Method and apparatus for priority control of incoming calls at ISDN terminals

• US 4,958,153 A
• Filed: 04/06/1988
• Issued: 09/18/1990
• Est. Priority Date: 04/08/1987
• Status: Expired due to Term

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Murata, Hatsuho, Ikeda, Hiroshi
• Primary Examiner(s): Yusko, Donald J.
• Assistant Examiner(s): Holloway, III, Edwin C.
• Application Number:
  US07/178,131
• Time in Patent Office: 895 Days
• Field of Search: 340/825.5, 340/825.51, 370/58, 370/60, 370/85, 370/94, 370/95, 370/110.1, 370/58.1, 370/85.6, 370/94.1, 370/95.1
• US Class Current: 370/462
• CPC Class Codes: H04M 1/253 Telephone sets using digital voice transmission
• CPC Class Codes: H04M 1/715 using two or more extensions per line cordless telephones H04M1/725
• CPC Class Codes: H04Q 11/0471 Terminal access circuits
• CPC Class Codes: H04Q 2213/07 Call distribution; Call detection; Call signalling by common apparatus
• CPC Class Codes: H04Q 2213/31 Delay devices; Circuits, e.g. shift memories

Abstract

The invention relates to method and apparatus by which the order in which ISDN terminals answer incoming calls can be easily established and changed by the ISDN user. The order is established by assigning a waiting time to each terminal, this waiting time being determined, e.g., by the subscriber number of an incoming caller or the type of call. A terminal only signals its eligibility to accept an incoming call after the waiting time has elapsed and its compatibility with the call has been established.

Claims

1. A method of controlling a priority order for an incoming call of an integrated service digital network (ISDN) to a plurality of ISDN terminals connected to an ISDN user network interface, said terminals having a common subscriber number telecommunication service attribute information and no subaddress, said network including a network termination which supplies a SETUP message containing a calling party number and a telecommunication service attribute information, the method comprising the steps of:

(a) providing in each terminal a timer and starting the timer when the SETUP message of an incoming call of the ISDN is received in a terminal;

(b) checking an ISDN compatibility to determine whether a terminal responds to the SETUP message by comparing the telecommunication service attribute information contained in the received SETUP message with the telecommunication service attribute information given to the terminal;

(c) providing in each terminal a memory storing at least one of waiting time set values for establishing a desired priority order concerning the type of the telecommunication service attribute information;

(d) determining whether the memory in said terminal stores the telecommunication service attribute information contained in the received SETUP message;

(e) where the telecommunication service attribute information is stored in said memory, outputting a setting signal for one of the waiting time set values, which corresponds to the telecommunication service attribute information;

(f) comparing a count of said timer with said waiting time set value and outputting a count-up signal when a timing operation of the timer has continued for at least said waiting time set value; and

(g) upon detection of said count-up signal, responding to the network with an ISDN CONNECT message which indicates that the terminal is eligible to accept said incoming call, whereby a priority order for responding to the incoming call of the ISDN in the plurality of ISDN terminals is variable according to a telecommunication service attribute of the incoming call of the ISDN.

2. A method of controlling a priority order for an incoming call of an integrated service digital network (ISDN) to a plurality of ISDN terminals connected to an ISDN user network interface, said terminals having a common subscriber number telecommunication service attribute information and no subaddress, said network including a network termination which supplies a SETUP message containing a predetermined calling party number and telecommunication service attribute information said method comprising the steps of:

(a) providing a timer in each terminal and starting a timer when the SETUP message of an incoming call of the ISDN is received in a terminal;

(b) checking an ISDN compatibility to determine whether a terminal responds to the SETUP message by comparing the telecommunication service attribute information contained in the received SETUP message with the telecommunication service attribute information given to the terminal;

(c) providing in each terminal a memory storing a waiting time set value for establishing a desired priority order concerning a predetermined calling party number;

(d) determining whether the memory in the terminal stores the calling party number contained in the received SETUP message;

(e) where the calling party number is stored in said memory, outputting a setting signal for the waiting time set value which corresponds to the calling party number;

(f) comparing a count of said timer with said waiting time set value and outputting a count-up signal when a timing operation of the timer has continued for at least said waiting time set value; and

(g) upon detection of said count-up signal, responding to the network with an ISDN CONNECT message which indicates that the terminal is eligible to accept said incoming call, whereby a priority order for responding to the ISDN incoming call in the plurality of ISDN terminals is variable according to the predetermined calling party number.

3. A circuit for controlling a priority order in which a terminal connected to an interface of an integrated service digital network (ISDN) answers a SETUP message indicating an incoming call of an ISDN, the circuit comprising:

priority order setting means for establishing a desired priority order, the priority order setting means including a memory storing at least one of waiting time set values, each of the waiting time set values corresponding to a type of a telecommunication service attribute which is given to the terminal of the ISDN;

timer means for timing an interval which begins when the SETUP message arrives at the network and which ends at one of the waiting time set values corresponding to the type of the telecommunication service attribute of an arrived SETUP message; and

signalling processing means for sending an ISDN CONNECT message when said timer means has timed said interval and when the terminal has capabilities to accept the SETUP message.

4. The circuit of claim 3, wherein said priority order setting means is constructed so as to further store a waiting time set value corresponding to a calling party number to determine a priority order for responding to an incoming call of the ISDN from a predetermined calling party number.