In North America, satellite radio is powerful enough that there is no need for a dish. The band used in the North American continent is 2.3 GHZs. This signal can be transmitted by the use of no more than three satellites because they are situated very high in space above the continent. Sometimes in areas with tall buildings, the clear signal of the satellite is blocked. In these instances, repeaters must be used to receive a crisp signal. High traffic areas and bad weather also tend to make it difficult to receive a clear signal. The use of repeaters give satellite radio the ability to pick up a strong signal anywhere.