Methods and apparatus for characterization, adjustment and optimization of wireless networks

• US 6,842,431 B2
• Filed: 11/04/1999
• Issued: 01/11/2005
• Est. Priority Date: 11/04/1999
• Status: Expired due to Fees

• Current Assignee: Lucent Technologies, Inc. (Nokia Corporation)
• Original Assignee: Lucent Technologies, Inc. (Nokia Corporation)
• Inventors: Mankiewich, Paul Matthew, Hobby, John D., Hampel, Karl Georg, Polakos, Paul Anthony, Clarkson, Kenneth L.
• Primary Examiner(s): Pham, Chi
• Assistant Examiner(s): JONES, PRENELL P
• Application Number:
  US09/434,579
• Publication Number:
  US 20030147353A1
• Time in Patent Office: 1,895 Days
• Field of Search: 370/254, 370335-342, 370/465, 370/252, 370433-438, 370/321, 455/426, 455435-446, 455 67- 69, 455/522, 455410-418, 455/452, 455/266, 455/422.1, 375/150, 375146-149
• US Class Current: 370/254
• CPC Class Codes: H04W 24/00 Supervisory, monitoring or testing arrangements
• CPC Class Codes: H04W 52/34 TPC management, i.e. sharing limited amount of power among users or channels or data types, e.g. cell loading

Abstract

Improved techniques for characterizing, adjusting and optimizing the overall performance of a wireless network. In an illustrative embodiment, the overall network performance for a particular network configuration is characterized by a vector with two components, one representing network coverage and another representing network capacity. Network coverage is defined by the likelihood of service under load, including interference, and may be further weighted by traffic density. Network capacity is defined by an amount of traffic with a given spatial distribution that can be served at a given overall target-blocking rate. The overall network performance may be characterized using a two-dimensional capacity/coverage diagram which plots overall network performance vectors, each including a network capacity component and a network coverage component, for various network configurations. The overall network performance may be improved or optimized with respect to a given subset of network parameters by using an algorithm that proposes potential network configurations and evaluates them with respect to their overall network performance.

Claims

1. A processor-implemented method for characterizing the performance of a wireless network, the method comprising the steps of:

determining values for a plurality of network parameters; and

processing the network parameter values to generate a measure of the performance of the wireless network, the measure including components representative of network coverage and network capacity;

wherein the network coverage component comprises at least one of an area-weighted network coverage component and a traffic-weighted network coverage component.

2. The method of claim 1 wherein at least a subset of the network parameters comprise link parameters.

5. The method of claim 1 wherein the network coverage component is weighted in accordance with a weighting factor.

6. The method of claim 5 wherein the weighting factor is representative of traffic density within a particular coverage area.

17. The method of claim 1 further including the step of representing the performance of the wireless network in a two-dimensional diagram which allows visual comparison of different network performance measures generated for a plurality of different network configurations.

18. The method of claim 17 wherein the two-dimensional diagram includes representations of the network performance measures for the plurality of different network configurations so as to illustrate a performance tradeoff among the multiple configurations based on a tradeoff between the network coverage and network capacity components.

19. The method of claim 17 wherein the two-dimensional diagram includes a tradeoff curve for each of the plurality of configurations, each of the tradeoff curves including multiple points each corresponding to a network performance measure generated for the corresponding configuration under a particular network resource constraint.

20. The method of claim 19 wherein an outer envelope of at least a subset of a set of points of the tradeoff curves defines an optimum tradeoff curve between the network coverage and network capacity components for the plurality of network configurations.

3. A processor-implemented method for characterizing the performance of a wireless network, the method comprising the steps of:

determining values for a plurality of network parameters; and

processing the network parameter values to generate a measure of the performance of the wireless network, the measure including components representative of network coverage and network capacity;

wherein the network coverage component is defined at least in part as a fraction of area in which quality of service is above a specified threshold, with respect to a target coverage area.

4. The method of claim 3 wherein the quality of service comprises at least one communication channel in a particular link of the wireless network.

7. A processor-implemented method for characterizing the performance of a wireless network, the method comprising the steps of:

determining values for a plurality of network parameters; and

processing the network parameter values to generate a measure of the performance of the wireless network, the measure including components representative of network coverage and network capacity;

wherein the network coverage component for a given communication channel of the wireless network is configured to include interference from other communication channels in the wireless network, so as to reflect a reduction of coverage under traffic load.

8. A processor-implemented method for characterizing the performance of a wireless network, the method comprising the steps of:

determining values for a plurality of network parameters; and

processing the network parameter values to generate a measure of the performance of the wireless network, the measure including components representative of network coverage and network capacity;

wherein the network coverage component comprises an overall area-weighted network coverage component defined by;

${\mathrm{Cov}}_{\mathrm{tot}}={\int <br><br>}_{\mathrm{TCA}}<br><br>\mathrm{Cov}<br><br>\left(x,\text{\hspace{1em}<br><br>}<br><br>y\right)·<br><br><br><br>\text{\hspace{1em}<br><br>}<br><br>d<br><br>x·<br><br>d<br><br>y/{\int <br><br>}_{\mathrm{TCA}}<br><br>d<br><br>x·<br><br>d<br><br>y,$

where TCA denotes a target coverage area and Cov(x,y) is a coverage function that assigns a coverage indication to a given Location (x,y).

9. The method of claim 8 wherein the coverage function Cov(x,y) is defined as $\mathrm{Cov}$

(x, 

⁢

y)={0if⁢

 

⁢

location⁢

 

⁢

 

(x,y)⁢

 

⁢

is⁢

 

⁢

not⁢

 

⁢

covered1if⁢

 

⁢

location⁢

 

⁢

(x,y)⁢

 

⁢

is⁢

 

⁢

covered⁢

 

.⁢

 

10. A processor-implemented method for characterizing the performance of a wireless network, the method comprising the steps of:

determining values for a plurality of network parameters; and

processing the network parameter values to generate a measure of the performance of the wireless network, the measure including components representative of network coverage and network capacity;

wherein the network coverage component comprises an overall traffic-weighted coverage component defined by;

${\mathrm{Cov}}_{\mathrm{tot}}={\int <br><br>}_{\mathrm{TCA}}<br><br>\mathrm{TD}<br><br>\left(x,y\right)·<br><br>\mathrm{Cov}<br><br>\left(x,y\right)·<br><br>d<br><br>x·<br><br>d<br><br>y/{\int <br><br>}_{\mathrm{TCA}}<br><br>\mathrm{TD}<br><br>\left(x,y\right)·<br><br>d<br><br>x·<br><br>d<br><br>y$

where

TD(x,y) is a local traffic density function and Cov(x,y) is a coverage function that assigns a coverage indication to a given location (x,y).

11. The method of claim 10 wherein the coverage function Cov(x,y) is defined as $\mathrm{Cov}$

(x,y)={0if⁢

 

⁢

location⁢

 

⁢

(x,y)⁢

 

⁢

is⁢

 

⁢

not⁢

 

⁢

covered1if⁢

 

⁢

location⁢

 

⁢

(x,y)⁢

 

⁢

is⁢

 

⁢

covered.

12. A processor-implemented method for characterizing the performance of a wireless network, the method comprising the steps of:

determining values for a plurality of network parameters; and

processing the network parameter values to generate a measure of the performance of the wireless network, the measure including components representative of network coverage and network capacity;

wherein the network capacity component is defined at least in part by an amount of traffic having a given spatial distribution, and represents the ability of the wireless network to match the spatial traffic distribution.

13. A processor-implemented method for characterizing the performance of a wireless network, the method comprising the steps of:

determining values for a plurality of network parameters; and

processing the network parameter values to generate a measure of the performance of the wireless network, the measure including components representative of network coverage and network capacity;

wherein the network capacity component further represents an amount of traffic having a given spatial distribution that can be carried by the network with a specified target blocking rate.

14. The method of claim 13 wherein the specified target blocking rate is defined as:

${\mathrm{BR}}_0=\frac{\begin{array}{c}\mathrm{Failed}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{attempts}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{to}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{originate}<br><br>\text{\hspace{1em}<br><br>}<br><br>a<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{service}\\ \mathrm{in}<br><br>\text{\hspace{1em}<br><br>}<br><br>a<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{target}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{coverage}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{area}<br><br>\text{\hspace{1em}<br><br>}\end{array}}{\begin{array}{c}\mathrm{Total}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{amount}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{of}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{service}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{requests}\\ \mathrm{in}<br><br>\text{\hspace{1em}<br><br>}<br><br>a<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{target}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{coverage}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{area}<br><br>\text{\hspace{1em}<br><br>}\end{array}},$

where the failed attempts are service origination failures attributable to an overload of network resources.

15. The method of claim 13 wherein the network capacity component is defined as:

Network capacity=τ

·

Network coverage,

where τ

is a multiplier to a normalized traffic distribution, and is set to a value such that the corresponding traffic load can be handled by the network at the specified target blocking rate.

16. A processor-implemented method for characterizing the performance of a wireless network, the method comprising the steps of:

determining values for a plurality of network parameters; and

processing the network parameter values to generate a measure of the performance of the wireless network, the measure including components representative of network coverage and network capacity;

wherein the network capacity component is defined at least in part by an amount of blocked service requests at a given traffic load.

21. A processor-implemented method for characterizing the performance of a wireless network, the method comprising the steps of:

determining values for a plurality of network parameters;

processing the network parameter values to generate a measure of the performance of the wireless network, the measure including components representative of network coverage and network capacity; and

optimizing the performance of the wireless network using an optimization algorithm that generates proposed network configurations, wherein the proposed network configurations are evaluated using the network performance measure.

22. The method of claim 21 wherein the optimization algorithm comprises a frequency planning tool.

23. The method of claim 21 wherein the optimization algorithm comprises a derivative-based optimization process.

24. A processor-implemented method for characterizing the performance of a wireless network, the method comprising the steps of:

determining values for a plurality of network parameters;

processing the network Parameter values to generate a measure of the performance of the wireless network, the measure including components representative of network coverage and network capacity; and

optimizing the performance of the wireless network using an optimization algorithm that determines a network configuration for specified values of at least one of the network coverage and network capacity components of the performance measure.

25. The method of claim 24 wherein the optimization algorithm determines a network configuration for an objective other than a particular network coverage or network capacity.

26. The method of claim 24 wherein the optimization algorithm optimizes a particular one of the network coverage and network capacity components for different constraint values associated with the other component.

27. The method of claim 24 wherein the optimization algorithm optimizes a network performance objective specified as a linear combination of the network coverage component and the network capacity component.

28. The method of claim 27 wherein the network performance objective is specified as:

a·

Coverage+(1−

a)·

Capacity, aε

[0,1].

where “

Coverage”

denotes the network coverage component and “

Capacity”

denotes the network capacity component.

29. An apparatus for characterizing the performance of a wireless network, the apparatus comprising:

a processor-based system operative (i) to determine values for a plurality of network parameters; and

(ii) to process the network parameter values to generate a measure of the performance of the wireless network, the measure including components representative of network coverage and network capacity;

wherein the network coverage component comprises at least one of an area-weighted network coverage component and a traffic-weighted network coverage component.

30. An article of manufacture comprising a computer-readable medium storing one or more software programs for use in characterizing the performance of a wireless network, wherein the one or more programs when executed by a processor perform the steps of:

determining values for a plurality of network parameters; and

processing the network parameter values to generate a measure of the performance of the wireless network, the measure including components representative of network coverage and network capacity;

wherein the network coverage component comprises at least one of an area-weighted network coverage component and a traffic-weighted network coverage component.

31. A processor-implemented method for characterizing the performance of a wireless network, the method comprising the steps of:

determining values for a plurality of network parameters; and

processing the network parameter values to generate a measure of the performance of the wireless network, the measure comprising a vector having at least two dimensions and being representative of the performance of the wireless network for a given set of network resources.

32. The method of claim 31 wherein the vector includes a first dimension corresponding to network coverage and a second dimension corresponding to network capacity.

33. An apparatus for characterizing the performance of a wireless network, the apparatus comprising:

a processor-based system operative (i) to determine values for a plurality of network parameters; and

(ii) to process the network parameter values to generate a measure of the performance of the wireless network, the measure comprising a vector having at least two dimensions and being representative of the performance of the wireless network for a given set of network resources.

34. The apparatus of claim 33 wherein the vector includes a first dimension corresponding to network coverage and a second dimension corresponding to network capacity.

35. An article of manufacture comprising a computer-readable medium storing one or more software programs for use in characterizing the performance of a wireless network, wherein the one or more programs when executed by a processor include:

determining values for a plurality of network parameters; and

processing the network parameter values to generate a measure of the performance of the wireless network, the measure comprising a vector having at least two dimensions and being representative of the performance of the wireless network for a given set of network resources.

36. The article of manufacture of claim 35 wherein the vector includes a first dimension corresponding to network coverage and a second dimension corresponding to network capacity.