JP2002535886A - Bandwidth mobile switching system - Google Patents

Abstract

(57) Abstract Various customer equipments (12a-g) including a local area network (44) are connected from a customer premises (42) to a carrier central office (56) via a subscriber line (50). A bandwidth mobile switching system (100) that delivers switched circuit traffic to a central office switch (60) and data packet traffic to a wide area network (64) such as the Internet. An access concentrator (104, 140) is used at the customer premises (42), a remote concentrator (106, 140) and an optional relay node (160, 140) are used in the subscriber line (50); A transfer switch (108, 140) is used at the central office (56). Copper lines (166) and fiber optic lines (168) are used to handle standard protocols such as POTS, E1 / T1 / xDSL and SONET between the various forwarding nodes (140).

Description

DETAILED DESCRIPTION OF THE INVENTION

TECHNICAL FIELD [0001] The present invention relates generally to telecommunications, and more particularly, to network communications through a public switched telephone system.

BACKGROUND ART FIG. 1 (Background Art) is a block diagram illustrating an existing infrastructure 10 of a public switched telephone network (PSTN). A variety of devices can communicate via the existing infrastructure 10, and modern users often own and use multiple such devices. In FIG. 1, the telephone 12a, facsimile 12b, modem 12c, computer 12d
, And a special service device 12 e are connected to the PSTN 14 and another telephone 12
a, facsimile 12b, modem 12c, computer 12d, and special service device 12e are also connected to PSTN 14. Telephone 12a and facsimile 12b are analog-type devices capable of communicating with similar individual devices. Modem 12c in FIG. 1 is a digital device (not shown) that produces digital signals that are converted to and from analog type signals, but otherwise communicate using analog technology. ) Is a stylistic representation of the general situation. In contrast, the computer 12d and special service device 12e in this figure stylistically represent a true digital type device.

[0003] While it is relatively well known that a computer 12d is present in the existing infrastructure 10, some readers may not know about the special service device 12e.
Today this device is relatively common, but little recognized. Some examples include remotely meterable utility meters and alarm systems. Usually, such a special service device 12e requires a much lower data transfer rate than a system such as a computer 12d.

For communication between sets of similar devices, the analog “traffic” is completely PS
It is possible through TN14. Digital traffic for computer 12d, on the other hand, starts on PSTN 14 and then proceeds over the Internet Protocol network (IP network 18). Similarly, the digital traffic of the special service equipment 12e can start on the PSTN 14 and then proceed over a signaling network such as the SS7 network 20 shown.

FIG. 2 (Background Art) is a block diagram illustrating the methodology of the most common digital connection, the “Internet call” connection. A digital device (not shown) generates a digital signal, which the modem 12c converts to an analog type signal. Modem 12c is connected to entrance switch 22 via a conventional voice line or (generally) a conventional telephone service line (POTS line 24). The ingress switch 22 is connected directly to the egress switch 26 via a POTS line 24 or to a tandem switch 28, which is further connected to the egress switch 26 via an interoffice trunk 30. The exit switch 26 is connected via the POTS line 24 to an Internet service provider point of presence (IS).
P POP32). The ISP may use a plurality of POTS lines 24 or an ISDN primary rate interface configured in a hunt group.
interface). An example is shown in FIG. ISP POP3
2 is finally connected to the IP network 18. Needless to say, digital communication going in the other direction basically follows the reverse path.

FIG. 3 (Prior Art) is a block diagram representing a currently evolving network evolution model, in which the IP network 18 evolves into a single common packet backbone. Analog devices, such as telephone 12a and facsimile 12b (FIG. 1), convert the signal into a digital data packet. Same operation for modem 1
2c (FIG. 1) analog output can be used, but is generally meaningless. Existing digital devices, such as computer 12d, continue to connect to IP network 18, and special service devices 12e also evolve to a type that can connect to IP network 18. Digital voice telephone 12f and video device 12g (
New digital audio-video devices, such as, for example, cameras, ie, "CAMs" often referred to in the art, can be connected directly to the IP network 18 as well. Unfortunately, there are problems with this evolutionary model. In particular, as will be discussed more broadly elsewhere herein, this evolutionary model renders current PSTN technology investments obsolete and creates multiple transitional technical problems.

FIG. 4 is a block diagram showing a more appropriate network evolution model. The various communication devices (12a-g) are connected to an access network 34,
The network 34 is a PSTN 14 (essentially already a key element in the existing infrastructure 10), an IP network 18, an SS7 network 20,
It is also connected to a broadband network 36. The IP network 18 can handle most existing bandwidth digital communications, and the broadband network 36 can handle high bandwidth communications such as digital video. Under this alternative network evolution model, the broadband network 36 is initially optional and will only be added as needed.

FIG. 5 (Background Art) is a block diagram of a current conventional digital loop carrier communication architecture (DLC architecture 40). LAN4 at customer premises 42
4 is a network device 46 and what is referred to herein as customer premises equipment (CPE4).
8. Channel Service Equipment / Data Service Equipment, Analog / ISDN / x
DSL type modem). Customer premises 42 may also include conventional telephone service (POTS) devices, such as telephone 12a shown.

The next part in the communication architecture is the subscriber line 50. It mainly includes the remote terminal 52. Digital traffic from CPE 48 to remote terminal 5
Connected to 2 is one or more T1 / E1 / DSx lines 54 (which here may also include all digital “copper” protocols, for example, xDSL and ISDN). It is one or more POTS lines 24 that carry analog (eg, voice, facsimile, and modem) POTS traffic to remote terminal 52. Typically, a plurality of such customer premises 42 are served by respective remote terminals 52.

Following in the communication architecture is a central office 56, which includes a central office terminal 58 connected to a central office switch 60 (typically a large central office has a plurality of central office terminals 58. And a plurality of central office switches 60, which may also connect remote terminals 52 directly to central office switch 60). Optionally, an internet router 62 from an internet service provider (ISP) may also be connected to the central office switch 60.

For simplicity, the Internet is used here as a general example of a special application network, but it should be understood that many other examples may exist. Alert systems and video conferencing networks are two common examples, each of which may use SS7 network 20 (FIGS. 1 and 4) and broadband network 36 (FIG. 4). For purposes of explanation, such a distributed network operating through a public switched telephone system, or in some sections in parallel with the public switched telephone system, is referred to herein as a wide area network (WAN 64). .

With continued reference to FIG. 5 (background art), typically, a plurality of subscriber lines 50 are serviced by each central office terminal 58 and a plurality of special network devices (eg, Internet routers 62) are connected to each central office switch 60. Serviced by At present, the connection from the remote terminal 52 to the central office terminal 58, the connection from the central office terminal 58 to the central office switch 60, and the connection from the central office switch 60 to the Internet router 62 are usually all performed by the T1 / E1 / DSx line 54. is there. FIG.
Connected to another device (not shown) by a / 100/1000 base-T line
It includes an example of a special network for the SP's Internet router 62. This example assumes the current practice of using a T1 / E1 / DSx line 54 to connect special network equipment directly to central office switch 60. Older equipment, smaller ISPs, and other specialized networks can still use the modem bank.

In this conventional architecture, a recent approach to increasing switching system bandwidth has been the development of new technologies. An example is a digital subscriber line (xDSL)
). This increases the existing copper bandwidth, but by adding yet another set of protocols. It also addresses the problem in only one part of the communications architecture, namely the customer premises 42 to the subscriber line 50, and thus has a hierarchical approach. This approach uses Asynchronous Transfer Mode (ATM), which requires new hardware throughout the communication architecture, and is therefore not a hierarchical approach. ATM also requires fixed-length packets, which is not always efficient when dealing with a variety of data types. ATM is very promising for a very distant future, but it is by no means an immediate or low-cost solution.

FIGS. 6 a-b (prior art) are block diagrams of a current digital subscriber line (xDSL) architecture, FIG. 6 a representing a hardware architecture, and FIG.
b represents the software architecture. In FIG. 6a, at customer premises 42, computer 12d uses an ATM transmitter--remote (ATU-R66);
DSL access of the telecommunications company central office 56 via the xDSL interface 68
The ATU in the multiplexer (DSLAM72) is connected to the center (ATU-C70). A further connection is then made via the asynchronous transfer mode network (ATM 74) to the broadband access server (BAS 76) of the network service provider 78. 6b uses network protocol 80, point-to-point protocol 82, ATM adaptation layer (AAL 584), ATM protocol 86, and asynchronous DSL protocol (ADSL protocol 88). At the central office 56, an ATM protocol 86 and an ADSL protocol 88 are used with a physical protocol 90.
In network service provider 78, another (layer) physical protocol 90
, ATM protocol 86, AAL5 84, point-to-point protocol 82, and network protocol 80 are used. Some of these layers may be the same and some may be different. For example, the physical protocol 90 typically must be the same on adjacent nodes, and the network protocol 80 is typically the same corresponding node.

[0015] In summary, the communication architecture used today is quite complex and increasingly complex. A myriad of different networks and protocols are already in use, some of which are becoming increasingly obsolete, and new ones are gaining in importance. It is simply unrealistic to expect such an old system to be immediately replaced by a new one, so what is needed is a system for a proper upgrade. Such a system should enable the integration of both existing systems and systems that are emerging or not yet developed.

DISCLOSURE OF THE INVENTION It is therefore an object of the present invention to provide a system for upgrading existing Public Switched Telephone Network (PSTN) systems to additionally handle packet transfer communication traffic.

It is another object of the present invention to provide a system for reducing or eliminating subscriber line bottlenecks in existing PSTN systems without resorting to a parallel packet switched network.

Another object of the present invention is to provide a streamlined high bandwidth packet forwarding public network that utilizes much of the existing PSTN infrastructure and investment.

Briefly stated, one preferred embodiment of the present invention is a public switched telephone network (PSTN).
) Is an improved communication system of the type that connects both circuit-switched and packet-forwarded communication device types at various customer premises through at least one carrier central office. This improvement includes an access concentrator located at the customer premises, a remote concentrator located between the customer premises and the carrier central office, and an access network having a forwarding switch located at the carrier central office. included. The access concentrator receives both switching and packet signals from the communication device and communicates it as an end node signal to the remote concentrator via the internal interface. The remote concentrator has access
It receives an end node signal from the concentrator and communicates it as a distributor node signal to the transfer switch via another internal interface. The forwarding switch receives the distributor node signal from the remote concentrator and separates the switching and packet signals from the distributor node signal. The forwarding switch then sends the switching signal to the intended final circuit-switched type communication device. And the transfer switch also sends the packet signal,
Route toward the intended final packet transfer type of communication device.

An advantage of the present invention is that it efficiently distributes both circuit-switched and packet-forwarded network traffic over the network backbone in existing PSTN systems.
Therefore, they can be integrated very economically.

Another advantage of the present invention is that packet forwarding network traffic is transmitted particularly efficiently by using spoofing of a network control package, such as a media access control (MAC) address, in a subscriber line of a communication network, for example. And thus reduce or eliminate the need to transfer this information.

Another advantage of the present invention is that it integrates existing and new analog and digital systems for computers and other data, voice, and video.

Another advantage of the present invention is that it reduces peripheral problems related to communication, such as lack of current IP addresses, network security, unification of directory services, and provision of additional numbers in a finite numbering scheme.

[0024] The above and other objects and advantages of the present invention will be apparent to those skilled in the art of the industrial applicability of the preferred embodiment described herein and illustrated in the several figures of the drawings, And will become apparent from the description of the currently best known manner of carrying out the invention.

The objects and advantages of the present invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The preferred embodiment of the present invention is an improved architecture for communicating primarily through conventional telecommunications systems. As shown in the various drawings herein,
In particular, in FIG. 7, a preferred embodiment of the inventive device is designated by the general reference numeral 100.

Briefly summarized as an introduction, a bandwidth transfer switching system
The basic principle behind the switching system (BTSS) 100 is that
It integrates the packet switching function with the efficient bitframing technology implemented in E1 circuit switching technology. This method uses T1 / T1 for circuit switching.
A packet switching function is added using the transmission efficiency of E1. This basic principle is then adapted to the subscriber line. Here, no dynamic routing function is required. The result is a simplified switching system, BTSS 100, that provides both circuit-switched and packet-switched functions in the subscriber line while maintaining compatibility with external interfaces outside the subscriber line.

In FIG. 7, the BTSS 100 according to the present invention provides an architecture that can include not only high bandwidth network communications, but also legacy communications of the old type. This enables an efficient implementation of a heterogeneous network consisting of both circuit-switched and packet-switched technologies in a public switched telephone system. In contrast to the approach of developing a completely new technology as described in the background section above, the BTSS 100 is a T1 that has already been validated from the customer premises 42 to the subscriber line 50.
/ E1 / DSx line 54 (or xDSL with little change) and then S
The data is transported to the central office 56 using ONET 102 (SONET is an optical line standard utilizing fiber optic cables). Although the SONET 102 connection is shown as a single link, this is typically implemented as a fiber optic ring.

Implementation of this architecture requires three new devices: an access concentrator 104, a remote concentrator 106, and a forwarding switch 108. Between these new devices, the BTSS 100 uses two communication channels, one for control and management functions and the other for transferring application packets under HDLC framing, in which case framing is performed. The resulting application packets may include Ethernet, TCP / IP, video streams, voice over IP, alarm signaling, meter polling, etc.

In order to eliminate current bandwidth bottlenecks both within the subscriber line 50 and the central office 56, and to provide deployment flexibility and higher network efficiency, the BTSS 100 is installed on the customer premises 42 The packet-switched and circuit-switched traffic at the earliest access point outside the In this way, different network architectures, technologies, and deployment strategies can be used to implement data, voice, video, and other services, and enable specialized network optimization for different data types. Such special network access at the central office 56 is becoming increasingly important. For example, WAN64 access to services such as the Internet is increasing. In the following discussion, we will discuss traditional telephone-type circuit-switched traffic and Internet traffic.
Although the type of packet traffic is used in the examples, and the details are sometimes specific to them, the same model can easily be extended and applied to other protocols.

The main advantage of BTSS 100 is that for both circuit and packet switching,
To enhance established network architectures and technologies, such as existing public telephone switching systems. The BTSS 100 handles circuit switched traffic in substantially the same manner as currently used (further described below),
Packet data is handled differently.

Application packet data originating on the Ethernet local area network LAN 44 (ie, “local LAN”)
4 is routed to WAN 64 for some purpose of itself, or
It is often desirable to route from 4 to another LAN 44 (ie, a “remote LAN”). For example, whether the source LAN 44 is the customer premises 42 accessing the ISP network (basically, a simple LAN
44 to the WAN 64 and back again, which is the example shown in FIG. 7), or packet data is transferred from the first LAN 44 of one customer premises 42 to the WAN.
It may be intended to travel via 64 to a second LAN 44 of the second customer premises 42.

The BTSS 100 is basically a LAN / WAN or local LA according to the prior art.
It achieves similar results as N / WAN / remote LAN communication, but in a different way. Except for spoofing, only the physical layer and / or link layer devices (Layer 1 and Layer 2 of the ISO network model) are implemented in the BTSS 100. During provisioning, a synchronization control channel (based on HDLC) is established between the access concentrator 104, the remote concentrator 106, and the transfer switch 108. These special T1 / E1 / xDSL
In the line 110, two types of packet channels are implemented in addition to a dedicated line channel for voice. One is for system control and management functions and the other is for payload propagation. Thus, this control channel carries provisioning, control, and management information. In particular, this control channel is used to transparently present the MAC (Ethernet address) of the network device 46 on the LAN 44 to the WAN 64 via the interface 112 during provisioning (eg, the Internet router 62). What).

When the BTSS 100 is correctly provisioned, the forwarding switch 108 monitors the Ethernet traffic on the interface 112 and filters it based on the media access control address (MAC address, ie, Ethernet address), and The traffic is forwarded to the appropriate remote concentrator 106 to be forwarded to the access concentrator 104, which then delivers that traffic to the LAN 44 with the final target network device 46. Access concentrator 104 monitors LAN 44 traffic in a similar manner, filters it based on the MAC address, and then routes the appropriate traffic to the remote
The data is transferred to the concentrator 106 and further transferred to the transfer switch 108. Forwarding switch 108 then removes the framing and presents the traffic to interface 112, or to another appropriate application network, or to central office switch 60.

For traffic destined for the WAN 64, this may be via a WAN 64 connection directly from the forwarding switch 108 using the interface 112 shown in FIG. 7, or as shown in FIG. (Available) via a conventional T1 / E1 / DSx line 54 shown in FIG. A "payload frame" in this scenario is an application packet encapsulated inside an HDLC frame. This is where you end up
Requires a concentrator 104. All that is required between each access concentrator 104 and the forwarding switch 108 is a single payload HDLC stream, but redundancy can be provided if desired. The channels available in the T1 / E1 / DSx line 54 are assigned at provisioning time to the unique voice service connection assigned to the subscriber at the customer premises 42. Where T1 / E1 / DS
Not all available channels in x-line 54 need be dedicated to service to a particular customer premises 42. Concentration techniques may be used where there are more subscribers than channels available in the T1 / E1 / DSx line 54.

Data transfer between LAN 44 and WAN 64 need only be performed for actual data packets. The control packet is the access concentrator 10
4 and forwarding switch 108, and an appropriate response is generated as needed, thereby removing some traffic throughout the system. Using the control channel in this manner, the access concentrator 104 can communicate with the forwarding switch 108, maintain the correct status of each network node, and can spoof control messages, Is access concentrator 10
4 and the transfer switch 108. Therefore BTSS100
Is that no "routing" in the traditional sense is used at the stage between the access concentrator 104 and the forwarding switch 108. The Internet router 62 on the WAN 64 and the network device 46 on the LAN 44
Effectively "see" each other as if they were connected on a simple network. The BTSS 100 essentially implements a subnetwork with its own intelligence and traffic routing between the application and the transport network.

As mentioned above, the BTSS 100 handles analog traffic basically in the same manner as currently used. To support a traditional “telephone” connection, access concentrator 104 may include the ability to connect to POTS line 24 (and thus a POTS device). Thus, analog traffic (eg, voice, facsimile, and true modems) may be packetized and transmitted as Voice over IP, or transmitted using standard DS0 channels using fractional T1 / E1, T1 / E1 / xDSL line 11
0 on the subscriber line 50.

The access concentrator 104 may provide other types of network connections (not shown) such as safety alarm and utility meter connections and similar appliance networking that require only slow network access (not shown). ) Can also be provided. These additional network services may also be carried over the subscriber line 50 and may be diverted at the forwarding switch 108 onto an appropriate network providing these services. Broadcast T
Services that require higher speeds, such as V and video services such as video on demand (eg, to the broadband network 36 (FIG. 4)) can be provided in this architecture as well.

In summary, the approach of using the BTSS 100 facilitates the use of extensive and large-scale deployments of the already proven components of T1 / E1 / DSx technology while at the same time improving the efficiency and high bandwidth of the SONET 102 hierarchy. Also provides high bandwidth communication and reduces the cost per unit compared to other methods currently used.

FIG. 8 is a block diagram illustrating a general implementation of a forwarding node protocol layer for use within BTSS 100. Access concentrator 104 in customer premises 42, remote concentrator 106 in subscriber line 50, central office 56
All the transfer switches 108 are connected to each physical layer 120. This physical layer 120 then connects to each link layer 122. The link layer 122 then accesses
In the concentrator 104 and the remote concentrator 106, a connection is made to a network layer 124 that includes a POTS sublayer 126 and a packet sublayer 128, respectively. Eventually, the access concentrator 104, the remote concentrator 106, and the forwarding switch 108 all become the management layer 13
Contains 0.

The BTSS 100 fully maintains compatibility with the existing PSTN infrastructure 10 (FIG. 1). Referring again to FIG. 5, in addition to taking into account the requirements of the subscriber line 50 and eliminating network protocol components not needed here, the BTSS 100 outperforms competing high-speed WAN 64 access solutions. Provides essential economic benefits. From this point of view, BTSS100
Needs to provide a bridge function between three major equipment categories: customer premises equipment (CPE 48), central office switch 60 (eg, class 5 switch), and carrier class IP router (eg, Internet router 62). is there.
External interfaces for customer premises equipment (CPE 48) are typically POTS, R
Includes J-11, RJ-45 and Ethernet protocols. Central office exchange 6
0 is usually POTS, T1 / E1, DSx, SLC
-96, GR-303, and SONET protocols. And the external interface for Internet router 62 is some version of Ethernet.

FIG. 9 is a block diagram illustrating a more specific implementation of a protocol layer in the forwarding node 140 for use in the BTSS 100, which includes the compatibility features required to interface with the appropriate external interface 142. Is particularly taken into account. The transfer node 140 connects to other transfer nodes 140 in the BTSS 100 via one or more internal interfaces 144. The physical layer 146 handles traffic to and from the internal interface 144. Physical layer 146 includes leased line sublayer 148 and shared packet sublayer 150. The system management layer 152 or the transfer function layer 154 controls the physical layer 146, as appropriate for management and data transfer tasks. Finally, a compatibility function layer 156 "exists" on top of all of these, handling traffic to and from the external interface 142.

The “generic” forwarding node 140 of FIG. 9 may be any of five different types that are more specific. One is a user's various communication devices (12a-g) (FIG. 1).
And the end node of the customer premises equipment type, such as the access concentrator 104 connected to FIGS. The second is a central office type central node such as a forwarding switch 108 that connects to the central office switch 60 (eg, a class 5 switch). The third is an ISP-type central node that is again connected to a carrier class IP router (eg, Internet router 62), such as forwarding switch 108. Fourth is a distributor type node, such as a remote concentrator 106 that connects only to other types of other nodes. Finally, a fifth is a relay type node, which also only connects to other nodes, but which is not necessarily another type of node. These second and third, central office and ISP types, may be implemented in one forwarding switch 108 if both communication categories are required, but this is not a requirement. Distributor and relay type notes have no layers above external interface 142 or packet sublayer 150. The relay type note is included here for completeness and will be described in detail below.

The basic principle behind the BTSS 100 combines circuit switching and packet switching in a manner that enhances networking in the subscriber line 50 (FIG. 7), but with reduced complexity. This functionality is independent of the physical layer connection, and is based on various xDSL technologies,
It is possible to provide physical connectivity using coax or even wirelessly. The physical layer 146 may implement a logical DS1 (T1 / E1) scheme. This DS1 system can provide compatibility with existing OSS (Operation Support System). Therefore, the high-speed Internet service provided by the BTSS 100 can be managed as a “consumer DS1” using the existing support system. Some key functions where the DS1 feature is used are service provisioning, alert detection, monitoring, and propagation. The data rate on the consumer DS1 depends on the particular physical layer 146 used.

FIG. 10 is a block diagram illustrating bandwidth allocation within the line sublayer 148 and packet sublayer 150 of the physical layer 146. The physical layer 146 bandwidth is divided into dedicated DS0 channels 158 (eg, 64 kbps each) for voice and other analog data connections. Each subscriber connection may consist of one or more dedicated DS0 channels 158, and optionally a common channel for packet sublayer 150 if data services are available. It is. After providing the dedicated DS0 channel 158, all remaining bandwidth may be used in a single packet sublayer 150 that can implement the HDLC framing link layer. It can use a 16-bit address field and HDLC framing,
Fields are used to implement multiple logical links, including control links for performing management functions.

In this manner, BTSS 100 can increase efficiency and simplicity by removing all dynamic routing requirements between various forwarding nodes 140. The voice call is conveyed over a dedicated DS0 channel 158 using a standard scheme for implementing a voice connection. The assignment of the DS0 channel 158 is made during service provisioning, and for data services (eg, Internet connections), logical links are provisioned across all connection forwarding nodes 140, along with a unique link layer address for each connection segment. Is done. Thus, the bandwidth available in the packet sublayer 150 is shared between all data connections served by that partition. A priority scheme may be implemented to provide different service levels. Control links used for system management are typically implemented as priority links between forwarding nodes 140.

FIG. 11 is a block diagram summarizing typical interfaces in BTSS 100, in particular, possible interfaces between various forwarding nodes 140. The forwarding node 140 is connected to the access concentrator 104 (terminal node or TN).
), A remote concentrator 106 (distributed note or DN), and a forwarding switch 108 (central node or CN). Although not described in detail so far, a relay node 160 (RN) is also included.

The analog user device, specifically the telephone 12a,
a (such as the POTS connection in the figure) to the access concentrator 104. The digital user device, specifically the computer 12d or network device 46, is connected to the access concentrator 104 via another external interface 142b (such as the illustrated Ethernet connection).

The access concentrator 104 is connected to the relay node 160 via an internal interface 144a, and the relay node 160 is connected to the remote concentrator 106 via another internal interface 144a. Also probably as either T1, E1, xDSL, or POTS). The remote concentrator 106 is shown as being another internal interface 144b (here, either T1, E1, xDSL, POTS, or SONET; ie, a SONET has been added and this is preferred). 108.

The remote concentrator 106 connects to the central office switch 60 via an external interface 142c (shown here as either POTS or DS1).
The remote concentrator 106 is also connected to the Internet router 62 via another external interface 142d (here, Ethernet, but a faster version is preferred).

The relay node 160 is optional but can be used when the signal is transmitted over long distances or when the signal needs to be boosted for an electrically “noisy” environment . For example, almost all protocols have some usable distance limitations, but xDSL is particularly prominent in this regard.

There are several possible arrangements for implementing BTSS 100 based on different network topologies. 12a-b show a typical metropolitan area deployment where the distance between the central office 56 and the customer premises 42 is short. Figures 13a-b show arrangements in a typical suburban area. 14a-b show a typical countryside arrangement where the distance between the central office 56 and the customer premises 42 is significantly longer,
The signal must be regenerated.

FIG. 12 a is a schematic block diagram illustrating equipment locations for deployment in a typical metropolitan area. The distance between the access concentrator 104 at the customer premises 42 and the forwarding switch 108 in the central office 56 is short. This allows for the removal of the remote concentrator 106 and any relay nodes 160 (see, for example, FIGS. 11, 13a, 14a).

FIG. 12 b is a schematic block diagram illustrating the layer arrangement within the various forwarding nodes 140 used in FIG. 12 a. As can be seen, both the access concentrator 104 and the forwarding switch 108 are essentially the same layer (122, 1).
24, 126, 128, 130).

FIG. 13 a is a schematic block diagram illustrating equipment locations for deployment in a typical suburban area. Here, the customer premises 4 which are likely to be large and more dispersed
2 access concentrator 104 and forwarding switch 108 in central office 56.
Are longer than in the metropolitan area of FIG. 13a. Thus, in this implementation, a remote concentrator 106 is provided.

FIG. 13b is a schematic block diagram showing the layer arrangement in the various forwarding nodes 140 used in FIG. 13a. As can be seen, both access concentrator 104 and forwarding switch 108 are essentially the same layer (146, 14).
8, 150, 152, 154, 156), but the remote concentrator 106 does not have the compatibility function layer 156 or any external interface 142.

FIG. 14 a is a schematic block diagram showing equipment locations for placement in a typical countryside. In this case, the distance between the first access concentrator 104a in the first customer premises 42 and the remote concentrator 106 is considerably long. Therefore, two relay nodes 160 are added between the first access concentrator 104 and the remote concentrator 106. This is particularly useful for protocols such as xDSL where the distance is very limited. On the other hand, a closer second (such as third) access concentrator 104b may be connected directly to the remote concentrator 106 as shown.

FIG. 14 b is a schematic block diagram showing the layer arrangement within the various forwarding nodes 140 used in FIG. 14 a. As can be seen from this figure, the access concentrators (104a, 104b) and the transfer switch 108 are basically at the same layer (1
46, 148, 150, 152, 154, 156),
The remote concentrator 106 has no compatibility function layer 156 and no external interface 142, and the relay node 160 has only the physical layer 146 and the line sublayer 148. In this case, the relay node 160 can implement the physical layer 146 and the line sublayer 148 using a bit frame and a built-in control channel implemented on a regular T1 / E1 interface.
The embedded control channel may support alert monitoring, sensing, and propagation from the access concentrators (104a, 104b) to the forwarding switch 108. Thus, relay node 160 allows to extend the distance over which service can be provided, possibly without restrictions.

The BTSS 100 is particularly useful in reducing current IP address shortages, increasing network security, providing a unified directory service, and handling additional number services. sell.

Returning to FIG. 7, it can be seen that the access concentrator 104, the remote concentrator 106, and the forwarding switch 108 form a hierarchical boundary within a given service area. This is very useful for reducing current IP address shortages. At a first level, access concentrator 104 provides connectivity to LAN 44 at customer premises 42. This LAN 44 is "
It can be implemented as either a "closed network" or an "open network". If it is desirable to provide external open access to all of the systems at the customer premises 42, a method of providing addressing would be a globally unique I / O that can be routed across a WAN 64, such as the Internet.
That is, a P address (RFC1918, BCP5) is used. However, if such a system has limited access, the way to provide addressing is to use non-routable private IP addresses. Remote concentrator 106 and forwarding switch 108 form a logical network access control point to and from the external service area covered by remote concentrator 106 or forwarding switch 108, respectively. By providing a private IP address as the default addressing scheme for the network traversing the subscriber line 50, the BTSS 100 technology can dramatically reduce the need for a unique IP address when widely deployed. This implementation does not depend on the user equipment addressing scheme since all forwarding nodes 140 (FIG. 11) do not route for customer data. Thus, implementing Network Address Translation (NAT) with private IP addresses can significantly reduce the current shortage of IP addresses.

The BTSS 100 also facilitates providing higher network security and privacy. By implementing NAT (Network Address Translation) on the central transfer switch 108, an isolated LAN 44 with built-in security can be provided to each subscriber. Enhanced security features, such as a proxy server, may be implemented on the forwarding switch 108 for additional security needs. Remote concentrator 106 and forwarding switch 108 become ordinary network access points and implement various protection and access control techniques that can be used to implement network security and privacy features. Further, access concentrator 104, remote concentrator 106, and transfer switch 108 form a network access control point. This allows implementing the same network access control method for different levels of security needs. Since these devices are on the perimeter of any connection network, such as LAN 44 and WAN 64, the security functions implemented can enhance any additional security measures implemented within such connection networks. In addition, being on the outer perimeter of such a connecting network, the forwarding node 140 can implement network isolation, intrusion detection, and firewall schemes as basic functions.

As the variety of methods we use for communication has increased, it has become desirable to provide a unified directory service. Telephone companies are, for example, telephone numbers,
We have long implemented easily accessible globally common systems for distributing subscriber information, such as telephone directory assistance. Such a numbering scheme and its associated directory assistance provide a complete set of tools to make PSTN 14 (FIG. 1) useful. As public WANs 64, such as the Internet, become increasingly common, the need for similar directory services is becoming apparent.
Currently, the domain names and e-mail addresses used are distributed or issued in an ad hoc manner, and thus there is no global reach and available uniformity using phone book type methods. However, if the customer's phone is
By linking to all identifying information related to (especially the Internet)
Customers who wish to publish (privately or publicly) can simplify or avoid the current problems associated with distributing that identity. Access concentrator 1
A suitable embodiment of 04 allows the customer to compose the selected identity and associate it with his telephone number. A suitable embodiment of the forwarding switch 108 makes this information available to the telephone operating system and makes it available as additional information available about the customer. The information provided in this manner can be retrieved manually, for example, by conventional operator assistance techniques, or the forwarding node 140 can provide a directory search service using a telephone number as a base identifier.

Similarly, as the various services we use for communication increase, the total number of dedicated additional telephone numbers required for such services becomes unmanageable.
However, in BTSS 100, terminal transfer node 140 can provide one or more POTS connections per customer line. This allows for the provision of additional telephone lines, such as dedicated lines for fax and pager services,
No dedicated phone number is required. Although dedicated lines are assigned for specific service types (fax, pager, second line, etc.), there is no need to provide a separate number for each under the BTSS 100. The service type can be identified by the access concentrator 104 or the forwarding switch 108. PST
N14 can route the call to the customer telephone number as any other call. Terminal forwarding node 140 can also properly terminate the call based on its particular type. In this manner, the need for different telephone numbers for each of the different services can be eliminated. Deploying such features on a large scale can reduce the need for individual telephone numbers and thus reduce the current shortage of numbers.

FIGS. 15 a-d show how the BTSS 100 enhances the subscriber line 50,
It shows step by step whether you can upgrade. Currently, subscriber line 5
The technology implemented within 0 addresses only the need for voice services. To provide next-generation services, subscriber lines must be enhanced and upgraded to provide voice, data, and video services. This is an enormous effort in terms of time and resources, and the only practical way to achieve such enhanced functionality is by implementing it step by step. Figures 15a-d show how this upgrade and enhancement can be implemented in five stages. FIG. 15a shows step 0 (current situation), in which the subscriber line 50 comprises customer equipment 162 in the customer premises 42, terminal equipment 164 in the telecommunication company central office 56, and a copper line 166 connecting them. I have. FIG. 15b shows step 1, where the forwarding node 140 is located in the subscriber line 50 but only provides POTS type services. FIG. 15c illustrates step 2, where the data (eg, Internet) service is additionally provided by adding an access concentrator 104. FIG. 15c also illustrates step 3, where a fiber optic line 168 (eg, SONET) is placed between the central forwarding node 140 (eg, the remote concentrator 106 and the transfer switch 108) to limit the bandwidth in the subscriber line 50. Is removed. Finally, FIG. 15d shows step 4, where flexible and reconfigurable in subscriber line 50 to provide high bandwidth services (eg, HDTV, video) and using the network of forwarding nodes 140 Additional remote concentrators 106 are deployed for additional service selection using different sub-networks.

The following is a simplified overview of the functions of the access concentrator 104. P
Connection to OTS phone; TCP / IP interface over Ethernet; T1 / E1 / xDSL interface to remote concentrator 106; Establishment and management of control channel to forwarding switch 108; Packet and voice time division multiplexing (TDM) Dynamic channel allocation with optional traffic or available bandwidth to Voice over IP; conversion of Ethernet packets from LAN 44 to HDLC framed packets and transmission to forwarding switch; forwarding switch 108 to LAN 44 Translation and transmission of remote HDLC packets to Ethernet packets within; management and maintenance of Ethernet MAC addresses to and from HDLC addresses; addresses to all currently active remote devices Constant network control package spoofing (
This requires partial IP level filtering and processing); compression and decompression of different data types; secure data encryption and management and processing of digital certificates for authentication; eg analog Combining different traffic types, such as voice, video, data, etc. into a data stream.

The following is a simplified overview of the functions of the remote concentrator 106. Multiple T1 / E1 / xDSL interfaces to multiple access concentrators 104; DSx / xDSL / SONET interfaces to central office 56 forwarding switch 108; maintaining a control channel between forwarding switch 108 and remote concentrator 106; access concentrator 104 Dropping and insertion of T1 / E1 / xDSL interface from SONET interface to SONET interface.

The following is a simplified overview of the function of the transfer switch 108. Maintaining multiple T1 / E1 / DSx interfaces from multiple remote concentrators 106; maintaining multiple 10/100/1000 base-T interfaces to Internet router 62 (for data traffic); multiple T1 to central office switch 60 / E
Maintain 1 / DSx interface (for voice data); Establish and manage control channel (via HDLC frame link) to access concentrator 104; Receive Ethernet MAC address from access concentrator 104; and Internet router Presenting them to the 10/100/1000 Base-T interface to T.62; controlling and managing TDM voice calls to access concentrator 104, or providing voice over IP; addressing all currently active remote units Spoofing of specified network control packages (this requires partial IP level filtering and processing); compression and decompression of different data types;
Management and processing of digital certificates for secure data encryption and authentication;
The data stream is sent to a different traffic type, eg, analog, voice, video, data, for transfer to a different application network, such as a central office switch 60, an Internet router 62, an alarm system, a power company instrument polling, etc. Be separated into

While various embodiments have been described above, it should be understood that they have been presented by way of example only, and not limitation. Accordingly, the breadth and scope of the preferred embodiment should not be limited by any of the above-described exemplary embodiments,
It should be defined only by the following claims and their equivalents.

Industrial Applicability This bandwidth mobile switching system (BTSS 100) is well suited for applications to upgrade existing PSTN 14. As modern communications evolve from analog-based systems to digital-based systems, the ability to handle both analog and digital data types, i.e., commonly known switched network and data packet communication traffic. Is increasingly needed. The ultimate goal is arguably to reach an Internet Protocol-based system where only data packets are used, but switching the existing PSTN 14 to an Internet Protocol network (IP network 18) is by no means the only one. Not realistic. A transitional approach to constructing the IP network 18 in parallel with the existing PSTN 14 is also not practical. As a result, a fragmentary hybrid approach has been devised that forces both switched network and data packet traffic through at least a portion of the existing PSTN 14, but with the consequence that some portions are very burdensome. occured.

The BTSS 100 provides the access network 34 to the customer premises 42, and then separates traffic types at the carrier central office 56 or earlier in the remote concentrator 106 (ie, distributor node). Enables an incremental approach to the problem of upgrading our communications infrastructure. The BTSS 100 allows for continued use of the current investment in current copper lines 166, replacing it progressively with fiber optic lines 168 appropriately, high traffic volumes, and segments of the communication system.

According to this method, the BTSS 100 transmits a telephone 12a, a facsimile 12b, a modem 12c, a computer 12d, a special service device 12e (for example, an alarm and power meter system), a digital voice telephone 12f, a video device 12g, and a LAN 44.
, WAN 64 (including the Internet) can be efficiently and economically integrated. In addition, BTSS 100 performs these at the same time as the current I
It can also help reduce peripheral communication problems such as lack of P addresses, network security and privacy, unification of directory services, and provision of additional number services in a finite numbering scheme.

For these and other reasons, it is anticipated that the BTSS 100 of the present invention will have broad industrial applicability. Therefore, the commercial utility of the present invention is expected to be widespread and long lasting.

[Brief description of the drawings]

FIG. 1 (Background Art) is a block diagram illustrating the existing infrastructure of the Public Switched Telephone Network (PSTN).

FIG. 2 (Background Art) is a block diagram illustrating the most common digital or “Internet call” connection method currently in use.

FIG. 3 (Prior Art) is a block diagram representing a currently popular network evolution model in which an Internet Protocol network evolves into a single common packet backbone for all communications.

FIG. 4 is a block diagram representing a proposed more appropriate network evolution model.

FIG. 5 is a block diagram of a conventional current digital loop carrier communication architecture.

FIG. 6 (Prior Art) is a block diagram of a current digital subscriber line (xDSL) architecture, which shows the hardware architecture (a) and the current digital subscriber line (xDSL).
FIG. 2B is a block diagram of the xDSL) architecture, and is a diagram (b) representing a software architecture.

FIG. 7 is a block diagram of a forwarding switch access architecture according to the present invention.

FIG. 8 is a block diagram illustrating a general implementation of a forwarding node protocol layer used in the present invention.

FIG. 9 is a block diagram illustrating a more specific implementation of the forwarding node protocol layer used in the present invention.

FIG. 10 is a block diagram illustrating bandwidth allocation of a line sublayer and a packet sublayer in the physical layer according to the present invention.

FIG. 11 is a block diagram illustrating an external interface of a transfer node according to the present invention.

FIG. 12 is a block diagram showing a metropolitan area implementation suitable for use in the present invention, wherein FIG. 12 (a) shows equipment connection and a block showing a metropolitan area implementation suitable for use in the present invention; It is a figure and is a figure (b) which expresses transfer node connection using protocol layering notionally.

FIG. 13 is a block diagram illustrating a suburban area implementation suitable for use in the present invention, in which FIG. 13A illustrates a device connection and a block diagram illustrating a suburban area implementation suitable for use in the present invention. FIG. 5B is a diagram conceptually illustrating a forwarding node connection using protocol layering.

FIG. 14a is a block diagram illustrating a rural implementation suitable for use with the present invention, illustrating device connections.

FIG. 14b is a block diagram illustrating a rural implementation suitable for use with the present invention, conceptually illustrating a forwarding node connection using protocol layering.

FIG. 15 is a block diagram illustrating how the present invention allows for the gradual enhancement and upgrade of the public switched telephone network, FIG. 15 (a) illustrating an existing network, and how the present invention is implemented. FIG. 4 is a block diagram showing whether incremental enhancement and upgrade of the public switched telephone network is possible, showing the addition of a centralized forwarding node (b)
FIG. 4) is a block diagram illustrating how the present invention allows for gradual enhancement and upgrade of the public switched telephone network, including the addition of customer premise forwarding nodes and the addition of copper interfaces to fiber optic interfaces; FIG. 4C is a block diagram showing how the present invention allows for gradual enhancement and upgrade of the public switched telephone network, especially for providing high bandwidth capabilities; FIG. 11D is a diagram showing that a further configured forwarding node is added.

[Procedure amendment]

[Submission date] July 17, 2001 (Jul. 17, 2001)

[Procedure amendment 1]

[Document name to be amended] Drawing

[Correction target item name] FIG.

[Correction method] Added

[Contents of correction]

FIG.

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Claims (22)

[Claims] 1. A public switched telephone network having both circuit-switched and packet-forwarding type communication devices located at a plurality of customer premises which communicate with each other via at least one telecommunications company central office by respective similar type communication devices. An access concentrator located at the first customer premises, a remote concentrator located between the first customer premises and the first telecommunication company central office, and an access concentrator located at the first telecommunication company central office. An improvement includes an access network that includes a switched transfer switch, wherein the access concentrator provides both a switched signal from the communication device of the circuit switched type and a packet signal from the communication device of the packet transfer type. Receiving the exchange signal and the packet signal as an end node signal via a first internal interface. Suitable for communicating to a remote concentrator, the remote concentrator receiving the end node signal from the access concentrator, and using the end node signal as a distributor node signal via a second internal interface. Suitable for communicating to the transfer switch, the transfer switch receiving the distributor node signal from the remote concentrator, and of the circuit-switched type at another of the customer premises other than the first customer premises. Separating the exchange signal from the distributor node signal for transmission to an instance of the communication device; and an instance of the packet transfer type of communication device at another of the customer premises other than the first customer premises. Route to To constant, with the type of an improved communication system suitable for separating the packet signal from the distributor node signal. 2. The system according to claim 1, wherein the communication device of the circuit switched type uses an analog signal protocol, and the access concentrator has at least one conventional telephone system for receiving the switched signal from the communication device of the circuit switched type. The improved communication system of claim 1 including an interface. 3. The communication device of the circuit switched type includes a member of a set consisting of a telephone device, a facsimile device, a modem device, and a special service signaling device, and wherein the switching signal is transmitted from the communication device of the circuit switched type. , The access concentrator comprises at least one conventional telephone system (POT).
2. The improved communication system according to claim 1, including an S) interface. 4. The communication device of the packet transfer type uses an Ethernet (registered trademark) signal protocol, and the access concentrator is configured to receive the packet signal from the communication device of the packet transfer type. The improved communication system according to claim 1, comprising one Ethernet interface. 5. The communication device of the packet transfer type, comprising: a computer;
Computerized digital devices, digital network devices, digital
Claims: A video device, and a member of a set of digital audio devices, wherein the access concentrator includes at least one digital network interface for receiving the packet signal from the communication device of the packet transfer type. Item 2. An improved communication system according to Item 1. 6. An improved communication system wherein said terminating node includes a circuit layer for said switched signal and a packet layer for said packet signal, wherein said access network is first provisioned. The circuit layer is configured exclusively for the number of sets of sub-lines, so that it is possible to support a similar said number of said switched signals, said packet layer being dynamically shared, thereby changing from nothing to plural 2. The improved communication system of claim 1, wherein the communication system can include up to an amount of the packet signal. 7. The method according to claim 1, wherein said first internal interface is a POTS, T1, E1, D
The improved communication system of claim 1, wherein the communication system uses a protocol that is a member of a set consisting of Sx and xDSL. 8. The method according to claim 8, wherein said second internal interface is a POTS, T1, E1,
The improved communication system of claim 1, wherein the communication system uses a protocol that is a member of a set consisting of DSx, SLC-96, GR-303, and SONET. 9. The central office of a telecommunications company, wherein the central office of the telecommunications company includes a central office switch that connects to the instance of the communication device of the circuit-switched type at the other customer premises other than the first customer premises. Comprises a router connected to a digital network that connects to the instance of the communication device of the packet transfer type located at the other customer premises other than the first customer premises, wherein the forwarding switch is connected to a central office switch. A first external interface connected, wherein the first external interface directs the exchange signal to a central office switch using a protocol that is a member of a set consisting of T1, E1, and DSx. A second external interface connected to a digital network, said second external interface Improved communication system of claim 1 including a second external interface using digital network protocols. 10. The improved communication system according to claim 9, wherein said digital network protocol is an Ethernet protocol. 11. At least one relay node located between the access concentrator and the remote concentrator for communicating the termination node signal over a long distance between a customer premises and a telecommunications company central office. The improved communication system according to claim 1, comprising: 12. A method of bandwidth transfer on a public telecommunications network, wherein communication devices using switched and packet signals are located at a plurality of customer premises and communicate with each other via at least one telecommunications company central office. Wherein the method comprises the steps of: (1) receiving at least one customer signal from a communication device into an access concentrator, wherein each customer signal is a member of a set consisting of a switching signal and a packet signal. (2) integrating all of the customer signals received at the access concentrator into a termination node signal; and (3) communicating the termination node signal to a remote concentrator through a first internal interface. (4) at least one of the remote concentrators Receiving an end node signal; (5) integrating all the end node signals received at the remote concentrator into a distributor node signal; and (6) integrating the distributor node signal through a second internal interface. Communicating to a forwarding switch; (7) receiving at least one of said distributor node signals at said forwarding switch; and (8) separating all said exchanged signals from said distributor node signal; Transmitting the switching signal to an instance of the circuit-switched type communication device at another customer premises other than the customer premises; (9) separating all the packet signals from the distributor node signal; And the first customer Toward instance of another of said communication device of said packet transfer type in the customer premises other than the inner, methods bandwidth mobile on the public telecommunication network comprising the step of routing the packet signal. 13. The method of claim 12, wherein the customer signal is an instance of a switching signal, and wherein step (1) comprises receiving the customer signal into a conventional telephone system interface. 14. The customer signal is a member of a set consisting of a telephone device, a facsimile device, a modem device, and a special service signaling device, and the step (1) comprises the steps of: 13. The method of claim 12, including receiving during an interface. 15. The method of claim 12, wherein the customer signal is an instance of a packet signal, and wherein step (1) comprises receiving the customer signal over an Ethernet interface. 16. The customer signal is from a member of a set consisting of a computer, a computerized digital device, a digital network device, a digital video device, and a digital audio device, wherein the step (1) comprises: The method of claim 12, comprising receiving a customer signal into a digital network interface. 17. The termination node signal includes a circuit layer for the switched signal and a packet layer for the packet signal, wherein the circuit layer is a sub-layer when the access network is first provisioned. Dedicated to the number of sets of circuits, so that a similar said number of said switched signals can be accommodated, said packet layer being dynamically shared, whereby an amount ranging from nothing to a plurality 13. The method of claim 12, which can include a packet signal. 18. The method of claim 12, wherein step (3) comprises using a protocol on the first internal interface that is a member of a set consisting of POTS, T1, E1, DSx, and xDSL. 19. The method according to claim 19, wherein the step (6) comprises: POTS, T1, E1, DSx,
13. The method of claim 12, comprising using a protocol that is a member of a set consisting of SLC-96, GR-303, and SONET on the second internal interface. 20. A telecommunications company central office comprising: a central office switch connected to said instance of said circuit-switched type communication device at said another customer premises other than said first customer premises; Comprises a router connected to said instance of said communication device of said packet transfer type located in said another customer premises other than said first customer premises, said step (8) comprising: 13. The method of claim 12, comprising transmitting a switching signal, wherein said step (9) comprises routing said packet signal through said router. 21. The method of claim 20, wherein step (9) further comprises using an Ethernet protocol in routing the packet signal through the router. 22. At least one relay node located between said access concentrator and said remote concentrator for communicating said termination node signal over a long distance between a customer premises and a telecommunications company central office. 13. The method of claim 12, further comprising passing the end node signal through.