Abstract:
A system and techniques for managing power utilization in a wireless local area network are disclosed. The system can utilize an infrastructure power management module that is configured to identify and power down one or more unused wireless devices and/or dynamically reconfigure the wireless operation of one or more wireless devices to consume lower power while still operating according to network requirements.

Description:
TECHNICAL FIELD 
       [0001]    This disclosure relates to wireless network operation, and more particularly to low power infrastructure operation of wireless networks. 
       BACKGROUND 
       [0002]    Over the past few years, IEEE 802.11 based wireless networking has seen rapid advances. Today, wireless networks are now able to meet or exceed mobility, security, quality of service and performance requirements in an enterprise. Many vendors are announcing products based on 802.11n technology that have achieved up to 300 Mbps network speed. The increased performance and security have been achieved by Wireless Local Area Networking (WLAN) vendors using purpose built hardware platforms that can use multiple cores for computation. This has unfortunately increased the power consumption and hence the cost of operating the wireless network. 
         [0003]    In this context, enterprises have deployed wireless switches and/or access points to provide wireless access to its employees and customers. There are, however, a number of factors that can influence the number of wireless switches, access points and their deployed placement. For example, in some embodiments, the following factors are considered: number of wireless users, desired application throughput per user, coverage area for the wireless network, desired application throughput at a given distance from an access point, user density, seamless roaming for applications such as voice, greater access point density for improved location tracking accuracy, as well as type of wireless client. 
         [0004]    Typically, a wireless network is over deployed for capacity and function in anticipation of future growth. For example, administrators may choose multi-radio access points even though a single radio access point may suffice for their current needs. Although wireless standards such as 802.11 have focused on reduced power consumption of wireless clients, the standards have left the larger power consumption issue of WLAN infrastructure relatively unaddressed. This over deployment has resulted in WLAN infrastructure consuming and radiating more power than is required for the present needs of the enterprise. This can lead to unnecessary RF transmissions that can impact the performance of the wireless network. For example, in some 802.11 based wireless networks where wireless clients and access points contend for access to the medium, large numbers of 802.11 transmitters can reduce the available transmission opportunities for remaining clients thus negatively impacting the performance of the wireless network. 
         [0005]    Accordingly, there is a need for improved systems and techniques for the management and control of power consumption in WLAN infrastructures. 
       SUMMARY 
       [0006]    A system and techniques for managing power utilization in a wireless local area network are disclosed. The system can utilize an infrastructure power management module that is configured to identify and power down one or more unused wireless devices and/or dynamically reconfigure the wireless operation of one or more wireless devices to consume lower power while still operating according to network requirements. 
         [0007]    Various aspects of the invention relate to monitoring and reconfiguring network components. For example, according to one aspect, a method of managing power utilization in a wireless local area network (WLAN) infrastructure includes monitoring network operation information of a first network component included in the WLAN infrastructure, the network operation information including a power utilization of the first network component, comparing the power utilization of the first network component to a threshold utilization value defined for the first network component, and reconfiguring the first network component to operate at the threshold utilization value based on the comparison. The first network component can be a wireless switch or a wireless access port. The method also can include powering down the first network component based on the comparison. 
         [0008]    In one embodiment, the method further includes defining a rule for the first network component, the rule including operational network control information for the first network component and the threshold utilization value, and applying the rule to the first network component during the reconfiguration. Applying the rule can include identifying the rule from a plurality of rules stored for a plurality of network components included in the WLAN infrastructure, each of the rules associated with at least one of the plurality of network components. 
         [0009]    In another embodiment, reconfiguring the first network component includes minimizing power utilization of the first network component based on the comparison. 
         [0010]    In one embodiment, the method includes monitoring network operation information of a second network component included in the WLAN infrastructure, the network operation information of the second network component including a second network component utilization, and powering on the first network component if the second network component utilization exceeds a second threshold value, wherein the second network component is at least one of a wireless switch and wireless access port. 
         [0011]    The method can include powering on the first network component periodically to monitor the network operation information of the second network component. The first network component also can be powered off based on inactivity information included in network operation information. 
         [0012]    In yet another embodiment, the method includes reconfiguring the first network component to operate at a full power utilization level. The power utilization obtained from the first network component can be averaged over a period of time. If the first network component is powered off, the method can include powering on the first network component in response to receiving location information indicating a mobile device approaching a coverage area defined for the first network component. 
         [0013]    In yet another embodiment, at least one of the monitoring, the comparing, and the reconfiguring steps are integrated in and executed from a network management platform of the WLAN infrastructure. In an alternative embodiment, at least one the monitoring, the comparing, and the reconfiguring are integrated in and executed from the first network component. 
         [0014]    In another aspect, a system for managing power consumption of a WLAN infrastructure includes a wireless network, a first network component operatively coupled to the network, the first network component being at least one of a wireless switch and a wireless access port, and an infrastructure power management module. The power management module is configured to 1) monitor network operation information of a first network component included in the WLAN infrastructure, the network operation information including a power utilization of the first network component at a first point in time, 2) compare the power utilization utilized by the first network component to a threshold utilization value defined for the first network component, and 3) reconfigure the first network component to operate at the threshold utilization value based on the comparison. the first network component can be a wireless switch or a wireless access port. 
         [0015]    In one embodiment, the infrastructure power management module is configured to define a rule for the first network component, the rule including operational network control information for the first network component and the threshold utilization value, and apply the rule to the first network component during the reconfiguration. 
         [0016]    In another embodiment, the infrastructure power management module is configured to power off the first network component based on the comparison. 
         [0017]    In yet another embodiment, the infrastructure power management module is configured to monitor network operation information of a second network component included in the WLAN infrastructure, the network operation information of the second network component including a second network component utilization, and power on the first network component if the second network component utilization exceeds a second threshold value, wherein the second network component is at least one of a wireless switch and wireless access port. 
         [0018]    Several benefits can be derived from the present invention. For example, by reducing power consumption by powering down unused or under used wireless devices, there may be an increased cost saving if auxiliary systems, such as a cooling system, can be powered down to take advantage of wireless infrastructure downtime. In addition, powering down unused wireless devices or disabling unused LANs can reduce the amount of radio frequency (RF) energy radiated in the environment. This can reduce the RF noise floor of other networks and improve the overall performance of 802.11 wireless networks due to contention to access the wireless medium being reduced. 
         [0019]    The present invention can also be used to enforce a spectrum management discipline necessary to maintain a high performance network. In addition, the window of time when wireless intrusion attacks can be initiated against the network would be reduced by powering down access devices outside of normal business hours. 
         [0020]    Additional features and advantages will be readily apparent from the following detailed description, the accompanying drawings and claims. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0021]      FIG. 1  is a schematic representation of a system according to an embodiment of the present invention. 
           [0022]      FIG. 2  is a state transition diagram showing normal and power down states for infrastructure network components according to an embodiment of the present invention. 
           [0023]      FIG. 3  illustrates an exemplary method executed by an infrastructure power management module according to an embodiment of the present invention. 
       
    
    
       [0024]    Like reference symbols in the various drawings indicate like elements. 
       DETAILED DESCRIPTION 
       [0025]      FIG. 1  is a schematic representation of a system  10  in accordance with an example embodiment of the invention. In this example, the system  10  includes a network management platform  12  that is configured to manage and control infrastructure resources (wireless switches  20 A-B and access ports  22 A-B) of a wireless network  18 . The network  18  may include or communicate with any number of additional network components, such as a traditional local area network (“LAN’). A practical embodiment can have any number of wireless switches, each supporting any number of wireless access devices, and each wireless access device supporting any number of wireless mobile units  24 A-J. Indeed, the topology and configuration of the system  10  can vary to suit the needs of a particular application and FIG.  1  is not intended to limit the application or scope of the invention in any way. 
         [0026]    As shown in  FIG. 1 , each wireless access device  22 A-B is a wireless access port, which is a “thin” device that relies on network intelligence and management functions provided by the network management platform  12 . Each wireless access port  22 A-B as described herein is configured to receive data from the mobile units  22 A-J over wireless links. Once data is captured by the wireless access device, the data is processed for communication within the network  18 . For example, data can be encapsulated into a packet format compliant with a suitable data communication protocol. In the example embodiment, data is routed within the network  18  using conventional Ethernet 802.3 addressing (including standard Ethernet destination and source packet addresses). In alternate embodiments, data can be routed within computer network  10  using conventional Internet Protocol (“IP”) techniques. 
         [0027]    The wireless mobile units  22 A-J are wireless devices that can physically move around the network  18  and communicate with network components via the wireless access ports  22 A-B. Examples of mobile units include, but are not limited to, cellular phones, smart phones, personal digital assistants (PDA), and laptop computers. 
         [0028]    The network management platform  12  provides centralized management for mobile units  22 A-J and infrastructure devices  20 A-B,  22 A-B. For example, in one embodiment, the network management platform  12  is configured to automatically stage mobile devices, update software resident on deployed infrastructure devices and mobile devices, easily troubleshoot user problems by creating and delivering customized messages to users, and monitor and analyze mobile device statistics and network infrastructure. As such, the network management platform  12  can monitor the number of radios (e.g., access ports and switches) currently operational and number of mobile devices that are connected to the wireless network using a particular radio. In one embodiment, the management platform  12  is a rack-mounted appliance with a Web-based console for wireless network management and mobile device management. One example of the network management platform  12  is the Mobility Services Platform  3  provided by Motorola, Inc. 
         [0029]    As shown in  FIG. 1 , in one embodiment, the management platform  12  includes a power management module (PMM)  14 . It will be appreciated by one skilled in the art that the present invention is not limited to the PMM  14  being included in the management platform  12 . For example, in one embodiment, the PMM  14  is configured to operate on one or more switches  20 A-B. 
         [0030]    The PMM  14  allows a network administrator to specify one or more rules of wireless network operation for network infrastructure components. The rules are then stored and enforced by the PMM  14 . In one embodiment, rules specified by a network administrator are stored in a relational database and are accessible to the PMM  14  for enforcement. In another embodiment, specified rules are stored by the PMM  14  in a directory server, such as a Lightweight Directory Access Protocol (&#39;LDAP&#39;) server, and are accessible to the PMM  14  for enforcement. In other embodiments, specified rules are stored in either a configured area in the memory of the network management platform  12 , a configured area in the memory of one or more switches  20 A-B, or both the network management platform  12  and switches  20 A-B. 
         [0031]    As used in this disclosure, the term ‘enforced’ refers to the ability of the PMM  14  to act upon and reconfigure network components according to rule specifications. Examples of various rules that can be specified and enforced by the PMM  14  are described in Table 1. It will be appreciated by one skilled in the art that the present invention is not limited to the rules described below and these rules are merely exemplary. 
         [0000]    
       
         
               
               
               
             
           
               
                   
                 TABLE 1 
               
               
                   
                   
               
               
                   
                 RULE FOR PMM 
                 ACTION TAKEN BY PMM 
               
               
                   
                   
               
             
             
               
                   
                 2.4 GHz is the only 
                 Power Management Module 
               
               
                   
                 allowed frequency band 
                 (PMM) sends configuration 
               
               
                   
                 for IT wireless 
                 messages to wireless 
               
               
                   
                 operations 
                 switches and access points 
               
               
                   
                   
                 to shutdown radios that are 
               
               
                   
                   
                 operating at a different 
               
               
                   
                   
                 GHz. If a single radio 
               
               
                   
                   
                 access point is operating 
               
               
                   
                   
                 on a different GHz band, 
               
               
                   
                   
                 PMM can send a message to a 
               
               
                   
                   
                 Power over Ethernet (PoE) 
               
               
                   
                   
                 switch to shutdown a 
               
               
                   
                   
                 particular PoE port 
               
               
                   
                 Wireless access points 
                 PMM analyzes mobile user 
               
               
                   
                 that have not been used 
                 associations over the last 
               
               
                   
                 for access for 15 
                 15 days for every wireless 
               
               
                   
                 consecutive days must 
                 device and makes a 
               
               
                   
                 be shutdown. 
                 determination to shutdown 
               
               
                   
                   
                 the unused wireless 
               
               
                   
                   
                 devices. 
               
               
                   
                 Wireless access points 
                 PMM analyzes network 
               
               
                   
                 with 1% or less 
                 utilization over the last 
               
               
                   
                 utilization for 15 
                 15 days for every wireless 
               
               
                   
                 consecutive days must 
                 device and identifies 
               
               
                   
                 be shutdown if 
                 under-utilized wireless 
               
               
                   
                 neighboring wireless 
                 devices. PMM also inspects 
               
               
                   
                 devices are available 
                 neighboring APs and 
               
               
                   
                 for access. 
                 determines if they can 
               
               
                   
                   
                 modify their transmit power 
               
               
                   
                   
                 and data rates to fill any 
               
               
                   
                   
                 coverage hole of the under- 
               
               
                   
                   
                 utilized AP. If the 
               
               
                   
                   
                 coverage hole can be filled 
               
               
                   
                   
                 by neighboring AP&#39;s, the 
               
               
                   
                   
                 under utilized AP is 
               
               
                   
                   
                 powered down. 
               
               
                   
                 Wireless access points 
                 PMM enforces this policy by 
               
               
                   
                 must be used during 
                 sending power down message 
               
               
                   
                 normal business hours 
                 to wireless devices outside 
               
               
                   
                 only. 
                 normal business hours. 
               
               
                   
                 Wireless service set 
                 PMM enforces this policy by 
               
               
                   
                 identifiers (SSID&#39;s) 
                 examining the SSID&#39;s used 
               
               
                   
                 that have not been used 
                 for mobile user 
               
               
                   
                 for access on any 
                 associations across all 
               
               
                   
                 access point (AP) for 
                 access point radios. If any 
               
               
                   
                 15 consecutive days 
                 SSID is unused for wireless 
               
               
                   
                 must be turned off. 
                 connection in any radio 
               
               
                   
                   
                 over the last 15 days, SSID 
               
               
                   
                   
                 operation is disabled on 
               
               
                   
                   
                 that radio. 
               
               
                   
                   
               
             
          
         
       
     
         [0032]    An example state transition diagram showing normal and power down states associated with network infrastructure components is shown in connection with  FIG. 2 . It will be appreciated by one skilled in the art that the present invention is not limited to powering down network components to reduce power consumption. For example, in one embodiment, the PMM is configured to reconfigure infrastructure components (e.g., access ports and switches) from a low or zero power utilization back to a normal power utilization based on rules specified. 
         [0033]    For example, in one embodiment, when an access port  22 A is powered down due to low or no utilization, the PMM  12  can configure neighboring access ports  22 B to process data traffic from mobile users  24 A-E associated with the powered down access port. If the PMM  14  detects an increased load on the neighboring access port  22 B and data traffic exceeds a pre-defined threshold level defined in a rule for the access port  22 B, the PMM  14  can reconfigure the powered down access port  22 A to operate at normal power levels. 
         [0034]    In another embodiment, where the network  18  is configured to include a locationing system (not shown), the PMM  14  can power down network infrastructure devices  20 A-B,  22 A-B based on whether mobile device users are in the area covered by the locationing system. Likewise, if the locationing system reports that a mobile user is on the verge of entering its coverage area, the PMM  14  can configure appropriate network infrastructure devices to provide services to the mobile user. 
         [0035]    In yet another embodiment, infrastructure devices are configured to periodically be powered on to listen for probe requests from mobile units. If the PMM  14  detects that the powered on device is receiving a stronger signal than a neighboring infrastructure device, the PMM  14  configures the powered on device to remain on. 
         [0036]    Referring now to  FIG. 3 , an example method executed by the PMM  14  is shown. First, the PMM  14  allows a network administrator to specify one or more rules for a first network component included in the WLAN  32 . Next, once the rule is specified, the PMM  14  stores the one or more network component rules  34  into a data store. Next, the PMM  14  monitors network operation of a first network component  36 . The monitoring can be done continuously or periodically to identify network operation information of the component. For example, in one embodiment, the network operation information includes a power utilization of the first network component. The PMM  14  can average the power utilization over a period of time. 
         [0037]    Next, the PMM  14  identifies at least one rule associated with the monitored first network component from the stored rules  38 . The PMM  14  then compares network operation information of the first network component to a threshold value specified in the stored rule  40 . For example, in one embodiment, the PMM  14  compares the power utilization of the first network component to a threshold power value defined for the first network component. 
         [0038]    Next, the PMM  14  reconfigures the first network component based on the comparison  42 . For example, in one embodiment, reconfiguring the first network component includes minimizing power utilization of the first network component. In another embodiment, reconfiguring the first network component includes operating the network component at a full power utilization level. The reconfiguring of the first network component can also include powering off the first network component. For example, in another embodiment, the first network component is powered-off based on inactivity information included in the network operation information. 
         [0039]    In one embodiment, if the first network component is powered off, the PMM  14  powers on the first network component in response to receiving location information that a mobile device is approaching a coverage area defined for the first network component. This embodiment can include a locationing system operatively coupled to the WLAN to provide the location information. The PMM  14  can also power off the first network component based on inactivity information included in the network operation information. 
         [0040]    The PMM  14  can monitor more than one network component. For example, in one embodiment, as shown in  FIG. 3  at step  44 , the PMM  14  can be implemented to monitor network operation information of a second network component included in the WLAN infrastructure. The second network component can be a wireless switch or wireless access port. The network operation information of the second network component can include a second network component utilization. The PMM  14  can then reconfigure the first network component based on power utilization of the second network component  46 . For example, in one embodiment, the PMM  14  can power on the first network component if the second network component utilization exceeds a second threshold value. In yet another embodiment, the PMM  14  powers on the first network component periodically to monitor the network operation information of the second network component. 
         [0041]    Various features of the system may be implemented in hardware, software, or a combination of hardware and software. For example, some features of the system may be implemented in computer programs executing on programmable computers. Each program may be implemented in a high level procedural or object-oriented programming language to communicate with a computer system or other machine. Furthermore, each such computer program may be stored on a storage medium such as read-only-memory (ROM) readable by a general or special purpose programmable computer or processor, for configuring and operating the computer to perform the functions described above.