 operating in the ISM (Industrial, Scientific and Medical) frequency band at 2.4 GHz. The 802.11a/g interfaces have a bit rate of 6, 9, 12, 18, 24, 36, 48 or 54 Mbps depending on the modulation and coding scheme (MCS): - the sub-carriers of the OFDM system are modulated in BPSK (Binary Phase Shift Keying), QPSK (Quadrature Phase Shift Keying), 16-QAM (Quadrature Amplitude Modulation) or 64-QAM; - the binary convolutional coding (BCC) is used with a coding rate of 1/2, 2/3 or 3/4. The 802.11n interface defines the HT (High Throughput) physical layer operating in the U-NII and ISM frequency bands at 5 and 2.4 GHz. The 802.11n interface uses the OFDM system for which the modulation of the sub-carriers is the one defined for the 802.11a/g interfaces and introduces a new value (equal to 5/6) for the coding rate and a new error correction code LDPC (Low-Density Parity Check). The 802.11n interface has a maximum rate of 600 Mbps obtained from two new features: - the aggregation of two radio channels to obtain a bandwidth of 40 - the spatial multiplexing SU-MIMO (Single User - Multiple Input Multiple Output) of two to four streams for a user. Introduction The 802.11ac interface defines the VHT (Very High Throughput) physical layer operating only in the U-NII frequency band at 5 GHz. The 802.11ac interface introduces new features to achieve a maximum rate of 6.9 Gbps: - the aggregation of eight radio channels to obtain a bandwidth of 160 - the spatial multiplexing SU-MIMO of two to eight streams for a user; - the space multiplexing MU-MIMO (Multi-User - MIMO) supporting four users, with a maximum of four streams for each user, the total number of streams being limited to eight; - the 256-QAM modulation. I.3. Wi-Fi integration into the 4G mobile network The integration of the Wi-Fi network into the 4G mobile network has an impact on the architecture of the EPC core network, which has several variants depending on the following characteristics: - the Wi-Fi access is trusted or untrusted by the operator; - the mobility is ma