Space Exploration Technologies Corp. (NASDAQ:SPCX), led by Elon Musk, is challenging proposed spectrum restrictions supported by T-Mobile US Inc. (NASDAQ:TMUS) and the Aerospace and Flight Test Radio Coordinating Council (AFTRCC) while assessing a potential US wireless expansion. In an October 28 letter, SpaceX told the FCC (U.S. communications regulator) that proposed base-station protections could create 250-mile-wide buffer zones around cell towers and exclude millions from direct-to-cell service in underserved border communities. The company argued that directional cell-tower antennas are inherently more resistant to interference from satellite transmissions. Separately, telecommunications expert William Webb estimates SpaceX may need another $120 billion to $130 billion beyond nearly $28 billion in agreed spectrum deals to approach the scale of major US carriers, while network construction could add $30 billion to $40 billion. Lower-cost rural expansion estimates range from $10 billion to $15 billion excluding additional spectrum, but would not initially match the capacity of T-Mobile, AT&T Inc. (NYSE:T) or Verizon Communications Inc. (NYSE:VZ).