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Core network aspects 1

9.2.2 Traffic adjustment mechanism initiated by the network

Suppose that UE_A is an ordinary UE accessing only the WLAN access network, and MUE_B is an MPT-
enhanced MUE with two interfaces simultaneously accessing to the WLAN (IF (1)) and 3G (IF (2)) access
networks. Consider the example scenario where UE_A initiates a large file transfer service to MPT-enhanced
MUE_B. To achieve a larger bandwidth for time savings, the MPT-enhanced SCF splits the file transfer to go
through the WLAN path and the 3G path simultaneously to MPT-enhanced MUE_B on behalf of UE A.

During the transmission, MPT-enhanced SCF communicates with UE_A by single path but communicates with
MPT-enhanced MUE_B by multi-path, simultaneously, as a multi-path transmission proxy for UE_A. If
necessary, the MPT-enhanced MPC-FE may push the access networks' performance parameters to the MPT-
enhanced SCF as the traffic adjustment reference periodically.
The detailed information flow of this example scenario is shown in Figure 9-4.

Figure 9-4 – Traffic adjustment procedure initiated by the network

0-1) data packets of a large file are transferred from UE_A to MPT-enhanced MUE_B through the WLAN
path and the 3G path simultaneously for a larger aggregated bandwidth;
2) MPC-FE collects and analyses the access networks' performance parameters, and periodically
pushes them to the MPT-enhanced SCF as the traffic adjustment reference when necessary;
3) MPT-enhanced SCF collects and analyses path performance parameters of the WLAN path and the
3G path on behalf of UE_A, and finds that the 3G path becomes more congested than earlier;
4-5) considering both path conditions and performances of each access network, the MPT-enhanced SCF
adjusts the traffic transmission ratio of each, and the WLAN path balances some traffic of the 3G
path.

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