GPB has placed most of its stations on VHF due to the lower effective radiated power requirements (20 or 32 kW instead of 1000 kW), which in turn reduces the cost of purchasing the transmitter and using the electrical power for it. For WABW and WCES, this makes them one of the few television stations in the country to operate on low-band VHF channels (2 to 6), which require larger receiving antennas, are prone to tropospheric ducting (weather) and impulse noise, make mobile TV (ATSC-M/H) difficult, and for 5 and 6 are also an obstacle to expanding the FM broadcast band. The high-band VHF channels also have these problems, but not to a major extent.