Method for monitoring a metric for a base station's downlink/uplink path utilizing a radio frequency scanner and the radio frequency scanner

In one embodiment, the radio frequency scanner includes a detector configured to receive signals for transmission by the base station, and to detect a presence metric for each carrier expected in the received signals. A processor is configured to determine if the base station is operating improperly based on the detected presence metrics.

BACKGROUND

Typically, base station diagnostics concentrate on voltage standing wave ratio (VSWR) for poor antenna connection or RF path mal-function. These widely used approaches across the industry add cost to each radio and filter. Furthermore, these approaches do not necessarily detect all issues with radio, cables/connectors, combiners or filter assemblies.

SUMMARY

At least one embodiment relates to radio frequency scanner for monitoring a base station.

In one embodiment, the radio frequency scanner includes a detector configured to receive signals for transmission by the base station, and to detect a presence metric for each carrier expected in the received signals. A processor is configured to determine if the base station is operating improperly based on the detected presence metrics.

In one embodiment, the detector is configured to receive signals coupled from output of at least one radio frequency filter prior to transmission antenna.

In one embodiment, the detector is configured to receive at least one signal corresponding to each sector associated with the base station, and the processor is configured to determine if the base station is operating improperly with respect to each sector associated with the base station.

In one embodiment, the detector is configured to receive more than one signal corresponding to each sector of the base station, and each signal corresponding to a sector is associated with a different diversity of the sector. The processor may be configured to determine if the base station is operating improperly with respect to each diversity of each sector associated with the base station.

As examples only, the presence metric may be one of average envelop power, peak power, and a combination of average envelope power and peak power.

In another embodiment, the processor is configured to determine a number of detected carriers based on the presence metrics, and the processor is configured to determine whether the base station is operating improperly based on the determined number of detected carriers and an expected number of detected carriers.

In one embodiment, the processor is configured to determine whether the base station is operating improperly based on the determined number of detected carriers for each sector associated with the base station and an expected number of detected carriers for each sector associated with the base station.

In one embodiment, the processor is configured to perform a carrier detection operation to determine if a carrier is detected, the carrier detection operation being based on the presence metric associated with the carrier and a metric threshold.

Also, in another embodiment, the processor may be configured to perform the carrier detection operation a number of times for each carrier, and the processor is configured to determine the carrier is detected if at least a threshold number of carrier detection operations produces a positive detection result.

In one embodiment, the processor is configured to generate an alarm if the processor determines the base station is operating improperly. The processor may also be configured to output the alarm from the radio frequency scanner.

In one embodiment, the processor may determine the carrier air interface type by analyzing detected envelope information

In one embodiment, the processor may store carrier's traffic information as the result of carrier's RF power detection.

At least one embodiment relates to a method of monitoring a base station.

In one embodiment, the method includes obtaining signals for transmission by the base station, detecting a presence metric for each carrier expected in the obtained signals, and determining, by a processor, if the base station is operating improperly based on the detected presence metrics.

In one embodiment, the obtaining obtains the signals from output of at least one radio frequency filter prior to transmission.

In another embodiment, the obtaining obtains at least one signal corresponding to each sector associated with the base station, and the determining determines if the base station is operating improperly with respect to each sector associated with the base station.

As examples only, the presence metric may be one of average envelop power, peak power, and a combination of average envelope power and peak power.

In one embodiment, the determining determines a number of detected carriers based on the presence metrics, and determines whether the base station is operating improperly based on the determined number of detected carriers and an expected number of detected carriers.

In one embodiment, the method further includes generating an alarm if the determining determines the base station is operating improperly.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Note also that the software implemented aspects of example embodiments are typically encoded on some form of tangible (or recording) storage medium or implemented over some type of transmission medium. As disclosed herein, the term “storage medium” may represent one or more devices for storing data, including read only memory (ROM), random access memory (RAM), magnetic RAM, magnetic disk storage mediums, optical storage mediums, flash memory devices and/or other tangible machine readable mediums for storing information. The term “computer-readable medium” may include, but is not limited to, portable or fixed storage devices, optical storage devices, and various other mediums capable of storing, containing or carrying instruction(s) and/or data.

A code segment may represent a procedure, function, subprogram, program, routine, subroutine, module, software package, class, or any combination of instructions, data structures or program statements. A code segment may be coupled to another code segment or a hardware circuit by passing and/or receiving information, data, arguments, parameters or memory contents. Information, arguments, parameters, data, etc. may be passed, forwarded, or transmitted via any suitable means including memory sharing, message passing, token passing, network transmission, etc.

As used herein, the term “terminal” may be synonymous to a mobile user, mobile station, mobile terminal, user, subscriber, wireless terminal, user equipment and/or remote station and may describe a remote user of wireless resources in a wireless communication network. Accordingly, terminal may be a wireless phone, wireless equipped laptop, wireless equipped appliance, etc.

The term “base station” may be understood as a one or more cell sites, base stations, base transceiver stations, nodeBs, enhanced NodeBs, access points, and/or any terminus of radio frequency communication. Although current network architectures may consider a distinction between mobile/user devices and access points/cell sites, the example embodiments described hereafter may generally be applicable to architectures where that distinction is not so clear, such as ad hoc and/or mesh network architectures, for example.

Communication from the base station to the terminal is typically called downlink or forward link communication. Communication from the terminal to the base station is typically called uplink or reverse link communication.

FIG. 1illustrates a base station including a radio frequency scanner according to an example embodiment. As shown, a base station100may include a digital shelf102with various electronics (e.g., processors, etc.) providing the functionality of the base station, an amplifier shelf104with various amplifiers for amplifying signals for transmission, and a filter bank106including a plurality of radio frequency (RF) filters110. The filter bank106filters the amplified signals output from the amplifier shelf prior to transmission via respective antennas120.

In this embodiment, the base station100serves a coverage area divided into three sectors. The three sectors may be referred to as Alpha, Beta and Gamma. As shown inFIG. 1, two filters110are associated with each sector. The two filters110and respective antennas120for each sector also provide different transmit diversity referred to as “Div-0” and “Div-1”. Each filter110filters a respective amplified signal for transmission in a desired frequency band. The frequency bands associated with the different filters110may differ, and are generally prescribed by the wireless protocol or protocols supported by the base station100. For example, the base station100may support one or more of 2G, 3G, 4G, etc.

According to one embodiment, a radio frequency scanner150may be coupled to the filters110. For example, the filters110may provide coupled ports for transmission/reception monitoring, and the radio frequency scanner150may receive as input the coupled transmission output from the filters110. Alternatively, external couplers that couple the signals to be transmitted as output from the filters110may be used to supply the input to the radio frequency scanner150. As will be described in detail below with respect toFIGS. 2-4, the radio frequency scanner150determines if the base station is operating improperly, and if improper operation is determined, the radio frequency scanner150may issue one or more alarms and/or an alarm report. The alarm may be a message or report that the radio frequency scanner150provides to the electronics of the digital shelf102. These electronics may then report the alarm to a remote operator (e.g., as one or more user alarms).

FIG. 2illustrates the radio frequency scanner ofFIG. 1in greater detail according to an example embodiment. As shown, the radio frequency scanner150includes a switch152, a down converter154, a filter156, a detector160, a microprocessor162, a buffer164, and a frequency synthesizer166. The switch152, under the control of the microprocessor162, selectively outputs the signals obtained from the filters110. The frequency synthesizer166receives a reference signal (e.g., a 15 MHz reference signal), and supplies a mixing signal to the down converter154. The down converter154down converts the output from the switch152by mixing the mixing signal and the output from the switch152. For example, the down converter154down converts output from the switch152from radio frequency to an intermediate frequency range based on output from the frequency synthesizer166. In one embodiment, the intermediate frequency range is a preferred frequency range for the detector160. The filter156filters the output of the down converter154to provide cleaner signals to the detector160.

The detector160detects a presence metric for each carrier expected in the received signals. The presence metric may be one of average envelop power, peak power, a combination of average envelope power and peak power, etc. The processor162determines if the base station is operating improperly based on the detected presence metrics. For example, in one embodiment, the processor162determines a number of detected carriers based on the presence metrics, and the processor determines whether the base station is operating improperly based on the determined number of detected carriers and an expected number of detected carriers.

In one embodiment, the processor162performs a detection operation using the presence metric corresponding to the signal from each filter110to determine whether a carrier is detected. For instance, the processor162may compare the presence metric (e.g., average envelope power) to a metric threshold. If the presence metric exceeds the metric threshold, then the processor162determines a carrier is detected. The metric threshold may be a design parameter determined through empirical study.

As shown inFIG. 2, the microprocessor162may receive input from a DIP switch indicating the expected number of carriers. However, it will be understood that the microprocessor162may be programmed or provided with this information in any manner. Also, the microprocessor162may be configured to determine a number of carriers over a testing window of time, and use this determined number as the expected number during future monitoring.

As will be appreciated fromFIGS. 1 and 2, through operation of the switch152, the detector160receives at least one signal corresponding to each sector associated with the base station. Accordingly, the detector160produces at least one presence metric associated with each sector, and the processor162may determine if the base station is operating improperly with respect to each sector associated with the base station. Still further, in the embodiment ofFIGS. 1 and 2, the detector160may receive more than one signal corresponding to each sector of the base station, and each signal corresponding to a sector is associated with a different diversity of the sector. Accordingly, the detector160produces two presence metrics associated with each sector, and each of the present metrics is associated with a different diversity. The processor162may determine if the base station is operating improperly with respect to each diversity of each sector associated with the base station.

FIG. 3illustrates an example of detector output over three frame scans for the zero diversity Div-0of each sector. As shown, a vector represents the magnitude of the presence metric inFIG. 3. Each vector is labeled with the corresponding sector and diversity (e.g., Alpha-0for sector Alpha and diversity Div-0). Also,FIG. 3indicates the frame scan, where F1is the first frame scan, F2is the second frame scan and F3is the third frame scan.

FIG. 4illustrates another example of detector output over three frame scans for the zero diversity Div-0of each sector.FIG. 4is the same asFIG. 3, except that the presence metric for sector Beta and diversity Div-0during the second frame F2does not meet the threshold requirement. Accordingly, the processor162may determine that the base station is not operating properly with respect to sector Beta and diversity Div-0.

However, as will be appreciated, numerous factors may contribute to an occasion failure to meet the detection or threshold requirement. Accordingly, to prevent falsely determining improper operation, the processor162may determine improper operation based on monitoring over a time period. For example, the processor162may perform the carrier detection operation a number of times for each expected carrier (e.g., for each diversity at each sector), and the processor162determines the carrier is detected if at least a threshold number of carrier detection operations produces a positive detection result. The threshold number may be 1, for example. Namely, as long as one detection operation produces a positive result, the carrier is detected. As another example, the threshold number may equal the number of detection operations. Here, if one detection operation fails, then the detection operation produces a negative result. Accordingly, the threshold number is a design parameter that may be set based on the desired sensitivity for determining improper operation. The monitoring time period may be the time to perform a number of frames (or scans), an actual time period (e.g., 8 am to 10 am), etc.

If the processor162determines the base station is operating improperly, the processor162generates an alarm or alarm report. The alarm or alarm report may indicate the base station is operating improperly, a particular sector is operating improperly, the diversity and sector that are operating improperly, and/or, etc.

The processor162may store the alarm or alarm report in the buffer164. Also, the processor162may output the alarm or alarm report directly or from the buffer164to the electronics of the digital shelf102. For example, the processor162may be connected to the digital shelf102via an Ethernet cable, wirelessly (e.g., blue tooth), etc. As discussed above, the alarms or reports may then be communicated to a remoter operator.

While the example embodiments discussed above pertained to a base station with three sectors, the example embodiments are also applicable to omni-directional base stations, or base stations with any number of sectors. Further, the example embodiments are not limited to sectors with diversity or with a diversity of two. Still further, the example embodiments are applicable to any wireless standard, or base stations complying with multiple standards.

It will also be understood that the radio frequency scanner may be modified in various ways. For example, instead of a frequency synthesizer, down converter and filter, an analog-to-digital converter may be provided to convert the output from the switch152to digital baseband signals. In this embodiment, the processor162would include the detector160as a digital detection module executed at the processor162.