19. Simplified LTE network elements and interfaces 3GPP TS 36.300 Figure 4: Overall Architecture eNB = E-UTRAN Node B All radio interface-related functions MME = Mobile Management entity – Manages mobility, UE identity, and security parameters. S-GW = Serving Gateway – Node that terminates the interface towards E-UTRAN. P-GW = PDN (Packet Data Network) Gateway – Node that terminates the interface towards PDN.
20.
21. PDCP = Packet Data Convergence Protocol RRC = Radio Resource Control RLC = Radio Link Control
41. GTP-U tunneling SAE GW UPE eNB Server UE L1 L2 X1 S1 S11 SGi S5 PDN SAE GW Header compression & encryption Radio L1 MAC PDCP IPv6/v4 u Application TCP/UDP RLC L1 L2 IP UDP GTP-U L2 L1 IP UDP GTP-U L2 L1 IP UDP GTP-U L2 L1 IPv6/v4 TCP/UDP Application L1 L2 IP UDP GTP-U L2 L1 IP UDP GTP-U L2 L1 IP UDP GTP-U L2 L1 Radio L1 MAC RLC PDCP ENC
42. Non-3GPP access tunneling PDN SAE GW HA AP Server UE IP L2 L1 IPv6/v4 TCP/UDP Application L1 L2 WLAN S2 SGi L2 L1 IP MIP IPv4/6 IP UDP IP MIP IPv4/6 UDP IP L2 L1 IP L2 L1 L1 L2 L1 L2
90. Spatial Multiplexing Spatial multiplexing allows to transmit different streams of data simultaneously on the same downlink resource block(s). These data streams can belong to one single user (single user MIMO / SU-MIMO) or to different users (multi user MIMO / MU-MIMO). While SU-MIMO increases the data rate of one user, MU-MIMO allows to increase the overall capacity. Spatial multiplexing is only possible if the mobile radio channel allows it.
94. Collaborative/Network MIMO overview Coordinate transmission and reception of signals among multiple bases. Reduces intercell interference and improves cell-edge performance and overall throughput. Collaborative MIMO : share user data and long-term noncoherent channel information. Coherent network MIMO : share user data and short-term coherent channel information.