Balancing paging load and tracking area updates

Abstract

A method for assigning a tracking area (TA) is disclosed. A mobility state of a wireless transmit/receive unit (WTRU) is determined and the TA is assigned based on the determined mobility state. Also disclosed is a method for accessing a closed subscriber group (CSG) TA. A CSG TA identifier is received at a WTRU and is stored. A CSG TA broadcast is received and the broadcast CSG TA is accessed if an identifier of the broadcast CSG TA matches the stored CSG TA identifier. Also disclosed is a method for changing a mobility state of a WTRU. A current mobility state of the WTRU is determined and a predetermined metric of the WTRU is examined. The predetermined metric is evaluated to determine if the metric has crossed a threshold and the mobility state is changed based on the evaluated metric.

What is claimed is: 
     
         1 . A wireless transmit/receive unit (WTRU) for use in a wireless communication network, the WTRU comprising:
 circuitry configured to:
 receive a list of closed subscriber group (CSG) cell identities that the WTRU is permitted to access; 
 camp on a CSG cell whose identity is not in the list; and 
 on a condition that the WTRU is camping on a CSG cell whose identity is not on the list, transmit a tracking area update request message to the wireless communication network, wherein the tracking area update request message is transmitted to balance a signaling load; and 
 receive, in response, a tracking area update accept message from the wireless communication network. 
   
     
     
         2 . The WTRU of  claim 1 , wherein the WTRU is assigned to a plurality of Long Term Evolution (LTE) tracking areas, wherein the plurality of LTE tracking areas are used at the edges of at least one of the plurality of LTE tracking areas. 
     
     
         3 . The WTRU of  claim 1 , wherein the circuitry is further configured to transmit an indication that the WTRU has selected a CSG cell whose identity is not on the list. 
     
     
         4 . The WTRU of  claim 1 , wherein the circuitry is further configured to periodically update a tracking area of the WTRU in response to an expiration of a timer. 
     
     
         5 . The WTRU of  claim 1 , wherein the circuitry is further configured to transmit mobility information. 
     
     
         6 . The WTRU of  claim 1 , wherein the tracking area update accept message includes a new list of tracking area IDs assigned to the WTRU. 
     
     
         7 . The WTRU of  claim 1 , wherein the circuitry is further configured to exchange non-access stratum (NAS) signaling. 
     
     
         8 . A method performed by a wireless transmit/receive unit (WTRU) for use in a wireless communication network, the method comprising:
 receiving a list of closed subscriber group (CSG) cell identities that the WTRU is permitted to access;   camping on a CSG cell whose identity is not in the list; and   on a condition that the WTRU is camping on a CSG cell whose identity is not on the list, transmitting a tracking area update request message to the wireless communication network, wherein the tracking area update request message is transmitted to balance a signaling load; and   receiving, in response, a tracking area update accept message from the wireless communication network.   
     
     
         9 . The method of  claim 8 , wherein the WTRU is assigned to a plurality of Long Term Evolution (LTE) tracking areas, wherein the plurality of LTE tracking areas are used at the edges of at least one of the plurality of LTE tracking areas. 
     
     
         10 . The method of  claim 8 , further comprising transmitting an indication that the WTRU has selected a CSG cell whose identity is not on the list. 
     
     
         11 . The method of  claim 8 , further comprising periodically updating a tracking area of the WTRU in response to an expiration of a timer. 
     
     
         12 . The method of  claim 8 , further comprising transmitting mobility information. 
     
     
         13 . The method of  claim 8 , wherein the tracking area update accept message includes a new list of tracking area IDs assigned to the WTRU. 
     
     
         14 . The method of  claim 8 , further comprising exchanging non-access stratum (NAS) signaling. 
     
     
         15 . A method performed by a wireless transmit/receive unit (WTRU) for use in a wireless communication network, the method comprising:
 receiving a list of closed subscriber group (CSG) cell identities that the WTRU is permitted to access;   camping on a CSG cell whose identity is not in the list;   on a condition that the WTRU is camping on a CSG cell whose identity is not on the list, transmitting a tracking area update request message to the wireless communication network;   receiving, in response, a tracking area update accept message from the wireless communication network; and   periodically updating the tracking area in response to an expiration of a timer.   
     
     
         16 . The method of  claim 15 , further comprising transmitting an indication that the WTRU has selected a CSG cell whose identity is not on the list. 
     
     
         17 . The method of  claim 15 , further comprising exchanging non-access stratum (NAS) signaling. 
     
     
         18 . The method of  claim 15 , further comprising transmitting the tracking area update request message to balance a signaling load. 
     
     
         19 . The method of  claim 15 , wherein the WTRU is assigned to a plurality of Long Term Evolution (LTE) tracking areas and further wherein the plurality of LTE tracking areas are used at the edges of at least one of the plurality of LTE tracking areas. 
     
     
         20 . The method of  claim 15 , further comprising transmitting mobility information.