Get almost-free Internet access to your laptop at any time

Get almost-free Internet access to your laptop at any time, from anywhere, using your mobile phone as the data modem. No WiFi coverage is needed!

As a business traveler, I've always longed for Internet access on the roadnot only for my mobile phone, but also for my laptop. After all, it's much more convenient to compose email and browse the Web on a laptop than on a phone. A killer mobile phone application for me is to use the phone as a data modem to hook my laptop to the Internet anytime, anywhere. It complements public WiFi networks, and helps me to get around the limitations of WiFi hotspots!

While WiFi networks have made great progress in providing public wireless Internet access, the mobile phone data network still offers several notable advantages when it comes to business users. First, WiFi hotspot coverage is still limited. For instance, typically there is no WiFi coverage in parks, in many government facilities, or at highway rest areas. The mobile phone data network, on the other hand, is ubiquitous. It is available in most cities and along major highways. This always-on feature is a major selling point for business travelers.

Even in places with WiFi coverage, the network is often commercial and requires a per-use fee. For instance, different commercial WiFi networks might be installed in the coffee shop around the corner, in the bookstore, in the hotel, and in the airport. So, if you travel to several of these places in one day, you might need to pay tens of dollars in WiFi access fees. The mobile phone data network, on the other hand, is operated by national operators. You know exactly what you need to pay for data access each month.

Today's wide area mobile data networks are built on several different technologies. Which network is available to you depends on your device, location, and service plan. In general, the faster data networks (e.g., UMTS, 1xEV-DO, and EDGE) are more expensive to use and more limited in coverage when compared with slower and more ubiquitous networks, such as General Packet Radio Service (GPRS).

Most mobile network operators offer special data service plans for laptop computers these days. Those plans give you prorated bandwidth of wireless data, or even unlimited access for a flat monthly fee. You can simply purchase a GPRS or EDGE wireless card and plug it into your laptop. The wireless card requires a valid SIM card from the operator to authenticate the laptop to your service account on the network. Those special data plans do not include any voice minutes.

As an alternative, you can do a SIM-swap with your mobile phone, if you have a data plan that is designed to work with PC cards. For example, T-Mobile's inexpensive, unlimited data plan ($20 per month with most voice plans, $30 otherwise) will work great with the very low-cost Merlin G100 data card, which you should be able to find on eBay for less than $50. Although the companion software is Windows only, most Merlin G100s will work out-of-the-box with Mac OS X and Linux, appearing as serial ports that you can configure to dial the same number (*99#) you'd use with your phone, as shown later in this hack.

When you want to dial out using the data card, swap the SIM card out of your phone and into the card, and swap it back when you're done. As an added bonus, no one will be able to bother you by phone while you're online!

However, if you are a casual and budget-minded wireless data user like I am, the dedicated wireless card and a data-only service subscription, in addition to your voice service, are probably a little too expensive. Instead, you can simply add GPRS or EDGE Internet service to your existing mobile phone service plan and then share the connection from the phone to the laptop computer. This is also known as tethered Internet access. Once connected, you should be able to use the laptop to browse the Web, check email, and telnet/ssh/ftp to other sites.