CROSS REFERENCE TO THE RELATED APPLICATIONS

This application is the national phase entry of International Application No. PCT/CN2018/110906, filed on Oct. 18, 2018, which is based upon and claims priority to Chinese Patent Application No. 201811121680.7, filed on Sep. 26, 2018, the entire contents of which are incorporated herein by reference.

TECHNICAL FIELD

The present invention belongs to the technical field of air interface communication, and more specifically relates to a method for reserving and allocating resources for an ultra-low-latency uplink service flow based on an air interface slice.

BACKGROUND

An air interface communication refers to a communication between a mobile terminal and a base station. An air interface is a wireless communication protocol between the base station and the mobile terminal, which defines the frequency, bandwidth, access timing, coding method, and hand-off of each wireless channel. The latency of the air interface communication is mainly affected by factors including a data transmission duration, a data transmission resource request waiting time, a feedback delay caused by data processing and the like.

However, the existing air interface communication has the following disadvantages:

1. In the prior art, the wireless terminal switches from the idle mode to a connected mode by means of actively applying for resource allocation. The resource is allocated by the base station according to the reported buffer status report (BSR), which cannot meet the latency requirement of several milliseconds.

2. The existing transmission frame structure is composed of 10 subframes to form a 10 ms frame, which cannot meet the latency requirement of ultra-low latency of less than 10 ms.

3. The existing dynamic scheduling methods all have a certain scheduling delay. The resources in each frame must be scheduled in advance for each terminal to transmit data. The ultra-low-latency service cannot tolerate this scheduling delay.

SUMMARY

An objective of the present invention is to provide a method for reserving and allocating resources for an ultra-low-latency uplink service flow based on an air interface slice, so as to solve the above-mentioned problems in the prior art.

To achieve the above objective, the technical solution used by the present invention is as follows.

A method for reserving and allocating resources for an ultra-low-latency uplink service flow based on an air interface slice includes:

virtualizing an air interface resource of a base station side into an ultra-low-latency slice resource and a non-ultra-low-latency slice resource;

recording a collision situation on reserved resources in each retry window, and dynamically adjusting a size of the reserved ultra-low-latency slice resource according to the collision situation;

reallocating the ultra-low-latency service resource in response to the detection of a terminal on the ultra-low-latency slice resource to transmit ultra-low-latency data, and determining whether an idle resource is presented in the non-ultra-low-latency slice resource;

if the idle resource is presented, then allocating the idle resource to the terminal transmitting the ultra-low-latency data and returning the borrowed non-ultra-low-latency slice resource after transmitting the ultra-low-latency data; and

if the idle resource is not presented, then borrowing the non-ultra-low-latency slice resource that has been allocated to a non-ultra-low-latency terminal and returning the borrowed non-ultra-low-latency slice resource after transmitting the ultra-low-latency data.

Preferably, a method for negotiating ultra-low latency reserved resources includes:

initiating an ultra-low-latency service registration request by an ultra-low-latency terminal or an application server, and requesting the base station to reserve resources for an ultra-low-latency service slice; and

parsing, by the base station, the resource reservation request, and judging and approving the resource reservation request by the base station, and indicating a location and time slot of the reserved resource through a bitmap.

Preferably, a method for transmitting the ultra-low-latency data includes:

receiving an ultra-low-latency reserved slice resource indication by bitmap from the base station, following by parsing the position and time slot of the reserved resource in the bitmap;

counting, by the base station, the number of terminals having collisions in a retry window, followed by predicting the number of terminals participating in a competition in a next retry window, thereby realizing a dynamic adjustment of reserved resources; and

retransmitting, in the first subframe of the next retry window, the ultra-low-latency reserved slice resource indication by bitmap to notify each terminal of the adjustment result of the reserved resources.

Preferably, a method for scheduling and borrowing ultra-low-latency service resources includes:

when the base station detects ultra-low-latency data is transmitted on the ultra-low-latency slice resource, first determining whether a utilization rate of the non-ultra-low-latency slice resource is less than a preset threshold;

if the current utilization rate of the non-ultra-low-latency slice resource is less than or equal to the preset threshold, allocating the idle non-ultra-low-latency slice resource to a terminal needing to transmit the ultra-low-latency data and allocating the idle non-ultra-low-latency slice resource to the ultra-low-latency service on the terminal through a physical downlink control channel (PDCCH) control signaling by the base station; and

if the current utilization rate of the non-ultra-low-latency slice resource is greater than the preset threshold, borrowing the non-ultra-low-latency slice resource that has been allocated for the non-ultra-low-latency service terminal, namely, the signaling that is originally configured to notify the non-ultra-low-latency service terminal through the PDCCH control signaling is transmitted to the ultra-low-latency service terminal, the ultra-low-latency terminal borrows the non-ultra-low-latency slice resource to transmit the ultra-low-latency data, and meanwhile, the non-ultra-low-latency terminal borrows a shared buffer of the ultra-low-latency user and transmits the shared buffer to the ultra-low-latency terminal through a device-to-device (D2D) mode, so as to buffer the data configured to be transmitted.

Preferably, a method for returning the ultra-low-latency slice resource includes:

when a buffer status report (BSR) reported by the ultra-low-latency terminal is empty, completing the ultra-low-latency data transmission, returning the borrowed non-ultra-low-latency slice resource to the previous non-ultra-low-latency terminal by the base station.

Preferably, the terminal of the non-ultra-low-latency slice resource returns the shared buffer resource of the ultra-low-latency slice to the ultra-low-latency user through the D2D transmission mode.

Preferably, the transmission frame structure is divided into 100 transmission time intervals (TTIs), and each transmission frame is divided into a plurality of retry windows.

Preferably, the terminal to transmit an ultra-low-latency service actively applies for reserved resource for the ultra-low-latency service, or parses the location and time slot of resource reserved by the base station for ultra-low-latency service from the resource indication frames periodically broadcasted by the base station.

Preferably, the base station in the first subframe of each retry window notifies each terminal of the location and time slot of the reserved resource corresponding to the ultra-low-latency service flow by broadcasting the bitmap.

Preferably, the collisions on the reserved resources in the retry windows include a collision of separate random access channel (RACH) resources and a collision of physical downlink shared channel (PDSCH) resources.

The method for reserving and allocating the resources for the ultra-low-latency uplink service flow based on the air interface slice provided by the present invention has the following advantages.

The present invention uses a dynamic resource reservation method for resource allocation and time delay access, which avoids excessive interaction and delay of resource request signaling of conventional terminals, meets the latency requirements of ultra-low-latency data, and reduces the probability of collisions in the use of reserved resources by terminals. In addition, the base station detects whether there is ultra-low-latency data transmission, and if there is data transmission, then resources are immediately allocated. Meanwhile, when the individual resources are immediately allocated for the ultra-low-latency services, the resources of non-ultra-low-latency services can be preempted, that is, the non-ultra-low-latency resources are borrowed for the data transmission, which reduces the transmission delay of ultra-low-latency data.

