METHOD FOR OPTICAL PATH ASSIGNMENT IN FIBER OPTIC COMMUNICATION NETWORKS WITH REDUCED ENERGY CONSUMPTION THROUGH CLIMATE AWARENESS

Description

1 / 9 METHOD FOR OPTICAL PATH ASSIGNMENT IN FIBER OPTIC COMMUNICATION NETWORKS WITH REDUCED ENERGY CONSUMPTION THROUGH CLIMATE AWARENESS

[001] This descriptive report deals with a method for routing fiber optic communication networks that optimizes network energy consumption while meeting other functional requirements, such as bit rate, spectrum usage, and latency. The optimization method considers the energy used directly by communication equipment, such as transmitters, routers, and amplifiers, as well as the energy used indirectly for temperature control of the station housing this equipment. In particular, the method, named CARLA, from its English acronym, "Climatic-Aware Routes for Lightpath Assignment," takes into account the climatic conditions of the locations at each of the network nodes to make a more accurate estimate of the energy consumption required to route an optical signal through that node, allowing routing to be performed with the lowest possible energy consumption. FIELD OF APPLICATION

[002] The method for routing fiber optic communication networks with reduced energy consumption through climate awareness applies in the field of telecommunications systems, and more specifically in the field of optical communications. OBJECTIVE OF THE INVENTION

[003] The objective of the present invention is to reduce electricity consumption in communication networks by considering the total energy used to establish a communication route between two network nodes, considering both the energy used directly for the operation of communication equipment and the energy used indirectly for maintaining the temperature of the location housing this equipment. Consequently, the costs associated with electricity consumption by these communication networks are also reduced, as well as the environmental impacts of generating this energy. Petition 870240110296, dated 12 / 26 / 2024, p. 6 / 43 2 / 9 PROBLEM TO BE SOLVED

[004] Optical communication networks form the largest part of the global telecommunications system, comprising intercontinental networks, large transport networks, metropolitan networks, and access systems. In order to optimize their performance and provide greater flexibility for solutions, these networks can exhibit dynamic behavior in the routing of optical signals. To this end, as shown in Figure 1, one can consider, in a simplified example, a network composed of nodes

[101] and the links that connect them

[102] . Thus, information that must be sent from node A

[103] to node B

[104] can be routed in several different ways through the network, such as through paths

[105] or

[106] . Several factors can influence the path that will be chosen for the transmission of information between these two nodes, including the reduction of the operating cost of the optical network.

[005] In particular, the main factor that makes up the operating cost of these networks is the consumption of electrical energy. At each node in the network, optical signals can pass through various active equipment, such as routers, transceivers, and optical amplifiers, which have a certain energy consumption for their operation. This consumption can vary according to the characteristics of the optical signals themselves and the links used by this node, but in general it is on the order of tens of watts per optical channel used. This is a direct energy consumption, which can be optimized by aggregation and routing techniques present in the state of the art and mentioned later in this descriptive report.

[006] However, most of the energy consumption for operating the nodes of an optical network is indirect. The equipment in a node must operate at controlled temperatures, generally through air conditioning systems. Considering that optical signals in an optical fiber have about one thousandth of a watt of power per wavelength, it follows that almost all the electrical energy consumed by the equipment in the node is not added to the optical signals, but rather dissipated into the environment as heat. This heat, usually concentrated in large data centers, needs to be removed from the environment where the equipment is located. Petition 870240110296, dated 12 / 26 / 2024, page 7 / 43 3 / 9 operate through air conditioning equipment, which, due to its non-ideal efficiency, consumes a certain amount of electrical energy that exceeds the thermal energy removed from the environment in a given period of time.

[007] As an additional factor, it can be considered that the indirect energy consumption resulting from air conditioning systems at a given network node can vary depending on several climatic factors of the location where the communication equipment is operating, especially the external temperature, solar irradiance, wind speed and direction, and relative humidity. By not considering this indirect cost when assigning optical paths, a network may present an unnecessarily high operating cost. However, in the current state of the art, as highlighted in the subsequent prior art review, such indirect energy consumption factors are not usually accounted for in optimization and routing problems in optical telecommunications networks, leading to suboptimal results since they fail to consider the impact of a significant portion of the energy consumption of the complete system. STATE OF THE ART

[008] Within the context proposed for the present invention and among the techniques present in the technical literature, those aimed at reducing the energy consumption of optical networks stand out. In particular, the non-patented prior art Dong et al. 2012 (DOI 10.1109 / JLT.2012.2186557) presents an example of an optical network routing method focused on reducing energy consumption. The method considers the direct energy cost of the aggregation and transmission equipment of optical signals, optimizing energy consumption by estimating direct consumption using a database that correlates energy consumption and the different operating modes of the optical network. The method proposed in the present invention differs from this prior art by also considering indirect energy consumption, related to temperature control for the operation of optical communication equipment, incorporating climatic information to estimate consumption. Petition 870240110296, dated 12 / 26 / 2024, p. 8 / 43 4 / 9

[009] Similarly, the non-patented prior art Kyriakopoulos et al. 2015 (DOI 10.1109 / ICUMT.2014.7002072) presents an example of an optical network routing method focused on reducing energy consumption. The method considers the direct energy cost of the aggregation and transmission equipment of optical signals, optimizing energy consumption by estimating direct consumption using a database that correlates energy consumption and the different operating modes of the optical network. Here, the authors place greater emphasis on the choice of the heuristic method for optimal routing, analyzing trade-offs between the quality of the solution found and the processing time required to define the optimal routing.Again, the method proposed in the present invention differs from this prior invention by also considering indirect energy consumption related to temperature control for the operation of optical communication equipment, incorporating climatic information to estimate consumption.

[010] Similarly, the prior art US20200052786A1 presents a multi-objective optical communications network design method, including reducing energy consumption, again considering the direct energy costs of aggregation and optical transmission equipment. Again, the proposed method differs from this prior art by also considering indirect energy consumption related to temperature control for the operation of optical communication equipment, incorporating climatic information to estimate consumption.

[011] The prior art US20200052786A1 presents an apparatus and its method of use for physically performing optical routing. This apparatus has constructive characteristics that differentiate it from others in the state of the art in several respects, one of which is the potential reduction in energy consumption of optical routers. In contrast, the method proposed in the present invention differs from this prior art by offering a method that allows the optimization of the optical network, and consequent reduction of energy consumption, as a whole and not only of one of its constituent elements. Specifically, the reduction in energy consumption of this prior art is restricted to the direct energy consumption of optical routers, one of the various optical devices that can operate in a network node. The proposed method, however, Petition 870240110296, dated 12 / 26 / 2024, p. 9 / 43 5 / 9 also allows for a reduction in the indirect cost of electricity used to maintain the temperature of all optical communication equipment at the network node.

[012] Similarly, the prior art CN107710702B presents an apparatus and its method of use for physically performing optical routing. This apparatus has constructive characteristics that differentiate it from others in the state of the art in several respects, one of which is the potential reduction in energy consumption of optical routers. In contrast, the method proposed in the present invention differs from this prior art by offering a method that allows the optimization of the optical network, and consequent reduction of energy consumption, as a whole and not only of one of its constituent elements. Specifically, the reduction in energy consumption of this prior art is limited to the direct energy consumption of optical routers, one of the various optical devices that can operate in a network node.The proposed method also allows for a reduction in the indirect cost of electricity used to maintain the temperature of all optical communication equipment at the network node. DESCRIPTION OF THE FIGURES

[013] The figures included in this descriptive report are described below.

[014] Figure 1 presents a simplified diagram of an optical network with nodes

[101] and the links that connect them

[102] . Information that must be sent from node A

[103] to node B

[104] can be routed in several different ways through the network, such as through the dashed path

[105] or the dotted path

[106] .

[015] Figure 2 presents a description of the preferred way of implementing the proposed method. Initially, the network connection requirements are presented

[201] , that is, what information must be transmitted between two nodes of the network. These requirements may include functional attributes that must be respected, such as the bit rate of the signals and the maximum latency allowed in the communication between the two nodes. The routing method must mandatorily meet these requirements, while also seeking to find routing paths that reduce indirect energy consumption. To this end, an estimator

[203] uses a database

[205] that correlates the Petition 870240110296, dated 12 / 26 / 2024, page 10 / 43 6 / 9 Indirect energy consumption per unit of power and direct energy consumption per wavelength are combined with external climatic conditions such as temperature, solar irradiance, wind direction and speed, and relative humidity. The estimator also uses a current measurement of these climatic conditions

[204] to estimate indirect energy consumption at a given node. Based on the estimates of indirect energy consumption at each node, a heuristic method

[202] determines the signal routing to meet the functional attributes and minimize indirect energy consumption. During network operation, direct and indirect energy consumption are monitored and used, together with the current measurement of these climatic conditions

[204] , to update the database

[205] . GENERAL DESCRIPTION OF THE INVENTION

[016] The proposed method uses three main steps. The first is the construction of a database with the energy consumption characteristics of the network, both direct and indirect consumption. Direct consumption characteristics can be obtained from the specifications of the optical communication equipment itself, which provide such values ​​for different operating modes. Alternatively, they can also be obtained from previously made energy consumption measurements. In particular, the direct consumption information in the database aims to relate the direct consumption values ​​to the operating modes, which include the number of optical carriers, the optical power of the carriers, and the bit rates transmitted per carrier—parameters that must be considered during the optimization process.

[017] Indirect consumption characteristics can be obtained through previous measurements, since their behavior is particular to each network node. For each node, a set of indirect consumption values ​​must be collected along with their respective direct consumptions at that moment and the climatic conditions at the node, such as outside temperature, relative humidity, solar irradiance, wind speed and direction. Petition 870240110296, dated 12 / 26 / 2024, page 11 / 43 7 / 9

[018] The second stage is the iterative operation between an energy consumption estimator as a function of a certain optical network routing choice and a search method that looks for the routing configuration that meets the connection demands with the lowest indirect energy consumption. In this stage, the network is not actually altered, but instead, the estimator provides a prediction of consumption values, according to the information present in the database and the current measurements of the climatic factors of the nodes. To this end, the search method tests different network configurations as input to the consumption estimator in order to find the configuration that presents the lowest energy consumption estimate.

[019] Finally, the third step is the assignment of optimal routing to the optical network, with the effective assignment of optical path routes. At this point, new measurements of direct and indirect energy consumption can be made to assess whether the prediction provided by the estimator was accurate and, if necessary, update the database. DETAILED DESCRIPTION AND METHOD OF CARRYING OUT THE INVENTION

[020] Figure 2 presents a description of the preferred embodiment of the proposed method, in which, initially, the network connection requirements are provided

[201] .

[021] These requirements include functional attributes that must be respected, such as the bit rate between two network nodes and the maximum latency allowed in communication between the two nodes. The routing method must mandatorily meet these requirements, while simultaneously seeking to find routing paths that reduce indirect energy consumption. To this end, an estimator

[203] uses a database

[205] that correlates indirect energy consumption per unit of power with direct energy consumption per wavelength with external climatic conditions, such as temperature, solar irradiance, wind direction and speed, and relative humidity.The estimator also uses a current measure of these climatic conditions

[204] to estimate indirect energy consumption at a given node. Based on estimates of direct and indirect energy consumption at each node, a heuristic method

[202] determines the signal routing to meet functional attributes and minimize total energy consumption. Additionally, during network operation, direct and indirect energy consumption is monitored. Petition 870240110296, dated 12 / 26 / 2024, page 12 / 43 8 / 9

[206] , which are used, together with the current measurement of these climatic conditions

[204] , to update the database

[205] .

[022] Current climate measurements can be obtained from meteorological services, but preferably, the location housing the operating equipment of a node can use real-time monitoring of local climate conditions by means of a small weather station installed near the heat exchangers of the air conditioning system. This local measurement can refine the results of the method, since the impact of some variables on indirect consumption, such as solar irradiance and wind direction, may depend on the physical aspects of the building housing the node's equipment, as well as its surroundings.

[023] In turn, the estimation of indirect consumption from the current measurement can be done by the least squares method, to interpolate consumption according to current climatic conditions from the data present in the database, or by another convenient estimation method.

[024] The heuristic method for determining routing paths can be based on optimization criteria with multiple objectives. Among the multiple objectives may be the minimization of energy consumption and the mandatory functional parameters of the network, as a function of different network routing options. Particle swarm methods, genetic algorithms, evolutionary algorithms, brute force methods, among others, can be used for this search.

[025] In addition to determining the best routing for reducing energy consumption at the moment, the method can be used to make predictions for the best future routings. Both climatic factors and connection demands can have daily periodicity, which can be observed in the database and used in a prediction method. The predictive model can also use future climatic information, provided by meteorological monitoring services, which can be adjusted according to instantaneous real conditions, reducing the search space of the optimization heuristic employed. Petition 870240110296, dated 12 / 26 / 2024, page 13 / 43 9 / 9 ADVANTAGES

[026] Thus, as detailed in this descriptive report, the invention proposed here presents an innovative and unique solution for reducing energy consumption in optical networks, by incorporating the cost of energy used to maintain the temperature of optical communication equipment into the decision on the best routing configuration of optical paths, taking into account the external climatic conditions of each node and how these conditions impact indirect energy consumption. Petition 870240110296, dated 12 / 26 / 2024, p. 14 / 43

Claims

1 / 2 CLAIMS 1 - Method for assigning optical paths in fiber optic communication networks with reduced energy consumption through climate awareness, characterized by assigning the routing of optical channels in telecommunications networks with reduced energy consumption, considering, in addition to the energy spent by each element of the network, the energy spent indirectly to maintain the temperature of the optical equipment at each node of the network, incorporating in this decision information about the climatic conditions at each of these nodes and how these climatic conditions influence the total energy consumption of each of the network nodes. 2 - A method for assigning optical paths in fiber optic communication networks with reduced energy consumption through climate awareness, according to claim 1, characterized by building and maintaining a database that records the functional characteristics of each node in the optical network, such as which equipment is in operation and with what configuration, its direct energy consumption, referring to the energy consumed for the operation of this equipment at each node, the indirect energy consumption, referring to the energy consumption of the ambient temperature control systems to keep the operating temperature of the equipment at each node controlled, and the external climatic conditions of each node, especially those that have the greatest impact on indirect energy consumption, including external temperature, solar irradiance, relative humidity, and wind speed and direction. 3 - Method for assigning optical paths in fiber optic communication networks with reduced energy consumption through climate awareness, according to claim 1, characterized by employing an estimator to, according to a proposed optical path assignment, predict the direct and indirect energy cost of operating the nodes involved, using the database described in claim 2. Petition 870240110296, dated 12 / 26 / 2024, page 15 / 43 2 / 2 4 - A method for assigning optical paths in fiber optic communication networks with reduced energy consumption through climate awareness, according to claim 1, characterized by employing a search method to test, according to network connection definitions, various optical path assignment proposals, recording the energy consumption prediction results and assigning the routing with the lowest total energy consumption by adding direct and indirect consumption. 5 - A method for assigning optical paths in fiber optic communication networks with reduced energy consumption through climate awareness, according to claim 2, characterized by employing a database that relates the functional characteristics of the optical network, the characteristics of direct and indirect energy consumption, and the climatic characteristics, and, for this purpose, preferably using a local measurement of the climatic characteristics, or, alternatively, the characteristics measured by meteorological monitoring services. 6 - Method for assigning optical paths in fiber optic communication networks with reduced energy consumption through climate awareness, according to claim 2, characterized by employing a database that relates the functional characteristics of the optical network, the characteristics of direct and indirect energy consumption, and the climatic characteristics, and, for this purpose, constantly updating the database with new data obtained from the actual operation of the network in different operating and climatic configurations, allowing refinement of the results obtained in new provisioning of optical channels. Petition 870240110296, dated 12 / 26 / 2024, p. 16 / 43

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