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US 7,889,990 B2Granted
Optical line terminal capable of active bandwidth allocation for passive optical network system
AssigneeHitachi, Ltd.
InventorsTohru Kazawa, Kenichi Sakamoto, Ryosuke Nishino
Life of this patent
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Abstract
In a GPON system conforming to ITU-T Recommendations G.984.3, an optical line terminal is provided which has an active bandwidth allocation function that preferentially puts small bandwidth signals in a particular segment of a frame, e.g., at a head of the frame, to prevent fragmentations that may occur particularly when allocating small bandwidths of about 100 kbits/s.
Claims8
An optical line terminal, or carrier side device, connected through a coupler module to a plurality of optical network units (ONUs), or subscriber side devices, the optical line terminal comprising:
- an active bandwidth allocation unit to allocate data lengths to the respective ONUs, for data transmission in a first period;
- and
- a data sending permission unit to determine an order of data to be sent from the plurality of ONUs according to the data lengths allocated to the respective ONUs by the active bandwidth allocation unit, and to determine according to the determined order, a data transmission timing for each of the plurality of ONUs to send the data in a plurality of second periods shorter than the first period, wherein
- the data sending permission unit determines the order and timing to avoid a data transmission timing of an ONU from being overlapped with neighboring second periods.
1 more element
Dependencies are inferred from the claim text.