1. CeTAS 1 Determining the Optimum Fourth Generation (4G) Access Network Architecture R. van den Bergh and Dr. P. Chitamu Centre For Telecommunications Access and Services University of the Witwatersrand, Johannesburg http://www.ee.wits.ac.za/comms/

2. CeTAS 2 Outline Brief history of Mobile Communications Why is industry starting to look beyond 3G? What is 4G? Proposals for the 4G Access Architecture Purpose of and anticipated contribution from the research

3. CeTAS 3 Brief History of Mobile Communications Mobile GenerationImportant Characteristics First Generation (1G)Analogue, important mobile technologies developed Second Generation (2G)Digital, primarily intended for voice 2G Extension (2.5G)Addition of packet switching and higher data rates Third Generation (3G)New systems and services, multimedia supported, main access technologies are CDMA2000 and WCDMA

4. CeTAS 4 Why is industry starting to look beyond 3G? Major Current Trends –Substitution of Wired by Wireless – Mobility –Growing adoption rate of VoIP –Demand for Broadband - WiMAX –Convergence between: Broadcasting and Telecoms Fixed and Mobile Voice, Data and Video Driving Demand for Low Cost High Data Rates Need for Convergence of Existing Standards

5. CeTAS 5 Why will the next Mobile Generation be especially relevant for SA? Bridging the digital divide More efficient use of the frequency spectrum

6. CeTAS 6 What is Fourth Generation (4G) Mobile? Any Service, Any Time, Any Place Many opinions – no universal approach to 4G Access Network standards Some concrete decisions made –IP Multimedia Sub-System (IMS) Core using IPv6 –Wireless World Initiative has set target peak data rates of: 100Mbps for Mobile 1Gbps Nomadic or pedestrian situations –Deployment around 2010

7. CeTAS 7 Objectives of 4G Heterogeneity with Pervasive Coverage Higher Capacity, i.e. Data Rates Personalization and User-Oriented Services –Broadcasting and Multicasting – TV –Gaming and Video Downloads –Teleworking and Security

8. CeTAS 8 Key Development Areas for 4G Orthogonal Frequency Division Multiplexing (OFDM) Software Defined Radio Multiple-Input Multiple-Output (MIMO) Systems Handover and Mobility Schemes Security Issues Service Dependent QoS

9. CeTAS 9 Proposals for the 4G Access Architecture Convergence Architecture –Follows Convergence Trends –Uses Multi-Technology Approach –Transforms Vertical Architecture to Horizontal Model –Will include new technologies such as WiMAX

10. CeTAS 10 Converged 4G Access Architecure Access Network s BluetoothWiFiGSM 3G WiMAX Satellite HAP IMS Core Services Environment PANLAN MAN Global

11. CeTAS 11 Proposals for the 4G Access Architecture Pure Air Interface Approach –Overlay new air interface on 2G and 3G Networks –OFDM, Multi-Carrier CDMA (MC-CDMA), etc. Hybrid Approach IMS Core Services Environment 2G3G4G Access Networks

12. CeTAS 12 Purpose of the Research Determine the Optimum 4G Access Architecture for South Africa Process –Model various components of the three proposed Access Architectures –Simulate their performance in the SA Environment –Determine which architecture delivers the optimum performance Contribution –The optimum architecture and its performance characteristics

13. CeTAS 13 Conclusions Large number of trends driving the need for low cost high data rates The objectives of 4G are: –To provide heterogeneous networks with pervasive coverage –High capacity and personalised services –All at a reasonably low cost Extensive development required to determine optimum access architecture standards Purpose of research: –Determine optimum 4G Access Architecture for SA