Packet transmission system, packet transmission method, packet transmission program, and recording medium on which the recorded program is recorded

• US 20040196869A1
• Filed: 12/29/2003
• Published: 10/07/2004
• Est. Priority Date: 06/29/2001
• Status: Active Grant

• Current Assignee: Rakuten Group, Inc.
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Mukai, Hiroaki, Takemoto, Michiya, Asashiba, Yoshihiro, Kawate, Ryusuke, Tsuchida, Mitsuru, Horiuchi, Eiichi
• Granted Patent: US 7,403,518 B2
• Time in Patent Office: Days
• US Class Current: 370/468
• CPC Class Codes: H04L 12/44 Star or tree networks
• CPC Class Codes: H04Q 11/0066 Provisions for optical burst or packet networks
• CPC Class Codes: H04Q 11/0067 Provisions for optical access or distribution networks, e.g. Gigabit Ethernet Passive Optical Network (GE-PON), ATM-based Passive Optical Network (A-PON), PON-Ring
• CPC Class Codes: H04Q 2011/0064 Arbitration, scheduling or medium access control aspects

Abstract

An OLT 1 sequentially allocates transmission permission of a packet on an upstream transmission line to a plurality of ONUs 2 registered, and performs packet communication in a simplified method with control by using a first timer for detecting a packet signal and a second timer for controlling transmission permission time, in order to transmit an IP packet of variable length without mounting a function of complex processing for analyzing an upstream packet in the OLT 1.

Claims

1. A packet communication system comprising:

a master station for transmitting a downstream packet signal including identification information for identifying transmission permission in order to give transmission permission without receiving transmission request to the master station itself; and

a slave station for receiving the downstream packet signal transmitted from the above master station and judging if transmission has been permitted based on the identification information in the downstream packet signal received.

2. The packet communication system of claim 1, wherein the above slave station transmits an upstream packet signal to the master station when the slave station judges that transmission has been permitted.

3. The packet communication system of claim 2, wherein the above master station includes a timer 1 for detecting packet which measures limit time when the master station can judge if the upstream packet signal has been transmitted from the above slave station to which transmission has been permitted, wherein the master station judges if the master station has received the upstream packet signal transmitted from the above slave station within the limit time measured by the timer 1 for detecting packet, stops the timer 1 for detecting packet when the master station has received the upstream packet signal, and updates the identification information for identifying transmission permission when the master station has not received the upstream packet signal.

4. The packet communication system of claim 3, wherein the above master station includes a timer 2 for permitting transmission which measures limit time when the master station can continuously receive the upstream packet signal transmitted from the above slave station to which transmission has been permitted, wherein the master station judges if receipt of the upstream packet signal transmitted from the above slave station has ended within the limit time measured by the timer 2 for permitting transmission, stops the timer 2 for permitting transmission when the receipt has ended, and updates the identification information for identifying transmission permission when the receipt has not ended.

5. The packet communication system of claim 2, wherein the above master station transmits a downstream packet signal including overhead information indicating time when output of the upstream packet signal is unstable, wherein the above slave station adds an overhead which is a group of signals which are not reproduced by the above master station on a head of the upstream packet signal corresponding to the overhead information in the downstream packet signal transmitted from the above master station.

6. The packet communication system of claim 1, wherein the above master station includes a buffer for accumulating the downstream packet signal separately according to signal transmission speeds, wherein the master station reads out the downstream packet signal of various speeds accumulated in the buffer separately according to the signal transmission speeds, transmits the downstream packet signal of the various speeds read out, and permits a slave station which has been able to be synchronized with transmission speed of the downstream packet signal to transmit an upstream packet signal.

7. The packet communication system of claim 4, wherein the above master station monitors upstream packet communication volume of each slave station and controls a value of the timer 2 for permitting transmission for the above slave station based on the upstream packet communication volume.

8. The packet communication system of claim 4, wherein the above slave station informs the above master station of volume of the upstream packet signal to be accumulated in the buffer when transmission permission is given to the slave station, wherein the above master station controls a value of the timer 2 for permitting transmission for the above slave station based on upstream packet accumulation volume informed by the above slave station.

9. The packet communication system of claim 4, wherein the above slave station informs the above master station of ending information indicating that no upstream packet signal is to be transmitted when no upstream packet signal is accumulated in the buffer when transmission permission is given to the slave station, wherein the above master station receives the above ending information informed by the above slave station and gives transmission permission to a next slave station after the above slave station without waiting until the timer 2 for permitting transmission expires.

10. The packet communication system of claim 4, wherein when transmission permission is given to the above slave station and the above slave station has ended transmission of all of the upstream packet signals accumulated in the buffer to the above master station, the above slave station informs the above master station of ending information indicating that there is no upstream packet signal is to be transmitted, wherein the above master station receives the above ending information informed by the above slave station and gives transmission permission to a next slave station after the above slave station without waiting until the timer 2 for permitting transmission expires.

11. The packet communication system of claim 4, wherein the above master station specifies volume of packet which can be transmitted continuously by the above slave station when the above master station gives transmission permission to the above slave station, wherein the above slave station ends processing of packet transmission based on the volume of packet which can be transmitted continuously, specified for specifying.

12. A packet communication method, wherein a master station transmits a downstream packet signal including identification information for identifying transmission permission, wherein a slave station receives the downstream packet signal transmitted from the above master station and judges if transmission has been permitted based on an identification number of the downstream packet signal received.

13. A packet communication program characterized in processing that a master station transmits a downstream packet signal including identification information for identifying transmission permission by a master station and processing that a slave station receives the downstream packet signal transmitted from the above master station and judges if transmission has been permitted based on the identification number in the downstream packet signal received.

14. A computer-readable recording medium for recording a packet communication program for making a computer execute processing that a master station transmits a downstream packet signal including identification information for identifying transmission permission and processing that the slave station receives the downstream packet signal transmitted from the above master station and judges if transmission has been permitted based on an identification number of the downstream packet signal received.