CN1870818A - Method for quickly switchover using appointed range finding code - Google Patents

Abstract

A rapid switchover method realized by a designated location code includes the steps: a user station sends out switching request to a target station by a current service base station using the signaling channels among the base stations, the target base station designates 'quick switchover measurement code' for the user station and / or the area it is located and the user station launches switchover request with the' quick switchover measurement code ' to the target station. According to the detected code, the target station receives relevant information of the user station for switchover. Among the existing communication systems using access codes and / or location code, such as broadband metropolitan area network standard (IEEE 802.16e standard. HIPERMAN series standards), users can reduce the information exchange between user's station and the target base stations.

Description

Method of Realizing Fast Switching by Using Designated Ranging Code

technical field

The invention relates to a wireless communication system using an access code and/or a distance-measuring code, in particular to a method for realizing fast switching by using a designated distance-measuring code.

Background technique

Access code: refers to the code word used for access (including initial access, periodic access and other access operations) and switching in the wireless communication system. By using the access code, the system can identify the user's Various requests such as access and switching.

The access code is also called the ranging code (Ranging Code) in some documents. In this article, unless otherwise stated, the two are used equally.

In systems using access codes and/or ranging codes, a subscriber station may use the access codes and/or ranging codes to initiate a handover procedure. For example: IEEE802.16 is a broadband wireless metropolitan area network specification, IEEE802.16e is an extension mode of IEEE802.16, the design goal of IEEE802.16e is based on the IEEE802.16 specification, and extends IEEE802 on the basis of supporting fixed access of users .16 to support user mobility.

In the physical layer specification of IEEE802.16e, for the switching process of the OFDMA mode, a method based on switching ranging codes is used. The switching ranging code and the initial ranging code are selected within the range of 0 to 255 (8-bit code length), and the range of the switching ranging code and the initial ranging code is set by the base station (for example: the range of switching ranging code can be set to 17 ~64, the initial access code range is 65~96), the user station uses the handover ranging code when switching, and uses the initial ranging code when initial accessing, the base station detects the different codewords used by the user station, for the user Requests from stations are handled differently.

As shown in Figure 1, the user station uses the "handover ranging code" to initiate the handover process. The specific implementation steps are as follows:

1. The user station uses the "handover ranging code" to send a handover request, indicating to the target base station that the user station is initiating handover;

2. The target base station learns the handover request of the subscriber station by detecting the "handover ranging codeword"; Timing and other physical parameters are adjusted to better construct the physical layer link between the two. This process may require multiple repetitions to complete;

3. The target base station allocates an uplink transmission time slot (realized by using an uplink time slot allocation message UL-MAP) for the user station in a subsequent frame, for the user station to send an access request message (RNG-REQ);

4. In the access slot specified by the target base station, the user station sends an access request message including the media access control (MAC) address, the previous serving BS ID (Serving BS ID), and the user's previous authentication information. (RNG-REQ);

5. After receiving the access request message (RNG-REQ) of the user station, the target base station confirms the information of the user station through the signaling channel between the base stations, and gives the corresponding access request response message in the subsequent frame (RNG-RSP). The message includes: a new basic management connection identifier (B-CID) and a new primary management connection identifier (P-CID) of the subscriber station;

6. After receiving the above-mentioned access request response message (RNG-RSP), the subscriber station can use the new basic management connection identifier and primary management connection identifier in the new cell, thereby completing the handover process.

The handover methods used in existing systems using access codes and/or ranging codes (such as the IEEE802.16e/D5 specification) do not make full use of the signaling channels between base stations, and there are many steps in the handover process. The real-time performance is disadvantageous, and there is a certain waste in the use of channel resources on the air interface.

Contents of the invention

The purpose of the present invention is to provide a method for realizing fast switching by using designated access code and/or ranging code.

In order to achieve the above purpose, a method for realizing fast switching by using a specified ranging code, comprising steps:

The subscriber station initiates a handover request to the target base station through the current serving base station using the inter-base station signaling channel;

The target base station is the subscriber station and/or the cell where the subscriber station is located, and specifies the "fast switching ranging code";

When the subscriber station uses the "fast handover ranging code" to initiate a handover request to the target base station;

The target base station obtains relevant information of the subscriber station according to the detected "fast handover ranging code" for handover.

In existing communication systems using access codes and/or ranging codes, such as broadband metropolitan area network specifications (IEEE802.16e specifications, HIPERMAN series specifications, etc.), using the method of the present invention can reduce the number of connections between subscriber stations and targets. The information exchange between the base stations realizes the fast switching operation and improves the transmission efficiency of the air interface.

Description of drawings

Fig. 1 is a schematic diagram of an air interface interaction process using a ranging code to realize switching;

Fig. 2 is a schematic diagram of an air interface interaction process using a specified ranging code to realize fast switching;

Fig. 3 is a reference message sequence diagram including network-assisted handover process requested by the base station and decided by the subscriber station;

Fig. 4 is a reference message sequence diagram including network-assisted fast handover process requested by the base station and decided by the subscriber station.

Detailed ways

Firstly, the "fast switching ranging code" is described, and then a method of using the "fast switching ranging code" to realize "fast switching" is proposed.

The composition of "fast switching ranging code":

"Fast handover ranging code" is a subset of "ranging code", reserved by the base station for fast handover.

与切换测距码的关系

Relationship with handover ranging code

The "fast switching ranging code" can be a subset of the original "switching ranging code", so that the base station can independently determine the "fast switching ranging code" subset and the "non-fast switching ranging code" subset according to the situation. Switching the scaling relationship of the ranging code" subset.

When the "fast handover ranging code" subset is expanded to be equal to the "handover ranging code" set, if dynamic assignment is used, a good fast handover effect can be achieved. It also has the most information; if static assignment is used, it can be configured to achieve the same effect as the original system, that is, the system that does not use the "fast switching ranging code".

Assignment of "Fast Handover Ranging Code"

The base station informs the surrounding adjacent base stations of the designated "fast switching ranging code" through the signaling channel between the base stations. Subsequently, each adjacent base station can transmit the information to the subscriber station in the respective cell through the air interface, so that they can use it for fast handover to the target base station.

动态指配和静态指配

Dynamic assignment and static assignment

Dynamic assignment refers to the assignment of "fast switching ranging code" for each handover. After each fast switching process is completed, the "fast switching ranging code" needs to be withdrawn; dynamic assignment is essentially for users station assignment;

Static assignment refers to maintaining the assignment of "fast switching ranging code" within a certain period of time, that is, assigning the "fast switching ranging code" to a certain cell and keeping it for a certain period of time; static assignment is essentially for assignment of base stations;

The following part is mainly for the dynamic assignment, that is, the user station assignment; the static assignment, that is, the assignment principle and process for the base station are similar.

The user station uses the "fast handover ranging code" to initiate the fast handover process. The specific implementation steps are as follows:

1. When the subscriber station or the current serving base station is about to initiate a handover, the current serving base station uses the inter-base station signaling channel to initiate a request to the target base station, and the request information includes the relevant information of the subscriber station; the target base station responds to the request and returns a response information and the "Fast Handover Ranging Code" it has assigned for this subscriber station handover. The current serving base station uses the air interface to notify the subscriber stations in the cell to be handed over;

(Note: Compared with the "Description of Handover Process" in the "Description of Prior Art", step 1 adds the content of information exchange between the current serving base station and the target base station for "fast handover ranging code".)

2. The subscriber station sends a handover request to the target base station by using the "fast handover ranging codeword" obtained from the current serving base station, and indicates to the target base station that the subscriber station is initiating a handover;

3. The target base station learns the handover request of the subscriber station by detecting the "fast handover ranging codeword"; by sending a ranging response (RNG-RSP) message containing power and timing adjustment parameters, the transmission power of the subscriber station, Timing and other physical parameters are adjusted to better construct the physical layer link between the two. This process may require multiple repetitions to complete;

4. Since the target base station has obtained the required subscriber station information through the inter-base station signaling channel, in the subsequent frame, it can directly send the access request response message, which contains: the subscriber station's new basic management connection identifier (B-CID) and the new Primary Management Connection ID (P-CID). After receiving the above-mentioned access request response message (RNG-RSP), the subscriber station can use the new basic management connection identifier and primary management connection identifier in the new cell, thereby completing the handover process.

The interactive process of the air interface (including steps 2, 3, 4) is shown in Fig. 2 . From the above description of the process, and in comparison with the "Description of the Handover Process" in the "Description of the Prior Art", it can be found that due to the use of the signaling channel in front of the base station to transmit the user information and the designated "Rapid Handover Ranging Code", the The purpose of reducing the air interface interaction steps.

The following steps are no longer needed in "fast handover": the target base station allocates time slots for the user station to send information, and the user station sends information requests including MAC address and current serving base station identifier, thereby realizing a fast handover process, and Air interface resources are saved.

Example

In the IEEE802.16e/D5 specification, a reference message sequence diagram (MSC) including network-assisted handover process requested by the base station and determined by the user station is given, that is, Figure E.11 of the IEEE802.16e/D5 specification. In the present invention, as shown in FIG. 3 , a reference message sequence diagram (provided by IEEE802.16e specification) including network-assisted handover process requested by the base station and decided by the subscriber station.

The implementation steps of applying the fast switching method in this case are shown in Fig. 4, where the added parts of the fast switching method are specially marked.

Claims (8)

1. A method utilizing a specified ranging code to realize fast switching, comprising steps: The subscriber station initiates a handover request to the target base station through the current serving base station using the inter-base station signaling channel; The target base station is the subscriber station and/or the cell where the subscriber station is located, and specifies a "fast switching ranging code"; When the subscriber station uses the "fast handover ranging code" to initiate a handover request to the target base station; The target base station obtains relevant information of the subscriber station according to the detected "fast handover ranging code" for handover. 2. The method of claim 1, further comprising: The base station informs the surrounding adjacent base stations of the designated "fast switching ranging code" through the signaling channel between the base stations; Each adjacent base station transmits the specified "fast switching ranging code" to the subscriber station in each cell through the air interface. 3. The method according to claim 1, characterized in that said "fast switching ranging code" is a subset of "ranging code". 4. The method according to claim 1, characterized in that the assignment of "fast switching ranging code" includes dynamic assignment or static assignment. 5. by the described method of claim 1, it is characterized in that also comprising the step: The current serving base station uses the air interface to notify the subscriber stations in the cell to be handed over. 6. The method according to claim 1, characterized in that said subscriber station related information includes transmission power and timing parameters. 7. The method according to claim 6, wherein the target base station adjusts the transmit power and timing parameters of the subscriber station in order to better construct the physical layer link between them. 8. The method according to claim 1, wherein said switching comprises: The target base station directly sends an access request corresponding message to the subscriber station, where the message is a new basic management connection identifier and a new primary management connection identifier of the subscriber station; After receiving the above request response message, the subscriber station uses the new basic management connection identifier and primary management connection identifier to complete the handover process in the new cell.

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