Abstract:
A method and system is disclosed for providing intelligent remote access to wireless transmit/receive units (WTRUs). A translator is provided in base stations so that system controllers may issue application level network management protocol messages to base stations. The messages are transmitted by the translator to a medium access control (MAC) messaging protocol and forwarded to WTRUs. Information provided by WTRUs to base stations is translated from a MAC protocol to an application level network management protocol so that the information may be accessed by system controllers using application level network management protocols.

Description:
CROSS REFERENCE TO RELATED APPLICATION  
       [0001]     This application claims priority from U.S. Provisional Application No. 60/517,687 filed on Nov. 5, 2003 which is incorporated by reference as if fully set forth. 
     
    
     FIELD OF INVENTION  
       [0002]     The present invention is related to wireless communication systems. More particularly, the present invention is related to a method and system for providing remote access to wireless/transmit receive units so that network management functions may be efficiently communicated to and from WTRUs.  
       BACKGROUND  
       [0003]     Referring initially to  FIG. 1 , there is shown a conventional wireless communication system  100 . The system  100  includes at least one wireless transmit/receive unit (WTRU)  102 , at least base station  104 , and at least one system controller  106  for controlling and otherwise managing communications within the system  100 .  
         [0004]     Typically, system functionality is decomposed into modules called layers to simplify and separate the tasks associated with data transmission. Therefore, for purposes of clarity, also shown in  FIG. 1  is a sample protocol stack  108 . In protocol stack  108 , the highest level is the application layer  112 . The application layer  112  is the layer where processes of two entities communicate with each other. Below the application layer  112  is the transport layer  114 , which provides for logical communication between two communicating entities so that, from the application&#39;s perspective, it is if the two entities are directly connected to each other. There are two dominant transport layer protocols; transmission control protocol (TCP) and user datagram protocol (UDP). Beneath the transport layer  114  is the network layer  116 . The network layer  116  encapsulates datagrams from the transport layer  114  and encapsulates them in packets and routes them through a network to their respective destinations using the Internet Protocol (IP). Such packets are often referred to as IP packets. Below the network layer  116  are the data link layer  118  and the physical layer  120  where the task of moving IP packets between individual links is performed. The protocols implemented at the link layer  118  and physical layer  120  may vary depending on the type of link being crossed (e.g. wire or wireless). Herein, purely for convenience, protocols implemented at the link layer  118  and physical layer  120  are collectively referred to as medium access control (MAC) messaging protocols. It is noted that the use of the term MAC messaging protocols is not limiting and may include all types of link layer channels including, but not limited to, broadcast and point-to-point channels.  
         [0005]     A system controller  106  typically communicates with a base station  104  regarding network management functions using some type of application level network management protocol implemented at the application layer  112 . Because the communications are carried out at the application layer  112 , there is a fair amount of data exchanged between the controller  106  and base station  104  dedicated solely to management. Since communications between the system controller  106  and base station  104  are typically performed over a wired interface having plenty of bandwidth, communicating management functions at the application layer  112  is typically not a problem. Further, both entities typically both utilize and support the relevant application level protocol.  
         [0006]     Communicating network management functions at the application layer  112 , however, is often difficult or impossible to implement between a base station and a WTRU  102 . As an initial matter, application level protocols tend to be relatively complex requiring functionality at each layer of the protocol stack  108  and significant amounts of data to be exchanged over the air. For example, where an application level network management protocol is used, each message  122  (also shown in  FIG. 1 ) is encapsulated with a TCP or UDP datagram  124 , which is encapsulated within an IP packet  126  within a MAC frame  128 . Therefore, communicating management functions to and from a WTRU using an application level network management protocol is a very inefficient use of bandwidth. Further, even where such inefficient use of bandwidth may be tolerable, WTRUs often do not implement application level software for performing network management functions thereby making such communications impossible.  
         [0007]     It would therefore be desirable to provide a method and system whereby network management functions may be efficiently communicated to and from WTRUs.  
       SUMMARY  
       [0008]     The present invention is a method and system for providing intelligent remote access to wireless transmit/receive units (WTRUs). A translator is provided in base stations so that system controllers may issue application level network management protocol messages to base stations. The messages are translated by the translator to a medium access control (MAC) messaging protocol and forwarded to WTRUs. Information provided by WTRUs to base stations is translated from a MAC protocol to an application level network management protocol so that the information may be accessed by system controllers using application level network management protocols. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]      FIG. 1  is a block diagram of a conventional wireless communication system, protocol stack, and encapsulated application layer message.  
         [0010]      FIG. 2  is a block diagram of a wireless communication system in accordance with the present invention.  
         [0011]      FIG. 3  is block diagram of an 802.11 type wireless network.  
         [0012]      FIG. 4  is a block diagram of a base station, a WTRU, and a network management station of the 802.11 type wireless network shown in  FIG. 3  wherein network management functions are communicated to and from a WTRU in accordance with the present invention.  
         [0013]      FIG. 5  is a flow diagram of a method wherein a system controller may obtain parameters from a WTRU in accordance with the present invention.  
         [0014]      FIG. 6  is a flow diagram of a method wherein a system controller may update or otherwise change parameters of a WTRU in accordance with the present invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0015]     Herein, a base station includes, but is not limited to, a Node B, an access point, a site controller or other interfacing device in a wireless environment that provides WTRUs with wireless access to a network with which the base station is associated. Herein a WTRU includes, but is not limited to, a user equipment, a mobile station, a fixed or mobile subscriber unit, a pager, or any other type of device capable of operating in a wireless environment. WTRUs include personal communication devices, such as phones, video phones, and Internet ready phones that have network connections, and portable personal computing devices, such as PDAs and notebook computers with wireless modems that have similar network capabilities. Herein, a system controller includes a radio network controller (RNC), a network management station (NMS), or any other type of controller for performing system control features in a wireless communication system.  
         [0016]     The use of MAC messaging protocols over an air interface between a base station and WTRU is much more efficient than using application level network management protocols, as described in the Background section. Further, the use of MAC messaging protocols is preferred because they utilize the data link and physical layers where the information of interest to the system controller is located. To explain further, the type of information related to the management of WTRUs that is of interest to a site controller includes WTRU performance, configuration, and fault reporting. For example, the performance parameters may include a received/transmitted packet error rate, the configuration parameters may include a WTRU&#39;s preferred service provider, and the fault reporting parameters may include a number of failed authentication attempts. Since these items are available at the data link and physical layers, the present invention uses MAC messaging protocols between base stations and WTRUs and application level network management protocols between the controllers and base stations. Further, a translator is provided in base stations so that the system controllers have direct access to the WTRUs.  
         [0017]     By way of example, referring now to  FIG. 2 , there is shown a system  200  in accordance with the present invention. The system  200  includes at least one WTRU  202 , at least one base station  204 , and at least one system controller  206 . In this embodiment, a translator  208  is provided at the base station  204 . The translator  208  is configured to translate back and forth between application level network management protocols and MAC messaging protocols.  
         [0018]     In one embodiment, when the WTRU  202  begins operating within a coverage area provided by the base station  204 , the base station  204  uses a MAC message protocol to obtain (i.e. request and receive) the WTRU&#39;s  202  settings and/or parameters (hereinafter collectively referred to as “parameters”), which may include any information within the WTRU  202  that is relevant to network management. The parameters are translated by translator  208  from an MAC messaging protocol to an application level network management protocol and stored in a database  210  in the base station  204 . The system controller  206  may then access the parameters of WTRU  202  as desired from the base station  204  using an application level network management protocol. The base station  204  is preferably configured to periodically query the WTRU  202  for its parameters to avoid having outdated data in its database  210 .  
         [0019]     In another embodiment, the system controller  206  may not only read the parameters of WTRU  202 , but may also write to them as well. In this embodiment, the system controller  206  may transmit updated parameters to the WTRU  202  by sending a message using an application level network management protocol to base station  204 . Then, once the updated parameters are received by base station  204 , the translator  208  translates them into a MAC messaging protocol format and forwards the translated parameters to WTRU  202 . WTRU  202  then updates its parameters accordingly. The system controller  206  may also utilize this embodiment to send messages (via base station  204 ) to WTRU  202  instructing it to report back to the base station  204 , who will forward the report to the system controller  206 , when certain events occur.  
         [0020]     To provide a more specific example of how the present invention may be implemented in an 802.11 type network, reference is made to  FIGS. 3 and 4 . It is noted that while the network shown in  FIG. 3  is referred to as a “802.11 type network,” the system may be any type of network in the 802 family of networks including but not limited to wireless local area networks (WLANs), wireless personal area networks (WPANs), wireless metropolitan area networks (WMANs), etc. In  FIG. 3 , a schematic block diagram of a wireless network  300  is shown. The wireless network  300  comprises a network management station (NMS)  306 , a plurality of base stations  314 ,  316 , and a plurality of WTRUs  312 ,  318 . WTRUs  312 ,  318  are grouped with there respective base stations  314 ,  316 . These groupings are commonly referred to as basic service sets (BSSs)  320 ,  322 . A plurality of BSSs  320 ,  322  are connected via a distribution system (DS)  324  wherein a plurality of BSSs are commonly referred to as an extended service set (ESS). The base stations  314 ,  316  are preferably connected to the NMS  306  over a network  319 .  
         [0021]     Referring now to  FIG. 4 , a block diagram of a WTRU  312 , a base station  314 , and NMS  306  in network  300  of  FIG. 3  is shown. The NMS  306  communicates network management information to and from base station  314  using an application level network management protocol. Purely by way of example, the application level network management protocol shown in this embodiment is the simple network management protocol (SNMP), but any application level protocol, propriety or otherwise may be used. An example of another type of application level network management protocol that may be used is the extended markup language (XML) protocol.  
         [0022]     The NMS  306  may transmit SNMP messages through an SNMP port  400 . It is noted that with respect to the transport level, either TCP or UDP may be used as desired. The parameters that are of interest to an NMS  306  in an 802.11 type network are maintained in a management information base (MIB). Typically, in 802.11 type networks, base stations and WTRUs each maintain a MIB wherein their respective parameters are stored. For example, in the present invention, base station  314  includes a database  402  wherein a MIB is maintained for the base station itself (i.e. MIB base station . Additionally, the base station  314  includes a database  404  wherein a MIB of all WTRUs associated with base station  314  are maintained (i.e. MIB WTRUs ). As explained above, base station  314  also includes a translator  406  for translating back and forth between SNMP and a MAC messaging protocol. In this embodiment, the MAC messaging protocol is preferably an 802.11k messaging protocol. The 802.11k messaging protocol is a data link layer/physical layer protocol communicating parameters of a WTRU  312  to a base station  314 .  
         [0023]     For the NMS  306  to obtain MIB information regarding a base station  314 , the NMS  306  simply sends a request using SNMP (i.e. an SNMP Get message) and the base station  314  receives the request and responds as requested. Therefore, in the present invention, the base station  314  preferably periodically obtains the WTRU&#39;s  312  MIB using 802.11k messaging and stores it in database  404  so that the WTRU MIBs are available in the base station  314 . It is noted that the MIB may be translated to SNMP upon receipt by the base station  314  for storing in translated format or the MIB may be translated when an NMS  306  requests it. In either case, the MIB is transmitted to the NMS  306  in SNMP format. Further, in another embodiment, the base station  314  does not periodically obtain the WTRU MIBs and instead obtains WTRU&#39;s  312  MIB when the NMS  306  requests it.  
         [0024]     To obtain the WTRU&#39;s  312  parameters, the NMS  306  requests the parameters using an SNMP message through its SNMP port  400 . In SNMP, such a request may be referred to as a Get message, as indicated above. The base station  314  receives the request at its SNMP port  408  and provides the WTRU&#39;s  312  parameters to the NMS  306  in SNMP format. Where the MIBs are stored in database  404  in SNMP format, the MIB for WTRU  312  is simply transmitted to the NMS  306 . Where the MIBs are stored in 802.11k messaging format, the MIB for WTRU  312  is translated by the translator  406  and then sent to the NMS  306 . The MIBs are preferably provided from the base station  314  to the NMS  306  using the SNMP ports  408 ,  400 . As noted above, if WTRU&#39;s  312  MIB is stale (i.e. has been in database  404  for over a predetermined amount of time), base station  314  will obtain a fresh MIB from WTRU  312 .  
         [0025]     In another embodiment of the present invention, the NMS  306  may send an SNMP message to base station  314  requesting that certain WTRU  312  traps are set whereby WTRU  312  will report when certain events happen. The NMS  306  sends an SNMP message (i.e. an SNMP Trap message) to a base station  314  for a particular WTRU  312 . The base station  314  receives the SNMP message through the SNMP port  408 . The translator  406  in the base station  314  translates the SNMP message into an 802.11k message. Then, the base station  314  transmits the 802.11k message to request the particular WTRU  312  report the trap condition to the base station  314  when the triggering event has occurred. Once the event actually occurs, the WTRU  312  sends an 802.11k message to the base station  314 . The translator  406  of the base station  314  then translates the message into SNMP and sends it to the NMS  306 .  
         [0026]     As described herein, the NMS  306  can set MIB parameters of WTRU  312  by sending an SNMP message to a base station  314  wherein the base station translates the updated parameters to 802.11k and forwards the updated parameters to WTRU  312 . However, the NMS  306  may, in certain circumstances, wish to interface directly with the WTRU  312 . Therefore, in another embodiment, the NMS  306  is configured to transmit and receive SNMP messages to and from a WTRU SNMP agent so that the WTRU&#39;s  312  MIB parameters may be set via a standard SNMP (Set) message sent over the air. Even though this signaling is transmitted using SNMP messaging over the air, this is typically low volume signaling, and therefore the adverse effect is not substantial.  
         [0027]     Further, the setting of WTRU  312  MIB configuration parameters using SNMP over the air may be optimized using the teachings of the present invention. For example, by setting parameters and/or certain triggers using the translator of the present invention, WTRUs may be configured to revert to certain default configurations based on certain events. More specifically, a WTRU  312  may be configured to revert to a default configuration when it returns to its home network, for example. This may be used to eliminate the need for low volume SNMP signaling altogether for purposes of setting WTRU parameters. Alternatively, the parameters may be set using the translator and a combination of application level and MAC level messaging, as described herein.  
         [0028]     The base station  314  components described herein are preferably implemented on a single integrated circuit, such as an application specific integrated circuit (ASIC). However, the components may also be readily implemented on multiple separate integrated circuits.  
         [0029]     Referring now to  FIG. 5 , there is shown a flow diagram of a method  600  wherein a system controller may obtain parameters from a WTRU. The method  600  begins in step  602  when a WTRU enters a coverage area of a wireless communication system. Then, in step  604 , a base station associated with the WTRU requests the WTRU&#39;s parameters using a MAC messaging protocol. Next, in step  606 , the WTRU transmits the parameters to the base station using a MAC messaging protocol. The base station translates the parameters from the MAC messaging protocol to an application level management protocol (step  608 ) and stores the translated parameters (step  610 ). The translated parameters are preferably stored in a database residing in or otherwise affiliated with the base station. As noted above, steps  604  to  610  may be repeated as necessary to maintain a fresh set of data. Once the translated parameters are stored at the base station, the controller may obtain them from the base station as needed using any type of application level network management protocol (step  612 ). It is noted that, in an additional embodiment, the translation step may be triggered once an actual request for parameters is received. In this case, the parameters are stored in MAC messaging format.  
         [0030]     Referring now to  FIG. 6 , there is shown a flow diagram of a method  700  wherein a system controller may update or otherwise change parameters of a WTRU. In this embodiment, the system controller has write access to the parameters of the WTRU. The method  700  begins in step  702  where a system controller issues a request using an application level network management protocol to update parameters of a WTRU(s). The updated parameters are preferably sent with the request. In step  704 , the request is received at the base station and translated to MAC messaging protocol format. The base station then forwards the request to the WTRU in step  706 . The WTRU then updates its parameters according to the request in step  708 . Method  700  may also be used to set traps at WTRUs where WTRUs perform certain actions when certain events occur, as explained above.  
         [0031]     It is important to note that the present invention may be implemented in any type of wireless communication system. By way of example, the present invention may be implemented in UMTS-TDD, UMTS-FDD, CDMA2000, TDSCDMA, GSM, WLAN, WPAN, WMAN or any other type of wireless communication system. Further, although the features and elements of the present invention are described in the preferred embodiments in particular combinations, each feature or element can be used alone or in various combinations with or without other features and elements of the present invention.