Recently, the researches about WDM (Wavelength Division Multiplexing) have been remarked in terms of pursuing more high-capacity photonic network. In WDM technology, the bandwidth of an optical fiber are effectively used by dividing the bandwidth fiber into some wavelengths and assigning a wavelength for links which are between source – destination nodes. To make the most of the wide bandwidth by WDM, the nodes which consist the network dynamically need control the wavelength and establish the lightpath by reserving the proper wavelength between the source -destination nodes.
In WDM networks, the wavelength reservation protocols are classified into two categories, one-way wavelength reservation protocol and two-way wavelength reservation protocol. In two-way wavelength reservation protocol, a reliable data transmission can be realized by starting data transmission after reserving the wavelength between source – destination nodes by signaling. The other hand, in one-way wavelength reservation protocol, source nodes start the data transmission without verification of success of reserving a wavelength after transmitting a connection request. In one-way wavelength reservation protocol, the highly-frequent wavelength reservation and release are worked out because of the delay time between occurring a connection request and starting a data transmission. However, since data transmission is started even if the reserving wavelength is failed, it is not guaranteed that data will be successfully reached the destination node. Then, in the situation that a client require the fixed bandwidth, two-way wavelength reservation protocol need be used.
A Wavelength/Route Reservation Scheme Using Signaling Protocol
In a conventional two-way wavelength reservation protocol, there is a problem that traffic load is concentrated on specific links since the shortest path is always used for the route between source and destination nodes. We propose a new two-way wavelength reservation protocol using multi-route signaling protocol. In our proposed protocol, nodes collect two information which are the link distance and the frequency of use for wavelengths, when a connection request occurred. And destination nodes select the proper couple of route and wavelength which has the lowest cost calculated by the two collected information, and initiate reservation. According to computer simulations, blocking probability can be reduced by our proposed signaling scheme. As a result, we show the performance effectiveness of our proposed signaling scheme.
- Junichiro HONMA, Takanori ITO, Daisuke ISHII, Naoaki YAMANAKA, “A Wavelength/Route Reservation Scheme Using Signaling Protocol in WDM networks,” Technical Report IEICE, NS2004-312, pp.321-324, March 2005
- Junichiro HONMA, Daisuke ISHII, Naoaki YAMANAKA, “An Effective Wavelength/Route Reservation Scheme Using Signaling Protocol in nonuniform WDM networks,” Technical Report IEICE, PN2005-39, pp.31-36, Octover 2005