BFWAtg - Guard Bands 28GHz Draft 26GHz Recommendation: –Two FDD systems At least one 28MHz “slot” or single polarisation only in adjacent slots. –Two TDD or TDD/FDD mix Two 28MHz “slots” required. –Or: No guard bands but “edge slots” and mutual co- operation. BFWAtg(00)20

BFWAtg-Guard Bands 28GHz TM4 Work Item DETR/TM04069: –Two TDMA/FDD systems, 28MHz channels: No guard band with site sharing No guard band with near site sharing but better NFD required. One 28MHz guard channel required for unco- ordinated deployment. Contd…….

BFWAtg-Guard Bands 28GHz TM4 Work Item DETR/TM04069: –One TDMA/FDD and one FDMA system, 28MHz channels: One guard channel with site sharing. One guard channel with near site sharing. Two 28MHz guard channels required for unco- ordinated deployment.

BFWAtg-Guard Bands 28GHz RA/Aegis Study: –Two systems with similar characteristics: One guard channel required. –Two dissimilar systems (i.e.different channelisation). One guard channel in each assignment, but mutual co-operation and co-ordination may allow some use.

Summary Guard channel = 0 –Mutual co-operation reqd including site sharing/near site sharing, tighter NFD’s needed. Guard Channel = 1 –Unco-ordinated deployment, dissimilar multiple access, similar FDD systems. Guard channels = 2 –Unco-ordinated dissimilar multiple access, TDD or TDD/FDD mix

Summary Therefore for maximum protection and greatest freedom for deployment, 2 guard channels would seem appropriate. For greatest spectrum use “Edge Bands” / co-operation zones seem appropriate but co- operation must take place. Could depend on the size of assignments.