 3G standards Release Technology Downlink (Mbps) Uplink (Mbps) HSDPA 0.384 HSUPA 2 X data Multi-carrier 2 X 2 MIMO DL (10) 2 x 2 MIMO UL (20) 4 X 4 MIMO (40) 336-672 upload large files or stream data including images and video through applications such as Facebook. Table 10.5 shows transmission rate specifications for HSDPA and HSUPA (together known as HSPA) systems for different releases of 3GPP standards. MIMO Antennas Multiple-input and multiple-output (MIMO) in gen- eral refers to installation of multiple antennas at both transmitter and receiver sides as illustrated. MIMO systems provide two main advantages: one, they create diversity transmission and reception, thereby mitigating the fading channel characteristics. More importantly they create virtual parallel channels, thereby increasing the system's telecommunications capacity. For example the 2 x 2 MIMO system in the figure creates two parallel channels and therefore doubles transmission capacity. In general an M X M MIMO system is capable of providing M-times capacity. Packet-switched Telecommunications in Mobile Networks HSPA systems transmit data using packet-switched technology. In a wireless configuration the RNC acting together with a base station operate as an edge router which sends packets to, or receives them from, an end-user. The network nodes may have several queues which give priority to different traffic. For example, a voice over IP call, which has delay constraints can be switched faster than email traffic. The operation of a base station in a packet-switched system is illustrated in Figure 10.21. Orthogonal Frequency Division Multiplexing The fourth generation of mobile telecommunication standards are based on a novel modula- tion and multiple access technology, called Orthogonal Frequency Division Multiplexing (OFDM). OFDM is a similar technology to Frequency Division Multiplexing (FDM) used in Broadband Telecommunications Technologies and Management Server IP network Priority-based Base station queues Figure 10.21 Base station in a pa