A variable-band distributed switching node comprises a plurality of independent modules (MU.sub.1 . . . MGm) inserted between subscriber or trunk lines and a common bus (1). Each module includes an input/output portion (IU, HL, SL, PL), processing line information, and an interface (IB) toward the bus...http://www.google.co.uk/patents/US4611321?utm_source=gb-gplus-sharePatent US4611321 - Variable-band distributed switching node with dynamic hybrid-frame processing
