CN103179581B - Controlled in wireless plane failure manipulation in segmentation plane deployment - Google Patents

Abstract

The present invention relates to radio control plane failure handling in split plane deployments. A method, apparatus and computer program product are presented for providing wireless control plane failover handling in a split plane deployment. A first AP in a split-plane deployment detects a failure of a Wireless Control Plane (WCP) device. The first AP hides the SSID in the beacon broadcast by the first AP. The first AP stores information of existing Mobile Units (MUs) that were disassociated after detection of a failure of the WCP device. The first AP will respond to probes from existing MUs; and also respond to probes from MUs whose information is stored in the AP, so that the first AP is exposed to existing MUs while behaving to new MUs hidden.

Description

Radio Control Plane Fault Handling in Split-Plane Deployments

Background technique

Wireless networks have become ubiquitous. A wireless network refers to any type of computer network that is wireless and is typically associated with a telecommunications network in which nodes can be interconnected without the use of wires. Wireless telecommunication networks are generally implemented using some type of telematics transmission system carried by electromagnetic waves, such as radio waves, so the implementation usually takes place at the physical or network level.

A typical wireless network may include one or more access points (APs), one or more wireless controllers (WCs), and one or more mobile units (MUs). MUs may include laptop computers, mobile phones, personal digital assistants (PDAs), and the like.

Wireless Local Area Networks (LANs) are a popular and inexpensive way to enable users of multiple "Mobile Units" (MUs) to communicate with each other, access a wired LAN, access a local server, access a remote server (eg, via the Internet, etc.), etc. A wireless local area network (WLAN) typically includes an access point (AP) and one or more mobile units.

A wireless AP is a device that allows a wireless communication device to connect to a wireless network. Access points allow wireless mobile units to communicate with each other and with the infrastructure connected to the AP.

Servers are used to provide services such as access to application programs (eg, email systems, word processing programs, accounting systems, and/or private databases). Wireless LANs are used in facilities such as corporations, university classrooms or buildings, airport lounges, hotel meeting rooms, and the like. When the user is physically near the access point, the mobile unit's transceiver communicates with the access point so that a connection to the wireless LAN is established.

The AP and the mobile unit transmit data in units of frames through a shared communication channel. Frames transmitted from the mobile unit to the AP are called uplink frames, and frames transmitted from the AP to the mobile unit are called downlink frames. In situations where two or more mobile units (or an AP and a mobile unit) transmit frames simultaneously, one or more of the frames may be corrupted (referred to herein as a collision). Accordingly, wireless local area networks (WLANs) typically employ one or more protocols to ensure that a mobile unit or AP can obtain exclusive access to a shared communication channel for predetermined time intervals in order to transmit its frames without collisions.

Certain wireless network protocols (e.g., Institute of Electrical and Electronics Engineers [IEEE] 802.11, etc.) specify that the AP periodically broadcasts a signal that can be heard by mobile units in the BSA (Basic Service Area, i.e., the area covered by the AP) called Special frames for beacons. Beacons contain various information that enable mobile units to establish and maintain communications in an orderly fashion (e.g., time stamps), thereby enabling mobile units to synchronize their local clocks and signaling information (e.g., channel numbers, frequency hopping pattern, dwell time, etc.).

A wireless network may also include one or more virtual local area networks (VLANs). A VLAN includes a group of devices with a common set of requirements to communicate as if belonging to the same broadcast domain, regardless of their physical location. VLANs have the same properties as physical LANs, but allow devices to be grouped together even if they are not located on the same network switch.

While wireless control plane (WCP) functions are implemented in virtual or physical equipment within the enterprise data center, split-plane deployments reuse existing switching infrastructure components at customer sites for wireless data forwarding. The WCP function is responsible for the configuration, control and monitoring of the wireless access medium. MU association, authentication and disassociation are handled by WCP. The Wireless Switching Plane (WSP) performs repetitive but high-capacity data forwarding actions.

Since network outages can occur frequently due to failures in hardware or software or management errors, redundancy and failover are important aspects of network deployment. Administrators need the ability to shut down, move and restart virtual WCP applications based on resource needs within the data center. The ability of the wireless network to operate during these transitions without impacting wireless users is critical to the success of the split-plane architecture.

The most common deployment model is an overlay approach, where the WCP and WSP functions are combined into a single device called a wireless controller (WC). In this case, a connection failure between the AP and the WC affects both control and data forwarding.

Contents of the invention

Conventional mechanisms as described above suffer from various drawbacks. In a split-plane architecture, a failure of a WCP does not affect wireless data forwarding. This allows the AP to continue to provide data forwarding services for the associated MUs, which was previously described as one of the advantages of the split-plane architecture. Another commercial solution to solve the redundancy problem is to transfer the WCP function to the AP, where most of the functions are performed in the AP, and the controller only performs configuration and monitoring, which does not affect the normal operation of the wireless access. This is a completely different architecture, and is popular for small scale deployments, but does not scale well as the number of APs increases. In general, WCP functions are computationally intensive, and these functions scale well when concentrated on powerful CPUs, while WSP functions scale well when decentralized. This benefit is only available from split-plane architectures.

Current solutions proposed for failover do not fully address the problems that may arise during failover. This issue is critical to the feasibility of the proposed concept that an AP can continue to forward data for a longer period of time without re-establishing the connection to the WCP equipment in the split-plane model. This problem arises because the AP cannot access WCP functionality to support association for new or roaming MUs but it continues to broadcast its presence in the wireless environment through 802.11 beacons and probe responses for new or roaming MUs. As the AP stays in this state longer and longer, more and more MUs start to experience wireless service interruption.

Current solutions add to the deployment concerns where cellular redundancy is built into the deployment by intelligently load balancing APs across WCPs. In this approach, as is popular in coverage deployments, neighboring APs in the RF domain are assigned to alternate WCP devices. Thus, when the WCP equipment fails, there is always some AP in a given physical location of the enterprise that maintains a connection to the working WCP and provides full WCP functionality to the MU. In coverage deployments, cellular redundancy provides faster recovery because once an AP detects a loss of connectivity to a WC, it turns off the radio and the MU can immediately roam to neighboring APs that still provide radio service. In split-plane deployments, the solutions discussed completely ignore the advantages of turning off the radio to restore coverage while addressing the problem of unimpaired data forwarding.

Embodiments of the present invention significantly overcome these deficiencies and provide mechanisms and techniques that provide a split-plane failover mechanism such that the advantages of the split-plane architecture are maintained for MUs that do not roam during failover, while Roaming MUs are still allowed to receive service in wireless networks designed with cellular redundancy. The mechanisms described in this invention can allow affected APs to operate for longer durations without full access to WCP functionality.

In a particular embodiment of a method for providing wireless control plane handling in a split-plane deployment, the method includes detecting, by a first access point (AP) in the split-plane deployment, a failure of a wireless control plane (WCP) device. The method further includes concealing the SSID of the first AP in a beacon broadcast by the first AP, and storing information of existing Mobile Units (MUs) disassociated after detection of a failure of the WCP device in the first AP's high-speed in cache. Additionally, the method includes responding to probes from existing MUs and responding to probes from MUs with information in the cache such that the first AP behaves to new MUs while being exposed to existing MUs. hidden.

Other embodiments include a computer readable medium having computer readable code thereon for providing wireless control plane handling in a split plane deployment. A computer-readable medium includes instructions for detecting failure of a wireless control plane (WCP) device by a first access point (AP) in a split-plane deployment. The computer-readable medium further includes instructions for hiding the SSID of the first AP in a beacon broadcast by the first AP and information for existing Mobile Units (MUs) to be disassociated upon detection of a failure of the WCP device Instructions stored in the cache of the first AP. Additionally, the computer-readable medium includes instructions for responding to probes from existing MUs, and instructions for responding to probes from MUs with information in the cache such that the first AP is exposed to Existing MUs also appear to be hidden from new MUs.

Still other embodiments include computerized apparatus configured to process all of the method operations disclosed herein as embodiments of the invention. In these embodiments, a computerized device (eg, AP) includes a memory system, a processor, and a communication interface in an interconnection mechanism connecting these components. The storage system is encoded with a process, as described herein, that provides wireless control plane manipulation in a split-plane deployment, when executed on a processor (e.g., when executed), as described herein, Runs in the AP to perform all method embodiments and operations described herein as embodiments of the present invention. Accordingly, any computerized apparatus that performs or is programmed to perform the processes described herein is an embodiment of the present invention.

Other arrangements of embodiments of the invention disclosed herein include software programs for performing the method embodiment steps and operations summarized above and disclosed in detail below. More specifically, a computer program product is one embodiment having a computer-readable medium comprising computer program logic encoded thereon that, when executed in a computerized apparatus, provides an associated Operations, as described herein, provide wireless control plane manipulation in a split plane deployment. The computer program logic, when executed on at least one processor of a computing system, causes the processor to perform the operations (eg, methods) noted herein as embodiments of the invention. Such arrangements of the present invention are typically provided as software, code and/or other data structures disposed or encoded on a computer readable medium, such as an optical medium (eg, CD-ROM), floppy or hard disk, or other medium, For example, firmware or microcode in one or more ROM or RAM or PROM chips, either provided as an Application Specific Integrated Circuit (ASIC), or as a downloadable software image in one or more modules, shared libraries, or the like. Software or firmware or other such configurations may be installed in a computerized device to cause one or more processors in the computerized device to perform the techniques described herein as embodiments of the invention. A software process running in a set of computerized devices (eg, in a set of data communication devices or other entities) may also provide the system of the invention. The system of the present invention can be distributed among many software processes on several data communication devices, or all processes can run on a small group of dedicated computers or run on a single computer.

It should be understood that embodiments of the present invention may be strictly implemented as a software program, software and hardware, or only hardware and/or circuitry within a data communication device, for example. The features of the invention described herein may be used in a data communication device and/or in a software system for such a device (manufactured, for example, by Avaya, Inc. of Basking Ridge, New Jersey).

Note that each of the different features, techniques, configurations, etc. discussed in this disclosure can be implemented independently or in combination. Accordingly, the present invention can be implemented and viewed in many different ways. Additionally, note that the Summary of the Invention section herein does not specifically describe every embodiment and/or additional novel aspect of the present disclosure or described inventions. Rather, the Summary provides only a preliminary discussion of various embodiments and corresponding novelties over the conventional art. For additional details, elements, and/or possible aspects (permutations) of the present invention, the reader should turn to the Detailed Description section, discussed further below, and the corresponding figures of the present disclosure.

Description of drawings

The foregoing will be apparent from the following more particular description of preferred embodiments of the invention, as shown in the accompanying drawings, wherein like reference numerals designate like parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention.

FIG. 1 is a block diagram depicting prior art overlay model deployment;

Figure 2 is a block diagram depicting a prior art coverage model deployment where a wireless controller has failed;

3 is a block diagram depicting a prior art coverage model deployment where an access point has its radio turned off;

4 is a block diagram depicting a prior art overlay model deployment where an access point associates with another wireless controller and begins providing radio frequency (RF) services;

Figure 5 is a block diagram depicting a prior art split plane model deployment;

6 is a block diagram depicting a prior art split plane model deployment where a wireless control plane device has failed;

7 is a block diagram depicting a prior art split-plane model deployment in which a wireless switch plane device searches for another wireless control plane device but continues to forward data communications for an AP. APs that have lost connection to the WCP continue to operate over the radio to serve the associated MUs. However, the new MU cannot get service because the AP does not have a WCP connection to complete the association for the new MU;

8 is a block diagram depicting a prior art split-plane model deployment where wireless switching plane devices and APs have associated with another WCP and resumed full service to all MUs;

Figure 9 is a block diagram illustrating the use of cellular redundancy in an overlay deployment;

Figure 10 is a block diagram illustrating the use of cellular redundancy in an overlay deployment where a wireless controller has failed;

Figure 11 is a block diagram illustrating the use of cellular redundancy in an overlay deployment where a wireless controller has failed, where the AP managed by the WC shuts down the radio, and the affected MU roams to connect to another WC and broadcast the RF domain Neighboring access points for WLAN services;

Figure 12 is a block diagram illustrating the use of cellular redundancy in a split-plane deployment;

13 is a block diagram illustrating the use of cellular redundancy in a split-plane deployment where a wireless control plane device has failed;

14 is a block diagram illustrating the use of cellular redundancy in a split-plane deployment where a wireless control plane device has failed and new clients are not receiving service in AP cells not managed by any WCP;

15A and 15B are flowcharts of specific embodiments of methods for providing wireless control plane failover handling in split plane deployments; and

Figure 16 is a flowchart of a particular embodiment of a method for providing wireless control plane failover handling in a split plane deployment in which wireless data service (WDS) links are used.

detailed description

The embodiments set forth below represent the necessary information to enable those skilled in the art to practice the invention and illustrate the best mode of carrying out embodiments of the invention. After reading the following description with reference to the accompanying drawing figures, those skilled in the art will understand the concepts of the invention and recognize applications of these concepts not specifically addressed herein. It should be understood that these concepts and applications fall within the scope of the disclosure and the appended claims.

The overlay architecture model is a commonly used wireless network deployment model. In this case, the Wireless Control Plane (WCP) and the Wireless Switching Plane (WSP) reside on the same device called the Wireless Controller (WC). Referring to Figure 1, an overlay architecture model is shown. In this example, the first building includes a first wireless controller WCl. Solid lines between devices represent data tunnels, light dotted lines represent control channels, and darker dotted lines represent data communication over data tunnels. Control channels are established between WC1 and AP1, AP2 and AP3 respectively. And control channels are respectively established between WC2 and AP4, AP5 and WC1. Establish data tunnels between WC1 and AP1, AP2, and AP3. Establish data tunnels between WC2 and AP4, AP5, and WC1. Data communication between MU1 and MU2 occurs from MU1 to AP1 , from AP1 to WC1 , from WC1 through the L2/L3 cloud to WC2, from WC2 to AP4, and from AP4 to MU2.

Referring now to Figure 2, WC2 has failed. Since WC2 fails, both the wireless control and wireless switching functions no longer work. The MU1-MU2 connection is interrupted. Sometimes AP4 and AP5 detect the failure of WC2 after the actual failure. As shown in Figure 3, AP4 and AP5 turn off their radios. MU2 is disassociated because the radios in its RF neighborhood are turned off. AP4 and AP5 try to discover another wireless controller in the mobility domain. As shown in Figure 4, AP4 and AP5 discover WC1 and establish a data tunnel with WC1. AP4 and AP5 also establish a control channel with newly discovered WCl. AP4 and AP5 then turn on their radios and provide RF service. MU2 can then associate with the wireless network again and communication with MU1 can be re-established.

As shown in Figures 2 to 4, WCP and WSP failed simultaneously. The failure is detected by the AP with some delay, however the data flow for the MU on the AP is interrupted immediately. The AP turns off the radio after detecting WCP and WSP failures, causing the MUs to disassociate. The AP discovers another WCP and WSP device and establishes a control and data tunnel with that device. AP turns on radio and accepts MU again. MU's data forwarding is interrupted for a longer duration. Many wireless devices that are not moving will not be able to get service until the AP restores connection to the WCP and WSP devices.

A split-plane architecture separates the Wireless Control Plane (WCP) functions from the Wireless Switching Plane (WSP) functions. WCP functions can be implemented in virtual equipment or actual hardware. One of the advantages of the proposed split-plane deployment model is its potential to allow WCP failures without affecting data forwarding for existing customers. Referring to Figure 5, a split plane architectural model is shown. In this example, the first building includes a first wireless control plane device (WCP1). Corresponding control channels are established between WCP1 and AP1, AP2, AP3, and WSP1. And a control channel is established between WCP2 and WCP1, AP4, AP5 and WSP2. Establish data tunnels between WSP1 and AP1, AP2, and AP3 respectively. And establish data tunnels between WSP2 and AP4, AP5 and WSP1 respectively. The data communication between MU1 and MU2 traverses from MU1 to AP1, from AP1 to WSP1, from WSP1 to WSP2 through the L2/L3 cloud, from WSP2 to AP4, and from AP4 to MU2.

Referring now to Figure 6, WCP2 has failed. Even though WCP2 has failed, the MU1-MU2 connection has not been interrupted. AP4 and AP5 are able to maintain their data tunnel with WSP2 and not turn off their radios.

As shown in Figure 7, WSP2 detects a failure of WCP2 and searches for another WCP device. AP4 and AP5 detect the failure of WCP2 and attempt to discover another WCP device. The data tunnels between AP4 and WSP2 and between AP5 and WSP2 continue to maintain and carry wireless data. The radiocell is still running but new clients or roaming devices (eg MU3, MU4 or MU5) cannot associate because association is a WCP function. Referring now to FIG. 8, WSP2 discovers WCP1 and establishes a control channel with it. AP4 and AP5 also establish corresponding control channels with WCP1. As a result, new or roaming devices (such as MU3, MU4 and/or MU5) are now able to acquire service.

Cellular redundancy is achieved by designing the network such that adjacent APs are managed by different WCPs. Cellular redundancy can be achieved through the AP-WC load balancing algorithm and can ensure that not all APs in a building or floor are out of service in the event of a WCP failure. Referring now to FIG. 9, an exemplary cellular redundancy in an overlay deployment is shown. AP1 has established a control channel and a data tunnel with WC1, and MU1 is associated with AP1. AP2, which is adjacent to AP1 and AP3, has established a control channel and a data tunnel with WC2. AP3 has established a control channel and a data tunnel with WCl and MU2 is associated with AP3. AP4 adjacent to AP3 has established a control channel and a data tunnel with WC2. When a WC (eg, WC1 in Figure 10) fails, both data and control channels from the AP to the failed WC are affected. As shown in FIG. 11 , the previously existing data tunnel and control channel between AP1 and WC1 and the previously existing data tunnel and control channel between AP3 and WC1 have been interrupted. When WC1 fails, communication from MU1 and MU2 is immediately affected. AP1 and AP3 will turn off their radios when they detect the failure of WC1. After AP1 and AP3 turn off their radios, MU1 and MU2 will immediately roam to neighboring APs that continue to provide wireless service. MU1 will establish a network connection with AP2, and MU2 will establish a network connection with AP4.

In the event of a WC failure, cellular redundancy in the coverage provides faster restoration of the wireless connection than without cellular redundancy. Assigning an AP to an alternate WC also assigns WSP functionality to an alternate WC. This may not be desirable if the alternate WC is not in the best location from a data forwarding perspective (eg, the WCs are located in geographically separate buildings).

Cellular redundancy is used in coverage deployment models, but its use in split-plane models has faced some challenges. Referring to Figure 12, a network incorporating cellular redundancy within a split-plane deployment is shown.

AP1 has established a control channel with WCP1 and a data tunnel with WSP1, and MU1 is associated with AP1. AP2, which is adjacent to AP1 and AP3, has established a control channel with WCP2 and a data tunnel with WSP1. AP3 has established a control channel with WCP1 and a data tunnel with WSP2 and MU2 is associated with AP3. AP4 adjacent to AP3 has established a control channel with WCP2 and a data tunnel with WSP2. WCP1 also has control channels with WCP2 and WSP1. WCP2 has a control channel with WSP2. There is also a data tunnel between WSP1 and WSP2. MU1 communicates with MU2 through AP1, WSP1, WSP2, and AP3. In this environment, neighboring APs are managed by different WCP devices.

When a WCP (eg, WCP1 in FIG. 13) fails, the control channel with that WCP is interrupted. In the split plane model, MU data communication is not affected. In a split-plane deployment, affected APs do not turn off their radios. New clients roaming into the affected AP's cell will experience WLAN service interruption because the affected AP does not provide access to WCP functionality. Existing customers in the affected AP cell will be disconnected if they temporarily roam into an adjacent cell and return. The split-plane failover mechanism needs to be enhanced to support cellular redundancy, since affected APs do not turn off the radio.

The split-plane solution described herein avoids shutting down the radio on the affected APs, allowing AP cells to maintain WSP functionality to existing MUs. Leaving the radio on attracted new devices to roam to the affected AP. Any device newly roaming into the cell of an affected AP will experience service interruption due to the inability of the new device to complete the association on the affected AP due to the unavailability of WCP functionality from the AP. For example, in Figure 14, MU3 and MU4 will not be able to complete the association and will experience a service outage.

MUs that are on the overlapping region of two cells tend to roam between cells frequently. Therefore, some MUs in the affected AP cell may roam back and forth. There is no known mechanism for a split-plane deployment that provides cellular redundancy for roaming clients and non-disruptive service for fixed clients in affected AP cells.

With the method and apparatus for wireless control plane manipulation in split-plane deployment described herein, when an AP detects a failure of a WCP in split-plane deployment, the AP performs the following actions. The AP will hide the SSID broadcast in the AP beacon. SSID is the name of the WLAN network associated with the MU. The AP will further cache association information for MUs disassociated after a WCP failure event and before the AP has established a connection with another WCP. The AP only responds to probes from existing MUs or from MUs for which association information is cached. When a new MU roams near the affected AP cell, it will not be able to detect the SSID in the beacon from the affected AP because the affected AP hides the SSID in the beacon. When the new MU probes on the channel of the affected AP cell, it will not get any response from the affected AP. Since the new MU cannot detect the affected AP through active or passive scanning, it will not be attracted to the affected AP and will try to connect only to APs that are visible to it. In case of split plane failover, this mechanism preserves cellular redundancy for the new MU.

When an existing MU roams to a neighboring AP, it will get connectivity on the neighboring AP due to cellular redundancy. When the existing MU roams back to the affected AP, the affected AP will be visible to the MU because the MU will get a response to the probe from the affected AP. Affected APs can accept MUs based on previously cached information.

In deployments designed with cellular redundancy, it is possible that affected APs utilize AP-AP Wireless Distribution System (WDPS) with neighboring APs to receive access to WCP functionality. This can be used to extend WLAN service on the affected AP to the new MU. Access to the WCP functionality should be secured as it is used to delay sensitive association data from the MU to the WCP. The control channel between AP and WCP is encrypted. In order for an AP to gain secure access to WCP functions through WDS links with neighboring APs, the WDS links should also be encrypted. For WDS link security, all APs receive a pre-shared encryption key from the WCP in the mobile zone when establishing a connection with the WCP. This pre-shared encryption key can be periodically modified and pushed to all APs.

The AP broadcasts WDS service in its RF neighborhood to support access to the WCP functionality of neighboring APs that have lost connection to the WCP. When a WCP fails, the affected AP continues to provide services to existing clients according to the mechanism described above in the present invention. Affected APs stop broadcasting WDS service in their neighborhood while unaffected APs continue broadcasting WDS service. The affected AP also scans its RF neighborhood to identify any neighboring APs that are broadcasting WDS service. Once a neighboring working AP is identified, the affected AP establishes a temporary WDS link with the working AP, thereby gaining access to WCP functions through the working AP. When a new MU is associated with the affected AP, the affected AP sends a request to the WCP over the WDS link with the working AP.

Because the AP provides service on all radios, it is possible that the affected AP only tunes for a brief interval to send a request to the WCP by a neighboring AP. When a response arrives from the WCP, the neighboring AP may tune to the affected AP's operating channel and forward the response to the affected AP. This ensures that both the affected AP and the working AP continue to serve the MUs in their RF neighborhood (with little time spent communicating with the WCP through the neighbor AP).

The methods and apparatus described herein for providing wireless control plane handling in split-plane deployments allow for full cellular redundancy in split-plane deployments while maintaining the benefits of split-plane WCP failover. Furthermore, the methods and apparatus described herein allow affected APs to operate for longer durations without access to WCP functionality and support connectivity of roaming MUs and stationary MUs during failover.

A flowchart of a specific embodiment of the method 100 disclosed herein is depicted in FIGS. 15A and 15B . A rectangular element is denoted herein as a "processing block" and represents a computer software instruction or set of instructions. Alternatively, processing blocks represent steps performed by functionally equivalent circuits, such as digital signal processor circuits, or application specific integrated circuits (ASICs). These flowcharts do not depict the syntax of any particular programming language. Rather, these flowcharts illustrate the functional information required by one skilled in the art to fabricate circuits or generate computer software to perform the processes required in accordance with the present invention. It should be noted that many routine program elements (eg initialization of loops and variables and use of temporary variables) are not shown. Those skilled in the art will appreciate that unless otherwise indicated herein, the specific order of the steps described is illustrative only and may be varied without departing from the spirit of the invention. Accordingly, unless otherwise indicated, the steps described below are out-of-order, meaning that, where possible, the steps can be performed in any convenient or desired order.

Method 100 begins at processing block 102, which discloses detecting, by a first access point (AP) in a split-plane deployment, a failure of a wireless control plane (WCP) device. A WCP device can fail for any number of reasons, including hardware failure, software failure, or interconnect failure.

Processing block 104 states that the SSID of the first AP is concealed in a beacon broadcast by the first AP. SSID is the name of the WLAN. All devices on the WLAN use the same SSID to communicate with each other.

Processing block 106 states that information of existing Mobile Units (MUs) that were disassociated after detection of a failure of the WCP device is stored in the first AP's cache. Processing block 108 discloses responding to probes from existing MUs. Processing block 110 states responding to probes from MUs with information in the cache such that the first AP appears hidden to new MUs while being exposed to existing MUs.

Processing block 112 states that when an existing MU roams to a neighboring AP and then roams back to the first AP, the first AP is visible to the MU because the MU received a response to the probe from the first AP. Processing block 114 discloses that the first AP accepts the MU based on the information in the cache.

Processing continues to processing block 116, which states that the first AP is in a cellular redundancy arrangement, wherein the neighboring APs are managed by different wireless control plane devices than the first AP.

Processing block 118 states that a new MU roaming into the vicinity of the first AP cannot hear beacons from the first AP. When the new MU roams near the affected AP cell, it will not be able to receive beacons from the affected AP. When the new MU probes on the channel of the affected AP cell, it will not get any response from the affected AP.

Processing block 120 discloses that the first AP does not respond to probes from new MUs roaming into the vicinity of the first AP. Because the new MU cannot detect affected APs through active or passive scanning, it will not be attracted to affected APs and will attempt to connect only to APs that are visible to it.

Referring now to FIG. 16, an embodiment is shown in which an affected AP is able to provide service. Method 150 begins at processing block 152, which states that a first AP scans its radio frequency (RF) neighborhood to determine whether neighboring APs are broadcasting Wireless Data Service (WDS). When a WCP fails, the affected APs continue to serve existing customers. Affected APs stop broadcasting wireless data services, while unaffected APs continue broadcasting WDS services. The affected AP can also scan its RF neighborhood to determine any neighboring APs that are broadcasting WDS service.

Processing block 154 discloses that the first AP establishes a temporary WDS link with a neighboring AP to gain access to wireless control plane functions through the neighboring AP while the neighboring AP is broadcasting WDS service.

Once a neighboring working AP is identified, the affected AP establishes a temporary WDS link with the working AP to gain access to WCP functions through the working AP.

Processing block 156 states that when a new MU is associated with the first AP, the first AP sends a request to the wireless control plane device through the neighboring AP via the temporary wireless WDS link.

References to "microprocessor" and "processor", or "the microprocessor" and "the processor" may be understood to include one or more microprocessors that may communicate in a standalone and/or distributed environment processor, and thus may be configured to communicate with other processors by wired or wireless communication, where such one or more processors may be configured as one or more processors in a device which may be similar or different run in a controlled device. Accordingly, use of the term "microprocessor" or "processor" may also be understood to include central processing units, arithmetic logic units, application specific integrated circuits (ICs), and/or task engines, and these examples are for illustration provided for non-limiting purposes.

Furthermore, unless otherwise stated, references to memory may include one or more processor-readable and accessible storage elements and/or components that may be internal to a processor-controlled device, in The processor-controlled device is external to, and/or can be accessed over a wired or wireless network using various communication protocols, and unless otherwise stated, can be configured to include a combination of external and internal storage, where such Memory can be contiguous and/or partitioned based on application. Accordingly, references to databases may be understood to include one or more memory associations, where such references may include commercially available database products (e.g., SQL, Informix, Oracle) as well as proprietary databases, and may also include Other structures for associative memory are included, such as links, queues, graphs, trees, which are provided for purposes of illustration and not limitation.

Unless otherwise stated, references to networks may include one or more intranets and/or the Internet, as well as virtual networks. Reference herein to microprocessor instructions or microprocessor-executable instructions in light of the foregoing may be understood to include programmable hardware.

Unless otherwise stated, the use of the word "substantially" can be understood to include precise relationships, states, arrangements, orientations, and/or other characteristics, and deviations thereof that are not material, as understood by those skilled in the art. significantly affect the disclosed methods and systems.

Throughout this disclosure, unless specifically stated otherwise, the articles "a" or "an" used to modify a noun will be understood to be used for convenience and to include one or more than one of the noun being modified.

Unless otherwise specified herein, elements, parts, modules, and/or portions thereof depicted by the drawings as communicating with, associated with, and/or based on something else may be understood as being in communication with something else as such To communicate, relate to and/or be based directly and/or indirectly on something else.

Although the methods and systems have been described by specific embodiments, they are not limited thereto. Obviously many modifications and variations may be apparent in light of the above teaching. Many other changes in details, materials, and arrangement of parts described and illustrated herein may be made by those skilled in the art.

Having described preferred embodiments of the invention, it will now be apparent to those skilled in the art that other embodiments that incorporate these concepts may be employed. Furthermore, software embodied as part of the present invention can be embodied in a computer program product comprising a computer usable medium. For example, such a computer-usable medium may include a readable storage device storing computer-readable program code segments, such as a hard disk drive, a CD-ROM, a DVD-ROM, or a computer floppy disk. The computer-readable medium may also include optical, wired, or wireless communication links carrying program code segments as digital or analog signals. Accordingly, the invention should not be considered limited to the described embodiments, but should be limited only by the spirit and scope of the appended claims.

Claims (7)

1. a method for computer execution, comprising:

The first access point AP in being disposed by segmentation plane detects the fault of controlled in wireless plane WCP device;

Hide the SSID of the described first access point AP in the beacon of being broadcasted by described first access point AP;

The information of the existing mobile unit MU of disassociation after the fault described controlled in wireless plane WCP device being detected is stored in the high-speed cache of described first access point AP;

Detection from existing mobile unit MU is responded; And

The detection of the mobile unit MU from the information had in described high-speed cache is responded, thus described first access point AP is shown as new mobile unit MU while being exposed to existing mobile unit MU be hidden, wherein

When existing mobile unit MU roam into neighboring access point AP then roam back described first access point AP time, because described mobile unit MU have received the response for detection from described first access point AP, so described first access point AP is visible for described mobile unit MU, described first access point AP accepts described mobile unit MU based on the described information in described high-speed cache, described first access point AP is in honeycomb redundant arrangement, wherein, neighboring access point AP and described first access point AP are managed by different controlled in wireless plane devices.

2. method according to claim 1, wherein, the new mobile unit MU roamed near described first access point AP can not listen to the beacon from described first access point AP.

3. method according to claim 1, wherein, described first access point AP does not respond to the detection from the new mobile unit MU roamed near described first access point AP.

4. method according to claim 1, comprises described first access point AP further and scans its radio frequency neighborhood, to judge whether neighboring access point AP reports wireless data service WDS.

5. method according to claim 4, wherein, when neighboring access point AP is reporting wireless data service WDS, described first access point AP is being set up with the interim wireless data service WDS link of described neighboring access point AP to be obtained the access to controlled in wireless surface function by described neighboring access point AP.

6. method according to claim 5, wherein, when new mobile unit MU is associated with described first access point AP, described first access point AP is sent request to controlled in wireless plane device by described neighboring access point AP via described interim wireless data service WDS link.

7. the first access point AP, comprising:

Memory;

Processor;

Communication interface;

Interconnection mechanism, this interconnection mechanism connects described memory, described processor and described communication interface; And

Wherein, described memory is by with following application code, controlled in wireless plane failure transfer manipulation during described application program provides segmentation plane to dispose, described application program is provided for the process of process information when being performed in described processor, described process makes described first access point AP perform following operation:

Described first access point AP in being disposed by segmentation plane detects the fault of controlled in wireless plane WCP device;

Hide the SSID of the described first access point AP in the beacon of being broadcasted by described first access point AP;

The information of the existing mobile unit MU of disassociation after the fault described controlled in wireless plane WCP device being detected is stored in the high-speed cache of described first access point AP;

Detection from existing mobile unit MU is responded;

The detection of the mobile unit MU from the information had in described high-speed cache is responded, thus described first access point AP is shown as new mobile unit MU while being exposed to existing mobile unit MU be hidden;

Wherein, when existing mobile unit MU roam into neighboring access point AP then roam back described first access point AP time, because described mobile unit MU have received the response for detection from described first access point AP, so described first access point AP is visible for described mobile unit MU, and wherein, described first access point AP accepts described mobile unit MU based on the information in described high-speed cache; And

Wherein, described first access point AP is in honeycomb redundant arrangement, and wherein neighboring access point AP and described first access point AP are by different controlled in wireless plane WCP device managements.