Method of deploying a fixed wireless access communications network such that a specified level of link performance is maintained

• US 7,142,863 B1
• Filed: 02/25/2000
• Issued: 11/28/2006
• Est. Priority Date: 02/25/2000
• Status: Expired due to Fees

• Current Assignee: RPX Clearinghouse LLC (RPX Corporation)
• Original Assignee: Nortel Networks Limited (Nortel Networks Corporation)
• Inventors: Robson, Julius, Smith, Martin
• Primary Examiner(s): NGUYEN, THUAN T
• Application Number:
  US09/512,910
• Time in Patent Office: 2,468 Days
• Field of Search: 455/446, 455/447, 455/448, 455/449, 455/452.1, 455/452.2, 455/453, 455/454, 455/450, 455/456.1, 455/456.2, 455/456.5, 455/456.6, 455/435.2, 455/439, 455/422.1, 455/513
• US Class Current: 455/446
• CPC Class Codes: H04W 16/18 Network planning tools
• CPC Class Codes: H04W 84/14 WLL [Wireless Local Loop]; RLL [Radio Local Loop]

Abstract

Current deployment methods for fixed wireless access communications networks typically give rise to a trade off between link performance and capacity. It is difficult to maintain specified levels of link performance while maximizing capacity. When a request to change a fixed wireless access network is received, for example, by adding a subscriber, moving a subscriber or adding a sector to a base station, the link performance at each communications link is determined. For example, by measuring the link performance at each link or by predicting or estimating these link performance levels. If the proposed change to the network does not compromise link performance, that is, the predicted or actual link performance levels are greater than a specified level, proposed change is implemented. Otherwise the now subscriber is placed on hold, pending change to the network such as addition of a new base station or sector. Estimates of the link budgets for each communications link are calculated for “worst case” scenario situations. This may be done using known deployment tools. The method is used in conjunction with fixed frequency planning or without fixed frequency planning. In the absence of fixed frequency planning, deployment of the communications network is eased.

Claims

1. A method of deploying a fixed wireless access communications network such that a specified level of link performance is maintained, said network comprising a plurality of fixed base stations and a plurality of fixed subscriber stations, each subscriber station being arranged to communicate with one of the base stations via a communications link and each of the communications links being associated with one of a plurality of communications channels, said method comprising the steps of:

—

(i) receiving a request including a proposed change comprising the addition of an additional subscriber station to the communications network after the fixed wireless access communications network has been deployed;

(ii) selecting a chosen base station with which the additional subscriber station is to communicate if the proposed change is effected;

(iii) selecting a channel for communication between the additional subscriber station and the chosen base station on the basis of a fixed frequency plan;

(iv) determining a level of link performance provided by each of the communications links taking into account the proposed change; and

(v) effecting the proposed change if each of said determined levels of link performance are greater than the specified level of link performance.

2. A method as claimed in claim 1 wherein said step (iv) of determining comprises calculating a predicted level of link performance on the basis of location information regarding each base station, and each subscriber station and information about the communications links between each subscriber station and its associated base station.

3. A method as claimed in claim 2 wherein said information about the communications links comprises information about a fixed frequency plan used to arrange the communications network.

4. A method as claimed in claim 2 wherein said predicted link performance levels are determined on the basis of estimated link budgets.

5. A method as claimed in claim 2 wherein said predicted link performance levels are determined on the basis of a calculated value C/(I+A+N), where C is an estimate of a carrier level for the link, I is an estimate an interference level for the link, A is an estimate of an interference level for an adjacent channel for the link, and N is an estimate of a noise level for the link.

6. A method as claimed in claim 1 wherein said step (iv) of determining comprises measuring the level of link performance.

7. A method as claimed in claim 1 wherein said proposed change to the communications network comprises the addition of an additional subscriber station, and wherein said step (v) further comprises, then keeping said additional subscriber station on hold and not effecting the proposed change if at least one of said determined levels of link performance is not greater than said specified level.

8. A method as claimed in claim 7 which further comprises the step of calculating a ratio of a number of additional subscriber stations placed on hold to a total number of requests including a proposed change to the communications network comprising the proposed additional of an additional subscriber station.

9. A method as claimed in claim 1 wherein said channel is selected on the basis of information about the communications network in an arbitrary manner.

10. A method as claimed in claim 1 wherein if at least one of said determined levels of link performance is not greater than said specified level for said channel, the method further comprises selecting a different channel for communication between the additional subscriber station and the chosen base station.

11. A method as claimed in claim 1 wherein the specified level of link performance level is different for different subscriber stations.

12. A method as claimed in claim 1 wherein said fixed wireless access communications network is organised according to a fixed frequency plan.

13. A method as claimed in claim 1 wherein said fixed wireless access communications network is not organised according to a fixed frequency plan.

14. A computer system for deploying a fixed wireless access communications network such that a specified level of link performance is maintained, said network comprising a plurality of fixed base stations and a plurality of fixed subscriber stations, each subscriber station being arranged to communicate with one of the base stations via a communications link and each of the communications links being associated with one of a plurality of communications channels, said computer system comprising:

—

(i) an input arranged to receive a request including a proposed change comprising the addition of an additional subscriber station to the communications network after the fixed wireless access communications network has been deployed;

(ii) a processor arranged to determine a chosen base station with which the additional subscriber station is to communicate if the proposed change is effected;

selecting a channel for communication between the additional subscriber station and the chosen base station on the basis of a fixed frequency plan;

determine a level of link performance provided by each of the communications links, taking into account the proposed changed to the communications network; and

wherein said processor is further arranged to allow the proposed change to be effected if each of said determined levels of link performance are greater than the specified level of link performance.

15. A computer program stored on a computer readable medium and arranged to control a computer system such that a fixed wireless access communications network may be deployed whilst a specified level of link performance is maintained, said network comprising a plurality of fixed base stations and a plurality of fixed subscriber stations, each subscriber station being arranged to communicate with one of the base stations via a communications link and each of the communications links being associated with one of a plurality of communications channels, said computer program being arranged to control said computer system such that:

—

(i) a request is received including a proposed change comprising the addition of an additional subscriber station to the communications network after the fixed wireless access communications network has been deployed;

(ii) a level of link performance provided by each of the communications links is determined, taking into account the proposed change;

(iii) a chosen base station is selected with which the additional subscriber station is to communicate if the proposed change is effected;

(iv) a channel for communication between the additional subscriber station and the chosen base station is selected on the basis of a fixed frequency plan; and

(v) said change is effected if each of said determined levels of link performance are greater than the specified level of link performance.

16. A fixed wireless access communications network comprising:

—

(i) a plurality of fixed base stations and a plurality of fixed subscriber stations;

(ii) a communications link associated with one of a plurality of communications channels between each subscriber station and one of the base stations;

wherein each said communications link provides a specified level of link performance;

and wherein locations of the base stations are selected according to a fixed frequency plan, and the frequencies of each communications links is selected according to the fixed frequency plan.

17. A method of deploying a fixed wireless access communications network such that a specified level of link performance is maintained, said network comprising a plurality of fixed base stations and a plurality of fixed subscriber stations, each subscriber station being arranged to communicate with one of the base stations via a communications link and each of the communications links being associated with one of a plurality of communications channels, said method comprising the steps of:

—

(i) receiving a request including a proposed change comprising the addition of an additional subscriber station to the communications network after the fixed wireless access communications network has been deployed;

(ii) selecting a chosen base station with which the additional subscriber station is to communicate if the proposed change is effected;

(iii) selecting a channel for communication between the additional subscriber station and the chosen base station on the basis of a fixed frequency plan;

(iv) determining a level of link performance provided by each of the communications links taking into account the proposed change;

(v) carrying out one of the group comprising;

effecting the proposed change if each of said determined levels of link performance are greater than the specified level of link performance and keeping said additional subscriber station on hold and not effecting the proposed change if at least one of said determined levels of link performance is not greater than said specified level; and

(vi) calculating a ratio of a number of additional subscriber stations placed on hold to a total number of requests including a proposed change to the communications network comprising the proposed additional of an additional subscriber station.