Maximising Bandwdith Efficency of Statistical Multiplexer Architecture using Frame Droping Methods

<span>It is generally considered that remote and rural telephone users generate less traffic as compared<span> to urban area users. This lowers the attraction of investment in rural areas by the<span> telecommunications companies and service providers. The financial implications of wiring a<span> vast area for low telephone traffic causes most telephone service providers to ignore those<span> regions. Still, it is known that telecommunications are essential to the economic development of<span> a region and that traffic increases rapidly as soon as the service is available. A satellite–based<span> telephone network can provide efficient long distance telephone service to remote rural<span> communities at a lower cost than land-based wired networks in most cases. Mobile satellite<span> systems already provide this service, but are limited in capacity and charge high per-minute fees<span> for the satellite link. Small earth stations and GEO satellites can provide this service more<span> efficiently and at lower cost. On top of that, bandwidth efficient multiplexing with compressed<span> speech, Voice Activity Detection (VAD) and Packet discarding methods can even further reduce <span>the cost of service for the users in rural areas. In this paper, Statistical Time Division Multiplexer<span> (STDM) architecture was simulated. Two packet discarding methods, random packet discarding<span> and cyclic packet discarding are used to maximize bandwidth utilization along with VAD.<span> Results indicate that considering monologue speech source, with 80%, activity for each 6.4 kbps<span> sources, on a channel of 64 kbps, 12 users can be allowed to be multiplexed instead of 9,<span> therefore a Digital Speech Interpolation (DSI) advantage of 1.33 is achieved with 3% packet<span> loss. Furthermore, it is observed that cyclic packet discarding technique perform better than<span> random packet discarding in terms of subjective quality<br /><br class="Apple-interchange-newline" /></span></span></span></span></span></span></span></span><br /><br class="Apple-interchange-newline" /></span></span></span></span></span></span></span></span></span></span></span></span>

Digital Speech Interpolation Advantage of Statistical Time Division Multiplexer

This paper discusses Digital Speech Interpolation (DSI) advantage of Statistical Time Division Multiplexer (STDM) for Random Packet Loss scenarios. In order to harness this advantage each source speech is compressed at 6.4 kbps, Voice Activity Detector (VAD) is used for each source, and packet loss mechanism is introduced to achieve maximum DSI advantage. It is observed that for maximum of 9 users channel capacity, extra 3 users, i.e. total 12 users can be accommodated with 3% speech frame losses, which results in an advantage of 12/9 = 1.33.