 Mbps 1.63 Mbps 0.65 Mbps Wi-Fi Maritime Communications Using TV White Spaces

Wi-Fi Maritime Communications Using TV White Spaces Scenario ANACOM Restrictions: Max Tx Power: 28 dBm Channel Width: 5 MHz Frequencies between: 770-780 MHz Wi-Fi Maritime Communications Using TV White Spaces

Wi-Fi Maritime Communications Using TV White Spaces Hardware Hardware 2x Alix 3D3 Pc engine 2x Flash compact cards 2x Ubiquiti XR7 Proprietary 700MHz, based on 802.11g OFDM TX Channel Width Support 5MHz / 10MHz / 20MHz Outdoor range up to 50 Km 2x Omni Directional Antenna 700-2700 MHz 3 dBi gain GPS USB Omni Directional Antenna Ubiquiti XR7 card Alix 3D3 Wi-Fi Maritime Communications Using TV White Spaces

Wi-Fi Maritime Communications Using TV White Spaces Experiments Analyse the performance of the 700 MHz link in maritime environment with the following parameters: Range – Average distance possible to establish a connection between the land station and the boat Connection throughput – Average bandwidth for different ranges between the land station and the boat. Packet delay and Packet loss – Round Trip Time and the percentage of packets loss for different ranges Jitters - Variation of time between arriving packets RSSI throughput – Received Signal Strength in dB TCP and UDP tests Analyse the results with meteorological conditions Wi-Fi Maritime Communications Using TV White Spaces

Wi-Fi Maritime Communications Using TV White Spaces Theoretical Results Considering following parameters: Transmitted: Tx Power: 30 dBm Antenna Height: 20m Antenna gain: 3 dBi Attenuation: 0.94 dB Received: Min Power: -88 dBm Antenna Height: 5m Tolerance: 6 dB Max Path loss: 118.16 dB Max Distance: 7530 m Fresnel Zone: 27.25 m Wi-Fi Maritime Communications Using TV White Spaces