Take the 2-minute tour ×
Server Fault is a question and answer site for professional system and network administrators. It's 100% free, no registration required.

A very long time ago, I had to build a LAN for a bunch of laptops, in a couple of tents. We ended up bringing a bunch of generators, stringing about 2 miles of networking and power cables, and generally having very little fun - mostly trying to keep alive a wireless radio link to the Internet.

Fast forward to now.

I'm worried that I'll be forced to set up another LAN in the woods. But I was thinking that perhaps since laptops have longer lives, and what with WiFi - I might be able to dispense with most of the cabling, maybe just set up one generator, which would mainly serve to power the router I'll have hooked up to a cellular link.

Has anyone else done something like this? Ideas? Advice?

I'd like to get rid of the generator entirely (since it's the most expensive item I'll need to rent), but I don't think I can. Is there a way?

share|improve this question
    
How is this different to "programming at sea"? –  Guy Apr 30 '09 at 14:40
    
Programming at sea involves ONE computer slightly off-the-grid. This involves setting up a network at the edge of the grid. –  Scottie T Apr 30 '09 at 15:17
3  
One thing to keep in mind is that normal "wifi" is 2.4ghz...which is also the frequency that causes water to absorb the waves and vibrate...and what's in tree leaves? water. You'd be well off if you could find some non-2.4ghz gear if you're not going to have line of sight in the woods. –  Matt Simmons Jul 20 '09 at 16:47
    
@Matt: You're being silly, right? Because by that same token, 2.4 GHz should also make the water in your body boil. And it doesn't. –  Ernie Jul 20 '09 at 16:57
3  
@Ernie, he's saying that the leaves will absorb the signal, not that it will boil or anything.... –  Tatas Jul 20 '09 at 17:34

8 Answers 8

There's been much mention of inverters and such for powering the router. From an efficiency standpoint there's likely an even better approach considering the actual power you need.

Most SOHO routers are supplied with DC under 12 volts, so you would gain by getting an adequate converter/regulator to go from standard automotive 12 volts (usually 13.8v) to the appropriate input voltage (likely 9 volts). This would probably save you a lot of juice simply not having the chain of voltage conversion and de/modulation (i.e. 13.8vDC => 120vAC => 9vDC).

What about some 9 volt power tool batteries wired up in parallel? You could probably run a solid state device for quite a while considering those batteries are designed for high draw motorized tools. I remember my dad used to run our first VHS video camera on Makita batteries.

share|improve this answer
1  
+1 absolutely true. I'd have to fiddle with the wiring, but a good idea is a good idea! –  scraimer Apr 30 '09 at 20:42
    
Beats my invertor answer as long as you can produce the wiring. –  Stevo3000 May 7 '09 at 8:21
    
There's also the question of "how will it get there". Lead-acid batteries are bloody heavy. If you're going to carry them in your truck, you might as well use the cigarette lighter for your 12v source. And there's lots of places you can get voltage converters from that source. Alternatively, you can use 12v solar panels, assuming you can get some sunlight through the trees. You wouldn't need a very large array to power a router, but the laptops would be a different story. –  Ernie Jul 20 '09 at 17:02

How about a battery powered wireless router:

http://www.cradlepoint.com/products/phs300-personal-wifi-hotspot

Some spare batteries pre-charged and you will be good to go. No wires needed - at all.

share|improve this answer
1  
+1 Oh, kick ass! –  scraimer Apr 30 '09 at 20:42

Have you investigated solar panels (with a battery)? a wireless router doesn't pull that much juice, so you might be able to tie a solar panel into a 12v battery, and power the router off of that. It would also be silent, which might be a plus, depending on your reasons for building a network in the woods.

A few weeks after writing this answer, I cam across this link to Popular Science, detailing how to do just this.

share|improve this answer
    
+1 excellent idea. I think I saw some 2w solar cells going for 2-3 US dollars on ebay... could be a very nifty idea in the summer! –  scraimer Apr 30 '09 at 20:41

Freeplay Energy sells a product called the Weza which is a foot powered charger with battery. It has a 12v adapter that you might be able to plug into with a converter.

I'm not sure about Windows but if you use a Mac you can get a 3G connection and then use Network Sharing through WiFi to create an AdHoc network. This is how we do roaming demos sites. We use one Mac as the 3G up-link machine and the others connect to it over WiFi.

share|improve this answer

If you have line of site you can go quite a long way with standard wifi equipment. Look at what these guys have done as an example.

share|improve this answer

I recently watch a couple episodes of Systm on Revision3 that showed methods for power needs.

The first is creating a 48hour UPS using car batteries. Hacked UPS

The second is funny, but at the same time shows what could be done with human power. Human powered hamster wheel

Combine the power with a Wifi router and you're in business. For internet access there are several Wifi routers that can connect via the Cell towers.

If you have a Windows Mobile phone with high speed and Wifi you can use WMWifiRouter to create a lan.

share|improve this answer

Not sure how deep (and how high) in the woods you are, but you might be able to skip the "hops" in the middle by using a directional antenna to hit a distant cell tower. This page talks about using a Yagi antenna to boost cellular signal.

share|improve this answer

Car battery(s) and an inverter. This would depend on how long the network was required for and how many batteries you could procure.

For a description of an inverter look at Wikipedia.

Just think of it as a big home brewed UPS (but a damn site cheaper).

share|improve this answer
    
Really? An invertor? This sounds kinda dangerous... –  scraimer Apr 30 '09 at 13:21
    
Inverter (typo had it as invertor). Very safe, used more frequently than you would think. All it does is convert DC to AC. –  Stevo3000 Apr 30 '09 at 13:26
    
Oh. kewl :) –  scraimer Apr 30 '09 at 20:40

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.