JPS6084048A - Line/packet centralized exchange system - Google Patents

Abstract

PURPOSE:To realize various communication services with a single exchange by handling a line exchange signal and a packet exchange signal in a form of identical hybrid packet. CONSTITUTION:Each communication node 20 classifies by destination communication node at each prescribed period in common between nodes a talking signal of a line exchange mode among talking signals incoming to the corresponding node in many talkings, collects plural classified talking signals and forms a line exchange hybrid packet at each destination communication node. Moreover, the line exchange hybrid packet formed in this way is transmitted to a communication loop in the next prescribed period. The line exchange signal and the packet exchange signal are handled unifiedly in a form of the hybrid packet in this way. The difference of the two depends whether or not the hybrid packet is transmitted and received at a prescribed period. On the other hand, since the hybrid packet is formed with respect to the line exchange mode and the packet exchange mode, complicated control is avoided in comparison with the method constituting the hybrid packet while collecting the two.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of configuring a circuit/packet integrated switching system that exchanges both circuit switching signals and packet switching signals in a mixed manner.

As is well known, switching methods include circuit switching methods and packet switching methods. Both ζ have their own advantages and disadvantages, and are said to have different application areas.

In other words, the circuit switching system has the characteristics that a call connection path with the required bandwidth or speed is secured from the start to the end of each call (or call), and that the delay is small and there is no variation in delay. It is also advantageous for data communications such as facsimiles and file transfers in which a large amount of data to be sent is generated continuously. However, T8S (Time
For interactive data communication in which data is generated only intermittently and in small amounts, such as Sharing System services and makeshift services, the line usage efficiency is poor, which is disadvantageous. On the other hand, the packet switching method stores the data to be sent in a buffer and makes it wait, allowing the data to be efficiently (multiplexed) on the line, which is advantageous over the above-mentioned interactive data communication. becomes.

However, compared to the circuit switching method, the delay is large and the delay fluctuates considerably, so it is generally considered disadvantageous for voice communications, etc.

As described above, the suitable switching method differs depending on the type of service, but currently it is common to configure a separate communication network for each service and adopt the switching method suitable for that service. . For example, a voice communication network (circuit switching system), a telex network (circuit switching system), a circuit switching network for data, and a packet switching network for data are constructed separately.

This method has the advantage that each communication network can be optimized for the services it provides. but,
On the other hand, because there are multiple communication networks that have slightly different methods or characteristics but are generally similar, there are many overlapping parts, making the operation and management of communication networks complicated.
Since the scale of individual communication networks becomes smaller, the so-called large grouping effect cannot be obtained, and the efficiency of communication equipment as a whole is reduced. Furthermore, if the communication networks differ for each service, many countries will need to provide a complex service that combines multiple services, and in order to realize new services, communication networks will be required. There will be a need to build one.

Therefore, it would be extremely effective if both circuit switching and packet switching could be integrated into a single communication network, and a wide variety of services could be centrally provided in a format suitable for each. It's big. for that purpose,
Each of the transmission lines and exchanges that make up the communication network
It is essential to realize a packet integrated transmission line and circuit +111I/packet integrated switch.

Conventionally, the configuration shown in Figure 1 has been considered as a line/packet integrated switch.In other words, in Figure 1, circuit switched signals and packet switched signals arriving from the transmission line 10 are distributed to the switched switch. The circuit-switched signals are transmitted to the circuit-switched section 13 via the link 12, and the packet-switched signals are transmitted to the packet-switched section 15 via the link 14. The line switching section 13 and the packet switching section 15 are each based on conventional IC! It is equivalent to a 1-line converter or a packet switch.

The circuit switching signals and packet switching signals exchanged in each switching section are transmitted again to the switching section 11 via each of the four links 12 and 14. The exchange unit 11 outputs both signals to the transmission line 10 of the destination route. The allocation is exchange part 1]
In the transmission path 10, the configuration of the circuit-switched signal and the packet-switched signal differs depending on what form the circuit-switched signal and the packet-switched signal are in. Or, conversely, the two may be combined and output on the transmission line.

However, in the configuration shown in FIG. 1, even though same-sex exchange and packet exchange are apparently realized within the exchange, they are logically completely separate and cannot be called true integration. In other words, the circuit switching section and the packet switching section must be configured separately based on the characteristics of the circuit switching signal and the packet switching signal, respectively, and there are still overlapping parts, and a decrease in efficiency is inevitable. The circuit switching mentioned earlier/
On the other hand, in private closed communication networks, especially local area networks (LANs), which have recently been attracting attention, circuit-switched signals and packet-switched signals are transmitted on the same communication network. Attempts have been made to improve service T above, and it is also conceivable to configure the telephone switch network of an exchange after a local area network. For example, as shown in FIG. 2, a configuration can be considered in which a plurality of modules (hereinafter referred to as communication nodes J) 20 accommodating a large number of terminals or inter-office trunk lines are connected by a plurality of communication loops 21. .

In this case, the traditional local area network structure
According to the X method, for example, each communication loop 21 is provided with a frame with a fixed time period as shown in FIG. K'X will be released. These time slots are then separated into time slots for circuit switching and θ) time slots for packet switching, each with +1. The lI receiving node uses the time slot I-4 allocated for circuit switching to transmit the circuit switched signal and i'f! for packet switching. Send and receive packet-switched signals using assigned time slots
At that time, each line must be crossed! The signal is transmitted on a loop using the same time slot as the frame during the call connection,
On the other hand, the packet switching signal is a time slot signal well known to those skilled in the art.
An appropriate algorithm among the access algorithms (f
The data is transmitted using a token passing method.

In the above method #ζ, time 1. i Q What is the difference between the tie time slot for ilJ and the time slot for packet exchange?
If 11 is fixed, even if there is an empty time slot in one of the time slots, the other signal will not be able to use it, resulting in wasted time. Efficiency will decrease, and this father-in-law, physically, it will be 11 times! ! Paget exchange is an integrated fin, but it is logically completely different and there is no difference from the method shown in Figure 1, and the merits of the (mouth) exchange/nogukerato exchange integration mentioned earlier. is not obtained. For this 11, 1111 minutes are squared,
The so-called town's boundary (mouth) 0vablebounda
ry) method, it is possible to allocate the number of time slots according to the traffic of each line switch and packet switch, and it is possible to reduce the drop in efficiency due to the generation of waste mentioned above. I can tell fortunes. However, in that case, each intersection 4
! Did you see the traffic at 8 traffic lights? μmj, a control node having the function of instructing the boundaries of time slots is required. Alternatively, if a control node already exists, it is necessary to add the above function to that node. However, even in this case, it is impossible to instantaneously measure the number of traffic people, and therefore it is impossible to instantaneously change the allocation of the number of time slots during IM and eliminate waste. This is an essential problem arising from the distinction between circuit-switched and packet-switched time slots.

On the other hand, several methods have been proposed that aim at true integration of the two. One method is to apply the packet switching system to signals, such as voice, for which conventional circuit switching systems were appropriate, and to integrate all communications using the packet switching system. In the case of audio, in this method, digitized audio signals within a predetermined time period are grouped together to form a packet, and the packet is transmitted to the destination using conventional packet switching techniques. Each packet has a destination address, logical channel USJd-6
N Cow If Eight JI IM JiL X-jto1. J
J 8 car -h< L+ 4In -Je 4q
The packet is transmitted at the destination while checking the header of r+e. In this case, in order to prevent a drop in transmission efficiency due to the header, the size of one packet must be made thicker.For this reason, for resuscitation signals, so-called packets, This increases the delay due to the amount of time it takes to accumulate the amount of packing signals necessary to form a packet of a predetermined size. In addition, in the packet switching method, 1
．． (Because the packets are accumulated and transmitted while waiting for the transmission path to become available, the waiting time varies depending on the packet, even if the packets belong to the same call or calls.) Therefore, for communications that require time transparency (the property that the delay is always constant), such as voice communications, a reception buffer is required to absorb delay fluctuations, which further increases the delay time. In a communication network that spreads over a wide area, when the caller passes through many exchanges from the caller to the receiver, the delays at each exchange accumulate, resulting in an extremely large delay, resulting in echoes or the communication itself being delayed. In order to reduce the 6° delay without deterioration of speech quality due to the delay, it is necessary to shorten the packet length and shorten the packet assembly time, as well as reduce the capacity of the delay absorption buffer. in case of,
Quality deterioration occurs due to reduced transmission efficiency and packet loss.

On the other hand, there is also a method in which circuit switching is applied to communications that are considered suitable for packet switching, and the circuit/package and yt exchanged signals are integrated using the circuit switching method. An example is the high-speed line switching system (f ast (41)).
The method called ``transmission'' prevents unnecessary suspension of the transmission line by setting up a new line each time transmission data occurs intermittently during a single call, and restoring the line immediately upon completion of transmission. This is a method that aims to improve efficiency. In this method, line settings,
The most important issue is how fast recovery can be performed. However, in a communication network that spreads over a wide area as mentioned above, setting a route from the sender to the recipient,
Restoration must be carried out via multiple exchanges,
In reality, it is extremely unreasonable to set this time to be sufficiently smaller than the time during which the transmission data itself occupies the transmission path. Therefore, a decrease in efficiency of the transmission line is unavoidable. In addition, when there are various bandwidths (or speeds) for the data to be transmitted, or when dealing with so-called multiple traffic, the communication connection path with the required communication band or signal speed for each communication service is determined. Control to maintain 8 (p) for each call and over all routes, control to block multiple secured unit bands or unit speed call connection paths as one call, etc. are required, and control becomes extremely complicated. This will lead to an increase in the scale and complexity of the hardware and software of the father switch.

To enumerate the shortcomings of the conventional methods mentioned above, they are as follows: (1) true integration of circuit switching and packet switching is not performed, improving equipment efficiency, unifying operation, and management; There are few benefits of integration. (In case of circuit switching and packet switching coexistence method) (
2) The spread is large for circuit-switched signals such as voice signals. (In the case of an integrated system using a packet switching system) (3) There is no time transparency for circuit switching signals such as voice signals. (
(In the case of an integrated method using a packet switching method) (4) Efficiency is improved for communications that generate intermittent transmission data (In the case of an integrated method using a circuit switching method) (5) Control over multi-source traffic becomes complicated.

The purpose of the present invention is to eliminate all of these drawbacks (in the case of circuit-switched integrated systems), to truly integrate circuit switching and packet switching, and to reduce the delay for circuit-switched signals in less time. The aim is to realize a line/packet convergence switch that maintains transparency, does not reduce efficiency in response to intermittent communications, and can easily handle multiple traffic.

In other words, according to the present invention, in a circuit/packet integrated switching network consisting of a communication loop or a plurality of communication loops and a plurality of communication nodes that commonly access the communication loops, frames, and each communication node classifies circuit-switched signals arriving from subscriber terminals or trunk lines by destination communication node for each period of the frame, and classifies a plurality of circuit-switched signals for each of the same destination communication nodes. It creates one or more circuit-switched mixed packets and transmits them through the communication loop I, and classifies the packet-switched signals arriving from subscriber terminals or relay lines by destination communication node, and divides them into each same destination communication node. One or more υ packet-switched mixed packets are created and sent to the communication loop, and at the same time, each communication node generates the circuit-switched mixed packets and packet-switched mixed packets that are transmitted on the communication loop I. Among the packets, the mixed packet for circuit switching and the mixed packet for J packet switching addressed to the own node are found and received, and the extended mixed packet for circuit switching and mixed packet for packet switching are combined with the individual circuit switching signals and packets. A circuit/packet integrated switching system is obtained which is characterized in that the switching signal is decomposed into switching signals and sent to subscriber terminals or p-junction lines.

The present invention will be described in detail below with reference to the drawings.

The present invention is realized on a call switch circuit network configuration in which a plurality of communication nodes 20 shown in FIG. 2 are connected by a plurality of communication loops 21 (including a single communication loop 21). Second
The communication nodes 20 in the figure each accommodate a large number of subscriber terminals 22, 23, 24 or inter-office relay lines 25, and further transmit and receive call signals arriving from the first and second communication nodes between arbitrary communication nodes. By sending those call signals again to any subscriber terminal or inter-office trunk line, a large number of calls (or calls) of various types such as sewing, data, image, circuit switching mode, packet switching mode, etc. can be transmitted as a whole. ) can be exchanged arbitrarily and simultaneously. Here, the circuit switching mode and the packet switching mode represent exchange forms applied to the exchange of a certain call.

Of the call signals that arrive at the node in these many calls, each communication node 20 transmits call signals in circuit switching mode at a fixed cycle common to the nodes, for example, a standard coding cycle for crying signals. Each 125μ type is classified by destination communication node, and a mixed packet for line intersection 4 (as shown in FIG. 4) is created for each destination communication node by combining a plurality of classified call signals.Furthermore, The created circuit switching congestion packet is transmitted onto the communication loop within the next fixed period.From the method ζ described later,
Circuit-switched mixed packets can be transmitted within -periods. In FIG. 4, the line V switching mixed packet includes a destination communication node address field D1, a source communication node address field S, an exchange mode display field M, and a control signal field C.
1 retrospective exchange signal (41> (according to I from 38. The destination communication node address field D and the source communication node address field S are literally the address numbers of the destination communication node and the source communication node of the circuit-switched mixed packet. This is the part that stores the .

The multi-switching mode display section M is a section that displays whether the mixed packet is for a call signal in circuit switching mode or for a call signal in packet switching mode as described in 1-1 below. ``1'' is displayed in the case of ``1-0'' in the ``completion'' of the packet switching mode. Generally, two types of mixed packets, one for circuit switching and one for packet switching, are transmitted and received between a set of nodes, so it is necessary to display such an exchange mode.

On the other hand, the circuit switching signal section O8 is 081.082 in FIG.
As shown in O83,..., it generally consists of call signals in multiple circuit switching modes, and each call is in its band (
or speed), it occupies a certain amount of space in the circuit-switched mixed packet every cycle. This is because, in a circuit-switched mode call, a certain amount of call signals depending on the band arrive at the communication node at regular intervals, and the call signals are transmitted to the communication node.

This is because all the data must be sent to the destination communication node in the next cycle without being stored in the file memory or the like. For example, in Figure 4, the period is 125μ type % type % For voice by POM, 8 pi l-,082 is 192k
In the case of b/s high-speed facsimile, the space of a single bit is occupied in a circuit-switched mixed packet every cycle. On the other hand, when a new circuit-switched mode call occurs, a space for the corresponding call signal is added to the end of the circuit-switched signal section O8, and when the currently connected call ends (e. The space for the circuit-switched signal is deleted from the circuit-switched signal portion O8, and the subsequent call signal is carried forward.In other words, the circuit-switched mixed packet changes in length depending on the initiation/termination of a call in circuit-switched mode. The control signal unit C is responsible for communication between communication nodes, such as setting up and restoring calls in circuit switching mode, notification of required bandwidth, and information on incoming and outgoing subscribers. This is the part that stores control signals.

On the other hand, among the single-talk signals arriving at the communication node 20, the packet-switched mode call signals are classified by destination communication node, and each destination communication node is divided into packet-switched mixers as shown in FIG. A packet is created and sent onto the communication loop.

In FIG. 5, the destination communication node address section I), the source communication node address section 81, and the exchange mode display section M are as described in FIG. The classified exchange signal part PS stores classified call signals in the exchange mode. Since there are generally a plurality of calls in the packet switching mode, they are accommodated in the packet switching signal section PS in a shared manner as shown by PSl and P82 in FIG.

The mixed packet for packet exchange configured in this manner is sent to the communication loop. However, in the case of mixed packets for packet exchange, transmission is not necessarily completed within one period of the period.

Therefore, each time a new cycle begins, a new destination communication node address field, etc.8 is added to the beginning of the remaining packet signal part Ps, and at the end of each cycle, the mixed packet format shown in Figure 5 is transmitted. Send to loop.

At this time, the length of the packet-switched signal part Ps of each mixed packet generally changes from cycle to cycle depending on the amount of packet-switched mode speech signals arriving at the communication node and the congestion of the ETL communication loop. Therefore, in general, one traffic signal (packet) belonging to a call in a certain packet switching mode may be sent across multiple mixed packets for packet switching, and one mixed packet may contain multiple calls. There may be signals (packets) present.

That is, for calls in the packet switching mode, the packet switching signal section PS can be regarded as a packet multiplex transmission path that changes the communication capacity "r4-".

Note that depending on the amount of call signals and the congestion of the communication loop, there may be periods in which mixed packets for packet exchange are not transmitted. Unlike calls in circuit-switched mode, in packet-switched mode calls, the call signals arriving at the communication node are allowed to wait in the buffer memory, making the transmission method described above possible. .

On the other hand, control signals for setting up a packet-switched mode call, restoring Il1, etc. are usually included in the call signal.

Therefore, the portion corresponding to the control signal section C in FIG. 4 is not necessarily necessary for the packet exchange JJ mode, and is not included in the configuration of FIG. 5.

As described above, each communication node sends a mixed circuit-switched and packet-switched packet onto all communication loops, and also sends out a large number of circuit-switched and packet-switched packets transmitted from other communication nodes on the communication loop. Among the mixed packets, those addressed to the own node are detected, removed from the communication loop, and taken into the own node.

With this method, for circuit-switched calls,
Since a fixed amount of speech signals depending on the band or speed is transmitted and received every cycle using circuit-switched mixed packets, the delay between nodes is constant, and time transparency with respect to circuit-switched signals is maintained.

Furthermore, since one header (address, control signal, etc.) is added to multiple circuit-switched mode call signals, the proportion of headers per individual call is reduced. As a result, efficiency is achieved even if the amount of call signals for each of the 216 conversations in the circuit-switched mixed packet is small. Therefore, it is possible to shorten the assembling/sending cycle of the line-switched mixed packets mentioned above, and it is possible to reduce the delay caused by the so-called packet H1l setup time. For example, in Figure 4,
Assuming that the line-switched mixed packet assembly/transmission cycle is the 125μ formula mentioned earlier, when the line-switched signal section 08 is 80 bits for 10 voice calls, the conventional method that configures one packet I-i for only one voice call In this method, in order to equalize the efficiency loss caused by ζ and DA, ζ is equal to 80 bits of audio, or 1.25 mK! c packet assembly time is required. By using the mixed packet method of the present invention as described above, it is possible to significantly reduce the delay time compared to the case of the normal packet exchange method.

On the other hand, even for multiple traffic in circuit switching mode with different bandwidths or speeds, as shown in Figure 4, a certain amount of space is occupied in the circuit switching mixed packet according to the bandwidth or speed. There is no need for complex control such as individually securing a unit band or speed IW and grouping them together.

Furthermore, according to this method, circuit switching signals and packet switching signals can be handled uniformly in the form of mixed packets. The only difference between the two is whether or not it is necessary to send and receive mixed packets at regular intervals.On the other hand, in order to create mixed packets for both circuit switching mode and packet switching mode, it is necessary to mix both together. Compared to the method of configuring packets, etc., it is also possible to avoid complicated control.

Next, a method for transmitting and receiving the line switching and packet switching mixed packets between each communication node will be explained. First, in the configuration shown in Fig. 2, in which multiple communication nodes are coupled by a single or multiple communication loops, each communication loop has a loop-to-circle signal transmission time that is longer than the circuit-switched mixed packet described above. Assembly cycle (for example, 1
25μII! lc) or an integral multiple thereof. That is, one of the communication nodes is provided with such a delay adjustment function, or a dedicated node for delay adjustment is provided. Then, on each communication loop, a communication frame is provided, which has a period much larger than the circuit switching packet assembly period, in the above example, a period of 125 μm. Furthermore, the communication frame is divided into multiple time slots, as shown in FIG. In addition, the 6th
The figure omits the frame synchronization pattern bits. Each communication node sends the circuit-switched and packet-switched two-combined packets (hereinafter, the term "mixed packet" refers to both the circuit-switched and packet-switched mixed packets) in this time slot. It divides the frame into different sizes, monitors it from the beginning of the frame, and when it detects an empty time slot, it sequentially sends the divided mixed packets onto the communication loop. It should be noted that the above vacant time slots: y and 1 also include vacant time slots that occur when a mixed packet addressed to the node itself is taken into the node. Therefore, one mixed packet consists of multiple packets within one frame, and moreover, there are multiple packets intermittently υ)
It will be transmitted using time slots. If there are many signals to be transmitted within one frame, it is also possible to transmit the mixed node using all the time slots.

Each time slot is provided with several indicators in order to indicate whether each time slot is free/occupied and to distinguish between a plurality of mixed packets. For example, as shown in FIG. 6, an occupancy indicator I/I3. Provide a mixed packet head display section H and a mixed packet recording section PID. Air block display section I/1
3 (J) It is displayed whether the time slot is free or in use, and when sending a mixed packet, the communication node first monitors this part of each time slot to detect a free time slot. Then, it changes this part of the timeslot to "in use" and sends one mixed packet divided into the size of the timeslot onto that timeslot.It also sends a mixed packet addressed to its own node. Among the transmitted time slots, the I of the time slot that the own node does not use for sending mixed packets.
/H is written to indicate the presence of nitrogen. In the mixed packet head display section IH, when the time slot corresponds to the head of the mixed packet when the time slot concerned sends out the mixed packet, for example, "10 before the month" is drawn. On the receiving side, for time slots that are displayed as "in use", the mixed packet head display area H is also observed, and if the head is displayed here, the information in that time slot is The destination communication node address field D (see FIGS. 4 and 5) at the beginning is monitored. If the packet is addressed to its own node, it continues to receive the source communication node address section 8 and the exchange mode display section M, and identifies the destination node and the line-switched/packet-switched mixed packet. Based on the result, the subsequent control signal section O1, line exchange signal section O8, packet exchange signal section PS, etc. are received and distributed to a predetermined location such as a buffer memory. In this way, it becomes possible to detect and receive the first time slot of a mixed packet addressed to the own node.

Further, a number for identifying a large number of mixed buckets sent out from each communication node is written in the mixed packet classification section PID. For example, the slot number of the first time slot of the mixed packet is written in the PID of the time slots belonging to the same mixed packet. A specific example is shown in FIG. In FIG. 7, one mixed packet consists of discrete time slots #2, #4, #5,
#7, . . . is divided into In-1 and sent onto a certain communication loop. In the PID of those time slots, the first time slot number #2 is written, and in the second time slot #2, the above-mentioned mixed packet first display section Hf is displayed. Needless to say, "in use" is displayed on the empty display section I/B of these time slots. On the other hand, on the receiving side, by monitoring the mixed packet head display section and the destination communication node address mentioned above, it is possible to detect the preceding time slot of the mixed packet addressed to its own node and memorize that number. When it comes to time slots, by extracting the time slots whose numbers are written in the PID, even mixed packets that are transmitted after being divided into discrete time slots can be restored to their original state. At this time, it doesn't matter what is written in the PID of the first time slot of the mixed packet, but if you write the own time slot number here, this alone will indicate that it is the beginning of the mixed packet. be able to. Therefore, it is also possible to eliminate the need for the mixed packet head display section H mentioned above. Also, among the communication nodes, there is a special node that controls the operation and management of switching equipment outage, for example, and a specific time slot is fixedly assigned for communication between this special node and other general communication nodes. , if there are time slots that are not used for communication between general communication nodes, or if there are time slot numbers that do not exist, write those time slot numbers in the PID section as an alternative method for displaying free space. Other methods are also possible. In other words, by doing this, it is possible to perform equivalent operations without specifically providing the occupancy display unit I/B, and the overhead within the communication frame can be reduced. A possible method is to connect the time slots IIF belonging to the same mixed packet in a chain, and write the slot number of the preceding time slot in the PID of each time slot. A specific example is shown in FIG. FIG. 8 shows time slots 4#2#4, #5, #7, .
-1 is shown, but the slot street number of the previous time slot belonging to the same mixed packet is written in the PID of the mixed packet 2nd day. The receiving side detects the first time slot, detects the next time slot that has that slot number in the PID part,
By following the chain in the same manner, it is possible to restore the mixed packet in almost the same way as in the case of FIG. In this method, the last time slot number (In in Figure 8) is not written in the PID (because one mixed packet is completed within one frame), so this ff number is used as an empty display or a packet It is also possible to use this instead of the first display. Also, as in the case of the example in Figure 7, if there is a time slot or time slot number that is not used for communication between general communication nodes, that number can be used instead of an empty display or a packet head display. It is also possible.

As yet another method of identifying mixed packets, it is also possible to allocate unique and different box numbers to each mixed packet and write the numbers in the mixed packet identification section PIDt. There are two methods for assigning a unique number to each combination of transmitting and receiving communication nodes, and a method for assigning a unique number to each combination of transmitting and receiving communication nodes.
There is a method of monitoring the communication loop for a predetermined period of time and selecting an unused number as a unique number. A typical example of the former is a method in which the destination communication node address and the source communication node address are arranged as they are, and (1) is used as a unique number.

On the other hand, independently of the communication node address, sending and receiving;
number -8? for each combination of receiving nodes. -1f split
1) is also possible, and the hit width of the PID can be reduced by about 1 bit compared to the case where the addresses are lined up as they are. In these methods, the PID is directly or indirectly Since information regarding the node address and source communication node address is included, it is possible to omit the communication node addresses D and S of the components of the mixed packet shown in FIGS. 4 and 5. can.

On the other hand, in the method of selecting an empty number that does not appear on the communication loop and using it as a unique number when starting to send a mixed packet,
First, there is a procedure to declare to other communication nodes the relationship between the unique number and the sending/receiving communication node address of the mixed packet, and a procedure to prevent duplication of the unique number with similar declarations from other communication nodes. Although necessary, once the declaration is successful, it is possible to identify a mixed packet only by its unique number. Therefore, in this case as well, addresses D and S can be omitted among the components of the mixed packet. In the case of these methods as well, a specific unique number is provided in place of the vacancy display, and the vacancy display section I/B is omitted.
It is possible. Furthermore, since the time slot in which each unique number first appears in the PID when monitoring from the beginning of the frame is the first time slot of the corresponding mixed packet, even in these methods, it is not necessary to display the packet beginning display part H. There is no need to provide it.

In addition, when using this method, if the mixed packet identification part PID also has an exchange mode display function (for example, by adding T1 hit indicating the exchange mode to the PID), the exchange mode display part M ( (see FIGS. 4 and 5) is also no longer necessary.

In this case, for mixed packets for packet exchange, there is virtually no need to be aware of frames, and by finding an empty time slot, the required mixed packet identification part PID
It is only necessary to send out mixed packets together with the above, and control is significantly simplified.

Regardless of the method described above, according to the present invention, each time slot is indicated as being empty in some form, and each communication node is able to determine whether the last time slot (for communication addressed to its own node) is , including time slots that become vacant at its own node) from the beginning of the communication frame, and transmits each mixed paget. Therefore, when the amount of speech signals to be transmitted is large, mixed packets can be transmitted using all available time slots. In other words, the transmission capacity of the communication loop can be reduced to 100% without distinguishing between circuit-switched signals and packet-switched signals.
%, it is extremely efficient. Moreover, circuit-switched mixed packets can be transmitted every frame. The reason for this will be explained below. However, here, calls in each circuit switching mode are full-duplex with blue signals at signal speeds in both upstream and downstream directions.

As mentioned above, in the present invention, each communication loop is -
The frame period transmission time ζ is configured so that it is equal to the frame period or an integral multiple thereof. Therefore, any time slot within a frame always exists somewhere on the communication loop and circulates between communication nodes as time passes. In other words, it can be thought of as a belt conveyor circulating between communication nodes. Therefore, in each communication node, the time slot addressed to the own node that has gone around the loop and reached the own node is released and becomes an empty time slot, so it must be used for mixed packet transmission from the own node. I can do it. In other words, if n time slots are sent to the own node within one frame, there are generally several other free time slots, so the lowest number of time slots are used for transmission from the own node. You will be able to do that. So, for example, when communication nodes A and I3 try to start transmitting and receiving circuit-switched mixed packets using one time slot, communication node A monitors the time slots on the communication loop and determines which time slots are available. One time slot is detected and an attempt is made to send the line-switched mixed packet of #f shown in FIG. 4 to that time slot. The control signal portion C of this circuit-switched mixed packet contains an instruction to the node B to use one time slot for the circuit-switched mixed packet. When node B receives this circuit-switched mixed packet and decodes the instruction, it also detects one free time slot and attempts to exit the circuit-switched mixed packet addressed to node A. Generally, the deciphering of the instructions is performed by node A
Since the time slot used by the mixed packet cannot be immediately used to transmit the circuit switched mixed packet from node B to node A, node B also has free time slots. Time slot exploration is a must. Thereafter, node A and node B each attempt to send a circuit-switched mixed packet addressed to the other node in one time slot per frame.2 If one of the nodes succeeds in sending out the packet using the mechanism described above, then, In that frame, the other node must also be able to transmit. This kind of transmission is possible for all the frames that exist during one round of the communication loop, because from then on, both nodes must continue to send one time slot of circuit-switched mixed packets to each other every frame. over 17 L/-
As a result, it is possible to continuously secure the transmission 41 of each frame, which is essential for the 1-line, 1-line exchange signal. The number of time slots required for transmitting and receiving circuit switching signals can be increased in the same manner as described above, using the control signal ``+l(0'') to negotiate between communication nodes, and also to acquire the required number of time slots at both nodes. In this way, once the continuous transmission and reception of circuit-switched mixed packets for the specified number of time slots is established between nodes A and B, the other nodes can be sent and received without any special control. node A without interfering with access from the node.
, B1 can maintain transmission and reception of circuit switched signals for each frame. Note that from the start of time slot acquisition until the transmission of bidirectional circuit switching signals is established,
There will be a space in the outgoing circuit-switched mixed baguette.

Generally, each communication node sends out a plurality of mixed packets for circuit switching and packet switching for each destination communication node. It is necessary to send out all mixed baguettes for packet exchange before sending out mixed packets for packet exchange.

On the other hand, in the packet switching mode, communication signals are sent out onto the communication loop efficiently and efficiently while waiting according to the number of available time slots, as mentioned above, and transmission data is generated intermittently. The line/packet integration method according to the present invention is sufficiently efficient even for such calls.

In the above description, for the sake of simplicity, it is assumed that each communication node transmits a mixed packet destined for any other node to any one communication loop.

In fact, in the case of a configuration in which a plurality of physical communication loops exist, it is best to consider these as one logical communication loop and apply the same method as described above. Alternatively, the method described above may be employed in which the mixed packets are each sent to one of the physical communication loops.

In this case, if the amount of communication between specific communication nodes is large, the necessary amount of communication can be secured by creating multiple mixed packets between those nodes and sending them to separate physical communication loops. The method can also be easily configured.

FIG. 9 and FIG. 10 are schematic diagrams showing one configuration example of a communication node in the present invention. However, in this example, the MI when one mixed packet is sent to the same communication loop is
This is a perfect example. In FIG. 9, the communication node 20 is provided with a mixed packet transmitting/receiving unit 30 for each of the plurality of communication loops 21, and among the mixed packets sent from each node according to any of the methods described above, The mixed packets are scattered from the communication loop, and the mixed packets destined for other nodes are sent onto the communication loop. The mixed packet assembly/disassembly circuit 3 assembles the communication signal in the communication mode and the communication signal in the packet exchange mode, which come from the transmission line 10, into mixed packets for circuit switching and packet switching for each destination communication node. and sends each mixed packet to one of the mixed packet transmitting/receiving sections 30. At the same time, it receives the mixed packet addressed to its own node from the communication loop 21 transferred from each mixed packet transmitter/receiver 30, and decomposes it into the original call signal in circuit switching mode and the call signal in packet switching mode. and sends it to the destination transmission path 10. Control unit 32
creates/analyzes the control signal part C (see FIG. 4) of the line-switched mixed packets to be transmitted and received, processes speech signals in packet-switched mode, and controls the entire communication node.

The clock unit 33 supplies an operating clock within the communication node synchronized with the unified clock within the exchange, and also supplies various timing signals within the communication node. Clock synchronization is well known to those skilled in the art and will not be described in detail.

FIG. 10 shows the mixed packet transmitter/receiver 30 in FIG.
FIG. 2 is an explanatory diagram showing a more detailed configuration. In FIG. 10, a signal transmitted from another node on the communication loop 21 is received by a receiving circuit 34, equalized and amplified, and regenerated into a digital signal. The frame synchronization circuit 35 detects the frame phase from the reproduced digital signal sequence, and creates a timing signal for the operation within the mixed packet transmitter/receiver 30 based on it. Based on this timing signal, the reception time slot control circuit 36 monitors the empty/busy indicator I/B and the mixed packet head indicator NH-mixed packet identifier PID of each time slot, and checks whether the mixed packet addressed to its own node is Detects the existing time slot and stores its contents in the reception buffer memory circuit 37a,
37b. A mixed packet for line switching is stored in the reception buffer memory circuit 37a, and a mixed packet for packet switching is stored in the receiving buffer memory circuit 37b. The mixed packet written to the receive buffer memory is transferred to mixed packet assembly/disassembly circuit 31 in FIG. On the other hand, the sending@mixed packet transferred from the mixed packet assembly/disassembly circuit 31 is temporarily stored in the sending buffer memory 3.
After being stored in 8a and 38b, the data is transmitted on the communication loop under the control of the transmission time slot control circuit 39. The transmission buffer memory circuit 38a stores mixed packets for circuit switching, and the transmission buffer memory circuit 38b stores mixed packets for packet switching. The reception time slot control circuit 36 detects a time slot in which a mixed packet addressed to its own node exists, and at the same time detects an empty time slot, and controls the transmission time slot to control the combined mixed packet transmission time of 1 and 2. Notify circuit 39. If the mixed packet to be sent exists in the sending buffer memory circuits 38a, 38b, the transmission time slot control circuit 39 sends it out to the mixing bucket)+the relevant time slot according to 3fi+knowledge. At this time, the mixed packet for circuit switching is sent out before the mixed packet for full packet switching, as described above. May: Necessary signals are also written in the empty display section 1/B1 mixed packet head display section H2 mixed packet sorting section PID of the time slot by the method described above.

On the other hand, if there is no mixed packet to be sent even if there is a time slot that can be sent, an empty display signal is written in the empty display section I/H of the time slot. When writing a PID or the like or sending out a mixed packet, the switch 40 selects the insertion side terminal 41 under the control of the sending time slot control circuit 39. When a time slot in use is occupied by a mixed packet from another communication node, the switch 40 selects the pass-through terminal 42 and allows the signal sent from the other communication node to pass through as is. The delay circuit 43 analyzes the I/B, H, PIDr &: of each time slot by the reception time slot control circuit 36, and the transmission time slot control circuit 391 analyzes the new I/B, H, PIDr &:.
/B is a circuit for compensating for the delay until the first HSPID is written. The signal selected by the switch 40 is sent out again onto the communication loop 21 by the transmitting circuit 44 and transmitted to the next communication node.

As described above, according to the present invention, circuit switching signals and packet switching signals can be handled uniformly in the form of the same mixture, N6 get, and true integration can be realized. Therefore, there is no need to allocate the transmission capacity of the communication loop to both parties in advance (the capacity can be dynamically occupied instantaneously as needed, so control is simple and there is no need to allocate the transmission capacity of the communication loop to both parties in advance) Furthermore, once the required number of time slots can be secured between specific nodes, circuit-switched mixed packets can be sent every frame from then on. First, there is no delay variation characteristic of packet-switched signals, and time transparency is guaranteed.

Furthermore, a mixture that integrates multiple simultaneous call signals)
The amount of A talk signals per call can be reduced.

As a result, the so-called packet assembly time can be shortened, making it possible to shorten the so-called packet assembly time, making it possible to shorten the so-called packet assembly time.

Since the transmission interval TfA, that is, the frame period, can be shortened, the overall transmission delay can be kept small. In addition, by providing a mixed packet identification section PID section in each time slot, it is possible to combine as many time slots as necessary for each frame and send out mixed packets of variable length. It is possible to provide a highly flexible switching function even for different communications and communications with different traffic characteristics, that is, so-called multi-source traffic. Therefore, the present invention is extremely effective as a method of integrating line switching/packet switching and realizing various communication services using a single switching device. Furthermore, although the configuration shown in FIG. 2 can be regarded as a local area network, the present invention is equally applicable to local area networks.
Moreover, it has a thick effect.

[Brief explanation of drawings]

Figure 1 is a block diagram showing the configuration of a conventional line/packet convergence switch, Figure 2 is a block diagram showing the configuration of a line/packet convergence switch inferred from the conventional local network system, and Figure 3 is Conventional method l in the configuration shown in Figure 2
FIG.
FIG. 6 is an explanatory diagram showing the structure of a mixed packet for packet exchange according to the present invention, FIG. 6 is an explanatory diagram showing the frame structure according to the present invention, and FIGS. 7 and 8 are explanatory diagrams showing how to use the frame according to the present invention. , FIG. 9, and FIG. 4110 are block diagrams showing configuration examples of communication nodes in the present invention. In the figure, 10, 12, and 14 are transmission lines, 11 is a differential switching section, 13 is a line switching section, 15 is a packet switching section, and 2
0 is a communication node, 21 is a communication loop, 30 is a mixed packet transmission/reception circuit, 3■ is a mixed packet assembly/branch circuit,
32 is a communication node control unit, 33 is a clock circuit, 34 is a reception circuit, 35 is a frame synchronization circuit, 36 is a reception time slot control circuit, 37 is a reception buffer memory circuit,
38 is a transmission buffer memory circuit, 39 is a transmission time slot control circuit, 40 is a switch, 43 is a delay circuit, 4
4 is a transmitting circuit. -m-～ Posted / Figure 3 Figure 4 Concave Figure 6 Figure ri ro

Claims (1)

[Claims] 1. A line/line consisting of a single or multiple communication loops and a plurality of communication nodes that commonly access the communication loops.
In the packet integrated switching network, the communication loop is provided with frames of a fixed time period, and each of the communication nodes classifies circuit switched signals arriving from subscriber terminals or trunk lines by destination communication node for each cycle of the frame. A plurality of circuit-switched signals for each destination communication node are created into one or more circuit-switched mixed packets and transmitted to the communication loop, and the packet-switched signals arriving from subscriber terminals or trunk lines are Sort by destination communication node, create one or more mixed packets for packet exchange for each same destination communication node, and send them to the communication loop, and at the same time, each communication node transmits on the communication loop. Among the circuit-switched mixed packets and packet-switched mixed packets that are received, the circuit-switched mixed packets and packet-switched mixed packets addressed to the own node are found and received, and the received circuit-switched mixed packets and packets are A line/packet integrated switching system characterized by disassembling mixed exchange packets into individual circuit switching signals and packet switching signals and sending them to subscriber terminals or relay lines. 2. The frame is divided into a plurality of times,
2. The circuit/packet integrated switching system according to claim 1, wherein the circuit-switched mixed packet order and the packet-switched mixed packet are transmitted using the required number of time slots.