KR100248661B1 - Method for processing additional channel require primitive according to the delay equalization protocol in isdn - Google Patents

Abstract

The present invention relates to a method for processing a channel addition request primitive in a DEQ negotiation control layer in a delay equalization protocol structure composed of a call control layer, a delay equalization negotiation control layer, and a delay equalization multiframe control layer.

Conventional protocol implementations receive primitives according to the state after determining the current state, and then run the primitive processing routines according to the determined state. there was. However, the protocol implementation of the present invention classifies received primitives and then considers the statuses for them. Therefore, when the processing of each state is similar or identical for the same primitive, it is easy to merge these processing procedures and the code size is reduced to process. You can expect an increase in speed.

According to the present invention, when a channel addition request primitive is generated, the current state of the DEQ multiframe control layer, that is, the full channel synchronization state, the local synchronization standby state, and the null state are separated into appropriate procedures and primitives according to each state. Occurs and transitions to the next state.

Description

Method of processing additional channel require primitive according to delay equalization protocol in ISDN

The present invention relates to a delay equalization protocol for bonding a plurality of 56/64 kbit / s channels in order to deliver broadband data in an ISDN, in particular, call control. In the delay equalization (DEQ) protocol structure consisting of a Control layer, a DEQ Negotiation Control layer, and a DEQ multiframe control layer, a negotiation is performed between the DEQ negotiation control layer and the DEQ multiframe control layer. A method of handling a multiframing delay compensation timer termination primitive.

As the information society has progressed, communication demands have diversified, and the media handled by communication networks such as voice, data, and video have also diversified, so that individual networks established by services cannot provide efficient services. Therefore, the ISDN, which can integrate and digitize individual networks established by services and provide comprehensive services, has emerged. These ISDNs are designed to unify various terminals in order to accommodate users and manganese. The interface is standardized by Digital Subscriber Signaling System (DSS1), and the interface between the network and the network is also standardized by No.7 Common Line Signaling (CCS).

DSS1, which is a signaling method of the user-network interface (UNI) of ISDN, is implemented in layers 1 through 3 by an OSI (Open Systems Interconnection) reference model, as shown in FIG. The overview and its relationship with the recommendations of the ITU-T are shown in Table 1 below.

Digital subscriber line signaling Layer Feature Overview Corresponding recommendations Layer 1 Electrical physical conditions I.430, I.431 Layer 2 Link setting control and error control for message transmission Q.920, Q.921 Layer 3 Set up, opening Q.930, Q.931

Referring to FIG. 1, a first network terminal device NT1 located in a house (or building) is connected to an ISDN exchange located in a telephone station through a subscriber line, and an ISDN terminal TE1 is connected to an ISDN terminal in a building through an S / T point. Alternatively, the second network terminal device NT2 is connected to the first network terminal device NT1.

Here, 'NT1' (network terminal device 1) is a transceiver in a house for transmitting a digital signal to a subscriber line, and 'NT2' (network terminal device 2) is a device corresponding to a private branch exchange (PBX). The terminal TE1 can be accommodated, and the TE1 is an ISDN standard terminal that is directly connected to NT1 and may be connected via NT2, and an existing terminal that does not have an ISDN corresponding function, 'TE2' is not shown. It is connected to the ISDN network through a terminal adapter (TA).

In addition, the interface point between NT1 and NT2 is called 'T' point, and the interface point between NT2 and TE1 is called 'S' point. Since the interface specification of S point is determined to be based on T point, TE1 is The point to be connected is called the 'S / T' point.

In addition, the subscriber terminal, such as the ISDN terminal, is connected according to the above-described protocols of the layers 1 to 3 so as to be connected to the ISDN exchange, and the recommendations for defining such a connection are shown in Table 1 above.

That is, in Table 1, Layer 1 is a user-network interface of the physical layer recommended by ISDN Recommendations I.430 and I431, and has a basic interface of 2B + D access and a primary group speed interface of 23B + D or 30B + D. In the basic interface, the frame structure consists of 48 bits in 250us units.

Layer 2 is commonly referred to as Link Access Procedure on the D channel (LAPD), which first adopts HDLC's BALANCE mode, which is the standard for the standardized data link layer, and its basic format is Flag. And an address field, a control field, an information field, a frame check sequence (FCS), and a flag.

Layer 3 controls the establishment, maintenance, and release of communication paths required by the network and packet switched services, and various additional service requests. The message is analyzed, and a call establishment related message is formed and sent to the other party through the lower layer. General content relating to Layer 3 is described in Q.930, and call processing procedures for basic calls are recommended by Q.931.

In order to implement an ISDN terminal, the functions described above should be implemented. The "protocol" is defined as an appointment between the same layers, and the "primitive" is defined as a logical exchange between upper and lower layers. . That is, each layer has entities that implement the functions of the layer, and these entities are configured to exchange information between upper and lower sides through primitives.

These primitives are divided into four types: REQUEST, INDICATE, RESPONSE, and CONFIRM. Most of the primitives related to data transfer are REQUEST passed from the upper layer to the lower layer. ) Primitives, and INDICATE primitives passed from the lower layer to the upper layer.

The CONFIRM primitive is a primitive that notifies the upper tier when a lower tier is obliged to respond to a particular request primitive from a higher tier, and the RESPONSE primitive is for a particular indication primitive from the lower tier. It is a primitive to inform the lower tier if the upper tier is obliged to respond.

Channels provided by ISDN include 64Kbps "B" channel, 16kbps "D" channel, 384Kbps "H0" channel, and 2.048Mbps "H1" channel. The basic interface provided by the combination of these channels is "2B". + D ", and the primary group interface is defined as" 23B + D "or" 30B + D ". However, when a wideband communication connection is required for a video service in narrowband ISDN, multiple (N) 56 or 64 kbit / s channels may be used in combination. That is, if the basic interface or the primary group interface has a fixed bandwidth but various bandwidths are required according to a service, the ISDN network may provide an "N x 56/64 kbit / s" band.

In order to provide "N x 56/64 kbit / s" as described above, bonding of 56/64 kbit / s channels set independently of each other is required. In this case, since each 56/64 kbit / s channels are individually connected by the digital switching network, each channel has an individual delay. Therefore, the key technical details of multiple coupling are related to delay equalization, so follow "Delay EQualization protocol" to provide N x 56/64 kbit / s. That is, the delay equalization protocol is also called a bonding protocol, and is a protocol for equalizing delay between channels when combining N 56/64 kbit / s channels.

As shown in FIG. 2, the delay equalization protocol is composed of a Call Control layer, a DEQ negotiation control layer 22, and a DEQ multiframe control layer 23. User data received from the application layer 21 is transmitted, and primitives are transferred to each other as shown in FIG. 3. In FIG. 2, the DEQ multiframe control layer 23 is connected to the physical medium through each channel control and physical medium dependency (PMDL) layer 24a to 24c below.

Referring to FIG. 3, primitives transmitted from the call control layer 25 to the DEQ negotiation control layer 22 include an initial request (DQ_INIT_REQ), a connection request (DQ_CONN_REQ), a disconnect request (DQ_DISC_REQ), and a channel deletion request (DQ_DEL_CH_REQ). , Channel add request (DQ_ADD_CH_REQ), abandonment request (DQ_ABORT_REQ), and the timers used in the DEQ negotiation control layer 22 include TCID_EXP, TCINIT_EXP, TAINIT_EXP, TANULL_EXP, TCADD01_EXP, and TAADD01_EXP. DEQ negotiation with primitive transmitted to the control layer (22) of the control layer 25 from the DQ_INIT_IND, DQ_DISC_IND, DQ_DISC_CONF, DQ_DEL_CH_CONF, DQ_DEL_CH_IND, DQ_DEL_CH_FAIL_IND, DQ_ADD_CH_IND, DQ_ADD_CH_CONF, DQ_ADD_CH_FAIL_IND, DQ_CID_FAIL_IND, DQ_LLOS_IND, DQ_RLOS_IND, DQ_ABORT_CONF, DQ_LL_IND, DQ_LL_OFF_IND, DQ_RL_IND, DQ_RL_OFF_IND, and the like.

In this case, xx_xxxx_REQ represents a request primitive, xx_xxxx_IND represents an indication primitive, xx_xxxx_RES represents a response primitive, and xx_xxxx_CFM represents an confirm primitive. CC_xxxx_xxx is a primitive between the DEQ multiframe control layer 23 and the DEQ negotiation control layer 22, and DQ_xxxx_xxx is a primitive between the DEQ negotiation control layer 22 and the call control layer 25.

Primitives transmitted from the DEQ negotiation control layer 22 to the DEQ multiframe control layer 23 include CC_ADD_REQ, CC_INFO_REQ, and CC_DEL_REQ. The timers used in this layer include TAFA_EXP and TXDEQ_EXP, and the DEQ multiframe control layer 23 The primitives transmitted to the DEQ negotiation control layer 22 are CC_LSYNCH_IND, CC_RSYNCH_IND, CC_RSYNCH_FAIL_IND, CC_INFO_IND, CC_FAIL_IND, CC_LLOS_IND, and CC_RLOS_IND. These primitives are described in detail in the "Interoperation Specification for Nx56 / 64 kbit / s Call (Version 1.1)" issued by the Bonding Consortium, dated September 2, 1993, and further description thereof is omitted.

On the other hand, the conventional scheme for handling such primitives in Layer 3 has been proposed as SDL in Appendix A (ANNEX A) of the recommendation, which is roughly summarized as shown in FIG.

Referring to FIG. 8, the conventional method first determines a current state of a corresponding layer (S1), and when a primitive is received (S2), drives a primitive processing routine for processing the corresponding primitive according to the determined state (S3). ).

However, in the conventional method of FIG. 8, even though the processing is similar or the same in different states with respect to the same primitive, processing routines may be duplicated according to each state, resulting in a large amount of redundant code and a long processing time in software implementation. There is a problem. If the subroutine call method is used to avoid such code duplication, it is difficult to construct a subroutine that is appropriately divided over various states even though the amount of code is reduced. There was a problem that the processing speed was lowered.

Accordingly, the present invention has been proposed to solve the above-described problems of the prior art, and in the delay equalization protocol, after separating the processing routine in consideration of the current state according to the type of primitive, proceeding the processing procedure according to the primitive again. In particular, an object of the present invention is to provide a method for processing a channel addition request primitive, which minimizes a processing procedure, particularly when a channel addition request primitive is received.

The channel addition request primitive processing method of the present invention for achieving the above object comprises the steps of: (a) receiving a channel addition request primitive (CC_ADD_REQ) generated in the DEQ negotiation control layer in the DEQ multiframe control layer; (b) determining a current state in the DEQ multiframe control layer to determine whether the current state is a full null synchronization state, a local synchronization wait state for a new channel, or a null state; (c) if the determination result of b) is a full channel synchronization state, driving the transmission and synchronization search procedure and starting a multi-framing search timer to initiate synchronization of the local terminal and then transitioning to the local synchronization standby state; (d) If the determination in b) indicates that there is a local synchronization wait for a new channel, the required channel count procedure is driven to increase the number of channels, and the framing search timer for that channel is driven after the framing search and transmission procedure is driven on the channel. Driving a procedure to stop the process and then transitioning to a local synchronization standby state; And (e) if the determination result of b) is null, checking the channel identifier CID, and then driving a procedure according to the result to transition to a local synchronization wait state or an unidentified synchronization search state. .

1 shows a user-network connection of an ISDN;

2 shows a reference architecture of a delay equalization protocol;

3 is a schematic diagram illustrating primitives carried between layers to implement a delay equalization protocol in ISDN,

4 illustrates a frame structure in a delay equalization protocol;

5 shows an information message format;

6 is a flowchart illustrating a process of establishing a call in a delay equalization protocol;

7 is a flowchart of processing a channel addition request primitive according to the present invention;

8 is a schematic diagram illustrating a procedure for processing a conventional primitive.

Explanation of symbols on the main parts of the drawings

21: Application Layer 22: Delay Equalization Negotiation Control Layer

23: Delay Equalized Multiframe Control Layer 24a, 24b, 24c: Channel Control Physical Layer

25: call control layer

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

FIG. 2 is a diagram illustrating a reference architecture of a delay equalization protocol, FIG. 3 is a schematic diagram illustrating primitives transmitted between three layers for implementing a delay equalization protocol in ISDN, and FIG. 4 is a diagram illustrating a frame structure in a delay equalization protocol. Figure is shown. 5 is a diagram illustrating an information message format.

Referring to FIG. 2, the delay equalization protocol is implemented by a call control (CC) layer 25, a delay equalization negotiation control (DEQ NC) layer 22, and a delay equalization multiframe control (DEQ MC) layer 23. As shown in FIG. 3, various primitives are transmitted between the layers.

In order to deliver the serial bit stream coming down from the application layer by multiple combinations of N 56/64 kbit / s channels, as shown in FIG. 4, framing is required, and the framed data is allocated to each bearer channel. Will be delivered.

As shown in FIG. 4, the framing structure according to the delay equalization protocol is composed of 256 octets, and 64 frames are gathered to form one multiframe. The octets in each frame are numbered from 1 to 256, and four overhead octets are used for information exchange and framing. That is, in one frame, octet 64 is assigned to a frame alignment word (FAW), octet 128 is assigned to an information channel (IC), and octet 192 is assigned to a frame count (FC). Is assigned. Octet 256 is assigned to a cyclic redundancy check (CRC).

Looking more closely at each overhead octet, the FAW (octet 64) has a fixed value of "0001,1011", the IC (octet 128) is used for information exchange between terminals, and the FC (octet 192) is an individual channel. It is used to measure the relative change in delay between modulo 64 counters (6 bits), incremented by 1 per frame. In CRC (octet 256), bit 1 and bit 8 are 1, bit 2 is defined as "A", bit 3 as "E", and bits 4 to 7 are used for CRC4. Here, "A" is an alignment bit, indicating that the remote terminal has lost framing, and "E" is an error bit, indicating that the remote terminal has detected an error by CRC4.

This overhead distributes the overhead octets across all channels as evenly as possible by allowing them to be distributed over each channel at 125usec intervals.

On the other hand, the information channel (IC) message format, as shown in Figure 5, consists of 16 octets to transfer control information between the two terminals. Referring to FIG. 5, the first octet of the information channel frame has a constant value of "0111,1111" as an alignment (ALIGN), and the second octet may dial N calls simultaneously as a channel ID (Channel ID: CID). It is used to identify individual channels in each call setup. CID is a 6-bit binary number encoded with a number in the range of 0 to 63, and a CID of 0 indicates parameter negotiation.

The third octet of the information channel message is a group identifier (GID), which is used to uniquely identify a group of bearer channels associated with a particular call. Octet 4 (bits 2 through 4) indicates the operation mode (MODE), where "0" indicates operation mode 0, "1" indicates operation mode 1, "10" indicates operation mode 2, and "11" indicates operation mode. 3 is shown, respectively.

In octet 5 (bits 2 to 4) of FIG. 5, "RMULT" is the rate multiplier, which, together with "SUBMULT" in octet 6, defines the bandwidth of the application for the call, and the BCR represents the bearer channel rate. 0 indicates 56kbit / s base and 1 indicates 64kbit / s base. In octet 6, " MFG ", if set to 1 as the manufacturer ID flag, indicates that the manufacturer ID is loaded in the digit fields of octets 10-16. In octet 7, " RI " is a remote indicator for informing the counterpart of whether the delay equalization is complete, and a value of 1 indicates an equal delay (delay equalization completion). In octet 7, "RL REQ" indicates a remote loopback request and "RL IND" indicates a remote loopback indication. "REV" represents the revision level, octet 8 represents the subaddress, and octet 9 represents the transfer flag as "XFLAG". Octet 10 to octet 16 indicate telephone number dial digits (Digit-1 to Digit-7).

6 is a sequence diagram illustrating a message flow in call setup.

First, the terms used in the present invention are briefly defined as follows. The answering terminal is a terminal for receiving a call, and the calling terminal is a terminal for initiating a call. The bearer channel is a channel provided by a network used for data transmission, for example, a B channel of BRI or PRI, a T1 DS0, etc., and an information message is a 16 octet message as shown in FIG. It is conveyed through the information channel of the multiframe structure or by the full bandwidth of the master channel during initial parameter negotiation. Master channel is a channel used to communicate control information between each end, which is call setup, channel delete, channel addition, remote loopback ) Provides a path for initial parameter negotiation for call disconnection and the like.

In case of using the delay equalization protocol, four operation modes are defined.

"Operation Mode 0" supports initial parameter negotiation and DIRECTORY NUMBER exchange on the master channel, and then transfers the data without delay equalization when call setup is complete. This mode is useful when the calling endpoint requires a phone number, but delay equalization must be done by other means. That is, in operation mode 0, delay equalization (delay compensation) is not performed.

"Operation Mode 1" is the default (common) mode of the delay equalization protocol that supports the user data rate multiplied by the bearer rate, and does not provide in-band monitoring for errors. Thus, the overhead octets for detecting errors are eliminated after the call is aligned, and one or more on-channel error conditions that prevent all system synchronization are not automatically recognized after the call is ACTIVE.

"Operation Mode 2" supports user data rates that are 63/64 times the bearer rate. This mode of operation provides in-band monitoring and the user data rate is the remaining band after the insertion of the overhead octets. That is, the error is checked while the multiframing structure is maintained even after being activated.

"Operation Mode 3" is the user data rate is an integer multiple of 8kbit / s, including Nx56 and Nx64. All channels use the same bearer channel rate and provide in-band monitoring to support continuous equalization (CRC) for delay equalization and end-to-end bit error test. The overhead octets required for error monitoring are provided with additional bandwidth. Thus, a sufficient user data rate can be provided, and overhead octets are included in each bearer channel.

Based on the understanding of such a definition, a process of actually setting up a call according to a bonding protocol and transmitting data will be described with reference to FIG. 6.

First, when a high speed serial data stream comes down from the application layer, data is transmitted through N bearer channels. Each bearer channel is then individually connected by digital network exchange. On the originating terminal side, the user data is framed according to the framing structure as shown in FIG. 4 and then delivered to each bearer channel. On the destination terminal side, the received data is synchronized and aligned to restore the original bit stream. do. Framing and synchronization should be transparent to all applications. In the delay equalization protocol, the entire operation is performed by the call establishment process, the process of adding the bandwidth to the existing call after the channel connection is established by the call establishment, and the bandwidth is deleted from the existing call in order to reduce the user data without sudden degradation of the entire call. There is a process.

The call setup process involves establishing an initial channel (called a master channel), adding N-1 other channels by multiple combining after the initial channel is established, and implementing delay equalization when each channel is connected. There is a delay equalization (DEQ) process.

6 is a flowchart illustrating a call setup process, wherein the initial channel setup includes steps 601 to 604, the multiple combining process includes steps 605 and 606, and the DEQ process includes steps 607 to 609. After the call setup is made, user data of the application layer is allocated to each channel through a framing process in an active state.

The initial call setup procedure begins with the connection of the first channel on an N x 56/64 kbit / s call. This channel is called the master channel (601). The parametric negotiation process is performed by this channel, and the originating terminal makes additional calls after the complete negotiation process is completed. Once the originating terminal is connected to the master channel, the originating terminal repeatedly transmits an information message (see FIG. 5) with a channel identifier (CID) set to 0 to start a negotiation process (602). The starter (TCINIT_EXP) timer is started. At this time, the originating terminal transmits by setting each parameter of the information message to a specific value. The group identifier (GID) is set to 0, and RI = 0 and RL = 0, respectively. In the first information message, the calling terminal sets the MFG to 1, sends the manufacturer's ID with the ID in the digit field, and the XFLAG is set to all 1's. If the calling terminal fails to transmit the manufacturer ID, the MFG flag is set to 0 and the digit fields are all set to 1. If the calling terminal supports sub-addressing, the sub-address area includes the sub-address, and if not, the corresponding area is set to all zeros.

When a call is received and connected with the other party, the destination terminal sends all 1s to the channel, starts the destination NULL (TANULL_EXP) timer, and searches for multi-frame information or information message.

Once the end of incoming call detects a valid information message, it considers the channel as the master channel of the new call and stops the terminating null timer (TANULL_EXP). If a multi-frame is detected, the called terminal regards the current call as an additional channel, stops the called party NULL (TANULL_EXP) timer, and uses a group identifier (GID) to identify the current call.

In the master channel of the new call, if the called terminal accepts the requested parameter, it returns the same value as the received value and starts the called party's initial (TAINIT_EXP) timer. If not accepted, the RMULT and SUBMULT = 0 return with the valid mode value in the information message, and the called party initiates the truncation procedure or returns a set value different from the received parameter. In the additional channel of the current call, the called terminal allocates the group identifier (GID) of the call and returns the call in the group identifier (GID) area. The call can be identified in the call received by the group identifier to the called terminal. At this time, the XFLAG region of the information message is set to one.

When the called terminal determines the manufacturer ID return, the MFG flag of the information message is set to 1, puts the ID in the digit field, and returns the information message with other parameters as the initial response to the calling terminal. If the destination terminal does not want to return the manufacturer ID, the MFG flag of the information message is set to 0 and the digit field is set to 1.

The calling terminal detects that the response is from the called terminal when CID = 0 and the MODE receives a valid information message from the called terminal. Therefore, the calling terminal analyzes the parameters of the received information message and performs the truncation procedure if it cannot accept or cannot accept the parameters requested by the called terminal. If the MFG flag of the received information message is 1, the manufacturer ID contained in the digit field is received. If the MFG flag is 0, the digit area is ignored, and the XMFG flag is ignored.

Subsequently, the originating terminal requests an initial telephone number (Directory Number: DN) by transmitting an information message with CID = 0 and a transmission flag set to 1 and all of the digit fields to 1 (603).

After the initial response, when the called terminal receives the information message with the XFLAG set to 1, the destination terminal sets the XFLAG of the information message to 1 and carries the telephone number in the digit field and returns the information message again. In this way, the calling terminal and the called terminal exchange telephone numbers (DN). If the number of channels is N, exchange N-1 phone numbers (DNs).

That is, when the calling party receives DQ_CONN_REQ from the call control layer to the DEQ negotiation control layer, the DEQ carries an INIT REQ message on the CC_INFO_REQ primitive and delivers it to the called party. When the called party receives the INIT REQ message through CC_INFO_IND, the called party sends the INIT ACK message to the called party. The calling party sends a DN REQ message to the called party and requests a phone number. When the called party receives a DN REQ message, the called party generates a DN RESP message and sends the telephone number to the calling party. This telephone number exchange operation is repeated N-1 times (603).

Subsequently, when the telephone number exchange is completed, the calling terminal transmits an information message of CID = 1 to signal the end of the negotiation process, and when the called terminal receives an information message of CID = 1, the calling terminal returns an information message of CID = 1 and adds it. Inform that the channel is ready for acceptance. At this time, the called terminal stops the called party initial (TAINIT_EXP) timer and starts the called channel addition (TAADD01_EXP) timer (604,605).

When the originating terminal receives the information message with CID = 1, the originating terminal (TCINIT_EXP) timer is stopped, the originating channel addition (TCADD01_EXP) timer is started, and connection to the additional channel is started (606).

Once each additional channel is connected, each terminal stops the channel add (TXADD01) timer. When each channel is ready, the terminating terminal starts a delay equalization (TXDEQ_EXP) timer and uses a frame counter (FC) to measure the relative delay balance between individual channels of Nx56 / 64 kbit / s (607). . In addition, since the incoming call arrival order cannot be guaranteed to be the same as the call establishment order, each terminal uses the received CID to align the channel (607). Each terminal is rearranged, and if the delay is equalized between channels for the call, RI = 1 of the information message is transmitted in all channels of other terminals (608). In each of the modes 2 and 3, when each terminal receives RI = 1 as an information message in all channels, it will consider that call setup is completed, and the delay equalization (TXDEQ_EXP) timer is stopped and user data transmission is started (609, 610).

In operation mode 1, when each terminal receives RI = 1, it will transmit a ready indication for data transmission to A = 0 in all bearer channels. When A = 0 is transmitted, each UE waits for A = 0 reception on each bearer channel. When each terminal receives A = 0 in the bearer channel, it stops transmitting the framing pattern and considers the call setup to be completed. At this time, each terminal will remove the multiframe structure from all channels. In addition, after transmitting RI = 1 and A = 0, if the frame synchronization loss is detected in all bearer channels before the UE receives A = 0, the call setup is considered complete and the multiframe structure is removed from the bearer channel. In modes 2 and 3, each terminal continuously monitors each channel of the call for delay equalization and frame alignment. Each terminal also monitors bit errors between terminals, transmits RI = 1, and stops the delay equalization (TXDEQ_EXP) timer when it detects RI = 1.

On the other hand, when a call is established by multiple combining in this way, each state of the DEQ multiframe control layer and the DEQ negotiation control layer is defined as shown in Tables 2 to 4 below.

Status of the DEQ negotiation control layer (calling party) State name Mark Contents Null state 0 No call exists Call initiation One Calling party sends INIT REQ on the first channel and waits for INIT ACK Initiate-CID1 Wait 1a Waiting for CID = 1 after completing parameter negotiation and DN exchange at the calling party and sending CID = 1 Wait for phone number 2 Calling party waits for receiving after requesting additional DN Additional Channel 3 Status of setting remaining channel after completing parameter negotiation and DN exchange active 8 All channels are set up so that DEQ multiframe can transmit data Active-Delete Initiation 8a Waiting for response after calling party requests channel deletion Active-start 8b-1 Calling party waits for response after requesting channel Active-Additional Channel 8b-2 The originator sets up additional channels after receiving a positive response to the channel part. Active-CID1 Standby 8c The calling party waits for a response after sending CID = 1 as a signal of completion of a channel addition or deletion. Active mode 1 8d Mode 1 is active and information messages are not exchanged and messages are transferred between CC and DEQ MC. Release request 9 Waiting for response after calling party requests release

Status of DEQ negotiation control layer (receive side) State name Mark Contents Null state 0 No call exists Receive call 4 The called party receives the channel connection request INIT Receive 5 Received INIT ACK and received INIT ACK Additional Channel Standby 6 Waiting for setting for the rest of channel after parameter negotiation and DN exchange are completed at called party active 8 All channels are set up so that DEQ multiframe can transmit data Active-Delete Initiation 8a Called party waits for response after requesting channel deletion Active-start 8b-1 The called party waits for a response after requesting channel addition Active-Additional Channel 8b-2 The called party sets up additional channels after receiving a positive response to the channel part. Active-CID1 Standby 8c The called party waits for a response after sending CID = 1 as a signal of completion of a channel addition or deletion. Active mode 1 8d Mode 1 is active and information messages are not exchanged and messages are transferred between CC and DEQ MC. Release request 9 Waiting for response after called party requests to release

DEQ multiframe control layer State name Mark Contents Null state 0 Waiting for channel to be connected to multi-frame function Unknown synchronous search state 0a After the called party is connected to the channel, it is waiting to receive an information message such as multi-frame synchronization or initial channel. Local synchronous standby One The endpoint waits for multiframe synchronization for all channels while sending a multiframe pattern Remote Sync Standby 2 Waiting for the endpoint to be multi-frame synchronized after multi-frame synchronization for all channels is complete Mode 1 Handshake 2a In mode 1, the endpoint is waiting for A = 0 or loss of synchronization after sending RI = 1 or A = 0. All Channel Synchronization 3 Multi-frame synchronization and DEQ equalization completed on all channels Mode 1 active 3a Framing is removed and data is passed in mode 1

7 is a flowchart illustrating a flow of processing a channel addition request primitive according to the present invention.

Referring to the case where the channel addition request primitive is generated, the DEQ negotiation control layer sends a channel addition request primitive (CC_ADD_REQ) to the DEQ multiframe control layer to request a designated channel or change the data distribution rate. In this case, in order to change only the data distribution rate without changing the number of channels, only the mode 3 is required and a newly changed RMULT / SUBMULT value is required. When the called terminal sends a channel addition request primitive to the channel number N, a call identifier, and a channel identifier having a null value, the DEQ multiframe control layer examines the full-band information channel message (in the initial channel), and the channel belongs. Investigate multiframe synchronization to determine the call.

Referring to FIG. 7, in step (a), the DEQ multiframe control layer that has received the channel addition request primitive generated from the DEQ negotiation control layer determines the current state in step (b) and, according to the result, the three states. Diverge.

As a result of the determination in (b), if the current state is the full channel synchronization state, that is, the multi-frame synchronization and the DEQ delay compensation have been completed in all connected channels, branching to step (c) to start the procedure for finding the transmission situation and synchronization, and then Then, the procedure for synchronizing the channels of the local terminal is driven (c1, c2, c3). After step (c), the process proceeds to step (h) to transition to the local synchronization standby state.

As a result of the determination in (b), if the current state is a local synchronization wait state to be allocated a new channel, that is, if the local endpoint transmits a multiframe pattern and waits for the multiframe synchronization for all channels, the process branches to step (d). Increase the number of new channels N required in step (a) by one, start the framing search and transmission procedures, and then start the procedure to stop the framing search (TXFA) timer (d1, d2, d3, d4). . After step (d), the process proceeds to (h) to transition to the local synchronization standby state.

As a result of the determination in (b), if the current state is a null state, that is, a state waiting for a channel to be connected to the multi-frame function, branching to step (e) determines whether the channel identifier specified in step (a) is a (CID) null value or not. (E1, e2).

As a result of the determination in (e), if the channel identifier is not a null value, the flow branches to step (f) to start a framing search (TXFA) timer, and drives the framing search and transmission procedure (f1, f2). After step (f), the process proceeds to (h) to transition to the local synchronization standby state.

As a result of the determination in (e), if the channel identifier is a null value, this is a channel addition request primitive sent from the called party. , g2). After step (g), the process proceeds to step (i) and transitions to an unidentified synchronous search state, that is, a called party waits to receive an information message of multi-frame synchronous or first channel after being connected to a channel.

As described above, when the channel addition request primitive is generated, the present invention grasps the current state, drives appropriate primitives and procedures according to the state, and transitions to the next state. Compared to the method of receiving a primitive according to the state after the determination of the conventional state and driving the primitive processing routine according to the determined state again, the present invention classifies the primitive and considers the state for the primitive. Even when the processing procedures in each state are similar or identical, it is easy to merge the processing procedures and the code size can be reduced to improve the processing speed.

Claims (2)

Delay equalization protocols for multiplexing N channels to provide the required broadband for service and equalizing the delay of the combined channels include a call control layer (CC), a delay equalization negotiation control layer (DEQ NC), and a delay equalization multi In a general information communication network including a frame control layer (DEQ MC), (a) receiving, at the DEQ multiframe control layer, a channel add request primitive (CC_ADD_REQ) generated at the DEQ negotiation control layer; (b) determining a current state in the DEQ multiframe control layer to determine whether the current state is a full null synchronization state, a local synchronization wait state for a new channel, or a null state; (c) if the determination result of b) is a full channel synchronization state, driving the transmission and synchronization search procedure and starting a multi-framing search timer to initiate synchronization of the local terminal and then transitioning to the local synchronization standby state; (d) If the determination in b) indicates that there is a local synchronization wait for a new channel, the required channel count procedure is driven to increase the number of channels, and the framing search timer for that channel is driven after the framing search and transmission procedure is driven on the channel. Driving a procedure to stop the process and then transitioning to a local synchronization standby state; (e) if the determination result of b) is null, checking the channel identifier CID, and then driving the procedure according to the result to transition to the local synchronization waiting state or the unchecked synchronization search state. Method of processing channel addition request primitive according to delay equalization protocol in information communication network. The method of claim 1, further comprising: if the CID = NULL result of the check in step (e), driving a procedure for starting a framing search timer, driving a framing search and transmission procedure, and then transitioning to a local synchronization waiting state ( f); and (g) if the CID = NULL, driving a TANULL procedure on the DEQ negotiation control layer, determining a channel identifier CID, initializing a full-band channel, and then transitioning to an unidentified synchronous search state. Channel addition request primitive processing method according to the delay equalization protocol in a comprehensive information communication network.

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