CLIAMS:
1. A method for providing data offloading in a heterogeneous wireless network, the method comprising of:
receiving, at the heterogeneous network, a UE assistance data transmitted from a user equipment (UE);
determining a priority of the UE from the UE assistance data; and
redirecting at least one UE from a heterogeneous network cell to a macro cell based on the identified priority of the UE;
wherein the UE assistance data comprises of a Total Estimated Data (TED) associated with the UE which is to be uploaded to the heterogeneous network.

2. The method of claim 1, wherein the total estimated data comprises of an information element (IE) and a Buffer Status Report (BSR) indicating a size of data associated with the UE which is to be uploaded to the network.

3. The method of claim 1, wherein the priority of the UE is determined based on a plurality of parameters comprising at least one of:
a Channel Quality Indicator (CQI);
the Buffer Status Report;
the total estimated data (TED); and
a Logical Channel Identifier (LCID).

4. The method of claim 1, wherein identifying the priority of the UE comprises of:
checking if the TED is greater than zero and if the BSR is null or not;
verifying if the data load to be uploaded to the heterogeneous network is greater than a pre-defined threshold if the TED is greater than zero and the BSR is not null; and
obtaining the priority of the UE if the data to be uploaded is greater than the predefined threshold.

5. The method of claim 1, wherein redirecting the UE to a macro cell comprises of:
checking for one or more UE’s in the heterogeneous network having a priority less than the incoming UE;
selecting at least one UE having a priority less than the incoming UE; and
redirecting the UE having the less priority from the heterogeneous network cell to the macro cell.

6. The method of claim 1, wherein the TED associated with the UE comprises at least one of:
a TED value which is an aggregate of the data sizes provided by a plurality of applications involved in a selected data session;
a plurality of TED values, where each TED value represents a data size pertaining to one of a logical channel or a logical channel group.

7. The method of claim 2, wherein the UE transmits the IE in a MAC UL PDU to inform the heterogeneous network about the estimated data which is to be uploaded by the UE.

8. The method of claim 1, further comprising adapting the UE to the heterogeneous network cell if the network load is less than the predefined threshold.

9. A system for providing data offloading in a heterogeneous wireless network; the system comprising:
at least one user equipment (UE), adapted for:
transmitting a UE assistance data to the heterogeneous network;
one or more eNBs having at least one network element adapted for:
determining a priority of the UE from the UE assistance data; and
redirecting at least one UE from a heterogeneous network cell to a macro cell based on the identified priority of the UE;
wherein the UE assistance data comprises of a Total Estimated Data (TED) indicating a size of data associated with the UE which is to be uploaded to the heterogeneous network.

10. The system of claim 1, wherein the UE transmits the TED as an Information Element (IE) in MAC UL PDU to the heterogeneous network.
,TagSPECI:FIELD OF THE INVENTION

The embodiments herein generally relates to wireless communication, and particularly relates to a method and system for providing data bearer management, data offloading and user equipment (UE) measurements in heterogeneous networks (HetNet).

BACKGROUND OF THE INVENTION

In 3GPP radio access network (RAN) LTE systems, the transmission station can be a combination of Evolved Universal Terrestrial Radio Access Network (E-UTRAN) Node Bs (also commonly denoted as evolved Node Bs, enhanced Node Bs, eNodeBs, or eNBs) and Radio Network Controllers (RNCs), which communicates with the wireless mobile device, known as a user equipment (UE). Here a downlink (DL) transmission is referred as a communication from the transmission station (or eNodeB) to the wireless mobile device (or UE), and an uplink (UL) transmission is a communication from the wireless mobile device to the transmission station.

Generally, in LTE systems, heterogeneous networks (HetNets) are used to handle the increased traffic loads on the macro nodes due to increased usage and functionality of mobile devices. HetNets includes a layer of planned high power macro nodes (or macro-eNBs) overlaid with layers of low power nodes (micro-eNBs, Pico-eNBs, Femto-eNBs, or home eNBs [HeNBs]) that can be deployed in a less well planned or even entirely uncoordinated manner within the coverage area of the macro nodes. The macro nodes can be used for basic coverage, and the low power nodes can be used to fill coverage holes, to improve capacity in hot-zones or at the boundaries between the macro nodes' coverage areas, and improve indoor coverage where building structures impede signal transmission.

In current 3GPP study items related to HetNet mobility, it has become apparent that future networks will require a number of small cells (small relative to a macro cell in which the small cells are located) to be deployed in order to cope with the expected increase in demand for higher data rates and faster connections. To achieve this, small cells need to be detected by the UE and reported to the network in order to gain the benefits that can be realized from the deployment of the small cells.

The existing 3GPP performs a Buffer Status Reporting procedure which provides the serving eNB with information about the amount of data available for transmission in the UL buffers of the UE. Generally UE sends this data report to the network on a periodic or aperiodic basis, which allows the network to schedule the uplink resources to the UE in conjunction with other parameters related to cell load, traffic distribution, channel quality etc. However BSR provides only the information of the data that is queued up in the radio protocol stack layers and does not provide any information regarding the overall data that eventually needs to be transferred before ending the data session.

If Network node uses BSR as the criteria to decide the offloading/transfer of one or more bearers to a HetNet cell, then the network node need to access multiple BSRs to guess that the UE is available for a data transfer and further transfer the data bearer to a HetNet cell. However it is possible that the moment the data bearer is transferred to a HetNet cell or if the eNB makes a decision based on very less BSRs, then there is not much data left to transfer. In such cases, additional signaling required for the transfer of the data bearer to a HetNet cell and subsequent bearer teardown is an overhead. This negatively impacts the data offloading as there is no way to differentiate data bearers/user sessions that has heavier bandwidth requirements. Further the currently specified BSR’s can accommodate data varying from only a few bytes to a few kilobytes. However, the network requires higher metrics (running into Megabytes, Gigabytes of data) to understand the need of data applications.

Similarly, if the UE has a large data to transmit and the UE is indicating high BSR continuously, it is required to hand over the data bearer to a high capacity HetNet cell to avoid eNB resource crunch.

In view of the foregoing, there is a need for a method and system which provides for efficient offloading or transfer of one or more data bearers from a LTE cell to a HetNet cell.

The foregoing examples of the related art and limitations related therewith are intended to be illustrative and not exclusive. Other limitations of the related art will become apparent upon a reading of the specification and a study of the drawings.

SUMMARY OF THE INVENTION

The primary objective of the embodiments herein is to provide method and system for providing a UE assistance data to the eNB for transfer of data bearers for HetNet cells.

Another objective of the embodiments herein is to provide a method and system to manage load at eNB and hetNet cells.

The various embodiments herein provide a method and system for providing data offloading in a heterogeneous wireless network. The method comprising the steps of receiving, at the heterogeneous network, a UE assistance data transmitted from a user equipment (UE) k, determining a priority of the UE from the UE assistance data, and redirecting at least one UE from a heterogeneous network cell to a macro cell based on the identified priority of the UE. Here the UE assistance data comprises of a total estimated data (TED) associated with the UE which is to be uploaded to the heterogeneous network.

According to an embodiment herein, the total estimated data (TED) comprises of an information element (IE) and a buffer status report (BSR) indicating a size of data associated with the UE which is to be uploaded to the network.

According to an embodiment herein, the priority of the UE is determined based on a plurality of parameters comprising at least one of a channel quality indicator (CQI), the buffer status report (BSR), the total estimated data (TED), the logic channel identifier (LCID).

According to an embodiment herein, the method of identifying the priority of the UE comprises of checking if the TED is greater than zero and if the BSR is null or not, verifying if the data load to be uploaded to the heterogeneous network is greater than a pre-defined threshold if the TED is greater than zero and the BSR is not null and obtaining the priority of the UE if the data to be uploaded is greater than the predefined threshold.

According to an embodiment herein, the method of redirecting the UE to a macro cell comprises of checking for one or more UE’s in the heterogeneous network having a priority less than the incoming UE, selecting at least one UE having a priority less than the incoming UE, and redirecting the UE having the less priority from the heterogeneous network cell to the macro cell.

According to an embodiment herein, the TED associated with the UE comprises at least one of a TED value which is an aggregate of the data sizes provided by a plurality of applications involved in a selected data session, a plurality of TED values, where each TED value represents a data size pertaining to one of a logical channel or a logical channel group.

According to an embodiment herein, the UE transmits the IE in a MAC UL PDU to inform the heterogeneous network about the estimated data which is to be uploaded by the UE.

According to an embodiment herein, the method for providing data offloading in a heterogeneous wireless network further comprises of adapting the UE to the heterogeneous network cell if the network load is less than the predefined threshold.

Embodiments herein further disclose a system for providing data offloading in a heterogeneous wireless network. The system comprises an at least one user equipment (UE) adapted for transmitting a UE assistance data to the heterogeneous network wherein the UE assistance data comprises of a Total Estimated Data (TED) indicating a size of data associated with the UE which is to be uploaded to the heterogeneous network, one or more eNBs having at least one network element adapted for determining a priority of the UE from the UE assistance data and redirecting at least one UE from a heterogeneous network cell to a macro cell based on the identified priority of the UE.

According to an embodiment herein, the UE is adapted to transmit the TED as an Information Element (IE) in MAC UL PDU to the heterogeneous network.

The foregoing has outlined, in general, the various aspects of the invention and is to serve as an aid to better understanding the more complete detailed description which is to follow. In reference to such, there is to be a clear understanding that the present invention is not limited to the method or application of use described and illustrated herein. It is intended that any other advantages and objects of the present invention that become apparent or obvious from the detailed description or illustrations contained herein are within the scope of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The other objects, features and advantages will occur to those skilled in the art from the following description of the preferred embodiment and the accompanying drawings in which:

FIG. 1 is a system diagram illustrating an environment for providing data offloading in heterogeneous networks, according to an embodiment of the present invention.

FIG. 2 is a block diagram illustrating a data format of the UE assistance data for Short-BSR’s, according to an embodiment of the present invention.

FIG. 3A-3B is a block diagram illustrating a data format of the UE assistance data for Long-BSR’s, according to an embodiment of the present invention.

FIG. 4 is a flow chart illustrating a method for enabling data offloading in heterogeneous networks, according to an embodiment of the present invention.

Although specific features of the present invention are shown in some drawings and not in others, this is done for convenience only as each feature may be combined with any or all of the other features in accordance with the present invention.

DETAILED DESCRIPTION OF THE INVENTION
The present invention provides a method and system for providing data offloading in a heterogeneous wireless network. In the following detailed description of the embodiments of the invention, reference is made to the accompanying drawings that form a part hereof, and in which are shown by way of illustration specific embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be utilized and that changes may be made without departing from the scope of the present invention. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is defined only by the appended claims.

FIG. 1 is a system diagram illustrating an environment for providing data offloading in heterogeneous networks, according to an embodiment of the present invention. According to Figure 1, there exists a macro eNB 102 that provides a coverage area. Within this coverage area, there are at least two pico cells 104, which can be used to improve capacity in high use areas by allowing the macro eNB 102 to offload to the Pico cells 104. Another pico cell 104 is illustrated as existing on the edge of the coverage area. This pico cell 104 can be used to fill coverage holes within the macro node's coverage area and at the boundaries between the macro node’s coverage area.

According to an embodiment of the present invention, a macro node's coverage area may include hundreds or even thousands of pico nodes. For example, pico nodes configured as HeNBs may be located in hundreds or thousands of homes that are within the coverage area of a single macro node. Each pico cell comprises of a plurality of user equipments (UE) 106 having a large amount of data to be transmitted to the network. Whenever plurality of UEs 106 has to transmit a large amount of data to the network, each of the plurality of UEs 106 send a Total Estimated Data (TED) associated with each UE which is to be uploaded to the heterogeneous network. The size of the data (TED) corresponds to the total size of the upload provided by the application layer to the radio protocol stack.

During the transmission, the UE transmits the TED as a new information element in medium access control (MAC) uplink protocol data unit (UL PDU) to inform the network about the data that UE has to upload. In an embodiment of the present invention, the UE also transmits the buffer status report (BSR) message along with the TED to the network. The BSR message indicates the network the size of the data that is queued up in the radio protocol stack layers. The BSR comprises of a short BSR data structure or a long BSR data structure.

In an embodiment of the present invention, the TED is transmitted with a TED value which is an aggregate of the data size provided by all or specifically chosen applications making use of a data session. This can be indicated to the network in the same way as a short BSR is indicated (as explained in Figure 2).

According to another embodiment of the present invention, the TED can also be transmitted as multiple TED values, each representing the data size pertaining either to a logical channel or to a logical channel group. This can be indicated to the network in the same way as a long BSR is indicated (Long BSR have multiple 'Buffer Size' field, each of which represent one LCG). According to yet another embodiment of the present invention, the UE 106 adds multiple TED values to an aggregated TED value while considering the amount of padding bits available during transmission of long BSR. This added TED values is the sum of the TED available for each logical channel or to a logical channel group.

According to an embodiment of the present invention, the network transmits a control message to the UE indicating the UE 106 to transmit only one of the BSR or TED values. The network send this control message in order to avoid overhead of transmitting both TED and BSR values. In such a case, the UE 106 transmits either the BSR value or the TED value to the network.

According to an embodiment of the present invention, the UE 106 updates the remaining TED that it has to upload along with the BSR which UE sends in MAC UL PDU. In this embodiment, the UE informs the network about the remaining TED that UE 106 has to upload using two additional bytes in MAC UL PDU. When there are higher data sizes coming from different application levels, different data ranges are mapped to different TED values. For example, 0 TED_Threshold) and BSR reported is not NULL for period of previous ‘N’ iterations.

Priority 2 - (CQI > CQI_ Threshold) and (TED > TED_Threshold) and BSR reported and very less resources available at eNB.

Priority 3 - (CQI < CQI_Threshold) and (TED < TED_Threshold) and (TED > TED_Lower_Limit) and BSR reported.

Priority 4 - (CQI > CQI_ Threshold) and (TED < TED_Threshold)and TED > TED_Lower_Limit and BSR reported and less resources available at eNB.

Priority 5 - (CQI > CQI_ Threshold) and TED > TED_Threshold and BSR reported and enough resources at eNB.

Priority 6 - (CQI > CQI_ Threshold) and TED < TED_Thres and TED > TED_Lower_Limit and BSR reported and enough resources at eNB.
Priority 7 – Remaining conditions.

For the L-BSR, the priority can be calculated by taking TED as total TED for all LCID’s and LCID priority as highest “BSR reported” LCID’s priority.

According to an embodiment of the present invention, the network makes a decision whether to retain some or all bearers of a UE with itself or to transfer them to a HetNet cell based on the several inputs either provided by the UE or already available with the network.

According to an embodiment of the present invention, when a UE is up for uploading data and reporting BSR, if the hetNet cell load is less than its threshold limit then the incoming UE is directly moved to use HetNEt services. On the other hand, if the HetNet cell load is greater than its threshold limit then we check for the priority of incoming UE, the incoming UE is replaced with the least priority UE which is currently using the HetNet services if it has lower priority than the incoming UE. Also according to another embodiment, if the UE is reporting TED (>0) and if BSR is not reported, then eNB makes the UE stay in the HetNet till the timer expires.

FIG. 4 is a flow chart illustrating a method for enabling data offloading in heterogeneous networks, according to an embodiment of the present invention. At step 402, a UE assistance data is received from a user equipment. The UE assistance data comprises of a total estimated data (TED) associated with the UE which is to be uploaded to the heterogeneous network. The TED comprises of an information element and a BSR indicating a size of data associated with the UE which is to be uploaded to the network. Further, the TED associated with the UE comprises of a TED value which is an aggregate of the data sizes provided by a plurality of applications involved in a selected data session. Also, the TED associated with the UE comprises of a plurality of TED values where each TED value represents a data size pertaining to one of a logical channel or a logical channel group. Additionally, the UE transmits the IE in a MAC UL PDU top inform the heterogeneous network about the estimated data which is to be uploaded by the UE.

At step 404, verify if the TED value>0 and BSR # value is null or not. If the TED value>0 and BSR # value is not null, then at step 406, the UE is made to stay in the same cell or is redirected to the macro cell. If the TED value not greater than 0 and BSR # value is null, then at step 408, it determined whether the data to be uploaded to the network is greater than a predefined threshold value or not. If the data to be uploaded to the network is not greater than the predefined threshold value, then at step 410, the incoming UE is redirected or retained in the HetNet cell. If the data to be uploaded to the network is greater than the predefined threshold value, then at step 412, then obtain the priority of the incoming UE based on a plurality of parameters. The plurality of parameters includes a channel quality indicator (CQI), the buffer status report, the total estimated data (TED) and the logical channel identifier (LCID).

At step 414, check if any UE’s having priority less than the incoming UE are available in the network. At step 416, it is determined whether there is any UE with less priority available or not. If there is any UE available with less priority, then at step 418, the UE having the less priority is redirected from the heterogeneous network cell to the macro cell. Upon redirecting the UE having the less priority to the macro cell, the incoming UE is added or redirected to the HetNet cell. On the contrary, if there is no UE available with less priority, then the incoming UE remains or is redirected to the macro cell (410).

The embodiments herein enable the network to take an efficient decision on offloading/transfer of one or more bearers to a HetNet cell when the UE is up for a data transfer. The present invention also helps the network to transfer the data bearers from a LTE cell to a HetNEt cell when the UE has a large amount of data to be uploaded and the UE is indicating high BSR continuously to the network. The present invention is also applicable for UL data for example FTP, video uploading and so on based on UE assistance data.

The present embodiments have been described with reference to specific example embodiments; it will be evident that various modifications and changes may be made to these embodiments without departing from the broader spirit and scope of the various embodiments. Furthermore, the various devices, modules, and the like described herein may be enabled and operated using hardware circuitry, firmware, and/or software embodied in a machine readable medium. Although the embodiments herein are described with various specific embodiments, it will be obvious for a person skilled in the art to practice the invention with modifications. However, all such modifications are deemed to be within the scope of the claims. It is also to be understood that the following claims are intended to cover all of the generic and specific features of the embodiments described herein and all the statements of the scope of the embodiments which as a matter of language might be said to fall there between.