Atm transport system.

PCT

WORLDINTELLECTUAL PROPERTY ORGANIZATION Intemattonal Bureo

INTERNATIONAL APPLICATION PUBLISHED UNDER THE PATENT COOPERATION TREATY (PCT) (51) Interaatkmal Patent CMfleatlai ⁶ : H04L 12/66 (11) International PubUcation Numben WO 974) 9809 (43) International Publfcation Date: 13 March 1997 (13.03.97)

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(21) International Applfcation Noutber: PCT / US96 / I4129 (22) International Ffling Date: 3 September 1996 (03.09.96) (30) Priorlty Data:

08 / 525,897 8 September 1995 (08.09.95) US

087562,206 22 November 1995 (22.11.95) US (81) Derignated States: AL, AM, AT, AU, AZ, BB, BG, BR, BY, CA, CH. CN, CU. CZ, DE, DK, EE, ES, FI, GB, GE, HU. IL, IS, JP, KE, KG, KP, KR, KZ, LK, LR, LS, LT, LU, LV, MD, MG, MK, MN, MW, MX, NO, NZ, PL, PT, RO, RU, SD, SE, SG, SI, SK, TJ, TM, TR, TT, UA, UG, UZ, VN, ARIPO patent (KE, LS, MW, SD, SZ, UG), Eurasian patent (AM, AZ , BY, KG, KZ, MD, RU, TI, TM), European patent (AT, BE, CH, DE, DK. ES, H, FR, GB, GR, ΙΕ, ΓΓ, LU, MC, NL, PT, SE), OAPI patent (BF, BJ, CF, CG, CI, CM, GA, GN, ML, MR, NE, SN, ID, TG) l (71) Appllcant: SPRINT COMMUNICATIONS COMPANY, LT.

[USAIS]; 8140 Ward Parkway, Kansas City, MO 641140417 (US).

(72) Inventor: CHRISTIE, Joseph, Michael; 536 Groen Avenue,

San Bruno, CA 94066 (US).

(74) Agent: DICKEY, Steven, R4 Hovey, Williams, Tlnunons &amp; Collins, Suite 400, 2403 Grand Boulevaid, Kansas City, MO 64108 (US).

Puhlbbed

WifA intcmatítmal search report.

(54) Hile ATM TRANSPORT SYSTEM

T *

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(57) Abstract *

An ATM transpon system (105, 110, 115) transport user infarmation fram a continuáis signal transpon system (100), Tbe ATM transpon system (105, 110, 115) uses telecommunfcatians slgnaling aesociated with tbe contínuous signáis to determine if the contínuous signáis ara transpcrtmg any user inftwnatlon. If so, ATM celia coctainíng user infarmation are generated and ttansmittecL An ATM interworking multiplexer (105) and a processor (110) are induded in the syttem.

TRANSPORTATION MODE TRANSPORTATION SYSTEM

ASYNCHRONIC

Background

Currently, asynchronous transfer mode (ATM) technology is being used to provide high-speed transport for traffic carried by older transport formats such as DS1 and DSO. This ATM transport technique uses an ATM interconnect multiplexer (ATM mux) to convert telecommunication traffic from older cell formats.

ATM that can be transported over broadband connections.

At the termination end of a broadband system, the cells of

ATM will be converted back to the older format by another mux from

ATM for distribution to the oldest transportation system.

ancient continues

Many of them require the transport formats even more so when no signal transmission is being transported user traffic

For example, a connection

DSO continuously transmits a signal

000 bits / second yes or no the DSO connection is

REF .: 027013 carrying some user traffic. This causes a problem in the transport scenario described above. The ATM mux will convert the DSO signal into ATM cells for transport, and since the DSO signal is continuous, a direct stream of ATM cells must be carried over the ATM network. This occurs even when user traffic is not being carried. The inactive DSO signal is still carried in empty ATM cells. Methods for detecting these inactive continuous signals that do not carry user information have included analyzing the information samples from the continuous signals to detect inactive codes. However, these inactive codes are emulated by user information such as voice or data. This causes problems when trying to determine whether or not a signal carries user information.

The current situation represents a waste of resources. Presently, there is a need for an ATM system that can carry continuous signal formats when carrying user traffic, but not when not carrying user traffic.

Short description

The invention includes an asynchronous transfer mode (ATM) system for transporting user information in ATM cells. ATM cells contain a virtual route identification / virtual channel identification (VPI / VCI). User information is from a continuous signal transport system that produces telecommunications signaling related to the continuous signal. The continuous signal is associated with the VPI / VCI.

The system comprises an ATM interconnect processor and multiplexer. The processor receives the telecommunication signaling and detects, based on the telecommunication signaling, when the continuous signal is carrying the user information and when the continuous signal is not carrying the user information. The processor associates the continuous signal with the VPI / VCI. The processor also provides a control instruction to allow or enable VPI / VCI when the continuous signal is carrying user information and provides a control instruction to disable or disallow VPI / VCI when the continuous signal is not carrying information. of the user.

ATM interconnect multiplexer is coupled to the processor

The interconnect multiplexer associates it with the vpi / vci.

The interconnect multiplexer

ATM receives the control instructions from the processor and generates and transmits

ATM containing the

VPI / VCI and user information in response to the permission control instruction.

The ATM interconnect multiplexer for the generation and transmission of ATM cells containing the VPI / VCI in response to the disable or disable control command.

The invention has many variations. The telecommunication signaling protocol might processor may use an initial address message of

SS7 to detect when the continuous signal carries user information,

The processor could use a Circuit Identification Code (CIC) in the SS7 IAM to identify the continuous signal and to associate the continuous signal with the VPI / VCI. The processor may use a message from

<td>release</td><td>(REL) from SS7 or</td><td>full message</td><td>of</td>

<td>release</td><td>(RLC) to detect</td><td colspan="2">ar when the signal</td>

<td>continue no</td><td>transport for more</td><td colspan="2">time information</td>

<td>of user.</td><td></td><td></td><td></td>

<td>The</td><td>invention could</td><td>include a point</td><td>of</td>

<td>transience</td><td>to signal (STP)</td><td>which binds</td><td>to the</td>

<td>processor</td><td>and that transfers</td><td>signage</td><td>of</td>

telecommunications to the processor. The STP could transfer copies of signaling system message routing labels # 7 (SS7) to the processor. The STP could transfer copies of the routing labels for Initial Address Message (IAM), Release Message (REL), Complete Release Message (RLC) from SS7 to the processor. The STP could transfer copies of the SS7 routing labels to the processor that has particular point of origin (OPC) codes and destination point codes (DPC).

The ATM interconnect multiplexer can receive either a continuous DS3 signal or a continuous DS1 signal. The ATM interconnect multiplexer could transmit the ATM cells over a connection in SONET. In some embodiments, the ATM interconnect multiplexer supports multiple signals. The individual VPIs / VCIs will correspond to the individual continuous signals. The ATM interconnect multiplexer will include: a continuous signal interface to receive the continuous signals, an ATM adaptation layer (AAL) to convert the continuous signals into ATM cells with the corresponding VPI / VCI, an ATM interface to transmit the ATM cells and a control interface to receive the control instructions and control the AAL and to generate and transmit cells with VPI / VCI enabled or allowed and to stop the generation and transmission of ATM cells with VPI / VCI not authorized or not allowed.

The invention provides the advantage of making the ATM system transport only cells that actually carry user information. Cells that contain the continuous signal but no user information are not transmitted. This provides efficient allocation of efficient use of bandwidth for the ATM system.

Brief Description of Drawings

Figure 1 is a block diagram of a version of the present invention.

Figure 2 is a block diagram of a version of the present invention.

Detailed description

For clarity purposes, the term connection will be used to refer to the connection medium used to carry user traffic. The term link will be used to refer to the transmission medium to carry the signaling. In the figures, connections are shown by a single line and signaling links are shown by double lines.

Figure 1 depicts a version of the present invention. Switch 100, ATM interconnect multiplexer (mux) 101, mapper 110, ATM system 115, and signal transfer point (STP) 120 are shown. These components are connected by connections 150-152 and they are linked by links 160-163 as shown. Those of skill in the art will be aware that large networks have many more components than shown, but the number of these compounds has been restricted for clarity. The invention is fully applicable to a large network.

Switch 100 is a conventional switch that transmits user traffic with continuous signals. Examples of continuous signals are DS3, DS1, or DSO signals. Connections 150 and 151 are conventional transmission media that propagate continuous signals to carry user information. The ATM system at connection 152 with conventional components that carry ATM cells the components mentioned in this paragraph are well known in the art.

Telecommunication signaling is used to establish and bring down the connections for a call. STP 120 routes signaling over signaling links 160-163.

describes in terms of the conscious signaling system those skilled in the art so that it could also be used with this signaling system. Signaling links

160-163 could be links

SS7 well known.

The

STP 120 is a signaling device.

for example it could be a

Conventional STP, which has been altered according to the invention.

In other modalities described below, STP alteration will not be required.

-9In this modality, the STP. 120 is altered to copy the routing labels of the particular SS7 messages and transmit them to the mapper 120 over the link 160. The routing label of an SS7 message conveys the routing information for the signaling message such as the point code source (OPC) and the destination point code (DPC) of the message. The routing tag contains a circuit identification code (CIC) for a type of message. The CIC identifies the actual circuit that carries user traffic on a given call. Typically, the CIC identifies a DS0 connection. The message type identifies the type of message. In SS7, the initial address message (IAM) is used to establish the call, and the release message (REI) and / or the complete release message (RLC) is used to drop the call. Typically, a REL causes a call connection to be released, and the RLC is an acknowledgment of the release. But occasionally, the REL is not received and the REL actually causes the release of a call connection.

Mapper 110 will only need IAMs and RELs for calls using connection 151. For a stronger system, RLCs are also

-1010 could use.

The RLC will act as an acknowledgment

<td>when</td><td>receives</td><td>the</td><td>REL,</td><td>but</td><td>it will be used</td><td>for him</td>

<td>dejection</td><td colspan="2">when</td><td>not</td><td>I know</td><td>receive</td><td>REL.</td>

<td colspan="2">Alternatively,</td><td>the</td><td>use of</td><td>RLC</td><td>it could</td><td>skip yes</td>

REL messages not received still allowed tolerable performance.

Those skilled in the art are familiar with various ways to select these routing labels. A discrimination function could select the messages appropriate to the message type, the OPC and / or the DPC. For example, the message type would be selected by IAM, REL, or RLC codes. These messages would then be selected for the OPC or DPC of switch 100. The additional selection criteria will be appreciated by those skilled in the art. The discrimination function could be on STP 120, on mapper 110, or distributed between the two. For example, the STP 110 could send only routing labels of

<td> 20</td><td>IAM, REL, and</td><td>RLC to the mapper</td><td>110, and</td><td>the mapper</td><td> 110</td>

<td></td><td>would only use</td><td>the tags</td><td colspan="2">routing</td><td>than</td>

<td></td><td>they had a</td><td>combination of</td><td>OPC / DPC</td><td>associated with</td><td>the</td>

<td></td><td>connection 151.</td><td></td><td></td><td></td><td></td>

<td></td><td>The</td><td>mapper 110</td><td>will be</td><td>typically</td><td>a</td>

<td> 25</td><td colspan="3">processor that has elements of</td><td>programming</td><td>of</td>

-1111 conventional interface that is functional to receive and process routing labels provided by STP 120; however, other processing configurations that support the requirements of the invention are also contemplated. Furthermore, the mapper 110 will be functional to use the OPC, DPC, and CIC of the signaling messages to retrieve the predefined virtual connection associated with the particular CIC. The virtual connection will be identified by the combination of a virtual route identification (VPI) and a virtual channel identification (VCI). ATM VPIs and VCIs are well known. Typically each DSO on one side of the mux

105 You must have a corresponding VPI / VCI on the other.

In addition, mapper 110 will be functional to send control messages to mux 105. For call establishment, the control message will instruct mux 105 to allow the VPI / VCI associated with the call. For call establishment, the control message will instruct mux 105 to disable or disallow the VPI / VCI associated with the call.

The mux

105 it will be configured to interconnect the DSOs on connection 151 with their corresponding VPIs / VCIs on connection 152.

The mux 105

-1212 will convert user traffic from the DSO into ATM cells that identify the corresponding VPI / VCI. Mux 105 will then transmit the ATM cells over connection 152 to ATM system 120. Mux 105 is also functional to perform reciprocal processing for ATM cells from connection 152 that contains user information that is bound for transport over connection 151. The mux 105 will be functional to allow and disallow VPIs / VCIs as instructed by mapper 110 control messages. This means that ATM cells will only be transmitted over one allowed VPI / VCI. If VPI / VCI is not allowed or disabled, the mux 105 will not transmit cells on that virtual connection.

In one embodiment, the system will operate as follows for a call coming in on connection 150. A DSO on connection 150 will be sized for a call connection to switch 100. An IAM will be received on link 160 and routed through the STP. 120 on link 161 to switch 100. The switch will process the IAM and select a DSO on connection 151. Switch 100 will generate another IAM for transfer to the network on link 161 and STP 120.

-1313

STP 120 will verify the type of message, the

OPC, and the DPC to determine that this was an IAM from switch 100 that relates to connection 151. As a result, STP 120 will copy the IAM routing tag and transfer it to the mapper

115 over link 162. Mapper 115 will identify the VPI / VCI that corresponds to the OPC / DPC / CIC in the IMA.

Mapper 110 will then send a control message to mux 105 instructing mux 105 to allow VPI / VCI. Once VPI / VCI is allowed, mux 105 will start ATM cells using VPI / VCI on connection 152 to ATM system 115.

The cells will contain information from the DSO on connection 151 identified by the IAM routing tag.

When the call ends, a REL will be transmitted over the signaling system to the switch

<td></td><td> 100 .</td><td>The</td><td>STP</td><td>100 will verify the type of</td><td>message</td><td>and the</td>

<td></td><td>DPC</td><td>for</td><td colspan="2">determine that this was a REL</td><td colspan="2">to switch</td>

<td> 20</td><td> 100</td><td>than</td><td>I know</td><td>related to connection</td><td> 151.</td><td>How</td>

As a result, STP 120 will copy the REL routing label and transfer it to Mapper 110 over link 162. Mapper 110 will identify the VPI / VCI that corresponds to the OPC / DPC / CIC in the REL.

Mapper 110 will then send a control message to the

-1414 mux 105 instructing you to disable or disallow VPI / VCI. As a result, the mux 105 will not transmit cells over the unauthorized or unauthorized VPI / VCI. If RELs are used, they will act as an acknowledgment for the REL, and if the REL was not received, then the RLC will be used in the same manner as the REL was previously used.

A similar procedure will occur for calls that are established from the opposite direction, from the ATM system.

115 to the connection

150.

In this case, the

VCI / VPI will be enabled / disabled based on the

IAM and the

REL (and possibly RELs related to connection 151.

The invention has a significant advantage in that virtual connections are used only when needed during a call and are disabled when the call is on them. This prevents the mux from transmitting empty cells that do not contain any user traffic. This allows a more efficient allocation and use of the bandwidth of the ATM network.

Figure 2 shows a more detailed version of the mux and the mapper. Continuous signal interface 200, ATM adaptation layer (AAL) shown

-1515

205, ATM interface 210, control interface 215, and mapper 220. Continuous signal connection 251, ATM connection 252, and signaling link 262 are also shown.

Continuous signal connection 251 carries user traffic using continuous signals with an example being DS3 signals. ATM connection 252 carries ATM cells with an example being a SONET connection. An example of signaling link 262 will be the SS7 link. Continuous signal interface 220 is operable to receive user information in continuous signal formats, such as the DS3 format. Signals such as DS3 and

DS1 is typically demultiplexed into component DSO signals over continuous signal interface 200.

The AAL 205 comprises both a convergence sub-layer and a segmentation and reassembly (SAR) layer. The AAL 2 50 is rational to accept user information from continuous signal interface 200 and convert the information into ATM cells The AAL 205 will select the VPI / VCI for the ATM cells based on the particular inbound connection For example, a particular inbound DSO will use a pre-assigned VPI / VCI.

-1616

AALs are known in the art and information about AALs is provided by document 1,363.1 of the International Telecommunications Union (ITU). An AAL for voice is also described in Patent Application Serial No. 08 / 395,745, filed on February 18, 1995 entitled Cell Processing for Voice Transmission, and is thus incorporated by reference herein. ATM interface 210 is operational to accept ATM cells and transmit them over ATM connection 252.

Control interface 215 is functional to accept control messages from mapper 220 and cause particular VPI / VCI to be enabled / disabled. This could be used by having the AAL 205 verify the VPI / VCI is enabled before generating the cells. This could also be done by having ATM interface 210 select ATM cells with a VPI / VCI disabled. Those skilled in the art will appreciate various ways to suppress transmission of cells over disabled or disallowed VPIs / VCIs.

Mapper 220 is functional to accept routing labels from signaling link 262 and to determine if a VPI / VCI is

-1717 could allow or disallow. . Mapper 220 will require interface programming elements to operate on link 162 and communicate with control interface 215. Mapper 220 may have a discrimination logic to select appropriate routing labels for further processing. These elements have been discussed previously.

The system operates as follows. The routing labels of the signaling message arrive at link 262 and

As discussed.

discrimination for routing it

Only the establishment and connection tags are processed with the 220 mapper.

he can determine if he should

251

The mapper requiring some tag to process for drop routing needs to be mapper 220.

associated with that of processed calls.

220 will determine the affected VPI / VCI using the OPC, DPC and CIC.

control message

If the type was for a ΙΆΜ, it will be sent from VPI / VCI

215. If the type of authorization message is e-mail, a VPI / VCI de-authorization will be sent to the

215.

the interface was for a

REL (or message and interface of

In this way, the ATM control control cells are only

-1818 will transmit during the actual call. When the call ends, the VPI / VCI is disabled so that empty cells are not transmitted. When another call requires the VPI / VCI, it will be enabled allowing cell transmission. This saves significant bandwidth over previous systems that transmit cells with respect to whether or not an actual call required connection.

Those skilled in the art will appreciate variations of the embodiment described above. In some embodiments, other signaling, such as C7 or UNI signaling, could be used in place of SS7. In some embodiments, the location of the message discrimination could be on the mapper, or on the STP, or distributed on both. In some embodiments, the switch could be programmed to send copies of the appropriate routing labels to the mapper. A conventional STP could be used in this case. In some modes, actual messages could be passed through the mapper so that no copying is required. The mapper

<td>will read</td><td>passively</td><td>the</td><td>relevant information.</td><td>In</td>

<td>any</td><td>s modalities,</td><td>. the</td><td colspan="2">function of the mapper will reside</td>

<td>at</td><td>switch,</td><td>the</td><td>STP, or independently</td><td>of</td>

<td>others</td><td>components.</td><td>In</td><td>these cases the mapper</td><td>I know</td>

-1919 will communicate with the mux over a conventional control channel. Also, multiple mappers could be used or a single mapper could be used to control multiple muxes. In addition to these modalities, other variations will be appreciated by those skilled in the art. As such, the scope of the invention is not limited to the specified embodiments, but is only restricted to the following claims *

It is noted that in relation to this date, the best method known by the applicant for practicing the present invention is the one that is clear from the present description of the invention.

Having described the invention as above, the content of the following is claimed as property:

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