My N900 has a SIM card with a flat-rate 3G data plan. My laptop hasn’t.
What do I do when I want to use the Internet on my laptop somewhere that
doesn’t have WiFi? Well, there are many options:
Option 1: N900 as a USB modem
Use the provided USB cable to connect the N900 to the laptop. Choose “PC
Suite” mode on the N900 when you get the USB connection menu. The laptop
now sees your N900 as a bog-standard USB 3G modem. Use Network Manager to
connect to the internet.
Pros: no extra setup required. The N900 and the laptop can both access
the Internet at the same time.
Cons: you have to use a USB cable (I hate cables). You cannot ssh into your
N900 (and ssh is my primary file transfer protocol between the laptop and the
Option 2: N900 as a Bluetooth DUN modem
Install Bluetooth DUN
support from Maemo Extras. Then use it like you would any other phone
that has Bluetooth DUN.
Pros: no cables.
Cons: Bluetooth is the worst technology ever. I never had it
work reliably. Plus, Network Manager in Ubuntu 10.04 doesn’t support
Bluetooth DUN (it supports only Bluetooth PAN, as far as I know).
Option 3: N900 as a WiFi access point with Joikuspot
I haven’t tried this.
Pros: simple (hopefully), no cables required.
Cons: Joikuspot is non-free. I’m not an absolute zealot, but I will
avoid closed-source stuff when open-source alternatives are available.
Option 4: N900 as a WiFi access point with Mobilehotspot
I haven’t tried this either.
Pros: it’s an open-source app available from Maemo Extras. No cables
Cons: requires a non-standard kernel (or so I’ve heard). Way outside my
Option 5: N900 as a WiFi access point with shell scripts
Here’s the shell script I run on my N900: share-wifi. It sets up an ad-hoc WiFi
network, and starts a DHCP and DNS server (dnsmasq). Sadly, it cannot set up
connection sharing (NAT), so I rely on OpenSSH as a SOCKS5 proxy. The whole
setup is like this:
- You want the latest firmware (PR 1.2) to avoid this bug.
- You need to have OpenSSH installed on
the N900. Also, setting up key-based authentication makes it more
- The script assumes that you’ve set up sudo on the N900 so that you
can run any command as root.
- You need to have wireless-tools
installed. It’s in the main SSU repository so you should be able to sudo
apt-get install it (if it’s not preinstalled; I don’t remember).
- On the N900 run share-wifi in a terminal (optionally passing a
WiFi channel number from 1 to 11, in case you need to avoid interference with
- On the laptop connect to the new n900 WLAN and run
ssh -D 1080 [email protected]. You will get a shell session; the SOCKS proxy
will be active while it is open.
- Reconfigure your laptop to use a SOCKS5 proxy on localhost:1080.
For GNOME systems I’ve a couple of shell scripts: proxy-on and proxy-off. For applications
that do not use the GNOME proxy settings (such as Subversion access
over SSH), use tsocks.
- When done, hit Ctrl-C on the N900 to terminate the sharing script.
Pros: no non-free software or custom kernel required. No cables.
Cons: complicated to set up. No WLAN power savings available for ad-hoc
networks, so battery life is extremely poor (~2 hours). But, hey, no