3G Handset and Network Design

CHAPTER 16

The Traffic Mix Shift

In earlier chapters we showed how handset hardware is changing the traffic mix in a wireless network. The bandwidth of the CMOS imager, audio codec, and MPEG-4 encoder determines the uplink offered traffic mix; the bandwidth of the display, display driver, and speaker determine the downlink offered traffic mix. In earlier chapters we showed how handset software is changing the traffic mix in a wireless network—how session persistency and session complexity increase over time, and how session complexity increases as session persistency increases. This means the longer the session, the more complex you can make it.

The Job of Software

In essence, the job of the software in the handset is to prompt the user to use the handset. For example, if the user has taken pictures or a short video with the in-built camera, then the software prompts the user to send the pictures either to other people or other places—for example, to a virtual storage site. The software provides the option of choosing 6-bit, 8-bit, or 24-bit color depth, providing a choice of resolution. For video, a choice of frame rate is provided and, for audio, a choice of narrowband or wideband (high-fidelity) sound. If the user has a buddy list, this provides the option to send the video and audio clip to multiple destinations. If a number of these recipients reply, there is an opportunity to build a complex real-time exchange where a number of people are supported in a conference session ...