Downlink message forwarding method and serving gateway (S-GW)

[0052] Example one

[0053] In this embodiment, the target eNB and the source eNB belong to the same MME and S-GW, that is, this embodiment is the S1 handover within the MME and S-GW.

[0054] Figure 4 When performing S1 handover in this embodiment, the S-GW processes the data and signaling flow of the downlink message, as shown in Figure 4 As shown, in this embodiment, when S1 handover occurs, the signaling flow and image 3 Similarity, the difference is that since the source MME and the destination MME are the same, therefore, Figure 4 in image 3 Message 2 and Message 5 are reduced on the basis of.

[0055] Figure 5 In this embodiment, after the source eNB sends the handover command message to the UE, the flow chart of data forwarding is as follows: Figure 5 As shown, the source eNB forwarding data mainly includes the following steps:

[0056] Step 501: S1 handover occurs. After the source eNB sends out the handover command message, it starts to forward the message (the message th

[0062] Example two

[0063] In this embodiment, the S1 handover within the MME and across the SGW is taken as an example for description.

[0064] Image 6 This is a schematic diagram of the flow of data flow and signaling flow during S1 handover in this embodiment, such as Image 6 As shown, the signaling flow in this embodiment is Figure 4 Basically, the data flow is from the source eNB to the source S-GW to the target S-GW, and finally to the target eNB.

[0065] Figure 7 In this embodiment, after the source eNB sends the handover command message to the UE, the flow chart for forwarding the data stream is as follows: Figure 7 As shown, in this embodiment, the source S-GW forwarding data mainly includes the following steps:

[0066] Step 701: S1 handover occurs. After the source eNB sends a handover command message, it starts to forward the message to the source S-GW through the reverse transmission tunnel between it and the source S-GW;

[0067] Step 702: After receiving the first pa

[0072] Example three

[0073] In this embodiment, cross-MME and cross-SGW S1 handover is taken as an example for description.

[0074] Figure 8 This is a schematic diagram of the flow of data flow and signaling flow during S1 handover in this embodiment, as Figure 8 As shown, the signaling flow in this embodiment is image 3 The data flow is basically the same as Image 6 similar.

[0075] Picture 9 In this embodiment, after the source eNB sends the handover command message to the UE, the flow chart for forwarding the data stream is as follows: Picture 9 As shown, in this embodiment, the source S-GW forwarding data mainly includes the following steps:

[0076] Step 901: S1 handover occurs. After the source eNB sends a handover command message, it starts to forward the received message that needs to be sent to the UE to the source S-GW through the reverse transmission tunnel between it and the source S-GW;

[0077] Step 902: After receiving the first packet of the forwarding message sen