Much WiFi

[Chris Edwards]

So I have a satellite comms unit providing external internet access by acting as a localised wifi source (wireless connection to multiple clients onboard), an AIS transceiver providing targets in hardwired NMEA and a radar allowing wifi control from an ipad over wifi (but a different wifi circuit to the satcoms).

Im currently running one ipad loaded with the Transas iSailor charting App and their coastal AIS data through the internet AIS service. This uses a dedicated Garmin GLO GPS over bluetooth.

I have another ipad running the radar as a standalone, relative motion anti collision and landfall early warning device.

Id like to be able to run everything on one ipad.

Does an inteface exist which can take multiple wifi inputs and output one single wifi single to go to my ipad ?

IN OTHER WORDS, WITH MANY BOAT SENSORS INCREASINGLY COMMUNICATING INDEPENDENTLY ON DIFFERENT WIFI CIRCUITS AS WE APPROACH THE WIRE-LESS BOAT, CAN THESE BE COMBINED SO THEY COMMUNICATE WITH ONE IPAD CLIENT ? I.e multiple wifi inputs in and one out ?

 

[RobbieW]

Probably ? Either by feeding all the signals into the SATCOM router or by putting a new router in place to combine the various signals. The new router would treat your SATCOM as a WAN source and combine the others, most easily doable if those signals can be provided by ethernet cable. I've been doing something like this with, currently, a variant of OpenWRT on an AR750

 

[Chris Edwards]

Thanks for the reply.

I had a look at that device. Maybe its my ignorance but although they have some interesting products, I dont think it quite does what I need,

With so many bits of kit outputting random wifi these days, Im surprised nothing exists but maybe people tend to go more for more organised systems.

Im not a great fan of organised integration as it often gives a single point of failure.

Probably �� Either by feeding all the signals into the SATCOM router or by putting a new router in place to combine the various signals. The new router would treat your SATCOM as a WAN source and combine the others, most easily doable if those signals can be provided by ethernet cable. I've been doing something like this with, currently, a variant of OpenWRT on an AR750

 

[RobbieW]

Thanks for the reply.

I had a look at that device. Maybe its my ignorance but although they have some interesting products, I dont think it quite does what I need,

With so many bits of kit outputting random wifi these days, Im surprised nothing exists but maybe people tend to go more for more organised systems.

Im not a great fan of organised integration as it often gives a single point of failure.

I think thats the biggest difficulty, if you want to combine 'n' wifi signals youll need a device with n+1 wifi connections - most are designed with a single connection in mind. Some wifi cards support two connections simultaneously, relaying an existing hotspot through your router is one use and mesh systems are another, but this is not universal.

Raymarine, I think, offered an integrated system which wanted to own the outbound connection to the internet as well combining various boaty systems - but generally not radar over wifi due to the way that data is handled. The problem there was that the options for external connection were limited, not providing the flexibility you'd want while cruising.

Where I came from was having a router onboard to handle dongles and therefore the external internet - this was before mifi devices became popluar. I then wanted to let that router handle NMEA data over wifi, so eventually got kplex running on the router software. Plugged some USB cables into the router to let kplex do its thing and provide NMEA data through TCP packets. It also handles radar data from a SIMRAD 3G head unit into OpenCPN. That combination did what I needed, but my requirement wasnt exactly where you're starting from.

I think the technology is evolving, it may get to a point where you can buy off the shelf the sort of device you'd need but I dont know of one today. Its probably possible to roll your own with a Pi as the base processor running one of the open router OSs with some add on packages to handle your requirement. Youd need to be quite careful in the choice of wifi devices to use as theyre not all the same, finding out which chip they use is the basis for assessment.

 

[Chris Edwards]

A lot of that went over my head technically, but I get the gist.

From the yachtsmans POV, I like the idea of being free of maker specific signal cables. If you could combine numerous wifi based sensors on one display without being tied to one manufacturer, that would be cool. It makes upgrading easier.

Not what the big electronics navaid suppliers want to hear, im sure.

Nearest I can find to this concept is TZ iboat who combine the Furuno wifi radar and separate wifi AIS on their charting app.

 

[GHA]

From the yachtsmans POV, I like the idea of being free of maker specific signal cables. If you could combine numerous wifi based sensors on one display without being tied to one manufacturer, that would be cool. It makes upgrading easier.

That exists already, signalk running on a raspberry pi. Send the data as NMEA1083, signalk or MQTT either from serial/usb or over wifi. N2K works well as well apparently, about 50 quid for canbus/usb to get at the N2K data, haven't tried it though.
http://signalk.org/demo.html

Screenshot below is mostly home made sensors (very accurate and vary cheap! ) Then do what you want with the data, upload to a cloud based signalk for remote monitoring, send to a database for plotting, loads of plugins already. Just needs the manufacturers to add a few quids worth of chips and a few hours programming. If only.......

Should be OK to add a few wifi/usb dongles to the Pi to connect to various wifi networks created by other kit onboard so have all the data on one network, though never tried it.

 

[Chris Edwards]

Yes but I fail to see how I can interface my wifi radar or wifi linked satcom or other device to signalK?
Clever but does it solve the OP?

That exists already, signalk running on a raspberry pi. Send the data as NMEA1083, signalk or MQTT either from serial/usb or over wifi. N2K works well as well apparently, about 50 quid for canbus/usb to get at the N2K data, haven't tried it though.
http://signalk.org/demo.html

Screenshot below is mostly home made sensors (very accurate and vary cheap! ) Then do what you want with the data, upload to a cloud based signalk for remote monitoring, send to a database for plotting, loads of plugins already. Just needs the manufacturers to add a few quids worth of chips and a few hours programming. If only.......

Should be OK to add a few wifi/usb dongles to the Pi to connect to various wifi networks created by other kit onboard so have all the data on one network, though never tried it.

 

[GHA]

Yes but I fail to see how I can interface my wifi radar or wifi linked satcom or other device to signalK?
Clever but does it solve the OP?

Not sure, the post was in reply to

"From the yachtsmans POV, I like the idea of being free of maker specific signal cables. If you could combine numerous wifi based sensors on one display without being tied to one manufacturer, that would be cool. It makes upgrading easier."


It might join your networks, but haven't tried that.

Should be OK to add a few wifi/usb dongles to the Pi to connect to various wifi networks created by other kit onboard so have all the data on one network, though never tried it.

Radar, AIS receiver display & GPS are the 3 bits I would very much prefer to have available stand alone ( even if networked as well) on a cruising boat.

PS Just tried speedtest connected directly to a mobile phone then connected to the Pi access point so the wifi goes through the Pi - ~1Mbps direct to mobile & 3.25Mbps through the Pi then 3.25Mbps back on the mobile, which tells us nothing much, other than at those relatively low speeds there isn't much throttling , if any, as the data goes through the Pi.

 

[prv]

This is essentially a networking question - the answer is going to be in terms of address ranges and routing and DHCP and so on. It is undoubtedly doable though. To make a plan you'd need to find out a little more about what the various devices are doing and the extent to which they can be configured - getting comfortable with WireShark would be a good start.

In terms of hardware, if I was doing this I'd probably start by looking at Mikrotik's catalogue - they're extremely capable and flexible (albeit often at a cost of being fiddly to configure) and reasonably priced compared to other products with the same features. WiFi is something they're particularly strong on.

If you can better characterise what you need to achieve in terms that networking people are familiar with, then there are Mikrotik forums who can help.

Pete

 

[ShinyShoe]

It seems odd that these devices can't join an existing network... That's what you want...

So tell us what devices are talking to what... Names/models etc.

 

[Chris Edwards]

In essence, the problem is that I want to continue to run Transas iSailor charting on my iPad and have real time radio based AIS superimposed on its charting. The iPad is currently connected by wifi to my Inmarsat satellite terminal to provide continuous internet access for email, chart corrections and browsing etc and its connected to my Garmin GLO GPS on its bluetooth connection for position, COG and SOG.

Im currently getting internet AIS on iSailor - it works but I would like the possibility to receive live AIS on iSailor.

Ive got a Raymarine AIS-500 which is currently putting AIS targets on my fixed Raymarine plotter independently of whats going on with iPads and wifi, so I would have to take another output from that and convert it somehow.

 

[ShinyShoe]

So... Your current AIS doesn't do WiFi as I understand it. You will need an NMEA to WIFI converter. Quark do one for <£100. It can work via a router/access point.

I don't know enough about your SatComs to know if it is an access point or can be one. Or you need something else as well.

A RasPi would be another option... Adding a second WiFi adaptor if required to bridge the sat Comms. But... I'd want as much cables as possible. But the Pi can be the multiplexer and the Access Point / Bridge etc.

 

[Chris Edwards]

The satcom also has an RJ45 POE outlet with dynamic IP. Im no programmer but I can plug stuff in and handle simple set ups.
If I buy a converter for the AIS, to convert NMEA0183 Sentences to something else, could I plug both satcom and AIS into a WAP/ router using ethernet cables and then let that provide wifi to the ipad ?

What router should I use for a boat (12-15VDC)?

So... Your current AIS doesn't do WiFi as I understand it. You will need an NMEA to WIFI converter. Quark do one for <£100. It can work via a router/access point.

I don't know enough about your SatComs to know if it is an access point or can be one. Or you need something else as well.

A RasPi would be another option... Adding a second WiFi adaptor if required to bridge the sat Comms. But... I'd want as much cables as possible. But the Pi can be the multiplexer and the Access Point / Bridge etc.

 

[prv]

could I plug both satcom and AIS into a WAP/ router using ethernet cables and then let that provide wifi to the ipad ?

I thought your Inmarsat terminal already created a WiFi network?

Pete

 

[Chris Edwards]

It can do either.
The ipad can only work on one wifi source at a time I believe, so if its associated with the satcom wifi, it cant work off the ais derived one and vice versa ?

The crux of the problem and something not directly addressed so far, is how do I feed two sources i.e. satcom and ais into one ipad without writing code or making stuff - Im looking for pluggable readily available hardware solutions.

I thought your Inmarsat terminal already created a WiFi network?

Pete

 

[fifer]

Can all the wifi devices be configured to run in station mode as well as as Ad Hoc wifi access points? If they can, then you choose one single wifi AP and configure the others to connect to that AP. If doing this it might be useful to use a RPi with openplotter as the "master" to multiplex any nmea data.

 

[Chris Edwards]

Not as far as Im aware.
Nothing in the menu or handbook that suggests this is possible.

Can all the wifi devices be configured to run in station mode as well as as Ad Hoc wifi access points? If they can, then you choose one single wifi AP and configure the others to connect to that AP. If doing this it might be useful to use a RPi with openplotter as the "master" to multiplex any nmea data.

 

[prv]

It can do either.
The ipad can only work on one wifi source at a time I believe, so if its associated with the satcom wifi, it cant work off the ais derived one and vice versa ?

So don't create yet another WiFi network for the AIS - that would be making things more difficult and complicated for no readily apparent reason. Just have it join the network created by the Inmarsat terminal, either using WiFi or, if the Inmarsat bridges between its WiFi and Ethernet sides, by plugging it into the ethernet socket.

The crux of the problem and something not directly addressed so far, is how do I feed two sources i.e. satcom and ais into one ipad

That's not the problem - if Inmarsat, AIS, and iPad are all on the same network then they can all talk to each other by default, that's what a network is. You just need to tell whatever-it-is that's converting the AIS data from serial into (presumably) UDP packets, where to send those packets.

The problem you originally posed was about "combining" networks, because you have a radar and an Inmarsat terminal that both insist on being a wireless access point and creating two separate networks, and even if you set up a bridge from one to the other you also need to ensure that there's no more than one DHCP server (both access points will probably be running one by default), that said DHCP server tells its clients that the Inmarsat is the default gateway (or, that something else is and that thing knows to route via the Inmarsat), and that whatever the radar and its app do still works. If it were a Navico radar that would be an RFC 3927 address for control and a UDP multicast group for the data, but I suspect yours might be a Furuno and I have no idea how they work. That's why it would be useful to have a look at the traffic using Wireshark to understand what's going on and set things up so it will work.

But you seem to have stopped considering the radar side of the problem?

Pete

 

[Chris Edwards]

In hindsight and from practical experience now, Ive got the radar running on a different and dedicated ipad so thats out of the equation now. It doesnt need access to the internet or any other prgrams or sensors to do that.

My amended “problem” is as per the later posts.

Are you saying I can plug the AIS converter (which Ive yet to identify/source) into the POE port on the satcom ?

So don't create yet another WiFi network for the AIS - that would be making things more difficult and complicated for no readily apparent reason. Just have it join the network created by the Inmarsat terminal, either using WiFi or, if the Inmarsat bridges between its WiFi and Ethernet sides, by plugging it into the ethernet socket.



That's not the problem - if Inmarsat, AIS, and iPad are all on the same network then they can all talk to each other by default, that's what a network is. You just need to tell whatever-it-is that's converting the AIS data from serial into (presumably) UDP packets, where to send those packets.

The problem you originally posed was about "combining" networks, because you have a radar and an Inmarsat terminal that both insist on being a wireless access point and creating two separate networks, and even if you set up a bridge from one to the other you also need to ensure that there's no more than one DHCP server (both access points will probably be running one by default), that said DHCP server tells its clients that the Inmarsat is the default gateway (or, that something else is and that thing knows to route via the Inmarsat), and that whatever the radar and its app do still works. If it were a Navico radar that would be an RFC 3927 address for control and a UDP multicast group for the data, but I suspect yours might be a Furuno and I have no idea how they work. That's why it would be useful to have a look at the traffic using Wireshark to understand what's going on and set things up so it will work.

But you seem to have stopped considering the radar side of the problem?

Pete

 

[prv]

Are you saying I can plug the AIS converter (which Ive yet to identify/source) into the POE port on the satcom ?

Assuming the satcom passes traffic from that port onto the WiFi network, which seems likely but not guaranteed, then yes.

Pete