The dedicated resource restoration scheme in a survivable optical network supports faster restoration time and guarantees on the restoration ability. Common optical layer restoration and protection schemes require line traffic to be uni-directional, whether the application is single wavelength or WDM. In such 1+1 optical protection, the signal is dual fed on diversely routed working and protection fibers. However, this method cannot be used in bi-directional WDM network.

The primary bi-directional path is the default path to be protected by the Wavelength Division Multiplexing Light Path Protection Switch (WLPS). The secondary path is used to restore the light path connection in the event that path failure happened at the primary path such that the primary path light power is lower than a preset threshold value, or vice versa. The status of both primary and secondary paths is always monitored by a microprocessor.

The WLPS allows 1:1 optical path protection on bi-directional WDM transmission. Simultaneous switching between both ends of WLPS achieved within 25 ms without using either in-band or out-of-band signaling. With 2x2 WLPS, the protection fiber can be further utilized to accommodate low priority traffic. The built-in proprietary monitor methodology for bi-directional protection is patent pending, which prevents false triggering of the switch as a result of Near-end Crosstalk (NeXT).

With a 2x2 Bridge-WLPS, a 3-node WDM Bi-directional Ring Optical Path Protection can be realized. The protection fibers can also be utilized to accommodate low priority traffic. In the event that the primary fiber is cut, the low-priority is dropped and the high-priority traffic is re-routed via the protection fibers, the trunk efficiency is then fully utilized.

Features

• Design for WDM bi-directional path restoration
• Automatic optical switching within 25 ms
Synchronized to switch without in-band or out-of-band signaling
• Independent of transmission rate and format
• Monitoring on both primary/secondary paths
• Programmable thresholds
• Exceed 40 dB power monitor range
• Alarm/status notification via Fax/On-screen alert, Email, SNMP, and SMS message
• Accessible via the Internet and dial-up
• PC and PDA (Pocket PC) GUI available
• Data-logging on optical power level and alarm history

Applications

• Optical Path Protection for Gigabit Ethernet, CATV, PDH, Video, Point-to-point/Long haul optical systems, and Metropolitan optical network
• Bi-directional WDM, CWDM or DWDM transmission Protection
• FTTx Optical Path Protection
  

Compliance

• FCC Part 15, Class A
• EN 60950
• EN 55022
• EN 55024