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EP-3646633-B1 - RADIO SENSOR COVERAGE ESTIMATION FOR WIRELESS NETWORK ASSURANCE

EP3646633B1EP 3646633 B1EP3646633 B1EP 3646633B1EP-3646633-B1

Inventors

  • DESAI, VISHAL S.

Dates

Publication Date
20260506
Application Date
20180621

Claims (13)

  1. A network controller (101), comprising: a processor (201); and a memory (202) containing a program that, when executed on the processor, performs an operation, the operation comprising: estimating (410) a first network sensor coverage level for a plurality of candidate access points, APs, based on hypothetical use of the plurality of candidate APs as network sensors to measure at least one key performance indicator, KPI; determining (414) a subset of the plurality of candidate APs, based on evaluating the plurality of candidate APs for use as network sensors; estimating (416) a second network sensor coverage level for the subset of the plurality of candidate APs, based on hypothetical use of the subset of the plurality of candidate APs as network sensors; determining that the second network sensor coverage level is within a pre-defined threshold of the first network sensor coverage level; and provisioning a radio in each AP in the subset of the plurality of candidate APs as a network sensor to measure the at least one KPI, wherein determining the subset of the plurality of candidate APs, based on evaluating the plurality of candidate APs for use as network sensors further comprises: identifying a first redundant AP based on determining that an identifier associated with an AP in the plurality of candidate APs is not listed as a sensor AP in a list of covered neighbor APs and is listed as a sensor AP in a list of supplemental neighbor APs; and selecting the subset of the plurality of candidate APs from the plurality of candidate APs such that the subset does not include the first redundant AP, wherein: the list of covered neighbor APs and the list of supplemental neighbor APs each list identifiers associated with sensor APs against identifiers of respective neighbor APs; the neighbor APs are covered by the radios of their respective sensor APs; each sensor and neighbor AP is an AP of the plurality of candidate network APs; and each neighbor AP in the list of supplemental neighbor APs is also listed as a neighbor AP in the list of covered neighbor APs.
  2. The network controller (101) of claim 1, wherein evaluating the plurality of candidate APs for use as network sensors, comprises: selecting a first AP of the plurality of candidate APs; determining a plurality of allowed frequencies for the first AP; determining a base power range for the first AP; and determining one or more neighbor APs for the first AP.
  3. The network controller (101) of claim 2, wherein determining the plurality of allowed frequencies for the first AP further comprises: choosing a subset of available frequencies based on PHY constraints; and determining channel quality for the subset of available frequencies.
  4. The network controller (101) of claim 2 or 3, wherein determining the one or more neighbor APs for the first AP further comprises: selecting a first neighbor AP of the one or more neighbor APs; and determining that the first neighbor AP is operating on at least one of the plurality of allowed frequencies.
  5. The network controller (101) of claim 2, 3, or 4, wherein evaluating the plurality of candidate APs for use as network sensors further comprises: selecting a first neighbor AP of the one or more neighbor APs; and evaluating a signal-to-noise ratio related to the first neighbor AP based on a pre-determined cutoff.
  6. The network controller (101) of claim 2, 3, or 4, wherein evaluating the plurality of candidate APs for use as network sensors further comprises: selecting a first neighbor AP of the one or more neighbor APs; and adding an identifier associated with the first neighbor AP to a list of covered neighbors based on determining that the identifier is not already present in the list of covered neighbors.
  7. The network controller (101) of any preceding claim, wherein determining the subset of the plurality of candidate APs, based on evaluating the plurality of candidate APs for use as network sensors further comprises: identifying a first one or more unnecessary APs of the plurality of candidate APs that produce zero sensor coverage or have a zero sensor reachability factor; identifying a second one or more unnecessary APs of the plurality of candidate APs that have minimal sensor reachability; and selecting the subset of the plurality of candidate APs from the plurality of candidate APs such that the subset does not include the first one or more unnecessary APs and the second one or more unnecessary APs.
  8. A computer implemented method performed in a network controller, the method comprising: estimating (410) a first network sensor coverage level for a plurality of candidate APs, based on hypothetical use of the plurality of candidate APs as network sensors to measure at least one key performance indicator, KPI; determining (414) a subset of the plurality of candidate APs, based on evaluating the plurality of candidate APs for use as network sensors; estimating (416) a second network sensor coverage level for the subset of the plurality of candidate APs, based on hypothetical use of the subset of the plurality of candidate APs as network sensors; determining that the second network sensor coverage level is within a predefined threshold of the first network sensor coverage level; and provisioning a radio in each AP in the subset of the plurality of candidate APs as a network sensor to measure the at least one KPI, wherein determining the subset of the plurality of candidate APs, based on evaluating the plurality of candidate APs for use as network sensors further comprises: identifying a first redundant AP based on determining that an identifier associated with an AP in the plurality of candidate APs is not listed as a sensor AP in a list of covered neighbor APs and is listed as a sensor AP in a list of supplemental neighbor APs; and selecting the subset of the plurality of candidate APs from the plurality of candidate APs such that the subset does not include the first redundant AP, wherein: the list of covered neighbor APs and the list of supplemental neighbor APs each list identifiers associated with sensor APs against identifiers of respective neighbor APs; the neighbor APs are covered by the radios of their respective sensor APs; each sensor and neighbor AP is an AP of the plurality of candidate network APs; and each neighbor AP in the list of supplemental neighbor APs is also listed as a neighbor AP in the list of covered neighbor APs.
  9. The method of claim 8, wherein evaluating the plurality of candidate APs for use as network sensors further comprises: selecting a first AP of the plurality of candidate APs; determining a plurality of allowed frequencies for the first AP; determining a base power range for the first AP; and determining one or more neighbor APs for the first AP.
  10. The method of claim 9, wherein determining the plurality of allowed frequencies for the first AP further comprises: choosing a subset of available frequencies based on PHY constraints; and determining channel quality for the subset of available frequencies; and wherein determining one or more neighbor APs for the first AP further comprises: selecting a first neighbor AP of the one or more neighbor APs; and determining that the first neighbor AP is operating on at least one of the plurality of allowed frequencies.
  11. The method of claim 9 or 10, wherein evaluating the plurality of candidate APs for use as network sensors further comprises: selecting a first neighbor AP of the one or more neighbor APs; evaluating a signal-to-noise ratio related to the first neighbor AP based on a pre-determined cutoff; and adding an identifier associated with the first neighbor AP to a list of covered neighbors based on determining that the identifier is not already present in the list of covered neighbors.
  12. The method of any of claims 8 to 11, wherein determining the subset of the plurality of candidate APs, based on evaluating the plurality of candidate APs for use as network sensors further comprises: identifying a first one or more unnecessary APs of the plurality of candidate APs that produce zero sensor coverage or have a zero sensor reachability factor; identifying a second one or more unnecessary APs of the plurality of candidate APs that have minimal sensor reachability; and selecting the subset of the plurality of candidate APs from the plurality of candidate APs such that the subset does not include the first one or more unnecessary APs and the second one or more unnecessary APs.
  13. A computer program product, comprising a non-transitory computer-readable storage medium having computer readable program code embodied therewith, the computer readable program code configured, when implemented by a network controller, to cause the method of any of claims 8 to 12 to be performed.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application claims benefit to US Provisional Application Serial No. 62/527,810 filed on June 30, 2017, and US Patent Application Serial No. 15/875,650, filed January 19, 2018. TECHNICAL FIELD This disclosure is directed to radio sensor coverage estimation for wireless network assurance. BACKGROUND High-density wireless deployments have become more common in recent years. With the proliferation of these deployments, monitoring network performance has become increasingly important to, for example, avoid network problems, ensure a desired performance level, and ensure compliance with service level agreements. In wireless networks system metrics and performance can vary significantly over time. Therefore, it is important to determine network health and performance on an ongoing basis. This can be done using network sensors to measure network performance. For example, network technicians can visit a client site with dedicated sensors, and use these sensors to monitor and troubleshoot the network. But this is expensive, inefficient, and inflexible, requiring technicians to visit client sites in person and to set up dedicated sensors. US 2009/0316585 is directed to methods and apparatus that enable a deployment of a system of wireless nodes, e.g., femtocells, which can self-configure themselves into a balanced and optimized wireless network. Access points switch between a network monitoring mode in which network monitoring is performed and a communications mode in which the access point serves one or more wireless terminals and communicates traffic data to/from the wireless terminals. Traffic data transmission to wireless terminals are not supported in network monitoring mode. Based on information gathered from one or more access nodes while they operating in network monitoring mode of operation, access point configuration information is generated and one or more access points are automatically configured. LI XUN ET AL: IEEE Mechatronics and Automation (ICMA) conference paper, pages 1068-1073 is directed to "Energy-efficient data acquisition in wireless sensor networks through spatial correlation". SUMMARY An invention is set out in the claims. BRIEF DESCRIPTION OF THE DRAWINGS So that the manner in which the above-recited features of the present disclosure can be understood in detail, a more particular description of the disclosure, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this disclosure and are therefore not to be considered limiting of its scope, for the disclosure may admit to other equally effective embodiments. Figure 1 illustrates a network controller controlling multiple Access Points (APs) in a network, according an embodiment.Figure 2 illustrates a network controller, according to an embodiment.Figure 3 illustrates a neighborhood including multiple APs, according to an embodiment.Figure 4 is a flowchart for evaluating radio sensor coverage, according to an embodiment.Figure 5 is a flowchart for choosing APs and selecting allowed frequencies when evaluating radio sensor coverage, according to an embodiment.Figure 6 is a flowchart for evaluating neighboring nodes for an AP when evaluating radio sensor coverage, according to an embodiment.Figure 7 is a flowchart for optimized pruning when evaluating radio sensor coverage, according to an embodiment.Figures 8A-8D illustrate an example of evaluating radio sensor coverage for the neighborhood illustrated in Figure 3, according to an embodiment. To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is contemplated that elements disclosed in one embodiment may be beneficially utilized on other embodiments without specific recitation. DESCRIPTION OF EXAMPLE EMBODIMENTS Instead of using on-site technicians and dedicated hardware, it is possible to determine the network health and performance of a wireless network using the existing Access Points (APs) in the wireless network as wireless sensors for other APs and clients. These sensors can be used to measure key performance indicators (KPI), continuously or at intervals, and can report any degradation in the key performance indicators. Key performance indicators may include: wireless client troubleshooting, radio performance, client throughput estimation, radio signal coverage, network authentication issues, coverage holes, and other indicators. Such degradation can be due to numerous factors including, for example, wireless interference. When an AP is used as a sensor, however, the radio being used for sensing cannot be used to service clients. One solution is to setup dedicated APs to use as permanent sensors. This allows consistent monitoring of the network, but using a dedicated AP can be expe