In this paper we discuss a quantitative framework for best- effort protection of the optical layer. This framework provides a way to bridge the gap between two known protection grades of fully protected connections vis-a-vis unprotected protection. The framework allows to specify the probability with which the connection will be protected, providing the customer with a full range of protection guarantees at possibly different prices. Since connections may be partially protected, the required protection bandwidth can be reduced. The amount of protection bandwidth is shown to depend on an 'equivalent survivable bandwidth.' The framework also extends to preemptable (low priority) connections and to different ring architectures.
A wavelength division multiplexed network is considered for arbitrary topologies. The network allows optical signals to pass through nodes, which often results in less electronic and opto-electronic equipment than networks that do not, i.e., networks that only switch traffic electronically. A disadvantage of having optical pass through is that there is less capability to switch tributary traffic streams and so there may be more blocking. However, it is shown that the network operates as well as a network with only electronic switching under a particular incremental traffic model. Examples are given that shows that the network can have lower cost when the cost is dominated by the line terminating equipment. A simple heuristic design algorithm is also given to configure the network to minimize its cost.
A wavelength division multiplexed (WDM) broadcast star network is considered. The network has N tunable transmitters and receivers with nonnegligible tuning delay T. The network traffic is composed of continuous flows whose transmissions may be preempted and resumed. The traffic is delay constrained so that a bit cannot be delayed by more than a predefined number of time units denoted by D. Guaranteed nodal throughput results are presented for traffic patterns that are fair. In particular, if the nodal throughput is (lambda) then all nodes can transmit/receive at rate (lambda) as long as they do not transmit/receive more than this rate. When T very much less than D and NT very much greater than D, then the upper and lower bounds for (lambda) are approximately 4 D/NT and 1/4 D/NT, respectively. Notice that the conditions T very much less than D and NT very much greater than D mean that a single tuning delay is a small contribution to delay, but the aggregation of all the tuning delays may be a large contribution to delay.
Conference Committee Involvement (2)
Network Architectures, Management, and Applications
13 November 2011 | Shanghai, China
Network Architectures, Management, and Applications II