WiFi Antenna

High Power WiFi

Windows XP


WiFi Access Points





Internet Connections WiFi / GPRS / GSM

The three main options available for low cost internet onboard are WiFi, GPRS and GSM. The next step up would require a two-way Satellite link – with the added expense of a gyro stabilized satellite dome to keep the dish pointed at the satellite as the wind heels and yaws your boat about – even in a marina.

The best option described here is to buy decent WiFi equipment and connect to free Access Points, that way you get a free always-on broadband connection to your boat.

All of the connections described here can benefit from some form of software acceleration if you are achieveing connection speeds below 300Kbits/second. If you are getting better speeds already then you may find the acceleration software takes longer to execute than the speed it saves! These tools work by compressing the text and images that are being sent to you. They work well for web browsing and for eMail over unencrypted connections. They do nothing to speed up any encrypted connection, so whenever you go online to view your bank statement, or if you download your eMail from an encrypted SSL connection (as GMail does over POP3) or if you use Hotmail from Outlook or Outlook Express, this uses IMAP you will see no benefit. A good example of the service offered is OnSpeed, click here http://www.onspeed.com/en/ to visit their site. Other applications can prevent accelerators working - particularly Anti-Virus software, which my be intercepting your internet traffic to check for viruses in eMail or Web pages - in which case the accelaration software won't get a look-in.

WiFi is a wireless network. You communicate with other PCs or to internet service providers’ Access Points using a WiFi card which you plug in to your laptop. Some laptops come with WiFi built-in, but unfortunately, as we will discuss later, that will only work when you happen to be berthed right next to an Access Point.
The range of your WiFi connection is all important. The world record for a 2.4GHz WiFi connection is just under 70 miles, but that was using very sensitive high gain directional antennae. A standard WiFi card without an external antenna may reach up to 100 metres, but only if you take your laptop upstairs to the cockpit. WiFi uses 2.4GHz Microwaves which require a reasonable line of sight and if you are down below, your signal may be blocked. Microwaves do not like water – and if your chart table is near water level you may have a problem. Also concrete, often used to build the pontoons in the Med, is full to the brim of water – and will block your signal. Finally, some fibre-glass boats have very high carbon content – even if they are not made of carbon-fibre. Carbon is a very good conductor and will block microwave radiation.

There are two things that can be done to get better range. Do both and you should could achieve up to 8 mile range, according to the manufacturers. We have achieved 4 miles with good quality reception.

The first is to get an external antenna; the cheapest option is to buy a rubber whip antenna with enough flex to reach from your cockpit tent down to your chart table. The second option is to install a proper marine 2.4GHz antenna on the pushpit. Most antennae, including any that are a vertical pole or tube, are omnidirectional, that is to say you mount them vertically and they have just as good a range in all directions. You can also buy directional antenna, which you will have to aim to find the best signal strength, and given the boats movement, even when tied up in a marina, may not be convenient. If you do decide to try a directional antenna, look in the technical specification for the beam-width at ‘half-gain’ and look for at least 30 degrees, or you will forever lose signal strength as the wind moves your boat. The advantage of directional antennae is that all the signal strength is concentrated in the direction in which it is pointed. The quality of the cable is important, use LMR400 for runs up to 10 metres and consider LMR600 for anything longer. There is no point buying a 4dB gain rubber whip antenna with four metres of cable, if the cheap cable (the thickness of a mouse cord) has losses of 1dB per metre, you have gained nothing! When ordering cable or an antenna with cable, make sure it has the correct connection for your WiFi PC card. There are 6 types of connector – check your card’s documentation.

The second way to increase performance, but only if you already have an external antenna, is to get a high powered WiFi card. Standard WiFi cards transmit at 30mW. It is possible to buy cards with transmit power of 200mW, almost 7 times more powerful. These cards will have FCC (USA) approval, but will not have a CE mark; the EU limit for transmission power is 100mW – if you wish to remain legal. There are a number of manufacturers producing these cards, but they are of two fundamental types depending on the chipset that they use. Make sure you buy a card with a Prism 2.5 chipset, not a Prism 3 (sometimes called Mercury). The Prism 2.5 cards cost more but have an extra receive stage in their circuitry and achieve up to 96dB receive sensitivity at 1Mbit transmission rates: it is no good pumping out lots of power if you cannot receive! If your PC card has 2 external antenna connectors you will be able to use a diversity antenna (2 antenna mounted 1-2 metres apart to make the most of signal reception) - but you will probably find that all the transmit power is directed to just one antenna - so if using just one external antenna make sure it is connected to the socket that transmits!

When buying a WiFi PC card, do not worry about the card’s speed. There are two main choices 802.11b and 802.11g. The former has a maximum speed of 11Mbit/second while the latter goes up to 54Mbit/second. Given that your internet provider is probably only going to provide 512Kbit/second, possibly 1024Kbit/second if you are lucky, both types of card will be working at their slowest WiFi speed of 1Mbit/second!

A note on Microwave safety: To comply with the current recommendations, if you are pumping 200mW out of a pushpit mounted 20" omnidirectional antenna you should not permit anyone to get closer than 1 metre when you are transmitting. If you use a directional antenna, please mount it above head-height, or one day, some of your neighbours may stop to chat on the pontoon beside your boat and unwittingly fry their brains. That said, microwave radiation is not as harmful as X-Rays, who do their damage because their wavelength is very similar to the size of your DNA and certain protein molecules - bear in mind that a mobile telephone pumps out up to 600mW 25mm away from your skull!

Problems with Windows XP
Windows XP does a lot to help you run a wireless network, but sometimes it tries a little too hard and causes interruptions or “Data Frame Errors – Check WEP Settings”. If you suffer interruptions you must stop the Windows Wireless Configuration Service (WZC). To do this I have created a shortcut on my desktop, with the ‘target’ set to “%windir%\system32\net.exe stop wzcsvc”. If you get the Data Frame Error, you must stop the WZC as above and then ‘Repair’ the network connection. To do this find the Wireless network icon in the System tray at the bottom right of your computer screen, it will look like a little computer with three radio waves radiating out. Right click on this icon and choose ‘Repair’. This is XP trying to remember the wrong WEP settings - you could get this even if your connection does not use WEP. You may have to go into your card's settings, through it's icon in the System Tray and turn the WEP on and then off to flush the incorrect setting from memory! If this problem becomes persistent, then the only solution I have found is to right click on the WiFi card's system tray icon and choose Disable Radio before turning the laptop off - this means that when you next reboot the WZC will not find the WiFI card - and can do nothing to upset it. When you next reboot, end the WZC before you Enable the WiFi card's radio, so the card is turned on only after the WZC has ended.

Using NetStumbler
NetStumbler is a very useful application that can be downloaded here http://www.netstumbler.com/downloads/ It will search for Access Points, tell you how strong they are and will even work with your GPS if it is connected to your laptop to plot the positions of best signal strength as you motor through an anchorage.

Access Points
There are three types of Access Point, free, chargeable and WEP secured. There are a lot of free access points, sometimes provided as a public service and sometimes because a member of the public is being generous with their home or office broadband connection. There are almost as many Access Points where you have to pay. When you connect to one of these, the first time you open a web browser you will be automatically redirected to the internet Service provider’s home page where any payment details will be explained – and if you don’t like them just connect to another Access point.
The third type of Access Point will be listed as WEP secured. There are other types of security, but they will still be listed as WEP. You should not access these, even though it is very easy to do so (see note below “A Word About Security”) you will be breaking the law.

A word about Security
When you set up or join a WiFi connection you should be aware of the security risks. Even if you use WEP security, which will be offered by your card, this can easily be broken. If you don’t believe me, download AirCrack from here http://www.cr0.net:8040/code/network/aircrack/ and try it on your own network. I have tried it on our network, and after listening to network traffic for a day, it was able to crack the WEP key in less than two seconds. So, always use a Firewall – see the information about Firewalls on this site.

Mobile Phone Connections
Mobiles now offer three ways to connect to the internet. 3G is the fastest and most expensive and as availability is still very patchy I’ll move straight on to GPRS. GPRS is a digital connection over your mobile that can achieve the same speeds as a traditional modem on a standard home PSTN phone line. GSM is a slow technology that manages to transmit analogue data through a digital network. Daft and slow.

With a GPRS phone you can connect your computer to the internet using your telecom provider as an Internet Service Provider. It can be expensive to use GPRS while ‘Roaming’ outside the country where you purchased your SIM card. You can save a lot of money by paying to have your phone ‘unlocked’ to any network and then buying pay as you go (PAYG) SIMs in each country you cruise in. Make sure the PAYG service you use supports GPRS and then use the settings provided by your SIM provider, or use our table here GPRS Settings for Mobile Phones to configure your mobile phone. In Windows you will need to create an internet connection for your GPRS phone, use *99# as the telephone number.
GPRS costs are related to the amount of data you transfer, not to how long you remain connected, so if you are browsing the web, make sure you stop other applications from accessing the internet. You may have many applications that sit in the background like Skype and Messenger, others try to ‘phone home’ occasionally to check for new versions. The worst culprit is Microsoft Windows Update – turn Automatic Updates OFF!!

GSM offers just 9.6Kbit/second, that is 50 times slower than you are likely to get with a WiFi connection. Use this exactly as you would use a standard modem connection at home.

There are two types of eMail you can use, WebMail and POP3/SMTP from an application such as Outlook or Outlook Express.
If your Internet Connection is relatively expensive, say GPRS, then an ‘Offline’ POP3 account is better because you can read and write your eMails without an internet connection and then connect just to Send and Receive.
If you usually have an always on connection through a WiFi connection then a WebMail based account may be more convenient – you never have to worry about backing up your emails.
The three main providers are GMail from Google, Yahoo and Hotmail from Microsoft.

GMail is the newest and offers the most flexible WebMail interface and also offers free POP3 access. At the moment you cannot apply to get a GMail account, you have to be invited by an existing user. If you are interested, we still have some invites left, so contact us by eMail to request one.
Yahoo and Hotmail both offer WebMail and POP3 access though both charge for POP3, Yahoo is the cheaper, Microsoft’s offering currently 3 times more expensive.