KR101988476B1 - Effective bandwidth calculating system for assure the QoS of real-time voice in Geostationary Orbit Satellite and method of resource allocation thereof - Google Patents

Abstract

The present invention relates to a system for calculating an effective bandwidth for real-time voice quality guarantee in a geostationary satellite system and a resource allocation method using the same. More particularly, at least one user terminal generating voice traffic to be transmitted to the geostationary satellite system Voice traffic modeling unit 100 for modeling (UT, User Terminal) 10, multiplexing the modeled voice traffic received from the voice traffic modeling unit 100, and preset QoS (Quality of Service) requirements Receive downlink satellite resource allocation requests from a plurality of downlink satellite terminals (RCST) 200 and a plurality of downlink satellite terminals 200 that calculate an effective bandwidth based on the respective downlink satellites. Network control center (NCC) 300 for controlling communication by allocating satellite resources according to the effective bandwidth of the terminal 200 The present invention relates to an effective bandwidth calculation system for guaranteeing real-time voice quality in a geostationary satellite system.

Description

Effective bandwidth calculating system for assure the QoS of real-time voice in Geostationary Orbit Satellite and method of resource allocation according to geostationary satellite system

The present invention relates to a system for calculating an effective bandwidth for real-time voice quality guarantee in a geostationary satellite system and a resource allocation method using the same, and more particularly, to a plurality of user terminals multiplexed in a satellite channel (RCST). Effective bandwidth can be calculated to guarantee the quality of service (QoS) of voice traffic of UT (User Terminal), so that limited and limited quality of voice traffic such as disaster, tactics, and satellite networks can be effectively used for strict communication resources. The present invention relates to an effective bandwidth calculation system for real-time speech quality guarantee and a resource allocation method using the same in geostationary satellite systems.

A geostationary satellite is a satellite that orbits the earth at a constant height above the earth at the same speed as the earth's rotational speed. It is called a geostationary satellite because it always appears to be in a fixed position. Doing.

These geostationary satellites can cover a large area with a small number of satellites, so they are widely used for providing various satellite communication services as well as for international communication and broadcasting, but because the radio waves are weakened while high-altitude radio waves are transmitted. The satellite or terrestrial antenna needs to be large and the repeater output of the satellite must be high.

In order to effectively use such a geostationary satellite as a communication resource, a call admission control algorithm (CAC) has been proposed for efficient control of real-time multimedia video sources. Although not only video traffic but also voice traffic has been proposed for traffic modeling, there is an unrealistic problem because the traffic that is transmitted at a constant bit rate (CBR) is modeled.

In addition, a capacity request algorithm has been proposed based on cross-layer design and voice over IP (VoIP) voice traffic. The capacity request algorithm uses a queuing theory and voice traffic multiplexing technique to estimate the capacity required for transmission of voice traffic. However, the method used for the capacity request is RBDC (Rate Based Dynamic Capacity). There is a problem that a significant delay occurs in the process of estimating capacity, requesting and allocating it to a network control center (NCC).

In addition, a dynamic allocation scheme of downlink slots in a DVB-RCS-based satellite system has been proposed to capture the effects of the dynamics of satellite links. However, the quality of service (QoS) factors such as latency and packet loss rate have been proposed. There is a problem that no consideration is made.

In this regard, Korean Patent No. 10-1375299 ("Voice / Data Integration System and Bandwidth Management Method of the System") checks whether bandwidth is allocated for real-time data service, and if real-time data service cannot be allocated, The present invention discloses a system capable of performing real-time data service without delay by performing real-time data service when a bandwidth allocation for the service is reserved and allocated.

Domestic Patent Publication No. 10-1375299 (Registration date 2014.03.11.)

The present invention has been made to solve the problems of the prior art as described above, an object of the present invention is the voice traffic of a plurality of user terminals (UT, User Terminal) multiplexed in a satellite terminal (RCST, Return Channel Satellite Terminal) Effective bandwidth can be calculated to guarantee the quality of service (QoS) of real-time, and real-time in geostationary satellite system that can effectively utilize limited communication quality of strict communication resources such as disaster, tactic, satellite network An effective bandwidth calculating system for guaranteeing voice quality and a resource allocation method using the same are provided.

In the geostationary satellite system according to an embodiment of the present invention, the effective bandwidth calculation system for real-time voice quality guarantee includes at least one user terminal (UT) for generating voice traffic to be transmitted to the geostationary satellite system. Voice traffic modeling unit 100 for performing modeling, multiplexing the modeled voice traffic received from the voice traffic modeling unit 100, and calculating an effective bandwidth based on a predetermined Quality of Service (QoS) requirement. Receives satellite resource allocation requests from a plurality of downlink satellite terminals (RCST) 200 and the plurality of downlink satellite terminals 200, and transmits them to the effective bandwidth of each downlink satellite terminal 200. It is characterized in that it comprises a network control center (NCC, 300) for allocating satellite resources to control communications.

Furthermore, the downlink satellite terminal 200 in the packet classifier 210 and the packet classifier 210 classify packets of the received voice traffic and set different priorities according to a predetermined QoS requirement. A packet manager 220 for storing classified packets in an IP queue and measuring the number of packets stored in each IP queue, and a packet mapping unit 230 for mapping the packets to a MAC (Medium Access Control) queue. And an effective bandwidth calculator 240 that calculates the effective bandwidth based on a predetermined QoS requirement.

Further, the downlink satellite terminal 200 is characterized in that it further comprises an effective bandwidth request unit 250 for monitoring the length of the MAC queue mapped by the packet mapping unit 230.

Furthermore, the effective bandwidth calculator 240 calculates the effective bandwidth of the corresponding downlink satellite terminal based on the length of the MAC queue monitored by the effective bandwidth requester 250 and a predetermined QoS requirement. And, it is stored in a specific field and characterized in that for transmitting to the network management center (300).

Further, the network management center 300 is characterized in that to allocate the satellite resources in order in accordance with the effective bandwidth of the downlink satellite terminal 200.

A resource allocation method using an effective bandwidth calculation system for real-time voice quality guarantee in a geostationary satellite system according to an embodiment of the present invention, the voice traffic modeling unit, at least one for generating voice traffic to be transmitted to the geostationary satellite system In the voice traffic modeling step (S100) for performing the above-described modeling of the user terminal (UT, User Terminal), a plurality of downlink satellite terminals (RCST, Return Channel Satellite Terminal), the user terminal is preset for each downlink satellite terminal Effective bandwidth calculation step (S200) and a network management center for multiplexing the voice traffic modeled by the voice traffic modeling step (S100) and calculating an effective bandwidth based on a predetermined Quality of Service (QoS) requirement In the Network Control Center (NCC), each downlink calculated by the effective bandwidth calculating step (S200) According to the effective bandwidth of the terminal gender, in order characterized in that the assigned satellite resources, including the satellite resource allocation step (S300) for controlling the communication.

Further, the effective bandwidth calculation step (S200) is a packet classification step (S210), and the packet classification step (S210) for classifying and setting the priority of the packets of the voice traffic that has been modeled according to a predetermined QoS requirements, differently Packet mapping step (S220) of mapping the packets classified by N) into a MAC queue, an effective bandwidth request step (S230) of monitoring the length of the MAC queue to which the packets are mapped (S230), and the effective bandwidth request step (S230) An effective bandwidth calculation step (S240) of calculating an effective bandwidth of a corresponding downlink satellite terminal and storing the calculated effective bandwidth in a specific field based on the length of the monitored MAC queue and a predetermined QoS requirement. It features.

Furthermore, the packet classification step S210 stores the packets classified in the IP queue, and further comprises a packet management step S250 for measuring the number of the packets stored in each IP queue. .

In the geostationary satellite system of the present invention as described above, an effective bandwidth calculation system for real-time voice quality guarantee and a resource allocation method using the same are generated in a plurality of user terminals (UT, User Terminals), and satellite terminals (RCST, Return). Channel Satellite Terminal) has the advantage of calculating the effective bandwidth for guaranteeing the Quality of Service (QoS) of the multiplexed voice traffic.

In particular, in the event of a disaster or tactical operation, if a given amount of communication resources is very limited, such as a suddenly established network or a satellite system-based network, or a very strict quality measure, such as voice service, There is an advantage to use.

1 is a block diagram illustrating an effective bandwidth calculation system for real-time voice quality guarantee in a geostationary satellite system according to an embodiment of the present invention.
2 is a block diagram illustrating an effective bandwidth calculation system for real-time voice quality guarantee in a geostationary satellite system according to an embodiment of the present invention.
3 is a flowchart illustrating a resource allocation method using an effective bandwidth calculation system for guaranteeing real-time voice quality in a geostationary satellite system according to an embodiment of the present invention.

Hereinafter, an effective bandwidth calculation system and a resource allocation method using the same will be described in detail in the geostationary satellite system of the present invention with reference to the accompanying drawings. The drawings introduced below are provided by way of example so that the spirit of the invention to those skilled in the art can fully convey. Accordingly, the present invention is not limited to the drawings presented below and may be embodied in other forms. Also, like reference numerals denote like elements throughout the specification.

In this case, unless there is another definition in the technical terms and scientific terms used, it has the meaning commonly understood by those of ordinary skill in the art to which the invention belongs, and the gist of the invention in the following description and the accompanying drawings. The description of well-known functions and configurations that may unnecessarily obscure them will be omitted.

In the geostationary satellite system according to an embodiment of the present invention, an effective bandwidth calculation system for real-time voice quality guarantee and a resource allocation method using the same have a variable bit rate in order to solve the problem of the conventional technology considering only fixed bit rate voice traffic. In order to improve the delay time for satellite resource allocation every specific unit time, considering the voice traffic of (VBR, Variable Bit Rate), a CRA (Continuous Rate Assignment) method is used to allocate fixed capacity when initializing satellite terminals. The present invention relates to an effective bandwidth calculation system for real-time voice quality guarantee and a resource allocation method using the same in a geostationary satellite system that guarantees QoS of voice traffic.

More specifically, geostationary satellite according to an embodiment of the present invention because geostationary satellite system is spotlighted as an alternative solution for providing real-time voice service in areas where communication infrastructure is lacking (mountain, cabin, battlefield, etc.). An effective bandwidth calculation system and a resource allocation method using the same for guaranteeing real-time voice quality in the system are related to a system and method for calculating an effective effective bandwidth for satellite resource allocation of real-time voice traffic. In an effective bandwidth calculation system for real-time voice quality guarantee and a resource allocation method using the same in a geostationary satellite system according to an embodiment of the present invention, a plurality of user terminals are connected to one downlink satellite terminal. The multiplexing of the voice traffic generated from one downlink satellite terminal is performed. At this time, it is preferable that the number of downlink satellite terminals is configured, and a plurality of downlink satellite terminals are connected to one network management center, and each downlink is based on an effective bandwidth set in each downlink satellite terminal. Communication can be controlled by allocating satellite resources to link satellite terminals in order.

In particular, the effective bandwidth calculation system for real-time voice quality guarantee and the resource allocation method using the same in the geostationary satellite system according to an embodiment of the present invention, compared to the conventional techniques that considered only the fixed bit rate voice traffic, Considering the voice traffic, it is generated in one or two or more user terminals and multiplexed in the downlink satellite terminal, it is possible to increase the reality compared to the conventional.

In addition, in order to solve the delay time generated by allocating satellite resources at a specific unit time, the most suitable geostationary satellite system is utilized by utilizing a Continuous Rate Assignment (CRA) method that allocates fixed capacity when initializing downlink satellite terminals. It is about.

1 and 2 are diagrams illustrating an effective bandwidth calculation system for real-time voice quality guarantee in a geostationary satellite system according to an embodiment of the present invention, with reference to FIGS. 1 and 2. The effective bandwidth calculation system for real time voice quality guarantee in geostationary satellite system according to the present invention will be described in detail.

The effective bandwidth calculation system for real-time voice quality guarantee in the geostationary satellite system according to an embodiment of the present invention, as shown in Figures 1 and 2, a plurality of user terminals (UT, 10), voice Traffic modeling unit 100, a plurality of downlink satellite terminal (RCST) 200 and a network control center (NCC) 300 to manage them and control communication to be configured Can be.

In the geostationary satellite system according to an embodiment of the present invention, the effective bandwidth calculation system for real-time voice quality guarantee is real because there is a cost / time limit in configuring and calculating the environment as a real user terminal. Instead of receiving voice traffic from the user terminal, the voice traffic modeling unit 100 may be configured to model a virtual user terminal that generates the voice traffic expected to be generated by the actual user terminal.

To learn more about each configuration,

As shown in FIG. 2, the user terminal 10 may be formed in plural, and may generate voice traffic for communication in a geostationary satellite system.

The voice traffic modeling unit 100 includes at least one user terminal (UT) 10 for generating voice traffic to be transmitted to the geostationary satellite system, and the voice traffic generated by the user terminal 10. Can be modeled.

That is, the user terminal 10 generating voice traffic to be transmitted to the geostationary satellite system may be modeled.

At this time, as described above, the voice traffic modeling unit 100 receives voice traffic expected to be generated by the actual user terminal from the virtual user terminal 10 and performs modeling.

The reason for modeling voice traffic is that when using satellite system to provide real-time voice service, limited bandwidth, delay time, jitter, packet loss, etc. act as the limiting factors, and effectively limit the limited bandwidth under these limiting factors. Voice traffic modeling is essential to take advantage of this.

The downlink satellite terminal 200 multiplexes the modeled voice traffic received from the voice traffic modeling unit 100 and, in other words, is based on a preset quality of service (QoS) requirement. The effective bandwidth of each downlink satellite terminal 200 may be calculated based on quality of service factors such as packet loss rate.

In detail, as illustrated in FIGS. 1 and 2, the downlink satellite terminal 200 includes a packet classification unit 210, a packet management unit 220, a packet mapping unit 230, and an effective bandwidth calculator 240. ) And the effective bandwidth request unit 250.

The packet classifier 210 may classify packets of the received voice traffic and set priorities differently according to a preset QoS requirement.

In this case, as illustrated in FIG. 1, the downlink satellite terminal 200 classifies packets of voice traffic to different levels of priorities by performing voice modeling received from the voice traffic modeling unit 100. Can be set to

In other words, the downlink satellite terminal 200 may classify the packets to be serviced at different priorities according to a predetermined QoS requirement. In the case of voice traffic, it may be classified as Expedited Forwarding Per-Hop Behavior (EF PHB) so that it can be serviced with the highest priority among packets.

After the voice traffic generated in the user terminal 10 is generated in the form of voice generation and cancellation, the voices are generated in each user terminal 10 and modeled through the voice traffic modeling unit 100, The downlink satellite terminal 200 is transmitted to the multiplexing.

,

,

를 하나의 하향 링크 위성 단말(200)에서 다중화되는 다수의 사용자 단말(10)의 음성 트래픽의 평균 발생률, 최대 발생률 및 시차의 자기상관계수(이웃 시점(lag) 간의 상관계수를 나타내는 상수)라고 정의하고, 하나의 하향 링크 위성 단말(200)에서 다중화되는 음성들은

개의 사용자 단말(100)에서 독립적으로 발생한다고 가정하고, 상기 사용자 단말(10)의 활동은 음성의 발생(On)과 소거(Off) 상태의 반복인 재생과정(renewal process)로 특정할 경우,In detail, to model the voice traffic received from the voice traffic modeling unit 100,

,

,

Is defined as an average incidence rate, maximum incidence rate, and parallax autocorrelation coefficient (constant coefficient representing a correlation coefficient between neighboring lags) of voice traffic of a plurality of user terminals 10 multiplexed in one downlink satellite terminal 200. The voices multiplexed in one downlink satellite terminal 200 are

It is assumed that the two user terminals 100 occur independently, and when the activity of the user terminal 10 is specified as a repetition process of repetition of on and off states of voice,

)동안 음성의 발생 상태에서 소거 상태로의 천이 확률은

, 음성의 소거 상태에서 발생 상태로의 천이 확률은

의 확률로 기하분포를 갖게 된다. 이 때, 두 가지의 천이 확률은

,

,

를 대입하여 산출할 수 있다.Given time interval (

Transition probability from the state of generation of voice to the state of

, The probability of transition from the silenced state to the generated state is

Will have a geometric distribution. In this case, the two transition probabilities are

,

,

Can be calculated by substituting

단위의

이산 레벨들이 다중화되어 0에서

사이의 비트값을 갖게 된다.Through this, the bit rate of the voice traffic multiplexed in the i-th downlink satellite terminal 200 is

Unit of

Discrete levels are multiplexed at 0

It will have a bit value in between.

로 나타낼 수 있으며, 하기의 수학식 1과 같이 정리할 수 있다.The m-k transition probability matrix of the plurality of user terminals 10 generating voice traffic in the i-th downlink satellite terminal 200

It can be represented by, can be summarized as in Equation 1 below.

이며,here,

Is,

는 t번째 시간 간격에서 음성 트래픽을 발생 중인 사용자 단말(10)들의 개수를 의미한다.

Denotes the number of user terminals 10 generating voice traffic in the t-th time interval.

Since the states of the user terminals 10 in Equation 1 are independent of each other, when the number of the user terminals 10 in the t th time interval is m, voice traffic occurs in the (t + 1) th time interval. The number of user terminals 10 to be used may be represented by n, and the number of user terminals 10 to which voice is erased may be represented by kn.

In Equation 2 above, two probabilities after the sum symbol may be expanded as in Equation 3 below.

If the above Equation 3 is applied to the above Equation 2 and developed, it can be expressed as Equation 4 below.

는 하기의 수학식 5와 같이,

의 배수를 대각 행렬로 갖게 된다.This allows bit rate vectors

Is as shown in Equation 5 below,

You will have a multiple of m in a diagonal matrix.

The packet manager 220 may store the packets classified by the packet classifier 210 in an Internet Protocol (IP) queue, and measure the number of packets stored in each IP queue. This process is referred to as traffic metering, as shown in FIG.

The packet mapping unit 230 may map packets stored in the IP queue to a medium access control (MAC) queue. In detail, the packets may be mapped to the real-time media access control queue, and the mapping degree at this time may be monitored by the effective bandwidth request unit 250.

That is, the effective bandwidth request unit 250 may monitor the length of the MAC queue mapped by the packet mapping unit 230. Here, the length of the queue refers to the number of packets included in the buffer, and the effective bandwidth request unit 250 may be monitored by a bandwidth on demand (BoD) function.

The effective bandwidth calculator 240 may satisfy the length of the MAC queue monitored by the effective bandwidth requester 250, that is, the statistical result measured by BoD, the length of the MAC queue, and a predetermined QoS requirement. The effective bandwidth of each downlink satellite terminal 200 may be calculated.

The effective bandwidth calculator 240 may store the calculated effective bandwidth in a specific field and transmit the calculated bandwidth to the network management center 300.

가 계산된다. 이 때, 미리 설정된 QoS 요구조건으로는 상술한 바와 같이, 지연시간과 패킷손실률을 고려하는 것이 바람직하다.In detail, the effective bandwidth calculator 240 is an effective bandwidth of each of the downlink satellite terminals 200.

Is calculated. At this time, it is preferable to consider the delay time and the packet loss rate as described above as the preset QoS requirements.

)은 통신 메시지 중 DULM(Data Unit Labelling Method) 메시지의 RC_Capacity_Parameters 필드에 저장되어 상기 망관리센터(300)로 위성자원 할당을 요청하게 된다.The effective bandwidth calculated by the effective bandwidth calculating unit 240 (

) Is stored in the RC_Capacity_Parameters field of the data unit labeling method (DULM) message of the communication message to request the satellite resource allocation to the network management center (300).

,

)에 의한 이산시간 마르코프 연쇄로 특징지어 하기의 수학식 6과 같이, 산출하는 것이 바람직하다.As an example of the effective bandwidth calculating unit 240, the effective bandwidth of the i-th downlink satellite terminal 200 is defined by two matrices (

,

It is preferable to calculate by the following formula (6) characterized by the discrete time Markov chain by

)(

)

는 두 상태들 간에 시간 간격을 나타내며,here,

Represents the time interval between the two states,

는

로 정의된 QoS 파라미터를 의미하며,

Is

QoS parameter defined as

,

는 임의 시간의 큐의 상태와 MAC 계층에서의 큐의 길이이며,

,

Is the state of the queue at any time and the length of the queue at the MAC layer,

는 G 행렬의 스펙트럼 반경을 의미한다.

Denotes the spectral radius of the G matrix.

는 i번째 하향 링크 위성 단말에서 발생한 음성 트래픽의 양을 의미한다.That is, the equation (6)

Denotes the amount of voice traffic generated in the i-th downlink satellite terminal.

If the length (size) of the queue in the downlink satellite terminal 200 is too large, the waiting time of packets becomes long. On the contrary, if the length of the queue is too small, there is insufficient place to store the packets. Since it can occur, the effective bandwidth is calculated while setting and monitoring the length of the queue that satisfies the requirement to minimize the following Equation 8 (objective function) subject to the following Equation 7 (linear constraint). It is preferable.

는 i번째 하향 링크 위성 단말에서의 음성 트래픽 유입률을 나타내며, 미리 설정된 QoS 요구조건을 만족하는 큐의 길이(

)를 찾기 위해서는, 큐에 존재하는 트래픽의 양(

) 뿐 아니라, 유입되는 트래픽의 양(

)이 고려되어야 한다.here,

Denotes the inflow rate of voice traffic at the i-th downlink satellite terminal, and the length of the queue satisfying the preset QoS requirements (

To find the amount of traffic in the queue (

) As well as the amount of traffic coming in (

) Should be considered.

는 현재 시간에 유입되는 트래픽을 제외한 큐에 존재하는 패킷의 개수를 의미한다.

Means the number of packets present in the queue excluding traffic flowing in the current time.

)는 하기의 수학식 9와 같이 나타낼 수 있다.Accordingly, the length of the Real-time MAC queue (

) May be expressed as in Equation 9 below.

In the geostationary satellite system according to an embodiment of the present invention, an effective bandwidth calculation system for real-time voice quality guarantee includes bursting ATM traffic such that voice packets transmitted through one downlink satellite terminal are delivered to another one or more downlink satellite terminals. It is preferred to assume that is used.

According to the DVB-RCS standard, ATM traffic burst is preferably an N _atm of ATM cells to the L _atm bytes long and, L _{p, atm} the prefix in bytes long (prefix) is configured as one, and in this case, the prefix is optional It is desirable.

)은 하기의 수학식 10과 같다.Through this assumption, the actual satellite resource allocation capacity requested to the network management center 300 through the i-th downlink satellite terminal, that is, the effective bandwidth calculated and stored by the i-th downlink satellite terminal (

) Is as shown in Equation 10 below.

Here, the length of L _atm means the sum of the payload length and the header length of the ATM cell.

은 실효대역폭(

)을 L_pld,atm으로 나눈 값의 올림으로 하기의 수식과 같이 나타낼 수 있다.

Is the effective bandwidth (

) Can be expressed by the following formula by raising the value divided by L _{pld, atm} .

은 i번째 하향 링크 위성 단말에서 헤더의 크기 등을 고려하여 실제 상기 망관리센터(300)에 요구되어야 하는 트래픽의 양을 의미하고,

는 i번째 하향 링크 위성 단말에서

를 요청하여 실제 할당된 용량을 의미한다.That is, the equation (10)

Denotes the amount of traffic actually required for the network management center 300 in consideration of the size of the header in the i-th downlink satellite terminal,

In the i downlink satellite terminal

Request the actual allocated capacity.

와 실제 할당된 용량인

가 같거나, 상이하게 할당될 수 있다.At this time, the amount of traffic that must be

And the actual allocated capacity

May be assigned the same or different.

보다 현재 남아있는 위성 용량, 다시 말하자면 먼저 할당이 진행되고 남아있는 위성 용량이 적은 경우, 이를 할당하는 경우에는 요구된 트래픽의 양인

보다 실제 할당된 용량인

이 적게 할당될 수 있으며, 뿐만 아니라, 남아있는 위성 용량이 아예 부족하다고 판단될 경우, 실제 할당된 용량인

은 '0'으로 리턴될 수도 있다.For example, the amount of traffic that must be requested

More current satellite capacity, i.e., if the allocation is made first and there is less satellite space remaining, the amount of traffic required

The more actually allocated capacity,

May be allocated less, and if the remaining satellite capacity is determined to be insufficient,

May be returned as '0'.

)을 DUML 메시지에 포함시켜 상기 망관리센터(300)로 전송함으로써, 위성자원 할당 용량을 요청하게 된다.Through this, the downlink satellite terminal 200 is the effective bandwidth of the corresponding downlink satellite terminal 200 calculated using the above-described equation (especially, equation (10)) through the effective bandwidth calculation unit 240 (

) Is included in the DUML message and transmitted to the network management center 300 to request the satellite resource allocation capacity.

When the network management center 300 receives a capacity request from the downlink satellite terminal 200, it is preferable to allocate satellite communication resources in order of capacity request unless a special policy is set.

Table 1 below is an algorithm showing a satellite resource allocation process for the t-th superframe in the network management center (300).

It is one of the problems that must be solved in the network using satellite system because the waste of communication resources is very serious. CRA capacity that can provide N _rest as the number of ATM bursts in the satellite system C _CRA allocates the satellite communication resource capacity requested by the downlink satellite terminals 200 to the number of timeslots.

)를 곱한 값이다.At this time, the C _CRA is the ratio of the downlink total capacity C _RC to the CRA capacity (

Multiplied by).

Here, C _RC may be calculated by Shannon's theorem as shown in Equation 11 below.

Here, B _RC means channel bandwidth,

S / N means signal to noise ratio.

S / N may be reduced due to rainfall reduction, as shown in Equation 12 below, and the available C _RC is also reduced by affecting the overall performance of the downlink.

Here, S / N _{S, C} means S / N when the weather is clear,

A _RAIN means rainfall attenuation of the return channel.

In the algorithm shown in Table 1, the initial value of N _REST is preferably given as [C _CRA / L _ts ], which is the number of CRA timeslots.

L _ts means the length of one timeslot, and it is preferable to have a number limit as shown in Equation 13 below.

)을 L_ts로 나누어 산출할 수 있으며, i번째 하향 링크 위성 단말에 할당된 타임슬롯의 개수(

)를 N_REST로부터 제거하면서, 상기 망관리센터(300)가 더 이상 위성통신 자원을 할당할 수 없을 때까지, 다수의 하향 링크 위성 단말(200)들로부터 요청된 용량 할당에 대한 동작을 반복 수행하게 된다.In addition, the number of timeslots requested by the i-th downlink satellite terminal is the effective bandwidth (

) Can be calculated by dividing by L _ts , and the number of timeslots allocated to the i th downlink satellite terminal (

) Is removed from the N _REST , and the network management center 300 repeatedly performs the operation for the capacity allocation requested from the plurality of downlink satellite terminals 200 until the satellite communication resources can no longer be allocated. Done.

Further, when it is difficult to allocate capacity for the capacity requested by the i-th downlink satellite terminal, the network management center 300 sends a rejection message for the satellite resource request from the i-th downlink satellite terminal to the N-th downlink satellite terminal. The satellite resource allocation operation in the superframe is stopped.

In this case, the number N _av of available downlink satellite terminals accepted by the network management center 300 for the satellite resource allocation requests from the plurality of downlink satellite terminals 200 is determined by the algorithm described in Table 1 above. Can be calculated by

After performing the satellite resource allocation operation, the network management center 300 may calculate a ratio of resource waste (RRW) in terms of overall network performance.

To this end, as shown in Equation 14 below, it is possible to define the amount of resources (C _rest ) remaining unallocated to downlink satellite terminals requesting resources.

As shown in Equation 15 below, the amount of resources (C _waste ) allocated to N _av downlink satellite terminals but not used in each downlink satellite terminal may be defined.

RRW (R _rw ) may be calculated through Equations 14 and 15, and may be expressed as Equation 16 below.

3 is a flowchart illustrating a resource allocation method using an effective bandwidth calculation system for real-time voice quality guarantee in a geostationary satellite system according to an embodiment of the present invention. Referring to FIG. Resource allocation method using effective bandwidth calculation system for real-time voice quality guarantee in geostationary satellite system.

As shown in FIG. 3, a resource allocation method using an effective bandwidth calculation system for real-time voice quality guarantee in a geostationary satellite system according to an embodiment of the present invention includes a voice traffic modeling step (S100) and an effective bandwidth calculation step ( S200) and the phase resource allocation step (S300) may be configured.

To learn more about each step,

The voice traffic modeling step S100 may perform modeling of voice traffic generated by at least one user terminal 10 generating voice traffic to be transmitted to the geostationary satellite system.

At this time, the voice traffic modeling step (S100) receives the voice traffic expected to be generated by the actual user terminal from the virtual user terminal 10, as described above, in the voice traffic modeling unit 100, Modeling will be performed.

The reason for performing voice traffic modeling is that, as described above, when the satellite system is used to provide a real-time voice service, limited bandwidth, delay time, jitter, packet loss, etc. act as a limiting factor. Voice traffic modeling is essential to effectively utilize the limited bandwidth below.

Voice traffic generated in the user terminal 10 is generated in the form of voice generation and cancellation, and voices are generated in each user terminal 10 to be delivered to the downlink satellite terminal 200 and multiplexed. .

,

,

를 하나의 하향 링크 위성 단말(200)에서 다중화되는 다수의 사용자 단말(100)의 음성 트래픽의 평균 발생률, 최대 발생률 및 시차의 자기상관계수(이웃 시점(lag) 간의 상관계수를 나타내는 상수)라고 정의하고, 하나의 하향 링크 위성 단말(200)에서 다중화되는 음성들은

개의 사용자 단말(10)에서 독립적으로 발생한다고 가정하고, 상기 사용자 단말(10)의 활동은 음성의 발생(On)과 소거(Off) 상태의 반복인 재생과정(renewal process)로 특정할 경우,The voice traffic modeling step (S100)

,

,

Is defined as the average incidence rate, maximum incidence rate, and parallax autocorrelation coefficient (constant coefficient between neighboring lags) of a plurality of user terminals 100 multiplexed in one downlink satellite terminal 200. The voices multiplexed in one downlink satellite terminal 200 are

Assume that the user terminal 10 occurs independently, the activity of the user terminal 10 is specified by the repetition process (renewal process) of the repetition of the on (On) and off (Off) state of the voice,

)동안 음성의 발생 상태에서 소거 상태로의 천이 확률은

, 음성의 소거 상태에서 발생 상태로의 천이 확률은

의 확률로 기하분포를 갖게 된다. 이 때, 두 가지의 천이 확률은

,

,

를 대입하여 산출할 수 있다.Given time interval (

Transition probability from the state of generation of voice to the state of

, The probability of transition from the silenced state to the generated state is

Will have a geometric distribution. In this case, the two transition probabilities are

,

,

Can be calculated by substituting

단위의

이산 레벨들이 다중화되어 0에서

사이의 비트값을 갖게 된다.Through this, the bit rate of the voice traffic multiplexed in the i-th downlink satellite terminal 200 is

Unit of

Discrete levels are multiplexed at 0

It will have a bit value in between.

The effective bandwidth calculation step (S200) is modeled by the voice traffic modeling step (S100) from a plurality of downlink satellite terminals 200 from the user terminals that are preset and connected to each downlink satellite terminal The voice traffic may be received and multiplexed, and an effective bandwidth may be calculated for each downlink satellite terminal 200 based on a predetermined QoS requirement.

As shown in FIG. 3, the effective bandwidth calculation step S200 may include a packet classification step S210, a packet mapping step S220, an effective bandwidth request step S230, and an effective bandwidth calculation step S240. .

In the packet classification step S210, packets of the voice traffic modeled by the voice traffic modeling step S100 may be classified according to a preset QoS requirement to differently set priorities.

That is, as illustrated in FIG. 1, the downlink satellite terminal 200 performs modeling on voice traffic received from the plurality of user terminals 10, and then delivers the voice to the packet classifier 210. Packets of traffic may be classified and set to different priorities.

In other words, when receiving the modeled voice traffics from the plurality of user terminals 10 to which the downlink satellite terminal 200 is connected, the downlink satellite terminal 200 may serve different priorities according to a predetermined QoS requirement. Packets can be classified to be In the case of voice traffic, it may be classified as Expedited Forwarding Per-Hop Behavior (EF PHB) so that it can be serviced with the highest priority among packets.

The packet mapping step S220 may map the packets classified by the packet classification step S210 to a MAC queue.

In detail, the packets may be mapped to the real-time medium access control queue, and the mapping degree at this time may be monitored by the effective bandwidth request step (S230). Here, the length of the queue refers to the number of packets included in the buffer and can be monitored by a bandwidth on demand (BoD) function.

The effective bandwidth calculating step (S240) calculates and calculates an effective bandwidth of a corresponding downlink satellite terminal based on the length of the MAC queue and the preset QoS requirement monitored by the effective bandwidth requesting step (S230). The effective bandwidth can be stored in a specific field.

In detail, the effective bandwidth of each downlink satellite terminal 200 may be calculated to satisfy the length of the monitored MAC queue, that is, the statistical result measured in BoD, the length of the MAC queue, and a predetermined QoS requirement. Can be.

In the effective bandwidth calculation step (S240), the calculated effective bandwidth may be stored in a specific field and transmitted to the network management center 300.

가 계산된다. 이 때, 미리 설정된 QoS 요구조건으로는 상술한 바와 같이, 지연시간과 패킷손실률을 고려하는 것이 바람직하다.That is, the effective bandwidth calculation step (S240) is the effective bandwidth of each of the downlink satellite terminal 200

Is calculated. At this time, it is preferable to consider the delay time and the packet loss rate as described above as the preset QoS requirements.

)은 통신 메시지 중 DULM(Data Unit Labelling Method) 메시지의 RC_Capacity_Parameters 필드에 저장되어 상기 망관리센터(300)로 위성자원 할당을 요청하게 된다.In addition, the calculated effective bandwidth (

) Is stored in the RC_Capacity_Parameters field of the data unit labeling method (DULM) message of the communication message to request the satellite resource allocation to the network management center (300).

,

)에 의한 이산시간 마르코프 연쇄로 특징지어 상기의 수학식 6과 같이 산출하는 것이 바람직하다.As an example of the effective bandwidth calculating unit 240, the effective bandwidth of the i-th downlink satellite terminal 200 is defined by two matrices (

,

It is preferable to calculate as shown in Equation 6 above, characterized by the discrete time Markov chain.

As a result of the monitoring in the effective bandwidth request step (S260), if the length (size) of the queue in the downlink satellite terminal 200 is too large, the waiting time of packets becomes long, and conversely, the length of the queue is too small. Since there is a lack of a place to store the multi-sided packets and packet loss may occur, the above-described requirements for minimizing the above Equation 8 (objective function) subject to Equation 7 (linear constraint) are satisfied. It is desirable to calculate the effective bandwidth while setting and monitoring the length of the queue.

)는 상기의 수학식 9와 같이 나타낼 수 있다.Further, in consideration of Equations 7 and 8, the length of the queue (

) May be expressed as in Equation 9 above.

In a resource allocation method using an effective bandwidth calculation system for real-time voice quality guarantee in a geostationary satellite system according to an embodiment of the present invention, one or more downlink satellite terminals in which voice packets transmitted through one downlink satellite terminal are different It is desirable to assume that ATM traffic bursts are used to be forwarded.

According to the DVB-RCS standard, ATM traffic burst is preferably an N _atm of ATM cells to the L _atm bytes long and, L _{p, atm} the prefix in bytes long (prefix) is configured as one, and in this case, the prefix is optional It is desirable.

)은 상기의 수학식 10과 같다.Through this assumption, the actual satellite resource allocation capacity requested to the network management center 300 through the i-th downlink satellite terminal, that is, the effective bandwidth calculated and stored by the i-th downlink satellite terminal (

) Is the same as Equation 10 above.

The satellite resource allocation step (S300) is performed by the network management center 300, by allocating satellite resources in order according to the effective bandwidth of each downlink satellite terminal calculated by the effective bandwidth calculation step (S200) Can be controlled.

)을 DUML 메시지에 포함시켜 상기 망관리센터(300)로 전송함으로써, 위성자원 할당 용량을 요청하게 된다.In detail, the downlink satellite terminal 200 is effective of the corresponding downlink satellite terminal 200 calculated using the above-described equations (particularly, equations 10) through the effective bandwidth calculator 240. Bandwidth (

) Is included in the DUML message and transmitted to the network management center 300 to request the satellite resource allocation capacity.

In the satellite resource allocation step (S300), when a capacity request is received from the downlink satellite terminal 200, it is preferable to allocate satellite communication resources in order of capacity request unless a special policy is set.

Table 1 is an algorithm showing a satellite resource allocation process for the t th superframe in the network management center 300.

It is one of the problems that must be solved in the network using satellite system because the waste of communication resources is very serious. CRA capacity that can provide N _rest as the number of ATM bursts in the satellite system C _CRA allocates the satellite communication resource capacity requested by the downlink satellite terminals 200 to the number of timeslots.

The satellite resource allocation step (S300) repeats the operation for the capacity allocation requested from the plurality of downlink satellite terminals 200 until the network management center 300 can no longer allocate satellite communication resources. Will be performed.

Further, when it is difficult to allocate capacity for the capacity requested by the i-th downlink satellite terminal, the network management center 300 sends a rejection message for the satellite resource request from the i-th downlink satellite terminal to the N-th downlink satellite terminal. The satellite resource allocation operation in the superframe is stopped.

In this case, the number N _av of available downlink satellite terminals accepted by the network management center 300 for the satellite resource allocation requests from the plurality of downlink satellite terminals 200 is determined by the algorithm described in Table 1 above. Can be calculated by

After performing the satellite resource allocation operation, the network management center 300 may calculate a ratio of resource waste (RRW) in terms of overall network performance.

In addition, the resource allocation method using the effective bandwidth calculation system for real-time voice quality guarantee in the geostationary satellite system according to an embodiment of the present invention, as shown in Figure 3, after performing the packet classification step (S210) , Packet management step S250 may be further performed.

In the packet management step S250, the packets classified by the packet classification step S210 may be stored in an IP queue, and the number of packets stored in each IP queue may be measured. This process is referred to as traffic metering, as shown in FIG.

In other words, an effective bandwidth calculation system for real-time voice quality guarantee and a resource allocation method using the same in a geostationary satellite system according to an embodiment of the present invention are generated in a plurality of user terminals and multiplexed in a downlink satellite terminal. The effective bandwidth for guaranteeing the QoS of voice traffic can be calculated, so that the limited quality of service of the voice traffic such as disaster, tactics, and satellite networks can be effectively used for strict communication resources.

As described above, the present invention has been described by specific embodiments such as specific components and the like. However, this is merely provided to help a more general understanding of the present invention, and the present invention is limited to the above embodiment. However, various modifications and variations are possible to those skilled in the art to which the present invention pertains.

Therefore, the spirit of the present invention should not be limited to the described embodiments, and all the things equivalent to or equivalent to the claims as well as the following claims will fall within the scope of the present invention. .

10: user terminal
100: voice traffic modeling unit
200: downlink satellite terminal
210: packet classification unit 220: packet management unit
230: packet mapping unit 240: effective bandwidth calculation unit
250: effective bandwidth request unit
5300: Network Management Center

Claims (8)

Voice traffic modeling unit 100 connected to at least one user terminal (UT) 10, a plurality of downlink satellite terminal (RCST) 200, network management center (NCC) In the effective bandwidth calculation system for guaranteeing real-time voice quality in a geostationary satellite system comprising a network control center (300),
The voice traffic modeling unit 100 receives voice traffic to be transmitted to the geostationary satellite system generated by each of the user terminals 10 and performs voice traffic modeling.
Each downlink satellite terminal 200 receives and multiplexes modeled voice traffic of the user terminals 10 connected in advance, and guarantees a predetermined delay time and a packet loss rate, which are predetermined QoS requirements. To calculate the effective bandwidth for each corresponding downlink satellite terminal 200 based on the requirements,
The network management center 300 receives satellite resource allocation requests from the plurality of downlink satellite terminals 200, and allocates capacity of satellite resources in order according to the effective bandwidth of each downlink satellite terminal 200. An effective bandwidth calculation system for guaranteeing real-time voice quality in a geostationary satellite system characterized by controlling communication.
The method of claim 1,
The downlink satellite terminal 200 is
A packet classification unit 210 for classifying packets of the received voice traffic and setting different priorities according to a predetermined QoS requirement;
A packet manager 220 for storing the packets classified by the packet classifier 210 in an IP queue and measuring the number of the packets stored in each IP queue;
A packet mapping unit 230 for mapping the packets to a MAC (Medium Access Control) queue; And
An effective bandwidth calculator 240 for calculating the effective bandwidth based on a predetermined QoS requirement;
Effective bandwidth calculation system for real-time speech quality guarantee in geostationary satellite system comprising a.
The method of claim 2,
The downlink satellite terminal 200 is
An effective bandwidth request unit (250) for monitoring the length of the MAC queue mapped by the packet mapping unit (230);
Effective bandwidth calculation system for real-time voice quality guarantee in geostationary satellite system characterized in that it further comprises.
The method of claim 3,
The effective bandwidth calculator 240
Based on the length of the MAC queue monitored by the effective bandwidth requesting unit 250 and a predetermined QoS requirement, the effective bandwidth of the corresponding downlink satellite terminal is calculated, stored in a specific field, and stored in the network management center ( 300) Effective bandwidth calculation system for real-time voice quality guarantee in geostationary satellite system.
The method of claim 4, wherein
The network management center 300
An effective bandwidth calculation system for real-time voice quality guarantee in a geostationary satellite system, characterized in that the satellite resources are allocated in order according to the effective bandwidth of the downlink satellite terminal (200).
In the voice traffic modeling unit, a voice traffic modeling step (S100) for performing voice traffic modeling of at least one user terminal (UT) for generating voice traffic to be transmitted to the geostationary satellite system;
In a plurality of downlink satellite terminals (RCST), the voice traffic modeled by the voice traffic modeling step (S100) from the user terminals that are preset and connected to each downlink satellite terminal are An effective bandwidth calculation step of multiplexing each other and calculating an effective bandwidth for each downlink satellite terminal based on the requirements in order to ensure a predetermined delay time and packet loss rate, which are predetermined Quality of Service (QoS) requirements (S200). ); And
In the Network Control Center (NCC), satellites which control communication by allocating capacity of satellite resources in order according to the effective bandwidth of each downlink satellite terminal calculated by the effective bandwidth calculating step (S200) Resource allocation step (S300);
Resource allocation method using the effective bandwidth calculation system for real-time voice quality guarantee in geostationary satellite system comprising a.
The method of claim 6,
The effective bandwidth calculation step (S200) is
A packet classification step (S210) of classifying the packets of the voice traffic that has been modeled according to a predetermined QoS requirement and setting different priorities;
A packet mapping step (S220) of mapping the packets classified by the packet classification step (S210) to a MAC queue;
An effective bandwidth request step (S230) of monitoring the length of the MAC queue to which the packets are mapped; And
Calculating an effective bandwidth of a corresponding downlink satellite terminal based on the length of the MAC queue monitored by the effective bandwidth request step (S230) and a predetermined QoS requirement, and storing the calculated effective bandwidth in a specific field; An effective bandwidth calculation step (S240);
A resource allocation method using an effective bandwidth calculation system for guaranteeing real-time voice quality in a geostationary satellite system.
The method of claim 7, wherein
A packet management step (S250) of storing the packets classified by the packet classification step (S210) in an IP queue and measuring the number of the packets stored in each IP queue;
A resource allocation method using an effective bandwidth calculation system for real-time speech quality guarantee in a geostationary satellite system, characterized in that it further comprises.

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