Kyocera KI-G100/SD-66K

Along with the Internet, mobile phones represent one of the biggest growth industries of the past decade. Mobile phone coverage has become so widespread that you're likely to find a GSM signal in almost every town in the world.

This is all well and good, but if you're not travelling to a town, or even to an inhabited area, your GSM mobile phone won't do you much good. You could be hiking in the Himalayas or trekking through the Amazon, where mobile phone coverage is needed but sadly lacking. However, there's an answer to this problem and it's called the Iridium network.

Unlike standard mobile phone networks, Iridium doesn't use cells to keep in contact with all its users. Instead, it has a network of 66 satellites that beam the signal to and from its phones. This means you can use an Iridium phone almost anywhere on the planet, making it ideal for adventurers.

Of course, the situation isn't perfect. Because you are beaming a signal to a satellite, you need to have line of sight to the sky. An Iridium phone won't work if you're inside a building, unless you can point the aerial out of a window.

One of the first companies to produce a phone using the Iridium standard is Kyocera. The company is more commonly known for making printers, so this is quite a departure. That said, it has done a fine job of implementing this new technology. Although Kyocera produces an Iridium-only phone, we decided to look at its Iridium/GSM combo unit.

This package comprises a KI-G100 GSM mobile phone and an SD-66K Iridium unit. The beauty of this solution is that you can use the GSM phone separately when you're in an area with coverage, then slip it into the Iridium unit when you aren't.

Considering that GSM phones are getting smaller and sexier all the time, Kyocera has done a good job with the KI-G100. It measures 41 x 130 x 25.5mm (W x H x D) and weighs only 105g. It offers approximately two hours' talk time and 70 hours' standby. It boasts all the usual mobile phone features and has a useful jog shuttle for scrolling through your address book and options.

The phone uses the GSM 900 standard, which gives you coverage in almost every country with the exception of the US. For some reason the Americans decided to launch their GSM network on the 1900 standard, used by no other country in the world.

If you find yourself without GSM 900 coverage, as I recently did while in Las Vegas, you can slip the KI-G100 into the SD-66K unit and use Iridium instead. Once the two units are joined, it looks similar to the early brick-sized mobile phones. Although you can use a specific Iridium SIM card, if you have a Cellnet GSM SIM card in the KI-G100, you can use that to make calls on the Iridium network as well.

In use, Iridium wasn't perfect. It generally took about 10 dropped calls before a connection was actually made. Once the call was put through, though, the sound quality was every bit as good as a standard GSM call. Although standing on the streets of London or Las Vegas watching call after call being dropped wasn't much fun, if I was stuck in the jungle and needed help, a few dropped calls would be a small price to pay.

Call charges vary from the country of origin and range from $1.18 (72p) to $2.74 (£1.67) per minute of call time.

The Iridium module comes complete with two lithium ion batteries and a smart little remote vibrating buzzer. This is particularly useful if you've got lots of heavy-weather clothing on and you can't hear the phone ringing. If you place the small buzzer near your body, when the phone receives a call it will vibrate to alert you.

On the whole Kyocera has come up with a great product. The market for this type of equipment may not be huge, but if you find yourself out in the wilderness, it's exactly what you need.

Contact Kyocera 0118 923 0789