Wi-Fi on a Boat

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{{Welcome}} {{GoogleSearch}} {{Contributions}} {{Donate}} '''Making shore-based Wi-Fi Internet work well on a boat.''' {{Wi-Fi Articles}} == Common Problems == In locations where shore-based Wi-Fi signals are strong, using them for Internet access on a boat is comparable to using Wi-Fi [[wikipedia:Hotspot (Wi-Fi) | hotspots]] on land. However, the marine environment tends to exacerbate general Wi-Fi problems and create other problems of its own: * Boat hulls and sailboat masts can block radio signals, reducing range. * Movement of other boats can cause interruptions of Wi-Fi connections. * Location of a Wi-Fi antenna in a cabin below deck can further reduce range. * It may be difficult to get close enough to the Wi-Fi access point for sufficient signal, especially when anchored. * Boat movement can result in aiming problems with highly directional antennas (even when tied up). * Moisture in the marine environment can result in electronic failures. == Improving Wi-Fi == === Higher Power === [[Image:Alligator.jpg|thumb|American Alligator]] While it may seem that higher power Wi-Fi might help to improve your range, that's ''not'' necessarily true, since higher power only helps on ''transmit'', not ''receive''. Thus it's only likely to help if the other end of your connection is using higher power as well, which is often not the case. In other words, what you may well wind up with is an ''alligator'', big mouth but small ears. Also, unnecessarily high transmit power will tend to increase your interference with other Wi-Fi users, making you a bad neighbor. ''It's usually much better to just improve your antenna, which helps both transmit and receive.'' === Better Antenna === [[Image:Wireless ap outdoor.jpg|thumb|Outdoor wireless access point with high-gain omnidirectional antenna.]] Usually the best way to improve range is to use a ''better antenna'' (or ''[[wikipedia:Reflector (antenna) | reflector]]'' with a standard antenna), which helps both transmit and receive. Better antennas work by being ''[[wikipedia:Directional antenna | directional]]'': * ''concentrating radio energy/sensitivity'' to/from the desired direction instead of wasting it in pointless directions, and * ''reducing [[wikipedia:Co-channel interference | interference]]'' from other radio sources not in the desired direction (path). The improvement in antenna performance is referred to as ''[[wikipedia:Antenna gain | gain]]'', where a higher number indicates the amount of performance improvement expressed in ''[[wikipedia:Decibel | dBi]]''. ''It takes an increase of 6 dB to double range; e.g.,'' as compared to a typical 2 dBi antenna, an 8 dBi antenna has double the range. However, a highly directional antenna can be problematic on a boat, since it must be kept aimed accurately at the remote end of the connection, which can be difficult on a boat floating in the water (even when tied up). The width (angle) of the directional pattern (both vertically and horizontally) can be used to see how accurately the antenna must be aimed. The simplest and easiest improvement is to use a higher-gain [[wikipedia:Omnidirectional antenna | omnidirectional antenna]] (4-8 dBi), thereby avoiding the need to aim the antenna horizontally (point it at the shore-based wireless access point). Such an antenna works by concentrating energy/sensitivity in the horizontal direction that would otherwise be wasted vertically (up and down). Beyond about 8 dBi the vertical beam angle becomes so narrow that vertical aiming can be problematic on a boat: {| | {| border="1" cellpadding="2" bgcolor="#FFFFCC" style="font-size:90%; line-height:1.1em;" ! align="center" | Omnidirectional<br>Antenna Gain ! align="center" | Example of<br>Vertical Beam Angle |- | align="right" | {| width="100%" bgcolor="#FFFFCC" style="font-size:90%;" | align="center" | &nbsp;&nbsp;4 dBi |- | align="center" | &nbsp;&nbsp;6 dBi |- | align="center" | &nbsp;&nbsp;8 dBi |- | align="center" | 10 dBi |- | align="center" | 12 dBi |} | align="center" | {| width="100%" bgcolor="#FFFFCC" style="font-size:90%;" | align="center" | 50° |- | align="center" | 28° |- | align="center" | 15° |- | align="center" | 11° |- | align="center" | &nbsp;&nbsp;8° |} |} |&nbsp;[[Image:Omni Antenna Patterns.svg.png]] |} === Antenna Location === Higher antenna locations tend to have less interference (''e.g.,'' from other boats) than lower locations, so in general it's a good idea to ''locate the antenna as high as is practical''. On a sailboat, the ideal location is at the top of the mast. Since signal loss in the cable between the radio unit and the antenna increases rapidly with the length of the cable, it's better to locate the radio unit next to the antenna, and use lossless cable to support the radio unit, either [[wikipedia:Universal Serial Bus | USB]] or [[wikipedia:Ethernet | Ethernet]], both of which have advantages and disadvantages (as noted below). === Automatic Tracking === There are products than can be used to keep a directional antenna aimed at an access point as a boat swings or drifts with precision of better than one degree (''e.g.,'' [http://www.track-it-tv.com Track-It-TV]). However, they are relatively expensive, and they only track in the horizontal plane, so it's important that the vertical beam width take into account rolling and pitching of the boat. Usually a vertical beam angle of 10 degrees or so is adequate for all but the roughest conditions, but even beam angles of 20 degrees or more can still result in substantial improvement in gain over an omnidirectional antenna. == Temporary Setup == Setup as needed, packed away when not in use. Ideally the radio unit and antenna are located together as high as possible (''e.g.,'' outside on the top of the cabin), usually connected by cable: === USB === [[ Image:Hawking HWU8DD Hi-Gain USB Wireless-G Dish Adapter.jpg |thumb|Hawking HWU8DD Hi-Gain USB Wireless-G Dish Adapter]] '''Advantages:''' * Simplicity * Lower cost * Power over USB cable standard '''Typical USB setup:''' * [http://www.hawkingtech.com/products/productlist.php?CatID=32&FamID=60&ProdID=280 Hawking HWU8DD Hi-Gain USB Wireless-G Dish Adapter]<br>(8 dBi, must be aimed) '''Caveat:''' Maximum length of a USB cable is 5 meters (about 16 feet), although that distance can be multiplied by means of one or more USB active extension cable(s), effectively a standard USB cable married to a one-port USB hub (''e.g.,'' [http://www.startech.com/Product/ItemDetail.aspx?productid=USB2FAAEXT15&c=US StarTech USB 2.0 Active Extension Cable USB2FAAEXT15]). '''Note:''' USB Internet connection can be ''shared'' by means of [[wikipedia:Internet Connection Sharing | Internet Connection Sharing]] and a separate network (''e.g.,'' Ethernet). === Ethernet === [[Image:Buffalo Wireless-G High Power Ethernet Converter WLI-TX4-G54HP.jpg|thumb|Buffalo Wireless-G High Power Ethernet Converter WLI-TX4-G54HP]] '''Advantages:''' * Long cable (up to 100 meters) * No USB driver needed (universal) * Support multiple clients with a hub or switch '''Caveat:''' Not all Wireless Ethernet [client] Bridges support multiple clients. Check manufacturer specs and/or [[Wi-Fi#Wireless Ethernet Bridges |Wi-Fi Wireless Ethernet Bridges]]. '''Typical Ethernet setup:''' * [http://www.buffalotech.com/products/wireless/wireless-g-mimo-performance/wireless-g-mimo-performance-ethernet-converter Buffalo Wireless-G High Power Ethernet Converter WLI-TX4-G54HP] * [http://www.buffalotech.com/products/wireless/wireless-accessories/6-dbi-detachable-high-gain-directional-antenna Buffalo 6 dBi Detachable High Gain Directional Antenna WLE-AT-DACB] (if needed, must be aimed) '''Power:''' Separate power cable, or it may be possible to use [[wikipedia:Power over Ethernet | Power over Ethernet]]. Check manufacturer specs. == Permanent Installation == [[Image:SENAO Outdoor Wireless Multi-Client Bridge-Access Point-WDS SOC-3220.jpg|thumb|SENAO Outdoor Wireless Multi-Client Bridge/Access Point/WDS SOC-3220]] Will give far more range than regular Wi-Fi at deck or cabin level: *Install weatherized high-gain omnidirectional antenna as high as is practical (if on a sailboat, ideally at top of mast) *Install weatherized Ethernet ''client bridge'' (''e.g., ''SENAO [http://www.senao-me.com/products-details.asp?CatId=3&SubCatId=5&ProdId=67 SL-2611CB5 EXT] or [http://www.senao-me.com/products-details.asp?CatId=3&SubCatId=5&ProdId=74 SOC-3220]) as close to antenna as possible (as in outdoor access point picture above, in order to minimize signal loss in antenna cable) *Run weatherized [[wikipedia:Category 5 cable|CAT5 cable]] from Ethernet client bridge (if on a sailboat, down/inside mast) *Power client bridge with [[wikipedia:Power over Ethernet|Power over Ethernet]] *At cabin end of Ethernet cable, put: ** Hub or switch (for wired network connections) ** Wi-Fi access point (for Wi-Fi network connections) ** Bluetooth access point (''e.g., ''[http://www.anycom.com/anycom/products/prod_main.php?prodid=CC3052&lang=us ANYCOM AP-2002]) (for [[wikipedia:Bluetooth|Bluetooth]] network connections) === Managing a Wireless Ethernet Bridge === [[ Image:Wi-Fi Boat Permanent.svg.png|frame|right|Wi-Fi at top of sailboat mast]] When using a wireless Ethernet [client] bridge, [[wikipedia:IP address | IP addresses]] of networked clients on the boat (wired or wireless) are normally assigned by a shore-based [[wikipedia:Dynamic Host Configuration Protocol | DHCP]] server. The problem is that the wireless Ethernet [client] bridge will typically have a fixed IP address for management that won't necessarily be on the same [[wikipedia:Subnetwork | subnet]] as IP addresses set by shore-based DHCP servers, preventing networked clients from directly managing the wireless Ethernet [client] bridge. Two possible solutions to this problem: # Use ''two'' network adapters {wired or wireless) on a given networked client: ## One configured by (shore-based) DHCP for Internet access ## The other configured manually just for managing the wireless Ethernet [client] bridge # Use a [http://www.petri.co.il/configure_tcp_ip_to_use_dhcp_and_a_static_ip_address_at_the_same_time.htm multi-homed Ethernet adapter with both a static address and a DHCP address] === Wired versus Wireless Clients === :[[ Image:Boat Wi-Fi Wired vs Wireless.svg.png]] ''Note:'' In order to minimize possible interference, a ''boat Wi-Fi access point should ideally be on a different minimally-overlapping channel (1, 6, 11 in the USA) from the shore access point''. == Power == Many standalone low-end networking devices that use separate "wall wart" type power supplies are able to tolerate a relatively wide range of input voltage, and can be run directly from 12 VDC boat power with an appropriate adapter cable. Check manufacturer input voltage specs if possible. == LAN on a boat == * When the boat has its own wireless access point (or wired hub or switch), and multiple network devices that get their [[wikipedia:IP address|IP addresses]] from a remote [[wikipedia:Dynamic Host Configuration Protocol|DHCP]] server, then all those IP addresses will be on the same [[wikipedia:Subnetwork|subnet]], and are thus part of a [[wikipedia:Local area network|local area network]] (LAN). * It won't necessarily be a ''private'' LAN -- unless the remote wireless access point implements ''wireless-to-wireless isolation'' (which many do not), all boats will be on the ''same'' LAN, and should ''take precautions'' accordingly -- see ''[[Wi-Fi How To#Secure Internet access in a public hotspot|Secure Internet access in a public hotspot]]''. * That kind of LAN will be "up" (working) only when connected to remote Wi-Fi; otherwise it will be "down" (not working). * To have a private LAN, and one that works even when not connected to remote Wi-Fi, then use a local wireless router instead of a local wireless access point (or wired router instead of a wired hub or switch). That creates a "double NAT" which will usually work fine, although it can cause problems with certain older network protocols and applications. To access the LAN management port of the wireless Ethernet (client) bridge: ** ''Good method:'' If supported by your local wireless router, configure a ''manual route'' from LAN to WAN for a ([http://www.rfc-editor.org/rfc/rfc1918.txt RFC 1918]) ''private'' IP address on the LAN management port. (The wireless router shouldn't forward private addresses without a manual route.) ** ''Crude method:'' Set a ''fake non-conflicting public'' IP address on the LAN management port of the wireless Ethernet (client) bridge, which your local wireless router will automatically forward to its WAN port (since it's not a local or private address). == Relaying and Mesh Networks == When some boats are too distant from a shore access point for a direct Wi-Fi connection, it may be possible to setup nearer boats to repeat or relay the Wi-Fi signal to more distant boats. See ''[[wikipedia:Wireless Distribution System | Wireless Distribution System]]''. == International Use == Wi-Fi channels are standardized, but vary slightly in different parts of the world. Many Wi-Fi devices will work properly anywhere in the world, either by means of a configuration option (preferable), or by means of different firmware loads (clumsy). See ''[[Wi-Fi#Wi-Fi_Channels | Wi-Fi Channels]]''. == External Links == * [http://www.wifimarine.org/ Wi-Fi Internet solutions for boaters and marinas] * [http://www.radiolabs.com RadioLabs] ** [http://www.radiolabs.com/products/wireless/wireless-marine-antenna.php WaveRV Marine] (complete USB system) * [http://www.marinenet.net/Wifi/Default.htm MarineNet Wireless] ** [http://www.marinenet.net/satantennatips.htm WiFi Antenna Installations] * [http://www.hyperlinktech.com HyperLink Technologies] ** [http://www.hyperlinktech.com/item.aspx?id=2165 2.4 GHz 8.5 dBi Omni Marine Antenna] (3ft RP-SMA Plug Connector) ** [http://www.hyperlinktech.com/web/12v_to_48v_dc-dc_converter.php 12 Volt to 48 Volt DC/DC Boost Converter] (for Power over Ethernet) * [http://www.linksys.com Linksys] ** [http://www.linksys.com/servlet/Satellite?c=L_Product_C2&childpagename=US%2FLayout&cid=1134690840850&pagename=Linksys%2FCommon%2FVisitorWrapper WAP54GP Wireless-G Access Point with Power Over Ethernet] (also works as Bridge) * [http://www.mini-box.com Mini-Box.com] ** [http://www.mini-box.com/s.nl/sc.8/category.19/.f WRAP WIFI] (modular components) * [http://www.trendnet.com TRENDnet] ** [http://www.trendnet.com/products/TPE-101I.htm Power over Ethernet (PoE) Injector TPE-101I] * [http://www.track-it-tv.com/ Track-It-TV Marine grade automatic tracking system for use with directional Wi-Fi antenna systems] * [http://www.thewifishop.net/ The Wifi Shop] (Good marine solutions and fast international service) [[Category:Wi-Fi]]

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