CONTROL OF TOKEN HOLDING IN MULTI-TOKEN OPTICAL NETWORK

摘要

A node (260, 50) for a multi-token optical communications network has optical channels between the node and other nodes, each channel having a token (T1, T2, T3), passed between nodes, to indicate that a corresponding optical channel is available for transmission during a token holding time. The node has a transmitter (280) for transmitting packets over the optical channels, a buffer (170, 270) for queuing packets before transmission, and a transmit controller (170, 290) configured to control the buffer to forward an initial packet or packets from the buffer to the transmitter once a token has been received. The transmit controller determines how much of the token holding time remains after the transmission of the initial packet or packets, and then controls the buffer to forward a further packet according to the remaining token holding time. A maximum packet delay can be reduced where there is asymmetric traffic. A token holding time can be different for different nodes.