Note:

The local cell phone Service Provider for the Desire and Cancun area of Mexico is a company called Telcel, they provide GSM service on the 1900 MHz band

In order to determine if your cell phone will work at Desire you must answer YES to all the following points:

1. Is your cell phone a GSM (Global System for Mobile communications) model ?
2. Does your GSM cell phone support the 1900 MHz band ?
3. Do you have International Roaming enabled on your GSM cell phone ?
4. Is your local Service Provider listed below:

Service Providers with Roaming Agreements with Telcel(Mexico)

United States
- Cincinnati Bell Wireless (Cincinnati Bell Wireless - Cincinnati, OH)
- Cingular Wireless
- Dobson Communications Corporation
- Dobson Communications Corporation (Dobson MI - Petoskey, MI)
- Dobson Communications Corporation (Dobson MI - Traverse City, MI)
- T-Mobile USA, Inc
- Triton PCS License Company LLC (SunCom AT&T - Knoxville)
- Triton PCS License Company LLC (SunCom AT&T - Richmond-Norfolk)
- Triton PCS License Company LLC (SunCom AT&T - Atlanta)
- Triton PCS License Company LLC (SunCom AT&T - Washington-Baltimore)
- Triton PCS License Company LLC (SunCom AT&T - Charlotte-Greensboro-Greenvill)
- Western Wireless Corporation
- Wireless Alliance
- AT&T Wireless PCS LLC (Cingular Wireless)

(Note from DennyP: My Verizon Wireless phone works fine from the resort)

Canada
- Rogers Wireless
- Microcell Telecommunications Inc (Fido)

United Kingdom
- O2 (UK) Limited
- Orange PCS Ltd
- T-Mobile (UK) Limited
- Vodafone Ltd
- Hutchison 3G UK Ltd.

For Service Providers for other countries that have roaming agreements with Telcel look here: http://www.gsmworld.com/roaming/gsminfo/roa_mxrm.shtml

If all of the above answers are YES then your cell phone will probably work at the Cancun Airport, Cancun Hotel zone and Desire.

Telcel Coverage map around Desire - updated Feb '06
http://img344.imageshack.us/img344/7748/telcelmap057om.jpg