Optical access network method, optical access network, and optical switch for optical access network
First Claim
1. An optical access network method wherein:
- a center terminal, a plurality of remote terminals, and one or more optical switches are formed in a tree structure; and
the optical switch forwards a downlink signal transmitted from the center terminal to one of the remote terminals specified by the center terminal based on information from the downlink signal, and forwards an uplink signal transmitted from the remote terminal specified by the center terminal to the center terminal based on the information from the downlink signal.
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Accused Products
Abstract
An optical access network method, an optical access network and an optical switch for an optical access network, capable of solving all the three problems in the conventional GE-PON: transmission distance problem, security problem and communication interference problem. The optical access network comprises an OLT, a plurality of ONUs and one or more stages of optical switches, which are connected one another. In the direction from the OLT to the ONU, each frame (packet) transmitted from the OLT to one of the ONUs is checked so that only the destination ONU specified in the frame (packet) is connected to the OLT. In the direction from the ONU to the OLT, a control message transmitted from the OLT to one of the ONUs is checked so that only one ONU which has been given a transmission allowance from the OLT is connected to the OLT with respect to each frame (packet).
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Citations
20 Claims
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1. An optical access network method wherein:
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a center terminal, a plurality of remote terminals, and one or more optical switches are formed in a tree structure; and
the optical switch forwards a downlink signal transmitted from the center terminal to one of the remote terminals specified by the center terminal based on information from the downlink signal, and forwards an uplink signal transmitted from the remote terminal specified by the center terminal to the center terminal based on the information from the downlink signal. - View Dependent Claims (3, 5, 7, 9, 11, 16)
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2. An optical access network method comprising the steps of:
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setting one n1×
1 optical switch (n1;
an integer) as the first optical switch from a center terminal;
setting at most n1 pieces of n2×
1 optical switches (n2;
an integer) as the second optical switches from the center terminal;
setting at most n1·
n2 pieces of n3×
1 optical switches (n3;
an integer) as the third optical switches from the center terminal;
setting at most n1·
n2·
n3 . . . nk−
1 pieces of nk×
1 optical switches (nk;
an integer) as the kth optical switches from the center terminal;
setting at most n1·
n2·
n3 . . . nk . . . ns−
1 pieces of ns×
1 optical switches (ns;
an integer, k≦
s) as the last optical switches from the center terminal;
connecting the center terminal to the 1 side of the first n1×
1 optical switch through an optical fiber;
connecting the n1 side of the first n1×
1 optical switch to remote terminals or the 1 sides of the second n2×
1 optical switches through optical fibers;
connecting the n2 side of the second n2×
1 optical switch to remote terminals or the 1 sides of the third n3×
1 optical switches through optical fibers;
connecting the 1 side of the kth nk×
1 optical switch to the nk−
1 side of the (k−
1)th nk−
1×
1 optical switch from the center terminal through an optical fiber;
connecting the nk side of the kth nk×
1 optical switch to remote terminals or the 1 sides of the (k+1)th nk+1×
1 optical switches from the center terminal through optical fibers;
connecting the 1 side of the sth ns−
1×
1 optical switch to the ns−
1 side of the (s−
1)th ns−
1×
1 optical switch from the center terminal through an optical fiber; and
connecting the ns side of the sth ns×
1 optical switch to remote terminals;
wherein the ni×
1 optical switch (i=1, 2, 3, . . . , k, . . . s) forwards a downlink signal transmitted from the center terminal to one remote terminal specified by the center terminal based on information from the downlink signal, and forwards an uplink signal transmitted from the remote terminal specified by the center terminal to the center terminal based on the information from the downlink signal. - View Dependent Claims (4, 6, 8, 10, 12, 13, 17)
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14. An optical access network comprising a center terminal, a plurality of remote terminals, and one or more optical switches, which are formed in a tree structure, wherein the optical switch forwards a downlink signal transmitted from the center terminal to one of the remote terminals specified by the center terminal based on information from the downlink signal, and forwards an uplink signal transmitted from the remote terminal specified by the center terminal to the center terminal based on the information from the downlink signal.
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15. An optical access network comprising:
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one n1×
1 optical switch (n1;
an integer) as the first optical switch from a center terminal;
at most n1 pieces of n2×
1 optical switches (n2;
an integer) as the second optical switches from the center terminal;
at most n1·
n2 pieces of n3×
1 optical switches (n3;
an integer) as the third optical switches from the center terminal;
at most n1·
n2·
n3 . . . nk−
1 pieces of nk×
1 optical switches (nk;
an integer) as the kth optical switches from the center terminal;
at most n1·
n2·
n3 . . . nk . . . ns−
1 pieces of ns×
1 optical switches (ns;
an integer, k≦
s) as the last optical switches from the center terminal;
wherein;
the center terminal is connected through an optical fiber to the 1 side of the first n1×
1 optical switch;
the n1 side of the first n1×
1 optical switch is connected through optical fibers to remote terminals or the 1 sides of the second n2×
1 optical switches;
the n2 side of the second n2×
1 optical switch is connected through optical fibers to remote terminals or the 1 sides of the third n3×
1 optical switches;
the 1 side of the kth nk×
1 optical switch is connected through an optical fiber to the nk−
1 side of the (k−
1)th nk−
1×
1 optical switch from the center terminal;
the nk side of the kth nk×
1 optical switch is connected through optical fibers to remote terminals or the 1 sides of the (k+1)th nk+1×
1 optical switches from the center terminal;
the 1 side of the sth ns×
1 optical switch is connected through an optical fiber to the ns×
1 side of the (s−
1)th ns−
1×
1 optical switch from the center terminal;
the ns side of the sth ns×
1 optical switch is connected to remote terminals; and
the n1×
1 optical switch (i=1, 2, 3, . . . , k, . . . s) forwards a downlink signal transmitted from the center terminal to one remote terminal specified by the center terminal based on information from the downlink signal, and forwards an uplink signal transmitted from the remote terminal specified by the center terminal to the center terminal based on the information from the downlink signal.
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18. An optical switch for an optical access network comprising, at least:
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a received frame analyzer for analyzing a downlink signal from a center terminal;
an uplink optical switch device; and
a downlink optical switch device;
wherein based on the analysis result obtained by the received frame analyzer, the uplink and downlink optical switch devices perform switching per packet. - View Dependent Claims (19, 20)
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Specification