|Issue:||Asia-Pacific II 1999|
|Topic:||From 2nd to 3rd generation wireless communications: Lucent Technologies suggests the transition path to 3G|
|Organisation:||Wireless Communications Business Unit, Lucent Technologies Microelectronics|
For mobility, speed and greater freedom of wireless communication access, the wireless communication system is moving from current mobile communication to the next generation. However in between the two present generations arevarious impending wireless applications, such as Global Packet Radio Services (GPRS), Wireless Application Protocol (WAP), Internet Protocol (IP), Email, and Video imaging. The wireless communication market has shown unlimited growth and capacity for expansion. Wireless communication terminals and equipment are facing the challenge of rolling out a migration plan and design that embraces the convergence emerging between 2nd and 3rd generation wireless systems. Terminal design considerations today must take into account the fact that many of the features required for a 3G system would be available on 2nd generation networks. GSM (adopted widely throughout the world), Personal Digital Communications (PDC) used in Japan, TDMA and CDMA (available in North America, South Korea and other markets) are the major commercial 2nd generation wireless communication systems.
GSM approach to 3rd generation The GSM MOU have specified a 3rd generation standard called Universal Mobile Telecommunications Services (UMTS). Originally, UMTS was specified to provide high-speed data as it was believed that the consumer market for digital cellular could be released only through the provision of high-speed data. But the widespread adoption and rapid evolution of the GSM family appears to have superseded this original requirement. UMTS is now being refocused to address the capacity, data speed, and economics of a deregulated telecommunications marketplace. UMTS has to offer significant additional business opportunities and/or (longer term) reduced operating costs if it is to be of value to current GSM operators. In addition, the GSM community is now so large and diverse that it is unlikely that there is a single way ahead for all members of the GSM community. For new operators, UMTS has to offer flexibility to fit a variety of business models. Some new operators may be integrating their UMTS network into an existing telecommunications network whilst others may be starting from scratch. It is clear that there is a great deal of uncertainty about the speed and direction of the development of the market, the future regulatory environment and how key technologies will develop. Therefore, the equipment manufacturer – and more specifically the design manager – has to develop a product concept that relies on careful evolution to future wireless standards. How the GSM equipment and GSM terminal providers can minimise risk of design decision and market entry are critical. Single silicon or software providers may not serve all requirements. A system solution provider has to have a clear migration path. A distribution channel with a clear path from today wireless market to the next generation market implementation, will be the key. How does UMTS Interact with GSM? Two scenarios for the rollout of UMTS exist: one is where an incumbent GSM operator wins a UMTS license and the other is where a new entrant wins. In the first scenario the rollout of the UMTS network will be carefully planned to compliment and supplement the existing GSM network infrastructure. New services will be introduced but the emphasis will likely be on using the spectrum and efficiencies of the UMTS to bring much-needed capacity and data speed to high traffic areas. Operators will seek to strike a balance between their existing infrastructure investment and UMTS. One thing is for certain, dual-mode terminals will be a certainty as these operators attempt to provide their new UMTS subscribers with a wide degree of coverage. But interestingly, the alternative scenario is very similar. If an existing operator or a new entrant to the field of wireless telecommunications wins a UMTS license they will be faced with the prospect of rolling-out an UMTS infrastructure that operates at higher frequencies and supports higher bit rates. More base stations will be needed, raising the cost of initial rollout. Either the new entrant limits their coverage or an alliance with an incumbent GSM operator is required. Given the degree of competition that these new entrants will be facing, they will be likely to opt for the alliance with an incumbent. Again, dual-mode terminals are essential. Is GPRS the road to 3G? Two drivers have revolutionised the telecommunications market in recent years: mobility and the Internet. These drivers have been the catalyst for enhancements to GSM and the basis for UMTS. When GSM was first conceived, ISDN was the buzz in Telecommunications – so it is logical that Internet Protocol (IP) telephony should be the buzz driving the 3rd generation developments. Furthermore, as the deregulation of the telecommunications industry evolves and matures, circuit switching will decline in importance, routing will rise and IP will dominate in both public and private networks, while GSM, UMTS, and other wireless standards that embrace IP technology will go from strength to strength. For the first time since the growth of wireless networks, there is an enabler for mobile data. The unparalleled growth in the corporate use of the Internet, Intranets and e-mail has created for the first time a real need for mass-market mobile data. This is the real motivator behind increasing the speed of todays 9.6kbps networks. GSM High Speed Circuit Switched Data (HSCSD) () boosts data speeds from the current 9.6 kbit/s to 14.4 kbit/s in a single traffic channel and using multiplexing techniques operators will be able to offer data rates up to 57.6 kbit/s – six times faster than what is currently available. Add some compression and it should be possible to provide fast Internet access or transmit live images through GSM networks. One potential challenge for HSCSD is spectrum requirement and the fact that it may only be attractive to networks that do not have spectrum allocation pressures. It is difficult to see how HSCSD alone can be beneficial and help ease spectrum capacity constraints that operators are facing. The solution is GPRS with its packet data element It does not tie up a whole channel end-to-end for one user. GPRS is essentially a separate network so it is more efficient. It is the transition from the switched environment towards IP. From an experience point of view, GPRS is a logical transition and much of the work undertaken will be proven by the time the 3G networks go into service. This way, manufacturers and operators can exploit a step-by-step upgrade of speed and capacity and introduce smart terminals and data-centred devices to a market broader than that reached to date, once an application or terminal is developed and established. Most manufacturers are looking at a number of solutions to encourage the broadest application of new technologies offering higher speeds: screen-phones, handheld computers, interface between laptop computers and phones and modem cards for laptops. But it will take some time before these really take off. Lucent Technologies (LTME) provide the path to 3G The importance of having a clear product development roadmap starting at todays systems moving through packet-based enhancements and converging with Wide-Band CDMA and UMTS is essential. The Lucent Technologies Microelectronics (LTME) next generation wireless communication system solution, silicon processing, software modular, wireless communication chipset, and terminal platforms are designed to support roadmaps for GSM, phase 2+ terminals through to UMTS. LTME has devised a scalable architecture that allows a high degree of hardware, software, platform and system commonality whether it is a basic budget terminal or a highly featured multimedia wireless terminal that the design brief is asking for. This allows the designer to share a greater amount of development effort between designs, reducing time to market and development effort. The LTME new generation wireless communication system design architecture is based on its own proven Digital Signal Processor (DSP) core, which leads the industry in providing the optimum balance of performance, code density and power consumption. It also features the industry standard ARM micro-controller core. Operating voltages down to 1.8 V can be catered for. LTME has addressed prototyping issues by offering a DSP platform with the flexibility and customisability of an Application-Specific Integrated Circuit (ASIC) design approach with the design economy, low risk, and time to market the advantages of standard products. An on-chip ASIC area is available for customer specific prototyping. On-chip flash is provided for prototyping DSP Read Only Memory (ROM) code. When proven, the code can be easily migrated from flash to ROM in production silicon. SceptreTM wireless communication chipset is supported by LTME DSP software – a combination of proven software and new Phase 2+ software supporting features such as multi-slotting (for HSCSD and GPRS), hands-free operation, voice tri-coder (Half Rate/Full Rate/Enhanced Full Rate (HR/FR/EFR) and AMR. Whilst designed as a complete solution, the modular nature of the DSP software also allows the customer to develop his own software modules for use with those from LTME in any combination. Micro-controller software for both protocol stack and Man-Machine Interface (MMI) is available from LTMEs subsidiary Optimay. For the development of the customers own micro-controller software, the ARM micro-controller is supported by a full set of ARM and third party tools. SceptreTM is supported by phase accurate models that fit into the Mentor Seamless hardware/software co-simulation environment. This allows system simulation and development of integrated DSP, ARM and custom logic. LTME Platforms are supported by the above technologies and software/hardware modular. The platforms are designed to support time to market, offer lower costs, provide a small form factor, and offer longer standby time. The completed platform Full Type Approval (FTA) reduces terminal FTA cost and testing time. The optional features such as service access point (SAT), Wireless Application Protocol (WAP) support high-end terminal integration. Platforms are available to modify for Personal Digital Assistants (PDA), Windows CE handle applications. Conclusion The LTME architecture has the common digital architecture for CDMA, IS136 and GSM as they converge towards UMTS. This offers the wireless system designer unrivalled flexibility in terminal design decisions. It gives the designer: Flexible & Scalable technology platform for IP integration and product portfolio spread Modular design for easy IP integration and variationUnrivalled time to market for a phase 2+ GPRS features Complete offering of a hardware, software and development environment Complete FTA proven platforms to achieve Time to Market Optional features that support wireless terminal products and PDA, Windows CE handle products Technology roadmap and business vision Linkage to GSM and 3G timeframes Risk management Rapid prototyping Full compliment of system tools Investing in UMTS is highly risky from the handset manufacturers point-of-view because it is a market whose timetable, size and growth rate is currently still under development. However, it is a risk that the manufacturers must take if they want to ensure that they remain at the forefront of the wireless communication market.