Free-Space Optics and E-Band Radio: Complementary Techniques for Gbit/Sec Wireless

Free Space Optics (FSO) and E-band links operating in parallel are investigated. In contrast to previous work in this field equal transmission rate of the two is assumed- 1 Gbit/sec in existing systems with a likely increase in the near future. Propagation characteristics are briefly presented. It is shown that practical difficulties preclude microwave backup to FSO links. Equal transmission rate leads to the possible application of parallel MIMO techniques. Outage capacity based on that is determined regarding for both binary and quaternary modulation and both Direct Detection (DD) and heterodyne techniques in the FSO link. The unexpected conclusion is that it is more the FSO link that serves as backup to the E-band link than the converse.