Natalee Case Discussion #691 11/23 - 11/24/2007

[Observer]

Cell site Range

In practice, cell sites are grouped in areas of high population density, with the most potential users. Cell phone traffic through a single cell mast is limited by the mast's capacity; there is a finite number of calls that a mast can handle at once. This limitation is another factor affecting the spacing of cell mast sites. In suburban areas, mast are commonly spaced 1-2 miles apart and in dense urban areas, mast may be as close as ¼-½ mile apart. Cell masts always reserve part of their available bandwidth for emergency calls.

The maximum range of a mast (where it is not limited by interference with other masts nearby) depends on the same circumstances. Some technologies, such as GSM, have a fixed maximum range of 40km (25 miles), which is imposed by technical limitations. CDMA and iDEN have no built-in limit, but the limiting factor is really the ability of a low-powered personal cell phone to transmit back to the mast. As a rough guide, based on a tall mast and flat terrain, it is possible to get between 50 to 70 km (30-45 miles). When the terrain is hilly, the maximum distance can vary from as little as 5 to 8 km (3 to 5 miles).[2]

http://en.wikipedia.org/wiki/Cell_site#Cell_site_range

[Observer]

If someone's Aruban cellphone was picked up from a Venezuelan or Colombian tower they would have to have a agreement between countries and compatable systems. Kind of like when we use to roam between networks here in the states and you recieved the extra charges in your bill. Nowadays lots of people have there phones activated to use in other countries simply by calling their carrier and having the correct sim card/frequency.

It will be interesting to see what communications if any were picked up in Ven/Col. We still have Sanders cell phone that we haven't heard much about. He said it was stolen the day Natalee went missing.