Patent ID: 7349432
Filing Date: 2008-03-25
Classification: H04Q

Abstract:
1. A method for increasing the bandwidth of a protected circuit switched channel in a fiber based time division multiplexed network, wherein said network comprising a plurality of nodes that are interconnected via network links, each link comprising a respective bitstream that is divided into a recurring frame, said recurring frame being divided into time slots, each time slot comprising a number of bits, a protected channel is established to comprise a first circuit switched channel and a second circuit switched channel, said first circuit switched channel is established from a first node of said nodes to a second node of said nodes over a first network path comprising a first set of one or more links of said network interconnecting said first node to said second node via zero or more intermediate nodes, said second circuit switched channel is established from said first node to said second node over a second network path comprising a second set of one or more links of said network interconnecting said first node to said second node via zero or more intermediate nodes, said first circuit switched channel being defined by a respective first set of time slots within each respective recurring frame of each respective bitstream of said first set of links, said second circuit switched channel being defined by a second respective set of time slots within each respective recurring frame of each respective bitstream of said second set of links, payload data for said protected channel is copied into both the first circuit switched channel and the second circuit switched channel so that copies of the same payload data is transported in parallel over said first network path and said second network path, wherein increasing the bandwidth of said protected channel comprises the steps of: reserving one or more additional time slots within each respective recurring frame of the respective bitstreams of said first set of links, continuing using said first respective set of time slots for transmitting said payload data, and providing information indicating that said one or more additional time slots are currently not used for transferring payload data; and reserving one or more additional time slots within each respective recurring frame of the respective bitstreams of said second set of links, continuing using said second respective set of time slots for transmitting said payload data, and providing information indicating that said one or more additional time slots are currently not used for transferring payload data; and establishing information indicating that the nodes of said network receiving or switching said first circuit switched channel and the nodes of said network receiving or switching said second circuit switched channel, and nodes downstream thereof receiving or switching said protected channel, are ready to handle payload data of said protected channel at a higher bandwidth using said additional time slots and, thereupon, discontinuing indicating that said one or more additional time slots are currently not used for transferring payload data and start using said first and second respective set of time slots as well as said additional time slots for transmitting said payload data of said protected channel.