1. An optical submarine transmission system comprising:
a main line cable laid between a land terminal station and a beach manhole, and connected to an underwater cable in the beach manhole;
a backup line cable laid between the land terminal station and the beach manhole in a different route from a route in which the main line cable is laid, and connected to the underwater cable in the beach manhole;
a break detecting unit arranged in the land terminal station, and configured to detect a break of the main line cable; and
a path switching unit arranged in the land terminal station, and configured to switch an optical transmission path from the main line cable to the backup line cable when the break detecting unit detects the break, wherein
the beach manhole includes only passive parts that are capable of operating without a power supply.
2. The optical submarine transmission system according to claim 1, wherein each of the main line cable and the backup line cable, includes a reception cable and a transmission cable in pair, the reception cable configured to transmit a main signal from the beach manhole to the land terminal station, the transmission cable configured to transmit the main signal from the land terminal station to the beach manhole.
3. The optical submarine transmission system according to claim 2, wherein the beach manhole includes
an optical dividing unit configured to divide the main signal transmitted from the underwater cable into a signal to be transmitted to the reception cable of the main line cable and a signal to be transmitted to the reception cable of the backup line cable; and
an optical coupling unit configured to couple the transmission cable of the main line cable and the transmission cable of the backup line cable with the underwater cable.
4. The optical submarine transmission system according to claim 3, wherein the break detecting unit is configured to detect the break based on a received-light level of the main signal transmitted from the underwater cable through the reception cable of the main line cable.
5. The optical submarine transmission system according to claim 3, wherein the break detecting unit is further configured to detect a break of the backup line cable based on a received-light level of the main signal transmitted from the underwater cable through the reception cable of the backup line cable.
6. The optical submarine transmission system according to claim 3, wherein the break detecting unit is configured to output a monitor signal having a wavelength different from that of the main signal, to the beach manhole through the transmission cable of the main line cable, and to detect the break based on a received-light level of output monitor signal that has been reflected by the beach manhole to be returned through the reception cable of the main line cable.
7. The optical submarine transmission system according to claim 6, wherein the break detecting unit is further configured to detect a break of the backup line cable based on a received-light level of transmitted monitor signal that has been reflected by the beach manhole to be returned through the reception cable of the backup line cable.
8. The optical submarine transmission system according to claim 6, wherein the beach manhole further includes a fiber grating configured to pass the main signal and to reflect the monitor signal.
9. The optical submarine transmission system according to claim 8, wherein the beach manhole further includes an optical director configured to control the monitor signal reflected by the fiber grating to be input to the optical dividing unit.
10. The optical submarine transmission system according to claim 3, wherein the break detecting unit is configured to output a first monitor signal having a wavelength different from that of the main signal, to the beach manhole through the transmission cable of the main line cable, and to detect the break based on a received-light level of output first monitor signal that has been reflected by the beach manhole to be returned through the reception cable of the main line cable, and to output a second monitor signal having a wavelength different from that of the main signal and that of the first monitor signal, to the beach manhole through the transmission cable of the backup line cable, and to detect a break of the backup line cable based on a received-light level of output second monitor signal that has been reflected by the beach manhole to be returned through the reception cable of the backup line cable.
11. The optical submarine transmission system according to claim 10, wherein the beach manhole further includes a fiber grating configured to pass the main signal and to reflect the first monitor signal and the second monitor signal.
12. The optical submarine transmission system according to claim 11, wherein the beach manhole further includes an optical director configured to control the first monitor signal and the second monitor signal that have been reflected by the fiber grating to be input to the optical dividing unit.
13. The optical submarine transmission system according to claim 2, wherein the path switching unit includes an optical switch configured to switch from the reception cable and the transmission cable of the main line cable to the reception cable and the transmission cable of the backup line cable.
14. An optical submarine transmission system comprising:
a main line cable laid between a land terminal station and a beach manhole and carrying a main signal;
a backup line cable laid between the land terminal station and the beach manhole in a different route from a route in which the main line cable is laid;
a break detecting unit arranged in the land terminal station, and configured to detect a break of the main line cable; and
a path switching unit arranged in the land terminal station, and configured to switch an optical transmission path of the main signal from the main line cable to the backup line cable when the break detecting unit detects the break, wherein
the break detecting unit is configured to output a monitor signal having a wavelength different from that of the main signal, to the beach manhole through a transmission cable of the main line cable, and to detect the break based on a received-light level of the output monitor signal that has been reflected by the beach manhole to be returned through a reception cable of the main line cable.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. An illuminating device comprising:
a hollow body, having a first opening end, a second opening end and a pair of first hooking portions, wherein a bore of the second opening end is larger than a bore of the first opening end, and the pair of first hooking portions are disposed on the first opening end; and
a circuit board, disposed in the hollow body and having a pair of second hooking portions, wherein the pair of first hooking portions interfere with the pair of second hooking portions.
2. The illuminating device as claimed in claim 1, wherein the first opening end is a threaded portion.
3. The illuminating device as claimed in claim 1, wherein the pair of first hooking portions is located at two ends of a diameter of the first opening end.
4. The illuminating device as claimed in claim 1, wherein hooking directions of the pair of first hooking portions are toward the circuit board.
5. The illuminating device as claimed in claim 4, wherein the pair of second hooking portions is located outside the hollow body, with its hooking directions being toward the hollow body.
6. The illuminating device as claimed in claim 1, wherein the pair of first hooking portions is formed by hollowing out a portion of a side wall of the hollow body.
7. The illuminating device as claimed in claim 1, wherein the hollow body has a first necked-down portion, the circuit board has a second necked-down portion, and the second necked-down portion leans against the first necked-down portion.
8. The illuminating device as claimed in claim 1, wherein the hollow body further has a pair of tracks disposed therein near the pair of first hooking portions, and the circuit board is inserted into the pair of tracks.
9. The illuminating device as claimed in claim 1, further comprising a heat sink disposed on the second opening end.
10. The illuminating device as claimed in claim 9, further comprising a lamp shade combined with the heat sink, wherein the heat sink is located between the lamp shade and the hollow body.
11. The illuminating device as claimed in claim 1, further comprising a threaded base engaging with the first opening end of the hollow body.
12. The illuminating device as claimed in claim 1, further comprising a thermal compound filled inside the hollow body.