Method and apparatus for controlling calls in a code division multiple access system

• US 5,666,356 A
• Filed: 10/04/1995
• Issued: 09/09/1997
• Est. Priority Date: 10/04/1995
• Status: Expired due to Term

• Current Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Stolyar, Aleksandr, Fleming, Philip Joseph
• Primary Examiner(s): Olms, Douglas W.
• Assistant Examiner(s): Jung, Min
• Application Number:
  US08/539,032
• Time in Patent Office: 706 Days
• Field of Search: 370/18, 370/95.1, 370/328, 370/331, 370/332, 370/461, 370/462, 370/230, 375/205, 375/206, 455/33.1, 455/54.1, 455/54.2, 455/56.1, 455/67.1, 455/226.1
• US Class Current: 370/328
• CPC Class Codes: H04B 10/291 in which processing or amplification is carried out without conversion of the main signal from optical form
• CPC Class Codes: H04B 10/2912 characterised by the medium used for amplification or processing
• CPC Class Codes: H04W 36/18 for allowing seamless reselection, e.g. soft reselection
• CPC Class Codes: H04W 48/06 based on traffic conditions

Abstract

A method and apparatus for blocking a call attempt in a CDMA system. The method includes the steps of receiving a call attempt request to be placed over a target cell of the CDMA system (202), calculating an effective load for the cell (204), comparing the effective load to a threshold (206), and denying the call attempt request by sending a denial message if the effective load exceeds the threshold (212). The apparatus includes a base station (101) and a base station controller (200) coupled to the base station (101). The base station (101) includes a plurality of transceivers (120) providing a radio communication channel and defining a target cell (130). The base station controller (200) receives a call attempt request to be placed over one of the transceivers (120) of the base station (101). The base station controller (200) calculates an effective load for the base station (101), compares the effective load to a threshold, and denies the call attempt request by sending a denial message if the effective load exceeds the threshold.

Claims

1. A method of controlling a call in a code division multiple access, CDMA, system comprising the steps of:

receiving a call attempt request to be placed over a target cell of the CDMA system;

calculating an effective load based on a measurement indicative of non-target cell interference or a number of calls in soft handoff with the target cell for the target cell;

comparing the effective load to a threshold; and

denying the call attempt request by sending a denial message if the effective load exceeds the threshold.

2. A method of selecting a carrier from a group of carriers supported by a target cell of a code division multiple access, CDMA, system comprising the steps of:

calculating a first effective load based on a measurement indicative of non-target cell interference or a member of calls in soft handoff with the target cell for a first carrier of the group of carriers;

calculating a second effective load based on a measurement indicative of non-target cell interference or a number of calls in soft handoff with the target cell for a second carrier of the group of carriers;

comparing the first effective load to the second effective load; and

selecting one of the first and second carriers in response to the comparison.

3. An apparatus for selectively blocking a call attempt in a code division multiple access, CDMA, system base station comprising:

a base station including a plurality of transceivers providing a radio communication channel and defining a target cell;

a base station controller coupled to the base station;

said base station controller receiving a call attempt request to be placed over one of the transceivers of the base station;

said base station controller calculating an effective load based on a measurement indicative of non-target cell interference or a number of calls in soft handoff with the target cell, comparing the effective load to a threshold, and denying the call attempt request by sending a denial message if the effective load exceeds the threshold.

4. The apparatus of claim 3, wherein the non-target cell interference is estimated based on an inverse of a propagation law exponent.

5. A code division multiple access, CDMA, system comprising:

a base station including a plurality of transceivers providing a radio communication channel and defining a target cell;

a communication unit located within the target cell;

a base station controller coupled to the base station;

said base station controller receiving a call attempt request from the communication unit over the radio communication channel;

said base station controller calculating an effective load based on a measurement indicative of non-target cell interference or a number of calls in soft handoff with the target cell, comparing the effective load to a threshold, and denying the call attempt request by sending a denial message to the communication unit if the effective load exceeds the threshold.

6. An apparatus for selecting a carrier from a group of carriers supported by a target cell of a code division multiple access, CDMA, system comprising:

means for calculating a first effective load based on a measurement indicative of non-target cell interference or a number of calls in soft handoff with the target cell for a first carrier of the group of carriers;

means for calculating a second effective load based on a measurement indicative of non-target cell interference or a number of calls in soft handoff with the target cell for a second carrier of the group of carriers;

means for comparing the first effective load to the second effective load; and

means for selecting one of the first and second carriers in response to the comparison.

7. The apparatus of claim 6, wherein the CDMA system comprises one of a personal communication system and a wireless local loop system.