Wireless transmit receive unit (wtru) reachability

Abstract

A wireless transmit/receive unit (WTRU) may receive/transmit data by employing a discontinuous reception cycle, which may include an awake state and a sleep state. For example, while in an awake state, a WTRU may monitor a PDCCH for a subset of time instances. During the remaining time instances, the WTRU may enter a sleep state, in which the WTRU may switch its receiving circuitry off (e.g., to reduce power consumption). A WTRU may receive (e.g., may expect to receive) one or more transmissions, during an awake state, before entering a sleep state. The durations of an awake state and/or the durations of subsequent sleep states may be determined based on whether the WTRU receives a transmission during the awake state and/or what the transmission was for. The WTRU may modify the value of a sleep state timer based on previous sleep state and/or awake state timer values.

1 . A wireless transmit/receive unit (WTRU), the WTRU comprising:
 a memory; and   a processor configured to:
 monitor a channel for a plurality of types of signals during a first monitoring period, wherein the plurality of types of signals comprises a first type of signal and a second type of signal, and wherein the first type of signal comprises an indication that indicates the channel has been acquired, and the second type of signal comprises a message that comprises scheduling information for a transmission to or from the WTRU on the channel; 
 on a condition that the first type of signal is received during the first monitoring period, determine that a second monitoring period will occur at a first time; and 
 on a condition that the first type of signal is not received during the first monitoring period, determine that the second monitoring period will occur at a second time, the second time being earlier than the first time. 
   
     
     
         2 . The WTRU of  claim 1 , wherein a minimum duration of the second monitoring period is a first duration on a condition that the first type of signal but not the second type of signal is received during the first monitoring period, and the minimum duration of the second monitoring period is a second duration on a condition that neither the first type of signal nor the second type of signal is received during the first monitoring period, the first duration being longer than the second duration. 
     
     
         3 . The WTRU of  claim 1 , wherein the processor is configured to:
 on a condition that the second type of signal is received during the first monitoring period, send or receive the transmission based on the scheduling information.   
     
     
         4 . The WTRU of  claim 1 , wherein the channel is comprised in an unlicensed band. 
     
     
         5 . The WTRU of  claim 1 , wherein the first type of signal comprises a reference signal (RS). 
     
     
         6 . The WTRU of  claim 1 , wherein the first type of signal comprises downlink control information (DCI) indicating that the channel has been acquired. 
     
     
         7 . The WTRU of  claim 1 , wherein the first and second monitoring periods correspond to active periods of a discontinuous reception (DRX) cycle, and a time between an end of the first monitoring period and a start of the second monitoring period corresponds to a sleep period of the DRX cycle, and wherein the first time is determined based on a long DRX cycle configuration and the second time is determined based on a short DRX cycle configuration. 
     
     
         8 . The WTRU of  claim 1 , wherein the first monitoring period corresponds to a first paging occasion and the second monitoring period corresponds to a second paging occasion. 
     
     
         9 . The WTRU of  claim 8 , wherein the processor is further configured to:
 activate a conditional paging occasion for the second paging occasion during the second monitoring period to monitor the channel based on not receiving the first type of signal.   
     
     
         10 . The WTRU of  claim 1 , wherein the processor is configured to:
 determine the first type of signal as an indication that indicates the WTRU can go to sleep until a start of the second monitoring period based on a condition that the first type of signal but not the second type of signal is received during the first monitoring period.   
     
     
         11 . A method comprising:
 monitoring a channel, by a wireless transmit/receive unit (WTRU), for a plurality of types of signals during a first monitoring period, wherein the plurality of types of signals comprises a first type of signal and a second type of signal, and wherein the first type of signal comprises an indication that indicates the channel has been acquired, and the second type of signal comprises a message that comprises scheduling information for a transmission to or from the WTRU on the channel;   on a condition that the first type of signal is received during the first monitoring period, determining that a second monitoring period will occur at a first time based; and   on a condition that the first type of signal is not received during the first monitoring period, determining that the second monitoring period will occur at a second time, the second time being earlier than the first time.   
     
     
         12 . The method of  claim 11 , wherein a minimum duration of the second monitoring period is a first duration on a condition that the first type of signal but not the second type of signal is received during the first monitoring period, and the minimum duration of the second monitoring period is a second duration on a condition that neither the first type of signal nor the second type of signal is received during the first monitoring period, the first duration having longer duration than the second duration. 
     
     
         13 . The method of  claim 11 , wherein the first and second monitoring periods correspond to active periods of a discontinuous reception (DRX) cycle, and a time between an end of the first monitoring period and a start of the second monitoring period corresponds to a sleep period of the DRX cycle, and wherein the first time is determined based on a long DRX cycle configuration and the second time is determined based on a short DRX cycle configuration. 
     
     
         14 . The method of  claim 11 , wherein the first monitoring period corresponds to a first paging occasion and the second monitoring period corresponds to a second paging occasion. 
     
     
         15 . A wireless transmit/receive unit (WTRU), the WTRU comprising:
 a memory; and   a processor configured to:
 monitor a channel for a plurality of types of signals during a first monitoring period, wherein the plurality of types of signals comprises a first type of signal and a second type of signal, and wherein the first type of signal comprises an indication that indicates the channel has been acquired, and the second type of signal comprises a message that comprises scheduling information for a transmission to or from the WTRU on the channel; 
 on a condition that the first type of signal but not the second type of signal is received during the first monitoring period, determine that a second monitoring period will occur at a first time; and 
 on a condition that neither the first type of signal nor the second type of signal is received during the first monitoring period, determine that the second monitoring period will occur at a second time, the second time being earlier than the first time. 
   
     
     
         16 . The WTRU of  claim 15 , wherein the first and second monitoring periods correspond to active periods of a discontinuous reception (DRX) cycle, and a time between an end of the first monitoring period and a start of the second monitoring period corresponds to a sleep period of the DRX cycle, and wherein the first time is determined based on a long DRX cycle configuration and the second time is determined based on a short DRX cycle configuration. 
     
     
         17 . The WTRU of  claim 15 , wherein the first monitoring period corresponds to a first paging occasion and the second monitoring period corresponds to a second paging occasion. 
     
     
         18 . The method of  claim 11 , wherein the channel is comprised in an unlicensed band, and wherein the first type of signal comprises at least one of a reference signal (RS) or downlink control information (DCI) indicating that the channel has been acquired. 
     
     
         19 . The method of  claim 14 , further comprising:
 activating a conditional paging occasion for the second paging occasion during the second monitoring period to monitor the channel based on not receiving the first type of signal.   
     
     
         20 . The method of  claim 11 , comprising:
 determining the first type of signal as an indication indicating that the WTRU can go to sleep until a start of the second monitoring period based on a condition that the first type of signal but not the second type of signal is received during the first monitoring period.