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Yes, there are lots of "dead-zones" here. As an example: When we had Sprint, we had no service in our house. We switched to T-Mobile and oddly enough, there is no coverage at the University of Maryland. When we had Verizon, we had coverage, pretty much everywhere, but they are too expensive. They are also the only company that has service on the Metro underground. All the other carriers, you loose your coverage in the tunnels. Each carrier has dead-zones. That is why here we have the saying, "can you hear me now?"