Electrostatic ion waves with frequencies 0.5-6 kHz are often described in the solar wind upstream of the bow shock. The ion waves are correlated with the low-frequency magnetic field fluctuations that are driven by upstreaming protons of energies 4-7 keV. In terms of the frequency of occurrence, the ion waves occur primarily in the region connected to the bow shock by the solar wind magnetic field. The ion waves therefore appear to be driven by a beam-plasma interaction involving the 4- to 7-keV protons streaming into the solar wind along magnetic field lines connected to the bow shock. A statistical study of the characteristic ion wave spectrum suggests that it may contain waves similar to Buneman waves with rest frame frequencies f~3.5fpi, where fpi is the ion plasma frequency and wavelengths &lgr;~1 km. We suggest that the ion waves are driven by a Landau resonant wave-particle interaction with the 4- to 7-keV protons, after initial excitation by upstreaming suprathermal electrons. The study suggests that previously detected ion acoustic waves are not the only waves associated with upstreaming protons. Bragg scattering off ion waves with wavelengths of 1-2 km is suggested to explain distant (>10 Re) source locations for terrestrial kilometric radiation. The ion waves are also suggested as a possible upstream agent for stochastically accelerating the >30-keV protons that are correlated with the upstreaming 4- to 7-keV protons. Electron plasma oscillations, associated with upstreaming electrons, often appear to be anticorrelated with the ion waves, implying some interaction that damps electron plasma oscillations.