John, thanks for pointing out that this issue is a bit more complicated than I let on. As you note, there is no technical imperative for portability to be limited to a rate center. A white paper on this is located at:My summary regarding rate centers and their relevance to porting was oversimplified. The general rule for wireline carrier number porting to other wireline carriers is rate center dependent. However, this is not the case with respect to certain ports between wireline and wireless.
A wireline carrier must port to a wireless carrier even if the wireless carrier doesn't have numbering resources in the rate center where the number is located. The wireline carriers took the position that they didn't have to do so, but the FCC ruled in November 2003 that wireline-to-wireless ports were required as long as the wireless carrier has service covering the rate center (using Zip codes for that determination, apparently). It did not require wireless-to-wireline ports where the wireline carrier doesn't have numbering resources in the rate center where the ported number is located, however; that issue has been put on hold pending further study. The order is online atThere is also an October 2003 order holding that wireless-to-wireless porting does not require a common rate center. This order, is online at
Michael D. Sullivan Bethesda, MD (USA) (Replace "example.invalid" with "com" in my address.)