TWI554066B - Discontinuous reception mode control method in long term evolution system - Google Patents

Description

Control method of DRX mode of LTE system

The present invention relates to a control method for an LTE system, and more particularly to a method for controlling a DRX mode of an LTE system.

Due to the rapid development of wireless communication, many information is transmitted through wireless communication, but because the general portable user equipment (User equipment) can carry a limited amount of power, if the user equipment is in the awake mode of the receiving state at any time (Active mode) When the power consumption of the user equipment is quickly exhausted, the Long Term Evolution (LTE) system has a DRX (Discontinuous Reception) mode to save power consumption of the user equipment. The DRX mode defines many parameters for the carrier to use. For example, an inactivity timer, an on-duration timer, a DRX short DRX cycle, and a DRX long cycle (Long DRX cycle).

Please refer to FIG. 1 , which is a basic operation principle of the DRX mode of the LTE system. The block represents a frame time frame of the user equipment receiving the signal. When the user equipment is in the active mode, the inactive is inactive. The timer T _in starts counting down. If there is a downlink (Downlink) packet to be received, the inactive counter T _in is reset and cannot be counted down. If there is no downlink packet to be received, and the inactive timer T _{in is} counted down, The user equipment enters the DRX mode, and the user equipment can reduce the frequency of the physical downlink control channel (Physical downlink control channel) in the DRX mode, and even more, the RF module is turned off to save power.

Referring to FIG. 1 , when the user equipment enters the DRX mode, the DRX short period T _SDC is first entered, and in the DRX short period T _SDC , a standby listening time is first passed before entering a sleep time, where the user equipment group The standby listening time is to reduce the frequency of the downlink control channel of the listening entity, but the downlink packet can still be received. The user equipment group is in the sleep time to completely shut down the radio frequency module and cannot receive the downlink packet. Referring to FIG. 1 , after two DRX short period T _SDCs , the user equipment enters the DRX long period T _LDC , and since the sleep time in the DRX long period T _LDC is longer than the sleep time of the DRX short period T _SDC , Therefore, the user equipment entering the DRX long period T _LDC can save more power.

Referring to FIG. 2, in order to enable the user equipment to continuously receive packet receiving capability when entering the DRX mode, if the user equipment is in the standby listening time and a new downlink packet needs to be received, the inactivity timer T _in will start counting down to extend the standby listening time while maintaining the user equipment to receive the downlink packet, and if the user equipment is in the sleep time and a new downlink packet is to be received, the user equipment cannot Receiving the downlink packet, therefore, the packet is temporarily stored in the packet buffer of the base station, and the countdown of the inactive counter is performed in the next DRX cycle to extend the standby listening time, so that the user equipment can receive the temporary storage in the packet temporary storage. The packet in the device.

Referring to FIG. 3, in the third DRX cycle of the DRX mode, if a downlink packet is continuously received, the inactivity timer T _in is continuously reset, and the user equipment is always in the standby state. . However, if the amount of downlink packets is small, and the packet buffer is still in an affordable state, it is not necessary to extend the multiple standby listening time T _in to complete the transmission of the packet in the subsequent DRX cycle. The continual reset of the inactivity timer T _in and the extended standby listening time causes unnecessary energy loss of the user equipment, but relatively, if the active counter is not used to extend the standby listening time, the packet may be temporarily stored. The device is out of its state of being able to withstand the loss of the packet.

The main purpose of the present invention is to determine the standby listening time and sleep in the next DRX cycle by judging the state of the packet buffer in a DRX cycle and the reciprocal of the double timer through the idle timer and the overload timer. The length of time, and the sleep time of the user equipment can be increased when the packet buffer is still loadable, so that the user equipment can save more power, and increase the standby listening time of the user equipment when the packet buffer exceeds the load, thereby increasing The packet receiving capability of the user equipment avoids the loss of the packet, and improves the quality of experience (QoE) of the user equipment UE.

The DRX mode control method of an LTE system of the present invention is used to adjust an on-duration and an off-duration of a user equipment in a DRX cycle, and the control method includes a base according to a base A packet of a packet buffer of the station determines the state of the packet buffer, wherein the packet buffer is configured with a no-load threshold and an overload threshold, and when the packet is lower than the no-load threshold, The packet buffer is in an idle state. When the packet amount is higher than the overload threshold, the packet register is in an overload state; when the packet buffer is in an idle state, a no-load timer is counted down. If the packet amount is lower than the no-load threshold during the countdown period of the no-load timer, the idle timer completes the reciprocal, and in the next DRX cycle, the user equipment is in standby in a DRX cycle. The monitoring time is reduced by at least one frame time slot, and the user equipment increases the sleep time in a DRX cycle by at least one frame time slot; and when the packet register is in an overload state, an overload timer counts down If the packet amount is higher than the overload threshold during the countdown period of the overload timer, the overload timer completes the countdown, and in the next DRX cycle, the standby monitoring time of the user equipment in a DRX cycle increases. At least one frame time slot, and the sleep time of the user equipment in a DRX cycle is relatively reduced by at least one frame time slot.

The double timer of the idle timer and the overload timer is designed to increase the sleep time in the DRX cycle when the packet amount of the packet buffer is lower than a no-load threshold. Avoiding the redundant standby listening time increases the power consumption of the user equipment UE, and increasing the standby listening time in the DRX period when the packet amount of the packet buffer is higher than an overload threshold to increase the The user equipment UE receives the capability of the downlink packet, and improves the user quality of the user equipment UE.

Referring to Figures 4 and 5, in the wireless communication system, a base station BS is configured to transmit a downlink packet DP to the user equipment UE, or, if the user equipment is outside the coverage of the base station BS, the base The station BS can transmit the downlink packet DP to the user equipment UE through a relay point RN. Referring to FIG. 5, the base station BS has a packet buffer 100 for temporarily storing the downlink packet DP. In this embodiment, the packet buffer 100 is configured with a no-load threshold. 110 and an overload threshold 120, the no-load threshold 110 and the overload threshold 120 are set according to the capacity of the packet buffer 100.

Please refer to FIG. 6 , which is a flowchart of a method 10 for controlling a DRX mode of an LTE system according to an embodiment of the present invention. Referring to FIGS. 7 and 8 , in the awake mode of the user equipment UE, an inactive timing is performed. The device T _in is counted down, and when no downlink packet is to be received _{in the} countdown time of the inactivity timer T _in , the inactivity timer T _in completes the reciprocal, so that the user equipment UE enters the DRX mode. In the DRX mode, the user equipment UE first enters a DRX cycle, where the DRX cycle can be set to a short cycle or a long cycle to determine one of the standby listening time (on-duration) and one sleep time (off-) in one DRX cycle. In the embodiment, the standby listening time of the DRX cycle is 6 frame time slots, and the sleep time of the DRX cycle is 6 frames. Slot, but the invention is not limited thereto.

Referring to FIGS. 5 and 6, the user equipment UE enters the DRX cycle and performs the step of "determining the state 11 of the packet buffer", and determines the state of the packet register 100 according to the amount of packets of the base station BS. When the packet amount is lower than the no-load threshold 110, the packet register 100 is in an idle state. When the packet amount is higher than the overload threshold 120, the packet register 100 is in an overload state, and when When the packet amount is between the no-load threshold 110 and the overload threshold 120, the packet register 100 is in a general state. Referring to FIG. 5, preferably, the base station BS has an empty flag. empFlag and an overload flag overloadFlag, wherein when the packet buffer 100 is in the no-load state, the idle flag empFlag is set to 1 and the overload flag overloadFlag is set to 0, and the packet buffer 100 is in an overload state. The idle flag empFlag is set to 0 and the overload flag overloadFlag is set to 1, and when the packet register 100 is in a normal state, the empty flag empFlag and the overload flag overloadFlag are both set to zero.

Referring to Figures 6 and 7, when it is determined that the packet register 100 is in an idle state, the steps of "the idle timer is counted down 12a" and "whether the countdown 12b is completed" are performed, if the idle timer is counted down During the period of time, the packet amount of the packet register 100 is lower than the no-load threshold, and the idle timer completes the reciprocal. In the embodiment, the no-load flag empFlag is used to determine the no-load. Whether the timer completes the reciprocal, that is, when the packet amount of the packet buffer 100 is lower than the no-load threshold, the idle flag empFlag is set to 1, and if the next DRX cycle starts, if the space is empty The flag empFlag is 1, indicating that the idle timer 100 completes the reciprocal in the previous DRX cycle. Conversely, if the idle flag empFlag is 0 at the beginning of the next DRX cycle, the no-load timer 100 is represented by The last DRX cycle did not complete the countdown. Referring to FIG. 7, in the first DRX cycle in which the user equipment UE enters the DRX mode, the no-load timer 100 is in an idle state, the idle flag empFlag is set to 1, and due to the first DRX cycle. The packet is not transmitted by the downlink packet, so that the packet amount of the packet buffer 100 is lower than the no-load threshold. Therefore, at the beginning of the next DRX cycle, the idle flag empFlag is 1, so that the idle timing is The device 100 completes the countdown.

Referring to FIGS. 6 and 7, since the idle timer of the first DRX cycle completes the reciprocal, step 12c is performed, and the standby monitoring time of the user equipment UE in one DRX cycle is decreased in the next DRX cycle. At least one frame time slot, and the user equipment UE increases the sleep time in a DRX cycle by at least one frame time slot. Referring to FIG. 7, in the second DRX cycle, the base station BS transmits a DRX command to the user equipment UE early, so that the user equipment UE enters the sleep time early, thereby enabling The standby listening time is reduced by two frame time slots, and the sleep time is also relatively increased by two frame time slots, wherein the standby listening time and the sleeping time are respectively reduced and the number of frame time slots is increased. Demand setting. Since the sleep time of the user equipment is longer than the first DRX period in the second DRX cycle, the standby listening time can be saved unnecessary and the user equipment UE is more power-saving.

Referring to FIG. 7, in the second DRX cycle, the standby listening time has a downlink packet to be received, and the reciprocal of the inactive counter T _in is performed to extend the standby listening time of the user equipment UE, but In the DRX cycle, the base station BS transmits the DRX command to the user equipment early, so that the user equipment UE enters the sleep time. Therefore, when the base station transmits the DRX command to the user equipment UE, the inactivity timer The timing is stopped, and the user equipment UE enters the sleep time. This can prevent the user equipment UE from repeatedly entering the extended standby listening time due to the repeated repetition of the inactivity timer, resulting in unnecessary power consumption, so that the user equipment UE can save more power.

Referring to FIG. 7, the DRX mode control method 10 of the LTE system of the present invention is also repeated in the second DRX cycle, wherein the packet is temporarily stored in the step of "determining the state of the packet buffer 11". The device 100 is in a normal state, that is, the packet amount of the packet buffer 100 is between the no-load threshold 110 and the overload threshold 120, and the idle timer and the overload timer are not counted down. The idle flag empFlag and the overload flag overloadFlag are both set to 0, so that the standby listening time and the sleep time of the next DRX cycle are unchanged.

Referring to FIG. 8, after entering the DRX mode by the reciprocal of the inactive counter T _in , in the first DRX cycle, since the packet amount of the packet buffer 100 is higher than the overload threshold, it is in an overload state. Therefore, in the steps of "the overload timer performs the countdown 13a" and "whether the countdown 13b is completed", the overload timer completes the countdown, that is, when the overload timer counts down, the overload flag overloadFlag is set to 1. At the beginning of the next DRX cycle, the overload flag overloadFlag is still 1, indicating that the overload timer completes the reciprocal in the previous DRX cycle, so step 13c is performed. In the next DRX cycle, the user equipment UE is in a DRX. The standby listening time in the period is increased by at least one frame time slot, and the sleep time of the user equipment UE in one DRX cycle is relatively reduced by at least one frame time slot. Referring to FIG. 8 , in the second DRX cycle, the base station BS delays transmitting the DRX command to the user equipment UE, so that the user equipment UE delays entering the sleep time. In addition, the standby listening time is increased by three frame time slots, and the sleep time is also relatively reduced by three frame time slots, wherein the standby monitoring time and the sleeping time increase and decrease the number of frame time slots respectively. Then set according to the demand. The standby listening time of the user equipment UE is longer than the first DRX period in the second DRX period, thereby increasing the capability of the user equipment UE to receive the downlink packet DP to avoid the packet buffer. 100 is out of load and the packet is lost, thereby improving the quality of experience (QoE) of the user equipment UE.

Please refer to FIG. 8. In the second DRX cycle, since the countdown timer also completes the countdown, the standby monitor time is also increased by three frame time slots in the third DRX cycle to enhance the user reception. The ability to downlink the DP, wherein if the standby listening time is extended to reach the length of one DRX cycle, the base station BS does not transmit the DRX command to the user equipment UE, so that the user equipment UE continues to be activated. Status, waiting to receive the downstream packet DP.

The double timer of the idle timer and the overload timer is designed to increase the sleep time in the DRX cycle when the packet amount of the packet buffer 100 is lower than a no-load threshold 110. In order to avoid unnecessary standby listening time, the power consumption of the user equipment UE is increased, and the standby listening time in the DRX cycle may be increased when the packet amount of the packet buffer 100 is higher than an overload threshold 120. In order to increase the capability of the user equipment UE to receive the downlink packet, the user quality of the user equipment UE is improved.

The scope of the present invention is defined by the scope of the appended claims, and any changes and modifications made by those skilled in the art without departing from the spirit and scope of the invention are within the scope of the present invention. .

10‧‧‧Control method for DRX mode of LTE system
11‧‧‧Determining the status of the packet register
12a‧‧‧No-load timer for countdown
12b‧‧‧ Whether to complete the countdown
12c‧‧‧In the next DRX cycle, the standby listening time is reduced by at least one frame time slot and the sleep time is increased by at least one frame time slot.
13a‧‧‧Overload timer to count down
13b‧‧‧ Whether to complete the countdown
13c‧‧‧In the next DRX cycle, the standby listening time is increased by at least one frame time slot and the sleep time is reduced by at least one frame time slot.
100‧‧‧Package register
110‧‧‧ no-load threshold
120‧‧‧Overload threshold
DP‧‧‧ downlink packet
BS‧‧‧ base station
UE‧‧‧User equipment
RN‧‧‧ Relay Point
empFlag‧‧‧ empty flag
overloadFlag‧‧‧Overload flag
T _in ‧‧‧ Stand by to listen to time
T _SDC ‧‧‧DRX short cycle
T _LDC ‧‧‧DRX long cycle

Figure 1: Schematic diagram of the operation of the conventional DRX mode. Figure 2: Schematic diagram of the operation of the conventional DRX mode. Figure 3: Schematic diagram of the operation of the conventional DRX mode. Figure 4 is a schematic illustration of a base station, a relay point, and a user equipment in accordance with an embodiment of the present invention. Figure 5 is a schematic illustration of a packet register in accordance with an embodiment of the present invention. Figure 6 is a flow chart showing a method of controlling the DRX mode of an LTE system according to an embodiment of the present invention. Figure 7 is a schematic illustration of the operation of the DRX mode in accordance with an embodiment of the present invention. Figure 8 is a schematic illustration of the operation of the DRX mode in accordance with an embodiment of the present invention.

100‧‧‧Package register

110‧‧‧ no-load threshold

120‧‧‧Overload threshold

DP‧‧‧ downlink packet

empFlag‧‧‧ empty label

overloadFlag‧‧‧Overload flag

Claims (6)

A DRX mode control method for an LTE system, configured to adjust an on-duration and an off-duration of a user equipment in a DRX cycle, the control method comprising: according to a base A packet of a packet buffer of the station determines the state of the packet buffer, wherein the packet buffer is configured with a no-load threshold and an overload threshold, and when the packet is lower than the no-load threshold, The packet buffer is in an idle state. When the packet amount is higher than the overload threshold, the packet register is in an overload state; when the packet buffer is in an idle state, a no-load timer is counted down. If the packet amount is lower than the no-load threshold during the countdown period of the no-load timer, the idle timer completes the reciprocal, and in the next DRX cycle, the user equipment is in standby in a DRX cycle. The monitoring time is reduced by at least one frame time slot, and the sleep time of the user equipment in a DRX cycle is relatively increased by at least one frame time slot; when the packet buffer is in an overload state, an overload timer is counted down, If at During the countdown period of the overload timer, the packet amount is higher than the overload threshold, and the overload timer completes the countdown, and in the next DRX cycle, the user equipment increases the standby listening time in a DRX cycle by at least one message. a time slot, and the user equipment reduces the sleep time in a DRX cycle by at least one frame time slot; and an idle flag, when the idle timer counts down, the idle flag is set to 1. When the packet amount of the packet buffer is higher than the no-load threshold, the no-load flag is set to 0, and when the next DRX cycle starts, if the no-load flag is 1, it represents the space. The timer is counted down in the last DRX cycle. For example, the control method of the DRX mode of the LTE system described in claim 1 is When the packet amount is between the no-load threshold and the overload threshold, the packet register is in a general state, and when the packet register is in a general state, the idle timer and the overload timer The device does not count down. The method for controlling the DRX mode of the LTE system according to claim 1, wherein when the user equipment is in the standby listening time in the DRX cycle, the base station transmits a DRX command to the user equipment, In order for the user equipment to enter the sleep time, when the idle timer completes the countdown, the base station transmits the DRX instruction at least one frame time slot early, and when the overload timer completes the countdown, the base station delays at least The frame time slot transmits the DRX instruction. The method for controlling the DRX mode of the LTE system according to claim 3, further comprising an inactivity timer, which is received when the user equipment is in the standby listening time in the DRX cycle. When the packet is encapsulated, the inactivity timer begins to count down to extend the standby listening time of the user equipment, wherein the inactivity timer stops timing when the base station transmits the DRX command to the user equipment. The method for controlling the DRX mode of the LTE system according to claim 1, further comprising an overload flag, when the overload timer performs a countdown, the overload flag is set to 1, when the packet buffer is When the packet amount is lower than the overload threshold, the overload flag is set to 0, and when the next DRX cycle starts, if the overload flag is 1, it indicates that the overload timer completes the reciprocal in the previous DRX cycle. A DRX mode control method for an LTE system, configured to adjust an on-duration and an off-duration of a user equipment in a DRX cycle, the control method comprising: according to a base A packet of a packet buffer of the station determines the state of the packet register, wherein the packet buffer is set with a no-load threshold and an overload threshold, when the packet is lower than the idle The threshold value, the packet register is in an idle state, when the packet amount is higher than the overload threshold, the packet register is in an overload state; when the packet register is in an idle state, an idle timer Performing a reciprocal, if the packet amount is lower than the no-load threshold during the countdown period of the no-load timer, the no-load timer completes the reciprocal, and in the next DRX cycle, the user equipment is in a DRX cycle. The standby listening time is reduced by at least one frame time slot, and the user equipment increases the sleep time in a DRX cycle by at least one frame time slot; when the packet register is in an overload state, an overload timer Performing a reciprocal, if the packet amount is higher than the overload threshold during the countdown period of the overload timer, the overload timer completes the reciprocal, and in the next DRX cycle, the user equipment is in standby in a DRX cycle. The monitoring time is increased by at least one frame time slot, and the user equipment reduces the sleep time in one DRX cycle by at least one frame time slot; and an overload flag when the overload timer counts down The overload flag is set to 1. When the packet amount of the packet buffer is lower than the overload threshold, the overload flag is set to 0, and when the next DRX cycle starts, if the overload flag is 1, Represents the overload timer to complete the countdown in the previous DRX cycle.