Mobile Internet

In 2010 I had given some consideration regarding our internet access requirements on our planned narrowboat.  UK mobile phone coverage was ‘patchy’ and I had decided to purchase an Australian made outback 3G mobile phone antenna.  These were normally found on outback 4WD vehicles.  The antenna would be fitted to the roof of the boat and connect to a mobile phone which would in turn be connected to a battery powered wifi router. 

Within a week of arriving in the UK I had identified the wifi router was superfluous as the mobile phone could be configured as a wifi hotspot.  This setup worked and I can’t recall many occasions where we didn’t have internet coverage.

Time and technology move on and we’ve already progressed from 3G to 4G and now 5G.  This new technology means I can no longer connect an external antenna directly to a mobile phone if I want to receive good coverage. 

Most modern wireless routers now contain two antennas using a technology known as MiMo (multi in multi out).  This means an external MiMo antenna will also have two antennas combined into one casing with two leads from the antenna to the router.

Switching from a mobile phone hotspot to a wireless router doesn’t particularly bother me as we rarely made phone calls on the boat.  Moreover there has been a change in rules regarding the ability of mobile network providers to separate phone and data services.  Simply stated a UK SIM card will work in a phone or a router.

For narrowboats and motorhomes the relevant antenna types are Yagi and Omni.  Yagi antennas are directional.  for example, the TV aerial on the roof of a house is a Yagi.  It points in the direction of the TV Transmitter mast.  We had a small Yagi TV antenna on our narrowboat which looked much like a shark’s fin.  I would stand on the gunwale and rotate it until it was pointing at the TV Transmitter mast.  The external mobile phone antenna was an Omni.  This type of antenna has 360deg coverage meaning no requirement to point it at the transmitter.

If mobile phone coverage is good then an omni antenna is suitable.  However if the coverage is weak then a yagi will provide a better signal.  Most wireless routers have an internal omni antenna. 

As we would likely want to use the internet whilst moving we would need an omni external antenna and the logical place to locate it is on the roof.   Now we get to the interesting part.  All antennas are designed and manufactured with a gain measured in dBi.  Most antennas are manufactured with dBi gains between 0 and 25.  The higher the number, the greater the gain or ability to reach out and receive a transmitted signal.  One might think the best antenna is one with the highest gain.  However this isn’t true.  A low gain antenna has a signal receiving profile shaped like a dome.  It can reach up for a signal or outwards.  But not as far out as a high gain antenna.  In contrast a high gain antenna can reach out further but not up.  Essentially its signal receiving profile is like a DVD, whereas the low gain is like an upturned soup bowl.  Therefore if you were travelling over very flat terrain a high gain antenna would be the better option.  But if you are in hilly terrain then low gain is better.  Lack of mobile phone coverage is usually caused by intervening hills so a low gain antenna would be the preferred option for a motorhome.

Having decided on an external low gain antenna, say 5dBi, it would also need to be MiMo.  I would also want a low profile antenna as a tall antenna on top of a motorhome is likely to be regularly struck.  The ‘puck’ style antenna appears to be the best option.   Prices vary wildly.  I’ve seen them advertised for $100’s in the UK and less than $25 from China.  The chances are the connectors on the end of the antenna leads will be incompatible with the router.  This will require patch leads to achieve the connection. 

In summary

• MiMo technology
• Omni style antenna
• Low gain

Smoke

Visibility in our suburb has been very poor over the last two days.  Actually this is true for the entire Perth region.  The cause is a combination of controlled burning and a weather inversion.  Currently there are some 46 controlled scrub and forest fires in the region.  This is an annual autumn event where the relevant authorities attempt to remove summer bushfire risks by burning ground based fuel during the cooler months.  Unfortunately this year it’s been accompanied by a weather inversion which traps the smoke close to the ground.  Jan is suffering and we’ve made a decision to stay indoors until there is a weather change.  We’ve also just come out of lock-down so it’s not much of an issue to wait a few more days.

I did venture out yesterday morning to receive my first AstraZeneca injection before fitting a temporary “condom” to the dust extractor lean-to.

 

 Molly has check it out and apparently it’s OK.  Hopefully I’ll have it clad by next week.