Base station transceiver subsystem carrier selection at a CDMA cell site

• US 6,330,232 B1
• Filed: 07/16/1997
• Issued: 12/11/2001
• Est. Priority Date: 07/16/1997
• Status: Expired due to Term

• Current Assignee: Ericsson AB (Telefonaktiebolaget LM Ericsson)
• Original Assignee: Nortel Networks Limited (Nortel Networks Corporation)
• Inventors: Fapojuwo, Abraham Olatunji
• Primary Examiner(s): Ton, Dang
• Assistant Examiner(s): NGUYEN, TOAN D
• Application Number:
  US08/895,200
• Time in Patent Office: 1,609 Days
• Field of Search: 370/328, 370/329, 370/335, 370/342, 370/441, 370/462, 370/468, 370/348, 370/443, 455/524, 455/525, 455/522, 455/450, 455/452
• US Class Current: 370/342
• CPC Class Codes: H04W 28/0861 between base stations
• CPC Class Codes: H04W 72/00 Local resource management

Abstract

An apparatus for selecting a CDMA base station transceiver subsystem from a plurality of base station transceiver subsystems to handle a call in a cellular telephone network, in response to a call request. The apparatus includes a receiver for receiving a representation of available call capacity from each of the base stations, a processor for examining the representation of available call capacity from each of the base stations to determine which of the base stations has the greatest available call capacity and a transmitter for transmitting to the base station with the greatest call capacity, an enabling message enabling the base station to handle the call.

Claims

1. A method of estimating available call capacity at a Code Division Multiple Access (CDMA) base station transceiver subsystem, the method comprising the steps of:

a) determining available power to support additional calls by said base station transceiver subsystem;

b) determining the average power used per channel;

c) dividing a value representing the available power to support additional calls by a value representing the average power used per channel to determine the call capacity available;

d) measuring the power consumed by each channel in use;

e) cumulatively adding values representing the power consumed by each channel in use to obtain a total forward transmit power usage value;

f) determining the number of channels in use;

g) dividing a value representing the total power usage by the number of channels in use to obtain the average power used per channel; and

h) subtracting a value representing the total forward transmit power usage, a value representing a LoCall Blocking Threshold power and a value representing a pilot power of said base station transceiver subsystem from a value representing a maximum allowable total transmit power, to obtain a value representing the available power to support additional calls.

2. An apparatus for estimating available call capacity at a Code Division Multiple Access (CDMA) base station transceiver subsystem having a plurality of traffic channel elements, a known maximum allowable total transmit power, a known pilot power and a known LoCall Blocking Threshold power, the apparatus comprising:

a) a channel counter for counting the number of channels in use at any given time;

b) a plurality of sensors for determining the power consumed by each channel in use;

c) a processor for;

i) subtracting a value representing the power consumed by all channels in use, a value representing the known LoCall Blocking Threshold power and a value representing the pilot power from a value representing the known maximum allowable total transmit power to determine the total transmit power available to support additional calls;

ii) dividing a value representing the power consumed by all channels in use by the number of channels in use to determine an average power used per channel; and

iii) dividing a value representing the total transmit power available to support additional calls by a value representing the average power used per channel to determine an available call capacity of the CDMA base station transceiver subsystem; and

d) a transmitter for transmitting to a selector bank subsystem an available capacity response message including a representation of said available call capacity.

3. An apparatus as claimed in claim 2 wherein said processor is operable to cumulatively add values representing the power consumed by each channel in use to obtain a total forward transmit power usage value.

4. A method of selecting a base station transceiver subsystem from a plurality of base station transceiver subsystems in a cellular telephone network, the method comprising the steps of:

a) transmitting an available capacity request message from a selector bank subsystem to said base station transceiver subsystems;

b) receiving said available capacity request message at said base station transceiver subsystems;

c) at each base station transceiver subsystem;

i) determining the available power to support additional calls by the base station transceiver subsystem;

ii) determining the average power used per channel;

iii) dividing a value representing the available power to support additional calls, by a value representing the average power used per channel to determine a call capacity available; and

iv) transmitting an available capacity response message to the selector bank subsystem, the available capacity response message including a representation of the call capacity available;

d) receiving at said selector bank subsystem said available capacity response messages from each base station transceiver subsystem;

e) determining at said selector bank subsystem which of said base station transceiver subsystems has the greatest call capacity available; and

f) transmitting an enabling message to a base station transceiver subsystem having the greatest call capacity available.

5. A method as claimed in claim 4 further including the step of measuring the power consumed by each channel in use.

6. A method as claimed in claim 5 further including the step of cumulatively adding values representing the power consumed by each channel in use to obtain a total forward transmit power usage value.

7. A method as claimed in claim 6 further including the step of determining the number of channels in use.

8. A method as claimed in claim 7 further including the step of dividing the total forward transmit power usage value by the number of channels in use to obtain said average power used per channel.

9. A method as claimed in claim 8 further including the step of subtracting the total forward transmit power usage value, a value representing a LoCall Blocking Threshold power and a value representing a pilot power from a value representing the maximum allowable total transmit power to determine the available power to support additional calls.

10. A cellular telephone apparatus for conducting a cellular telephone call in response to a call request, the apparatus comprising:

a) a selector bank subsystem;

b) a plurality of base station transceiver subsystems in communication with said selector bank subsystem and operable to handle cellular telephone calls;

c) a selector bank subsystem transmitter at said selector bank subsystem for transmitting an available capacity request message to each of said base station transceiver subsystems, in response to said call request;

d) a base station receiver at each base station transceiver subsystem for receiving said available capacity request message;

e) a base station processor at each base station transceiver subsystem for;

i) determining the available power to support additional calls at the base station;

ii) determining the average power used per channel;

iii) dividing a value representing the available power to support additional calls by a value representing the average power used per channel to determine the call capacity available; and

f) a base station transmitter at each of said base stations for transmitting to said selector bank subsystem an available capacity response message including a representation of said call capacity available;

g) a selector bank subsystem receiver at said selector bank subsystem for receiving said available capacity response message from said base stations; and

h) a selector bank subsystem processor at said selector bank subsystem for;

i) reading said available capacity response messages to determine which of said base stations has the greatest available call capacity; and

ii) for directing said selector bank subsystem transmitter to transmit an enabling message to said base station having the greatest available call capacity, such that said base station transceiver subsystem having the greatest available call capacity receives said enabling message and is rendered operative to handle said cellular telephone call.

11. An apparatus as claimed in claim 10 wherein each of said base station transceiver subsystems includes:

a) a channel counter for counting the number of channels in use at any given time;

b) a plurality of sensors for determining the power consumed by each channel in use; and

c) a processor for;

i) subtracting a value representing the power consumed by all channels in use, a value representing said known LoCall Blocking Threshold power and a value representing a pilot power, from a value representing said known maximum allowable total transmit power to support additional calls;

ii) dividing a value representing the power consumed by all channels in use by the number of channels in use to determine an average power used per channel; and

iii) dividing a value representing the available power to support additional calls by a value representing the average power used per channel to determine the call capacity available.

12. An apparatus as claimed in claim 11 wherein said sensor is operable to measure the power consumed by each channel in use.

13. An apparatus as claimed in claim 12 wherein said processor is operable to cumulatively add values representing the power consumed by each channel in use to obtain a total power usage value.