I use this presentation for opening 4G Mobile Technology seminar sessions. Usually it will be continued with 1 other presentation on LTE, 1 on WiMAX II, and 1 on applications.
16. Multiparty Conferencing Resource Sharing Virtual Collaboration Broadcasting Games …. Application Service SIP Applications Server Parlay / OSA …. SIP Diameter Session Control I-CSCF P-CSCF HSS S-CSCF MGCF SIP H.248 MGW Access PSTN WiFi/WiMAX GPRS UMTS
17. AS S-CSCF HSS P-CSCF IMS IMS Lain I-CSCF GGSN IMS Lain IMS, Internet Multimedia Subsystem CSCF, Call Session Control Function (Serving, Proxy, Interrogating) GGSN, Gateway GPRS Support Node SGSN, Serving GPRS Support Node UTRAN, UMTS Terrestrial Radio Access Network UMTS, Universal Mobile Telecom System HSS, Home Subscriber Server SGSN RNC UTRAN IMS
18. AAA PDG S-CSCF HSS WiMAX CSN P-CSCF IMS I-CSCF GGSN IMS Lain SGSN SFM SFA WiMAX ASN RNC IP ROUTER UTRAN ASN Lain
19. BGCF MGCF BGCF MGCF 3GPP2 PDF MGW MGW 3GPP S-CSCF MRFC P-CSCF S-CSCF MRFC P-CSCF MS UE AS MRFP I-CSCF AAA AS MRFP HSS I-CSCF Data base SLF Position Server PDE
20. IMS: Enhanced Voice Charging Function Subscriber Profile Function SIP Video Phone CFCS Signalling Function Application Policy Function SIP HTTP RTSP RTSP signal proxy Video Streaming RTSP HTTP signal proxy HTTP TV QoS Policy & Media Function Media Transfer Function RTP HTTP Web
23. Cognitive radio (CR), also related to software-defined radio (SDR), is a type of Radio in which communication systems are aware of their environment and internal state and can make decisions about their radio operating behavior based on that information and predefined objectives. Cognitive Radio
25. IEEE 1900 is a suite to support cognitive radio (CR), dynamic spectrum access (DSA), and coexistence. Previous standards s.a. WiFi (802.11), Zigbee (802.15.4), and WiMAX (802.16) have included certain level of CR. CR will be related to dynamic spectrum access (DSA), which is the real-time adjustment of Spectrum Utilization in response to changing circumstances and objectives. The most interesting aspect is coexistence: resource selection to determine the type of wireless/mobile access. IEEE 1900
29. New access schemes like Orthogonal FDMA (OFDMA), Single Carrier FDMA (SC-FDMA), Interleaved FDMA and Multi-carrier CDMA (MC-CDMA) are gaining more importance for the next generation systems. WiMAX: OFDMA LTE: OFDMA (downlink), IFDMA (uplink) The other important advantage of the above is that they require less complexity for equalization at the receiver. This is an added advantage especially in the MIMO environments since the spatial multiplexing transmission of MIMO systems inherently requires high complexity equalization at the receiver. In addition to improvements in these multiplexing systems, improved modulation techniques are being used. Whereas earlier standards largely used PSK, more efficient systems such as 64QAM are being proposed for use with the LTE Access Scheme
30. Orthogonal frequency-division multiplexing FDM in which sub-channels overlap without interfering OFDM Single Carrier Transmission (WCDMA etc) 5 MHz Subcarriers Orthogonal Frequency Division Multiplexing e.g. 5 MHz
31. Adaptable to severe channel conditions without complex equalization. Robust against narrow-band co-channel interference. Robust against intersymbol interference (ISI) and fading caused by multipath propagation. High spectral efficiency. Efficient implementation using FFT Low sensitivity to time synchronization errors. Facilitates Single Frequency Networks (SFNs), i.e. transmitter macrodiversity. OFDM Advantages
32. TDMA/FDMA operation = OFDMA Frequency sub-channels are composed of multiple, non-adjacent carriers OFDMA: Combining TDMA and FDMA
34. OFDM modulates in parallel multiple narrow band sub-carriers Multipath duration becomes short relative to symbol duration Pilot and guard sub-carriers are also inserted Multipath – The Solution
35. The sub-carriers are converted by IFFT to a time domain signal A guard interval (cyclic prefix) is added to collect multipath A long guard interval (GI) reduces efficiency but enhances multipath handling capability Multipath – The Solution
36. Narrowband Interference Rejection Easy to Avoid/Reject Narrowband Dominant Interference . Less Interfered Part of the Carrier Can Still Be Used . Interference Rejection/Avoidance
37. Using shaping on the signal peaks Limiting the PAPR to a constant value by vector reduction PAPR Reduction
43. FDD (Frequency Division Duplexing) uses one frequency for the downlink, and a second frequency for the uplink. TDD (Time Division Duplexing) uses the same frequency for the downlink and the uplink. In both configuration the access method is OFDMA/TDMA . Duplexing (cont’d)
45. Multiple antenna technologies are emerging to achieve high rate, high reliability, and long range communications. Spatial multiplexing gained importance for its bandwidth conservation and power efficiency. It involves deploying multiple antennas at the transmitter and at the receiver. Independent streams can then be transmitted simultaneously from all the antennas. This increases the data rate into multiple folds with the number equal to minimum of the number of transmit and receive antennas. This is called MIMO (as a branch of intelligent antenna). Spatial Multiplexing
51. Space Time Coding A space–time code (STC) is a method employed to improve the reliability of data transmission in wireless communication systems using multiple transmit antennas. STCs rely on transmitting multiple, redundant copies of a data stream to the receiver in the hope that at least some of them may survive the physical path between transmission and reception in a good enough state to allow reliable decoding.
52. Space Time Coding IFFT Filter DAC RF Tx Diversity Encoder IFFT Input Packing Subcarrier Modulation IFFT Filter DAC RF Diversity Combiner Sub channel Demod Decoder RF ADC Filter FFT
64. User layer (anywhere, anytime) Personal Service Platform User experience management Service Discovery Service Composition Pervasiveness Context Management Conventional Service Platform e-Services 2G 3G LTE WiMAX Network access