KR20060034539A - Method to transmitting/receiving of uplink/downlink channel information messages in broadband wireless access system for transmitting the uplink/downlink channel information messages - Google Patents

Abstract

The present invention relates to a broadband wireless access system for transmitting uplink / downlink channel information messages and a method for transmitting and receiving uplink / downlink channel information messages in the system. To this end, when the base station transmits an uplink / downlink channel information message and transmits an index of one of the indices of the burst profile information table in the uplink / downlink burst profile field, the mobile station receives the uplink / downlink channel information message. When the burst profile information corresponding to the index is extracted from the burst profile information table by using the index included in the up / down burst profile field in the message, the channel information is confirmed and applied.

Broadband Wireless Access System, Mobile Internet, Uplink / Downlink Channel Information Message

Description

Method for Transmitting / Receiving Of Uplink / Downlink Channel Information Messages In Broadband Wireless Access System For Transmitting The Uplink / Downlink Channel Information Messages}             

1 is an exemplary diagram of a typical data frame structure of an OFDMA wideband wireless access communication system;

2 is a control flowchart for transmitting a DCD / UCD message in a base station according to an embodiment of the present invention;

3 is a flowchart illustrating a process of receiving a DCD / UCD message in a mobile terminal according to an embodiment of the present invention.

The present invention relates to a method for transmitting / receiving channel information in a communication system, and more particularly, to a broadband wireless access system for transmitting uplink / downlink channel information messages and a method for transmitting and receiving uplink / downlink channel information messages in the system.

In general, communication systems have been developed mainly for voice services, and are gradually developing as communication systems capable of not only voice but also data services and various multimedia services. However, since the voice-oriented communication system has a relatively small data transmission bandwidth and a high usage fee, the voice-oriented communication system cannot meet the rapidly increasing demand for users. In addition, due to the development of the communication industry and increasing user demand for Internet services, there is an increasing need for a communication system that can efficiently provide Internet services. As a result, Broadband Wireless Access (BWA) has been introduced to efficiently provide Internet services with broadband enough to meet the demands of rapidly increasing users.

The broadband wireless access system is a system for integrating and supporting not only voice but also various low speed and high speed data services and multimedia application services such as high definition video. The broadband wireless access system can access PSTN and PSDN networks, Internet networks, IMT-2000 networks, ATM networks, etc. in a mobile or fixed environment based on wireless media using broadband such as 2 GHz, 5 GHz, 26 GHz and 60 GHz. It is a wireless communication system that can support more than a channel rate. The broadband wireless access system may be classified into a broadband wireless subscriber network, a broadband mobile access network, and a high-speed wireless LAN according to the mobility (fixed or mobile) and communication environment (indoor or outdoor) of a terminal, and a channel rate.

The wireless access method of the broadband wireless access system is standardized by the IEEE 802.16 standardization group of the Institute of Electrical and Electronics Engineers, one of the international standardization organizations, and currently provides wireless broadband Internet service to fixed terminals. The IEEE 802.16d standard is being promoted as a standard for this purpose.

The IEEE 802.16d / e standard has a wider bandwidth of data than a conventional wireless technology for voice service, and can perform a lot of data transmission in a short time, and can efficiently use a channel by sharing all user channels. Do. In addition, quality of service (QoS) is guaranteed so that a user can receive different quality of services according to the characteristics of the service. In the IEEE 802.16d / e system, all users connected to the base station share and use a common channel, and the interval in which each user uses the channel is allocated by the base station in every uplink and downlink frame. Uplink and downlink access information should be informed so that channels can be used separately.

In the IEEE 802.16d / e system, channel information is divided into an uplink channel and a downlink channel, information about each channel is defined as a TLV (Type, Length, Value), a downlink channel descriptor (DCD), and an uplink channel descriptor (UCD) message. By including the channel information in the transmission to all the user terminal in a certain period to inform the terminal of the characteristic information about the channel.

In the IEEE 802.16 standard, such a wideband wireless communication system, a plurality of down-link sub-frames and up-link sub-frames may be different from each other. It is distributed to subscriber terminals and used. To this end, the wideband wireless communication system transmits control messages such as DL-Map and Up-Map in every frame, downlink channel descriptor (DDC) and uplink channel descriptor (UCD). Control message such as) must be shared between the base station and the subscriber station. The DL-map, UL-map, DCD and UCD will be described in detail with reference to FIG. 1.

1 is a diagram illustrating a typical frame structure of an orthogonal frequency division multiple access (OFDMA) type wide band wireless access communication system.

Referring to FIG. 1, a data frame of a typical broadband wireless access communication system includes both up / down links within the frame and transmits a TTG (Transmit) between the uplink and the downlink. Time Gap) and Receive Time Gap (RTG). In the example of FIG. 1, a DL sub-frame for downlink is included on the left side, and a UL sub-frame for uplink is included on the right side, and each frame has one preamble. UL-map (up-link map) and down-link map (DL-map). In particular, the example of FIG. 1 illustrates an example of a frame including a DCU, UCD message for transmitting uplink / downlink channel information.

In this case, information related to channel encoding (eg, frequency, contention-based reservation timeout, channel width, initial ranging code, periodic ranging code, bandwidth request) in addition to uplink burst profile information may be included in the UCD message. code, periodic ranging backoff start, periodic ranging backoff end). Some of these information can be changed depending on the channel, and others are fixed depending on the system. In particular, the number of uplink burst profiles of the UCD message is the total number of available UIUCs. The UCD message, which is a control message of the wideband system, has a UCD channel encoding value of the OFDMA Physical Layer method. The internal values are information encoded by type, length, and value (hereinafter, described by TLV). The DCD message also has a DCD channel encoding value like the UCD message described above, and the values therein are TLV encoded information.

Table 1 below is a general DCD message format for transmitting downlink channel information broadcast from a base station.

Syntax Size Notes DCD_Message_Format () { Management Message Type = 1 8bits Downlink channel ID 8bits Configuration Change Count 8bits TLV Encoded information for the overall channel variable TLV specific Begin PHY Specific Section { See applicable PHY section for (i = 1, i <= n; i ++) { For each downlink burst profile 1 to n Downlink_Burst_Profile PHY specific        }     } }

As shown in Table 1, a general DCD message includes an 8-bit message type field, an 8-bit Downlink Channel ID field indicating a downlink channel ID, and an 8-bit value that increases when channel information is changed. Configuration Change Count field and PHY specification part field. At this time, the size of the PHY specification part has the size as shown in Equation 1 below.

The format of the downlink burst profile will be described with reference to Table 2 below. Table 2 below is a format of a downlink burst profile that specifies a downlink user data section of a frame.

As shown in Table 2, the format of a downlink burst profile includes an 8-bit type field, a length field indicating an 8-bit profile length, and a 4-bit reserved field. A 4-bit downlink interval usage code (DIUC) field indicating a downlink usage interval code and a 9-byte TLV encoding information field.

That is, as shown in Table 2, the downlink burst profile consisting of the TLV is included in the PHY specification field of Table 1 as many as the number of downlink burst profiles (Downlink burst_profile).

Meanwhile, the UCD message format is configured as shown in Table 3 below. Table 3 below is an original UCD message format for transmitting uplink channel information broadcast from a base station.

As shown in Table 3, a general UCD message includes an 8-bit message type field, an 8-bit Configuration Change Count field for increasing a value when channel information is changed, and an 8-bit initial ranging. A Ranging Backoff Start field indicating the initial backoff window size for the first time, a Ranging Backoff End field indicating the final backoff window size of 8 bits, and a bandwidth request for 8 bits of bandwidth. A Request Backoff Start field indicating the initial backoff window size, a Request ackoff End field indicating the bandwidth end backoff size of 8 bits, and a PHY specification unit field. At this time, the size of the PHY specification part has the size as shown in Equation 2 below.

The format of the uplink burst profile will be described with reference to Table 4 below. Table 4 below is a format of an uplink burst profile that specifies an uplink user data section of a frame.

As shown in Table 4, the format of an uplink burst profile includes an 8-bit type field, a length field indicating an 8-bit profile length, and a 4-bit reserved field. And a 4-bit Uplink Interval Usage Code (UIUC) field indicating an uplink usage interval code, and a 13-byte TLV encoding information field. That is, as shown in Table 4, an uplink burst profile composed of TLVs is included in the PHY specification field of Table 3 as many as the number of downlink burst profiles.

The base station broadcasts the UCD and DCD messages shown in the table at regular intervals to inform the mobile station of uplink / downlink channel information. The burst profile TLV size of the message increases as the number increases, thus reducing transmission efficiency and causing the worst. In this case, it may happen that all messages cannot be delivered in one frame.

The base station broadcasts the UCD and DCD messages including the TLV values shown in the above table at regular intervals to inform all mobile terminals providing the service of uplink / downlink channel information. At this time, the size of the burst profile TLV of the UCD and DCD messages increases as the number increases. As such, when the size of the TLV including the channel information is increased, the size of the UCD and DCD messages is increased, thereby reducing the data transmission efficiency. In the worst case, the message may not be transmitted in one frame.

 Accordingly, an object of the present invention is to provide a system and method for a base station compressing uplink / downlink channel information messages to a mobile station in a broadband wireless access system.

Another object of the present invention is to provide a system and method for processing a compressed up / down channel information message when a base station transmits a compressed up / down channel information message to a mobile terminal in a broadband wireless access system. have.

It is also an object of the present invention to provide a system and method for increasing transmission efficiency by reducing overhead when a base station transmits an uplink / downlink channel information message to a mobile terminal in a broadband wireless access system.

The system for achieving the objects of the present invention, the burst profile information table indexed to one or more burst profile information that specifies the user's use period of the uplink / downlink channel information, and up / down channel information message The base station transmitting one of the indexes of the burst profile information table by including the index of the burst profile information table in the up / down burst profile field, and at least one burst profile information that specifies a user's use period of the uplink / downlink channel information. Storing an indexed burst profile information table and receiving an uplink / downlink channel information message, the index corresponding to the index in the burst profile information table using an index included in the uplink / downlink burst profile field in the message; Add burst profile information It is characterized in that after checking the channel information comprises a mobile terminal for applying them.                         

The method for achieving the objects of the present invention, the base station includes the step of transmitting one of the indexes of the index of the burst profile information table in the up / down burst profile field when transmitting the up / down channel information message; When the mobile terminal receives the up / down channel information message, the burst profile information corresponding to the index is extracted from the burst profile information table using an index included in the up / down burst profile field in the message. It includes the process of checking the information and applying it.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description of the present invention, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

The present invention to be described later is applied to the IEEE 802.16d / e system, in the embodiment of the present invention, a method for compressing and broadcasting the uplink / downlink channel information message broadcasted by a base station in a certain period in the IEEE 802.16d / e and a mobile terminal It will be described how to receive and process this.

Table 5 below is a format of a DCD message which is downlink channel information broadcast by a base station according to the present invention.                     

Table 5 is a DCD message format according to the present invention. The DCD message includes an 8-bit message type field, an 8-bit Downlink Channel ID field indicating a downlink channel ID, and a value when channel information is changed. 8-bit Configuration Change Count field and Downlink Burst Profile (Downlink_Burst_Profile) field are included.

In this case, the downlink burst profile (Downlink_Burst_Profile) field is shown in Table 5, the format of the downlink burst profile is an 8-bit type field and a length field indicating the 8-bit profile length A pre-defined profile flag field indicating transmission of a 1-bit compressed message, and a 4-bit downlink interval usage code (DIUC) field indicating a downlink usage interval code in 4 bits; Is made of. In this case, a 4-bit downlink interval usage code (DIUC) field indicating a downlink usage interval code includes an index value of a predefined burst profile information table. In this case, the predefined burst profile information table includes a plurality of indexes and burst profile information corresponding to each index.

In addition, the burst profile information table must share the same table between the base station and the mobile terminal. In addition, this table should be stored in the terminal and the base station as a fixed table during the manufacturing process of the manufacturer, and can be updated as needed.

That is, the base station sets a pre-defined profile flag field to 1 and transmits a compressed DCD message, and among the indexes included in the burst profile information table in the downlink interval usage code (DIUC) field. Include one.

When using the compressed DCD message described in the present invention, the mobile terminal has a set of pre-defined burst profile information, that is, a burst profile information table. That is, since the mobile terminal already stores the TLV information necessary for all the burst profile information through the burst profile information table, the base station does not need to broadcast the TLV information of the burst profile every time a message is transmitted. Instead, the system of the present invention allocates one bit of the reserved field to the Pre-defined Profile Flag field to check whether there are predefined profiles. If the field is set to 1, since the terminal already has profile information, the base station transmits the index of the profile information table only once in the DIUC field, and the mobile station refers to the index in the profile information table and the desired profile information. Can be applied. In this case, since the TLV information of the downlink burst profile does not need to be transmitted separately, the size becomes 0, and the size required to transmit the downlink burst profile is 3 bytes.

Then, it is compared with the size required to transmit the downlink burst profile when transmitting the DCD message and the size required to transmit the downlink burst profile when transmitting the DCD message according to the present invention.

The DCD message in Table 1 includes downlink burst profile information as many as downlink burst profiles. In this case, since the size of the downlink burst profile shown in Table 2 is 12 bytes including the TLV, if a total of 12 burst profiles exist, a total size of 144 bytes is required to transmit the burst profile information.

Since the TLV information of the downlink burst profile does not need to be transmitted separately, the size becomes zero. That is, since the TLV encoded information having a size of 9 bytes is stored in the profile information table, the size of the TLV information of the downlink burst profile that the base station should transmit has a size of 0 bytes.

Accordingly, the downlink burst profile includes an 8-bit type field of the downlink burst profile, an 8-bit length field, and a DIUC field including an 8-bit predefined profile flag and an index number of the burst profile. The size required to transmit the burst profile is 3 bytes.

Therefore, in the present invention, it is possible to compress 144 bytes, which were necessary for transmitting a downlink burst profile, to 3 bytes in the present invention.

Table 6 below shows a compressed format of a UCD message, which is uplink channel information broadcast by a base station.

As shown in Table 6, the compressed UCD message according to the present invention includes an 8-bit message type field, an 8-bit Configuration Change Count field for increasing a value when channel information is changed, and an 8-bit initial lane. Ranging Backoff Start field indicating the initial backoff window size for initial ranging, Ranging Backoff End field indicating the final backoff window size of 8 bits, and 8 bits A Request Backoff Start field indicating an initial backoff window size for a bandwidth request of the UE, a Request Backoff End field indicating an bandwidth end backoff size of 8 bits, and an uplink burst profile field.

In this case, the uplink burst profile (Uplink_Burst_Profile) field is shown in Table 6. The format of the uplink burst profile is an 8-bit type field and a length field indicating an 8-bit profile length. A pre-defined profile flag field indicating transmission of a 1-bit compressed message, and a 4-bit uplink interval usage code (UIUC) field indicating an uplink usage code in 4 bits. Is made of. In this case, the 4-bit UIUC field indicating the uplink usage interval code includes an index value of a predefined burst profile information table.

In the case of using the compressed UCD message described in the present invention, the base station does not broadcast the TLV information of the burst profile every time the message is transmitted, as in the method of transmitting the compressed DCD message, and indexes the profile information table in the UIUC field. Send only once. Then, the mobile terminal can apply the desired profile information by referring to the index in the profile information table. In this case, since the TLV information of the uplink burst profile does not need to be transmitted separately, the size becomes 0, and the size required to transmit the downlink burst profile is 3 bytes.

Then, it is compared with the size required for transmitting the uplink burst profile when transmitting the normal UCD message and the size required for transmitting the uplink burst profile when transmitting the UCD message according to the present invention.

The UCD message in Table 3 includes uplink burst profile information as many as uplink burst profiles. In this case, since the size of the uplink burst profile shown in Table 4 is 16 bytes including the TLV, if a total of 10 burst profiles exist, a total size of 160 bytes is required to transmit the burst profile information.

However, since the TLV information of the uplink burst profile according to the present invention does not need to be transmitted separately, the size becomes zero. That is, since TLV encoded information having a size of 13 bytes is stored in the profile information table, the size of TLV information of an uplink burst profile that the base station should transmit has a size of 0 bytes.

Therefore, the uplink burst profile includes an 8-bit type field of the uplink burst profile, an 8-bit length field, and an UIUC field including an 8-bit predefined profile flag and an index number of the burst profile. The size required to transmit the data is 3 bytes.

Therefore, in the case of the conventional UCD message, it is possible to compress the 160 bytes required to transmit 10 uplink burst profile UIUC values into 3 bytes.                     

Then, a process for transmitting the UCD / DCD message from the base station to the mobile terminal will now be described with reference to FIG. 2. 2 is a control flowchart for transmitting a DCD / UCD message in a base station according to an embodiment of the present invention.

First, the base station should store in the burst profile information table that specifies the user's use period of the uplink / downlink channel information.

In step 200, the base station checks whether it is a cycle for transmitting a DCD / UCD message. If it is a period for transmitting the DCD / UCD message, the flow proceeds to step 204 and the predefined profile flag in the up / down burst profile field in the DCD / UCD message is set to 1, and then the flow proceeds to step 206. Include the index number included in the table in DIUC / UIUC. That is, the base station does not transmit all burst profile information to be broadcast to the terminal, but broadcasts only an index for one of a set of predefined burst profile information in the DIUC and UIUC fields. In step 208, the base station broadcasts the DCD / UCD message set in steps 204 and 206.

Next, when the mobile terminal receives the DCD / UCD message broadcasted as shown in FIG. 2, the process for processing the message will be described with reference to FIG. 3. 3 is a flowchart illustrating a process of receiving a DCD / UCD message in a mobile terminal according to an embodiment of the present invention. First, the mobile terminal should have a predefined up / down burst profile information table.

When the mobile terminal receives the DCD / UCD message in step 300, it first checks a value of a pre-defined profile flag field in step 302. If the predefined profile flag field value is set to 1, the flow proceeds to step 304. If the predefined profile flag field value is not set to 1, the service is not possible and ends. That is, it can be seen that the system supports the compressed DCD / UCD format according to a predefined profile flag field value.

In step 304, the mobile terminal recognizes the DIUC / UIUC field value as an index value of a predefined burst profile information set, and then extracts and applies a burst profile using the index value.

As described above, in the present invention, the uplink / downlink channel information message broadcast by the base station transmits only the index of the burst profile information table stored in the mobile terminal, not all burst profile information. Then, the mobile terminal extracts burst profile information from its table using the received index to obtain channel information.

As described above, the present invention can increase transmission efficiency by reducing overhead when a base station transmits an uplink / downlink channel information message to a mobile station in a broadband wireless access system. In addition, the present invention compresses and transmits a large sized uplink / downlink channel information message broadcasted by a base station at regular intervals in a broadband wireless access system, and thus the transmission efficiency is reduced because the message occupies a space for carrying actual data. In the worst case, it can solve the problem of not sending all the messages in one frame.

Claims (7)

A broadband wireless access system for transmitting uplink / downlink channel information message, Stores a burst profile information table indexed to one or more burst profile information that specifies a user's usage interval among uplink / downlink channel information, and the burst profile in the uplink / downlink burst profile field when an uplink / downlink channel information message is transmitted. A base station transmitting and including one of the indexes of the information table; Storing a burst profile information table indexed to at least one burst profile information specifying a user's usage interval among uplink / downlink channel information, and receiving the uplink / downlink channel information message; And a mobile terminal extracting burst profile information corresponding to the index from the burst profile information table using the index included in the burst profile field to check channel information and applying the same. A broadband wireless access system for transmitting uplink / downlink channel information messages and a method for transmitting and receiving uplink / downlink channel information messages in the system, Transmitting, by the base station, one of the indices of the burst profile information table in the up / down burst profile field when transmitting the uplink / downlink channel information message; When the mobile terminal receives the up / down channel information message, the burst profile information corresponding to the index is extracted from the burst profile information table using an index included in the up / down burst profile field in the message. And checking the information and applying the same. 3. The method of claim 2, further comprising the step of providing a burst profile information table in which the base station and the mobile terminal have indexed one or more burst profile information that specifies a user's usage interval among uplink / downlink channel information. Said method. A broadband wireless access system for transmitting uplink / downlink channel information message and a method for transmitting uplink / downlink channel information message by a base station in the system, Generating an uplink / downlink channel information message by including one of the indices of the burst profile information table in the uplink / downlink burst profile field when the uplink / downlink channel information message is transmitted; Transmitting the generated uplink / downlink channel information message. 5. The method as claimed in claim 4, further comprising a step of providing a burst profile information table indicative of at least one burst profile information indicating a user's usage interval among uplink / downlink channel information. A broadband wireless access system for transmitting an uplink / downlink channel information message and a method for receiving a uplink / downlink channel information message by a mobile terminal in the system, Receiving an uplink / downlink channel information message, identifying an index included in the uplink / downlink burst profile field in the message; And extracting burst profile information corresponding to the index from the burst profile information table using the identified index to check channel information and then applying the same. 7. The method as claimed in claim 6, further comprising the step of providing in advance a burst profile information table indexing at least one burst profile information specifying a user's usage interval among uplink / downlink channel information.

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