|3G Handset and Network Design
This book is written for hardware and software engineers presently involved or wanting to be involved in 3G handset or 3G network design. Over the next 20 chapters, we study handset hardware, handset software, network hardware, and network software.
A Brief Overview of the Technology
Each successive generation of cellular technology has been based on a new enabling technology. By new, we often mean the availability of an existing technology at low cost, or, for handset designers, the availability of a technology sufficiently powerefficient to be used in a portable device. For example:
First generation (1G).
AMPS/ETACS handsets in the 1980s required low-cost microcontrollers to manage the allocation of multiple RF (radio frequency) channels (833 × 30 kHz channels for AMPS, 1000 × 25 kHz channels for ETACS) and low-cost RF components that could provide acceptable performance at 800/900 MHz.
Second generation (2G).
GSM, TDMA, and CDMA handsets in the 1990s required low-cost digital signal processors (DSPs) for voice codecs and related baseband processing tasks, and low-cost RF components that could provide acceptable performance at 800/900 MHz, 1800 MHz, and 1900 MHz.
Third generation (3G).
W-CDMAand CDMA2000 handsets require—in addition to low-cost microcontrollers and DSPs—low-cost, low power budget CMOS or CCD image sensors; low-cost, low power budget image and video encoders;low-cost, low power budget memory; low-cost RF components that can provide acceptable performance at 1900/2100 MHz; and high-density battery technologies.
Bandwidth Quantity and Quality
Over the next few chapters we analyze bandwidth quantity and quality. We show how application bandwidth quality has to be preserved as we move complex content (rich media) into and through a complex network. We identify how bandwidth quality can be measured, managed, and used as the foundation for quality-based billing methodologies.We show how the dynamic range available to us at the application layer will change over the next 3 to 5 years and how this will influence radio bandwidth and network topology.We define bandwidth quality in terms of application bandwidth, processor bandwidth,memory bandwidth, radio bandwidth, and network bandwidth, and then we identify what we need to do to deliver consistently good end-to-end performance.