ข้อมูลสัญลักษณ์จำแนกการออกแบบผลิตภัณฑ์ระหว่างประเทศ


รหัส / code คำอธิบาย / code name Version
H04B0003100000 by pilot signal 1
H04B0003110000 using pilot wire (H04B0003120000 take precedence);; 1
H04B0003120000 in negative-feedback path of line amplifier 1
H04B0003140000 characterised by the equalising network used 1
H04B0003160000 characterised by the negative-impedance network used 1
H04B0003180000 wherein the network comprises semiconductor devices 1
H04B0003200000 Reducing echo effects or singing; Opening or closing transmitting path; Conditioning for transmission in one direction or the other 1
H04B0003210000 using a set of bandfilters 1
H04B0003230000 using a replica of transmitted signal in the time domain, e.g. echo cancellers 1
H04B0003260000 Improving frequency characteristic by the use of loading coils 1
H04B0003280000 Reducing interference caused by currents induced in cable sheathing or armouring 1
H04B0003300000 Reducing interference caused by unbalance current in a normally balanced line 1
H04B0003320000 Reducing cross-talk, e.g. by compensating 1
H04B0003340000 by systematic interconnection of lengths of cable during laying; by addition of balancing components to cable during laying 1
H04B0003360000 Repeater circuits (H04B0003580000 takes precedence);; 1