  The excesses of the cosmic positron fraction recently measured by PAMELA and
the electron spectra by ATIC, PPB-BETS, Fermi and H.E.S.S. indicate the
existence of primary electron and positron sources. The possible explanations
include dark matter annihilation, decay, and astrophysical origin, like
pulsars. In this work we show that these three scenarios can all explain the
experimental results of the cosmic $e^\pm$ excess. However, it may be difficult
to discriminate these different scenarios by the local measurements of
electrons and positrons. We propose possible discriminations among these
scenarios through the synchrotron and inverse Compton radiation of the primary
electrons/positrons from the region close to the Galactic center. Taking
typical configurations, we find the three scenarios predict quite different
spectra and skymaps of the synchrotron and inverse Compton radiation, though
there are relatively large uncertainties. The most prominent differences come
from the energy band $10^4\sim 10^9$ MHz for synchrotron emission and $\gtrsim
10$ GeV for inverse Compton emission. It might be able to discriminate at least
the annihilating dark matter scenario from the other two given the high
precision synchrotron and diffuse $\gamma$-ray skymaps in the future.
