WO2017115130A1

WO2017115130A1 - Method and scheduling apparatus for transmitting uplink scheduling information for an unlicensed band

Info

Publication number: WO2017115130A1
Application number: PCT/IB2016/001905
Authority: WO
Inventors: Tao Tao; Jianguo Liu; Feng Han; Yan Meng; Junrong GU; Gang Shen
Original assignee: Alcatel Lucent
Priority date: 2015-12-30
Filing date: 2016-12-14
Publication date: 2017-07-06
Also published as: CN106937395A

Abstract

The inventors of the present invention desire to provide through at least one embodiment of the present invention, a method of and apparatus for transmitting uplink scheduling information that belongs to an unlicensed band from a network device to a user equipment. Through implementing the embodiments of the present invention, if a user equipment is to perform uplink transmission on an unlicensed band, it has to obtain uplink scheduling information from a network end; however, because strong resource contention might exist on the unlicensed band, if the uplink scheduling information is also transmitted over the unlicensed band, timely transmission of the information cannot be guaranteed. If the uplink scheduling information is transmitted over a licensed band whose resources are more guaranteed, its timely transmission can be assured, and the user equipment can obtain the information required by uplink transmission on the unlicensed band, coexistence of the LTE or LTE-A network with other networks or protocols such as Zigbee or Wi-Fi on the unlicensed band can be more effectively achieved.

Description

M ETHOD AN D SCHEDULING APPARATUS FOR TRANSM ITTING UPLIN K SCH EDULING

IN FORMATION FOR AN UN LICENSED BAN D

FIELD OF THE INVENTION

[0001] The present invention relates to transmitting uplink scheduling information in a communication network, and more specifically relates to a method of transmitting uplink scheduling information for an unlicensed band in a wireless communication network with coexistence of licensed bands and unlicensed bands, and a scheduling apparatus. BACKGROUND OF THE INVENTION

[0002] LTE (Long Term Evolution) refers to long term evolution of the UMTS (Universal Mobile Telecommunications System) formulated by the 3GPP (the 3 Generation Partnership Project) organization. The LTE system, with introduction of key technologies like OFDM (Orthogonal Frequency Division Multiplexing) and M IMO (Multi-Input & Multi-Output), significantly enhances spectrum efficiency and data transmission rate, and supports a plurality of bandwidth allocations and worldwide dominant 2G/3G bands and some new bands; therefore, its spectrum allocation is more flexible, and system capacity and coverage are also significantly enhanced.

[0003] LTE-A (LTE-Advanced), as an evolved version of LTE, has a good backward compatibility to LTE. The LTE-A exploits key technologies such as carrier aggregation, multi-point coordinated transmission, relay, heterogeneous network interference coordination enhancement, etc., such that it can enhance a peak data rate, peak spectrum efficiency, and cell average spectrum efficiency of the wireless communication system, as well as cell boundary user performance, and meanwhile can also enhance networking efficiency of the entire network. This makes the LTE-A system to become dominant in wireless communication development in recent years.

[0004] With rapid development of mobile smart devices, the number of wireless users also increases expeditiously. Fast emergency of high-definition multimedia stream services, expensive and limited licensed bands cannot meet the increasing demands of spectrum resources. In order to relieve the pressure of licensed mobile networks, an idea develops to handle the challenge of mass data amount using unlicensed bands that have relatively abundant resources. Various carriers have deployed Wi-Fi (Wireless Fidelity) and other systems on unlicensed bands to alleviate the burden on wireless networks so as to shunt wireless traffic through unlicensed bands.

[0005] On one hand, technical improvement may enhance mobile network performance; on the other hand, the mobile communication performance may also be enhanced by seeking more spectrum resources. To wireless communications, spectrum resources are fundamental to determine wireless bandwidth, like oil to the Earth. The wider the band is, the faster the transmission rate is, and the larger the system throughput is. However, spectrum resources allocated to the carriers are very limited and expensive, such that the carriers will try every means to sufficiently utilize the hard-won spectrum resources. However, even this can hardly meet the increasing user demands. Among domestic carriers, China Mobile's LTE spectrum resources are 130MHz in total, 90MHz for China Unicom, and 100MHz for China Telecom, while for unlicensed spectrum resources where Wi-Fi is deployed, about 90M Hz nearby 2.4GHz is available, and as much as 900MHz nearby 5GHz band is available. Relevant abundant and free unlicensed bands suffice to drive carriers and device manufacturers to earnestly develop relevant technologies and devices.

[0006] With deploying LIE on an unlicensed band, an LTE air interface protocol is employed on the unlicensed band to implement communication, i.e., LTE advanced in unlicensed spectrums, shortly referred to as LTE-U. With the LTE-U technology, technologies like centralized scheduling, interference coordination, and adaptive repeat request (HARQ) may be exploited. Compared with access technologies like Wi-Fi, the LTE-U has a better robustness, which may achieve a higher spectrum efficiency and provide a larger coverage and a better user experience. Currently, many companies and research institutions have proposed, to the 3GPP, deploying LTE technologies (i.e., LTE-U) in unlicensed bands, so as to facilitate indoor transmission of LTE. Main candidate solutions include: LAA (Licensed-Assisted Access), DC (Dual Connect), Unlicensed-Assisted Access (Standalone) technologies, etc. LTE-U, as a 5^th Generation Mobile Communication System (5G) enhancement technology, has attracted wide attention from worldwide researchers in mobile communications.

[0007] However, nobody in the hart has proposed how to address uplink resource scheduling on unlicensed bands and how to guarantee success rate of such scheduling when licensed bands and unlicensed bands coexist.

SUMMARY OF THE INVENTION

[0008] In order to solve the above problems in the art, the inventors of the present invention desire to provide, through at least one embodiment of the present invention, a method of and apparatus for transmitting uplink scheduling information that belongs to an unlicensed band (e.g., a band shared with Zigbee or Wi-Fi) from a network device (e.g., a base station (NodeB), an evolved base station (e-NodeB) or a higher-layer network device) to a user equipment (e.g., a mobile phone or other wireless terminal).

[0009] According to at least one embodiment in a first aspect of the present invention, there is provided a method of transmitting, in a wireless communication network where a licensed band and an unlicensed band coexist, uplink scheduling information for the unlicensed band from a network device to a user equipment, comprising steps of: transmitting, by the network device, the uplink scheduling information for the unlicensed band to the user equipment via the licensed band.

[0010] Further, the network device and the user equipment work in a time-division duplexing (TDD) mode on the unlicensed band.

[0011] Further, the method may also comprise a step of transmitting, by the network device, configuration information to the user equipment, the configuration information indicating a temporal-domain correspondence relationship between the uplink scheduling information transmitted by the network device and uplink transmission performed by the user equipment based on the uplink scheduling information.

[0012] Further, transmitting of the uplink scheduling information is at least 4 sub-frames earlier than uplink transmission corresponding to the uplink scheduling information.

[0013] Further, transmitting of the uplink scheduling information is at most 7 sub-frames earlier than uplink transmission corresponding to the uplink scheduling information.

[0014] According to at least one embodiment of a second aspect of the present invention, there is provided a scheduling apparatus for transmitting, in a wireless communication network where a licensed band and an unlicensed band coexist, uplink scheduling information for the unlicensed band from a network device to a user equipment, wherein the scheduling apparatus is configured to transmitting the uplink scheduling information for the unlicensed band to the user equipment via the licensed band.

[0015] Further, the network device and the user equipment work in a time-division duplexing (TDD) mode on the unlicensed band.

[0016] Further, the scheduling apparatus may also comprise: a transmitting unit configured to transmit configuration information to the user equipment, the configuration information indicating a temporal-domain correspondence relationship between the uplink scheduling information transmitted by the network device and uplink transmission performed by the user equipment based on the uplink scheduling information.

[0017] Further, transmitting of the uplink scheduling information is at least 4 sub-frames earlier than uplink transmission corresponding to the uplink scheduling information.

[0018] Further, transmitting of the uplink scheduling information is at most 7 sub-frames earlier than uplink transmission corresponding to the uplink scheduling information.

[0019] Further, the licensed band includes a band based on any of network technologies below: LTE, LTE-A, or GSM.

[0020] Further, the unlicensed band includes a band based on any of network technologies: Zigbee or Wi-Fi.

[0021] According to at least one embodiment in a third aspect of the present invention, there is provided a network device in a system where a licensed band and unlicensed band coexist, including any scheduling apparatus mentioned above.

[0022] Through implementing the embodiments of the present invention, if a user equipment is to perform uplink transmission (including, but not limited to, voice, video, word, or any data traffic information) on an unlicensed band, it has to obtain uplink scheduling information from a network end; however, because strong resource contention might exist on the unlicensed band, if the uplink scheduling information is also transmitted over the unlicensed band, timely transmission of the information cannot be guaranteed. If the uplink scheduling information is transmitted over a licensed band whose resources are more guaranteed, its timely transmission can be assured, and the user equipment can obtain the information required by uplink transmission on the unlicensed band, coexistence of the LTE or LTE-A network with other networks or protocols such as Zigbee or Wi-Fi on the unlicensed band can be more effectively achieved. The method and apparatus above particularly address the following and other problems which the LTE-U faces:

[0023] 1. On the unlicensed band, before the user equipment starts uplink transmission on the PUSCH (Physical Uplink Shared Channel), it shall follow an LBT (Listen Before Talk) rule (e.g., in Japan and Europe). However, the LBT sets some restrictions for uplink scheduling (including, but not limited to, transmitting, by the base station uplink, scheduling information).

[0024] If self-carrier-scheduling (i.e., transmitting uplink scheduling information within the present band) is exploited for uplink transmission within the present band, it is required that the base station and the UE (user equipment) must perform resource contention with other devices or protocols using the band to win in advance the resources for transmitting of uplink scheduling information and for corresponding uplink transmission. However, it is a pity that such resource contention has certain indefiniteness on an unlicensed band, which results in that the base station even cannot ensure transmission of uplink transmission information and also lowers the possibility for the UE to perform uplink transmission over PUSCH.

[0025] 3. Configuration of a primary cell (shortly referred to as "PCell") is always different from configuration of a secondary cell (shortly referred to as "SCell") in time domain. This brings challenges to transmission of uplink scheduling information.

BRIEF DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] In order to describe a method, apparatus, network/ user equipment that can obtain the above and other advantages and features of the present invention, various aspects briefly describe d the graphical representations in the drawings. It should be understood that these drawings describe only typical embodiments of the present invention and thus should not be regarded as limitations to the scope of the present invention.

[0027] Fig. 1 illustrates a schematic diagram of partitioning an unlicensed frequency band in LTE-U;

[0028] Fig. 2 illustrates a schematic diagram of carrier aggregation in LTE-U, i.e., aggregating a licensed carrier (band) and an unlicensed band;

[0029] Fig. 3 illustrates a flow diagram of a method of transmitting, in a wireless communication network where a licensed band and an unlicensed band coexist, uplink scheduling information for the unlicensed band from a network device to a user equipment according to an embodiment of the present invention;

[0030] Fig. 4 illustrates a block diagram of a scheduling apparatus for transmitting, in a wireless communication network where a licensed band and an unlicensed band coexist, uplink scheduling information for the unlicensed band from a network device to a user equipment according to an embodiment of the present invention;

[0031] Fig. 5 illustrates uplink scheduling information, transmitted on a primary carrier, for uplink transmission on a secondary carrier, and a correspondence relationship between the corresponding primary carrier and secondary carrier under a certain specific configuration.

[0032] In the drawings, same or similar reference numerals represent same or corresponding steps, means, units or other modules. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0033] Compared with Wi-Fi, deploying LTE on the unlicensed band has great advantages: from the perspective of a user, an LTE-U in combination with LTE will provide a higher data rate, a better coverage performance, and a higher reliability to a user, which will undoubtedly be a perfect user experience; from the perspective of a mobile carrier, it is much convenient for operation management and upgrade of a mobile network that a core network simultaneously runs on licensed and unlicensed bands. Next, basic principles for LTE-U's band selection, channel sharing, access manner, and scenario deployment will be introduced first.

Selection of Unlicensed Band

[0034] It is our first consideration to select an appropriate unlicensed band to deploy LTE-U. first, a band lower than 6GHz can better resist path loss; 2.4GHz band around has been densely occupied by access technologies such as Wi-Fi and Bluetooth; 5GHz band around is occupied by WLAN; therefore, the band most suitable for deploying LTE-U is 5-6GHz band, particularly the band close to 6GHz. Table 0 shows unlicensed band conditions in various countries/ regions around the world: Table 0 Unlicensed Band Around 5GHz

[0035] Table 0 summarizes occupancy of unlicensed bands around 5GHz in several major countries around the world. With a comprehensive consideration, in China, preferable unlicensed bands for deploying LTE-U can be 5725-5825 MHz and 5470-5725MHz bands.

Fair Utilization of Spectrums

[0036] a. Coexistence between Different Access Technologies

[0037] The first issue faced to deploy the LTE-U in 5GHz unlicensed band is the coexistence with other access technologies. Fair use of unlicensed band between the LTE-U and a prior access technology is a precondition for coexistence thereof.

[0038] The current LTE system uses a licensed band exclusively for continuous transmission, not sharing spectrum resources with other carriers or wireless access technologies. However, an unlicensed band, as an open resource, allows any wireless access technology to use. If the LTE directly occupies resources on an unlicensed band without any processing, it will violate laws regarding use of unlicensed bands, and it is also unfair for other wireless access systems deployed in the unlicensed band. The LTE-U may share available channels with access technologies like Wi-Fi using CSAT (Carrier Sensing Adaptive Transmission) technology.

[0039] Coexistence between Different Carriers

[0040] It is well known that an unlicensed band is an open access spectrum resource. As long as a wireless device works on the unlicensed band meets relevant national or regional laws, the user terminal or device may use the unlicensed band without verification, which means the unlicensed band does not limit type and number of carriers; a situation of simultaneous occupation by multiple RAT systems might exist on the unlicensed band within a same region. To deploy the LTE-U in the unlicensed band, it will be needed to consider friendly coexistence between different carriers.

[0041] In deployment of LTE-U, the unlicensed band may be divided to different carriers according to bands, or divided according to both time and bands. As illustrated in Fig. 1, the unlicensed band will be subject to temporally permanent division to be allocated to different carriers. This division method is simple and feasible, but with a lower spectrum utilization; in addition, the unlicensed band resources may be divided according to time and band based on business situations of different carriers. This division manner has a greater complexity, but can achieve a higher spectrum utilization.

LTE-U Access Manner [0042] LTE-U may select different access manners, e.g., LAA (Licensed-Assisted Access). The LAA is a spectrum utilization solution that achieves efficient sharing between a licensed band and an unlicensed band, which exploits a carrier aggregation (CA) technology to aggregate the licensed band and the unlicensed band, as illustrated in Fig. 2.

[0043] The licensed band as a primary carrier cell (PCC) transmits key information and guarantees quality of service (QoS), while the unlicensed band as a secondary carrier cell (SCC) may be configured into a downlink supplementary link or an uplink and downlink, so as to provide extra radio resources. It may be seen from Fig. 2 that the unlicensed band resources are centrally scheduled and allocated by the base station, such that the resources are dynamically used through use and release of the unlicensed band based on activation/ deactivation operations by the media access control (MAC) unit. With the LAA, when the LAA base station activates the unlicensed band resources, the LTE transmits cellular data on the unlicensed band; when the LAA base station deactivates the unlicensed band resources, Wi-Fi and other access systems may use the unlicensed band resources, thereby fulfilling the objective of flexibly using the unlicensed band by various access technologies.

Scene Deployment

[0044] The LTE-U may employ two different scene deployments, i.e., carrier management and non-independent deployment. By setting a small base station outdoor, the carrier performs access of the LTE-U, which is different from Wi-Fi and other access technologies where a user automatically performs access. Besides, the LTE-U may employ a co-building architecture to share a same base station with the LTE. This manner may significantly lower the architecture cost and operation cost of the LTE-U; it may also employ a non-co-building architecture, where an enough number of LTE-U microcell base stations are built in the LTE macro cell.

[0045] As a result of LTE system evolution in an unlicensed band, the LTE-U will inherit many advanced technologies of the LTE system. Meanwhile, in order to realize channel sharing with existing other communication systems running on the unlicensed band, the LTE-U will introduce its own unique channel sharing policy. The policy will be specifically introduced below:

Centralized Scheduling Technology

[0046] The LTE-U uses a technology of centralized scheduling, i.e., time, space, spectrum, and other wireless resources are centrally controlled and centrally allocated by the base station, and it is not needed to contend for resources between terminals. Contrary to the centralized scheduling employed by LTE-U, the Wi-Fi employs a preemptive scheduling technology; when the number of served users is much less, the scheduling technology may embody its advantages; however, after the number of users exceeds the base station's serving capabilities, because it cannot respond to these users' requests, a consequence of server crash might occur; meanwhile, with increase of the served users, crash phenomenon will occur frequently, which greatly lower the resource utilization efficiency.

[0047] To address the series of scheduling problems in the Wi-Fi technology, the LTE-U employs centralized scheduling, such that data crash phenomenon will not exist, which effectively avoids resource waste; for a region with dense users, in order to enhance an LTE-U base station's service capability, load on a single base station may be shared by increasing base stations. Compared with Wi-Fi, the LTE-U has apparent advantages in the aspect of scheduling technologies.

ICIC (Inter Cell Interference Coordination) Technology [0048] The ICIC (Inter Cell Interference Coordination) technology in the LTE-U system mainly performs reasonable allocation of resource blocks and power according to different users' specific conditions by performing limitation and coordination to system resources (time frequency resources, power, etc.), so as to achieve an objective of interference coordination between neighboring cells.

[0049] Specifically, in order to augment cell edge capacities, a frequency multiplexing approach is exploited by ICIC technologies. In the LTE-U system, a frequency multiplexing factor is selected to be 3. Because different bands are employed in neighboring cells, interference between neighboring cell frequencies can be well avoided. In order to further limit the inter-cell interference, the base station notifies its neighboring cell of a downlink interference condition through a transmit power indicator (RNTP), and the neighboring cell base station, after receiving the indicator signal, will further adjusts its own transmit power based on the interference condition.

[0050] In an LTE macro cell, in order to enhance the cell edge service quality, the LTE-U exploits an elCIC policy. A principle of this scheme is to configure one or more sub-frames as blank subframe (ABS). Such ABS sub-frames specifically provide services to UEs in a micro cell, picocell, or at a edge of a home base station cell, thereby effectively avoiding main interferences from the macro cell and effectively enhancing the service rate to the UEs at a cell edge.

[0051] In the Wi-Fi system, an AP will occupy all spectrum resources after it seizes the resources, such that there is no way to coordinate on the frequency. Although the AP can perform resource scheduling in time, waste of system resources will be caused due to contention and fallback.

Adaptive Repeat Request (HARQ) Technology

[0052] With the adaptive repeat request technology, when error occurs to transmission of physical layer data blocks, the LTE-U receiving end will not drop the mistakenly transmitted data blocks; instead, it will wait for arrival of retransmitted data blocks. The receiving end will perform a merge operation after receiving the retransmitted data blocks.

[0053] The HARQ technology can effectively utilize the previous transmission energy, thereby enhancing the energy efficiency and transmission success rate. Compared with the policy of directly discarding the error data blocks in the Wi-Fi system, the LTE-U outperforms in energy efficiency and transmission success rate.

CA (Carrier Aggregation) Technology

[0054] The commercial LTE network starts from Cat3 and Cat4. Initially, the LTE does not use the CA (Carrier Aggregation) technology. With application of the CA technology, the capacity of the LTE system is enhanced in multiples; this will undoubtedly bring a better use experience of data traffic to the user.

[0055] In the initial Cat4, the LTE uses a 20MHz continuous spectrum. The CA technology first appeared in the LTE system in 2013 when aggregation of two 10MHz spectrums was first implemented; afterwards, through constant development and evolution, the bands aggregated using the CA technology become increasingly wider, such that the system capacity increases in multiples year by year.

[0056] Now, spectrum resources become scares. In order to achieve efficient utilization of spectrum resources, the LTE-U system running on an unlicensed band will also employ the CA technology. Specifically, the LTE-U may use a licensed band as a primary carrier (PCell), such that the terminal and the base station may establish a wireless resource control connection on the licensed band; then obtains the currently idle unlicensed band resources through carrier sensing, thereby using the unlicensed band as a secondary carrier for transmitting data. Correspondingly, the unlicensed band may be used as a secondary carrier (SCell).

Channel Sharing Policy

[0057] When the LTE-U runs on the unlicensed band, it is inevitable that channel conflict situation with the Wi-Fi system will occur. In order to address this issue, the LTE-U will employ a plurality of policies of channel sharing. Currently, proposed solutions include LBT, CSAT, DFS, and TPC.

[0058] In a cell where Wi-Fi and LTE-U are densely deployed, the LTE-U system possibly cannot detect an idle channel. In this case, the LTE-U may implement channel sharing with Wi-Fi or LTE-U in the same cell and the neighboring cell through CSAT (Carrier Sensing Adaptive Transmission) technology. The CSAT mechanism defines a transmit cycle period. During this cycle period, the LTE-U performs data transmission only using a part of time interval, wherein the duty cycle for transmission execution and transmission suspension is decided by an active degree of other transmission systems within the cell. This may ensure channel sharing and service quality.

[0059] For example, in a downlink transmission process, the base station end performs carrier listening. Only when the unlicensed band is guaranteed to be idle, will the base station use it to perform data transmission; likely, the unlicensed band listening work in the uplink may be performed by the user end.

[0060] The LTE-U inherits a series of advantageous technologies in the LTE standard. This solidly supports enhancement of system performances. Now, the carrier aggregation technology and ecological cell of the LTE system have become very mature, such that it becomes possible to deploy an LTE-U system in the micro cell to implement aggregation with the licensed band. Due to worldwide universality of most unlicensed bands, this will make the technology promoted more easily. Meanwhile, the LTE-U supports service provision to fast moving users, and may implement inter-cell seamless access. In these aspects, the access technologies on other unlicensed bands are incomparable.

[0061] As deployment of wireless networks becomes increasingly dense, interference between various systems will become more and more serious; then interference coordination will become one of key issues restricting system performance enhancement. Because the LTE-U services will be provided by the carrier, interference coordination will become much easier than Wi-Fi and other access technologies. Based on the interference coordination, the LTE-U combines the centralized scheduling technology, CA, HARQ, QoS Assurance technology. These advantages will all ensure that the system achieves a higher spectrum efficiency, a larger system capacity, and therefore a better user experience.

[0062] In the aspect of LTE-U network deployment, the existing LTE devices may be sufficiently utilized. Of course, it is also needed to make certain modification to the LTE air interface protocol, such that the LTE may smoothly run on the unlicensed band. This will be a smart selection for the carrier to reduce costs, and the user will also achieve a huge benefit.

[0063] Regarding coexistence between the LTE-U and other protocols on the unlicensed band, besides reading the explanations of various embodiments of the present invention, it may also further refer to: Qualcomm Research - LTE in Unlicensed Spectrum: Harmonious Coexistence with Wi-Fi, June 2014 (also referred to "LTE-Unlicensed- Coexistence- Whitepaper"). [0064] Next, a method of transmitting, in a wireless communication network where a licensed band and an unlicensed band coexist, uplink scheduling information for the unlicensed band from a network device (e.g., a base station) to a user equipment (e.g., a user equipment) will be introduced through an embodiment of the present invention. Refer to Fig. 3, in which a flow diagram of the method is presented.

[0065] First , in step S30, the base station transmits configuration information to the user equipment, the configuration information indicating a time-domain correspondence relationship between the uplink scheduling information transmitted by the base station and the uplink transmission performed by the user equipment based on the uplink scheduling information. For example, the base station may indicate, in this step, employing 0# configuration of the primary carrier shown in table 1, and 1# configuration of for example a secondary carrier therein. Then, the user equipment will know that the base station will transmit uplink scheduling information on the first and sixth subframes of each frame via the first wireless network. The scheduling information is for the user equipment to perform uplink transmission in the second wireless network, and this uplink transmission should occur on the sixth or seventh subframe after transmitting the uplink scheduling information. For another example, the base station may indicate 2# configuration of the primary carrier as shown in Table 3 and the 2# configuration of for example the secondary carrier therein. Then, the user equipment will know that the base station will transmit uplink scheduling information on the third and eighth subframes of each frame. The scheduling information is for scheduling uplink transmission on PUSCH with 4 subframes later than transmission of the scheduling information.

[0066] It should be noted that step S30 is an optional step. In a varied example, the user equipment pre-stores desired mapping information statically or quasi-statically. In other words, it knows in advance the configuration information of the primary carrier and/or secondary carrier used between the base station and itself, and knows the correspondence relationship between time-domain resource on the primary canner and the time-domain resource on the secondary carrier. For example, the user equipment pre-stores the mapping relationship as illustrated in Fig. 5, or pre-stores content in any of table 1 - table 8, and runs its own uplink transmission based on the content in the table and the received uplink scheduling information.

[0067] In step S32, the network device transmits uplink scheduling information for an unlicensed band to the user equipment via the licensed band. For example, the uplink scheduling information may be transmitted over PDCCH (Physical Downlink Control Channel) using DCI (Downlink Control Information). Of course, if necessary, the existing DCI format may be adjusted to adapt multiple carriers (e.g., licensed and unlicensed) corresponding to a UE. For example, lengthening the existing DCI such that it carries relevant information of multiple carriers; or a plurality of DCI information may be utilized to carrier relevant information of different carriers, respectively, e.g., respective uplink scheduling information of various carriers. Specifically, further illustration may be made with reference to Fig. 5.

[0068] Fig. 5 illustrates a time-domain mapping relationship between a primary carrier and a secondary carrier that may be implemented under an action of step S30 or the pre-stored configuration and then through transmitting of the uplink scheduling information in step S30. It is also a differentiated expression of the first configuration of the sub-carrier in Table 3. It is seen that on neighboring subframes of the primary carrier, the resources are allocated with D-S-U-D-D as a unit to cycle on the time domain, wherein D denotes downlink; S denotes spatial, which is mainly for uplink and downlink switching; U denotes uplink (in the subframe, the user equipment performs uplink transmission), i.e., 0# subframe of the first frame is for downlink transmission (control signaling or traffic data), #1 subframe of the first frame is S subframe; then, #2 sub-frame is an uplink subframe; #3 and #4 subframes are downlink subframes; #5 subframe is a beginning of a next D-S-U-D-D cycle, which will not be detailed.

[0069] Specifically, according to the #0 configuration of the primary carrier and the #1 configuration of the secondary carrier, as illustrated in Fig. 5, uplink scheduling information is transmitted at #8 and #9 subframes of each frame (due to space limitation, only the first frame is illustrated), for the UE's uplink transmission after 4 subframes, e.g., after issuing in the first frame, what is actually scheduled by the uplink scheduling information is uplink transmission using the unlicensed band in #2 subframe (spaced with 4 subframes from the #8 subframe of the first frame) and the #3 subframe (spaced with 4 subframes from #9 subframe of the first frame). Further, at the #3 subframe and the #4 subframe of each frame, the second wireless network transmits the uplink scheduling information, and what is specifically scheduled thereby is the uplink transmission in the second wireless network when the user equipment is located after 4 subframes, i.e., #7 and 8 subframes of the same frame.

[0070] Therefore, it may be further illustrated that in the embodiment of the present invention, the transmitting step of step S32 comprises: transmitting uplink scheduling information on the unlicensed band to the user equipment via the licensed band.

[0071] In addition, it may also be seen from the example above that according to the embodiments of the present invention, the first wireless network and the second wireless network work in a time division duplexing mode.

[0072] Without loss of generality, in order to meet the requirements of the standard, transmitting of the uplink scheduling information in the embodiment may be made at least 4 subframes earlier than the uplink transmission scheduled by the uplink scheduling information (or corresponding thereto). In the example shown in Fig. 5, this time interval is just 4 subframes.

[0073] Without loss of generality, if the standard requires, transmitting of the uplink scheduling information may be set at most 7 subframes earlier than uplink transmission scheduled by the uplink scheduling information (or corresponding thereto). This will be understood more intuitively through reading Table 1-Table 8 and corresponding textual explanations. However, those skilled in the art should understand that these limitations are only for satisfying the requirements of the standard where necessary, not for limiting the protection scope of the present invention. The present invention does not compulsorily require such time interval upper limit or lower limit.

[0074] Table 1 - Table 8 list various examples the inventors may list, wherein each table corresponds to one configuration manner of the primary carrier, while each table further illustrates 7 configurations of the secondary carriers, respectively. Therefore, according to different embodiments, there are about 56 combination manners. Certain combination thereof may be implemented on the base station and the user equipment through different information contents in step S32 and the optional step S30.

[0075] With Table 1 as an example, it illustrates 7 configurations in total, including #0 configuration of the primary carrier and # 0 -6 configurations of the corresponding secondary carrier. Hereinafter, "configuration [x, y]" is used to refer to a combination, where x is 1-8, indicating a corresponding primary carrier configuration in tables 1-8, while y is 0-6, indicating a corresponding configuration of the secondary carrier.

Table 1: #0 configuration of the primary carrier

(the scheduling information transmitted by the n^th subcarrier is for uplink transmission of the secondary carrier on the n+k^th subframe)

[0076] In the configuration combination [1, 0] of Table 1, the base station transmits uplink transmission information at #0, #1, #5, and #6 subframes of each frame, for scheduling uplink transmission of PUSCH at the #4 subframe, #6 or 7 subframe, #4 subframe, and #6 or 7 subframe after the scheduling. Similarly, in the configuration combination [1, 1] of Table 1, the base station transmits the uplink scheduling information on the #1 and #6 subframes of each frame through the licensed band, for scheduling uplink transmission after the #6/7 subframe on the unlicensed band.

Table 2: #1 configuration of the primary carrier

Table 3: #2 configuration of the primary carrier

Secondary Subframe number n

configuration 0 1 2 3 4 5 6 7 8 9 No.

0 4 4 4 4 4 4

Table 4: #3 configuration of the primary carrier

Table 5: #4 configuration of the primary carrier

Table 6: #5 configuration of the primary carrier

(the scheduling information transmitted by the n^th subcarrier is for uplink transmission of the secondary carrier on the n+k^th subframe) Secondary Subframe number n

configuration 0 1 2 3 4 5 6 7 8 9 No.

0 4 4 4 4 4 4

1 4 4 4 4

2 4 4

3 4 4 4

4 4 4

5 4

6 4 4 4 4 4

Table 7: #6 configuration of the primary carrier

Table 8: #7 configuration of the primary carrier

[0077] For configurations 0-1, 3-4, and 6, the following manner may also be adopted, namely, in a 5ms or 10ms switch periodicity, the number of downlink subframes of the primary carrier is less than the number of uplink subframes in the second carrier; then scheduling of multiple subcarriers may be supported. For example, in the LTE standard, an uplink scheduling information packet may be supported using an uplink index (UL index) in the PDCCH or EPDCCH. If the most significant bit (MSB) in the uplink index and the least significant bit (LSB) in the uplink index are provided at subframe n, then UE will perform corresponding uplink transmission on subframes n+7 and n+k (e.g., k=4); otherwise, the UE will only perform uplink transmission on the subframe n+k.

[0078] Particularly, the scheduling delay shown in Table 8 is slightly smaller than the example in Table 7.

[0079] If elMTA is configured in the primary carrier, the indication transmitted in step S30 might be needed. In order to complete the indication, a bitmap and a 3-bit indication may be used for UE-specific RNC signaling:

- 10-bit bitmap (corresponding to 10 subframes in one frame): "1" denotes an uplink subframe. For configuration 0, e.g., "0011100111," namely, in all of the 10 subframes from #0-#9, subframes 2-4 and 7-9 are uplink subframes, while the remaining are S-subframe or downlink subfrme.

- three-bit indication: "000" indicates configuration 0, "001" indicates configuration 1, "101" indicates configuration 7. The remaining values may be reserved o number newly introduced configurations.

[0080] Fig. 4 illustrates a block diagram of a scheduling apparatus 40 for transmitting, in a wireless communication network where a licensed band and an unlicensed band coexist, uplink scheduling information for the unlicensed band from a network device (e.g., base station 4) to a user equipment (e.g., mobile phone) according to an embodiment of the present invention. The scheduling module 40 is configured to transmit uplink scheduling information for the unlicensed band to the user equipment via the licensed band.

[0081] Preferably, the network device and the user equipment work in a time-division duplexing (TDD) mode on the unlicensed band.

[0082] Preferably, the scheduling apparatus 40 may also comprise: a transmitting unit 400 configured to transmit configuration information to the user equipment, the configuration information indicating a temporal-domain correspondence relationship between the uplink scheduling information transmitted by the network device and uplink transmission performed by the user equipment based on the uplink scheduling information.

[0083] Preferably, transmitting of the uplink scheduling information is at least 4 sub-frames earlier than uplink transmission corresponding to the uplink scheduling information.

[0084] Preferably, transmitting of the uplink scheduling information is at most 7 sub-frames earlier than uplink transmission corresponding to the uplink scheduling information.

[0085] Without loss of generality, the licensed band includes a band based on any of network technologies below: LTE, LTE-A, or GSM.

[0086] Without loss of generality, the unlicensed band includes a band based on any of network technologies: Zigbee or Wi-Fi.

[0087] In the several embodiments provided by the present invention, it should be understood that the disclosed system and method may be implemented through other manners. For example, the system embodiment described above is only schematic, e.g., partitioning of respective functional units may only be logic function partitioning; in actual implementations, there may be other partitioning manners.

[0088] Units illustrated as separate components may be physically separated or may not be. Components shown as units may be physical units or may not be, i.e., they may be disposed at one place, or may be distributed onto a plurality of network units. Part or all of the units may be selected as needed to achieve the objectives of the solutions of the present embodiments.

[0089] In addition, respective functional units in respective embodiments of the present invention may be integrated into one processing unit; or respective units may be physically existent individually; or two or more units are integrated into one unit. The integrated unit may be embodied as hardware or embodied as a hardware plus software functional unit.

[0090] What have been described above are only preferred embodiments of the present invention, not for limiting the present invention. Any modifications, equivalent substitutions, and improvements within the spirit and principle of the present invention should be included within the protection scope of the present invention.

Claims

1. A method of transmitting, in a wireless communication network where a licensed band and an unlicensed band coexist, uplink scheduling information for the unlicensed band from a network device (4) to a user equipment, comprising steps of:

transmitting (S32), by the network device, the uplink scheduling information for the unlicensed band to the user equipment via the licensed band.

2. The method according to claim 1, wherein the network device and the user equipment work in a time-division duplexing mode on the unlicensed band.

3. The method according to claim 1, further comprising:

b. transmitting (S30), by the network device, configuration information to the user equipment, the configuration information indicating a temporal-domain correspondence relationship between the uplink scheduling information transmitted by the network device and uplink transmission performed by the user equipment based on the uplink scheduling information.

4. The method according to claim 1 or 4, wherein transmitting of the uplink scheduling information is at least 4 sub-frames earlier than uplink transmission corresponding to the uplink scheduling information.

5. The method according to claim 5, wherein transmitting of the uplink scheduling information is at most 7 sub-frames earlier than uplink transmission corresponding to the uplink scheduling information.

6. The method according to any one of claims 1-5, wherein the licensed band includes a band based on any of network technologies below: LTE, LTE-A, or GSM.

7. The method according to any one of claims 1-5, wherein the unlicensed band includes a band based on any of network technologies: Zigbee or Wi-Fi.

8. A scheduling apparatus (40) for transmitting, in a wireless communication network where a licensed band and an unlicensed band coexist, uplink scheduling information for the unlicensed band from a network device (4) to a user equipment, wherein the scheduling apparatus is configured to transmitting the uplink scheduling information for the unlicensed band to the user equipment via the licensed band.

9. The scheduling apparatus according to claim 8, wherein the network device and the user equipment work in a time-division duplexing mode on the unlicensed band.

10. The scheduling apparatus according to claim 8, comprising:

a transmitting unit (400) configured to transmit configuration information to the user equipment, the configuration information indicating a temporal-domain correspondence relationship between the uplink scheduling information transmitted by the network device and uplink transmission performed by the user equipment based on the uplink scheduling information.

11. The scheduling apparatus according to any one of claims 8-10, wherein transmitting of the uplink scheduling information is at least 4 sub-frames earlier than uplink transmission corresponding to the uplink scheduling information.

12. The scheduling apparatus according to claim 11, wherein transmitting of the uplink scheduling information is at most 7 sub-frames earlier than uplink transmission corresponding to the uplink scheduling information.

13. The scheduling apparatus according to any one of claims 8-12, wherein the licensed band includes a band based on any of network technologies below: LTE, LTE-A, or GSM.

14. The scheduling apparatus according to any one of claims 8-10, wherein the unlicensed band includes a band based on any of network technologies: Zigbee or Wi-Fi.

15. A network device (4) in a system where a licensed band and unlicensed band coexist, including a scheduling apparatus (40) according to any one of claims 8-14.