Average Co-Inventor Count = 3.26
ph-index = 3
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. Hitachi Communication Technologies, Ltd. (3 from 129 patents)
2. Hitachi, Ltd. (2 from 42,494 patents)
5 patents:
1. 7738790 - WDM type passive optical network
2. 7725030 - WDM type passive optical network
3. 7616615 - Packet forwarding apparatus for connecting mobile terminal to ISP network
4. 7502563 - WDM type passive optical network
5. 7457875 - Access server with function of collecting communication statistics information