Radio Networking Issues

hi. Structure of my network. A Radio on the mast with the cat 5e outdoor landed on the router cisco 3800 series. this radio is pointing to another one at the other side out the network. i.e P-t-P. but from morning till evening the we use to experience downtime until the radio is restarted.
later i remove the cat 5e cable from the router and place directly on my laptop and it was wonderful and at the other end of the network it is working perfectly. can u pls help me out in troubleshooting this network.