Patent ID: 8897643

Claim:
A node suitable for a multi-token optical communications network, the network having optical channels between the node and other nodes, the network being arranged so that nodes hold and pass unique tokens, each token indicating to a node that a corresponding one or more of the optical channels is available for transmission while that node holds that token, during a token holding time, the node comprising: a transmitter for transmitting packets to the other nodes over the optical channels, a buffer for queuing packets before transmission by the transmitter, and a transmit controller configured to: control the buffer to forward at least one initial packet from the buffer to the transmitter once a token has been received, the at least one initial packet forwarded to the transmitter for transmission over an optical channel corresponding to the token and according to the token hold time; after the at least one initial packet is forwarded from the buffer to the transmitter, determine how much of the token holding time remains; and after determining how much of the token holding time remains, control the buffer to forward a further packet from the buffer to the transmitter according to the remaining token holding time.