Data transmission method in mobile communications system

Data transmission method of mobile communication system

The present invention relates to an E-UMTS (abbreviation of Evolved Universal Mobile Telecommunications System), and in particular, relates to a method for improving the efficiency of data transmission during the delivery of a mobile terminal.

Figure 1 shows the network structure of E-UMTS, which can be applied to related technologies and the present invention.

The E-UMTS system has evolved from the UMTS system, and 3GPP has prepared basic specifications that can be applied to it. The E-UMTS system can be classified as an LTE (Long Term Evolution, abbreviation for Long Term Evolution) system.

Regarding Figure 1, the E-UMTS network is divided into an E-UTRAN 20 and an EPC (abbreviation for Evolved Packet Core) 10. E-UTRAN 20 includes a terminal (User Equipment (UE)); a base station (eNB or eNodeB) 21 and an AG (Access Gateway) 11 (which can also be expressed as "MME /UPE"). The AG 11 can be divided into a part for processing user traffic and a part for processing control traffic. The AG part for processing new user traffic and the AG part for processing control traffic can communicate with each other through the newly defined interface.

One or more cells can exist in a single eNodeB (eNB) 21, and an interface for transmitting user traffic and controlling traffic can be used between eNodeBs.

The EPC 10 may include an AG 11, a node for user registration of the UE, and the like. At the same time, in the UMTS shown in Figure 1, an interface that can distinguish between E-UTRAN 20 and EPC 10 can be used. An S1 interface can connect multiple nodes between eNodeB 21 and AG 11 (that is, in a many-to-many manner). The eNodeBs are connected to each other through an X2 interface, and the X2 interface is always present between adjacent eNodeBs in the mesh network structure.

The multiple layers of the radio interface agreement between the UE and a network can be divided into a first layer according to the three lower layers of the open system interconnection (OSI) reference model that is well-known in the technical field of communication systems. Layer (L11), a second layer (L2), and a third layer (L3).

The first layer (L1) uses a physical channel to provide information transmission, and a radio resource control (RRC) layer located at the third layer (L3) controls the radio resources between the terminal and the network. For this reason, the RRC layer is Exchange RRC messages between the terminal and the network. The purpose of distributing the RRC layer is to deploy the RRC layer in network nodes such as eNodeB and AG, or to deploy only the RRC layer in eNodeB or AG.

Figure 2 shows the control plane structure of the radio access interface protocol between the terminal and UTRAN according to various 3GPP radio access network standards.

The radio access interface protocol has a horizontal layer, which includes a physical layer, a data link layer, and a network layer; and has a vertical plane, which includes a user plane for transmitting data information and a control signal for transmitting The control plane.

These protocol layers can be divided into a first layer (L1), a second layer (L2), and a third layer according to the three lower layers of the well-known Open System Interconnection (OSI) standard model in the technology of communication systems. Layer (L3). The control plane of the radio protocol in Figure 2 and the user plane of the radio protocol in Figure 3 will now be described.

The physical layer (the first layer) provides information transmission services to an upper layer by using a physical channel. The physical layer is connected to an upper media access control (MAC) layer through a transmission channel, and the data between the MAC layer and the physical layer is transmitted through the transmission channel. Between different physical layers (that is, between the physical layers of a transmitting side and a receiving side), data is transmitted through physical channels.

The MAC layer of layer 2 provides services to the radio link control (PLR) layer (which is the upper layer) via a logical channel. The RLC layer of layer 2 supports reliable data transmission. It should be noted that the RLC layer in Figures 2 and 3 is indicated by the dotted line, because if the RLC function is implemented in the MAC layer and executed by the MAC layer, the RLC layer itself does not need to exist. The PDCP layer of Layer 2 performs a header compression function, which reduces unnecessary control information, so that data transmitted by using Internet Protocol (IP) packets (such as IPv4 or IPv6) can be effectively sent to a Small bandwidth radio (wireless) interface.

A radio resource control (RRC) layer located at the bottom of the third layer (L3) is only defined in the control plane, and the control logic channels related to the configuration, reconfiguration and release of the radio bearer (RB), Transmission channel and physical channel. Here, RB means a service provided by the second layer (L2), which is used for data transmission between the terminal and UTRAN.

The downlink transmission channel used to transmit data from the network to the terminal, including a broadcast channel (BCH) for transmitting system information, and a downlink transmission channel for transmitting user traffic or control information Shared channel (shared channel, SCH for short). Downlink multicast and broadcast service traffic or control messages can be transmitted through the downlink SCH, or through a separate downlink multicast channel (multicast channel, MCH).

Used to transmit data from the terminal to the network uplink transmission channel, including a random access channel (randdom access channel, referred to as RACH) used to transmit initial control messages, and one used to transmit user traffic or control messages The uplink SCH.

In the related art, when a terminal and a base station communicate data units with each other, the terminal or one of the base stations will perform a reordering process to transmit the data units (ie SDU) in order. However, if the terminal moves to a new base station (that is, when a delivery occurs), and the terminal transmits one or more uplink data units to a specific base station, the specific base station stops the transmission within a period of time. The received data unit is sent to an upper node (i.e., a gateway) to receive one or more data units that have not been received by the specific base station (i.e., the data unit is transmitted to a new base station). The reason for this time delay is that the specific base station cannot determine whether the new base station properly receives data units that have not been received by the specific base station. Therefore, the transmission time of a data unit is delayed because the specific base station must wait to receive the data unit that has been received by the new base station, and the buffer in the specific base station is used unnecessarily because the specific base station is in a certain time period The received data unit is not transmitted sequentially to the upper node. In the related art, as far as it is concerned, when the terminal transmits the uplink data unit to the gateway and is delivered by the terminal, the disadvantage of inefficient transmission of the data unit will occur.

An exemplary feature of the present invention is to provide a method for improving the transmission efficiency of uplink data in the delivery procedure of a mobile terminal.

In order to implement at least the above features in whole or in part, the present invention provides a method for transmitting data in a mobile communication system. The method may include: when a mobile terminal performs delivery, a base station transmits a data unit related to reordering Information is sent to a gateway, and the gateway reorders the data units received from one or more base stations according to the information related to the reordering.

The data unit may be a radio link controller (RLC) service data unit (SDU).

The information related to the reordering can be transmitted through a signaling message, which is generated between an RLC layer of the base station and a PDCP layer of the gateway.

The sending message may be a reordering instruction information.

The reordering instruction information can be a one-way message or a two-way message.

The information related to the reordering can be transmitted or received via at least one of an RLC generating data unit, a single bit, and a header column of the RLC.

The base station can be a source base station or a target base station.

The base station can transmit a receiving data unit, which is received before delivery is performed, regardless of the sequence number for the gateway.

The reordering process of the data unit can be performed by a PDCP layer of the gateway or a lower layer under the PDCP layer, and the transmission data unit from the terminal can be stored in the reordering buffer of the gateway.

One aspect of the present invention relates to the cognition of the above-mentioned related technical problems by the present inventor, and is further explained below. Based on this knowledge, the features of the present invention have been developed.

Although it is shown that the present invention is implemented in a mobile communication system (such as UMTS developed under the 3GPP specifications), the present invention can also be applied to other communication systems operating according to different standards and specifications.

With the continuous development of network technology, it is foreseeable that RNCs may no longer be needed in future networks, because Node Bs with improved capabilities or other types of network entities (such as so-called access gateways) can handle existing RNCs. The operation performed. This long-term evolutionary topic further supports the need to develop and improve radio admission control technology, which will be used to accommodate new terminals (or establish new user links) and support the newly developed enhanced services of a large number of terminals managed by the network .

The present invention improves a method for transmitting uplink data of a submission procedure of a mobile terminal. That is, when the mobile terminal changes its connection from a first radio network node (the mobile terminal is currently connected to) to a second radio network node, the first radio network node or the second radio network node may change A reordering instruction for one or more data units, transmitted to a gateway (or different network entity), and at the same time one or more data units previously received from the terminal are transmitted to the gateway, regardless of the data unit Sequence number, so the transmission efficiency of the data unit is optimized.

The first radio network node may be a base station node source eNB, the mobile terminal is currently connected to the base station node source eNB to receive services; and the second radio network node may be a base station node target eNB, the mobile terminal It will move to the target eNB of the base station node to receive a service.

The present invention provides a method for performing a reordering process of data units (ie, SDUs). The data units are transmitted from the terminal through the base station when the data unit is submitted by a terminal.

That is, during the submission period, when the data unit is transmitted from the terminal to an upper node (ie, the gateway) through the base station, the base station can transmit any received data unit from the terminal to the terminal regardless of the sequence number of the data unit. The gateway, and the gateway can reorder the received data units from the base station in sequence order.

Specifically, the source base station can transmit a reordering instruction message (or other types of signaling) to the gateway to perform a reordering process through the gateway. The reordering instruction message can be transmitted to the gateway just before the terminal performs delivery or during the terminals delivery, and the reordering instruction message can be transmitted from the source base station or the target base station.

The data unit can represent a data block, which will be transmitted from a specific protocol (or node) to an upper protocol (or node). The data unit may be a Service Data Unit (SDU) of a Radio Link Control (RLC) entity. The base station can also transmit the message to the gateway in the form of a single bit, or instruct the reordering process by including the message in the header field of the RLC.

After knowing that the gateway will perform the reordering process, the base station will not consider the sequence number of the data unit. In other words, if the gateway is to be reordered, the base station itself does not perform the reordering process. Just as if any uplink data unit is received from the terminal, the base station can immediately transmit the received uplink data unit to the gateway regardless of the order of the data unit (ie, the sequence number).

For example, when the RLC of the base station receives PDUs from the lower layer to completely receive a specific sequence of SDUs, the RLC immediately transmits the received SDUs to the upper layer (ie, the gateway) regardless of the sequence number of each SDU. Here, the SDU transmitted to the gateway can also be received by one of the upper layers of the RLC (ie, PDCP).

When the gateway receives data units from the base station, it does not always receive the data units sequentially. At the same time, the gateway can receive the data units not only from a single base station but also from multiple base stations. The gateway can store received data units (unsequenced data units) in a reordering buffer, and transmit the received data units to the upper layer (or node) in the order of use. Similarly, after all unreceived data units are received by the gateway and when the sequence of the data units is completed, the gateway can transmit the data units to the upper layer (or node).

For example, the RLC of the base station can transmit the SDU to the gateway, and the PDCP layer of the gateway can receive the SDU from the base station. Here, the received SDUs may not be in sequence. Similarly, even if the SDU is transmitted from a terminal, the gateway can also receive the SDU through multiple base stations. The PDCP layer of the gateway or a layer below the PDCP of the gateway can store SDUs in a reordering buffer to form SDUs in sequential order. Whenever any sequential order of SDU is completed, the PDCP layer of the gateway can transmit the SDU to an upper layer (or node).

Figure 4 shows an exemplary delivery procedure between eNodeBs. First, the source eNodeB can exchange area restriction information with an access gateway (AG) or MME/UPE (S10). Here, the area restriction information may be included in a UE context.

The source eNodeB can transmit a radio resource measurement status to the UE (hereinafter referred to as "terminal") (S11), and the terminal can transmit the radio resource measurement result to the source eNodeB according to the received radio resource measurement status (S12). The source eNodeB can transmit the HO request message to the target eNodeB (S13, S14) after making a submission decision whether to connect to a neighboring base station (or cell) based on the received radio resource measurement result from the terminal.

The target eNodeB may decide whether to accept the HO request message based on the radio resources of the target eNodeB (S15). If the HO request message is accepted, the target base station can transmit a HO response message to the source eNodeB (S16), and then the source eNodeB can transmit a HO command to the terminal (S17).

The terminal receiving the HO command can perform a signaling to connect the target eNodeB and the layer 1 (L1) and layer 2 (L2) layers. This L1/L2 signaling may include a synchronization process. When the L1 and L2 connections are terminated, the terminal can transmit a HO completion message to the target eNodeB (S19), and the target eNodeB can transmit a HO completion message to the gateway (AG) (or MME/UPE) (S20).

The AG receiving the HO complete message can transmit a HO complete ACK message to the target eNodeB (S21), and the target eNodeB can transmit a resource release message to the source eNodeB (S22). After that, the source eNodeB that receives the resource release message can release all the radio resources for delivery, and the terminal can update the location (S23, S24).

Figure 5 shows the method of transmitting uplink data units in a mobile communication system.

As shown in Figure 5, during the delivery period, when the terminal transmits the data unit in the uplink, the source eNodeB and the target eNodeB may not perform a reordering process, but the gateway can perform this reordering process. Therefore, the gateway can receive uplink data units from the source eNodeB and the target eNodeB, which are transmitted from one or more terminals, and then perform a reordering process. The data unit can be stored in the reordering buffer of the gateway (the ellipse in AG in Figure 5). The reordering buffer can be located in the PDCP of the gateway or in a functional block of a lower layer under the PDCP.

Figure 6 shows the method of transmitting the data unit from the mobile terminal (such as SDU) to the RLC of the base station, and then transmitting the received data unit from the RLC to the gateway.

RLC is located above the MAC of the base station in E-UTRAN. RLC can generate an SDU from a receiving SDU. In Figure 6, "S" means SDU, "P" means PDU, "sNB" means source eNodeB, and "tNB" means target eNodeB.

Generally speaking, RLC may not receive PDUs in sequential order, and a receiving SDU by eNodeB may not in sequential order. In Figure 6, "S60", "S61", "S64" and "S65" can be regarded as fully received SDUs, because the corresponding PDUs have been fully received to generate SDUs. However, "S62" and "S63" are not fully received because the corresponding PDUs are not fully received.

Therefore, if delivery is not performed, the terminal can keep trying to retransmit the PDU to the source base station (sNB), and the gateway will receive the SDU by receiving the PDU through the source base station. However, if delivery is performed, the terminal can transmit the PDU to the target base station (tNB) instead of the source base station. Therefore, during the delivery period, even if the source base station does not receive a specific PDU, the target base station can still generate a specific SDU.

In Figure 6, the target base station can generate "S62" and "S63" by receiving the corresponding PDUs of "S62" and "S63". Here, the source base station may not know whether the target base station receives "S62" and "S63". Just as the source base station may request retransmission of "S62" and "S63" for the sequential order of SDUs, and it may cause unnecessary time delay.

Therefore, if the gateway can receive SDUs from multiple base stations, the reordering process performed by the gateway may be a more efficient method than performing the reordering process in the base stations (sNB, tNB) during the submission period.

Here, if complete reception is confirmed, the source base station can immediately transmit "S60", "S61", "S63" and "S64" to the upper node (gateway). If each SDU is completely received, the target base station can immediately transmit SDUs (ie "S62" and "S63") to the gateway, or the target base station can transmit SDUs (ie "S62" and "S63").

Figure 7 shows an exemplary data flow for the reordering process between eNodeB and AG for uplink data unit transmission.

The base station can determine whether the terminal needs to perform the submission by receiving the measurement information from the terminal. If the terminal needs to perform delivery (as shown in Figure 8), the base station can transmit a reordering instruction message to the gateway to perform the data unit reordering process through the gateway (S30).

The reordering instruction message can be a one-way message or a two-way message (S31). The reordering instruction message can be a sending message that can be generated between the base station and the gateway. Similarly, a request to perform the reordering function can be included in a data unit or a certain information column of other sending messages.

For example, when preparing to implement the delivery, the RLC of the base station may not implement the reordering function, and a request for a reordering process can be sent to the gateway through a signaling message. Similarly, the base station can indicate (or set) whether a reordering function needs to be performed by the gateway by using a message or signal in a certain column of the RLC or MAC. In addition, the base station can continue to perform the reordering process, and may allow the gateway to perform another reordering process. The gateway can transmit the uplink data unit after performing the data unit reordering process according to the reordering instruction message from the base station.

Figure 8 shows an exemplary data flow of the reordering process between eNode B and UE for downlink data unit transmission.

As shown in Figure 8, the base station transmits not only the uplink data unit transmission reordering instruction message, but also the downlink data unit transmission reordering instruction message (S40). In this case, the reordering instruction message can be a one-way message or a two-way message (S41).

The reordering instruction message can instruct the terminal how to perform the reordering process. The base station can request a reordering process in the PDCP layer of the terminal by generating a reordering instruction message. Here, the PDCP layer of the terminal can perform a reordering process by a PDCP sequence number. When the reordering process of the PDCP layer is performed, the reordering process of the RLC layer does not need to be performed. However, the sequencing process by both the PDCP layer and the RLC layer can be performed together for downlink data unit transmission.

The reordering instruction message may include information for determining whether the reordering process by the RLC layer must be continuously performed, or information for terminating the reordering process by the RLC layer. The reordering instruction message may be a message generated in a radio resource control (RRC) entity in the base station. When the RLC SDU is generated during the transmission of the downlink data unit, the reordering instruction message can be transmitted together with information including the reordering function associated with PDCP and RLC.

Figure 9 shows an exemplary E-UTRAN protocol architecture for uplink data unit transmission.

As shown in Figure 9, the wireless interface protocol is represented as a PDCP layer, an RLC layer, a MAC layer, a PHY layer, and so on. In contrast to the RLC layer and PDCP layer of the terminal, the RLC layer and PDCP layer of E-UTRAN are located in different network nodes such as an eNodeB and an access gateway (AG), respectively. The wireless interface protocols are related to each other. For example, the RLC layer of the base station and the PDCP layer of the gateway are related to each other, and for communication, a signaling message generated in the S1 interface can be used for data transmission and control between the two layers. Here, the generated signaling message can be used to transmit a reordering instruction message to the gateway. Similarly, an NBAP message defined in the lub interface can be used to transmit reordering instructions. The reordering instruction message can be included in the service data unit (SDU) generated by the RLC or in the header column of the RLC. A single bit can be used to represent the reordering instructions to minimize the sending traffic.

Figure 10 shows an exemplary E-UTRAN protocol architecture for downlink data unit transmission.

As shown in Figure 10, both the RLC layer of the terminal and the PDCP layer of the terminal can perform the reordering function at the same time. Similarly, one of the RLC layer of the terminal or the PDCP layer of the terminal can perform the reordering function. If the terminal implements the reordering process in the PDCP layer, the reordering instruction message can include a request for the reordering process in the PDCP layer.

If the terminal decides to perform a delivery procedure, the base station can transmit a reordering instruction message. The terminal can receive downlink data units from the gateway in the order in which the data units are transmitted according to the reordering function during the submission process. If the delivery process is over, the reordering process by the PDCP layer is no longer needed, so the base station can transmit a delivery completion message or a request message for terminating the reordering function to the terminal, and then when receiving this message, The terminal can terminate the reordering function through the PDCP layer. The reordering process by the PDCP layer can be implemented in a layer between the PDCP layer and the RLC layer. In this case, the certain layer is positioned below the PDCP layer and above the RLC layer. Similarly, if it is an uplink data unit transmission, the reordering process can be implemented under the PDCP layer of the gateway.

The present invention provides a method for receiving uplink data in a mobile communication system. The method includes: deciding to perform a submission for a terminal; and when the submission needs to be performed according to the determination step, transmitting an instruction to an access gateway (AG) to allow the AG to perform uplink data reordering upon receiving the instruction; wherein the instruction is generated by an RLC to generate a service data unit (SDU), a single bit, and a header of the RLC At least one of the columns is transmitted to the AG; where the indication is defined between a radio link control (RLC) layer of the base station and a packet data convergence protocol (PDCP) layer of an access gateway (AG) One is to send and receive a message; where the instruction is a one-way message or a two-way message; where the instruction is a reordering request message.

At the same time, the present invention provides a method for receiving downlink data in a mobile communication system. The method includes: receiving downlink data from one or more base stations; Reordering instruction; performing downlink data reordering after receiving the reordering instruction; and transmitting a reordering confirmation upon receiving the reordering instruction; wherein the downlink data reordering is performed by a terminal in a terminal Header compression entity processing; wherein the reordering instruction is a one-way message or a two-way message; wherein the reordering instruction is generated through an RLC service data unit, a single bit, and at least one of the header columns of the RLC The reordering instruction is generated by a radio resource control (RRC) layer of the one or more base stations; wherein one of the base stations is a source base station or a target base station.

At the same time, the present invention provides a method for communicating data in a mobile communication system. The method includes: when performing a submission, transmitting an instruction from a first node to a second node; communicating and communicating between the first node and the second node Data; and when the data is received, a reordering process of the data is performed by the second node; wherein the second node includes a header compression entity; wherein the first node is a base station and the second node is A terminal or an access channel (AG); wherein the uplink data reordering is performed by a header compression entity in the AG or by a lower layer processing under the header compression entity in the AG; wherein the AG includes a reordering buffer to store uplink data for uplink data reordering.

In addition, the present invention provides a mobile terminal for receiving downlink data in a mobile communication system. The mobile terminal includes: a lower-level protocol entity adapted to receive an instruction from a base station when performing delivery; and A header compression entity on the underlying protocol entity, which is adapted to perform a reordering process for downlink data when receiving the instruction.

Although the present invention is described in the context of mobile communications, the present invention can also be used in any wireless communication system using mobile devices, such as PDAs and laptop computers equipped with wireless communication capabilities (ie, interfaces). In addition, the use of certain terms used to describe the present invention is not intended to limit the scope of the present invention to a certain type of wireless communication system. The present invention can also be applied to other wireless communication systems using different air interfaces and/or physical layers, such as TDMA, CDMA, FDMA, WCDMA, OFDM, EV-DO, Wi-Max, Wi-Bro, etc.

Exemplary embodiments can be implemented as methods, equipment, or manufactured products using standard programming and/or engineering techniques to generate software, firmware, hardware, or any combination thereof. The term "article of manufacture" used here refers to the hardware logic (such as integrated circuit chip, field programmable gate array (FPGA), application specific integrated circuit (ASIC), etc.), or a computer Reading media (such as magnetic storage media (such as hard disk drives, floppy disks, tapes, etc.), optical storage (CD-ROM, optical disks, etc.), volatile and non-volatile memory devices (such as EEPROM, ROM, PROM, Code or logic implemented in RAM, DRAM, SRAM, firmware, programmable logic, etc.).

The code in the computer-readable medium can be accessed and executed by the processor. The code implemented in the exemplary embodiment can be further accessed through a transmission medium or from a file server on the network. In these cases, the manufactured product implemented by the code may include a transmission medium (such as a network transmission line), a wireless transmission medium, a signal transmitted through space, radio waves, infrared signals, and so on. Of course, those skilled in the art will recognize that many modifications to this configuration can be made without departing from the scope of the present invention, and the manufactured product can include any information-bearing medium known in the art.

In this specification, any reference to "a specific embodiment", "exemplary specific embodiment", etc., means that a specific feature, structure, or feature described in association with the specific embodiment is included in at least one of the present invention. In specific embodiments. The expressions appearing in various places in the specification do not necessarily all refer to the same specific embodiment. In addition, when a particular feature, structure, or feature is described in connection with any specific embodiment, it is deemed to fall within the scope of those skilled in the art making the feature, structure, or feature of the other relevant to the specific embodiment effective Inside.

Although the specific embodiments have been described with reference to some exemplary embodiments thereof, those skilled in the art should understand that many other modifications and specific embodiments based on the disclosed examples will also fall into the spirit and scope of the principles of this disclosure.Within. Available within. More specifically, various changes and modifications are feasible in the component parts and/or configurations of the subject combination configuration within the scope of the disclosure, the drawings, and the accompanying patent application. In addition to changes and modifications in component parts and/or configurations, those familiar with this technology will also understand alternative uses.

Because the present invention can be embodied in several forms without departing from its spirit or basic characteristics, it should also be understood that the above specific embodiments are not limited to any details previously described. Unless otherwise specified, it should be broadly regarded as an accompanying patent application. The scope definition is within its spirit and scope, and therefore falls within the measurement and limits of the scope of the patent application, or all changes and modifications of the equivalent of these measurements and limits, should be covered by the scope of the patent application.

<p>10. . . Evolutionary Packet Core/EPC</p><p>11. . . Access gateway/AG</p><p>20. . . E-UTRAN</p><p>twenty one. . . Base station/eNB/eNodeB</p><p>P. . . PDU</p><p>S. . . SDU</p><p>sNB. . . Source eNodeB</p><p>tNB. . . Target eNodeB</p>

Some exemplary embodiments will be described in detail by the following drawings, in which similar component symbols represent similar components. Among them: Figure 1 shows an exemplary network structure of E-UMTS, which is a related technology and the present invention. The mobile communication system to which the invention is applied.

Figure 2 is an exemplary structure of the control plane of the radio interface protocol between a terminal and a UTRAN based on the 3GPP radio access network specification.

Figure 3 is an exemplary structure of the user plane based on the 3GPP radio access network specification in the radio interface agreement between the terminal and UTRAN.

Figure 4 shows an exemplary inter-eNodeB handover procedure.

Figure 5 shows the method of transmitting uplink data units in a mobile communication system.

Figure 6 shows a method of transmitting data units from a terminal to an RLC of a base station, and then transmitting received data units from the RLC to a gateway.

Figure 7 shows an exemplary data flow for the reordering process between an eNodeB and an AG for uplink data unit transmission.

Figure 8 shows an exemplary data flow for the reordering process between an eNodeB and a UE for downlink data unit transmission.

Figure 9 shows an exemplary E-UTRAN protocol architecture for uplink data unit transmission.

Figure 10 shows an exemplary E-UTRAN protocol architecture for downlink data unit transmission.