Patent Application
20150311987
A wireless communication system typically provides one or more forms of wireless access to mobile access devices, enabling them to engage in voice and data communications with other devices—both wired and wireless—operating in or connected to the system, and to partake in various other communication services provided or supported by the system. The communication path from a mobile access device, such as a cellular telephone, personal digital assistant (PDA), or an appropriately equipped portable computer, for instance, to one or more other communication endpoints generally traverses a radio frequency (RF) air interface to a base transceiver station (BTS) or other form of access point, and on into a core transport network via a base station controller (BSC) connected to a mobile switching center (MSC) or to a packet data serving node (PDSN). The MSC supports primarily circuit voice communications, providing interconnectivity with other MSCs and PSTN switches, for example. The PDSN supports packet data communications, providing interconnectivity with packet-data networks, such as the Internet, via other packet-data switches and routers.
In a cellular wireless system, the BTS, BSC, MSC, and PDSN, among possibly other components, comprise the wireless access infrastructure, also sometimes referred to as the radio access network (RAN). A RAN is usually arranged according to a hierarchical architecture, with a distribution of multiple BTSs that provide areas of coverage (e.g., cells) within a geographic region, under the control of a smaller number of BSCs, which in turn are controlled by one or a few regional (e.g., metropolitan area) MSCs. As a mobile device moves about within the wireless system, it may hand off from one cell (or other form of coverage area) to another. Handoff is usually triggered by the RAN as it monitors the operating conditions of the mobile device by way of one or more signal power levels reported by the device to the RAN.
As the demand for wireless services has grown, and the variety of physical environments in which wireless access is provided becomes more diverse, the need for new topologies and technologies for coverage has become increasingly important. At the same time, alternative methods of wireless access, including WiFi and WiMax, are becoming more ubiquitous, particularly in metropolitan areas. Consequently, traditional cellular service providers are looking for ways to integrate different types of wireless access infrastructures within their core transport and services networks. In addition, as wireless access infrastructures of different service providers tend to overlap more and more within smaller spaces, the ability to share common infrastructure offers cost and operational benefits to network owners and operators.
Some embodiments of the present disclosure provide a smart combiner that includes a radio frequency (RF) power coupler having a first input, a second input, a first output, and a second output. The smart combiner further includes a first RF power detector coupled between the first input and the first output, and a second RF power detector coupled between the second input and the second output. The first RF power detector may be configured to monitor a power level of a signal at the first input, and the second RF power detector may be configured to monitor a power level of a signal at the second input. Further, the first RF power detector and the second RF power detector may be further configured to transmit a signal to an external computing device based on the monitored power levels.
Some embodiments of the present disclosure provide a method, that includes detecting a power level of a signal at a first input of a radio frequency (RF) power coupler, and detecting a power level of a signal at a second input of the RF power coupler. The method further includes receiving at a processing unit indications of the detected power levels from the first RF power detector and the second RF power detector, and based on the received indications of the detected power levels, determining that an alarm condition is satisfied. And the method includes, in response to determining that an alarm condition is satisfied, transmitting an alarm signal to an external device.
Some embodiments of the present disclosure provide a distributed antenna system (DAS). The DAS includes a plurality of antenna arrangements distributed throughout a network, and for each given antenna arrangement of the plurality of antenna arrangements, a radio frequency (RF) power coupler coupled to the given antenna arrangement. The RF power coupler may include at input and an output, with at least one of the input and the output being coupled to the given antenna arrangement, and an RF power detector coupled between the input and the output, the RF power detector being configured to monitor a power level of a signal at input. Further, in some embodiments, the RF power detector is configured to transmit a signal to a network operations center (NOC) based on the monitored power level.
These as well as other aspects, advantages, and alternatives will become apparent to those of ordinary skill in the art by reading the following detailed description, with reference where appropriate to the accompanying drawings. Further, it should be understood that this summary and other descriptions and figures provided herein are intended to illustrate the disclosure by way of example only and, as such, that numerous variations are possible. For instance, structural elements and process steps can be rearranged, combined, distributed, eliminated, or otherwise changed, while remaining within the scope of the disclosure as claimed.
The present disclosure will be described by way of example with reference to wireless access technologies including Code Division Multiple Access (CDMA), UMTS, GSM, WiFi, and WiMax, although the disclosure is not limited to these technologies. CDMA and GSM are typically deployed in cellular wireless communication systems, and generally encompass a number of related technologies that collectively and/or individually support both circuit-cellular communications, including voice and circuit-based packet communications, and native packet-data communications. For the purposes of the discussion herein, a “CDMA family of protocols” shall be taken to apply to all such technologies. Examples of protocols in the family include, without limitation and of one or more versions, IS-95, IS-2000, IS-856, and GSM, among others. Native packet-data wireless protocols and technologies, include, without limitation WiFi, WiMax, WLAN, and IEEE 802.11, some or all of which may be interrelated. The term “wireless Ethernet” is also sometimes used to describe one or another of these protocols or aspects of these protocols.
As indicated, the PDSN 116 is connected to a packet-switched network 118, which could be the Internet or a core packet transport network that is part of the wireless communication system. A computer 120 is also shown being connected to the packet network 118, and the wireless device 102 could engage in communications with the computer 120 via a path such as the one just described. It will be appreciated that, although not shown, other communication devices, as well as communication and application servers could be connected in one way or another to the network 118. In addition, the network 118 may comprise other equipment including, without limitation, routers, switches, transcoding gateways, security gateways and firewalls, and other components typical of a communication and transport network.
Also shown in
It should be understood that the depiction of just one of each network element in
The coverage area provided by the BTS (including the transmitting antennas) is typically a cell or cell sectors. By way of example, the BTS 206 (in conjunction with the antenna tower 208) is sectorized, such that it provides three sectors (labeled “Sector 1,” “Sector 2,” and “Sector 3”). An access device then communicates on a connection via one or more of the cells or sectors of a BTS in accordance with one or more of a family of CDMA protocols. For instance, under IS-2000, each cell or sector will be identified according to a locally unique identifier based on a bit offset within a 16-bit pseudo-random number (PN). An access device operating according to IS-2000 receives essentially the same signal from up to six sectors concurrently, each sector being identified and encoding transmissions according its so-called PN offset. The details of such communications are well-known in the art and not discussed further here.
Signals received from access devices connected via the antenna tower 208 are transmitted back to the BTS 206 via the connection 207. Unlike the BTS 206, which supplies the antenna tower 208, the BTS 210 is connected instead to a DAS head end 222 via a digital RF connection 211. The digital connection 211 is the same type of signal and physical interface as the connection 207. However, rather than supplying a single transmission tower, the DAS head end 222 splits and distributes the input signal from the BTS among several smaller and remote antenna nodes 224-1, 224-2, 224-3, . . . , 224-N, where N is a positive integer. Connections from the DAS head end 222 to each of the remote nodes 224-1, 224-2, 224-3, . . . , 224-N may be made via low-power digital-optical links 221-1, 221-2, 221-3, . . . , 221-N, respectively. Hatch marks interrupting each of the links 221 are meant to represent the remoteness of each node's location with respect to the DAS head end. The remote nodes could be distributed throughout one or more buildings, or across a residential area or small down-town locale or village where a larger antenna tower is impractical and/or impermissible according local zoning ordinances, for instance.
The combination of signals then transmitted from the remote nodes 224-1, 224-2, 224-3, . . . , 224-N provides the same signals that would be transmitted from one or more cells or sectors if they were connected to the BTS 210, but spread over a region according to the topological arrangement of the nodes and the splitting and routing of the input signals by the DAS head end (this is discussed further below). Signals received from access devices connected via one or more of the remote antenna nodes are received at the DAS head end, combined, then transmitted back to the BTS 210 via the connection 211, in the same way as in the traditional BTS (e.g., transmissions from the RF module 208 to the BTS 206).
While the connections 211 and 213 are of the same type, each carries a signal (or signals) that is (or are) specific to the particular service provider. For example, both service providers could be operating according to IS-2000, but each using a different RF carrier frequency. Alternatively or additionally, one carrier could be operating according to CDMA and the other according to GSM. Other combinations of technologies and RF carriers could be used. In addition, each carrier could have a different configuration of cell or sector identifiers. For instance, the BTS 210 could be configured for three sectors, while the BTS 220 could be configured for a single cell. Any similarities or differences between the two systems are incorporated into their respective signals prior to being modulated onto their respective carriers by their respective BTSs (210 and 220 in this example). The DAS head end just splits and routes the respective signals to the remote antenna nodes, which then transmit the various carrier signals concurrently. Thus, the output of the antenna nodes potentially comprises a mix of CDMA technologies, RF carrier frequencies, and coverage area (e.g., cell or sector) configuration.
As a general matter, a smart combiner may be utilized to provide cell sites, and ultimately the network at large with on-site, health monitoring of certain network components. For example, in the embodiment depicted in
On the other hand with regard to network performance, the smart combiner may determine whether communication signals are being adequately transmitted throughout the network. For example, if a mobile device is receiving a communication signal with insufficient signal strength, a smart combiner (or arrangement of smart combiners positioned throughout the network) may be able to localize the portion of the network giving rise to the insufficiency. Other uses for a smart combiner are possible as well.
Once a smart combiner detects a problem condition, the smart combiner may notify a network operations center (NOC) (not shown), which may dispatch a technician or otherwise provide for mitigation of the problem condition. Positioning smart combiners throughout a network, and particularly throughout a DAS network given the tendency of DAS networks to include components distributed throughout a relatively large geographic area, may enable the NOC (or other monitoring entity) to more efficiently monitor and maintain the overall health of the network.
In some embodiments, the smart combiner may be a traditionally passive component that includes some active components. For instance,
As also depicted, smart combiner 402 includes active components, such as a first RF power detector 412 positioned between input 404 and output 408, and a second RF power detector 414 positioned between and a second RF power detector 414, positioned between input 406 and output 410. RF power detector 412 operates to monitor various characteristics of signals at the input 404 and relay the monitored characteristics to a processor 416. RF power detector 414 likewise operates to monitor various characteristics of signals at the input 406 and relay the monitored characteristics to a processor 416. Processor 416 may be a special-purpose microprocessor or, alternatively, part of a more sophisticated computing device, such as a traditional desktop or notebook computer. As will be explained further below, the processor 416 may be programmed with, or otherwise configured to execute appropriate programming code in order to carry out one or more of the functions described herein with respect to the smart combiner. As further depicted the processor 416 is shown coupled to an external Gateway 418, which is configured to transmit signals to a NOC (not shown). In some configurations, RF power detectors 412 and 414, and processor 416 are enclosed within the same metallic housing, thereby encapsulating the components as a single, stand-alone device. However, in other configurations, the smart combiner may include more or fewer components, which may or may not be enclosed within a single housing.
In addition to the arrangement of the individual components of a smart combiner, the individual components of the smart combiner may be configured differently in different implementations of the smart combiner. For example, in accordance with one embodiment in which the smart combiner 402 is configured to monitor network integrity, the RF power detectors 412 and 414 may be configured to monitor the power provided at inputs 404 and 406 and transmit to the processor 416 an indication of the detected power levels. In one embodiment, the RF power detectors are configured to monitor the power level in a single frequency band; however, in other embodiments, the RF power detectors are configured to monitor the power level in multiple frequency bands, and perhaps monitor the power across the entire frequency spectrum.
Further, processor 416 may be configured to analyze the received indications of the power levels and determine whether any monitored power level falls below a particular threshold power level. And, in the event that the processor 416 detects that a monitored power level falls below a particular threshold power level, the processor 416 may generate and transmit to the NOC via Gateway 418 an appropriate alarm signal. Upon receiving the alarm signal, the NOC may dispatch a technician or otherwise provide for mitigation of the problem condition.
In accordance with another embodiment in which the smart combiner 402 is configured to monitor network integrity, the RF power detectors are configured to monitor undesirable harmonics (also known as RF noise) that may be present in signals at the inputs 404 and 406. Such harmonics may exist as a result of a damaged upstream network component, such as an antenna arrangement. RF power detectors 412 and 414 may be further configured to transmit to processor 416 an indication of any detected harmonics. Accordingly, processor 416 may be configured to analyze the received indications of the detected harmonics and determine whether there are at least a threshold level of unwanted harmonics present in a signal at one of the inputs 404 and 406. And, in the event that the processor 416 detects that there is at least a threshold level of unwanted harmonics present in a monitored signal, the processor 416 may generate and transmit to the NOC via Gateway 418 an appropriate alarm signal. Upon receiving the alarm signal, the NOC may dispatch a technician or otherwise provide for mitigation of the problem condition.
In accordance with another embodiment in which the smart combiner 402 is configured to monitor network performance, the RF power detectors are configured to monitor the signal-to-noise ratio (SNR) of signals at the inputs 404 and 406 and transmit to the processor 416 an indication of the detected SNR levels. Accordingly, processor 416 may be configured to analyze the received indications of the SNR levels and determine whether any monitored SNR level falls below a particular threshold SNR level. And, in the event that the processor 416 detects that a monitored SNR level falls below a particular threshold SNR level, the processor 416 may generate and transmit to the NOC via Gateway 418 an appropriate alarm signal. Upon receiving the alarm signal, the NOC may dispatch a technician or otherwise provide for mitigation of the problem condition. Other examples of smart combiner configurations are possible as well.
Similarly, network 500 also includes a second set of network equipment, namely MSC 512, BSC 514, BTS 516 and 520, and radio transmission tower 518, which may be a part of another service provider different than that of MSC 502, BSC 504, BTS 506 and 510, and radio transmission tower 508. Signals received from access devices connected via the antenna tower 508 are transmitted back to the BTS 506 via the connection 507 through the smart combiner 506-1. As such, the smart combiner 506-1 may be utilized to provide on-site health monitoring of antenna tower 508, in accordance with any of the implementations set forth above. Likewise, signals received from radio transmission tower 518 are transmitted back to the BTS 516 via the connection 517 through the smart combiner 506-2. As such, the smart combiner 506-2 may be utilized to provide on-site health monitoring of the radio transmission tower 518, in accordance with any of the implementations set forth above.
As further shown in
As further depicted in network 500, the connections from the DAS head end 522 to each of the remote nodes 524-1, 524-2, 524-3, . . . , 524-N are transmitted through smart combiners 506-3, 506-4, 506-5, . . . , 506-N. As such, the smart combiners 506-3, 506-4, 506-5, . . . , 506-N may be utilized to provide on-site health monitoring of remote nodes 524-1, 524-2, 524-3, . . . , 524-N, in accordance with any of the implementations set forth above. Other DAS network configuration that incorporate smart combiners are possible as well.
Furthermore, those skilled in the art will understand that the flowchart described herein illustrates functionality and operation of certain implementations of example embodiments. In this regard, each block of the flow diagram may represent a module, a segment, or a portion of program code, which includes one or more instructions executable by a processor (e.g., processor 416 described above with respect to
The method 600 begins at block 602, in which the smart combiner detects a power level of a signal at a first input of the smart combiner. As described above, the smart combiner may include an RF power detector positioned between an input and an output of the smart combiner. The RF power detector may be operable to monitor various characteristics of a signal at the input, including the power level.
Continuing at block 604, the smart combiner detects a power level of a signal at a second input of the smart combiner. As also described above, the smart combiner may include an RF power detector positioned between an additional input and an additional output of the smart combiner. The RF power detector may be operable to monitor various characteristics of a signal at the input, including the power level.
At block 606 the smart combiner receives at a processing unit indications of the power levels detected by the RF power detectors in blocks 602 and 604. As described above, the RF power detectors may transmit to the processing unit indications of the detected power levels upon detection.
Continuing at block 608, the smart combiner determines that an alarm condition is satisfied based on the received indications of the power levels. For instance, in one embodiment as described above, after receiving indications of the detected power levels, the processing unit may compare the detected levels to a threshold power level. And, in the event that the processor determines that one or more of the indicated power levels is less than or equal to the threshold power level, the processing unit may, as a result, determine that an alarm condition is satisfied.
For example, in some embodiments, the threshold power level is a constant number (e.g., 10 dBm). In this case, if the processing unit determines that an indicated power level is, for example, 8 dBm, then the processing unit may determine that the indicated power level is less than the threshold power level. In another example, the threshold power level is based on an average of some number of the previous indicated power levels (e.g., 90%). In this case, if the processing unit determines that an indicated power level has dropped by 10% or more from several of the previous indicated power levels, then the processing unit may determine that the indicated power level is less than the threshold power level. Other examples of determining whether an indicated power level is less than or equal to a threshold power level are possible as well.
In some embodiments, the processing unit may wait until an indicated power level has been less than the threshold power level for at least a threshold level of time (e.g., 2.0 seconds) before determining that the alarm condition is satisfied. This way, the smart combiner may let transient faults clear before taking an action with respect to the alarm condition.
Finally, at block 610, as a result of determining that an alarm condition is satisfied, the processing unit may transmit to an external device an alarm signal. For instance, as described above, the processing unit may transmit an alarm signal to an external device associated with an NOC, whereupon the NOC may, in response to receiving the alarm signal, dispatch a technician or otherwise provide for mitigation of the detected problem condition.
An example of an embodiment of the present disclosure has been described above. Those skilled in the art will understand, however, that changes and modifications may be made to the embodiment described without departing from the true scope and spirit of the disclosure, which is defined by the claims.
