Average Co-Inventor Count = 5.14
ph-index = 4
The patent ph-index is calculated by counting the number of publications for which an author has been cited by other authors at least that same number of times.
Company Filing History:
1. Nortel Networks Corporation (5 from 4,171 patents)
2. Northern Telecom Limited (1 from 2,276 patents)
6 patents:
1. 6940959 - Remote broadcast of call announce and call screening information
2. 6088362 - Key telephone system without common control
3. 6072826 - Key telephone system without common control
4. 6046995 - Key telephone system without common control
5. 5966432 - Remote answering of doorbell
6. 5787115 - Key telephone system without common control