# Marine Internet for Internetworking in Oceans: A Tutorial
## 4 Communication Systems in Oceans
### Satellites  
Satellites are the only solution available today that can provide Internet services with wide coverage. A geostationary Earth orbit (GEO) satellite runs in an orbit of 35,786 km with an orbit period of 24 h so that it seems to be fixed in the sky to a ground observer. Three GEO satellites can cover most of the Earth's surface except the polar areas. Immarsat uses GEO satellites to provide the following services: voice, IP data and access to GMDSS. The recently developed FleetBroadband can provide a shared-channel IP packet-switched service up to 492 kbps using a broadband terminal specially designed for fitting on ships, as listed in Table 4.  
A weakness of satellites is that their communication quality is susceptible to weather conditions due to the poor penetration ability of very high communication frequencies used by satellites. Particularly, the channel quality is affected by moisture and various forms of precipitation frequently present in marine environments [9]. With low-orbit satellites, it is challenging to keep the communication quality of the wireless link between a flying satellite and moving terminals with rapid handoff. Furthermore, satellites cannot support underwater networking since radio signal cannot propagate well underwater, as shown in Table 1.  
Due to high costs for satellite's construction, launching [9], operation and maintenance as well as communication devices [44], satellite Internet services are not cost-effective. Hardware upgrading and repairing of a running satellite almost means a new replacement. The system can work as expected only after all the satellites have been launched and operate successfully, which results in a long development period [44]. \begin{table}
\begin{tabular}{l c c c c} \hline \hline
**Service Package** & **Data Rate** & **Data Cost** & **Voice Cost per** & **Equipment’s** \\  & **(kbps)** & **per MB (\$)** & **Minute (\$)** & **Cost (\$)** \\ \hline Immarsat FleetBroadband G & \(\leq\)432 & 0.46 1–20.852 & 0.42–1.15 & 4700–16,914 \\ \hline Immarsat MCD-4800-BGAN & 448 & 4.70–6.99 & 0.98 & 13,733 \\ \hline Immarsat FleetPhone Global & 2.4 & 15–50 & 0.80–0.95 & 1899–2349 \\ \hline Iridium Pilot Global & 134 & 7.41–10.90 & 0.65–1.22 & \(\geq\)4495 \\ \hline \hline \end{tabular}  
* Advertised on [[http://www.groundcontrol.com](http://www.groundcontrol.com)]([http://www.groundcontrol.com](http://www.groundcontrol.com)) on 3 December 2013. 1 Two-year package at $33,480 per year, 2 Monthly package at $189 per month.  
\end{table} 
Table 4: Marine Internet services for maritime transports *. Table 4 lists some satellite Internet services available for maritime transports. For example, the FleetBroadband-G of Inmarsat provides the following packages: maximum data rate of 432 kbps for data transmission with $0.40-20.85 per megabyte, and $0.42-1.15 per minute for voice, along with an initial equipment cost of $4700-16, 914. Table 5 lists marine Internet services provided by the OpenPort airtime package of Iridium: per-minute cost of voice ranges $0.62-0.95, almost tens times that of terrestrial mobile cellular voice services. It is expected that satellite communication cost will decrease as advance of new technologies such as low-orbit small satellites [45] and satellite launching technologies using reusable rockets with multiple satellites per rocket, by which the costs for both construction and launching of satellites can be reduced significantly. There are several new initiatives for global Internet announced recently, which are all based on massive deployment of small satellites. For example, OneWeb (720 satellites), Amazon Kuiper (3236 satellites) and SpaceX Starlink (4425 satellites). These huge projects are very costly, and still under development for mature operation. To further reduce the cost of marine Internet users, it is important to attract more terrestrial users using satellite Internet in order to improve investment efficiency, whereas the technical evolution of running satellite networks is much slower than that for terrestrial networks.