Method and apparatus for minimizing cellular network costs when upgrading the electronics in an existing cellular system

• US 6,016,429 A
• Filed: 05/28/1997
• Issued: 01/18/2000
• Est. Priority Date: 05/28/1997
• Status: Expired due to Fees

• Current Assignee: Nortel Networks Limited (Nortel Networks Corporation)
• Original Assignee: Northern Telecom Limited (Nortel Networks Corporation)
• Inventors: Khafizov, Farid, Anandampillai, Damodar, Jain, Nikhil
• Primary Examiner(s): Chin, Wellington
• Assistant Examiner(s): Sobutka, Philip
• Application Number:
  US08/864,259
• Time in Patent Office: 965 Days
• Field of Search: 455/446, 455/447, 455/448, 455/449, 455/445, 455/422, 455/560, 455/561
• US Class Current: 455/446
• CPC Class Codes: H04W 24/02 Arrangements for optimising operational condition

Abstract

An algorithm or method for ascertaining minimum cellular system costs is presented based on the recognition that the proper distribution of wired network blocking probability is the prime consideration in optimizing system design for minimum cost. System costs are calculated for each of a series of VCs maximum blocking probabilities "b" wherein the total wired network blocking probability is "BP" and the channel element blocking probability for each of those calculations must not exceed "(BP-b))/(1-b)". An examination of the resulting calculations will then reveal the appropriate distribution of resources to minimize costs.

Claims

1. The method of utilizing a minimum cost distribution of wired network components in a cellular communication system having vocoders in a BSC (base station controller) and having a plurality of BTSs (base stations) each having channel elements, where the BSCs and the BTSs comprise a portion of a wired network, comprising, the steps of:

a) computing the number of vocoders N_-- VC required such that a first value of vocoder blocking probability "b" is not exceeded which value b is less than 1/2 the value of total allowed wired network blocking probability "BP";

b) computing the total number of channel cards N_-- CC required in all the BTSs such that a first value of vocoder blocking probability "(BP-b)/(1-b)" is not exceeded for any of the BTSs;

c) calculating wired system costs based on the numbers last obtained for N_--VC and N_--CC;

d) repeating, ((BP-b)/(1-b))/b additional times, steps a), b) and c) whereby a lowest wired system cost may be ascertained from examining the results of step c) and whereby ((BP-b)/(1-b))/b, if not a whole number is rounded up to a whole number; and

e) providing the vocoders and channel cards for the cellular communications system based on one or more of steps a) and b) above.

8. The method of claim 1, wherein the step of providing comprises operating, configuring or building, some or all of the cellular communication system.

2. The method of utilizing a cost effective cellular network communications system having a total network blocking value of "BP", a fixed number of base stations and a predetermined Erlang value of average busy hour traffic comprising, the steps of:

a) establishing a series of positive values from "b₁ " to "b_i " between 0 and BP where the number of values "i" in the series is greater than 2;

b) calculating the cost of a system where the blocking probability of the vocoder portion of the system is no greater than "b₁ " and the blocking probability of the channel element portion of the system is no greater than (BP-b₁))/(1-b₁);

c) repeating step b) for each of the established series of positive values from 2 to "i";

e) providing the vocoder portions and channel card portions for the cellular communications system based on step b) above.

3. The method of claim 2 comprising, in addition, the step of constructing a network communications system after examining a series of calculated costs as obtained in steps b) and c).

4. The method of claim 2 comprising, in addition, the step of examining a series of calculated costs as obtained in steps b) and c) to ascertain the distribution of components providing the most cost effective system.

9. The method of claim 2, wherein the step of providing comprises operating, configuring or building, some or all of the cellular communication system.

5. A cellular network communications system having a total wired network blocking value of "BP", a fixed number of base stations and a predetermined Erlang value of average busy hour traffic T where the number of channel elements in a base station and the number of VCs (vocoders) in a base station controller are the primary contributors in causing network blocking comprising, in combination:

a base station controller having a number of VCs such that the blocking probability is no greater than b for traffic T; and

a plurality of base stations each having a number of channel elements such that the blocking probability for each base station is no greater than BP-b for traffic T wherein,

the number of VCs in the base station controller and number of channel elements in each base station is selected by calculating the system cost for each of a plurality of blocking probability values of one of the VCs and channel elements and the numbers resulting in minimum system cost are utilized.

6. The method of utilizing a cost effective cellular communication system having VCs (vocoders) in a BSC (base station controller) and having a plurality of base stations each having channel elements, where the BSC and the base stations comprise a wired network, the total blocking probability of the wired network portion of the system is no greater than BP for average busy hour traffic T, comprising, the steps of:

a) calculating the number of VCs required to prevent the VC blocking probability "b" from exceeding the value b_i for a plurality of values i;

b) calculating the number of channel elements required in each base station to prevent the channel element blocking probability "(BP-b)/(1-b)" from exceeding "(BP-b_i)/(1-b_i)" for each of said plurality of values "b_i "; and

c) calculating the total system cost when using the numbers of elements obtained above for each of the plurality of values "b_i "; and

d) providing the vocoders and channel elements for the cellular communications system based on step b) above.

10. The method of claim 6, wherein the step of providing comprises operating, configuring or building, some or all of the cellular communication system.

7. System for providing a cost effective cellular network communications system having a total network blocking value of "BP", a fixed number of base stations and a predetermined Erlang value of average busy hour traffic comprising, in combination:

a) means for establishing a series of positive values from "b₁ ", to "b_i " strictly between 0 and BP where the number of values "i" in the series is greater than 2;

b) means for calculating the cost of a system where the blocking probability of the vocoder portion of the system is no greater than "b₁ " and the blocking probability of the channel element portion of the system is no greater than (BP-b₁))/(1-b₁);

c) means for repeating step b) for each of the established series of positive values from 2 to "i";

d) means for selecting a value of "b" representing a minimum system cost;

e) a vocoder portion and channel card portion for the cellular communications system configured based on step b) above.