CN1984470B

CN1984470B - Method for duplicating channel

Info

Publication number: CN1984470B
Application number: CN200610076079A
Authority: CN
Inventors: 吴志坚; 周军
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2006-04-27
Filing date: 2006-04-27
Publication date: 2010-05-12
Anticipated expiration: 2026-04-27
Also published as: CN1984470A

Abstract

The method comprises: a) base station controller sends down the data frame carrying service data in reference channel, and sends down the data frame only including head part in one or more than one non reference channel; b) base station copies the service data of reference channel data frame and format information into the non reference channel data frame. The invention can be used in single pointto multi point multimedia broadcast so as either to implement the copy of service data between channels or to avoid the repeated transmission of service data between base station controller and basestation.

Description

A kind of method of duplicating channel

Technical field

The present invention relates to the mobile communication technology field, particularly a kind of method of duplicating channel is particularly to forward access channel (Forward Access Channel, clone method FACH).

Background technology

Multimedia broadcasting and multicast (Multimedia Broadcast/Multicast Service, MBMS) business is the unidirectional multimedia service of a kind of single-point to multiple spot, it allows data to send to a plurality of recipients from the single source entity, utilizes high efficiency wireless forwarding method that identical data are downloaded to a plurality of mobile subscribers.Its main feature is can realize the taking for a long time of unidirectional down channel, realizes providing multimedia service to a large amount of mobile subscribers to the distribution mode of multiple spot with single-point.The MBMS business will be widely used in the next generation (NGN) wireless network.

At Wideband Code Division Multiple Access (WCDMA) (Wideband Code Division Multiple Access, WCDMA) in the system, the realization of MBMS business mainly is to handle MBMS indicating channel (MBMS Indication Channel in base station (Node B), MICH), carrying broadcast or multicast business information and on public FACH.As shown in Figure 1, suppose that there are three sub-districts the base station, base station and radio network controller (RNC) are mutual by Iub interface.For the user who makes different districts can receive identical MBMS business, require each sub-district can both broadcast from same business channel data.If according to existing MBMS business realizing scheme, corresponding to each sub-district, base station, need set up a common signal channel FACH respectively at Iub interface, after being sent to RNC from the MBMS business datum of service source in the core net, respectively by these FACH with the MBMS business data transmission to the base station, by the base station MBMS business is sent to each sub-district again.Can occur the common signal channel of many transmission identical datas like this on Iub interface, this is a very big waste to present rare Iub interface resource.

At this situation, a kind of feasible solution is: after being sent to RNC from the MBMS business datum of core net service source, by a common signal channel FACH in the Iub interface between base station and the RNC MBMS business datum is sent to the base station; At inside of base station, the MBMS business datum of being received copied to each FACH and be forwarded to each sub-district of this base station; Can realize belonging to the MBMS business datum of each sub-district, same base station like this and share, thereby reach the purpose of saving the Iub interface resource.

Finish such reproduction process and have several key technologies, one of them is exactly the Frame reproduction process on the common signal channel FACH, the data that are about to carry on the FACH channel of MBMS business datum copy on other FACH channels, guarantee the requirement of all kinds of indexs such as channel power, time-delay simultaneously, for convenience of description, below the FACH channel of described carrying MBMS business datum is called reference channel, described other FACH channels are called non-reference channel.Figure 2 shows that the data frame structure of FACH, comprise head (Header) and payload (Payload) two parts, wherein head comprises head cyclic redundancy check (CRC) (Header CRC), frame type (Frame Type again, FT), Connection Frame Number (ConnectionFrame Number, CFN), transformat indication (Transport Format Identification, TFI), transmission power level (Transmit Power Level, TPL), the reservation position and the head liner (Pad) of head; Payload comprise some transmission block (Transport Block, TB), payload CRC, the reservation position of payload and the liner of payload.

The MBMS business datum duplicates between above-mentioned reference channel and the non-reference channel, can adopt two kinds of technical schemes at present. first kind of scheme is that base station controller is when the base station issues the MBMS business datum, reference channel Frame carrying MBMS business datum, but not the reference channel Frame is empty; By the base station whole contents of reference channel is copied to non-reference channel, being about to the reference channel Frame and comprising that the each several part of head and payload intactly copies as non-reference channel Frame. this scheme can cause the loss of performances such as the time delay of business datum and power, and dispose under the non-vanishing situation of numerical value in vertical shift (Frame Offset), time-delay deviation can be very serious, the phenomenon that may cause signal to repeat or lose; Second kind of scheme is on the basis of first kind of scheme, by the compensation calculation mode CFN proofreaied and correct, and recomputates head CRC.This mode can make delay performance obtain limited improvement, but still has power loss, and has also increased the complexity that realizes.

Summary of the invention

In view of this, the objective of the invention is to, propose a kind of method of duplicating channel, can guarantee the quality of channel parameter, and implementation is simple.Comprise the steps:

A, base station controller informing base station are set up each sub-district, and are that a public forward access channel FACH channel is set up in each sub-district of being set up, described each public FACH channel be from base station controller through the base station to this common signal channel corresponding district; Base station controller selects a FACH channel as the reference channel in these FACH channels of being set up, and other FACH channels are non-reference channel;

B, base station controller generate separately data frame header respectively for all reference channels and non-reference channel; Multimedia broadcasting and multicast MBMS business datum are loaded into the payload part of reference channel Frame, issue the reference channel Frame that comprises head and payload at reference channel, issue at one or more non-reference channels and only comprise that head and payload are zero non-reference channel Frame;

C, base station copy to the MBMS business datum of reference channel Frame in the payload of each non-reference channel Frame, and the format information that the data frame header of reference channel is comprised copies in the head of each non-reference channel Frame.

Further comprise after the step C:

The head cyclic redundancy check (CRC) of each non-reference channel is recomputated in the base station.

Described non-reference channel head comprises head cyclic redundancy check CRC, frame type FT, Connection Frame Number CFN and transmission power level;

The data frame header of described reference channel comprises head cyclic redundancy check CRC, frame type FT, Connection Frame Number CFN, transformat indication TFI and transmission power level.

The described format information of step C is transformat indication TFI.

Described base station controller is a radio network controller (RNC).

As can be seen from the above technical solutions, base station controller is the normal data frames of bearer service data in the reference channel when the issuing service data of base station, but not in the reference channel for bearer service data not, only comprise the Frame of head; The base station copies to non-reference channel with business datum in the reference channel and format information, and recomputate the head cyclic redundancy check (CRC), and keep other channel parameters of head constant, so just both realized duplicating of interchannel business datum, avoid the business datum that transmission repeats between base station controller and the base station, guaranteed the quality of channel parameter in the Frame again, and implementation is simple, overhead is very little.

Description of drawings

Fig. 1 is the schematic diagram of existing techniques in realizing MBMS business;

Fig. 2 is a FACH channel data frame structural representation;

Fig. 3 realizes the flow chart of duplicating channel for the embodiment of the invention;

Fig. 4 is the non-reference channel data frame structure of an embodiment of the invention schematic diagram.

Embodiment

For making the purpose, technical solutions and advantages of the present invention clearer, the present invention is further elaborated below in conjunction with accompanying drawing.

Core content of the present invention is: base station controller is when the issuing service data of base station, and reference channel issues the normal data frames of bearer service data, and non-reference channel issues bearer service data not, only comprises the Frame of head; Business datum is carried out when duplicating in the base station, as long as the payload of the bearer service data of reference channel Frame is copied as the payload of non-reference channel Frame, upgrade the format information of non-reference channel payload, and recomputate non-reference channel head CRC, and other parts of non-reference channel Frame are remained unchanged.So just carry out duplicating of interchannel business datum, and guarantee the quality of channel parameters with a kind of very simple method realization base station.

Before the operation flow to the embodiment of the invention is described in detail, at first base station controller is carried out simple declaration to the beamhouse operation that the base station issues the MBMS business datum, described beamhouse operation comprises following content:

The RNC informing base station is set up each sub-district, and be the public FACH channel of setting up of each sub-district of being set up, described each public FACH channel be from RNC through the base station to this common signal channel corresponding district, the sign that each public FACH channel has comprises the cell ID at a channel logo and this common signal channel place; After public FACH channel is set up, synchronous again each FACH common signal channel; RNC selects a conduct with reference to channel in these FACH channels of being set up, and other FACH channels are non-reference channel, and by RNC or the maintenance console sign informing base station with reference channel and non-reference channel.Be the necessary preparation step of implementing the present invention program more than, but do not belong to technical solution of the present invention.

On the basis of above-mentioned beamhouse operation, the present invention program finishes duplicating of business datum between reference channel and the non-reference channel, and its specific implementation flow process comprises the steps: as shown in Figure 3

Step 301:RNC generates the channel parameter of data frame header separately respectively for all non-reference channels, and calculates head CRC; The channel parameter of described head comprises FT, CFN, TPL; In addition, because TFI is relevant with the particular content of payload, so temporarily do not generate, this part is empty;

Step 302:RNC is loaded into the payload part of reference channel Frame with the MBMS business datum and calculates its payload CRC, generates the channel parameter of head and calculates head CRC; Described head channel parameter comprises FT, CFN, TPL and TFI;

Step 303:RNC issues separately Frame respectively at reference channel and non-reference channel; Wherein, the Frame of reference channel comprises head and payload two parts, but not the reference channel Frame only comprises head, payload part is zero, its frame format as shown in Figure 4, the head various piece implication of data frame header various piece and Frame shown in Figure 2 is identical, but does not have payload part;

Step 304: after the Frame of reference channel and non-reference channel is received in the base station, the value of TFI in the reference channel Frame is copied to the TFI of each non-reference channel, and the payload part of reference channel is copied to the payload part of each non-reference channel;

Step 305: the head CRC of each non-reference channel is recomputated in the base station.

In above-mentioned duplicating channel process, the CFN by RNC calculates each non-reference channel self has considered the factor of each channel delay, so need not CFN to be proofreaied and correct again.

By said process, the base station is finished business datum is duplicated to each non-reference channel from reference channel, next just can the MBMS business datum be sent to each sub-district by each public FACH channel.

Those skilled in the art will be appreciated that, though above embodiment is with the example that copies as of FACH interchannel MBMS business datum, but the present invention program can be applied to carry other single-points equally in the reproduction process of the channel spare business datum of the unidirectional multimedia service of multiple spot. and the system that the inventive method was suitable for is except the WCDMA system, can also comprise other wireless communication systems, as code division multiplexing (CDMA) system, CDMA2000 system, time division synchronous code division multiplexing (TD-SCDMA) etc.

The above only is preferred embodiment of the present invention, not in order to restriction the present invention, all any modifications of being done within the spirit and principles in the present invention, is equal to and replaces and improvement etc., all should be included within protection scope of the present invention.

Claims

1. the method for a duplicating channel is characterized in that, comprises the steps:

2. method according to claim 1 is characterized in that, further comprises after the step C:

3. method according to claim 1 is characterized in that, the data frame header of described non-reference channel comprises head cyclic redundancy check CRC, frame type FT, Connection Frame Number CFN and transmission power level;

4. method according to claim 1 is characterized in that, the described format information of step C is transformat indication TFI.

5. according to each described method of claim 1 to 4, it is characterized in that described base station controller is a radio network controller (RNC).