Frame synchronization in a network of time multiplexed optical space switches
US4912706A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Nov 18, 1988 |
| Grant date | Mar 27, 1990 |
| Priority date | — |
| Expiry date | Nov 18, 2008 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L7/0008
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
In an optical switching network, a master optical space switch is interconnected with remote slave equipment for switching block-multiplexed messages among the remote equipment. The master optical space switch responds to a frequency reference clock and steps through a sequence of states, or configurations, for establishing various routes among the remote equipment for appropriately routing the messages to correct destinations. The frequency reference clock also is distributed to the remote equipment. During one of the states per frame, each remote slave equipment transmits a distinct signature signal. All of the slave equipments are connected through the master optical space switch to return to themselves their own signals transmitted during that time slot. Each remote slave equipment compares the returned signal with the originally transmitted signature signal to determine how much the round trip delay has varied from a nominal value. Phase of a local control clock signal in the slave equipment is adjusted to counteract the variation of the round trip delay. Thus the operation of the slave equipment is adjusted into synchronization with the master optical space switch so that mes…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.