| Audio transmission over data networks or voice over IP is an essential technology for the next generation. Quality of services (QoS) criteria are used to guarantee the performance and quality of recovered audio signals at the destination. This thesis reports on an experimental study of the effect of parameters and conditions that affect directly the performance and quality of audio transmissions in terms of time variations or jitter. For the experimental setup all functions are emulated in real time using TI-C6711 DSK boards with TMS320C6711 DSP chip operating under the Hypersignal RIDE software. Wireless LANs (WLAN), both IEEE 802.11b and draft 802.11g, are used in the study due to their popularity. External interference and multipath fading are introduced in order to assess their impact on jitter for WLAN. The general findings are jitter is much greater for WLAN than for LAN, and jitter buffer plays a significant role in reducing jitter both LAN and WLAN. |
