I recently transfered my service from Nextel (IDEN) to Sprint (CDMA). Living in a relatively rural part of Virginia (Shenandoah Valley), I have not experienced the issues with Nextel that some in more urban areas have experienced with regard to the sales of new Nextel accounts exceeding the network capacity. What was happening however, was that Sprint has continued to build out their CDMA system, while the Nextel IDEN system coverage has pretty much remained the same. To expand my coverage, and not being much concerned about losing Nextel's direct connect, I switched to Sprint CDMA. I tend to do a good bit of hiking in the Shenandoah National Park. Many of these hiking trails lead to mountaintop locations with elevations exceeding 3000 feet above sea level. It was rare to not have a full Nextel signal from most of these locations. The phone worked in most instances and it was rare not to have a useable Nextel signal. Since my switch to Sprint, I have noticed pretty much the same signal strength from these same locations as Nextel, but my phone will not make a call and is basically, unusable. After researching the issue, I have discovered that the cause of this is probably something known as pilot pollution. Being at a high elevation, the phone is probably seeing signals from many towers (maybe as far away as Richmond or northern Virginia) and it renders the phone unusable. This apparently is a common issue with CDMA carriers. This isn't a horrible issue, but a disappoinment in that I actually switched to Sprint hoping for better coverage, and in the SNP, actually have less coverage. Are there any known solutions to this technical issue with CDMA??? I believe this is not an issue for TDMA technology like IDEN of GSM.