BELL CANADA
32Patents
0Active
32Granted
39Portfolio score
Filing activity: Jul 30, 1984 → Apr 8, 2004
Most-cited patents
| Patent | Title | Area | Cited by | Status |
|---|---|---|---|---|
| US5479488A | Method and apparatus for automation of directory assistance using speech recognition | Electricity | 367 | Expired |
| US6097804A | Method and system for completing a voice connection between first and second voice terminals in a switched telephone network | Emerging Cross-Sectional Technologies | 138 | Expired |
| US5390278A | Phoneme based speech recognition | Physics | 134 | Expired |
| US6226289A | Method and apparatus for dynamically routing calls in an intelligent network | Electricity | 82 | Expired |
| US6940973B1 | Method and apparatus for cancelling common mode noise occurring in communications channels | Electricity | 67 | Expired |
| USD288441S | Tubular telephone unit | General | 66 | Expired |
| US5881132A | Method and apparatus for monitoring selected telecommunications sessions in an intelligent switched telephone network | Electricity | 62 | Expired |
| US6236722A | Method and system for using TCAP signaling for improved call setup from a virtual switching point | Electricity | 59 | Expired |
| US6456657B1 | Frequency division multiplexed transmission of sub-band signals | Electricity | 59 | Expired |
| US6476749B1 | High speed analog-to-digital converter and digital-to-analog converter | Electricity | 53 | Expired |
| US6735293B2 | Method and system for facilitating telecommunications service provisioning and service assurance | Electricity | 48 | Expired |
| US5179420A | Optical time domain reflectometer using a tunable optical source | Physics | 43 | Expired |
| US6959056B2 | RFI canceller using narrowband and wideband noise estimators | Physics | 39 | Expired |
| US6584179B1 | Method and apparatus for improving the utility of speech recognition | Electricity | 36 | Expired |
| US6111946A | Method and system for providing answer supervision in a switched telephone network | Electricity | 29 | Expired |
| US6687350B1 | Smart card reader and transaction system | Physics | 28 | Expired |
| US5933481A | Method of controlling call traffic in a telecommunication system | Electricity | 26 | Expired |
| US6546057B1 | Suppression of radio frequency interference and impulse noise in communications channels | Electricity | 26 | Expired |
| US5167226A | Combined clapping and vibrating device for expelling retained obstructive secretions in the lungs | Human Necessities | 21 | Expired |
| US4567115A | Pressure impregnation of wood poles for preservation | Emerging Cross-Sectional Technologies | 16 | Expired |
| US5719930A | Method of volume screening signalling messages in a telecommunication system | Electricity | 15 | Expired |
| US6961415B2 | Method and system for facilitating telecommunications service provisioning and service assurance | Electricity | 14 | Expired |
| US4847002A | Improved stabilization of wood preservative solutions and preservation of wood by such solutions | Emerging Cross-Sectional Technologies | 10 | Expired |
| US5698829A | Photodegradation of toxic contaminants | Human Necessities | 9 | Expired |
| US5966433A | Method and apparatus for screening calls in telephone networks | Electricity | 7 | Expired |
Source: USPTO / EPO open patent data. Counts and citation impact are objective bibliographic measures.