Multiplex communications – Pathfinding or routing – Combined circuit switching and packet switching
Reexamination Certificate
1997-12-17
2001-03-13
Jung, Min (Department: 2663)
Multiplex communications
Pathfinding or routing
Combined circuit switching and packet switching
C370S466000
Reexamination Certificate
active
06201806
ABSTRACT:
BACKGROUND
1. Technical Field
The present invention relates generally to the communication systems; and more particularly to a wired communication system facilitating both voice and data communications, the wired communication system employing an (asynchronous transfer mode) ATM network for a portion of its switching path.
2. Related Art
Wired communication systems that facilitate voice communications are well known in the art. Further, enterprise based wired communication systems are also well known in the art. In such enterprise communication systems, an organization purchases or rents its own switching equipment to facilitate voice communications within the organization. In such systems, the user typically purchases a local switch referred to as a private branch exchange (PBX) to provide local switching for end point devices, such as telephones, as well as to provide an interface to the Public Switched Telephone Network (PSTN).
In its operation, the PBX sets up and routes voice communications between end point devices that are located within the organization. Further, the PBX also sets up communications between the end point devices it serves and distant endpoint device connected to the PBX by an enterprise network or the PSTN. In some enterprise communication systems, peripheral equipment is also installed to service endpoint devices which provide interfaces to a number of endpoint devices. For example, a university or large corporation may have a centrally located PBX and have peripheral equipment located at each physical location where end point devices reside.
The peripheral equipment is linked to the PBX via a dedicated time switched line such as a T1 line. In such systems, the PBX typically sets up all calls between the end point devices. Further, in some systems, the PBX routes all calls within the enterprise communication system. Thus, in some systems, the peripheral equipment acts merely to package calls onto and from the lines linking the PBX to the peripheral equipment. Such packaging of calls, which may be coded in a pulse code modulated (PCM) format, is typically accomplished via a time division multiplexing (TDM) scheme.
As organizations expand at their physical locations, the number of endpoint devices increases, and additional peripheral equipment must be installed to service the additional end point devices. Additional dedicated lines must also be installed from the new peripheral equipment to the PBX. The cost of these lines is often substantial since the lines must typically be leased from a local phone company or be completed with dedicated hardware connections that are expensive to install.
In many organizations, local area networks, wide area networks, and global area networks service data transfer among computer systems operating within the organization. An example of such a network is an asynchronous transfer mode (ATM) network. An ATM network is packet based and is typically a dedicated network having its own set of switches, routers, repeaters and other equipment which is interconnected by dedicated communication lines. Network computers connect either directly to the ATM network or via a bridge between another type of computer network, e.g. an Ethernet network, and the ATM network. Operation of the ATM network is incompatible with the time switched voice communication network since the ATM network is a packet based network and the voice communications network operates in a time switched fashion. Thus, when an organization expands, the ATM network must be expanded in addition to expansion of the voice network to facilitate additional computer resources.
Thus, there is a need in the art for a system that combines resources required for voice communications and data transfer so that required expansions for the transmission of data between computers and required expansions for voice communications in an enterprise type system may combine resources.
SUMMARY OF THE INVENTION
In order to overcome the above described shortcomings of the prior devices, among other limitations, a communication system constructed according to the present invention facilitates both voice and data communications between endpoint devices and includes a switch and at least one peripheral device. The switch includes a switch interface while each peripheral devices includes a peripheral device interface. In combination, the switch and the peripheral device route communications through an asynchronous transfer mode (ATM) network. However, the switch interface and the peripheral device interface operate so that the communications, from the viewpoint of the switch and the peripheral device, are seamlessly transferred in a native communication protocol. In a described embodiment, the native communication protocol is a time switched protocol.
In the construction of the communication system, each peripheral device couples to a respective plurality of endpoint devices. Each peripheral device then connects to the ATM network via a respective peripheral device interface. The switch couples to the ATM network via the switch interface. In its operation, the switch sets up calls from one endpoint device to another endpoint device. In setting up the calls, the switch manages the peripheral devices and determines routing via the ATM network for the call. Such call setup functions may be performed either via a connection to the peripheral device over the ATM network or may be performed on a dedicated control line.
The switch also interfaces to the public switched telephone network and routes communications from one endpoint device to another endpoint device via both the ATM network and the public switched telephone network. At least one of the endpoint devices provides both voice and data communications. In such case, the voice communications may be routed by the switch while the data communications may be routed by the respective peripheral device via the ATM network if the data communications have a differing destination.
Both the switch interface and each peripheral device interface include an input buffer, an output buffer and control circuitry. The control circuitry extracts communication data and link information from ATM cells and, based upon the link information, writes the communication data to the input buffer. The control circuitry also reads communication data from the output buffer, generates link information and builds ATM cells that include the communication data and the generated link information.
In setting up the call, the switch receives destination digits from the first peripheral device and, based upon the destination digits, determines an ATM path for routing of the communication and directs the destination device to receive the communication via the ATM path. Dedicated bandwidth may be established within the ATM network for calls or may be allocated as required. In a described construction, the native communication protocol is time switched and provides endpoint device state information to the switch. Further, the native communication protocol facilitates enhanced services. A method of operation according to the present invention facilitates both voice and data communications. According to the method, a switch sets up and facilitates calls between endpoint devices. In setting up the calls, the switch determines a route for the call to travel, such route including passage on the ATM network between the switch and a peripheral device. Thus, the call is routed through the ATM network from the coupled endpoint device to a destination endpoint device, the call appearing to progress according to the native communication protocol to the switch and the peripheral device.
Moreover, other aspects of the present invention will become apparent with further reference to the drawings and specification which follow.
REFERENCES:
patent: 5737333 (1998-04-01), Civanlar et al.
patent: 5742596 (1998-04-01), Baratz et al.
patent: 5784371 (1998-07-01), Iwai
patent: 5926479 (1999-07-01), Baran
patent: 5953331 (1999-09-01), Duncan et al.
patent: 5991639 (1999-11-01), Rautiola et al.
patent: 60
Garlick Bruce E.
Harrison James A.
Jung Min
Mothew Neil
Nortel Networks LTD
LandOfFree
Communication system and method of operation for interfacing... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Communication system and method of operation for interfacing..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Communication system and method of operation for interfacing... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2549406