Page 305 - 5G Basics - Core Network Aspects

Core network aspects 1

interface. In this scenario, the FTP server is MPT-enhanced MUE_B. After the establishment of control
connection, MPT-enhanced MUE_A decides to establish two data transmission paths using the 3G path and
the WLAN path.
The detailed information flow of this example scenario is shown in Figure 9-1.

Figure 9-1 – Path selection procedure initiated by MPT-enhanced MUE

0) MPT-enhanced MUE_A maintains the connection status of each available access network for the
incoming services;

1) MPT-enhanced MUE_A launches an FTP service request to MPT-enhanced MUE_B to establish an
MPT connection. This service request will be intercepted by MPT-enhanced SCF of the
corresponding node;
2) MPT-enhanced SCF initiates an MPT request to MPT-enhanced MPC-FE to query whether the
corresponding node and corresponding networks’ performance allow multi-path transmission;
3) after receiving the MPT request from MPT-enhanced SCF, MPT-enhanced MPC-FE obtains the
profile information of the FTP server from MUP-FE and judges whether the FTP server is MPT
enhanced;
4-5) MPT-enhanced MPC-FE makes MPT policy decisions, and returns an MPT responds message to the
MPT-enhanced SCF indicating that the FTP server is an MPT-enhanced MUE and the corresponding
networks’ performance is able to support MPT;
6) as the FTP server can support the multi-path transmission, the MPT-enhanced SCF will not act as a
multi-path transmission proxy for the FTP server;
7) MPT-enhanced SCF forwards the service initial request to the IF(1) of MPT-enhanced MUE_B;
8) MPT-enhanced MUE_B accepts the FTP service request and sends a service initial response message
to the IF(1) of MPT-enhanced MUE_A;
9) after the establishment of control connection, MPT-enhanced MUE_A establishes two data
transmission paths with MPT-enhanced MUE_B using the IF(1) and IF(2), respectively.
After the above steps, the download traffic would be separated to transmit through two paths according to
the paths' performance, and the traffic transmitted through different paths will be aggregated and delivered
to the upper layer at the receiving end.

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