It is relatively easy to build an inexpensive high-speed broadband network in your boat for Internet and streaming media like audio and video.
2008 © David Shaw
2008 © David Shaw
Design Considerations
The goal in this section is to design a data network with Internet connectivity, for the boat’s activities, business meetings and home entertainment.A basic system consists of a satellite-based Internet Service Provider (ISP), an antenna connected to a receiver and modem, a router connected to the modem, a network connected to the router, and various devices connected to the network. These devices can be computers, printers or for home-entertainment. Any file servers or other critical devices should be on a Universal Power Supply (UPS).
Internet Service Provider
As we will see, it is relatively easy to build an inexpensive high-speed broadband network in your home, small office or on your boat. The components are widely available, costing in the hundreds of dollars each, not the thousands.On land, the bottleneck is always the so-called last mile. The wiring or cabling between your Internet Service Provider (ISP) and your location determines whether you can use low-speed 28k or 56k dial-up, or a high-speed service like DSL.
For a boat, the bottleneck is the satellite service, and its geographic coverage, as provided by a global ISP. Typically with satellite service, the download speed (e.g., 2 Mb/s) is faster than the upload speed (e.g., 512kb/s). The Internet connectivity is sometimes bundled with telephone and fax service. Telephone service, called Voice Over IP (VoIP) is also feasible over the Internet. In North America, major telephone companies were readying VoIP service in late 2004.
Global satellite ISPs include: KVH [23], VSAT [24]. Satellite Signals has a web site listing regional providers around the world [25].
Router
A router is a kind of computer device that routes packets of data from one device to another. Think of it as a kind of switch. Routers also serve as gateways to the Internet. Routers suited for a small office or boat usually include four ports for direct cable connections and a firewall.A firewall prevents intruders on your network as follows: Internet services are assigned a standard TCP/IP port number. For example, web browsing uses the http service at port #80, which you have seen in your browser as http:// in front of a www address. A firewall restricts access to the ports. If you close all ports except #80, outsiders cannot get direct access to your network while you can still surf the web. The UPnP protocol is insecure, so make sure you can turn it off. Typical vendors suited to a small office or boat are: Belkin, D-Link, LinkSys and NexLand [2-5]. If you have both a local and a satellite ISP, you may want to consider a balancing router like the NexLand, which will make switching more seamless. Routers are also available with a wireless function.
Switch
If you need more ports for direct connections than provided by your router, you can daisy chain a five-port Ethernet switch [3-5]. Typically, the router has a designated port for this.Network Connectivity
Wireless is the Way to Go
Because we’re fitting out a new trawler, we can install a high-performance network for streaming media like video and audio. For every day use, phone-line, power-line and 802.11b wireless suffice. But for streaming media, in rank of performance, the choices in connecting a network are:
- Cable
- Gigabit Ethernet
- Fast Ethernet
- Wireless 802.11g
- Wireless 802.11b
Using Ethernet over cable gives the highest performance (bandwidth and speed). Think of speed as the length of time it takes you to go to the fridge for a beer. Think of bandwidth as the number of beers you bring back at one time. Think of performance as how fast you get drunk…. [9]
However, wireless (Wi-Fi) has the great advantage that you can work anywhere in the wireless reception area without being hooked up to or trailing a cable. Although 802.11b is too slow for streaming media, newer protocols like 802.11g are satisfactory. The other big advantage is that more and more devices, such as TVs and stereos, are available every day with wireless connectivity. Wireless is the future.
Wi-Fi has a range of 300 ft. Of course, wireless signals are degraded when they have to pass through walls, and will be reflected by steel bulkheads and hulls. These are not issues in a fibreglass hull.
The problem in a custom steel hull is that we don’t really know how the wireless will perform after everything is built. We can only assume that coverage will not be uniform. For example, a single wireless router in the pilothouse is unlikely to propagate through a steel hull via a companionway to the forward accommodation. But it’s remotely possible because the wavelengths are very short. To box clever, run Cat5e or Cat6 plenum cable from the incoming router to the salon and pilothouse, and also the fore and aft accommodation. At every termination point, you will need an AC power outlet, unless you use Power over Ethernet (PoE).
PoE uses an Injector located near the router to put a DC voltage on the Cat5 cable. Your wireless access points may be able to use this directly, through the RJ45 jack (looks like a telephone jack on steroids). These devices are sold as PoE-Compatible or Active Ethernet Compatible.
Devices that are not compatible can use a small converter called a Picker, Tap or Active Ethernet Splitter to connect to the regular DC power jack.
These termination points can be used for individual network connections or wireless access points. In the worst case, if the wireless router does not have enough coverage through the hull, you can install a wireless access point anywhere there is a termination for a data cable. This should ensure adequate coverage. Each access point should be set to a different channel, thereby setting up zones to cover different parts of the boat. In a steel hull, position access points so they have a good line-sight through doorways.
In addition, we may want to put a wireless antenna on the mast, to give coverage outside on the boat deck and in the aft cockpit.
To retrofit an older boat, pull plenum data cable through to distribution points wherever you can, and put Active Ethernet wireless routers at these nodes. If you can’t get cable through, or the wireless coverage is insufficient, consider using phone- or power-line adaptors with the resulting lower bandwidth.
Security
Because wireless networks broadcast their presence with a radio signal, other people can access them if you don’t secure them properly. Buy only access-point devices that have Wi-Fi Protected Access (WPA, WPA2) with MAC, and are capable of closing the network. Don’t buy devices with the older WEP security standard.MAC (Medium Access Control) allows you to create an access control list (ACL). To do this, you enter the MAC address of all wireless devices allowed to access your network. If other devices attempt to log on, they are call-blocked.
Most wireless networks ship with a default password provided by the manufacturer, and automatically broadcast a default network name, called a Service Set Identifier (SSID). This means that an outsider can detect your network by looking for the radio signal and its default SSID, log-on using the SSID and default password, and gain access.
Fortunately WPA makes it easy to secure your network if you follow these steps [1]:
- Enable WPA, following the manufacturer’s instructions.
- Change the default password.
- Change the default network name (SSID).
- Close the network by blocking automatic broadcasting of the SSID. (You will still be broadcasting a wireless signal, but it will have no network name.)
- Enter the MAC address of all devices into the access-control list.
Devices
With a network in place, consider attaching some of these devices.File Server
A file server is a computer where you store your files. Usually it will have a tape unit, or writeable DVD for backups. The file server is connected directly to the router with a network cable, so the two should be co-located. Whether you chose Linux or Windows for the server depends on your level of comfort. In my office, we run both. We regularly re-start (reboot) the Windows servers every month or so. Some of the Linux servers have been running for two years without a reboot. Network Area Servers (NAS) are available as network appliances. Usually these are Linux based but because they are designed as appliances they hide the operating system from you. You don’t have to be familiar with Linux to use them.Print Server
An inexpensive wireless print server allows you to connect a printer to the network without using a print server (a dedicated computer) or connecting the printer to the file server. Wireless print servers are available from: Belkin [2], D-Link [3], Hewlett-Packard [7], LinkSys [4] and Netgear [8]. Hewlett-Packard makes printers such as the DeskJet 5850 with a built-in wireless server.Fax Server
An inexpensive fax server will let you send and receive faxes from any Windows program or attached scanner [32].Voice Over IP
Voice over IP (VOIP) is a mechanism for routing telephone calls over the Internet instead of through the switching circuits and trunk cables of the telephone companies. It’s a new technology that has matured very rapidly. Its chief advantage is very low-cost flat rates for long-distance calls. Its chief disadvantage is possible delays in the signal. VOIP went commercial in 2004. VOIP also operates over Wi-Fi, where it is called VoWIP. VoWIP should be available from HP, Mitel, Motorola, NEC, Nokia and others in mid-2005. To work with VoWIP, your wireless access points must have SpectraLink Voice Priority (SVP).Cameras
Wireless cameras are an excellent way to provide security or monitor blind spots. Some places to consider are:- Boat deck
- Aft cockpit
- Side decks
The IK-WB11A supports resolutions ranging from 160-by-120 to 1,280-by-960 pixels. It delivers 112 degrees of pan and 54 degrees of tilt, plus a 5X digital zoom control. It's based on 802.11b technology, which is compatible with an 802.11g network. Unfortunately it only supports WEP not the more secure WPA. This is an acceptable risk in a boat.
Entertainment
Personal Video Recorder
A Personal Video Recorder (PVR), also called a Digital Video Recorder (DVR) performs the same function as a VHS tape recorder, but instead stores the program in a compressed digital format (MPEG) on a hard drive like that in your computer. Unlike VCRs, DVRs let you easily skip around, wind back, pause, jump ahead, and skip commercials. (A proposed USA federal law makes it illegal to skip commercials!) Some of them are combined with recordable DVDs. Others are combined with satellite and cable receivers, and work only with a subscription service. Stand-alone units record off-the-air.Products are available from: EchoStar, Fusion, Hughes DirecTV, LG Electronics, MythTV, Pace, Panasonic [13], Pioneer, ReplayTV [28], Sky [29], Thompson, TiVo [14], Toshiba, Zenith.
The Electronic Frontier Foundation publishes a cookbook for building your own before the USA FCC restrictions of July 30, 2005 are imposed on manufacturers [26]. ExtremeTech also has DIY guide [27].
Music Receiver
Products are available from: Apple [20], Creative Labs [12], LinkSys [4], Slim Devices [22], NetGear [8] and others.Media Receiver
A media receiver (also known as a media hub or media adapter) lets you stream digital audio, photos, and video files from the file server or a networked computer to a stereo system or TV set. Typically a media receiver plays MP3, WMA, PLS, RMP, and M3U audio formats; displays pictures in JPG, GIF, BMP, and PNG graphic formats; and plays composite Video, S-Video, and RCA audio on the TV. Products are available from: ADS [19], Creative Labs [12], D-Link [3], Hauppauge [16], Hewlett-Packard [15], LinkSys [4], Omnifi [18], Philips [20], Prismiq [10], SMC Networks [11], Sony [17] and others.DVD Player
Most DVD players have an embedded code that matches the code, called a region lock, in DVDs that you buy locally. This means that a DVD player sold in the USA won’t play DVDs bought in Europe or any of the other four regions (six total). This allows the media companies to charge different local rates for the same content. The movie you buy in the USA for $12 might be legitimately available in Mexico for $2. It also means, for a passage maker, that you can’t buy locally on your next world voyage. Fortunately, some code-free DVD players are available from outlets like CodeFreeDVD [30].Digital Music System
A digital music system consists of a hub attached to a PVR or other network area storage (NAS) device. The hub drives multiple remote speakers. Systems such as the SONOS™ use wireless distribution up to 32 zones and can play different tunes in different zones [31].Summary
Internet connectivity supports the boat’s activities, business meetings and home entertainment. Basic system is a satellite-based Internet Service Provider, antenna, receiver and modem, router and network. Network is gigabit Ethernet over Cat5e cable and 802.11g wireless nodes. Security is provided with a firewall, WPA and MAC. Connected devices include computers; file, printer and fax servers; VOIP, cameras, personal video recorders, music and media receivers.References
1. Wi-Fi Alliance, http://www.wi-fi.org/2. Belkin, http://www.belkin.com/
3. D-Link, http://www.dlink.com/
4. LinkSys Group, Inc., http://www.linksys.com
5. NexLand Inc, http://www.nexland.com/
6. Toshiba, http://www.toshiba.com/taisisd/netcam/products/wb11a.htm
7. Hewlett-Packard Co., http://www.hp.com/
8. Netgear, http://www.netgear.com/
9. Attribution unknown.
10. Prismiq Inc., http://www.prismiq.com/
11. SMC Networks Inc., http://www.smc.com/
12. Creative Labs Inc., http://www.creative.com/
13. Matsushita Electric Corp. of America, http://www.panasonic.com/
14. TiVo Inc., http://www.tivo.com/
15. Hewlett-Packard, http://products.hp-at-home.com/
16. Hauppauge, http://www.hauppauge.com/
17. Sony, http://www.sonystyle.com/
18. Omnifi, http://www.omnifimedia.com/
19. ADS Tech, http://www.adstech.com
20. Royal Philips Electronics, http://www.philips.com/
21. Apple Computers, http://www.apple.com/
22. Slim Devices, http://www.slimdevices.com/
23. KVH Industries, Inc., http://www.kvh.com/
24. VSAT Systems, http://www.vsat-systems.com/
25. Satellite Signals, http://www.satsig.net/
26. Electronic Frontier Foundation, http://www.eff.org/broadcastflag/hdtv-introHY.php
27. ExtremeTech, http://www.extremetech.com/article2/0,3973,1121844,00.asp
28. ReplayTV DNNA, ?
29. Sky, http://www.sky.com/
30. CodeFreeDVD, http://www.codefreedvd.com/
31. SONOS™, http://www.sonos.com/
32. SnappySoftware.com, http://www.snappysoftware.com/
