Such as this one used by the Red Cross

Imagine that your entire city was covered by a high-speed wireless network. That means cheap (if not free) VoIP calls wherever you go. In England, a company called Hutchinson 3G (or simply 3) has partnered with the popular VoIP service Skype to introduce the 3 Skype phone. The Skype phone allows users to make free cell phone calls to other Skype users. The phone can also make regular cell-phone calls to non-Skype users for the normal fees. Here’s how it works: To make a Skype call using the 3 Skype phone, you have to be on 3’s cellular network. To initiate a Skype call, find a Skype user in your phone’s address book and press the big “Skype” button. The call first goes over 3’s cellular GSM network to a fixed Internet line, which then connects the call to Skype From your 3 Skype phone, you can make free VoIP calls to other Skype users whether they have a Skype phone or not.

You can talk to Skype users Saudi Arabia Phone Number List on their PCs or using other Skype VoIP products. The 3 Skype phone isn’t currently available in the United States. Use of VoIP in Amateur Radio Amateur or ham radio operators can use VoIP technology to set up temporary stations following Sept. 11. Amateur or ham radio operators can use VoIP technology to set up temporary stations such as this one used by the Red Cross following Sept. Think of amateur radio, or ham radio, as an early version of the Internet. Using a worldwide network of radio towers, antennas and transceivers, amateur radio enthusiasts are able to communicate with fellow hobbyists around the globe, sometimes by voice and sometimes by Morse code. Amateur radio is limited by the distance that radio waves can travel. To send a signal to the other side of the world requires calculated timing and more than a little bit of luck. Every 11 years, for example, there’s a peak in the number of sunspots produced by the sun, which increases the intensity of something called ionospheric propagation.

By bouncing radio signals high into the ionosphere, ham radio users can send long-distance messages. During off-peak years it’s much more difficult. Now amateur radio fans are using VoIP technology to link users around the globe. Here’s how it works. Ham radio has always relied on FM repeaters, large radio towers that act as base stations for accessing the radio network from home. By attaching an Internet-connected PC to these repeater stations, people can communicate with the repeater using VoIP. Several amateur radio fans have developed special software that helps connect home radio transceivers to the Internet. Users can connect their ham radio transceivers to their PC sound card and use the computer software to search for available repeater stations across the world.