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(12) United States Patent (io) Patent No.: US 6,888,849 B2
Daniels (45) Date of Patent: May 3,2005
(54) METHOD FOR EVALUATING CAPACITY UTILIZATION OF A TERMINUS IN A COMMUNICATION SYSTEM
(75) Inventor: William Rudolph Daniels, Warrenville, IL (US)
(73) Assignee: Lucent Technologies Inc., Murray Hill, NJ (US)
( * ) Notice: Subject to any disclaimer, the term of this patent is extended or adjusted under 35 U.S.C. 154(b) by 868 days.
(21) Appl. No.: 09/882,968
(22) Filed: Jun. 15, 2001
(65) Prior Publication Data
US 2003/0012227 Al Jan. 16, 2003
(51) Int. C I. 1104.1 1 00
(52) U.S. CI 370/485; 370/252; 370/465;
(58) Field of Search 370/252, 465,
370/535, 541, 485, 463, 537, 538, 540, 543, 544, 545, 468; 375/222
(56) References Cited
U.S. PATENT DOCUMENTS
6,195,355 Bl * 2/2001 Demizu 370/397
A method for evaluating capacity utilization of a terminus in a communication system where the terminus has a maximum capacity and accommodates a plurality of communication lines in coupled relationship with the terminus, includes the steps of: (a) identifying the plurality of communication lines; each respective line has a respective line speed and a respective character-type that is one charactertype of a plurality of character-types extant in the communication system; (b) identifying the respective line speed and the respective character-type for each respective line; (c) determining type line speed contribution by respective lines having a particular the respective character-type; (d) summing the type line speed contribution by all the respective character-types to determine a total line speed contribution for all of the plurality of lines; and (e) comparing the total line speed contribution with the maximum capacity to effect the evaluating.
8 Claims, 2 Drawing Sheets
METHOD FOR EVALUATING CAPACITY
UTILIZATION OF A TERMINUS IN A
BACKGROUND OF THE INVENTION
The present invention is directed to communication systems, and especially to a method for evaluating capacity utilization of particular apparatuses in a telecommunication system. 10
With the introduction of high-speed, communication lines, such as ADSL (Asymmetric Digital Subscriber Line), users may transmit and receive information much more quickly than was possible using older technologies, such as conventional 56 Kbps (kilobits per second) modems. Typical data rates associated with newer high-speed technology lines are in the megabits per second range. In order to save costs, high speed lines are commonly multiplexed together into a larger transmission facility or large bandwidth "pipe" for transmission into a network by a communication switch, 20 such as an ATM (Asynchronous Transfer Mode) switch.
When information transferred via communication lines is data files, such as computer data files, there is no real-time aspect necessary for transmission of the data. That is, if the 2J data is delayed in transmission, such as when data bits are dropped and information needs to be sent again, a user is not aware of the delay that is necessarily incurred.
Nowadays more and more delay-sensitive information is being transferred over communication lines and delays 30 cannot be tolerated. Examples of such delay-sensitive information include voice information sent over a data network such as the Internet (i.e., voice over IP) and real time video transfer, such as video streaming. If a portion of the data associated with information transfer involving such appli- 35 cations is delayed, the aberration resulting in the received information is immediately noticeable by a party receiving the information.
There is a need for a method for use by a communication system designer to be able to ascertain how many high- 40 speed lines can be accommodated by a terminus in a communication system before the bandwidth capability of the terminus is exhausted. Specifically, by way of example and not by way of limitation, a communication system designer needs a method for determining how may ADSL 45 lines can be handled or accommodated by a multiplexer unit for provision to an ATM switch for transmission into a telecommunication network before the capacity or bandwidth of the multiplexer unit is surpassed.
SUMMARY OF THE INVENTION 50
A method for evaluating capacity utilization of a terminus in a communication system where the terminus has a maximum capacity and accommodates a plurality of communication lines in coupled relationship with the terminus, 55 includes the steps of: (a) identifying the plurality of communication lines; each respective communication line of the plurality of communication lines has a respective line speed and a respective character-type; the respective charactertype is one character-type of a plurality of character-types 60 extant in the communication system; (b) identifying the respective line speed and the respective character-type for each respective communication line; (c) determining type line speed contribution by respective communication lines having a particular the respective character-type; (d) sum- 65 ming the type line speed contribution by all the respective character-types to determine a total line speed contribution
for all of the plurality of communication lines; and (e) comparing the total line speed contribution with the maximum capacity to effect the evaluating.
In one embodiment of the invention, the method further includes an interim step following step (d) and preceding step (e): (d) (1) adjusting the total line speed contribution by a limiter factor to determine an adjusted total line speed contribution for all of the plurality of communication lines. The limiter factor establishes a limit regarding the number of the plurality of communication lines that operate simultaneously. This alternate embodiment of the invention alters step (e) to require comparing the adjusted total line speed contribution with the maximum capacity to effect the evaluating.
Both embodiments of the invention may be manifested in a terminus in a telecommunication system apparatus for selectively coupling respective telecommunication lines with at least one telecommunication switching apparatus.
It is, therefore, an object of the present invention to provide a method for evaluating capacity utilization of a terminus in a communication system before the bandwidth capability of the terminus is exhausted.
Further objects and features of the present invention will be apparent from the following specification and claims when considered in connection with the accompanying drawings, in which like elements are labeled using like reference numerals in the various figures, illustrating the preferred embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic block diagram of a portion of a telecommunication system with which the present invention may be advantageously employed.
FIG. 2 is a flow diagram illustrating the practice of the present invention.
DETAILED DESCRIPTION OF THE
The method of the present invention provides solutions to two dilemmas: (1) how many communication lines can be coupled with a communication terminus before the capacity or bandwidth of the terminus is exhausted, and (2) if the communication lines to be coupled with the terminus have different delay sensitivities, how do their differences impact the capacity of the terminus.
The second dilemma deals with the issue of sensitivity of transmitted data to delays. Certain types of data are sensitive to delays; they cannot be delayed without disruption resulting. Examples of such delay-sensitive information include voice over IP and video streaming. The second dilemma requires that the method must be capable of taking into account various classes of service that can be assigned to a communication line. For example, in the case of ADSL systems, several standards committees have developed a designation system for identifying ADSL lines based upon the tolerance of an ADSL line to tolerate delay in data transmission. ATM Forum UNI4.0 has published five levels of ADSL line classes based upon tolerance of an ADSL line's data transmission priority requirements. The levels are referred to as Quality of Service (QoS) levels. From highest level of service to lowest level of service:  CBR (Constant Bit Rate),  rt-VBR (real time-Variable Bit Rate),  nrt-VBR (non real time-Variable Bit Rate),  UBR (Unspecified Bit Rate) and  ABR (Available Bit Rate). Service Levels  and  are the levels associated with