Process for subchannel bandwidth allocation and extraction by an ISDN communications controller

• US 6,215,796 B1
• Filed: 03/12/1997
• Issued: 04/10/2001
• Est. Priority Date: 03/12/1996
• Status: Expired due to Term

• Current Assignee: RPX Clearinghouse LLC (RPX Corporation)
• Original Assignee: Nortel Networks Limited (Nortel Networks Corporation)
• Inventors: Smith, Jr., Robert Lynn
• Primary Examiner(s): Kizou, Hassan
• Assistant Examiner(s): SLAVITT, MITCHELL R
• Application Number:
  US08/820,335
• Time in Patent Office: 1,490 Days
• Field of Search: 370/410, 370/431, 370/437, 370/493, 370/465, 370/468, 370/432
• US Class Current: 370/493
• CPC Class Codes: H04Q 11/0457 Connection protocols
• CPC Class Codes: H04Q 2213/13034 A/D conversion, code compression/expansion
• CPC Class Codes: H04Q 2213/13093 Personal computer, PC
• CPC Class Codes: H04Q 2213/13106 Microprocessor, CPU
• CPC Class Codes: H04Q 2213/13176 Common channel signaling, CCS7
• CPC Class Codes: H04Q 2213/13204 Protocols
• CPC Class Codes: H04Q 2213/13209 ISDN
• CPC Class Codes: H04Q 2213/13292 Time division multiplexing, TDM
• CPC Class Codes: H04Q 2213/13298 Local loop systems, access network
• CPC Class Codes: H04Q 2213/13367 Hierarchical multiplexing, add-drop multiplexing
• CPC Class Codes: H04Q 2213/13389 LAN, internet

Abstract

A system includes a plurality of end-user devices coupled to a communications controller which is connected to an integrated services digital network (ISDN) line of a telecommunications network. The ISDN line has two bearer channels bandwidth and a data channel. A method of subchannel bandwidth allocation from the bearer channels is initiated by establishing, as demanded for a particular end-user device, a call connection though the telecommunications network between the communications controller and another network terminator. The controller inquires, over the data channel, whether the network terminator is a compatible communications controller. If a positive compatibility indication, the two controllers allocate to the particular end-user device a subchannel from the bandwidth of the two bearer channels, wherein the subchannel consists of bandwidth up to the full bandwidth if the particular end-user device is a data processing unit or bandwidth sufficient for a controller-encoded voice signal if the particular end-user device is a telephone. If the positive compatibility indication is not received, allocating by the communications controller to the particular end-user device one of the two bearer channels.

Claims

1. In a system having a plurality of end-user devices coupled to a communications controller which is connected to an integrated services digital network (ISDN) line of a telecommunications network, the ISDN line having two bearer channels of predetermined bandwidth and a data channel, a method of subchannel bandwidth allocation comprising:

establishing, as demanded for a particular end-user device, a call connection through the telecommunications network between the communications controller and another network terminator;

inquiring, over the data channel, whether the network terminator is a compatible communications controller, wherein the compatible communications controller has a plurality of end-user devices coupled thereto, and wherein the plurality of end-user devices includes a plurality of telephones;

responsive to receiving a positive compatibility indication, allocating by the two controllers to the particular end-user device a subchannel from the predetermined bandwidth of the two bearer channels, wherein the subchannel consists of bandwidth up to the predetermined bandwidth if the particular end-user device is a data processing unit or bandwidth sufficient for a controller-encoded voice signal if the particular end-user device is a telephone, and wherein the particular end user device is a data processing unit having been allocated the subchannel of bandwidth up to the predetermined bandwidth as a data subchannel;

responsive to receiving the positive compatibility indication, each of the two controllers informing the other, over the data subchannel, of identifiers and types of coupled devices;

responsive to not receiving the positive compatibility indication, allocating by the communications controller to the particular end-user device one of the two bearer channels;

transmitting, over the subchannel or one bearer channel, outgoing signals from and incoming signals to the particular end-user device;

dialing, at a first telephone of the telephones coupled to one of the two communications controllers, the identifier corresponding to a second telephone of the telephones coupled to the other controller; and

the one controller sending, on the data channel, a suballocation request for a voice subchannel to the other controller, wherein the suballocation request includes the identifier of the second telephone and specifies extraction of bandwidth from the data processing unit subchannel for the voice subchannel;

the other controller investigating state of the second telephone, which state is either idle, busy or non-working, and reporting the state to the one controller;

if the state is idle, the other controller instigating ringing at the second telephone and the one controller reflecting a ringing tone to the first telephone;

if the second telephone is answered, the other controller ceasing to ring and transmitting on the data channel an accession message, coincident with which the other controller extracting sufficient bandwidth from the data processing unit subchannel to form the specified voice subchannel;

after a specific period at close of the accession message, the other controller effecting the bandwidth changeover in its full channel transmission towards the one controller;

the one controller transmitting an acknowledgement message on the data channel; and

after the specific period at close of the acknowledgement message, the one controller effecting the bandwidth changeover in its transmissions towards the other controller;

whereby voice communication proceeds on the voice subchannel, using the controller-encoded voice signal, simultaneously with data transfer on the data processing unit subchannel.

2. A method as claimed in claim 1, comprising the steps of:

sending, responsive to either of the first or second telephones going on-hook, a deallocation message from the one controller to which that telephone is coupled to the other controller, wherein the deallocation message identifies the voice subchannel to be deallocated;

after the specific period at close of the deallocation message, the one controller restoring that amount of bandwidth to the data processing unit subchannel and effecting the bandwidth changeover in its full transmissions toward the other controller;

the other controller transmitting an acknowledgement message on the data channel to the one controller; and

after the specific period at close of the acknowledgement message, the other controller changing over to the larger data processing unit subchannel bandwidth.

3. A method as claimed in claim 2, wherein the specific period is a predetermined time interval following the close of any of the accession message, the deallocation message and the acknowledgement message.

4. A method as claimed in claim 2, wherein the specific period is immediately following the close of any of the accession message, the deallocation message and the acknowledgement message.

5. A controller for use with a basic rate integrated services digital network (ISDN) service, the basic rate ISDN service having a first bearer channel with a predetermined bandwidth, a second bearer channel, and a data channel, the controller comprising:

a partitioner, wherein the partitioner divides the first bearer channel into a first partition and a second partition, such that each of the first and second partitions have less than the predetermined bandwidth;

an allocation manager coupled to the partitioner, wherein the allocation manager assigns the first partition to a telephone connection for a telephone and assigns the second partition to a second connection, wherein the second connection does not connect the same two end devices, such that the first bearer chapel is shared by two different connections, and wherein the second connection also includes bandwidth simultaneously from the first and second bearer channels;

a framer coupled to the allocation manager, wherein the framer inserts information into a frame for sending the information over the first bearer channel in the partitioned bandwidth assigned to the telephone connection, and wherein the information originates at the telephone; and

a deframer coupled to the allocation manager, wherein the deframer extracts information from a frame which is received over the first bearer channel in the partitioned bandwidth assigned to the telephone connection, and wherein the information is intended for the telephone.

6. The controller of claim 5, further comprising an analog-to-digital converter coupled to the framer, wherein the analog-to-digital converter converts analog data into digital data using adaptive differential pulse code modulation (ADPCM).

7. The controller of claim 5, further comprising a digital-to-digital converter coupled to the framer, wherein the digital-to-digital converter converts digital data in pulse code modulation (PCM) format into adaptive differential pulse code modulation (ADPCM) format.

8. A method of sharing bandwidth in a single first bearer channel between two different connections, the first bearer channel having a predetermined bandwidth and being part of an integrated services digital network (ISDN) line, the ISDN line also having a second bearer channel, the method comprising:

partitioning the first bearer channel into a first partition and a second partition, such that each of the first and second partitions have less than the predetermined bandwidth;

assigning the first partition to a telephone connection for a telephone;

assigning the second partition to a second connection, wherein the second connection does not connect the same two end devices as the telephone connection, and wherein the second connection also includes bandwidth simultaneously from the first and second bearer channels;

packetizing information to be sent over the first bearer channel in the partitioned bandwidth assigned to the telephone connection, wherein the information originates at the telephone; and

depacketizing information received over the first bearer channel in the partitioned bandwidth assigned to the telephone connection, wherein the information is intended for the telephone.

9. A controller for use with an integrated services digital network (ISDN) line, the ISDN line having a first bearer channel with a predetermined bandwidth, a second bearer channel, and a data channel, the controller comprising:

an ISDN interface;

a bandwidth controller coupled to the ISDN interface, wherein the bandwidth controller allocates available bandwidth from the predetermined bandwidth of the first bearer channel, and wherein the bandwidth controller can allocate less than the entire predetermined bandwidth to a connection thus allowing the first bearer channel to be shared by a telephone connection and another connection, wherein the another connection does not connect the same two end devices as the telephone connection does, and wherein the another connection also includes bandwidth simultaneously from the first and second bearer channels; and

a coder/decoder coupled to the bandwidth controller, wherein the coder/decoder encodes information for transmitting over the first bearer channel in the bandwidth allocated to the telephone connection, and wherein the coder/decoder decodes information received over the first bearer channel in the bandwidth allocated to the telephone connection.

10. The controller of claim 9, wherein the bandwidth controller can deallocate and allocate individual connections without affecting another existing connection which is sharing the first bearer channel.

11. The controller of claim 9, wherein two telephone connections share the first bearer channel.

12. The controller of claim 9, wherein two analog telephone connections share the first bearer channel.

13. The controller of claim 9, wherein the coder/decoder uses adaptive differential pulse code modulation (ADPCM) to encode analog telephone signals.

14. The controller of claim 9, wherein the coder/decoder uses adaptive differential pulse code modulation (ADPCM) to encode digital pulse code modulation (PCM) signals.

15. The controller of claim 9, further comprising a plain ordinary telephony service (POTS) interface coupled to the coder/decoder.

16. A method of sharing bandwidth in a single first bearer channel between two different connections, the first bearer channel having a predetermined bandwidth and being part of an integrated services digital network (ISDN) line, the ISDN line also having a second bearer channel, the method comprising:

allocating bandwidth from the first bearer channel to a first connection which is a telephone connection and to a second connection, wherein the two connections do not connect the same two end devices, and wherein the second connection also includes bandwidth simultaneously from the first and second bearer channels;

encoding information for transmission over the first bearer channel in the bandwidth allocated to the telephone connection;

interfacing to the ISDN line; and

decoding information received over the first bearer channel in the bandwidth allocated to the telephone connection.