KR100677505B1 - Method for providing channel aggregation in mobile communication system - Google Patents

Abstract

The present invention relates to channel aggregation applied when a base station allocates an additional traffic channel to a terminal in order to increase data throughput between the terminal and the base station in a wireless access network. In particular, the present invention relates to a method for defining and configuring a message transmitted over a radio section in order to simultaneously assign a plurality of traffic channels to a specific terminal.

Channel Aggregation, Traffic Channel Allocation, Control Message

Description

How to provide channel aggregation in mobile communication system {METHOD FOR PROVIDING CHANNEL AGGREGATION IN MOBILE COMMUNICATION SYSTEM}

1 is a network structure of a wireless access network system applied to the prior art and the present invention.

2 is a radio interface protocol structure between a terminal and a base station.

3 is a diagram illustrating a channel allocation method for data transmission between a conventional terminal and a base station.

4 is a diagram illustrating a format of an aggregation control message according to an embodiment of the present invention.

5 is a diagram illustrating channel aggregation in downlink data transmission according to the present invention.

6 is a diagram illustrating channel aggregation in uplink data transmission according to the present invention.

***** Explanation of symbols for the main parts of the drawing *****

EUD: End User Device

MAC: Medium Access Control

CN: Core Network

The present invention relates to a TDMA / SDMA wireless access network system, and more particularly, to a method of providing channel aggregation between a terminal and a base station.

As wireless communication advances, there is a need for more efficient use of allocated frequency bands, that is, a technique for increasing the transmission capacity of information within a limited available bandwidth. As a method for increasing information transmission capacity, for example, time division multiple access (TDMA), code division multiple access (CDMA), and space division multiple access (SDMA) are known.

Among them, TDMA assigns individual time slots to data so that users share a single frequency channel, and SDMA spatially divides the same time slots of the same frequency to spatially multiplex multiple wireless users to a base station. to be.

In a multi-subscriber, single carrier communication system using time division multiplexing (TDM), the channels may be shared by multiple subscribers in time division. That is, the channel may be used by one subscriber at one time and by another subscriber at another time. In addition, in a multi-carrier communication system, a multi-carrier may be allocated to each subscriber, and subscribers may simultaneously use the multi-carrier. In this case, the transmission rate / reliability (performance) of the other carriers assigned to a specific subscriber may be different, and the transmission rate / reliability of different subscribers for a specific carrier may be different.

1 is a structure of a wireless access network system applied to the prior art and the present invention.

As shown in FIG. 1, a radio access network system is largely composed of a terminal, a base station, and a core network (CN).

FIG. 2 is a structure of a radio interface protocol between a terminal and a base station in the radio access network system of FIG. 1. Referring to FIG. 2, the radio interface protocol includes a physical layer, a medium access control layer, a radio link control layer, and a radio resource control layer.

In addition, the protocol layers shown in FIG. 2 are based on the lower three layers of the Open System Interconnection (OSI) reference model, which are well known in communication systems, based on L1 (first layer) and L2 (second layer). , L3 (third layer).

The physical layer (PHY) provides an information transfer service to a higher layer using various wireless transmission technologies. The physical layer is connected to the medium access control (MAC) layer through a transport channel to exchange data.

The Medium Access Control (MAC) layer provides radio resource allocation and is connected to the Radio Link Control layer through a logical channel to provide user data transfer service.

The radio link control layer provides an automatic retransmission request (ARQ) function for reliable data transmission, and the L3 layer provides efficient management of radio resources.

Hereinafter, the conventional radio channel allocation and channel aggregation will be described.

In the TDMA / SDMA system, in order for a terminal to exchange data with a base station through a wireless section, a channel including a carrier having a frequency band of a certain section, a time slot having a certain time domain, and a spatial offset representing a specific space are provided. You must seize resources.

To this end, when data to be transmitted through a wireless section is generated, the base station allocates a channel to the terminal, and the terminal transmits data to or receives data from the base station through the assigned channel.

2 is a diagram illustrating a channel assignment between a terminal and a base station and a data transmission process through the same.

As shown in FIG. 2, when user data to be transmitted from an end user device (EUD) is input, the terminal requests allocation of a traffic channel (TCH) to the base station.

That is, when data is input from the EUD (user equipment) (S10), the terminal L3 requests the terminal MAC to allocate a traffic channel (TCH) (S11), and the terminal MAC requests a traffic channel to the base station for random access. (RA: Random access) message is transmitted (S12). After receiving the RA message, the base station MAC sets information on a channel to be allocated, transmits an access assignment (AA) message to the terminal (S13), and instructs the base station L3 to allocate the traffic channel (S14). . Therefore, the base station L3 updates the registration ID of the terminal and the information on the allocated channel (S15).

Meanwhile, the MAC of the terminal receiving the AA message informs L3 of the terminal that the traffic channel is newly allocated (S16), and L3 of the terminal updates the registration ID and information on the allocated channel (S17). When the above procedure is completed, the terminal transmits the user data to the base station through the newly allocated traffic channel (S18).

In the state in which the traffic channel is allocated as described above, the terminal requests an additional traffic channel to be allocated to the base station to receive a new channel from the base station. do. In order to increase the data throughput, the base station allocates an additional traffic channel to the terminal is called channel aggregation.

When allocating an additional traffic channel through the channel aggregation, the base station transmits information on the allocated channel to the terminal through a message so that the terminal and the base station can share the same channel information.

However, when performing channel aggregation, the base station conventionally allocates only one channel information in a message and transmits it to the terminal to additionally allocate one channel. Therefore, when aggregating n channels, the base station must repeatedly perform n message (including AA and RA) transmission and n channel allocation processes.

As a result, when aggregating a plurality of channels, the aggregation process for each channel is sequentially performed, which wastes time for channel allocation, and especially when a large amount of data is generated momentarily, during the aggregation process. Loss of data may occur.

In addition, in order to support the multi-carrier method, not only the time slots in the currently allocated carrier but also all the time slots in other carriers must be allocated. In this case, the aggregation process takes too much time. There is a disadvantage.

Accordingly, an object of the present invention is to provide a channel aggregation method that can minimize the time required for channel allocation between a base station and a terminal by aggregating a plurality of channels simultaneously.

Another object of the present invention is to provide a channel aggregation method that enables aggregation between timeslots and different carriers in the same carrier.

Another object of the present invention is to provide a channel aggregation method that can minimize the loss of data generated during the aggregation process when a large amount of data between the terminal and the base station instantaneously occurs.

It is still another object of the present invention to provide a channel aggregation method that can be applied to both a space division multiple access (SDMA) and a time division multiple access (TDMA) scheme.

In order to achieve the above object, in a wireless network system that performs channel aggregation to increase data throughput between a terminal and a base station, the method of providing channel aggregation according to the present invention is performed once using a message. It is characterized by allocating a plurality of traffic channels to the terminal at the same time by the aggregation of the channel.

Preferably, the message includes a control message and a random access (RA) / access assignment (AA) message.

Advantageously, said control message is transmitted on a traffic channel (TCH).

Preferably, the RA / AA message is sent over a random access channel (RACH).

Preferably, the message includes channel information such as the number of channels to aggregate, the conventional channel number, and the spatial offset.

Preferably, the channel information is set based on the amount of data to be transmitted between the terminal or the base station.

Preferably, the control message includes different channel information according to the modulation scheme of the wireless network system. For example, if the system uses a time division multiple access (TDMA) scheme, it may include a message ID, the number of channels allocated and the convention channel number, and the time division multiple access (TDMA) and / or space division multiple access (SDMA) scheme. In this case, the message ID, the number of channels to be allocated, the convention channel number, and the spatial offset value are included.

In order to achieve the above object, in a wireless access network system performing channel aggregation to allocate a plurality of traffic channels to a terminal to which a traffic channel is allocated, the channel aggregation method according to the present invention is a transmission method. Determining channel aggregation at the base station based on the amount of data to be; Setting channel information to be aggregated in a control message; Allocating a plurality of channels by transmitting a set control message to a terminal; And transmitting data between the terminal and the base station through the assigned channels.                         

Preferably, the channel information is transmitted through a traffic channel, and includes a number of channels to aggregate, a convention channel number, and a spatial offset.

Preferably, the control message includes a message ID, a number of channels to be allocated and a convention channel number when a TDMA scheme is used.

Preferably, the control message includes a message ID, a number of channels allocated, a convention channel number, and a space offset when the time division multiple access (TDMA) and / or the space division multiple access (SDMA) scheme is used.

Hereinafter, the preferred embodiment of the present invention will be described.

The present invention is implemented in a mobile communication system based on a multi-carrier method and a TDMA / SDMA method. However, the present invention can also be applied to communication systems operating according to other standards. The present invention is useful in a variety of wireless or wired systems, in particular the system may have various hardware / software configurations such as base stations or mobile or stationary user terminals.

The wireless communication system applied to the present invention employs a spatial division multiple access (SDMA) technique in various multiple access systems such as time division multiple access (TDMA), frequency division multiple access (FDMA), code division multiple access (CDMA), and the like. It may be a fixed access or mobile access wireless network for use with a multiple access system.

In the present invention, the user device may be, for example, a cellular phone, a two pager, a PDA with wireless communication capability, a wireless modem capable of interfacing with a data processing device (laptop computer, PDA, game machine or other computing device), or And other communication devices that route voice and / or data signals between remote user terminals and the network (PSTN, Internet, and / or other voice or data networks). Thus, the user device may include, for example, a portable information terminal, laptop / laptop computer, computing cellular telephone handset, etc.) or may be interfaced via a web browser.

The present invention proposes a method of configuring a message capable of time slot and inter-carrier aggregation when a base station allocates a traffic channel of a specific terminal. When performing channel aggregation, in order to enable aggregation between timeslots and carriers, channel information of a message should be able to allocate not only a single channel but also multiple channels at the same time. To this end, the present invention allows the message used for channel aggregation to include all information of the channel to be allocated, such as the number of channels to be allocated, the number of conventional channels, and the offset of the spatial channel. .

4 is an example of an aggregation control message format according to the present invention.

As shown in FIG. 4, the aggregation control message includes information such as a message ID, the number of channels to be aggregated, the number of conventional channels, and a spatial channel offset value. At this time, the Ext bit is set to "00".

The conventional channel number is a number of channels to be aggregated and is determined by a combination of eight carriers and three timeslots assigned to each carrier. In addition, the spatial offset value is a value for spatially distinguishing channels having the same conventional channel number. Therefore, the aggregation control message in the TDMA system will include only the message ID, the number of channels to be allocated, and the conventional channel number. In the TDMA / SDMA system, the aggregation control message will contain the message ID, the number of channels to be allocated, and conventional. It will contain the channel number and spatial offset value.

The structure of the aggregation control message as described above is an embodiment for allocating additional channels to a single user using timeslot and intercarrier aggregation, and is not limited thereto. A variety of message structures may be provided. Could be.

5 is a diagram illustrating a channel aggregation process during downlink data transmission. In this case, it is assumed that the terminal occupies one or more traffic channels for data transmission and reception, and the base station also has a radio resource for additionally allocating a new channel to the terminal.

First, the core network CN transmits user data to the L3 layer of the base station, and the transferred user data is temporarily stored in a buffer (S20). The base station L3 received the data checks whether the amount of data to be transmitted exceeds the threshold and determines whether to perform channel aggregation. If the amount of data to be transmitted exceeds the threshold, the base station L3 informs the number of channels to aggregate, the timeslot to aggregate, and the carrier, that is, the number of channels to be allocated, the channel number, and the spatial offset value. Channel information such as the above is set in the aggregation control message (S23) and then transmitted to the base station MAC together with the aggregation request (S22).

Preferably, the aggregation control message optionally includes the number of channels allocated to the system type (TDMA / SDMA), conventional channel number and / or spatial offset value. The conventional channel number is determined by a combination of eight carriers and three timeslots assigned to each carrier. Accordingly, in the present invention, when allocating multiple channels to one user, not only the time slots in the currently allocated carrier but also all the time slots in the other carrier may be effectively supported in the multi-carrier scheme. . That is, the present invention supports both aggregation between timeslots and aggregation between different carriers in the same carrier. In addition, the present invention may further increase the data transmission capacity by further spatially classifying channels having the same conventional channel number using the spatial offset value.

The base station MAC transmits the aggregation control message transmitted from the base station L3 to the terminal through a previously formed traffic channel (TCH) (S23). Upon receipt of the aggregation control message, the terminal MAC transmits an aggregation control message to the terminal L3 (S24), and the terminal L3 requests an allocation of a traffic channel (TCH) to the terminal MAC (S25). Accordingly, the terminal MAC transmits a RA message requesting the allocation of the traffic channel to the base station through a random access channel (RACH) according to the TCH allocation request of the terminal L3 (S26).

The base station MAC receiving the RA message transmits an AA message including the information of the channel to be allocated through the RACH to the terminal MAC (S27), and the MAC of the terminal receiving the AA (Access Assignment) message is newly assigned a traffic channel. Notifies the terminal L3 (S28). As described above, when a plurality of channels are aggregated, the present invention transmits the RA and AA messages only once, rather than the number of channels to be allocated.

In addition, the base station MAC requests the allocation of the traffic channel (TCH) to the base station L3 (S29). The base station L3 updates the registration ID of the terminal and the information on the allocated channel (S30), and the terminal L3 updates the registration ID and the information on the assigned channel, respectively (S31). When all of the above procedures are completed, the base station transmits the data stored in the buffer to the terminal through the newly allocated traffic channel (S32).

6 is a diagram illustrating a channel advising process during uplink data transmission.

As shown in FIG. 4, the terminal represents a terminal assigned with one or more traffic channels for data transmission and reception in a state registered with the base station, and the base station also needs to have resources for additional allocation of new traffic channels to the terminal.

As shown in FIG. 6, the EUD (user device) transfers data to be transmitted to L3 of the terminal (S40), and the transferred data is temporarily stored in a buffer. L3 of the terminal requests data transmission to the terminal MAC (S41), and the terminal MAC transmits the amount of data currently stored in the buffer to the base station through a queue depth control message (S42). In this case, the EUD is not limited to the terminal and includes any type of communication equipment (eg, a laptop personal computer, a personal digital assistant (PDA), etc.) commonly used by subscribers of communication systems. do.

The base station MAC receiving the queue depth control message transmits the control message to the base station L3 (S43), and the base station L3 determines whether to perform channel aggregation by checking whether the amount of data to be transmitted by the terminal exceeds the threshold. If the amount of data to be transmitted exceeds the threshold, the base station L3 may include information about the number of channels to be aggregated, information on the timeslot and carrier to be aggregated, that is, the number of channels to be allocated, the channel number, and the space offset value. The channel information is set in the aggregation control message (S44), and then transmitted to the base station MAC together with the aggregation request (S45). In this case, the allocated channel is classified by a conventional channel number and a spatial offset value.

The base station MAC transmits the aggregation control message transmitted from the base station L3 to the terminal through a previously formed traffic channel (TCH) (S46). The MAC of the terminal receiving the aggregation control message transfers the aggregation control message to the terminal L3 (S47), and the terminal L3 requests the allocation of the traffic channel (TCH) to the terminal MAC again (S48). Accordingly, the terminal MAC transmits a RA message requesting the allocation of the traffic channel to the base station through the RACH according to the TCH allocation request of the terminal L3 (S49).

The base station MAC receiving the RA message transmits information of the channel to be allocated to the terminal MAC through the AA message (S50), and the MAC of the terminal receiving the AA message informs L3 of the terminal of the newly allocated traffic channel (S51). ). In addition, the base station MAC requests the allocation of the traffic channel (TCH) to the base station L3 (S52). Accordingly, the base station L3 updates the registration ID of the terminal and the information on the allocated channel (S53), and the terminal L3 updates the registration ID and the information on the assigned channel, respectively (S54).

When the above procedures are completed, the base station transmits the data stored in the buffer to the terminal through the newly allocated traffic channel (S55).

As described above, conventionally, when performing channel aggregation, only one channel is set in a message to allocate a traffic channel. As a result, when aggregating multiple channels, channel aggregation processes (including RA and AA messages) must be performed as many as the number of channels to be allocated. Therefore, waste of time required for channel aggregation and channel allocation is required. Occurred. In addition, since a channel is sequentially allocated when aggregating several channels, data loss occurs when a large amount of data is instantaneously generated.

According to the present invention, a message is set so that several channels can be simultaneously allocated during channel aggregation, and then a plurality of traffic channels are simultaneously assigned to the terminal using the set message. It is effective to minimize network resources and manage network resources efficiently.

In addition, the present invention can effectively support a multi-carrier scheme by allocating a channel by allocating all timeslots in other carriers as well as timeslots in a currently allocated carrier.

The invention may be provided as a computer program product such as a machine-readable medium having stored thereon instructions used to program a computer to perform a process according to the invention. Machine-readable media include floppy diskettes, optical disks, CD-ROMs, and magneto-optical disks, ROM, RAM, EPROM, EEPROM, magnet cards, optical cards, flash memory, and other types of machine-readable media suitable for storing electronic instructions. Media is included, but is not limited to this type. The invention may also be downloaded as a computer program product, in which case the program is transferred from the remote computer to the requesting computer by means of a data signal implemented on a carrier wave or other propagation medium via a communication link (eg, a modem or network connection). Can be sent.

Although the present invention has been described in terms of a wireless Internet data system (eg, a wireless modem capable of interfacing with various portable data processing devices) for a portable handset or other user terminal device, other types of wireless with which data may be exchanged. It should be understood that it can also be applied to a wide range of systems. Such systems include voice, video, music, broadcast, and other types of data systems without external connections. In addition, the present invention can be applied to fixed user terminals as well as low and high mobility terminals.

In addition, although specific embodiments of the present invention have been described with reference to the embodiments illustrated in the drawings, these are merely exemplary, and a person having ordinary knowledge in the art may have various modifications and equivalent other embodiments. Will understand. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

Claims (21)

delete delete delete delete delete delete delete delete delete delete delete delete delete Determining whether to perform channel aggregation at the base station; If it is determined to perform the channel aggregation, setting a plurality of channel information in one aggregation control message and transmitting the same to the terminal; Requesting, by the terminal receiving the aggregation control message, from the base station to allocate a plurality of traffic channels; The base station allocates a plurality of traffic channels in response to a request of the terminal, and transmits the information of the assigned traffic channel to the terminal, The plurality of channel information includes a message ID, the number of channels to be allocated, a channel number and a spatial offset value. 15. The method of claim 14, wherein the base station And performing channel aggregation when the amount of data to be transmitted exceeds the branch point or the amount of data to be transmitted by the terminal exceeds the branch point. 15. The method of claim 14, wherein the aggregation control message Channel aggregation method in a mobile communication system including a message ID, the number of channels to be allocated, a channel number and a space offset value. 17. The method of claim 16, wherein the aggregation control message And a channel number or a space offset value according to a modulation scheme of the system. 15. The method of claim 14, wherein the base station And allocating the plurality of traffic channels at the same time. 15. The method of claim 14, wherein the aggregation control message Channel aggregation method in a mobile communication system comprising different channel information according to the modulation method of the system. 15. The method of claim 14, wherein the allocation request of the plurality of traffic channels is A method of channel aggregation in a mobile communication system, characterized by one random access (RA) message. 15. The method of claim 14, wherein the allocated plurality of traffic channel information is A channel aggregation method in a mobile communication system, characterized in that transmitted to the terminal via one AA (Access Assignment) message.

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