When an Internet connection has to be set-up and shared in a location without any Internet infrastructure, D-Link's DIR-451 will come in handy. It's a 3G router that can distribute a 3G signal over its four-port 10/100 Ethernet switch or 802.11g wireless access point.

You can't use it to distribute an ADSL connection—it's purely a device for plugging in a data card that will access the Internet over the 3G mobile phone network. It will accept 32-bit PC Card-based UMTS and HSDPA data cards only. Users with newer ExpressCard-based data cards will have to look elsewhere.

Setting up the router is a relatively simple exercise: plug in your data card, switch on the router, and go through the wizard to select your network details. Of course, the Internet bandwidth available will vary depending on the location you're in, but in areas with a strong signal, many users will be able to check e-mail and browse the Web comfortably.

Once your Internet connection is up and running, the DIR-451 is a standard router: it has a DHCP server, network address translation, network filtering and port forwarding. Encryption for data travelling over the wireless network can be implemented using WEP, WPA or WPA2 (TKIP and AES) and the router does have a built-in active firewall, as well as VPN passthrough options (PPTP, L2TP and IPSec).

Its wireless access point supports Super-G transfer rates, so you can get reasonably fast transfer rates over short distances (approximately 3MBps) when copying files across the local area network. In 802.11g mode, the wireless signal will be usable at up to approximately 20m, but this will depend on the physical environment.

Because it can be set-up to provide Internet and network access at remote locations, it's ideal for travelling business users and also for temporary set-ups, such as outdoor exhibitions or even building sites. It doesn't ship with a car adapter, so contractors hoping to set-up mobile Internet access while on the road might have to find another solution or get their own adapter.