Abstract
In this paper, a dynamic impairment-aware routing and wavelength assignment (RWA) algorithm is proposed to
efficiently provide signal-quality-guaranteed connections and achieve lower blocking probability in all-optical wavelength
division multiplexing (WDM) network with high speed optical channel. In the all-optical network, optical connection is
set up to carry data signal from source node to destination node without optical-electrical-optical (OEO) conversion via
all-optical lightpath. During the travel, the signal transmitted along the lightpath must pass through a number of optical
components, such as optical amplifiers, optical crossconnect switches (OXCs) and fiber segments. While the optical signal
propagates to the destination, the impairment would accumulate along the all-optical lightpath with these components,
which makes the quality of signal degrade continuously. When the impairment accumulation comes to a serious degree,
the bit-error rate (BER) would be too high to be acceptable in the destination receiver, the good quality of service for a
connection request could not be provided in physical layer and the connect request would be rejected in control plane
because of impairment accumulation. Therefore new techniques in both physical layer and network layer are necessary for
decrease the influence of impairment accumulation. Here we investigate a new dynamic RWA algorithm to lower
blocking probability of connection. By jointly consideration of both available wavelength and wavelength dependent
impairments, the routing weight functions can be dynamically updated to accommodate between wavelength blocking and
physical layer blocking. Simulation results indicate that the proposed algorithm can achieve lower blocking probability.
