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Which smartphone for your nav software?

PhonesI havent updated my page on Phones here for sometime – for one thing the market innovation has just raced at such a speed it is almost impossible to keep up!

There can be no doubt that small handheld devices, more powerful than todays laptops will become commonplace – connected to huge datacentres like Amazon Cloud Front, Google, or Microsoft Azure and across the web for the provision all sorts of services from weather to location to social networks.

By the way this does raise all sorts of global warming issues that Greenpeace and others have highlighted. These mega datacentres use enormous amounts of power for chilling as well as for running the equipment. Google for one has begun a “follow the moon” strategy so that loads can be swtiched to centres across that world that will have cheaper power at night and also climates where chilling is less important.

Anyway, back to phones, the question is simply – if I was to buy a phone today in order to run some of the nav software available for boats – which one would I choose? hmmm….tricky, everyone hates to buy something that is out of date by the time it is delivered !

I have prepared a spreadsheet with the phone models that I am considering and of course the choice between Android v Apple OS v Windows Mobile 6.5 is absolutely fundamantal to the choice of phone. Then there is Windows 7 for mobile…..

One big issue so far for iPhone is that its operating system did not do proper multi-tasking. In other words it would not allow more than one application to share the memory space available in the phone and operate together. This is pretty important if you are running nav software!.

Apple have launched OS-4 which does do multi-tasking BUT it will create priorities for applications based on the Apple iStore classification that might not allow an application as much processing power as you’d like it to have.

I would refer you to these interesting posts on the subject:

There are thousands of comments like those above on the web – but you can see how this may impact on the choice of phone for your chartplotting / nav software πŸ™‚

I will be doing a post on navigation software for phones “soon”…

But, in the meantime I have summarised my phone comparison so far… To download a PDF of my spreadsheet just click here…this is a work in progress πŸ™‚

I would be interested in comments from developers as well as sailors on this subject.


Has your phone got UMTS or CDMA?…..what on earth?!

In my section on using mobile phones on board I keep referring obliquely to “modern phones”. One reader picked me up on this and asked me all sorts of questions about their phone. Unfortunately the reader was in the States so I did little bit of research on what is going on in the US with the mobile phones network. This is one technology where we in Europe can justly feel proud of the advanced technology that we get to use compared with our poor cousins in the USA,…sorry πŸ™‚

Firstly – since many readers of this blog are all over the world you may have all sorts of technology being deployed at the same time even some quite old ones so watch out – even your laptop mobile broadband dongle that you just bought may still be out of date technology.

Originally data transmissions – which is what we are interested in on our boat – was sent over the analogue mobile phone network in much the same way as modems used to send data over computer dial up networks – i.e. as sounds -this practice even continued when the first GSM mobile network was deployed.

Stage 1 – CSD
The first digital systems for data was Circuit Switched Data (CSD). This is a real digital transmission of data using the GSM network. Unfortunately when the transmission left the GSM network to go to the internet for example – the transmission was converted back to analogue – and was not IP based – which is how the internet transmits data around the world. Data transfer was relatively slow: 14.4 kbps (kilobits per second) for GSM 1800 networks (Orange and T-Mobile) and 9.6 kbps for GSM 900 networks (Vodafone and O2).

Stage 1a – HSCD
HSCSD (High Speed Circuit Switched Data) enables data to be transferred more rapidly than the standard GSM (Circuit Switched Data) system by using multiple channels. The maximum number of timeslots that can be used is four, giving a maximum data transfer rate of 57.6 kbps (or 38.4 kbps on a GSM 900 network). HSCSD is more expensive to use than GPRS, because all four slots are used simultaneously – it does not transmit data in packets. Because of this, HSCSD is not as popular as GPRS and is being replaced by GPRS/EDGE.

Stage 2 – GPRS (or 2.5G)
Following this came GPRS – General Packet Radio Service. This is sometimes called 2.5G. This brought a full data channel of about 32/48kb/sec via the GPRS service to/from the internet. Most Blackberries use GPRS it is perfectly ok for email and light internet access. The class of a GPRS phone determines the speed at which data can be transferred. Technically the class refers to the number of timeslots available for upload (sending data from the phone) or download (receiving data from the network). The timeslots used for data are in addition to the slot that is reserved for voice calls. These timeslots are available simultaneously, so the greater the number of slots, the faster the data transfer speed. Because GPRS transmits data in packets, the timeslots are not in use all the time, but are shared amongst all users of the network. That increases the overall data capacity of the network, and it also means that you are billed for the quantity of data transmitted, not the time that you are online. It may mean that during busy times, data transfer rates slow down, because the network will give priority to voice calls.

GPRS Class Time slot Max Data Transfer Speed
Class 2 3 8 – 12 kbps upload / 16 – 24 kbps download
Class 4 4 8 – 12 kbps upload / 24 – 36 kbps download
Class 6 4 24 – 36 kbps upload / 24 – 36 kbps download
Class 8 5 8 – 12 kbps upload / 32 – 40 kbps download
Class 10 5 16 – 24 kbps upload / 32 – 48 kbps download
Class 12 5 32 – 48 kbps upload / 32 – 48 kbps download

Stage 2a – EDGE
An enhancement of GPRS is called EDGE or “Enhanced Data rates for GSM Evolution” – aren’t acronyms great πŸ™‚ EDGE increases the speed of each timeslot to 48 kbps and allows the use of up to 8 timeslots, giving a maximum data transfer rate of 384 kbps.

Stage 3 – UMTS (or 3G)
This is the minimum standard for what I am calling a “modern phone”. Throughput should be up to 384kb/sec but because UMTS uses a different radio frequency to GPRS/GSM you should see a separate icon on your phone display indicating whether you have a “3G” signal or not. You can have one and not the other.

Stage 4 – HSDPA (or 3.5G)
An enhancement to UMTS/3G is High Speed Download Packet Access (HSDPA). This can give throughput from 14Mb/sec (downlink) and 6Mb/sec (uplink) – depending on your phone provider and proximity to a 3G aerial. This is sometime called 3.5G…

In the States they dont follow these standards of course ! They use CDMA (Code division multiple access)..

To see a summary of the GSM service around the world have a look at this site. If you are in the UK – then check out this site for extensive reviews of mobile phone networks and phones and their capabilities

The bottom line is that your “modern phone” in Europe at least..should have options to access data and the internet using all the standards from 2G upwards. These should be selectable in the configurations so that you can choose to not use HSDPA fro example if you suspect that you happen to be somewhere where there is a lot of competition for that signal e.g St Katherines Dock in the City of London, or Gosport Marina in Portsmouth perhaps – then setting your phone “down” to 2G or 2.5G may in fact get a better uncontended link to the local aerial and therefore better internet access on the phone, laptop dongle or laptop connected by phone to the internet.

..oh, and 4G is on the way


Radar Images for Weather on your phone..and much more…

palm700 thumbThe Memory Map application for mobile phones and PDA’s is fantastic example of software development for mobile devices. This application has been around for some time, and is the work of US based developer Richard Stevens and his team. Richard is a software developer with 15 year’s experience in scientific super-computing and high-performance real-time systems such as medical imaging machines and high-end radar systems.

From the MemoryMap web site …

Memory-Map Weather Radar is an application to display live National Weather RadarWeather Service doppler radar images and animated loops from radars located throughout the United States. Radar is the most effective tool to detect precipitation, especially thunderstorms, and has been used by NWS forecasters since the 1940’s. Memory-Map now brings this information, conveniently and efficiently, right to your phone or PDA.

With Memory-Map Weather Radar, when you update the image, the radar data is downloaded as a compressed overlay, without having to download the whole base image each time. There are no usage fees or subscriptions for using the service, except your mobile carrier’s normal data access fees. If the sky is clear, the download is only 1 or 2 kbytes; if there is widespread rain, it might be 10 kbytes. The first time you view each radar station, the base map image is downloaded, which is 50 to 100kbytes….”

Although the radar product is limited to the USA, what I didn’t realise is that his company has produced a full navigation product Memory-Map Navigator – for hiking and sailing that covers the UK!. Take look at the excellent video here.

This takes the use of the built in GPS on a smartphone into a whole different realm….


Accesing the internet while sailing..

DSC01794Of course you can simply browse the internet directly using a modern phone with GPRS. But even my Samsung i780 is a sloth when using Internet Explorer or oven the Opera browser to do this. Stick the phone into a laptop using the USB cable and suddenly browsing the internet becomes bearable – even “acceptable” – its magic…see the picture – my phone is the tiny display behind the laptop.

You can of course use bluetooth to connect the phone and the laptop – if the GPRS signal is weak try putting the phone in a (dry) place in the cockpit while using the laptop in the saloon. This will give a better GPRS signal to the phone but the bluetooth signal to the laptop is slightly slower than having the phone wired directly in using USB. Experiment with both methods.

So on my recent sailing holiday to the Normandy coast I thought I would try out the possibility of using this combination. I can happily report that both in the marina at Fecamp and even sailing along the coast – while in proximity to the coast of course – you can access my weather page – and all the weather links and the UK Met Office 24hr forecast.

What I do is then copy and paste the forecast, and right click on images like the barometric charts and save them to a table in a Word document that I keep as a passage plan. Very useful for reviewing as the passage develops – and the possibility of having to change plan dawns on you!

If you want more information about using your mobile phone on board check out my dedicated “phones page”….


Mobile phone confusion !

My little venture into experimenting with mobile phones and their use on my boat has stirred up a lot of readers of this blog it appears see comments here

Questions include:

– Can I use my smartphone to connect my laptop to the internet?
– Can I use my phone as a chart plotter?
– Which software and maps can I use on my phone?
– How can I improve the interface on my phone? – I cant get to the Bluetooth and other settings easily because they buried under so many menu options…
– Can I get the Met Office weather forecast and barometric charts on my phone?

I had not realised that so many of you are as frustrated as I am in getting more out of my expensive smartphone when they seem to promise so much….

Just to make one point absolutely clear I am referring to the latest crop of smartphones “not the common or garden phones” – and I dont care if you have 3G, MP3, or any other acronym – I mean a phone that is running a real mini operating system such as Windows Mobile 6 or Symbian.

As a result of all this interest I have decide to create a whole new section dedicated to mobile phone use on boats – look across the tabs at the top of the page….and you will see a tab called “Phones”.

I have only just started, but please – come back and check because I will be trying to answer the questions raised as best as I can on this new section.