This paper proposes a proactive contention avoidance mechanism through dedicated wavelength assignment
method in the optical burst switching network. In our scheme, one or more dedicate wavelengths are assigned to
each ingress node and each ingress node transmits incoming bursts to various destination with its dedicated
wavelength. Therefore contention at intermediate core nodes can be avoided and contention is localized at each
ingress node, in where this situation can be resolved by means of electric buffer. Furthermore, based on the status
of traffic distribution, we propose a constructive scheme to construct a load-balanced spanning tree for each
ingress node, where input loads are balanced appropriately among each output port of ingress node. And,
identical wavelength can be shared with bursts transmitted to different destination nodes within the spanning tree.
Thus our scheme has statistical multiplex gain and it expected to utilize wavelength effectively. Simulation result
indicates the burst loss performance can be improved drastically without wavelength conversion comparing with
those algorithms that completely shared wavelength link.