RU2783589C1 - Method for functioning of a radio relay network with packet switching - Google Patents

Abstract

FIELD: communication.

SUBSTANCE: to realise the technical result, the level of traffic service quality and the nature of variation in the bandwidth of one-dimensional transmission routes K_o and the multidimensional transmission route K_m of the RRN are estimated; the time interval for determining the nature of variation in the bandwidth and the upper limit of bandwidth of each one-dimensional transmission route K_{o add} and the multidimensional transmission route K_{m add} is set; when the value of the nature of variation in the bandwidth of the multidimensional transmission route K_m reaches the threshold value K_{m add}, the nature of variation in the real bandwidth γ of the RRN is calculated; when the nature of variation in the real bandwidth γ reaches the set required bandwidth γ_req, the RRN is reconfigured into a structure providing the required level of traffic service quality based on the nature of variation in the bandwidth of one-dimensional and multidimensional routes, thereby raising the operating efficiency thereof.

EFFECT: increase in the operating efficiency of a radio relay network (RRN) with packet switching due to the structural reconfiguration thereof and increase in the amount of serviced packet traffic.

2 cl, 18 dwg

Description

The invention relates to the field of communication networks and can be used in the design and construction of new or improvement of existing radio relay communication networks with packet switching.

A known method for modeling the processes of ensuring the technical readiness of communication networks during technical operation and a system for its implementation (See RF Patent No. 2336566, G06N 1/00, publ. 20.10.2008, bull. No. 29), is to determine the circuit characteristics of the elements of the communication network , establishing their relationship, describing the structure of the communication network, dividing all links into main and backup, setting arbitrary combinations of damage to the elements of the communication network, determining the value of the indicator of the failure rate of the state of links between the elements of the communication network, modeling the process of ensuring technical readiness during the operation of the communication network, simulating various types failures, damages and failures of the main elements of the communication network, replacing damaged links with backup ones, determining the value of the indicator of restoration of the communication network, collecting statistics, forecasting the technical condition of the main elements of the communication network and calculating the main indicators of the functioning of communication networks.

The disadvantage of this method is the relatively low efficiency of the functioning of the radio relay network (CPC) with packet switching, since the reconfiguration of the communication network is performed without taking into account the requirements for the service level and estimating changes in throughput in the transmission routes. The effectiveness of the CPC functioning is understood as the amount of serviced packet traffic over a period of time with the required level of quality of service.

A known method for ensuring the stability of communication networks under conditions of external destructive influences (See Patent RU 2379753 C1, IPC G06F 21/20, G06N 3/02, published on January 20, 2010, bull. No. 2), consists in controlling external destructive influences, estimating throughput ability and, by distributing the available resource among subscribers, ensuring the timeliness of the provision of information services.

The disadvantage of this method is the relatively low efficiency of the packet-switched CPC, since the throughput is estimated only taking into account destructive influences and does not allow taking into account the throughput losses due to network congestion.

The closest in technical essence to the claimed invention (prototype) is a method for improving the efficiency of the communication system (See RF Patent No. 2729556, C1. class H04L 29/02, H04W 28/02, publ. 08/07/2020). The known method consists in measuring the actual bandwidth γ of the communication system, setting the required bandwidth γ _tr , based on the measured real bandwidth γ and the specified required bandwidth γ _tr calculate the probability of blocking the communication system P _bl , measure downtime and operating time elements of the communication system, on the basis of which the availability factor of the communication system and the probability of connectivity of the communication system P _sv are calculated, based on the probability of blocking the communication system P _bl , the probability of connectivity of the communication system P _sv , the real bandwidth γ and the specified required bandwidth γ _tr calculate the risk of loss throughput of the communication system R, compare it with the set allowable value _Radd , and if the set allowable value is exceeded, the communication system is reconfigured.

The disadvantage of the prototype method is the relatively low efficiency of the packet-switched CPC. This is because packet-switched CPC reconfiguration is performed without considering service level requirements and estimating changes in throughput in transmission paths. The reconfiguration of the packet-switched CPC is carried out only on the basis of the calculated bandwidth loss risk value, which does not allow choosing the optimal variant of its reconfiguration depending on the trend of bandwidth change in one-dimensional and multidimensional transmission routes.

The technical result when using the claimed method of functioning of the SRS with packet switching is to increase the efficiency of its functioning by reconfiguring the structure before the appearance of congestion in a multidimensional route and increasing the amount of packet traffic served over a period of time with the required level of quality of service.

The technical result is achieved by the fact that in the known method of functioning of the SRS, which consists in measuring the actual bandwidth γ SRS, set the required bandwidth γ _tr . Based on the measured real throughput γ and the given required throughput γ _tr calculate the probability of blocking CPC R _bl . Downtime and operating time of radio relay stations are measured, on the basis of which the availability factor and the probability of connectivity CPC R _St are calculated. Additionally, the level of traffic quality of service and the nature of the change in the capacity of one-dimensional transmission routes K _o CPC are evaluated. Based on the nature of the change in the capacity of the one-dimensional transmission routes, the nature of the change in the capacity of the multidimensional transmission route K _m CPC is estimated. Set the time interval for determining the nature of changes in throughput and the upper limit of the bandwidth of each one-dimensional transmission route K _{about ext} , as well as the upper limit of the bandwidth of the multidimensional transmission route K _{m ext} . Upon reaching the value of the nature of the change in the capacity of the one-dimensional transmission route K _about to the boundary value K _{about additional} add to the multidimensional route the nearest less loaded one-dimensional transmission route, which provides the required level of quality of service. Upon reaching the value of the nature of the change in the throughput of the multidimensional transmission route K _m to the boundary value K _{m additional} calculate the nature of the change in the real throughput γ CRS. Upon reaching the nature of the change in the real throughput γ of the specified required throughput γ _tr reconfigure the SRS.

Thanks to a new set of essential features, the method implements the possibility of reconfiguring the packet-switched CPC to a structure that provides the required level of quality of service for traffic based on the nature of the change in the throughput of one-dimensional and multidimensional routes, which increases the efficiency of the packet-switched CPC.

The claimed method is illustrated by drawings, which show:

fig. 1 is a general view of a packet-switched CPC that implements the proposed method;

fig. 2 - norms for services with distribution by service classes;

fig. 3 - representation of the CPC in the form of a directed acyclic graph;

fig. 4 - parameters of the adaptive modes of the MD-310E modem of the R-416GM radio relay station;

fig. 5 - an example of changing the throughput of radio relay intervals at time intervals t ₁ t ₁₂ ;

fig. 6 shows an example of change in throughput in one-dimensional and multidimensional routes in the SRS at time intervals t ₁ - t ₁₂ ;

fig. 7 - an example of the distribution of bandwidth in the SRS at time intervals t ₁ , t ₂ ;

fig. 8 - an example of the distribution of bandwidth in the SRS on the time interval t ₄ ;

fig. 9 - an example of the distribution of bandwidth in the SRS on the time interval t ₇ ;

fig. 10 - an example of the distribution of bandwidth in the SRS on the time interval t ₈ ;

fig. 11 - an example of the distribution of bandwidth in the SRS on the time interval t ₉ ;

fig. 12 - an example of the distribution of bandwidth in the SRS on the time interval t ₁₀ ;

fig. 13 - an example of the distribution of bandwidth in the SRS on the time interval t ₁₁ ;

fig. 14 - an example of the distribution of bandwidth in the SRS on the time interval t ₁₂ ;

fig. 15 is an example of capacity dynamics in a 1-2-3 one-dimensional route;

fig. 16 is an example of capacity dynamics in a one-dimensional 4-5-6 route;

fig. 17 is an example of the dynamics of capacity change in a one-dimensional route 1-5-3;

fig. 18 is an example of capacity dynamics in a multidimensional route.

The possibility of implementing the claimed method is explained as follows. In accordance with FIG. 1, a radio relay network with packet switching is built on the basis of radio relay stations with channel-forming equipment in the form of routers that provide packet switching.

The maximum possible throughput of the radio-relay line, when the number of distinguishable states of the information parameter of the signal is selected in advance, taking into account the possibilities of their stable recognition by the receiver of the radio-relay station, is written as C=2Δƒ _l log ₂ M, where Δƒ _l is the bandwidth of the line, Hz; M - the number of distinguishable states of the information parameter of the signal (Digital radio relay stations: Textbook for higher educational institutions of communication / S.A. Yakushenko, S.A. Bondarenko, S.O. Burlakov. - St. Petersburg: VAS, 2011. - 336 p. page 39).

In high-speed radio relay stations, adaptive quadrature amplitude shift keying M-QAM is implemented, where M is the number of modulation positions (M=4, 64, 128), which allows you to select the number of positions depending on the current signal-to-noise ratio on the radio-relay communication line. With a decrease in the signal-to-noise ratio on a radio relay communication line, the number of modulation positions is automatically reduced, while the throughput of the communication channel decreases. With an increase in the signal-to-noise ratio on the radio-relay communication line, the modulation ratio increases, while the throughput of the communication channel increases.

A one-dimensional transmission path in a packet-switched CPC is a set of serially connected communication channels in a point-to-point connection between the radio relay station, which is the source of messages, and the radio relay station, the recipient of messages.

A multidimensional message path in the CPC is a plurality of independent one-dimensional transmission paths connected in parallel over which the packet traffic constituting the message is transmitted. Depending on the service level of the one-dimensional transmission path, the information load is selected. In case of degradation of the service level of the one-dimensional transmission path, the number of message packets sent by the router of the radio relay station along the one-dimensional transmission route is reduced to a value that provides a given level of message service. By improving the service level of a one-dimensional transmission path, its load can be increased.

The level of service is understood as a set of technical parameters that characterize the compliance of a certain group of resources with the incoming load under certain conditions [Recommendation E. 800 "Terms and definitions for traffic engineering"; Lemeshko AV, Model and method of overload prevention with active queue management at the nodes of a telecommunication network // Problems of telecommunications. - 2014. - S. 91-104; Srinivas V., Quality of service in IP: textbook. Allowance / V. Srinivas. - M.: Williams Publishing House, 2003. - 368 p.]. The quality of service level of each data stream is determined by the timeliness of packet delivery, estimated by the achievable maximum end-to-end packet delay of the i-th end-to-end data stream of the s-th class from the set S of traffic classes t _reach , not exceeding the required value t _required , determined by recommendation Y.1541: ∀s ∈ {S}, ∀i ∈ {1,…,n} t sat _{≤t req} .

In FIG. 2 presents the norms for services with a distribution by quality of service classes, expressed in terms of the maximum allowable packet transmission delay between the radio relay station, which is the source of messages, and the radio relay station - the recipient of messages t _req . The guaranteed quality of service of the provided multiservice services is achieved by providing the required delay in the processing of packets of the i-th stream in the router of the radio relay station - the recipient of messages.

The level of quality of service for traffic is assessed using an integral indicator for various categories and types of traffic, which is calculated by the formula

Q _ku \u003d (T _ku , P _ku , D _ku ),

where Q _ku is a generalized indicator of the quality of service of packet traffic, T _ku is the delay time, P _ku is the probability of timely delivery and D _ku is the delay variation for various traffic categories k∈[1, K] and traffic type u∈[1, U] .

The indicator Q _ku is calculated as an integral assessment of three indicators, taking into account the weight coefficients g, which are determined by the method of expert assessments.

Parameters T _ku , P _ku , D _ku are normalized according to the formula

- нормированное значение параметра в диапазоне [0,1]; X_max X_min - максимальное и минимальное значение нормируемого параметра соответственно, которые определены на фиг. 2, х - текущее значение нормируемого параметра.where

- normalized value of the parameter in the range [0,1]; X _max X _min - the maximum and minimum values of the normalized parameter, respectively, which are defined in FIG. 2, x - current value of the normalized parameter.

Taking into account the above, the assessment of the level of quality of service of packet traffic is carried out according to the formula:

- нормированные значения задержки, потерь и вариации задержки для соответствующей категории и типа трафика.where g ₁ ,g ₂ ,g ₃ - weight coefficients for the corresponding indicators,

- normalized values of delay, loss and delay variation for the corresponding category and type of traffic.

The nature of the change in the capacity of one-dimensional and multidimensional transmission routes K _o and K _m of the radio relay network can be calculated using various methods, for example, the method of exponentially weighted moving averages [Forecasting socio-economic processes: Educational and methodological manual. // Author-compiler: Kapitanova O.V. - Nizhny Novgorod: Nizhny Novgorod State University, 2016 - 74 p. page 34]

where y _t - the actual levels of the time series, t - points in time, and - the weight attributed to the level of the series.

The value of the trend is determined by the totality of previous values, the influence of which weakens exponentially.

The required bandwidth γ _tr of a radio relay network is determined based on the needs of users in services and types of communication (Olifer V., Olifer N. Computer networks. Principles, technologies, protocols: Textbook for universities. 5th ed. - St. Petersburg: Peter, 2016. - 992 p.). Measure the actual throughput. Based on the required throughput γ _tr and the measured real throughput of the radio relay network γ, the probability of blocking the radio relay network R _bl is determined (Schwartz M. Communication networks: protocols, modeling and analysis: in 2 hours. Part 1. Per. in English - M.: Nauka, 1992). The operating time and idle time of radio relay stations are measured, for example, using software-implemented stopwatches. Calculate the availability factor of the radio relay network (GOST R 53111 - 2008. Stability of the public communication network. Requirements and verification methods. - M.: Standartinform, 2009 - 19 p.). On the basis of the availability factor, the probability of connectivity of information directions R _s is determined (GOST R 53111 - 2008. Stability of the public communication network. Requirements and verification methods. - M .: Standartinform, 2009 - 19 p.).

In FIG. As an example, Figure 1 shows the structure of the SRS, built on the basis of R-416GM radio relay stations, in which operating modes with adaptive modulation are implemented. The radio relay communication network is presented as a directed acyclic graph (Fig. 3). Radio relay stations R-416GM are located at communication centers. Node "A" is the source of messages, and node "B" is the corresponding node.

In FIG. 4 shows the parameters of the adaptive modes of the MD-310E modem from the R-416GM composition [MD-310E modem unit Operation manual KSYUV.467762.047-11RE].

In FIG. 5 and FIG. 6 shows the change in the throughput of microwave intervals in the SRS shown in FIG. 2. In FIG. 5 and FIG. 6 the following designations are accepted: With _RPS - real throughput; C _TPN - the nature of the change in throughput; With _OPS - residual capacity. Due to the fact that the indicator of the throughput of the modem MD-310E of the radio relay station R-416GM takes fixed values (Fig. 4), then for the values of the nature of the change in throughput, these values are taken, following in descending or increasing order.

The throughput distribution in the SRS at time intervals t ₁ , t ₂ is shown in FIG. 7.

At the time interval t ₃ , the throughput of the radio relay interval 1-2, which is included in the one-dimensional traffic transmission route 1-2-3, decreases, and therefore part of the traffic at the time interval t ₄ is redistributed to another nearest less loaded one-dimensional route 4-5- 6 (FIG. 8).

At the time interval t ₇ , the capacity of the one-dimensional route 1-2-3 continues to decrease, in connection with which there is a further redistribution of traffic to the one-dimensional route 4-5-6 (Fig. 9).

At the time interval t ₈ , the capacity of one-dimensional routes 1-2-3 and 4-5-6 continues to decrease, as a result of which traffic is redistributed to the one-dimensional route 1-5-3. The total throughput of the multidimensional route between nodes A and B in the CPC is reduced (FIG. 10).

At the time interval t ₉ , the throughput of one-dimensional routes 1-2-3 and 4-5-6 continues to decrease, as a result of which the redistribution of traffic to the one-dimensional route 1-5-3 continues. The total capacity of the multidimensional route between nodes A and B is close to the threshold value (Fig. 11).

On the time interval t ₁₀ the capacity of one-dimensional routes 1-2-3 and 4-5-6 continues to decrease. The decrease in the capacity of the one-dimensional route 1-5-3 has begun. The total throughput of the multidimensional route between nodes A and B has approached the threshold value (Fig. 12). At this point in time, the CPC needs to be reconfigured. If the SRS is not reconfigured, then on the time interval t ₁₁ the decrease in the capacity of all involved one-dimensional routes will continue. The value of the total throughput of the multidimensional route in the SRS will take a value below the threshold, the minimum required, as a result of which there will be an overload of the SRS in the next time interval (Fig. 13). At the time interval t ₁₂ , the radio relay network is overloaded, the bandwidth of the multidimensional route is less than necessary (Fig. 14).

The dynamics of traffic transmission in the one-dimensional route 1-2-3 is shown in Fig. 15. The dynamics of traffic transmission in the one-dimensional route 4-5-6 is shown in FIG. 16. The dynamics of traffic transmission in the one-dimensional route 1-5-3 is shown in FIG. 17, while the multidimensional route between communication nodes A and B in FIG. eighteen.

The reconfiguration of the SRS with packet switching is carried out by switching communication lines between radio relay stations and redistributing traffic between them.

Claims (4)

1. The method of operation of the radio relay network with packet switching, which consists in the fact that the real throughput γ of the radio relay network is measured, the required throughput γ _tr is set, based on the measured real throughput γ and the specified required throughput γ _tr , the probability of blocking is calculated radio relay networks R _bl , measure downtime and operation time of radio relay stations, on the basis of which the availability factor of the radio relay network and the probability of connectivity of the radio relay network R _s are calculated, characterized in that they additionally estimate the level of traffic quality of service and the nature of the change in the throughput of one-dimensional routes transmission K _about the radio relay network, based on the nature of the change in the capacity of one-dimensional transmission routes, the nature of the change in the capacity of the multidimensional transmission route K _m of the radio relay network is estimated, the time interval is set the shaft for determining the nature of the change in bandwidth and the upper limit of the bandwidth of each one-dimensional transmission route K _{about ext} , as well as the upper limit of the bandwidth of the multidimensional transmission route K _{m ext} , when the value of the nature of the change in the capacity of the one-dimensional transmission route K _o to the boundary value K _{o ext} the nearest less loaded one-dimensional transmission route is added to the multidimensional route, in which the required level of quality of service is provided, upon reaching the value of the nature of the change in the capacity of the multidimensional transmission route K _m to the boundary value K _{m additional} , the nature of the change in the real throughput γ of the radio relay network is calculated, upon reaching the nature of the change in the actual throughput γ of the given required throughput γ _tr reconfigure the radio relay network. 2. The method of functioning of the radio relay network with packet switching according to claim 1, characterized in that the level of traffic quality of service is evaluated using an integral indicator, which is calculated by the formula Q _ku =(T _ku ,P _ku ,D _ku ), where Q _ku is a generalized indicator of the quality of service of packet traffic, T _ku is the delay time, P _ku is the probability of timely delivery and D _ku is the delay variation for various traffic categories k∈[1,K] and traffic type u∈[1,U] .

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