WO2018027791A1

WO2018027791A1 - Method and apparatus for implementing contention-based uplink transmission with an efficient transmission switching strategy

Info

Publication number: WO2018027791A1
Application number: PCT/CN2016/094611
Authority: WO
Inventors: Yuantao Zhang; Hongchao Li; Jingyuan Sun; Yanji Zhang; Yi Zhang; Zhuyan Zhao
Original assignee: Nokia Technologies Oy; Nokia Technologies (Beijing) Co., Ltd.
Priority date: 2016-08-11
Filing date: 2016-08-11
Publication date: 2018-02-15
Also published as: CN109565881B; CN109565881A

Abstract

A method and apparatus may include determining, by a user equipment, a data packet to transmit to a network node. The method can also include transmitting first data blocks of the data packet using contention-based transmission within a contention-based transmission zone. The contention-based transmission zone corresponds to a time period between a first preamble occurrence and a second preamble occurrence. The method can also include switching from contention-based transmission to schedule-based transmission, if not all data blocks of the data packet are able to be transmitted within the contention-based transmission zone. The method can also include transmitting second data blocks of the data packet using schedule-based transmission, wherein the second data blocks comprise data blocks of the data packet that were not able to be transmitted within the contention-based transmission zone.

Description

METHOD AND APPARATUS FOR IMPLEMENTING CONTENTION-BASED UPLINK TRANSMISSION WITH AN EFFICIENT TRANSMISSION SWITCHING STRATEGY

BACKGROUND： Field：

Certain embodiments of the present invention relate to implementing contention-based uplink transmission with an efficient transmission switching strategy.

Description of the Related Art：

Long-term Evolution (LTE) is a standard for wireless communication that seeks to provide improved speed and capacity for wireless communications by using new modulation/signal processing techniques. The standard was proposed by the 3^rd Generation Partnership Project (3GPP) ， and is based upon previous network technologies. Since its inception， LTE has seen extensive deployment in a wide variety of contexts involving the communication of data.

The 5G new radio (NR) is a next generation wireless system beyond LTE， where small packet-oriented design needs to be specially handled. For such case， the physical layer resource management and scheduling methodology need to accommodate the small payload feature to achieve high transmission efficiency in terms of low control overhead and lower End to End latency.

SUMMARY：

According to a first embodiment， a method can include determining， by a user equipment， a data packet to transmit to a network node. The method can also include transmitting first data blocks of the data packet using contention-based transmission within a contention-based transmission zone. The contention-based transmission zone corresponds to a time period between a first preamble occurrence and a second preamble occurrence. The method can also include switching from contention-based transmission to schedule-based transmission， if not all data blocks of the data packet are able to be transmitted within the contention-based transmission zone. The method can also include transmitting second data blocks of the data packet using schedule-based transmission. The second data blocks comprise data blocks of the data packet that were not able to be transmitted within the contention-based transmission zone.

In the method of the first embodiment， the first preamble occurrence and the second preamble occurrence comprise a user-equipment-specific preamble occurrence and a system-level occurrence.

In the method of the first embodiment， the first preamble occurrence and the second preamble occurrence comprise two user-equipment-specific preamble occurrences.

In the method of the first embodiment， transmitting data blocks of the data packet comprises starting a preamble transmission in a nearest user-equipment-specific preamble transmission occurrence.

In the method of the first embodiment， the method may also include transmitting buffer status reports with data blocks that are transmitted within the contention-based transmission zone.

In the method of the first embodiment， the number of buffer status reports that are transmitted in a contention-based transmission zone is through the network configuration.

In the method of the first embodiment， the number of first blocks of the data packet using contention-based transmission within a contention-based transmission zone is configured by the network.

According to a second embodiment， an apparatus can include at least one memory comprising computer program code. The apparatus can also include at least one processor. The at least one memory and the computer program code are configured， with the at least one processor， to cause the apparatus at least to perform a process according to the first embodiment.

According to a third embodiment， an apparatus can include determining means to determine a data packet to transmit to a network node. The apparatus can also include first transmitting means to transmit first data blocks of the data packet using contention-based transmission within a contention-based transmission zone. The contention-based transmission zone corresponds to a time period between a first preamble occurrence and a second preamble occurrence. The apparatus can also include switching means to switch from contention-based transmission to schedule-based transmission， if not all data blocks of the data packet are able to be transmitted within the contention-based transmission zone. The apparatus can also include second transmitting second data blocks of the data packet using schedule-based transmission. The second data blocks comprise data blocks of the data packet that were not able to be transmitted within the contention-based transmission zone.

In the apparatus of the third embodiment， the first preamble occurrence and the second preamble occurrence comprise a user-equipment-specific preamble occurrence and a system-level occurrence.

In the apparatus of the third embodiment， the first preamble occurrence and the second preamble occurrence comprise two user-equipment-specific preamble occurrences.

In the apparatus of the third embodiment， transmitting data blocks of the data packet comprises starting a preamble transmission in a nearest user-equipment-specific preamble transmission occurrence.

In the apparatus of the third embodiment， the apparatus can also include third transmitting means to transmit a buffer status reports with data blocks that are transmitted within the contention-based transmission zone.

According to a fourth embodiment， a computer program product can be embodied on a non-transitory computer readable medium. The computer program product configured to control a processor to perform a method according to the first embodiment.

According to a fifth embodiment， a method can include configuring， by a network node， preamble occurrences for a user equipment. The method can also include receiving a data packet fiom the user equipment. First data blocks of the data packet are transmitted by the user equipment using contention-based transmission within a contention-based transmission zone， and the contention-based transmission zone corresponds to a time period between a first preamble occurrence and a second preamble occurrence. The method can also include receiving second data blocks of the data packet. The second data blocks are transmitted by the user equipment using schedule-based transmission， and the second data blocks comprise data blocks of the data packet that were not able to be transmitted by the user equipment within the contention-based transmission zone.

In the method of the fifth embodiment， the first preamble occurrence and the second preamble occurrence comprise a user-equipment-specific preamble occurrence and a system-level occurrence.

In the method of the fifth embodiment， receiving data blocks of the data packet comprises receiving a preamble transmission in a nearest user-equipment-specific preamble transmission occurrence.

In the method of the fifth embodiment， the method can also include receiving buffer status reports with data blocks that are received within the contention-based transmission zone.

According to a sixth embodiment， an apparatus can include at least one memory comprising computer program code. The apparatus can also include at least one processor. The at least one memory and the computer program code are configured， with the at least one processor， to cause the apparatus at least to perform a process according to the fifth embodiment.

According to a seventh embodiment， an apparatus can include configuring means to configure preamble occurrences for a user equipment. The apparatus can also include first receiving means to receive a data packet from the user equipment. First data blocks of the data packet are transmitted by the user equipment using contention-based transmission within a contention-based transmission zone， and the contention-based transmission zone corresponds to a time period between a first preamble occurrence and a second preamble occurrence. The apparatus can also include second receiving means to receive second data blocks of the data packet. The second data blocks are transmitted by the user equipment using schedule-based transmission. The second data blocks comprise data blocks of the data packet that were not able to be transmitted by the user equipment within the contention-based transmission zone.

In the apparatus of the seventh embodiment， the first preamble occurrence and the second preamble occurrence comprise a user-equipment-specific preamble occurrence and a system-level occurrence.

In the apparatus of the seventh embodiment， receiving data blocks of the data packet comprises receiving a preamble transmission in a nearest user-equipment-specific preamble transmission occurrence.

In the apparatus of the seventh embodiment， the apparatus can also include third receiving means to receive buffer status reports with data blocks that are received within the contention-based transmission zone.

In the apparatus of the seventh embodiment， the number of buffer status reports that are transmitted in a contention-based transmission zone is through the network configuration.

In the apparatus of the seventh embodiment， the number of first blocks of the data packet using contention-based transmission within a contention-based transmission zone is configured by the network.

According to an eighth embodiment， a computer program product can be embodied on a non-transitory computer readable medium. The computer program product configured to control a processor to perform a method according to the fifth embodiment.

BRIEF DESCRIPTION OF THE DRAWINGS：

For proper understanding of the invention， reference should be made to the accompanying drawings， wherein：

Fig. 1 illustrates a Long Term Evolution Uplink scheduling-based (contention-free) data transmission process.

Fig. 2 illustrates a contention-based transmission zone for user equipment in different subsets， in accordance with certain embodiments of the present invention.

Fig. 3 illustrates a procedure of Time Division Multiplexed， contention-based transmission， in accordance with certain embodiments of the present invention.

Fig. 4 illustrates a flowchart of a method in accordance with certain embodiments of the invention.

Fig. 5 illustrates a flowchart of a method in accordance with certain embodiments of the invention.

Fig. 6 illustrates an apparatus in accordance with certain embodiments of the invention.

Fig. 7 illustrates an apparatus in accordance with certain embodiments of the invention.

Fig. 8 illustrates an apparatus in accordance with certain embodiments of the invention.

DETAILED DESCRIPTION：

Certain embodiments of the present invention relate to implementing contention-based uplink transmission with an efficient transmission switching strategy. Certain embodiments of the present invention are directed to a non-scheduled， grant-free， UL multiple access， which is currently studied in 3GPP RAN1 New Radio (NR， i.e.， 5G) . During the RANl#84bis meeting， the following agreements were reached.

Agreements：

(1) Non-orthogonal multiple access should be investigated for diversified NR usage scenarios and use cases

(2) At least for UL mMTC， autonomous/grant-free/contention based non-orthogonal multiple access should be studied

One motivation for introducing non-scheduled multiple access is to improve the throughput and efficiency over the traditional methods of performing scheduled-based UL transmission. Improvements can be achieved in terms of reducing signalling overhead， achieving lower latency， and achieving lower power consumption， at least for small packet transmission. Small packet transmission is the typical case in massive Machine Type Communication (mMTC) ， and also various smartphone applications. Example applications can include Voice-Over-IP (VoIP) ， gaming applications， Transmission Control Protocol ACK (TCP ACK) ， and Ultra-Reliable Low Latency Communication (URLLC) with real-time remote control.

The scheduled based transmission is used extensively in 3GPP LTE (and HSDPA) . When a UE has data available in the logic buffer that is ready for UL transmission， the UE needs to request uplink resources for data transmission by typically sending a scheduling request (SR) to base station. After base station successfully detects the SR， the base station would send an UL grant to the UE to allocate certain PUSCH resources for the UE to send a buffer status report (BSR) . The UE would send the BSR (i.e.， the amount of data available in its logical buffer) after detecting this UL grant. In the next step， the base station allocates corresponding UL resources by means of another UL grant to the UE for data transmission， taking the uplink radio condition between UE and base station into account. Figure 1 illustrates the above-described process.

Fig. 1 illustrates a Long Term Evolution Uplink scheduling-based (contention-free) data transmission process. The data transmission process of Fig. 1 generally results in a relatively high latency for base station-UE handshaking (typically on the order of 17.5ms for LTE before any data transmissions) . This transmission process can also result in overhead from an exchange of several downlink/uplink (DL/UL) control signalling messages. As such， the data transmission process of Fig. 1 is generally not efficient for massive UL small packet transmissions.

The 5G study item referred to as New Radio (NR) has been ongoing since March 2016 in 3GPP. The RP-160671 outlines the study item description and schedule. The key scenarios， requirements， and Key Performance Indicators (KPIs) are specified in 3GPP TR 38.913 V0.2.0. Moreover， there may be efforts to introduce non-scheduled access to NR with Tdoc [R1-162892 Uplink contention-based access in 5G New Radio] .

Contention based (CB) transmission can be more efficient for UL small-packet transmission， in terms of lower overhead and lower latency， but CB transmission may be less efficient for medium to large packet transmission. CB transmission may be less efficient for medium to large packet transmission due to normally semi-static allocated fixed resource pool (s) ， and semi-static configured conservative Modulation and Coding Scheme (MCS) for CB data transmission. From this point of view， it is more efficient to use mainly schedule-based transmission for such incoming packets.

As a straightforward method， if an incoming packet size is larger than a predefined/configured threshold， a UE may use schedule-based transmission， otherwise， the UE may use contention-based transmission. However， in this way， the base station needs to allocate a unique Scheduling Request (SR) sequence ID for each UE， even though the UE does not use schedule-based transmission. Therefore， a SR resource shortage may occur in NR with a massive connection.

Therefore， certain embodiments are directed to another method that enables the UE to use contention-based transmission at the beginning. The method relies on efficiently switching between contention-based and schedule-based transmission to meet different requirements (relating to， for example， latency， overhead， and/or spectral efficiency) in view of the variable nature of incoming data packet. Certain embodiments do not need to allocate an SR to the UE， and， therefore， may avoid the issue of SR resource shortage. In other words， certain embodiments may make use of aprinciple that CB UEs are not allocated any SR resources. Besides， LTE NB-IoT notes that， when supporting a large number Internet-of-Things (IoT) UEs， no SR is to be allocated to UE. Certain embodiments of the present invention are directed to a solution that enables efficiently switching between contention-based and schedule-based transmission.

Certain embodiments of the present invention provide a new solution for achieving efficient switching between UL contention-based and scheduled-based transmission. The solution of certain embodiments may be based on the basic structure where a preamble is transmitted before a data transmission. This kind of structure has been pursued for the contention-based channel structure. Certain embodiments are directed to the following proposals.

In accordance to a proposal of certain embodiments， a contention-based transmission zone is defined in a time period between two preamble occurrences. Among these two preamble occurrences， one preamble occurrence could be a UE-specific preamble occurrence， and the other preamble occurrence can be a system-level preamble occurrence. This is based on a Time Division Multiplexed (TDM) contention-based transmission for a different subset of UEs. It should be noted that if the UE specific preamble occurrences are same with the system specific preamble occurrences， the contention based transmission zone is defined in the time period between each two UE specific preamble occurrences.

For a massive connection in 5G， a plurality of UEs that are configured with CB transmission may be allocated a same resource pool. In order to reduce the collision rate between the UEs， the UEs can be grouped into multiple subsets and can use Time Division Multiplexed transmission from a different subset of UEs. Because a different subset of UEs use different resources in the time domain， the collision rate can be largely reduced.

In order to fulfil the requirements of Time Division Multiplexed transmission under the supported channel structure， two configurations are proposed. One configuration indicates system-level preamble occurrences. Based on this configuration， UEs that are in schedule-based transmission can perform corresponding rate-matching or puncturing. The other configuration indicates a UE-specific preamble occurrence. The UE-specific preamble occurrences are configured on top of system-level preamble occurrences， and the configuration is the same for UEs that are in a same subset， but the configuration is different for UEs in different subsets.

For a specific UE， the time period between each UE-specific preamble occurrence and the next system-level preamble occurrence can be referred to as a contention-based transmission zone for this UE. If a new data packet is to be transmitted by the UE， the UE will start a preamble transmission in the nearest UE specific preamble transmission occurrence， and then transmit UL data blocks in the contention-based transmission zone. If transmission of the packet cannot be finished in such a zone， the UE will turn to schedule-based transmission. The Time Division Multiplexed transmission from a different subset of UEs is fulfilled by the different contention-based zones based on such a proposed structure.

Iftransmission of a data packet cannot be finished in a CB transmission zone， this packet is considered to be a medium to large packet， and the UE uses schedule-based transmission for transmitting the rest of the data bits for this packet. The base station can control the size of the CB transmission zone by configuring the periodicity of system-level preamble occurrences.

Fig. 2 illustrates a contention-based transmission zone for user equipment in different subsets， in accordance with certain embodiments of the present invention. Fig. 2 illustrates an example embodiment where the periodicity of system level preamble occurrences is T， and the periodicity of UE-specific preamble occurrences is 2T.

For UE set 1， the configured UE-specific occurrences include time point n+T， n+3T， n+5T， and so on， while， for UE set 2， the configured UE-specific occurrences are n， n+2T， n+4T， and so on. The contention-based transmission zone for UEs in different subset is also illustrated.

Therefore， the contention-based transmission zone defines the number of Transmission Time Intervals (TTIs) and defines the corresponding number of transport blocks (one transport block per TTI) that can be transmitted using contention-based transmission. If the number of divided transport blocks for the incoming packet is larger than the number that can be transmitted in the contention-based transmission zone， the UE will turn to scheduled-based transmission in order to transmit the rest of the transport blocks.

With certain embodiments， the base station could further configure another time period for contention-based transmission， which starts from the UE-specific preamble occurrence. The size of such a period can be less than the CB transmission zone. The size of the period can depend on a predetermined /previsioned traffic type that is transmitted in this duration， and/or depend on a required Quality-of-Service (QoS) parameter， for example， relating to latency， and/or reliability. To be more specific， if high reliability is required， while requiring latency to be controlled within a certain range， then a sufficiently short time period should be configured and used by the switching from contention-based transmission to schedule-based operation. On the other hand， if the traffic’s Key Performance Indicators (KPI) are tolerant to latency， and if the error rate can be controlled with multiple retransmissions， then the time period can be configured with a large value to save control-signalling overhead. In most cases， under this assumption， a traffic burst can be delivered within such a period， and there is no need to switch from contention-mode to schedule-mode. However， if the buffer size is accumulated by frequent traffic bursts to a large enough value， then such accumulation means that the schedule-based method is then more efficient than the pre-configured contention mode. Here， the UE can then autonomously switch from contention-mode to schedule-mode. Therefore， this adaptive operation can improve the operational efficiency of contention-based access by proper configuration of the periods based on the service type， previsioned traffic density， and also UE number.

In accordance with certain embodiments of the present invention， certain embodiments implement Buffer Status Report piggy backing (BSR piggy backing) in all， or in a configured number， of transport blocks that are transmitted in the CB transmission zone. BSR is piggy backing on each transport block that is transmitted in the contention-based transmission zone， in order to enable robust BSR transmission using CB. The base station can determine the amount of remaining data bits in the buffer and perform corresponding scheduling， if necessary. UE can add an item or a specific index to indicate “0 bits BSR” in the transport block， if there is not any data in the buffer. In another embodiment， a base station can configure UE to perform BSR transmission for a maximum number times in the contention-based transmission zone.

With regard to configuring UE to transmit a maximnm number of transport blocks in the CB transmission zone， in practice， the maximum number of transport blocks that can be transmitted by UE in the contention-based transmission zone can be configured by base station. The actual number of transport blocks transmitted in the CB period depends on the incoming packet size， the configured resources for CB transmission， and the configured Modulation and Coding Scheme (MCS) ， for example.

As described above， certain embodiments of the present invention may include some or all of the following inventive aspects. With regard to a contention-based transmission zone， the zone defines the number of Transmission Time Intervals (TTIs) or transport blocks (for an incoming packet) that can be transmitted using contention-based transmission. The zone is defined between a UE-specific preamble occurrence and a system-level preamble occurrence. If the incoming packet cannot be fully transmitted in a zone， the UE will turn to schedule-based transmission.

With certain embodiments， BSR is transmitted together with all the transport blocks that are transmitted in the contention-based transmission zone. A “0bit” indication can indicate to the base station that the buffer is empty.

Further， with certain embodiments， the base station can configure UE for BSR transmission. For example， a base station may configure UE to perform BSR transmission for a maximum number of times， in the contention-based transmission zone. The base station can configure the maximum number of transport blocks that can be transmitted in the contention-based transmission zone.

Fig. 3 illustrates a procedure of certain embodiments of the present invention. In the procedure of Fig. 3， in the first step， the base station configures UE as using contention-based UL transmission， and configures a UE with a resource pool. The base station also configures system level preamble occurrences and UE-specific preamble occurrences， respectively. The configuration may include indications of a periodicity and an offset for each type of occurrences.

System-level preamble occurrences are configured using broadcast signalling. Based on this broadcasted signalling， UEs that are in schedule-based transmission can perform corresponding rate matching or puncturing.

UE-specific preamble occurrences can be configured using UE-specific signalling (e.g.， Radio Resource Control (RRC) signalling， for example) . UE-specific preamble occurrences can be configured based on the system-level preamble occurrence configuration. For example， the periodicity of UE-specific preamble occurrence is times of system-level preamble occurrence， therefore， the configuration can be just the number of times and offsets. Referring to the example in Fig. 2， the periodicity of UE specific preamble occurrences for both subset 1 and subset 2 UEs is two times of that of system specific preamble occurrences.

The system-level preamble occurrences are common for all subsets of UEs that are configured in the same resources for contention based transmission， while UE-specific preamble occurrences are the sane for UEs that are in a same subset， but are different for UEs in different subsets.

If new data comes to the UE buffer to be transmitted by the UE， the UE will transmit the preamble in the nearest UE specific preamble occurrence， and then perform following data transmission in the CB transmission zone. Referring to the example in Fig. 2， for a UE1 in UE subset 1， ifnew data comes in between (2T， 3T) ， UE1 will transmit preamble in 3T. UE1 will transmit data transport blocks in the CB transmission zone in TTIs between (3T， 4T) . If transmission of the data packet cannot be finished in this zone， the UE will switch to schedule-based transmission.

Fig. 3 illustrates a procedure of Time Division Multiplexed， contention-based transmission， in accordance with certain embodiments of the present invention. BSR can accompany each transport block that is transmitted in the contention-based transmission zone， so that the base station can determine the amount of remaining data bits in the buffer. The base station can then perform corresponding scheduling， if necessary. The UE will add an item to indicate “0 bits BSR” in the transport block， if there is not any data in the buffer. With another embodiment， the base station can configure UE to perform BSR transmission for a maximum number of times in the contention-based transmission zone. In such a case， the base station can perform the configuration in the first step.

In practice， the maximum number of transport blocks that can be transmitted by UE during the time period between the two above-described preamble occurrences can be configured by a base station. In such a case， the base station can perform the configuration in the first step. The actual number of transport blocks transmitted in the CB period can depend on the incoming packet size， the configured resources for CB transmission， and the configured MCS， for example.

Certain embodiments of the present invention can provide some or all of the following benefits. Certain embodiments can achieve efficient switching between contention-based and schedule-based transmission， therefore enabling higher system throughput with adaptive switching， according to an incoming packet size. Certain embodiments of the present invention can perform Time-Division-Multiplexed contention-based transmission， and can， therefore， achieve a low collision rate.

Fig. 4 illustrates a flowchart of a method in accordance with certain embodiments of the invention. The method may include， at 410， determining， by a user equipment， a data packet to transmit to a network node. The method can also include， at 420， transmitting first data blocks of the data packet using contention-based transmission within a contention-based transmission zone. The contention-based transmission zone corresponds to a time period between a first preamble occurrence and a second preamble occurrence. The method can also include， at 430， switching from contention-based transmission to schedule-based transmission， if not all data blocks of the data packet are able to be transmitted within the contention-based transmission zone. The method can also include， at 440， transmitting second data blocks of the data packet using schedule-based transmission， wherein the second data blocks comprise data blocks of the data packet that were not able to be transmitted within the contention-based transmission zone.

Fig. 5 illustrates a flowchart of another method in accordance with certain embodiments of the invention. The method may include， at 510， configuring， by a network node， preamble occurrences for a user equipment. The method can also include， at 520， receiving a data packet from the user equipment. First data blocks of the data packet are transmitted by the user equipment using contention-based transmission within a contention-based transmission zone， and the contention-based transmission zone corresponds to a time period between a first preamble occurrence and a second preamble occurrence. The method can also include， at 530， receiving second data blocks of the data packet， wherein the second data blocks are transmitted by the user equipment using schedule-based transmission， and the second data blocks comprise data blocks of the data packet that were not able to be transmitted by the user equipment within the contention-based transmission zone.

Fig. 6 illustrates an apparatus in accordance with certain embodiments of the invention. In one embodiment， the apparatus can be a network node such as an evolved Node B and/or base station， for example. In another embodiment， the apparatus may correspond to a user equipment， for example. Apparatus 10 can include a processor 22 for processing information and executing instructions or operations. Processor 22 can be any type of general or specific purpose processor. While a single processor 22 is shown in Fig. 6， multiple processors can be utilized according to other embodiments. Processor 22 can also include one or more of general-purpose computers， special purpose computers， microprocessors， digital signal processors (DSPs) ， field-programmable gate arrays (FPGAs) ， application-specific integrated circuits (ASICs) ， and processors based on a multi-core processor architecture， as examples.

Apparatus 10 can further include a memory 14， coupled to processor 22， for storing information and instructions that can be executed by processor 22. Memory 14 can be one or more memories and of any type suitable to the local application environment， and can be implemented using any suitable volatile or nonvolatile data storage technology such as a semiconductor-based memory device， a magnetic memory device and system， an optical memory device and system， fixed memory， and removable memory. For example， memory 14 may include any combination of random access memory (RAM) ， read only memory (ROM) ， static storage such as a magnetic or optical disk， or any other type of non-transitory machine or computer readable media. The instructions stored in memory 14 can include program instructions or computer program code that， when executed by processor 22， enable the apparatus 10 to perform tasks as described herein.

Apparatus 10 can also include one or more antennas (not shown) for transmitting and receiving signals and/or data to and from apparatus 10. Apparatus 10 can further include a transceiver 28 that modulates information on to a cartier waveform for transmission by the antenna (s) and demodulates information received via the antenna (s) for further processing by other elements of apparatus 10. In other embodiments， transceiver 28 can be capable of transmitting and receiving signals or data directly.

Processor 22 can perform functions associated with the operation of apparatus 10 including， without limitation， precoding of antenna gain/phase parameters， encoding and decoding of individual bits forming a communication message， formatting of information， and overall control of the apparatus 10， including processes related to management of communication resources.

In an embodiment， memory 14 can store software modules that provide functionality when executed by processor 22. The modules can include an operating system 15 that provides operating system functionality for apparatus 10. The memory can also store one or more functional modules 18， such as an application or program， to provide additional functionality for apparatus 10. The components of apparatus 10 can be implemented in hardware， or as any suitable combination of hardware and software.

Fig. 7 illustrates an apparatus in accordance with certain embodiments of the invention. Apparatus 700 can be a user equipment， for example. Apparatus 700 can include a determining unit 710 that determines a data packet to transmit to a network node. Apparatus 700 can also include a first transmitting unit 720 that transmits first data blocks of the data packet using contention-based transmission within a contention-based transmission zone. The contention-based transmission zone corresponds to a time period between a first preamble occurrence and a second preamble occurrence. Apparatus 700 can also include a switching unit 730 that switches from contention-based transmission to schedule-based transmission， ifnot all data blocks of the data packet are able to be transmitted within the contention-based transmission zone. Apparatus 700 can also include a second transmitting unit 740 that transmits second data blocks of the data packet using schedule-based transmission. The second data blocks comprise data blocks of the data packet that were not able to be transmitted within the contention-based transmission zone.

Fig. 8 illustrates an apparatus in accordance with certain embodiments of the invention. Apparatus 800 can be a base station and/or eNB， for example. Apparatus 800 can include a configuring unit 810 that configures preamble occurrences for a user equipment. Apparatus 800 can also include a first receiving unit 820 that receives a data packet from the user equipment， wherein first data blocks of the data packet are transmitted by the user equipment using contention-based transmission within a contention-based transmission zone， and the contention-based transmission zone corresponds to a time period between a first preamble occurrence and a second preamble occurrence. Apparatus 800 can also include a second receiving unit 830 that receives second data blocks of the data packet， wherein the second data blocks are transmitted by the user equipment using schedule-based transmission， and the second data blocks comprise data blocks of the data packet that were not able to be transmitted by the user equipment within the contention-based transmission zone.

The described features， advantages， and characteristics of the invention can be combined in any suitable manner in one or more embodiments. One skilled in the relevant art will recognize that the invention can be practiced without one or more of the specific features or advantages of a particular embodiment. In other instances， additional features and advantages can be recognized in certain embodiments that may not be present in all embodiments of the invention. One having ordinary skill in the art will readily understand that the invention as discussed above may be practiced with steps in a different order， and/or with hardware elements in configurations which are different than those which are disclosed. Therefore， although the invention has been described based upon these preferred embodiments， it would be apparent to those of skill in the art that certain modifications， variations， and alternative constructions would be apparent， while remaining within the spirit and scope of the invention.

Claims

A method， comprising：

determining， by a user equipment， a data packet to transmit to a network node；

transmitting first data blocks of the data packet using contention-based transmission within a contention-based transmission zone， wherein the contention-based transmission zone corresponds to a time period between a first preamble occurrence and a second preamble occurrence；

switching from contention-based transmission to schedule-based transmission， if not all data blocks of the data packet are able to be transmitted within the contention-based transmission zone； and

transmitting second data blocks of the data packet using schedule-based transmission， wherein the second data blocks comprise data blocks of the data packet that were not able to be transmitted within the contention-based transmission zone.
The method according to claim 1， wherein the first preamble occurrence and the second preamble occurrence comprise a user-equipment-specific preamble occurrence and a system-level occurrence.
The method according to claim 1， wherein the first preamble occurrence and the second preamble occurrence comprise two user-equipment-specific preamble occurrences.
The method according to claim 1-3， wherein transmitting data blocks of the data packet comprises starting a preamble transmission in a nearest user-equipment-specific preamble transmission occurrence.
The method according to any of claims 1-4， further comprising transmitting buffer status reports with data blocks that are transmitted within the contention-based transmission zone.
The method according to claim 5， wherein the number of buffer status reports that are transmitted in a contention-based transmission zone is through the network configuration.
The method according to claim 1， wherein the number of first blocks of the data packet using contention-based transmission within a contention-based transmission zone is configured by the network.
An apparatus comprising：

at least one memory comprising computer program code；

at least one processor；

wherein the at least one memory and the computer program code are configured， with the at least one processor， to cause the apparatus at least to perform a process according to any of claims 1-7.
An apparatus， comprising：

determining means to determine a data packet to transmit to a network node；

first transmitting means to transmit first data blocks of the data packet using contention-based transmission within a contention-based transmission zone， wherein the contention-based transmission zone corresponds to a time period between a first preamble occurrence and a second preamble occurrence；

switching means to switch from contention-based transmission to schedule-based transmission， if not all data blocks of the data packet are able to be transmitted within the contention-based transmission zone； and

second transmitting second data blocks of the data packet using schedule-based transmission， wherein the second data blocks comprise data blocks of the data packet that were not able to be transmitted within the contention-based transmission zone.
The apparatus according to claim 9， wherein the first preamble occurrence and the second preamble occurrence comprise a user-equipment-specific preamble occurrence and a system-level occurrence.
The apparatus according to claim 9， wherein the first preamble occurrence and the second preamble occurrence comprise two user-equipment-specific preamble occurrences.
The apparatus according to claim 9-11， wherein transmitting data blocks of the data packet comprises starting a preamble transmission in a nearest user-equipment-specific preamble transmission occurrence.
The apparatus according to any of claims 9-12， further comprising third transmitting means to transmit a buffer status reports with data blocks that are transmitted within the contention-based transmission zone.
A computer program product， embodied on a non-transitory computer readable medium， the computer program product configured to control a processor to perform a method according to claim 1.
A method， comprising：

configuring， by a network node， preamble occurrences for a user equipment；

receiving a data packet from the user equipment， wherein first data blocks of the data packet are transmitted by the user equipment using contention-based transmission within a contention-based transmission zone， and the contention-based transmission zone corresponds to a time period between a first preamble occurrence and a second preamble occurrence； and

receiving second data blocks of the data packet， wherein the second data blocks are transmitted by the user equipment using schedule-based transmission， and the second data blocks comprise data blocks of the data packet that were not able to be transmitted by the user equipment within the contention-based transmission zone.
The method according to claim 15， wherein the first preamble occurrence and the second preamble occurrence comprise a user-equipment-specific preamble occurrence and a system-level occurrence.
The method according to claim 15 or 16， wherein receiving data blocks of the data packet comprises receiving a preamble transmission in a nearest user-equipment-specific preamble transmission occurrence.
The method according to any of claims 15-17， further comprising receiving buffer status reports with data blocks that are received within the contention-based transmission zone.
An apparatus comprising：

at least one memory comprising computer program code；

at least one processor；

wherein the at least one memory and the computer program code are configured， with the at least one processor， to cause the apparatus at least to perform a process according to any of claims 15-18.
An apparatus， comprising：

configuring means to configure preamble occurrences for a user equipment；

first receiving means to receive a data packet from the user equipment， wherein first data blocks of the data packet are transmitted by the user equipment using contention-based transmission within a contention-based transmission zone， and the contention-based transmission zone corresponds to a time period between a first preamble occurrence and a second preamble occurrence； and

second receiving means to receive second data blocks of the data packet， wherein the second data blocks are transmitted by the user equipment using schedule-based transmission， and the second data blocks comprise data blocks of the data packet that were not able to be transmitted by the user equipment within the contention-based transmission zone.
The apparatus according to claim 20， wherein the first preamble occurrence and the second preamble occurrence comprise a user-equipment-specific preamble occurrence and a system-level occurrence.
The apparatus according to claim 20 or 21， wherein receiving data blocks of the data packet comprises receiving a preamble transmission in a nearest user-equipment-specific preamble transmission occurrence.
The apparatus according to any of claims 20-22， further comprising third receiving means to receive buffer status reports with data blocks that are received within the contention-based transmission zone.
The method according to claim 5， wherein the number of buffer status reports that are transmitted in a contention-based transmission zone is through the network configuration.
The method according to claim 1， wherein the number of first blocks of the data packet using contention-based transmission within a contention-based transmission zone is configured by the network.
A computer program product， embodied on a non-transitory computer readable medium， the computer program product configured to control a processor to perform a method according to claim 15.