Methods of operating wireless terminals and network nodes using high speed vehicle network indicators and related wireless terminals and network nodes
摘要
說(shuō)明書
A more accurate system clock may be used during DRX (Discontinuous Reception) when the UE is configured with the indicator associated with HSVN operation in a cell or cells of one or more carriers. During a DRX cycle, the UE wakes up during each ON duration to read control channels such as PDCCH and E-PDCCH, and the UE may also perform radio measurements during the ON duration. A more accurate clock may enable the UE to more accurately maintain the system timing and information about stored data, etc., since at higher speed, the signals may vary at a higher rate. When operating in an HSVN network, for example, the UE may not use the deepest sleep (power saving) modes (where the UE may maintain system timing using a low frequency and low accuracy oscillator). From a UE perspective, the timing error after DRX may be caused by both changes in propagation conditions and internal errors due to UE clock drift relative to the eNB clock. By using a more accurate (and more power consuming) UE oscillator, a greater contribution from the changes in propagation conditions may be tolerated by the UE, as would be expected in a high speed environment.
When in a high speed environment, the UE may allow/use larger time inaccuracy margins when waking up after a deep sleep. By using larger time inaccuracy margins, the UE may accommodate larger oscillator frequency errors due to Doppler shifts as well as a larger time inaccuracy due to the high speed, and the UE may thereby accommodate larger distance differences between the measurement occasions.
