Call admission control method and cell flow monitoring method in the same method

• US 4,984,264 A
• Filed: 02/20/1990
• Issued: 01/08/1991
• Est. Priority Date: 02/22/1989
• Status: Expired due to Term

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Katsube, Yasuhiro
• Primary Examiner(s): Schrefver, Stafford D.
• Application Number:
  US07/482,018
• Time in Patent Office: 322 Days
• Field of Search: 379/111, 379/133, 379/134, 379/188, 379/196, 379/197, 379/220, 379/243, 379/93, 379/94, 379/95, 370/54
• US Class Current: 379/197
• CPC Class Codes: H04L 12/5602 Bandwidth control in ATM Networks, e.g. leaky bucket
• CPC Class Codes: H04L 2012/5614 User Network Interface
• CPC Class Codes: H04L 2012/563 Signalling, e.g. protocols, reference model
• CPC Class Codes: H04L 2012/5632 Bandwidth allocation
• CPC Class Codes: H04L 2012/5636 Monitoring or policing, e.g. compliance with allocated rate, corrective actions

Abstract

In a network in which all information from terminals having various traffic characteristics is transmitted/switched by a fixed length block including a virtual channel id, a terminal requesting communication declares destination address information and traffic characteristics of the requested communication upon set-up to a network. The exchange in the network expresses traffic characteristics of an individual terminal and an offered load (estimated cell flow) in the network. The traffic characteristics of each terminal are expressed as a maximum cell flow generated from the terminal in time units Δ(i) (i=1, 2, . . . , n) having n predetermined lengths. The predicated offered load of the line supposing that a new request call is accepted is expressed as an estimated cell flow predicted to be transmitted to the line in the time unit Δt(i) by using traffic characteristic values of the calls currently transmitting on the line and a new request call. In a call admission control method, the estimated cell flow is compared with a maximum allowable cell flow obtained from a circuit capacity, thereby determining "accept" or "reject" of admission of the request call. In a cell flow monitoring method, a cell flow generated from a terminal in time units Δt(i) is counted in a plurality of time units Δt(i). If a cell flow in any one time unit Δt(i) exceeds a traffic characteristic value grasped beforehand by a network, "violation" is determined for the terminal and a regulation sequence is performed.

Claims

1. A call admission control method wherein, in a network in which all information generated from terminals having various traffic characteristics are transmitted/switched by a fixed length block called a "cell" having a cell header including a virtual channel id, a terminal requesting communication declares destination address information and traffic characteristics of requested communication to said network upon set-up request, and an exchange in said network performs call processing for a request call on the basis of the destination address information and traffic characteristics declared by said terminal and a current offered load in said network, comprising the steps of:

grasping a current offered load of a line accommodated by said exchange in said network as an estimated cell flow A(i) (i is a positive integer) to be transmitted to said line in time units Δ

t(i) (i is a positive integer of 1, 2, . . . , n) having a plurality of (n) predetermined lengths;

grasping traffic characteristics of each call as a maximum cell flow a(j,i) (j is an identification number of a terminal) generated from said terminal in the time units Δ

t(i) having the n lengths;

calculating a predicted offered load of said line predicted to be obtained when the new request call is accepted as an estimated cell flow A'"'"'(i) (i is a positive integer) predicted to be transmitted to said line in the time unit Δ

t(i) by using the cell flow A(i) (i is a positive integer) representing the current offered load of said line and the maximum cell flow a(k+1,i) representing the traffic characteristics of new request call;

comparing the estimated cell flow A'"'"'(i) with a transmittable maximum allowable cell flow A_max(i) of said line obtained from a circuit capacity;

accepting admission of the request call in accordance with the comparison result obtained in said comparison step; and

rejecting admission of the request call.

2. A method according to claim 1, wherein the estimated cell flow A(i) (i is a positive integer 1, 2, . . . , n) representing a current offered load of said line and the estimated cell flow A'"'"'(i) (i is a positive integer) representing a predicted offered load of said line predicted to be obtained when a new request call is accepted are expressed as follows by using traffic characteristics a(j,i) of all calls j (j is a positive integer 1, 2, . . . , k) currently transiting on said line, traffic characteristics a(k+1,i) of the request call k+1, a current coefficient α

(i) (0<

α

(i)≦

1), and coefficient α

_new (i) (0<

α

_new (i)≦

1) to be used when the new request call is accepted;

##EQU4##

3. A cell flow monitoring method for monitoring cell flows transmitted from terminals during communication by counting the cell flows in time units Δ

t(i) (i is a positive integer 1, 2, . . . , n) having a plurality of lengths, and if the cell flow within the time unit Δ

t(i) exceeds a traffic characteristic value a(j,i) of said terminals grasped beforehand by a network, for immediately determining "violation" and performing a regulation sequence.