KR20140004183U - Apparatus for dynamic controlling of packet - Google Patents

Abstract

The present invention relates to a dynamic packet control device capable of compensating for jitter and delay of a real-time voice or video packet. The dynamic packet control apparatus of the present invention determines the type of a received packet and controls whether a jitter buffer is passed or not.

Description

[0001] APPARATUS FOR DYNAMIC CONTROLLING OF PACKET [0002]

The present invention relates to a mobile communication system, and more particularly, to a dynamic packet control apparatus capable of compensating for jitter and delay of a real-time voice or video packet.

FIG. 1 is a diagram illustrating a configuration of an IP backbone network, and FIG. 2 is a table showing the sizes and transmission intervals of voice and video packets. In the network structure of 3GPP (3rd generation partnership project) Release 5, in order to effectively cope with an increase in the line service capacity as the number of subscribers of the core switching (CS) domain increases, the IP backbone protocol backbone network and provides a separate relay switching system by differentiating the function of the toll exchanger relaying the incoming / outgoing relay. On a board that is responsible for IP matching of the IP backbone and the relay switching system, real-time voice or video packets pass through the IP network and are used for jitter / delay / packet loss / duplicate packet Resulting in loss of voice and video calls and deterioration of quality.

Korean Patent Publication No. 10-2000-0044522 (published on July 15, 2000) Korean Patent Publication No. 10-2007-0079135 (published on Aug. 6, 2007) Korean Patent Laid-Open No. 10-2011-0017981 (published on Feb. 23, 2011)

The present invention provides a dynamic packet control device capable of compensating for jitter and delay of real-time voice or video packets.

The dynamic packet control apparatus of the present invention includes a packet control unit for determining the type of a received packet and controlling whether a jitter buffer is passed or not.

According to the present invention, a jitter buffer delay of an UP control packet for a call setup is reduced, so that a call setup can be performed quickly, and a self-timer of a session- Compensates or adjusts the jitter and delay of the traffic through a more precise timer, performs silence detection using the starvation detection function, In case of a buffer under-run, the delay of received traffic is immediately processed. In case of buffer overflow, the loss of traffic can be minimized by decreasing the interval of traffic using the characteristic of vocoder which is an end point have.

1 is an exemplary view showing a configuration of an IP backbone network;
2 is a table showing the size and transmission interval of voice and video packets;
3 is a flow chart illustrating a call setup procedure according to an embodiment of the present invention;
4 is a block diagram showing a configuration of a dynamic packet control apparatus according to an embodiment of the present invention.
FIG. 5 is a flowchart illustrating a packet processing procedure according to an embodiment of the present invention; FIG.
FIG. 6 is a diagram illustrating a procedure for tick calculation and stab detection according to an embodiment of the present invention; FIG.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, in the following description, detailed description of well-known functions and configurations will be omitted when there is a concern that the gist of the present invention may be unnecessarily blurred.

The present embodiment relates to a dynamic jitter buffer for compensating jitter, delay, and the like of traffic generated in an IP network in an IP network matching of an Nb UP interface in a relay switching system. The Nb UP interface refers to a user plane plane protocol between media gateways in a core switching (CS) core network according to the 3GPP (3rd generation partnership project) international standard. It reduces the jitter buffer delay of the UP control packet for call setup so that the call setup is quick and compensates and adjusts the self delay of each session by adding a more accurate timer And compensates for the jitter and delay of traffic through the network and performs silence detection through starvation detection and buffer under-run due to traffic loss and delay. The delay of the traffic can be immediately processed and the traffic interval can be reduced using the characteristic of the vocoder which is an end point in case of buffer overflow to minimize traffic loss. In the transmission and reception stages, packets are generated, transmitted or received at regular intervals. Since the transmission and reception stages are not the same system, there is a deviation in the system clock value. If the transmission terminal clock is fast, the generated packet will be larger than the packet expected to be received by the receiving terminal. At this time, the phenomenon that the buffer stored in the buffer exceeds the buffer storage capacity due to the increase in the number of packets that are deleted from the buffer (read) is referred to as a buffer overrun. On the contrary, Is called a buffer underrun.

3 is a flowchart illustrating a call setup procedure according to an embodiment of the present invention.

As shown in FIG. 3, the basic storage delay time of the jitter buffer operated in each IP interface (6, 7) can be set to various values according to the initial setting value. Usually, it is set to 60 ms (3 packets). In this case, the round trip time delay becomes 120 ms, and the call setup time may be delayed. In this case, it is possible to shorten the call setup time by minimizing round trip time delay by dividing the type of the received packet in real time and controlling whether the jitter buffer is passed or not.

4 is a block diagram showing a configuration of a dynamic packet control apparatus according to an embodiment of the present invention.

4, the dynamic packet control apparatus 100 includes a packet receiving unit 110, a packet controlling unit 120, a stabbing detecting unit 130, a packet checking unit 140, a jitter buffer 150, a packet transmitting unit 160 And a tick calculation unit 170. [

The packet receiving unit 110 may receive a voice or video packet from the IP network. The packet receiving unit 110 may transmit the received voice or video packet to the packet control unit 120.

The packet controller 120 determines the type of the received voice or video packet and controls whether the jitter buffer 150 is passed or not. In one embodiment, the packet control unit 120 determines whether the received packet is an UP control packet by referring to the up control packet lookup table. If the received packet is an up control packet, the packet control unit 120 does not pass the jitter buffer 150 To the packet transmission unit 160, and to pass through the jitter buffer 150 when the packet is not an up control packet.

The starvation detection unit 130 detects whether there is a simple delay (network delay) or an underrun due to a loss in a received packet, and the delayed packet does not pass through the jitter buffer 150, At the same time, the packet transmission unit 160 may be configured to minimize the system delay. Also, the stab detection unit 130 determines whether silence detection is performed by referring to the time stamp and the sequence number of the received packet, and disables the packet sequence time slot when silence detection is detected disable the packet sequence time slot, and set the packet sequence time slot to be updated so that the jitter compensation function can be performed immediately when the normal packet is received. A technique that does not generate traffic in a silent conversation can be used as a method of reducing traffic load in a voice call. Therefore, the jitter buffer 150 can not receive the packet, and an underrun occurs. When the voice call packet of a normal call is received in the future, a packet sequence time slot can not be obtained, The strobing detector 130 can solve the problem that it takes a long time until the strobing is detected.

The IP packet check unit 140 may perform a re-ordering, a duplicate packet drop, a packet format check, a sequence number check ), Time stamp error check (timestamp error check, etc.), and corrects, checks, and discards errors that have occurred through the IP network. The function of the packet checking unit 140 is not limited to the above embodiment.

The jitter buffer 150 may temporarily store the received packet. In one embodiment, the jitter buffer 150 may receive only packets for which the delay is not detected in the stab detection unit 130. [

The packet transmission unit 160 may transmit the IP packet transmitted from the jitter buffer 150 to the IP network. The packet transmission unit 160 may transmit the IP packet transmitted from the packet control unit 120 or the stab detection unit 130 without passing through the jitter buffer 150 to the IP network.

The tick calculation unit 170 determines whether or not the capacity of the packet stored in the jitter buffer 150 is greater than the threshold value. If the capacity of the packet stored in the jitter buffer 150 is greater than the threshold value, Thereby reducing the loss of traffic. That is, if the storage capacity of the jitter buffer 150 exceeds a threshold value due to a buffer overrun due to a congestion or a packet generation clock of a vocoder, etc., the tick calculation unit 170 may refer to a profile table (PT) Extracts and transmits packets in the jitter buffer 150 at a maximum rate matching the traffic characteristics of the session, and performs operation by mutually linking through modification and control of a stream (session) timer. The jitter buffer 150 overflows Thereby minimizing the packet loss caused by the packet loss. The profile table PT stores the traffic characteristics and operating conditions according to the state of the jitter buffer 150. [ In one embodiment, if a condition that a jitter buffer 150 exceeds a threshold value occurs at a time of 20 ms in case of a voice packet, an operation for blocking a buffer full by adjusting a transmission interval of a voice packet to 19 ms is performed And at the time when the buffer pool is generated, additional values for adjusting the interval are stored.

The tick computation unit 170 compares the time stamp of the global timer 180 with the value of the time stamp of the global timer 180 at the active time of the stream (session) timer, and refers to the profile table PT and the session timer table ST (Session) timer to calculate the self-jitter of the stream (session) timer and then control the value of the next stream (session) timer to minimize the jitter value of the stream (session) timer. In one embodiment, the tick calculation unit 170 determines whether the difference value between the stream (session) timer and the global timer is within the range of the predetermined tick value stored in the session timer table using the packet time stamp value, If the difference value is within the range of the tick value, it is stored in the jitter buffer 150. If the difference value exceeds the tick value range, the packet can be transmitted to the IP network by applying the profile. The global timer 180 may use a separate precision hardware clock with a deviation of the level of 100 PPM that is not subjected to a timer load. If a jitter buffer for each stream (session) is used rather than a global jitter buffer, a timer for each stream (session) must be operated. If the number of timers to be operated increases, the accuracy of the timer becomes exponentially lower . As a result, the jitter and jitter generated in the timer itself is applied to the traffic processing process, and the jitter of the traffic that has passed through the jitter buffer 150 becomes larger. The global jitter buffer has a high precision because it operates all the streams (sessions) through one buffer, and the timer operated in the buffer is operated with one or minimum. However, since all the traffic has to pass through one buffer, it may compete with traffic of another stream (session) in the jitter buffer 150, resulting in additional delay or jitter. Since the jitter buffer 150 for each stream (session) is operated as a buffer for each stream (session), there is no interference between the traffic. However, since many timers are used, the accuracy of the timer drops.

5 is a flowchart illustrating a packet processing procedure according to an embodiment of the present invention.

As shown in FIG. 5, when a packet is received through the packet receiving unit 110 (S110), the packet control unit 120 determines whether the received packet is an up control packet by referring to the up control packet busy up table (S120 ). If it is determined that the packet is an up control packet, the packet control unit 120 controls the packet to be transmitted without passing the packet through the jitter buffer 150 (S130). If it is not an up control packet, the time stamp of the received packet is read (S140). The tick calculation unit 170 calculates a difference value between the stream timer and the global timer using the packet time stamp value at step S150 and determines whether the difference value is within the range of the predetermined tick value stored in the session timer table If the difference value is within the range of the tick value, the profile is stored in the jitter buffer 150 (S170). If the difference value exceeds the range of the tick value, the profile of the profile table PT is applied, IP network (S180).

6 is a diagram illustrating a procedure for tick calculation and stab detection according to an embodiment of the present invention.

As shown in FIG. 6, the state of the jitter buffer 150 is periodically checked (S210), and it is determined whether or not a packet exists in the jitter buffer 150 (S220). If a packet exists, the packet is transmitted S230). If the packet does not exist, it is determined whether silence detection is performed (S240). If silence detection is detected, the packet sequence time slot is disabled (S250), and the packet sequence time slot is updated when a normal packet is received (S260) so that the jitter compensation function can be immediately operated.

Although the present disclosure has been described in connection with some embodiments, it should be understood that various modifications and changes may be made thereto without departing from the spirit and scope of the present invention as understood by those skilled in the art to which the present invention belongs. something to do. It is also contemplated that such variations and modifications are within the scope of the claims appended hereto.

100: dynamic packet control device 110: packet receiver
120: Packet control unit 130: Stability detection unit 130:
140: packet checker 150: jitter buffer
160: packet transmission unit 170: tick calculation unit

Claims (8)

1. A dynamic packet control device comprising:
And a packet control unit for determining the type of the received packet and controlling whether a jitter buffer is passed or not. The method according to claim 1,
The packet control unit,
Control packet look-up table to determine whether or not the received packet is an up control packet and to control not to pass through the jitter buffer when the received packet is the up control packet, And to pass through the jitter buffer when the received packet is not an up control packet. The method according to claim 1,
Further comprising a stab detection unit for determining whether or not the received packet is delayed and controlling whether a buffer is passed or not. The method of claim 3,
Wherein the stab detection part comprises:
The method comprising: determining whether silence detection is performed with reference to a time stamp and a sequence number of the received packet; disabling a packet sequence time slot if the silence detection is detected; And sets the jitter compensation function so that the jitter compensation function can be operated. The method according to claim 1,
And a tick calculation unit for determining whether a capacity of a packet stored in the jitter buffer is greater than a threshold value and decreasing a traffic interval of the packet when the capacity of the packet stored in the jitter buffer is greater than the threshold value, controller. 6. The method of claim 5,
The tick computation unit,
And controls to extract and transmit a packet in the jitter buffer at a rate matching the traffic characteristic of a specific session with reference to a profile table when the storage capability of the jitter buffer exceeds the threshold value. 6. The method of claim 5,
The tick computation unit,
Compares the global timer and the time stamp value at the active time of the one-stream (session) timer, calculates the self-jitter of the one-stream (session) timer by referring to the profile table and the session timer table, Session) timer. 6. The method of claim 5,
The tick computation unit,
Determining whether a difference value between the one-stream (session) timer and the global timer is within a predetermined tick value stored in the session timer table using the time stamp value of the packet, and if the difference value is within the range of the predetermined tick value Stores the packet in the jitter buffer, and controls the transmission of the packet by applying a profile when the difference value exceeds the predetermined tick value range.

Images