Protection of Telecommunication Network From Natural Hazards of Global Warming

Recently, the number of natural disasters caused by climate change on Earth has been growing in the world. To develop measures to protect hardware resources from the effects of natural disasters, the project method was used. The method developed in accordance with its provisions includes the phased collection of information on the impact of natural disasters on resources, their analysis and the development of appropriate countermeasures.<br><br>The actions and manifestations of the damaging factors that were not included in the families of the corresponding damaging factors of the list "The nature of the actions and manifestations of the damaging factors of natural emergencies", but whose action is caused by certain sources of potential emergencies and affects the performance of the hardware, are revealed. A matrix of the nature of the effects and manifestations of the damaging factors of natural emergencies has been developed.<br><br>Based on the Classifier of Emergency Situations of Ukraine, a Register of natural threats to the telecommunication network hardware has been built. New sources of threats have been discovered (13 items). The global warming process has amplified the harmful effects of known dangers and identified a number of new ones that are proposed to be classified. The “catalyst” of dangers can be anthropogenic impact, which is distinguished by the promotion of climate change, the artificial modification of the environment.<br><br>The variability of the environment does not allow to present a complete list of detailed systematized threats, actions and manifestations of damaging factors and their compliance with certain threats. The list of known protective actions includes organizational measures and countermeasures. According to existing experience, the network hardware resources must comply with the principle of redundancy, in which the operational reconfiguration is performed. It is proposed to apply redundancy of communication lines by means of three-level multiplexing with mutually independent levels.


Introduction
Over the past few decades, the number of natural disasters caused by global climate change on Earth has been increasing worldwide: -frequency of hydrometeorological disasters is growing: floods, droughts, heat and cold waves, hurricanes and storms [1,2]; -frequency of geological disasters is growing: landslides, avalanches, soil erosion [2,3]; -frequency and prevalence of fires is growing in savannahs and forests [2,4].
Such extreme events periodically occur in each of the regions of the world. The economic damage from them is measured in huge amounts [3].
It is noted that the most threatening consequences of warming for the regions of the world are waiting for the seafood industry, agriculture, tourism, insurance compa-nies; in addition, coastal settlements sensitive to sea level rise [3].
The increase in the number of disasters caused by global climate change, determine the need to develop recommendations for the protection of one of the main sectors of modern production -telecommunications, for example [5][6][7][8][9].
However, the variability of the modern natural-anthropogenic environment can cause changes in the intensity, power and the list of threats. Global warming is one of the factors that accelerates the invasive process, the available information about the "aggression" of invasive species in relation to the local environment [10]. The seismicity of the regions is largely determined by microseismic oscillations of the lithosphere, which are caused by a shift in the frequency spectrum of natural oscillations of water bodies, in turn, depend on the water level [11].
This state of affairs forces to review the list of threats, analyze their effect, and develop protective measures.

Literature review and problem statement
The Recommendation of the Telecommunication Standardization Sector of the International Telecommunication Union (ITU) ITU-T L.92 (10/2012) presents the most devastating natural disasters threatening telecommunications [6].
The effects of hazards on telecommunications determine the resources of the telecommunications network (TCN). Fig. 1 presents a matrix of environmental factors caused by natural disasters and the stability of TCN hardware resources to this action. Elements of the matrix represent the degree of influence of the factor on the resource: insignificant (I), moderate (M) and significant (S). Table 1 shows typical effects of natural disasters on TCN elements in more detail.  Table 1 Typical consequences of natural disasters and possible measures to reduce damage from them [6] Disaster Effects G Protection Measures  The precautionary measures to reduce losses from natural disasters for TCN, proposed in accordance with ITU-T Recommendations L.92, are divided into groups (Table 1). Separately, groups of measures (G) for the prevention of natural disasters were identified: preventive measures (P), countermeasures (C), monitoring (M) [6].
ITU recommendations [6,7] are limited to the list of the most destructive dangers to date and how to protect against their action. However, they do not address other potential dangers for telecommunications.
An extended list of natural disasters in the amount of 38 items that may occur in Ukraine in various sectors of the national economy of the country is given in the National Classifier DK 019: 2010 "Classifier of emergency situations" (from 11.10.2010, No. 457). However, in DK 019:2010 there are no "indicative" dangers of the global warming period: temperature rise [7,8], sea level rise [7,8], and changes in precipitation regimes [8]. In addition, the document does not discuss how to protect a telecommunication network.
The performed analysis of the literature shows the feasibility of conducting a study devoted to examining the growing threats of the telecommunication network as a result of global warming, analyzing their impact on network hardware resources and developing countermeasures.

The aim and objectives of research
The aim of research is to develop measures to reduce the losses of the telecommunication network from the effects of natural disasters in general, and new threats of global warming in particular.
To achieve this aim it is necessary to solve the following objectives: -determine the list of threats to the hardware resources of the telecommunications network, which may be stipulated by global warming; -analyze the effect of threats on the telecommunications network; -develop countermeasures.

Method of developing measures to protect the telecommunications network from the effects of natural disasters
The research material is a natural and anthropogenic environment, which is exposed to natural disasters.
A method to achieve this aim is technology, which should end with reasonable proposals for protecting the telecommunications network from the effects of natural disasters.
The developed method for developing measures to protect the telecommunications network from the effects of natural disasters includes the phased collection of information about the effects of natural disasters on the hardware resources of the telecommunications network, their analysis and the development of appropriate countermeasures.
At the initial stage, a list of threats is determined, the occurrence of which can be caused by processes that accompany global warming of the climate on Earth.
At the second stage, an analysis is made of the influence of observations of the effects of natural disasters on the functioning of the telecommunication network.
At the final stage, a synthesis of possible measures to reduce losses from certain threats is performed.

1. Threats, the occurrence of which may be caused by processes that accompany global warming on Earth
The stability of hardware resources in natural threats is ensured provided that the onset of the limiting state is not allowed [12]: where ( ) , S r t  -value of the resistance criterion to the action of the damaging factor (DF), r  -radius vector of the point of the DF field; t -time; ( ) , F r t  -DF value. Table 2 is a list of the damaging factors of natural emergencies, the nature of their actions and manifestations, according to the RF standard GOST R 22.0.06-95.
The damaging factors form a matrix, the rows of which are their names in alphabetical order, and the columns are the characters of action and manifestation in decreasing order of frequency of occurrence in the list. The matrix elements are denoted in the form F n_ f , where n -the number in order of DF name, f -the number in order of the characteristic action and manifestation of the damaging factor in a variety of items. A fragment of the matrix is shown in Fig. 2. For the trouble-free operation of telecommunications equipment subject to extreme heat or cold, appropriate countermeasures should be provided; for the trouble-free operation of telecommunication equipment located in places with sharp temperature fluctuations, appropriate countermeasures must be provided C Protection of cable sewers from snow penetration by sewer manholes and the use of antifreeze as a coolant in GMCLP Table 2 The nature of the actions and manifestations of the damaging factors of natural emergencies [13] Emergency source DF name/designation The nature of DF action and manifestations  Table 3 provides a list of natural disasters that could lead to emergencies. The National Classifier DK 019:2010 was taken as the basis. The table is supplemented by phenomena that were not included in the classifier: from the matrix of environmental factors caused by climate change and the hardware resources of the telecommunication network, Fig. 1 [7]; Table 1 "Typical consequences of natural disasters and possible measures to reduce damage from them" [6]; from Table 2 "The nature of the actions and manifestations of the damaging factors of natural emergencies" [13].   [14]; to protect cables from the effects of EMF (F 11_2 ), calibration, cascade protection and grounding of CL, the installation of arresters and fuses are used; the establishment of lightning rods on OCL and cables -on CL [15] Solar flare Radio emissions, increasing magnetic field strength [15,16] Alerts, changes in regulations and standards that determine the parameters of equipment operation, the creation of a reserve of necessary facilities and equipment, and the training of forces for restoration (repair) [16]; from the EMF action (F 11 _ 2 ) -as in an earthquake (code 20110) 20200. GEOLOGICAL PHENOMENA

Eruption of a mud volcano
See Table 2 See Fig. 3 [6] 20220. Landslide See Fig. 1, Table 1, 2 See Table 1, Fig. 3 20230. Collapse or talus See Fig. 1, Table 1, 2 See Table 1, Fig. 3 20240. Deposition (failure) of the earth's surface See Table 2 See Fig. 3 20250. Karst dips See Table 2 See Fig. 3 20260. Rising groundwater table (flooding)) See Table 2 See Fig. 3, protection of underground metal structures from corrosion (F 4_4 ) can be carried out by insulating coatings, tread, cathode or electrodrainage installations, line-protective grounding [14]; restrictions on the location of telecommunication facilities in areas of possible flooding [8,9]; artificial increase of planning marks of the surface of the territory; normative compaction of the soil when filling of pits and trenches; ensuring proper drainage of surface water, the construction of protective structures [17] 20300. METEOROLOGICAL PHENOMENA

Precipitation-related phenomena
Flooding, flooding [8] As for cases of flooding (code 20260), flooding (code 20590) 20311. Heavy rain See Fig. 1, Table 2 See Fig. 3 20312. Large hail See Table 2 Undefined 20313. Very heavy snow See Fig. 1, Table 1, 2 See Table 1, Fig. 3 20314. Very heavy rain (rain and sleet) The combined effect of heavy rain (code 20311) and very heavy snowfall (code 20313) Accordingly, as for heavy rain and very heavy snowfall

Change in precipitation patterns
May cause precipitation (abyss) of the earth's surface (code 20240) [8] Accordingly, measures -as in the case of precipitation (abyss) of the earth's surface Continuation of Table 3 1 2 20320. Meteorological temperature 20321. Very severe frost See Table 1, 2  See Table 1 20322. Very intense heat See Table 1, 2  See Table 1 Temperature increase See Fig. 1, may cause equipment overheating [8] Application of ventilation and air conditioning systems [7,8]; revision of equipment protection requirements [8] 20330. Meteorological, other 20331. Strong wind, including squalls and tornadoes, hurricanes, typhoons, wind storms See Fig. 1 20335. Snow drifts See Table 2 See Table 1 20336. Snowstorm See Table 2; overvoltage on the OCL wires [15] See Fig. 3, from the action of EMF -as in an earthquake (code 20110) 20337. Heavy fog See Table 2 Not found Increased atmospheric moisture [7] See Fig. 1, can accelerate hardware corrosion [8] View equipment protection requirements; condensate monitoring [8] Lightning strikes [7,13] See Fig. 3, Table 2; the lead sheath of the underground cable melts, the jute braid burns out, the insulation burns, the cable conductors melt, etc. [15] Cable protection from electrical discharges (F 7_1 ) can be carried out by insulating coatings, tread, cathode or drainage systems, line-protective grounding [14]; protection of equipment from direct lightning strikes is carried out using an external lightning protection system [19]; shielding, connections of metal elements, grounding, surge protection devices are used to protect against secondary effects of lightning [19] 20400. HYDROLOGICAL MARINE PHENOMENA

Strong (high) unrest of the sea and the reservoir
The action is similar to the effect of a high water level (high water, high water) (code 20510) special foundations (F 2_13 ) are assigned for OCL supports [20] 20420. High or low sea level High sea level action similar to high water level action (code 20510) low sea level action similar to low water/drought action (code 20520) Accordingly, for the case of high sea level -as for high water level for the case of low sea level -as for low water/drought Sea level rise [7] See Fig. 1, corrosion acceleration of coastal infrastructure, flooding [8] Viewing the heights of reference points for some calculations of telecommunication equipment [8] 20430. Early freeze-up or fast ice  Table 2 See Fig. 3 The resulting registry (Table 3) includes both a detailed list of telecommunications network threats and a description of their impact on hardware and related countermeasures.

2. Analysis of observations of the effects of natural disasters on the functioning of the telecommunication network
Characteristic actions and manifestations of damaging factors that affect the performance of the hardware were found (Table 3), but are not mentioned in the list of Table 2 "The nature of the actions and manifestations of the damaging factors of natural emergencies", namely: -for phenomena related to precipitation (code 20310), to flooding (F 2_6 , code 20590) of linear-cable structures of telecommunication transport networks located in lowlands, inspection and inspection wells, as well as underground structures and data centers located in the coast and on urban lands, the risks of flooding are added (increase in groundwater level F 3_1 , hydrodynamic pressure of the groundwater Continuation of Table 3   1  2 20550. Snow avalanche See Table 2 See Fig. 3 20560. Low water The action is similar to the action of low water/drought (code 20520) How to protect against water shortage/drought 20570. Early ice formation and the appearance of ice in navigable water bodies and rivers Undefined Undefined 20580. Intensive ice drift Damage to the OLC supports [20] On floodplains with severe ice conditions, special foundations are assigned to the OLC supports [20] 20590. Flooding See Table 2 See Fig. 3 Shore processing [13] See Table 2 See Fig. 3 Channel erosion [13] See  Table 5 -gnawing See Table 4 [21] See Table 5 -destruction See See Table 5 -chem. action of released substances See  Table 5 Biocorrosion See Table 4 [21] See Table 5 flow F 2_15 , soil contamination (salinization) F 4_3 , corrosion of underground metal structures F 4_4 , code 20260) [8]; -in cases of a strong dust storm (blowing and filling of the topsoil F 1_5 , code 20332) and a strong snowstorm (snow load F 2_11 , wind load F 2_2 , snow drifts F 2_12 , code 20336) small grains of sand and ice crystals flying at high speed above the ground as a result of friction, they receive electric charges that they give to hanging wires in a collision with the latter. As a result, overvoltages are created on overhead lines; -the thermal damaging factor "Heat flow" F 10_3 is assigned to the phenomena associated with fires in natural ecological systems (code 20600). At the same time, the consequences of strong heating of the underground cable can be a lightning strike; -the physical damaging factor "Electromagnetic field" (F 11_2 ) is assigned to the phenomena associated with the earthquake (code 20110). At the same time, as a result of changes in the magnetic field of the Earth, they can be caused by a magnetic storm caused by a solar flare; -the physical damaging factor "Electromagnetic field" (F 11_2 ) is assigned to the phenomena associated with the earthquake (code 20110). At the same time, overvoltages on the OCL overhead wires , caused by the action of an electromagnetic field, are created as a result of climbing over small grains of sand (strong dust storm, code 20332) and ice crystals (strong snowstorm, code 20336).
Identified natural threats to hardware that are not included in the base table "Register of natural threats to telecommunications network hardware".
1. In the "traditional" for global warming, an increase in temperature, an increase in the atmospheric moisture content, changes in precipitation regimes and an increase in sea level are attached: -severe ice due to an ice storm (let's note that only in the USA during 1949-2000. Ice storms led to 87 largescale accidents, causing damage in the amount of 16.3 billion USD [22]); -solar flares (for example: September 1-2, 1859 disabling telegraph networks in Europe and America; August 4, 1972the telephone network of the state of Illinois (USA), it is noted that significant differences arising from a sharp change in the Earth's magnetic field due to a magnetic storm potentials between points on the earth's surface that are remote from each other affect the operation of single-core communication circuits (remote supply via wire-to-ground system, signaling circuits, etc.) [16]. For long-term passage along the circuit, earth currents can lead to damage in electronic equipment [15]); -lightning strikes [15]. 2. There is evidence of biological attacks on communication cables [10]: -high humidity and temperature contribute to the growth of molds, which reduce the strength of the protective covers of the cable and change the properties of water-blocking materials; -termites, ants, tree bugs and larvae damage the protective cover of the cable; ants and termites release active acid secretion, which, when in contact with the cable, can cause corrosion of metal elements; -overhead cables damage birds; in addition, their livelihoods are characterized by a high content of chemically and biologically active substances, which are aggressive environments for cable sheaths.
The development and behavior of native species in the context of global warming, their impact on telecommunication equipment requires a detailed study. Invasive species require even more calculated attention.
Known methods for disrupting the operational state of electronic and electronic computing devices that can cause a combination of organisms or their communities are given in Table 4. Table 4 Classification of biological damage to electronic and electronic computing devices [21] Biodeterioration type Explanation 1. Mechanical failure upon contact (caused mainly by macroorganisms having dimensions comparable to product dimensions): -collisions birds with radio antennas -gnawing materials by rodents, or species -destruction usually occurs in the process of feeding organisms 2. Deterioration of operational parameters: -biocontamination allocation of organisms and their metabolic products, the action of which as a result of wetting with water or absorbing moisture from the air leads to a change in product parameters -bioobstruction spores of fungi and bacteria, plant seeds, parts of mycelium of fungi, bird droppings, excreta of organisms, dying organisms -biofouling * bacteria, fungi, sponges, mollusks and other organisms, enhances metal corrosion 3. Biochemical destruction (caused mainly by microorganisms that are microscopic in size and invisible to the naked eye): -biological consumption during nutrition associated with preliminary chemical destruction by the enzymes of the starting material, sometimes only one component (usually a low molecular weight compound, for example a plasticizer, stabilizer). Such destruction opens the way for physical and chemical corrosion, leads to a deterioration in the thermodynamic properties of the material and its mechanical destruction under the action of operational loads -chemical effects of released substances the chemical effect of the products of the exchange of microorganisms, which increases the aggressiveness of the environment, stimulates corrosion processes 4. Biocorrosion biocorrosion on the face of the material-organism is due to the action of amino and organic acids, as well as hydrolysis products; it is based on electrochemical processes of metal corrosion under the action of microorganisms Note: * -lightning currents that flow along the roots of plants can cause damage to the underground cable [15]. The fact that an increase in temperature stimulates their growth is noted in [8] In the literature accessible to the authors, no data were found on the effects on the hardware of a telecommunication network of the following natural threats: -early ice formation or fast ice (code 20430); -threatening icing of ships (code 20440); -early ice formation and the appearance of ice in navigable water bodies and rivers (code 20570).

3. Synthesis of possible measures to reduce losses from certain threats
Specific measures known from the literature for protecting telecommunications network hardware from certain natural hazards are summarized in the Register (Table 3). The generalized measures are described further and are reduced to recommendations for the protection of linear cable structures and organizational measures.
Practical recommendations for protecting key telecommunications facilities, communication cables, from some pests are given in Table 5. To protect the line-cable structures from atmospheric and hydrological threats, it is proposed to lay them underground. Fig. 3 presents examples of enhanced measures to protect underground linear cable structures.
To protect hardware from natural threats (Table 3), the following organizational measures are proposed: -to protect against geophysical (code 20100) and geological phenomena -to maintain the readiness of monitoring, forecasting, warning systems; decide on the feasibility of building in hazardous areas; maintain the readiness of forces and means to eliminate the consequences of the action; -for protection against meteorological phenomena (code 20300) -to identify precursors, detect disasters; notify the population; establish a strict procedure for building codes in high-risk areas; develop emergency plans in in high-risk areas; -for protection against hydrological marine phenomena (code 20400) -conduct and refine risk assessments and hazard identification; organize a centralized monitoring and control system; identify and specify areas with the most dangerous and frequent anomalies and determine the risks of emergencies in them; strengthen measures to protect territories in hazardous areas; create a reserve of funds and equipment for recovery; -to the extent possible, eliminate or minimize the linking of communication infrastructure to the electricity network infrastructure, providing backup power through diesel generators, autonomous wind and solar power plants.
When assessing the reliability of a telecommunication channel, its resistance to threats is determined by the channel availability coefficient, which is calculated by the formula [24]: where t w , w t -the duration, respectively, of the work and disability of the channel, the stability of which is determined by inequality (1), after a certain control time interval ( ) .
w w t t + Fig. 3. Examples of measures to protect underground line-cable structures from the experience of Japanese telecommunications experts [6]: 1 -sliding joint for manholes (a gas pipe connection); 2 -sliding joint for gas pipelines; 3 -sliding connection with a stopper; 4 -flexible connection for sinking the wall of the cable shaft; 5 -flexible connection of cable channels; 6 -flexible connection of sections of the gas pipeline for penetration into the building; 7 -flexible connection; 8 -sliding joint+coupling; 9 -sliding connection with a stopper+concrete cable tray; 10 -sliding connection with a stopper+connecting sleeve; 11 -reinforced concrete manhole cover; 12 -building user services; 13 -cable channel; 14 -cable shaft; 15 -cable duct; 16 -sinking bridge; 17 -inspection well (IW); 18 -revision well (RW); 19 -normal soil; 20 -water-saturated soils; 21 -directions of displacements; 22 -wall of the building; 23 -flexible corrugated gas pipeline According to existing experience, the hardware resources of a telecommunication network must comply with the principle of redundancy, in which an operational reconfiguration is performed. It is proposed to apply reservation of communication lines due to alternative technologies, for example, optical transmission technology in free space, high-frequency communication over power lines. All this, first of all, concerns the transport network common for telecommunication services users. Fig. 4 shows the functional diagram of the network, the increase in resources of which is carried out due to three-level multiplexing with mutually independent multiplexing levels. The principle of independence is also supported within the levels: due to the frequency and time separation of signals, separation of signals by physical nature (electrical, optical), separation by media (free space, artificial guides). The availability factor of the proposed communication system, built from n duplicated channels of the telecommunication network, is calculated by the formula: where i k -availability factor of the i-th communication channel.

Discussion of the results of the study of natural threats to the telecommunications network and measures to reduce damage from them
As a result of studies, characteristic actions and manifestations of damaging factors that were not included in the Table 2 "The nature of the actions and manifestations of the damaging factors of natural emergencies" were revealed, but the effect of which affects the operability of hardware (Table 3) -6 positions of emergency sources. Natural threats to hardware were identified that were not included in the register of natural threats to telecommunication network hardware (Table 3) -13 positions of emergency sources. No data were revealed on the impacts on the hardware of the telecommunications threat network -3 positions of emergency sources.
Global warming is one of the factors that accelerates the invasive process. Available information on the "aggression" of invasive species in relation to local flora and fauna. The danger catalyst can be anthropogenic impact, which is distinguished by the promotion of climate change, the artificial modification of the environment. There is evidence of attacks on communication cables, electronic and electronic computing tools that can cause invasive and indigenous populations of organisms or their communities, plants under global warming.
The limited amount of work, the variability of both natural and anthropogenic (artificial) environments do not allow, firstly, to provide reasonable, systematized actions and manifestations of damaging factors in detail and their compliance with certain natural threats, and secondly, a complete list of protective actions that has become would be a panacea for all ills and forever.
Therefore, no data has been identified on the protection of hardware from a number of actions and manifestations. To protect the TCN, in addition to organizational measures, cable laying and installation of linear cable structures underground is proposed. Recommendations are given on protecting communication cables from rodents, birds, ants and termites, woodpeckers, wood insects and their larvae.
According to existing experience, the hardware resources of a telecommunication network must comply with the principle of redundancy, in which an operational reconfiguration is performed. It is proposed to apply the reservation of communication lines by three-level multiplexing with mutually independent multiplexing levels. The principle of independence is also supported within the levels: due to the frequency and time separation of signals, separation of signals by physical nature (electrical, optical), separation by media (free space, artificial guides).
As a result of the study, the ES sources have been identified; they constitute natural threats to hardware, but are not mentioned in the National Classifier of Ukraine DK 019:2010. The global warming process has amplified the harmful effects of known dangers and identified a number of new ones that are proposed to be classified. A significant threat to the telecommunications network is the accelerated evolution of bio-vision in a changing natural environment. The "catalyst" of the danger can be anthropogenic impact, which is distinguished by the promotion of climate change, artificial modification of the environment.
The study is a continuation, firstly, of ITU's research to identify threats inherent in global warming, and secondly, to identify measures to protect telecommunication network resources from them. Future research should continue to identify possible "latest" threats, acting on their prevention. This will prevent emergency situations, in particular in the field of telecommunications. Another area of future research is a deeper analysis of the effects of natural disasters. As practice shows, they can have a significant list of damaging factors, which requires advancing additional requirements for the stability of hardware resources.

1.
A method has been developed to develop measures to protect the telecommunications network from the effects of natural disasters. The method is easily formalized and algorithmized, and includes a phased collection of informa-tion about the effects of natural disasters on the hardware resources of the telecommunication network, their analysis and the development of appropriate countermeasures. The method can be used in the formation of orders for information and communication research, in studies of a wide range of extreme impacts on the natural and anthropogenic environment, in particular those that have departmental and regional directions, in developing measures to counter impacts, in developing relevant strategic and current research plans programs.
2. A register of natural threats to the telecommunication network hardware has been developed, containing data on the impact of the hazard and measures to protect it. The main position of the registry is that measures to protect any resource of a telecommunication network are adequate influential phenomena on the resource, and are directly dependent on the nature of the action and the manifestations of threats that form the appropriate matrix.
3. To protect the telecommunications network from natural threats of global warming, it is proposed to use a network whose resources are increased through three-level multiplexing with multiplexing levels that are independent of each other. Three-level multiplexing allows to optimize the telecommunications network at the design and modernization stages, in particular, duplicated network resources in the conditions of established restrictions.