Mesh networking for laptops, pda, etc

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Mesh networking for laptops, pda, etc

Post by jamoni » Wed Dec 20, 2006 3:40 pm

Since just about everyone I know has a wifi enabled device of some sort, I'm wondering about the uses of mesh networking in a survival setting. Specifically, I'm thinking of vehicular use, where a mobile network could be used to track other vehicles, provide maps, video, pics, situation logs etc. to other vehicles in a convoy. You could also share a VOIP link, satellite internet, or some other wireless internet connections. I don't know if there would even be any real usefulness to something like this, but it sure would be cool, right? :D
http://www.instructables.com/id/EQARE4I ... /?ALLSTEPS
http://www.turnpoint.net/wireless/has.html
Etc. Directional, but still cool.
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Post by zXzGrifterzXz » Wed Dec 20, 2006 6:36 pm

Tell Kbar to get working on that for the ZS van.
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Post by Aeon » Wed Dec 20, 2006 7:46 pm

(Yay a subject i can speak proffesionally and fluently about)

Creating a mobile WLAN is easy, cheap and is an exsessivly fun way to keep in touch, much like CB radio (which ill drone on about in a minute) all you need is a laptop (PDA's arnt really suited for creating networks it uses up too much of their already limited power reserves. An Antenna (which needs careful planning) and enough power to boradcast to the other vehicles.

It all depends upon how far away your wanting to be; if its for a squadron who'll never get further than a few hundred meters of one another then its an ideal solution for sharing data on:

Local Information (where the Hopsitals and Supermarkets are)
Mapping Info on the terrain
General intelligence through VoIP or more simpler methods (Net Send)
An internet connection or better yet an Intranet connection
Etc, etc, etc.
All this data could also be relayed from the mobile units to the main base of ops.

If you need a high bandiwdth connection between all vehicles your pretty much gonna be stuck to within 100 meters max,that'll get you (with the best 802.11n tech) ~30MBitps which is enough to send images, video, streaming media or plain text over.

If you need long distances than your best bet is to adopt a different approach; by using one vehicale as a mobile command centre, you can rigg it with an omnidirectional antenna and a high power transciever which you can then connect to your peripheral of choice to send your data, which allows for a good range in all directions but bandwidth decreases with distance from the MCV. This is called the extended star network, as there is one central point and many devices connected in series to this point in many different directions. To tackle this bandwidth problem each separate truck/car/motorbike could carry its own wireless repeater (which acts in much the same way as a CBor Ham repeater). This should boost overall network coverage and performance by a factor of 4 (dont ask why it take ages to explain and several annoying calculations).

Before any of this is possible theres the whole concern about power, if your going to go for a centralised network running on an extended star, its going to require a lot of power for 1) your MCV to supply enough power to the antenna (which im getting to) to achieve an effective range and 2) Each of the repeaters (if any) also require their own pwoer supplies and are greedy beggars at that.

Using the extended-star network has a major downfall, it represents what we call a single point of failure. If the central MCV goes down your network nodes are left stranded. However it is the most cheap and is highly scalable, meaning many devices can be added before the topology needs to be revised.

Im not an expert in CB/Ham comms (...yet) but i do beleive it is possible (while im sure isnt legal) to modify the radio transciever to transmit data, this would provide a much more stable network, with almost double or tripple the coverage. That being said we dont condone illegal behaviour so dont do it.

Whichever option you choose for your mobile network, its a great way to share data on the local surroundings and would make logistics a hell of a lot easier. It would be a good idea if not entirly practical which would help members keep in contact, share intel on the whereabouts of survivors, threats, resources. Which, in all fairness, a radio could do just as easily, but isnt as secure.

But im rambling again, i can go off on such tangents sometimes. I do this day in day out so if anyones got any questions on it PM me and ill be more than happy to dicuss it with you.

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Post by BejamminR » Wed Dec 20, 2006 9:31 pm

Orion wrote:Im not an expert in CB/Ham comms (...yet) but i do beleive it is possible (while im sure isnt legal) to modify the radio transciever to transmit data, this would provide a much more stable network, with almost double or tripple the coverage. That being said we dont condone illegal behaviour so dont do it.
I know it can be done, although I don't know how yet. And as far as I'm aware, it's perfectly legal in North America at least, provided that the data you're transmitting isn't obscene or illegal.

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Post by jamoni » Wed Dec 20, 2006 11:15 pm

Damn, I love zombie squad. thanks Orion!
For power, we re looking at kitting out the van with an upgraded alternator and a battery bank. That should do it. I'm considering a similiar mod for my jeep, so I can run a mobile ham unit while powered down, and for charging cordless tools, etc.
I'm going to have to look into ham/packet radio stuff.
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Post by Aeon » Thu Dec 21, 2006 7:32 am

How rude of me, i never went over atenna types:

Directional (pringles can/makeshift dish) these are usually for fixed position networks, they allow a reasonable coverage whilst not using too much power but only in one set direction, the bandiwdth also decreases rapidly with incrased distance from the antenna.

Omni-Directional (standard stick antenna) are great if you want to cover the area immediatly all around you, but as such offer limited coverage distance and bandwidth drops dramaically. Even if more power is provided you get a doughnut effect, the area immediatly around the antenna recieves no coverage than as you move further away coverage becomes stronger until signal attenuation kicks in.

Bi-Directional: these are the same as omni-/directional save they only broadcast in opposite directions which incrases range and bandwidth. But as they are "blinckered" it does mean you get tunnel vision coverage and you have to line all your nodes up in a column. If you're wanting to set up a connection between 2 bases then these can make good bridges, each direction faces toward the last antenna, whilst the opposite side shows you where the place the next antenna, this is a fairly reliable setup though if one dies then the neworks are segmented once more.

Yagi: (My personal best) Is an antenna which focuses the signal into a single beam (wide or narrow which can be adjusted by yourself). A wide beam get more coverage (even to the same point an a directional antenna) yet looses bandwidth with distance. A shorter beam acts more or less like a searchlight and can carry the signal much much further (even miles if the tarrain is right), as such it provides coverage only where the signal is aimed at. This is widly used as a media between buildings accross towns, when two are iamed at one another they create a reliable bridge between internal LAN's with a high throughput and yet half the power requirments of using many riectional or bi-direcitonal antenna to reach the same distance.

Again im babbling; sorry guys, CCNA talking.

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Post by hellion » Wed Dec 27, 2006 2:14 pm

If you just wanted a simple convoy network, it could easily, and cheaply be achieved by a $30 power inverter, and a laptop per vehicle, and the vehicle in the middle would need a slightly larger power inverter and a wireless router.

It'd be a basic peer to peer network, but if you know what your doing, for your application, you would all be connected. You could really get into it with beefing up the central cars power system with more batteries and a heavy duty alternator and put a domain server, and hook each vehicle's computer up to that, which would give you greater structure but add a lot more to cost and power consumption.

If setup right, you could easily setup something like Teamspeak (http://www.goteamspeak.com/) with a server on one, and clients on all, and you could effectively have cheap (cost of microphones/headsets) VOIP communication between all.

If you had a server, you could run ArcGIS StreetMap software, and each client could have access to detailed street maps drawn, sat, or hybrid for all of north america (think of google maps, but 10 times better). However that software is by no means cheap.
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Post by Givens » Wed Dec 27, 2006 3:50 pm

I thought about the pringles can antenna, they seemed a bit chincy though. But, as I'm always wandering around my house trying to find a strong enough signal to pirate... the strainer looks like a sweet option. That's a project soon coming! 8)
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Post by AwPhuch » Wed Dec 27, 2006 5:36 pm

Guys...why do all that!!!

http://www.wlanparts.com/

They sell ultra power AP/Routers...high gain omni antennas

I got this link from some guys building Wifi nodes spanning 40+ miles in Australia....and if anyone knows how to build a HUUUUUGE wifi network its the aussies!

Such as this
http://www.wlanparts.com/product/ZWA-G192-ZP2419ENC
19db gain weatherproof directional antenna w/ 200mW AP built in!

High power mini-pci wifi card
http://www.wlanparts.com/product/SR2 400mW!!!!!!!!!!!

They even have a pre-built and pympin wardriving kit
http://www.wlanparts.com/product/WDNL2511CDPLUSEXT2
Long operating range, up to three times range of standard products
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Post by Aeon » Wed Dec 27, 2006 6:30 pm

AwPhuch wrote:Guys...why do all that!!!

http://www.wlanparts.com/

They sell ultra power AP/Routers...high gain omni antennas

I got this link from some guys building Wifi nodes spanning 40+ miles in Australia....and if anyone knows how to build a HUUUUUGE wifi network its the aussies!

Such as this
http://www.wlanparts.com/product/ZWA-G192-ZP2419ENC
19db gain weatherproof directional antenna w/ 200mW AP built in!

High power mini-pci wifi card
http://www.wlanparts.com/product/SR2 400mW!!!!!!!!!!!

They even have a pre-built and pympin wardriving kit
http://www.wlanparts.com/product/WDNL2511CDPLUSEXT2
Long operating range, up to three times range of standard products
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Router, Bridge or Access Point
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Wireless Security: WPA(TKIP) WPA2 (AES), 802.1x, MAC (via RADIUS)
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Power Supply Requirements: Power over Ethernet : +48VDC
Antenna Connection: MMCX
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*Sigh* lets start from the top shall we:

Bridges are used to connect two networks together, you'd actually need 2 networks to begin with. Likewise Access Points (AP's) are simply wireless nodes you would use to extend the coverage of your current wired network by transmitting over the air. Routers are secure and reliable but power hungry and for the data that your mobile platoon will be sharing hardly seems nessessary, i mean who's gonna be trying to hack your wireless network when they're running form zombies.

In the mean time however:
The problem with the 802.11 standard is that whilst being very good at connecting various devices over a relativly small area, they tend to encorporate some rather large flaws into the technology each time they add an extension to the standard, mainly security cracks and the inability for them(the 802.11 standards) to compensate for the rapid connection and disconnection of devices.
Which brings us onto our security, WPA (WiFi Protected Access) is easily crackable, RADIUS (Remote Authentication Dial In User service) authentication requires there to be a RADIUS server connected to the network which is (in a PAW situation) both resouce consuming and a waste of space. The rest i can't find much wrong with beyond the lack of throughput.

...Oh and no matter what antenna you think you might use 2.4GHz on a Broadrange STP (for redundancy) connection is only gonna get you so far, and will certainly not like the random interconnectivity when your vehicles move in and out of range.

That being said the company seems to be offering a fairly good service, I'd just be careful to make the distinction between what they're telling you the very expensive equpitment can do and what it can actually do. I've seen a few companies in some serious debt because the infrastructure they invested in is totally unsuited for their requirements and cost them a bomb. If your going mobile you need 3 main things:

Range,
Interoperability,
Scalability,

Which are all affected by the types/amount of data you need to send/recieve. I'll compile a list of requirements and get em posted when ive got a free week :wink:

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Post by Aeon » Wed Dec 27, 2006 6:32 pm

Sorry guys, i get a lil enthused when theres a networking problem at hand, can get to my head. I'm assured its a positive personality flaw that needs a few rough edges grinding :lol:

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Post by AwPhuch » Wed Dec 27, 2006 7:15 pm

NO WEP is crackable...WPA is much much more hard to break thru

And I guess you have never heard of
MadWifi
or
WDS - Wireless Distribution System
or
Wireless mesh network

But its designed to increase the coverage of wifi by using multiple nodes...

like roofnet
or
http://www.netequality.org/
http://www.roofnet.net/
Our first access device is the Meraki Mini, a small indoor 802.11b/g access point designed for mesh networking. Each Mini covers a radius of 150 to 500 feet. Networks containing dozens of Minis can provide seamless indoor coverage across entire apartment complexes and neighborhoods.
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Post by Aeon » Thu Dec 28, 2006 7:04 am

AwPhuch wrote:NO WEP is crackable...WPA is much much more hard to break thru

And I guess you have never heard of
MadWifi
or
WDS - Wireless Distribution System
or
Wireless mesh network

But its designed to increase the coverage of wifi by using multiple nodes...

like roofnet
or
http://www.netequality.org/
http://www.roofnet.net/
Our first access device is the Meraki Mini, a small indoor 802.11b/g access point designed for mesh networking. Each Mini covers a radius of 150 to 500 feet. Networks containing dozens of Minis can provide seamless indoor coverage across entire apartment complexes and neighborhoods.
Actually i think you'll find both WEP and WPA(Inclusive of PSK) are easily crackable given time and the right tools to gather runt packages containing segments of the security key, trust me, i've done it whilst doing my CCNA during which i covered WDS, WiMAX, Aeronet and several other technologies availible.

And i'm not sure you understand my point;
I am not aruging that you could not create a network, i am weighing up the pro's and con's given the availible technology in an emenrgency situation. It dosn't matter whether or not you're using a mesh topology with wSTP or a line-of-sight microwave link, it is all power consuming and for what you'll be using the network for is a waste of resources, a CB or Ham radio network is much more power efficient. The maintainance alone would robb you of a large portion of human resouces and power. Lest we forget that for these networks to be implemented many of your suggestions would require a permenant base of operations (RADIUS network), after time any mobile unit would exhaust towns to scavange/people to save which leaves the unit moving out of your network area whether meshed or not.

Some of the technologies you have highlighted whilst being highly advantageous to todays safe environments which have preestablished networks ready for expansion. Many of both of our suggestions would simply not be viable in an emergency situation and certainly not sustainable in a PAW. I think we need to discuss the types of information we would need to share or access before hyped up hybrid topologies and supercharged yagi antennas are boasted first.

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Post by hellion » Thu Dec 28, 2006 4:44 pm

wifi is easy to crack, no matter how high the encryption or type, all it takes is a laptop, the right network card, some software and traffic over the wifi network
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Post by jamoni » Thu Dec 28, 2006 7:13 pm

Orion wrote:
AwPhuch wrote:NO WEP is crackable...WPA is much much more hard to break thru

And I guess you have never heard of
MadWifi
or
WDS - Wireless Distribution System
or
Wireless mesh network

But its designed to increase the coverage of wifi by using multiple nodes...

like roofnet
or
http://www.netequality.org/
http://www.roofnet.net/
Our first access device is the Meraki Mini, a small indoor 802.11b/g access point designed for mesh networking. Each Mini covers a radius of 150 to 500 feet. Networks containing dozens of Minis can provide seamless indoor coverage across entire apartment complexes and neighborhoods.
Actually i think you'll find both WEP and WPA(Inclusive of PSK) are easily crackable given time and the right tools to gather runt packages containing segments of the security key, trust me, i've done it whilst doing my CCNA during which i covered WDS, WiMAX, Aeronet and several other technologies availible.

And i'm not sure you understand my point;
I am not aruging that you could not create a network, i am weighing up the pro's and con's given the availible technology in an emenrgency situation. It dosn't matter whether or not you're using a mesh topology with wSTP or a line-of-sight microwave link, it is all power consuming and for what you'll be using the network for is a waste of resources, a CB or Ham radio network is much more power efficient. The maintainance alone would robb you of a large portion of human resouces and power. Lest we forget that for these networks to be implemented many of your suggestions would require a permenant base of operations (RADIUS network), after time any mobile unit would exhaust towns to scavange/people to save which leaves the unit moving out of your network area whether meshed or not.

Some of the technologies you have highlighted whilst being highly advantageous to todays safe environments which have preestablished networks ready for expansion. Many of both of our suggestions would simply not be viable in an emergency situation and certainly not sustainable in a PAW. I think we need to discuss the types of information we would need to share or access before hyped up hybrid topologies and supercharged yagi antennas are boasted first.
Makes sense to me. Someone in the "Surprised it took them so long" thread made a similiar point. There is no reason to use power hungry broadband technologies to say "We are over here, we need some bullets" when you can pick up a radio and say the same thing.
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Post by AwPhuch » Thu Dec 28, 2006 7:29 pm

hellion wrote:wifi is easy to crack, no matter how high the encryption or type, all it takes is a laptop, the right network card, some software and traffic over the wifi network
You have done this personally...or just repeating the mantra by all the "gurus" that have heard its hard but havent done it themselves...I guess you also dont realize that you can run an enctypted tunnel inside that WEP using such software as "OpenVPN" so yah..you can strip the outer layer..but good luck getting to the encrypted tunnel inside

99% of all the so called "gurus" get blocked by a simple WEP...besides, most people leave thier wireless wide open cause they are ignorant of wireless security

P.S. It takes a few hours to get enough packets to break the encryption...WEP can be broken, WPA changes its key on a rolling basis..so its much much much much much much much much harder to break
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Post by Aeon » Fri Dec 29, 2006 6:29 am

AwPhuch wrote:
hellion wrote:wifi is easy to crack, no matter how high the encryption or type, all it takes is a laptop, the right network card, some software and traffic over the wifi network
You have done this personally...or just repeating the mantra by all the "gurus" that have heard its hard but havent done it themselves...I guess you also dont realize that you can run an enctypted tunnel inside that WEP using such software as "OpenVPN" so yah..you can strip the outer layer..but good luck getting to the encrypted tunnel inside

99% of all the so called "gurus" get blocked by a simple WEP...besides, most people leave thier wireless wide open cause they are ignorant of wireless security

P.S. It takes a few hours to get enough packets to break the encryption...WEP can be broken, WPA changes its key on a rolling basis..so its much much much much much much much much harder to break
I think you're getting a little hung up on security here, the point has changed to:

Is a computer based network more/less efficient for what your going to use it for than a radio one?

No need to start arguing semantics of tunnel/less VPN's in a PAW, there'd be no-one left to hack it, not that they'd want to anyway!

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Post by AwPhuch » Fri Dec 29, 2006 5:52 pm

Exactly..but any time you talk about Wifi..the naysayers come out of the woodwork!

I have seen the video of the guys shooting a wifi signal over 125 miles...and I am sure with a few daisy chain repeaters you could run wifi internet out there really far

With a PAW or ZPAW if you had to have communication after everything a wifi grid would be good to have

Plus eventually humanity will come back, and being able to communicate over long distances would really really really help speed up growth and rebuilding...computers/radios will play a HUGE part of this process

Who says you have to use 2.4GH either...they have 900Mhz wifi too

P.S. It would take massive massive massive effort to rebuild standard communications lines..however radios would be easier to impliment..plus even a weak old beat down computer can be used to create a HUGE VOIP phone network!
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