JPH0515091B2 - - Google Patents
Info
- Publication number
- JPH0515091B2 JPH0515091B2 JP58064668A JP6466883A JPH0515091B2 JP H0515091 B2 JPH0515091 B2 JP H0515091B2 JP 58064668 A JP58064668 A JP 58064668A JP 6466883 A JP6466883 A JP 6466883A JP H0515091 B2 JPH0515091 B2 JP H0515091B2
- Authority
- JP
- Japan
- Prior art keywords
- packet
- time
- line
- transmission
- delay time
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
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Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L12/00—Data switching networks
- H04L12/64—Hybrid switching systems
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Data Exchanges In Wide-Area Networks (AREA)
Description
【発明の詳細な説明】
〔発明の利用分野〕
本発明はパケツトによる総合通信方式に関し、
特にパケツトの遅延時間を制御する方式に関する
ものである。[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a comprehensive communication system using packets.
In particular, it relates to a method for controlling packet delay time.
周知のように、交換方式には回線交換形とパケ
ツト交換形がある。このうち、回線交換方式は遅
延時間が小さく、例えば音声通信の様な会話形通
信に適するが、回線の使用効率が悪い欠点があ
り、一方、パケツト交換方式はある程度の遅延時
間を許容すれば回線の使用効率を上げられるとい
う特徴を持つており、それぞれ別の網で実現され
ている。
As is well known, there are two types of switching systems: circuit switching and packet switching. Among these, the circuit switching method has a small delay time and is suitable for conversational communication such as voice communication, but it has the disadvantage of poor line usage efficiency.On the other hand, the packet switching method has a short delay time and is suitable for conversational communication such as voice communication. Each network is implemented using a different network.
近年、網の効率的運用、ユーザの利便性等の観
点から網及びサービスの統合が言われている。総
合化への一つのアプローチとして、パケツト交換
網にて総合化を実現する方法が考えられる。この
場合、実時間性の要求の厳しい会話形通信の遅延
時間をいかに短かくするかがポイントとなる。こ
れは特にパケツト網にて会話形音声通信を行なう
場合に重要となる。すなわち、会話形音声通信に
おいては、パケツトの遅延時間がある程度以上に
なると会話に支障をきたし、また受信パケツトの
遅延時間がばらつく場合は元の音声に復元しにく
くなる。しかし、逆に音声情報の数％まで廃棄さ
れても会話には特に支障がないことが知られてい
る。従来、この両性質に着目して、パケツト網で
会話形音声通信を実現する方式として、ある程度
の廃棄率を犠牲にして遅延時間を短縮し、かつば
らつきを補正する方法が提案されている。しか
し、従来方法では、網内の遅延時間の分布を知る
ことが出来ないために受信側での遅延補正のため
の制御が複雑であり、また受信端へ来てはじめて
廃棄されるパケツトがあり、網資源の利用上不効
率であるという欠点があつた。このような従来方
式の欠点を以下に詳述する。 In recent years, integration of networks and services has been talked about from the viewpoint of efficient network operation and user convenience. One possible approach to integration is to implement integration using a packet switching network. In this case, the key point is how to shorten the delay time of conversational communication, which requires real-time performance. This is especially important when performing conversational voice communication over a packet network. That is, in conversational voice communication, if the delay time of packets exceeds a certain level, it will interfere with conversation, and if the delay time of received packets varies, it will be difficult to restore the original voice. However, it is known that even if up to a few percent of audio information is discarded, there is no particular problem in conversation. Conventionally, focusing on both of these properties, methods have been proposed to realize conversational voice communication in a packet network by shortening delay time and correcting variations at the expense of a certain level of drop rate. However, in the conventional method, the delay correction control on the receiving side is complicated because it is not possible to know the distribution of delay times within the network, and some packets are discarded only after reaching the receiving end. The drawback was that it was inefficient in terms of the use of network resources. The drawbacks of such conventional methods will be explained in detail below.
従来の方法では、例えば、音声パケツトの受信
端にて、有音部分の最初のパケツトを受信した
後、一定時間Tcだけそれを待たせた後に再生し、
以後同一の有音部に属するパケツトを一定の速さ
で再生し、この再生を開始すべき時刻までに受信
されないパケツトは廃棄していた。この方法で
は、受信端にて常に一定遅延Tcが付加されるた
め、全体の遅延時間が増加すること、また、受信
端に来てはじめてパケツトが廃棄されるので、無
効なトラヒツクが存在するという欠点があつたの
である。 In the conventional method, for example, after receiving the first packet of the voice packet at the voice packet receiving end, it is played back after waiting for a certain period of time Tc .
Thereafter, packets belonging to the same sound part are played back at a constant speed, and packets that are not received by the time when playback should start are discarded. In this method, a constant delay Tc is always added at the receiving end, which increases the overall delay time.Also, since packets are discarded only after they reach the receiving end, invalid traffic may exist. It had its flaws.
また別の方法においては、パケツトのヘツダー
部に送信時刻を示すタイムスタンプを付加し、受
信端にて、このタイムスタンプと受信時刻との差
をとることにより、該パケツトの実際の遅延時間
を求め、この遅延時間が決められた値以下であれ
ば、該パケツトを決められた値から実際の遅延時
間だけ待たせて再生し、もし該パケツトの伝送遅
延が決められた値より大きかつた場合、該パケツ
トを廃棄していた。この方法の欠点は、実際の遅
延時間を正確に知るためには、発信側と受信側で
同一の時計を持つていなければならず、これを実
現するために、受信側では、受信パケツトのタイ
ムスタンプの値から推定される時刻をもとに受信
側の時計をその都度修正することにより両方の時
計を合わせるという制御が必要な点である。 In another method, a timestamp indicating the transmission time is added to the header of the packet, and the receiving end calculates the actual delay time of the packet by calculating the difference between this timestamp and the reception time. , if this delay time is less than a predetermined value, the packet is played after waiting for the actual delay time from the predetermined value, and if the transmission delay of the packet is greater than the predetermined value, The packet was discarded. The disadvantage of this method is that in order to accurately know the actual delay time, the sending and receiving sides must have the same clock; The point is that control is required to synchronize both clocks by adjusting the clock on the receiving side each time based on the time estimated from the stamp value.
本発明は、パケツト交換網において、網内で転
送されるパケツトの伝送遅延時間を一定時間以下
に抑え、かつ無効に滞留するパケツトを網内から
自律的に廃棄することができる効率的なパケツト
通信方式を実現することを目的とする。
The present invention provides efficient packet communication in a packet-switched network, which is capable of suppressing the transmission delay time of packets transferred within the network to a certain period of time or less, and autonomously discarding invalidly accumulated packets from within the network. The purpose is to realize the method.
本発明は、上記目的を実現するため、発信局で
は遅延時間をカウントするため所定の時間値が設
定されたカウンタ部をパケツトに設定し、各中継
局は自局内滞留時間と次局までの伝送遅延時間と
により該カウンタ部を減算してパケツトの送出の
可否を判断し、着信局では中継局と同様なカウン
タ減算によりパケツトの端末回線への送出タイミ
ングを生成することを最も大きな特徴とするもの
である。
In order to achieve the above object, the present invention sets a counter part in a packet to a predetermined time value in order to count the delay time at the originating station, and each relay station calculates the residence time within itself and the transmission to the next station. The main feature of this system is that it determines whether or not the packet can be sent by subtracting the counter section based on the delay time, and the receiving station generates the timing for sending the packet to the terminal line by subtracting the counter in the same way as the relay station. It is.
第１図はパケツト交換網の接続例を示したもの
で、以下、これにより本発明の内容を説明する。
FIG. 1 shows an example of a connection in a packet switching network, and the content of the present invention will be explained below using this diagram.
第１図において、端末１から発せられたパケツ
トは端末回線３により発信局２において受信され
る。発信局２では、受信したパケツトに後述する
網内滞留時間計測用のカウンタ部を付加し、これ
を所定の値Ｔ（例えば音声通信ではＴ＝200mS程
度）に設定して中継回線４へ送出する。中継局５
では、回線４からパケツトを受信し、第２図に示
す流れ図に従つた処理を行う。即ち、中継局５は
回線４からパケツトを受信すると（ステツプ
100）、その受信時刻をパケツト対応に記憶して
（ステツプ101）、所定の中継処理を行う（ステツ
プ102）。しかる後、出回線が空き状態になると
（ステツプ103）、該当パケツトを中継回線６に送
出する時点で送信開始時刻を求め、先に記憶して
おいた受信時刻との差により該パケツトの中継局
内での滞留時間を算出し、更に、送出する回線の
速度、伝送路距離、パケツト長より、送出遅延時
間、伝播遅延時間を算出する（ステツプ104）。次
に、ステツプ104での計算結果に基づき網内滞留
時間を得て、当該パケツトの網内時間計測用のカ
ウンタ部の値を更新する（ステツプ105）。次に、
該更新されたカウンタ部の値を予め定めた閾値
α、例えば“０”と比較し（ステツプ106）、これ
に等しいか又は小さい場合には、該パケツトを網
内滞留時間の閾値を越えた無効パケツトとして直
ちに廃棄し（ステツプ107）、閾値より大きい場合
には、該パケツトをそのまま中断回線６へ送出す
る（ステツプ108）。 In FIG. 1, a packet originating from a terminal 1 is received at a transmitting station 2 via a terminal line 3. In FIG. The originating station 2 adds a counter section for measuring the residence time in the network, which will be described later, to the received packet, sets it to a predetermined value T (for example, T = about 200 mS for voice communication), and sends it to the relay line 4. . Relay station 5
Then, a packet is received from line 4 and processed according to the flowchart shown in FIG. That is, when relay station 5 receives a packet from line 4 (step
100), the reception time is stored corresponding to the packet (step 101), and predetermined relay processing is performed (step 102). After that, when the outgoing line becomes idle (step 103), the transmission start time is determined at the time when the corresponding packet is sent to the relay line 6, and the transmission start time of the packet is determined based on the difference with the previously stored reception time. The residence time at the destination is calculated, and the transmission delay time and propagation delay time are further calculated from the transmission line speed, transmission path distance, and packet length (step 104). Next, the in-network residence time is obtained based on the calculation result in step 104, and the value of the counter section for measuring the in-network time of the packet is updated (step 105). next,
The updated value of the counter section is compared with a predetermined threshold value α, for example "0" (step 106), and if it is equal to or smaller than this value, the packet is invalidated as the packet has exceeded the network residence time threshold value. The packet is immediately discarded as a packet (step 107), and if it is larger than the threshold, the packet is sent as is to the interrupted line 6 (step 108).
着信局７では、中継回線６から受信したパケツ
トについて第３図に示す流れ図に従つた処理を行
う。即ち、着信局７は回線６からパケツトを受信
すると（ステツプ200）、各パケツトの受信時刻を
求め、パケツト対応に記憶する（ステツプ201）。
次に、該パケツトに対して着信局内での所定の処
理を行う（ステツプ202）。しかる後中継局５と同
様に、該パケツト内の滞留時間計測用カウンタ部
の値及び先に記憶した受信時刻及び現在の時刻よ
り滞留時間を算出し、更に、送出する回線の速
度、伝送距離、パケツト長より送出遅延時間、伝
播遅延時間を送出し、これらに基づいて各パケツ
トの滞留時間計測用カウンタ部を更新し、該カウ
ンタ部の値が予め定められた値αになるまで該パ
ケツトを記憶しておき、予め定められた値αにな
つた時点で端末回線８へ送出することにより、各
パケツトの遅延時間が一定になるように遅延時間
を制御する（ステツプ203，204）。 The receiving station 7 processes the packet received from the relay line 6 according to the flowchart shown in FIG. That is, when the receiving station 7 receives a packet from the line 6 (step 200), it determines the reception time of each packet and stores it corresponding to the packet (step 201).
Next, the packet is subjected to predetermined processing within the destination station (step 202). Thereafter, similarly to the relay station 5, the residence time is calculated from the value of the residence time measurement counter in the packet, the previously stored reception time, and the current time, and the transmission line speed, transmission distance, The transmission delay time and propagation delay time are sent based on the packet length, and based on these, the counter unit for measuring the residence time of each packet is updated, and the packet is stored until the value of the counter unit reaches a predetermined value α. The delay time is controlled so that the delay time of each packet becomes constant by transmitting it to the terminal line 8 when the packet reaches a predetermined value α (steps 203 and 204).
第４図は発信局２、中継局５、着信局７等にお
ける本発明に関係する部分の構成例を示したもの
で、以下、これによつて各局の動作を詳述する。 FIG. 4 shows an example of the configuration of the parts related to the present invention in the transmitting station 2, the relay station 5, the receiving station 7, etc., and the operation of each station will be explained in detail below.
発信局２においては、端末回線３からパケツト
を受信し、受信バツフア１１に格納する。処理装
置１２は該受信パケツトに対し、網内滞留時間計
測用カウンタ部を付加し、これを所定の値Ｔに設
定する。第５図は該パケツトのフオーマツト例を
示したもので、１３は網内滞留時間計測用カウン
タ部、１４は受信パケツトである。処理装置１２
は、また、該パケツトの受信番号をメモリ装置２
２の受信パケツト番号領域１５に設定すると共
に、タイマ９の値を読み取り、各受信パケツト番
号対応に受信時刻記憶領域１６に設定する。ま
た、この時、網内滞留時間計測用カウンタ部まで
含めたパケツト長（第５図のPlビツト）もパケツ
ト対応に領域１８に記憶しておく。 The transmitting station 2 receives the packet from the terminal line 3 and stores it in the receiving buffer 11. The processing device 12 adds a counter section for measuring the residence time within the network to the received packet and sets it to a predetermined value T. FIG. 5 shows an example of the format of the packet, where 13 is a counter section for measuring residence time in the network, and 14 is a received packet. Processing device 12
Also, the reception number of the packet is stored in the memory device 2.
At the same time, the value of the timer 9 is read and set in the reception time storage area 16 corresponding to each received packet number. At this time, the packet length (Pl bit in FIG. 5) including the in-network residence time measurement counter section is also stored in the area 18 corresponding to the packet.
該発信局でのパケツト処理が終了すると、パケ
ツトは送信バツフア１０に格納され、中継回線４
への送出を待つことになる。回線４が空き、パケ
ツトの送出が可能になつた時点で、処理装置１２
はタイマ９の値を再び読み取り、受信時刻記憶領
域１６の該当パケツトの値との差を求め、更に、
２０で示す各対地名毎に、２１で示す伝送路速度
Ｖと伝送路距離ｌが対応付けてある対地別の回線
条件テーブル１９を用いて、パケツト長Pl（領域
１８に格納されている）と伝送路速度Ｖ、伝送路
距離ｌより、パケツト送出時間Pl／Ｖ及び伝播遅
延時間ｄ＝ｌ×d0（d0は単位長さ当りの伝播遅延
で、例えば5ns／ｍ）を求め、これらにより決ま
る網内滞留時間に基づいてパケツトのカウンタ部
１３の値Ｔを減算更新し、直ちに中継回線４へ送
出する。 When the packet processing at the transmitting station is completed, the packet is stored in the transmission buffer 10 and transmitted to the trunk line 4.
We will be waiting for it to be sent to. When the line 4 becomes free and packet transmission becomes possible, the processing device 12
reads the value of the timer 9 again, finds the difference from the value of the corresponding packet in the reception time storage area 16, and further,
For each destination name indicated by 20, the packet length Pl (stored in area 18) is calculated using the destination-by-destination line condition table 19 in which the transmission path speed V and transmission path distance l shown by 21 are associated with each other. From the transmission path speed V and the transmission path distance l, find the packet sending time Pl/V and the propagation delay time d=l×d 0 (d 0 is the propagation delay per unit length, for example, 5 ns/m), and from these, The value T of the packet counter section 13 is subtracted and updated based on the determined residence time in the network, and the packet is immediately sent to the trunk line 4.
中継局５においては、発信局２からの第５図で
示すパケツトを中継回線４より受信し、受信バツ
フア１１に格納する。この時、発信局２と同様に
して、処理装置１２は該パケツトの受信時刻をタ
イマ９より読み取り、パケツト対応にメモリ装置
２２の受信時刻記憶領域１６に記憶する。同時
に、パケツトの長さPlを領域１８に記憶する。中
継回線６への送出時になると、処理装置１２は再
びタイマ９の値を読み取り、これと受信時刻記憶
領域１６の値との差により局内滞留時間を求め、
更に、パケツトの長さ記憶領域１８と対地別の回
線条件テーブル１９を用いて、パケツト長Plと伝
播路速度Ｖと伝送路距離ｌより決まる送出遅延時
間、伝播遅延時間を求め、これらに基づいてパケ
ツトのカウンタ部１３の値を減算更新する。そし
て、この更新値をレジスタ１７に予め設定してあ
る閾値αと比較し、該αより大きい場合は中継回
線６へ送出するが、そうでない場合は該パケツト
を直ちに廃棄する。 Relay station 5 receives the packet shown in FIG. 5 from originating station 2 through relay line 4 and stores it in reception buffer 11. At this time, similarly to the transmitting station 2, the processing device 12 reads the reception time of the packet from the timer 9 and stores it in the reception time storage area 16 of the memory device 22 corresponding to the packet. At the same time, the length Pl of the packet is stored in area 18. When it is time to send to the relay line 6, the processing device 12 reads the value of the timer 9 again, calculates the in-office residence time from the difference between this value and the value in the reception time storage area 16,
Furthermore, using the packet length storage area 18 and the line condition table 19 for each destination, the transmission delay time and propagation delay time determined by the packet length Pl, propagation path speed V, and transmission path distance l are determined, and based on these, the transmission delay time and propagation delay time are determined. The value of the packet counter section 13 is updated by subtraction. Then, this updated value is compared with a threshold value α set in advance in the register 17, and if it is larger than α, the packet is sent to the trunk line 6, but if not, the packet is immediately discarded.
着信局７においては、中継局５からのパケツト
を中継回線６より受信し、受信バツフア１１に格
納する。この時、発信局２や中継局５の場合と同
様に、処理装置１２はタイマ９により受信時刻を
読み取り、受信時刻記憶領域１６に記憶するが、
以後の動作は発信局２や中継局５と少し異なる。
即ち、着信局７では、交換網内での全体の遅延時
間を各パケツトについて、ある一定値以下におさ
えるための遅延補正を行う必要がある。 The receiving station 7 receives the packet from the relay station 5 through the relay line 6 and stores it in the receiving buffer 11. At this time, as in the case of the transmitting station 2 and the relay station 5, the processing device 12 reads the reception time using the timer 9 and stores it in the reception time storage area 16.
The subsequent operations are slightly different from those of the transmitting station 2 and the relay station 5.
That is, at the receiving station 7, it is necessary to perform delay correction to keep the total delay time within the switching network below a certain value for each packet.
処理装置１２は、送出バツフア１０内で送出待
ちのパケツトについて、所定の周期でタイマ９の
値を読み取り、この値とパケツト対応の受信時刻
記憶領域１６の値との差により局内滞留時間を算
出し、更に、パケツト対応のパケツト長さ記憶領
域１８と対地別の回線条件テーブル１９を用い
て、パケツト長Plと端末回線の速度Ｖ、伝送距離
ｌにより送出遅延時間と伝播遅延時間を算出し、
これらに基づいて該当パケツトのカウンタ部１３
を更新する。ただし、送出遅延時間と伝播遅延時
間については、最初の１回のみ考慮し、以後のパ
ケツトのカウンタ部１３の更新はタイマ９の値の
みによつて行う。このパケツトのカウンタ部１３
の更新結果が、レジスタ１７に設定してある閾値
αに等しくなつた時、処理装置１２は、はじめて
該当パケツトを端末回線８へ送出する。なお、端
末回線８へ送出する時は、パケツトのカウンタ部
１３を削除した形に直して送出する。 The processing device 12 reads the value of the timer 9 at a predetermined period for packets waiting to be sent in the sending buffer 10, and calculates the in-office residence time based on the difference between this value and the value in the reception time storage area 16 corresponding to the packet. Furthermore, using the packet length storage area 18 corresponding to the packet and the line condition table 19 for each destination, the transmission delay time and the propagation delay time are calculated from the packet length Pl, the terminal line speed V, and the transmission distance l,
Based on these, the counter unit 13 of the corresponding packet
Update. However, the transmission delay time and the propagation delay time are taken into consideration only once at the beginning, and subsequent updates of the packet counter section 13 are performed using only the value of the timer 9. This packet counter section 13
When the updated result becomes equal to the threshold value α set in the register 17, the processing device 12 sends the corresponding packet to the terminal line 8 for the first time. Note that when sending out to the terminal line 8, the packet is converted into a form with the counter section 13 removed and sent out.
この様に制御することにより、発信局２から送
出されたパケツトは、網内滞留時間があらかじめ
定められた遅延時間Ｔよりも大きい場合は網内で
廃棄され、着信局７に到着した時点での滞留時間
が定められた遅延時間Ｔより小さい場合には、最
終的な遅延時間がＴになる様に着信局７で遅延補
正され、パケツトの遅延時間は一定値Ｔに抑えら
れる。 By controlling in this way, packets sent from the originating station 2 are discarded within the network if their residence time in the network is longer than the predetermined delay time T, and the packets sent from the originating station 2 are discarded within the network when they arrive at the destination station 7. If the residence time is smaller than the predetermined delay time T, the receiving station 7 corrects the delay so that the final delay time becomes T, and the packet delay time is suppressed to a constant value T.
なお、上記説明で、受信バツフア１１、送信バ
ツフア１０は必ずしも分離している必要がなく、
同一メモリでもさしつかえない。また、中継数は
何段でも良い。交換局内のタイマ９は、数msec
の精度で充分であり、汎用のIC回路で実現可能
である。さらに、パケツトに種別を設け、パケツ
トの種別により閾値α（又は遅延時間Ｔ）を変え
ることも可能である。これら閾値の決定は、伝送
路伝播遅延時間と、伝送路へのパケツト送出遅延
時間（パケツト長及び伝送速度により異なる）、
端末でのパケツト組立時間等、全体の遅延要因と
その大きさを考慮した上で行なう必要がある。 Note that in the above description, the receiving buffer 11 and the transmitting buffer 10 do not necessarily have to be separated;
The same memory can also be used. Further, the number of relay stages may be any number. Timer 9 in the exchange is several milliseconds
The accuracy is sufficient and can be realized using a general-purpose IC circuit. Furthermore, it is also possible to provide packet types and change the threshold value α (or delay time T) depending on the packet type. These thresholds are determined based on the transmission path propagation delay time, the packet sending delay time to the transmission path (varies depending on the packet length and transmission speed),
This needs to be done after considering the overall delay factors and their magnitudes, such as the packet assembly time at the terminal.
また、各局において、該当パケツトを廃棄する
か否かを判断する機会としては、上記では、各局
において、該パケツトを受信した時及び伝送路へ
送出する時とがあつたが、もし受信バツフア及び
送信バツフアに蓄積されている各パケツトについ
て一定周期で、計測用カウンタ部の更新を行なう
様にすれば、より迅速に遅延時間オーバーのパケ
ツトを廃棄することができる。 In addition, in the above, each station has the opportunity to judge whether or not to discard the packet when it receives the packet and when it sends it to the transmission path. If the measurement counter section is updated at regular intervals for each packet stored in the buffer, packets whose delay time has exceeded can be discarded more quickly.
以上説明したように、本発明によれば、パケツ
トの遅延時間のばらつきをなくし、かつ、遅延時
間を一定値以下にすることが可能であり、また、
一定値以上遅延した無効パケツトを転送せずに廃
棄できるので、実時間性が厳しく要求される会話
形音声通信をパケツト交換網を用いて効率的に実
現することができる。
As explained above, according to the present invention, it is possible to eliminate variations in packet delay time and to keep the delay time below a certain value.
Since invalid packets delayed by a certain value or more can be discarded without being forwarded, conversational voice communication, which requires real-time performance, can be efficiently realized using a packet switching network.
また、本発明では、発信局が予め所定の遅延時
間Ｔを設定し、その遅延時間Ｔを各局が減算する
形でパケツトの廃棄を判定するため、許容最大遅
延時間の異なる複数種のパケツトの廃棄制御も極
めて容易に処理することができる。すなわち、パ
ケツト種（例えば、呼接続用パケツトと情報用パ
ケツト、あるいは音声用パケツトとデータ用パケ
ツトなど）の違いにより許容最大遅延時間が異な
る場合、発信局が予め設定する所定の遅延時間Ｔ
をパケツト種別毎に換えるだけで異なる遅延時間
によるパケツト廃棄が実現できる。この場合、そ
の他の局はパケツト種別によらず一つのしきい値
（例えば０）でパケツト廃棄を判定すればよく極
めて簡単な制御となる。 Furthermore, in the present invention, the originating station sets a predetermined delay time T in advance, and each station subtracts the delay time T to determine whether or not to discard a packet. Control can also be handled very easily. That is, if the maximum allowable delay time differs depending on the packet type (for example, a call connection packet and an information packet, or a voice packet and a data packet, etc.), the predetermined delay time T set in advance by the originating station is
Packet discarding due to different delay times can be achieved by simply changing . In this case, the other stations only need to determine whether or not to discard a packet based on one threshold value (for example, 0) regardless of the packet type, resulting in extremely simple control.
さらに、本発明では、各局が計測する遅延時間
には自局内滞留時間の他、次局へ転送する際にか
かると予想される伝送遅延時間も含まれるため、
網内の無効なパケツト転送をより効果的に削減す
ることができる。すなわち、本発明では自局から
次の局に転送するまでの予想遅延時間（局内滞留
時間＋次局への伝送遅延時間）でパケツト廃棄を
判定するため、前もつて次局までの無効なパケツ
ト転送を行わずに済み、パケツト交換網の使用効
率をさらに向上させることができる。 Furthermore, in the present invention, the delay time measured by each station includes not only the residence time within the own station but also the transmission delay time expected to be taken when transferring to the next station.
Invalid packet transfer within the network can be more effectively reduced. In other words, in the present invention, packet discard is determined based on the expected delay time from the local station to the next station (retention time within the station + transmission delay time to the next station). There is no need for transfer, and the usage efficiency of the packet switching network can be further improved.
第１図はパケツト交換網の構成例を示す図、第
２図は本発明による中継局の動作を説明する流れ
図、第３図は本発明による着信局の動作を説明す
る流れ図、第４図は交換局の一実施例を示す図、
第５図はパケツトのフオーマツト例を示す図であ
る。
１……発側端末、２……発信局、３……端末回
線、４……中継回線、５……中継局、６……中継
回線、７……着信局、８……端末回線、９……タ
イマ、１０……送信バツフア、１１……受信バツ
フア、１２……パケツト処理装置、１３……カウ
ンタ部、１４……パケツト部、２２……メモリ装
置。
FIG. 1 is a diagram showing an example of the configuration of a packet switching network, FIG. 2 is a flowchart explaining the operation of a relay station according to the present invention, FIG. 3 is a flowchart explaining the operation of a receiving station according to the present invention, and FIG. A diagram showing an example of an exchange,
FIG. 5 is a diagram showing an example of a packet format. 1... Originating terminal, 2... Originating station, 3... Terminal line, 4... Relay line, 5... Relay station, 6... Relay line, 7... Terminating station, 8... Terminal line, 9 ...Timer, 10...Transmission buffer, 11...Reception buffer, 12...Packet processing device, 13...Counter section, 14...Packet section, 22...Memory device.
Claims (1)
方式において、 発信局では、入力情報とカウンタ部を含むパケ
ツトを構成し、回線へのパケツト送出が可能にな
つた時点で前記カウンタ部を所定の値に設定して
該パケツトを回線へ送出し、 中継局では、前記パケツトを受信すると、パケ
ツト受信時刻を設定し、前記パケツトの回線への
送出が可能になつた時点で、送信開始時刻と前記
パケツト受信時刻との差によりパケツト滞留時間
を算出し、前記パケツトのパケツト長とパケツト
送出先回線の伝送速度、伝送距離とにより伝送遅
延時間を算出し、前記パケツト滞留時間と前記伝
送遅延時間とを前記パケツトのカウンタ部のカウ
ンタ値から減算更新し、前記減算更新したカウン
タ値がしきい値より大きい場合は前記パケツトを
回線に送出し、そうでない場合には前記パケツト
を廃棄し、 着信局では、前記パケツトを受信すると、パケ
ツト受信時刻を設定し、前記パケツトの回線への
送出が可能になつた時点で、伝送開始時刻と前記
パケツト受信時刻との差によりパケツト滞留時間
を算出し、前記パケツトのパケツト長とパケツト
送出先回線の伝送速度、伝送距離とにより伝送遅
延時間を算出し、前記パケツト滞留時間と前記伝
送遅延時間とを前記パケツトのカウンタ部のカウ
ンタ値から減算更新し、前記減算更新したカウン
タ値がしきい値になるまでカウントした後、前記
パケツトを回線に送出することを特徴とするパケ
ツト通信方式。[Scope of Claims] 1. In a packet communication system that transmits information in the form of packets, a transmitting station configures a packet including input information and a counter section, and when it becomes possible to send the packet to a line, the counter section is set to a predetermined value and the packet is sent to the line, and when the relay station receives the packet, it sets the packet reception time and starts transmission when it becomes possible to send the packet to the line. The packet residence time is calculated from the difference between the time and the packet reception time, the transmission delay time is calculated from the packet length of the packet, the transmission speed of the packet destination line, and the transmission distance, and the packet residence time and the transmission delay are calculated. time and time from the counter value of the counter section of the packet, and if the subtracted and updated counter value is greater than a threshold value, the packet is sent to the line, otherwise, the packet is discarded, and the packet is received. When the station receives the packet, it sets the packet reception time, and when it becomes possible to send the packet to the line, calculates the packet residence time based on the difference between the transmission start time and the packet reception time, A transmission delay time is calculated based on the packet length of the packet, the transmission speed of the packet destination line, and the transmission distance, and the packet residence time and the transmission delay time are updated by subtracting from the counter value of the packet counter section. A packet communication system characterized in that the packets are sent to a line after counting until the subtracted and updated counter value reaches a threshold value.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP58064668A JPS59190757A (en) | 1983-04-13 | 1983-04-13 | Packet communication system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP58064668A JPS59190757A (en) | 1983-04-13 | 1983-04-13 | Packet communication system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS59190757A JPS59190757A (en) | 1984-10-29 |
| JPH0515091B2 true JPH0515091B2 (en) | 1993-02-26 |
Family
ID=13264796
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP58064668A Granted JPS59190757A (en) | 1983-04-13 | 1983-04-13 | Packet communication system |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS59190757A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2008125073A (en) * | 2006-11-13 | 2008-05-29 | Fujitsu Ltd | Invalid data removal using WiMAX scheduler latency count |
Families Citing this family (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5042032A (en) * | 1989-06-23 | 1991-08-20 | At&T Bell Laboratories | Packet route scheduling in a packet cross connect switch system for periodic and statistical packets |
| GB9909436D0 (en) * | 1999-04-23 | 1999-06-23 | Pact | Routing device |
| JP3844686B2 (en) | 2001-12-13 | 2006-11-15 | 株式会社エヌ・ティ・ティ・ドコモ | Router device, terminal device, communication system, and routing method |
| DE602004017423D1 (en) * | 2003-02-20 | 2008-12-11 | Zarlink Semiconductor Inc | SYNCHRONIZATION OF STEPS THROUGH SEVERAL PACKET NETWORKS |
| US7924711B2 (en) * | 2004-10-20 | 2011-04-12 | Qualcomm Incorporated | Method and apparatus to adaptively manage end-to-end voice over internet protocol (VolP) media latency |
| US8050259B2 (en) * | 2006-06-23 | 2011-11-01 | Alcatel Lucent | Method and apparatus of precedence identification for real time services |
| WO2008102564A1 (en) * | 2007-02-23 | 2008-08-28 | Panasonic Corporation | Network node and mobile terminal |
| JP2009071537A (en) * | 2007-09-12 | 2009-04-02 | Toshiba Corp | Data transfer system and data transfer method |
| JP6001516B2 (en) * | 2013-09-24 | 2016-10-05 | 株式会社日立製作所 | Communication system and communication apparatus |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS54153503A (en) * | 1978-05-25 | 1979-12-03 | Fujitsu Ltd | Processing system for delayed information frame |
| JPS5840399B2 (en) * | 1979-08-17 | 1983-09-05 | 富士通株式会社 | Voice packet call setting method |
-
1983
- 1983-04-13 JP JP58064668A patent/JPS59190757A/en active Granted
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2008125073A (en) * | 2006-11-13 | 2008-05-29 | Fujitsu Ltd | Invalid data removal using WiMAX scheduler latency count |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS59190757A (en) | 1984-10-29 |
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